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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 B2912C10F0E for ; Mon, 15 Apr 2019 18:45:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D8B62073F for ; Mon, 15 Apr 2019 18:45:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555353957; bh=n4inz8fgTcSK7q+sPQjPtVdlfG1PqBQbmbjq/62cAfs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=n4w8mDmEJv/8LOompvgijdxNNbZdAPhDOKr5geKzTKrTldwSrfXbPvzyTwUjgTacJ sjdAIPK9822O4UaDz4B5Hs/PXnmiub5LD8UChrzZBKgWzimeskNK17N2M+bpNQ42q+ 1RWMKrgcN+xMjGsqfgvPbROCxvJ1qUhIU2fW+gxo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728484AbfDOSp4 (ORCPT ); Mon, 15 Apr 2019 14:45:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:48382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728473AbfDOSpx (ORCPT ); Mon, 15 Apr 2019 14:45:53 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A308B2073F; Mon, 15 Apr 2019 18:45:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555353953; bh=n4inz8fgTcSK7q+sPQjPtVdlfG1PqBQbmbjq/62cAfs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xGa3V8N9VghJvZtRGY6//0a/jqpyXHNL+5VK7u/CwiJPNNhAjEe2clY1nvaxabiwW 9gOzFi02VwGV8TbuRcJxjs6SxvDxiIJ28i+EzzlG+y/kwlciWD3DCFbwGWY+bUKNEo 4cPhlp59RKNGYrHnV4pfE0nMag+TaYV3f7CYC2KQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Suchanek , Michael Ellerman , Sasha Levin Subject: [PATCH 4.9 17/76] powerpc/64: Use barrier_nospec in syscall entry Date: Mon, 15 Apr 2019 20:43:41 +0200 Message-Id: <20190415183712.229837735@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190415183707.712011689@linuxfoundation.org> References: <20190415183707.712011689@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 Signed-off-by: Sasha Levin --- 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 */ -- 2.19.1