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-rw-r--r--kernel/trace/trace.c10645
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diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
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+++ b/kernel/trace/trace.c
@@ -0,0 +1,10645 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ring buffer based function tracer
+ *
+ * Copyright (C) 2007-2012 Steven Rostedt <srostedt@redhat.com>
+ * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
+ *
+ * Originally taken from the RT patch by:
+ * Arnaldo Carvalho de Melo <acme@redhat.com>
+ *
+ * Based on code from the latency_tracer, that is:
+ * Copyright (C) 2004-2006 Ingo Molnar
+ * Copyright (C) 2004 Nadia Yvette Chambers
+ */
+#include <linux/ring_buffer.h>
+#include <generated/utsrelease.h>
+#include <linux/stacktrace.h>
+#include <linux/writeback.h>
+#include <linux/kallsyms.h>
+#include <linux/security.h>
+#include <linux/seq_file.h>
+#include <linux/irqflags.h>
+#include <linux/debugfs.h>
+#include <linux/tracefs.h>
+#include <linux/pagemap.h>
+#include <linux/hardirq.h>
+#include <linux/linkage.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <linux/ftrace.h>
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/splice.h>
+#include <linux/kdebug.h>
+#include <linux/string.h>
+#include <linux/mount.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
+#include <linux/ctype.h>
+#include <linux/init.h>
+#include <linux/panic_notifier.h>
+#include <linux/poll.h>
+#include <linux/nmi.h>
+#include <linux/fs.h>
+#include <linux/trace.h>
+#include <linux/sched/clock.h>
+#include <linux/sched/rt.h>
+#include <linux/fsnotify.h>
+#include <linux/irq_work.h>
+#include <linux/workqueue.h>
+
+#include <asm/setup.h> /* COMMAND_LINE_SIZE */
+
+#include "trace.h"
+#include "trace_output.h"
+
+/*
+ * On boot up, the ring buffer is set to the minimum size, so that
+ * we do not waste memory on systems that are not using tracing.
+ */
+bool ring_buffer_expanded;
+
+#ifdef CONFIG_FTRACE_STARTUP_TEST
+/*
+ * We need to change this state when a selftest is running.
+ * A selftest will lurk into the ring-buffer to count the
+ * entries inserted during the selftest although some concurrent
+ * insertions into the ring-buffer such as trace_printk could occurred
+ * at the same time, giving false positive or negative results.
+ */
+static bool __read_mostly tracing_selftest_running;
+
+/*
+ * If boot-time tracing including tracers/events via kernel cmdline
+ * is running, we do not want to run SELFTEST.
+ */
+bool __read_mostly tracing_selftest_disabled;
+
+void __init disable_tracing_selftest(const char *reason)
+{
+ if (!tracing_selftest_disabled) {
+ tracing_selftest_disabled = true;
+ pr_info("Ftrace startup test is disabled due to %s\n", reason);
+ }
+}
+#else
+#define tracing_selftest_running 0
+#define tracing_selftest_disabled 0
+#endif
+
+/* Pipe tracepoints to printk */
+static struct trace_iterator *tracepoint_print_iter;
+int tracepoint_printk;
+static bool tracepoint_printk_stop_on_boot __initdata;
+static DEFINE_STATIC_KEY_FALSE(tracepoint_printk_key);
+
+/* For tracers that don't implement custom flags */
+static struct tracer_opt dummy_tracer_opt[] = {
+ { }
+};
+
+static int
+dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
+{
+ return 0;
+}
+
+/*
+ * To prevent the comm cache from being overwritten when no
+ * tracing is active, only save the comm when a trace event
+ * occurred.
+ */
+static DEFINE_PER_CPU(bool, trace_taskinfo_save);
+
+/*
+ * Kill all tracing for good (never come back).
+ * It is initialized to 1 but will turn to zero if the initialization
+ * of the tracer is successful. But that is the only place that sets
+ * this back to zero.
+ */
+static int tracing_disabled = 1;
+
+cpumask_var_t __read_mostly tracing_buffer_mask;
+
+/*
+ * ftrace_dump_on_oops - variable to dump ftrace buffer on oops
+ *
+ * If there is an oops (or kernel panic) and the ftrace_dump_on_oops
+ * is set, then ftrace_dump is called. This will output the contents
+ * of the ftrace buffers to the console. This is very useful for
+ * capturing traces that lead to crashes and outputing it to a
+ * serial console.
+ *
+ * It is default off, but you can enable it with either specifying
+ * "ftrace_dump_on_oops" in the kernel command line, or setting
+ * /proc/sys/kernel/ftrace_dump_on_oops
+ * Set 1 if you want to dump buffers of all CPUs
+ * Set 2 if you want to dump the buffer of the CPU that triggered oops
+ */
+
+enum ftrace_dump_mode ftrace_dump_on_oops;
+
+/* When set, tracing will stop when a WARN*() is hit */
+int __disable_trace_on_warning;
+
+#ifdef CONFIG_TRACE_EVAL_MAP_FILE
+/* Map of enums to their values, for "eval_map" file */
+struct trace_eval_map_head {
+ struct module *mod;
+ unsigned long length;
+};
+
+union trace_eval_map_item;
+
+struct trace_eval_map_tail {
+ /*
+ * "end" is first and points to NULL as it must be different
+ * than "mod" or "eval_string"
+ */
+ union trace_eval_map_item *next;
+ const char *end; /* points to NULL */
+};
+
+static DEFINE_MUTEX(trace_eval_mutex);
+
+/*
+ * The trace_eval_maps are saved in an array with two extra elements,
+ * one at the beginning, and one at the end. The beginning item contains
+ * the count of the saved maps (head.length), and the module they
+ * belong to if not built in (head.mod). The ending item contains a
+ * pointer to the next array of saved eval_map items.
+ */
+union trace_eval_map_item {
+ struct trace_eval_map map;
+ struct trace_eval_map_head head;
+ struct trace_eval_map_tail tail;
+};
+
+static union trace_eval_map_item *trace_eval_maps;
+#endif /* CONFIG_TRACE_EVAL_MAP_FILE */
+
+int tracing_set_tracer(struct trace_array *tr, const char *buf);
+static void ftrace_trace_userstack(struct trace_array *tr,
+ struct trace_buffer *buffer,
+ unsigned int trace_ctx);
+
+#define MAX_TRACER_SIZE 100
+static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
+static char *default_bootup_tracer;
+
+static bool allocate_snapshot;
+static bool snapshot_at_boot;
+
+static char boot_instance_info[COMMAND_LINE_SIZE] __initdata;
+static int boot_instance_index;
+
+static char boot_snapshot_info[COMMAND_LINE_SIZE] __initdata;
+static int boot_snapshot_index;
+
+static int __init set_cmdline_ftrace(char *str)
+{
+ strscpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
+ default_bootup_tracer = bootup_tracer_buf;
+ /* We are using ftrace early, expand it */
+ ring_buffer_expanded = true;
+ return 1;
+}
+__setup("ftrace=", set_cmdline_ftrace);
+
+static int __init set_ftrace_dump_on_oops(char *str)
+{
+ if (*str++ != '=' || !*str || !strcmp("1", str)) {
+ ftrace_dump_on_oops = DUMP_ALL;
+ return 1;
+ }
+
+ if (!strcmp("orig_cpu", str) || !strcmp("2", str)) {
+ ftrace_dump_on_oops = DUMP_ORIG;
+ return 1;
+ }
+
+ return 0;
+}
+__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
+
+static int __init stop_trace_on_warning(char *str)
+{
+ if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0))
+ __disable_trace_on_warning = 1;
+ return 1;
+}
+__setup("traceoff_on_warning", stop_trace_on_warning);
+
+static int __init boot_alloc_snapshot(char *str)
+{
+ char *slot = boot_snapshot_info + boot_snapshot_index;
+ int left = sizeof(boot_snapshot_info) - boot_snapshot_index;
+ int ret;
+
+ if (str[0] == '=') {
+ str++;
+ if (strlen(str) >= left)
+ return -1;
+
+ ret = snprintf(slot, left, "%s\t", str);
+ boot_snapshot_index += ret;
+ } else {
+ allocate_snapshot = true;
+ /* We also need the main ring buffer expanded */
+ ring_buffer_expanded = true;
+ }
+ return 1;
+}
+__setup("alloc_snapshot", boot_alloc_snapshot);
+
+
+static int __init boot_snapshot(char *str)
+{
+ snapshot_at_boot = true;
+ boot_alloc_snapshot(str);
+ return 1;
+}
+__setup("ftrace_boot_snapshot", boot_snapshot);
+
+
+static int __init boot_instance(char *str)
+{
+ char *slot = boot_instance_info + boot_instance_index;
+ int left = sizeof(boot_instance_info) - boot_instance_index;
+ int ret;
+
+ if (strlen(str) >= left)
+ return -1;
+
+ ret = snprintf(slot, left, "%s\t", str);
+ boot_instance_index += ret;
+
+ return 1;
+}
+__setup("trace_instance=", boot_instance);
+
+
+static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata;
+
+static int __init set_trace_boot_options(char *str)
+{
+ strscpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
+ return 1;
+}
+__setup("trace_options=", set_trace_boot_options);
+
+static char trace_boot_clock_buf[MAX_TRACER_SIZE] __initdata;
+static char *trace_boot_clock __initdata;
+
+static int __init set_trace_boot_clock(char *str)
+{
+ strscpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE);
+ trace_boot_clock = trace_boot_clock_buf;
+ return 1;
+}
+__setup("trace_clock=", set_trace_boot_clock);
+
+static int __init set_tracepoint_printk(char *str)
+{
+ /* Ignore the "tp_printk_stop_on_boot" param */
+ if (*str == '_')
+ return 0;
+
+ if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0))
+ tracepoint_printk = 1;
+ return 1;
+}
+__setup("tp_printk", set_tracepoint_printk);
+
+static int __init set_tracepoint_printk_stop(char *str)
+{
+ tracepoint_printk_stop_on_boot = true;
+ return 1;
+}
+__setup("tp_printk_stop_on_boot", set_tracepoint_printk_stop);
+
+unsigned long long ns2usecs(u64 nsec)
+{
+ nsec += 500;
+ do_div(nsec, 1000);
+ return nsec;
+}
+
+static void
+trace_process_export(struct trace_export *export,
+ struct ring_buffer_event *event, int flag)
+{
+ struct trace_entry *entry;
+ unsigned int size = 0;
+
+ if (export->flags & flag) {
+ entry = ring_buffer_event_data(event);
+ size = ring_buffer_event_length(event);
+ export->write(export, entry, size);
+ }
+}
+
+static DEFINE_MUTEX(ftrace_export_lock);
+
+static struct trace_export __rcu *ftrace_exports_list __read_mostly;
+
+static DEFINE_STATIC_KEY_FALSE(trace_function_exports_enabled);
+static DEFINE_STATIC_KEY_FALSE(trace_event_exports_enabled);
+static DEFINE_STATIC_KEY_FALSE(trace_marker_exports_enabled);
+
+static inline void ftrace_exports_enable(struct trace_export *export)
+{
+ if (export->flags & TRACE_EXPORT_FUNCTION)
+ static_branch_inc(&trace_function_exports_enabled);
+
+ if (export->flags & TRACE_EXPORT_EVENT)
+ static_branch_inc(&trace_event_exports_enabled);
+
+ if (export->flags & TRACE_EXPORT_MARKER)
+ static_branch_inc(&trace_marker_exports_enabled);
+}
+
+static inline void ftrace_exports_disable(struct trace_export *export)
+{
+ if (export->flags & TRACE_EXPORT_FUNCTION)
+ static_branch_dec(&trace_function_exports_enabled);
+
+ if (export->flags & TRACE_EXPORT_EVENT)
+ static_branch_dec(&trace_event_exports_enabled);
+
+ if (export->flags & TRACE_EXPORT_MARKER)
+ static_branch_dec(&trace_marker_exports_enabled);
+}
+
+static void ftrace_exports(struct ring_buffer_event *event, int flag)
+{
+ struct trace_export *export;
+
+ preempt_disable_notrace();
+
+ export = rcu_dereference_raw_check(ftrace_exports_list);
+ while (export) {
+ trace_process_export(export, event, flag);
+ export = rcu_dereference_raw_check(export->next);
+ }
+
+ preempt_enable_notrace();
+}
+
+static inline void
+add_trace_export(struct trace_export **list, struct trace_export *export)
+{
+ rcu_assign_pointer(export->next, *list);
+ /*
+ * We are entering export into the list but another
+ * CPU might be walking that list. We need to make sure
+ * the export->next pointer is valid before another CPU sees
+ * the export pointer included into the list.
+ */
+ rcu_assign_pointer(*list, export);
+}
+
+static inline int
+rm_trace_export(struct trace_export **list, struct trace_export *export)
+{
+ struct trace_export **p;
+
+ for (p = list; *p != NULL; p = &(*p)->next)
+ if (*p == export)
+ break;
+
+ if (*p != export)
+ return -1;
+
+ rcu_assign_pointer(*p, (*p)->next);
+
+ return 0;
+}
+
+static inline void
+add_ftrace_export(struct trace_export **list, struct trace_export *export)
+{
+ ftrace_exports_enable(export);
+
+ add_trace_export(list, export);
+}
+
+static inline int
+rm_ftrace_export(struct trace_export **list, struct trace_export *export)
+{
+ int ret;
+
+ ret = rm_trace_export(list, export);
+ ftrace_exports_disable(export);
+
+ return ret;
+}
+
+int register_ftrace_export(struct trace_export *export)
+{
+ if (WARN_ON_ONCE(!export->write))
+ return -1;
+
+ mutex_lock(&ftrace_export_lock);
+
+ add_ftrace_export(&ftrace_exports_list, export);
+
+ mutex_unlock(&ftrace_export_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(register_ftrace_export);
+
+int unregister_ftrace_export(struct trace_export *export)
+{
+ int ret;
+
+ mutex_lock(&ftrace_export_lock);
+
+ ret = rm_ftrace_export(&ftrace_exports_list, export);
+
+ mutex_unlock(&ftrace_export_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_export);
+
+/* trace_flags holds trace_options default values */
+#define TRACE_DEFAULT_FLAGS \
+ (FUNCTION_DEFAULT_FLAGS | \
+ TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | \
+ TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | \
+ TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | \
+ TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS | \
+ TRACE_ITER_HASH_PTR)
+
+/* trace_options that are only supported by global_trace */
+#define TOP_LEVEL_TRACE_FLAGS (TRACE_ITER_PRINTK | \
+ TRACE_ITER_PRINTK_MSGONLY | TRACE_ITER_RECORD_CMD)
+
+/* trace_flags that are default zero for instances */
+#define ZEROED_TRACE_FLAGS \
+ (TRACE_ITER_EVENT_FORK | TRACE_ITER_FUNC_FORK)
+
+/*
+ * The global_trace is the descriptor that holds the top-level tracing
+ * buffers for the live tracing.
+ */
+static struct trace_array global_trace = {
+ .trace_flags = TRACE_DEFAULT_FLAGS,
+};
+
+LIST_HEAD(ftrace_trace_arrays);
+
+int trace_array_get(struct trace_array *this_tr)
+{
+ struct trace_array *tr;
+ int ret = -ENODEV;
+
+ mutex_lock(&trace_types_lock);
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (tr == this_tr) {
+ tr->ref++;
+ ret = 0;
+ break;
+ }
+ }
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+}
+
+static void __trace_array_put(struct trace_array *this_tr)
+{
+ WARN_ON(!this_tr->ref);
+ this_tr->ref--;
+}
+
+/**
+ * trace_array_put - Decrement the reference counter for this trace array.
+ * @this_tr : pointer to the trace array
+ *
+ * NOTE: Use this when we no longer need the trace array returned by
+ * trace_array_get_by_name(). This ensures the trace array can be later
+ * destroyed.
+ *
+ */
+void trace_array_put(struct trace_array *this_tr)
+{
+ if (!this_tr)
+ return;
+
+ mutex_lock(&trace_types_lock);
+ __trace_array_put(this_tr);
+ mutex_unlock(&trace_types_lock);
+}
+EXPORT_SYMBOL_GPL(trace_array_put);
+
+int tracing_check_open_get_tr(struct trace_array *tr)
+{
+ int ret;
+
+ ret = security_locked_down(LOCKDOWN_TRACEFS);
+ if (ret)
+ return ret;
+
+ if (tracing_disabled)
+ return -ENODEV;
+
+ if (tr && trace_array_get(tr) < 0)
+ return -ENODEV;
+
+ return 0;
+}
+
+int call_filter_check_discard(struct trace_event_call *call, void *rec,
+ struct trace_buffer *buffer,
+ struct ring_buffer_event *event)
+{
+ if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
+ !filter_match_preds(call->filter, rec)) {
+ __trace_event_discard_commit(buffer, event);
+ return 1;
+ }
+
+ return 0;
+}
+
+/**
+ * trace_find_filtered_pid - check if a pid exists in a filtered_pid list
+ * @filtered_pids: The list of pids to check
+ * @search_pid: The PID to find in @filtered_pids
+ *
+ * Returns true if @search_pid is found in @filtered_pids, and false otherwise.
+ */
+bool
+trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)
+{
+ return trace_pid_list_is_set(filtered_pids, search_pid);
+}
+
+/**
+ * trace_ignore_this_task - should a task be ignored for tracing
+ * @filtered_pids: The list of pids to check
+ * @filtered_no_pids: The list of pids not to be traced
+ * @task: The task that should be ignored if not filtered
+ *
+ * Checks if @task should be traced or not from @filtered_pids.
+ * Returns true if @task should *NOT* be traced.
+ * Returns false if @task should be traced.
+ */
+bool
+trace_ignore_this_task(struct trace_pid_list *filtered_pids,
+ struct trace_pid_list *filtered_no_pids,
+ struct task_struct *task)
+{
+ /*
+ * If filtered_no_pids is not empty, and the task's pid is listed
+ * in filtered_no_pids, then return true.
+ * Otherwise, if filtered_pids is empty, that means we can
+ * trace all tasks. If it has content, then only trace pids
+ * within filtered_pids.
+ */
+
+ return (filtered_pids &&
+ !trace_find_filtered_pid(filtered_pids, task->pid)) ||
+ (filtered_no_pids &&
+ trace_find_filtered_pid(filtered_no_pids, task->pid));
+}
+
+/**
+ * trace_filter_add_remove_task - Add or remove a task from a pid_list
+ * @pid_list: The list to modify
+ * @self: The current task for fork or NULL for exit
+ * @task: The task to add or remove
+ *
+ * If adding a task, if @self is defined, the task is only added if @self
+ * is also included in @pid_list. This happens on fork and tasks should
+ * only be added when the parent is listed. If @self is NULL, then the
+ * @task pid will be removed from the list, which would happen on exit
+ * of a task.
+ */
+void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
+ struct task_struct *self,
+ struct task_struct *task)
+{
+ if (!pid_list)
+ return;
+
+ /* For forks, we only add if the forking task is listed */
+ if (self) {
+ if (!trace_find_filtered_pid(pid_list, self->pid))
+ return;
+ }
+
+ /* "self" is set for forks, and NULL for exits */
+ if (self)
+ trace_pid_list_set(pid_list, task->pid);
+ else
+ trace_pid_list_clear(pid_list, task->pid);
+}
+
+/**
+ * trace_pid_next - Used for seq_file to get to the next pid of a pid_list
+ * @pid_list: The pid list to show
+ * @v: The last pid that was shown (+1 the actual pid to let zero be displayed)
+ * @pos: The position of the file
+ *
+ * This is used by the seq_file "next" operation to iterate the pids
+ * listed in a trace_pid_list structure.
+ *
+ * Returns the pid+1 as we want to display pid of zero, but NULL would
+ * stop the iteration.
+ */
+void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos)
+{
+ long pid = (unsigned long)v;
+ unsigned int next;
+
+ (*pos)++;
+
+ /* pid already is +1 of the actual previous bit */
+ if (trace_pid_list_next(pid_list, pid, &next) < 0)
+ return NULL;
+
+ pid = next;
+
+ /* Return pid + 1 to allow zero to be represented */
+ return (void *)(pid + 1);
+}
+
+/**
+ * trace_pid_start - Used for seq_file to start reading pid lists
+ * @pid_list: The pid list to show
+ * @pos: The position of the file
+ *
+ * This is used by seq_file "start" operation to start the iteration
+ * of listing pids.
+ *
+ * Returns the pid+1 as we want to display pid of zero, but NULL would
+ * stop the iteration.
+ */
+void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos)
+{
+ unsigned long pid;
+ unsigned int first;
+ loff_t l = 0;
+
+ if (trace_pid_list_first(pid_list, &first) < 0)
+ return NULL;
+
+ pid = first;
+
+ /* Return pid + 1 so that zero can be the exit value */
+ for (pid++; pid && l < *pos;
+ pid = (unsigned long)trace_pid_next(pid_list, (void *)pid, &l))
+ ;
+ return (void *)pid;
+}
+
+/**
+ * trace_pid_show - show the current pid in seq_file processing
+ * @m: The seq_file structure to write into
+ * @v: A void pointer of the pid (+1) value to display
+ *
+ * Can be directly used by seq_file operations to display the current
+ * pid value.
+ */
+int trace_pid_show(struct seq_file *m, void *v)
+{
+ unsigned long pid = (unsigned long)v - 1;
+
+ seq_printf(m, "%lu\n", pid);
+ return 0;
+}
+
+/* 128 should be much more than enough */
+#define PID_BUF_SIZE 127
+
+int trace_pid_write(struct trace_pid_list *filtered_pids,
+ struct trace_pid_list **new_pid_list,
+ const char __user *ubuf, size_t cnt)
+{
+ struct trace_pid_list *pid_list;
+ struct trace_parser parser;
+ unsigned long val;
+ int nr_pids = 0;
+ ssize_t read = 0;
+ ssize_t ret;
+ loff_t pos;
+ pid_t pid;
+
+ if (trace_parser_get_init(&parser, PID_BUF_SIZE + 1))
+ return -ENOMEM;
+
+ /*
+ * Always recreate a new array. The write is an all or nothing
+ * operation. Always create a new array when adding new pids by
+ * the user. If the operation fails, then the current list is
+ * not modified.
+ */
+ pid_list = trace_pid_list_alloc();
+ if (!pid_list) {
+ trace_parser_put(&parser);
+ return -ENOMEM;
+ }
+
+ if (filtered_pids) {
+ /* copy the current bits to the new max */
+ ret = trace_pid_list_first(filtered_pids, &pid);
+ while (!ret) {
+ trace_pid_list_set(pid_list, pid);
+ ret = trace_pid_list_next(filtered_pids, pid + 1, &pid);
+ nr_pids++;
+ }
+ }
+
+ ret = 0;
+ while (cnt > 0) {
+
+ pos = 0;
+
+ ret = trace_get_user(&parser, ubuf, cnt, &pos);
+ if (ret < 0)
+ break;
+
+ read += ret;
+ ubuf += ret;
+ cnt -= ret;
+
+ if (!trace_parser_loaded(&parser))
+ break;
+
+ ret = -EINVAL;
+ if (kstrtoul(parser.buffer, 0, &val))
+ break;
+
+ pid = (pid_t)val;
+
+ if (trace_pid_list_set(pid_list, pid) < 0) {
+ ret = -1;
+ break;
+ }
+ nr_pids++;
+
+ trace_parser_clear(&parser);
+ ret = 0;
+ }
+ trace_parser_put(&parser);
+
+ if (ret < 0) {
+ trace_pid_list_free(pid_list);
+ return ret;
+ }
+
+ if (!nr_pids) {
+ /* Cleared the list of pids */
+ trace_pid_list_free(pid_list);
+ pid_list = NULL;
+ }
+
+ *new_pid_list = pid_list;
+
+ return read;
+}
+
+static u64 buffer_ftrace_now(struct array_buffer *buf, int cpu)
+{
+ u64 ts;
+
+ /* Early boot up does not have a buffer yet */
+ if (!buf->buffer)
+ return trace_clock_local();
+
+ ts = ring_buffer_time_stamp(buf->buffer);
+ ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts);
+
+ return ts;
+}
+
+u64 ftrace_now(int cpu)
+{
+ return buffer_ftrace_now(&global_trace.array_buffer, cpu);
+}
+
+/**
+ * tracing_is_enabled - Show if global_trace has been enabled
+ *
+ * Shows if the global trace has been enabled or not. It uses the
+ * mirror flag "buffer_disabled" to be used in fast paths such as for
+ * the irqsoff tracer. But it may be inaccurate due to races. If you
+ * need to know the accurate state, use tracing_is_on() which is a little
+ * slower, but accurate.
+ */
+int tracing_is_enabled(void)
+{
+ /*
+ * For quick access (irqsoff uses this in fast path), just
+ * return the mirror variable of the state of the ring buffer.
+ * It's a little racy, but we don't really care.
+ */
+ smp_rmb();
+ return !global_trace.buffer_disabled;
+}
+
+/*
+ * trace_buf_size is the size in bytes that is allocated
+ * for a buffer. Note, the number of bytes is always rounded
+ * to page size.
+ *
+ * This number is purposely set to a low number of 16384.
+ * If the dump on oops happens, it will be much appreciated
+ * to not have to wait for all that output. Anyway this can be
+ * boot time and run time configurable.
+ */
+#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */
+
+static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
+
+/* trace_types holds a link list of available tracers. */
+static struct tracer *trace_types __read_mostly;
+
+/*
+ * trace_types_lock is used to protect the trace_types list.
+ */
+DEFINE_MUTEX(trace_types_lock);
+
+/*
+ * serialize the access of the ring buffer
+ *
+ * ring buffer serializes readers, but it is low level protection.
+ * The validity of the events (which returns by ring_buffer_peek() ..etc)
+ * are not protected by ring buffer.
+ *
+ * The content of events may become garbage if we allow other process consumes
+ * these events concurrently:
+ * A) the page of the consumed events may become a normal page
+ * (not reader page) in ring buffer, and this page will be rewritten
+ * by events producer.
+ * B) The page of the consumed events may become a page for splice_read,
+ * and this page will be returned to system.
+ *
+ * These primitives allow multi process access to different cpu ring buffer
+ * concurrently.
+ *
+ * These primitives don't distinguish read-only and read-consume access.
+ * Multi read-only access are also serialized.
+ */
+
+#ifdef CONFIG_SMP
+static DECLARE_RWSEM(all_cpu_access_lock);
+static DEFINE_PER_CPU(struct mutex, cpu_access_lock);
+
+static inline void trace_access_lock(int cpu)
+{
+ if (cpu == RING_BUFFER_ALL_CPUS) {
+ /* gain it for accessing the whole ring buffer. */
+ down_write(&all_cpu_access_lock);
+ } else {
+ /* gain it for accessing a cpu ring buffer. */
+
+ /* Firstly block other trace_access_lock(RING_BUFFER_ALL_CPUS). */
+ down_read(&all_cpu_access_lock);
+
+ /* Secondly block other access to this @cpu ring buffer. */
+ mutex_lock(&per_cpu(cpu_access_lock, cpu));
+ }
+}
+
+static inline void trace_access_unlock(int cpu)
+{
+ if (cpu == RING_BUFFER_ALL_CPUS) {
+ up_write(&all_cpu_access_lock);
+ } else {
+ mutex_unlock(&per_cpu(cpu_access_lock, cpu));
+ up_read(&all_cpu_access_lock);
+ }
+}
+
+static inline void trace_access_lock_init(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ mutex_init(&per_cpu(cpu_access_lock, cpu));
+}
+
+#else
+
+static DEFINE_MUTEX(access_lock);
+
+static inline void trace_access_lock(int cpu)
+{
+ (void)cpu;
+ mutex_lock(&access_lock);
+}
+
+static inline void trace_access_unlock(int cpu)
+{
+ (void)cpu;
+ mutex_unlock(&access_lock);
+}
+
+static inline void trace_access_lock_init(void)
+{
+}
+
+#endif
+
+#ifdef CONFIG_STACKTRACE
+static void __ftrace_trace_stack(struct trace_buffer *buffer,
+ unsigned int trace_ctx,
+ int skip, struct pt_regs *regs);
+static inline void ftrace_trace_stack(struct trace_array *tr,
+ struct trace_buffer *buffer,
+ unsigned int trace_ctx,
+ int skip, struct pt_regs *regs);
+
+#else
+static inline void __ftrace_trace_stack(struct trace_buffer *buffer,
+ unsigned int trace_ctx,
+ int skip, struct pt_regs *regs)
+{
+}
+static inline void ftrace_trace_stack(struct trace_array *tr,
+ struct trace_buffer *buffer,
+ unsigned long trace_ctx,
+ int skip, struct pt_regs *regs)
+{
+}
+
+#endif
+
+static __always_inline void
+trace_event_setup(struct ring_buffer_event *event,
+ int type, unsigned int trace_ctx)
+{
+ struct trace_entry *ent = ring_buffer_event_data(event);
+
+ tracing_generic_entry_update(ent, type, trace_ctx);
+}
+
+static __always_inline struct ring_buffer_event *
+__trace_buffer_lock_reserve(struct trace_buffer *buffer,
+ int type,
+ unsigned long len,
+ unsigned int trace_ctx)
+{
+ struct ring_buffer_event *event;
+
+ event = ring_buffer_lock_reserve(buffer, len);
+ if (event != NULL)
+ trace_event_setup(event, type, trace_ctx);
+
+ return event;
+}
+
+void tracer_tracing_on(struct trace_array *tr)
+{
+ if (tr->array_buffer.buffer)
+ ring_buffer_record_on(tr->array_buffer.buffer);
+ /*
+ * This flag is looked at when buffers haven't been allocated
+ * yet, or by some tracers (like irqsoff), that just want to
+ * know if the ring buffer has been disabled, but it can handle
+ * races of where it gets disabled but we still do a record.
+ * As the check is in the fast path of the tracers, it is more
+ * important to be fast than accurate.
+ */
+ tr->buffer_disabled = 0;
+ /* Make the flag seen by readers */
+ smp_wmb();
+}
+
+/**
+ * tracing_on - enable tracing buffers
+ *
+ * This function enables tracing buffers that may have been
+ * disabled with tracing_off.
+ */
+void tracing_on(void)
+{
+ tracer_tracing_on(&global_trace);
+}
+EXPORT_SYMBOL_GPL(tracing_on);
+
+
+static __always_inline void
+__buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *event)
+{
+ __this_cpu_write(trace_taskinfo_save, true);
+
+ /* If this is the temp buffer, we need to commit fully */
+ if (this_cpu_read(trace_buffered_event) == event) {
+ /* Length is in event->array[0] */
+ ring_buffer_write(buffer, event->array[0], &event->array[1]);
+ /* Release the temp buffer */
+ this_cpu_dec(trace_buffered_event_cnt);
+ /* ring_buffer_unlock_commit() enables preemption */
+ preempt_enable_notrace();
+ } else
+ ring_buffer_unlock_commit(buffer);
+}
+
+int __trace_array_puts(struct trace_array *tr, unsigned long ip,
+ const char *str, int size)
+{
+ struct ring_buffer_event *event;
+ struct trace_buffer *buffer;
+ struct print_entry *entry;
+ unsigned int trace_ctx;
+ int alloc;
+
+ if (!(tr->trace_flags & TRACE_ITER_PRINTK))
+ return 0;
+
+ if (unlikely(tracing_selftest_running && tr == &global_trace))
+ return 0;
+
+ if (unlikely(tracing_disabled))
+ return 0;
+
+ alloc = sizeof(*entry) + size + 2; /* possible \n added */
+
+ trace_ctx = tracing_gen_ctx();
+ buffer = tr->array_buffer.buffer;
+ ring_buffer_nest_start(buffer);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
+ trace_ctx);
+ if (!event) {
+ size = 0;
+ goto out;
+ }
+
+ entry = ring_buffer_event_data(event);
+ entry->ip = ip;
+
+ memcpy(&entry->buf, str, size);
+
+ /* Add a newline if necessary */
+ if (entry->buf[size - 1] != '\n') {
+ entry->buf[size] = '\n';
+ entry->buf[size + 1] = '\0';
+ } else
+ entry->buf[size] = '\0';
+
+ __buffer_unlock_commit(buffer, event);
+ ftrace_trace_stack(tr, buffer, trace_ctx, 4, NULL);
+ out:
+ ring_buffer_nest_end(buffer);
+ return size;
+}
+EXPORT_SYMBOL_GPL(__trace_array_puts);
+
+/**
+ * __trace_puts - write a constant string into the trace buffer.
+ * @ip: The address of the caller
+ * @str: The constant string to write
+ * @size: The size of the string.
+ */
+int __trace_puts(unsigned long ip, const char *str, int size)
+{
+ return __trace_array_puts(&global_trace, ip, str, size);
+}
+EXPORT_SYMBOL_GPL(__trace_puts);
+
+/**
+ * __trace_bputs - write the pointer to a constant string into trace buffer
+ * @ip: The address of the caller
+ * @str: The constant string to write to the buffer to
+ */
+int __trace_bputs(unsigned long ip, const char *str)
+{
+ struct ring_buffer_event *event;
+ struct trace_buffer *buffer;
+ struct bputs_entry *entry;
+ unsigned int trace_ctx;
+ int size = sizeof(struct bputs_entry);
+ int ret = 0;
+
+ if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
+ return 0;
+
+ if (unlikely(tracing_selftest_running || tracing_disabled))
+ return 0;
+
+ trace_ctx = tracing_gen_ctx();
+ buffer = global_trace.array_buffer.buffer;
+
+ ring_buffer_nest_start(buffer);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
+ trace_ctx);
+ if (!event)
+ goto out;
+
+ entry = ring_buffer_event_data(event);
+ entry->ip = ip;
+ entry->str = str;
+
+ __buffer_unlock_commit(buffer, event);
+ ftrace_trace_stack(&global_trace, buffer, trace_ctx, 4, NULL);
+
+ ret = 1;
+ out:
+ ring_buffer_nest_end(buffer);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__trace_bputs);
+
+#ifdef CONFIG_TRACER_SNAPSHOT
+static void tracing_snapshot_instance_cond(struct trace_array *tr,
+ void *cond_data)
+{
+ struct tracer *tracer = tr->current_trace;
+ unsigned long flags;
+
+ if (in_nmi()) {
+ trace_array_puts(tr, "*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n");
+ trace_array_puts(tr, "*** snapshot is being ignored ***\n");
+ return;
+ }
+
+ if (!tr->allocated_snapshot) {
+ trace_array_puts(tr, "*** SNAPSHOT NOT ALLOCATED ***\n");
+ trace_array_puts(tr, "*** stopping trace here! ***\n");
+ tracer_tracing_off(tr);
+ return;
+ }
+
+ /* Note, snapshot can not be used when the tracer uses it */
+ if (tracer->use_max_tr) {
+ trace_array_puts(tr, "*** LATENCY TRACER ACTIVE ***\n");
+ trace_array_puts(tr, "*** Can not use snapshot (sorry) ***\n");
+ return;
+ }
+
+ local_irq_save(flags);
+ update_max_tr(tr, current, smp_processor_id(), cond_data);
+ local_irq_restore(flags);
+}
+
+void tracing_snapshot_instance(struct trace_array *tr)
+{
+ tracing_snapshot_instance_cond(tr, NULL);
+}
+
+/**
+ * tracing_snapshot - take a snapshot of the current buffer.
+ *
+ * This causes a swap between the snapshot buffer and the current live
+ * tracing buffer. You can use this to take snapshots of the live
+ * trace when some condition is triggered, but continue to trace.
+ *
+ * Note, make sure to allocate the snapshot with either
+ * a tracing_snapshot_alloc(), or by doing it manually
+ * with: echo 1 > /sys/kernel/tracing/snapshot
+ *
+ * If the snapshot buffer is not allocated, it will stop tracing.
+ * Basically making a permanent snapshot.
+ */
+void tracing_snapshot(void)
+{
+ struct trace_array *tr = &global_trace;
+
+ tracing_snapshot_instance(tr);
+}
+EXPORT_SYMBOL_GPL(tracing_snapshot);
+
+/**
+ * tracing_snapshot_cond - conditionally take a snapshot of the current buffer.
+ * @tr: The tracing instance to snapshot
+ * @cond_data: The data to be tested conditionally, and possibly saved
+ *
+ * This is the same as tracing_snapshot() except that the snapshot is
+ * conditional - the snapshot will only happen if the
+ * cond_snapshot.update() implementation receiving the cond_data
+ * returns true, which means that the trace array's cond_snapshot
+ * update() operation used the cond_data to determine whether the
+ * snapshot should be taken, and if it was, presumably saved it along
+ * with the snapshot.
+ */
+void tracing_snapshot_cond(struct trace_array *tr, void *cond_data)
+{
+ tracing_snapshot_instance_cond(tr, cond_data);
+}
+EXPORT_SYMBOL_GPL(tracing_snapshot_cond);
+
+/**
+ * tracing_cond_snapshot_data - get the user data associated with a snapshot
+ * @tr: The tracing instance
+ *
+ * When the user enables a conditional snapshot using
+ * tracing_snapshot_cond_enable(), the user-defined cond_data is saved
+ * with the snapshot. This accessor is used to retrieve it.
+ *
+ * Should not be called from cond_snapshot.update(), since it takes
+ * the tr->max_lock lock, which the code calling
+ * cond_snapshot.update() has already done.
+ *
+ * Returns the cond_data associated with the trace array's snapshot.
+ */
+void *tracing_cond_snapshot_data(struct trace_array *tr)
+{
+ void *cond_data = NULL;
+
+ local_irq_disable();
+ arch_spin_lock(&tr->max_lock);
+
+ if (tr->cond_snapshot)
+ cond_data = tr->cond_snapshot->cond_data;
+
+ arch_spin_unlock(&tr->max_lock);
+ local_irq_enable();
+
+ return cond_data;
+}
+EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data);
+
+static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
+ struct array_buffer *size_buf, int cpu_id);
+static void set_buffer_entries(struct array_buffer *buf, unsigned long val);
+
+int tracing_alloc_snapshot_instance(struct trace_array *tr)
+{
+ int ret;
+
+ if (!tr->allocated_snapshot) {
+
+ /* allocate spare buffer */
+ ret = resize_buffer_duplicate_size(&tr->max_buffer,
+ &tr->array_buffer, RING_BUFFER_ALL_CPUS);
+ if (ret < 0)
+ return ret;
+
+ tr->allocated_snapshot = true;
+ }
+
+ return 0;
+}
+
+static void free_snapshot(struct trace_array *tr)
+{
+ /*
+ * We don't free the ring buffer. instead, resize it because
+ * The max_tr ring buffer has some state (e.g. ring->clock) and
+ * we want preserve it.
