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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 C643AC04E53 for ; Wed, 15 May 2019 11:03:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9834020881 for ; Wed, 15 May 2019 11:03:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557918194; bh=scCfIzNpmx/HUPT7/wV27o0Y/gkLYQtDtefb/hRmiz4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ML8dxSxK+rOtqAh6B2SFKzHsscKMAGKfusvtl+VlKgy0bgotzZ1wPCX2av9c246oh 17QhP9qsqUn6qBxEKqzVmCR7rK/ySVCaTbF5FO6J1mCTmTNCU8rb7aO7UJMlzjP7M4 2HqQXNv/ZY0CDFx9EbZmvyjsfpOebsGx+hRc9Bbc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728105AbfEOLDN (ORCPT ); Wed, 15 May 2019 07:03:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:60732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728083AbfEOLDN (ORCPT ); Wed, 15 May 2019 07:03:13 -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 22DDD20644; Wed, 15 May 2019 11:03:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557918192; bh=scCfIzNpmx/HUPT7/wV27o0Y/gkLYQtDtefb/hRmiz4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=x+/DS1JTc2vzOpVvhkyB2VDHtrUUJ9ICgzwLUMZdW9HX0PBxEELsddGN2QXTRwFzP 1GOPhwbg9LuLhsFN4+Ao5aWCQBisKvgwuxqrkNaQQQ0DsqmfptWNSVj7n13ZeikeLV KeqeV2I9OgRV7lKaiJbS7KOFQQ20UmtS7skCL8v8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Suchanek , Michael Ellerman Subject: [PATCH 4.4 041/266] powerpc/64: Use barrier_nospec in syscall entry Date: Wed, 15 May 2019 12:52:28 +0200 Message-Id: <20190515090723.875913416@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190515090722.696531131@linuxfoundation.org> References: <20190515090722.696531131@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Michael Ellerman 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: Greg Kroah-Hartman --- arch/powerpc/kernel/entry_64.S | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -36,6 +36,7 @@ #include #include #include +#include #ifdef CONFIG_PPC_BOOK3S #include #else @@ -177,6 +178,15 @@ system_call: /* label this so stack tr 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 */