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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /kernel/trace/ftrace.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c8472
1 files changed, 8472 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
new file mode 100644
index 000000000..552956ccb
--- /dev/null
+++ b/kernel/trace/ftrace.c
@@ -0,0 +1,8472 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Infrastructure for profiling code inserted by 'gcc -pg'.
+ *
+ * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
+ * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
+ *
+ * Originally ported from the -rt patch by:
+ * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
+ *
+ * Based on code in the latency_tracer, that is:
+ *
+ * Copyright (C) 2004-2006 Ingo Molnar
+ * Copyright (C) 2004 Nadia Yvette Chambers
+ */
+
+#include <linux/stop_machine.h>
+#include <linux/clocksource.h>
+#include <linux/sched/task.h>
+#include <linux/kallsyms.h>
+#include <linux/security.h>
+#include <linux/seq_file.h>
+#include <linux/tracefs.h>
+#include <linux/hardirq.h>
+#include <linux/kthread.h>
+#include <linux/uaccess.h>
+#include <linux/bsearch.h>
+#include <linux/module.h>
+#include <linux/ftrace.h>
+#include <linux/sysctl.h>
+#include <linux/slab.h>
+#include <linux/ctype.h>
+#include <linux/sort.h>
+#include <linux/list.h>
+#include <linux/hash.h>
+#include <linux/rcupdate.h>
+#include <linux/kprobes.h>
+
+#include <trace/events/sched.h>
+
+#include <asm/sections.h>
+#include <asm/setup.h>
+
+#include "ftrace_internal.h"
+#include "trace_output.h"
+#include "trace_stat.h"
+
+#define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__"
+
+#define FTRACE_WARN_ON(cond) \
+ ({ \
+ int ___r = cond; \
+ if (WARN_ON(___r)) \
+ ftrace_kill(); \
+ ___r; \
+ })
+
+#define FTRACE_WARN_ON_ONCE(cond) \
+ ({ \
+ int ___r = cond; \
+ if (WARN_ON_ONCE(___r)) \
+ ftrace_kill(); \
+ ___r; \
+ })
+
+/* hash bits for specific function selection */
+#define FTRACE_HASH_DEFAULT_BITS 10
+#define FTRACE_HASH_MAX_BITS 12
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+#define INIT_OPS_HASH(opsname) \
+ .func_hash = &opsname.local_hash, \
+ .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
+#else
+#define INIT_OPS_HASH(opsname)
+#endif
+
+enum {
+ FTRACE_MODIFY_ENABLE_FL = (1 << 0),
+ FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1),
+};
+
+struct ftrace_ops ftrace_list_end __read_mostly = {
+ .func = ftrace_stub,
+ .flags = FTRACE_OPS_FL_STUB,
+ INIT_OPS_HASH(ftrace_list_end)
+};
+
+/* ftrace_enabled is a method to turn ftrace on or off */
+int ftrace_enabled __read_mostly;
+static int __maybe_unused last_ftrace_enabled;
+
+/* Current function tracing op */
+struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
+/* What to set function_trace_op to */
+static struct ftrace_ops *set_function_trace_op;
+
+static bool ftrace_pids_enabled(struct ftrace_ops *ops)
+{
+ struct trace_array *tr;
+
+ if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
+ return false;
+
+ tr = ops->private;
+
+ return tr->function_pids != NULL || tr->function_no_pids != NULL;
+}
+
+static void ftrace_update_trampoline(struct ftrace_ops *ops);
+
+/*
+ * ftrace_disabled is set when an anomaly is discovered.
+ * ftrace_disabled is much stronger than ftrace_enabled.
+ */
+static int ftrace_disabled __read_mostly;
+
+DEFINE_MUTEX(ftrace_lock);
+
+struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
+ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
+struct ftrace_ops global_ops;
+
+/* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */
+void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs);
+
+static inline void ftrace_ops_init(struct ftrace_ops *ops)
+{
+#ifdef CONFIG_DYNAMIC_FTRACE
+ if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
+ mutex_init(&ops->local_hash.regex_lock);
+ ops->func_hash = &ops->local_hash;
+ ops->flags |= FTRACE_OPS_FL_INITIALIZED;
+ }
+#endif
+}
+
+static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
+{
+ struct trace_array *tr = op->private;
+ int pid;
+
+ if (tr) {
+ pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid);
+ if (pid == FTRACE_PID_IGNORE)
+ return;
+ if (pid != FTRACE_PID_TRACE &&
+ pid != current->pid)
+ return;
+ }
+
+ op->saved_func(ip, parent_ip, op, fregs);
+}
+
+static void ftrace_sync_ipi(void *data)
+{
+ /* Probably not needed, but do it anyway */
+ smp_rmb();
+}
+
+static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
+{
+ /*
+ * If this is a dynamic, RCU, or per CPU ops, or we force list func,
+ * then it needs to call the list anyway.
+ */
+ if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
+ FTRACE_FORCE_LIST_FUNC)
+ return ftrace_ops_list_func;
+
+ return ftrace_ops_get_func(ops);
+}
+
+static void update_ftrace_function(void)
+{
+ ftrace_func_t func;
+
+ /*
+ * Prepare the ftrace_ops that the arch callback will use.
+ * If there's only one ftrace_ops registered, the ftrace_ops_list
+ * will point to the ops we want.
+ */
+ set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
+ lockdep_is_held(&ftrace_lock));
+
+ /* If there's no ftrace_ops registered, just call the stub function */
+ if (set_function_trace_op == &ftrace_list_end) {
+ func = ftrace_stub;
+
+ /*
+ * If we are at the end of the list and this ops is
+ * recursion safe and not dynamic and the arch supports passing ops,
+ * then have the mcount trampoline call the function directly.
+ */
+ } else if (rcu_dereference_protected(ftrace_ops_list->next,
+ lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
+ func = ftrace_ops_get_list_func(ftrace_ops_list);
+
+ } else {
+ /* Just use the default ftrace_ops */
+ set_function_trace_op = &ftrace_list_end;
+ func = ftrace_ops_list_func;
+ }
+
+ update_function_graph_func();
+
+ /* If there's no change, then do nothing more here */
+ if (ftrace_trace_function == func)
+ return;
+
+ /*
+ * If we are using the list function, it doesn't care
+ * about the function_trace_ops.
+ */
+ if (func == ftrace_ops_list_func) {
+ ftrace_trace_function = func;
+ /*
+ * Don't even bother setting function_trace_ops,
+ * it would be racy to do so anyway.
+ */
+ return;
+ }
+
+#ifndef CONFIG_DYNAMIC_FTRACE
+ /*
+ * For static tracing, we need to be a bit more careful.
+ * The function change takes affect immediately. Thus,
+ * we need to coordinate the setting of the function_trace_ops
+ * with the setting of the ftrace_trace_function.
+ *
+ * Set the function to the list ops, which will call the
+ * function we want, albeit indirectly, but it handles the
+ * ftrace_ops and doesn't depend on function_trace_op.
+ */
+ ftrace_trace_function = ftrace_ops_list_func;
+ /*
+ * Make sure all CPUs see this. Yes this is slow, but static
+ * tracing is slow and nasty to have enabled.
+ */
+ synchronize_rcu_tasks_rude();
+ /* Now all cpus are using the list ops. */
+ function_trace_op = set_function_trace_op;
+ /* Make sure the function_trace_op is visible on all CPUs */
+ smp_wmb();
+ /* Nasty way to force a rmb on all cpus */
+ smp_call_function(ftrace_sync_ipi, NULL, 1);
+ /* OK, we are all set to update the ftrace_trace_function now! */
+#endif /* !CONFIG_DYNAMIC_FTRACE */
+
+ ftrace_trace_function = func;
+}
+
+static void add_ftrace_ops(struct ftrace_ops __rcu **list,
+ struct ftrace_ops *ops)
+{
+ rcu_assign_pointer(ops->next, *list);
+
+ /*
+ * We are entering ops into the list but another
+ * CPU might be walking that list. We need to make sure
+ * the ops->next pointer is valid before another CPU sees
+ * the ops pointer included into the list.
+ */
+ rcu_assign_pointer(*list, ops);
+}
+
+static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
+ struct ftrace_ops *ops)
+{
+ struct ftrace_ops **p;
+
+ /*
+ * If we are removing the last function, then simply point
+ * to the ftrace_stub.
+ */
+ if (rcu_dereference_protected(*list,
+ lockdep_is_held(&ftrace_lock)) == ops &&
+ rcu_dereference_protected(ops->next,
+ lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
+ *list = &ftrace_list_end;
+ return 0;
+ }
+
+ for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
+ if (*p == ops)
+ break;
+
+ if (*p != ops)
+ return -1;
+
+ *p = (*p)->next;
+ return 0;
+}
+
+static void ftrace_update_trampoline(struct ftrace_ops *ops);
+
+int __register_ftrace_function(struct ftrace_ops *ops)
+{
+ if (ops->flags & FTRACE_OPS_FL_DELETED)
+ return -EINVAL;
+
+ if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return -EBUSY;
+
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ /*
+ * If the ftrace_ops specifies SAVE_REGS, then it only can be used
+ * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
+ * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
+ */
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
+ !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
+ return -EINVAL;
+
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
+ ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
+#endif
+ if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT))
+ return -EBUSY;
+
+ if (!is_kernel_core_data((unsigned long)ops))
+ ops->flags |= FTRACE_OPS_FL_DYNAMIC;
+
+ add_ftrace_ops(&ftrace_ops_list, ops);
+
+ /* Always save the function, and reset at unregistering */
+ ops->saved_func = ops->func;
+
+ if (ftrace_pids_enabled(ops))
+ ops->func = ftrace_pid_func;
+
+ ftrace_update_trampoline(ops);
+
+ if (ftrace_enabled)
+ update_ftrace_function();
+
+ return 0;
+}
+
+int __unregister_ftrace_function(struct ftrace_ops *ops)
+{
+ int ret;
+
+ if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
+ return -EBUSY;
+
+ ret = remove_ftrace_ops(&ftrace_ops_list, ops);
+
+ if (ret < 0)
+ return ret;
+
+ if (ftrace_enabled)
+ update_ftrace_function();
+
+ ops->func = ops->saved_func;
+
+ return 0;
+}
+
+static void ftrace_update_pid_func(void)
+{
+ struct ftrace_ops *op;
+
+ /* Only do something if we are tracing something */
+ if (ftrace_trace_function == ftrace_stub)
+ return;
+
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+ if (op->flags & FTRACE_OPS_FL_PID) {
+ op->func = ftrace_pids_enabled(op) ?
+ ftrace_pid_func : op->saved_func;
+ ftrace_update_trampoline(op);
+ }
+ } while_for_each_ftrace_op(op);
+
+ update_ftrace_function();
+}
+
+#ifdef CONFIG_FUNCTION_PROFILER
+struct ftrace_profile {
+ struct hlist_node node;
+ unsigned long ip;
+ unsigned long counter;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ unsigned long long time;
+ unsigned long long time_squared;
+#endif
+};
+
+struct ftrace_profile_page {
+ struct ftrace_profile_page *next;
+ unsigned long index;
+ struct ftrace_profile records[];
+};
+
+struct ftrace_profile_stat {
+ atomic_t disabled;
+ struct hlist_head *hash;
+ struct ftrace_profile_page *pages;
+ struct ftrace_profile_page *start;
+ struct tracer_stat stat;
+};
+
+#define PROFILE_RECORDS_SIZE \
+ (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
+
+#define PROFILES_PER_PAGE \
+ (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
+
+static int ftrace_profile_enabled __read_mostly;
+
+/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
+static DEFINE_MUTEX(ftrace_profile_lock);
+
+static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
+
+#define FTRACE_PROFILE_HASH_BITS 10
+#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
+
+static void *
+function_stat_next(void *v, int idx)
+{
+ struct ftrace_profile *rec = v;
+ struct ftrace_profile_page *pg;
+
+ pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
+
+ again:
+ if (idx != 0)
+ rec++;
+
+ if ((void *)rec >= (void *)&pg->records[pg->index]) {
+ pg = pg->next;
+ if (!pg)
+ return NULL;
+ rec = &pg->records[0];
+ if (!rec->counter)
+ goto again;
+ }
+
+ return rec;
+}
+
+static void *function_stat_start(struct tracer_stat *trace)
+{
+ struct ftrace_profile_stat *stat =
+ container_of(trace, struct ftrace_profile_stat, stat);
+
+ if (!stat || !stat->start)
+ return NULL;
+
+ return function_stat_next(&stat->start->records[0], 0);
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+/* function graph compares on total time */
+static int function_stat_cmp(const void *p1, const void *p2)
+{
+ const struct ftrace_profile *a = p1;
+ const struct ftrace_profile *b = p2;
+
+ if (a->time < b->time)
+ return -1;
+ if (a->time > b->time)
+ return 1;
+ else
+ return 0;
+}
+#else
+/* not function graph compares against hits */
+static int function_stat_cmp(const void *p1, const void *p2)
+{
+ const struct ftrace_profile *a = p1;
+ const struct ftrace_profile *b = p2;
+
+ if (a->counter < b->counter)
+ return -1;
+ if (a->counter > b->counter)
+ return 1;
+ else
+ return 0;
+}
+#endif
+
+static int function_stat_headers(struct seq_file *m)
+{
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ seq_puts(m, " Function "
+ "Hit Time Avg s^2\n"
+ " -------- "
+ "--- ---- --- ---\n");
+#else
+ seq_puts(m, " Function Hit\n"
+ " -------- ---\n");
+#endif
+ return 0;
+}
+
+static int function_stat_show(struct seq_file *m, void *v)
+{
+ struct ftrace_profile *rec = v;
+ char str[KSYM_SYMBOL_LEN];
+ int ret = 0;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ static struct trace_seq s;
+ unsigned long long avg;
+ unsigned long long stddev;
+#endif
+ mutex_lock(&ftrace_profile_lock);
+
+ /* we raced with function_profile_reset() */
+ if (unlikely(rec->counter == 0)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ avg = div64_ul(rec->time, rec->counter);
+ if (tracing_thresh && (avg < tracing_thresh))
+ goto out;
+#endif
+
+ kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+ seq_printf(m, " %-30.30s %10lu", str, rec->counter);
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ seq_puts(m, " ");
+
+ /* Sample standard deviation (s^2) */
+ if (rec->counter <= 1)
+ stddev = 0;
+ else {
+ /*
+ * Apply Welford's method:
+ * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
+ */
+ stddev = rec->counter * rec->time_squared -
+ rec->time * rec->time;
+
+ /*
+ * Divide only 1000 for ns^2 -> us^2 conversion.
+ * trace_print_graph_duration will divide 1000 again.
+ */
+ stddev = div64_ul(stddev,
+ rec->counter * (rec->counter - 1) * 1000);
+ }
+
+ trace_seq_init(&s);
+ trace_print_graph_duration(rec->time, &s);
+ trace_seq_puts(&s, " ");
+ trace_print_graph_duration(avg, &s);
+ trace_seq_puts(&s, " ");
+ trace_print_graph_duration(stddev, &s);
+ trace_print_seq(m, &s);
+#endif
+ seq_putc(m, '\n');
+out:
+ mutex_unlock(&ftrace_profile_lock);
+
+ return ret;
+}
+
+static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
+{
+ struct ftrace_profile_page *pg;
+
+ pg = stat->pages = stat->start;
+
+ while (pg) {
+ memset(pg->records, 0, PROFILE_RECORDS_SIZE);
+ pg->index = 0;
+ pg = pg->next;
+ }
+
+ memset(stat->hash, 0,
+ FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
+}
+
+static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
+{
+ struct ftrace_profile_page *pg;
+ int functions;
+ int pages;
+ int i;
+
+ /* If we already allocated, do nothing */
+ if (stat->pages)
+ return 0;
+
+ stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
+ if (!stat->pages)
+ return -ENOMEM;
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+ functions = ftrace_update_tot_cnt;
+#else
+ /*
+ * We do not know the number of functions that exist because
+ * dynamic tracing is what counts them. With past experience
+ * we have around 20K functions. That should be more than enough.
+ * It is highly unlikely we will execute every function in
+ * the kernel.
+ */
+ functions = 20000;
+#endif
+
+ pg = stat->start = stat->pages;
+
+ pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
+
+ for (i = 1; i < pages; i++) {
+ pg->next = (void *)get_zeroed_page(GFP_KERNEL);
+ if (!pg->next)
+ goto out_free;
+ pg = pg->next;
+ }
+
+ return 0;
+
+ out_free:
+ pg = stat->start;
+ while (pg) {
+ unsigned long tmp = (unsigned long)pg;
+
+ pg = pg->next;
+ free_page(tmp);
+ }
+
+ stat->pages = NULL;
+ stat->start = NULL;
+
+ return -ENOMEM;
+}
+
+static int ftrace_profile_init_cpu(int cpu)
+{
+ struct ftrace_profile_stat *stat;
+ int size;
+
+ stat = &per_cpu(ftrace_profile_stats, cpu);
+
+ if (stat->hash) {
+ /* If the profile is already created, simply reset it */
+ ftrace_profile_reset(stat);
+ return 0;
+ }
+
+ /*
+ * We are profiling all functions, but usually only a few thousand
+ * functions are hit. We'll make a hash of 1024 items.
+ */
+ size = FTRACE_PROFILE_HASH_SIZE;
+
+ stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL);
+
+ if (!stat->hash)
+ return -ENOMEM;
+
+ /* Preallocate the function profiling pages */
+ if (ftrace_profile_pages_init(stat) < 0) {
+ kfree(stat->hash);
+ stat->hash = NULL;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int ftrace_profile_init(void)
+{
+ int cpu;
+ int ret = 0;
+
+ for_each_possible_cpu(cpu) {
+ ret = ftrace_profile_init_cpu(cpu);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+/* interrupts must be disabled */
+static struct ftrace_profile *
+ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
+{
+ struct ftrace_profile *rec;
+ struct hlist_head *hhd;
+ unsigned long key;
+
+ key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
+ hhd = &stat->hash[key];
+
+ if (hlist_empty(hhd))
+ return NULL;
+
+ hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
+ if (rec->ip == ip)
+ return rec;
+ }
+
+ return NULL;
+}
+
+static void ftrace_add_profile(struct ftrace_profile_stat *stat,
+ struct ftrace_profile *rec)
+{
+ unsigned long key;
+
+ key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
+ hlist_add_head_rcu(&rec->node, &stat->hash[key]);
+}
+
+/*
+ * The memory is already allocated, this simply finds a new record to use.
+ */
+static struct ftrace_profile *
+ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
+{
+ struct ftrace_profile *rec = NULL;
+
+ /* prevent recursion (from NMIs) */
+ if (atomic_inc_return(&stat->disabled) != 1)
+ goto out;
+
+ /*
+ * Try to find the function again since an NMI
+ * could have added it
+ */
+ rec = ftrace_find_profiled_func(stat, ip);
+ if (rec)
+ goto out;
+
+ if (stat->pages->index == PROFILES_PER_PAGE) {
+ if (!stat->pages->next)
+ goto out;
+ stat->pages = stat->pages->next;
+ }
+
+ rec = &stat->pages->records[stat->pages->index++];
+ rec->ip = ip;
+ ftrace_add_profile(stat, rec);
+
+ out:
+ atomic_dec(&stat->disabled);
+
+ return rec;
+}
+
+static void
+function_profile_call(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *ops, struct ftrace_regs *fregs)
+{
+ struct ftrace_profile_stat *stat;
+ struct ftrace_profile *rec;
+ unsigned long flags;
+
+ if (!ftrace_profile_enabled)
+ return;
+
+ local_irq_save(flags);
+
+ stat = this_cpu_ptr(&ftrace_profile_stats);
+ if (!stat->hash || !ftrace_profile_enabled)
+ goto out;
+
+ rec = ftrace_find_profiled_func(stat, ip);
+ if (!rec) {
+ rec = ftrace_profile_alloc(stat, ip);
+ if (!rec)
+ goto out;
+ }
+
+ rec->counter++;
+ out:
+ local_irq_restore(flags);
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static bool fgraph_graph_time = true;
+
+void ftrace_graph_graph_time_control(bool enable)
+{
+ fgraph_graph_time = enable;
+}
+
+static int profile_graph_entry(struct ftrace_graph_ent *trace)
+{
+ struct ftrace_ret_stack *ret_stack;
+
+ function_profile_call(trace->func, 0, NULL, NULL);
+
+ /* If function graph is shutting down, ret_stack can be NULL */
+ if (!current->ret_stack)
+ return 0;
+
+ ret_stack = ftrace_graph_get_ret_stack(current, 0);
+ if (ret_stack)
+ ret_stack->subtime = 0;
+
+ return 1;
+}
+
+static void profile_graph_return(struct ftrace_graph_ret *trace)
+{
+ struct ftrace_ret_stack *ret_stack;
+ struct ftrace_profile_stat *stat;
+ unsigned long long calltime;
+ struct ftrace_profile *rec;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ stat = this_cpu_ptr(&ftrace_profile_stats);
+ if (!stat->hash || !ftrace_profile_enabled)
+ goto out;
+
+ /* If the calltime was zero'd ignore it */
+ if (!trace->calltime)
+ goto out;
+
+ calltime = trace->rettime - trace->calltime;
+
+ if (!fgraph_graph_time) {
+
+ /* Append this call time to the parent time to subtract */
+ ret_stack = ftrace_graph_get_ret_stack(current, 1);
+ if (ret_stack)
+ ret_stack->subtime += calltime;
+
+ ret_stack = ftrace_graph_get_ret_stack(current, 0);
+ if (ret_stack && ret_stack->subtime < calltime)
+ calltime -= ret_stack->subtime;
+ else
+ calltime = 0;
+ }
+
+ rec = ftrace_find_profiled_func(stat, trace->func);
+ if (rec) {
+ rec->time += calltime;
+ rec->time_squared += calltime * calltime;
+ }
+
+ out:
+ local_irq_restore(flags);
+}
+
+static struct fgraph_ops fprofiler_ops = {
+ .entryfunc = &profile_graph_entry,
+ .retfunc = &profile_graph_return,
+};
+
+static int register_ftrace_profiler(void)
+{
+ return register_ftrace_graph(&fprofiler_ops);
+}
+
+static void unregister_ftrace_profiler(void)
+{
+ unregister_ftrace_graph(&fprofiler_ops);
+}
+#else
+static struct ftrace_ops ftrace_profile_ops __read_mostly = {
+ .func = function_profile_call,
+ .flags = FTRACE_OPS_FL_INITIALIZED,
+ INIT_OPS_HASH(ftrace_profile_ops)
+};
+
+static int register_ftrace_profiler(void)
+{
+ return register_ftrace_function(&ftrace_profile_ops);
+}
+
+static void unregister_ftrace_profiler(void)
+{
+ unregister_ftrace_function(&ftrace_profile_ops);
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+static ssize_t
+ftrace_profile_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;
+
+ val = !!val;
+
+ mutex_lock(&ftrace_profile_lock);
+ if (ftrace_profile_enabled ^ val) {
+ if (val) {
+ ret = ftrace_profile_init();
+ if (ret < 0) {
+ cnt = ret;
+ goto out;
+ }
+
+ ret = register_ftrace_profiler();
+ if (ret < 0) {
+ cnt = ret;
+ goto out;
+ }
+ ftrace_profile_enabled = 1;
+ } else {
+ ftrace_profile_enabled = 0;
+ /*
+ * unregister_ftrace_profiler calls stop_machine
+ * so this acts like an synchronize_rcu.
+ */
+ unregister_ftrace_profiler();
+ }
+ }
+ out:
+ mutex_unlock(&ftrace_profile_lock);
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static ssize_t
+ftrace_profile_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64]; /* big enough to hold a number */
+ int r;
+
+ r = sprintf(buf, "%u\n", ftrace_profile_enabled);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static const struct file_operations ftrace_profile_fops = {
+ .open = tracing_open_generic,
+ .read = ftrace_profile_read,
+ .write = ftrace_profile_write,
+ .llseek = default_llseek,
+};
+
+/* used to initialize the real stat files */
+static struct tracer_stat function_stats __initdata = {
+ .name = "functions",
+ .stat_start = function_stat_start,
+ .stat_next = function_stat_next,
+ .stat_cmp = function_stat_cmp,
+ .stat_headers = function_stat_headers,
+ .stat_show = function_stat_show
+};
+
+static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
+{
+ struct ftrace_profile_stat *stat;
+ char *name;
+ int ret;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ stat = &per_cpu(ftrace_profile_stats, cpu);
+
+ name = kasprintf(GFP_KERNEL, "function%d", cpu);
+ if (!name) {
+ /*
+ * The files created are permanent, if something happens
+ * we still do not free memory.
+ */
+ WARN(1,
+ "Could not allocate stat file for cpu %d\n",
+ cpu);
+ return;
+ }
+ stat->stat = function_stats;
+ stat->stat.name = name;
+ ret = register_stat_tracer(&stat->stat);
+ if (ret) {
+ WARN(1,
+ "Could not register function stat for cpu %d\n",
+ cpu);
+ kfree(name);
+ return;
+ }
+ }
+
+ trace_create_file("function_profile_enabled",
+ TRACE_MODE_WRITE, d_tracer, NULL,
+ &ftrace_profile_fops);
+}
+
+#else /* CONFIG_FUNCTION_PROFILER */
+static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
+{
+}
+#endif /* CONFIG_FUNCTION_PROFILER */
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+static struct ftrace_ops *removed_ops;
+
+/*
+ * Set when doing a global update, like enabling all recs or disabling them.
+ * It is not set when just updating a single ftrace_ops.
+ */
+static bool update_all_ops;
+
+#ifndef CONFIG_FTRACE_MCOUNT_RECORD
+# error Dynamic ftrace depends on MCOUNT_RECORD
+#endif
+
+struct ftrace_func_probe {
+ struct ftrace_probe_ops *probe_ops;
+ struct ftrace_ops ops;
+ struct trace_array *tr;
+ struct list_head list;
+ void *data;
+ int ref;
+};
+
+/*
+ * We make these constant because no one should touch them,
+ * but they are used as the default "empty hash", to avoid allocating
+ * it all the time. These are in a read only section such that if
+ * anyone does try to modify it, it will cause an exception.
+ */
+static const struct hlist_head empty_buckets[1];
+static const struct ftrace_hash empty_hash = {
+ .buckets = (struct hlist_head *)empty_buckets,
+};
+#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
+
+struct ftrace_ops global_ops = {
+ .func = ftrace_stub,
+ .local_hash.notrace_hash = EMPTY_HASH,
+ .local_hash.filter_hash = EMPTY_HASH,
+ INIT_OPS_HASH(global_ops)
+ .flags = FTRACE_OPS_FL_INITIALIZED |
+ FTRACE_OPS_FL_PID,
+};
+
+/*
+ * Used by the stack unwinder to know about dynamic ftrace trampolines.
+ */
+struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
+{
+ struct ftrace_ops *op = NULL;
+
+ /*
+ * Some of the ops may be dynamically allocated,
+ * they are freed after a synchronize_rcu().
+ */
+ preempt_disable_notrace();
+
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+ /*
+ * This is to check for dynamically allocated trampolines.
+ * Trampolines that are in kernel text will have
+ * core_kernel_text() return true.
+ */
+ if (op->trampoline && op->trampoline_size)
+ if (addr >= op->trampoline &&
+ addr < op->trampoline + op->trampoline_size) {
+ preempt_enable_notrace();
+ return op;
+ }
+ } while_for_each_ftrace_op(op);
+ preempt_enable_notrace();
+
+ return NULL;
+}
+
+/*
+ * This is used by __kernel_text_address() to return true if the
+ * address is on a dynamically allocated trampoline that would
+ * not return true for either core_kernel_text() or
+ * is_module_text_address().
+ */
+bool is_ftrace_trampoline(unsigned long addr)
+{
+ return ftrace_ops_trampoline(addr) != NULL;
+}
+
+struct ftrace_page {
+ struct ftrace_page *next;
+ struct dyn_ftrace *records;
+ int index;
+ int order;
+};
+
+#define ENTRY_SIZE sizeof(struct dyn_ftrace)
+#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
+
+static struct ftrace_page *ftrace_pages_start;
+static struct ftrace_page *ftrace_pages;
+
+static __always_inline unsigned long
+ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
+{
+ if (hash->size_bits > 0)
+ return hash_long(ip, hash->size_bits);
+
+ return 0;
+}
+
+/* Only use this function if ftrace_hash_empty() has already been tested */
+static __always_inline struct ftrace_func_entry *
+__ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
+{
+ unsigned long key;
+ struct ftrace_func_entry *entry;
+ struct hlist_head *hhd;
+
+ key = ftrace_hash_key(hash, ip);
+ hhd = &hash->buckets[key];
+
+ hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
+ if (entry->ip == ip)
+ return entry;
+ }
+ return NULL;
+}
+
+/**
+ * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
+ * @hash: The hash to look at
+ * @ip: The instruction pointer to test
+ *
+ * Search a given @hash to see if a given instruction pointer (@ip)
+ * exists in it.
