Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756232AbZDWMEP (ORCPT ); Thu, 23 Apr 2009 08:04:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753233AbZDWMD7 (ORCPT ); Thu, 23 Apr 2009 08:03:59 -0400 Received: from cmpxchg.org ([85.214.51.133]:48957 "EHLO cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752370AbZDWMD7 (ORCPT ); Thu, 23 Apr 2009 08:03:59 -0400 Date: Thu, 23 Apr 2009 14:02:19 +0200 From: Johannes Weiner To: Andi Kleen Cc: arjan@linux.intel.com, linux-kernel@vger.kernel.org, torvalds@osdl.org, akpm@osdl.org Subject: Re: [PATCH] Eliminate thousands of warnings in WARN_ON with gcc 3.2 build Message-ID: <20090423120219.GA23479@cmpxchg.org> References: <20090422221134.GA1753@basil.nowhere.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090422221134.GA1753@basil.nowhere.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3120 Lines: 82 Hi Andi, On Thu, Apr 23, 2009 at 12:11:34AM +0200, Andi Kleen wrote: > Eliminate thousands of warnings with gcc 3.2 build > > When building with gcc 3.2 I get thousands of warnings about passing > a NULL format string to warn_on_slowpath(). Split this case out > into a separate call. This should also shrink the kernel > slightly in theory (haven't done numbers) > > Signed-off-by: Andi Kleen > > --- > include/asm-generic/bug.h | 7 ++++--- > kernel/panic.c | 12 +++++++++--- > 2 files changed, 13 insertions(+), 6 deletions(-) > > Index: linux-2.6.30-rc2-ak/include/asm-generic/bug.h > =================================================================== > --- linux-2.6.30-rc2-ak.orig/include/asm-generic/bug.h 2009-01-11 20:20:40.000000000 +0100 > +++ linux-2.6.30-rc2-ak/include/asm-generic/bug.h 2009-04-22 23:52:48.000000000 +0200 > @@ -58,12 +58,13 @@ > */ > #ifndef __WARN > #ifndef __ASSEMBLY__ > -extern void warn_slowpath(const char *file, const int line, > +extern void warn_slowpath_fmt(const char *file, const int line, > const char *fmt, ...) __attribute__((format(printf, 3, 4))); > +extern void warn_slowpath_null(const char *file, const int line); > #define WANT_WARN_ON_SLOWPATH > #endif > -#define __WARN() warn_slowpath(__FILE__, __LINE__, NULL) > -#define __WARN_printf(arg...) warn_slowpath(__FILE__, __LINE__, arg) > +#define __WARN() warn_slowpath_null(__FILE__, __LINE__) > +#define __WARN_printf(arg...) warn_slowpath_fmt(__FILE__, __LINE__, arg) > #else > #define __WARN_printf(arg...) do { printk(arg); __WARN(); } while (0) > #endif > Index: linux-2.6.30-rc2-ak/kernel/panic.c > =================================================================== > --- linux-2.6.30-rc2-ak.orig/kernel/panic.c 2009-04-19 19:29:07.000000000 +0200 > +++ linux-2.6.30-rc2-ak/kernel/panic.c 2009-04-22 23:53:55.000000000 +0200 > @@ -342,7 +342,7 @@ > } > > #ifdef WANT_WARN_ON_SLOWPATH > -void warn_slowpath(const char *file, int line, const char *fmt, ...) > +void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...) > { > va_list args; > char function[KSYM_SYMBOL_LEN]; > @@ -358,7 +358,7 @@ > if (board) > printk(KERN_WARNING "Hardware name: %s\n", board); > > - if (fmt) { > + if (*fmt) { > va_start(args, fmt); > vprintk(fmt, args); > va_end(args); > @@ -369,7 +369,13 @@ > print_oops_end_marker(); > add_taint(TAINT_WARN); > } > -EXPORT_SYMBOL(warn_slowpath); > +EXPORT_SYMBOL(warn_slowpath_fmt); > + > +void warn_slowpath_null(const char *file, int line) > +{ > + warn_slowpath_fmt(file, line, ""); > +} > +EXPORT_SYMBOL(warn_slowpath_null); That should still emit a warning due to passing in a zero-length format string. Using (const char *){ 0 } as the literal would suppress it (on gcc 4.3.3 at least) but I'm not sure if it's worth the uglyness... -- 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/