Commit-ID: f2513cde93f0957d5dc6c09bc24b0cccd27d8e1d Gitweb: http://git.kernel.org/tip/f2513cde93f0957d5dc6c09bc24b0cccd27d8e1d Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> AuthorDate: Mon, 6 Jun 2011 12:32:43 +0200 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Tue, 7 Jun 2011 12:25:50 +0200 lockdep: Fix lock_is_held() on recursion The main lock_is_held() user is lockdep_assert_held(), avoid false assertions in lockdep_off() sections by unconditionally reporting the lock is taken. [ the reason this is important is a lockdep_assert_held() in ttwu() which triggers a warning under lockdep_off() as in printk() which can trigger another wakeup and lock up due to spinlock recursion, as reported and heroically debugged by Arne Jansen ] Reported-and-tested-by: Arne Jansen <lists@xxxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxx> Link: http://lkml.kernel.org/r/1307398759.2497.966.camel@laptop Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/lockdep.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 63437d0..298c927 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3426,7 +3426,7 @@ int lock_is_held(struct lockdep_map *lock) int ret = 0; if (unlikely(current->lockdep_recursion)) - return ret; + return 1; /* avoid false negative lockdep_assert_held() */ raw_local_irq_save(flags); check_flags(flags); -- 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
|