From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 27 Jul 2015 22:02:55 +0200 (CEST) Received: from mailapp01.imgtec.com ([195.59.15.196]:37478 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27011425AbbG0UCWuexWX (ORCPT ); Mon, 27 Jul 2015 22:02:22 +0200 Received: from KLMAIL01.kl.imgtec.org (unknown [192.168.5.35]) by Websense Email Security Gateway with ESMTPS id 0FD38C27C710E; Mon, 27 Jul 2015 21:02:13 +0100 (IST) Received: from LEMAIL01.le.imgtec.org (192.168.152.62) by KLMAIL01.kl.imgtec.org (192.168.5.35) with Microsoft SMTP Server (TLS) id 14.3.195.1; Mon, 27 Jul 2015 21:02:16 +0100 Received: from localhost (10.100.200.213) by LEMAIL01.le.imgtec.org (192.168.152.62) with Microsoft SMTP Server (TLS) id 14.3.210.2; Mon, 27 Jul 2015 21:02:16 +0100 Date: Mon, 27 Jul 2015 13:02:14 -0700 From: Paul Burton To: Guenter Roeck , Ralf Baechle CC: , , Subject: Re: Crash in -next due to 'MIPS: Move FP usage checks into protected_{save, restore}_fp_context' Message-ID: <20150727200214.GH7289@NP-P-BURTON> References: <20150715160918.GA27653@roeck-us.net> <20150727150652.GA1756@roeck-us.net> <20150727172142.GE7289@NP-P-BURTON> <20150727174622.GA10708@roeck-us.net> <20150727180442.GG7289@NP-P-BURTON> <20150727194401.GC14674@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline In-Reply-To: <20150727194401.GC14674@roeck-us.net> User-Agent: Mutt/1.5.23 (2014-03-12) X-Originating-IP: [10.100.200.213] Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 48470 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: paul.burton@imgtec.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On Mon, Jul 27, 2015 at 12:44:01PM -0700, Guenter Roeck wrote: > On Mon, Jul 27, 2015 at 11:04:42AM -0700, Paul Burton wrote: > > On Mon, Jul 27, 2015 at 10:46:22AM -0700, Guenter Roeck wrote: > > > On Mon, Jul 27, 2015 at 10:21:42AM -0700, Paul Burton wrote: > > > > On Mon, Jul 27, 2015 at 08:06:52AM -0700, Guenter Roeck wrote: > > > > > On Wed, Jul 15, 2015 at 09:09:18AM -0700, Guenter Roeck wrote: > > > > > > Hi, > > > > > > > > > > > my qemu test for mipsel crashes with next-20150715 as follows. > > > > > > > > > > > ping ... problem is still seen as of next-20150727. > > > > > > > > Hi Guenter, > > > > > > > > Apologies for the delay. Could you share your affected kernel > > > > configuration & which userland you're running? > > > > > > > > I've just tested with a malta_defconfig kernel & a buildroot based > > > > initramfs without problems, and things are also fine on my physical > > > > MIPSr6 setups. If you have any directions with which I can reproduce > > > > this problem that would be great. > > > > > > > This is with qemu in little endian mode. Big endian works fine. > > > > Yup, I was using little endian in both cases. malta_defconfig is little > > endian - sadly use of the el suffix is pretty inconsistent... > > > > Hi Paul, > > some more data: > > I tried with mipsel64, using malta_defconfig from 4.2-rc4 as starting point. > Same failure. All releases from 3.2 up to 4.2-rc4 pass the test, linux-next > as of today fails. > > Here is the log: > > http://server.roeck-us.net:8010/builders/qemu-mipsel64-next/builds/0/steps/qemubuildcommand/logs/stdio > > I pushed the initramfs, configuration, and test script into rootfs/mipsel64 > of https://github.com/groeck/linux-build-test. Hi Guenter, I'm currently mailing out v2 of the series which should fix your problem. It was an issue where the kernel would check the FP context for whether a SIGFPE should be generated even in cases where FP had not been used by userland, and thus had not been initialised. My userland is hard