+ */
+ ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS);
+ set_buffer_entries(&tr->max_buffer, 1);
+ tracing_reset_online_cpus(&tr->max_buffer);
+ tr->allocated_snapshot = false;
+}
+
+/**
+ * tracing_alloc_snapshot - allocate snapshot buffer.
+ *
+ * This only allocates the snapshot buffer if it isn't already
+ * allocated - it doesn't also take a snapshot.
+ *
+ * This is meant to be used in cases where the snapshot buffer needs
+ * to be set up for events that can't sleep but need to be able to
+ * trigger a snapshot.
+ */
+int tracing_alloc_snapshot(void)
+{
+ struct trace_array *tr = &global_trace;
+ int ret;
+
+ ret = tracing_alloc_snapshot_instance(tr);
+ WARN_ON(ret < 0);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
+
+/**
+ * tracing_snapshot_alloc - allocate and take a snapshot of the current buffer.
+ *
+ * This is similar to tracing_snapshot(), but it will allocate the
+ * snapshot buffer if it isn't already allocated. Use this only
+ * where it is safe to sleep, as the allocation may sleep.
+ *
+ * This causes a swap between the snapshot buffer and the current live
+ * tracing buffer. You can use this to take snapshots of the live
+ * trace when some condition is triggered, but continue to trace.
+ */
+void tracing_snapshot_alloc(void)
+{
+ int ret;
+
+ ret = tracing_alloc_snapshot();
+ if (ret < 0)
+ return;
+
+ tracing_snapshot();
+}
+EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);
+
+/**
+ * tracing_snapshot_cond_enable - enable conditional snapshot for an instance
+ * @tr: The tracing instance
+ * @cond_data: User data to associate with the snapshot
+ * @update: Implementation of the cond_snapshot update function
+ *
+ * Check whether the conditional snapshot for the given instance has
+ * already been enabled, or if the current tracer is already using a
+ * snapshot; if so, return -EBUSY, else create a cond_snapshot and
+ * save the cond_data and update function inside.
+ *
+ * Returns 0 if successful, error otherwise.
+ */
+int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data,
+ cond_update_fn_t update)
+{
+ struct cond_snapshot *cond_snapshot;
+ int ret = 0;
+
+ cond_snapshot = kzalloc(sizeof(*cond_snapshot), GFP_KERNEL);
+ if (!cond_snapshot)
+ return -ENOMEM;
+
+ cond_snapshot->cond_data = cond_data;
+ cond_snapshot->update = update;
+
+ mutex_lock(&trace_types_lock);
+
+ ret = tracing_alloc_snapshot_instance(tr);
+ if (ret)
+ goto fail_unlock;
+
+ if (tr->current_trace->use_max_tr) {
+ ret = -EBUSY;
+ goto fail_unlock;
+ }
+
+ /*
+ * The cond_snapshot can only change to NULL without the
+ * trace_types_lock. We don't care if we race with it going
+ * to NULL, but we want to make sure that it's not set to
+ * something other than NULL when we get here, which we can
+ * do safely with only holding the trace_types_lock and not
+ * having to take the max_lock.
+ */
+ if (tr->cond_snapshot) {
+ ret = -EBUSY;
+ goto fail_unlock;
+ }
+
+ local_irq_disable();
+ arch_spin_lock(&tr->max_lock);
+ tr->cond_snapshot = cond_snapshot;
+ arch_spin_unlock(&tr->max_lock);
+ local_irq_enable();
+
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+
+ fail_unlock:
+ mutex_unlock(&trace_types_lock);
+ kfree(cond_snapshot);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tracing_snapshot_cond_enable);
+
+/**
+ * tracing_snapshot_cond_disable - disable conditional snapshot for an instance
+ * @tr: The tracing instance
+ *
+ * Check whether the conditional snapshot for the given instance is
+ * enabled; if so, free the cond_snapshot associated with it,
+ * otherwise return -EINVAL.
+ *
+ * Returns 0 if successful, error otherwise.
+ */
+int tracing_snapshot_cond_disable(struct trace_array *tr)
+{
+ int ret = 0;
+
+ local_irq_disable();
+ arch_spin_lock(&tr->max_lock);
+
+ if (!tr->cond_snapshot)
+ ret = -EINVAL;
+ else {
+ kfree(tr->cond_snapshot);
+ tr->cond_snapshot = NULL;
+ }
+
+ arch_spin_unlock(&tr->max_lock);
+ local_irq_enable();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable);
+#else
+void tracing_snapshot(void)
+{
+ WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used");
+}
+EXPORT_SYMBOL_GPL(tracing_snapshot);
+void tracing_snapshot_cond(struct trace_array *tr, void *cond_data)
+{
+ WARN_ONCE(1, "Snapshot feature not enabled, but internal conditional snapshot used");
+}
+EXPORT_SYMBOL_GPL(tracing_snapshot_cond);
+int tracing_alloc_snapshot(void)
+{
+ WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used");
+ return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
+void tracing_snapshot_alloc(void)
+{
+ /* Give warning */
+ tracing_snapshot();
+}
+EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);
+void *tracing_cond_snapshot_data(struct trace_array *tr)
+{
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data);
+int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update)
+{
+ return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(tracing_snapshot_cond_enable);
+int tracing_snapshot_cond_disable(struct trace_array *tr)
+{
+ return false;
+}
+EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable);
+#define free_snapshot(tr) do { } while (0)
+#endif /* CONFIG_TRACER_SNAPSHOT */
+
+void tracer_tracing_off(struct trace_array *tr)
+{
+ if (tr->array_buffer.buffer)
+ ring_buffer_record_off(tr->array_buffer.buffer);
+ /*
+ * This flag is looked at when buffers haven't been allocated
+ * yet, or by some tracers (like irqsoff), that just want to
+ * know if the ring buffer has been disabled, but it can handle
+ * races of where it gets disabled but we still do a record.
+ * As the check is in the fast path of the tracers, it is more
+ * important to be fast than accurate.
+ */
+ tr->buffer_disabled = 1;
+ /* Make the flag seen by readers */
+ smp_wmb();
+}
+
+/**
+ * tracing_off - turn off tracing buffers
+ *
+ * This function stops the tracing buffers from recording data.
+ * It does not disable any overhead the tracers themselves may
+ * be causing. This function simply causes all recording to
+ * the ring buffers to fail.
+ */
+void tracing_off(void)
+{
+ tracer_tracing_off(&global_trace);
+}
+EXPORT_SYMBOL_GPL(tracing_off);
+
+void disable_trace_on_warning(void)
+{
+ if (__disable_trace_on_warning) {
+ trace_array_printk_buf(global_trace.array_buffer.buffer, _THIS_IP_,
+ "Disabling tracing due to warning\n");
+ tracing_off();
+ }
+}
+
+/**
+ * tracer_tracing_is_on - show real state of ring buffer enabled
+ * @tr : the trace array to know if ring buffer is enabled
+ *
+ * Shows real state of the ring buffer if it is enabled or not.
+ */
+bool tracer_tracing_is_on(struct trace_array *tr)
+{
+ if (tr->array_buffer.buffer)
+ return ring_buffer_record_is_on(tr->array_buffer.buffer);
+ return !tr->buffer_disabled;
+}
+
+/**
+ * tracing_is_on - show state of ring buffers enabled
+ */
+int tracing_is_on(void)
+{
+ return tracer_tracing_is_on(&global_trace);
+}
+EXPORT_SYMBOL_GPL(tracing_is_on);
+
+static int __init set_buf_size(char *str)
+{
+ unsigned long buf_size;
+
+ if (!str)
+ return 0;
+ buf_size = memparse(str, &str);
+ /*
+ * nr_entries can not be zero and the startup
+ * tests require some buffer space. Therefore
+ * ensure we have at least 4096 bytes of buffer.
+ */
+ trace_buf_size = max(4096UL, buf_size);
+ return 1;
+}
+__setup("trace_buf_size=", set_buf_size);
+
+static int __init set_tracing_thresh(char *str)
+{
+ unsigned long threshold;
+ int ret;
+
+ if (!str)
+ return 0;
+ ret = kstrtoul(str, 0, &threshold);
+ if (ret < 0)
+ return 0;
+ tracing_thresh = threshold * 1000;
+ return 1;
+}
+__setup("tracing_thresh=", set_tracing_thresh);
+
+unsigned long nsecs_to_usecs(unsigned long nsecs)
+{
+ return nsecs / 1000;
+}
+
+/*
+ * TRACE_FLAGS is defined as a tuple matching bit masks with strings.
+ * It uses C(a, b) where 'a' is the eval (enum) name and 'b' is the string that
+ * matches it. By defining "C(a, b) b", TRACE_FLAGS becomes a list
+ * of strings in the order that the evals (enum) were defined.
+ */
+#undef C
+#define C(a, b) b
+
+/* These must match the bit positions in trace_iterator_flags */
+static const char *trace_options[] = {
+ TRACE_FLAGS
+ NULL
+};
+
+static struct {
+ u64 (*func)(void);
+ const char *name;
+ int in_ns; /* is this clock in nanoseconds? */
+} trace_clocks[] = {
+ { trace_clock_local, "local", 1 },
+ { trace_clock_global, "global", 1 },
+ { trace_clock_counter, "counter", 0 },
+ { trace_clock_jiffies, "uptime", 0 },
+ { trace_clock, "perf", 1 },
+ { ktime_get_mono_fast_ns, "mono", 1 },
+ { ktime_get_raw_fast_ns, "mono_raw", 1 },
+ { ktime_get_boot_fast_ns, "boot", 1 },
+ { ktime_get_tai_fast_ns, "tai", 1 },
+ ARCH_TRACE_CLOCKS
+};
+
+bool trace_clock_in_ns(struct trace_array *tr)
+{
+ if (trace_clocks[tr->clock_id].in_ns)
+ return true;
+
+ return false;
+}
+
+/*
+ * trace_parser_get_init - gets the buffer for trace parser
+ */
+int trace_parser_get_init(struct trace_parser *parser, int size)
+{
+ memset(parser, 0, sizeof(*parser));
+
+ parser->buffer = kmalloc(size, GFP_KERNEL);
+ if (!parser->buffer)
+ return 1;
+
+ parser->size = size;
+ return 0;
+}
+
+/*
+ * trace_parser_put - frees the buffer for trace parser
+ */
+void trace_parser_put(struct trace_parser *parser)
+{
+ kfree(parser->buffer);
+ parser->buffer = NULL;
+}
+
+/*
+ * trace_get_user - reads the user input string separated by space
+ * (matched by isspace(ch))
+ *
+ * For each string found the 'struct trace_parser' is updated,
+ * and the function returns.
+ *
+ * Returns number of bytes read.
+ *
+ * See kernel/trace/trace.h for 'struct trace_parser' details.
+ */
+int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char ch;
+ size_t read = 0;
+ ssize_t ret;
+
+ if (!*ppos)
+ trace_parser_clear(parser);
+
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+
+ read++;
+ cnt--;
+
+ /*
+ * The parser is not finished with the last write,
+ * continue reading the user input without skipping spaces.
+ */
+ if (!parser->cont) {
+ /* skip white space */
+ while (cnt && isspace(ch)) {
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+ }
+
+ parser->idx = 0;
+
+ /* only spaces were written */
+ if (isspace(ch) || !ch) {
+ *ppos += read;
+ ret = read;
+ goto out;
+ }
+ }
+
+ /* read the non-space input */
+ while (cnt && !isspace(ch) && ch) {
+ if (parser->idx < parser->size - 1)
+ parser->buffer[parser->idx++] = ch;
+ else {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+ }
+
+ /* We either got finished input or we have to wait for another call. */
+ if (isspace(ch) || !ch) {
+ parser->buffer[parser->idx] = 0;
+ parser->cont = false;
+ } else if (parser->idx < parser->size - 1) {
+ parser->cont = true;
+ parser->buffer[parser->idx++] = ch;
+ /* Make sure the parsed string always terminates with '\0'. */
+ parser->buffer[parser->idx] = 0;
+ } else {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ *ppos += read;
+ ret = read;
+
+out:
+ return ret;
+}
+
+/* TODO add a seq_buf_to_buffer() */
+static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
+{
+ int len;
+
+ if (trace_seq_used(s) <= s->seq.readpos)
+ return -EBUSY;
+
+ len = trace_seq_used(s) - s->seq.readpos;
+ if (cnt > len)
+ cnt = len;
+ memcpy(buf, s->buffer + s->seq.readpos, cnt);
+
+ s->seq.readpos += cnt;
+ return cnt;
+}
+
+unsigned long __read_mostly tracing_thresh;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+static const struct file_operations tracing_max_lat_fops;
+
+#ifdef LATENCY_FS_NOTIFY
+
+static struct workqueue_struct *fsnotify_wq;
+
+static void latency_fsnotify_workfn(struct work_struct *work)
+{
+ struct trace_array *tr = container_of(work, struct trace_array,
+ fsnotify_work);
+ fsnotify_inode(tr->d_max_latency->d_inode, FS_MODIFY);
+}
+
+static void latency_fsnotify_workfn_irq(struct irq_work *iwork)
+{
+ struct trace_array *tr = container_of(iwork, struct trace_array,
+ fsnotify_irqwork);
+ queue_work(fsnotify_wq, &tr->fsnotify_work);
+}
+
+static void trace_create_maxlat_file(struct trace_array *tr,
+ struct dentry *d_tracer)
+{
+ INIT_WORK(&tr->fsnotify_work, latency_fsnotify_workfn);
+ init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq);
+ tr->d_max_latency = trace_create_file("tracing_max_latency",
+ TRACE_MODE_WRITE,
+ d_tracer, tr,
+ &tracing_max_lat_fops);
+}
+
+__init static int latency_fsnotify_init(void)
+{
+ fsnotify_wq = alloc_workqueue("tr_max_lat_wq",
+ WQ_UNBOUND | WQ_HIGHPRI, 0);
+ if (!fsnotify_wq) {
+ pr_err("Unable to allocate tr_max_lat_wq\n");
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+late_initcall_sync(latency_fsnotify_init);
+
+void latency_fsnotify(struct trace_array *tr)
+{
+ if (!fsnotify_wq)
+ return;
+ /*
+ * We cannot call queue_work(&tr->fsnotify_work) from here because it's
+ * possible that we are called from __schedule() or do_idle(), which
+ * could cause a deadlock.
+ */
+ irq_work_queue(&tr->fsnotify_irqwork);
+}
+
+#else /* !LATENCY_FS_NOTIFY */
+
+#define trace_create_maxlat_file(tr, d_tracer) \
+ trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, \
+ d_tracer, tr, &tracing_max_lat_fops)
+
+#endif
+
+/*
+ * Copy the new maximum trace into the separate maximum-trace
+ * structure. (this way the maximum trace is permanently saved,
+ * for later retrieval via /sys/kernel/tracing/tracing_max_latency)
+ */
+static void
+__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
+{
+ struct array_buffer *trace_buf = &tr->array_buffer;
+ struct array_buffer *max_buf = &tr->max_buffer;
+ struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu);
+ struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu);
+
+ max_buf->cpu = cpu;
+ max_buf->time_start = data->preempt_timestamp;
+
+ max_data->saved_latency = tr->max_latency;
+ max_data->critical_start = data->critical_start;
+ max_data->critical_end = data->critical_end;
+
+ strncpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
+ max_data->pid = tsk->pid;
+ /*
+ * If tsk == current, then use current_uid(), as that does not use
+ * RCU. The irq tracer can be called out of RCU scope.
+ */
+ if (tsk == current)
+ max_data->uid = current_uid();
+ else
+ max_data->uid = task_uid(tsk);
+
+ max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
+ max_data->policy = tsk->policy;
+ max_data->rt_priority = tsk->rt_priority;
+
+ /* record this tasks comm */
+ tracing_record_cmdline(tsk);
+ latency_fsnotify(tr);
+}
+
+/**
+ * update_max_tr - snapshot all trace buffers from global_trace to max_tr
+ * @tr: tracer
+ * @tsk: the task with the latency
+ * @cpu: The cpu that initiated the trace.
+ * @cond_data: User data associated with a conditional snapshot
+ *
+ * Flip the buffers between the @tr and the max_tr and record information
+ * about which task was the cause of this latency.
+ */
+void
+update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
+ void *cond_data)
+{
+ if (tr->stop_count)
+ return;
+
+ WARN_ON_ONCE(!irqs_disabled());
+
+ if (!tr->allocated_snapshot) {
+ /* Only the nop tracer should hit this when disabling */
+ WARN_ON_ONCE(tr->current_trace != &nop_trace);
+ return;
+ }
+
+ arch_spin_lock(&tr->max_lock);
+
+ /* Inherit the recordable setting from array_buffer */
+ if (ring_buffer_record_is_set_on(tr->array_buffer.buffer))
+ ring_buffer_record_on(tr->max_buffer.buffer);
+ else
+ ring_buffer_record_off(tr->max_buffer.buffer);
+
+#ifdef CONFIG_TRACER_SNAPSHOT
+ if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data)) {
+ arch_spin_unlock(&tr->max_lock);
+ return;
+ }
+#endif
+ swap(tr->array_buffer.buffer, tr->max_buffer.buffer);
+
+ __update_max_tr(tr, tsk, cpu);
+
+ arch_spin_unlock(&tr->max_lock);
+
+ /* Any waiters on the old snapshot buffer need to wake up */
+ ring_buffer_wake_waiters(tr->array_buffer.buffer, RING_BUFFER_ALL_CPUS);
+}
+
+/**
+ * update_max_tr_single - only copy one trace over, and reset the rest
+ * @tr: tracer
+ * @tsk: task with the latency
+ * @cpu: the cpu of the buffer to copy.
+ *
+ * Flip the trace of a single CPU buffer between the @tr and the max_tr.
+ */
+void
+update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
+{
+ int ret;
+
+ if (tr->stop_count)
+ return;
+
+ WARN_ON_ONCE(!irqs_disabled());
+ if (!tr->allocated_snapshot) {
+ /* Only the nop tracer should hit this when disabling */
+ WARN_ON_ONCE(tr->current_trace != &nop_trace);
+ return;
+ }
+
+ arch_spin_lock(&tr->max_lock);
+
+ ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->array_buffer.buffer, cpu);
+
+ if (ret == -EBUSY) {
+ /*
+ * We failed to swap the buffer due to a commit taking
+ * place on this CPU. We fail to record, but we reset
+ * the max trace buffer (no one writes directly to it)
+ * and flag that it failed.
+ * Another reason is resize is in progress.
+ */
+ trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_,
+ "Failed to swap buffers due to commit or resize in progress\n");
+ }
+
+ WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY);
+
+ __update_max_tr(tr, tsk, cpu);
+ arch_spin_unlock(&tr->max_lock);
+}
+
+#endif /* CONFIG_TRACER_MAX_TRACE */
+
+static int wait_on_pipe(struct trace_iterator *iter, int full)
+{
+ int ret;
+
+ /* Iterators are static, they should be filled or empty */
+ if (trace_buffer_iter(iter, iter->cpu_file))
+ return 0;
+
+ ret = ring_buffer_wait(iter->array_buffer->buffer, iter->cpu_file, full);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ /*
+ * Make sure this is still the snapshot buffer, as if a snapshot were
+ * to happen, this would now be the main buffer.
+ */
+ if (iter->snapshot)
+ iter->array_buffer = &iter->tr->max_buffer;
+#endif
+ return ret;
+}
+
+#ifdef CONFIG_FTRACE_STARTUP_TEST
+static bool selftests_can_run;
+
+struct trace_selftests {
+ struct list_head list;
+ struct tracer *type;
+};
+
+static LIST_HEAD(postponed_selftests);
+
+static int save_selftest(struct tracer *type)
+{
+ struct trace_selftests *selftest;
+
+ selftest = kmalloc(sizeof(*selftest), GFP_KERNEL);
+ if (!selftest)
+ return -ENOMEM;
+
+ selftest->type = type;
+ list_add(&selftest->list, &postponed_selftests);
+ return 0;
+}
+
+static int run_tracer_selftest(struct tracer *type)
+{
+ struct trace_array *tr = &global_trace;
+ struct tracer *saved_tracer = tr->current_trace;
+ int ret;
+
+ if (!type->selftest || tracing_selftest_disabled)
+ return 0;
+
+ /*
+ * If a tracer registers early in boot up (before scheduling is
+ * initialized and such), then do not run its selftests yet.
+ * Instead, run it a little later in the boot process.
+ */
+ if (!selftests_can_run)
+ return save_selftest(type);
+
+ if (!tracing_is_on()) {
+ pr_warn("Selftest for tracer %s skipped due to tracing disabled\n",
+ type->name);
+ return 0;
+ }
+
+ /*
+ * Run a selftest on this tracer.
+ * Here we reset the trace buffer, and set the current
+ * tracer to be this tracer. The tracer can then run some
+ * internal tracing to verify that everything is in order.
+ * If we fail, we do not register this tracer.
+ */
+ tracing_reset_online_cpus(&tr->array_buffer);
+
+ tr->current_trace = type;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (type->use_max_tr) {
+ /* If we expanded the buffers, make sure the max is expanded too */
+ if (ring_buffer_expanded)
+ ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size,
+ RING_BUFFER_ALL_CPUS);
+ tr->allocated_snapshot = true;
+ }
+#endif
+
+ /* the test is responsible for initializing and enabling */
+ pr_info("Testing tracer %s: ", type->name);
+ ret = type->selftest(type, tr);
+ /* the test is responsible for resetting too */
+ tr->current_trace = saved_tracer;
+ if (ret) {
+ printk(KERN_CONT "FAILED!\n");
+ /* Add the warning after printing 'FAILED' */
+ WARN_ON(1);
+ return -1;
+ }
+ /* Only reset on passing, to avoid touching corrupted buffers */
+ tracing_reset_online_cpus(&tr->array_buffer);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (type->use_max_tr) {
+ tr->allocated_snapshot = false;
+
+ /* Shrink the max buffer again */
+ if (ring_buffer_expanded)
+ ring_buffer_resize(tr->max_buffer.buffer, 1,
+ RING_BUFFER_ALL_CPUS);
+ }
+#endif
+
+ printk(KERN_CONT "PASSED\n");
+ return 0;
+}
+
+static int do_run_tracer_selftest(struct tracer *type)
+{
+ int ret;
+
+ /*
+ * Tests can take a long time, especially if they are run one after the
+ * other, as does happen during bootup when all the tracers are
+ * registered. This could cause the soft lockup watchdog to trigger.
+ */
+ cond_resched();
+
+ tracing_selftest_running = true;
+ ret = run_tracer_selftest(type);
+ tracing_selftest_running = false;
+
+ return ret;
+}
+
+static __init int init_trace_selftests(void)
+{
+ struct trace_selftests *p, *n;
+ struct tracer *t, **last;
+ int ret;
+
+ selftests_can_run = true;
+
+ mutex_lock(&trace_types_lock);
+
+ if (list_empty(&postponed_selftests))
+ goto out;
+
+ pr_info("Running postponed tracer tests:\n");
+
+ tracing_selftest_running = true;
+ list_for_each_entry_safe(p, n, &postponed_selftests, list) {
+ /* This loop can take minutes when sanitizers are enabled, so
+ * lets make sure we allow RCU processing.
+ */
+ cond_resched();
+ ret = run_tracer_selftest(p->type);
+ /* If the test fails, then warn and remove from available_tracers */
+ if (ret < 0) {
+ WARN(1, "tracer: %s failed selftest, disabling\n",
+ p->type->name);
+ last = &trace_types;
+ for (t = trace_types; t; t = t->next) {
+ if (t == p->type) {
+ *last = t->next;
+ break;
+ }
+ last = &t->next;
+ }
+ }
+ list_del(&p->list);
+ kfree(p);
+ }
+ tracing_selftest_running = false;
+
+ out:
+ mutex_unlock(&trace_types_lock);
+
+ return 0;
+}
+core_initcall(init_trace_selftests);
+#else
+static inline int run_tracer_selftest(struct tracer *type)
+{
+ return 0;
+}
+static inline int do_run_tracer_selftest(struct tracer *type)
+{
+ return 0;
+}
+#endif /* CONFIG_FTRACE_STARTUP_TEST */
+
+static void add_tracer_options(struct trace_array *tr, struct tracer *t);
+
+static void __init apply_trace_boot_options(void);
+
+/**
+ * register_tracer - register a tracer with the ftrace system.
+ * @type: the plugin for the tracer
+ *
+ * Register a new plugin tracer.
+ */
+int __init register_tracer(struct tracer *type)
+{
+ struct tracer *t;
+ int ret = 0;
+
+ if (!type->name) {
+ pr_info("Tracer must have a name\n");
+ return -1;
+ }
+
+ if (strlen(type->name) >= MAX_TRACER_SIZE) {
+ pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);
+ return -1;
+ }
+
+ if (security_locked_down(LOCKDOWN_TRACEFS)) {
+ pr_warn("Can not register tracer %s due to lockdown\n",
+ type->name);
+ return -EPERM;
+ }
+
+ mutex_lock(&trace_types_lock);
+
+ for (t = trace_types; t; t = t->next) {
+ if (strcmp(type->name, t->name) == 0) {
+ /* already found */
+ pr_info("Tracer %s already registered\n",
+ type->name);
+ ret = -1;
+ goto out;
+ }
+ }
+
+ if (!type->set_flag)
+ type->set_flag = &dummy_set_flag;
+ if (!type->flags) {
+ /*allocate a dummy tracer_flags*/
+ type->flags = kmalloc(sizeof(*type->flags), GFP_KERNEL);
+ if (!type->flags) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ type->flags->val = 0;
+ type->flags->opts = dummy_tracer_opt;
+ } else
+ if (!type->flags->opts)
+ type->flags->opts = dummy_tracer_opt;
+
+ /* store the tracer for __set_tracer_option */
+ type->flags->trace = type;
+
+ ret = do_run_tracer_selftest(type);
+ if (ret < 0)
+ goto out;
+
+ type->next = trace_types;
+ trace_types = type;
+ add_tracer_options(&global_trace, type);
+
+ out:
+ mutex_unlock(&trace_types_lock);
+
+ if (ret || !default_bootup_tracer)
+ goto out_unlock;
+
+ if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
+ goto out_unlock;
+
+ printk(KERN_INFO "Starting tracer '%s'\n", type->name);
+ /* Do we want this tracer to start on bootup? */
+ tracing_set_tracer(&global_trace, type->name);
+ default_bootup_tracer = NULL;
+
+ apply_trace_boot_options();
+
+ /* disable other selftests, since this will break it. */
+ disable_tracing_selftest("running a tracer");
+
+ out_unlock:
+ return ret;
+}
+
+static void tracing_reset_cpu(struct array_buffer *buf, int cpu)
+{
+ struct trace_buffer *buffer = buf->buffer;
+
+ if (!buffer)
+ return;
+
+ ring_buffer_record_disable(buffer);
+
+ /* Make sure all commits have finished */
+ synchronize_rcu();
+ ring_buffer_reset_cpu(buffer, cpu);
+
+ ring_buffer_record_enable(buffer);
+}
+
+void tracing_reset_online_cpus(struct array_buffer *buf)
+{
+ struct trace_buffer *buffer = buf->buffer;
+
+ if (!buffer)
+ return;
+
+ ring_buffer_record_disable(buffer);
+
+ /* Make sure all commits have finished */
+ synchronize_rcu();
+
+ buf->time_start = buffer_ftrace_now(buf, buf->cpu);
+
+ ring_buffer_reset_online_cpus(buffer);
+
+ ring_buffer_record_enable(buffer);
+}
+
+/* Must have trace_types_lock held */
+void tracing_reset_all_online_cpus_unlocked(void)
+{
+ struct trace_array *tr;
+
+ lockdep_assert_held(&trace_types_lock);
+
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (!tr->clear_trace)
+ continue;
+ tr->clear_trace = false;
+ tracing_reset_online_cpus(&tr->array_buffer);
+#ifdef CONFIG_TRACER_MAX_TRACE
+ tracing_reset_online_cpus(&tr->max_buffer);
+#endif
+ }
+}
+
+void tracing_reset_all_online_cpus(void)
+{
+ mutex_lock(&trace_types_lock);
+ tracing_reset_all_online_cpus_unlocked();
+ mutex_unlock(&trace_types_lock);
+}
+
+/*
+ * The tgid_map array maps from pid to tgid; i.e. the value stored at index i
+ * is the tgid last observed corresponding to pid=i.
+ */
+static int *tgid_map;
+
+/* The maximum valid index into tgid_map. */
+static size_t tgid_map_max;
+
+#define SAVED_CMDLINES_DEFAULT 128
+#define NO_CMDLINE_MAP UINT_MAX
+/*
+ * Preemption must be disabled before acquiring trace_cmdline_lock.
+ * The various trace_arrays' max_lock must be acquired in a context
+ * where interrupt is disabled.
+ */
+static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
+struct saved_cmdlines_buffer {
+ unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
+ unsigned *map_cmdline_to_pid;
+ unsigned cmdline_num;
+ int cmdline_idx;
+ char *saved_cmdlines;
+};
+static struct saved_cmdlines_buffer *savedcmd;
+
+static inline char *get_saved_cmdlines(int idx)
+{
+ return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN];
+}
+
+static inline void set_cmdline(int idx, const char *cmdline)
+{
+ strncpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
+}
+
+static int allocate_cmdlines_buffer(unsigned int val,
+ struct saved_cmdlines_buffer *s)
+{
+ s->map_cmdline_to_pid = kmalloc_array(val,
+ sizeof(*s->map_cmdline_to_pid),
+ GFP_KERNEL);
+ if (!s->map_cmdline_to_pid)
+ return -ENOMEM;
+
+ s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);
+ if (!s->saved_cmdlines) {
+ kfree(s->map_cmdline_to_pid);
+ return -ENOMEM;
+ }
+
+ s->cmdline_idx = 0;
+ s->cmdline_num = val;
+ memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP,
+ sizeof(s->map_pid_to_cmdline));
+ memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP,
+ val * sizeof(*s->map_cmdline_to_pid));
+
+ return 0;
+}
+
+static int trace_create_savedcmd(void)
+{
+ int ret;
+
+ savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL);
+ if (!savedcmd)
+ return -ENOMEM;
+
+ ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd);
+ if (ret < 0) {
+ kfree(savedcmd);
+ savedcmd = NULL;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+int is_tracing_stopped(void)
+{
+ return global_trace.stop_count;
+}
+
+static void tracing_start_tr(struct trace_array *tr)
+{
+ struct trace_buffer *buffer;
+ unsigned long flags;
+
+ if (tracing_disabled)
+ return;
+
+ raw_spin_lock_irqsave(&tr->start_lock, flags);
+ if (--tr->stop_count) {
+ if (WARN_ON_ONCE(tr->stop_count < 0)) {
+ /* Someone screwed up their debugging */
+ tr->stop_count = 0;
+ }
+ goto out;
+ }
+
+ /* Prevent the buffers from switching */
+ arch_spin_lock(&tr->max_lock);
+
+ buffer = tr->array_buffer.buffer;
+ if (buffer)
+ ring_buffer_record_enable(buffer);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ buffer = tr->max_buffer.buffer;
+ if (buffer)
+ ring_buffer_record_enable(buffer);
+#endif
+
+ arch_spin_unlock(&tr->max_lock);
+
+ out:
+ raw_spin_unlock_irqrestore(&tr->start_lock, flags);
+}
+
+/**
+ * tracing_start - quick start of the tracer
+ *
+ * If tracing is enabled but was stopped by tracing_stop,
+ * this will start the tracer back up.
+ */
+void tracing_start(void)
+
+{
+ return tracing_start_tr(&global_trace);
+}
+
+static void tracing_stop_tr(struct trace_array *tr)
+{
+ struct trace_buffer *buffer;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&tr->start_lock, flags);
+ if (tr->stop_count++)
+ goto out;
+
+ /* Prevent the buffers from switching */
+ arch_spin_lock(&tr->max_lock);
+
+ buffer = tr->array_buffer.buffer;
+ if (buffer)
+ ring_buffer_record_disable(buffer);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ buffer = tr->max_buffer.buffer;
+ if (buffer)
+ ring_buffer_record_disable(buffer);
+#endif
+
+ arch_spin_unlock(&tr->max_lock);
+
+ out:
+ raw_spin_unlock_irqrestore(&tr->start_lock, flags);
+}
+
+/**
+ * tracing_stop - quick stop of the tracer
+ *
+ * Light weight way to stop tracing. Use in conjunction with
+ * tracing_start.
+ */
+void tracing_stop(void)
+{
+ return tracing_stop_tr(&global_trace);
+}
+
+static int trace_save_cmdline(struct task_struct *tsk)
+{
+ unsigned tpid, idx;
+
+ /* treat recording of idle task as a success */
+ if (!tsk->pid)
+ return 1;
+
+ tpid = tsk->pid & (PID_MAX_DEFAULT - 1);
+
+ /*
+ * It's not the end of the world if we don't get
+ * the lock, but we also don't want to spin
+ * nor do we want to disable interrupts,
+ * so if we miss here, then better luck next time.
+ *
+ * This is called within the scheduler and wake up, so interrupts
+ * had better been disabled and run queue lock been held.
+ */
+ lockdep_assert_preemption_disabled();
+ if (!arch_spin_trylock(&trace_cmdline_lock))
+ return 0;
+
+ idx = savedcmd->map_pid_to_cmdline[tpid];
+ if (idx == NO_CMDLINE_MAP) {
+ idx = (savedcmd->cmdline_idx + 1) % savedcmd->cmdline_num;
+
+ savedcmd->map_pid_to_cmdline[tpid] = idx;
+ savedcmd->cmdline_idx = idx;
+ }
+
+ savedcmd->map_cmdline_to_pid[idx] = tsk->pid;
+ set_cmdline(idx, tsk->comm);
+
+ arch_spin_unlock(&trace_cmdline_lock);
+
+ return 1;
+}
+
+static void __trace_find_cmdline(int pid, char comm[])
+{
+ unsigned map;
+ int tpid;
+
+ if (!pid) {
+ strcpy(comm, "<idle>");
+ return;
+ }
+
+ if (WARN_ON_ONCE(pid < 0)) {
+ strcpy(comm, "<XXX>");
+ return;
+ }
+
+ tpid = pid & (PID_MAX_DEFAULT - 1);
+ map = savedcmd->map_pid_to_cmdline[tpid];
+ if (map != NO_CMDLINE_MAP) {
+ tpid = savedcmd->map_cmdline_to_pid[map];
+ if (tpid == pid) {
+ strscpy(comm, get_saved_cmdlines(map), TASK_COMM_LEN);
+ return;
+ }
+ }
+ strcpy(comm, "<...>");
+}
+
+void trace_find_cmdline(int pid, char comm[])
+{
+ preempt_disable();
+ arch_spin_lock(&trace_cmdline_lock);
+
+ __trace_find_cmdline(pid, comm);
+
+ arch_spin_unlock(&trace_cmdline_lock);
+ preempt_enable();
+}
+
+static int *trace_find_tgid_ptr(int pid)
+{
+ /*
+ * Pairs with the smp_store_release in set_tracer_flag() to ensure that
+ * if we observe a non-NULL tgid_map then we also observe the correct
+ * tgid_map_max.
+ */
+ int *map = smp_load_acquire(&tgid_map);
+
+ if (unlikely(!map || pid > tgid_map_max))
+ return NULL;
+
+ return &map[pid];
+}
+
+int trace_find_tgid(int pid)
+{
+ int *ptr = trace_find_tgid_ptr(pid);
+
+ return ptr ? *ptr : 0;
+}
+
+static int trace_save_tgid(struct task_struct *tsk)
+{
+ int *ptr;
+
+ /* treat recording of idle task as a success */
+ if (!tsk->pid)
+ return 1;
+
+ ptr = trace_find_tgid_ptr(tsk->pid);
+ if (!ptr)
+ return 0;
+
+ *ptr = tsk->tgid;
+ return 1;
+}
+
+static bool tracing_record_taskinfo_skip(int flags)
+{
+ if (unlikely(!(flags & (TRACE_RECORD_CMDLINE | TRACE_RECORD_TGID))))
+ return true;
+ if (!__this_cpu_read(trace_taskinfo_save))
+ return true;
+ return false;
+}
+
+/**
+ * tracing_record_taskinfo - record the task info of a task
+ *
+ * @task: task to record
+ * @flags: TRACE_RECORD_CMDLINE for recording comm
+ * TRACE_RECORD_TGID for recording tgid
+ */
+void tracing_record_taskinfo(struct task_struct *task, int flags)
+{
+ bool done;
+
+ if (tracing_record_taskinfo_skip(flags))
+ return;
+
+ /*
+ * Record as much task information as possible. If some fail, continue
+ * to try to record the others.
+ */
+ done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(task);
+ done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(task);
+
+ /* If recording any information failed, retry again soon. */
+ if (!done)
+ return;
+
+ __this_cpu_write(trace_taskinfo_save, false);
+}
+
+/**
+ * tracing_record_taskinfo_sched_switch - record task info for sched_switch
+ *
+ * @prev: previous task during sched_switch
+ * @next: next task during sched_switch
+ * @flags: TRACE_RECORD_CMDLINE for recording comm
+ * TRACE_RECORD_TGID for recording tgid
+ */
+void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
+ struct task_struct *next, int flags)
+{
+ bool done;
+
+ if (tracing_record_taskinfo_skip(flags))
+ return;
+
+ /*
+ * Record as much task information as possible. If some fail, continue
+ * to try to record the others.
+ */
+ done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(prev);
+ done &= !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(next);
+ done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(prev);
+ done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(next);
+
+ /* If recording any information failed, retry again soon. */
+ if (!done)
+ return;
+
+ __this_cpu_write(trace_taskinfo_save, false);
+}
+
+/* Helpers to record a specific task information */
+void tracing_record_cmdline(struct task_struct *task)
+{
+ tracing_record_taskinfo(task, TRACE_RECORD_CMDLINE);
+}
+
+void tracing_record_tgid(struct task_struct *task)
+{
+ tracing_record_taskinfo(task, TRACE_RECORD_TGID);
+}
+
+/*
+ * Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq
+ * overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function
+ * simplifies those functions and keeps them in sync.