+ *
+ * Returns the entry that holds the @ip if found. NULL otherwise.
+ */
+struct ftrace_func_entry *
+ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
+{
+ if (ftrace_hash_empty(hash))
+ return NULL;
+
+ return __ftrace_lookup_ip(hash, ip);
+}
+
+static void __add_hash_entry(struct ftrace_hash *hash,
+ struct ftrace_func_entry *entry)
+{
+ struct hlist_head *hhd;
+ unsigned long key;
+
+ key = ftrace_hash_key(hash, entry->ip);
+ hhd = &hash->buckets[key];
+ hlist_add_head(&entry->hlist, hhd);
+ hash->count++;
+}
+
+static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
+{
+ struct ftrace_func_entry *entry;
+
+ entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+
+ entry->ip = ip;
+ __add_hash_entry(hash, entry);
+
+ return 0;
+}
+
+static void
+free_hash_entry(struct ftrace_hash *hash,
+ struct ftrace_func_entry *entry)
+{
+ hlist_del(&entry->hlist);
+ kfree(entry);
+ hash->count--;
+}
+
+static void
+remove_hash_entry(struct ftrace_hash *hash,
+ struct ftrace_func_entry *entry)
+{
+ hlist_del_rcu(&entry->hlist);
+ hash->count--;
+}
+
+static void ftrace_hash_clear(struct ftrace_hash *hash)
+{
+ struct hlist_head *hhd;
+ struct hlist_node *tn;
+ struct ftrace_func_entry *entry;
+ int size = 1 << hash->size_bits;
+ int i;
+
+ if (!hash->count)
+ return;
+
+ for (i = 0; i < size; i++) {
+ hhd = &hash->buckets[i];
+ hlist_for_each_entry_safe(entry, tn, hhd, hlist)
+ free_hash_entry(hash, entry);
+ }
+ FTRACE_WARN_ON(hash->count);
+}
+
+static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
+{
+ list_del(&ftrace_mod->list);
+ kfree(ftrace_mod->module);
+ kfree(ftrace_mod->func);
+ kfree(ftrace_mod);
+}
+
+static void clear_ftrace_mod_list(struct list_head *head)
+{
+ struct ftrace_mod_load *p, *n;
+
+ /* stack tracer isn't supported yet */
+ if (!head)
+ return;
+
+ mutex_lock(&ftrace_lock);
+ list_for_each_entry_safe(p, n, head, list)
+ free_ftrace_mod(p);
+ mutex_unlock(&ftrace_lock);
+}
+
+static void free_ftrace_hash(struct ftrace_hash *hash)
+{
+ if (!hash || hash == EMPTY_HASH)
+ return;
+ ftrace_hash_clear(hash);
+ kfree(hash->buckets);
+ kfree(hash);
+}
+
+static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
+{
+ struct ftrace_hash *hash;
+
+ hash = container_of(rcu, struct ftrace_hash, rcu);
+ free_ftrace_hash(hash);
+}
+
+static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
+{
+ if (!hash || hash == EMPTY_HASH)
+ return;
+ call_rcu(&hash->rcu, __free_ftrace_hash_rcu);
+}
+
+/**
+ * ftrace_free_filter - remove all filters for an ftrace_ops
+ * @ops - the ops to remove the filters from
+ */
+void ftrace_free_filter(struct ftrace_ops *ops)
+{
+ ftrace_ops_init(ops);
+ free_ftrace_hash(ops->func_hash->filter_hash);
+ free_ftrace_hash(ops->func_hash->notrace_hash);
+}
+EXPORT_SYMBOL_GPL(ftrace_free_filter);
+
+static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
+{
+ struct ftrace_hash *hash;
+ int size;
+
+ hash = kzalloc(sizeof(*hash), GFP_KERNEL);
+ if (!hash)
+ return NULL;
+
+ size = 1 << size_bits;
+ hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
+
+ if (!hash->buckets) {
+ kfree(hash);
+ return NULL;
+ }
+
+ hash->size_bits = size_bits;
+
+ return hash;
+}
+
+
+static int ftrace_add_mod(struct trace_array *tr,
+ const char *func, const char *module,
+ int enable)
+{
+ struct ftrace_mod_load *ftrace_mod;
+ struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
+
+ ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL);
+ if (!ftrace_mod)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&ftrace_mod->list);
+ ftrace_mod->func = kstrdup(func, GFP_KERNEL);
+ ftrace_mod->module = kstrdup(module, GFP_KERNEL);
+ ftrace_mod->enable = enable;
+
+ if (!ftrace_mod->func || !ftrace_mod->module)
+ goto out_free;
+
+ list_add(&ftrace_mod->list, mod_head);
+
+ return 0;
+
+ out_free:
+ free_ftrace_mod(ftrace_mod);
+
+ return -ENOMEM;
+}
+
+static struct ftrace_hash *
+alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_hash *new_hash;
+ int size;
+ int ret;
+ int i;
+
+ new_hash = alloc_ftrace_hash(size_bits);
+ if (!new_hash)
+ return NULL;
+
+ if (hash)
+ new_hash->flags = hash->flags;
+
+ /* Empty hash? */
+ if (ftrace_hash_empty(hash))
+ return new_hash;
+
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ ret = add_hash_entry(new_hash, entry->ip);
+ if (ret < 0)
+ goto free_hash;
+ }
+ }
+
+ FTRACE_WARN_ON(new_hash->count != hash->count);
+
+ return new_hash;
+
+ free_hash:
+ free_ftrace_hash(new_hash);
+ return NULL;
+}
+
+static void
+ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
+static void
+ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
+
+static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
+ struct ftrace_hash *new_hash);
+
+static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_hash *new_hash;
+ struct hlist_head *hhd;
+ struct hlist_node *tn;
+ int bits = 0;
+ int i;
+
+ /*
+ * Use around half the size (max bit of it), but
+ * a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits).
+ */
+ bits = fls(size / 2);
+
+ /* Don't allocate too much */
+ if (bits > FTRACE_HASH_MAX_BITS)
+ bits = FTRACE_HASH_MAX_BITS;
+
+ new_hash = alloc_ftrace_hash(bits);
+ if (!new_hash)
+ return NULL;
+
+ new_hash->flags = src->flags;
+
+ size = 1 << src->size_bits;
+ for (i = 0; i < size; i++) {
+ hhd = &src->buckets[i];
+ hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
+ remove_hash_entry(src, entry);
+ __add_hash_entry(new_hash, entry);
+ }
+ }
+ return new_hash;
+}
+
+static struct ftrace_hash *
+__ftrace_hash_move(struct ftrace_hash *src)
+{
+ int size = src->count;
+
+ /*
+ * If the new source is empty, just return the empty_hash.
+ */
+ if (ftrace_hash_empty(src))
+ return EMPTY_HASH;
+
+ return dup_hash(src, size);
+}
+
+static int
+ftrace_hash_move(struct ftrace_ops *ops, int enable,
+ struct ftrace_hash **dst, struct ftrace_hash *src)
+{
+ struct ftrace_hash *new_hash;
+ int ret;
+
+ /* Reject setting notrace hash on IPMODIFY ftrace_ops */
+ if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
+ return -EINVAL;
+
+ new_hash = __ftrace_hash_move(src);
+ if (!new_hash)
+ return -ENOMEM;
+
+ /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
+ if (enable) {
+ /* IPMODIFY should be updated only when filter_hash updating */
+ ret = ftrace_hash_ipmodify_update(ops, new_hash);
+ if (ret < 0) {
+ free_ftrace_hash(new_hash);
+ return ret;
+ }
+ }
+
+ /*
+ * Remove the current set, update the hash and add
+ * them back.
+ */
+ ftrace_hash_rec_disable_modify(ops, enable);
+
+ rcu_assign_pointer(*dst, new_hash);
+
+ ftrace_hash_rec_enable_modify(ops, enable);
+
+ return 0;
+}
+
+static bool hash_contains_ip(unsigned long ip,
+ struct ftrace_ops_hash *hash)
+{
+ /*
+ * The function record is a match if it exists in the filter
+ * hash and not in the notrace hash. Note, an empty hash is
+ * considered a match for the filter hash, but an empty
+ * notrace hash is considered not in the notrace hash.
+ */
+ return (ftrace_hash_empty(hash->filter_hash) ||
+ __ftrace_lookup_ip(hash->filter_hash, ip)) &&
+ (ftrace_hash_empty(hash->notrace_hash) ||
+ !__ftrace_lookup_ip(hash->notrace_hash, ip));
+}
+
+/*
+ * Test the hashes for this ops to see if we want to call
+ * the ops->func or not.
+ *
+ * It's a match if the ip is in the ops->filter_hash or
+ * the filter_hash does not exist or is empty,
+ * AND
+ * the ip is not in the ops->notrace_hash.
+ *
+ * This needs to be called with preemption disabled as
+ * the hashes are freed with call_rcu().
+ */
+int
+ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
+{
+ struct ftrace_ops_hash hash;
+ int ret;
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ /*
+ * There's a small race when adding ops that the ftrace handler
+ * that wants regs, may be called without them. We can not
+ * allow that handler to be called if regs is NULL.
+ */
+ if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
+ return 0;
+#endif
+
+ rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
+ rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
+
+ if (hash_contains_ip(ip, &hash))
+ ret = 1;
+ else
+ ret = 0;
+
+ return ret;
+}
+
+/*
+ * This is a double for. Do not use 'break' to break out of the loop,
+ * you must use a goto.
+ */
+#define do_for_each_ftrace_rec(pg, rec) \
+ for (pg = ftrace_pages_start; pg; pg = pg->next) { \
+ int _____i; \
+ for (_____i = 0; _____i < pg->index; _____i++) { \
+ rec = &pg->records[_____i];
+
+#define while_for_each_ftrace_rec() \
+ } \
+ }
+
+
+static int ftrace_cmp_recs(const void *a, const void *b)
+{
+ const struct dyn_ftrace *key = a;
+ const struct dyn_ftrace *rec = b;
+
+ if (key->flags < rec->ip)
+ return -1;
+ if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
+ return 1;
+ return 0;
+}
+
+static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)
+{
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec = NULL;
+ struct dyn_ftrace key;
+
+ key.ip = start;
+ key.flags = end; /* overload flags, as it is unsigned long */
+
+ for (pg = ftrace_pages_start; pg; pg = pg->next) {
+ if (pg->index == 0 ||
+ end < pg->records[0].ip ||
+ start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
+ continue;
+ rec = bsearch(&key, pg->records, pg->index,
+ sizeof(struct dyn_ftrace),
+ ftrace_cmp_recs);
+ if (rec)
+ break;
+ }
+ return rec;
+}
+
+/**
+ * ftrace_location_range - return the first address of a traced location
+ * if it touches the given ip range
+ * @start: start of range to search.
+ * @end: end of range to search (inclusive). @end points to the last byte
+ * to check.
+ *
+ * Returns rec->ip if the related ftrace location is a least partly within
+ * the given address range. That is, the first address of the instruction
+ * that is either a NOP or call to the function tracer. It checks the ftrace
+ * internal tables to determine if the address belongs or not.
+ */
+unsigned long ftrace_location_range(unsigned long start, unsigned long end)
+{
+ struct dyn_ftrace *rec;
+
+ rec = lookup_rec(start, end);
+ if (rec)
+ return rec->ip;
+
+ return 0;
+}
+
+/**
+ * ftrace_location - return the ftrace location
+ * @ip: the instruction pointer to check
+ *
+ * If @ip matches the ftrace location, return @ip.
+ * If @ip matches sym+0, return sym's ftrace location.
+ * Otherwise, return 0.
+ */
+unsigned long ftrace_location(unsigned long ip)
+{
+ struct dyn_ftrace *rec;
+ unsigned long offset;
+ unsigned long size;
+
+ rec = lookup_rec(ip, ip);
+ if (!rec) {
+ if (!kallsyms_lookup_size_offset(ip, &size, &offset))
+ goto out;
+
+ /* map sym+0 to __fentry__ */
+ if (!offset)
+ rec = lookup_rec(ip, ip + size - 1);
+ }
+
+ if (rec)
+ return rec->ip;
+
+out:
+ return 0;
+}
+
+/**
+ * ftrace_text_reserved - return true if range contains an ftrace location
+ * @start: start of range to search
+ * @end: end of range to search (inclusive). @end points to the last byte to check.
+ *
+ * Returns 1 if @start and @end contains a ftrace location.
+ * That is, the instruction that is either a NOP or call to
+ * the function tracer. It checks the ftrace internal tables to
+ * determine if the address belongs or not.
+ */
+int ftrace_text_reserved(const void *start, const void *end)
+{
+ unsigned long ret;
+
+ ret = ftrace_location_range((unsigned long)start,
+ (unsigned long)end);
+
+ return (int)!!ret;
+}
+
+/* Test if ops registered to this rec needs regs */
+static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
+{
+ struct ftrace_ops *ops;
+ bool keep_regs = false;
+
+ for (ops = ftrace_ops_list;
+ ops != &ftrace_list_end; ops = ops->next) {
+ /* pass rec in as regs to have non-NULL val */
+ if (ftrace_ops_test(ops, rec->ip, rec)) {
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
+ keep_regs = true;
+ break;
+ }
+ }
+ }
+
+ return keep_regs;
+}
+
+static struct ftrace_ops *
+ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
+static struct ftrace_ops *
+ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude);
+static struct ftrace_ops *
+ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
+
+static bool skip_record(struct dyn_ftrace *rec)
+{
+ /*
+ * At boot up, weak functions are set to disable. Function tracing
+ * can be enabled before they are, and they still need to be disabled now.
+ * If the record is disabled, still continue if it is marked as already
+ * enabled (this is needed to keep the accounting working).
+ */
+ return rec->flags & FTRACE_FL_DISABLED &&
+ !(rec->flags & FTRACE_FL_ENABLED);
+}
+
+static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
+ int filter_hash,
+ bool inc)
+{
+ struct ftrace_hash *hash;
+ struct ftrace_hash *other_hash;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ bool update = false;
+ int count = 0;
+ int all = false;
+
+ /* Only update if the ops has been registered */
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return false;
+
+ /*
+ * In the filter_hash case:
+ * If the count is zero, we update all records.
+ * Otherwise we just update the items in the hash.
+ *
+ * In the notrace_hash case:
+ * We enable the update in the hash.
+ * As disabling notrace means enabling the tracing,
+ * and enabling notrace means disabling, the inc variable
+ * gets inversed.
+ */
+ if (filter_hash) {
+ hash = ops->func_hash->filter_hash;
+ other_hash = ops->func_hash->notrace_hash;
+ if (ftrace_hash_empty(hash))
+ all = true;
+ } else {
+ inc = !inc;
+ hash = ops->func_hash->notrace_hash;
+ other_hash = ops->func_hash->filter_hash;
+ /*
+ * If the notrace hash has no items,
+ * then there's nothing to do.
+ */
+ if (ftrace_hash_empty(hash))
+ return false;
+ }
+
+ do_for_each_ftrace_rec(pg, rec) {
+ int in_other_hash = 0;
+ int in_hash = 0;
+ int match = 0;
+
+ if (skip_record(rec))
+ continue;
+
+ if (all) {
+ /*
+ * Only the filter_hash affects all records.
+ * Update if the record is not in the notrace hash.
+ */
+ if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
+ match = 1;
+ } else {
+ in_hash = !!ftrace_lookup_ip(hash, rec->ip);
+ in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
+
+ /*
+ * If filter_hash is set, we want to match all functions
+ * that are in the hash but not in the other hash.
+ *
+ * If filter_hash is not set, then we are decrementing.
+ * That means we match anything that is in the hash
+ * and also in the other_hash. That is, we need to turn
+ * off functions in the other hash because they are disabled
+ * by this hash.
+ */
+ if (filter_hash && in_hash && !in_other_hash)
+ match = 1;
+ else if (!filter_hash && in_hash &&
+ (in_other_hash || ftrace_hash_empty(other_hash)))
+ match = 1;
+ }
+ if (!match)
+ continue;
+
+ if (inc) {
+ rec->flags++;
+ if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
+ return false;
+
+ if (ops->flags & FTRACE_OPS_FL_DIRECT)
+ rec->flags |= FTRACE_FL_DIRECT;
+
+ /*
+ * If there's only a single callback registered to a
+ * function, and the ops has a trampoline registered
+ * for it, then we can call it directly.
+ */
+ if (ftrace_rec_count(rec) == 1 && ops->trampoline)
+ rec->flags |= FTRACE_FL_TRAMP;
+ else
+ /*
+ * If we are adding another function callback
+ * to this function, and the previous had a
+ * custom trampoline in use, then we need to go
+ * back to the default trampoline.
+ */
+ rec->flags &= ~FTRACE_FL_TRAMP;
+
+ /*
+ * If any ops wants regs saved for this function
+ * then all ops will get saved regs.
+ */
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
+ rec->flags |= FTRACE_FL_REGS;
+ } else {
+ if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
+ return false;
+ rec->flags--;
+
+ /*
+ * Only the internal direct_ops should have the
+ * DIRECT flag set. Thus, if it is removing a
+ * function, then that function should no longer
+ * be direct.
+ */
+ if (ops->flags & FTRACE_OPS_FL_DIRECT)
+ rec->flags &= ~FTRACE_FL_DIRECT;
+
+ /*
+ * If the rec had REGS enabled and the ops that is
+ * being removed had REGS set, then see if there is
+ * still any ops for this record that wants regs.
+ * If not, we can stop recording them.
+ */
+ if (ftrace_rec_count(rec) > 0 &&
+ rec->flags & FTRACE_FL_REGS &&
+ ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
+ if (!test_rec_ops_needs_regs(rec))
+ rec->flags &= ~FTRACE_FL_REGS;
+ }
+
+ /*
+ * The TRAMP needs to be set only if rec count
+ * is decremented to one, and the ops that is
+ * left has a trampoline. As TRAMP can only be
+ * enabled if there is only a single ops attached
+ * to it.
+ */
+ if (ftrace_rec_count(rec) == 1 &&
+ ftrace_find_tramp_ops_any_other(rec, ops))
+ rec->flags |= FTRACE_FL_TRAMP;
+ else
+ rec->flags &= ~FTRACE_FL_TRAMP;
+
+ /*
+ * flags will be cleared in ftrace_check_record()
+ * if rec count is zero.
+ */
+ }
+ count++;
+
+ /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
+ update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE;
+
+ /* Shortcut, if we handled all records, we are done. */
+ if (!all && count == hash->count)
+ return update;
+ } while_for_each_ftrace_rec();
+
+ return update;
+}
+
+static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
+ int filter_hash)
+{
+ return __ftrace_hash_rec_update(ops, filter_hash, 0);
+}
+
+static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
+ int filter_hash)
+{
+ return __ftrace_hash_rec_update(ops, filter_hash, 1);
+}
+
+static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
+ int filter_hash, int inc)
+{
+ struct ftrace_ops *op;
+
+ __ftrace_hash_rec_update(ops, filter_hash, inc);
+
+ if (ops->func_hash != &global_ops.local_hash)
+ return;
+
+ /*
+ * If the ops shares the global_ops hash, then we need to update
+ * all ops that are enabled and use this hash.
+ */
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+ /* Already done */
+ if (op == ops)
+ continue;
+ if (op->func_hash == &global_ops.local_hash)
+ __ftrace_hash_rec_update(op, filter_hash, inc);
+ } while_for_each_ftrace_op(op);
+}
+
+static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
+ int filter_hash)
+{
+ ftrace_hash_rec_update_modify(ops, filter_hash, 0);
+}
+
+static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
+ int filter_hash)
+{
+ ftrace_hash_rec_update_modify(ops, filter_hash, 1);
+}
+
+/*
+ * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
+ * or no-needed to update, -EBUSY if it detects a conflict of the flag
+ * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
+ * Note that old_hash and new_hash has below meanings
+ * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
+ * - If the hash is EMPTY_HASH, it hits nothing
+ * - Anything else hits the recs which match the hash entries.
+ *
+ * DIRECT ops does not have IPMODIFY flag, but we still need to check it
+ * against functions with FTRACE_FL_IPMODIFY. If there is any overlap, call
+ * ops_func(SHARE_IPMODIFY_SELF) to make sure current ops can share with
+ * IPMODIFY. If ops_func(SHARE_IPMODIFY_SELF) returns non-zero, propagate
+ * the return value to the caller and eventually to the owner of the DIRECT
+ * ops.
+ */
+static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
+ struct ftrace_hash *old_hash,
+ struct ftrace_hash *new_hash)
+{
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec, *end = NULL;
+ int in_old, in_new;
+ bool is_ipmodify, is_direct;
+
+ /* Only update if the ops has been registered */
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return 0;
+
+ is_ipmodify = ops->flags & FTRACE_OPS_FL_IPMODIFY;
+ is_direct = ops->flags & FTRACE_OPS_FL_DIRECT;
+
+ /* neither IPMODIFY nor DIRECT, skip */
+ if (!is_ipmodify && !is_direct)
+ return 0;
+
+ if (WARN_ON_ONCE(is_ipmodify && is_direct))
+ return 0;
+
+ /*
+ * Since the IPMODIFY and DIRECT are very address sensitive
+ * actions, we do not allow ftrace_ops to set all functions to new
+ * hash.
+ */
+ if (!new_hash || !old_hash)
+ return -EINVAL;
+
+ /* Update rec->flags */
+ do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
+ /* We need to update only differences of filter_hash */
+ in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
+ in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
+ if (in_old == in_new)
+ continue;
+
+ if (in_new) {
+ if (rec->flags & FTRACE_FL_IPMODIFY) {
+ int ret;
+
+ /* Cannot have two ipmodify on same rec */
+ if (is_ipmodify)
+ goto rollback;
+
+ FTRACE_WARN_ON(rec->flags & FTRACE_FL_DIRECT);
+
+ /*
+ * Another ops with IPMODIFY is already
+ * attached. We are now attaching a direct
+ * ops. Run SHARE_IPMODIFY_SELF, to check
+ * whether sharing is supported.
+ */
+ if (!ops->ops_func)
+ return -EBUSY;
+ ret = ops->ops_func(ops, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF);
+ if (ret)
+ return ret;
+ } else if (is_ipmodify) {
+ rec->flags |= FTRACE_FL_IPMODIFY;
+ }
+ } else if (is_ipmodify) {
+ rec->flags &= ~FTRACE_FL_IPMODIFY;
+ }
+ } while_for_each_ftrace_rec();
+
+ return 0;
+
+rollback:
+ end = rec;
+
+ /* Roll back what we did above */
+ do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
+ if (rec == end)
+ goto err_out;
+
+ in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
+ in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
+ if (in_old == in_new)
+ continue;
+
+ if (in_new)
+ rec->flags &= ~FTRACE_FL_IPMODIFY;
+ else
+ rec->flags |= FTRACE_FL_IPMODIFY;
+ } while_for_each_ftrace_rec();
+
+err_out:
+ return -EBUSY;
+}
+
+static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
+{
+ struct ftrace_hash *hash = ops->func_hash->filter_hash;
+
+ if (ftrace_hash_empty(hash))
+ hash = NULL;
+
+ return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
+}
+
+/* Disabling always succeeds */
+static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
+{
+ struct ftrace_hash *hash = ops->func_hash->filter_hash;
+
+ if (ftrace_hash_empty(hash))
+ hash = NULL;
+
+ __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
+}
+
+static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
+ struct ftrace_hash *new_hash)
+{
+ struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
+
+ if (ftrace_hash_empty(old_hash))
+ old_hash = NULL;
+
+ if (ftrace_hash_empty(new_hash))
+ new_hash = NULL;
+
+ return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
+}
+
+static void print_ip_ins(const char *fmt, const unsigned char *p)
+{
+ char ins[MCOUNT_INSN_SIZE];
+
+ if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) {
+ printk(KERN_CONT "%s[FAULT] %px\n", fmt, p);
+ return;
+ }
+
+ printk(KERN_CONT "%s", fmt);
+ pr_cont("%*phC", MCOUNT_INSN_SIZE, ins);
+}
+
+enum ftrace_bug_type ftrace_bug_type;
+const void *ftrace_expected;
+
+static void print_bug_type(void)
+{
+ switch (ftrace_bug_type) {
+ case FTRACE_BUG_UNKNOWN:
+ break;
+ case FTRACE_BUG_INIT:
+ pr_info("Initializing ftrace call sites\n");
+ break;
+ case FTRACE_BUG_NOP:
+ pr_info("Setting ftrace call site to NOP\n");
+ break;
+ case FTRACE_BUG_CALL:
+ pr_info("Setting ftrace call site to call ftrace function\n");
+ break;
+ case FTRACE_BUG_UPDATE:
+ pr_info("Updating ftrace call site to call a different ftrace function\n");
+ break;
+ }
+}
+
+/**
+ * ftrace_bug - report and shutdown function tracer
+ * @failed: The failed type (EFAULT, EINVAL, EPERM)
+ * @rec: The record that failed
+ *
+ * The arch code that enables or disables the function tracing
+ * can call ftrace_bug() when it has detected a problem in
+ * modifying the code. @failed should be one of either:
+ * EFAULT - if the problem happens on reading the @ip address
+ * EINVAL - if what is read at @ip is not what was expected
+ * EPERM - if the problem happens on writing to the @ip address
+ */
+void ftrace_bug(int failed, struct dyn_ftrace *rec)
+{
+ unsigned long ip = rec ? rec->ip : 0;
+
+ pr_info("------------[ ftrace bug ]------------\n");
+
+ switch (failed) {
+ case -EFAULT:
+ pr_info("ftrace faulted on modifying ");
+ print_ip_sym(KERN_INFO, ip);
+ break;
+ case -EINVAL:
+ pr_info("ftrace failed to modify ");
+ print_ip_sym(KERN_INFO, ip);
+ print_ip_ins(" actual: ", (unsigned char *)ip);
+ pr_cont("\n");
+ if (ftrace_expected) {
+ print_ip_ins(" expected: ", ftrace_expected);
+ pr_cont("\n");
+ }
+ break;
+ case -EPERM:
+ pr_info("ftrace faulted on writing ");
+ print_ip_sym(KERN_INFO, ip);
+ break;
+ default:
+ pr_info("ftrace faulted on unknown error ");
+ print_ip_sym(KERN_INFO, ip);
+ }
+ print_bug_type();
+ if (rec) {
+ struct ftrace_ops *ops = NULL;
+
+ pr_info("ftrace record flags: %lx\n", rec->flags);
+ pr_cont(" (%ld)%s", ftrace_rec_count(rec),
+ rec->flags & FTRACE_FL_REGS ? " R" : " ");
+ if (rec->flags & FTRACE_FL_TRAMP_EN) {
+ ops = ftrace_find_tramp_ops_any(rec);
+ if (ops) {
+ do {
+ pr_cont("\ttramp: %pS (%pS)",
+ (void *)ops->trampoline,
+ (void *)ops->func);
+ ops = ftrace_find_tramp_ops_next(rec, ops);
+ } while (ops);
+ } else
+ pr_cont("\ttramp: ERROR!");
+
+ }
+ ip = ftrace_get_addr_curr(rec);
+ pr_cont("\n expected tramp: %lx\n", ip);
+ }
+
+ FTRACE_WARN_ON_ONCE(1);
+}
+
+static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
+{
+ unsigned long flag = 0UL;
+
+ ftrace_bug_type = FTRACE_BUG_UNKNOWN;
+
+ if (skip_record(rec))
+ return FTRACE_UPDATE_IGNORE;
+
+ /*
+ * If we are updating calls:
+ *
+ * If the record has a ref count, then we need to enable it
+ * because someone is using it.
+ *
+ * Otherwise we make sure its disabled.
+ *
+ * If we are disabling calls, then disable all records that
+ * are enabled.
+ */
+ if (enable && ftrace_rec_count(rec))
+ flag = FTRACE_FL_ENABLED;
+
+ /*
+ * If enabling and the REGS flag does not match the REGS_EN, or
+ * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
+ * this record. Set flags to fail the compare against ENABLED.
