From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 35558 invoked by alias); 27 Jun 2017 17:05:10 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 35391 invoked by uid 89); 27 Jun 2017 17:05:05 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-11.9 required=5.0 tests=BAYES_00,GIT_PATCH_2,GIT_PATCH_3,RP_MATCHES_RCVD,SPF_PASS autolearn=ham version=3.3.2 spammy=Hx-spam-relays-external:ESMTPA X-Spam-User: qpsmtpd, 2 recipients X-HELO: foss.arm.com Received: from foss.arm.com (HELO foss.arm.com) (217.140.101.70) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 27 Jun 2017 17:05:04 +0000 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 1E9C580D; Tue, 27 Jun 2017 10:05:03 -0700 (PDT) Received: from e103592.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 32BEC3F557; Tue, 27 Jun 2017 10:05:02 -0700 (PDT) From: Dave Martin To: linux-arm-kernel@lists.infradead.org Cc: Russell King , Edmund Grimley-Evans , libc-alpha@sourceware.org, gdb@sourceware.org Subject: [RFC PATCH v2 0/2] ARM: Fix unparseable signal frame with CONFIG_IWMMXT Date: Tue, 27 Jun 2017 17:05:00 -0000 Message-Id: <1498583067-14178-1-git-send-email-Dave.Martin@arm.com> X-SW-Source: 2017-06/txt/msg00034.txt.bz2 Changes since RFC v1: * Emit a dummy block instead of omitting ixmmxt_sigframe. A new magic, DUMMY_MAGIC, is defined for this purpose. * Optionally consume the dummy block on sigreturn, but don't maintain it in case some userspace is crafting its own sigframes. Limited manual testing, but not tested on iWMMXt hardware so far. Original blurb: In kernels with CONFIG_IWMMXT=y running on non-iWMMXt hardware, the signal frame can be left partially uninitialised in such a way that userspace cannot parse uc_regspace[] safely. In particular, this means that the VFP registers cannot be located reliably in the signal frame when a multi_v7_defconfig kernel is run on the majority of platforms. I don't know whether any userspace has implemented any sort of workaround for this, but the ABI by itself is insufficient anyway. This series attempts to omit the spurious iWMMXt record when appropriate. Not extensively tested, and the ABI impact is unknown for now. Dave Martin (2): ARM: iwmmxt: Add missing __user annotations to sigframe accessors ARM: signal: Fix unparseable iwmmxt_sigframe in uc_regspace[] arch/arm/include/asm/ucontext.h | 6 ++++ arch/arm/kernel/signal.c | 79 +++++++++++++++++++++++++++++++---------- 2 files changed, 67 insertions(+), 18 deletions(-) -- 2.1.4