+ */
+enum print_line_t trace_handle_return(struct trace_seq *s)
+{
+ return trace_seq_has_overflowed(s) ?
+ TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
+}
+EXPORT_SYMBOL_GPL(trace_handle_return);
+
+static unsigned short migration_disable_value(void)
+{
+#if defined(CONFIG_SMP)
+ return current->migration_disabled;
+#else
+ return 0;
+#endif
+}
+
+unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status)
+{
+ unsigned int trace_flags = irqs_status;
+ unsigned int pc;
+
+ pc = preempt_count();
+
+ if (pc & NMI_MASK)
+ trace_flags |= TRACE_FLAG_NMI;
+ if (pc & HARDIRQ_MASK)
+ trace_flags |= TRACE_FLAG_HARDIRQ;
+ if (in_serving_softirq())
+ trace_flags |= TRACE_FLAG_SOFTIRQ;
+ if (softirq_count() >> (SOFTIRQ_SHIFT + 1))
+ trace_flags |= TRACE_FLAG_BH_OFF;
+
+ if (tif_need_resched())
+ trace_flags |= TRACE_FLAG_NEED_RESCHED;
+ if (test_preempt_need_resched())
+ trace_flags |= TRACE_FLAG_PREEMPT_RESCHED;
+ return (trace_flags << 16) | (min_t(unsigned int, pc & 0xff, 0xf)) |
+ (min_t(unsigned int, migration_disable_value(), 0xf)) << 4;
+}
+
+struct ring_buffer_event *
+trace_buffer_lock_reserve(struct trace_buffer *buffer,
+ int type,
+ unsigned long len,
+ unsigned int trace_ctx)
+{
+ return __trace_buffer_lock_reserve(buffer, type, len, trace_ctx);
+}
+
+DEFINE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
+DEFINE_PER_CPU(int, trace_buffered_event_cnt);
+static int trace_buffered_event_ref;
+
+/**
+ * trace_buffered_event_enable - enable buffering events
+ *
+ * When events are being filtered, it is quicker to use a temporary
+ * buffer to write the event data into if there's a likely chance
+ * that it will not be committed. The discard of the ring buffer
+ * is not as fast as committing, and is much slower than copying
+ * a commit.
+ *
+ * When an event is to be filtered, allocate per cpu buffers to
+ * write the event data into, and if the event is filtered and discarded
+ * it is simply dropped, otherwise, the entire data is to be committed
+ * in one shot.
+ */
+void trace_buffered_event_enable(void)
+{
+ struct ring_buffer_event *event;
+ struct page *page;
+ int cpu;
+
+ WARN_ON_ONCE(!mutex_is_locked(&event_mutex));
+
+ if (trace_buffered_event_ref++)
+ return;
+
+ for_each_tracing_cpu(cpu) {
+ page = alloc_pages_node(cpu_to_node(cpu),
+ GFP_KERNEL | __GFP_NORETRY, 0);
+ /* This is just an optimization and can handle failures */
+ if (!page) {
+ pr_err("Failed to allocate event buffer\n");
+ break;
+ }
+
+ event = page_address(page);
+ memset(event, 0, sizeof(*event));
+
+ per_cpu(trace_buffered_event, cpu) = event;
+
+ preempt_disable();
+ if (cpu == smp_processor_id() &&
+ __this_cpu_read(trace_buffered_event) !=
+ per_cpu(trace_buffered_event, cpu))
+ WARN_ON_ONCE(1);
+ preempt_enable();
+ }
+}
+
+static void enable_trace_buffered_event(void *data)
+{
+ /* Probably not needed, but do it anyway */
+ smp_rmb();
+ this_cpu_dec(trace_buffered_event_cnt);
+}
+
+static void disable_trace_buffered_event(void *data)
+{
+ this_cpu_inc(trace_buffered_event_cnt);
+}
+
+/**
+ * trace_buffered_event_disable - disable buffering events
+ *
+ * When a filter is removed, it is faster to not use the buffered
+ * events, and to commit directly into the ring buffer. Free up
+ * the temp buffers when there are no more users. This requires
+ * special synchronization with current events.
+ */
+void trace_buffered_event_disable(void)
+{
+ int cpu;
+
+ WARN_ON_ONCE(!mutex_is_locked(&event_mutex));
+
+ if (WARN_ON_ONCE(!trace_buffered_event_ref))
+ return;
+
+ if (--trace_buffered_event_ref)
+ return;
+
+ /* For each CPU, set the buffer as used. */
+ on_each_cpu_mask(tracing_buffer_mask, disable_trace_buffered_event,
+ NULL, true);
+
+ /* Wait for all current users to finish */
+ synchronize_rcu();
+
+ for_each_tracing_cpu(cpu) {
+ free_page((unsigned long)per_cpu(trace_buffered_event, cpu));
+ per_cpu(trace_buffered_event, cpu) = NULL;
+ }
+
+ /*
+ * Wait for all CPUs that potentially started checking if they can use
+ * their event buffer only after the previous synchronize_rcu() call and
+ * they still read a valid pointer from trace_buffered_event. It must be
+ * ensured they don't see cleared trace_buffered_event_cnt else they
+ * could wrongly decide to use the pointed-to buffer which is now freed.
+ */
+ synchronize_rcu();
+
+ /* For each CPU, relinquish the buffer */
+ on_each_cpu_mask(tracing_buffer_mask, enable_trace_buffered_event, NULL,
+ true);
+}
+
+static struct trace_buffer *temp_buffer;
+
+struct ring_buffer_event *
+trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
+ struct trace_event_file *trace_file,
+ int type, unsigned long len,
+ unsigned int trace_ctx)
+{
+ struct ring_buffer_event *entry;
+ struct trace_array *tr = trace_file->tr;
+ int val;
+
+ *current_rb = tr->array_buffer.buffer;
+
+ if (!tr->no_filter_buffering_ref &&
+ (trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED))) {
+ preempt_disable_notrace();
+ /*
+ * Filtering is on, so try to use the per cpu buffer first.
+ * This buffer will simulate a ring_buffer_event,
+ * where the type_len is zero and the array[0] will
+ * hold the full length.
+ * (see include/linux/ring-buffer.h for details on
+ * how the ring_buffer_event is structured).
+ *
+ * Using a temp buffer during filtering and copying it
+ * on a matched filter is quicker than writing directly
+ * into the ring buffer and then discarding it when
+ * it doesn't match. That is because the discard
+ * requires several atomic operations to get right.
+ * Copying on match and doing nothing on a failed match
+ * is still quicker than no copy on match, but having
+ * to discard out of the ring buffer on a failed match.
+ */
+ if ((entry = __this_cpu_read(trace_buffered_event))) {
+ int max_len = PAGE_SIZE - struct_size(entry, array, 1);
+
+ val = this_cpu_inc_return(trace_buffered_event_cnt);
+
+ /*
+ * Preemption is disabled, but interrupts and NMIs
+ * can still come in now. If that happens after
+ * the above increment, then it will have to go
+ * back to the old method of allocating the event
+ * on the ring buffer, and if the filter fails, it
+ * will have to call ring_buffer_discard_commit()
+ * to remove it.
+ *
+ * Need to also check the unlikely case that the
+ * length is bigger than the temp buffer size.
+ * If that happens, then the reserve is pretty much
+ * guaranteed to fail, as the ring buffer currently
+ * only allows events less than a page. But that may
+ * change in the future, so let the ring buffer reserve
+ * handle the failure in that case.
+ */
+ if (val == 1 && likely(len <= max_len)) {
+ trace_event_setup(entry, type, trace_ctx);
+ entry->array[0] = len;
+ /* Return with preemption disabled */
+ return entry;
+ }
+ this_cpu_dec(trace_buffered_event_cnt);
+ }
+ /* __trace_buffer_lock_reserve() disables preemption */
+ preempt_enable_notrace();
+ }
+
+ entry = __trace_buffer_lock_reserve(*current_rb, type, len,
+ trace_ctx);
+ /*
+ * If tracing is off, but we have triggers enabled
+ * we still need to look at the event data. Use the temp_buffer
+ * to store the trace event for the trigger to use. It's recursive
+ * safe and will not be recorded anywhere.
+ */
+ if (!entry && trace_file->flags & EVENT_FILE_FL_TRIGGER_COND) {
+ *current_rb = temp_buffer;
+ entry = __trace_buffer_lock_reserve(*current_rb, type, len,
+ trace_ctx);
+ }
+ return entry;
+}
+EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve);
+
+static DEFINE_RAW_SPINLOCK(tracepoint_iter_lock);
+static DEFINE_MUTEX(tracepoint_printk_mutex);
+
+static void output_printk(struct trace_event_buffer *fbuffer)
+{
+ struct trace_event_call *event_call;
+ struct trace_event_file *file;
+ struct trace_event *event;
+ unsigned long flags;
+ struct trace_iterator *iter = tracepoint_print_iter;
+
+ /* We should never get here if iter is NULL */
+ if (WARN_ON_ONCE(!iter))
+ return;
+
+ event_call = fbuffer->trace_file->event_call;
+ if (!event_call || !event_call->event.funcs ||
+ !event_call->event.funcs->trace)
+ return;
+
+ file = fbuffer->trace_file;
+ if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
+ (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
+ !filter_match_preds(file->filter, fbuffer->entry)))
+ return;
+
+ event = &fbuffer->trace_file->event_call->event;
+
+ raw_spin_lock_irqsave(&tracepoint_iter_lock, flags);
+ trace_seq_init(&iter->seq);
+ iter->ent = fbuffer->entry;
+ event_call->event.funcs->trace(iter, 0, event);
+ trace_seq_putc(&iter->seq, 0);
+ printk("%s", iter->seq.buffer);
+
+ raw_spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
+}
+
+int tracepoint_printk_sysctl(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int save_tracepoint_printk;
+ int ret;
+
+ mutex_lock(&tracepoint_printk_mutex);
+ save_tracepoint_printk = tracepoint_printk;
+
+ ret = proc_dointvec(table, write, buffer, lenp, ppos);
+
+ /*
+ * This will force exiting early, as tracepoint_printk
+ * is always zero when tracepoint_printk_iter is not allocated
+ */
+ if (!tracepoint_print_iter)
+ tracepoint_printk = 0;
+
+ if (save_tracepoint_printk == tracepoint_printk)
+ goto out;
+
+ if (tracepoint_printk)
+ static_key_enable(&tracepoint_printk_key.key);
+ else
+ static_key_disable(&tracepoint_printk_key.key);
+
+ out:
+ mutex_unlock(&tracepoint_printk_mutex);
+
+ return ret;
+}
+
+void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
+{
+ enum event_trigger_type tt = ETT_NONE;
+ struct trace_event_file *file = fbuffer->trace_file;
+
+ if (__event_trigger_test_discard(file, fbuffer->buffer, fbuffer->event,
+ fbuffer->entry, &tt))
+ goto discard;
+
+ if (static_key_false(&tracepoint_printk_key.key))
+ output_printk(fbuffer);
+
+ if (static_branch_unlikely(&trace_event_exports_enabled))
+ ftrace_exports(fbuffer->event, TRACE_EXPORT_EVENT);
+
+ trace_buffer_unlock_commit_regs(file->tr, fbuffer->buffer,
+ fbuffer->event, fbuffer->trace_ctx, fbuffer->regs);
+
+discard:
+ if (tt)
+ event_triggers_post_call(file, tt);
+
+}
+EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
+
+/*
+ * Skip 3:
+ *
+ * trace_buffer_unlock_commit_regs()
+ * trace_event_buffer_commit()
+ * trace_event_raw_event_xxx()
+ */
+# define STACK_SKIP 3
+
+void trace_buffer_unlock_commit_regs(struct trace_array *tr,
+ struct trace_buffer *buffer,
+ struct ring_buffer_event *event,
+ unsigned int trace_ctx,
+ struct pt_regs *regs)
+{
+ __buffer_unlock_commit(buffer, event);
+
+ /*
+ * If regs is not set, then skip the necessary functions.
+ * Note, we can still get here via blktrace, wakeup tracer
+ * and mmiotrace, but that's ok if they lose a function or
+ * two. They are not that meaningful.
+ */
+ ftrace_trace_stack(tr, buffer, trace_ctx, regs ? 0 : STACK_SKIP, regs);
+ ftrace_trace_userstack(tr, buffer, trace_ctx);
+}
+
+/*
+ * Similar to trace_buffer_unlock_commit_regs() but do not dump stack.
+ */
+void
+trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
+ struct ring_buffer_event *event)
+{
+ __buffer_unlock_commit(buffer, event);
+}
+
+void
+trace_function(struct trace_array *tr, unsigned long ip, unsigned long
+ parent_ip, unsigned int trace_ctx)
+{
+ struct trace_event_call *call = &event_function;
+ struct trace_buffer *buffer = tr->array_buffer.buffer;
+ struct ring_buffer_event *event;
+ struct ftrace_entry *entry;
+
+ event = __trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
+ trace_ctx);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ entry->ip = ip;
+ entry->parent_ip = parent_ip;
+
+ if (!call_filter_check_discard(call, entry, buffer, event)) {
+ if (static_branch_unlikely(&trace_function_exports_enabled))
+ ftrace_exports(event, TRACE_EXPORT_FUNCTION);
+ __buffer_unlock_commit(buffer, event);
+ }
+}
+
+#ifdef CONFIG_STACKTRACE
+
+/* Allow 4 levels of nesting: normal, softirq, irq, NMI */
+#define FTRACE_KSTACK_NESTING 4
+
+#define FTRACE_KSTACK_ENTRIES (PAGE_SIZE / FTRACE_KSTACK_NESTING)
+
+struct ftrace_stack {
+ unsigned long calls[FTRACE_KSTACK_ENTRIES];
+};
+
+
+struct ftrace_stacks {
+ struct ftrace_stack stacks[FTRACE_KSTACK_NESTING];
+};
+
+static DEFINE_PER_CPU(struct ftrace_stacks, ftrace_stacks);
+static DEFINE_PER_CPU(int, ftrace_stack_reserve);
+
+static void __ftrace_trace_stack(struct trace_buffer *buffer,
+ unsigned int trace_ctx,
+ int skip, struct pt_regs *regs)
+{
+ struct trace_event_call *call = &event_kernel_stack;
+ struct ring_buffer_event *event;
+ unsigned int size, nr_entries;
+ struct ftrace_stack *fstack;
+ struct stack_entry *entry;
+ int stackidx;
+
+ /*
+ * Add one, for this function and the call to save_stack_trace()
+ * If regs is set, then these functions will not be in the way.
+ */
+#ifndef CONFIG_UNWINDER_ORC
+ if (!regs)
+ skip++;
+#endif
+
+ preempt_disable_notrace();
+
+ stackidx = __this_cpu_inc_return(ftrace_stack_reserve) - 1;
+
+ /* This should never happen. If it does, yell once and skip */
+ if (WARN_ON_ONCE(stackidx >= FTRACE_KSTACK_NESTING))
+ goto out;
+
+ /*
+ * The above __this_cpu_inc_return() is 'atomic' cpu local. An
+ * interrupt will either see the value pre increment or post
+ * increment. If the interrupt happens pre increment it will have
+ * restored the counter when it returns. We just need a barrier to
+ * keep gcc from moving things around.
+ */
+ barrier();
+
+ fstack = this_cpu_ptr(ftrace_stacks.stacks) + stackidx;
+ size = ARRAY_SIZE(fstack->calls);
+
+ if (regs) {
+ nr_entries = stack_trace_save_regs(regs, fstack->calls,
+ size, skip);
+ } else {
+ nr_entries = stack_trace_save(fstack->calls, size, skip);
+ }
+
+ event = __trace_buffer_lock_reserve(buffer, TRACE_STACK,
+ struct_size(entry, caller, nr_entries),
+ trace_ctx);
+ if (!event)
+ goto out;
+ entry = ring_buffer_event_data(event);
+
+ entry->size = nr_entries;
+ memcpy(&entry->caller, fstack->calls,
+ flex_array_size(entry, caller, nr_entries));
+
+ if (!call_filter_check_discard(call, entry, buffer, event))
+ __buffer_unlock_commit(buffer, event);
+
+ out:
+ /* Again, don't let gcc optimize things here */
+ barrier();
+ __this_cpu_dec(ftrace_stack_reserve);
+ preempt_enable_notrace();
+
+}
+
+static inline void ftrace_trace_stack(struct trace_array *tr,
+ struct trace_buffer *buffer,
+ unsigned int trace_ctx,
+ int skip, struct pt_regs *regs)
+{
+ if (!(tr->trace_flags & TRACE_ITER_STACKTRACE))
+ return;
+
+ __ftrace_trace_stack(buffer, trace_ctx, skip, regs);
+}
+
+void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
+ int skip)
+{
+ struct trace_buffer *buffer = tr->array_buffer.buffer;
+
+ if (rcu_is_watching()) {
+ __ftrace_trace_stack(buffer, trace_ctx, skip, NULL);
+ return;
+ }
+
+ if (WARN_ON_ONCE(IS_ENABLED(CONFIG_GENERIC_ENTRY)))
+ return;
+
+ /*
+ * When an NMI triggers, RCU is enabled via ct_nmi_enter(),
+ * but if the above rcu_is_watching() failed, then the NMI
+ * triggered someplace critical, and ct_irq_enter() should
+ * not be called from NMI.
+ */
+ if (unlikely(in_nmi()))
+ return;
+
+ ct_irq_enter_irqson();
+ __ftrace_trace_stack(buffer, trace_ctx, skip, NULL);
+ ct_irq_exit_irqson();
+}
+
+/**
+ * trace_dump_stack - record a stack back trace in the trace buffer
+ * @skip: Number of functions to skip (helper handlers)
+ */
+void trace_dump_stack(int skip)
+{
+ if (tracing_disabled || tracing_selftest_running)
+ return;
+
+#ifndef CONFIG_UNWINDER_ORC
+ /* Skip 1 to skip this function. */
+ skip++;
+#endif
+ __ftrace_trace_stack(global_trace.array_buffer.buffer,
+ tracing_gen_ctx(), skip, NULL);
+}
+EXPORT_SYMBOL_GPL(trace_dump_stack);
+
+#ifdef CONFIG_USER_STACKTRACE_SUPPORT
+static DEFINE_PER_CPU(int, user_stack_count);
+
+static void
+ftrace_trace_userstack(struct trace_array *tr,
+ struct trace_buffer *buffer, unsigned int trace_ctx)
+{
+ struct trace_event_call *call = &event_user_stack;
+ struct ring_buffer_event *event;
+ struct userstack_entry *entry;
+
+ if (!(tr->trace_flags & TRACE_ITER_USERSTACKTRACE))
+ return;
+
+ /*
+ * NMIs can not handle page faults, even with fix ups.
+ * The save user stack can (and often does) fault.
+ */
+ if (unlikely(in_nmi()))
+ return;
+
+ /*
+ * prevent recursion, since the user stack tracing may
+ * trigger other kernel events.
+ */
+ preempt_disable();
+ if (__this_cpu_read(user_stack_count))
+ goto out;
+
+ __this_cpu_inc(user_stack_count);
+
+ event = __trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
+ sizeof(*entry), trace_ctx);
+ if (!event)
+ goto out_drop_count;
+ entry = ring_buffer_event_data(event);
+
+ entry->tgid = current->tgid;
+ memset(&entry->caller, 0, sizeof(entry->caller));
+
+ stack_trace_save_user(entry->caller, FTRACE_STACK_ENTRIES);
+ if (!call_filter_check_discard(call, entry, buffer, event))
+ __buffer_unlock_commit(buffer, event);
+
+ out_drop_count:
+ __this_cpu_dec(user_stack_count);
+ out:
+ preempt_enable();
+}
+#else /* CONFIG_USER_STACKTRACE_SUPPORT */
+static void ftrace_trace_userstack(struct trace_array *tr,
+ struct trace_buffer *buffer,
+ unsigned int trace_ctx)
+{
+}
+#endif /* !CONFIG_USER_STACKTRACE_SUPPORT */
+
+#endif /* CONFIG_STACKTRACE */
+
+static inline void
+func_repeats_set_delta_ts(struct func_repeats_entry *entry,
+ unsigned long long delta)
+{
+ entry->bottom_delta_ts = delta & U32_MAX;
+ entry->top_delta_ts = (delta >> 32);
+}
+
+void trace_last_func_repeats(struct trace_array *tr,
+ struct trace_func_repeats *last_info,
+ unsigned int trace_ctx)
+{
+ struct trace_buffer *buffer = tr->array_buffer.buffer;
+ struct func_repeats_entry *entry;
+ struct ring_buffer_event *event;
+ u64 delta;
+
+ event = __trace_buffer_lock_reserve(buffer, TRACE_FUNC_REPEATS,
+ sizeof(*entry), trace_ctx);
+ if (!event)
+ return;
+
+ delta = ring_buffer_event_time_stamp(buffer, event) -
+ last_info->ts_last_call;
+
+ entry = ring_buffer_event_data(event);
+ entry->ip = last_info->ip;
+ entry->parent_ip = last_info->parent_ip;
+ entry->count = last_info->count;
+ func_repeats_set_delta_ts(entry, delta);
+
+ __buffer_unlock_commit(buffer, event);
+}
+
+/* created for use with alloc_percpu */
+struct trace_buffer_struct {
+ int nesting;
+ char buffer[4][TRACE_BUF_SIZE];
+};
+
+static struct trace_buffer_struct __percpu *trace_percpu_buffer;
+
+/*
+ * This allows for lockless recording. If we're nested too deeply, then
+ * this returns NULL.
+ */
+static char *get_trace_buf(void)
+{
+ struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer);
+
+ if (!trace_percpu_buffer || buffer->nesting >= 4)
+ return NULL;
+
+ buffer->nesting++;
+
+ /* Interrupts must see nesting incremented before we use the buffer */
+ barrier();
+ return &buffer->buffer[buffer->nesting - 1][0];
+}
+
+static void put_trace_buf(void)
+{
+ /* Don't let the decrement of nesting leak before this */
+ barrier();
+ this_cpu_dec(trace_percpu_buffer->nesting);
+}
+
+static int alloc_percpu_trace_buffer(void)
+{
+ struct trace_buffer_struct __percpu *buffers;
+
+ if (trace_percpu_buffer)
+ return 0;
+
+ buffers = alloc_percpu(struct trace_buffer_struct);
+ if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer"))
+ return -ENOMEM;
+
+ trace_percpu_buffer = buffers;
+ return 0;
+}
+
+static int buffers_allocated;
+
+void trace_printk_init_buffers(void)
+{
+ if (buffers_allocated)
+ return;
+
+ if (alloc_percpu_trace_buffer())
+ return;
+
+ /* trace_printk() is for debug use only. Don't use it in production. */
+
+ pr_warn("\n");
+ pr_warn("**********************************************************\n");
+ pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
+ pr_warn("** **\n");
+ pr_warn("** trace_printk() being used. Allocating extra memory. **\n");
+ pr_warn("** **\n");
+ pr_warn("** This means that this is a DEBUG kernel and it is **\n");
+ pr_warn("** unsafe for production use. **\n");
+ pr_warn("** **\n");
+ pr_warn("** If you see this message and you are not debugging **\n");
+ pr_warn("** the kernel, report this immediately to your vendor! **\n");
+ pr_warn("** **\n");
+ pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
+ pr_warn("**********************************************************\n");
+
+ /* Expand the buffers to set size */
+ tracing_update_buffers();
+
+ buffers_allocated = 1;
+
+ /*
+ * trace_printk_init_buffers() can be called by modules.
+ * If that happens, then we need to start cmdline recording
+ * directly here. If the global_trace.buffer is already
+ * allocated here, then this was called by module code.
+ */
+ if (global_trace.array_buffer.buffer)
+ tracing_start_cmdline_record();
+}
+EXPORT_SYMBOL_GPL(trace_printk_init_buffers);
+
+void trace_printk_start_comm(void)
+{
+ /* Start tracing comms if trace printk is set */
+ if (!buffers_allocated)
+ return;
+ tracing_start_cmdline_record();
+}
+
+static void trace_printk_start_stop_comm(int enabled)
+{
+ if (!buffers_allocated)
+ return;
+
+ if (enabled)
+ tracing_start_cmdline_record();
+ else
+ tracing_stop_cmdline_record();
+}
+
+/**
+ * trace_vbprintk - write binary msg to tracing buffer
+ * @ip: The address of the caller
+ * @fmt: The string format to write to the buffer
+ * @args: Arguments for @fmt
+ */
+int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
+{
+ struct trace_event_call *call = &event_bprint;
+ struct ring_buffer_event *event;
+ struct trace_buffer *buffer;
+ struct trace_array *tr = &global_trace;
+ struct bprint_entry *entry;
+ unsigned int trace_ctx;
+ char *tbuffer;
+ int len = 0, size;
+
+ if (unlikely(tracing_selftest_running || tracing_disabled))
+ return 0;
+
+ /* Don't pollute graph traces with trace_vprintk internals */
+ pause_graph_tracing();
+
+ trace_ctx = tracing_gen_ctx();
+ preempt_disable_notrace();
+
+ tbuffer = get_trace_buf();
+ if (!tbuffer) {
+ len = 0;
+ goto out_nobuffer;
+ }
+
+ len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args);
+
+ if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0)
+ goto out_put;
+
+ size = sizeof(*entry) + sizeof(u32) * len;
+ buffer = tr->array_buffer.buffer;
+ ring_buffer_nest_start(buffer);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
+ trace_ctx);
+ if (!event)
+ goto out;
+ entry = ring_buffer_event_data(event);
+ entry->ip = ip;
+ entry->fmt = fmt;
+
+ memcpy(entry->buf, tbuffer, sizeof(u32) * len);
+ if (!call_filter_check_discard(call, entry, buffer, event)) {
+ __buffer_unlock_commit(buffer, event);
+ ftrace_trace_stack(tr, buffer, trace_ctx, 6, NULL);
+ }
+
+out:
+ ring_buffer_nest_end(buffer);
+out_put:
+ put_trace_buf();
+
+out_nobuffer:
+ preempt_enable_notrace();
+ unpause_graph_tracing();
+
+ return len;
+}
+EXPORT_SYMBOL_GPL(trace_vbprintk);
+
+__printf(3, 0)
+static int
+__trace_array_vprintk(struct trace_buffer *buffer,
+ unsigned long ip, const char *fmt, va_list args)
+{
+ struct trace_event_call *call = &event_print;
+ struct ring_buffer_event *event;
+ int len = 0, size;
+ struct print_entry *entry;
+ unsigned int trace_ctx;
+ char *tbuffer;
+
+ if (tracing_disabled)
+ return 0;
+
+ /* Don't pollute graph traces with trace_vprintk internals */
+ pause_graph_tracing();
+
+ trace_ctx = tracing_gen_ctx();
+ preempt_disable_notrace();
+
+
+ tbuffer = get_trace_buf();
+ if (!tbuffer) {
+ len = 0;
+ goto out_nobuffer;
+ }
+
+ len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args);
+
+ size = sizeof(*entry) + len + 1;
+ ring_buffer_nest_start(buffer);
+ event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
+ trace_ctx);
+ if (!event)
+ goto out;
+ entry = ring_buffer_event_data(event);
+ entry->ip = ip;
+
+ memcpy(&entry->buf, tbuffer, len + 1);
+ if (!call_filter_check_discard(call, entry, buffer, event)) {
+ __buffer_unlock_commit(buffer, event);
+ ftrace_trace_stack(&global_trace, buffer, trace_ctx, 6, NULL);
+ }
+
+out:
+ ring_buffer_nest_end(buffer);
+ put_trace_buf();
+
+out_nobuffer:
+ preempt_enable_notrace();
+ unpause_graph_tracing();
+
+ return len;
+}
+
+__printf(3, 0)
+int trace_array_vprintk(struct trace_array *tr,
+ unsigned long ip, const char *fmt, va_list args)
+{
+ if (tracing_selftest_running && tr == &global_trace)
+ return 0;
+
+ return __trace_array_vprintk(tr->array_buffer.buffer, ip, fmt, args);
+}
+
+/**
+ * trace_array_printk - Print a message to a specific instance
+ * @tr: The instance trace_array descriptor
+ * @ip: The instruction pointer that this is called from.
+ * @fmt: The format to print (printf format)
+ *
+ * If a subsystem sets up its own instance, they have the right to
+ * printk strings into their tracing instance buffer using this
+ * function. Note, this function will not write into the top level
+ * buffer (use trace_printk() for that), as writing into the top level
+ * buffer should only have events that can be individually disabled.
+ * trace_printk() is only used for debugging a kernel, and should not
+ * be ever incorporated in normal use.
+ *
+ * trace_array_printk() can be used, as it will not add noise to the
+ * top level tracing buffer.
+ *
+ * Note, trace_array_init_printk() must be called on @tr before this
+ * can be used.
+ */
+__printf(3, 0)
+int trace_array_printk(struct trace_array *tr,
+ unsigned long ip, const char *fmt, ...)
+{
+ int ret;
+ va_list ap;
+
+ if (!tr)
+ return -ENOENT;
+
+ /* This is only allowed for created instances */
+ if (tr == &global_trace)
+ return 0;
+
+ if (!(tr->trace_flags & TRACE_ITER_PRINTK))
+ return 0;
+
+ va_start(ap, fmt);
+ ret = trace_array_vprintk(tr, ip, fmt, ap);
+ va_end(ap);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(trace_array_printk);
+
+/**
+ * trace_array_init_printk - Initialize buffers for trace_array_printk()
+ * @tr: The trace array to initialize the buffers for
+ *
+ * As trace_array_printk() only writes into instances, they are OK to
+ * have in the kernel (unlike trace_printk()). This needs to be called
+ * before trace_array_printk() can be used on a trace_array.
+ */
+int trace_array_init_printk(struct trace_array *tr)
+{
+ if (!tr)
+ return -ENOENT;
+
+ /* This is only allowed for created instances */
+ if (tr == &global_trace)
+ return -EINVAL;
+
+ return alloc_percpu_trace_buffer();
+}
+EXPORT_SYMBOL_GPL(trace_array_init_printk);
+
+__printf(3, 4)
+int trace_array_printk_buf(struct trace_buffer *buffer,
+ unsigned long ip, const char *fmt, ...)
+{
+ int ret;
+ va_list ap;
+
+ if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
+ return 0;
+
+ va_start(ap, fmt);
+ ret = __trace_array_vprintk(buffer, ip, fmt, ap);
+ va_end(ap);
+ return ret;
+}
+
+__printf(2, 0)
+int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
+{
+ return trace_array_vprintk(&global_trace, ip, fmt, args);
+}
+EXPORT_SYMBOL_GPL(trace_vprintk);
+
+static void trace_iterator_increment(struct trace_iterator *iter)
+{
+ struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu);
+
+ iter->idx++;
+ if (buf_iter)
+ ring_buffer_iter_advance(buf_iter);
+}
+
+static struct trace_entry *
+peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
+ unsigned long *lost_events)
+{
+ struct ring_buffer_event *event;
+ struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu);
+
+ if (buf_iter) {
+ event = ring_buffer_iter_peek(buf_iter, ts);
+ if (lost_events)
+ *lost_events = ring_buffer_iter_dropped(buf_iter) ?
+ (unsigned long)-1 : 0;
+ } else {
+ event = ring_buffer_peek(iter->array_buffer->buffer, cpu, ts,
+ lost_events);
+ }
+
+ if (event) {
+ iter->ent_size = ring_buffer_event_length(event);
+ return ring_buffer_event_data(event);
+ }
+ iter->ent_size = 0;
+ return NULL;
+}
+
+static struct trace_entry *
+__find_next_entry(struct trace_iterator *iter, int *ent_cpu,
+ unsigned long *missing_events, u64 *ent_ts)
+{
+ struct trace_buffer *buffer = iter->array_buffer->buffer;
+ struct trace_entry *ent, *next = NULL;
+ unsigned long lost_events = 0, next_lost = 0;
+ int cpu_file = iter->cpu_file;
+ u64 next_ts = 0, ts;
+ int next_cpu = -1;
+ int next_size = 0;
+ int cpu;
+
+ /*
+ * If we are in a per_cpu trace file, don't bother by iterating over
+ * all cpu and peek directly.
+ */
+ if (cpu_file > RING_BUFFER_ALL_CPUS) {
+ if (ring_buffer_empty_cpu(buffer, cpu_file))
+ return NULL;
+ ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events);
+ if (ent_cpu)
+ *ent_cpu = cpu_file;
+
+ return ent;
+ }
+
+ for_each_tracing_cpu(cpu) {
+
+ if (ring_buffer_empty_cpu(buffer, cpu))
+ continue;
+
+ ent = peek_next_entry(iter, cpu, &ts, &lost_events);
+
+ /*
+ * Pick the entry with the smallest timestamp:
+ */
+ if (ent && (!next || ts < next_ts)) {
+ next = ent;
+ next_cpu = cpu;
+ next_ts = ts;
+ next_lost = lost_events;
+ next_size = iter->ent_size;
+ }
+ }
+
+ iter->ent_size = next_size;
+
+ if (ent_cpu)
+ *ent_cpu = next_cpu;
+
+ if (ent_ts)
+ *ent_ts = next_ts;
+
+ if (missing_events)
+ *missing_events = next_lost;
+
+ return next;
+}
+
+#define STATIC_FMT_BUF_SIZE 128
+static char static_fmt_buf[STATIC_FMT_BUF_SIZE];
+
+char *trace_iter_expand_format(struct trace_iterator *iter)
+{
+ char *tmp;
+
+ /*
+ * iter->tr is NULL when used with tp_printk, which makes
+ * this get called where it is not safe to call krealloc().
+ */
+ if (!iter->tr || iter->fmt == static_fmt_buf)
+ return NULL;
+
+ tmp = krealloc(iter->fmt, iter->fmt_size + STATIC_FMT_BUF_SIZE,
+ GFP_KERNEL);
+ if (tmp) {
+ iter->fmt_size += STATIC_FMT_BUF_SIZE;
+ iter->fmt = tmp;
+ }
+
+ return tmp;
+}
+
+/* Returns true if the string is safe to dereference from an event */
+static bool trace_safe_str(struct trace_iterator *iter, const char *str,
+ bool star, int len)
+{
+ unsigned long addr = (unsigned long)str;
+ struct trace_event *trace_event;
+ struct trace_event_call *event;
+
+ /* Ignore strings with no length */
+ if (star && !len)
+ return true;
+
+ /* OK if part of the event data */
+ if ((addr >= (unsigned long)iter->ent) &&
+ (addr < (unsigned long)iter->ent + iter->ent_size))
+ return true;
+
+ /* OK if part of the temp seq buffer */
+ if ((addr >= (unsigned long)iter->tmp_seq.buffer) &&
+ (addr < (unsigned long)iter->tmp_seq.buffer + PAGE_SIZE))
+ return true;
+
+ /* Core rodata can not be freed */
+ if (is_kernel_rodata(addr))
+ return true;
+
+ if (trace_is_tracepoint_string(str))
+ return true;
+
+ /*
+ * Now this could be a module event, referencing core module
+ * data, which is OK.
+ */
+ if (!iter->ent)
+ return false;
+
+ trace_event = ftrace_find_event(iter->ent->type);
+ if (!trace_event)
+ return false;
+
+ event = container_of(trace_event, struct trace_event_call, event);
+ if ((event->flags & TRACE_EVENT_FL_DYNAMIC) || !event->module)
+ return false;
+
+ /* Would rather have rodata, but this will suffice */
+ if (within_module_core(addr, event->module))
+ return true;
+
+ return false;
+}
+
+static const char *show_buffer(struct trace_seq *s)
+{
+ struct seq_buf *seq = &s->seq;
+
+ seq_buf_terminate(seq);
+
+ return seq->buffer;
+}
+
+static DEFINE_STATIC_KEY_FALSE(trace_no_verify);
+
+static int test_can_verify_check(const char *fmt, ...)
+{
+ char buf[16];
+ va_list ap;
+ int ret;
+
+ /*
+ * The verifier is dependent on vsnprintf() modifies the va_list
+ * passed to it, where it is sent as a reference. Some architectures
+ * (like x86_32) passes it by value, which means that vsnprintf()
+ * does not modify the va_list passed to it, and the verifier
+ * would then need to be able to understand all the values that
+ * vsnprintf can use. If it is passed by value, then the verifier
+ * is disabled.
+ */
+ va_start(ap, fmt);
+ vsnprintf(buf, 16, "%d", ap);
+ ret = va_arg(ap, int);
+ va_end(ap);
+
+ return ret;
+}
+
+static void test_can_verify(void)
+{
+ if (!test_can_verify_check("%d %d", 0, 1)) {
+ pr_info("trace event string verifier disabled\n");
+ static_branch_inc(&trace_no_verify);
+ }
+}
+
+/**
+ * trace_check_vprintf - Check dereferenced strings while writing to the seq buffer
+ * @iter: The iterator that holds the seq buffer and the event being printed
+ * @fmt: The format used to print the event
+ * @ap: The va_list holding the data to print from @fmt.
+ *
+ * This writes the data into the @iter->seq buffer using the data from
+ * @fmt and @ap. If the format has a %s, then the source of the string
+ * is examined to make sure it is safe to print, otherwise it will
+ * warn and print "[UNSAFE MEMORY]" in place of the dereferenced string
+ * pointer.
+ */
+void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
+ va_list ap)
+{
+ const char *p = fmt;
+ const char *str;
+ int i, j;
+
+ if (WARN_ON_ONCE(!fmt))
+ return;
+
+ if (static_branch_unlikely(&trace_no_verify))
+ goto print;
+
+ /* Don't bother checking when doing a ftrace_dump() */
+ if (iter->fmt == static_fmt_buf)
+ goto print;
+
+ while (*p) {
+ bool star = false;
+ int len = 0;
+
+ j = 0;
+
+ /* We only care about %s and variants */
+ for (i = 0; p[i]; i++) {
+ if (i + 1 >= iter->fmt_size) {
+ /*
+ * If we can't expand the copy buffer,
+ * just print it.
