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-rw-r--r--kernel/trace/trace_boot.c358
1 files changed, 358 insertions, 0 deletions
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
new file mode 100644
index 000000000..0996d5975
--- /dev/null
+++ b/kernel/trace/trace_boot.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * trace_boot.c
+ * Tracing kernel boot-time
+ */
+
+#define pr_fmt(fmt) "trace_boot: " fmt
+
+#include <linux/bootconfig.h>
+#include <linux/cpumask.h>
+#include <linux/ftrace.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/trace.h>
+#include <linux/trace_events.h>
+
+#include "trace.h"
+
+#define MAX_BUF_LEN 256
+
+static void __init
+trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
+{
+ struct xbc_node *anode;
+ const char *p;
+ char buf[MAX_BUF_LEN];
+ unsigned long v = 0;
+
+ /* Common ftrace options */
+ xbc_node_for_each_array_value(node, "options", anode, p) {
+ if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
+ pr_err("String is too long: %s\n", p);
+ continue;
+ }
+
+ if (trace_set_options(tr, buf) < 0)
+ pr_err("Failed to set option: %s\n", buf);
+ }
+
+ p = xbc_node_find_value(node, "tracing_on", NULL);
+ if (p && *p != '\0') {
+ if (kstrtoul(p, 10, &v))
+ pr_err("Failed to set tracing on: %s\n", p);
+ if (v)
+ tracer_tracing_on(tr);
+ else
+ tracer_tracing_off(tr);
+ }
+
+ p = xbc_node_find_value(node, "trace_clock", NULL);
+ if (p && *p != '\0') {
+ if (tracing_set_clock(tr, p) < 0)
+ pr_err("Failed to set trace clock: %s\n", p);
+ }
+
+ p = xbc_node_find_value(node, "buffer_size", NULL);
+ if (p && *p != '\0') {
+ v = memparse(p, NULL);
+ if (v < PAGE_SIZE)
+ pr_err("Buffer size is too small: %s\n", p);
+ if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)
+ pr_err("Failed to resize trace buffer to %s\n", p);
+ }
+
+ p = xbc_node_find_value(node, "cpumask", NULL);
+ if (p && *p != '\0') {
+ cpumask_var_t new_mask;
+
+ if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
+ if (cpumask_parse(p, new_mask) < 0 ||
+ tracing_set_cpumask(tr, new_mask) < 0)
+ pr_err("Failed to set new CPU mask %s\n", p);
+ free_cpumask_var(new_mask);
+ }
+ }
+}
+
+#ifdef CONFIG_EVENT_TRACING
+static void __init
+trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node)
+{
+ struct xbc_node *anode;
+ char buf[MAX_BUF_LEN];
+ const char *p;
+
+ xbc_node_for_each_array_value(node, "events", anode, p) {
+ if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
+ pr_err("String is too long: %s\n", p);
+ continue;
+ }
+
+ if (ftrace_set_clr_event(tr, buf, 1) < 0)
+ pr_err("Failed to enable event: %s\n", p);
+ }
+}
+
+#ifdef CONFIG_KPROBE_EVENTS
+static int __init
+trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
+{
+ struct dynevent_cmd cmd;
+ struct xbc_node *anode;
+ char buf[MAX_BUF_LEN];
+ const char *val;
+ int ret = 0;
+
+ xbc_node_for_each_array_value(node, "probes", anode, val) {
+ kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
+
+ ret = kprobe_event_gen_cmd_start(&cmd, event, val);
+ if (ret) {
+ pr_err("Failed to generate probe: %s\n", buf);
+ break;
+ }
+
+ ret = kprobe_event_gen_cmd_end(&cmd);
+ if (ret) {
+ pr_err("Failed to add probe: %s\n", buf);
+ break;
+ }
+ }
+
+ return ret;
+}
+#else
+static inline int __init
+trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
+{
+ pr_err("Kprobe event is not supported.\n");
+ return -ENOTSUPP;
+}
+#endif
+
+#ifdef CONFIG_SYNTH_EVENTS
+static int __init
+trace_boot_add_synth_event(struct xbc_node *node, const char *event)
+{
+ struct dynevent_cmd cmd;
+ struct xbc_node *anode;
+ char buf[MAX_BUF_LEN];
+ const char *p;
+ int ret;
+
+ synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
+
+ ret = synth_event_gen_cmd_start(&cmd, event, NULL);
+ if (ret)
+ return ret;
+
+ xbc_node_for_each_array_value(node, "fields", anode, p) {
+ ret = synth_event_add_field_str(&cmd, p);
+ if (ret)
+ return ret;
+ }
+
+ ret = synth_event_gen_cmd_end(&cmd);
+ if (ret < 0)
+ pr_err("Failed to add synthetic event: %s\n", buf);
+
+ return ret;
+}
+#else
+static inline int __init
+trace_boot_add_synth_event(struct xbc_node *node, const char *event)
+{
+ pr_err("Synthetic event is not supported.\n");
+ return -ENOTSUPP;
+}
+#endif
+
+static void __init
+trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
+ struct xbc_node *enode)
+{
+ struct trace_event_file *file;
+ struct xbc_node *anode;
+ char buf[MAX_BUF_LEN];
+ const char *p, *group, *event;
+
+ group = xbc_node_get_data(gnode);
+ event = xbc_node_get_data(enode);
+
+ if (!strcmp(group, "kprobes"))
