The patch titled
lockdep: fix printk recursion logic
has been added to the -mm tree. Its filename is
lockdep-fix-printk-recursion-logic.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: lockdep: fix printk recursion logic
From: Ingo Molnar <mingo@xxxxxxx>
Bug reported and fixed by Tilman Schmidt <tilman@xxxxxxx>: 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@xxxxxxx>
Cc: Tilman Schmidt <tilman@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/printk.c | 11 ++---------
1 files changed, 2 insertions(+), 9 deletions(-)
diff -puN kernel/printk.c~lockdep-fix-printk-recursion-logic kernel/printk.c
--- a/kernel/printk.c~lockdep-fix-printk-recursion-logic
+++ a/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);
_
Patches currently in -mm which might be from mingo@xxxxxxx are
origin.patch
git-netdev-all.patch
bonding-lockdep-annotation.patch
spinlock-debug-all-cpu-backtrace.patch
spinlock-debug-all-cpu-backtrace-fix.patch
spinlock-debug-all-cpu-backtrace-fix-2.patch
spinlock-debug-all-cpu-backtrace-fix-3.patch
remove-the-old-bd_mutex-lockdep-annotation.patch
new-bd_mutex-lockdep-annotation.patch
sched-likely-profiling.patch
lockdep-annotate-nfs-nfsd-in-kernel-sockets.patch
lockdep-annotate-nfs-nfsd-in-kernel-sockets-tidy.patch
posix-cpu-timers-prevent-signal-delivery-starvation.patch
lockdep-use-build_bug_on.patch
fix-lockdep-designtxt.patch
lockdep-fix-printk-recursion-logic.patch
sched-add-above-background-load-function.patch
mm-implement-swap-prefetching.patch
sched-cleanup-remove-task_t-convert-to-struct-task_struct-prefetch.patch
gtod-exponential-update_wall_time.patch
gtod-persistent-clock-support-core.patch
gtod-persistent-clock-support-i386.patch
time-uninline-jiffiesh.patch
time-fix-msecs_to_jiffies-bug.patch
time-fix-timeout-overflow.patch
cleanup-uninline-irq_enter-and-move-it-into-a-function.patch
dynticks-extend-next_timer_interrupt-to-use-a-reference-jiffie.patch
hrtimers-namespace-and-enum-cleanup.patch
hrtimers-clean-up-locking.patch
hrtimers-state-tracking.patch
hrtimers-clean-up-callback-tracking.patch
hrtimers-move-and-add-documentation.patch
clockevents-core.patch
clockevents-drivers-for-i386.patch
high-res-timers-core.patch
gtod-mark-tsc-unusable-for-highres-timers.patch
dynticks-core.patch
dynticks-add-nohz-stats-to-proc-stat.patch
dynticks-i386-arch-code.patch
high-res-timers-dynticks-enable-i386-support.patch
debugging-feature-timer-stats.patch
detect-atomic-counter-underflows.patch
debug-shared-irqs.patch
make-frame_pointer-default=y.patch
mutex-subsystem-synchro-test-module.patch
vdso-print-fatal-signals.patch
vdso-improve-print_fatal_signals-support-by-adding-memory-maps.patch
-
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