diff options
| author | Kalle Valo <kvalo@qca.qualcomm.com> | 2012-03-05 19:32:58 +0200 |
|---|---|---|
| committer | Kalle Valo <kvalo@qca.qualcomm.com> | 2012-03-05 19:32:58 +0200 |
| commit | 05e5bd0f3daddb0368a433af5b58be68c62dc365 (patch) | |
| tree | a54c90523b72fb6e61b7bfe01fb8917e16825781 /kernel/panic.c | |
| parent | daa16bc52ad8e9513506fca29a038a1460e63638 (diff) | |
| parent | c288ec614e264b46853c65d3db9ccf91d53c9484 (diff) | |
Merge remote branch 'wireless-next/master' into ath6kl-next
Conflicts:
drivers/net/wireless/ath/ath6kl/cfg80211.c
Diffstat (limited to 'kernel/panic.c')
| -rw-r--r-- | kernel/panic.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/kernel/panic.c b/kernel/panic.c index 3458469eb7c3..80aed44e345a 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -49,6 +49,15 @@ static long no_blink(int state) long (*panic_blink)(int state); EXPORT_SYMBOL(panic_blink); +/* + * Stop ourself in panic -- architecture code may override this + */ +void __weak panic_smp_self_stop(void) +{ + while (1) + cpu_relax(); +} + /** * panic - halt the system * @fmt: The text string to print @@ -57,8 +66,9 @@ EXPORT_SYMBOL(panic_blink); * * This function never returns. */ -NORET_TYPE void panic(const char * fmt, ...) +void panic(const char *fmt, ...) { + static DEFINE_SPINLOCK(panic_lock); static char buf[1024]; va_list args; long i, i_next = 0; @@ -68,8 +78,14 @@ NORET_TYPE void panic(const char * fmt, ...) * It's possible to come here directly from a panic-assertion and * not have preempt disabled. Some functions called from here want * preempt to be disabled. No point enabling it later though... + * + * Only one CPU is allowed to execute the panic code from here. For + * multiple parallel invocations of panic, all other CPUs either + * stop themself or will wait until they are stopped by the 1st CPU + * with smp_send_stop(). */ - preempt_disable(); + if (!spin_trylock(&panic_lock)) + panic_smp_self_stop(); console_verbose(); bust_spinlocks(1); @@ -78,7 +94,11 @@ NORET_TYPE void panic(const char * fmt, ...) va_end(args); printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf); #ifdef CONFIG_DEBUG_BUGVERBOSE - dump_stack(); + /* + * Avoid nested stack-dumping if a panic occurs during oops processing + */ + if (!oops_in_progress) + dump_stack(); #endif /* |