Commit-ID: bbbf7af4bf8fc69bc751818cf30521080fa47dcb Gitweb: http://git.kernel.org/tip/bbbf7af4bf8fc69bc751818cf30521080fa47dcb Author: Gleb Natapov <gleb@xxxxxxxxxx> AuthorDate: Tue, 18 Oct 2011 19:55:51 +0200 Committer: Steven Rostedt <rostedt@xxxxxxxxxxx> CommitDate: Mon, 5 Dec 2011 13:28:46 -0500 jump_label: jump_label_inc may return before the code is patched 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@xxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Acked-by: Jason Baron <jbaron@xxxxxxxxxx> Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- kernel/jump_label.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/kernel/jump_label.c b/kernel/jump_label.c index bbdfe2a..66ff710 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -66,8 +66,9 @@ void jump_label_inc(struct jump_label_key *key) return; jump_label_lock(); - if (atomic_add_return(1, &key->enabled) == 1) + if (atomic_read(&key->enabled) == 0) jump_label_update(key, JUMP_LABEL_ENABLE); + atomic_inc(&key->enabled); jump_label_unlock(); } -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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