+ */
+ if (!trace_iter_expand_format(iter))
+ goto print;
+ }
+
+ if (p[i] == '\\' && p[i+1]) {
+ i++;
+ continue;
+ }
+ if (p[i] == '%') {
+ /* Need to test cases like %08.*s */
+ for (j = 1; p[i+j]; j++) {
+ if (isdigit(p[i+j]) ||
+ p[i+j] == '.')
+ continue;
+ if (p[i+j] == '*') {
+ star = true;
+ continue;
+ }
+ break;
+ }
+ if (p[i+j] == 's')
+ break;
+ star = false;
+ }
+ j = 0;
+ }
+ /* If no %s found then just print normally */
+ if (!p[i])
+ break;
+
+ /* Copy up to the %s, and print that */
+ strncpy(iter->fmt, p, i);
+ iter->fmt[i] = '\0';
+ trace_seq_vprintf(&iter->seq, iter->fmt, ap);
+
+ /*
+ * If iter->seq is full, the above call no longer guarantees
+ * that ap is in sync with fmt processing, and further calls
+ * to va_arg() can return wrong positional arguments.
+ *
+ * Ensure that ap is no longer used in this case.
+ */
+ if (iter->seq.full) {
+ p = "";
+ break;
+ }
+
+ if (star)
+ len = va_arg(ap, int);
+
+ /* The ap now points to the string data of the %s */
+ str = va_arg(ap, const char *);
+
+ /*
+ * If you hit this warning, it is likely that the
+ * trace event in question used %s on a string that
+ * was saved at the time of the event, but may not be
+ * around when the trace is read. Use __string(),
+ * __assign_str() and __get_str() helpers in the TRACE_EVENT()
+ * instead. See samples/trace_events/trace-events-sample.h
+ * for reference.
+ */
+ if (WARN_ONCE(!trace_safe_str(iter, str, star, len),
+ "fmt: '%s' current_buffer: '%s'",
+ fmt, show_buffer(&iter->seq))) {
+ int ret;
+
+ /* Try to safely read the string */
+ if (star) {
+ if (len + 1 > iter->fmt_size)
+ len = iter->fmt_size - 1;
+ if (len < 0)
+ len = 0;
+ ret = copy_from_kernel_nofault(iter->fmt, str, len);
+ iter->fmt[len] = 0;
+ star = false;
+ } else {
+ ret = strncpy_from_kernel_nofault(iter->fmt, str,
+ iter->fmt_size);
+ }
+ if (ret < 0)
+ trace_seq_printf(&iter->seq, "(0x%px)", str);
+ else
+ trace_seq_printf(&iter->seq, "(0x%px:%s)",
+ str, iter->fmt);
+ str = "[UNSAFE-MEMORY]";
+ strcpy(iter->fmt, "%s");
+ } else {
+ strncpy(iter->fmt, p + i, j + 1);
+ iter->fmt[j+1] = '\0';
+ }
+ if (star)
+ trace_seq_printf(&iter->seq, iter->fmt, len, str);
+ else
+ trace_seq_printf(&iter->seq, iter->fmt, str);
+
+ p += i + j + 1;
+ }
+ print:
+ if (*p)
+ trace_seq_vprintf(&iter->seq, p, ap);
+}
+
+const char *trace_event_format(struct trace_iterator *iter, const char *fmt)
+{
+ const char *p, *new_fmt;
+ char *q;
+
+ if (WARN_ON_ONCE(!fmt))
+ return fmt;
+
+ if (!iter->tr || iter->tr->trace_flags & TRACE_ITER_HASH_PTR)
+ return fmt;
+
+ p = fmt;
+ new_fmt = q = iter->fmt;
+ while (*p) {
+ if (unlikely(q - new_fmt + 3 > iter->fmt_size)) {
+ if (!trace_iter_expand_format(iter))
+ return fmt;
+
+ q += iter->fmt - new_fmt;
+ new_fmt = iter->fmt;
+ }
+
+ *q++ = *p++;
+
+ /* Replace %p with %px */
+ if (p[-1] == '%') {
+ if (p[0] == '%') {
+ *q++ = *p++;
+ } else if (p[0] == 'p' && !isalnum(p[1])) {
+ *q++ = *p++;
+ *q++ = 'x';
+ }
+ }
+ }
+ *q = '\0';
+
+ return new_fmt;
+}
+
+#define STATIC_TEMP_BUF_SIZE 128
+static char static_temp_buf[STATIC_TEMP_BUF_SIZE] __aligned(4);
+
+/* Find the next real entry, without updating the iterator itself */
+struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
+ int *ent_cpu, u64 *ent_ts)
+{
+ /* __find_next_entry will reset ent_size */
+ int ent_size = iter->ent_size;
+ struct trace_entry *entry;
+
+ /*
+ * If called from ftrace_dump(), then the iter->temp buffer
+ * will be the static_temp_buf and not created from kmalloc.
+ * If the entry size is greater than the buffer, we can
+ * not save it. Just return NULL in that case. This is only
+ * used to add markers when two consecutive events' time
+ * stamps have a large delta. See trace_print_lat_context()
+ */
+ if (iter->temp == static_temp_buf &&
+ STATIC_TEMP_BUF_SIZE < ent_size)
+ return NULL;
+
+ /*
+ * The __find_next_entry() may call peek_next_entry(), which may
+ * call ring_buffer_peek() that may make the contents of iter->ent
+ * undefined. Need to copy iter->ent now.
+ */
+ if (iter->ent && iter->ent != iter->temp) {
+ if ((!iter->temp || iter->temp_size < iter->ent_size) &&
+ !WARN_ON_ONCE(iter->temp == static_temp_buf)) {
+ void *temp;
+ temp = kmalloc(iter->ent_size, GFP_KERNEL);
+ if (!temp)
+ return NULL;
+ kfree(iter->temp);
+ iter->temp = temp;
+ iter->temp_size = iter->ent_size;
+ }
+ memcpy(iter->temp, iter->ent, iter->ent_size);
+ iter->ent = iter->temp;
+ }
+ entry = __find_next_entry(iter, ent_cpu, NULL, ent_ts);
+ /* Put back the original ent_size */
+ iter->ent_size = ent_size;
+
+ return entry;
+}
+
+/* Find the next real entry, and increment the iterator to the next entry */
+void *trace_find_next_entry_inc(struct trace_iterator *iter)
+{
+ iter->ent = __find_next_entry(iter, &iter->cpu,
+ &iter->lost_events, &iter->ts);
+
+ if (iter->ent)
+ trace_iterator_increment(iter);
+
+ return iter->ent ? iter : NULL;
+}
+
+static void trace_consume(struct trace_iterator *iter)
+{
+ ring_buffer_consume(iter->array_buffer->buffer, iter->cpu, &iter->ts,
+ &iter->lost_events);
+}
+
+static void *s_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct trace_iterator *iter = m->private;
+ int i = (int)*pos;
+ void *ent;
+
+ WARN_ON_ONCE(iter->leftover);
+
+ (*pos)++;
+
+ /* can't go backwards */
+ if (iter->idx > i)
+ return NULL;
+
+ if (iter->idx < 0)
+ ent = trace_find_next_entry_inc(iter);
+ else
+ ent = iter;
+
+ while (ent && iter->idx < i)
+ ent = trace_find_next_entry_inc(iter);
+
+ iter->pos = *pos;
+
+ return ent;
+}
+
+void tracing_iter_reset(struct trace_iterator *iter, int cpu)
+{
+ struct ring_buffer_iter *buf_iter;
+ unsigned long entries = 0;
+ u64 ts;
+
+ per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = 0;
+
+ buf_iter = trace_buffer_iter(iter, cpu);
+ if (!buf_iter)
+ return;
+
+ ring_buffer_iter_reset(buf_iter);
+
+ /*
+ * We could have the case with the max latency tracers
+ * that a reset never took place on a cpu. This is evident
+ * by the timestamp being before the start of the buffer.
+ */
+ while (ring_buffer_iter_peek(buf_iter, &ts)) {
+ if (ts >= iter->array_buffer->time_start)
+ break;
+ entries++;
+ ring_buffer_iter_advance(buf_iter);
+ }
+
+ per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = entries;
+}
+
+/*
+ * The current tracer is copied to avoid a global locking
+ * all around.
+ */
+static void *s_start(struct seq_file *m, loff_t *pos)
+{
+ struct trace_iterator *iter = m->private;
+ struct trace_array *tr = iter->tr;
+ int cpu_file = iter->cpu_file;
+ void *p = NULL;
+ loff_t l = 0;
+ int cpu;
+
+ mutex_lock(&trace_types_lock);
+ if (unlikely(tr->current_trace != iter->trace)) {
+ /* Close iter->trace before switching to the new current tracer */
+ if (iter->trace->close)
+ iter->trace->close(iter);
+ iter->trace = tr->current_trace;
+ /* Reopen the new current tracer */
+ if (iter->trace->open)
+ iter->trace->open(iter);
+ }
+ mutex_unlock(&trace_types_lock);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (iter->snapshot && iter->trace->use_max_tr)
+ return ERR_PTR(-EBUSY);
+#endif
+
+ if (*pos != iter->pos) {
+ iter->ent = NULL;
+ iter->cpu = 0;
+ iter->idx = -1;
+
+ if (cpu_file == RING_BUFFER_ALL_CPUS) {
+ for_each_tracing_cpu(cpu)
+ tracing_iter_reset(iter, cpu);
+ } else
+ tracing_iter_reset(iter, cpu_file);
+
+ iter->leftover = 0;
+ for (p = iter; p && l < *pos; p = s_next(m, p, &l))
+ ;
+
+ } else {
+ /*
+ * If we overflowed the seq_file before, then we want
+ * to just reuse the trace_seq buffer again.
+ */
+ if (iter->leftover)
+ p = iter;
+ else {
+ l = *pos - 1;
+ p = s_next(m, p, &l);
+ }
+ }
+
+ trace_event_read_lock();
+ trace_access_lock(cpu_file);
+ return p;
+}
+
+static void s_stop(struct seq_file *m, void *p)
+{
+ struct trace_iterator *iter = m->private;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (iter->snapshot && iter->trace->use_max_tr)
+ return;
+#endif
+
+ trace_access_unlock(iter->cpu_file);
+ trace_event_read_unlock();
+}
+
+static void
+get_total_entries_cpu(struct array_buffer *buf, unsigned long *total,
+ unsigned long *entries, int cpu)
+{
+ unsigned long count;
+
+ count = ring_buffer_entries_cpu(buf->buffer, cpu);
+ /*
+ * If this buffer has skipped entries, then we hold all
+ * entries for the trace and we need to ignore the
+ * ones before the time stamp.
+ */
+ if (per_cpu_ptr(buf->data, cpu)->skipped_entries) {
+ count -= per_cpu_ptr(buf->data, cpu)->skipped_entries;
+ /* total is the same as the entries */
+ *total = count;
+ } else
+ *total = count +
+ ring_buffer_overrun_cpu(buf->buffer, cpu);
+ *entries = count;
+}
+
+static void
+get_total_entries(struct array_buffer *buf,
+ unsigned long *total, unsigned long *entries)
+{
+ unsigned long t, e;
+ int cpu;
+
+ *total = 0;
+ *entries = 0;
+
+ for_each_tracing_cpu(cpu) {
+ get_total_entries_cpu(buf, &t, &e, cpu);
+ *total += t;
+ *entries += e;
+ }
+}
+
+unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu)
+{
+ unsigned long total, entries;
+
+ if (!tr)
+ tr = &global_trace;
+
+ get_total_entries_cpu(&tr->array_buffer, &total, &entries, cpu);
+
+ return entries;
+}
+
+unsigned long trace_total_entries(struct trace_array *tr)
+{
+ unsigned long total, entries;
+
+ if (!tr)
+ tr = &global_trace;
+
+ get_total_entries(&tr->array_buffer, &total, &entries);
+
+ return entries;
+}
+
+static void print_lat_help_header(struct seq_file *m)
+{
+ seq_puts(m, "# _------=> CPU# \n"
+ "# / _-----=> irqs-off/BH-disabled\n"
+ "# | / _----=> need-resched \n"
+ "# || / _---=> hardirq/softirq \n"
+ "# ||| / _--=> preempt-depth \n"
+ "# |||| / _-=> migrate-disable \n"
+ "# ||||| / delay \n"
+ "# cmd pid |||||| time | caller \n"
+ "# \\ / |||||| \\ | / \n");
+}
+
+static void print_event_info(struct array_buffer *buf, struct seq_file *m)
+{
+ unsigned long total;
+ unsigned long entries;
+
+ get_total_entries(buf, &total, &entries);
+ seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n",
+ entries, total, num_online_cpus());
+ seq_puts(m, "#\n");
+}
+
+static void print_func_help_header(struct array_buffer *buf, struct seq_file *m,
+ unsigned int flags)
+{
+ bool tgid = flags & TRACE_ITER_RECORD_TGID;
+
+ print_event_info(buf, m);
+
+ seq_printf(m, "# TASK-PID %s CPU# TIMESTAMP FUNCTION\n", tgid ? " TGID " : "");
+ seq_printf(m, "# | | %s | | |\n", tgid ? " | " : "");
+}
+
+static void print_func_help_header_irq(struct array_buffer *buf, struct seq_file *m,
+ unsigned int flags)
+{
+ bool tgid = flags & TRACE_ITER_RECORD_TGID;
+ static const char space[] = " ";
+ int prec = tgid ? 12 : 2;
+
+ print_event_info(buf, m);
+
+ seq_printf(m, "# %.*s _-----=> irqs-off/BH-disabled\n", prec, space);
+ seq_printf(m, "# %.*s / _----=> need-resched\n", prec, space);
+ seq_printf(m, "# %.*s| / _---=> hardirq/softirq\n", prec, space);
+ seq_printf(m, "# %.*s|| / _--=> preempt-depth\n", prec, space);
+ seq_printf(m, "# %.*s||| / _-=> migrate-disable\n", prec, space);
+ seq_printf(m, "# %.*s|||| / delay\n", prec, space);
+ seq_printf(m, "# TASK-PID %.*s CPU# ||||| TIMESTAMP FUNCTION\n", prec, " TGID ");
+ seq_printf(m, "# | | %.*s | ||||| | |\n", prec, " | ");
+}
+
+void
+print_trace_header(struct seq_file *m, struct trace_iterator *iter)
+{
+ unsigned long sym_flags = (global_trace.trace_flags & TRACE_ITER_SYM_MASK);
+ struct array_buffer *buf = iter->array_buffer;
+ struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu);
+ struct tracer *type = iter->trace;
+ unsigned long entries;
+ unsigned long total;
+ const char *name = type->name;
+
+ get_total_entries(buf, &total, &entries);
+
+ seq_printf(m, "# %s latency trace v1.1.5 on %s\n",
+ name, UTS_RELEASE);
+ seq_puts(m, "# -----------------------------------"
+ "---------------------------------\n");
+ seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |"
+ " (M:%s VP:%d, KP:%d, SP:%d HP:%d",
+ nsecs_to_usecs(data->saved_latency),
+ entries,
+ total,
+ buf->cpu,
+ preempt_model_none() ? "server" :
+ preempt_model_voluntary() ? "desktop" :
+ preempt_model_full() ? "preempt" :
+ preempt_model_rt() ? "preempt_rt" :
+ "unknown",
+ /* These are reserved for later use */
+ 0, 0, 0, 0);
+#ifdef CONFIG_SMP
+ seq_printf(m, " #P:%d)\n", num_online_cpus());
+#else
+ seq_puts(m, ")\n");
+#endif
+ seq_puts(m, "# -----------------\n");
+ seq_printf(m, "# | task: %.16s-%d "
+ "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
+ data->comm, data->pid,
+ from_kuid_munged(seq_user_ns(m), data->uid), data->nice,
+ data->policy, data->rt_priority);
+ seq_puts(m, "# -----------------\n");
+
+ if (data->critical_start) {
+ seq_puts(m, "# => started at: ");
+ seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
+ trace_print_seq(m, &iter->seq);
+ seq_puts(m, "\n# => ended at: ");
+ seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
+ trace_print_seq(m, &iter->seq);
+ seq_puts(m, "\n#\n");
+ }
+
+ seq_puts(m, "#\n");
+}
+
+static void test_cpu_buff_start(struct trace_iterator *iter)
+{
+ struct trace_seq *s = &iter->seq;
+ struct trace_array *tr = iter->tr;
+
+ if (!(tr->trace_flags & TRACE_ITER_ANNOTATE))
+ return;
+
+ if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
+ return;
+
+ if (cpumask_available(iter->started) &&
+ cpumask_test_cpu(iter->cpu, iter->started))
+ return;
+
+ if (per_cpu_ptr(iter->array_buffer->data, iter->cpu)->skipped_entries)
+ return;
+
+ if (cpumask_available(iter->started))
+ cpumask_set_cpu(iter->cpu, iter->started);
+
+ /* Don't print started cpu buffer for the first entry of the trace */
+ if (iter->idx > 1)
+ trace_seq_printf(s, "##### CPU %u buffer started ####\n",
+ iter->cpu);
+}
+
+static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
+{
+ struct trace_array *tr = iter->tr;
+ struct trace_seq *s = &iter->seq;
+ unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);
+ struct trace_entry *entry;
+ struct trace_event *event;
+
+ entry = iter->ent;
+
+ test_cpu_buff_start(iter);
+
+ event = ftrace_find_event(entry->type);
+
+ if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
+ if (iter->iter_flags & TRACE_FILE_LAT_FMT)
+ trace_print_lat_context(iter);
+ else
+ trace_print_context(iter);
+ }
+
+ if (trace_seq_has_overflowed(s))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ if (event) {
+ if (tr->trace_flags & TRACE_ITER_FIELDS)
+ return print_event_fields(iter, event);
+ return event->funcs->trace(iter, sym_flags, event);
+ }
+
+ trace_seq_printf(s, "Unknown type %d\n", entry->type);
+
+ return trace_handle_return(s);
+}
+
+static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
+{
+ struct trace_array *tr = iter->tr;
+ struct trace_seq *s = &iter->seq;
+ struct trace_entry *entry;
+ struct trace_event *event;
+
+ entry = iter->ent;
+
+ if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO)
+ trace_seq_printf(s, "%d %d %llu ",
+ entry->pid, iter->cpu, iter->ts);
+
+ if (trace_seq_has_overflowed(s))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ event = ftrace_find_event(entry->type);
+ if (event)
+ return event->funcs->raw(iter, 0, event);
+
+ trace_seq_printf(s, "%d ?\n", entry->type);
+
+ return trace_handle_return(s);
+}
+
+static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
+{
+ struct trace_array *tr = iter->tr;
+ struct trace_seq *s = &iter->seq;
+ unsigned char newline = '\n';
+ struct trace_entry *entry;
+ struct trace_event *event;
+
+ entry = iter->ent;
+
+ if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
+ SEQ_PUT_HEX_FIELD(s, entry->pid);
+ SEQ_PUT_HEX_FIELD(s, iter->cpu);
+ SEQ_PUT_HEX_FIELD(s, iter->ts);
+ if (trace_seq_has_overflowed(s))
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ event = ftrace_find_event(entry->type);
+ if (event) {
+ enum print_line_t ret = event->funcs->hex(iter, 0, event);
+ if (ret != TRACE_TYPE_HANDLED)
+ return ret;
+ }
+
+ SEQ_PUT_FIELD(s, newline);
+
+ return trace_handle_return(s);
+}
+
+static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
+{
+ struct trace_array *tr = iter->tr;
+ struct trace_seq *s = &iter->seq;
+ struct trace_entry *entry;
+ struct trace_event *event;
+
+ entry = iter->ent;
+
+ if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
+ SEQ_PUT_FIELD(s, entry->pid);
+ SEQ_PUT_FIELD(s, iter->cpu);
+ SEQ_PUT_FIELD(s, iter->ts);
+ if (trace_seq_has_overflowed(s))
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ event = ftrace_find_event(entry->type);
+ return event ? event->funcs->binary(iter, 0, event) :
+ TRACE_TYPE_HANDLED;
+}
+
+int trace_empty(struct trace_iterator *iter)
+{
+ struct ring_buffer_iter *buf_iter;
+ int cpu;
+
+ /* If we are looking at one CPU buffer, only check that one */
+ if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
+ cpu = iter->cpu_file;
+ buf_iter = trace_buffer_iter(iter, cpu);
+ if (buf_iter) {
+ if (!ring_buffer_iter_empty(buf_iter))
+ return 0;
+ } else {
+ if (!ring_buffer_empty_cpu(iter->array_buffer->buffer, cpu))
+ return 0;
+ }
+ return 1;
+ }
+
+ for_each_tracing_cpu(cpu) {
+ buf_iter = trace_buffer_iter(iter, cpu);
+ if (buf_iter) {
+ if (!ring_buffer_iter_empty(buf_iter))
+ return 0;
+ } else {
+ if (!ring_buffer_empty_cpu(iter->array_buffer->buffer, cpu))
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+/* Called with trace_event_read_lock() held. */
+enum print_line_t print_trace_line(struct trace_iterator *iter)
+{
+ struct trace_array *tr = iter->tr;
+ unsigned long trace_flags = tr->trace_flags;
+ enum print_line_t ret;
+
+ if (iter->lost_events) {
+ if (iter->lost_events == (unsigned long)-1)
+ trace_seq_printf(&iter->seq, "CPU:%d [LOST EVENTS]\n",
+ iter->cpu);
+ else
+ trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
+ iter->cpu, iter->lost_events);
+ if (trace_seq_has_overflowed(&iter->seq))
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ if (iter->trace && iter->trace->print_line) {
+ ret = iter->trace->print_line(iter);
+ if (ret != TRACE_TYPE_UNHANDLED)
+ return ret;
+ }
+
+ if (iter->ent->type == TRACE_BPUTS &&
+ trace_flags & TRACE_ITER_PRINTK &&
+ trace_flags & TRACE_ITER_PRINTK_MSGONLY)
+ return trace_print_bputs_msg_only(iter);
+
+ if (iter->ent->type == TRACE_BPRINT &&
+ trace_flags & TRACE_ITER_PRINTK &&
+ trace_flags & TRACE_ITER_PRINTK_MSGONLY)
+ return trace_print_bprintk_msg_only(iter);
+
+ if (iter->ent->type == TRACE_PRINT &&
+ trace_flags & TRACE_ITER_PRINTK &&
+ trace_flags & TRACE_ITER_PRINTK_MSGONLY)
+ return trace_print_printk_msg_only(iter);
+
+ if (trace_flags & TRACE_ITER_BIN)
+ return print_bin_fmt(iter);
+
+ if (trace_flags & TRACE_ITER_HEX)
+ return print_hex_fmt(iter);
+
+ if (trace_flags & TRACE_ITER_RAW)
+ return print_raw_fmt(iter);
+
+ return print_trace_fmt(iter);
+}
+
+void trace_latency_header(struct seq_file *m)
+{
+ struct trace_iterator *iter = m->private;
+ struct trace_array *tr = iter->tr;
+
+ /* print nothing if the buffers are empty */
+ if (trace_empty(iter))
+ return;
+
+ if (iter->iter_flags & TRACE_FILE_LAT_FMT)
+ print_trace_header(m, iter);
+
+ if (!(tr->trace_flags & TRACE_ITER_VERBOSE))
+ print_lat_help_header(m);
+}
+
+void trace_default_header(struct seq_file *m)
+{
+ struct trace_iterator *iter = m->private;
+ struct trace_array *tr = iter->tr;
+ unsigned long trace_flags = tr->trace_flags;
+
+ if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
+ return;
+
+ if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
+ /* print nothing if the buffers are empty */
+ if (trace_empty(iter))
+ return;
+ print_trace_header(m, iter);
+ if (!(trace_flags & TRACE_ITER_VERBOSE))
+ print_lat_help_header(m);
+ } else {
+ if (!(trace_flags & TRACE_ITER_VERBOSE)) {
+ if (trace_flags & TRACE_ITER_IRQ_INFO)
+ print_func_help_header_irq(iter->array_buffer,
+ m, trace_flags);
+ else
+ print_func_help_header(iter->array_buffer, m,
+ trace_flags);
+ }
+ }
+}
+
+static void test_ftrace_alive(struct seq_file *m)
+{
+ if (!ftrace_is_dead())
+ return;
+ seq_puts(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n"
+ "# MAY BE MISSING FUNCTION EVENTS\n");
+}
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+static void show_snapshot_main_help(struct seq_file *m)
+{
+ seq_puts(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n"
+ "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"
+ "# Takes a snapshot of the main buffer.\n"
+ "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)\n"
+ "# (Doesn't have to be '2' works with any number that\n"
+ "# is not a '0' or '1')\n");
+}
+
+static void show_snapshot_percpu_help(struct seq_file *m)
+{
+ seq_puts(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n");
+#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
+ seq_puts(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"
+ "# Takes a snapshot of the main buffer for this cpu.\n");
+#else
+ seq_puts(m, "# echo 1 > snapshot : Not supported with this kernel.\n"
+ "# Must use main snapshot file to allocate.\n");
+#endif
+ seq_puts(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n"
+ "# (Doesn't have to be '2' works with any number that\n"
+ "# is not a '0' or '1')\n");
+}
+
+static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter)
+{
+ if (iter->tr->allocated_snapshot)
+ seq_puts(m, "#\n# * Snapshot is allocated *\n#\n");
+ else
+ seq_puts(m, "#\n# * Snapshot is freed *\n#\n");
+
+ seq_puts(m, "# Snapshot commands:\n");
+ if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
+ show_snapshot_main_help(m);
+ else
+ show_snapshot_percpu_help(m);
+}
+#else
+/* Should never be called */
+static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { }
+#endif
+
+static int s_show(struct seq_file *m, void *v)
+{
+ struct trace_iterator *iter = v;
+ int ret;
+
+ if (iter->ent == NULL) {
+ if (iter->tr) {
+ seq_printf(m, "# tracer: %s\n", iter->trace->name);
+ seq_puts(m, "#\n");
+ test_ftrace_alive(m);
+ }
+ if (iter->snapshot && trace_empty(iter))
+ print_snapshot_help(m, iter);
+ else if (iter->trace && iter->trace->print_header)
+ iter->trace->print_header(m);
+ else
+ trace_default_header(m);
+
+ } else if (iter->leftover) {
+ /*
+ * If we filled the seq_file buffer earlier, we
+ * want to just show it now.
+ */
+ ret = trace_print_seq(m, &iter->seq);
+
+ /* ret should this time be zero, but you never know */
+ iter->leftover = ret;
+
+ } else {
+ ret = print_trace_line(iter);
+ if (ret == TRACE_TYPE_PARTIAL_LINE) {
+ iter->seq.full = 0;
+ trace_seq_puts(&iter->seq, "[LINE TOO BIG]\n");
+ }
+ ret = trace_print_seq(m, &iter->seq);
+ /*
+ * If we overflow the seq_file buffer, then it will
+ * ask us for this data again at start up.
+ * Use that instead.
+ * ret is 0 if seq_file write succeeded.
+ * -1 otherwise.
+ */
+ iter->leftover = ret;
+ }
+
+ return 0;
+}
+
+/*
+ * Should be used after trace_array_get(), trace_types_lock
+ * ensures that i_cdev was already initialized.
+ */
+static inline int tracing_get_cpu(struct inode *inode)
+{
+ if (inode->i_cdev) /* See trace_create_cpu_file() */
+ return (long)inode->i_cdev - 1;
+ return RING_BUFFER_ALL_CPUS;
+}
+
+static const struct seq_operations tracer_seq_ops = {
+ .start = s_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = s_show,
+};
+
+/*
+ * Note, as iter itself can be allocated and freed in different
+ * ways, this function is only used to free its content, and not
+ * the iterator itself. The only requirement to all the allocations
+ * is that it must zero all fields (kzalloc), as freeing works with
+ * ethier allocated content or NULL.
+ */
+static void free_trace_iter_content(struct trace_iterator *iter)
+{
+ /* The fmt is either NULL, allocated or points to static_fmt_buf */
+ if (iter->fmt != static_fmt_buf)
+ kfree(iter->fmt);
+
+ kfree(iter->temp);
+ kfree(iter->buffer_iter);
+ mutex_destroy(&iter->mutex);
+ free_cpumask_var(iter->started);
+}
+
+static struct trace_iterator *
+__tracing_open(struct inode *inode, struct file *file, bool snapshot)
+{
+ struct trace_array *tr = inode->i_private;
+ struct trace_iterator *iter;
+ int cpu;
+
+ if (tracing_disabled)
+ return ERR_PTR(-ENODEV);
+
+ iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter));
+ if (!iter)
+ return ERR_PTR(-ENOMEM);
+
+ iter->buffer_iter = kcalloc(nr_cpu_ids, sizeof(*iter->buffer_iter),
+ GFP_KERNEL);
+ if (!iter->buffer_iter)
+ goto release;
+
+ /*
+ * trace_find_next_entry() may need to save off iter->ent.
+ * It will place it into the iter->temp buffer. As most
+ * events are less than 128, allocate a buffer of that size.
+ * If one is greater, then trace_find_next_entry() will
+ * allocate a new buffer to adjust for the bigger iter->ent.
+ * It's not critical if it fails to get allocated here.
+ */
+ iter->temp = kmalloc(128, GFP_KERNEL);
+ if (iter->temp)
+ iter->temp_size = 128;
+
+ /*
+ * trace_event_printf() may need to modify given format
+ * string to replace %p with %px so that it shows real address
+ * instead of hash value. However, that is only for the event
+ * tracing, other tracer may not need. Defer the allocation
+ * until it is needed.
+ */
+ iter->fmt = NULL;
+ iter->fmt_size = 0;
+
+ mutex_lock(&trace_types_lock);
+ iter->trace = tr->current_trace;
+
+ if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL))
+ goto fail;
+
+ iter->tr = tr;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ /* Currently only the top directory has a snapshot */
+ if (tr->current_trace->print_max || snapshot)
+ iter->array_buffer = &tr->max_buffer;
+ else
+#endif
+ iter->array_buffer = &tr->array_buffer;
+ iter->snapshot = snapshot;
+ iter->pos = -1;
+ iter->cpu_file = tracing_get_cpu(inode);
+ mutex_init(&iter->mutex);
+
+ /* Notify the tracer early; before we stop tracing. */
+ if (iter->trace->open)
+ iter->trace->open(iter);
+
+ /* Annotate start of buffers if we had overruns */
+ if (ring_buffer_overruns(iter->array_buffer->buffer))
+ iter->iter_flags |= TRACE_FILE_ANNOTATE;
+
+ /* Output in nanoseconds only if we are using a clock in nanoseconds. */
+ if (trace_clocks[tr->clock_id].in_ns)
+ iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
+
+ /*
+ * If pause-on-trace is enabled, then stop the trace while
+ * dumping, unless this is the "snapshot" file
+ */
+ if (!iter->snapshot && (tr->trace_flags & TRACE_ITER_PAUSE_ON_TRACE))
+ tracing_stop_tr(tr);
+
+ if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
+ for_each_tracing_cpu(cpu) {
+ iter->buffer_iter[cpu] =
+ ring_buffer_read_prepare(iter->array_buffer->buffer,
+ cpu, GFP_KERNEL);
+ }
+ ring_buffer_read_prepare_sync();
+ for_each_tracing_cpu(cpu) {
+ ring_buffer_read_start(iter->buffer_iter[cpu]);
+ tracing_iter_reset(iter, cpu);
+ }
+ } else {
+ cpu = iter->cpu_file;
+ iter->buffer_iter[cpu] =
+ ring_buffer_read_prepare(iter->array_buffer->buffer,
+ cpu, GFP_KERNEL);
+ ring_buffer_read_prepare_sync();
+ ring_buffer_read_start(iter->buffer_iter[cpu]);
+ tracing_iter_reset(iter, cpu);
+ }
+
+ mutex_unlock(&trace_types_lock);
+
+ return iter;
+
+ fail:
+ mutex_unlock(&trace_types_lock);
+ free_trace_iter_content(iter);
+release:
+ seq_release_private(inode, file);
+ return ERR_PTR(-ENOMEM);
+}
+
+int tracing_open_generic(struct inode *inode, struct file *filp)
+{
+ int ret;
+
+ ret = tracing_check_open_get_tr(NULL);
+ if (ret)
+ return ret;
+
+ filp->private_data = inode->i_private;
+ return 0;
+}
+
+bool tracing_is_disabled(void)
+{
+ return (tracing_disabled) ? true: false;
+}
+
+/*
+ * Open and update trace_array ref count.
+ * Must have the current trace_array passed to it.
+ */
+int tracing_open_generic_tr(struct inode *inode, struct file *filp)
+{
+ struct trace_array *tr = inode->i_private;
+ int ret;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ filp->private_data = inode->i_private;
+
+ return 0;
+}
+
+/*
+ * The private pointer of the inode is the trace_event_file.
+ * Update the tr ref count associated to it.
+ */
+int tracing_open_file_tr(struct inode *inode, struct file *filp)
+{
+ struct trace_event_file *file = inode->i_private;
+ int ret;
+
+ ret = tracing_check_open_get_tr(file->tr);
+ if (ret)
+ return ret;
+
+ mutex_lock(&event_mutex);
+
+ /* Fail if the file is marked for removal */
+ if (file->flags & EVENT_FILE_FL_FREED) {
+ trace_array_put(file->tr);
+ ret = -ENODEV;
+ } else {
+ event_file_get(file);
+ }
+
+ mutex_unlock(&event_mutex);
+ if (ret)
+ return ret;
+
+ filp->private_data = inode->i_private;
+
+ return 0;
+}
+
+int tracing_release_file_tr(struct inode *inode, struct file *filp)
+{
+ struct trace_event_file *file = inode->i_private;
+
+ trace_array_put(file->tr);
+ event_file_put(file);
+
+ return 0;
+}
+
+int tracing_single_release_file_tr(struct inode *inode, struct file *filp)
+{
+ tracing_release_file_tr(inode, filp);
+ return single_release(inode, filp);
+}
+
+static int tracing_mark_open(struct inode *inode, struct file *filp)
+{
+ stream_open(inode, filp);
+ return tracing_open_generic_tr(inode, filp);
+}
+
+static int tracing_release(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+ struct seq_file *m = file->private_data;
+ struct trace_iterator *iter;
+ int cpu;
+
+ if (!(file->f_mode & FMODE_READ)) {
+ trace_array_put(tr);
+ return 0;
+ }
+
+ /* Writes do not use seq_file */
+ iter = m->private;
+ mutex_lock(&trace_types_lock);
+
+ for_each_tracing_cpu(cpu) {
+ if (iter->buffer_iter[cpu])
+ ring_buffer_read_finish(iter->buffer_iter[cpu]);
+ }
+
+ if (iter->trace && iter->trace->close)
+ iter->trace->close(iter);
+
+ if (!iter->snapshot && tr->stop_count)
+ /* reenable tracing if it was previously enabled */
+ tracing_start_tr(tr);
+
+ __trace_array_put(tr);
+
+ mutex_unlock(&trace_types_lock);
+
+ free_trace_iter_content(iter);
+ seq_release_private(inode, file);
+
+ return 0;
+}
+
+static int tracing_release_generic_tr(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+
+ trace_array_put(tr);
+ return 0;
+}
+
+static int tracing_single_release_tr(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+
+ trace_array_put(tr);
+
+ return single_release(inode, file);
+}
+
+static int tracing_open(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+ struct trace_iterator *iter;
+ int ret;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ /* If this file was open for write, then erase contents */
+ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
+ int cpu = tracing_get_cpu(inode);
+ struct array_buffer *trace_buf = &tr->array_buffer;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (tr->current_trace->print_max)
+ trace_buf = &tr->max_buffer;
+#endif
+
+ if (cpu == RING_BUFFER_ALL_CPUS)
+ tracing_reset_online_cpus(trace_buf);
+ else
+ tracing_reset_cpu(trace_buf, cpu);
+ }
+
+ if (file->f_mode & FMODE_READ) {
+ iter = __tracing_open(inode, file, false);
+ if (IS_ERR(iter))
+ ret = PTR_ERR(iter);
+ else if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
+ iter->iter_flags |= TRACE_FILE_LAT_FMT;
+ }
+
+ if (ret < 0)
+ trace_array_put(tr);
+
+ return ret;
+}
+
+/*
+ * Some tracers are not suitable for instance buffers.
+ * A tracer is always available for the global array (toplevel)
+ * or if it explicitly states that it is.
