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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-06-07 11:17:30 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-11-14 13:35:16 +0100 |
| commit | 94d24fc47219219b5aa23b45956cc37ee5aa5b01 (patch) | |
| tree | cc7f5fbf4f2e9c6243c9b3ce2439c2d3807d5f12 | |
| parent | 7f80850d3f9fd8fda23a317044aef3a6bafab06b (diff) | |
| download | op-kernel-dev-94d24fc47219219b5aa23b45956cc37ee5aa5b01.zip op-kernel-dev-94d24fc47219219b5aa23b45956cc37ee5aa5b01.tar.gz | |
printk, lockdep: Disable lock debugging on zap_locks()
zap_locks() is used by printk() in a last ditch effort to get data
out, clearly we cannot trust lock state after this so make it disable
lock debugging.
Also don't treat printk recursion through lockdep as a normal
recursion bug but try hard to get the lockdep splat out.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-kqxwmo4xz37e1s8w0xopvr0q@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/linux/lockdep.h | 4 | ||||
| -rw-r--r-- | kernel/printk.c | 3 |
2 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index b6a56e3..d36619e 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -343,6 +343,8 @@ extern void lockdep_trace_alloc(gfp_t mask); #define lockdep_assert_held(l) WARN_ON(debug_locks && !lockdep_is_held(l)) +#define lockdep_recursing(tsk) ((tsk)->lockdep_recursion) + #else /* !LOCKDEP */ static inline void lockdep_off(void) @@ -392,6 +394,8 @@ struct lock_class_key { }; #define lockdep_assert_held(l) do { } while (0) +#define lockdep_recursing(tsk) (0) + #endif /* !LOCKDEP */ #ifdef CONFIG_LOCK_STAT diff --git a/kernel/printk.c b/kernel/printk.c index 1455a0d..6d08794 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -688,6 +688,7 @@ static void zap_locks(void) oops_timestamp = jiffies; + debug_locks_off(); /* If a crash is occurring, make sure we can't deadlock */ raw_spin_lock_init(&logbuf_lock); /* And make sure that we print immediately */ @@ -856,7 +857,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) * recursion and return - but flag the recursion so that * it can be printed at the next appropriate moment: */ - if (!oops_in_progress) { + if (!oops_in_progress && !lockdep_recursing(current)) { recursion_bug = 1; goto out_restore_irqs; } |
