From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linutronix.de (146.0.238.70:993) by crypto-ml.lab.linutronix.de with IMAP4-SSL for ; 11 Dec 2018 00:04:12 -0000 Received: from mga07.intel.com ([134.134.136.100]) by Galois.linutronix.de with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1gWVX0-000808-T5 for speck@linutronix.de; Tue, 11 Dec 2018 01:04:11 +0100 Date: Mon, 10 Dec 2018 16:03:59 -0800 From: Andi Kleen Subject: [MODERATED] Re: [PATCH v2 2/8] MDSv2 1 Message-ID: <20181211000359.GC16024@tassilo.jf.intel.com> References: MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: speck@linutronix.de List-ID: On Mon, Dec 10, 2018 at 11:49:43PM +0100, speck for Jiri Kosina wrote: > On Mon, 10 Dec 2018, speck for Andi Kleen wrote: > > > From: Andi Kleen > > Subject: x86/speculation/mds: Clear CPU buffers on kernel exit > > for 64bit > [ ... snip ... ] > > +.macro EXIT_MDS > > + /* Clear CPU buffers that could leak. Instruction must be in memory form. */ > > + ALTERNATIVE_2 "", __stringify(push $__USER_DS ; verw (% _ASM_SP ) ; add $8, % _ASM_SP ),\ > > + X86_FEATURE_MB_CLEAR, \ > > + "call do_clear_cpu", \ > > + X86_BUG_MDS_CLEAR_CPU > > The software clearing sequence is introduced later in the series, so this > seems not to be bisectable. Yes good point. Looks like I mismerged a hunk. Will fix. -Andi