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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 12EB2C433DF for ; Tue, 16 Jun 2020 15:36:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D98EA2145D for ; Tue, 16 Jun 2020 15:36:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592321801; bh=+TEMy27BblOXnMlqgiWZu2b8YQF3RwzOnroYFUg/yFw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SxP2mDpOErebgSr9fz5FD10V+VK2LACldqA46ol1p07WToHzNl3nVGhF2hkVtewAG oMSZxVMtvBrvc2oEHc/22CnmayfVoZk6zvXoghsHjZep9Nhh4EQxL/9bTgKEA4n2hi 0SYqW5MwBkd1fHcfQUrYBN8VYiA44sjDuNVw/5uY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730022AbgFPPgi (ORCPT ); Tue, 16 Jun 2020 11:36:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:47374 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729997AbgFPPgd (ORCPT ); Tue, 16 Jun 2020 11:36:33 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B4B2B21475; Tue, 16 Jun 2020 15:36:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592321793; bh=+TEMy27BblOXnMlqgiWZu2b8YQF3RwzOnroYFUg/yFw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TnIcMfvIDK0dMlwRIu8bM5I0zfRggw/+tK2v8LBd7ypvxxWDYxb/VXL95s+jiLohi UnFcfRdQWF03uCwuMo8ypE+R0oPAEkO6KdBb7UVmP3oRJWldLa1l9mVAuxOevVESgl 08q7cLL2p9DAHSgrolSogt2uTzsLY9wtzlHdJ2Ws= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oleg Nesterov , Fredrik Strupe , Russell King , Sasha Levin Subject: [PATCH 5.4 010/134] ARM: 8977/1: ptrace: Fix mask for thumb breakpoint hook Date: Tue, 16 Jun 2020 17:33:14 +0200 Message-Id: <20200616153101.179709255@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200616153100.633279950@linuxfoundation.org> References: <20200616153100.633279950@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 324352787aea..db9401581cd2 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