From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 8 Jan 2010 09:30:25 +0100 From: Martin Schwidefsky Subject: Re: s390 && user_enable_single_step() (Was: odd utrace testing results on s390x) Message-ID: <20100108093025.28ec0907@mschwide.boeblingen.de.ibm.com> In-Reply-To: <20100107214642.579F27300@magilla.sf.frob.com> References: <20100104155225.GA16650@redhat.com> <20100104171626.22ea2d9c@mschwide.boeblingen.de.ibm.com> <20100104181412.GA21146@redhat.com> <20100104211147.4CC94D532@magilla.sf.frob.com> <20100105105030.66bb8a0a@mschwide.boeblingen.de.ibm.com> <20100105153633.GA9376@redhat.com> <20100105164610.388effd3@mschwide.boeblingen.de.ibm.com> <20100105155913.GA10652@redhat.com> <20100105170301.GA13641@redhat.com> <20100105195818.GA20358@redhat.com> <20100106201722.GB26204@redhat.com> <20100106211329.DB4F5134D@magilla.sf.frob.com> <20100107101855.13248dc2@mschwide.boeblingen.de.ibm.com> <20100107214642.579F27300@magilla.sf.frob.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Roland McGrath Cc: Oleg Nesterov , caiqian@redhat.com, Heiko Carstens , Jan Kratochvil , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, utrace-devel@redhat.com List-ID: On Thu, 7 Jan 2010 13:46:42 -0800 (PST) Roland McGrath wrote: > > Clear the TIF_SINGLE_STEP bit in copy_thread. If the new process is > > not auto-attached by the tracer it is wrong to delivere SIGTRAP to > > the new process. > > The change is right, but this log entry is confusing. "auto-attached" has > nothing to do with it, nor does anything about tracing the new process or > not. The new process has not experienced a PER trap of its own, so it is > wrong to deliver a SIGTRAP that is meant for its creator. Ok, I changed the wording slightly: Clear the TIF_SINGLE_STEP bit in copy_thread. The new process did not get a PER event of its own. It is wrong deliver a SIGTRAP that was meant for the parent process. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.