+ * Same for direct calls.
+ */
+ if (flag) {
+ if (!(rec->flags & FTRACE_FL_REGS) !=
+ !(rec->flags & FTRACE_FL_REGS_EN))
+ flag |= FTRACE_FL_REGS;
+
+ if (!(rec->flags & FTRACE_FL_TRAMP) !=
+ !(rec->flags & FTRACE_FL_TRAMP_EN))
+ flag |= FTRACE_FL_TRAMP;
+
+ /*
+ * Direct calls are special, as count matters.
+ * We must test the record for direct, if the
+ * DIRECT and DIRECT_EN do not match, but only
+ * if the count is 1. That's because, if the
+ * count is something other than one, we do not
+ * want the direct enabled (it will be done via the
+ * direct helper). But if DIRECT_EN is set, and
+ * the count is not one, we need to clear it.
+ */
+ if (ftrace_rec_count(rec) == 1) {
+ if (!(rec->flags & FTRACE_FL_DIRECT) !=
+ !(rec->flags & FTRACE_FL_DIRECT_EN))
+ flag |= FTRACE_FL_DIRECT;
+ } else if (rec->flags & FTRACE_FL_DIRECT_EN) {
+ flag |= FTRACE_FL_DIRECT;
+ }
+ }
+
+ /* If the state of this record hasn't changed, then do nothing */
+ if ((rec->flags & FTRACE_FL_ENABLED) == flag)
+ return FTRACE_UPDATE_IGNORE;
+
+ if (flag) {
+ /* Save off if rec is being enabled (for return value) */
+ flag ^= rec->flags & FTRACE_FL_ENABLED;
+
+ if (update) {
+ rec->flags |= FTRACE_FL_ENABLED;
+ if (flag & FTRACE_FL_REGS) {
+ if (rec->flags & FTRACE_FL_REGS)
+ rec->flags |= FTRACE_FL_REGS_EN;
+ else
+ rec->flags &= ~FTRACE_FL_REGS_EN;
+ }
+ if (flag & FTRACE_FL_TRAMP) {
+ if (rec->flags & FTRACE_FL_TRAMP)
+ rec->flags |= FTRACE_FL_TRAMP_EN;
+ else
+ rec->flags &= ~FTRACE_FL_TRAMP_EN;
+ }
+
+ if (flag & FTRACE_FL_DIRECT) {
+ /*
+ * If there's only one user (direct_ops helper)
+ * then we can call the direct function
+ * directly (no ftrace trampoline).
+ */
+ if (ftrace_rec_count(rec) == 1) {
+ if (rec->flags & FTRACE_FL_DIRECT)
+ rec->flags |= FTRACE_FL_DIRECT_EN;
+ else
+ rec->flags &= ~FTRACE_FL_DIRECT_EN;
+ } else {
+ /*
+ * Can only call directly if there's
+ * only one callback to the function.
+ */
+ rec->flags &= ~FTRACE_FL_DIRECT_EN;
+ }
+ }
+ }
+
+ /*
+ * If this record is being updated from a nop, then
+ * return UPDATE_MAKE_CALL.
+ * Otherwise,
+ * return UPDATE_MODIFY_CALL to tell the caller to convert
+ * from the save regs, to a non-save regs function or
+ * vice versa, or from a trampoline call.
+ */
+ if (flag & FTRACE_FL_ENABLED) {
+ ftrace_bug_type = FTRACE_BUG_CALL;
+ return FTRACE_UPDATE_MAKE_CALL;
+ }
+
+ ftrace_bug_type = FTRACE_BUG_UPDATE;
+ return FTRACE_UPDATE_MODIFY_CALL;
+ }
+
+ if (update) {
+ /* If there's no more users, clear all flags */
+ if (!ftrace_rec_count(rec))
+ rec->flags &= FTRACE_FL_DISABLED;
+ else
+ /*
+ * Just disable the record, but keep the ops TRAMP
+ * and REGS states. The _EN flags must be disabled though.
+ */
+ rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
+ FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN);
+ }
+
+ ftrace_bug_type = FTRACE_BUG_NOP;
+ return FTRACE_UPDATE_MAKE_NOP;
+}
+
+/**
+ * ftrace_update_record - set a record that now is tracing or not
+ * @rec: the record to update
+ * @enable: set to true if the record is tracing, false to force disable
+ *
+ * The records that represent all functions that can be traced need
+ * to be updated when tracing has been enabled.
+ */
+int ftrace_update_record(struct dyn_ftrace *rec, bool enable)
+{
+ return ftrace_check_record(rec, enable, true);
+}
+
+/**
+ * ftrace_test_record - check if the record has been enabled or not
+ * @rec: the record to test
+ * @enable: set to true to check if enabled, false if it is disabled
+ *
+ * The arch code may need to test if a record is already set to
+ * tracing to determine how to modify the function code that it
+ * represents.
+ */
+int ftrace_test_record(struct dyn_ftrace *rec, bool enable)
+{
+ return ftrace_check_record(rec, enable, false);
+}
+
+static struct ftrace_ops *
+ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
+{
+ struct ftrace_ops *op;
+ unsigned long ip = rec->ip;
+
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+
+ if (!op->trampoline)
+ continue;
+
+ if (hash_contains_ip(ip, op->func_hash))
+ return op;
+ } while_for_each_ftrace_op(op);
+
+ return NULL;
+}
+
+static struct ftrace_ops *
+ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude)
+{
+ struct ftrace_ops *op;
+ unsigned long ip = rec->ip;
+
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+
+ if (op == op_exclude || !op->trampoline)
+ continue;
+
+ if (hash_contains_ip(ip, op->func_hash))
+ return op;
+ } while_for_each_ftrace_op(op);
+
+ return NULL;
+}
+
+static struct ftrace_ops *
+ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
+ struct ftrace_ops *op)
+{
+ unsigned long ip = rec->ip;
+
+ while_for_each_ftrace_op(op) {
+
+ if (!op->trampoline)
+ continue;
+
+ if (hash_contains_ip(ip, op->func_hash))
+ return op;
+ }
+
+ return NULL;
+}
+
+static struct ftrace_ops *
+ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
+{
+ struct ftrace_ops *op;
+ unsigned long ip = rec->ip;
+
+ /*
+ * Need to check removed ops first.
+ * If they are being removed, and this rec has a tramp,
+ * and this rec is in the ops list, then it would be the
+ * one with the tramp.
+ */
+ if (removed_ops) {
+ if (hash_contains_ip(ip, &removed_ops->old_hash))
+ return removed_ops;
+ }
+
+ /*
+ * Need to find the current trampoline for a rec.
+ * Now, a trampoline is only attached to a rec if there
+ * was a single 'ops' attached to it. But this can be called
+ * when we are adding another op to the rec or removing the
+ * current one. Thus, if the op is being added, we can
+ * ignore it because it hasn't attached itself to the rec
+ * yet.
+ *
+ * If an ops is being modified (hooking to different functions)
+ * then we don't care about the new functions that are being
+ * added, just the old ones (that are probably being removed).
+ *
+ * If we are adding an ops to a function that already is using
+ * a trampoline, it needs to be removed (trampolines are only
+ * for single ops connected), then an ops that is not being
+ * modified also needs to be checked.
+ */
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+
+ if (!op->trampoline)
+ continue;
+
+ /*
+ * If the ops is being added, it hasn't gotten to
+ * the point to be removed from this tree yet.
+ */
+ if (op->flags & FTRACE_OPS_FL_ADDING)
+ continue;
+
+
+ /*
+ * If the ops is being modified and is in the old
+ * hash, then it is probably being removed from this
+ * function.
+ */
+ if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
+ hash_contains_ip(ip, &op->old_hash))
+ return op;
+ /*
+ * If the ops is not being added or modified, and it's
+ * in its normal filter hash, then this must be the one
+ * we want!
+ */
+ if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
+ hash_contains_ip(ip, op->func_hash))
+ return op;
+
+ } while_for_each_ftrace_op(op);
+
+ return NULL;
+}
+
+static struct ftrace_ops *
+ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
+{
+ struct ftrace_ops *op;
+ unsigned long ip = rec->ip;
+
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+ /* pass rec in as regs to have non-NULL val */
+ if (hash_contains_ip(ip, op->func_hash))
+ return op;
+ } while_for_each_ftrace_op(op);
+
+ return NULL;
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+/* Protected by rcu_tasks for reading, and direct_mutex for writing */
+static struct ftrace_hash *direct_functions = EMPTY_HASH;
+static DEFINE_MUTEX(direct_mutex);
+int ftrace_direct_func_count;
+
+/*
+ * Search the direct_functions hash to see if the given instruction pointer
+ * has a direct caller attached to it.
+ */
+unsigned long ftrace_find_rec_direct(unsigned long ip)
+{
+ struct ftrace_func_entry *entry;
+
+ entry = __ftrace_lookup_ip(direct_functions, ip);
+ if (!entry)
+ return 0;
+
+ return entry->direct;
+}
+
+static struct ftrace_func_entry*
+ftrace_add_rec_direct(unsigned long ip, unsigned long addr,
+ struct ftrace_hash **free_hash)
+{
+ struct ftrace_func_entry *entry;
+
+ if (ftrace_hash_empty(direct_functions) ||
+ direct_functions->count > 2 * (1 << direct_functions->size_bits)) {
+ struct ftrace_hash *new_hash;
+ int size = ftrace_hash_empty(direct_functions) ? 0 :
+ direct_functions->count + 1;
+
+ if (size < 32)
+ size = 32;
+
+ new_hash = dup_hash(direct_functions, size);
+ if (!new_hash)
+ return NULL;
+
+ *free_hash = direct_functions;
+ direct_functions = new_hash;
+ }
+
+ entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return NULL;
+
+ entry->ip = ip;
+ entry->direct = addr;
+ __add_hash_entry(direct_functions, entry);
+ return entry;
+}
+
+static void call_direct_funcs(unsigned long ip, unsigned long pip,
+ struct ftrace_ops *ops, struct ftrace_regs *fregs)
+{
+ struct pt_regs *regs = ftrace_get_regs(fregs);
+ unsigned long addr;
+
+ addr = ftrace_find_rec_direct(ip);
+ if (!addr)
+ return;
+
+ arch_ftrace_set_direct_caller(regs, addr);
+}
+
+struct ftrace_ops direct_ops = {
+ .func = call_direct_funcs,
+ .flags = FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS
+ | FTRACE_OPS_FL_PERMANENT,
+ /*
+ * By declaring the main trampoline as this trampoline
+ * it will never have one allocated for it. Allocated
+ * trampolines should not call direct functions.
+ * The direct_ops should only be called by the builtin
+ * ftrace_regs_caller trampoline.
+ */
+ .trampoline = FTRACE_REGS_ADDR,
+};
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
+
+/**
+ * ftrace_get_addr_new - Get the call address to set to
+ * @rec: The ftrace record descriptor
+ *
+ * If the record has the FTRACE_FL_REGS set, that means that it
+ * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
+ * is not set, then it wants to convert to the normal callback.
+ *
+ * Returns the address of the trampoline to set to
+ */
+unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
+{
+ struct ftrace_ops *ops;
+ unsigned long addr;
+
+ if ((rec->flags & FTRACE_FL_DIRECT) &&
+ (ftrace_rec_count(rec) == 1)) {
+ addr = ftrace_find_rec_direct(rec->ip);
+ if (addr)
+ return addr;
+ WARN_ON_ONCE(1);
+ }
+
+ /* Trampolines take precedence over regs */
+ if (rec->flags & FTRACE_FL_TRAMP) {
+ ops = ftrace_find_tramp_ops_new(rec);
+ if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
+ pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
+ (void *)rec->ip, (void *)rec->ip, rec->flags);
+ /* Ftrace is shutting down, return anything */
+ return (unsigned long)FTRACE_ADDR;
+ }
+ return ops->trampoline;
+ }
+
+ if (rec->flags & FTRACE_FL_REGS)
+ return (unsigned long)FTRACE_REGS_ADDR;
+ else
+ return (unsigned long)FTRACE_ADDR;
+}
+
+/**
+ * ftrace_get_addr_curr - Get the call address that is already there
+ * @rec: The ftrace record descriptor
+ *
+ * The FTRACE_FL_REGS_EN is set when the record already points to
+ * a function that saves all the regs. Basically the '_EN' version
+ * represents the current state of the function.
+ *
+ * Returns the address of the trampoline that is currently being called
+ */
+unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
+{
+ struct ftrace_ops *ops;
+ unsigned long addr;
+
+ /* Direct calls take precedence over trampolines */
+ if (rec->flags & FTRACE_FL_DIRECT_EN) {
+ addr = ftrace_find_rec_direct(rec->ip);
+ if (addr)
+ return addr;
+ WARN_ON_ONCE(1);
+ }
+
+ /* Trampolines take precedence over regs */
+ if (rec->flags & FTRACE_FL_TRAMP_EN) {
+ ops = ftrace_find_tramp_ops_curr(rec);
+ if (FTRACE_WARN_ON(!ops)) {
+ pr_warn("Bad trampoline accounting at: %p (%pS)\n",
+ (void *)rec->ip, (void *)rec->ip);
+ /* Ftrace is shutting down, return anything */
+ return (unsigned long)FTRACE_ADDR;
+ }
+ return ops->trampoline;
+ }
+
+ if (rec->flags & FTRACE_FL_REGS_EN)
+ return (unsigned long)FTRACE_REGS_ADDR;
+ else
+ return (unsigned long)FTRACE_ADDR;
+}
+
+static int
+__ftrace_replace_code(struct dyn_ftrace *rec, bool enable)
+{
+ unsigned long ftrace_old_addr;
+ unsigned long ftrace_addr;
+ int ret;
+
+ ftrace_addr = ftrace_get_addr_new(rec);
+
+ /* This needs to be done before we call ftrace_update_record */
+ ftrace_old_addr = ftrace_get_addr_curr(rec);
+
+ ret = ftrace_update_record(rec, enable);
+
+ ftrace_bug_type = FTRACE_BUG_UNKNOWN;
+
+ switch (ret) {
+ case FTRACE_UPDATE_IGNORE:
+ return 0;
+
+ case FTRACE_UPDATE_MAKE_CALL:
+ ftrace_bug_type = FTRACE_BUG_CALL;
+ return ftrace_make_call(rec, ftrace_addr);
+
+ case FTRACE_UPDATE_MAKE_NOP:
+ ftrace_bug_type = FTRACE_BUG_NOP;
+ return ftrace_make_nop(NULL, rec, ftrace_old_addr);
+
+ case FTRACE_UPDATE_MODIFY_CALL:
+ ftrace_bug_type = FTRACE_BUG_UPDATE;
+ return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
+ }
+
+ return -1; /* unknown ftrace bug */
+}
+
+void __weak ftrace_replace_code(int mod_flags)
+{
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+ bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
+ int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
+ int failed;
+
+ if (unlikely(ftrace_disabled))
+ return;
+
+ do_for_each_ftrace_rec(pg, rec) {
+
+ if (skip_record(rec))
+ continue;
+
+ failed = __ftrace_replace_code(rec, enable);
+ if (failed) {
+ ftrace_bug(failed, rec);
+ /* Stop processing */
+ return;
+ }
+ if (schedulable)
+ cond_resched();
+ } while_for_each_ftrace_rec();
+}
+
+struct ftrace_rec_iter {
+ struct ftrace_page *pg;
+ int index;
+};
+
+/**
+ * ftrace_rec_iter_start - start up iterating over traced functions
+ *
+ * Returns an iterator handle that is used to iterate over all
+ * the records that represent address locations where functions
+ * are traced.
+ *
+ * May return NULL if no records are available.
+ */
+struct ftrace_rec_iter *ftrace_rec_iter_start(void)
+{
+ /*
+ * We only use a single iterator.
+ * Protected by the ftrace_lock mutex.
+ */
+ static struct ftrace_rec_iter ftrace_rec_iter;
+ struct ftrace_rec_iter *iter = &ftrace_rec_iter;
+
+ iter->pg = ftrace_pages_start;
+ iter->index = 0;
+
+ /* Could have empty pages */
+ while (iter->pg && !iter->pg->index)
+ iter->pg = iter->pg->next;
+
+ if (!iter->pg)
+ return NULL;
+
+ return iter;
+}
+
+/**
+ * ftrace_rec_iter_next - get the next record to process.
+ * @iter: The handle to the iterator.
+ *
+ * Returns the next iterator after the given iterator @iter.
+ */
+struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
+{
+ iter->index++;
+
+ if (iter->index >= iter->pg->index) {
+ iter->pg = iter->pg->next;
+ iter->index = 0;
+
+ /* Could have empty pages */
+ while (iter->pg && !iter->pg->index)
+ iter->pg = iter->pg->next;
+ }
+
+ if (!iter->pg)
+ return NULL;
+
+ return iter;
+}
+
+/**
+ * ftrace_rec_iter_record - get the record at the iterator location
+ * @iter: The current iterator location
+ *
+ * Returns the record that the current @iter is at.
+ */
+struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
+{
+ return &iter->pg->records[iter->index];
+}
+
+static int
+ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec)
+{
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return 0;
+
+ ret = ftrace_init_nop(mod, rec);
+ if (ret) {
+ ftrace_bug_type = FTRACE_BUG_INIT;
+ ftrace_bug(ret, rec);
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * archs can override this function if they must do something
+ * before the modifying code is performed.
+ */
+void __weak ftrace_arch_code_modify_prepare(void)
+{
+}
+
+/*
+ * archs can override this function if they must do something
+ * after the modifying code is performed.
+ */
+void __weak ftrace_arch_code_modify_post_process(void)
+{
+}
+
+void ftrace_modify_all_code(int command)
+{
+ int update = command & FTRACE_UPDATE_TRACE_FUNC;
+ int mod_flags = 0;
+ int err = 0;
+
+ if (command & FTRACE_MAY_SLEEP)
+ mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
+
+ /*
+ * If the ftrace_caller calls a ftrace_ops func directly,
+ * we need to make sure that it only traces functions it
+ * expects to trace. When doing the switch of functions,
+ * we need to update to the ftrace_ops_list_func first
+ * before the transition between old and new calls are set,
+ * as the ftrace_ops_list_func will check the ops hashes
+ * to make sure the ops are having the right functions
+ * traced.
+ */
+ if (update) {
+ err = ftrace_update_ftrace_func(ftrace_ops_list_func);
+ if (FTRACE_WARN_ON(err))
+ return;
+ }
+
+ if (command & FTRACE_UPDATE_CALLS)
+ ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL);
+ else if (command & FTRACE_DISABLE_CALLS)
+ ftrace_replace_code(mod_flags);
+
+ if (update && ftrace_trace_function != ftrace_ops_list_func) {
+ function_trace_op = set_function_trace_op;
+ smp_wmb();
+ /* If irqs are disabled, we are in stop machine */
+ if (!irqs_disabled())
+ smp_call_function(ftrace_sync_ipi, NULL, 1);
+ err = ftrace_update_ftrace_func(ftrace_trace_function);
+ if (FTRACE_WARN_ON(err))
+ return;
+ }
+
+ if (command & FTRACE_START_FUNC_RET)
+ err = ftrace_enable_ftrace_graph_caller();
+ else if (command & FTRACE_STOP_FUNC_RET)
+ err = ftrace_disable_ftrace_graph_caller();
+ FTRACE_WARN_ON(err);
+}
+
+static int __ftrace_modify_code(void *data)
+{
+ int *command = data;
+
+ ftrace_modify_all_code(*command);
+
+ return 0;
+}
+
+/**
+ * ftrace_run_stop_machine - go back to the stop machine method
+ * @command: The command to tell ftrace what to do
+ *
+ * If an arch needs to fall back to the stop machine method, the
+ * it can call this function.
+ */
+void ftrace_run_stop_machine(int command)
+{
+ stop_machine(__ftrace_modify_code, &command, NULL);
+}
+
+/**
+ * arch_ftrace_update_code - modify the code to trace or not trace
+ * @command: The command that needs to be done
+ *
+ * Archs can override this function if it does not need to
+ * run stop_machine() to modify code.
+ */
+void __weak arch_ftrace_update_code(int command)
+{
+ ftrace_run_stop_machine(command);
+}
+
+static void ftrace_run_update_code(int command)
+{
+ ftrace_arch_code_modify_prepare();
+
+ /*
+ * By default we use stop_machine() to modify the code.
+ * But archs can do what ever they want as long as it
+ * is safe. The stop_machine() is the safest, but also
+ * produces the most overhead.
+ */
+ arch_ftrace_update_code(command);
+
+ ftrace_arch_code_modify_post_process();
+}
+
+static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
+ struct ftrace_ops_hash *old_hash)
+{
+ ops->flags |= FTRACE_OPS_FL_MODIFYING;
+ ops->old_hash.filter_hash = old_hash->filter_hash;
+ ops->old_hash.notrace_hash = old_hash->notrace_hash;
+ ftrace_run_update_code(command);
+ ops->old_hash.filter_hash = NULL;
+ ops->old_hash.notrace_hash = NULL;
+ ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
+}
+
+static ftrace_func_t saved_ftrace_func;
+static int ftrace_start_up;
+
+void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
+{
+}
+
+/* List of trace_ops that have allocated trampolines */
+static LIST_HEAD(ftrace_ops_trampoline_list);
+
+static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops)
+{
+ lockdep_assert_held(&ftrace_lock);
+ list_add_rcu(&ops->list, &ftrace_ops_trampoline_list);
+}
+
+static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops)
+{
+ lockdep_assert_held(&ftrace_lock);
+ list_del_rcu(&ops->list);
+ synchronize_rcu();
+}
+
+/*
+ * "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols
+ * for pages allocated for ftrace purposes, even though "__builtin__ftrace" is
+ * not a module.
+ */
+#define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace"
+#define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline"
+
+static void ftrace_trampoline_free(struct ftrace_ops *ops)
+{
+ if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) &&
+ ops->trampoline) {
+ /*
+ * Record the text poke event before the ksymbol unregister
+ * event.
+ */
+ perf_event_text_poke((void *)ops->trampoline,
+ (void *)ops->trampoline,
+ ops->trampoline_size, NULL, 0);
+ perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
+ ops->trampoline, ops->trampoline_size,
+ true, FTRACE_TRAMPOLINE_SYM);
+ /* Remove from kallsyms after the perf events */
+ ftrace_remove_trampoline_from_kallsyms(ops);
+ }
+
+ arch_ftrace_trampoline_free(ops);
+}
+
+static void ftrace_startup_enable(int command)
+{
+ if (saved_ftrace_func != ftrace_trace_function) {
+ saved_ftrace_func = ftrace_trace_function;
+ command |= FTRACE_UPDATE_TRACE_FUNC;
+ }
+
+ if (!command || !ftrace_enabled)
+ return;
+
+ ftrace_run_update_code(command);
+}
+
+static void ftrace_startup_all(int command)
+{
+ update_all_ops = true;
+ ftrace_startup_enable(command);
+ update_all_ops = false;
+}
+
+int ftrace_startup(struct ftrace_ops *ops, int command)
+{
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ ret = __register_ftrace_function(ops);
+ if (ret)
+ return ret;
+
+ ftrace_start_up++;
+
+ /*
+ * Note that ftrace probes uses this to start up
+ * and modify functions it will probe. But we still
+ * set the ADDING flag for modification, as probes
+ * do not have trampolines. If they add them in the
+ * future, then the probes will need to distinguish
+ * between adding and updating probes.
+ */
+ ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
+
+ ret = ftrace_hash_ipmodify_enable(ops);
+ if (ret < 0) {
+ /* Rollback registration process */
+ __unregister_ftrace_function(ops);
+ ftrace_start_up--;
+ ops->flags &= ~FTRACE_OPS_FL_ENABLED;
+ if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
+ ftrace_trampoline_free(ops);
+ return ret;
+ }
+
+ if (ftrace_hash_rec_enable(ops, 1))
+ command |= FTRACE_UPDATE_CALLS;
+
+ ftrace_startup_enable(command);
+
+ /*
+ * If ftrace is in an undefined state, we just remove ops from list
+ * to prevent the NULL pointer, instead of totally rolling it back and
+ * free trampoline, because those actions could cause further damage.
+ */
+ if (unlikely(ftrace_disabled)) {
+ __unregister_ftrace_function(ops);
+ return -ENODEV;
+ }
+
+ ops->flags &= ~FTRACE_OPS_FL_ADDING;
+
+ return 0;
+}
+
+int ftrace_shutdown(struct ftrace_ops *ops, int command)
+{
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ ret = __unregister_ftrace_function(ops);
+ if (ret)
+ return ret;
+
+ ftrace_start_up--;
+ /*
+ * Just warn in case of unbalance, no need to kill ftrace, it's not
+ * critical but the ftrace_call callers may be never nopped again after
+ * further ftrace uses.
+ */
+ WARN_ON_ONCE(ftrace_start_up < 0);
+
+ /* Disabling ipmodify never fails */
+ ftrace_hash_ipmodify_disable(ops);
+
+ if (ftrace_hash_rec_disable(ops, 1))
+ command |= FTRACE_UPDATE_CALLS;
+
+ ops->flags &= ~FTRACE_OPS_FL_ENABLED;
+
+ if (saved_ftrace_func != ftrace_trace_function) {
+ saved_ftrace_func = ftrace_trace_function;
+ command |= FTRACE_UPDATE_TRACE_FUNC;
+ }
+
+ if (!command || !ftrace_enabled)
+ goto out;
+
+ /*
+ * If the ops uses a trampoline, then it needs to be
+ * tested first on update.
+ */
+ ops->flags |= FTRACE_OPS_FL_REMOVING;
+ removed_ops = ops;
+
+ /* The trampoline logic checks the old hashes */
+ ops->old_hash.filter_hash = ops->func_hash->filter_hash;
+ ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
+
+ ftrace_run_update_code(command);
+
+ /*
+ * If there's no more ops registered with ftrace, run a
+ * sanity check to make sure all rec flags are cleared.
+ */
+ if (rcu_dereference_protected(ftrace_ops_list,
+ lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+
+ do_for_each_ftrace_rec(pg, rec) {
+ if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
+ pr_warn(" %pS flags:%lx\n",
+ (void *)rec->ip, rec->flags);
+ } while_for_each_ftrace_rec();
+ }
+
+ ops->old_hash.filter_hash = NULL;
+ ops->old_hash.notrace_hash = NULL;
+
+ removed_ops = NULL;
+ ops->flags &= ~FTRACE_OPS_FL_REMOVING;
+
+out:
+ /*
+ * Dynamic ops may be freed, we must make sure that all
+ * callers are done before leaving this function.
+ * The same goes for freeing the per_cpu data of the per_cpu
+ * ops.
+ */
+ if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
+ /*
+ * We need to do a hard force of sched synchronization.
+ * This is because we use preempt_disable() to do RCU, but
+ * the function tracers can be called where RCU is not watching
+ * (like before user_exit()). We can not rely on the RCU
+ * infrastructure to do the synchronization, thus we must do it
+ * ourselves.
+ */
+ synchronize_rcu_tasks_rude();
+
+ /*
+ * When the kernel is preemptive, tasks can be preempted
+ * while on a ftrace trampoline. Just scheduling a task on
+ * a CPU is not good enough to flush them. Calling
+ * synchronize_rcu_tasks() will wait for those tasks to
+ * execute and either schedule voluntarily or enter user space.
+ */
+ if (IS_ENABLED(CONFIG_PREEMPTION))
+ synchronize_rcu_tasks();
+
+ ftrace_trampoline_free(ops);
+ }
+
+ return 0;
+}
+
+static u64 ftrace_update_time;
+unsigned long ftrace_update_tot_cnt;
+unsigned long ftrace_number_of_pages;
+unsigned long ftrace_number_of_groups;
+
+static inline int ops_traces_mod(struct ftrace_ops *ops)
+{
+ /*
+ * Filter_hash being empty will default to trace module.
+ * But notrace hash requires a test of individual module functions.
+ */
+ return ftrace_hash_empty(ops->func_hash->filter_hash) &&
+ ftrace_hash_empty(ops->func_hash->notrace_hash);
+}
+
+static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
+{
+ bool init_nop = ftrace_need_init_nop();
+ struct ftrace_page *pg;
+ struct dyn_ftrace *p;
+ u64 start, stop;
+ unsigned long update_cnt = 0;
+ unsigned long rec_flags = 0;
+ int i;
+
+ start = ftrace_now(raw_smp_processor_id());
+
+ /*
+ * When a module is loaded, this function is called to convert
+ * the calls to mcount in its text to nops, and also to create
+ * an entry in the ftrace data. Now, if ftrace is activated
+ * after this call, but before the module sets its text to
+ * read-only, the modification of enabling ftrace can fail if
+ * the read-only is done while ftrace is converting the calls.
