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authorIngo Molnar <mingo@elte.hu>2006-10-11 01:22:08 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-11 11:14:24 -0700
commit256a6b41365e17cebe5c2fc91ddff716c9aa055a (patch)
treec491008b3e2fefed6a42ac7f824d191e023fb11f /kernel/printk.c
parent5fcce7432a731e67f1cd3ef1e71dca9ea84dedb1 (diff)
downloadop-kernel-dev-256a6b41365e17cebe5c2fc91ddff716c9aa055a.zip
op-kernel-dev-256a6b41365e17cebe5c2fc91ddff716c9aa055a.tar.gz
[PATCH] lockdep: fix printk recursion logic
Bug reported and fixed by Tilman Schmidt <tilman@imap.cc>: if lockdep is enabled then log messages make it to /var/log/messages belatedly. The reason is a missed wakeup of klogd. Initially there was only a lockdep_internal() protection against lockdep recursion within vprintk() - it grew the 'outer' lockdep_off()/on() protection only later on. But that lockdep_off() made the release_console_sem() within vprintk() always happen under the lockdep_internal() condition, causing the bug. The right solution to remove the inner protection against recursion here - the outer one is enough. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Tilman Schmidt <tilman@imap.cc> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/printk.c')
-rw-r--r--kernel/printk.c11
1 files changed, 2 insertions, 9 deletions
diff --git a/kernel/printk.c b/kernel/printk.c
index 771f5e8..f7d427e 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -820,15 +820,8 @@ void release_console_sem(void)
console_locked = 0;
up(&console_sem);
spin_unlock_irqrestore(&logbuf_lock, flags);
- if (wake_klogd && !oops_in_progress && waitqueue_active(&log_wait)) {
- /*
- * If we printk from within the lock dependency code,
- * from within the scheduler code, then do not lock
- * up due to self-recursion:
- */
- if (!lockdep_internal())
- wake_up_interruptible(&log_wait);
- }
+ if (wake_klogd && !oops_in_progress && waitqueue_active(&log_wait))
+ wake_up_interruptible(&log_wait);
}
EXPORT_SYMBOL(release_console_sem);
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