+ */
+static bool
+trace_ok_for_array(struct tracer *t, struct trace_array *tr)
+{
+ return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances;
+}
+
+/* Find the next tracer that this trace array may use */
+static struct tracer *
+get_tracer_for_array(struct trace_array *tr, struct tracer *t)
+{
+ while (t && !trace_ok_for_array(t, tr))
+ t = t->next;
+
+ return t;
+}
+
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct trace_array *tr = m->private;
+ struct tracer *t = v;
+
+ (*pos)++;
+
+ if (t)
+ t = get_tracer_for_array(tr, t->next);
+
+ return t;
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+ struct trace_array *tr = m->private;
+ struct tracer *t;
+ loff_t l = 0;
+
+ mutex_lock(&trace_types_lock);
+
+ t = get_tracer_for_array(tr, trace_types);
+ for (; t && l < *pos; t = t_next(m, t, &l))
+ ;
+
+ return t;
+}
+
+static void t_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&trace_types_lock);
+}
+
+static int t_show(struct seq_file *m, void *v)
+{
+ struct tracer *t = v;
+
+ if (!t)
+ return 0;
+
+ seq_puts(m, t->name);
+ if (t->next)
+ seq_putc(m, ' ');
+ else
+ seq_putc(m, '\n');
+
+ return 0;
+}
+
+static const struct seq_operations show_traces_seq_ops = {
+ .start = t_start,
+ .next = t_next,
+ .stop = t_stop,
+ .show = t_show,
+};
+
+static int show_traces_open(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+ struct seq_file *m;
+ int ret;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ ret = seq_open(file, &show_traces_seq_ops);
+ if (ret) {
+ trace_array_put(tr);
+ return ret;
+ }
+
+ m = file->private_data;
+ m->private = tr;
+
+ return 0;
+}
+
+static int show_traces_release(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+
+ trace_array_put(tr);
+ return seq_release(inode, file);
+}
+
+static ssize_t
+tracing_write_stub(struct file *filp, const char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ return count;
+}
+
+loff_t tracing_lseek(struct file *file, loff_t offset, int whence)
+{
+ int ret;
+
+ if (file->f_mode & FMODE_READ)
+ ret = seq_lseek(file, offset, whence);
+ else
+ file->f_pos = ret = 0;
+
+ return ret;
+}
+
+static const struct file_operations tracing_fops = {
+ .open = tracing_open,
+ .read = seq_read,
+ .read_iter = seq_read_iter,
+ .splice_read = copy_splice_read,
+ .write = tracing_write_stub,
+ .llseek = tracing_lseek,
+ .release = tracing_release,
+};
+
+static const struct file_operations show_traces_fops = {
+ .open = show_traces_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = show_traces_release,
+};
+
+static ssize_t
+tracing_cpumask_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ struct trace_array *tr = file_inode(filp)->i_private;
+ char *mask_str;
+ int len;
+
+ len = snprintf(NULL, 0, "%*pb\n",
+ cpumask_pr_args(tr->tracing_cpumask)) + 1;
+ mask_str = kmalloc(len, GFP_KERNEL);
+ if (!mask_str)
+ return -ENOMEM;
+
+ len = snprintf(mask_str, len, "%*pb\n",
+ cpumask_pr_args(tr->tracing_cpumask));
+ if (len >= count) {
+ count = -EINVAL;
+ goto out_err;
+ }
+ count = simple_read_from_buffer(ubuf, count, ppos, mask_str, len);
+
+out_err:
+ kfree(mask_str);
+
+ return count;
+}
+
+int tracing_set_cpumask(struct trace_array *tr,
+ cpumask_var_t tracing_cpumask_new)
+{
+ int cpu;
+
+ if (!tr)
+ return -EINVAL;
+
+ local_irq_disable();
+ arch_spin_lock(&tr->max_lock);
+ for_each_tracing_cpu(cpu) {
+ /*
+ * Increase/decrease the disabled counter if we are
+ * about to flip a bit in the cpumask:
+ */
+ if (cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
+ !cpumask_test_cpu(cpu, tracing_cpumask_new)) {
+ atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled);
+ ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu);
+#ifdef CONFIG_TRACER_MAX_TRACE
+ ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu);
+#endif
+ }
+ if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
+ cpumask_test_cpu(cpu, tracing_cpumask_new)) {
+ atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled);
+ ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu);
+#ifdef CONFIG_TRACER_MAX_TRACE
+ ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu);
+#endif
+ }
+ }
+ arch_spin_unlock(&tr->max_lock);
+ local_irq_enable();
+
+ cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new);
+
+ return 0;
+}
+
+static ssize_t
+tracing_cpumask_write(struct file *filp, const char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ struct trace_array *tr = file_inode(filp)->i_private;
+ cpumask_var_t tracing_cpumask_new;
+ int err;
+
+ if (!zalloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
+ return -ENOMEM;
+
+ err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
+ if (err)
+ goto err_free;
+
+ err = tracing_set_cpumask(tr, tracing_cpumask_new);
+ if (err)
+ goto err_free;
+
+ free_cpumask_var(tracing_cpumask_new);
+
+ return count;
+
+err_free:
+ free_cpumask_var(tracing_cpumask_new);
+
+ return err;
+}
+
+static const struct file_operations tracing_cpumask_fops = {
+ .open = tracing_open_generic_tr,
+ .read = tracing_cpumask_read,
+ .write = tracing_cpumask_write,
+ .release = tracing_release_generic_tr,
+ .llseek = generic_file_llseek,
+};
+
+static int tracing_trace_options_show(struct seq_file *m, void *v)
+{
+ struct tracer_opt *trace_opts;
+ struct trace_array *tr = m->private;
+ u32 tracer_flags;
+ int i;
+
+ mutex_lock(&trace_types_lock);
+ tracer_flags = tr->current_trace->flags->val;
+ trace_opts = tr->current_trace->flags->opts;
+
+ for (i = 0; trace_options[i]; i++) {
+ if (tr->trace_flags & (1 << i))
+ seq_printf(m, "%s\n", trace_options[i]);
+ else
+ seq_printf(m, "no%s\n", trace_options[i]);
+ }
+
+ for (i = 0; trace_opts[i].name; i++) {
+ if (tracer_flags & trace_opts[i].bit)
+ seq_printf(m, "%s\n", trace_opts[i].name);
+ else
+ seq_printf(m, "no%s\n", trace_opts[i].name);
+ }
+ mutex_unlock(&trace_types_lock);
+
+ return 0;
+}
+
+static int __set_tracer_option(struct trace_array *tr,
+ struct tracer_flags *tracer_flags,
+ struct tracer_opt *opts, int neg)
+{
+ struct tracer *trace = tracer_flags->trace;
+ int ret;
+
+ ret = trace->set_flag(tr, tracer_flags->val, opts->bit, !neg);
+ if (ret)
+ return ret;
+
+ if (neg)
+ tracer_flags->val &= ~opts->bit;
+ else
+ tracer_flags->val |= opts->bit;
+ return 0;
+}
+
+/* Try to assign a tracer specific option */
+static int set_tracer_option(struct trace_array *tr, char *cmp, int neg)
+{
+ struct tracer *trace = tr->current_trace;
+ struct tracer_flags *tracer_flags = trace->flags;
+ struct tracer_opt *opts = NULL;
+ int i;
+
+ for (i = 0; tracer_flags->opts[i].name; i++) {
+ opts = &tracer_flags->opts[i];
+
+ if (strcmp(cmp, opts->name) == 0)
+ return __set_tracer_option(tr, trace->flags, opts, neg);
+ }
+
+ return -EINVAL;
+}
+
+/* Some tracers require overwrite to stay enabled */
+int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set)
+{
+ if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set)
+ return -1;
+
+ return 0;
+}
+
+int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
+{
+ int *map;
+
+ if ((mask == TRACE_ITER_RECORD_TGID) ||
+ (mask == TRACE_ITER_RECORD_CMD))
+ lockdep_assert_held(&event_mutex);
+
+ /* do nothing if flag is already set */
+ if (!!(tr->trace_flags & mask) == !!enabled)
+ return 0;
+
+ /* Give the tracer a chance to approve the change */
+ if (tr->current_trace->flag_changed)
+ if (tr->current_trace->flag_changed(tr, mask, !!enabled))
+ return -EINVAL;
+
+ if (enabled)
+ tr->trace_flags |= mask;
+ else
+ tr->trace_flags &= ~mask;
+
+ if (mask == TRACE_ITER_RECORD_CMD)
+ trace_event_enable_cmd_record(enabled);
+
+ if (mask == TRACE_ITER_RECORD_TGID) {
+ if (!tgid_map) {
+ tgid_map_max = pid_max;
+ map = kvcalloc(tgid_map_max + 1, sizeof(*tgid_map),
+ GFP_KERNEL);
+
+ /*
+ * Pairs with smp_load_acquire() in
+ * trace_find_tgid_ptr() to ensure that if it observes
+ * the tgid_map we just allocated then it also observes
+ * the corresponding tgid_map_max value.
+ */
+ smp_store_release(&tgid_map, map);
+ }
+ if (!tgid_map) {
+ tr->trace_flags &= ~TRACE_ITER_RECORD_TGID;
+ return -ENOMEM;
+ }
+
+ trace_event_enable_tgid_record(enabled);
+ }
+
+ if (mask == TRACE_ITER_EVENT_FORK)
+ trace_event_follow_fork(tr, enabled);
+
+ if (mask == TRACE_ITER_FUNC_FORK)
+ ftrace_pid_follow_fork(tr, enabled);
+
+ if (mask == TRACE_ITER_OVERWRITE) {
+ ring_buffer_change_overwrite(tr->array_buffer.buffer, enabled);
+#ifdef CONFIG_TRACER_MAX_TRACE
+ ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled);
+#endif
+ }
+
+ if (mask == TRACE_ITER_PRINTK) {
+ trace_printk_start_stop_comm(enabled);
+ trace_printk_control(enabled);
+ }
+
+ return 0;
+}
+
+int trace_set_options(struct trace_array *tr, char *option)
+{
+ char *cmp;
+ int neg = 0;
+ int ret;
+ size_t orig_len = strlen(option);
+ int len;
+
+ cmp = strstrip(option);
+
+ len = str_has_prefix(cmp, "no");
+ if (len)
+ neg = 1;
+
+ cmp += len;
+
+ mutex_lock(&event_mutex);
+ mutex_lock(&trace_types_lock);
+
+ ret = match_string(trace_options, -1, cmp);
+ /* If no option could be set, test the specific tracer options */
+ if (ret < 0)
+ ret = set_tracer_option(tr, cmp, neg);
+ else
+ ret = set_tracer_flag(tr, 1 << ret, !neg);
+
+ mutex_unlock(&trace_types_lock);
+ mutex_unlock(&event_mutex);
+
+ /*
+ * If the first trailing whitespace is replaced with '\0' by strstrip,
+ * turn it back into a space.
+ */
+ if (orig_len > strlen(option))
+ option[strlen(option)] = ' ';
+
+ return ret;
+}
+
+static void __init apply_trace_boot_options(void)
+{
+ char *buf = trace_boot_options_buf;
+ char *option;
+
+ while (true) {
+ option = strsep(&buf, ",");
+
+ if (!option)
+ break;
+
+ if (*option)
+ trace_set_options(&global_trace, option);
+
+ /* Put back the comma to allow this to be called again */
+ if (buf)
+ *(buf - 1) = ',';
+ }
+}
+
+static ssize_t
+tracing_trace_options_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct seq_file *m = filp->private_data;
+ struct trace_array *tr = m->private;
+ char buf[64];
+ int ret;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ ret = trace_set_options(tr, buf);
+ if (ret < 0)
+ return ret;
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static int tracing_trace_options_open(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+ int ret;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ ret = single_open(file, tracing_trace_options_show, inode->i_private);
+ if (ret < 0)
+ trace_array_put(tr);
+
+ return ret;
+}
+
+static const struct file_operations tracing_iter_fops = {
+ .open = tracing_trace_options_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = tracing_single_release_tr,
+ .write = tracing_trace_options_write,
+};
+
+static const char readme_msg[] =
+ "tracing mini-HOWTO:\n\n"
+ "# echo 0 > tracing_on : quick way to disable tracing\n"
+ "# echo 1 > tracing_on : quick way to re-enable tracing\n\n"
+ " Important files:\n"
+ " trace\t\t\t- The static contents of the buffer\n"
+ "\t\t\t To clear the buffer write into this file: echo > trace\n"
+ " trace_pipe\t\t- A consuming read to see the contents of the buffer\n"
+ " current_tracer\t- function and latency tracers\n"
+ " available_tracers\t- list of configured tracers for current_tracer\n"
+ " error_log\t- error log for failed commands (that support it)\n"
+ " buffer_size_kb\t- view and modify size of per cpu buffer\n"
+ " buffer_total_size_kb - view total size of all cpu buffers\n\n"
+ " trace_clock\t\t- change the clock used to order events\n"
+ " local: Per cpu clock but may not be synced across CPUs\n"
+ " global: Synced across CPUs but slows tracing down.\n"
+ " counter: Not a clock, but just an increment\n"
+ " uptime: Jiffy counter from time of boot\n"
+ " perf: Same clock that perf events use\n"
+#ifdef CONFIG_X86_64
+ " x86-tsc: TSC cycle counter\n"
+#endif
+ "\n timestamp_mode\t- view the mode used to timestamp events\n"
+ " delta: Delta difference against a buffer-wide timestamp\n"
+ " absolute: Absolute (standalone) timestamp\n"
+ "\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n"
+ "\n trace_marker_raw\t\t- Writes into this file writes binary data into the kernel buffer\n"
+ " tracing_cpumask\t- Limit which CPUs to trace\n"
+ " instances\t\t- Make sub-buffers with: mkdir instances/foo\n"
+ "\t\t\t Remove sub-buffer with rmdir\n"
+ " trace_options\t\t- Set format or modify how tracing happens\n"
+ "\t\t\t Disable an option by prefixing 'no' to the\n"
+ "\t\t\t option name\n"
+ " saved_cmdlines_size\t- echo command number in here to store comm-pid list\n"
+#ifdef CONFIG_DYNAMIC_FTRACE
+ "\n available_filter_functions - list of functions that can be filtered on\n"
+ " set_ftrace_filter\t- echo function name in here to only trace these\n"
+ "\t\t\t functions\n"
+ "\t accepts: func_full_name or glob-matching-pattern\n"
+ "\t modules: Can select a group via module\n"
+ "\t Format: :mod:<module-name>\n"
+ "\t example: echo :mod:ext3 > set_ftrace_filter\n"
+ "\t triggers: a command to perform when function is hit\n"
+ "\t Format: <function>:<trigger>[:count]\n"
+ "\t trigger: traceon, traceoff\n"
+ "\t\t enable_event:<system>:<event>\n"
+ "\t\t disable_event:<system>:<event>\n"
+#ifdef CONFIG_STACKTRACE
+ "\t\t stacktrace\n"
+#endif
+#ifdef CONFIG_TRACER_SNAPSHOT
+ "\t\t snapshot\n"
+#endif
+ "\t\t dump\n"
+ "\t\t cpudump\n"
+ "\t example: echo do_fault:traceoff > set_ftrace_filter\n"
+ "\t echo do_trap:traceoff:3 > set_ftrace_filter\n"
+ "\t The first one will disable tracing every time do_fault is hit\n"
+ "\t The second will disable tracing at most 3 times when do_trap is hit\n"
+ "\t The first time do trap is hit and it disables tracing, the\n"
+ "\t counter will decrement to 2. If tracing is already disabled,\n"
+ "\t the counter will not decrement. It only decrements when the\n"
+ "\t trigger did work\n"
+ "\t To remove trigger without count:\n"
+ "\t echo '!<function>:<trigger> > set_ftrace_filter\n"
+ "\t To remove trigger with a count:\n"
+ "\t echo '!<function>:<trigger>:0 > set_ftrace_filter\n"
+ " set_ftrace_notrace\t- echo function name in here to never trace.\n"
+ "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
+ "\t modules: Can select a group via module command :mod:\n"
+ "\t Does not accept triggers\n"
+#endif /* CONFIG_DYNAMIC_FTRACE */
+#ifdef CONFIG_FUNCTION_TRACER
+ " set_ftrace_pid\t- Write pid(s) to only function trace those pids\n"
+ "\t\t (function)\n"
+ " set_ftrace_notrace_pid\t- Write pid(s) to not function trace those pids\n"
+ "\t\t (function)\n"
+#endif
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ " set_graph_function\t- Trace the nested calls of a function (function_graph)\n"
+ " set_graph_notrace\t- Do not trace the nested calls of a function (function_graph)\n"
+ " max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n"
+#endif
+#ifdef CONFIG_TRACER_SNAPSHOT
+ "\n snapshot\t\t- Like 'trace' but shows the content of the static\n"
+ "\t\t\t snapshot buffer. Read the contents for more\n"
+ "\t\t\t information\n"
+#endif
+#ifdef CONFIG_STACK_TRACER
+ " stack_trace\t\t- Shows the max stack trace when active\n"
+ " stack_max_size\t- Shows current max stack size that was traced\n"
+ "\t\t\t Write into this file to reset the max size (trigger a\n"
+ "\t\t\t new trace)\n"
+#ifdef CONFIG_DYNAMIC_FTRACE
+ " stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace\n"
+ "\t\t\t traces\n"
+#endif
+#endif /* CONFIG_STACK_TRACER */
+#ifdef CONFIG_DYNAMIC_EVENTS
+ " dynamic_events\t\t- Create/append/remove/show the generic dynamic events\n"
+ "\t\t\t Write into this file to define/undefine new trace events.\n"
+#endif
+#ifdef CONFIG_KPROBE_EVENTS
+ " kprobe_events\t\t- Create/append/remove/show the kernel dynamic events\n"
+ "\t\t\t Write into this file to define/undefine new trace events.\n"
+#endif
+#ifdef CONFIG_UPROBE_EVENTS
+ " uprobe_events\t\t- Create/append/remove/show the userspace dynamic events\n"
+ "\t\t\t Write into this file to define/undefine new trace events.\n"
+#endif
+#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS) || \
+ defined(CONFIG_FPROBE_EVENTS)
+ "\t accepts: event-definitions (one definition per line)\n"
+#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
+ "\t Format: p[:[<group>/][<event>]] <place> [<args>]\n"
+ "\t r[maxactive][:[<group>/][<event>]] <place> [<args>]\n"
+#endif
+#ifdef CONFIG_FPROBE_EVENTS
+ "\t f[:[<group>/][<event>]] <func-name>[%return] [<args>]\n"
+ "\t t[:[<group>/][<event>]] <tracepoint> [<args>]\n"
+#endif
+#ifdef CONFIG_HIST_TRIGGERS
+ "\t s:[synthetic/]<event> <field> [<field>]\n"
+#endif
+ "\t e[:[<group>/][<event>]] <attached-group>.<attached-event> [<args>] [if <filter>]\n"
+ "\t -:[<group>/][<event>]\n"
+#ifdef CONFIG_KPROBE_EVENTS
+ "\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
+ "place (kretprobe): [<module>:]<symbol>[+<offset>]%return|<memaddr>\n"
+#endif
+#ifdef CONFIG_UPROBE_EVENTS
+ " place (uprobe): <path>:<offset>[%return][(ref_ctr_offset)]\n"
+#endif
+ "\t args: <name>=fetcharg[:type]\n"
+ "\t fetcharg: (%<register>|$<efield>), @<address>, @<symbol>[+|-<offset>],\n"
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+#ifdef CONFIG_PROBE_EVENTS_BTF_ARGS
+ "\t $stack<index>, $stack, $retval, $comm, $arg<N>,\n"
+ "\t <argname>[->field[->field|.field...]],\n"
+#else
+ "\t $stack<index>, $stack, $retval, $comm, $arg<N>,\n"
+#endif
+#else
+ "\t $stack<index>, $stack, $retval, $comm,\n"
+#endif
+ "\t +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n"
+ "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, char, string, symbol,\n"
+ "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n"
+ "\t symstr, <type>\\[<array-size>\\]\n"
+#ifdef CONFIG_HIST_TRIGGERS
+ "\t field: <stype> <name>;\n"
+ "\t stype: u8/u16/u32/u64, s8/s16/s32/s64, pid_t,\n"
+ "\t [unsigned] char/int/long\n"
+#endif
+ "\t efield: For event probes ('e' types), the field is on of the fields\n"
+ "\t of the <attached-group>/<attached-event>.\n"
+#endif
+ " events/\t\t- Directory containing all trace event subsystems:\n"
+ " enable\t\t- Write 0/1 to enable/disable tracing of all events\n"
+ " events/<system>/\t- Directory containing all trace events for <system>:\n"
+ " enable\t\t- Write 0/1 to enable/disable tracing of all <system>\n"
+ "\t\t\t events\n"
+ " filter\t\t- If set, only events passing filter are traced\n"
+ " events/<system>/<event>/\t- Directory containing control files for\n"
+ "\t\t\t <event>:\n"
+ " enable\t\t- Write 0/1 to enable/disable tracing of <event>\n"
+ " filter\t\t- If set, only events passing filter are traced\n"
+ " trigger\t\t- If set, a command to perform when event is hit\n"
+ "\t Format: <trigger>[:count][if <filter>]\n"
+ "\t trigger: traceon, traceoff\n"
+ "\t enable_event:<system>:<event>\n"
+ "\t disable_event:<system>:<event>\n"
+#ifdef CONFIG_HIST_TRIGGERS
+ "\t enable_hist:<system>:<event>\n"
+ "\t disable_hist:<system>:<event>\n"
+#endif
+#ifdef CONFIG_STACKTRACE
+ "\t\t stacktrace\n"
+#endif
+#ifdef CONFIG_TRACER_SNAPSHOT
+ "\t\t snapshot\n"
+#endif
+#ifdef CONFIG_HIST_TRIGGERS
+ "\t\t hist (see below)\n"
+#endif
+ "\t example: echo traceoff > events/block/block_unplug/trigger\n"
+ "\t echo traceoff:3 > events/block/block_unplug/trigger\n"
+ "\t echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > \\\n"
+ "\t events/block/block_unplug/trigger\n"
+ "\t The first disables tracing every time block_unplug is hit.\n"
+ "\t The second disables tracing the first 3 times block_unplug is hit.\n"
+ "\t The third enables the kmalloc event the first 3 times block_unplug\n"
+ "\t is hit and has value of greater than 1 for the 'nr_rq' event field.\n"
+ "\t Like function triggers, the counter is only decremented if it\n"
+ "\t enabled or disabled tracing.\n"
+ "\t To remove a trigger without a count:\n"
+ "\t echo '!<trigger> > <system>/<event>/trigger\n"
+ "\t To remove a trigger with a count:\n"
+ "\t echo '!<trigger>:0 > <system>/<event>/trigger\n"
+ "\t Filters can be ignored when removing a trigger.\n"
+#ifdef CONFIG_HIST_TRIGGERS
+ " hist trigger\t- If set, event hits are aggregated into a hash table\n"
+ "\t Format: hist:keys=<field1[,field2,...]>\n"
+ "\t [:<var1>=<field|var_ref|numeric_literal>[,<var2>=...]]\n"
+ "\t [:values=<field1[,field2,...]>]\n"
+ "\t [:sort=<field1[,field2,...]>]\n"
+ "\t [:size=#entries]\n"
+ "\t [:pause][:continue][:clear]\n"
+ "\t [:name=histname1]\n"
+ "\t [:nohitcount]\n"
+ "\t [:<handler>.<action>]\n"
+ "\t [if <filter>]\n\n"
+ "\t Note, special fields can be used as well:\n"
+ "\t common_timestamp - to record current timestamp\n"
+ "\t common_cpu - to record the CPU the event happened on\n"
+ "\n"
+ "\t A hist trigger variable can be:\n"
+ "\t - a reference to a field e.g. x=current_timestamp,\n"
+ "\t - a reference to another variable e.g. y=$x,\n"
+ "\t - a numeric literal: e.g. ms_per_sec=1000,\n"
+ "\t - an arithmetic expression: e.g. time_secs=current_timestamp/1000\n"
+ "\n"
+ "\t hist trigger arithmetic expressions support addition(+), subtraction(-),\n"
+ "\t multiplication(*) and division(/) operators. An operand can be either a\n"
+ "\t variable reference, field or numeric literal.\n"
+ "\n"
+ "\t When a matching event is hit, an entry is added to a hash\n"
+ "\t table using the key(s) and value(s) named, and the value of a\n"
+ "\t sum called 'hitcount' is incremented. Keys and values\n"
+ "\t correspond to fields in the event's format description. Keys\n"
+ "\t can be any field, or the special string 'common_stacktrace'.\n"
+ "\t Compound keys consisting of up to two fields can be specified\n"
+ "\t by the 'keys' keyword. Values must correspond to numeric\n"
+ "\t fields. Sort keys consisting of up to two fields can be\n"
+ "\t specified using the 'sort' keyword. The sort direction can\n"
+ "\t be modified by appending '.descending' or '.ascending' to a\n"
+ "\t sort field. The 'size' parameter can be used to specify more\n"
+ "\t or fewer than the default 2048 entries for the hashtable size.\n"
+ "\t If a hist trigger is given a name using the 'name' parameter,\n"
+ "\t its histogram data will be shared with other triggers of the\n"
+ "\t same name, and trigger hits will update this common data.\n\n"
+ "\t Reading the 'hist' file for the event will dump the hash\n"
+ "\t table in its entirety to stdout. If there are multiple hist\n"
+ "\t triggers attached to an event, there will be a table for each\n"
+ "\t trigger in the output. The table displayed for a named\n"
+ "\t trigger will be the same as any other instance having the\n"
+ "\t same name. The default format used to display a given field\n"
+ "\t can be modified by appending any of the following modifiers\n"
+ "\t to the field name, as applicable:\n\n"
+ "\t .hex display a number as a hex value\n"
+ "\t .sym display an address as a symbol\n"
+ "\t .sym-offset display an address as a symbol and offset\n"
+ "\t .execname display a common_pid as a program name\n"
+ "\t .syscall display a syscall id as a syscall name\n"
+ "\t .log2 display log2 value rather than raw number\n"
+ "\t .buckets=size display values in groups of size rather than raw number\n"
+ "\t .usecs display a common_timestamp in microseconds\n"
+ "\t .percent display a number of percentage value\n"
+ "\t .graph display a bar-graph of a value\n\n"
+ "\t The 'pause' parameter can be used to pause an existing hist\n"
+ "\t trigger or to start a hist trigger but not log any events\n"
+ "\t until told to do so. 'continue' can be used to start or\n"
+ "\t restart a paused hist trigger.\n\n"
+ "\t The 'clear' parameter will clear the contents of a running\n"
+ "\t hist trigger and leave its current paused/active state\n"
+ "\t unchanged.\n\n"
+ "\t The 'nohitcount' (or NOHC) parameter will suppress display of\n"
+ "\t raw hitcount in the histogram.\n\n"
+ "\t The enable_hist and disable_hist triggers can be used to\n"
+ "\t have one event conditionally start and stop another event's\n"
+ "\t already-attached hist trigger. The syntax is analogous to\n"
+ "\t the enable_event and disable_event triggers.\n\n"
+ "\t Hist trigger handlers and actions are executed whenever a\n"
+ "\t a histogram entry is added or updated. They take the form:\n\n"
+ "\t <handler>.<action>\n\n"
+ "\t The available handlers are:\n\n"
+ "\t onmatch(matching.event) - invoke on addition or update\n"
+ "\t onmax(var) - invoke if var exceeds current max\n"
+ "\t onchange(var) - invoke action if var changes\n\n"
+ "\t The available actions are:\n\n"
+ "\t trace(<synthetic_event>,param list) - generate synthetic event\n"
+ "\t save(field,...) - save current event fields\n"
+#ifdef CONFIG_TRACER_SNAPSHOT
+ "\t snapshot() - snapshot the trace buffer\n\n"
+#endif
+#ifdef CONFIG_SYNTH_EVENTS
+ " events/synthetic_events\t- Create/append/remove/show synthetic events\n"
+ "\t Write into this file to define/undefine new synthetic events.\n"
+ "\t example: echo 'myevent u64 lat; char name[]; long[] stack' >> synthetic_events\n"
+#endif
+#endif
+;
+
+static ssize_t
+tracing_readme_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_read_from_buffer(ubuf, cnt, ppos,
+ readme_msg, strlen(readme_msg));
+}
+
+static const struct file_operations tracing_readme_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_readme_read,
+ .llseek = generic_file_llseek,
+};
+
+static void *saved_tgids_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ int pid = ++(*pos);
+
+ return trace_find_tgid_ptr(pid);
+}
+
+static void *saved_tgids_start(struct seq_file *m, loff_t *pos)
+{
+ int pid = *pos;
+
+ return trace_find_tgid_ptr(pid);
+}
+
+static void saved_tgids_stop(struct seq_file *m, void *v)
+{
+}
+
+static int saved_tgids_show(struct seq_file *m, void *v)
+{
+ int *entry = (int *)v;
+ int pid = entry - tgid_map;
+ int tgid = *entry;
+
+ if (tgid == 0)
+ return SEQ_SKIP;
+
+ seq_printf(m, "%d %d\n", pid, tgid);
+ return 0;
+}
+
+static const struct seq_operations tracing_saved_tgids_seq_ops = {
+ .start = saved_tgids_start,
+ .stop = saved_tgids_stop,
+ .next = saved_tgids_next,
+ .show = saved_tgids_show,
+};
+
+static int tracing_saved_tgids_open(struct inode *inode, struct file *filp)
+{
+ int ret;
+
+ ret = tracing_check_open_get_tr(NULL);
+ if (ret)
+ return ret;
+
+ return seq_open(filp, &tracing_saved_tgids_seq_ops);
+}
+
+
+static const struct file_operations tracing_saved_tgids_fops = {
+ .open = tracing_saved_tgids_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ unsigned int *ptr = v;
+
+ if (*pos || m->count)
+ ptr++;
+
+ (*pos)++;
+
+ for (; ptr < &savedcmd->map_cmdline_to_pid[savedcmd->cmdline_num];
+ ptr++) {
+ if (*ptr == -1 || *ptr == NO_CMDLINE_MAP)
+ continue;
+
+ return ptr;
+ }
+
+ return NULL;
+}
+
+static void *saved_cmdlines_start(struct seq_file *m, loff_t *pos)
+{
+ void *v;
+ loff_t l = 0;
+
+ preempt_disable();
+ arch_spin_lock(&trace_cmdline_lock);
+
+ v = &savedcmd->map_cmdline_to_pid[0];
+ while (l <= *pos) {
+ v = saved_cmdlines_next(m, v, &l);
+ if (!v)
+ return NULL;
+ }
+
+ return v;
+}
+
+static void saved_cmdlines_stop(struct seq_file *m, void *v)
+{
+ arch_spin_unlock(&trace_cmdline_lock);
+ preempt_enable();
+}
+
+static int saved_cmdlines_show(struct seq_file *m, void *v)
+{
+ char buf[TASK_COMM_LEN];
+ unsigned int *pid = v;
+
+ __trace_find_cmdline(*pid, buf);
+ seq_printf(m, "%d %s\n", *pid, buf);
+ return 0;
+}
+
+static const struct seq_operations tracing_saved_cmdlines_seq_ops = {
+ .start = saved_cmdlines_start,
+ .next = saved_cmdlines_next,
+ .stop = saved_cmdlines_stop,
+ .show = saved_cmdlines_show,
+};
+
+static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp)
+{
+ int ret;
+
+ ret = tracing_check_open_get_tr(NULL);
+ if (ret)
+ return ret;
+
+ return seq_open(filp, &tracing_saved_cmdlines_seq_ops);
+}
+
+static const struct file_operations tracing_saved_cmdlines_fops = {
+ .open = tracing_saved_cmdlines_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static ssize_t
+tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ int r;
+
+ preempt_disable();
+ arch_spin_lock(&trace_cmdline_lock);
+ r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num);
+ arch_spin_unlock(&trace_cmdline_lock);
+ preempt_enable();
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
+{
+ kfree(s->saved_cmdlines);
+ kfree(s->map_cmdline_to_pid);
+ kfree(s);
+}
+
+static int tracing_resize_saved_cmdlines(unsigned int val)
+{
+ struct saved_cmdlines_buffer *s, *savedcmd_temp;
+
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ if (allocate_cmdlines_buffer(val, s) < 0) {
+ kfree(s);
+ return -ENOMEM;
+ }
+
+ preempt_disable();
+ arch_spin_lock(&trace_cmdline_lock);
+ savedcmd_temp = savedcmd;
+ savedcmd = s;
+ arch_spin_unlock(&trace_cmdline_lock);
+ preempt_enable();
+ free_saved_cmdlines_buffer(savedcmd_temp);
+
+ return 0;
+}
+
+static ssize_t
+tracing_saved_cmdlines_size_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ /* must have at least 1 entry or less than PID_MAX_DEFAULT */
+ if (!val || val > PID_MAX_DEFAULT)
+ return -EINVAL;
+
+ ret = tracing_resize_saved_cmdlines((unsigned int)val);
+ if (ret < 0)
+ return ret;
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static const struct file_operations tracing_saved_cmdlines_size_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_saved_cmdlines_size_read,
+ .write = tracing_saved_cmdlines_size_write,
+};
+
+#ifdef CONFIG_TRACE_EVAL_MAP_FILE
+static union trace_eval_map_item *
+update_eval_map(union trace_eval_map_item *ptr)
+{
+ if (!ptr->map.eval_string) {
+ if (ptr->tail.next) {
+ ptr = ptr->tail.next;
+ /* Set ptr to the next real item (skip head) */
+ ptr++;
+ } else
+ return NULL;
+ }
+ return ptr;
+}
+
+static void *eval_map_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ union trace_eval_map_item *ptr = v;
+
+ /*
+ * Paranoid! If ptr points to end, we don't want to increment past it.
+ * This really should never happen.
+ */
+ (*pos)++;
+ ptr = update_eval_map(ptr);
+ if (WARN_ON_ONCE(!ptr))
+ return NULL;
+
+ ptr++;
+ ptr = update_eval_map(ptr);
+
+ return ptr;
+}
+
+static void *eval_map_start(struct seq_file *m, loff_t *pos)
+{
+ union trace_eval_map_item *v;
+ loff_t l = 0;
+
+ mutex_lock(&trace_eval_mutex);
+
+ v = trace_eval_maps;
+ if (v)
+ v++;
+
+ while (v && l < *pos) {
+ v = eval_map_next(m, v, &l);
+ }
+
+ return v;
+}
+
+static void eval_map_stop(struct seq_file *m, void *v)
+{
+ mutex_unlock(&trace_eval_mutex);
+}
+
+static int eval_map_show(struct seq_file *m, void *v)
+{
+ union trace_eval_map_item *ptr = v;
+
+ seq_printf(m, "%s %ld (%s)\n",
+ ptr->map.eval_string, ptr->map.eval_value,
+ ptr->map.system);
+
+ return 0;
+}
+
+static const struct seq_operations tracing_eval_map_seq_ops = {
+ .start = eval_map_start,
+ .next = eval_map_next,
+ .stop = eval_map_stop,
+ .show = eval_map_show,
+};
+
+static int tracing_eval_map_open(struct inode *inode, struct file *filp)
+{
+ int ret;
+
+ ret = tracing_check_open_get_tr(NULL);
+ if (ret)
+ return ret;
+
+ return seq_open(filp, &tracing_eval_map_seq_ops);
+}
+
+static const struct file_operations tracing_eval_map_fops = {
+ .open = tracing_eval_map_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static inline union trace_eval_map_item *
+trace_eval_jmp_to_tail(union trace_eval_map_item *ptr)
+{
+ /* Return tail of array given the head */
+ return ptr + ptr->head.length + 1;
+}
+
+static void
+trace_insert_eval_map_file(struct module *mod, struct trace_eval_map **start,
+ int len)
+{
+ struct trace_eval_map **stop;
+ struct trace_eval_map **map;
+ union trace_eval_map_item *map_array;
+ union trace_eval_map_item *ptr;
+
+ stop = start + len;
+
+ /*
+ * The trace_eval_maps contains the map plus a head and tail item,
+ * where the head holds the module and length of array, and the
+ * tail holds a pointer to the next list.
+ */
+ map_array = kmalloc_array(len + 2, sizeof(*map_array), GFP_KERNEL);
+ if (!map_array) {
+ pr_warn("Unable to allocate trace eval mapping\n");
+ return;
+ }
+
+ mutex_lock(&trace_eval_mutex);
+
+ if (!trace_eval_maps)
+ trace_eval_maps = map_array;
+ else {
+ ptr = trace_eval_maps;
+ for (;;) {
+ ptr = trace_eval_jmp_to_tail(ptr);
+ if (!ptr->tail.next)
+ break;
+ ptr = ptr->tail.next;
+
+ }
+ ptr->tail.next = map_array;
+ }
+ map_array->head.mod = mod;
+ map_array->head.length = len;
+ map_array++;
+
+ for (map = start; (unsigned long)map < (unsigned long)stop; map++) {
+ map_array->map = **map;
+ map_array++;
+ }
+ memset(map_array, 0, sizeof(*map_array));
+
+ mutex_unlock(&trace_eval_mutex);
+}
+
+static void trace_create_eval_file(struct dentry *d_tracer)
+{
+ trace_create_file("eval_map", TRACE_MODE_READ, d_tracer,
+ NULL, &tracing_eval_map_fops);
+}
+
+#else /* CONFIG_TRACE_EVAL_MAP_FILE */
+static inline void trace_create_eval_file(struct dentry *d_tracer) { }
+static inline void trace_insert_eval_map_file(struct module *mod,
+ struct trace_eval_map **start, int len) { }
+#endif /* !CONFIG_TRACE_EVAL_MAP_FILE */
+
+static void trace_insert_eval_map(struct module *mod,
+ struct trace_eval_map **start, int len)
+{
+ struct trace_eval_map **map;
+
+ if (len <= 0)
+ return;
+
+ map = start;
+
+ trace_event_eval_update(map, len);
+
+ trace_insert_eval_map_file(mod, start, len);
+}
+
+static ssize_t
+tracing_set_trace_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ char buf[MAX_TRACER_SIZE+2];
+ int r;
+
+ mutex_lock(&trace_types_lock);
+ r = sprintf(buf, "%s\n", tr->current_trace->name);
+ mutex_unlock(&trace_types_lock);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+int tracer_init(struct tracer *t, struct trace_array *tr)
+{
+ tracing_reset_online_cpus(&tr->array_buffer);
+ return t->init(tr);
+}
+
+static void set_buffer_entries(struct array_buffer *buf, unsigned long val)
+{
+ int cpu;
+
+ for_each_tracing_cpu(cpu)
+ per_cpu_ptr(buf->data, cpu)->entries = val;
+}
+
+static void update_buffer_entries(struct array_buffer *buf, int cpu)
+{
+ if (cpu == RING_BUFFER_ALL_CPUS) {
+ set_buffer_entries(buf, ring_buffer_size(buf->buffer, 0));
+ } else {
+ per_cpu_ptr(buf->data, cpu)->entries = ring_buffer_size(buf->buffer, cpu);
+ }
+}
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+/* resize @tr's buffer to the size of @size_tr's entries */
+static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
+ struct array_buffer *size_buf, int cpu_id)
+{
+ int cpu, ret = 0;
+
+ if (cpu_id == RING_BUFFER_ALL_CPUS) {
+ for_each_tracing_cpu(cpu) {
+ ret = ring_buffer_resize(trace_buf->buffer,
+ per_cpu_ptr(size_buf->data, cpu)->entries, cpu);
+ if (ret < 0)
+ break;
+ per_cpu_ptr(trace_buf->data, cpu)->entries =
+ per_cpu_ptr(size_buf->data, cpu)->entries;
+ }
+ } else {
+ ret = ring_buffer_resize(trace_buf->buffer,
+ per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id);
+ if (ret == 0)
+ per_cpu_ptr(trace_buf->data, cpu_id)->entries =
+ per_cpu_ptr(size_buf->data, cpu_id)->entries;
+ }
+
+ return ret;
+}
+#endif /* CONFIG_TRACER_MAX_TRACE */
+
+static int __tracing_resize_ring_buffer(struct trace_array *tr,
+ unsigned long size, int cpu)
+{
+ int ret;
+
+ /*
+ * If kernel or user changes the size of the ring buffer
+ * we use the size that was given, and we can forget about
+ * expanding it later.
