From patchwork Sat Jan 20 19:22:54 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KarimAllah Ahmed X-Patchwork-Id: 10176671 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 33ADD6056F for ; Sat, 20 Jan 2018 19:24:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1FC44205AF for ; Sat, 20 Jan 2018 19:24:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 142BC205AD; Sat, 20 Jan 2018 19:24:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 897C5205AF for ; Sat, 20 Jan 2018 19:24:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932690AbeATTYE (ORCPT ); Sat, 20 Jan 2018 14:24:04 -0500 Received: from smtp-fw-33001.amazon.com ([207.171.190.10]:49196 "EHLO smtp-fw-33001.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932562AbeATTXs (ORCPT ); Sat, 20 Jan 2018 14:23:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazon201209; t=1516476227; x=1548012227; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=1GTayTy8nk5BwNQrcIcRPKQ1G24jirQNjNDNfrtuUDA=; b=d62zcGcb0V0G61tud+yd1WRe5A/IGyJVJkDdOPnOCeXPl9QG7ubW5cOw 5WV7EMDYwG4h3nt22zLWaWfoa2Tfcko1MINIMBFLiFi4L0d0W8DDEMPn2 37Agjw7MW2DzqBQiivV0r3/YkNPevp62ISME6RfGOLx3zBdCyVvz8J64k Q=; X-IronPort-AV: E=Sophos;i="5.46,387,1511827200"; d="scan'208";a="716423176" Received: from sea3-co-svc-lb6-vlan2.sea.amazon.com (HELO email-inbound-relay-1e-303d0b0e.us-east-1.amazon.com) ([10.47.22.34]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 20 Jan 2018 19:23:42 +0000 Received: from u54e1ad5160425a4b64ea.ant.amazon.com (iad1-ws-svc-lb91-vlan3.amazon.com [10.0.103.150]) by email-inbound-relay-1e-303d0b0e.us-east-1.amazon.com (8.14.7/8.14.7) with ESMTP id w0KJNRhn129147 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 20 Jan 2018 19:23:29 GMT Received: from u54e1ad5160425a4b64ea.ant.amazon.com (localhost [127.0.0.1]) by u54e1ad5160425a4b64ea.ant.amazon.com (8.15.2/8.15.2/Debian-3) with ESMTP id w0KJNPJ3005256; Sat, 20 Jan 2018 20:23:25 +0100 Received: (from karahmed@localhost) by u54e1ad5160425a4b64ea.ant.amazon.com (8.15.2/8.15.2/Submit) id w0KJNNRr005255; Sat, 20 Jan 2018 20:23:23 +0100 From: KarimAllah Ahmed To: linux-kernel@vger.kernel.org Cc: KarimAllah Ahmed , Andi Kleen , Andrea Arcangeli , Andy Lutomirski , Arjan van de Ven , Ashok Raj , Asit Mallick , Borislav Petkov , Dan Williams , Dave Hansen , David Woodhouse , Greg Kroah-Hartman , "H . Peter Anvin" , Ingo Molnar , Janakarajan Natarajan , Joerg Roedel , Jun Nakajima , Laura Abbott , Linus Torvalds , Masami Hiramatsu , Paolo Bonzini , Peter Zijlstra , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Thomas Gleixner , Tim Chen , Tom Lendacky , kvm@vger.kernel.org, x86@kernel.org Subject: [RFC 03/10] x86/speculation: Use Indirect Branch Prediction Barrier in context switch Date: Sat, 20 Jan 2018 20:22:54 +0100 Message-Id: <1516476182-5153-4-git-send-email-karahmed@amazon.de> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1516476182-5153-1-git-send-email-karahmed@amazon.de> References: <1516476182-5153-1-git-send-email-karahmed@amazon.de> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Thomas Gleixner [peterz: comment] Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: David Woodhouse --- arch/x86/mm/tlb.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index a156195..304de7d 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -6,13 +6,14 @@ #include #include #include +#include #include #include +#include #include #include #include -#include /* * TLB flushing, formerly SMP-only @@ -220,6 +221,13 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, u16 new_asid; bool need_flush; + /* + * Avoid user/user BTB poisoning by flushing the branch predictor + * when switching between processes. This stops one process from + * doing Spectre-v2 attacks on another. + */ + indirect_branch_prediction_barrier(); + if (IS_ENABLED(CONFIG_VMAP_STACK)) { /* * If our current stack is in vmalloc space and isn't