From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 917C1C282DA for ; Thu, 11 Apr 2019 11:46:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68D982184B for ; Thu, 11 Apr 2019 11:46:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726636AbfDKLqq (ORCPT ); Thu, 11 Apr 2019 07:46:46 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:44451 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726264AbfDKLqq (ORCPT ); Thu, 11 Apr 2019 07:46:46 -0400 Received: by ozlabs.org (Postfix, from userid 1034) id 44fzl84R74z9sMQ; Thu, 11 Apr 2019 21:46:44 +1000 (AEST) From: Michael Ellerman To: stable@vger.kernel.org, gregkh@linuxfoundation.org Cc: linuxppc-dev@ozlabs.org, diana.craciun@nxp.com, msuchanek@suse.de, christophe.leroy@c-s.fr Subject: [PATCH stable v4.9 08/35] powerpc/64: Use barrier_nospec in syscall entry Date: Thu, 11 Apr 2019 21:46:03 +1000 Message-Id: <20190411114630.4042-9-mpe@ellerman.id.au> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190411114630.4042-1-mpe@ellerman.id.au> References: <20190411114630.4042-1-mpe@ellerman.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit 51973a815c6b46d7b23b68d6af371ad1c9d503ca upstream. Our syscall entry is done in assembly so patch in an explicit barrier_nospec. Based on a patch by Michal Suchanek. Signed-off-by: Michal Suchanek Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/entry_64.S | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index e24ae0fa80ed..11e390662384 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -38,6 +38,7 @@ #include #include #include +#include #include #ifdef CONFIG_PPC_BOOK3S #include @@ -180,6 +181,15 @@ system_call: /* label this so stack traces look sane */ clrldi r8,r8,32 15: slwi r0,r0,4 + + barrier_nospec_asm + /* + * Prevent the load of the handler below (based on the user-passed + * system call number) being speculatively executed until the test + * against NR_syscalls and branch to .Lsyscall_enosys above has + * committed. + */ + ldx r12,r11,r0 /* Fetch system call handler [ptr] */ mtctr r12 bctrl /* Call handler */ -- 2.20.1