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 7D6E0C433E1 for ; Fri, 5 Jun 2020 12:25:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 547D6207D5 for ; Fri, 5 Jun 2020 12:25:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591359931; bh=JaAgU929H/sHzVvkGs0E1ui40+lainALY9/ORBjgk5s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=u+88F/HxJfXmwZP2tcD3Uwg5EjW4v9wC0dYLbIAnI7WrkJoywQUVNiiCno8/D5Yg+ guOtMqj/+Z0VOWQ2AB11nATE8lUlfsK61xe5+Tce0vfuTHtLBFbPYNmjjbYH85C4e4 a+fAphc92tTdTIb8o1zqJ60k0D8NZbuxAAaaUDlA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726748AbgFEMZa (ORCPT ); Fri, 5 Jun 2020 08:25:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:56554 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726385AbgFEMZW (ORCPT ); Fri, 5 Jun 2020 08:25:22 -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 CCFC9206E6; Fri, 5 Jun 2020 12:25:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591359921; bh=JaAgU929H/sHzVvkGs0E1ui40+lainALY9/ORBjgk5s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mtgu/4HNqIJ9PtItDXtuIEDnQjoF/k2ofwpk8f3qCwWX7acYQ2Lw7bRl5MpvLJOre JyiyAL9WOViy3EoZ1n+boEG1VMdgfZTgvCId9MtlSltprBqe5Bd3HlkJL2xEeNTjvF 5Iy8FFbw8mrbFf2cQ3buETGBHb40ogtvjuNbcIsk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Fredrik Strupe , Oleg Nesterov , Russell King , Sasha Levin , linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 5.6 03/17] ARM: 8977/1: ptrace: Fix mask for thumb breakpoint hook Date: Fri, 5 Jun 2020 08:25:02 -0400 Message-Id: <20200605122517.2882338-3-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200605122517.2882338-1-sashal@kernel.org> References: <20200605122517.2882338-1-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: Fredrik Strupe [ Upstream commit 3866f217aaa81bf7165c7f27362eee5d7919c496 ] call_undef_hook() in traps.c applies the same instr_mask for both 16-bit and 32-bit thumb instructions. If instr_mask then is only 16 bits wide (0xffff as opposed to 0xffffffff), the first half-word of 32-bit thumb instructions will be masked out. This makes the function match 32-bit thumb instructions where the second half-word is equal to instr_val, regardless of the first half-word. The result in this case is that all undefined 32-bit thumb instructions with the second half-word equal to 0xde01 (udf #1) work as breakpoints and will raise a SIGTRAP instead of a SIGILL, instead of just the one intended 16-bit instruction. An example of such an instruction is 0xeaa0de01, which is unallocated according to Arm ARM and should raise a SIGILL, but instead raises a SIGTRAP. This patch fixes the issue by setting all the bits in instr_mask, which will still match the intended 16-bit thumb instruction (where the upper half is always 0), but not any 32-bit thumb instructions. Cc: Oleg Nesterov Signed-off-by: Fredrik Strupe Signed-off-by: Russell King Signed-off-by: Sasha Levin --- arch/arm/kernel/ptrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index b606cded90cd..4cc6a7eff635 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -219,8 +219,8 @@ static struct undef_hook arm_break_hook = { }; static struct undef_hook thumb_break_hook = { - .instr_mask = 0xffff, - .instr_val = 0xde01, + .instr_mask = 0xffffffff, + .instr_val = 0x0000de01, .cpsr_mask = PSR_T_BIT, .cpsr_val = PSR_T_BIT, .fn = break_trap, -- 2.25.1