Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753177AbZGBSwz (ORCPT ); Thu, 2 Jul 2009 14:52:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751145AbZGBSwo (ORCPT ); Thu, 2 Jul 2009 14:52:44 -0400 Received: from mail-ew0-f215.google.com ([209.85.219.215]:58032 "EHLO mail-ew0-f215.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751117AbZGBSwn (ORCPT ); Thu, 2 Jul 2009 14:52:43 -0400 X-Greylist: delayed 470 seconds by postgrey-1.27 at vger.kernel.org; Thu, 02 Jul 2009 14:52:42 EDT DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=OKUoQEscrPzNFeUgL1/ZnBlM8xN+VDzc8slzsRJFCCpGWahpuq6MGAYedvPRi35N6A lYdYRCF3ntnCQQyW1jBapusOVi5HLbnw2n5XEYNUveO8iRv8///HHxA72z24XoMucyu1 B4KqMSlOGUVT1LXkdQ18iEkBcEk2XUU38oiyY= From: David Kilroy To: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org, David Kilroy , Ingo Molnar Subject: [PATCH] check spinlock_t/rwlock_t argument type on non-SMP builds Date: Thu, 2 Jul 2009 19:44:51 +0100 Message-Id: <1246560291-8104-1-git-send-email-kilroyd@googlemail.com> X-Mailer: git-send-email 1.6.0.6 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7614 Lines: 164 When writing code for UP without CONFIG_DEBUG_SPINLOCK it's easy to get the first argument to the spinlock/rwlock functions wrong. This is because the parameter is not actually used in this configuration. Typically you will only find out it's wrong * by rebuilding with CONFIG_SMP or CONFIG_DEBUG_SPINLOCK * after you've submitted your beautiful patch series. The first means a long wait, and the latter is a bit late. Add typechecking on the first argument of these macro functions. Note that since the typecheck now references the variable, the explicit read is redundant and can be removed. This change causes compiler warnings in net/ipv4/route.c, as this passes NULL as the first argument in the UP configuration. Simply cast this. Signed-off-by: David Kilroy Cc: Ingo Molnar --- I've checked the assembly and object output resulting from this change for x86. As far as I can tell there are only differences in the debugging symbols used to refer to some variables. The stripped objects which I checked are identical. I've also done an allyesconfig build (with various lock debugging options off to keep CONFIG_DEBUG_SPINLOCK off), and there are no extra compiler warnings (except those addressed in route.c). --- include/linux/spinlock_api_up.h | 90 +++++++++++++++++++------------------- net/ipv4/route.c | 2 +- 2 files changed, 46 insertions(+), 46 deletions(-) diff --git a/include/linux/spinlock_api_up.h b/include/linux/spinlock_api_up.h index 04e1d31..7780138 100644 --- a/include/linux/spinlock_api_up.h +++ b/include/linux/spinlock_api_up.h @@ -24,58 +24,58 @@ * flags straight, to suppress compiler warnings of unused lock * variables, and to add the proper checker annotations: */ -#define __LOCK(lock) \ - do { preempt_disable(); __acquire(lock); (void)(lock); } while (0) +#define __LOCK(type, lock) \ + do { typecheck(type*, lock); preempt_disable(); __acquire(lock); } while (0) -#define __LOCK_BH(lock) \ - do { local_bh_disable(); __LOCK(lock); } while (0) +#define __LOCK_BH(type, lock) \ + do { local_bh_disable(); __LOCK(type, lock); } while (0) -#define __LOCK_IRQ(lock) \ - do { local_irq_disable(); __LOCK(lock); } while (0) +#define __LOCK_IRQ(type, lock) \ + do { local_irq_disable(); __LOCK(type, lock); } while (0) -#define __LOCK_IRQSAVE(lock, flags) \ - do { local_irq_save(flags); __LOCK(lock); } while (0) +#define __LOCK_IRQSAVE(type, lock, flags) \ + do { local_irq_save(flags); __LOCK(type, lock); } while (0) -#define __UNLOCK(lock) \ - do { preempt_enable(); __release(lock); (void)(lock); } while (0) +#define __UNLOCK(type, lock) \ + do { typecheck(type*, lock); preempt_enable(); __release(lock); } while (0) -#define __UNLOCK_BH(lock) \ - do { preempt_enable_no_resched(); local_bh_enable(); __release(lock); (void)(lock); } while (0) +#define __UNLOCK_BH(type, lock) \ + do { typecheck(type*, lock); preempt_enable_no_resched(); local_bh_enable(); __release(lock); } while (0) -#define __UNLOCK_IRQ(lock) \ - do { local_irq_enable(); __UNLOCK(lock); } while (0) +#define __UNLOCK_IRQ(type, lock) \ + do { local_irq_enable(); __UNLOCK(type, lock); } while (0) -#define __UNLOCK_IRQRESTORE(lock, flags) \ - do { local_irq_restore(flags); __UNLOCK(lock); } while (0) +#define __UNLOCK_IRQRESTORE(type, lock, flags) \ + do { local_irq_restore(flags); __UNLOCK(type, lock); } while (0) -#define _spin_lock(lock) __LOCK(lock) -#define _spin_lock_nested(lock, subclass) __LOCK(lock) -#define _read_lock(lock) __LOCK(lock) -#define _write_lock(lock) __LOCK(lock) -#define _spin_lock_bh(lock) __LOCK_BH(lock) -#define _read_lock_bh(lock) __LOCK_BH(lock) -#define _write_lock_bh(lock) __LOCK_BH(lock) -#define _spin_lock_irq(lock) __LOCK_IRQ(lock) -#define _read_lock_irq(lock) __LOCK_IRQ(lock) -#define _write_lock_irq(lock) __LOCK_IRQ(lock) -#define _spin_lock_irqsave(lock, flags) __LOCK_IRQSAVE(lock, flags) -#define _read_lock_irqsave(lock, flags) __LOCK_IRQSAVE(lock, flags) -#define _write_lock_irqsave(lock, flags) __LOCK_IRQSAVE(lock, flags) -#define _spin_trylock(lock) ({ __LOCK(lock); 1; }) -#define _read_trylock(lock) ({ __LOCK(lock); 1; }) -#define _write_trylock(lock) ({ __LOCK(lock); 1; }) -#define _spin_trylock_bh(lock) ({ __LOCK_BH(lock); 1; }) -#define _spin_unlock(lock) __UNLOCK(lock) -#define _read_unlock(lock) __UNLOCK(lock) -#define _write_unlock(lock) __UNLOCK(lock) -#define _spin_unlock_bh(lock) __UNLOCK_BH(lock) -#define _write_unlock_bh(lock) __UNLOCK_BH(lock) -#define _read_unlock_bh(lock) __UNLOCK_BH(lock) -#define _spin_unlock_irq(lock) __UNLOCK_IRQ(lock) -#define _read_unlock_irq(lock) __UNLOCK_IRQ(lock) -#define _write_unlock_irq(lock) __UNLOCK_IRQ(lock) -#define _spin_unlock_irqrestore(lock, flags) __UNLOCK_IRQRESTORE(lock, flags) -#define _read_unlock_irqrestore(lock, flags) __UNLOCK_IRQRESTORE(lock, flags) -#define _write_unlock_irqrestore(lock, flags) __UNLOCK_IRQRESTORE(lock, flags) +#define _spin_lock(lock) __LOCK(spinlock_t, lock) +#define _spin_lock_nested(lock, subclass) __LOCK(spinlock_t, lock) +#define _read_lock(lock) __LOCK(rwlock_t, lock) +#define _write_lock(lock) __LOCK(rwlock_t, lock) +#define _spin_lock_bh(lock) __LOCK_BH(spinlock_t, lock) +#define _read_lock_bh(lock) __LOCK_BH(rwlock_t, lock) +#define _write_lock_bh(lock) __LOCK_BH(rwlock_t, lock) +#define _spin_lock_irq(lock) __LOCK_IRQ(spinlock_t, lock) +#define _read_lock_irq(lock) __LOCK_IRQ(rwlock_t, lock) +#define _write_lock_irq(lock) __LOCK_IRQ(rwlock_t, lock) +#define _spin_lock_irqsave(lock, flags) __LOCK_IRQSAVE(spinlock_t, lock, flags) +#define _read_lock_irqsave(lock, flags) __LOCK_IRQSAVE(rwlock_t, lock, flags) +#define _write_lock_irqsave(lock, flags) __LOCK_IRQSAVE(rwlock_t, lock, flags) +#define _spin_trylock(lock) ({ __LOCK(spinlock_t, lock); 1; }) +#define _read_trylock(lock) ({ __LOCK(rwlock_t, lock); 1; }) +#define _write_trylock(lock) ({ __LOCK(rwlock_t, lock); 1; }) +#define _spin_trylock_bh(lock) ({ __LOCK_BH(spinlock_t, lock); 1; }) +#define _spin_unlock(lock) __UNLOCK(spinlock_t, lock) +#define _read_unlock(lock) __UNLOCK(rwlock_t, lock) +#define _write_unlock(lock) __UNLOCK(rwlock_t, lock) +#define _spin_unlock_bh(lock) __UNLOCK_BH(spinlock_t, lock) +#define _write_unlock_bh(lock) __UNLOCK_BH(rwlock_t, lock) +#define _read_unlock_bh(lock) __UNLOCK_BH(rwlock_t, lock) +#define _spin_unlock_irq(lock) __UNLOCK_IRQ(spinlock_t, lock) +#define _read_unlock_irq(lock) __UNLOCK_IRQ(rwlock_t, lock) +#define _write_unlock_irq(lock) __UNLOCK_IRQ(rwlock_t, lock) +#define _spin_unlock_irqrestore(lock, flags) __UNLOCK_IRQRESTORE(spinlock_t, lock, flags) +#define _read_unlock_irqrestore(lock, flags) __UNLOCK_IRQRESTORE(rwlock_t, lock, flags) +#define _write_unlock_irqrestore(lock, flags) __UNLOCK_IRQRESTORE(rwlock_t, lock, flags) #endif /* __LINUX_SPINLOCK_API_UP_H */ diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 28205e5..8edfffd 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -242,7 +242,7 @@ static __init void rt_hash_lock_init(void) spin_lock_init(&rt_hash_locks[i]); } #else -# define rt_hash_lock_addr(slot) NULL +# define rt_hash_lock_addr(slot) ((spinlock_t *) NULL) static inline void rt_hash_lock_init(void) { -- 1.6.0.6 -- 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/