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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,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 2B431C67790 for ; Wed, 25 Jul 2018 13:45:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D87BE2088E for ; Wed, 25 Jul 2018 13:45:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D87BE2088E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729375AbeGYO5D (ORCPT ); Wed, 25 Jul 2018 10:57:03 -0400 Received: from foss.arm.com ([217.140.101.70]:39022 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729308AbeGYO5C (ORCPT ); Wed, 25 Jul 2018 10:57:02 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7DF2B15A2; Wed, 25 Jul 2018 06:45:17 -0700 (PDT) Received: from edgewater-inn.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 5044A3F6A8; Wed, 25 Jul 2018 06:45:17 -0700 (PDT) Received: by edgewater-inn.cambridge.arm.com (Postfix, from userid 1000) id 48CDA1AE0851; Wed, 25 Jul 2018 14:45:17 +0100 (BST) From: Will Deacon To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, arnd@arndb.de, linux@dominikbrodowski.net, ebiederm@xmission.com, akpm@linux-foundation.org, viro@zeniv.linux.org.uk, oleg@redhat.com, steve.mcintyre@arm.com, dave.martin@arm.com, Will Deacon Subject: [PATCH 0/2] Don't use SIGMINSTKSZ when enforcing alternative signal stack size for compat tasks Date: Wed, 25 Jul 2018 14:45:10 +0100 Message-Id: <1532526312-26993-1-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, The Debian folks have observed a failure in the 32-bit arm glibc testsuite when running under a 64-bit kernel. They tracked this down to sigaltstack(2) enforcing the alternative signal stack to be at least SIGMINSTKSZ bytes, which is higher for native arm64 tasks than compat 32-bit tasks. These patches resolve the issue by allowing an architecture to define COMPAT_SIGMINSTKSZ for compat tasks, which is then used by the sigaltstack checking code. Feedback welcome, Will --->8 Will Deacon (2): signal: Introduce COMPAT_SIGMINSTKSZ for use in compat_sys_sigaltstack arm64: compat: Provide definition for COMPAT_SIGMINSTKSZ arch/arm64/include/asm/compat.h | 1 + include/linux/compat.h | 3 +++ kernel/signal.c | 14 +++++++++----- 3 files changed, 13 insertions(+), 5 deletions(-) -- 2.1.4