+ * To prevent this, the module's records are set as disabled
+ * and will be enabled after the call to set the module's text
+ * to read-only.
+ */
+ if (mod)
+ rec_flags |= FTRACE_FL_DISABLED;
+
+ for (pg = new_pgs; pg; pg = pg->next) {
+
+ for (i = 0; i < pg->index; i++) {
+
+ /* If something went wrong, bail without enabling anything */
+ if (unlikely(ftrace_disabled))
+ return -1;
+
+ p = &pg->records[i];
+ p->flags = rec_flags;
+
+ /*
+ * Do the initial record conversion from mcount jump
+ * to the NOP instructions.
+ */
+ if (init_nop && !ftrace_nop_initialize(mod, p))
+ break;
+
+ update_cnt++;
+ }
+ }
+
+ stop = ftrace_now(raw_smp_processor_id());
+ ftrace_update_time = stop - start;
+ ftrace_update_tot_cnt += update_cnt;
+
+ return 0;
+}
+
+static int ftrace_allocate_records(struct ftrace_page *pg, int count)
+{
+ int order;
+ int pages;
+ int cnt;
+
+ if (WARN_ON(!count))
+ return -EINVAL;
+
+ /* We want to fill as much as possible, with no empty pages */
+ pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE);
+ order = fls(pages) - 1;
+
+ again:
+ pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
+
+ if (!pg->records) {
+ /* if we can't allocate this size, try something smaller */
+ if (!order)
+ return -ENOMEM;
+ order--;
+ goto again;
+ }
+
+ ftrace_number_of_pages += 1 << order;
+ ftrace_number_of_groups++;
+
+ cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
+ pg->order = order;
+
+ if (cnt > count)
+ cnt = count;
+
+ return cnt;
+}
+
+static void ftrace_free_pages(struct ftrace_page *pages)
+{
+ struct ftrace_page *pg = pages;
+
+ while (pg) {
+ if (pg->records) {
+ free_pages((unsigned long)pg->records, pg->order);
+ ftrace_number_of_pages -= 1 << pg->order;
+ }
+ pages = pg->next;
+ kfree(pg);
+ pg = pages;
+ ftrace_number_of_groups--;
+ }
+}
+
+static struct ftrace_page *
+ftrace_allocate_pages(unsigned long num_to_init)
+{
+ struct ftrace_page *start_pg;
+ struct ftrace_page *pg;
+ int cnt;
+
+ if (!num_to_init)
+ return NULL;
+
+ start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
+ if (!pg)
+ return NULL;
+
+ /*
+ * Try to allocate as much as possible in one continues
+ * location that fills in all of the space. We want to
+ * waste as little space as possible.
+ */
+ for (;;) {
+ cnt = ftrace_allocate_records(pg, num_to_init);
+ if (cnt < 0)
+ goto free_pages;
+
+ num_to_init -= cnt;
+ if (!num_to_init)
+ break;
+
+ pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
+ if (!pg->next)
+ goto free_pages;
+
+ pg = pg->next;
+ }
+
+ return start_pg;
+
+ free_pages:
+ ftrace_free_pages(start_pg);
+ pr_info("ftrace: FAILED to allocate memory for functions\n");
+ return NULL;
+}
+
+#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
+
+struct ftrace_iterator {
+ loff_t pos;
+ loff_t func_pos;
+ loff_t mod_pos;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *func;
+ struct ftrace_func_probe *probe;
+ struct ftrace_func_entry *probe_entry;
+ struct trace_parser parser;
+ struct ftrace_hash *hash;
+ struct ftrace_ops *ops;
+ struct trace_array *tr;
+ struct list_head *mod_list;
+ int pidx;
+ int idx;
+ unsigned flags;
+};
+
+static void *
+t_probe_next(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ struct trace_array *tr = iter->ops->private;
+ struct list_head *func_probes;
+ struct ftrace_hash *hash;
+ struct list_head *next;
+ struct hlist_node *hnd = NULL;
+ struct hlist_head *hhd;
+ int size;
+
+ (*pos)++;
+ iter->pos = *pos;
+
+ if (!tr)
+ return NULL;
+
+ func_probes = &tr->func_probes;
+ if (list_empty(func_probes))
+ return NULL;
+
+ if (!iter->probe) {
+ next = func_probes->next;
+ iter->probe = list_entry(next, struct ftrace_func_probe, list);
+ }
+
+ if (iter->probe_entry)
+ hnd = &iter->probe_entry->hlist;
+
+ hash = iter->probe->ops.func_hash->filter_hash;
+
+ /*
+ * A probe being registered may temporarily have an empty hash
+ * and it's at the end of the func_probes list.
+ */
+ if (!hash || hash == EMPTY_HASH)
+ return NULL;
+
+ size = 1 << hash->size_bits;
+
+ retry:
+ if (iter->pidx >= size) {
+ if (iter->probe->list.next == func_probes)
+ return NULL;
+ next = iter->probe->list.next;
+ iter->probe = list_entry(next, struct ftrace_func_probe, list);
+ hash = iter->probe->ops.func_hash->filter_hash;
+ size = 1 << hash->size_bits;
+ iter->pidx = 0;
+ }
+
+ hhd = &hash->buckets[iter->pidx];
+
+ if (hlist_empty(hhd)) {
+ iter->pidx++;
+ hnd = NULL;
+ goto retry;
+ }
+
+ if (!hnd)
+ hnd = hhd->first;
+ else {
+ hnd = hnd->next;
+ if (!hnd) {
+ iter->pidx++;
+ goto retry;
+ }
+ }
+
+ if (WARN_ON_ONCE(!hnd))
+ return NULL;
+
+ iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
+
+ return iter;
+}
+
+static void *t_probe_start(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ void *p = NULL;
+ loff_t l;
+
+ if (!(iter->flags & FTRACE_ITER_DO_PROBES))
+ return NULL;
+
+ if (iter->mod_pos > *pos)
+ return NULL;
+
+ iter->probe = NULL;
+ iter->probe_entry = NULL;
+ iter->pidx = 0;
+ for (l = 0; l <= (*pos - iter->mod_pos); ) {
+ p = t_probe_next(m, &l);
+ if (!p)
+ break;
+ }
+ if (!p)
+ return NULL;
+
+ /* Only set this if we have an item */
+ iter->flags |= FTRACE_ITER_PROBE;
+
+ return iter;
+}
+
+static int
+t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
+{
+ struct ftrace_func_entry *probe_entry;
+ struct ftrace_probe_ops *probe_ops;
+ struct ftrace_func_probe *probe;
+
+ probe = iter->probe;
+ probe_entry = iter->probe_entry;
+
+ if (WARN_ON_ONCE(!probe || !probe_entry))
+ return -EIO;
+
+ probe_ops = probe->probe_ops;
+
+ if (probe_ops->print)
+ return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
+
+ seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
+ (void *)probe_ops->func);
+
+ return 0;
+}
+
+static void *
+t_mod_next(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ struct trace_array *tr = iter->tr;
+
+ (*pos)++;
+ iter->pos = *pos;
+
+ iter->mod_list = iter->mod_list->next;
+
+ if (iter->mod_list == &tr->mod_trace ||
+ iter->mod_list == &tr->mod_notrace) {
+ iter->flags &= ~FTRACE_ITER_MOD;
+ return NULL;
+ }
+
+ iter->mod_pos = *pos;
+
+ return iter;
+}
+
+static void *t_mod_start(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ void *p = NULL;
+ loff_t l;
+
+ if (iter->func_pos > *pos)
+ return NULL;
+
+ iter->mod_pos = iter->func_pos;
+
+ /* probes are only available if tr is set */
+ if (!iter->tr)
+ return NULL;
+
+ for (l = 0; l <= (*pos - iter->func_pos); ) {
+ p = t_mod_next(m, &l);
+ if (!p)
+ break;
+ }
+ if (!p) {
+ iter->flags &= ~FTRACE_ITER_MOD;
+ return t_probe_start(m, pos);
+ }
+
+ /* Only set this if we have an item */
+ iter->flags |= FTRACE_ITER_MOD;
+
+ return iter;
+}
+
+static int
+t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
+{
+ struct ftrace_mod_load *ftrace_mod;
+ struct trace_array *tr = iter->tr;
+
+ if (WARN_ON_ONCE(!iter->mod_list) ||
+ iter->mod_list == &tr->mod_trace ||
+ iter->mod_list == &tr->mod_notrace)
+ return -EIO;
+
+ ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
+
+ if (ftrace_mod->func)
+ seq_printf(m, "%s", ftrace_mod->func);
+ else
+ seq_putc(m, '*');
+
+ seq_printf(m, ":mod:%s\n", ftrace_mod->module);
+
+ return 0;
+}
+
+static void *
+t_func_next(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ struct dyn_ftrace *rec = NULL;
+
+ (*pos)++;
+
+ retry:
+ if (iter->idx >= iter->pg->index) {
+ if (iter->pg->next) {
+ iter->pg = iter->pg->next;
+ iter->idx = 0;
+ goto retry;
+ }
+ } else {
+ rec = &iter->pg->records[iter->idx++];
+ if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
+ !ftrace_lookup_ip(iter->hash, rec->ip)) ||
+
+ ((iter->flags & FTRACE_ITER_ENABLED) &&
+ !(rec->flags & FTRACE_FL_ENABLED))) {
+
+ rec = NULL;
+ goto retry;
+ }
+ }
+
+ if (!rec)
+ return NULL;
+
+ iter->pos = iter->func_pos = *pos;
+ iter->func = rec;
+
+ return iter;
+}
+
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ loff_t l = *pos; /* t_probe_start() must use original pos */
+ void *ret;
+
+ if (unlikely(ftrace_disabled))
+ return NULL;
+
+ if (iter->flags & FTRACE_ITER_PROBE)
+ return t_probe_next(m, pos);
+
+ if (iter->flags & FTRACE_ITER_MOD)
+ return t_mod_next(m, pos);
+
+ if (iter->flags & FTRACE_ITER_PRINTALL) {
+ /* next must increment pos, and t_probe_start does not */
+ (*pos)++;
+ return t_mod_start(m, &l);
+ }
+
+ ret = t_func_next(m, pos);
+
+ if (!ret)
+ return t_mod_start(m, &l);
+
+ return ret;
+}
+
+static void reset_iter_read(struct ftrace_iterator *iter)
+{
+ iter->pos = 0;
+ iter->func_pos = 0;
+ iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ void *p = NULL;
+ loff_t l;
+
+ mutex_lock(&ftrace_lock);
+
+ if (unlikely(ftrace_disabled))
+ return NULL;
+
+ /*
+ * If an lseek was done, then reset and start from beginning.
+ */
+ if (*pos < iter->pos)
+ reset_iter_read(iter);
+
+ /*
+ * For set_ftrace_filter reading, if we have the filter
+ * off, we can short cut and just print out that all
+ * functions are enabled.
+ */
+ if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
+ ftrace_hash_empty(iter->hash)) {
+ iter->func_pos = 1; /* Account for the message */
+ if (*pos > 0)
+ return t_mod_start(m, pos);
+ iter->flags |= FTRACE_ITER_PRINTALL;
+ /* reset in case of seek/pread */
+ iter->flags &= ~FTRACE_ITER_PROBE;
+ return iter;
+ }
+
+ if (iter->flags & FTRACE_ITER_MOD)
+ return t_mod_start(m, pos);
+
+ /*
+ * Unfortunately, we need to restart at ftrace_pages_start
+ * every time we let go of the ftrace_mutex. This is because
+ * those pointers can change without the lock.
+ */
+ iter->pg = ftrace_pages_start;
+ iter->idx = 0;
+ for (l = 0; l <= *pos; ) {
+ p = t_func_next(m, &l);
+ if (!p)
+ break;
+ }
+
+ if (!p)
+ return t_mod_start(m, pos);
+
+ return iter;
+}
+
+static void t_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&ftrace_lock);
+}
+
+void * __weak
+arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+ return NULL;
+}
+
+static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
+ struct dyn_ftrace *rec)
+{
+ void *ptr;
+
+ ptr = arch_ftrace_trampoline_func(ops, rec);
+ if (ptr)
+ seq_printf(m, " ->%pS", ptr);
+}
+
+#ifdef FTRACE_MCOUNT_MAX_OFFSET
+/*
+ * Weak functions can still have an mcount/fentry that is saved in
+ * the __mcount_loc section. These can be detected by having a
+ * symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the
+ * symbol found by kallsyms is not the function that the mcount/fentry
+ * is part of. The offset is much greater in these cases.
+ *
+ * Test the record to make sure that the ip points to a valid kallsyms
+ * and if not, mark it disabled.
+ */
+static int test_for_valid_rec(struct dyn_ftrace *rec)
+{
+ char str[KSYM_SYMBOL_LEN];
+ unsigned long offset;
+ const char *ret;
+
+ ret = kallsyms_lookup(rec->ip, NULL, &offset, NULL, str);
+
+ /* Weak functions can cause invalid addresses */
+ if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
+ rec->flags |= FTRACE_FL_DISABLED;
+ return 0;
+ }
+ return 1;
+}
+
+static struct workqueue_struct *ftrace_check_wq __initdata;
+static struct work_struct ftrace_check_work __initdata;
+
+/*
+ * Scan all the mcount/fentry entries to make sure they are valid.
+ */
+static __init void ftrace_check_work_func(struct work_struct *work)
+{
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+
+ mutex_lock(&ftrace_lock);
+ do_for_each_ftrace_rec(pg, rec) {
+ test_for_valid_rec(rec);
+ } while_for_each_ftrace_rec();
+ mutex_unlock(&ftrace_lock);
+}
+
+static int __init ftrace_check_for_weak_functions(void)
+{
+ INIT_WORK(&ftrace_check_work, ftrace_check_work_func);
+
+ ftrace_check_wq = alloc_workqueue("ftrace_check_wq", WQ_UNBOUND, 0);
+
+ queue_work(ftrace_check_wq, &ftrace_check_work);
+ return 0;
+}
+
+static int __init ftrace_check_sync(void)
+{
+ /* Make sure the ftrace_check updates are finished */
+ if (ftrace_check_wq)
+ destroy_workqueue(ftrace_check_wq);
+ return 0;
+}
+
+late_initcall_sync(ftrace_check_sync);
+subsys_initcall(ftrace_check_for_weak_functions);
+
+static int print_rec(struct seq_file *m, unsigned long ip)
+{
+ unsigned long offset;
+ char str[KSYM_SYMBOL_LEN];
+ char *modname;
+ const char *ret;
+
+ ret = kallsyms_lookup(ip, NULL, &offset, &modname, str);
+ /* Weak functions can cause invalid addresses */
+ if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
+ snprintf(str, KSYM_SYMBOL_LEN, "%s_%ld",
+ FTRACE_INVALID_FUNCTION, offset);
+ ret = NULL;
+ }
+
+ seq_puts(m, str);
+ if (modname)
+ seq_printf(m, " [%s]", modname);
+ return ret == NULL ? -1 : 0;
+}
+#else
+static inline int test_for_valid_rec(struct dyn_ftrace *rec)
+{
+ return 1;
+}
+
+static inline int print_rec(struct seq_file *m, unsigned long ip)
+{
+ seq_printf(m, "%ps", (void *)ip);
+ return 0;
+}
+#endif
+
+static int t_show(struct seq_file *m, void *v)
+{
+ struct ftrace_iterator *iter = m->private;
+ struct dyn_ftrace *rec;
+
+ if (iter->flags & FTRACE_ITER_PROBE)
+ return t_probe_show(m, iter);
+
+ if (iter->flags & FTRACE_ITER_MOD)
+ return t_mod_show(m, iter);
+
+ if (iter->flags & FTRACE_ITER_PRINTALL) {
+ if (iter->flags & FTRACE_ITER_NOTRACE)
+ seq_puts(m, "#### no functions disabled ####\n");
+ else
+ seq_puts(m, "#### all functions enabled ####\n");
+ return 0;
+ }
+
+ rec = iter->func;
+
+ if (!rec)
+ return 0;
+
+ if (print_rec(m, rec->ip)) {
+ /* This should only happen when a rec is disabled */
+ WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED));
+ seq_putc(m, '\n');
+ return 0;
+ }
+
+ if (iter->flags & FTRACE_ITER_ENABLED) {
+ struct ftrace_ops *ops;
+
+ seq_printf(m, " (%ld)%s%s%s",
+ ftrace_rec_count(rec),
+ rec->flags & FTRACE_FL_REGS ? " R" : " ",
+ rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ",
+ rec->flags & FTRACE_FL_DIRECT ? " D" : " ");
+ if (rec->flags & FTRACE_FL_TRAMP_EN) {
+ ops = ftrace_find_tramp_ops_any(rec);
+ if (ops) {
+ do {
+ seq_printf(m, "\ttramp: %pS (%pS)",
+ (void *)ops->trampoline,
+ (void *)ops->func);
+ add_trampoline_func(m, ops, rec);
+ ops = ftrace_find_tramp_ops_next(rec, ops);
+ } while (ops);
+ } else
+ seq_puts(m, "\ttramp: ERROR!");
+ } else {
+ add_trampoline_func(m, NULL, rec);
+ }
+ if (rec->flags & FTRACE_FL_DIRECT) {
+ unsigned long direct;
+
+ direct = ftrace_find_rec_direct(rec->ip);
+ if (direct)
+ seq_printf(m, "\n\tdirect-->%pS", (void *)direct);
+ }
+ }
+
+ seq_putc(m, '\n');
+
+ return 0;
+}
+
+static const struct seq_operations show_ftrace_seq_ops = {
+ .start = t_start,
+ .next = t_next,
+ .stop = t_stop,
+ .show = t_show,
+};
+
+static int
+ftrace_avail_open(struct inode *inode, struct file *file)
+{
+ struct ftrace_iterator *iter;
+ int ret;
+
+ ret = security_locked_down(LOCKDOWN_TRACEFS);
+ if (ret)
+ return ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
+ if (!iter)
+ return -ENOMEM;
+
+ iter->pg = ftrace_pages_start;
+ iter->ops = &global_ops;
+
+ return 0;
+}
+
+static int
+ftrace_enabled_open(struct inode *inode, struct file *file)
+{
+ struct ftrace_iterator *iter;
+
+ /*
+ * This shows us what functions are currently being
+ * traced and by what. Not sure if we want lockdown
+ * to hide such critical information for an admin.
+ * Although, perhaps it can show information we don't
+ * want people to see, but if something is tracing
+ * something, we probably want to know about it.
+ */
+
+ iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
+ if (!iter)
+ return -ENOMEM;
+
+ iter->pg = ftrace_pages_start;
+ iter->flags = FTRACE_ITER_ENABLED;
+ iter->ops = &global_ops;
+
+ return 0;
+}
+
+/**
+ * ftrace_regex_open - initialize function tracer filter files
+ * @ops: The ftrace_ops that hold the hash filters
+ * @flag: The type of filter to process
+ * @inode: The inode, usually passed in to your open routine
+ * @file: The file, usually passed in to your open routine
+ *
+ * ftrace_regex_open() initializes the filter files for the
+ * @ops. Depending on @flag it may process the filter hash or
+ * the notrace hash of @ops. With this called from the open
+ * routine, you can use ftrace_filter_write() for the write
+ * routine if @flag has FTRACE_ITER_FILTER set, or
+ * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
+ * tracing_lseek() should be used as the lseek routine, and
+ * release must call ftrace_regex_release().
+ */
+int
+ftrace_regex_open(struct ftrace_ops *ops, int flag,
+ struct inode *inode, struct file *file)
+{
+ struct ftrace_iterator *iter;
+ struct ftrace_hash *hash;
+ struct list_head *mod_head;
+ struct trace_array *tr = ops->private;
+ int ret = -ENOMEM;
+
+ ftrace_ops_init(ops);
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ if (tracing_check_open_get_tr(tr))
+ return -ENODEV;
+
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ goto out;
+
+ if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX))
+ goto out;
+
+ iter->ops = ops;
+ iter->flags = flag;
+ iter->tr = tr;
+
+ mutex_lock(&ops->func_hash->regex_lock);
+
+ if (flag & FTRACE_ITER_NOTRACE) {
+ hash = ops->func_hash->notrace_hash;
+ mod_head = tr ? &tr->mod_notrace : NULL;
+ } else {
+ hash = ops->func_hash->filter_hash;
+ mod_head = tr ? &tr->mod_trace : NULL;
+ }
+
+ iter->mod_list = mod_head;
+
+ if (file->f_mode & FMODE_WRITE) {
+ const int size_bits = FTRACE_HASH_DEFAULT_BITS;
+
+ if (file->f_flags & O_TRUNC) {
+ iter->hash = alloc_ftrace_hash(size_bits);
+ clear_ftrace_mod_list(mod_head);
+ } else {
+ iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
+ }
+
+ if (!iter->hash) {
+ trace_parser_put(&iter->parser);
+ goto out_unlock;
+ }
+ } else
+ iter->hash = hash;
+
+ ret = 0;
+
+ if (file->f_mode & FMODE_READ) {
+ iter->pg = ftrace_pages_start;
+
+ ret = seq_open(file, &show_ftrace_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = iter;
+ } else {
+ /* Failed */
+ free_ftrace_hash(iter->hash);
+ trace_parser_put(&iter->parser);
+ }
+ } else
+ file->private_data = iter;
+
+ out_unlock:
+ mutex_unlock(&ops->func_hash->regex_lock);
+
+ out:
+ if (ret) {
+ kfree(iter);
+ if (tr)
+ trace_array_put(tr);
+ }
+
+ return ret;
+}
+
+static int
+ftrace_filter_open(struct inode *inode, struct file *file)
+{
+ struct ftrace_ops *ops = inode->i_private;
+
+ /* Checks for tracefs lockdown */
+ return ftrace_regex_open(ops,
+ FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
+ inode, file);
+}
+
+static int
+ftrace_notrace_open(struct inode *inode, struct file *file)
+{
+ struct ftrace_ops *ops = inode->i_private;
+
+ /* Checks for tracefs lockdown */
+ return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
+ inode, file);
+}
+
+/* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
+struct ftrace_glob {
+ char *search;
+ unsigned len;
+ int type;
+};
+
+/*
+ * If symbols in an architecture don't correspond exactly to the user-visible
+ * name of what they represent, it is possible to define this function to
+ * perform the necessary adjustments.
+*/
+char * __weak arch_ftrace_match_adjust(char *str, const char *search)
+{
+ return str;
+}
+
+static int ftrace_match(char *str, struct ftrace_glob *g)
+{
+ int matched = 0;
+ int slen;
+
+ str = arch_ftrace_match_adjust(str, g->search);
+
+ switch (g->type) {
+ case MATCH_FULL:
+ if (strcmp(str, g->search) == 0)
+ matched = 1;
+ break;
+ case MATCH_FRONT_ONLY:
+ if (strncmp(str, g->search, g->len) == 0)
+ matched = 1;
+ break;
+ case MATCH_MIDDLE_ONLY:
+ if (strstr(str, g->search))
+ matched = 1;
+ break;
+ case MATCH_END_ONLY:
+ slen = strlen(str);
+ if (slen >= g->len &&
+ memcmp(str + slen - g->len, g->search, g->len) == 0)
+ matched = 1;
+ break;
+ case MATCH_GLOB:
+ if (glob_match(g->search, str))
+ matched = 1;
+ break;
+ }
+
+ return matched;
+}
+
+static int
+enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
+{
+ struct ftrace_func_entry *entry;
+ int ret = 0;
+
+ entry = ftrace_lookup_ip(hash, rec->ip);
+ if (clear_filter) {
+ /* Do nothing if it doesn't exist */
+ if (!entry)
+ return 0;
+
+ free_hash_entry(hash, entry);
+ } else {
+ /* Do nothing if it exists */
+ if (entry)
+ return 0;
+
+ ret = add_hash_entry(hash, rec->ip);
+ }
+ return ret;
+}
+
+static int
+add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
+ int clear_filter)
+{
+ long index = simple_strtoul(func_g->search, NULL, 0);
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+
+ /* The index starts at 1 */
+ if (--index < 0)
+ return 0;
+
+ do_for_each_ftrace_rec(pg, rec) {
+ if (pg->index <= index) {
+ index -= pg->index;
+ /* this is a double loop, break goes to the next page */
+ break;
+ }
+ rec = &pg->records[index];
+ enter_record(hash, rec, clear_filter);
+ return 1;
+ } while_for_each_ftrace_rec();
+ return 0;
+}
+
+#ifdef FTRACE_MCOUNT_MAX_OFFSET
+static int lookup_ip(unsigned long ip, char **modname, char *str)
+{
+ unsigned long offset;
+
+ kallsyms_lookup(ip, NULL, &offset, modname, str);
+ if (offset > FTRACE_MCOUNT_MAX_OFFSET)
+ return -1;
+ return 0;
+}
+#else
+static int lookup_ip(unsigned long ip, char **modname, char *str)
+{
+ kallsyms_lookup(ip, NULL, NULL, modname, str);
+ return 0;
+}
+#endif
+
+static int
+ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
+ struct ftrace_glob *mod_g, int exclude_mod)
+{
+ char str[KSYM_SYMBOL_LEN];
+ char *modname;
+
+ if (lookup_ip(rec->ip, &modname, str)) {
+ /* This should only happen when a rec is disabled */
+ WARN_ON_ONCE(system_state == SYSTEM_RUNNING &&
+ !(rec->flags & FTRACE_FL_DISABLED));
+ return 0;
+ }
+
+ if (mod_g) {
+ int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
+
+ /* blank module name to match all modules */
+ if (!mod_g->len) {
+ /* blank module globbing: modname xor exclude_mod */
+ if (!exclude_mod != !modname)
+ goto func_match;
+ return 0;
+ }
+
+ /*
+ * exclude_mod is set to trace everything but the given
+ * module. If it is set and the module matches, then
+ * return 0. If it is not set, and the module doesn't match
+ * also return 0. Otherwise, check the function to see if
+ * that matches.
+ */
+ if (!mod_matches == !exclude_mod)
+ return 0;
+func_match:
+ /* blank search means to match all funcs in the mod */
+ if (!func_g->len)
+ return 1;
+ }
+
+ return ftrace_match(str, func_g);
+}
+
+static int
+match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
+{
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ struct ftrace_glob func_g = { .type = MATCH_FULL };
+ struct ftrace_glob mod_g = { .type = MATCH_FULL };
+ struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
+ int exclude_mod = 0;
+ int found = 0;
+ int ret;
+ int clear_filter = 0;
+
+ if (func) {
+ func_g.type = filter_parse_regex(func, len, &func_g.search,
+ &clear_filter);
+ func_g.len = strlen(func_g.search);
+ }
+
+ if (mod) {
+ mod_g.type = filter_parse_regex(mod, strlen(mod),
+ &mod_g.search, &exclude_mod);
+ mod_g.len = strlen(mod_g.search);
+ }
+
+ mutex_lock(&ftrace_lock);
+
+ if (unlikely(ftrace_disabled))
+ goto out_unlock;
+
+ if (func_g.type == MATCH_INDEX) {
+ found = add_rec_by_index(hash, &func_g, clear_filter);
+ goto out_unlock;
+ }
+
+ do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
+ if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
+ ret = enter_record(hash, rec, clear_filter);
+ if (ret < 0) {
+ found = ret;
+ goto out_unlock;
+ }
+ found = 1;
+ }
+ } while_for_each_ftrace_rec();
+ out_unlock:
+ mutex_unlock(&ftrace_lock);
+
+ return found;
+}
+
+static int
+ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
+{
+ return match_records(hash, buff, len, NULL);
+}
+
+static void ftrace_ops_update_code(struct ftrace_ops *ops,
+ struct ftrace_ops_hash *old_hash)
+{
+ struct ftrace_ops *op;
+
+ if (!ftrace_enabled)
+ return;
+
+ if (ops->flags & FTRACE_OPS_FL_ENABLED) {
+ ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
+ return;
+ }
+
+ /*
+ * If this is the shared global_ops filter, then we need to
+ * check if there is another ops that shares it, is enabled.
+ * If so, we still need to run the modify code.
