From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760799AbYGAUgS (ORCPT ); Tue, 1 Jul 2008 16:36:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754814AbYGAUgI (ORCPT ); Tue, 1 Jul 2008 16:36:08 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:47189 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754348AbYGAUgH (ORCPT ); Tue, 1 Jul 2008 16:36:07 -0400 Date: Tue, 1 Jul 2008 13:35:35 -0700 From: Andrew Morton To: Randy Dunlap Cc: linux-kernel@vger.kernel.org, andi@firstfloor.org, Len Brown Subject: Re: [PATCH -next] bug.h: add empty warn_on_slowpath() for CONFIG_BUG=n Message-Id: <20080701133535.f92a673c.akpm@linux-foundation.org> In-Reply-To: <23433248.1214943818230.JavaMail.oracle@acsmt302.oracle.com> References: <20080701103339.b5acc1f3.randy.dunlap@oracle.com> <20080701131714.5093fa49.akpm@linux-foundation.org> <23433248.1214943818230.JavaMail.oracle@acsmt302.oracle.com> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 1 Jul 2008 15:23:38 -0500 (CDT) Randy Dunlap wrote: > --- Original Message --- > > On Tue, 1 Jul 2008 10:33:39 -0700 > > Randy Dunlap wrote: > > > > > From: Randy Dunlap > > > > > > Add an empty function for warn_on_slowpath() when CONFIG_BUG=n so that > > > this build error does not happen: > > > > > > linux-next-20080701/drivers/acpi/utilities/utmisc.c: In function 'acpi_ut_error': > > > linux-next-20080701/drivers/acpi/utilities/utmisc.c:1028: error: implicit declaration of function 'warn_on_slowpath' > > > > > > Signed-off-by: Randy Dunlap > > > --- > > > include/asm-generic/bug.h | 5 +++++ > > > 1 file changed, 5 insertions(+) > > > > > > --- linux-next-20080701.orig/include/asm-generic/bug.h > > > +++ linux-next-20080701/include/asm-generic/bug.h > > > @@ -81,4 +81,9 @@ extern void warn_on_slowpath(const char > > > # define WARN_ON_SMP(x) do { } while (0) > > > #endif > > > > > > +#ifndef __ASSEMBLY__ > > > +static inline void warn_on_slowpath(const char *file, const int line) > > > +{ } > > > +#endif > > > + > > > #endif > > > > > > > This looks like a needed-in-mainline fix? or is there something > > in linux-next which causes the bug? > > Looks like only linux-next has this code: > > > > linux-next-20080701/drivers/acpi/utilities/utmisc.c: In function 'acpi_ut_error': > > > linux-next-20080701/drivers/acpi/utilities/utmisc.c:1028: error: implicit declaration of function 'warn_on_slowpath' > err... commit 9e030ab0bffdc8b6d8be663b639bd5e2374537f0 Author: Len Brown Date: Tue Jun 24 22:47:09 2008 -0400 ACPI: add standard linux WARN_ON() output to ACPI errors and exceptions In linux-2.6.27, we expect WARN() with printk semantics to become available, and we'll be able to simplify this code. Signed-off-by: Len Brown diff --git a/drivers/acpi/utilities/utmisc.c b/drivers/acpi/utilities/utmisc.c index 1f057b7..0a340b0 100644 --- a/drivers/acpi/utilities/utmisc.c +++ b/drivers/acpi/utilities/utmisc.c @@ -1028,6 +1028,7 @@ acpi_ut_error(char *module_name, u32 line_number, char *format, ...) { va_list args; + warn_on_slowpath(module_name, line_number); acpi_os_printf("ACPI Error (%s-%04d): ", module_name, line_number); va_start(args, format); @@ -1042,6 +1043,7 @@ acpi_ut_exception(char *module_name, { va_list args; + warn_on_slowpath(module_name, line_number); acpi_os_printf("ACPI Exception (%s-%04d): %s, ", module_name, line_number, acpi_format_exception(status)); Was there any particular reason for doing it this way? It's really quite wrong, given that an architecture can provide its own definition of WARN_ON() and __WARN() and might not even implement warn_on_slowpath() at all. The usual way of doing this is to go in via the front door: WARN_ON(1).