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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 28BE5C169C4 for ; Sun, 3 Feb 2019 13:52:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 039A0218D8 for ; Sun, 3 Feb 2019 13:52:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728655AbfBCNuY (ORCPT ); Sun, 3 Feb 2019 08:50:24 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53454 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728209AbfBCNtx (ORCPT ); Sun, 3 Feb 2019 08:49:53 -0500 Received: from cable-78.29.236.164.coditel.net ([78.29.236.164] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gqI9f-0003to-Al; Sun, 03 Feb 2019 13:49:51 +0000 Received: from ben by deadeye with local (Exim 4.92-RC4) (envelope-from ) id 1gqI9b-00074B-Jv; Sun, 03 Feb 2019 14:49:47 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Max Filippov" Date: Sun, 03 Feb 2019 14:45:08 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 143/305] xtensa: make sure bFLT stack is 16 byte aligned In-Reply-To: X-SA-Exim-Connect-IP: 78.29.236.164 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.63-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Max Filippov commit 0773495b1f5f1c5e23551843f87b5ff37e7af8f7 upstream. Xtensa ABI requires stack alignment to be at least 16. In noMMU configuration ARCH_SLAB_MINALIGN is used to align stack. Make it at least 16. This fixes the following runtime error in noMMU configuration, caused by interaction between insufficiently aligned stack and alloca function, that results in corruption of on-stack variable in the libc function glob: Caught unhandled exception in 'sh' (pid = 47, pc = 0x02d05d65) - should not happen EXCCAUSE is 15 Signed-off-by: Max Filippov Signed-off-by: Ben Hutchings --- arch/xtensa/include/asm/processor.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/arch/xtensa/include/asm/processor.h +++ b/arch/xtensa/include/asm/processor.h @@ -25,7 +25,11 @@ # error Linux requires the Xtensa Windowed Registers Option. #endif -#define ARCH_SLAB_MINALIGN XCHAL_DATA_WIDTH +/* Xtensa ABI requires stack alignment to be at least 16 */ + +#define STACK_ALIGN (XCHAL_DATA_WIDTH > 16 ? XCHAL_DATA_WIDTH : 16) + +#define ARCH_SLAB_MINALIGN STACK_ALIGN /* * User space process size: 1 GB.