+ */
+ if (ops->func_hash != &global_ops.local_hash)
+ return;
+
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+ if (op->func_hash == &global_ops.local_hash &&
+ op->flags & FTRACE_OPS_FL_ENABLED) {
+ ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
+ /* Only need to do this once */
+ return;
+ }
+ } while_for_each_ftrace_op(op);
+}
+
+static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
+ struct ftrace_hash **orig_hash,
+ struct ftrace_hash *hash,
+ int enable)
+{
+ struct ftrace_ops_hash old_hash_ops;
+ struct ftrace_hash *old_hash;
+ int ret;
+
+ old_hash = *orig_hash;
+ old_hash_ops.filter_hash = ops->func_hash->filter_hash;
+ old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
+ ret = ftrace_hash_move(ops, enable, orig_hash, hash);
+ if (!ret) {
+ ftrace_ops_update_code(ops, &old_hash_ops);
+ free_ftrace_hash_rcu(old_hash);
+ }
+ return ret;
+}
+
+static bool module_exists(const char *module)
+{
+ /* All modules have the symbol __this_module */
+ static const char this_mod[] = "__this_module";
+ char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
+ unsigned long val;
+ int n;
+
+ n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod);
+
+ if (n > sizeof(modname) - 1)
+ return false;
+
+ val = module_kallsyms_lookup_name(modname);
+ return val != 0;
+}
+
+static int cache_mod(struct trace_array *tr,
+ const char *func, char *module, int enable)
+{
+ struct ftrace_mod_load *ftrace_mod, *n;
+ struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
+ int ret;
+
+ mutex_lock(&ftrace_lock);
+
+ /* We do not cache inverse filters */
+ if (func[0] == '!') {
+ func++;
+ ret = -EINVAL;
+
+ /* Look to remove this hash */
+ list_for_each_entry_safe(ftrace_mod, n, head, list) {
+ if (strcmp(ftrace_mod->module, module) != 0)
+ continue;
+
+ /* no func matches all */
+ if (strcmp(func, "*") == 0 ||
+ (ftrace_mod->func &&
+ strcmp(ftrace_mod->func, func) == 0)) {
+ ret = 0;
+ free_ftrace_mod(ftrace_mod);
+ continue;
+ }
+ }
+ goto out;
+ }
+
+ ret = -EINVAL;
+ /* We only care about modules that have not been loaded yet */
+ if (module_exists(module))
+ goto out;
+
+ /* Save this string off, and execute it when the module is loaded */
+ ret = ftrace_add_mod(tr, func, module, enable);
+ out:
+ mutex_unlock(&ftrace_lock);
+
+ return ret;
+}
+
+static int
+ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
+ int reset, int enable);
+
+#ifdef CONFIG_MODULES
+static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
+ char *mod, bool enable)
+{
+ struct ftrace_mod_load *ftrace_mod, *n;
+ struct ftrace_hash **orig_hash, *new_hash;
+ LIST_HEAD(process_mods);
+ char *func;
+
+ mutex_lock(&ops->func_hash->regex_lock);
+
+ if (enable)
+ orig_hash = &ops->func_hash->filter_hash;
+ else
+ orig_hash = &ops->func_hash->notrace_hash;
+
+ new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
+ *orig_hash);
+ if (!new_hash)
+ goto out; /* warn? */
+
+ mutex_lock(&ftrace_lock);
+
+ list_for_each_entry_safe(ftrace_mod, n, head, list) {
+
+ if (strcmp(ftrace_mod->module, mod) != 0)
+ continue;
+
+ if (ftrace_mod->func)
+ func = kstrdup(ftrace_mod->func, GFP_KERNEL);
+ else
+ func = kstrdup("*", GFP_KERNEL);
+
+ if (!func) /* warn? */
+ continue;
+
+ list_move(&ftrace_mod->list, &process_mods);
+
+ /* Use the newly allocated func, as it may be "*" */
+ kfree(ftrace_mod->func);
+ ftrace_mod->func = func;
+ }
+
+ mutex_unlock(&ftrace_lock);
+
+ list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
+
+ func = ftrace_mod->func;
+
+ /* Grabs ftrace_lock, which is why we have this extra step */
+ match_records(new_hash, func, strlen(func), mod);
+ free_ftrace_mod(ftrace_mod);
+ }
+
+ if (enable && list_empty(head))
+ new_hash->flags &= ~FTRACE_HASH_FL_MOD;
+
+ mutex_lock(&ftrace_lock);
+
+ ftrace_hash_move_and_update_ops(ops, orig_hash,
+ new_hash, enable);
+ mutex_unlock(&ftrace_lock);
+
+ out:
+ mutex_unlock(&ops->func_hash->regex_lock);
+
+ free_ftrace_hash(new_hash);
+}
+
+static void process_cached_mods(const char *mod_name)
+{
+ struct trace_array *tr;
+ char *mod;
+
+ mod = kstrdup(mod_name, GFP_KERNEL);
+ if (!mod)
+ return;
+
+ mutex_lock(&trace_types_lock);
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (!list_empty(&tr->mod_trace))
+ process_mod_list(&tr->mod_trace, tr->ops, mod, true);
+ if (!list_empty(&tr->mod_notrace))
+ process_mod_list(&tr->mod_notrace, tr->ops, mod, false);
+ }
+ mutex_unlock(&trace_types_lock);
+
+ kfree(mod);
+}
+#endif
+
+/*
+ * We register the module command as a template to show others how
+ * to register the a command as well.
+ */
+
+static int
+ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
+ char *func_orig, char *cmd, char *module, int enable)
+{
+ char *func;
+ int ret;
+
+ /* match_records() modifies func, and we need the original */
+ func = kstrdup(func_orig, GFP_KERNEL);
+ if (!func)
+ return -ENOMEM;
+
+ /*
+ * cmd == 'mod' because we only registered this func
+ * for the 'mod' ftrace_func_command.
+ * But if you register one func with multiple commands,
+ * you can tell which command was used by the cmd
+ * parameter.
+ */
+ ret = match_records(hash, func, strlen(func), module);
+ kfree(func);
+
+ if (!ret)
+ return cache_mod(tr, func_orig, module, enable);
+ if (ret < 0)
+ return ret;
+ return 0;
+}
+
+static struct ftrace_func_command ftrace_mod_cmd = {
+ .name = "mod",
+ .func = ftrace_mod_callback,
+};
+
+static int __init ftrace_mod_cmd_init(void)
+{
+ return register_ftrace_command(&ftrace_mod_cmd);
+}
+core_initcall(ftrace_mod_cmd_init);
+
+static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
+{
+ struct ftrace_probe_ops *probe_ops;
+ struct ftrace_func_probe *probe;
+
+ probe = container_of(op, struct ftrace_func_probe, ops);
+ probe_ops = probe->probe_ops;
+
+ /*
+ * Disable preemption for these calls to prevent a RCU grace
+ * period. This syncs the hash iteration and freeing of items
+ * on the hash. rcu_read_lock is too dangerous here.
+ */
+ preempt_disable_notrace();
+ probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
+ preempt_enable_notrace();
+}
+
+struct ftrace_func_map {
+ struct ftrace_func_entry entry;
+ void *data;
+};
+
+struct ftrace_func_mapper {
+ struct ftrace_hash hash;
+};
+
+/**
+ * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
+ *
+ * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
+ */
+struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
+{
+ struct ftrace_hash *hash;
+
+ /*
+ * The mapper is simply a ftrace_hash, but since the entries
+ * in the hash are not ftrace_func_entry type, we define it
+ * as a separate structure.
+ */
+ hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
+ return (struct ftrace_func_mapper *)hash;
+}
+
+/**
+ * ftrace_func_mapper_find_ip - Find some data mapped to an ip
+ * @mapper: The mapper that has the ip maps
+ * @ip: the instruction pointer to find the data for
+ *
+ * Returns the data mapped to @ip if found otherwise NULL. The return
+ * is actually the address of the mapper data pointer. The address is
+ * returned for use cases where the data is no bigger than a long, and
+ * the user can use the data pointer as its data instead of having to
+ * allocate more memory for the reference.
+ */
+void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
+ unsigned long ip)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_func_map *map;
+
+ entry = ftrace_lookup_ip(&mapper->hash, ip);
+ if (!entry)
+ return NULL;
+
+ map = (struct ftrace_func_map *)entry;
+ return &map->data;
+}
+
+/**
+ * ftrace_func_mapper_add_ip - Map some data to an ip
+ * @mapper: The mapper that has the ip maps
+ * @ip: The instruction pointer address to map @data to
+ * @data: The data to map to @ip
+ *
+ * Returns 0 on success otherwise an error.
+ */
+int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
+ unsigned long ip, void *data)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_func_map *map;
+
+ entry = ftrace_lookup_ip(&mapper->hash, ip);
+ if (entry)
+ return -EBUSY;
+
+ map = kmalloc(sizeof(*map), GFP_KERNEL);
+ if (!map)
+ return -ENOMEM;
+
+ map->entry.ip = ip;
+ map->data = data;
+
+ __add_hash_entry(&mapper->hash, &map->entry);
+
+ return 0;
+}
+
+/**
+ * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
+ * @mapper: The mapper that has the ip maps
+ * @ip: The instruction pointer address to remove the data from
+ *
+ * Returns the data if it is found, otherwise NULL.
+ * Note, if the data pointer is used as the data itself, (see
+ * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
+ * if the data pointer was set to zero.
+ */
+void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
+ unsigned long ip)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_func_map *map;
+ void *data;
+
+ entry = ftrace_lookup_ip(&mapper->hash, ip);
+ if (!entry)
+ return NULL;
+
+ map = (struct ftrace_func_map *)entry;
+ data = map->data;
+
+ remove_hash_entry(&mapper->hash, entry);
+ kfree(entry);
+
+ return data;
+}
+
+/**
+ * free_ftrace_func_mapper - free a mapping of ips and data
+ * @mapper: The mapper that has the ip maps
+ * @free_func: A function to be called on each data item.
+ *
+ * This is used to free the function mapper. The @free_func is optional
+ * and can be used if the data needs to be freed as well.
+ */
+void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
+ ftrace_mapper_func free_func)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_func_map *map;
+ struct hlist_head *hhd;
+ int size, i;
+
+ if (!mapper)
+ return;
+
+ if (free_func && mapper->hash.count) {
+ size = 1 << mapper->hash.size_bits;
+ for (i = 0; i < size; i++) {
+ hhd = &mapper->hash.buckets[i];
+ hlist_for_each_entry(entry, hhd, hlist) {
+ map = (struct ftrace_func_map *)entry;
+ free_func(map);
+ }
+ }
+ }
+ free_ftrace_hash(&mapper->hash);
+}
+
+static void release_probe(struct ftrace_func_probe *probe)
+{
+ struct ftrace_probe_ops *probe_ops;
+
+ mutex_lock(&ftrace_lock);
+
+ WARN_ON(probe->ref <= 0);
+
+ /* Subtract the ref that was used to protect this instance */
+ probe->ref--;
+
+ if (!probe->ref) {
+ probe_ops = probe->probe_ops;
+ /*
+ * Sending zero as ip tells probe_ops to free
+ * the probe->data itself
+ */
+ if (probe_ops->free)
+ probe_ops->free(probe_ops, probe->tr, 0, probe->data);
+ list_del(&probe->list);
+ kfree(probe);
+ }
+ mutex_unlock(&ftrace_lock);
+}
+
+static void acquire_probe_locked(struct ftrace_func_probe *probe)
+{
+ /*
+ * Add one ref to keep it from being freed when releasing the
+ * ftrace_lock mutex.
+ */
+ probe->ref++;
+}
+
+int
+register_ftrace_function_probe(char *glob, struct trace_array *tr,
+ struct ftrace_probe_ops *probe_ops,
+ void *data)
+{
+ struct ftrace_func_probe *probe = NULL, *iter;
+ struct ftrace_func_entry *entry;
+ struct ftrace_hash **orig_hash;
+ struct ftrace_hash *old_hash;
+ struct ftrace_hash *hash;
+ int count = 0;
+ int size;
+ int ret;
+ int i;
+
+ if (WARN_ON(!tr))
+ return -EINVAL;
+
+ /* We do not support '!' for function probes */
+ if (WARN_ON(glob[0] == '!'))
+ return -EINVAL;
+
+
+ mutex_lock(&ftrace_lock);
+ /* Check if the probe_ops is already registered */
+ list_for_each_entry(iter, &tr->func_probes, list) {
+ if (iter->probe_ops == probe_ops) {
+ probe = iter;
+ break;
+ }
+ }
+ if (!probe) {
+ probe = kzalloc(sizeof(*probe), GFP_KERNEL);
+ if (!probe) {
+ mutex_unlock(&ftrace_lock);
+ return -ENOMEM;
+ }
+ probe->probe_ops = probe_ops;
+ probe->ops.func = function_trace_probe_call;
+ probe->tr = tr;
+ ftrace_ops_init(&probe->ops);
+ list_add(&probe->list, &tr->func_probes);
+ }
+
+ acquire_probe_locked(probe);
+
+ mutex_unlock(&ftrace_lock);
+
+ /*
+ * Note, there's a small window here that the func_hash->filter_hash
+ * may be NULL or empty. Need to be careful when reading the loop.
+ */
+ mutex_lock(&probe->ops.func_hash->regex_lock);
+
+ orig_hash = &probe->ops.func_hash->filter_hash;
+ old_hash = *orig_hash;
+ hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
+
+ if (!hash) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = ftrace_match_records(hash, glob, strlen(glob));
+
+ /* Nothing found? */
+ if (!ret)
+ ret = -EINVAL;
+
+ if (ret < 0)
+ goto out;
+
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ if (ftrace_lookup_ip(old_hash, entry->ip))
+ continue;
+ /*
+ * The caller might want to do something special
+ * for each function we find. We call the callback
+ * to give the caller an opportunity to do so.
+ */
+ if (probe_ops->init) {
+ ret = probe_ops->init(probe_ops, tr,
+ entry->ip, data,
+ &probe->data);
+ if (ret < 0) {
+ if (probe_ops->free && count)
+ probe_ops->free(probe_ops, tr,
+ 0, probe->data);
+ probe->data = NULL;
+ goto out;
+ }
+ }
+ count++;
+ }
+ }
+
+ mutex_lock(&ftrace_lock);
+
+ if (!count) {
+ /* Nothing was added? */
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
+ hash, 1);
+ if (ret < 0)
+ goto err_unlock;
+
+ /* One ref for each new function traced */
+ probe->ref += count;
+
+ if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
+ ret = ftrace_startup(&probe->ops, 0);
+
+ out_unlock:
+ mutex_unlock(&ftrace_lock);
+
+ if (!ret)
+ ret = count;
+ out:
+ mutex_unlock(&probe->ops.func_hash->regex_lock);
+ free_ftrace_hash(hash);
+
+ release_probe(probe);
+
+ return ret;
+
+ err_unlock:
+ if (!probe_ops->free || !count)
+ goto out_unlock;
+
+ /* Failed to do the move, need to call the free functions */
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ if (ftrace_lookup_ip(old_hash, entry->ip))
+ continue;
+ probe_ops->free(probe_ops, tr, entry->ip, probe->data);
+ }
+ }
+ goto out_unlock;
+}
+
+int
+unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
+ struct ftrace_probe_ops *probe_ops)
+{
+ struct ftrace_func_probe *probe = NULL, *iter;
+ struct ftrace_ops_hash old_hash_ops;
+ struct ftrace_func_entry *entry;
+ struct ftrace_glob func_g;
+ struct ftrace_hash **orig_hash;
+ struct ftrace_hash *old_hash;
+ struct ftrace_hash *hash = NULL;
+ struct hlist_node *tmp;
+ struct hlist_head hhd;
+ char str[KSYM_SYMBOL_LEN];
+ int count = 0;
+ int i, ret = -ENODEV;
+ int size;
+
+ if (!glob || !strlen(glob) || !strcmp(glob, "*"))
+ func_g.search = NULL;
+ else {
+ int not;
+
+ func_g.type = filter_parse_regex(glob, strlen(glob),
+ &func_g.search, &not);
+ func_g.len = strlen(func_g.search);
+
+ /* we do not support '!' for function probes */
+ if (WARN_ON(not))
+ return -EINVAL;
+ }
+
+ mutex_lock(&ftrace_lock);
+ /* Check if the probe_ops is already registered */
+ list_for_each_entry(iter, &tr->func_probes, list) {
+ if (iter->probe_ops == probe_ops) {
+ probe = iter;
+ break;
+ }
+ }
+ if (!probe)
+ goto err_unlock_ftrace;
+
+ ret = -EINVAL;
+ if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
+ goto err_unlock_ftrace;
+
+ acquire_probe_locked(probe);
+
+ mutex_unlock(&ftrace_lock);
+
+ mutex_lock(&probe->ops.func_hash->regex_lock);
+
+ orig_hash = &probe->ops.func_hash->filter_hash;
+ old_hash = *orig_hash;
+
+ if (ftrace_hash_empty(old_hash))
+ goto out_unlock;
+
+ old_hash_ops.filter_hash = old_hash;
+ /* Probes only have filters */
+ old_hash_ops.notrace_hash = NULL;
+
+ ret = -ENOMEM;
+ hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
+ if (!hash)
+ goto out_unlock;
+
+ INIT_HLIST_HEAD(&hhd);
+
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
+
+ if (func_g.search) {
+ kallsyms_lookup(entry->ip, NULL, NULL,
+ NULL, str);
+ if (!ftrace_match(str, &func_g))
+ continue;
+ }
+ count++;
+ remove_hash_entry(hash, entry);
+ hlist_add_head(&entry->hlist, &hhd);
+ }
+ }
+
+ /* Nothing found? */
+ if (!count) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ mutex_lock(&ftrace_lock);
+
+ WARN_ON(probe->ref < count);
+
+ probe->ref -= count;
+
+ if (ftrace_hash_empty(hash))
+ ftrace_shutdown(&probe->ops, 0);
+
+ ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
+ hash, 1);
+
+ /* still need to update the function call sites */
+ if (ftrace_enabled && !ftrace_hash_empty(hash))
+ ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
+ &old_hash_ops);
+ synchronize_rcu();
+
+ hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
+ hlist_del(&entry->hlist);
+ if (probe_ops->free)
+ probe_ops->free(probe_ops, tr, entry->ip, probe->data);
+ kfree(entry);
+ }
+ mutex_unlock(&ftrace_lock);
+
+ out_unlock:
+ mutex_unlock(&probe->ops.func_hash->regex_lock);
+ free_ftrace_hash(hash);
+
+ release_probe(probe);
+
+ return ret;
+
+ err_unlock_ftrace:
+ mutex_unlock(&ftrace_lock);
+ return ret;
+}
+
+void clear_ftrace_function_probes(struct trace_array *tr)
+{
+ struct ftrace_func_probe *probe, *n;
+
+ list_for_each_entry_safe(probe, n, &tr->func_probes, list)
+ unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
+}
+
+static LIST_HEAD(ftrace_commands);
+static DEFINE_MUTEX(ftrace_cmd_mutex);
+
+/*
+ * Currently we only register ftrace commands from __init, so mark this
+ * __init too.
+ */
+__init int register_ftrace_command(struct ftrace_func_command *cmd)
+{
+ struct ftrace_func_command *p;
+ int ret = 0;
+
+ mutex_lock(&ftrace_cmd_mutex);
+ list_for_each_entry(p, &ftrace_commands, list) {
+ if (strcmp(cmd->name, p->name) == 0) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ }
+ list_add(&cmd->list, &ftrace_commands);
+ out_unlock:
+ mutex_unlock(&ftrace_cmd_mutex);
+
+ return ret;
+}
+
+/*
+ * Currently we only unregister ftrace commands from __init, so mark
+ * this __init too.
+ */
+__init int unregister_ftrace_command(struct ftrace_func_command *cmd)
+{
+ struct ftrace_func_command *p, *n;
+ int ret = -ENODEV;
+
+ mutex_lock(&ftrace_cmd_mutex);
+ list_for_each_entry_safe(p, n, &ftrace_commands, list) {
+ if (strcmp(cmd->name, p->name) == 0) {
+ ret = 0;
+ list_del_init(&p->list);
+ goto out_unlock;
+ }
+ }
+ out_unlock:
+ mutex_unlock(&ftrace_cmd_mutex);
+
+ return ret;
+}
+
+static int ftrace_process_regex(struct ftrace_iterator *iter,
+ char *buff, int len, int enable)
+{
+ struct ftrace_hash *hash = iter->hash;
+ struct trace_array *tr = iter->ops->private;
+ char *func, *command, *next = buff;
+ struct ftrace_func_command *p;
+ int ret = -EINVAL;
+
+ func = strsep(&next, ":");
+
+ if (!next) {
+ ret = ftrace_match_records(hash, func, len);
+ if (!ret)
+ ret = -EINVAL;
+ if (ret < 0)
+ return ret;
+ return 0;
+ }
+
+ /* command found */
+
+ command = strsep(&next, ":");
+
+ mutex_lock(&ftrace_cmd_mutex);
+ list_for_each_entry(p, &ftrace_commands, list) {
+ if (strcmp(p->name, command) == 0) {
+ ret = p->func(tr, hash, func, command, next, enable);
+ goto out_unlock;
+ }
+ }
+ out_unlock:
+ mutex_unlock(&ftrace_cmd_mutex);
+
+ return ret;
+}
+
+static ssize_t
+ftrace_regex_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos, int enable)
+{
+ struct ftrace_iterator *iter;
+ struct trace_parser *parser;
+ ssize_t ret, read;
+
+ if (!cnt)
+ return 0;
+
+ if (file->f_mode & FMODE_READ) {
+ struct seq_file *m = file->private_data;
+ iter = m->private;
+ } else
+ iter = file->private_data;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ /* iter->hash is a local copy, so we don't need regex_lock */
+
+ parser = &iter->parser;
+ read = trace_get_user(parser, ubuf, cnt, ppos);
+
+ if (read >= 0 && trace_parser_loaded(parser) &&
+ !trace_parser_cont(parser)) {
+ ret = ftrace_process_regex(iter, parser->buffer,
+ parser->idx, enable);
+ trace_parser_clear(parser);
+ if (ret < 0)
+ goto out;
+ }
+
+ ret = read;
+ out:
+ return ret;
+}
+
+ssize_t
+ftrace_filter_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
+}
+
+ssize_t
+ftrace_notrace_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
+}
+
+static int
+__ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
+{
+ struct ftrace_func_entry *entry;
+
+ ip = ftrace_location(ip);
+ if (!ip)
+ return -EINVAL;
+
+ if (remove) {
+ entry = ftrace_lookup_ip(hash, ip);
+ if (!entry)
+ return -ENOENT;
+ free_hash_entry(hash, entry);
+ return 0;
+ }
+
+ return add_hash_entry(hash, ip);
+}
+
+static int
+ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips,
+ unsigned int cnt, int remove)
+{
+ unsigned int i;
+ int err;
+
+ for (i = 0; i < cnt; i++) {
+ err = __ftrace_match_addr(hash, ips[i], remove);
+ if (err) {
+ /*
+ * This expects the @hash is a temporary hash and if this
+ * fails the caller must free the @hash.
+ */
+ return err;
+ }
+ }
+ return 0;
+}
+
+static int
+ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
+ unsigned long *ips, unsigned int cnt,
+ int remove, int reset, int enable)
+{
+ struct ftrace_hash **orig_hash;
+ struct ftrace_hash *hash;
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ mutex_lock(&ops->func_hash->regex_lock);
+
+ if (enable)
+ orig_hash = &ops->func_hash->filter_hash;
+ else
+ orig_hash = &ops->func_hash->notrace_hash;
+
+ if (reset)
+ hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
+ else
+ hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
+
+ if (!hash) {
+ ret = -ENOMEM;
+ goto out_regex_unlock;
+ }
+
+ if (buf && !ftrace_match_records(hash, buf, len)) {
+ ret = -EINVAL;
+ goto out_regex_unlock;
+ }
+ if (ips) {
+ ret = ftrace_match_addr(hash, ips, cnt, remove);
+ if (ret < 0)
+ goto out_regex_unlock;
+ }
+
+ mutex_lock(&ftrace_lock);
+ ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
+ mutex_unlock(&ftrace_lock);
+
+ out_regex_unlock:
+ mutex_unlock(&ops->func_hash->regex_lock);
+
+ free_ftrace_hash(hash);
+ return ret;
+}
+
+static int
+ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt,
+ int remove, int reset, int enable)
+{
+ return ftrace_set_hash(ops, NULL, 0, ips, cnt, remove, reset, enable);
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+
+struct ftrace_direct_func {
+ struct list_head next;
+ unsigned long addr;
+ int count;
+};
+
+static LIST_HEAD(ftrace_direct_funcs);
+
+/**
+ * ftrace_find_direct_func - test an address if it is a registered direct caller
+ * @addr: The address of a registered direct caller
+ *
+ * This searches to see if a ftrace direct caller has been registered
+ * at a specific address, and if so, it returns a descriptor for it.
+ *
+ * This can be used by architecture code to see if an address is
+ * a direct caller (trampoline) attached to a fentry/mcount location.
+ * This is useful for the function_graph tracer, as it may need to
+ * do adjustments if it traced a location that also has a direct
+ * trampoline attached to it.
+ */
+struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
+{
+ struct ftrace_direct_func *entry;
+ bool found = false;
+
+ /* May be called by fgraph trampoline (protected by rcu tasks) */
+ list_for_each_entry_rcu(entry, &ftrace_direct_funcs, next) {
+ if (entry->addr == addr) {
+ found = true;
+ break;
+ }
+ }
+ if (found)
+ return entry;
+
+ return NULL;
+}
+
+static struct ftrace_direct_func *ftrace_alloc_direct_func(unsigned long addr)
+{
+ struct ftrace_direct_func *direct;
+
+ direct = kmalloc(sizeof(*direct), GFP_KERNEL);
+ if (!direct)
+ return NULL;
+ direct->addr = addr;
+ direct->count = 0;
+ list_add_rcu(&direct->next, &ftrace_direct_funcs);
+ ftrace_direct_func_count++;
+ return direct;
+}
+
+static int register_ftrace_function_nolock(struct ftrace_ops *ops);
+
+/**
+ * register_ftrace_direct - Call a custom trampoline directly
+ * @ip: The address of the nop at the beginning of a function
+ * @addr: The address of the trampoline to call at @ip
+ *
+ * This is used to connect a direct call from the nop location (@ip)
+ * at the start of ftrace traced functions. The location that it calls
+ * (@addr) must be able to handle a direct call, and save the parameters
+ * of the function being traced, and restore them (or inject new ones
+ * if needed), before returning.
+ *
+ * Returns:
+ * 0 on success
+ * -EBUSY - Another direct function is already attached (there can be only one)
+ * -ENODEV - @ip does not point to a ftrace nop location (or not supported)
+ * -ENOMEM - There was an allocation failure.
+ */
+int register_ftrace_direct(unsigned long ip, unsigned long addr)
+{
+ struct ftrace_direct_func *direct;
+ struct ftrace_func_entry *entry;
+ struct ftrace_hash *free_hash = NULL;
+ struct dyn_ftrace *rec;
+ int ret = -ENODEV;
+
+ mutex_lock(&direct_mutex);
+
+ ip = ftrace_location(ip);
+ if (!ip)
+ goto out_unlock;
+
+ /* See if there's a direct function at @ip already */
+ ret = -EBUSY;
+ if (ftrace_find_rec_direct(ip))
+ goto out_unlock;
+
+ ret = -ENODEV;
+ rec = lookup_rec(ip, ip);
+ if (!rec)
+ goto out_unlock;
+
+ /*
+ * Check if the rec says it has a direct call but we didn't
+ * find one earlier?
