From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756333AbcHCSDu (ORCPT ); Wed, 3 Aug 2016 14:03:50 -0400 Received: from mail.skyhub.de ([78.46.96.112]:52149 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755211AbcHCSDq (ORCPT ); Wed, 3 Aug 2016 14:03:46 -0400 Date: Wed, 3 Aug 2016 19:54:12 +0200 From: Borislav Petkov To: Andy Lutomirski Cc: X86 ML , LKML Subject: Re: [PATCH] x86/entry: Clarify the RF saving/restoring situation with SYSCALL/SYSRET Message-ID: <20160803175412.GE2590@nazgul.tnic> References: <20160803101924.27247-1-bp@alien8.de> <20160803171429.GA2590@nazgul.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 03, 2016 at 10:24:18AM -0700, Andy Lutomirski wrote: > AFAICT the AMD people didn't think of any use cases involving doing > anything interesting between SYSCALL and SYSRET. Witness the > sysret_ss_attrs goof, for example: apparently SYSCALL; context switch; > IRET; interrupt; context switch; SYSRET didn't occur to AMD as a valid > use case. /me hands Andy a time machine to go fix this properly, before so much silicon ships. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --