From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966767AbcA0Tft (ORCPT ); Wed, 27 Jan 2016 14:35:49 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56292 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966184AbcA0TQ7 (ORCPT ); Wed, 27 Jan 2016 14:16:59 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, John Blackwood , Will Deacon Subject: [PATCH 4.1 117/127] arm64: Clear out any singlestep state on a ptrace detach operation Date: Wed, 27 Jan 2016 10:14:41 -0800 Message-Id: <20160127180811.684824199@linuxfoundation.org> X-Mailer: git-send-email 2.7.0 In-Reply-To: <20160127180805.624425994@linuxfoundation.org> References: <20160127180805.624425994@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: John Blackwood commit 5db4fd8c52810bd9740c1240ebf89223b171aa70 upstream. Make sure to clear out any ptrace singlestep state when a ptrace(2) PTRACE_DETACH call is made on arm64 systems. Otherwise, the previously ptraced task will die off with a SIGTRAP signal if the debugger just previously singlestepped the ptraced task. Signed-off-by: John Blackwood [will: added comment to justify why this is in the arch code] Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/ptrace.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -58,6 +58,12 @@ */ void ptrace_disable(struct task_struct *child) { + /* + * This would be better off in core code, but PTRACE_DETACH has + * grown its fair share of arch-specific worts and changing it + * is likely to cause regressions on obscure architectures. + */ + user_disable_single_step(child); } #ifdef CONFIG_HAVE_HW_BREAKPOINT