+ */
+ if (WARN_ON(rec->flags & FTRACE_FL_DIRECT))
+ goto out_unlock;
+
+ /* Make sure the ip points to the exact record */
+ if (ip != rec->ip) {
+ ip = rec->ip;
+ /* Need to check this ip for a direct. */
+ if (ftrace_find_rec_direct(ip))
+ goto out_unlock;
+ }
+
+ ret = -ENOMEM;
+ direct = ftrace_find_direct_func(addr);
+ if (!direct) {
+ direct = ftrace_alloc_direct_func(addr);
+ if (!direct)
+ goto out_unlock;
+ }
+
+ entry = ftrace_add_rec_direct(ip, addr, &free_hash);
+ if (!entry)
+ goto out_unlock;
+
+ ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0);
+
+ if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) {
+ ret = register_ftrace_function_nolock(&direct_ops);
+ if (ret)
+ ftrace_set_filter_ip(&direct_ops, ip, 1, 0);
+ }
+
+ if (ret) {
+ remove_hash_entry(direct_functions, entry);
+ kfree(entry);
+ if (!direct->count) {
+ list_del_rcu(&direct->next);
+ synchronize_rcu_tasks();
+ kfree(direct);
+ if (free_hash)
+ free_ftrace_hash(free_hash);
+ free_hash = NULL;
+ ftrace_direct_func_count--;
+ }
+ } else {
+ direct->count++;
+ }
+ out_unlock:
+ mutex_unlock(&direct_mutex);
+
+ if (free_hash) {
+ synchronize_rcu_tasks();
+ free_ftrace_hash(free_hash);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(register_ftrace_direct);
+
+static struct ftrace_func_entry *find_direct_entry(unsigned long *ip,
+ struct dyn_ftrace **recp)
+{
+ struct ftrace_func_entry *entry;
+ struct dyn_ftrace *rec;
+
+ rec = lookup_rec(*ip, *ip);
+ if (!rec)
+ return NULL;
+
+ entry = __ftrace_lookup_ip(direct_functions, rec->ip);
+ if (!entry) {
+ WARN_ON(rec->flags & FTRACE_FL_DIRECT);
+ return NULL;
+ }
+
+ WARN_ON(!(rec->flags & FTRACE_FL_DIRECT));
+
+ /* Passed in ip just needs to be on the call site */
+ *ip = rec->ip;
+
+ if (recp)
+ *recp = rec;
+
+ return entry;
+}
+
+int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
+{
+ struct ftrace_direct_func *direct;
+ struct ftrace_func_entry *entry;
+ struct ftrace_hash *hash;
+ int ret = -ENODEV;
+
+ mutex_lock(&direct_mutex);
+
+ ip = ftrace_location(ip);
+ if (!ip)
+ goto out_unlock;
+
+ entry = find_direct_entry(&ip, NULL);
+ if (!entry)
+ goto out_unlock;
+
+ hash = direct_ops.func_hash->filter_hash;
+ if (hash->count == 1)
+ unregister_ftrace_function(&direct_ops);
+
+ ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0);
+
+ WARN_ON(ret);
+
+ remove_hash_entry(direct_functions, entry);
+
+ direct = ftrace_find_direct_func(addr);
+ if (!WARN_ON(!direct)) {
+ /* This is the good path (see the ! before WARN) */
+ direct->count--;
+ WARN_ON(direct->count < 0);
+ if (!direct->count) {
+ list_del_rcu(&direct->next);
+ synchronize_rcu_tasks();
+ kfree(direct);
+ kfree(entry);
+ ftrace_direct_func_count--;
+ }
+ }
+ out_unlock:
+ mutex_unlock(&direct_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_direct);
+
+static struct ftrace_ops stub_ops = {
+ .func = ftrace_stub,
+};
+
+/**
+ * ftrace_modify_direct_caller - modify ftrace nop directly
+ * @entry: The ftrace hash entry of the direct helper for @rec
+ * @rec: The record representing the function site to patch
+ * @old_addr: The location that the site at @rec->ip currently calls
+ * @new_addr: The location that the site at @rec->ip should call
+ *
+ * An architecture may overwrite this function to optimize the
+ * changing of the direct callback on an ftrace nop location.
+ * This is called with the ftrace_lock mutex held, and no other
+ * ftrace callbacks are on the associated record (@rec). Thus,
+ * it is safe to modify the ftrace record, where it should be
+ * currently calling @old_addr directly, to call @new_addr.
+ *
+ * This is called with direct_mutex locked.
+ *
+ * Safety checks should be made to make sure that the code at
+ * @rec->ip is currently calling @old_addr. And this must
+ * also update entry->direct to @new_addr.
+ */
+int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
+ struct dyn_ftrace *rec,
+ unsigned long old_addr,
+ unsigned long new_addr)
+{
+ unsigned long ip = rec->ip;
+ int ret;
+
+ lockdep_assert_held(&direct_mutex);
+
+ /*
+ * The ftrace_lock was used to determine if the record
+ * had more than one registered user to it. If it did,
+ * we needed to prevent that from changing to do the quick
+ * switch. But if it did not (only a direct caller was attached)
+ * then this function is called. But this function can deal
+ * with attached callers to the rec that we care about, and
+ * since this function uses standard ftrace calls that take
+ * the ftrace_lock mutex, we need to release it.
+ */
+ mutex_unlock(&ftrace_lock);
+
+ /*
+ * By setting a stub function at the same address, we force
+ * the code to call the iterator and the direct_ops helper.
+ * This means that @ip does not call the direct call, and
+ * we can simply modify it.
+ */
+ ret = ftrace_set_filter_ip(&stub_ops, ip, 0, 0);
+ if (ret)
+ goto out_lock;
+
+ ret = register_ftrace_function_nolock(&stub_ops);
+ if (ret) {
+ ftrace_set_filter_ip(&stub_ops, ip, 1, 0);
+ goto out_lock;
+ }
+
+ entry->direct = new_addr;
+
+ /*
+ * By removing the stub, we put back the direct call, calling
+ * the @new_addr.
+ */
+ unregister_ftrace_function(&stub_ops);
+ ftrace_set_filter_ip(&stub_ops, ip, 1, 0);
+
+ out_lock:
+ mutex_lock(&ftrace_lock);
+
+ return ret;
+}
+
+/**
+ * modify_ftrace_direct - Modify an existing direct call to call something else
+ * @ip: The instruction pointer to modify
+ * @old_addr: The address that the current @ip calls directly
+ * @new_addr: The address that the @ip should call
+ *
+ * This modifies a ftrace direct caller at an instruction pointer without
+ * having to disable it first. The direct call will switch over to the
+ * @new_addr without missing anything.
+ *
+ * Returns: zero on success. Non zero on error, which includes:
+ * -ENODEV : the @ip given has no direct caller attached
+ * -EINVAL : the @old_addr does not match the current direct caller
+ */
+int modify_ftrace_direct(unsigned long ip,
+ unsigned long old_addr, unsigned long new_addr)
+{
+ struct ftrace_direct_func *direct, *new_direct = NULL;
+ struct ftrace_func_entry *entry;
+ struct dyn_ftrace *rec;
+ int ret = -ENODEV;
+
+ mutex_lock(&direct_mutex);
+
+ mutex_lock(&ftrace_lock);
+
+ ip = ftrace_location(ip);
+ if (!ip)
+ goto out_unlock;
+
+ entry = find_direct_entry(&ip, &rec);
+ if (!entry)
+ goto out_unlock;
+
+ ret = -EINVAL;
+ if (entry->direct != old_addr)
+ goto out_unlock;
+
+ direct = ftrace_find_direct_func(old_addr);
+ if (WARN_ON(!direct))
+ goto out_unlock;
+ if (direct->count > 1) {
+ ret = -ENOMEM;
+ new_direct = ftrace_alloc_direct_func(new_addr);
+ if (!new_direct)
+ goto out_unlock;
+ direct->count--;
+ new_direct->count++;
+ } else {
+ direct->addr = new_addr;
+ }
+
+ /*
+ * If there's no other ftrace callback on the rec->ip location,
+ * then it can be changed directly by the architecture.
+ * If there is another caller, then we just need to change the
+ * direct caller helper to point to @new_addr.
+ */
+ if (ftrace_rec_count(rec) == 1) {
+ ret = ftrace_modify_direct_caller(entry, rec, old_addr, new_addr);
+ } else {
+ entry->direct = new_addr;
+ ret = 0;
+ }
+
+ if (ret) {
+ direct->addr = old_addr;
+ if (unlikely(new_direct)) {
+ direct->count++;
+ list_del_rcu(&new_direct->next);
+ synchronize_rcu_tasks();
+ kfree(new_direct);
+ ftrace_direct_func_count--;
+ }
+ }
+
+ out_unlock:
+ mutex_unlock(&ftrace_lock);
+ mutex_unlock(&direct_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(modify_ftrace_direct);
+
+#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS)
+
+static int check_direct_multi(struct ftrace_ops *ops)
+{
+ if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
+ return -EINVAL;
+ if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS)
+ return -EINVAL;
+ return 0;
+}
+
+static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr)
+{
+ struct ftrace_func_entry *entry, *del;
+ int size, i;
+
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ del = __ftrace_lookup_ip(direct_functions, entry->ip);
+ if (del && del->direct == addr) {
+ remove_hash_entry(direct_functions, del);
+ kfree(del);
+ }
+ }
+ }
+}
+
+/**
+ * register_ftrace_direct_multi - Call a custom trampoline directly
+ * for multiple functions registered in @ops
+ * @ops: The address of the struct ftrace_ops object
+ * @addr: The address of the trampoline to call at @ops functions
+ *
+ * This is used to connect a direct calls to @addr from the nop locations
+ * of the functions registered in @ops (with by ftrace_set_filter_ip
+ * function).
+ *
+ * The location that it calls (@addr) must be able to handle a direct call,
+ * and save the parameters of the function being traced, and restore them
+ * (or inject new ones if needed), before returning.
+ *
+ * Returns:
+ * 0 on success
+ * -EINVAL - The @ops object was already registered with this call or
+ * when there are no functions in @ops object.
+ * -EBUSY - Another direct function is already attached (there can be only one)
+ * -ENODEV - @ip does not point to a ftrace nop location (or not supported)
+ * -ENOMEM - There was an allocation failure.
+ */
+int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+ struct ftrace_hash *hash, *free_hash = NULL;
+ struct ftrace_func_entry *entry, *new;
+ int err = -EBUSY, size, i;
+
+ if (ops->func || ops->trampoline)
+ return -EINVAL;
+ if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
+ return -EINVAL;
+ if (ops->flags & FTRACE_OPS_FL_ENABLED)
+ return -EINVAL;
+
+ hash = ops->func_hash->filter_hash;
+ if (ftrace_hash_empty(hash))
+ return -EINVAL;
+
+ mutex_lock(&direct_mutex);
+
+ /* Make sure requested entries are not already registered.. */
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ if (ftrace_find_rec_direct(entry->ip))
+ goto out_unlock;
+ }
+ }
+
+ /* ... and insert them to direct_functions hash. */
+ err = -ENOMEM;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ new = ftrace_add_rec_direct(entry->ip, addr, &free_hash);
+ if (!new)
+ goto out_remove;
+ entry->direct = addr;
+ }
+ }
+
+ ops->func = call_direct_funcs;
+ ops->flags = MULTI_FLAGS;
+ ops->trampoline = FTRACE_REGS_ADDR;
+
+ err = register_ftrace_function_nolock(ops);
+
+ out_remove:
+ if (err)
+ remove_direct_functions_hash(hash, addr);
+
+ out_unlock:
+ mutex_unlock(&direct_mutex);
+
+ if (free_hash) {
+ synchronize_rcu_tasks();
+ free_ftrace_hash(free_hash);
+ }
+ return err;
+}
+EXPORT_SYMBOL_GPL(register_ftrace_direct_multi);
+
+/**
+ * unregister_ftrace_direct_multi - Remove calls to custom trampoline
+ * previously registered by register_ftrace_direct_multi for @ops object.
+ * @ops: The address of the struct ftrace_ops object
+ *
+ * This is used to remove a direct calls to @addr from the nop locations
+ * of the functions registered in @ops (with by ftrace_set_filter_ip
+ * function).
+ *
+ * Returns:
+ * 0 on success
+ * -EINVAL - The @ops object was not properly registered.
+ */
+int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+ struct ftrace_hash *hash = ops->func_hash->filter_hash;
+ int err;
+
+ if (check_direct_multi(ops))
+ return -EINVAL;
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return -EINVAL;
+
+ mutex_lock(&direct_mutex);
+ err = unregister_ftrace_function(ops);
+ remove_direct_functions_hash(hash, addr);
+ mutex_unlock(&direct_mutex);
+
+ /* cleanup for possible another register call */
+ ops->func = NULL;
+ ops->trampoline = 0;
+ return err;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_direct_multi);
+
+static int
+__modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+ struct ftrace_hash *hash;
+ struct ftrace_func_entry *entry, *iter;
+ static struct ftrace_ops tmp_ops = {
+ .func = ftrace_stub,
+ .flags = FTRACE_OPS_FL_STUB,
+ };
+ int i, size;
+ int err;
+
+ lockdep_assert_held_once(&direct_mutex);
+
+ /* Enable the tmp_ops to have the same functions as the direct ops */
+ ftrace_ops_init(&tmp_ops);
+ tmp_ops.func_hash = ops->func_hash;
+
+ err = register_ftrace_function_nolock(&tmp_ops);
+ if (err)
+ return err;
+
+ /*
+ * Now the ftrace_ops_list_func() is called to do the direct callers.
+ * We can safely change the direct functions attached to each entry.
+ */
+ mutex_lock(&ftrace_lock);
+
+ hash = ops->func_hash->filter_hash;
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(iter, &hash->buckets[i], hlist) {
+ entry = __ftrace_lookup_ip(direct_functions, iter->ip);
+ if (!entry)
+ continue;
+ entry->direct = addr;
+ }
+ }
+
+ mutex_unlock(&ftrace_lock);
+
+ /* Removing the tmp_ops will add the updated direct callers to the functions */
+ unregister_ftrace_function(&tmp_ops);
+
+ return err;
+}
+
+/**
+ * modify_ftrace_direct_multi_nolock - Modify an existing direct 'multi' call
+ * to call something else
+ * @ops: The address of the struct ftrace_ops object
+ * @addr: The address of the new trampoline to call at @ops functions
+ *
+ * This is used to unregister currently registered direct caller and
+ * register new one @addr on functions registered in @ops object.
+ *
+ * Note there's window between ftrace_shutdown and ftrace_startup calls
+ * where there will be no callbacks called.
+ *
+ * Caller should already have direct_mutex locked, so we don't lock
+ * direct_mutex here.
+ *
+ * Returns: zero on success. Non zero on error, which includes:
+ * -EINVAL - The @ops object was not properly registered.
+ */
+int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr)
+{
+ if (check_direct_multi(ops))
+ return -EINVAL;
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return -EINVAL;
+
+ return __modify_ftrace_direct_multi(ops, addr);
+}
+EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi_nolock);
+
+/**
+ * modify_ftrace_direct_multi - Modify an existing direct 'multi' call
+ * to call something else
+ * @ops: The address of the struct ftrace_ops object
+ * @addr: The address of the new trampoline to call at @ops functions
+ *
+ * This is used to unregister currently registered direct caller and
+ * register new one @addr on functions registered in @ops object.
+ *
+ * Note there's window between ftrace_shutdown and ftrace_startup calls
+ * where there will be no callbacks called.
+ *
+ * Returns: zero on success. Non zero on error, which includes:
+ * -EINVAL - The @ops object was not properly registered.
+ */
+int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+ int err;
+
+ if (check_direct_multi(ops))
+ return -EINVAL;
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return -EINVAL;
+
+ mutex_lock(&direct_mutex);
+ err = __modify_ftrace_direct_multi(ops, addr);
+ mutex_unlock(&direct_mutex);
+ return err;
+}
+EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi);
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
+
+/**
+ * ftrace_set_filter_ip - set a function to filter on in ftrace by address
+ * @ops - the ops to set the filter with
+ * @ip - the address to add to or remove from the filter.
+ * @remove - non zero to remove the ip from the filter
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Filters denote which functions should be enabled when tracing is enabled
+ * If @ip is NULL, it fails to update filter.
+ *
+ * This can allocate memory which must be freed before @ops can be freed,
+ * either by removing each filtered addr or by using
+ * ftrace_free_filter(@ops).
+ */
+int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
+ int remove, int reset)
+{
+ ftrace_ops_init(ops);
+ return ftrace_set_addr(ops, &ip, 1, remove, reset, 1);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
+
+/**
+ * ftrace_set_filter_ips - set functions to filter on in ftrace by addresses
+ * @ops - the ops to set the filter with
+ * @ips - the array of addresses to add to or remove from the filter.
+ * @cnt - the number of addresses in @ips
+ * @remove - non zero to remove ips from the filter
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Filters denote which functions should be enabled when tracing is enabled
+ * If @ips array or any ip specified within is NULL , it fails to update filter.
+ *
+ * This can allocate memory which must be freed before @ops can be freed,
+ * either by removing each filtered addr or by using
+ * ftrace_free_filter(@ops).
+*/
+int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
+ unsigned int cnt, int remove, int reset)
+{
+ ftrace_ops_init(ops);
+ return ftrace_set_addr(ops, ips, cnt, remove, reset, 1);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_filter_ips);
+
+/**
+ * ftrace_ops_set_global_filter - setup ops to use global filters
+ * @ops - the ops which will use the global filters
+ *
+ * ftrace users who need global function trace filtering should call this.
+ * It can set the global filter only if ops were not initialized before.
+ */
+void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
+{
+ if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
+ return;
+
+ ftrace_ops_init(ops);
+ ops->func_hash = &global_ops.local_hash;
+}
+EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
+
+static int
+ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
+ int reset, int enable)
+{
+ return ftrace_set_hash(ops, buf, len, NULL, 0, 0, reset, enable);
+}
+
+/**
+ * ftrace_set_filter - set a function to filter on in ftrace
+ * @ops - the ops to set the filter with
+ * @buf - the string that holds the function filter text.
+ * @len - the length of the string.
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Filters denote which functions should be enabled when tracing is enabled.
+ * If @buf is NULL and reset is set, all functions will be enabled for tracing.
+ *
+ * This can allocate memory which must be freed before @ops can be freed,
+ * either by removing each filtered addr or by using
+ * ftrace_free_filter(@ops).
+ */
+int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
+ int len, int reset)
+{
+ ftrace_ops_init(ops);
+ return ftrace_set_regex(ops, buf, len, reset, 1);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_filter);
+
+/**
+ * ftrace_set_notrace - set a function to not trace in ftrace
+ * @ops - the ops to set the notrace filter with
+ * @buf - the string that holds the function notrace text.
+ * @len - the length of the string.
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Notrace Filters denote which functions should not be enabled when tracing
+ * is enabled. If @buf is NULL and reset is set, all functions will be enabled
+ * for tracing.
+ *
+ * This can allocate memory which must be freed before @ops can be freed,
+ * either by removing each filtered addr or by using
+ * ftrace_free_filter(@ops).
+ */
+int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
+ int len, int reset)
+{
+ ftrace_ops_init(ops);
+ return ftrace_set_regex(ops, buf, len, reset, 0);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_notrace);
+/**
+ * ftrace_set_global_filter - set a function to filter on with global tracers
+ * @buf - the string that holds the function filter text.
+ * @len - the length of the string.
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Filters denote which functions should be enabled when tracing is enabled.
+ * If @buf is NULL and reset is set, all functions will be enabled for tracing.
+ */
+void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
+{
+ ftrace_set_regex(&global_ops, buf, len, reset, 1);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
+
+/**
+ * ftrace_set_global_notrace - set a function to not trace with global tracers
+ * @buf - the string that holds the function notrace text.
+ * @len - the length of the string.
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Notrace Filters denote which functions should not be enabled when tracing
+ * is enabled. If @buf is NULL and reset is set, all functions will be enabled
+ * for tracing.
+ */
+void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
+{
+ ftrace_set_regex(&global_ops, buf, len, reset, 0);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
+
+/*
+ * command line interface to allow users to set filters on boot up.
+ */
+#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
+static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
+static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
+
+/* Used by function selftest to not test if filter is set */
+bool ftrace_filter_param __initdata;
+
+static int __init set_ftrace_notrace(char *str)
+{
+ ftrace_filter_param = true;
+ strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_notrace=", set_ftrace_notrace);
+
+static int __init set_ftrace_filter(char *str)
+{
+ ftrace_filter_param = true;
+ strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_filter=", set_ftrace_filter);
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
+static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
+static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
+
+static int __init set_graph_function(char *str)
+{
+ strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_graph_filter=", set_graph_function);
+
+static int __init set_graph_notrace_function(char *str)
+{
+ strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_graph_notrace=", set_graph_notrace_function);
+
+static int __init set_graph_max_depth_function(char *str)
+{
+ if (!str)
+ return 0;
+ fgraph_max_depth = simple_strtoul(str, NULL, 0);
+ return 1;
+}
+__setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
+
+static void __init set_ftrace_early_graph(char *buf, int enable)
+{
+ int ret;
+ char *func;
+ struct ftrace_hash *hash;
+
+ hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
+ if (MEM_FAIL(!hash, "Failed to allocate hash\n"))
+ return;
+
+ while (buf) {
+ func = strsep(&buf, ",");
+ /* we allow only one expression at a time */
+ ret = ftrace_graph_set_hash(hash, func);
+ if (ret)
+ printk(KERN_DEBUG "ftrace: function %s not "
+ "traceable\n", func);
+ }
+
+ if (enable)
+ ftrace_graph_hash = hash;
+ else
+ ftrace_graph_notrace_hash = hash;
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+void __init
+ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
+{
+ char *func;
+
+ ftrace_ops_init(ops);
+
+ while (buf) {
+ func = strsep(&buf, ",");
+ ftrace_set_regex(ops, func, strlen(func), 0, enable);
+ }
+}
+
+static void __init set_ftrace_early_filters(void)
+{
+ if (ftrace_filter_buf[0])
+ ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
+ if (ftrace_notrace_buf[0])
+ ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ if (ftrace_graph_buf[0])
+ set_ftrace_early_graph(ftrace_graph_buf, 1);
+ if (ftrace_graph_notrace_buf[0])
+ set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+}
+
+int ftrace_regex_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *m = (struct seq_file *)file->private_data;
+ struct ftrace_iterator *iter;
+ struct ftrace_hash **orig_hash;
+ struct trace_parser *parser;
+ int filter_hash;
+
+ if (file->f_mode & FMODE_READ) {
+ iter = m->private;
+ seq_release(inode, file);
+ } else
+ iter = file->private_data;
+
+ parser = &iter->parser;
+ if (trace_parser_loaded(parser)) {
+ int enable = !(iter->flags & FTRACE_ITER_NOTRACE);
+
+ ftrace_process_regex(iter, parser->buffer,
+ parser->idx, enable);
+ }
+
+ trace_parser_put(parser);
+
+ mutex_lock(&iter->ops->func_hash->regex_lock);
+
+ if (file->f_mode & FMODE_WRITE) {
+ filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
+
+ if (filter_hash) {
+ orig_hash = &iter->ops->func_hash->filter_hash;
+ if (iter->tr) {
+ if (list_empty(&iter->tr->mod_trace))
+ iter->hash->flags &= ~FTRACE_HASH_FL_MOD;
+ else
+ iter->hash->flags |= FTRACE_HASH_FL_MOD;
+ }
+ } else
+ orig_hash = &iter->ops->func_hash->notrace_hash;
+
+ mutex_lock(&ftrace_lock);
+ ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
+ iter->hash, filter_hash);
+ mutex_unlock(&ftrace_lock);
+ } else {
+ /* For read only, the hash is the ops hash */
+ iter->hash = NULL;
+ }
+
+ mutex_unlock(&iter->ops->func_hash->regex_lock);
+ free_ftrace_hash(iter->hash);
+ if (iter->tr)
+ trace_array_put(iter->tr);
+ kfree(iter);
+
+ return 0;
+}
+
+static const struct file_operations ftrace_avail_fops = {
+ .open = ftrace_avail_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+static const struct file_operations ftrace_enabled_fops = {
+ .open = ftrace_enabled_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+static const struct file_operations ftrace_filter_fops = {
+ .open = ftrace_filter_open,
+ .read = seq_read,
+ .write = ftrace_filter_write,
+ .llseek = tracing_lseek,
+ .release = ftrace_regex_release,
+};
+
+static const struct file_operations ftrace_notrace_fops = {
+ .open = ftrace_notrace_open,
+ .read = seq_read,
+ .write = ftrace_notrace_write,
+ .llseek = tracing_lseek,
+ .release = ftrace_regex_release,
+};
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static DEFINE_MUTEX(graph_lock);
+
+struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH;
+struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH;
+
+enum graph_filter_type {
+ GRAPH_FILTER_NOTRACE = 0,
+ GRAPH_FILTER_FUNCTION,
+};
+
+#define FTRACE_GRAPH_EMPTY ((void *)1)
+
+struct ftrace_graph_data {
+ struct ftrace_hash *hash;
+ struct ftrace_func_entry *entry;
+ int idx; /* for hash table iteration */
+ enum graph_filter_type type;
+ struct ftrace_hash *new_hash;
+ const struct seq_operations *seq_ops;
+ struct trace_parser parser;
+};
+
+static void *
+__g_next(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_graph_data *fgd = m->private;
+ struct ftrace_func_entry *entry = fgd->entry;
+ struct hlist_head *head;
+ int i, idx = fgd->idx;
+
+ if (*pos >= fgd->hash->count)
+ return NULL;
+
+ if (entry) {
+ hlist_for_each_entry_continue(entry, hlist) {
+ fgd->entry = entry;
+ return entry;
+ }
+
+ idx++;
+ }
+
+ for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
+ head = &fgd->hash->buckets[i];
+ hlist_for_each_entry(entry, head, hlist) {
+ fgd->entry = entry;
+ fgd->idx = i;
+ return entry;
+ }
+ }
+ return NULL;
+}
+
+static void *
+g_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ (*pos)++;
+ return __g_next(m, pos);
+}
+
+static void *g_start(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_graph_data *fgd = m->private;
+
+ mutex_lock(&graph_lock);
+
+ if (fgd->type == GRAPH_FILTER_FUNCTION)
+ fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
+ lockdep_is_held(&graph_lock));
+ else
+ fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
+ lockdep_is_held(&graph_lock));
+
+ /* Nothing, tell g_show to print all functions are enabled */
+ if (ftrace_hash_empty(fgd->hash) && !*pos)
+ return FTRACE_GRAPH_EMPTY;
+
+ fgd->idx = 0;
+ fgd->entry = NULL;
+ return __g_next(m, pos);
+}
+
+static void g_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&graph_lock);
+}
+
+static int g_show(struct seq_file *m, void *v)
+{
+ struct ftrace_func_entry *entry = v;
+
+ if (!entry)
+ return 0;
+
+ if (entry == FTRACE_GRAPH_EMPTY) {
+ struct ftrace_graph_data *fgd = m->private;
+
+ if (fgd->type == GRAPH_FILTER_FUNCTION)
+ seq_puts(m, "#### all functions enabled ####\n");
+ else
+ seq_puts(m, "#### no functions disabled ####\n");
+ return 0;
+ }
+
+ seq_printf(m, "%ps\n", (void *)entry->ip);
+
+ return 0;
+}
+
+static const struct seq_operations ftrace_graph_seq_ops = {
+ .start = g_start,
+ .next = g_next,
+ .stop = g_stop,
+ .show = g_show,
+};
+
+static int
+__ftrace_graph_open(struct inode *inode, struct file *file,
+ struct ftrace_graph_data *fgd)
+{
+ int ret;
+ struct ftrace_hash *new_hash = NULL;
+
+ ret = security_locked_down(LOCKDOWN_TRACEFS);
+ if (ret)
+ return ret;
+
+ if (file->f_mode & FMODE_WRITE) {
+ const int size_bits = FTRACE_HASH_DEFAULT_BITS;
+
+ if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
+ return -ENOMEM;
+
+ if (file->f_flags & O_TRUNC)
+ new_hash = alloc_ftrace_hash(size_bits);
+ else
+ new_hash = alloc_and_copy_ftrace_hash(size_bits,
+ fgd->hash);
+ if (!new_hash) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+
+ if (file->f_mode & FMODE_READ) {
+ ret = seq_open(file, &ftrace_graph_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = fgd;
+ } else {
+ /* Failed */
+ free_ftrace_hash(new_hash);
+ new_hash = NULL;
+ }
+ } else
+ file->private_data = fgd;
+
+out:
+ if (ret < 0 && file->f_mode & FMODE_WRITE)
+ trace_parser_put(&fgd->parser);
+
+ fgd->new_hash = new_hash;
+
+ /*
+ * All uses of fgd->hash must be taken with the graph_lock
+ * held. The graph_lock is going to be released, so force
+ * fgd->hash to be reinitialized when it is taken again.
