2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Peter Zijlstra <[email protected]> commit f2513cde93f0957d5dc6c09bc24b0cccd27d8e1d upstream. 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 <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Linus Torvalds <[email protected]> Signed-off-by: Andi Kleen <[email protected]> Link: http://lkml.kernel.org/r/1307398759.2497.966.camel@laptop Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- kernel/lockdep.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6.35.y/kernel/lockdep.c =================================================================== --- linux-2.6.35.y.orig/kernel/lockdep.c +++ linux-2.6.35.y/kernel/lockdep.c @@ -3250,7 +3250,7 @@ int lock_is_held(struct lockdep_map *loc 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); _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
