Remove the lockdep_off() usage from printk(). Also add a debug_locks_off() call to zap_locks() since that'll mess up the lock state in a royal way anyway, and zap_locks() when lockdep causes a printk() recursion so that we can at observe the splat. Further switch to local_irq_ ops so that the irq state is properly tracked (raw_local_irq_* isn't tracked by lockdep, causing confusion). Also drop superfluous preempt_disable(), disabling IRQs already avoids scheduling. Signed-off-by: Peter Zijlstra --- kernel/printk.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) Index: linux-2.6/kernel/printk.c =================================================================== --- linux-2.6.orig/kernel/printk.c +++ linux-2.6/kernel/printk.c @@ -686,6 +686,7 @@ static void zap_locks(void) oops_timestamp = jiffies; + debug_locks_off(); /* If a crash is occurring, make sure we can't deadlock */ spin_lock_init(&logbuf_lock); /* And make sure that we print immediately */ @@ -838,9 +839,8 @@ asmlinkage int vprintk(const char *fmt, boot_delay_msec(); printk_delay(); - preempt_disable(); /* This stops the holder of console_sem just where we want him */ - raw_local_irq_save(flags); + local_irq_save(flags); this_cpu = smp_processor_id(); /* @@ -854,14 +854,13 @@ asmlinkage int vprintk(const char *fmt, * 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; } zap_locks(); } - lockdep_off(); spin_lock(&logbuf_lock); printk_cpu = this_cpu; @@ -958,11 +957,9 @@ asmlinkage int vprintk(const char *fmt, if (console_trylock_for_printk(this_cpu)) console_unlock(); - lockdep_on(); out_restore_irqs: - raw_local_irq_restore(flags); + local_irq_restore(flags); - preempt_enable(); return printed_len; } EXPORT_SYMBOL(printk); diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index ef820a3..132d210 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/