+ */
+ fgd->hash = NULL;
+
+ return ret;
+}
+
+static int
+ftrace_graph_open(struct inode *inode, struct file *file)
+{
+ struct ftrace_graph_data *fgd;
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
+ if (fgd == NULL)
+ return -ENOMEM;
+
+ mutex_lock(&graph_lock);
+
+ fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
+ lockdep_is_held(&graph_lock));
+ fgd->type = GRAPH_FILTER_FUNCTION;
+ fgd->seq_ops = &ftrace_graph_seq_ops;
+
+ ret = __ftrace_graph_open(inode, file, fgd);
+ if (ret < 0)
+ kfree(fgd);
+
+ mutex_unlock(&graph_lock);
+ return ret;
+}
+
+static int
+ftrace_graph_notrace_open(struct inode *inode, struct file *file)
+{
+ struct ftrace_graph_data *fgd;
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
+ if (fgd == NULL)
+ return -ENOMEM;
+
+ mutex_lock(&graph_lock);
+
+ fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
+ lockdep_is_held(&graph_lock));
+ fgd->type = GRAPH_FILTER_NOTRACE;
+ fgd->seq_ops = &ftrace_graph_seq_ops;
+
+ ret = __ftrace_graph_open(inode, file, fgd);
+ if (ret < 0)
+ kfree(fgd);
+
+ mutex_unlock(&graph_lock);
+ return ret;
+}
+
+static int
+ftrace_graph_release(struct inode *inode, struct file *file)
+{
+ struct ftrace_graph_data *fgd;
+ struct ftrace_hash *old_hash, *new_hash;
+ struct trace_parser *parser;
+ int ret = 0;
+
+ if (file->f_mode & FMODE_READ) {
+ struct seq_file *m = file->private_data;
+
+ fgd = m->private;
+ seq_release(inode, file);
+ } else {
+ fgd = file->private_data;
+ }
+
+
+ if (file->f_mode & FMODE_WRITE) {
+
+ parser = &fgd->parser;
+
+ if (trace_parser_loaded((parser))) {
+ ret = ftrace_graph_set_hash(fgd->new_hash,
+ parser->buffer);
+ }
+
+ trace_parser_put(parser);
+
+ new_hash = __ftrace_hash_move(fgd->new_hash);
+ if (!new_hash) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ mutex_lock(&graph_lock);
+
+ if (fgd->type == GRAPH_FILTER_FUNCTION) {
+ old_hash = rcu_dereference_protected(ftrace_graph_hash,
+ lockdep_is_held(&graph_lock));
+ rcu_assign_pointer(ftrace_graph_hash, new_hash);
+ } else {
+ old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
+ lockdep_is_held(&graph_lock));
+ rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
+ }
+
+ mutex_unlock(&graph_lock);
+
+ /*
+ * We need to do a hard force of sched synchronization.
+ * This is because we use preempt_disable() to do RCU, but
+ * the function tracers can be called where RCU is not watching
+ * (like before user_exit()). We can not rely on the RCU
+ * infrastructure to do the synchronization, thus we must do it
+ * ourselves.
+ */
+ if (old_hash != EMPTY_HASH)
+ synchronize_rcu_tasks_rude();
+
+ free_ftrace_hash(old_hash);
+ }
+
+ out:
+ free_ftrace_hash(fgd->new_hash);
+ kfree(fgd);
+
+ return ret;
+}
+
+static int
+ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
+{
+ struct ftrace_glob func_g;
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+ struct ftrace_func_entry *entry;
+ int fail = 1;
+ int not;
+
+ /* decode regex */
+ func_g.type = filter_parse_regex(buffer, strlen(buffer),
+ &func_g.search, &not);
+
+ func_g.len = strlen(func_g.search);
+
+ mutex_lock(&ftrace_lock);
+
+ if (unlikely(ftrace_disabled)) {
+ mutex_unlock(&ftrace_lock);
+ return -ENODEV;
+ }
+
+ do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
+ if (ftrace_match_record(rec, &func_g, NULL, 0)) {
+ entry = ftrace_lookup_ip(hash, rec->ip);
+
+ if (!not) {
+ fail = 0;
+
+ if (entry)
+ continue;
+ if (add_hash_entry(hash, rec->ip) < 0)
+ goto out;
+ } else {
+ if (entry) {
+ free_hash_entry(hash, entry);
+ fail = 0;
+ }
+ }
+ }
+ } while_for_each_ftrace_rec();
+out:
+ mutex_unlock(&ftrace_lock);
+
+ if (fail)
+ return -EINVAL;
+
+ return 0;
+}
+
+static ssize_t
+ftrace_graph_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ ssize_t read, ret = 0;
+ struct ftrace_graph_data *fgd = file->private_data;
+ struct trace_parser *parser;
+
+ if (!cnt)
+ return 0;
+
+ /* Read mode uses seq functions */
+ if (file->f_mode & FMODE_READ) {
+ struct seq_file *m = file->private_data;
+ fgd = m->private;
+ }
+
+ parser = &fgd->parser;
+
+ read = trace_get_user(parser, ubuf, cnt, ppos);
+
+ if (read >= 0 && trace_parser_loaded(parser) &&
+ !trace_parser_cont(parser)) {
+
+ ret = ftrace_graph_set_hash(fgd->new_hash,
+ parser->buffer);
+ trace_parser_clear(parser);
+ }
+
+ if (!ret)
+ ret = read;
+
+ return ret;
+}
+
+static const struct file_operations ftrace_graph_fops = {
+ .open = ftrace_graph_open,
+ .read = seq_read,
+ .write = ftrace_graph_write,
+ .llseek = tracing_lseek,
+ .release = ftrace_graph_release,
+};
+
+static const struct file_operations ftrace_graph_notrace_fops = {
+ .open = ftrace_graph_notrace_open,
+ .read = seq_read,
+ .write = ftrace_graph_write,
+ .llseek = tracing_lseek,
+ .release = ftrace_graph_release,
+};
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+void ftrace_create_filter_files(struct ftrace_ops *ops,
+ struct dentry *parent)
+{
+
+ trace_create_file("set_ftrace_filter", TRACE_MODE_WRITE, parent,
+ ops, &ftrace_filter_fops);
+
+ trace_create_file("set_ftrace_notrace", TRACE_MODE_WRITE, parent,
+ ops, &ftrace_notrace_fops);
+}
+
+/*
+ * The name "destroy_filter_files" is really a misnomer. Although
+ * in the future, it may actually delete the files, but this is
+ * really intended to make sure the ops passed in are disabled
+ * and that when this function returns, the caller is free to
+ * free the ops.
+ *
+ * The "destroy" name is only to match the "create" name that this
+ * should be paired with.
+ */
+void ftrace_destroy_filter_files(struct ftrace_ops *ops)
+{
+ mutex_lock(&ftrace_lock);
+ if (ops->flags & FTRACE_OPS_FL_ENABLED)
+ ftrace_shutdown(ops, 0);
+ ops->flags |= FTRACE_OPS_FL_DELETED;
+ ftrace_free_filter(ops);
+ mutex_unlock(&ftrace_lock);
+}
+
+static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
+{
+
+ trace_create_file("available_filter_functions", TRACE_MODE_READ,
+ d_tracer, NULL, &ftrace_avail_fops);
+
+ trace_create_file("enabled_functions", TRACE_MODE_READ,
+ d_tracer, NULL, &ftrace_enabled_fops);
+
+ ftrace_create_filter_files(&global_ops, d_tracer);
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ trace_create_file("set_graph_function", TRACE_MODE_WRITE, d_tracer,
+ NULL,
+ &ftrace_graph_fops);
+ trace_create_file("set_graph_notrace", TRACE_MODE_WRITE, d_tracer,
+ NULL,
+ &ftrace_graph_notrace_fops);
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+ return 0;
+}
+
+static int ftrace_cmp_ips(const void *a, const void *b)
+{
+ const unsigned long *ipa = a;
+ const unsigned long *ipb = b;
+
+ if (*ipa > *ipb)
+ return 1;
+ if (*ipa < *ipb)
+ return -1;
+ return 0;
+}
+
+#ifdef CONFIG_FTRACE_SORT_STARTUP_TEST
+static void test_is_sorted(unsigned long *start, unsigned long count)
+{
+ int i;
+
+ for (i = 1; i < count; i++) {
+ if (WARN(start[i - 1] > start[i],
+ "[%d] %pS at %lx is not sorted with %pS at %lx\n", i,
+ (void *)start[i - 1], start[i - 1],
+ (void *)start[i], start[i]))
+ break;
+ }
+ if (i == count)
+ pr_info("ftrace section at %px sorted properly\n", start);
+}
+#else
+static void test_is_sorted(unsigned long *start, unsigned long count)
+{
+}
+#endif
+
+static int ftrace_process_locs(struct module *mod,
+ unsigned long *start,
+ unsigned long *end)
+{
+ struct ftrace_page *pg_unuse = NULL;
+ struct ftrace_page *start_pg;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ unsigned long skipped = 0;
+ unsigned long count;
+ unsigned long *p;
+ unsigned long addr;
+ unsigned long flags = 0; /* Shut up gcc */
+ int ret = -ENOMEM;
+
+ count = end - start;
+
+ if (!count)
+ return 0;
+
+ /*
+ * Sorting mcount in vmlinux at build time depend on
+ * CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in
+ * modules can not be sorted at build time.
+ */
+ if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) {
+ sort(start, count, sizeof(*start),
+ ftrace_cmp_ips, NULL);
+ } else {
+ test_is_sorted(start, count);
+ }
+
+ start_pg = ftrace_allocate_pages(count);
+ if (!start_pg)
+ return -ENOMEM;
+
+ mutex_lock(&ftrace_lock);
+
+ /*
+ * Core and each module needs their own pages, as
+ * modules will free them when they are removed.
+ * Force a new page to be allocated for modules.
+ */
+ if (!mod) {
+ WARN_ON(ftrace_pages || ftrace_pages_start);
+ /* First initialization */
+ ftrace_pages = ftrace_pages_start = start_pg;
+ } else {
+ if (!ftrace_pages)
+ goto out;
+
+ if (WARN_ON(ftrace_pages->next)) {
+ /* Hmm, we have free pages? */
+ while (ftrace_pages->next)
+ ftrace_pages = ftrace_pages->next;
+ }
+
+ ftrace_pages->next = start_pg;
+ }
+
+ p = start;
+ pg = start_pg;
+ while (p < end) {
+ unsigned long end_offset;
+ addr = ftrace_call_adjust(*p++);
+ /*
+ * Some architecture linkers will pad between
+ * the different mcount_loc sections of different
+ * object files to satisfy alignments.
+ * Skip any NULL pointers.
+ */
+ if (!addr) {
+ skipped++;
+ continue;
+ }
+
+ end_offset = (pg->index+1) * sizeof(pg->records[0]);
+ if (end_offset > PAGE_SIZE << pg->order) {
+ /* We should have allocated enough */
+ if (WARN_ON(!pg->next))
+ break;
+ pg = pg->next;
+ }
+
+ rec = &pg->records[pg->index++];
+ rec->ip = addr;
+ }
+
+ if (pg->next) {
+ pg_unuse = pg->next;
+ pg->next = NULL;
+ }
+
+ /* Assign the last page to ftrace_pages */
+ ftrace_pages = pg;
+
+ /*
+ * We only need to disable interrupts on start up
+ * because we are modifying code that an interrupt
+ * may execute, and the modification is not atomic.
+ * But for modules, nothing runs the code we modify
+ * until we are finished with it, and there's no
+ * reason to cause large interrupt latencies while we do it.
+ */
+ if (!mod)
+ local_irq_save(flags);
+ ftrace_update_code(mod, start_pg);
+ if (!mod)
+ local_irq_restore(flags);
+ ret = 0;
+ out:
+ mutex_unlock(&ftrace_lock);
+
+ /* We should have used all pages unless we skipped some */
+ if (pg_unuse) {
+ WARN_ON(!skipped);
+ ftrace_free_pages(pg_unuse);
+ }
+ return ret;
+}
+
+struct ftrace_mod_func {
+ struct list_head list;
+ char *name;
+ unsigned long ip;
+ unsigned int size;
+};
+
+struct ftrace_mod_map {
+ struct rcu_head rcu;
+ struct list_head list;
+ struct module *mod;
+ unsigned long start_addr;
+ unsigned long end_addr;
+ struct list_head funcs;
+ unsigned int num_funcs;
+};
+
+static int ftrace_get_trampoline_kallsym(unsigned int symnum,
+ unsigned long *value, char *type,
+ char *name, char *module_name,
+ int *exported)
+{
+ struct ftrace_ops *op;
+
+ list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) {
+ if (!op->trampoline || symnum--)
+ continue;
+ *value = op->trampoline;
+ *type = 't';
+ strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
+ strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);
+ *exported = 0;
+ return 0;
+ }
+
+ return -ERANGE;
+}
+
+#if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) || defined(CONFIG_MODULES)
+/*
+ * Check if the current ops references the given ip.
+ *
+ * If the ops traces all functions, then it was already accounted for.
+ * If the ops does not trace the current record function, skip it.
+ * If the ops ignores the function via notrace filter, skip it.
+ */
+static bool
+ops_references_ip(struct ftrace_ops *ops, unsigned long ip)
+{
+ /* If ops isn't enabled, ignore it */
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return false;
+
+ /* If ops traces all then it includes this function */
+ if (ops_traces_mod(ops))
+ return true;
+
+ /* The function must be in the filter */
+ if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
+ !__ftrace_lookup_ip(ops->func_hash->filter_hash, ip))
+ return false;
+
+ /* If in notrace hash, we ignore it too */
+ if (ftrace_lookup_ip(ops->func_hash->notrace_hash, ip))
+ return false;
+
+ return true;
+}
+#endif
+
+#ifdef CONFIG_MODULES
+
+#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
+
+static LIST_HEAD(ftrace_mod_maps);
+
+static int referenced_filters(struct dyn_ftrace *rec)
+{
+ struct ftrace_ops *ops;
+ int cnt = 0;
+
+ for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
+ if (ops_references_ip(ops, rec->ip)) {
+ if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT))
+ continue;
+ if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY))
+ continue;
+ cnt++;
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
+ rec->flags |= FTRACE_FL_REGS;
+ if (cnt == 1 && ops->trampoline)
+ rec->flags |= FTRACE_FL_TRAMP;
+ else
+ rec->flags &= ~FTRACE_FL_TRAMP;
+ }
+ }
+
+ return cnt;
+}
+
+static void
+clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
+{
+ struct ftrace_func_entry *entry;
+ struct dyn_ftrace *rec;
+ int i;
+
+ if (ftrace_hash_empty(hash))
+ return;
+
+ for (i = 0; i < pg->index; i++) {
+ rec = &pg->records[i];
+ entry = __ftrace_lookup_ip(hash, rec->ip);
+ /*
+ * Do not allow this rec to match again.
+ * Yeah, it may waste some memory, but will be removed
+ * if/when the hash is modified again.
+ */
+ if (entry)
+ entry->ip = 0;
+ }
+}
+
+/* Clear any records from hashes */
+static void clear_mod_from_hashes(struct ftrace_page *pg)
+{
+ struct trace_array *tr;
+
+ mutex_lock(&trace_types_lock);
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (!tr->ops || !tr->ops->func_hash)
+ continue;
+ mutex_lock(&tr->ops->func_hash->regex_lock);
+ clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash);
+ clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash);
+ mutex_unlock(&tr->ops->func_hash->regex_lock);
+ }
+ mutex_unlock(&trace_types_lock);
+}
+
+static void ftrace_free_mod_map(struct rcu_head *rcu)
+{
+ struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
+ struct ftrace_mod_func *mod_func;
+ struct ftrace_mod_func *n;
+
+ /* All the contents of mod_map are now not visible to readers */
+ list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
+ kfree(mod_func->name);
+ list_del(&mod_func->list);
+ kfree(mod_func);
+ }
+
+ kfree(mod_map);
+}
+
+void ftrace_release_mod(struct module *mod)
+{
+ struct ftrace_mod_map *mod_map;
+ struct ftrace_mod_map *n;
+ struct dyn_ftrace *rec;
+ struct ftrace_page **last_pg;
+ struct ftrace_page *tmp_page = NULL;
+ struct ftrace_page *pg;
+
+ mutex_lock(&ftrace_lock);
+
+ if (ftrace_disabled)
+ goto out_unlock;
+
+ list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
+ if (mod_map->mod == mod) {
+ list_del_rcu(&mod_map->list);
+ call_rcu(&mod_map->rcu, ftrace_free_mod_map);
+ break;
+ }
+ }
+
+ /*
+ * Each module has its own ftrace_pages, remove
+ * them from the list.
+ */
+ last_pg = &ftrace_pages_start;
+ for (pg = ftrace_pages_start; pg; pg = *last_pg) {
+ rec = &pg->records[0];
+ if (within_module_core(rec->ip, mod) ||
+ within_module_init(rec->ip, mod)) {
+ /*
+ * As core pages are first, the first
+ * page should never be a module page.
+ */
+ if (WARN_ON(pg == ftrace_pages_start))
+ goto out_unlock;
+
+ /* Check if we are deleting the last page */
+ if (pg == ftrace_pages)
+ ftrace_pages = next_to_ftrace_page(last_pg);
+
+ ftrace_update_tot_cnt -= pg->index;
+ *last_pg = pg->next;
+
+ pg->next = tmp_page;
+ tmp_page = pg;
+ } else
+ last_pg = &pg->next;
+ }
+ out_unlock:
+ mutex_unlock(&ftrace_lock);
+
+ for (pg = tmp_page; pg; pg = tmp_page) {
+
+ /* Needs to be called outside of ftrace_lock */
+ clear_mod_from_hashes(pg);
+
+ if (pg->records) {
+ free_pages((unsigned long)pg->records, pg->order);
+ ftrace_number_of_pages -= 1 << pg->order;
+ }
+ tmp_page = pg->next;
+ kfree(pg);
+ ftrace_number_of_groups--;
+ }
+}
+
+void ftrace_module_enable(struct module *mod)
+{
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+
+ mutex_lock(&ftrace_lock);
+
+ if (ftrace_disabled)
+ goto out_unlock;
+
+ /*
+ * If the tracing is enabled, go ahead and enable the record.
+ *
+ * The reason not to enable the record immediately is the
+ * inherent check of ftrace_make_nop/ftrace_make_call for
+ * correct previous instructions. Making first the NOP
+ * conversion puts the module to the correct state, thus
+ * passing the ftrace_make_call check.
+ *
+ * We also delay this to after the module code already set the
+ * text to read-only, as we now need to set it back to read-write
+ * so that we can modify the text.
+ */
+ if (ftrace_start_up)
+ ftrace_arch_code_modify_prepare();
+
+ do_for_each_ftrace_rec(pg, rec) {
+ int cnt;
+ /*
+ * do_for_each_ftrace_rec() is a double loop.
+ * module text shares the pg. If a record is
+ * not part of this module, then skip this pg,
+ * which the "break" will do.
+ */
+ if (!within_module_core(rec->ip, mod) &&
+ !within_module_init(rec->ip, mod))
+ break;
+
+ /* Weak functions should still be ignored */
+ if (!test_for_valid_rec(rec)) {
+ /* Clear all other flags. Should not be enabled anyway */
+ rec->flags = FTRACE_FL_DISABLED;
+ continue;
+ }
+
+ cnt = 0;
+
+ /*
+ * When adding a module, we need to check if tracers are
+ * currently enabled and if they are, and can trace this record,
+ * we need to enable the module functions as well as update the
+ * reference counts for those function records.
+ */
+ if (ftrace_start_up)
+ cnt += referenced_filters(rec);
+
+ rec->flags &= ~FTRACE_FL_DISABLED;
+ rec->flags += cnt;
+
+ if (ftrace_start_up && cnt) {
+ int failed = __ftrace_replace_code(rec, 1);
+ if (failed) {
+ ftrace_bug(failed, rec);
+ goto out_loop;
+ }
+ }
+
+ } while_for_each_ftrace_rec();
+
+ out_loop:
+ if (ftrace_start_up)
+ ftrace_arch_code_modify_post_process();
+
+ out_unlock:
+ mutex_unlock(&ftrace_lock);
+
+ process_cached_mods(mod->name);
+}
+
+void ftrace_module_init(struct module *mod)
+{
+ int ret;
+
+ if (ftrace_disabled || !mod->num_ftrace_callsites)
+ return;
+
+ ret = ftrace_process_locs(mod, mod->ftrace_callsites,
+ mod->ftrace_callsites + mod->num_ftrace_callsites);
+ if (ret)
+ pr_warn("ftrace: failed to allocate entries for module '%s' functions\n",
+ mod->name);
+}
+
+static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
+ struct dyn_ftrace *rec)
+{
+ struct ftrace_mod_func *mod_func;
+ unsigned long symsize;
+ unsigned long offset;
+ char str[KSYM_SYMBOL_LEN];
+ char *modname;
+ const char *ret;
+
+ ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str);
+ if (!ret)
+ return;
+
+ mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL);
+ if (!mod_func)
+ return;
+
+ mod_func->name = kstrdup(str, GFP_KERNEL);
+ if (!mod_func->name) {
+ kfree(mod_func);
+ return;
+ }
+
+ mod_func->ip = rec->ip - offset;
+ mod_func->size = symsize;
+
+ mod_map->num_funcs++;
+
+ list_add_rcu(&mod_func->list, &mod_map->funcs);
+}
+
+static struct ftrace_mod_map *
+allocate_ftrace_mod_map(struct module *mod,
+ unsigned long start, unsigned long end)
+{
+ struct ftrace_mod_map *mod_map;
+
+ mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL);
+ if (!mod_map)
+ return NULL;
+
+ mod_map->mod = mod;
+ mod_map->start_addr = start;
+ mod_map->end_addr = end;
+ mod_map->num_funcs = 0;
+
+ INIT_LIST_HEAD_RCU(&mod_map->funcs);
+
+ list_add_rcu(&mod_map->list, &ftrace_mod_maps);
+
+ return mod_map;
+}
+
+static const char *
+ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
+ unsigned long addr, unsigned long *size,
+ unsigned long *off, char *sym)
+{
+ struct ftrace_mod_func *found_func = NULL;
+ struct ftrace_mod_func *mod_func;
+
+ list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
+ if (addr >= mod_func->ip &&
+ addr < mod_func->ip + mod_func->size) {
+ found_func = mod_func;
+ break;
+ }
+ }
+
+ if (found_func) {
+ if (size)
+ *size = found_func->size;
+ if (off)
+ *off = addr - found_func->ip;
+ if (sym)
+ strlcpy(sym, found_func->name, KSYM_NAME_LEN);
+
+ return found_func->name;
+ }
+
+ return NULL;
+}
+
+const char *
+ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
+ unsigned long *off, char **modname, char *sym)
+{
+ struct ftrace_mod_map *mod_map;
+ const char *ret = NULL;
+
+ /* mod_map is freed via call_rcu() */
+ preempt_disable();
+ list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
+ ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
+ if (ret) {
+ if (modname)
+ *modname = mod_map->mod->name;
+ break;
+ }
+ }
+ preempt_enable();
+
+ return ret;
+}
+
+int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
+ char *type, char *name,
+ char *module_name, int *exported)
+{
+ struct ftrace_mod_map *mod_map;
+ struct ftrace_mod_func *mod_func;
+ int ret;
+
+ preempt_disable();
+ list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
+
+ if (symnum >= mod_map->num_funcs) {
+ symnum -= mod_map->num_funcs;
+ continue;
+ }
+
+ list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
+ if (symnum > 1) {
+ symnum--;
+ continue;
+ }
+
+ *value = mod_func->ip;
+ *type = 'T';
+ strlcpy(name, mod_func->name, KSYM_NAME_LEN);
+ strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
+ *exported = 1;
+ preempt_enable();
+ return 0;
+ }
+ WARN_ON(1);
+ break;
+ }
+ ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
+ module_name, exported);
+ preempt_enable();
+ return ret;
+}
+
+#else
+static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
+ struct dyn_ftrace *rec) { }
+static inline struct ftrace_mod_map *
+allocate_ftrace_mod_map(struct module *mod,
+ unsigned long start, unsigned long end)
+{
+ return NULL;
+}
+int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
+ char *type, char *name, char *module_name,
+ int *exported)
+{
+ int ret;
+
+ preempt_disable();
+ ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
+ module_name, exported);
+ preempt_enable();
+ return ret;
+}
+#endif /* CONFIG_MODULES */
+
+struct ftrace_init_func {
+ struct list_head list;
+ unsigned long ip;
+};
+
+/* Clear any init ips from hashes */
+static void
+clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
+{
+ struct ftrace_func_entry *entry;
+
+ entry = ftrace_lookup_ip(hash, func->ip);
+ /*
+ * Do not allow this rec to match again.
+ * Yeah, it may waste some memory, but will be removed
+ * if/when the hash is modified again.
+ */
+ if (entry)
+ entry->ip = 0;
+}
+
+static void
+clear_func_from_hashes(struct ftrace_init_func *func)
+{
+ struct trace_array *tr;
+
+ mutex_lock(&trace_types_lock);
+ list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+ if (!tr->ops || !tr->ops->func_hash)
+ continue;
+ mutex_lock(&tr->ops->func_hash->regex_lock);
+ clear_func_from_hash(func, tr->ops->func_hash->filter_hash);
+ clear_func_from_hash(func, tr->ops->func_hash->notrace_hash);
+ mutex_unlock(&tr->ops->func_hash->regex_lock);
+ }
+ mutex_unlock(&trace_types_lock);
+}
+
+static void add_to_clear_hash_list(struct list_head *clear_list,
+ struct dyn_ftrace *rec)
+{
+ struct ftrace_init_func *func;
+
+ func = kmalloc(sizeof(*func), GFP_KERNEL);
+ if (!func) {
+ MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n");
+ return;
+ }
+
+ func->ip = rec->ip;
+ list_add(&func->list, clear_list);
+}
+
+void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
+{
+ unsigned long start = (unsigned long)(start_ptr);
+ unsigned long end = (unsigned long)(end_ptr);
+ struct ftrace_page **last_pg = &ftrace_pages_start;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ struct dyn_ftrace key;
+ struct ftrace_mod_map *mod_map = NULL;
+ struct ftrace_init_func *func, *func_next;
+ struct list_head clear_hash;
+
+ INIT_LIST_HEAD(&clear_hash);
+
+ key.ip = start;
+ key.flags = end; /* overload flags, as it is unsigned long */
+
+ mutex_lock(&ftrace_lock);
+
+ /*
+ * If we are freeing module init memory, then check if
+ * any tracer is active. If so, we need to save a mapping of
+ * the module functions being freed with the address.
+ */
+ if (mod && ftrace_ops_list != &ftrace_list_end)
+ mod_map = allocate_ftrace_mod_map(mod, start, end);
+
+ for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
+ if (end < pg->records[0].ip ||
+ start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
+ continue;
+ again:
+ rec = bsearch(&key, pg->records, pg->index,
+ sizeof(struct dyn_ftrace),
+ ftrace_cmp_recs);
+ if (!rec)
+ continue;
+
+ /* rec will be cleared from hashes after ftrace_lock unlock */
+ add_to_clear_hash_list(&clear_hash, rec);
+
+ if (mod_map)
+ save_ftrace_mod_rec(mod_map, rec);
+
+ pg->index--;
+ ftrace_update_tot_cnt--;
+ if (!pg->index) {
+ *last_pg = pg->next;
+ if (pg->records) {
+ free_pages((unsigned long)pg->records, pg->order);
+ ftrace_number_of_pages -= 1 << pg->order;
+ }
+ ftrace_number_of_groups--;
+ kfree(pg);
+ pg = container_of(last_pg, struct ftrace_page, next);
+ if (!(*last_pg))
+ ftrace_pages = pg;
+ continue;
+ }
+ memmove(rec, rec + 1,
+ (pg->index - (rec - pg->records)) * sizeof(*rec));
+ /* More than one function may be in this block */
+ goto again;
+ }
+ mutex_unlock(&ftrace_lock);
+
+ list_for_each_entry_safe(func, func_next, &clear_hash, list) {
+ clear_func_from_hashes(func);
+ kfree(func);
+ }
+}
+
+void __init ftrace_free_init_mem(void)
+{
+ void *start = (void *)(&__init_begin);
+ void *end = (void *)(&__init_end);
+
+ ftrace_boot_snapshot();
+
+ ftrace_free_mem(NULL, start, end);
+}
+
+int __init __weak ftrace_dyn_arch_init(void)
+{
+ return 0;
+}
+
+void __init ftrace_init(void)
+{
+ extern unsigned long __start_mcount_loc[];
+ extern unsigned long __stop_mcount_loc[];
+ unsigned long count, flags;
+ int ret;
+
+ local_irq_save(flags);
+ ret = ftrace_dyn_arch_init();
+ local_irq_restore(flags);
+ if (ret)
+ goto failed;
+
+ count = __stop_mcount_loc - __start_mcount_loc;
+ if (!count) {
+ pr_info("ftrace: No functions to be traced?\n");
+ goto failed;
+ }
+
+ pr_info("ftrace: allocating %ld entries in %ld pages\n",
+ count, DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
+
+ ret = ftrace_process_locs(NULL,
+ __start_mcount_loc,
+ __stop_mcount_loc);
+ if (ret) {
+ pr_warn("ftrace: failed to allocate entries for functions\n");
+ goto failed;
+ }
+
+ pr_info("ftrace: allocated %ld pages with %ld groups\n",
+ ftrace_number_of_pages, ftrace_number_of_groups);
+
+ last_ftrace_enabled = ftrace_enabled = 1;
+
+ set_ftrace_early_filters();
+
+ return;
+ failed:
+ ftrace_disabled = 1;
+}
+
+/* Do nothing if arch does not support this */
+void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
+{
+}
+
+static void ftrace_update_trampoline(struct ftrace_ops *ops)
+{
+ unsigned long trampoline = ops->trampoline;
+
+ arch_ftrace_update_trampoline(ops);
+ if (ops->trampoline && ops->trampoline != trampoline &&
+ (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) {
+ /* Add to kallsyms before the perf events */
+ ftrace_add_trampoline_to_kallsyms(ops);
+ perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
+ ops->trampoline, ops->trampoline_size, false,
+ FTRACE_TRAMPOLINE_SYM);
+ /*
+ * Record the perf text poke event after the ksymbol register
+ * event.
