From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754264AbcHWRXw (ORCPT ); Tue, 23 Aug 2016 13:23:52 -0400 Received: from mail.skyhub.de ([78.46.96.112]:37966 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754038AbcHWRXu (ORCPT ); Tue, 23 Aug 2016 13:23:50 -0400 From: Borislav Petkov To: X86 ML Cc: LKML Subject: [PATCH] x86/CPU: Remove outdated comment about SYSCALL targets Date: Tue, 23 Aug 2016 19:23:56 +0200 Message-Id: <20160823172356.15879-1-bp@alien8.de> X-Mailer: git-send-email 2.8.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov The comment probably meant some old AMD64 incarnation which most likely never saw the light of day. STAR and LSTAR are two different registers and STAR sets CS/SS(DS) selectors for *all* modes, not only 32-bit. So simply remove that comment. Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/common.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index ce7a4c17f1bc..06919427d451 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1310,11 +1310,6 @@ static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks /* May not be marked __init: used by software suspend */ void syscall_init(void) { - /* - * LSTAR and STAR live in a bit strange symbiosis. - * They both write to the same internal register. STAR allows to - * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip. - */ wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS); wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64); -- 2.8.4