From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932214AbWDKAiz (ORCPT ); Mon, 10 Apr 2006 20:38:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932218AbWDKAiz (ORCPT ); Mon, 10 Apr 2006 20:38:55 -0400 Received: from saraswathi.solana.com ([198.99.130.12]:13028 "EHLO saraswathi.solana.com") by vger.kernel.org with ESMTP id S932214AbWDKAiy (ORCPT ); Mon, 10 Apr 2006 20:38:54 -0400 Message-Id: <200604102340.k3ANe2TW006880@ccure.user-mode-linux.org> X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.0.4 To: akpm@osdl.org cc: linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net, "S A" Subject: [PATCH 4/3] UML - Add missing __volatile__ Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 10 Apr 2006 19:40:02 -0400 From: Jeff Dike Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org We were missing __volatile__ on some bits of asm in the segfault handlers. On x86_64, this was messing up the move from %rdx to uc because that was moved to after the GET_FAULTINFO_FROM_SC, which changed %rdx. Also changed the other bit of asm and the one in the i386 handler to prevent any similar occurrences. Signed-off-by: Jeff Dike Index: linux-2.6.16-mm/arch/um/sys-x86_64/stub_segv.c =================================================================== --- linux-2.6.16-mm.orig/arch/um/sys-x86_64/stub_segv.c 2006-01-03 17:39:46.000000000 -0500 +++ linux-2.6.16-mm/arch/um/sys-x86_64/stub_segv.c 2006-04-10 19:56:10.000000000 -0400 @@ -33,7 +33,7 @@ stub_segv_handler(int sig) struct ucontext *uc; int pid; - __asm__("movq %%rdx, %0" : "=g" (uc) :); + __asm__ __volatile__("movq %%rdx, %0" : "=g" (uc) :); GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA), &uc->uc_mcontext); @@ -44,8 +44,8 @@ stub_segv_handler(int sig) * the signal frame. So, we use the ucontext pointer, which we know * already, to get the signal frame pointer, and add 8 to that. */ - __asm__("movq %0, %%rsp; movq %1, %%rax ; syscall": : - "g" ((unsigned long) container_of(uc, struct rt_sigframe, - uc) + 8), - "g" (__NR_rt_sigreturn)); + __asm__ __volatile__("movq %0, %%rsp; movq %1, %%rax ; syscall": : + "g" ((unsigned long) + container_of(uc, struct rt_sigframe, uc) + 8), + "g" (__NR_rt_sigreturn)); } Index: linux-2.6.16-mm/arch/um/sys-i386/stub_segv.c =================================================================== --- linux-2.6.16-mm.orig/arch/um/sys-i386/stub_segv.c 2006-01-03 17:39:46.000000000 -0500 +++ linux-2.6.16-mm/arch/um/sys-i386/stub_segv.c 2006-04-10 19:55:53.000000000 -0400 @@ -27,6 +27,6 @@ stub_segv_handler(int sig) * the stack in its original form when we do the sigreturn here, by * hand. */ - __asm__("mov %0,%%esp ; movl %1, %%eax ; " - "int $0x80" : : "a" (sc), "g" (__NR_sigreturn)); + __asm__ __volatile__("mov %0,%%esp ; movl %1, %%eax ; " + "int $0x80" : : "a" (sc), "g" (__NR_sigreturn)); }