+ */
+ perf_event_text_poke((void *)ops->trampoline, NULL, 0,
+ (void *)ops->trampoline,
+ ops->trampoline_size);
+ }
+}
+
+void ftrace_init_trace_array(struct trace_array *tr)
+{
+ INIT_LIST_HEAD(&tr->func_probes);
+ INIT_LIST_HEAD(&tr->mod_trace);
+ INIT_LIST_HEAD(&tr->mod_notrace);
+}
+#else
+
+struct ftrace_ops global_ops = {
+ .func = ftrace_stub,
+ .flags = FTRACE_OPS_FL_INITIALIZED |
+ FTRACE_OPS_FL_PID,
+};
+
+static int __init ftrace_nodyn_init(void)
+{
+ ftrace_enabled = 1;
+ return 0;
+}
+core_initcall(ftrace_nodyn_init);
+
+static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
+static inline void ftrace_startup_all(int command) { }
+
+static void ftrace_update_trampoline(struct ftrace_ops *ops)
+{
+}
+
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+__init void ftrace_init_global_array_ops(struct trace_array *tr)
+{
+ tr->ops = &global_ops;
+ tr->ops->private = tr;
+ ftrace_init_trace_array(tr);
+}
+
+void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
+{
+ /* If we filter on pids, update to use the pid function */
+ if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
+ if (WARN_ON(tr->ops->func != ftrace_stub))
+ printk("ftrace ops had %pS for function\n",
+ tr->ops->func);
+ }
+ tr->ops->func = func;
+ tr->ops->private = tr;
+}
+
+void ftrace_reset_array_ops(struct trace_array *tr)
+{
+ tr->ops->func = ftrace_stub;
+}
+
+static nokprobe_inline void
+__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *ignored, struct ftrace_regs *fregs)
+{
+ struct pt_regs *regs = ftrace_get_regs(fregs);
+ struct ftrace_ops *op;
+ int bit;
+
+ /*
+ * The ftrace_test_and_set_recursion() will disable preemption,
+ * which is required since some of the ops may be dynamically
+ * allocated, they must be freed after a synchronize_rcu().
+ */
+ bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START);
+ if (bit < 0)
+ return;
+
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+ /* Stub functions don't need to be called nor tested */
+ if (op->flags & FTRACE_OPS_FL_STUB)
+ continue;
+ /*
+ * Check the following for each ops before calling their func:
+ * if RCU flag is set, then rcu_is_watching() must be true
+ * if PER_CPU is set, then ftrace_function_local_disable()
+ * must be false
+ * Otherwise test if the ip matches the ops filter
+ *
+ * If any of the above fails then the op->func() is not executed.
+ */
+ if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
+ ftrace_ops_test(op, ip, regs)) {
+ if (FTRACE_WARN_ON(!op->func)) {
+ pr_warn("op=%p %pS\n", op, op);
+ goto out;
+ }
+ op->func(ip, parent_ip, op, fregs);
+ }
+ } while_for_each_ftrace_op(op);
+out:
+ trace_clear_recursion(bit);
+}
+
+/*
+ * Some archs only support passing ip and parent_ip. Even though
+ * the list function ignores the op parameter, we do not want any
+ * C side effects, where a function is called without the caller
+ * sending a third parameter.
+ * Archs are to support both the regs and ftrace_ops at the same time.
+ * If they support ftrace_ops, it is assumed they support regs.
+ * If call backs want to use regs, they must either check for regs
+ * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
+ * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
+ * An architecture can pass partial regs with ftrace_ops and still
+ * set the ARCH_SUPPORTS_FTRACE_OPS.
+ *
+ * In vmlinux.lds.h, ftrace_ops_list_func() is defined to be
+ * arch_ftrace_ops_list_func.
+ */
+#if ARCH_SUPPORTS_FTRACE_OPS
+void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
+{
+ __ftrace_ops_list_func(ip, parent_ip, NULL, fregs);
+}
+#else
+void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
+{
+ __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
+}
+#endif
+NOKPROBE_SYMBOL(arch_ftrace_ops_list_func);
+
+/*
+ * If there's only one function registered but it does not support
+ * recursion, needs RCU protection and/or requires per cpu handling, then
+ * this function will be called by the mcount trampoline.
+ */
+static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
+{
+ int bit;
+
+ bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START);
+ if (bit < 0)
+ return;
+
+ if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching())
+ op->func(ip, parent_ip, op, fregs);
+
+ trace_clear_recursion(bit);
+}
+NOKPROBE_SYMBOL(ftrace_ops_assist_func);
+
+/**
+ * ftrace_ops_get_func - get the function a trampoline should call
+ * @ops: the ops to get the function for
+ *
+ * Normally the mcount trampoline will call the ops->func, but there
+ * are times that it should not. For example, if the ops does not
+ * have its own recursion protection, then it should call the
+ * ftrace_ops_assist_func() instead.
+ *
+ * Returns the function that the trampoline should call for @ops.
+ */
+ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
+{
+ /*
+ * If the function does not handle recursion or needs to be RCU safe,
+ * then we need to call the assist handler.
+ */
+ if (ops->flags & (FTRACE_OPS_FL_RECURSION |
+ FTRACE_OPS_FL_RCU))
+ return ftrace_ops_assist_func;
+
+ return ops->func;
+}
+
+static void
+ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
+ struct task_struct *prev,
+ struct task_struct *next,
+ unsigned int prev_state)
+{
+ struct trace_array *tr = data;
+ struct trace_pid_list *pid_list;
+ struct trace_pid_list *no_pid_list;
+
+ pid_list = rcu_dereference_sched(tr->function_pids);
+ no_pid_list = rcu_dereference_sched(tr->function_no_pids);
+
+ if (trace_ignore_this_task(pid_list, no_pid_list, next))
+ this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
+ FTRACE_PID_IGNORE);
+ else
+ this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
+ next->pid);
+}
+
+static void
+ftrace_pid_follow_sched_process_fork(void *data,
+ struct task_struct *self,
+ struct task_struct *task)
+{
+ struct trace_pid_list *pid_list;
+ struct trace_array *tr = data;
+
+ pid_list = rcu_dereference_sched(tr->function_pids);
+ trace_filter_add_remove_task(pid_list, self, task);
+
+ pid_list = rcu_dereference_sched(tr->function_no_pids);
+ trace_filter_add_remove_task(pid_list, self, task);
+}
+
+static void
+ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
+{
+ struct trace_pid_list *pid_list;
+ struct trace_array *tr = data;
+
+ pid_list = rcu_dereference_sched(tr->function_pids);
+ trace_filter_add_remove_task(pid_list, NULL, task);
+
+ pid_list = rcu_dereference_sched(tr->function_no_pids);
+ trace_filter_add_remove_task(pid_list, NULL, task);
+}
+
+void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
+{
+ if (enable) {
+ register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
+ tr);
+ register_trace_sched_process_free(ftrace_pid_follow_sched_process_exit,
+ tr);
+ } else {
+ unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
+ tr);
+ unregister_trace_sched_process_free(ftrace_pid_follow_sched_process_exit,
+ tr);
+ }
+}
+
+static void clear_ftrace_pids(struct trace_array *tr, int type)
+{
+ struct trace_pid_list *pid_list;
+ struct trace_pid_list *no_pid_list;
+ int cpu;
+
+ pid_list = rcu_dereference_protected(tr->function_pids,
+ lockdep_is_held(&ftrace_lock));
+ no_pid_list = rcu_dereference_protected(tr->function_no_pids,
+ lockdep_is_held(&ftrace_lock));
+
+ /* Make sure there's something to do */
+ if (!pid_type_enabled(type, pid_list, no_pid_list))
+ return;
+
+ /* See if the pids still need to be checked after this */
+ if (!still_need_pid_events(type, pid_list, no_pid_list)) {
+ unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
+ for_each_possible_cpu(cpu)
+ per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE;
+ }
+
+ if (type & TRACE_PIDS)
+ rcu_assign_pointer(tr->function_pids, NULL);
+
+ if (type & TRACE_NO_PIDS)
+ rcu_assign_pointer(tr->function_no_pids, NULL);
+
+ /* Wait till all users are no longer using pid filtering */
+ synchronize_rcu();
+
+ if ((type & TRACE_PIDS) && pid_list)
+ trace_pid_list_free(pid_list);
+
+ if ((type & TRACE_NO_PIDS) && no_pid_list)
+ trace_pid_list_free(no_pid_list);
+}
+
+void ftrace_clear_pids(struct trace_array *tr)
+{
+ mutex_lock(&ftrace_lock);
+
+ clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
+
+ mutex_unlock(&ftrace_lock);
+}
+
+static void ftrace_pid_reset(struct trace_array *tr, int type)
+{
+ mutex_lock(&ftrace_lock);
+ clear_ftrace_pids(tr, type);
+
+ ftrace_update_pid_func();
+ ftrace_startup_all(0);
+
+ mutex_unlock(&ftrace_lock);
+}
+
+/* Greater than any max PID */
+#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
+
+static void *fpid_start(struct seq_file *m, loff_t *pos)
+ __acquires(RCU)
+{
+ struct trace_pid_list *pid_list;
+ struct trace_array *tr = m->private;
+
+ mutex_lock(&ftrace_lock);
+ rcu_read_lock_sched();
+
+ pid_list = rcu_dereference_sched(tr->function_pids);
+
+ if (!pid_list)
+ return !(*pos) ? FTRACE_NO_PIDS : NULL;
+
+ return trace_pid_start(pid_list, pos);
+}
+
+static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct trace_array *tr = m->private;
+ struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
+
+ if (v == FTRACE_NO_PIDS) {
+ (*pos)++;
+ return NULL;
+ }
+ return trace_pid_next(pid_list, v, pos);
+}
+
+static void fpid_stop(struct seq_file *m, void *p)
+ __releases(RCU)
+{
+ rcu_read_unlock_sched();
+ mutex_unlock(&ftrace_lock);
+}
+
+static int fpid_show(struct seq_file *m, void *v)
+{
+ if (v == FTRACE_NO_PIDS) {
+ seq_puts(m, "no pid\n");
+ return 0;
+ }
+
+ return trace_pid_show(m, v);
+}
+
+static const struct seq_operations ftrace_pid_sops = {
+ .start = fpid_start,
+ .next = fpid_next,
+ .stop = fpid_stop,
+ .show = fpid_show,
+};
+
+static void *fnpid_start(struct seq_file *m, loff_t *pos)
+ __acquires(RCU)
+{
+ struct trace_pid_list *pid_list;
+ struct trace_array *tr = m->private;
+
+ mutex_lock(&ftrace_lock);
+ rcu_read_lock_sched();
+
+ pid_list = rcu_dereference_sched(tr->function_no_pids);
+
+ if (!pid_list)
+ return !(*pos) ? FTRACE_NO_PIDS : NULL;
+
+ return trace_pid_start(pid_list, pos);
+}
+
+static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct trace_array *tr = m->private;
+ struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids);
+
+ if (v == FTRACE_NO_PIDS) {
+ (*pos)++;
+ return NULL;
+ }
+ return trace_pid_next(pid_list, v, pos);
+}
+
+static const struct seq_operations ftrace_no_pid_sops = {
+ .start = fnpid_start,
+ .next = fnpid_next,
+ .stop = fpid_stop,
+ .show = fpid_show,
+};
+
+static int pid_open(struct inode *inode, struct file *file, int type)
+{
+ const struct seq_operations *seq_ops;
+ struct trace_array *tr = inode->i_private;
+ struct seq_file *m;
+ int ret = 0;
+
+ ret = tracing_check_open_get_tr(tr);
+ if (ret)
+ return ret;
+
+ if ((file->f_mode & FMODE_WRITE) &&
+ (file->f_flags & O_TRUNC))
+ ftrace_pid_reset(tr, type);
+
+ switch (type) {
+ case TRACE_PIDS:
+ seq_ops = &ftrace_pid_sops;
+ break;
+ case TRACE_NO_PIDS:
+ seq_ops = &ftrace_no_pid_sops;
+ break;
+ default:
+ trace_array_put(tr);
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+
+ ret = seq_open(file, seq_ops);
+ if (ret < 0) {
+ trace_array_put(tr);
+ } else {
+ m = file->private_data;
+ /* copy tr over to seq ops */
+ m->private = tr;
+ }
+
+ return ret;
+}
+
+static int
+ftrace_pid_open(struct inode *inode, struct file *file)
+{
+ return pid_open(inode, file, TRACE_PIDS);
+}
+
+static int
+ftrace_no_pid_open(struct inode *inode, struct file *file)
+{
+ return pid_open(inode, file, TRACE_NO_PIDS);
+}
+
+static void ignore_task_cpu(void *data)
+{
+ struct trace_array *tr = data;
+ struct trace_pid_list *pid_list;
+ struct trace_pid_list *no_pid_list;
+
+ /*
+ * This function is called by on_each_cpu() while the
+ * event_mutex is held.
+ */
+ pid_list = rcu_dereference_protected(tr->function_pids,
+ mutex_is_locked(&ftrace_lock));
+ no_pid_list = rcu_dereference_protected(tr->function_no_pids,
+ mutex_is_locked(&ftrace_lock));
+
+ if (trace_ignore_this_task(pid_list, no_pid_list, current))
+ this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
+ FTRACE_PID_IGNORE);
+ else
+ this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
+ current->pid);
+}
+
+static ssize_t
+pid_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos, int type)
+{
+ struct seq_file *m = filp->private_data;
+ struct trace_array *tr = m->private;
+ struct trace_pid_list *filtered_pids;
+ struct trace_pid_list *other_pids;
+ struct trace_pid_list *pid_list;
+ ssize_t ret;
+
+ if (!cnt)
+ return 0;
+
+ mutex_lock(&ftrace_lock);
+
+ switch (type) {
+ case TRACE_PIDS:
+ filtered_pids = rcu_dereference_protected(tr->function_pids,
+ lockdep_is_held(&ftrace_lock));
+ other_pids = rcu_dereference_protected(tr->function_no_pids,
+ lockdep_is_held(&ftrace_lock));
+ break;
+ case TRACE_NO_PIDS:
+ filtered_pids = rcu_dereference_protected(tr->function_no_pids,
+ lockdep_is_held(&ftrace_lock));
+ other_pids = rcu_dereference_protected(tr->function_pids,
+ lockdep_is_held(&ftrace_lock));
+ break;
+ default:
+ ret = -EINVAL;
+ WARN_ON_ONCE(1);
+ goto out;
+ }
+
+ ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
+ if (ret < 0)
+ goto out;
+
+ switch (type) {
+ case TRACE_PIDS:
+ rcu_assign_pointer(tr->function_pids, pid_list);
+ break;
+ case TRACE_NO_PIDS:
+ rcu_assign_pointer(tr->function_no_pids, pid_list);
+ break;
+ }
+
+
+ if (filtered_pids) {
+ synchronize_rcu();
+ trace_pid_list_free(filtered_pids);
+ } else if (pid_list && !other_pids) {
+ /* Register a probe to set whether to ignore the tracing of a task */
+ register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
+ }
+
+ /*
+ * Ignoring of pids is done at task switch. But we have to
+ * check for those tasks that are currently running.
+ * Always do this in case a pid was appended or removed.
+ */
+ on_each_cpu(ignore_task_cpu, tr, 1);
+
+ ftrace_update_pid_func();
+ ftrace_startup_all(0);
+ out:
+ mutex_unlock(&ftrace_lock);
+
+ if (ret > 0)
+ *ppos += ret;
+
+ return ret;
+}
+
+static ssize_t
+ftrace_pid_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
+}
+
+static ssize_t
+ftrace_no_pid_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
+}
+
+static int
+ftrace_pid_release(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+
+ trace_array_put(tr);
+
+ return seq_release(inode, file);
+}
+
+static const struct file_operations ftrace_pid_fops = {
+ .open = ftrace_pid_open,
+ .write = ftrace_pid_write,
+ .read = seq_read,
+ .llseek = tracing_lseek,
+ .release = ftrace_pid_release,
+};
+
+static const struct file_operations ftrace_no_pid_fops = {
+ .open = ftrace_no_pid_open,
+ .write = ftrace_no_pid_write,
+ .read = seq_read,
+ .llseek = tracing_lseek,
+ .release = ftrace_pid_release,
+};
+
+void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
+{
+ trace_create_file("set_ftrace_pid", TRACE_MODE_WRITE, d_tracer,
+ tr, &ftrace_pid_fops);
+ trace_create_file("set_ftrace_notrace_pid", TRACE_MODE_WRITE,
+ d_tracer, tr, &ftrace_no_pid_fops);
+}
+
+void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
+ struct dentry *d_tracer)
+{
+ /* Only the top level directory has the dyn_tracefs and profile */
+ WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
+
+ ftrace_init_dyn_tracefs(d_tracer);
+ ftrace_profile_tracefs(d_tracer);
+}
+
+/**
+ * ftrace_kill - kill ftrace
+ *
+ * This function should be used by panic code. It stops ftrace
+ * but in a not so nice way. If you need to simply kill ftrace
+ * from a non-atomic section, use ftrace_kill.
+ */
+void ftrace_kill(void)
+{
+ ftrace_disabled = 1;
+ ftrace_enabled = 0;
+ ftrace_trace_function = ftrace_stub;
+}
+
+/**
+ * ftrace_is_dead - Test if ftrace is dead or not.
+ *
+ * Returns 1 if ftrace is "dead", zero otherwise.
+ */
+int ftrace_is_dead(void)
+{
+ return ftrace_disabled;
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+/*
+ * When registering ftrace_ops with IPMODIFY, it is necessary to make sure
+ * it doesn't conflict with any direct ftrace_ops. If there is existing
+ * direct ftrace_ops on a kernel function being patched, call
+ * FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER on it to enable sharing.
+ *
+ * @ops: ftrace_ops being registered.
+ *
+ * Returns:
+ * 0 on success;
+ * Negative on failure.
+ */
+static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_hash *hash;
+ struct ftrace_ops *op;
+ int size, i, ret;
+
+ lockdep_assert_held_once(&direct_mutex);
+
+ if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
+ return 0;
+
+ hash = ops->func_hash->filter_hash;
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ unsigned long ip = entry->ip;
+ bool found_op = false;
+
+ mutex_lock(&ftrace_lock);
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+ if (!(op->flags & FTRACE_OPS_FL_DIRECT))
+ continue;
+ if (ops_references_ip(op, ip)) {
+ found_op = true;
+ break;
+ }
+ } while_for_each_ftrace_op(op);
+ mutex_unlock(&ftrace_lock);
+
+ if (found_op) {
+ if (!op->ops_func)
+ return -EBUSY;
+
+ ret = op->ops_func(op, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER);
+ if (ret)
+ return ret;
+ }
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Similar to prepare_direct_functions_for_ipmodify, clean up after ops
+ * with IPMODIFY is unregistered. The cleanup is optional for most DIRECT
+ * ops.
+ */
+static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_hash *hash;
+ struct ftrace_ops *op;
+ int size, i;
+
+ if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
+ return;
+
+ mutex_lock(&direct_mutex);
+
+ hash = ops->func_hash->filter_hash;
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ unsigned long ip = entry->ip;
+ bool found_op = false;
+
+ mutex_lock(&ftrace_lock);
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+ if (!(op->flags & FTRACE_OPS_FL_DIRECT))
+ continue;
+ if (ops_references_ip(op, ip)) {
+ found_op = true;
+ break;
+ }
+ } while_for_each_ftrace_op(op);
+ mutex_unlock(&ftrace_lock);
+
+ /* The cleanup is optional, ignore any errors */
+ if (found_op && op->ops_func)
+ op->ops_func(op, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER);
+ }
+ }
+ mutex_unlock(&direct_mutex);
+}
+
+#define lock_direct_mutex() mutex_lock(&direct_mutex)
+#define unlock_direct_mutex() mutex_unlock(&direct_mutex)
+
+#else /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
+
+static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops)
+{
+ return 0;
+}
+
+static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
+{
+}
+
+#define lock_direct_mutex() do { } while (0)
+#define unlock_direct_mutex() do { } while (0)
+
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
+
+/*
+ * Similar to register_ftrace_function, except we don't lock direct_mutex.
+ */
+static int register_ftrace_function_nolock(struct ftrace_ops *ops)
+{
+ int ret;
+
+ ftrace_ops_init(ops);
+
+ mutex_lock(&ftrace_lock);
+
+ ret = ftrace_startup(ops, 0);
+
+ mutex_unlock(&ftrace_lock);
+
+ return ret;
+}
+
+/**
+ * register_ftrace_function - register a function for profiling
+ * @ops: ops structure that holds the function for profiling.
+ *
+ * Register a function to be called by all functions in the
+ * kernel.
+ *
+ * Note: @ops->func and all the functions it calls must be labeled
+ * with "notrace", otherwise it will go into a
+ * recursive loop.
+ */
+int register_ftrace_function(struct ftrace_ops *ops)
+{
+ int ret;
+
+ lock_direct_mutex();
+ ret = prepare_direct_functions_for_ipmodify(ops);
+ if (ret < 0)
+ goto out_unlock;
+
+ ret = register_ftrace_function_nolock(ops);
+
+out_unlock:
+ unlock_direct_mutex();
+ return ret;
+}
+EXPORT_SYMBOL_GPL(register_ftrace_function);
+
+/**
+ * unregister_ftrace_function - unregister a function for profiling.
+ * @ops: ops structure that holds the function to unregister
+ *
+ * Unregister a function that was added to be called by ftrace profiling.
+ */
+int unregister_ftrace_function(struct ftrace_ops *ops)
+{
+ int ret;
+
+ mutex_lock(&ftrace_lock);
+ ret = ftrace_shutdown(ops, 0);
+ mutex_unlock(&ftrace_lock);
+
+ cleanup_direct_functions_after_ipmodify(ops);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_function);
+
+static int symbols_cmp(const void *a, const void *b)
+{
+ const char **str_a = (const char **) a;
+ const char **str_b = (const char **) b;
+
+ return strcmp(*str_a, *str_b);
+}
+
+struct kallsyms_data {
+ unsigned long *addrs;
+ const char **syms;
+ size_t cnt;
+ size_t found;
+};
+
+static int kallsyms_callback(void *data, const char *name,
+ struct module *mod, unsigned long addr)
+{
+ struct kallsyms_data *args = data;
+ const char **sym;
+ int idx;
+
+ sym = bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp);
+ if (!sym)
+ return 0;
+
+ idx = sym - args->syms;
+ if (args->addrs[idx])
+ return 0;
+
+ if (!ftrace_location(addr))
+ return 0;
+
+ args->addrs[idx] = addr;
+ args->found++;
+ return args->found == args->cnt ? 1 : 0;
+}
+
+/**
+ * ftrace_lookup_symbols - Lookup addresses for array of symbols
+ *
+ * @sorted_syms: array of symbols pointers symbols to resolve,
+ * must be alphabetically sorted
+ * @cnt: number of symbols/addresses in @syms/@addrs arrays
+ * @addrs: array for storing resulting addresses
+ *
+ * This function looks up addresses for array of symbols provided in
+ * @syms array (must be alphabetically sorted) and stores them in
+ * @addrs array, which needs to be big enough to store at least @cnt
+ * addresses.
+ *
+ * This function returns 0 if all provided symbols are found,
+ * -ESRCH otherwise.
+ */
+int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
+{
+ struct kallsyms_data args;
+ int err;
+
+ memset(addrs, 0, sizeof(*addrs) * cnt);
+ args.addrs = addrs;
+ args.syms = sorted_syms;
+ args.cnt = cnt;
+ args.found = 0;
+ err = kallsyms_on_each_symbol(kallsyms_callback, &args);
+ if (err < 0)
+ return err;
+ return args.found == args.cnt ? 0 : -ESRCH;
+}
+
+#ifdef CONFIG_SYSCTL
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static void ftrace_startup_sysctl(void)
+{
+ int command;
+
+ if (unlikely(ftrace_disabled))
+ return;
+
+ /* Force update next time */
+ saved_ftrace_func = NULL;
+ /* ftrace_start_up is true if we want ftrace running */
+ if (ftrace_start_up) {
+ command = FTRACE_UPDATE_CALLS;
+ if (ftrace_graph_active)
+ command |= FTRACE_START_FUNC_RET;
+ ftrace_startup_enable(command);
+ }
+}
+
+static void ftrace_shutdown_sysctl(void)
+{
+ int command;
+
+ if (unlikely(ftrace_disabled))
+ return;
+
+ /* ftrace_start_up is true if ftrace is running */
+ if (ftrace_start_up) {
+ command = FTRACE_DISABLE_CALLS;
+ if (ftrace_graph_active)
+ command |= FTRACE_STOP_FUNC_RET;
+ ftrace_run_update_code(command);
+ }
+}
+#else
+# define ftrace_startup_sysctl() do { } while (0)
+# define ftrace_shutdown_sysctl() do { } while (0)
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+static bool is_permanent_ops_registered(void)
+{
+ struct ftrace_ops *op;
+
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+ if (op->flags & FTRACE_OPS_FL_PERMANENT)
+ return true;
+ } while_for_each_ftrace_op(op);
+
+ return false;
+}
+
+static int
+ftrace_enable_sysctl(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp, loff_t *ppos)
+{
+ int ret = -ENODEV;
+
+ mutex_lock(&ftrace_lock);
+
+ if (unlikely(ftrace_disabled))
+ goto out;
+
+ ret = proc_dointvec(table, write, buffer, lenp, ppos);
+
+ if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
+ goto out;
+
+ if (ftrace_enabled) {
+
+ /* we are starting ftrace again */
+ if (rcu_dereference_protected(ftrace_ops_list,
+ lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
+ update_ftrace_function();
+
+ ftrace_startup_sysctl();
+
+ } else {
+ if (is_permanent_ops_registered()) {
+ ftrace_enabled = true;
+ ret = -EBUSY;
+ goto out;
+ }
+
+ /* stopping ftrace calls (just send to ftrace_stub) */
+ ftrace_trace_function = ftrace_stub;
+
+ ftrace_shutdown_sysctl();
+ }
+
+ last_ftrace_enabled = !!ftrace_enabled;
+ out:
+ mutex_unlock(&ftrace_lock);
+ return ret;
+}
+
+static struct ctl_table ftrace_sysctls[] = {
+ {
+ .procname = "ftrace_enabled",
+ .data = &ftrace_enabled,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = ftrace_enable_sysctl,
+ },
+ {}
+};
+
+static int __init ftrace_sysctl_init(void)
+{
+ register_sysctl_init("kernel", ftrace_sysctls);
+ return 0;
+}
+late_initcall(ftrace_sysctl_init);
+#endif