Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754446Ab1DFQHH (ORCPT ); Wed, 6 Apr 2011 12:07:07 -0400 Received: from va3ehsobe003.messaging.microsoft.com ([216.32.180.13]:34595 "EHLO VA3EHSOBE003.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751202Ab1DFQHF (ORCPT ); Wed, 6 Apr 2011 12:07:05 -0400 X-SpamScore: 1 X-BigFish: VPS1(zzzz1202hzz8275bhz32i668h839h61h) X-Spam-TCS-SCL: 0:0 X-Forefront-Antispam-Report: KIP:(null);UIP:(null);IPVD:NLI;H:ausb3twp01.amd.com;RD:none;EFVD:NLI X-WSS-ID: 0LJ8NFF-01-82E-02 X-M-MSG: From: Hans Rosenfeld To: , CC: , , , , , , Hans Rosenfeld Subject: [PATCH] x86-32, fpu: Fix FPU exception handling on non-SSE systems Date: Wed, 6 Apr 2011 18:06:43 +0200 Message-ID: <1302106003-366952-1-git-send-email-hans.rosenfeld@amd.com> X-Mailer: git-send-email 1.5.6.5 In-Reply-To: <1302024392-610677-1-git-send-email-hans.rosenfeld@amd.com> References: <1302024392-610677-1-git-send-email-hans.rosenfeld@amd.com> MIME-Version: 1.0 Content-Type: text/plain X-OriginatorOrg: amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2499 Lines: 61 On 32bit systems without SSE (that is, they use FSAVE/FRSTOR for FPU context switches), FPU exceptions in user mode cause Oopses, BUGs, recursive faults and other nasty things: fpu exception: 0000 [#1] last sysfs file: /sys/power/state Modules linked in: psmouse evdev pcspkr serio_raw [last unloaded: scsi_wait_scan] Pid: 1638, comm: fxsave-32-excep Not tainted 2.6.35-07798-g58a992b-dirty #633 VP3-596B-DD/VT82C597 EIP: 0060:[] EFLAGS: 00010202 CPU: 0 EIP is at math_error+0x1b4/0x1c8 EAX: 00000003 EBX: cf9be7e0 ECX: 00000000 EDX: cf9c5c00 ESI: cf9d9fb4 EDI: c1372db3 EBP: 00000010 ESP: cf9d9f1c DS: 007b ES: 007b FS: 0000 GS: 00e0 SS: 0068 Process fxsave-32-excep (pid: 1638, ti=cf9d8000 task=cf9be7e0 task.ti=cf9d8000) Stack: 00000000 00000301 00000004 00000000 00000000 cf9d3000 cf9da8f0 00000001 <0> 00000004 cf9b6b60 c1019a6b c1019a79 00000020 00000242 000001b6 cf9c5380 <0> cf806b40 cf791880 00000000 00000282 00000282 c108a213 00000020 cf9c5380 Call Trace: [] ? need_resched+0x11/0x1a [] ? should_resched+0x5/0x1f [] ? do_sys_open+0xbd/0xc7 [] ? do_sys_open+0xbd/0xc7 [] ? do_coprocessor_error+0x0/0x11 [] ? error_code+0x65/0x70 Code: a8 20 74 30 c7 44 24 0c 06 00 03 00 8d 54 24 04 89 d9 b8 08 00 00 00 e8 9b 6d 02 00 eb 16 8b 93 5c 02 00 00 eb 05 e9 04 ff ff ff <9b> dd 32 9b e9 16 ff ff ff 81 c4 84 00 00 00 5b 5e 5f 5d c3 c6 EIP: [] math_error+0x1b4/0x1c8 SS:ESP 0068:cf9d9f1c This usually continues in slight variations until the system is reset. This bug was introduced by commit 58a992b9cbaf449aeebd3575c3695a9eb5d95b5e: x86-32, fpu: Rewrite fpu_save_init() Signed-off-by: Hans Rosenfeld --- arch/x86/include/asm/i387.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h index ef32890..c9e09ea 100644 --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -237,7 +237,7 @@ static inline void fpu_save_init(struct fpu *fpu) } else if (use_fxsr()) { fpu_fxsave(fpu); } else { - asm volatile("fsave %[fx]; fwait" + asm volatile("fnsave %[fx]; fwait" : [fx] "=m" (fpu->state->fsave)); return; } -- 1.5.6.5 -- 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/