float & thus makes use of the FPU early whilst I believe yours is soft float, which explains the difference in behaviour. I think the endian difference probably boils down to what garbage the initial FP context contained. Ralf: can you update the patches in -next please? Thanks, Paul From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailapp01.imgtec.com ([195.59.15.196]:37478 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27011425AbbG0UCWuexWX (ORCPT ); Mon, 27 Jul 2015 22:02:22 +0200 Date: Mon, 27 Jul 2015 13:02:14 -0700 From: Paul Burton Subject: Re: Crash in -next due to 'MIPS: Move FP usage checks into protected_{save, restore}_fp_context' Message-ID: <20150727200214.GH7289@NP-P-BURTON> References: <20150715160918.GA27653@roeck-us.net> <20150727150652.GA1756@roeck-us.net> <20150727172142.GE7289@NP-P-BURTON> <20150727174622.GA10708@roeck-us.net> <20150727180442.GG7289@NP-P-BURTON> <20150727194401.GC14674@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline In-Reply-To: <20150727194401.GC14674@roeck-us.net> Return-Path: Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-subscribe: List-owner: List-post: List-archive: To: Guenter Roeck , Ralf Baechle Cc: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@linux-mips.org Message-ID: <20150727200214.0CPTUv2YO4ZkJSMocKxVcBmSvL9zNkg5W5v-HnWxJOc@z> On Mon, Jul 27, 2015 at 12:44:01PM -0700, Guenter Roeck wrote: > On Mon, Jul 27, 2015 at 11:04:42AM -0700, Paul Burton wrote: > > On Mon, Jul 27, 2015 at 10:46:22AM -0700, Guenter Roeck wrote: > > > On Mon, Jul 27, 2015 at 10:21:42AM -0700, Paul Burton wrote: > > > > On Mon, Jul 27, 2015 at 08:06:52AM -0700, Guenter Roeck wrote: > > > > > On Wed, Jul 15, 2015 at 09:09:18AM -0700, Guenter Roeck wrote: > > > > > > Hi, > > > > > > > > > > > my qemu test for mipsel crashes with next-20150715 as follows. > > > > > > > > > > > ping ... problem is still seen as of next-20150727. > > > > > > > > Hi Guenter, > > > > > > > > Apologies for the delay. Could you share your affected kernel > > > > configuration & which userland you're running? > > > > > > > > I've just tested with a malta_defconfig kernel & a buildroot based > > > > initramfs without problems, and things are also fine on my physical > > > > MIPSr6 setups. If you have any directions with which I can reproduce > > > > this problem that would be great. > > > > > > > This is with qemu in little endian mode. Big endian works fine. > > > > Yup, I was using little endian in both cases. malta_defconfig is little > > endian - sadly use of the el suffix is pretty inconsistent... > > > > Hi Paul, > > some more data: > > I tried with mipsel64, using malta_defconfig from 4.2-rc4 as starting point. > Same failure. All releases from 3.2 up to 4.2-rc4 pass the test, linux-next > as of today fails. > > Here is the log: > > http://server.roeck-us.net:8010/builders/qemu-mipsel64-next/builds/0/steps/qemubuildcommand/logs/stdio > > I pushed the initramfs, configuration, and test script into rootfs/mipsel64 > of https://github.com/groeck/linux-build-test. Hi Guenter, I'm currently mailing out v2 of the series which should fix your problem. It was an issue where the kernel would check the FP context for whether a SIGFPE should be generated even in cases where FP had not been used by userland, and thus had not been initialised. My userland is hard float & thus makes use of the FPU early whilst I believe yours is soft float, which explains the difference in behaviour. I think the endian difference probably boils down to what garbage the initial FP context contained. Ralf: can you update the patches in -next please? Thanks, Paul