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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 62748C5B57D for ; Wed, 3 Jul 2019 02:16:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3BB2121882 for ; Wed, 3 Jul 2019 02:16:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562120218; bh=7890ukGK0uvbgV0YXqAeFAMoskfJQ11r8d0ywwmtTuk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FMNJGaufb0sb3ZAogxh4rn8jxS3JSbSoonU4l79F0K8oKn0Y+fOfy39M3qx7MokoM bZyowyOh8bFOCgVbBgH6a7+qgxFX+r/72znQVlCKvdixSL0OWTQTgt7lgo3eH0hlmR I+Tw0UCdpWFezeWOGp3PM/v/Fz6UmkELZ7Sh6xCM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728110AbfGCCQ4 (ORCPT ); Tue, 2 Jul 2019 22:16:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:55288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728096AbfGCCQy (ORCPT ); Tue, 2 Jul 2019 22:16:54 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4B0E221873; Wed, 3 Jul 2019 02:16:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562120213; bh=7890ukGK0uvbgV0YXqAeFAMoskfJQ11r8d0ywwmtTuk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CPWny0WDUqZ3O05J4zRNRA9eqokRXiMyUY6lS+nTd8CtdlPI80txsRy4qZtWs2tQU Eqo6z1ubQaOl4Y7mkncP/0GH7paDdOflGM9oJfmDrS03xwtyPZEj0M6Gzc8kpI3w6w ERTt62CuCVYjkgFhDXjanpzv/yBsJYatepz+EFxU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Kirill A. Shutemov" , "Kirill A . Shutemov" , Thomas Gleixner , Borislav Petkov , "H. Peter Anvin" , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Alexander Potapenko , Sasha Levin , clang-built-linux@googlegroups.com Subject: [PATCH AUTOSEL 4.19 20/26] x86/boot/64: Add missing fixup_pointer() for next_early_pgt access Date: Tue, 2 Jul 2019 22:16:19 -0400 Message-Id: <20190703021625.18116-20-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190703021625.18116-1-sashal@kernel.org> References: <20190703021625.18116-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Kirill A. Shutemov" [ Upstream commit c1887159eb48ba40e775584cfb2a443962cf1a05 ] __startup_64() uses fixup_pointer() to access global variables in a position-independent fashion. Access to next_early_pgt was wrapped into the helper, but one instance in the 5-level paging branch was missed. GCC generates a R_X86_64_PC32 PC-relative relocation for the access which doesn't trigger the issue, but Clang emmits a R_X86_64_32S which leads to an invalid memory access and system reboot. Fixes: 187e91fe5e91 ("x86/boot/64/clang: Use fixup_pointer() to access 'next_early_pgt'") Signed-off-by: Kirill A. Shutemov Signed-off-by: Thomas Gleixner Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Dave Hansen Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: Alexander Potapenko Link: https://lkml.kernel.org/r/20190620112422.29264-1-kirill.shutemov@linux.intel.com Signed-off-by: Sasha Levin --- arch/x86/kernel/head64.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index cc5b519dc687..250cfa85b633 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -184,7 +184,8 @@ unsigned long __head __startup_64(unsigned long physaddr, pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask(); if (la57) { - p4d = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr); + p4d = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], + physaddr); i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD; pgd[i + 0] = (pgdval_t)p4d + pgtable_flags; -- 2.20.1