This is a note to let you know that I've just added the patch titled
tracing: Protect ftrace_trace_arrays list in trace_events.c
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tracing-protect-ftrace_trace_arrays-list-in-trace_events.c.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a82274151af2b075163e3c42c828529dee311487 Mon Sep 17 00:00:00 2001
From: Alexander Z Lam <azl@xxxxxxxxxx>
Date: Mon, 1 Jul 2013 19:37:54 -0700
Subject: tracing: Protect ftrace_trace_arrays list in trace_events.c
From: Alexander Z Lam <azl@xxxxxxxxxx>
commit a82274151af2b075163e3c42c828529dee311487 upstream.
There are multiple places where the ftrace_trace_arrays list is accessed in
trace_events.c without the trace_types_lock held.
Link: http://lkml.kernel.org/r/1372732674-22726-1-git-send-email-azl@xxxxxxxxxx
Signed-off-by: Alexander Z Lam <azl@xxxxxxxxxx>
Cc: Vaibhav Nagarnaik <vnagarnaik@xxxxxxxxxx>
Cc: David Sharp <dhsharp@xxxxxxxxxx>
Cc: Alexander Z Lam <lambchop468@xxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/trace.c | 2 +-
kernel/trace/trace.h | 2 ++
kernel/trace/trace_events.c | 11 ++++++++++-
3 files changed, 13 insertions(+), 2 deletions(-)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -240,7 +240,7 @@ static struct tracer *trace_types __rea
/*
* trace_types_lock is used to protect the trace_types list.
*/
-static DEFINE_MUTEX(trace_types_lock);
+DEFINE_MUTEX(trace_types_lock);
/*
* serialize the access of the ring buffer
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -224,6 +224,8 @@ enum {
extern struct list_head ftrace_trace_arrays;
+extern struct mutex trace_types_lock;
+
/*
* The global tracer (top) should be the first trace array added,
* but we check the flag anyway.
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1011,6 +1011,7 @@ static int subsystem_open(struct inode *
int ret;
/* Make sure the system still exists */
+ mutex_lock(&trace_types_lock);
mutex_lock(&event_mutex);
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
list_for_each_entry(dir, &tr->systems, list) {
@@ -1026,6 +1027,7 @@ static int subsystem_open(struct inode *
}
exit_loop:
mutex_unlock(&event_mutex);
+ mutex_unlock(&trace_types_lock);
if (!system)
return -ENODEV;
@@ -1620,6 +1622,7 @@ static void __add_event_to_tracers(struc
int trace_add_event_call(struct ftrace_event_call *call)
{
int ret;
+ mutex_lock(&trace_types_lock);
mutex_lock(&event_mutex);
ret = __register_event(call, NULL);
@@ -1627,11 +1630,13 @@ int trace_add_event_call(struct ftrace_e
__add_event_to_tracers(call, NULL);
mutex_unlock(&event_mutex);
+ mutex_unlock(&trace_types_lock);
return ret;
}
/*
- * Must be called under locking both of event_mutex and trace_event_sem.
+ * Must be called under locking of trace_types_lock, event_mutex and
+ * trace_event_sem.
*/
static void __trace_remove_event_call(struct ftrace_event_call *call)
{
@@ -1643,11 +1648,13 @@ static void __trace_remove_event_call(st
/* Remove an event_call */
void trace_remove_event_call(struct ftrace_event_call *call)
{
+ mutex_lock(&trace_types_lock);
mutex_lock(&event_mutex);
down_write(&trace_event_sem);
__trace_remove_event_call(call);
up_write(&trace_event_sem);
mutex_unlock(&event_mutex);
+ mutex_unlock(&trace_types_lock);
}
#define for_each_event(event, start, end) \
@@ -1791,6 +1798,7 @@ static int trace_module_notify(struct no
{
struct module *mod = data;
+ mutex_lock(&trace_types_lock);
mutex_lock(&event_mutex);
switch (val) {
case MODULE_STATE_COMING:
@@ -1801,6 +1809,7 @@ static int trace_module_notify(struct no
break;
}
mutex_unlock(&event_mutex);
+ mutex_unlock(&trace_types_lock);
return 0;
}
Patches currently in stable-queue which might be from azl@xxxxxxxxxx are
queue-3.10/tracing-get-trace_array-ref-counts-when-accessing-trace-files.patch
queue-3.10/tracing-add-trace_array_get-put-to-event-handling.patch
queue-3.10/tracing-protect-ftrace_trace_arrays-list-in-trace_events.c.patch
queue-3.10/tracing-make-trace_marker-use-the-correct-per-instance-buffer.patch
queue-3.10/tracing-add-trace_array_get-put-to-handle-instance-refs-better.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html