This is a note to let you know that I've just added the patch titled
tracing: Fix preempt count leak
to the 2.6.37-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-fix-preempt-count-leak.patch
and it can be found in the queue-2.6.37 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 1dbd1951f39e13da579ffe879cce19586d0462de Mon Sep 17 00:00:00 2001
From: Li Zefan <[email protected]>
Date: Thu, 9 Dec 2010 15:47:56 +0800
Subject: tracing: Fix preempt count leak
From: Li Zefan <[email protected]>
commit 1dbd1951f39e13da579ffe879cce19586d0462de upstream.
While running my ftrace stress test, this showed up:
BUG: sleeping function called from invalid context at mm/mmap.c:233
...
note: cat[3293] exited with preempt_count 1
The bug was introduced by commit 91e86e560d0b3ce4c5fc64fd2bbb99f856a30a4e
("tracing: Fix recursive user stack trace")
Signed-off-by: Li Zefan <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
kernel/trace/trace.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1313,12 +1313,10 @@ ftrace_trace_userstack(struct ring_buffe
__this_cpu_inc(user_stack_count);
-
-
event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
sizeof(*entry), flags, pc);
if (!event)
- return;
+ goto out_drop_count;
entry = ring_buffer_event_data(event);
entry->tgid = current->tgid;
@@ -1333,8 +1331,8 @@ ftrace_trace_userstack(struct ring_buffe
if (!filter_check_discard(call, entry, buffer, event))
ring_buffer_unlock_commit(buffer, event);
+ out_drop_count:
__this_cpu_dec(user_stack_count);
-
out:
preempt_enable();
}
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.37/tracing-fix-preempt-count-leak.patch
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