[PATCH 2/3] printk, lockdep: Remove lockdep_off() usage

Peter Zijlstra
2011-06-09T13:14:32Z

[-- Attachment #1: printk-remove-lockdep_off.patch --]
[-- Type: text/plain, Size: 1661 bytes --]

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. 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 <a.p.zijlstra@chello.nl>
---
kernel/printk.c | 9 +++------
1 file changed, 3 insertions(+), 6 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();

/*
@@ -861,7 +861,6 @@ asmlinkage int vprintk(const char *fmt,
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);