From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937401AbXFHCFA (ORCPT ); Thu, 7 Jun 2007 22:05:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932156AbXFHCEx (ORCPT ); Thu, 7 Jun 2007 22:04:53 -0400 Received: from shawidc-mo1.cg.shawcable.net ([24.71.223.10]:33452 "EHLO pd2mo1so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764091AbXFHCEw (ORCPT ); Thu, 7 Jun 2007 22:04:52 -0400 Date: Thu, 07 Jun 2007 20:04:41 -0600 From: Robert Hancock Subject: Re: [PATCH] Make i386 kernel show the segfaults in kernel dmesg, like x86_64. In-reply-to: To: Masoud Asgharifard Sharbiani Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org Message-id: <4668B939.1070304@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit References: User-Agent: Thunderbird 2.0.0.0 (Windows/20070326) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Masoud Asgharifard Sharbiani wrote: > Hello, > This patch makes the i386 behave the same way that x86_64 does when a > segfault happens. A line gets printed to the kernel log so that tools > that need to check for failures can behave more uniformly between > different kernels. Like x86_64, it can be disabled by setting > debug.exception-trace sysctl variable to 0 (or by doing > echo 0 > /proc/sys/debug/exception-trace) > > Same behaviour can be extended to other architectures, if needed. > cheers, > Masoud. > > Signed-off-by: Masoud Sharbiani > > diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c > index 29d7d61..6aa56db 100644 > --- a/arch/i386/mm/fault.c > +++ b/arch/i386/mm/fault.c > @@ -283,6 +283,8 @@ static inline int vmalloc_fault(unsigned long address) > return 0; > } > > +int exception_trace = 1; > + > /* > * This routine handles page faults. It determines the address, > * and the problem, and then passes it off to one of the appropriate > @@ -464,7 +466,14 @@ bad_area_nosemaphore: > */ > if (is_prefetch(regs, address, error_code)) > return; > - > + if (exception_trace && unhandled_signal(tsk, SIGSEGV)) { > + printk( > + "%s%s[%d]: segfault at %08lx eip %08lx esp %08lx error %lx\n", > + tsk->pid > 1 ? KERN_INFO : KERN_EMERG, > + tsk->comm, tsk->pid, address, regs->eip, > + regs->esp, error_code); Shouldn't we use printk_ratelimit() here, to prevent some nasty person from creating some rapidly-segfaulting process that floods the kernel logs? (Same with the x86_64 version if it doesn't already..) -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/