Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753362Ab0H1QGO (ORCPT ); Sat, 28 Aug 2010 12:06:14 -0400 Received: from mail-yw0-f46.google.com ([209.85.213.46]:44080 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752882Ab0H1QGN (ORCPT ); Sat, 28 Aug 2010 12:06:13 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=ikNeqbO/uvsJ754ZxYKIqSLm5bATpvJSJOx0dwydvUSLZnGnRFKUdC0XC3ShEo3yyX pT5hbNsGJkNC+kTKQjuLxsc57LmH6r1wbcZsmj/0ZwC0QUgYQQSYT8CwjqxZDKa078JU WU8IDXIkKtUgM7hgTj+YK0HSMfr5mL72pj7UI= From: Brian Gerst To: hpa@zytor.com Cc: x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 06/11] x86-64: Fix %cs value in convert_from_fxsr() Date: Sat, 28 Aug 2010 12:04:33 -0400 Message-Id: <1283011478-27237-7-git-send-email-brgerst@gmail.com> X-Mailer: git-send-email 1.7.2.2 In-Reply-To: <1283011478-27237-1-git-send-email-brgerst@gmail.com> References: <1283011478-27237-1-git-send-email-brgerst@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1710 Lines: 51 While %ds still contains the userspace selector, %cs is KERNEL_CS at this point. Always get %cs from pt_regs. It actually is possible to get the correct segments for compat tasks, but that involves using the [f]xsave instruction without a REX.W prefix. Signed-off-by: Brian Gerst --- arch/x86/kernel/i387.c | 18 ++++++++---------- 1 files changed, 8 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index c795675..b1a732d 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -383,19 +383,17 @@ convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk) #ifdef CONFIG_X86_64 env->fip = fxsave->rip; env->foo = fxsave->rdp; + /* + * should be actually ds/cs at fpu exception time, but + * that information is not available in 64bit mode. + */ + env->fcs = task_pt_regs(tsk)->cs; if (tsk == current) { - /* - * should be actually ds/cs at fpu exception time, but - * that information is not available in 64bit mode. - */ - asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos)); - asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs)); + savesegment(ds, env->fos); } else { - struct pt_regs *regs = task_pt_regs(tsk); - - env->fos = 0xffff0000 | tsk->thread.ds; - env->fcs = regs->cs; + env->fos = tsk->thread.ds; } + env->fos |= 0xffff0000; #else env->fip = fxsave->fip; env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16); -- 1.7.2.2 -- 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/