Merge commit 'linus/master' into tracing/kprobes
Conflicts:
kernel/trace/Makefile
kernel/trace/trace.h
kernel/trace/trace_event_types.h
kernel/trace/trace_export.c
Merge reason:
Sync with latest significant tracing core changes.
diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
index 11ba5bb..e812f1c 100644
--- a/kernel/trace/trace_event_profile.c
+++ b/kernel/trace/trace_event_profile.c
@@ -5,8 +5,60 @@
*
*/
+#include <linux/module.h>
#include "trace.h"
+/*
+ * We can't use a size but a type in alloc_percpu()
+ * So let's create a dummy type that matches the desired size
+ */
+typedef struct {char buf[FTRACE_MAX_PROFILE_SIZE];} profile_buf_t;
+
+char *trace_profile_buf;
+EXPORT_SYMBOL_GPL(trace_profile_buf);
+
+char *trace_profile_buf_nmi;
+EXPORT_SYMBOL_GPL(trace_profile_buf_nmi);
+
+/* Count the events in use (per event id, not per instance) */
+static int total_profile_count;
+
+static int ftrace_profile_enable_event(struct ftrace_event_call *event)
+{
+ char *buf;
+ int ret = -ENOMEM;
+
+ if (atomic_inc_return(&event->profile_count))
+ return 0;
+
+ if (!total_profile_count++) {
+ buf = (char *)alloc_percpu(profile_buf_t);
+ if (!buf)
+ goto fail_buf;
+
+ rcu_assign_pointer(trace_profile_buf, buf);
+
+ buf = (char *)alloc_percpu(profile_buf_t);
+ if (!buf)
+ goto fail_buf_nmi;
+
+ rcu_assign_pointer(trace_profile_buf_nmi, buf);
+ }
+
+ ret = event->profile_enable(event);
+ if (!ret)
+ return 0;
+
+ kfree(trace_profile_buf_nmi);
+fail_buf_nmi:
+ kfree(trace_profile_buf);
+fail_buf:
+ total_profile_count--;
+ atomic_dec(&event->profile_count);
+
+ return ret;
+}
+
int ftrace_profile_enable(int event_id)
{
struct ftrace_event_call *event;
@@ -14,8 +66,9 @@
mutex_lock(&event_mutex);
list_for_each_entry(event, &ftrace_events, list) {
- if (event->id == event_id && event->profile_enable) {
- ret = event->profile_enable(event);
+ if (event->id == event_id && event->profile_enable &&
+ try_module_get(event->mod)) {
+ ret = ftrace_profile_enable_event(event);
break;
}
}
@@ -24,6 +77,33 @@
return ret;
}
+static void ftrace_profile_disable_event(struct ftrace_event_call *event)
+{
+ char *buf, *nmi_buf;
+
+ if (!atomic_add_negative(-1, &event->profile_count))
+ return;
+
+ event->profile_disable(event);
+
+ if (!--total_profile_count) {
+ buf = trace_profile_buf;
+ rcu_assign_pointer(trace_profile_buf, NULL);
+
+ nmi_buf = trace_profile_buf_nmi;
+ rcu_assign_pointer(trace_profile_buf_nmi, NULL);
+
+ /*
+ * Ensure every events in profiling have finished before
+ * releasing the buffers
+ */
+ synchronize_sched();
+
+ free_percpu(buf);
+ free_percpu(nmi_buf);
+ }
+}
+
void ftrace_profile_disable(int event_id)
{
struct ftrace_event_call *event;
@@ -31,7 +111,8 @@
mutex_lock(&event_mutex);
list_for_each_entry(event, &ftrace_events, list) {
if (event->id == event_id) {
- event->profile_disable(event);
+ ftrace_profile_disable_event(event);
+ module_put(event->mod);
break;
}
}