From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756441AbcBCXx6 (ORCPT ); Wed, 3 Feb 2016 18:53:58 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:46488 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752863AbcBCWej (ORCPT ); Wed, 3 Feb 2016 17:34:39 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: John Blackwood , Will Deacon , Luis Henriques Subject: [PATCH 3.16.y-ckt 031/180] arm64: Clear out any singlestep state on a ptrace detach operation Date: Wed, 3 Feb 2016 22:30:37 +0000 Message-Id: <1454538786-12215-32-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1454538786-12215-1-git-send-email-luis.henriques@canonical.com> References: <1454538786-12215-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt24 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ 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: Luis Henriques --- arch/arm64/kernel/ptrace.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 167c5edecad4..d2b9a3f7457d 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -55,6 +55,12 @@ */ 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