+ */
+ ring_buffer_expanded = true;
+
+ /* May be called before buffers are initialized */
+ if (!tr->array_buffer.buffer)
+ return 0;
+
+ /* Do not allow tracing while resizing ring buffer */
+ tracing_stop_tr(tr);
+
+ ret = ring_buffer_resize(tr->array_buffer.buffer, size, cpu);
+ if (ret < 0)
+ goto out_start;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (!tr->allocated_snapshot)
+ goto out;
+
+ ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu);
+ if (ret < 0) {
+ int r = resize_buffer_duplicate_size(&tr->array_buffer,
+ &tr->array_buffer, cpu);
+ if (r < 0) {
+ /*
+ * AARGH! We are left with different
+ * size max buffer!!!!
+ * The max buffer is our "snapshot" buffer.
+ * When a tracer needs a snapshot (one of the
+ * latency tracers), it swaps the max buffer
+ * with the saved snap shot. We succeeded to
+ * update the size of the main buffer, but failed to
+ * update the size of the max buffer. But when we tried
+ * to reset the main buffer to the original size, we
+ * failed there too. This is very unlikely to
+ * happen, but if it does, warn and kill all
+ * tracing.
+ */
+ WARN_ON(1);
+ tracing_disabled = 1;
+ }
+ goto out_start;
+ }
+
+ update_buffer_entries(&tr->max_buffer, cpu);
+
+ out:
+#endif /* CONFIG_TRACER_MAX_TRACE */
+
+ update_buffer_entries(&tr->array_buffer, cpu);
+ out_start:
+ tracing_start_tr(tr);
+ return ret;
+}
+
+ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
+ unsigned long size, int cpu_id)
+{
+ int ret;
+
+ mutex_lock(&trace_types_lock);
+
+ if (cpu_id != RING_BUFFER_ALL_CPUS) {
+ /* make sure, this cpu is enabled in the mask */
+ if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ ret = __tracing_resize_ring_buffer(tr, size, cpu_id);
+ if (ret < 0)
+ ret = -ENOMEM;
+
+out:
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+}
+
+
+/**
+ * tracing_update_buffers - used by tracing facility to expand ring buffers
+ *
+ * To save on memory when the tracing is never used on a system with it
+ * configured in. The ring buffers are set to a minimum size. But once
+ * a user starts to use the tracing facility, then they need to grow
+ * to their default size.
+ *
+ * This function is to be called when a tracer is about to be used.
+ */
+int tracing_update_buffers(void)
+{
+ int ret = 0;
+
+ mutex_lock(&trace_types_lock);
+ if (!ring_buffer_expanded)
+ ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size,
+ RING_BUFFER_ALL_CPUS);
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+}
+
+struct trace_option_dentry;
+
+static void
+create_trace_option_files(struct trace_array *tr, struct tracer *tracer);
+
+/*
+ * Used to clear out the tracer before deletion of an instance.
+ * Must have trace_types_lock held.
+ */
+static void tracing_set_nop(struct trace_array *tr)
+{
+ if (tr->current_trace == &nop_trace)
+ return;
+
+ tr->current_trace->enabled--;
+
+ if (tr->current_trace->reset)
+ tr->current_trace->reset(tr);
+
+ tr->current_trace = &nop_trace;
+}
+
+static bool tracer_options_updated;
+
+static void add_tracer_options(struct trace_array *tr, struct tracer *t)
+{
+ /* Only enable if the directory has been created already. */
+ if (!tr->dir)
+ return;
+
+ /* Only create trace option files after update_tracer_options finish */
+ if (!tracer_options_updated)
+ return;
+
+ create_trace_option_files(tr, t);
+}
+
+int tracing_set_tracer(struct trace_array *tr, const char *buf)
+{
+ struct tracer *t;
+#ifdef CONFIG_TRACER_MAX_TRACE
+ bool had_max_tr;
+#endif
+ int ret = 0;
+
+ mutex_lock(&trace_types_lock);
+
+ if (!ring_buffer_expanded) {
+ ret = __tracing_resize_ring_buffer(tr, trace_buf_size,
+ RING_BUFFER_ALL_CPUS);
+ if (ret < 0)
+ goto out;
+ ret = 0;
+ }
+
+ for (t = trace_types; t; t = t->next) {
+ if (strcmp(t->name, buf) == 0)
+ break;
+ }
+ if (!t) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if (t == tr->current_trace)
+ goto out;
+
+#ifdef CONFIG_TRACER_SNAPSHOT
+ if (t->use_max_tr) {
+ local_irq_disable();
+ arch_spin_lock(&tr->max_lock);
+ if (tr->cond_snapshot)
+ ret = -EBUSY;
+ arch_spin_unlock(&tr->max_lock);
+ local_irq_enable();
+ if (ret)
+ goto out;
+ }
+#endif
+ /* Some tracers won't work on kernel command line */
+ if (system_state < SYSTEM_RUNNING && t->noboot) {
+ pr_warn("Tracer '%s' is not allowed on command line, ignored\n",
+ t->name);
+ goto out;
+ }
+
+ /* Some tracers are only allowed for the top level buffer */
+ if (!trace_ok_for_array(t, tr)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* If trace pipe files are being read, we can't change the tracer */
+ if (tr->trace_ref) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ trace_branch_disable();
+
+ tr->current_trace->enabled--;
+
+ if (tr->current_trace->reset)
+ tr->current_trace->reset(tr);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ had_max_tr = tr->current_trace->use_max_tr;
+
+ /* Current trace needs to be nop_trace before synchronize_rcu */
+ tr->current_trace = &nop_trace;
+
+ if (had_max_tr && !t->use_max_tr) {
+ /*
+ * We need to make sure that the update_max_tr sees that
+ * current_trace changed to nop_trace to keep it from
+ * swapping the buffers after we resize it.
+ * The update_max_tr is called from interrupts disabled
+ * so a synchronized_sched() is sufficient.
+ */
+ synchronize_rcu();
+ free_snapshot(tr);
+ }
+
+ if (t->use_max_tr && !tr->allocated_snapshot) {
+ ret = tracing_alloc_snapshot_instance(tr);
+ if (ret < 0)
+ goto out;
+ }
+#else
+ tr->current_trace = &nop_trace;
+#endif
+
+ if (t->init) {
+ ret = tracer_init(t, tr);
+ if (ret)
+ goto out;
+ }
+
+ tr->current_trace = t;
+ tr->current_trace->enabled++;
+ trace_branch_enable(tr);
+ out:
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+}
+
+static ssize_t
+tracing_set_trace_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ char buf[MAX_TRACER_SIZE+1];
+ char *name;
+ size_t ret;
+ int err;
+
+ ret = cnt;
+
+ if (cnt > MAX_TRACER_SIZE)
+ cnt = MAX_TRACER_SIZE;
+
+ if (copy_from_user(buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ name = strim(buf);
+
+ err = tracing_set_tracer(tr, name);
+ if (err)
+ return err;
+
+ *ppos += ret;
+
+ return ret;
+}
+
+static ssize_t
+tracing_nsecs_read(unsigned long *ptr, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ int r;
+
+ r = snprintf(buf, sizeof(buf), "%ld\n",
+ *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
+ if (r > sizeof(buf))
+ r = sizeof(buf);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+tracing_nsecs_write(unsigned long *ptr, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ *ptr = val * 1000;
+
+ return cnt;
+}
+
+static ssize_t
+tracing_thresh_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return tracing_nsecs_read(&tracing_thresh, ubuf, cnt, ppos);
+}
+
+static ssize_t
+tracing_thresh_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ int ret;
+
+ mutex_lock(&trace_types_lock);
+ ret = tracing_nsecs_write(&tracing_thresh, ubuf, cnt, ppos);
+ if (ret < 0)
+ goto out;
+
+ if (tr->current_trace->update_thresh) {
+ ret = tr->current_trace->update_thresh(tr);
+ if (ret < 0)
+ goto out;
+ }
+
+ ret = cnt;
+out:
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+}
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+
+static ssize_t
+tracing_max_lat_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+
+ return tracing_nsecs_read(&tr->max_latency, ubuf, cnt, ppos);
+}
+
+static ssize_t
+tracing_max_lat_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+
+ return tracing_nsecs_write(&tr->max_latency, ubuf, cnt, ppos);
+}
+
+#endif
+
+static int open_pipe_on_cpu(struct trace_array *tr, int cpu)
+{
+ if (cpu == RING_BUFFER_ALL_CPUS) {
+ if (cpumask_empty(tr->pipe_cpumask)) {
+ cpumask_setall(tr->pipe_cpumask);
+ return 0;
+ }
+ } else if (!cpumask_test_cpu(cpu, tr->pipe_cpumask)) {
+ cpumask_set_cpu(cpu, tr->pipe_cpumask);
+ return 0;
+ }
+ return -EBUSY;
+}
+
+static void close_pipe_on_cpu(struct trace_array *tr, int cpu)
+{
+ if (cpu == RING_BUFFER_ALL_CPUS) {
+ WARN_ON(!cpumask_full(tr->pipe_cpumask));
+ cpumask_clear(tr->pipe_cpumask);
+ } else {
+ WARN_ON(!cpumask_test_cpu(cpu, tr->pipe_cpumask));
+ cpumask_clear_cpu(cpu, tr->pipe_cpumask);
+ }
+}
+
+static int tracing_open_pipe(struct inode *inode, struct file *filp)
+{
+ struct trace_array *tr = inode->i_private;
+ struct trace_iterator *iter;
+ int cpu;
+ int ret;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ mutex_lock(&trace_types_lock);
+ cpu = tracing_get_cpu(inode);
+ ret = open_pipe_on_cpu(tr, cpu);
+ if (ret)
+ goto fail_pipe_on_cpu;
+
+ /* create a buffer to store the information to pass to userspace */
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter) {
+ ret = -ENOMEM;
+ goto fail_alloc_iter;
+ }
+
+ trace_seq_init(&iter->seq);
+ iter->trace = tr->current_trace;
+
+ if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ /* trace pipe does not show start of buffer */
+ cpumask_setall(iter->started);
+
+ if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
+ iter->iter_flags |= TRACE_FILE_LAT_FMT;
+
+ /* Output in nanoseconds only if we are using a clock in nanoseconds. */
+ if (trace_clocks[tr->clock_id].in_ns)
+ iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
+
+ iter->tr = tr;
+ iter->array_buffer = &tr->array_buffer;
+ iter->cpu_file = cpu;
+ mutex_init(&iter->mutex);
+ filp->private_data = iter;
+
+ if (iter->trace->pipe_open)
+ iter->trace->pipe_open(iter);
+
+ nonseekable_open(inode, filp);
+
+ tr->trace_ref++;
+
+ mutex_unlock(&trace_types_lock);
+ return ret;
+
+fail:
+ kfree(iter);
+fail_alloc_iter:
+ close_pipe_on_cpu(tr, cpu);
+fail_pipe_on_cpu:
+ __trace_array_put(tr);
+ mutex_unlock(&trace_types_lock);
+ return ret;
+}
+
+static int tracing_release_pipe(struct inode *inode, struct file *file)
+{
+ struct trace_iterator *iter = file->private_data;
+ struct trace_array *tr = inode->i_private;
+
+ mutex_lock(&trace_types_lock);
+
+ tr->trace_ref--;
+
+ if (iter->trace->pipe_close)
+ iter->trace->pipe_close(iter);
+ close_pipe_on_cpu(tr, iter->cpu_file);
+ mutex_unlock(&trace_types_lock);
+
+ free_trace_iter_content(iter);
+ kfree(iter);
+
+ trace_array_put(tr);
+
+ return 0;
+}
+
+static __poll_t
+trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table)
+{
+ struct trace_array *tr = iter->tr;
+
+ /* Iterators are static, they should be filled or empty */
+ if (trace_buffer_iter(iter, iter->cpu_file))
+ return EPOLLIN | EPOLLRDNORM;
+
+ if (tr->trace_flags & TRACE_ITER_BLOCK)
+ /*
+ * Always select as readable when in blocking mode
+ */
+ return EPOLLIN | EPOLLRDNORM;
+ else
+ return ring_buffer_poll_wait(iter->array_buffer->buffer, iter->cpu_file,
+ filp, poll_table, iter->tr->buffer_percent);
+}
+
+static __poll_t
+tracing_poll_pipe(struct file *filp, poll_table *poll_table)
+{
+ struct trace_iterator *iter = filp->private_data;
+
+ return trace_poll(iter, filp, poll_table);
+}
+
+/* Must be called with iter->mutex held. */
+static int tracing_wait_pipe(struct file *filp)
+{
+ struct trace_iterator *iter = filp->private_data;
+ int ret;
+
+ while (trace_empty(iter)) {
+
+ if ((filp->f_flags & O_NONBLOCK)) {
+ return -EAGAIN;
+ }
+
+ /*
+ * We block until we read something and tracing is disabled.
+ * We still block if tracing is disabled, but we have never
+ * read anything. This allows a user to cat this file, and
+ * then enable tracing. But after we have read something,
+ * we give an EOF when tracing is again disabled.
+ *
+ * iter->pos will be 0 if we haven't read anything.
+ */
+ if (!tracer_tracing_is_on(iter->tr) && iter->pos)
+ break;
+
+ mutex_unlock(&iter->mutex);
+
+ ret = wait_on_pipe(iter, 0);
+
+ mutex_lock(&iter->mutex);
+
+ if (ret)
+ return ret;
+ }
+
+ return 1;
+}
+
+/*
+ * Consumer reader.
+ */
+static ssize_t
+tracing_read_pipe(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_iterator *iter = filp->private_data;
+ ssize_t sret;
+
+ /*
+ * Avoid more than one consumer on a single file descriptor
+ * This is just a matter of traces coherency, the ring buffer itself
+ * is protected.
+ */
+ mutex_lock(&iter->mutex);
+
+ /* return any leftover data */
+ sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
+ if (sret != -EBUSY)
+ goto out;
+
+ trace_seq_init(&iter->seq);
+
+ if (iter->trace->read) {
+ sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
+ if (sret)
+ goto out;
+ }
+
+waitagain:
+ sret = tracing_wait_pipe(filp);
+ if (sret <= 0)
+ goto out;
+
+ /* stop when tracing is finished */
+ if (trace_empty(iter)) {
+ sret = 0;
+ goto out;
+ }
+
+ if (cnt >= PAGE_SIZE)
+ cnt = PAGE_SIZE - 1;
+
+ /* reset all but tr, trace, and overruns */
+ trace_iterator_reset(iter);
+ cpumask_clear(iter->started);
+ trace_seq_init(&iter->seq);
+
+ trace_event_read_lock();
+ trace_access_lock(iter->cpu_file);
+ while (trace_find_next_entry_inc(iter) != NULL) {
+ enum print_line_t ret;
+ int save_len = iter->seq.seq.len;
+
+ ret = print_trace_line(iter);
+ if (ret == TRACE_TYPE_PARTIAL_LINE) {
+ /*
+ * If one print_trace_line() fills entire trace_seq in one shot,
+ * trace_seq_to_user() will returns -EBUSY because save_len == 0,
+ * In this case, we need to consume it, otherwise, loop will peek
+ * this event next time, resulting in an infinite loop.
+ */
+ if (save_len == 0) {
+ iter->seq.full = 0;
+ trace_seq_puts(&iter->seq, "[LINE TOO BIG]\n");
+ trace_consume(iter);
+ break;
+ }
+
+ /* In other cases, don't print partial lines */
+ iter->seq.seq.len = save_len;
+ break;
+ }
+ if (ret != TRACE_TYPE_NO_CONSUME)
+ trace_consume(iter);
+
+ if (trace_seq_used(&iter->seq) >= cnt)
+ break;
+
+ /*
+ * Setting the full flag means we reached the trace_seq buffer
+ * size and we should leave by partial output condition above.
+ * One of the trace_seq_* functions is not used properly.
+ */
+ WARN_ONCE(iter->seq.full, "full flag set for trace type %d",
+ iter->ent->type);
+ }
+ trace_access_unlock(iter->cpu_file);
+ trace_event_read_unlock();
+
+ /* Now copy what we have to the user */
+ sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
+ if (iter->seq.seq.readpos >= trace_seq_used(&iter->seq))
+ trace_seq_init(&iter->seq);
+
+ /*
+ * If there was nothing to send to user, in spite of consuming trace
+ * entries, go back to wait for more entries.
+ */
+ if (sret == -EBUSY)
+ goto waitagain;
+
+out:
+ mutex_unlock(&iter->mutex);
+
+ return sret;
+}
+
+static void tracing_spd_release_pipe(struct splice_pipe_desc *spd,
+ unsigned int idx)
+{
+ __free_page(spd->pages[idx]);
+}
+
+static size_t
+tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
+{
+ size_t count;
+ int save_len;
+ int ret;
+
+ /* Seq buffer is page-sized, exactly what we need. */
+ for (;;) {
+ save_len = iter->seq.seq.len;
+ ret = print_trace_line(iter);
+
+ if (trace_seq_has_overflowed(&iter->seq)) {
+ iter->seq.seq.len = save_len;
+ break;
+ }
+
+ /*
+ * This should not be hit, because it should only
+ * be set if the iter->seq overflowed. But check it
+ * anyway to be safe.
+ */
+ if (ret == TRACE_TYPE_PARTIAL_LINE) {
+ iter->seq.seq.len = save_len;
+ break;
+ }
+
+ count = trace_seq_used(&iter->seq) - save_len;
+ if (rem < count) {
+ rem = 0;
+ iter->seq.seq.len = save_len;
+ break;
+ }
+
+ if (ret != TRACE_TYPE_NO_CONSUME)
+ trace_consume(iter);
+ rem -= count;
+ if (!trace_find_next_entry_inc(iter)) {
+ rem = 0;
+ iter->ent = NULL;
+ break;
+ }
+ }
+
+ return rem;
+}
+
+static ssize_t tracing_splice_read_pipe(struct file *filp,
+ loff_t *ppos,
+ struct pipe_inode_info *pipe,
+ size_t len,
+ unsigned int flags)
+{
+ struct page *pages_def[PIPE_DEF_BUFFERS];
+ struct partial_page partial_def[PIPE_DEF_BUFFERS];
+ struct trace_iterator *iter = filp->private_data;
+ struct splice_pipe_desc spd = {
+ .pages = pages_def,
+ .partial = partial_def,
+ .nr_pages = 0, /* This gets updated below. */
+ .nr_pages_max = PIPE_DEF_BUFFERS,
+ .ops = &default_pipe_buf_ops,
+ .spd_release = tracing_spd_release_pipe,
+ };
+ ssize_t ret;
+ size_t rem;
+ unsigned int i;
+
+ if (splice_grow_spd(pipe, &spd))
+ return -ENOMEM;
+
+ mutex_lock(&iter->mutex);
+
+ if (iter->trace->splice_read) {
+ ret = iter->trace->splice_read(iter, filp,
+ ppos, pipe, len, flags);
+ if (ret)
+ goto out_err;
+ }
+
+ ret = tracing_wait_pipe(filp);
+ if (ret <= 0)
+ goto out_err;
+
+ if (!iter->ent && !trace_find_next_entry_inc(iter)) {
+ ret = -EFAULT;
+ goto out_err;
+ }
+
+ trace_event_read_lock();
+ trace_access_lock(iter->cpu_file);
+
+ /* Fill as many pages as possible. */
+ for (i = 0, rem = len; i < spd.nr_pages_max && rem; i++) {
+ spd.pages[i] = alloc_page(GFP_KERNEL);
+ if (!spd.pages[i])
+ break;
+
+ rem = tracing_fill_pipe_page(rem, iter);
+
+ /* Copy the data into the page, so we can start over. */
+ ret = trace_seq_to_buffer(&iter->seq,
+ page_address(spd.pages[i]),
+ trace_seq_used(&iter->seq));
+ if (ret < 0) {
+ __free_page(spd.pages[i]);
+ break;
+ }
+ spd.partial[i].offset = 0;
+ spd.partial[i].len = trace_seq_used(&iter->seq);
+
+ trace_seq_init(&iter->seq);
+ }
+
+ trace_access_unlock(iter->cpu_file);
+ trace_event_read_unlock();
+ mutex_unlock(&iter->mutex);
+
+ spd.nr_pages = i;
+
+ if (i)
+ ret = splice_to_pipe(pipe, &spd);
+ else
+ ret = 0;
+out:
+ splice_shrink_spd(&spd);
+ return ret;
+
+out_err:
+ mutex_unlock(&iter->mutex);
+ goto out;
+}
+
+static ssize_t
+tracing_entries_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct inode *inode = file_inode(filp);
+ struct trace_array *tr = inode->i_private;
+ int cpu = tracing_get_cpu(inode);
+ char buf[64];
+ int r = 0;
+ ssize_t ret;
+
+ mutex_lock(&trace_types_lock);
+
+ if (cpu == RING_BUFFER_ALL_CPUS) {
+ int cpu, buf_size_same;
+ unsigned long size;
+
+ size = 0;
+ buf_size_same = 1;
+ /* check if all cpu sizes are same */
+ for_each_tracing_cpu(cpu) {
+ /* fill in the size from first enabled cpu */
+ if (size == 0)
+ size = per_cpu_ptr(tr->array_buffer.data, cpu)->entries;
+ if (size != per_cpu_ptr(tr->array_buffer.data, cpu)->entries) {
+ buf_size_same = 0;
+ break;
+ }
+ }
+
+ if (buf_size_same) {
+ if (!ring_buffer_expanded)
+ r = sprintf(buf, "%lu (expanded: %lu)\n",
+ size >> 10,
+ trace_buf_size >> 10);
+ else
+ r = sprintf(buf, "%lu\n", size >> 10);
+ } else
+ r = sprintf(buf, "X\n");
+ } else
+ r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10);
+
+ mutex_unlock(&trace_types_lock);
+
+ ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+ return ret;
+}
+
+static ssize_t
+tracing_entries_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct inode *inode = file_inode(filp);
+ struct trace_array *tr = inode->i_private;
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ /* must have at least 1 entry */
+ if (!val)
+ return -EINVAL;
+
+ /* value is in KB */
+ val <<= 10;
+ ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode));
+ if (ret < 0)
+ return ret;
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static ssize_t
+tracing_total_entries_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ char buf[64];
+ int r, cpu;
+ unsigned long size = 0, expanded_size = 0;
+
+ mutex_lock(&trace_types_lock);
+ for_each_tracing_cpu(cpu) {
+ size += per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10;
+ if (!ring_buffer_expanded)
+ expanded_size += trace_buf_size >> 10;
+ }
+ if (ring_buffer_expanded)
+ r = sprintf(buf, "%lu\n", size);
+ else
+ r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size);
+ mutex_unlock(&trace_types_lock);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+tracing_free_buffer_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ /*
+ * There is no need to read what the user has written, this function
+ * is just to make sure that there is no error when "echo" is used
+ */
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static int
+tracing_free_buffer_release(struct inode *inode, struct file *filp)
+{
+ struct trace_array *tr = inode->i_private;
+
+ /* disable tracing ? */
+ if (tr->trace_flags & TRACE_ITER_STOP_ON_FREE)
+ tracer_tracing_off(tr);
+ /* resize the ring buffer to 0 */
+ tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS);
+
+ trace_array_put(tr);
+
+ return 0;
+}
+
+static ssize_t
+tracing_mark_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *fpos)
+{
+ struct trace_array *tr = filp->private_data;
+ struct ring_buffer_event *event;
+ enum event_trigger_type tt = ETT_NONE;
+ struct trace_buffer *buffer;
+ struct print_entry *entry;
+ ssize_t written;
+ int size;
+ int len;
+
+/* Used in tracing_mark_raw_write() as well */
+#define FAULTED_STR "<faulted>"
+#define FAULTED_SIZE (sizeof(FAULTED_STR) - 1) /* '\0' is already accounted for */
+
+ if (tracing_disabled)
+ return -EINVAL;
+
+ if (!(tr->trace_flags & TRACE_ITER_MARKERS))
+ return -EINVAL;
+
+ if (cnt > TRACE_BUF_SIZE)
+ cnt = TRACE_BUF_SIZE;
+
+ BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE);
+
+ size = sizeof(*entry) + cnt + 2; /* add '\0' and possible '\n' */
+
+ /* If less than "<faulted>", then make sure we can still add that */
+ if (cnt < FAULTED_SIZE)
+ size += FAULTED_SIZE - cnt;
+
+ buffer = tr->array_buffer.buffer;
+ event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
+ tracing_gen_ctx());
+ if (unlikely(!event))
+ /* Ring buffer disabled, return as if not open for write */
+ return -EBADF;
+
+ entry = ring_buffer_event_data(event);
+ entry->ip = _THIS_IP_;
+
+ len = __copy_from_user_inatomic(&entry->buf, ubuf, cnt);
+ if (len) {
+ memcpy(&entry->buf, FAULTED_STR, FAULTED_SIZE);
+ cnt = FAULTED_SIZE;
+ written = -EFAULT;
+ } else
+ written = cnt;
+
+ if (tr->trace_marker_file && !list_empty(&tr->trace_marker_file->triggers)) {
+ /* do not add \n before testing triggers, but add \0 */
+ entry->buf[cnt] = '\0';
+ tt = event_triggers_call(tr->trace_marker_file, buffer, entry, event);
+ }
+
+ if (entry->buf[cnt - 1] != '\n') {
+ entry->buf[cnt] = '\n';
+ entry->buf[cnt + 1] = '\0';
+ } else
+ entry->buf[cnt] = '\0';
+
+ if (static_branch_unlikely(&trace_marker_exports_enabled))
+ ftrace_exports(event, TRACE_EXPORT_MARKER);
+ __buffer_unlock_commit(buffer, event);
+
+ if (tt)
+ event_triggers_post_call(tr->trace_marker_file, tt);
+
+ return written;
+}
+
+/* Limit it for now to 3K (including tag) */
+#define RAW_DATA_MAX_SIZE (1024*3)
+
+static ssize_t
+tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *fpos)
+{
+ struct trace_array *tr = filp->private_data;
+ struct ring_buffer_event *event;
+ struct trace_buffer *buffer;
+ struct raw_data_entry *entry;
+ ssize_t written;
+ int size;
+ int len;
+
+#define FAULT_SIZE_ID (FAULTED_SIZE + sizeof(int))
+
+ if (tracing_disabled)
+ return -EINVAL;
+
+ if (!(tr->trace_flags & TRACE_ITER_MARKERS))
+ return -EINVAL;
+
+ /* The marker must at least have a tag id */
+ if (cnt < sizeof(unsigned int) || cnt > RAW_DATA_MAX_SIZE)
+ return -EINVAL;
+
+ if (cnt > TRACE_BUF_SIZE)
+ cnt = TRACE_BUF_SIZE;
+
+ BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE);
+
+ size = sizeof(*entry) + cnt;
+ if (cnt < FAULT_SIZE_ID)
+ size += FAULT_SIZE_ID - cnt;
+
+ buffer = tr->array_buffer.buffer;
+ event = __trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size,
+ tracing_gen_ctx());
+ if (!event)
+ /* Ring buffer disabled, return as if not open for write */
+ return -EBADF;
+
+ entry = ring_buffer_event_data(event);
+
+ len = __copy_from_user_inatomic(&entry->id, ubuf, cnt);
+ if (len) {
+ entry->id = -1;
+ memcpy(&entry->buf, FAULTED_STR, FAULTED_SIZE);
+ written = -EFAULT;
+ } else
+ written = cnt;
+
+ __buffer_unlock_commit(buffer, event);
+
+ return written;
+}
+
+static int tracing_clock_show(struct seq_file *m, void *v)
+{
+ struct trace_array *tr = m->private;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(trace_clocks); i++)
+ seq_printf(m,
+ "%s%s%s%s", i ? " " : "",
+ i == tr->clock_id ? "[" : "", trace_clocks[i].name,
+ i == tr->clock_id ? "]" : "");
+ seq_putc(m, '\n');
+
+ return 0;
+}
+
+int tracing_set_clock(struct trace_array *tr, const char *clockstr)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) {
+ if (strcmp(trace_clocks[i].name, clockstr) == 0)
+ break;
+ }
+ if (i == ARRAY_SIZE(trace_clocks))
+ return -EINVAL;
+
+ mutex_lock(&trace_types_lock);
+
+ tr->clock_id = i;
+
+ ring_buffer_set_clock(tr->array_buffer.buffer, trace_clocks[i].func);
+
+ /*
+ * New clock may not be consistent with the previous clock.
+ * Reset the buffer so that it doesn't have incomparable timestamps.
+ */
+ tracing_reset_online_cpus(&tr->array_buffer);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (tr->max_buffer.buffer)
+ ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
+ tracing_reset_online_cpus(&tr->max_buffer);
+#endif
+
+ mutex_unlock(&trace_types_lock);
+
+ return 0;
+}
+
+static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *fpos)
+{
+ struct seq_file *m = filp->private_data;
+ struct trace_array *tr = m->private;
+ char buf[64];
+ const char *clockstr;
+ int ret;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ clockstr = strstrip(buf);
+
+ ret = tracing_set_clock(tr, clockstr);
+ if (ret)
+ return ret;
+
+ *fpos += cnt;
+
+ return cnt;
+}
+
+static int tracing_clock_open(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+ int ret;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ ret = single_open(file, tracing_clock_show, inode->i_private);
+ if (ret < 0)
+ trace_array_put(tr);
+
+ return ret;
+}
+
+static int tracing_time_stamp_mode_show(struct seq_file *m, void *v)
+{
+ struct trace_array *tr = m->private;
+
+ mutex_lock(&trace_types_lock);
+
+ if (ring_buffer_time_stamp_abs(tr->array_buffer.buffer))
+ seq_puts(m, "delta [absolute]\n");
+ else
+ seq_puts(m, "[delta] absolute\n");
+
+ mutex_unlock(&trace_types_lock);
+
+ return 0;
+}
+
+static int tracing_time_stamp_mode_open(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+ int ret;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ ret = single_open(file, tracing_time_stamp_mode_show, inode->i_private);
+ if (ret < 0)
+ trace_array_put(tr);
+
+ return ret;
+}
+
+u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe)
+{
+ if (rbe == this_cpu_read(trace_buffered_event))
+ return ring_buffer_time_stamp(buffer);
+
+ return ring_buffer_event_time_stamp(buffer, rbe);
+}
+
+/*
+ * Set or disable using the per CPU trace_buffer_event when possible.
+ */
+int tracing_set_filter_buffering(struct trace_array *tr, bool set)
+{
+ int ret = 0;
+
+ mutex_lock(&trace_types_lock);
+
+ if (set && tr->no_filter_buffering_ref++)
+ goto out;
+
+ if (!set) {
+ if (WARN_ON_ONCE(!tr->no_filter_buffering_ref)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ --tr->no_filter_buffering_ref;
+ }
+ out:
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+}
+
+struct ftrace_buffer_info {
+ struct trace_iterator iter;
+ void *spare;
+ unsigned int spare_cpu;
+ unsigned int read;
+};
+
+#ifdef CONFIG_TRACER_SNAPSHOT
+static int tracing_snapshot_open(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+ struct trace_iterator *iter;
+ struct seq_file *m;
+ int ret;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ if (file->f_mode & FMODE_READ) {
+ iter = __tracing_open(inode, file, true);
+ if (IS_ERR(iter))
+ ret = PTR_ERR(iter);
+ } else {
+ /* Writes still need the seq_file to hold the private data */
+ ret = -ENOMEM;
+ m = kzalloc(sizeof(*m), GFP_KERNEL);
+ if (!m)
+ goto out;
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter) {
+ kfree(m);
+ goto out;
+ }
+ ret = 0;
+
+ iter->tr = tr;
+ iter->array_buffer = &tr->max_buffer;
+ iter->cpu_file = tracing_get_cpu(inode);
+ m->private = iter;
+ file->private_data = m;
+ }
+out:
+ if (ret < 0)
+ trace_array_put(tr);
+
+ return ret;
+}
+
+static void tracing_swap_cpu_buffer(void *tr)
+{
+ update_max_tr_single((struct trace_array *)tr, current, smp_processor_id());
+}
+
+static ssize_t
+tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct seq_file *m = filp->private_data;
+ struct trace_iterator *iter = m->private;
+ struct trace_array *tr = iter->tr;
+ unsigned long val;
+ int ret;
+
+ ret = tracing_update_buffers();
+ if (ret < 0)
+ return ret;
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ mutex_lock(&trace_types_lock);
+
+ if (tr->current_trace->use_max_tr) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ local_irq_disable();
+ arch_spin_lock(&tr->max_lock);
+ if (tr->cond_snapshot)
+ ret = -EBUSY;
+ arch_spin_unlock(&tr->max_lock);
+ local_irq_enable();
+ if (ret)
+ goto out;
+
+ switch (val) {
+ case 0:
+ if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
+ ret = -EINVAL;
+ break;
+ }
+ if (tr->allocated_snapshot)
+ free_snapshot(tr);
+ break;
+ case 1:
+/* Only allow per-cpu swap if the ring buffer supports it */
+#ifndef CONFIG_RING_BUFFER_ALLOW_SWAP
+ if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
+ ret = -EINVAL;
+ break;
+ }
+#endif
+ if (tr->allocated_snapshot)
+ ret = resize_buffer_duplicate_size(&tr->max_buffer,
+ &tr->array_buffer, iter->cpu_file);
+ else
+ ret = tracing_alloc_snapshot_instance(tr);
+ if (ret < 0)
+ break;
+ /* Now, we're going to swap */
+ if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
+ local_irq_disable();
+ update_max_tr(tr, current, smp_processor_id(), NULL);
+ local_irq_enable();
+ } else {
+ smp_call_function_single(iter->cpu_file, tracing_swap_cpu_buffer,
+ (void *)tr, 1);
+ }
+ break;
+ default:
+ if (tr->allocated_snapshot) {
+ if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
+ tracing_reset_online_cpus(&tr->max_buffer);
+ else
+ tracing_reset_cpu(&tr->max_buffer, iter->cpu_file);
+ }
+ break;
+ }
+
+ if (ret >= 0) {
+ *ppos += cnt;
+ ret = cnt;
+ }
+out:
+ mutex_unlock(&trace_types_lock);
+ return ret;
+}
+
+static int tracing_snapshot_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *m = file->private_data;
+ int ret;
+
+ ret = tracing_release(inode, file);
+
+ if (file->f_mode & FMODE_READ)
+ return ret;
+
+ /* If write only, the seq_file is just a stub */
+ if (m)
+ kfree(m->private);
+ kfree(m);
+
+ return 0;
+}
+
+static int tracing_buffers_open(struct inode *inode, struct file *filp);
+static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *ppos);
+static int tracing_buffers_release(struct inode *inode, struct file *file);
+static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len, unsigned int flags);
+
+static int snapshot_raw_open(struct inode *inode, struct file *filp)
+{
+ struct ftrace_buffer_info *info;
+ int ret;
+
+ /* The following checks for tracefs lockdown */
+ ret = tracing_buffers_open(inode, filp);
+ if (ret < 0)
+ return ret;
+
+ info = filp->private_data;
+
+ if (info->iter.trace->use_max_tr) {
+ tracing_buffers_release(inode, filp);
+ return -EBUSY;
+ }
+
+ info->iter.snapshot = true;
+ info->iter.array_buffer = &info->iter.tr->max_buffer;
+
+ return ret;
+}
+
+#endif /* CONFIG_TRACER_SNAPSHOT */
+
+
+static const struct file_operations tracing_thresh_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_thresh_read,
+ .write = tracing_thresh_write,
+ .llseek = generic_file_llseek,
+};
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+static const struct file_operations tracing_max_lat_fops = {
+ .open = tracing_open_generic_tr,
+ .read = tracing_max_lat_read,
+ .write = tracing_max_lat_write,
+ .llseek = generic_file_llseek,
+ .release = tracing_release_generic_tr,
+};
+#endif
+
+static const struct file_operations set_tracer_fops = {
+ .open = tracing_open_generic_tr,
+ .read = tracing_set_trace_read,
+ .write = tracing_set_trace_write,
+ .llseek = generic_file_llseek,
+ .release = tracing_release_generic_tr,
+};
+
+static const struct file_operations tracing_pipe_fops = {
+ .open = tracing_open_pipe,
+ .poll = tracing_poll_pipe,
+ .read = tracing_read_pipe,
+ .splice_read = tracing_splice_read_pipe,
+ .release = tracing_release_pipe,
+ .llseek = no_llseek,
+};
+
+static const struct file_operations tracing_entries_fops = {
+ .open = tracing_open_generic_tr,
+ .read = tracing_entries_read,
+ .write = tracing_entries_write,
+ .llseek = generic_file_llseek,
+ .release = tracing_release_generic_tr,
+};
+
+static const struct file_operations tracing_total_entries_fops = {
+ .open = tracing_open_generic_tr,
+ .read = tracing_total_entries_read,
+ .llseek = generic_file_llseek,
+ .release = tracing_release_generic_tr,
+};
+
+static const struct file_operations tracing_free_buffer_fops = {
+ .open = tracing_open_generic_tr,
+ .write = tracing_free_buffer_write,
+ .release = tracing_free_buffer_release,
+};
+
+static const struct file_operations tracing_mark_fops = {
+ .open = tracing_mark_open,
+ .write = tracing_mark_write,
+ .release = tracing_release_generic_tr,
+};
+
+static const struct file_operations tracing_mark_raw_fops = {
+ .open = tracing_mark_open,
+ .write = tracing_mark_raw_write,
+ .release = tracing_release_generic_tr,
+};
+
+static const struct file_operations trace_clock_fops = {
+ .open = tracing_clock_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = tracing_single_release_tr,
+ .write = tracing_clock_write,
+};
+
+static const struct file_operations trace_time_stamp_mode_fops = {
+ .open = tracing_time_stamp_mode_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = tracing_single_release_tr,
+};
+
+#ifdef CONFIG_TRACER_SNAPSHOT
+static const struct file_operations snapshot_fops = {
+ .open = tracing_snapshot_open,
+ .read = seq_read,
+ .write = tracing_snapshot_write,
+ .llseek = tracing_lseek,
+ .release = tracing_snapshot_release,
+};
+
+static const struct file_operations snapshot_raw_fops = {
+ .open = snapshot_raw_open,
+ .read = tracing_buffers_read,
+ .release = tracing_buffers_release,
+ .splice_read = tracing_buffers_splice_read,
+ .llseek = no_llseek,
+};
+
+#endif /* CONFIG_TRACER_SNAPSHOT */
+
+/*
+ * trace_min_max_write - Write a u64 value to a trace_min_max_param struct
+ * @filp: The active open file structure
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function implements the write interface for a struct trace_min_max_param.
