From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:41516 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726700AbeJKXKQ (ORCPT ); Thu, 11 Oct 2018 19:10:16 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Lutomirski , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Ingo Molnar Subject: [PATCH 4.4 04/27] x86/vdso: Fix vDSO syscall fallback asm constraint regression Date: Thu, 11 Oct 2018 17:34:51 +0200 Message-Id: <20181011152534.225856328@linuxfoundation.org> In-Reply-To: <20181011152534.014964888@linuxfoundation.org> References: <20181011152534.014964888@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski commit 02e425668f5c9deb42787d10001a3b605993ad15 upstream. When I added the missing memory outputs, I failed to update the index of the first argument (ebx) on 32-bit builds, which broke the fallbacks. Somehow I must have screwed up my testing or gotten lucky. Add another test to cover gettimeofday() as well. Signed-off-by: Andy Lutomirski Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: stable@vger.kernel.org Fixes: 715bd9d12f84 ("x86/vdso: Fix asm constraints on vDSO syscall fallbacks") Link: http://lkml.kernel.org/r/21bd45ab04b6d838278fa5bebfa9163eceffa13c.1538608971.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/entry/vdso/vclock_gettime.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -147,11 +147,11 @@ notrace static long vdso_fallback_gettim asm ( "mov %%ebx, %%edx \n" - "mov %2, %%ebx \n" + "mov %[clock], %%ebx \n" "call __kernel_vsyscall \n" "mov %%edx, %%ebx \n" : "=a" (ret), "=m" (*ts) - : "0" (__NR_clock_gettime), "g" (clock), "c" (ts) + : "0" (__NR_clock_gettime), [clock] "g" (clock), "c" (ts) : "memory", "edx"); return ret; } @@ -162,11 +162,11 @@ notrace static long vdso_fallback_gtod(s asm ( "mov %%ebx, %%edx \n" - "mov %2, %%ebx \n" + "mov %[tv], %%ebx \n" "call __kernel_vsyscall \n" "mov %%edx, %%ebx \n" : "=a" (ret), "=m" (*tv), "=m" (*tz) - : "0" (__NR_gettimeofday), "g" (tv), "c" (tz) + : "0" (__NR_gettimeofday), [tv] "g" (tv), "c" (tz) : "memory", "edx"); return ret; }