[PATCH] [ BUG: bad unlock balance detected! ] in 2.6.18-rc5

[PATCH] [ BUG: bad unlock balance detected! ] in 2.6.18-rc5

[Jarek Poplawski]

Hi,

Some time ago I wrote about this bug in rc3.
I see it's still in 2.6.18-rc5 so here is what
I've found: with config like this:

CONFIG_SMP=y
CONFIG_PREEMPT=y
CONFIG_LOCKDEP=y
CONFIG_DEBUG_LOCK_ALLOC=y
# CONFIG_PROVE_LOCKING is not set

spin_unlock_irqrestore() goes through lockdep
but spin_lock_irqrestore() doesn't.

I attach my proposal how to fix this.

Jarek P.

diff -Nru linux-2.6.18-rc5-/kernel/spinlock.c linux-2.6.18-rc5/kernel/spinlock.c
--- linux-2.6.18-rc5-/kernel/spinlock.c	2006-08-30 02:20:46.000000000 +0200
+++ linux-2.6.18-rc5/kernel/spinlock.c	2006-09-01 00:27:35.000000000 +0200
@@ -72,7 +72,7 @@
  * not re-enabled during lock-acquire (which the preempt-spin-ops do):
  */
 #if !defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP) || \
-	defined(CONFIG_PROVE_LOCKING)
+	defined(CONFIG_DEBUG_LOCK_ALLOC)
 
 void __lockfunc _read_lock(rwlock_t *lock)
 {

Re: [PATCH] [ BUG: bad unlock balance detected! ] in 2.6.18-rc5

[Jarek Poplawski]

On Fri, Sep 01, 2006 at 08:43:19AM +0200, Jarek Poplawski wrote:
...
> spin_unlock_irqrestore() goes through lockdep
> but spin_lock_irqrestore() doesn't.

but spin_lock_irqsave() doesn't!

Jarek P.

Re: [PATCH] [ BUG: bad unlock balance detected! ] in 2.6.18-rc5

[Ingo Molnar]

* Jarek Poplawski <jarkao2@o2.pl> wrote:

> spin_unlock_irqrestore() goes through lockdep but 
> spin_lock_irqrestore() doesn't.

good catch! Andrew: i think this is a must-have for 2.6.18.

Acked-by: Ingo Molnar <mingo@elte.hu>

	Ingo