jump_label: jump_label_inc may return before the code is patched
authorGleb Natapov <gleb@redhat.com>
Tue, 18 Oct 2011 17:55:51 +0000 (19:55 +0200)
committerGreg Kroah-Hartman <gregkh@suse.de>
Fri, 9 Dec 2011 16:55:54 +0000 (08:55 -0800)
commitcf246087a19a4958fba3123d21f1359b6177ddb5
tree9d857d9ddf07d826bb2718ceff8b80dfb210bb4e
parent6bdf07f3dd1c2874792bb07cd84d4210cbc15ca7
jump_label: jump_label_inc may return before the code is patched

commit bbbf7af4bf8fc69bc751818cf30521080fa47dcb upstream.

If cpu A calls jump_label_inc() just after atomic_add_return() is
called by cpu B, atomic_inc_not_zero() will return value greater then
zero and jump_label_inc() will return to a caller before jump_label_update()
finishes its job on cpu B.

Link: http://lkml.kernel.org/r/20111018175551.GH17571@redhat.com

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kernel/jump_label.c