+ if (trace_boot_add_kprobe_event(enode, event) < 0)
+ return;
+ if (!strcmp(group, "synthetic"))
+ if (trace_boot_add_synth_event(enode, event) < 0)
+ return;
+
+ mutex_lock(&event_mutex);
+ file = find_event_file(tr, group, event);
+ if (!file) {
+ pr_err("Failed to find event: %s:%s\n", group, event);
+ goto out;
+ }
+
+ p = xbc_node_find_value(enode, "filter", NULL);
+ if (p && *p != '\0') {
+ if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+ pr_err("filter string is too long: %s\n", p);
+ else if (apply_event_filter(file, buf) < 0)
+ pr_err("Failed to apply filter: %s\n", buf);
+ }
+
+ if (IS_ENABLED(CONFIG_HIST_TRIGGERS)) {
+ xbc_node_for_each_array_value(enode, "actions", anode, p) {
+ if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+ pr_err("action string is too long: %s\n", p);
+ else if (trigger_process_regex(file, buf) < 0)
+ pr_err("Failed to apply an action: %s\n", buf);
+ }
+ } else if (xbc_node_find_value(enode, "actions", NULL))
+ pr_err("Failed to apply event actions because CONFIG_HIST_TRIGGERS is not set.\n");
+
+ if (xbc_node_find_value(enode, "enable", NULL)) {
+ if (trace_event_enable_disable(file, 1, 0) < 0)
+ pr_err("Failed to enable event node: %s:%s\n",
+ group, event);
+ }
+out:
+ mutex_unlock(&event_mutex);
+}
+
+static void __init
+trace_boot_init_events(struct trace_array *tr, struct xbc_node *node)
+{
+ struct xbc_node *gnode, *enode;
+
+ node = xbc_node_find_child(node, "event");
+ if (!node)
+ return;
+ /* per-event key starts with "event.GROUP.EVENT" */
+ xbc_node_for_each_child(node, gnode)
+ xbc_node_for_each_child(gnode, enode)
+ trace_boot_init_one_event(tr, gnode, enode);
+}
+#else
+#define trace_boot_enable_events(tr, node) do {} while (0)
+#define trace_boot_init_events(tr, node) do {} while (0)
+#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static void __init
+trace_boot_set_ftrace_filter(struct trace_array *tr, struct xbc_node *node)
+{
+ struct xbc_node *anode;
+ const char *p;
+ char *q;
+
+ xbc_node_for_each_array_value(node, "ftrace.filters", anode, p) {
+ q = kstrdup(p, GFP_KERNEL);
+ if (!q)
+ return;
+ if (ftrace_set_filter(tr->ops, q, strlen(q), 0) < 0)
+ pr_err("Failed to add %s to ftrace filter\n", p);
+ else
+ ftrace_filter_param = true;
+ kfree(q);
+ }
+ xbc_node_for_each_array_value(node, "ftrace.notraces", anode, p) {
+ q = kstrdup(p, GFP_KERNEL);
+ if (!q)
+ return;
+ if (ftrace_set_notrace(tr->ops, q, strlen(q), 0) < 0)
+ pr_err("Failed to add %s to ftrace filter\n", p);
+ else
+ ftrace_filter_param = true;
+ kfree(q);
+ }
+}
+#else
+#define trace_boot_set_ftrace_filter(tr, node) do {} while (0)
+#endif
+
+static void __init
+trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
+{
+ const char *p;
+
+ trace_boot_set_ftrace_filter(tr, node);
+
+ p = xbc_node_find_value(node, "tracer", NULL);
+ if (p && *p != '\0') {
+ if (tracing_set_tracer(tr, p) < 0)
+ pr_err("Failed to set given tracer: %s\n", p);
+ }
+
+ /* Since tracer can free snapshot buffer, allocate snapshot here.*/
+ if (xbc_node_find_value(node, "alloc_snapshot", NULL)) {
+ if (tracing_alloc_snapshot_instance(tr) < 0)
+ pr_err("Failed to allocate snapshot buffer\n");
+ }
+}
+
+static void __init
+trace_boot_init_one_instance(struct trace_array *tr, struct xbc_node *node)
+{
+ trace_boot_set_instance_options(tr, node);
+ trace_boot_init_events(tr, node);
+ trace_boot_enable_events(tr, node);
+ trace_boot_enable_tracer(tr, node);
+}
+
+static void __init
+trace_boot_init_instances(struct xbc_node *node)
+{
+ struct xbc_node *inode;
+ struct trace_array *tr;
+ const char *p;
+
+ node = xbc_node_find_child(node, "instance");
+ if (!node)
+ return;
+
+ xbc_node_for_each_child(node, inode) {
+ p = xbc_node_get_data(inode);
+ if (!p || *p == '\0')
+ continue;
+
+ tr = trace_array_get_by_name(p);
+ if (!tr) {
+ pr_err("Failed to get trace instance %s\n", p);
+ continue;
+ }
+ trace_boot_init_one_instance(tr, inode);
+ trace_array_put(tr);
+ }
+}
+
+static int __init trace_boot_init(void)
+{
+ struct xbc_node *trace_node;
+ struct trace_array *tr;
+
+ trace_node = xbc_find_node("ftrace");
+ if (!trace_node)
+ return 0;
+
+ tr = top_trace_array();
+ if (!tr)
+ return 0;
+
+ /* Global trace array is also one instance */
+ trace_boot_init_one_instance(tr, trace_node);
+ trace_boot_init_instances(trace_node);
+
+ disable_tracing_selftest("running boot-time tracing");
+
+ return 0;
+}
+/*
+ * Start tracing at the end of core-initcall, so that it starts tracing
+ * from the beginning of postcore_initcall.
+ */
+core_initcall_sync(trace_boot_init);