From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751967AbeEQVds (ORCPT ); Thu, 17 May 2018 17:33:48 -0400 Received: from mail-wr0-f172.google.com ([209.85.128.172]:46362 "EHLO mail-wr0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750924AbeEQVdr (ORCPT ); Thu, 17 May 2018 17:33:47 -0400 X-Google-Smtp-Source: AB8JxZoKk8NOSyFJAv5hs6NbA1Oj6npL+onGZzEGwrEHN2zj2DabBBP0koahWCjsE7alrMDNvERCxw== Date: Fri, 18 May 2018 00:33:43 +0300 From: Alexey Dobriyan To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Cc: x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/3] x86: verify_cpu: restore flags later Message-ID: <20180517213343.GC4047@avx2> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org popf xor eax, eax formally doesn't restore flags because XOR clobber flags. Do POPF as last instruction and rearrange the other case for symmetry. Signed-off-by: Alexey Dobriyan --- arch/x86/kernel/verify_cpu.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/verify_cpu.S +++ b/arch/x86/kernel/verify_cpu.S @@ -132,11 +132,11 @@ ENTRY(verify_cpu) jmp .Lverify_cpu_sse_test # try again .Lverify_cpu_no_longmode: - popf # Restore caller passed flags movl $1,%eax + popf # Restore caller passed flags ret .Lverify_cpu_sse_ok: - popf # Restore caller passed flags xorl %eax, %eax + popf # Restore caller passed flags ret ENDPROC(verify_cpu)