Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 15 Jan 2003 09:06:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 15 Jan 2003 09:06:39 -0500 Received: from [65.193.106.66] ([65.193.106.66]:65048 "EHLO xchangeserver2.storigen.com") by vger.kernel.org with ESMTP id convert rfc822-to-8bit; Wed, 15 Jan 2003 09:06:38 -0500 X-MimeOLE: Produced By Microsoft Exchange V6.0.5762.3 content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Subject: RE: VIA C3 and random SIGTRAP or segfault Date: Wed, 15 Jan 2003 09:15:29 -0500 Message-ID: <7BFCE5F1EF28D64198522688F5449D5AC63352@xchangeserver2.storigen.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: VIA C3 and random SIGTRAP or segfault Thread-Index: AcK8kamBl5aKQjVHS96sjeIrnKt7hwADm9xA From: "Larry Sendlosky" To: "Dave Jones" , "Miklos Szeredi" Cc: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org We're seeing the same thing on a mini-ITX based system. init is segfaulting :(( . We've never seen this on our other non-C3 systems running the same codebase. We've instrumented the kernel to help catch the initial problem, hopefully it will trigger soon. Dave, will the cmov generate a segfault or illegal instr trap (SIGILL?) ? thanks larry -----Original Message----- From: Dave Jones [mailto:davej@codemonkey.org.uk] Sent: Wednesday, January 15, 2003 7:23 AM To: Miklos Szeredi Cc: linux-kernel@vger.kernel.org Subject: Re: VIA C3 and random SIGTRAP or segfault On Wed, Jan 15, 2003 at 10:29:01AM +0100, Miklos Szeredi wrote: > > I just bought a VIA C3 866 processor, and under very special > circumstances some programs (e.g. mplayer, xmms) randomly crash with > trace/breakpoint trap or segmentation fault. Otherwise the system > seems stable even under high load. Be sure that those programs aren't compiled for 686. The C3 lacks cmov, so it'll segfault when it hits that opcode. You can confirm this by running it under gdb, and disassembling where it segv's to. This is still a common problem thats biting some people. The debian folks had a broken libssl for months up until recently. Note to userspace developers: If you're compiling something as a 686 binary, you *NEED* to check the feature flags (in an i386 compiled program) to see if the CPU has cmov before you load 686 optimised parts of your app. This is *NOT* a kernel problem, it is *NOT* a CPU bug. The cmov extension is optional. VIA chose to save silicon space by not implementing it. Gcc unfortunatly always uses cmov when compiling for 686. Dave -- | Dave Jones. http://www.codemonkey.org.uk | SuSE Labs - 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/ - 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/