+ * The filp->private_data must point to a trace_min_max_param structure that
+ * defines where to write the value, the min and the max acceptable values,
+ * and a lock to protect the write.
+ */
+static ssize_t
+trace_min_max_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ struct trace_min_max_param *param = filp->private_data;
+ u64 val;
+ int err;
+
+ if (!param)
+ return -EFAULT;
+
+ err = kstrtoull_from_user(ubuf, cnt, 10, &val);
+ if (err)
+ return err;
+
+ if (param->lock)
+ mutex_lock(param->lock);
+
+ if (param->min && val < *param->min)
+ err = -EINVAL;
+
+ if (param->max && val > *param->max)
+ err = -EINVAL;
+
+ if (!err)
+ *param->val = val;
+
+ if (param->lock)
+ mutex_unlock(param->lock);
+
+ if (err)
+ return err;
+
+ return cnt;
+}
+
+/*
+ * trace_min_max_read - Read a u64 value from a trace_min_max_param struct
+ * @filp: The active open file structure
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function implements the read interface for a struct trace_min_max_param.
+ * The filp->private_data must point to a trace_min_max_param struct with valid
+ * data.
+ */
+static ssize_t
+trace_min_max_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ struct trace_min_max_param *param = filp->private_data;
+ char buf[U64_STR_SIZE];
+ int len;
+ u64 val;
+
+ if (!param)
+ return -EFAULT;
+
+ val = *param->val;
+
+ if (cnt > sizeof(buf))
+ cnt = sizeof(buf);
+
+ len = snprintf(buf, sizeof(buf), "%llu\n", val);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
+}
+
+const struct file_operations trace_min_max_fops = {
+ .open = tracing_open_generic,
+ .read = trace_min_max_read,
+ .write = trace_min_max_write,
+};
+
+#define TRACING_LOG_ERRS_MAX 8
+#define TRACING_LOG_LOC_MAX 128
+
+#define CMD_PREFIX " Command: "
+
+struct err_info {
+ const char **errs; /* ptr to loc-specific array of err strings */
+ u8 type; /* index into errs -> specific err string */
+ u16 pos; /* caret position */
+ u64 ts;
+};
+
+struct tracing_log_err {
+ struct list_head list;
+ struct err_info info;
+ char loc[TRACING_LOG_LOC_MAX]; /* err location */
+ char *cmd; /* what caused err */
+};
+
+static DEFINE_MUTEX(tracing_err_log_lock);
+
+static struct tracing_log_err *alloc_tracing_log_err(int len)
+{
+ struct tracing_log_err *err;
+
+ err = kzalloc(sizeof(*err), GFP_KERNEL);
+ if (!err)
+ return ERR_PTR(-ENOMEM);
+
+ err->cmd = kzalloc(len, GFP_KERNEL);
+ if (!err->cmd) {
+ kfree(err);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return err;
+}
+
+static void free_tracing_log_err(struct tracing_log_err *err)
+{
+ kfree(err->cmd);
+ kfree(err);
+}
+
+static struct tracing_log_err *get_tracing_log_err(struct trace_array *tr,
+ int len)
+{
+ struct tracing_log_err *err;
+ char *cmd;
+
+ if (tr->n_err_log_entries < TRACING_LOG_ERRS_MAX) {
+ err = alloc_tracing_log_err(len);
+ if (PTR_ERR(err) != -ENOMEM)
+ tr->n_err_log_entries++;
+
+ return err;
+ }
+ cmd = kzalloc(len, GFP_KERNEL);
+ if (!cmd)
+ return ERR_PTR(-ENOMEM);
+ err = list_first_entry(&tr->err_log, struct tracing_log_err, list);
+ kfree(err->cmd);
+ err->cmd = cmd;
+ list_del(&err->list);
+
+ return err;
+}
+
+/**
+ * err_pos - find the position of a string within a command for error careting
+ * @cmd: The tracing command that caused the error
+ * @str: The string to position the caret at within @cmd
+ *
+ * Finds the position of the first occurrence of @str within @cmd. The
+ * return value can be passed to tracing_log_err() for caret placement
+ * within @cmd.
+ *
+ * Returns the index within @cmd of the first occurrence of @str or 0
+ * if @str was not found.
+ */
+unsigned int err_pos(char *cmd, const char *str)
+{
+ char *found;
+
+ if (WARN_ON(!strlen(cmd)))
+ return 0;
+
+ found = strstr(cmd, str);
+ if (found)
+ return found - cmd;
+
+ return 0;
+}
+
+/**
+ * tracing_log_err - write an error to the tracing error log
+ * @tr: The associated trace array for the error (NULL for top level array)
+ * @loc: A string describing where the error occurred
+ * @cmd: The tracing command that caused the error
+ * @errs: The array of loc-specific static error strings
+ * @type: The index into errs[], which produces the specific static err string
+ * @pos: The position the caret should be placed in the cmd
+ *
+ * Writes an error into tracing/error_log of the form:
+ *
+ * <loc>: error: <text>
+ * Command: <cmd>
+ * ^
+ *
+ * tracing/error_log is a small log file containing the last
+ * TRACING_LOG_ERRS_MAX errors (8). Memory for errors isn't allocated
+ * unless there has been a tracing error, and the error log can be
+ * cleared and have its memory freed by writing the empty string in
+ * truncation mode to it i.e. echo > tracing/error_log.
+ *
+ * NOTE: the @errs array along with the @type param are used to
+ * produce a static error string - this string is not copied and saved
+ * when the error is logged - only a pointer to it is saved. See
+ * existing callers for examples of how static strings are typically
+ * defined for use with tracing_log_err().
+ */
+void tracing_log_err(struct trace_array *tr,
+ const char *loc, const char *cmd,
+ const char **errs, u8 type, u16 pos)
+{
+ struct tracing_log_err *err;
+ int len = 0;
+
+ if (!tr)
+ tr = &global_trace;
+
+ len += sizeof(CMD_PREFIX) + 2 * sizeof("\n") + strlen(cmd) + 1;
+
+ mutex_lock(&tracing_err_log_lock);
+ err = get_tracing_log_err(tr, len);
+ if (PTR_ERR(err) == -ENOMEM) {
+ mutex_unlock(&tracing_err_log_lock);
+ return;
+ }
+
+ snprintf(err->loc, TRACING_LOG_LOC_MAX, "%s: error: ", loc);
+ snprintf(err->cmd, len, "\n" CMD_PREFIX "%s\n", cmd);
+
+ err->info.errs = errs;
+ err->info.type = type;
+ err->info.pos = pos;
+ err->info.ts = local_clock();
+
+ list_add_tail(&err->list, &tr->err_log);
+ mutex_unlock(&tracing_err_log_lock);
+}
+
+static void clear_tracing_err_log(struct trace_array *tr)
+{
+ struct tracing_log_err *err, *next;
+
+ mutex_lock(&tracing_err_log_lock);
+ list_for_each_entry_safe(err, next, &tr->err_log, list) {
+ list_del(&err->list);
+ free_tracing_log_err(err);
+ }
+
+ tr->n_err_log_entries = 0;
+ mutex_unlock(&tracing_err_log_lock);
+}
+
+static void *tracing_err_log_seq_start(struct seq_file *m, loff_t *pos)
+{
+ struct trace_array *tr = m->private;
+
+ mutex_lock(&tracing_err_log_lock);
+
+ return seq_list_start(&tr->err_log, *pos);
+}
+
+static void *tracing_err_log_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct trace_array *tr = m->private;
+
+ return seq_list_next(v, &tr->err_log, pos);
+}
+
+static void tracing_err_log_seq_stop(struct seq_file *m, void *v)
+{
+ mutex_unlock(&tracing_err_log_lock);
+}
+
+static void tracing_err_log_show_pos(struct seq_file *m, u16 pos)
+{
+ u16 i;
+
+ for (i = 0; i < sizeof(CMD_PREFIX) - 1; i++)
+ seq_putc(m, ' ');
+ for (i = 0; i < pos; i++)
+ seq_putc(m, ' ');
+ seq_puts(m, "^\n");
+}
+
+static int tracing_err_log_seq_show(struct seq_file *m, void *v)
+{
+ struct tracing_log_err *err = v;
+
+ if (err) {
+ const char *err_text = err->info.errs[err->info.type];
+ u64 sec = err->info.ts;
+ u32 nsec;
+
+ nsec = do_div(sec, NSEC_PER_SEC);
+ seq_printf(m, "[%5llu.%06u] %s%s", sec, nsec / 1000,
+ err->loc, err_text);
+ seq_printf(m, "%s", err->cmd);
+ tracing_err_log_show_pos(m, err->info.pos);
+ }
+
+ return 0;
+}
+
+static const struct seq_operations tracing_err_log_seq_ops = {
+ .start = tracing_err_log_seq_start,
+ .next = tracing_err_log_seq_next,
+ .stop = tracing_err_log_seq_stop,
+ .show = tracing_err_log_seq_show
+};
+
+static int tracing_err_log_open(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+ int ret = 0;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ /* If this file was opened for write, then erase contents */
+ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC))
+ clear_tracing_err_log(tr);
+
+ if (file->f_mode & FMODE_READ) {
+ ret = seq_open(file, &tracing_err_log_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = tr;
+ } else {
+ trace_array_put(tr);
+ }
+ }
+ return ret;
+}
+
+static ssize_t tracing_err_log_write(struct file *file,
+ const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ return count;
+}
+
+static int tracing_err_log_release(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+
+ trace_array_put(tr);
+
+ if (file->f_mode & FMODE_READ)
+ seq_release(inode, file);
+
+ return 0;
+}
+
+static const struct file_operations tracing_err_log_fops = {
+ .open = tracing_err_log_open,
+ .write = tracing_err_log_write,
+ .read = seq_read,
+ .llseek = tracing_lseek,
+ .release = tracing_err_log_release,
+};
+
+static int tracing_buffers_open(struct inode *inode, struct file *filp)
+{
+ struct trace_array *tr = inode->i_private;
+ struct ftrace_buffer_info *info;
+ int ret;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ info = kvzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info) {
+ trace_array_put(tr);
+ return -ENOMEM;
+ }
+
+ mutex_lock(&trace_types_lock);
+
+ info->iter.tr = tr;
+ info->iter.cpu_file = tracing_get_cpu(inode);
+ info->iter.trace = tr->current_trace;
+ info->iter.array_buffer = &tr->array_buffer;
+ info->spare = NULL;
+ /* Force reading ring buffer for first read */
+ info->read = (unsigned int)-1;
+
+ filp->private_data = info;
+
+ tr->trace_ref++;
+
+ mutex_unlock(&trace_types_lock);
+
+ ret = nonseekable_open(inode, filp);
+ if (ret < 0)
+ trace_array_put(tr);
+
+ return ret;
+}
+
+static __poll_t
+tracing_buffers_poll(struct file *filp, poll_table *poll_table)
+{
+ struct ftrace_buffer_info *info = filp->private_data;
+ struct trace_iterator *iter = &info->iter;
+
+ return trace_poll(iter, filp, poll_table);
+}
+
+static ssize_t
+tracing_buffers_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ struct ftrace_buffer_info *info = filp->private_data;
+ struct trace_iterator *iter = &info->iter;
+ ssize_t ret = 0;
+ ssize_t size;
+
+ if (!count)
+ return 0;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (iter->snapshot && iter->tr->current_trace->use_max_tr)
+ return -EBUSY;
+#endif
+
+ if (!info->spare) {
+ info->spare = ring_buffer_alloc_read_page(iter->array_buffer->buffer,
+ iter->cpu_file);
+ if (IS_ERR(info->spare)) {
+ ret = PTR_ERR(info->spare);
+ info->spare = NULL;
+ } else {
+ info->spare_cpu = iter->cpu_file;
+ }
+ }
+ if (!info->spare)
+ return ret;
+
+ /* Do we have previous read data to read? */
+ if (info->read < PAGE_SIZE)
+ goto read;
+
+ again:
+ trace_access_lock(iter->cpu_file);
+ ret = ring_buffer_read_page(iter->array_buffer->buffer,
+ &info->spare,
+ count,
+ iter->cpu_file, 0);
+ trace_access_unlock(iter->cpu_file);
+
+ if (ret < 0) {
+ if (trace_empty(iter)) {
+ if ((filp->f_flags & O_NONBLOCK))
+ return -EAGAIN;
+
+ ret = wait_on_pipe(iter, 0);
+ if (ret)
+ return ret;
+
+ goto again;
+ }
+ return 0;
+ }
+
+ info->read = 0;
+ read:
+ size = PAGE_SIZE - info->read;
+ if (size > count)
+ size = count;
+
+ ret = copy_to_user(ubuf, info->spare + info->read, size);
+ if (ret == size)
+ return -EFAULT;
+
+ size -= ret;
+
+ *ppos += size;
+ info->read += size;
+
+ return size;
+}
+
+static int tracing_buffers_release(struct inode *inode, struct file *file)
+{
+ struct ftrace_buffer_info *info = file->private_data;
+ struct trace_iterator *iter = &info->iter;
+
+ mutex_lock(&trace_types_lock);
+
+ iter->tr->trace_ref--;
+
+ __trace_array_put(iter->tr);
+
+ iter->wait_index++;
+ /* Make sure the waiters see the new wait_index */
+ smp_wmb();
+
+ ring_buffer_wake_waiters(iter->array_buffer->buffer, iter->cpu_file);
+
+ if (info->spare)
+ ring_buffer_free_read_page(iter->array_buffer->buffer,
+ info->spare_cpu, info->spare);
+ kvfree(info);
+
+ mutex_unlock(&trace_types_lock);
+
+ return 0;
+}
+
+struct buffer_ref {
+ struct trace_buffer *buffer;
+ void *page;
+ int cpu;
+ refcount_t refcount;
+};
+
+static void buffer_ref_release(struct buffer_ref *ref)
+{
+ if (!refcount_dec_and_test(&ref->refcount))
+ return;
+ ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->page);
+ kfree(ref);
+}
+
+static void buffer_pipe_buf_release(struct pipe_inode_info *pipe,
+ struct pipe_buffer *buf)
+{
+ struct buffer_ref *ref = (struct buffer_ref *)buf->private;
+
+ buffer_ref_release(ref);
+ buf->private = 0;
+}
+
+static bool buffer_pipe_buf_get(struct pipe_inode_info *pipe,
+ struct pipe_buffer *buf)
+{
+ struct buffer_ref *ref = (struct buffer_ref *)buf->private;
+
+ if (refcount_read(&ref->refcount) > INT_MAX/2)
+ return false;
+
+ refcount_inc(&ref->refcount);
+ return true;
+}
+
+/* Pipe buffer operations for a buffer. */
+static const struct pipe_buf_operations buffer_pipe_buf_ops = {
+ .release = buffer_pipe_buf_release,
+ .get = buffer_pipe_buf_get,
+};
+
+/*
+ * Callback from splice_to_pipe(), if we need to release some pages
+ * at the end of the spd in case we error'ed out in filling the pipe.
+ */
+static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i)
+{
+ struct buffer_ref *ref =
+ (struct buffer_ref *)spd->partial[i].private;
+
+ buffer_ref_release(ref);
+ spd->partial[i].private = 0;
+}
+
+static ssize_t
+tracing_buffers_splice_read(struct file *file, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len,
+ unsigned int flags)
+{
+ struct ftrace_buffer_info *info = file->private_data;
+ struct trace_iterator *iter = &info->iter;
+ struct partial_page partial_def[PIPE_DEF_BUFFERS];
+ struct page *pages_def[PIPE_DEF_BUFFERS];
+ struct splice_pipe_desc spd = {
+ .pages = pages_def,
+ .partial = partial_def,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
+ .ops = &buffer_pipe_buf_ops,
+ .spd_release = buffer_spd_release,
+ };
+ struct buffer_ref *ref;
+ int entries, i;
+ ssize_t ret = 0;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (iter->snapshot && iter->tr->current_trace->use_max_tr)
+ return -EBUSY;
+#endif
+
+ if (*ppos & (PAGE_SIZE - 1))
+ return -EINVAL;
+
+ if (len & (PAGE_SIZE - 1)) {
+ if (len < PAGE_SIZE)
+ return -EINVAL;
+ len &= PAGE_MASK;
+ }
+
+ if (splice_grow_spd(pipe, &spd))
+ return -ENOMEM;
+
+ again:
+ trace_access_lock(iter->cpu_file);
+ entries = ring_buffer_entries_cpu(iter->array_buffer->buffer, iter->cpu_file);
+
+ for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) {
+ struct page *page;
+ int r;
+
+ ref = kzalloc(sizeof(*ref), GFP_KERNEL);
+ if (!ref) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ refcount_set(&ref->refcount, 1);
+ ref->buffer = iter->array_buffer->buffer;
+ ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file);
+ if (IS_ERR(ref->page)) {
+ ret = PTR_ERR(ref->page);
+ ref->page = NULL;
+ kfree(ref);
+ break;
+ }
+ ref->cpu = iter->cpu_file;
+
+ r = ring_buffer_read_page(ref->buffer, &ref->page,
+ len, iter->cpu_file, 1);
+ if (r < 0) {
+ ring_buffer_free_read_page(ref->buffer, ref->cpu,
+ ref->page);
+ kfree(ref);
+ break;
+ }
+
+ page = virt_to_page(ref->page);
+
+ spd.pages[i] = page;
+ spd.partial[i].len = PAGE_SIZE;
+ spd.partial[i].offset = 0;
+ spd.partial[i].private = (unsigned long)ref;
+ spd.nr_pages++;
+ *ppos += PAGE_SIZE;
+
+ entries = ring_buffer_entries_cpu(iter->array_buffer->buffer, iter->cpu_file);
+ }
+
+ trace_access_unlock(iter->cpu_file);
+ spd.nr_pages = i;
+
+ /* did we read anything? */
+ if (!spd.nr_pages) {
+ long wait_index;
+
+ if (ret)
+ goto out;
+
+ ret = -EAGAIN;
+ if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK))
+ goto out;
+
+ wait_index = READ_ONCE(iter->wait_index);
+
+ ret = wait_on_pipe(iter, iter->snapshot ? 0 : iter->tr->buffer_percent);
+ if (ret)
+ goto out;
+
+ /* No need to wait after waking up when tracing is off */
+ if (!tracer_tracing_is_on(iter->tr))
+ goto out;
+
+ /* Make sure we see the new wait_index */
+ smp_rmb();
+ if (wait_index != iter->wait_index)
+ goto out;
+
+ goto again;
+ }
+
+ ret = splice_to_pipe(pipe, &spd);
+out:
+ splice_shrink_spd(&spd);
+
+ return ret;
+}
+
+/* An ioctl call with cmd 0 to the ring buffer file will wake up all waiters */
+static long tracing_buffers_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct ftrace_buffer_info *info = file->private_data;
+ struct trace_iterator *iter = &info->iter;
+
+ if (cmd)
+ return -ENOIOCTLCMD;
+
+ mutex_lock(&trace_types_lock);
+
+ iter->wait_index++;
+ /* Make sure the waiters see the new wait_index */
+ smp_wmb();
+
+ ring_buffer_wake_waiters(iter->array_buffer->buffer, iter->cpu_file);
+
+ mutex_unlock(&trace_types_lock);
+ return 0;
+}
+
+static const struct file_operations tracing_buffers_fops = {
+ .open = tracing_buffers_open,
+ .read = tracing_buffers_read,
+ .poll = tracing_buffers_poll,
+ .release = tracing_buffers_release,
+ .splice_read = tracing_buffers_splice_read,
+ .unlocked_ioctl = tracing_buffers_ioctl,
+ .llseek = no_llseek,
+};
+
+static ssize_t
+tracing_stats_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ struct inode *inode = file_inode(filp);
+ struct trace_array *tr = inode->i_private;
+ struct array_buffer *trace_buf = &tr->array_buffer;
+ int cpu = tracing_get_cpu(inode);
+ struct trace_seq *s;
+ unsigned long cnt;
+ unsigned long long t;
+ unsigned long usec_rem;
+
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ trace_seq_init(s);
+
+ cnt = ring_buffer_entries_cpu(trace_buf->buffer, cpu);
+ trace_seq_printf(s, "entries: %ld\n", cnt);
+
+ cnt = ring_buffer_overrun_cpu(trace_buf->buffer, cpu);
+ trace_seq_printf(s, "overrun: %ld\n", cnt);
+
+ cnt = ring_buffer_commit_overrun_cpu(trace_buf->buffer, cpu);
+ trace_seq_printf(s, "commit overrun: %ld\n", cnt);
+
+ cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu);
+ trace_seq_printf(s, "bytes: %ld\n", cnt);
+
+ if (trace_clocks[tr->clock_id].in_ns) {
+ /* local or global for trace_clock */
+ t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu));
+ usec_rem = do_div(t, USEC_PER_SEC);
+ trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n",
+ t, usec_rem);
+
+ t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer));
+ usec_rem = do_div(t, USEC_PER_SEC);
+ trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem);
+ } else {
+ /* counter or tsc mode for trace_clock */
+ trace_seq_printf(s, "oldest event ts: %llu\n",
+ ring_buffer_oldest_event_ts(trace_buf->buffer, cpu));
+
+ trace_seq_printf(s, "now ts: %llu\n",
+ ring_buffer_time_stamp(trace_buf->buffer));
+ }
+
+ cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu);
+ trace_seq_printf(s, "dropped events: %ld\n", cnt);
+
+ cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu);
+ trace_seq_printf(s, "read events: %ld\n", cnt);
+
+ count = simple_read_from_buffer(ubuf, count, ppos,
+ s->buffer, trace_seq_used(s));
+
+ kfree(s);
+
+ return count;
+}
+
+static const struct file_operations tracing_stats_fops = {
+ .open = tracing_open_generic_tr,
+ .read = tracing_stats_read,
+ .llseek = generic_file_llseek,
+ .release = tracing_release_generic_tr,
+};
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+static ssize_t
+tracing_read_dyn_info(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ ssize_t ret;
+ char *buf;
+ int r;
+
+ /* 256 should be plenty to hold the amount needed */
+ buf = kmalloc(256, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ r = scnprintf(buf, 256, "%ld pages:%ld groups: %ld\n",
+ ftrace_update_tot_cnt,
+ ftrace_number_of_pages,
+ ftrace_number_of_groups);
+
+ ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+ kfree(buf);
+ return ret;
+}
+
+static const struct file_operations tracing_dyn_info_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_read_dyn_info,
+ .llseek = generic_file_llseek,
+};
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE)
+static void
+ftrace_snapshot(unsigned long ip, unsigned long parent_ip,
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void *data)
+{
+ tracing_snapshot_instance(tr);
+}
+
+static void
+ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip,
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void *data)
+{
+ struct ftrace_func_mapper *mapper = data;
+ long *count = NULL;
+
+ if (mapper)
+ count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
+
+ if (count) {
+
+ if (*count <= 0)
+ return;
+
+ (*count)--;
+ }
+
+ tracing_snapshot_instance(tr);
+}
+
+static int
+ftrace_snapshot_print(struct seq_file *m, unsigned long ip,
+ struct ftrace_probe_ops *ops, void *data)
+{
+ struct ftrace_func_mapper *mapper = data;
+ long *count = NULL;
+
+ seq_printf(m, "%ps:", (void *)ip);
+
+ seq_puts(m, "snapshot");
+
+ if (mapper)
+ count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
+
+ if (count)
+ seq_printf(m, ":count=%ld\n", *count);
+ else
+ seq_puts(m, ":unlimited\n");
+
+ return 0;
+}
+
+static int
+ftrace_snapshot_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
+ unsigned long ip, void *init_data, void **data)
+{
+ struct ftrace_func_mapper *mapper = *data;
+
+ if (!mapper) {
+ mapper = allocate_ftrace_func_mapper();
+ if (!mapper)
+ return -ENOMEM;
+ *data = mapper;
+ }
+
+ return ftrace_func_mapper_add_ip(mapper, ip, init_data);
+}
+
+static void
+ftrace_snapshot_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
+ unsigned long ip, void *data)
+{
+ struct ftrace_func_mapper *mapper = data;
+
+ if (!ip) {
+ if (!mapper)
+ return;
+ free_ftrace_func_mapper(mapper, NULL);
+ return;
+ }
+
+ ftrace_func_mapper_remove_ip(mapper, ip);
+}
+
+static struct ftrace_probe_ops snapshot_probe_ops = {
+ .func = ftrace_snapshot,
+ .print = ftrace_snapshot_print,
+};
+
+static struct ftrace_probe_ops snapshot_count_probe_ops = {
+ .func = ftrace_count_snapshot,
+ .print = ftrace_snapshot_print,
+ .init = ftrace_snapshot_init,
+ .free = ftrace_snapshot_free,
+};
+
+static int
+ftrace_trace_snapshot_callback(struct trace_array *tr, struct ftrace_hash *hash,
+ char *glob, char *cmd, char *param, int enable)
+{
+ struct ftrace_probe_ops *ops;
+ void *count = (void *)-1;
+ char *number;
+ int ret;
+
+ if (!tr)
+ return -ENODEV;
+
+ /* hash funcs only work with set_ftrace_filter */
+ if (!enable)
+ return -EINVAL;
+
+ ops = param ? &snapshot_count_probe_ops : &snapshot_probe_ops;
+
+ if (glob[0] == '!')
+ return unregister_ftrace_function_probe_func(glob+1, tr, ops);
+
+ if (!param)
+ goto out_reg;
+
+ number = strsep(&param, ":");
+
+ if (!strlen(number))
+ goto out_reg;
+
+ /*
+ * We use the callback data field (which is a pointer)
+ * as our counter.
+ */
+ ret = kstrtoul(number, 0, (unsigned long *)&count);
+ if (ret)
+ return ret;
+
+ out_reg:
+ ret = tracing_alloc_snapshot_instance(tr);
+ if (ret < 0)
+ goto out;
+
+ ret = register_ftrace_function_probe(glob, tr, ops, count);
+
+ out:
+ return ret < 0 ? ret : 0;
+}
+
+static struct ftrace_func_command ftrace_snapshot_cmd = {
+ .name = "snapshot",
+ .func = ftrace_trace_snapshot_callback,
+};
+
+static __init int register_snapshot_cmd(void)
+{
+ return register_ftrace_command(&ftrace_snapshot_cmd);
+}
+#else
+static inline __init int register_snapshot_cmd(void) { return 0; }
+#endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */
+
+static struct dentry *tracing_get_dentry(struct trace_array *tr)
+{
+ if (WARN_ON(!tr->dir))
+ return ERR_PTR(-ENODEV);
+
+ /* Top directory uses NULL as the parent */
+ if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
+ return NULL;
+
+ /* All sub buffers have a descriptor */
+ return tr->dir;
+}
+
+static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu)
+{
+ struct dentry *d_tracer;
+
+ if (tr->percpu_dir)
+ return tr->percpu_dir;
+
+ d_tracer = tracing_get_dentry(tr);
+ if (IS_ERR(d_tracer))
+ return NULL;
+
+ tr->percpu_dir = tracefs_create_dir("per_cpu", d_tracer);
+
+ MEM_FAIL(!tr->percpu_dir,
+ "Could not create tracefs directory 'per_cpu/%d'\n", cpu);
+
+ return tr->percpu_dir;
+}
+
+static struct dentry *
+trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent,
+ void *data, long cpu, const struct file_operations *fops)
+{
+ struct dentry *ret = trace_create_file(name, mode, parent, data, fops);
+
+ if (ret) /* See tracing_get_cpu() */
+ d_inode(ret)->i_cdev = (void *)(cpu + 1);
+ return ret;
+}
+
+static void
+tracing_init_tracefs_percpu(struct trace_array *tr, long cpu)
+{
+ struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu);
+ struct dentry *d_cpu;
+ char cpu_dir[30]; /* 30 characters should be more than enough */
+
+ if (!d_percpu)
+ return;
+
+ snprintf(cpu_dir, 30, "cpu%ld", cpu);
+ d_cpu = tracefs_create_dir(cpu_dir, d_percpu);
+ if (!d_cpu) {
+ pr_warn("Could not create tracefs '%s' entry\n", cpu_dir);
+ return;
+ }
+
+ /* per cpu trace_pipe */
+ trace_create_cpu_file("trace_pipe", TRACE_MODE_READ, d_cpu,
+ tr, cpu, &tracing_pipe_fops);
+
+ /* per cpu trace */
+ trace_create_cpu_file("trace", TRACE_MODE_WRITE, d_cpu,
+ tr, cpu, &tracing_fops);
+
+ trace_create_cpu_file("trace_pipe_raw", TRACE_MODE_READ, d_cpu,
+ tr, cpu, &tracing_buffers_fops);
+
+ trace_create_cpu_file("stats", TRACE_MODE_READ, d_cpu,
+ tr, cpu, &tracing_stats_fops);
+
+ trace_create_cpu_file("buffer_size_kb", TRACE_MODE_READ, d_cpu,
+ tr, cpu, &tracing_entries_fops);
+
+#ifdef CONFIG_TRACER_SNAPSHOT
+ trace_create_cpu_file("snapshot", TRACE_MODE_WRITE, d_cpu,
+ tr, cpu, &snapshot_fops);
+
+ trace_create_cpu_file("snapshot_raw", TRACE_MODE_READ, d_cpu,
+ tr, cpu, &snapshot_raw_fops);
+#endif
+}
+
+#ifdef CONFIG_FTRACE_SELFTEST
+/* Let selftest have access to static functions in this file */
+#include "trace_selftest.c"
+#endif
+
+static ssize_t
+trace_options_read(struct file *filp, char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct trace_option_dentry *topt = filp->private_data;
+ char *buf;
+
+ if (topt->flags->val & topt->opt->bit)
+ buf = "1\n";
+ else
+ buf = "0\n";
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
+}
+
+static ssize_t
+trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ struct trace_option_dentry *topt = filp->private_data;
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val != 0 && val != 1)
+ return -EINVAL;
+
+ if (!!(topt->flags->val & topt->opt->bit) != val) {
+ mutex_lock(&trace_types_lock);
+ ret = __set_tracer_option(topt->tr, topt->flags,
+ topt->opt, !val);
+ mutex_unlock(&trace_types_lock);
+ if (ret)
+ return ret;
+ }
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static int tracing_open_options(struct inode *inode, struct file *filp)
+{
+ struct trace_option_dentry *topt = inode->i_private;
+ int ret;
+
+ ret = tracing_check_open_get_tr(topt->tr);
+ if (ret)
+ return ret;
+
+ filp->private_data = inode->i_private;
+ return 0;
+}
+
+static int tracing_release_options(struct inode *inode, struct file *file)
+{
+ struct trace_option_dentry *topt = file->private_data;
+
+ trace_array_put(topt->tr);
+ return 0;
+}
+
+static const struct file_operations trace_options_fops = {
+ .open = tracing_open_options,
+ .read = trace_options_read,
+ .write = trace_options_write,
+ .llseek = generic_file_llseek,
+ .release = tracing_release_options,
+};
+
+/*
+ * In order to pass in both the trace_array descriptor as well as the index
+ * to the flag that the trace option file represents, the trace_array
+ * has a character array of trace_flags_index[], which holds the index
+ * of the bit for the flag it represents. index[0] == 0, index[1] == 1, etc.
+ * The address of this character array is passed to the flag option file
+ * read/write callbacks.
+ *
+ * In order to extract both the index and the trace_array descriptor,
+ * get_tr_index() uses the following algorithm.
+ *
+ * idx = *ptr;
+ *
+ * As the pointer itself contains the address of the index (remember
+ * index[1] == 1).
+ *
+ * Then to get the trace_array descriptor, by subtracting that index
+ * from the ptr, we get to the start of the index itself.
+ *
+ * ptr - idx == &index[0]
+ *
+ * Then a simple container_of() from that pointer gets us to the
+ * trace_array descriptor.
+ */
+static void get_tr_index(void *data, struct trace_array **ptr,
+ unsigned int *pindex)
+{
+ *pindex = *(unsigned char *)data;
+
+ *ptr = container_of(data - *pindex, struct trace_array,
+ trace_flags_index);
+}
+
+static ssize_t
+trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ void *tr_index = filp->private_data;
+ struct trace_array *tr;
+ unsigned int index;
+ char *buf;
+
+ get_tr_index(tr_index, &tr, &index);
+
+ if (tr->trace_flags & (1 << index))
+ buf = "1\n";
+ else
+ buf = "0\n";
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
+}
+
+static ssize_t
+trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt,
+ loff_t *ppos)
+{
+ void *tr_index = filp->private_data;
+ struct trace_array *tr;
+ unsigned int index;
+ unsigned long val;
+ int ret;
+
+ get_tr_index(tr_index, &tr, &index);
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val != 0 && val != 1)
+ return -EINVAL;
+
+ mutex_lock(&event_mutex);
+ mutex_lock(&trace_types_lock);
+ ret = set_tracer_flag(tr, 1 << index, val);
+ mutex_unlock(&trace_types_lock);
+ mutex_unlock(&event_mutex);
+
+ if (ret < 0)
+ return ret;
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static const struct file_operations trace_options_core_fops = {
+ .open = tracing_open_generic,
+ .read = trace_options_core_read,
+ .write = trace_options_core_write,
+ .llseek = generic_file_llseek,
+};
+
+struct dentry *trace_create_file(const char *name,
+ umode_t mode,
+ struct dentry *parent,
+ void *data,
+ const struct file_operations *fops)
+{
+ struct dentry *ret;
+
+ ret = tracefs_create_file(name, mode, parent, data, fops);
+ if (!ret)
+ pr_warn("Could not create tracefs '%s' entry\n", name);
+
+ return ret;
+}
+
+
+static struct dentry *trace_options_init_dentry(struct trace_array *tr)
+{
+ struct dentry *d_tracer;
+
+ if (tr->options)
+ return tr->options;
+
+ d_tracer = tracing_get_dentry(tr);
+ if (IS_ERR(d_tracer))
+ return NULL;
+
+ tr->options = tracefs_create_dir("options", d_tracer);
+ if (!tr->options) {
+ pr_warn("Could not create tracefs directory 'options'\n");
+ return NULL;
+ }
+
+ return tr->options;
+}
+
+static void
+create_trace_option_file(struct trace_array *tr,
+ struct trace_option_dentry *topt,
+ struct tracer_flags *flags,
+ struct tracer_opt *opt)
+{
+ struct dentry *t_options;
+
+ t_options = trace_options_init_dentry(tr);
+ if (!t_options)
+ return;
+
+ topt->flags = flags;
+ topt->opt = opt;
+ topt->tr = tr;
+
+ topt->entry = trace_create_file(opt->name, TRACE_MODE_WRITE,
+ t_options, topt, &trace_options_fops);
+
+}
+
+static void
+create_trace_option_files(struct trace_array *tr, struct tracer *tracer)
+{
+ struct trace_option_dentry *topts;
+ struct trace_options *tr_topts;
+ struct tracer_flags *flags;
+ struct tracer_opt *opts;
+ int cnt;
+ int i;
+
+ if (!tracer)
+ return;
+
+ flags = tracer->flags;
+
+ if (!flags || !flags->opts)
+ return;
+
+ /*
+ * If this is an instance, only create flags for tracers
+ * the instance may have.
