Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758884AbWLFAvQ (ORCPT ); Tue, 5 Dec 2006 19:51:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758889AbWLFAvQ (ORCPT ); Tue, 5 Dec 2006 19:51:16 -0500 Received: from twin.jikos.cz ([213.151.79.26]:44388 "EHLO twin.jikos.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758884AbWLFAvP (ORCPT ); Tue, 5 Dec 2006 19:51:15 -0500 Date: Wed, 6 Dec 2006 01:51:01 +0100 (CET) From: Jiri Kosina X-X-Sender: jikos@twin.jikos.cz To: Andrew Morton , Ingo Molnar cc: linux-kernel@vger.kernel.org Subject: [PATCH] let WARN_ON() output the condition Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2340 Lines: 60 [PATCH] let WARN_ON() output the condition It is possible, in some cases, that the output of WARN_ON() is ambiguous and can't be properly used to identify the exact condition which caused the warning to trigger. This happens whenever there is a macro that contains multiple WARN_ONs inside. Notable example is spin_lock_mutex(). If any of the two WARN_ONs trigger, we are not able to say which one was the cause (as we get only line number, which however belongs to the place where the macro was expanded). This patch lets WARN_ON() to output also the condition and fixes the DEBUG_LOCKS_WARN_ON() macro to pass the condition properly to WARN_ON. The possible drawback could be when someone passes a condition which has sideeffects. Then it would be evaluated twice, instead of current one evaluation. On the other hand, when anyone passes expression with sideeffects to WARN_ON(), he is asking for problems anyway. Patch against 2.6.19-rc6-mm2. Signed-off-by: Jiri Kosina --- include/asm-generic/bug.h | 4 ++-- include/linux/debug_locks.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index a06eecd..af7574e 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -35,8 +35,8 @@ #ifndef HAVE_ARCH_WARN_ON #define WARN_ON(condition) ({ \ typeof(condition) __ret_warn_on = (condition); \ if (unlikely(__ret_warn_on)) { \ - printk("WARNING at %s:%d %s()\n", __FILE__, \ - __LINE__, __FUNCTION__); \ + printk("WARNING (%s) at %s:%d %s()\n", #condition, \ + __FILE__,__LINE__, __FUNCTION__); \ dump_stack(); \ } \ unlikely(__ret_warn_on); \ diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h index 952bee7..1c2b682 100644 --- a/include/linux/debug_locks.h +++ b/include/linux/debug_locks.h @@ -25,7 +25,7 @@ ({ \ \ if (unlikely(c)) { \ if (debug_locks_off()) \ - WARN_ON(1); \ + WARN_ON(c); \ __ret = 1; \ } \ __ret; \ - 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/