From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757434Ab3D2P7R (ORCPT ); Mon, 29 Apr 2013 11:59:17 -0400 Received: from mail-we0-f170.google.com ([74.125.82.170]:42769 "EHLO mail-we0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757150Ab3D2P7P (ORCPT ); Mon, 29 Apr 2013 11:59:15 -0400 Date: Mon, 29 Apr 2013 17:59:11 +0200 From: Frederic Weisbecker To: Oleg Nesterov Cc: Andrew Morton , Alan Stern , Ingo Molnar , Jan Kratochvil , Prasad , linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/6] ptrace/x86: ptrace_write_dr7() should create bp if !disabled Message-ID: <20130429155909.GB31230@somewhere> References: <20130418184350.GA4407@redhat.com> <20130418184419.GA4444@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130418184419.GA4444@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 18, 2013 at 08:44:19PM +0200, Oleg Nesterov wrote: > 24f1e32c "hw-breakpoints: Rewrite the hw-breakpoints layer on top > of perf events" introduced the minor regression. Before this commit > > PTRACE_POKEUSER DR7, enableDR0 > PTRACE_POKEUSER DR0, address > > was perfectly valid, now PTRACE_POKEUSER(DR7) fails if DR0 was not > previously initialized by PTRACE_POKEUSER(DR0). > > Change ptrace_write_dr7() to do ptrace_register_breakpoint(addr => 0) > if !bp && !disabled. This fixes watchpoint-zeroaddr from ptrace-tests, > see https://bugzilla.redhat.com/show_bug.cgi?id=660204. > > Reported-by: Jan Kratochvil > Signed-off-by: Oleg Nesterov Acked-by: Frederic Weisbecker