+ */
+ if (!trace_ok_for_array(tracer, tr))
+ return;
+
+ for (i = 0; i < tr->nr_topts; i++) {
+ /* Make sure there's no duplicate flags. */
+ if (WARN_ON_ONCE(tr->topts[i].tracer->flags == tracer->flags))
+ return;
+ }
+
+ opts = flags->opts;
+
+ for (cnt = 0; opts[cnt].name; cnt++)
+ ;
+
+ topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL);
+ if (!topts)
+ return;
+
+ tr_topts = krealloc(tr->topts, sizeof(*tr->topts) * (tr->nr_topts + 1),
+ GFP_KERNEL);
+ if (!tr_topts) {
+ kfree(topts);
+ return;
+ }
+
+ tr->topts = tr_topts;
+ tr->topts[tr->nr_topts].tracer = tracer;
+ tr->topts[tr->nr_topts].topts = topts;
+ tr->nr_topts++;
+
+ for (cnt = 0; opts[cnt].name; cnt++) {
+ create_trace_option_file(tr, &topts[cnt], flags,
+ &opts[cnt]);
+ MEM_FAIL(topts[cnt].entry == NULL,
+ "Failed to create trace option: %s",
+ opts[cnt].name);
+ }
+}
+
+static struct dentry *
+create_trace_option_core_file(struct trace_array *tr,
+ const char *option, long index)
+{
+ struct dentry *t_options;
+
+ t_options = trace_options_init_dentry(tr);
+ if (!t_options)
+ return NULL;
+
+ return trace_create_file(option, TRACE_MODE_WRITE, t_options,
+ (void *)&tr->trace_flags_index[index],
+ &trace_options_core_fops);
+}
+
+static void create_trace_options_dir(struct trace_array *tr)
+{
+ struct dentry *t_options;
+ bool top_level = tr == &global_trace;
+ int i;
+
+ t_options = trace_options_init_dentry(tr);
+ if (!t_options)
+ return;
+
+ for (i = 0; trace_options[i]; i++) {
+ if (top_level ||
+ !((1 << i) & TOP_LEVEL_TRACE_FLAGS))
+ create_trace_option_core_file(tr, trace_options[i], i);
+ }
+}
+
+static ssize_t
+rb_simple_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ char buf[64];
+ int r;
+
+ r = tracer_tracing_is_on(tr);
+ r = sprintf(buf, "%d\n", r);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+rb_simple_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ struct trace_buffer *buffer = tr->array_buffer.buffer;
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ if (buffer) {
+ mutex_lock(&trace_types_lock);
+ if (!!val == tracer_tracing_is_on(tr)) {
+ val = 0; /* do nothing */
+ } else if (val) {
+ tracer_tracing_on(tr);
+ if (tr->current_trace->start)
+ tr->current_trace->start(tr);
+ } else {
+ tracer_tracing_off(tr);
+ if (tr->current_trace->stop)
+ tr->current_trace->stop(tr);
+ /* Wake up any waiters */
+ ring_buffer_wake_waiters(buffer, RING_BUFFER_ALL_CPUS);
+ }
+ mutex_unlock(&trace_types_lock);
+ }
+
+ (*ppos)++;
+
+ return cnt;
+}
+
+static const struct file_operations rb_simple_fops = {
+ .open = tracing_open_generic_tr,
+ .read = rb_simple_read,
+ .write = rb_simple_write,
+ .release = tracing_release_generic_tr,
+ .llseek = default_llseek,
+};
+
+static ssize_t
+buffer_percent_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ char buf[64];
+ int r;
+
+ r = tr->buffer_percent;
+ r = sprintf(buf, "%d\n", r);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+buffer_percent_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val > 100)
+ return -EINVAL;
+
+ tr->buffer_percent = val;
+
+ (*ppos)++;
+
+ return cnt;
+}
+
+static const struct file_operations buffer_percent_fops = {
+ .open = tracing_open_generic_tr,
+ .read = buffer_percent_read,
+ .write = buffer_percent_write,
+ .release = tracing_release_generic_tr,
+ .llseek = default_llseek,
+};
+
+static struct dentry *trace_instance_dir;
+
+static void
+init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer);
+
+static int
+allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size)
+{
+ enum ring_buffer_flags rb_flags;
+
+ rb_flags = tr->trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;
+
+ buf->tr = tr;
+
+ buf->buffer = ring_buffer_alloc(size, rb_flags);
+ if (!buf->buffer)
+ return -ENOMEM;
+
+ buf->data = alloc_percpu(struct trace_array_cpu);
+ if (!buf->data) {
+ ring_buffer_free(buf->buffer);
+ buf->buffer = NULL;
+ return -ENOMEM;
+ }
+
+ /* Allocate the first page for all buffers */
+ set_buffer_entries(&tr->array_buffer,
+ ring_buffer_size(tr->array_buffer.buffer, 0));
+
+ return 0;
+}
+
+static void free_trace_buffer(struct array_buffer *buf)
+{
+ if (buf->buffer) {
+ ring_buffer_free(buf->buffer);
+ buf->buffer = NULL;
+ free_percpu(buf->data);
+ buf->data = NULL;
+ }
+}
+
+static int allocate_trace_buffers(struct trace_array *tr, int size)
+{
+ int ret;
+
+ ret = allocate_trace_buffer(tr, &tr->array_buffer, size);
+ if (ret)
+ return ret;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ ret = allocate_trace_buffer(tr, &tr->max_buffer,
+ allocate_snapshot ? size : 1);
+ if (MEM_FAIL(ret, "Failed to allocate trace buffer\n")) {
+ free_trace_buffer(&tr->array_buffer);
+ return -ENOMEM;
+ }
+ tr->allocated_snapshot = allocate_snapshot;
+
+ allocate_snapshot = false;
+#endif
+
+ return 0;
+}
+
+static void free_trace_buffers(struct trace_array *tr)
+{
+ if (!tr)
+ return;
+
+ free_trace_buffer(&tr->array_buffer);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ free_trace_buffer(&tr->max_buffer);
+#endif
+}
+
+static void init_trace_flags_index(struct trace_array *tr)
+{
+ int i;
+
+ /* Used by the trace options files */
+ for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++)
+ tr->trace_flags_index[i] = i;
+}
+
+static void __update_tracer_options(struct trace_array *tr)
+{
+ struct tracer *t;
+
+ for (t = trace_types; t; t = t->next)
+ add_tracer_options(tr, t);
+}
+
+static void update_tracer_options(struct trace_array *tr)
+{
+ mutex_lock(&trace_types_lock);
+ tracer_options_updated = true;
+ __update_tracer_options(tr);
+ mutex_unlock(&trace_types_lock);
+}
+
+/* Must have trace_types_lock held */
+struct trace_array *trace_array_find(const char *instance)
+{
+ struct trace_array *tr, *found = NULL;
+
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (tr->name && strcmp(tr->name, instance) == 0) {
+ found = tr;
+ break;
+ }
+ }
+
+ return found;
+}
+
+struct trace_array *trace_array_find_get(const char *instance)
+{
+ struct trace_array *tr;
+
+ mutex_lock(&trace_types_lock);
+ tr = trace_array_find(instance);
+ if (tr)
+ tr->ref++;
+ mutex_unlock(&trace_types_lock);
+
+ return tr;
+}
+
+static int trace_array_create_dir(struct trace_array *tr)
+{
+ int ret;
+
+ tr->dir = tracefs_create_dir(tr->name, trace_instance_dir);
+ if (!tr->dir)
+ return -EINVAL;
+
+ ret = event_trace_add_tracer(tr->dir, tr);
+ if (ret) {
+ tracefs_remove(tr->dir);
+ return ret;
+ }
+
+ init_tracer_tracefs(tr, tr->dir);
+ __update_tracer_options(tr);
+
+ return ret;
+}
+
+static struct trace_array *trace_array_create(const char *name)
+{
+ struct trace_array *tr;
+ int ret;
+
+ ret = -ENOMEM;
+ tr = kzalloc(sizeof(*tr), GFP_KERNEL);
+ if (!tr)
+ return ERR_PTR(ret);
+
+ tr->name = kstrdup(name, GFP_KERNEL);
+ if (!tr->name)
+ goto out_free_tr;
+
+ if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL))
+ goto out_free_tr;
+
+ if (!zalloc_cpumask_var(&tr->pipe_cpumask, GFP_KERNEL))
+ goto out_free_tr;
+
+ tr->trace_flags = global_trace.trace_flags & ~ZEROED_TRACE_FLAGS;
+
+ cpumask_copy(tr->tracing_cpumask, cpu_all_mask);
+
+ raw_spin_lock_init(&tr->start_lock);
+
+ tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
+
+ tr->current_trace = &nop_trace;
+
+ INIT_LIST_HEAD(&tr->systems);
+ INIT_LIST_HEAD(&tr->events);
+ INIT_LIST_HEAD(&tr->hist_vars);
+ INIT_LIST_HEAD(&tr->err_log);
+
+ if (allocate_trace_buffers(tr, trace_buf_size) < 0)
+ goto out_free_tr;
+
+ if (ftrace_allocate_ftrace_ops(tr) < 0)
+ goto out_free_tr;
+
+ ftrace_init_trace_array(tr);
+
+ init_trace_flags_index(tr);
+
+ if (trace_instance_dir) {
+ ret = trace_array_create_dir(tr);
+ if (ret)
+ goto out_free_tr;
+ } else
+ __trace_early_add_events(tr);
+
+ list_add(&tr->list, &ftrace_trace_arrays);
+
+ tr->ref++;
+
+ return tr;
+
+ out_free_tr:
+ ftrace_free_ftrace_ops(tr);
+ free_trace_buffers(tr);
+ free_cpumask_var(tr->pipe_cpumask);
+ free_cpumask_var(tr->tracing_cpumask);
+ kfree(tr->name);
+ kfree(tr);
+
+ return ERR_PTR(ret);
+}
+
+static int instance_mkdir(const char *name)
+{
+ struct trace_array *tr;
+ int ret;
+
+ mutex_lock(&event_mutex);
+ mutex_lock(&trace_types_lock);
+
+ ret = -EEXIST;
+ if (trace_array_find(name))
+ goto out_unlock;
+
+ tr = trace_array_create(name);
+
+ ret = PTR_ERR_OR_ZERO(tr);
+
+out_unlock:
+ mutex_unlock(&trace_types_lock);
+ mutex_unlock(&event_mutex);
+ return ret;
+}
+
+/**
+ * trace_array_get_by_name - Create/Lookup a trace array, given its name.
+ * @name: The name of the trace array to be looked up/created.
+ *
+ * Returns pointer to trace array with given name.
+ * NULL, if it cannot be created.
+ *
+ * NOTE: This function increments the reference counter associated with the
+ * trace array returned. This makes sure it cannot be freed while in use.
+ * Use trace_array_put() once the trace array is no longer needed.
+ * If the trace_array is to be freed, trace_array_destroy() needs to
+ * be called after the trace_array_put(), or simply let user space delete
+ * it from the tracefs instances directory. But until the
+ * trace_array_put() is called, user space can not delete it.
+ *
+ */
+struct trace_array *trace_array_get_by_name(const char *name)
+{
+ struct trace_array *tr;
+
+ mutex_lock(&event_mutex);
+ mutex_lock(&trace_types_lock);
+
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (tr->name && strcmp(tr->name, name) == 0)
+ goto out_unlock;
+ }
+
+ tr = trace_array_create(name);
+
+ if (IS_ERR(tr))
+ tr = NULL;
+out_unlock:
+ if (tr)
+ tr->ref++;
+
+ mutex_unlock(&trace_types_lock);
+ mutex_unlock(&event_mutex);
+ return tr;
+}
+EXPORT_SYMBOL_GPL(trace_array_get_by_name);
+
+static int __remove_instance(struct trace_array *tr)
+{
+ int i;
+
+ /* Reference counter for a newly created trace array = 1. */
+ if (tr->ref > 1 || (tr->current_trace && tr->trace_ref))
+ return -EBUSY;
+
+ list_del(&tr->list);
+
+ /* Disable all the flags that were enabled coming in */
+ for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) {
+ if ((1 << i) & ZEROED_TRACE_FLAGS)
+ set_tracer_flag(tr, 1 << i, 0);
+ }
+
+ tracing_set_nop(tr);
+ clear_ftrace_function_probes(tr);
+ event_trace_del_tracer(tr);
+ ftrace_clear_pids(tr);
+ ftrace_destroy_function_files(tr);
+ tracefs_remove(tr->dir);
+ free_percpu(tr->last_func_repeats);
+ free_trace_buffers(tr);
+ clear_tracing_err_log(tr);
+
+ for (i = 0; i < tr->nr_topts; i++) {
+ kfree(tr->topts[i].topts);
+ }
+ kfree(tr->topts);
+
+ free_cpumask_var(tr->pipe_cpumask);
+ free_cpumask_var(tr->tracing_cpumask);
+ kfree(tr->name);
+ kfree(tr);
+
+ return 0;
+}
+
+int trace_array_destroy(struct trace_array *this_tr)
+{
+ struct trace_array *tr;
+ int ret;
+
+ if (!this_tr)
+ return -EINVAL;
+
+ mutex_lock(&event_mutex);
+ mutex_lock(&trace_types_lock);
+
+ ret = -ENODEV;
+
+ /* Making sure trace array exists before destroying it. */
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (tr == this_tr) {
+ ret = __remove_instance(tr);
+ break;
+ }
+ }
+
+ mutex_unlock(&trace_types_lock);
+ mutex_unlock(&event_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(trace_array_destroy);
+
+static int instance_rmdir(const char *name)
+{
+ struct trace_array *tr;
+ int ret;
+
+ mutex_lock(&event_mutex);
+ mutex_lock(&trace_types_lock);
+
+ ret = -ENODEV;
+ tr = trace_array_find(name);
+ if (tr)
+ ret = __remove_instance(tr);
+
+ mutex_unlock(&trace_types_lock);
+ mutex_unlock(&event_mutex);
+
+ return ret;
+}
+
+static __init void create_trace_instances(struct dentry *d_tracer)
+{
+ struct trace_array *tr;
+
+ trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer,
+ instance_mkdir,
+ instance_rmdir);
+ if (MEM_FAIL(!trace_instance_dir, "Failed to create instances directory\n"))
+ return;
+
+ mutex_lock(&event_mutex);
+ mutex_lock(&trace_types_lock);
+
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (!tr->name)
+ continue;
+ if (MEM_FAIL(trace_array_create_dir(tr) < 0,
+ "Failed to create instance directory\n"))
+ break;
+ }
+
+ mutex_unlock(&trace_types_lock);
+ mutex_unlock(&event_mutex);
+}
+
+static void
+init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
+{
+ struct trace_event_file *file;
+ int cpu;
+
+ trace_create_file("available_tracers", TRACE_MODE_READ, d_tracer,
+ tr, &show_traces_fops);
+
+ trace_create_file("current_tracer", TRACE_MODE_WRITE, d_tracer,
+ tr, &set_tracer_fops);
+
+ trace_create_file("tracing_cpumask", TRACE_MODE_WRITE, d_tracer,
+ tr, &tracing_cpumask_fops);
+
+ trace_create_file("trace_options", TRACE_MODE_WRITE, d_tracer,
+ tr, &tracing_iter_fops);
+
+ trace_create_file("trace", TRACE_MODE_WRITE, d_tracer,
+ tr, &tracing_fops);
+
+ trace_create_file("trace_pipe", TRACE_MODE_READ, d_tracer,
+ tr, &tracing_pipe_fops);
+
+ trace_create_file("buffer_size_kb", TRACE_MODE_WRITE, d_tracer,
+ tr, &tracing_entries_fops);
+
+ trace_create_file("buffer_total_size_kb", TRACE_MODE_READ, d_tracer,
+ tr, &tracing_total_entries_fops);
+
+ trace_create_file("free_buffer", 0200, d_tracer,
+ tr, &tracing_free_buffer_fops);
+
+ trace_create_file("trace_marker", 0220, d_tracer,
+ tr, &tracing_mark_fops);
+
+ file = __find_event_file(tr, "ftrace", "print");
+ if (file && file->ef)
+ eventfs_add_file("trigger", TRACE_MODE_WRITE, file->ef,
+ file, &event_trigger_fops);
+ tr->trace_marker_file = file;
+
+ trace_create_file("trace_marker_raw", 0220, d_tracer,
+ tr, &tracing_mark_raw_fops);
+
+ trace_create_file("trace_clock", TRACE_MODE_WRITE, d_tracer, tr,
+ &trace_clock_fops);
+
+ trace_create_file("tracing_on", TRACE_MODE_WRITE, d_tracer,
+ tr, &rb_simple_fops);
+
+ trace_create_file("timestamp_mode", TRACE_MODE_READ, d_tracer, tr,
+ &trace_time_stamp_mode_fops);
+
+ tr->buffer_percent = 50;
+
+ trace_create_file("buffer_percent", TRACE_MODE_WRITE, d_tracer,
+ tr, &buffer_percent_fops);
+
+ create_trace_options_dir(tr);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ trace_create_maxlat_file(tr, d_tracer);
+#endif
+
+ if (ftrace_create_function_files(tr, d_tracer))
+ MEM_FAIL(1, "Could not allocate function filter files");
+
+#ifdef CONFIG_TRACER_SNAPSHOT
+ trace_create_file("snapshot", TRACE_MODE_WRITE, d_tracer,
+ tr, &snapshot_fops);
+#endif
+
+ trace_create_file("error_log", TRACE_MODE_WRITE, d_tracer,
+ tr, &tracing_err_log_fops);
+
+ for_each_tracing_cpu(cpu)
+ tracing_init_tracefs_percpu(tr, cpu);
+
+ ftrace_init_tracefs(tr, d_tracer);
+}
+
+static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore)
+{
+ struct vfsmount *mnt;
+ struct file_system_type *type;
+
+ /*
+ * To maintain backward compatibility for tools that mount
+ * debugfs to get to the tracing facility, tracefs is automatically
+ * mounted to the debugfs/tracing directory.
+ */
+ type = get_fs_type("tracefs");
+ if (!type)
+ return NULL;
+ mnt = vfs_submount(mntpt, type, "tracefs", NULL);
+ put_filesystem(type);
+ if (IS_ERR(mnt))
+ return NULL;
+ mntget(mnt);
+
+ return mnt;
+}
+
+/**
+ * tracing_init_dentry - initialize top level trace array
+ *
+ * This is called when creating files or directories in the tracing
+ * directory. It is called via fs_initcall() by any of the boot up code
+ * and expects to return the dentry of the top level tracing directory.
+ */
+int tracing_init_dentry(void)
+{
+ struct trace_array *tr = &global_trace;
+
+ if (security_locked_down(LOCKDOWN_TRACEFS)) {
+ pr_warn("Tracing disabled due to lockdown\n");
+ return -EPERM;
+ }
+
+ /* The top level trace array uses NULL as parent */
+ if (tr->dir)
+ return 0;
+
+ if (WARN_ON(!tracefs_initialized()))
+ return -ENODEV;
+
+ /*
+ * As there may still be users that expect the tracing
+ * files to exist in debugfs/tracing, we must automount
+ * the tracefs file system there, so older tools still
+ * work with the newer kernel.
+ */
+ tr->dir = debugfs_create_automount("tracing", NULL,
+ trace_automount, NULL);
+
+ return 0;
+}
+
+extern struct trace_eval_map *__start_ftrace_eval_maps[];
+extern struct trace_eval_map *__stop_ftrace_eval_maps[];
+
+static struct workqueue_struct *eval_map_wq __initdata;
+static struct work_struct eval_map_work __initdata;
+static struct work_struct tracerfs_init_work __initdata;
+
+static void __init eval_map_work_func(struct work_struct *work)
+{
+ int len;
+
+ len = __stop_ftrace_eval_maps - __start_ftrace_eval_maps;
+ trace_insert_eval_map(NULL, __start_ftrace_eval_maps, len);
+}
+
+static int __init trace_eval_init(void)
+{
+ INIT_WORK(&eval_map_work, eval_map_work_func);
+
+ eval_map_wq = alloc_workqueue("eval_map_wq", WQ_UNBOUND, 0);
+ if (!eval_map_wq) {
+ pr_err("Unable to allocate eval_map_wq\n");
+ /* Do work here */
+ eval_map_work_func(&eval_map_work);
+ return -ENOMEM;
+ }
+
+ queue_work(eval_map_wq, &eval_map_work);
+ return 0;
+}
+
+subsys_initcall(trace_eval_init);
+
+static int __init trace_eval_sync(void)
+{
+ /* Make sure the eval map updates are finished */
+ if (eval_map_wq)
+ destroy_workqueue(eval_map_wq);
+ return 0;
+}
+
+late_initcall_sync(trace_eval_sync);
+
+
+#ifdef CONFIG_MODULES
+static void trace_module_add_evals(struct module *mod)
+{
+ if (!mod->num_trace_evals)
+ return;
+
+ /*
+ * Modules with bad taint do not have events created, do
+ * not bother with enums either.
+ */
+ if (trace_module_has_bad_taint(mod))
+ return;
+
+ trace_insert_eval_map(mod, mod->trace_evals, mod->num_trace_evals);
+}
+
+#ifdef CONFIG_TRACE_EVAL_MAP_FILE
+static void trace_module_remove_evals(struct module *mod)
+{
+ union trace_eval_map_item *map;
+ union trace_eval_map_item **last = &trace_eval_maps;
+
+ if (!mod->num_trace_evals)
+ return;
+
+ mutex_lock(&trace_eval_mutex);
+
+ map = trace_eval_maps;
+
+ while (map) {
+ if (map->head.mod == mod)
+ break;
+ map = trace_eval_jmp_to_tail(map);
+ last = &map->tail.next;
+ map = map->tail.next;
+ }
+ if (!map)
+ goto out;
+
+ *last = trace_eval_jmp_to_tail(map)->tail.next;
+ kfree(map);
+ out:
+ mutex_unlock(&trace_eval_mutex);
+}
+#else
+static inline void trace_module_remove_evals(struct module *mod) { }
+#endif /* CONFIG_TRACE_EVAL_MAP_FILE */
+
+static int trace_module_notify(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ struct module *mod = data;
+
+ switch (val) {
+ case MODULE_STATE_COMING:
+ trace_module_add_evals(mod);
+ break;
+ case MODULE_STATE_GOING:
+ trace_module_remove_evals(mod);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block trace_module_nb = {
+ .notifier_call = trace_module_notify,
+ .priority = 0,
+};
+#endif /* CONFIG_MODULES */
+
+static __init void tracer_init_tracefs_work_func(struct work_struct *work)
+{
+
+ event_trace_init();
+
+ init_tracer_tracefs(&global_trace, NULL);
+ ftrace_init_tracefs_toplevel(&global_trace, NULL);
+
+ trace_create_file("tracing_thresh", TRACE_MODE_WRITE, NULL,
+ &global_trace, &tracing_thresh_fops);
+
+ trace_create_file("README", TRACE_MODE_READ, NULL,
+ NULL, &tracing_readme_fops);
+
+ trace_create_file("saved_cmdlines", TRACE_MODE_READ, NULL,
+ NULL, &tracing_saved_cmdlines_fops);
+
+ trace_create_file("saved_cmdlines_size", TRACE_MODE_WRITE, NULL,
+ NULL, &tracing_saved_cmdlines_size_fops);
+
+ trace_create_file("saved_tgids", TRACE_MODE_READ, NULL,
+ NULL, &tracing_saved_tgids_fops);
+
+ trace_create_eval_file(NULL);
+
+#ifdef CONFIG_MODULES
+ register_module_notifier(&trace_module_nb);
+#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+ trace_create_file("dyn_ftrace_total_info", TRACE_MODE_READ, NULL,
+ NULL, &tracing_dyn_info_fops);
+#endif
+
+ create_trace_instances(NULL);
+
+ update_tracer_options(&global_trace);
+}
+
+static __init int tracer_init_tracefs(void)
+{
+ int ret;
+
+ trace_access_lock_init();
+
+ ret = tracing_init_dentry();
+ if (ret)
+ return 0;
+
+ if (eval_map_wq) {
+ INIT_WORK(&tracerfs_init_work, tracer_init_tracefs_work_func);
+ queue_work(eval_map_wq, &tracerfs_init_work);
+ } else {
+ tracer_init_tracefs_work_func(NULL);
+ }
+
+ rv_init_interface();
+
+ return 0;
+}
+
+fs_initcall(tracer_init_tracefs);
+
+static int trace_die_panic_handler(struct notifier_block *self,
+ unsigned long ev, void *unused);
+
+static struct notifier_block trace_panic_notifier = {
+ .notifier_call = trace_die_panic_handler,
+ .priority = INT_MAX - 1,
+};
+
+static struct notifier_block trace_die_notifier = {
+ .notifier_call = trace_die_panic_handler,
+ .priority = INT_MAX - 1,
+};
+
+/*
+ * The idea is to execute the following die/panic callback early, in order
+ * to avoid showing irrelevant information in the trace (like other panic
+ * notifier functions); we are the 2nd to run, after hung_task/rcu_stall
+ * warnings get disabled (to prevent potential log flooding).
+ */
+static int trace_die_panic_handler(struct notifier_block *self,
+ unsigned long ev, void *unused)
+{
+ if (!ftrace_dump_on_oops)
+ return NOTIFY_DONE;
+
+ /* The die notifier requires DIE_OOPS to trigger */
+ if (self == &trace_die_notifier && ev != DIE_OOPS)
+ return NOTIFY_DONE;
+
+ ftrace_dump(ftrace_dump_on_oops);
+
+ return NOTIFY_DONE;
+}
+
+/*
+ * printk is set to max of 1024, we really don't need it that big.
+ * Nothing should be printing 1000 characters anyway.
+ */
+#define TRACE_MAX_PRINT 1000
+
+/*
+ * Define here KERN_TRACE so that we have one place to modify
+ * it if we decide to change what log level the ftrace dump
+ * should be at.
+ */
+#define KERN_TRACE KERN_EMERG
+
+void
+trace_printk_seq(struct trace_seq *s)
+{
+ /* Probably should print a warning here. */
+ if (s->seq.len >= TRACE_MAX_PRINT)
+ s->seq.len = TRACE_MAX_PRINT;
+
+ /*
+ * More paranoid code. Although the buffer size is set to
+ * PAGE_SIZE, and TRACE_MAX_PRINT is 1000, this is just
+ * an extra layer of protection.
+ */
+ if (WARN_ON_ONCE(s->seq.len >= s->seq.size))
+ s->seq.len = s->seq.size - 1;
+
+ /* should be zero ended, but we are paranoid. */
+ s->buffer[s->seq.len] = 0;
+
+ printk(KERN_TRACE "%s", s->buffer);
+
+ trace_seq_init(s);
+}
+
+void trace_init_global_iter(struct trace_iterator *iter)
+{
+ iter->tr = &global_trace;
+ iter->trace = iter->tr->current_trace;
+ iter->cpu_file = RING_BUFFER_ALL_CPUS;
+ iter->array_buffer = &global_trace.array_buffer;
+
+ if (iter->trace && iter->trace->open)
+ iter->trace->open(iter);
+
+ /* Annotate start of buffers if we had overruns */
+ if (ring_buffer_overruns(iter->array_buffer->buffer))
+ iter->iter_flags |= TRACE_FILE_ANNOTATE;
+
+ /* Output in nanoseconds only if we are using a clock in nanoseconds. */
+ if (trace_clocks[iter->tr->clock_id].in_ns)
+ iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
+
+ /* Can not use kmalloc for iter.temp and iter.fmt */
+ iter->temp = static_temp_buf;
+ iter->temp_size = STATIC_TEMP_BUF_SIZE;
+ iter->fmt = static_fmt_buf;
+ iter->fmt_size = STATIC_FMT_BUF_SIZE;
+}
+
+void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
+{
+ /* use static because iter can be a bit big for the stack */
+ static struct trace_iterator iter;
+ static atomic_t dump_running;
+ struct trace_array *tr = &global_trace;
+ unsigned int old_userobj;
+ unsigned long flags;
+ int cnt = 0, cpu;
+
+ /* Only allow one dump user at a time. */
+ if (atomic_inc_return(&dump_running) != 1) {
+ atomic_dec(&dump_running);
+ return;
+ }
+
+ /*
+ * Always turn off tracing when we dump.
+ * We don't need to show trace output of what happens
+ * between multiple crashes.
+ *
+ * If the user does a sysrq-z, then they can re-enable
+ * tracing with echo 1 > tracing_on.
+ */
+ tracing_off();
+
+ local_irq_save(flags);
+
+ /* Simulate the iterator */
+ trace_init_global_iter(&iter);
+
+ for_each_tracing_cpu(cpu) {
+ atomic_inc(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
+ }
+
+ old_userobj = tr->trace_flags & TRACE_ITER_SYM_USEROBJ;
+
+ /* don't look at user memory in panic mode */
+ tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
+
+ switch (oops_dump_mode) {
+ case DUMP_ALL:
+ iter.cpu_file = RING_BUFFER_ALL_CPUS;
+ break;
+ case DUMP_ORIG:
+ iter.cpu_file = raw_smp_processor_id();
+ break;
+ case DUMP_NONE:
+ goto out_enable;
+ default:
+ printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
+ iter.cpu_file = RING_BUFFER_ALL_CPUS;
+ }
+
+ printk(KERN_TRACE "Dumping ftrace buffer:\n");
+
+ /* Did function tracer already get disabled? */
+ if (ftrace_is_dead()) {
+ printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n");
+ printk("# MAY BE MISSING FUNCTION EVENTS\n");
+ }
+
+ /*
+ * We need to stop all tracing on all CPUS to read
+ * the next buffer. This is a bit expensive, but is
+ * not done often. We fill all what we can read,
+ * and then release the locks again.
+ */
+
+ while (!trace_empty(&iter)) {
+
+ if (!cnt)
+ printk(KERN_TRACE "---------------------------------\n");
+
+ cnt++;
+
+ trace_iterator_reset(&iter);
+ iter.iter_flags |= TRACE_FILE_LAT_FMT;
+
+ if (trace_find_next_entry_inc(&iter) != NULL) {
+ int ret;
+
+ ret = print_trace_line(&iter);
+ if (ret != TRACE_TYPE_NO_CONSUME)
+ trace_consume(&iter);
+ }
+ touch_nmi_watchdog();
+
+ trace_printk_seq(&iter.seq);
+ }
+
+ if (!cnt)
+ printk(KERN_TRACE " (ftrace buffer empty)\n");
+ else
+ printk(KERN_TRACE "---------------------------------\n");
+
+ out_enable:
+ tr->trace_flags |= old_userobj;
+
+ for_each_tracing_cpu(cpu) {
+ atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
+ }
+ atomic_dec(&dump_running);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(ftrace_dump);
+
+#define WRITE_BUFSIZE 4096
+
+ssize_t trace_parse_run_command(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos,
+ int (*createfn)(const char *))
+{
+ char *kbuf, *buf, *tmp;
+ int ret = 0;
+ size_t done = 0;
+ size_t size;
+
+ kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+
+ while (done < count) {
+ size = count - done;
+
+ if (size >= WRITE_BUFSIZE)
+ size = WRITE_BUFSIZE - 1;
+
+ if (copy_from_user(kbuf, buffer + done, size)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ kbuf[size] = '\0';
+ buf = kbuf;
+ do {
+ tmp = strchr(buf, '\n');
+ if (tmp) {
+ *tmp = '\0';
+ size = tmp - buf + 1;
+ } else {
+ size = strlen(buf);
+ if (done + size < count) {
+ if (buf != kbuf)
+ break;
+ /* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */
+ pr_warn("Line length is too long: Should be less than %d\n",
+ WRITE_BUFSIZE - 2);
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+ done += size;
+
+ /* Remove comments */
+ tmp = strchr(buf, '#');
+
+ if (tmp)
+ *tmp = '\0';
+
+ ret = createfn(buf);
+ if (ret)
+ goto out;
+ buf += size;
+
+ } while (done < count);
+ }
+ ret = done;
+
+out:
+ kfree(kbuf);
+
+ return ret;
+}
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+__init static bool tr_needs_alloc_snapshot(const char *name)
+{
+ char *test;
+ int len = strlen(name);
+ bool ret;
+
+ if (!boot_snapshot_index)
+ return false;
+
+ if (strncmp(name, boot_snapshot_info, len) == 0 &&
+ boot_snapshot_info[len] == '\t')
+ return true;
+
+ test = kmalloc(strlen(name) + 3, GFP_KERNEL);
+ if (!test)
+ return false;
+
+ sprintf(test, "\t%s\t", name);
+ ret = strstr(boot_snapshot_info, test) == NULL;
+ kfree(test);
+ return ret;
+}
+
+__init static void do_allocate_snapshot(const char *name)
+{
+ if (!tr_needs_alloc_snapshot(name))
+ return;
+
+ /*
+ * When allocate_snapshot is set, the next call to
+ * allocate_trace_buffers() (called by trace_array_get_by_name())
+ * will allocate the snapshot buffer. That will alse clear
+ * this flag.
+ */
+ allocate_snapshot = true;
+}
+#else
+static inline void do_allocate_snapshot(const char *name) { }
+#endif
+
+__init static void enable_instances(void)
+{
+ struct trace_array *tr;
+ char *curr_str;
+ char *str;
+ char *tok;
+
+ /* A tab is always appended */
+ boot_instance_info[boot_instance_index - 1] = '\0';
+ str = boot_instance_info;
+
+ while ((curr_str = strsep(&str, "\t"))) {
+
+ tok = strsep(&curr_str, ",");
+
+ if (IS_ENABLED(CONFIG_TRACER_MAX_TRACE))
+ do_allocate_snapshot(tok);
+
+ tr = trace_array_get_by_name(tok);
+ if (!tr) {
+ pr_warn("Failed to create instance buffer %s\n", curr_str);
+ continue;
+ }
+ /* Allow user space to delete it */
+ trace_array_put(tr);
+
+ while ((tok = strsep(&curr_str, ","))) {
+ early_enable_events(tr, tok, true);
+ }
+ }
+}
+
+__init static int tracer_alloc_buffers(void)
+{
+ int ring_buf_size;
+ int ret = -ENOMEM;
+
+
+ if (security_locked_down(LOCKDOWN_TRACEFS)) {
+ pr_warn("Tracing disabled due to lockdown\n");
+ return -EPERM;
+ }
+
+ /*
+ * Make sure we don't accidentally add more trace options
+ * than we have bits for.
+ */
+ BUILD_BUG_ON(TRACE_ITER_LAST_BIT > TRACE_FLAGS_MAX_SIZE);
+
+ if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
+ goto out;
+
+ if (!alloc_cpumask_var(&global_trace.tracing_cpumask, GFP_KERNEL))
+ goto out_free_buffer_mask;
+
+ /* Only allocate trace_printk buffers if a trace_printk exists */
+ if (&__stop___trace_bprintk_fmt != &__start___trace_bprintk_fmt)
+ /* Must be called before global_trace.buffer is allocated */
+ trace_printk_init_buffers();
+
+ /* To save memory, keep the ring buffer size to its minimum */
+ if (ring_buffer_expanded)
+ ring_buf_size = trace_buf_size;
+ else
+ ring_buf_size = 1;
+
+ cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
+ cpumask_copy(global_trace.tracing_cpumask, cpu_all_mask);
+
+ raw_spin_lock_init(&global_trace.start_lock);
+
+ /*
+ * The prepare callbacks allocates some memory for the ring buffer. We
+ * don't free the buffer if the CPU goes down. If we were to free
+ * the buffer, then the user would lose any trace that was in the
+ * buffer. The memory will be removed once the "instance" is removed.
+ */
+ ret = cpuhp_setup_state_multi(CPUHP_TRACE_RB_PREPARE,
+ "trace/RB:prepare", trace_rb_cpu_prepare,
+ NULL);
+ if (ret < 0)
+ goto out_free_cpumask;
+ /* Used for event triggers */
+ ret = -ENOMEM;
+ temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE);
+ if (!temp_buffer)
+ goto out_rm_hp_state;
+
+ if (trace_create_savedcmd() < 0)
+ goto out_free_temp_buffer;
+
+ if (!zalloc_cpumask_var(&global_trace.pipe_cpumask, GFP_KERNEL))
+ goto out_free_savedcmd;
+
+ /* TODO: make the number of buffers hot pluggable with CPUS */
+ if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {
+ MEM_FAIL(1, "tracer: failed to allocate ring buffer!\n");
+ goto out_free_pipe_cpumask;
+ }
+ if (global_trace.buffer_disabled)
+ tracing_off();
+
+ if (trace_boot_clock) {
+ ret = tracing_set_clock(&global_trace, trace_boot_clock);
+ if (ret < 0)
+ pr_warn("Trace clock %s not defined, going back to default\n",
+ trace_boot_clock);
+ }
+
+ /*
+ * register_tracer() might reference current_trace, so it
+ * needs to be set before we register anything. This is
+ * just a bootstrap of current_trace anyway.
+ */
+ global_trace.current_trace = &nop_trace;
+
+ global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
+
+ ftrace_init_global_array_ops(&global_trace);
+
+ init_trace_flags_index(&global_trace);
+
+ register_tracer(&nop_trace);
+
+ /* Function tracing may start here (via kernel command line) */
+ init_function_trace();
+
+ /* All seems OK, enable tracing */
+ tracing_disabled = 0;
+
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &trace_panic_notifier);
+
+ register_die_notifier(&trace_die_notifier);
+
+ global_trace.flags = TRACE_ARRAY_FL_GLOBAL;
+
+ INIT_LIST_HEAD(&global_trace.systems);
+ INIT_LIST_HEAD(&global_trace.events);
+ INIT_LIST_HEAD(&global_trace.hist_vars);
+ INIT_LIST_HEAD(&global_trace.err_log);
+ list_add(&global_trace.list, &ftrace_trace_arrays);
+
+ apply_trace_boot_options();
+
+ register_snapshot_cmd();
+
+ test_can_verify();
+
+ return 0;
+
+out_free_pipe_cpumask:
+ free_cpumask_var(global_trace.pipe_cpumask);
+out_free_savedcmd:
+ free_saved_cmdlines_buffer(savedcmd);
+out_free_temp_buffer:
+ ring_buffer_free(temp_buffer);
+out_rm_hp_state:
+ cpuhp_remove_multi_state(CPUHP_TRACE_RB_PREPARE);
+out_free_cpumask:
+ free_cpumask_var(global_trace.tracing_cpumask);
+out_free_buffer_mask:
+ free_cpumask_var(tracing_buffer_mask);
+out:
+ return ret;
+}
+
+void __init ftrace_boot_snapshot(void)
+{
+#ifdef CONFIG_TRACER_MAX_TRACE
+ struct trace_array *tr;
+
+ if (!snapshot_at_boot)
+ return;
+
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (!tr->allocated_snapshot)
+ continue;
+
+ tracing_snapshot_instance(tr);
+ trace_array_puts(tr, "** Boot snapshot taken **\n");
+ }
+#endif
+}
+
+void __init early_trace_init(void)
+{
+ if (tracepoint_printk) {
+ tracepoint_print_iter =
+ kzalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL);
+ if (MEM_FAIL(!tracepoint_print_iter,
+ "Failed to allocate trace iterator\n"))
+ tracepoint_printk = 0;
+ else
+ static_key_enable(&tracepoint_printk_key.key);
+ }
+ tracer_alloc_buffers();
+
+ init_events();
+}
+
+void __init trace_init(void)
+{
+ trace_event_init();
+
+ if (boot_instance_index)
+ enable_instances();
+}
+
+__init static void clear_boot_tracer(void)
+{
+ /*
+ * The default tracer at boot buffer is an init section.
+ * This function is called in lateinit. If we did not
+ * find the boot tracer, then clear it out, to prevent
+ * later registration from accessing the buffer that is
+ * about to be freed.
+ */
+ if (!default_bootup_tracer)
+ return;
+
+ printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n",
+ default_bootup_tracer);
+ default_bootup_tracer = NULL;
+}
+
+#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
+__init static void tracing_set_default_clock(void)
+{
+ /* sched_clock_stable() is determined in late_initcall */
+ if (!trace_boot_clock && !sched_clock_stable()) {
+ if (security_locked_down(LOCKDOWN_TRACEFS)) {
+ pr_warn("Can not set tracing clock due to lockdown\n");
+ return;
+ }
+
+ printk(KERN_WARNING
+ "Unstable clock detected, switching default tracing clock to \"global\"\n"
+ "If you want to keep using the local clock, then add:\n"
+ " \"trace_clock=local\"\n"
+ "on the kernel command line\n");
+ tracing_set_clock(&global_trace, "global");
+ }
+}
+#else
+static inline void tracing_set_default_clock(void) { }
+#endif
+
+__init static int late_trace_init(void)
+{
+ if (tracepoint_printk && tracepoint_printk_stop_on_boot) {
+ static_key_disable(&tracepoint_printk_key.key);
+ tracepoint_printk = 0;
+ }
+
+ tracing_set_default_clock();
+ clear_boot_tracer();
+ return 0;
+}
+
+late_initcall_sync(late_trace_init);