From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5688 invoked by alias); 17 Sep 2006 22:26:26 -0000 Received: (qmail 5676 invoked by uid 22791); 17 Sep 2006 22:26:26 -0000 X-Spam-Check-By: sourceware.org Received: from nevyn.them.org (HELO nevyn.them.org) (66.93.172.17) by sourceware.org (qpsmtpd/0.31.1) with ESMTP; Sun, 17 Sep 2006 22:26:24 +0000 Received: from drow by nevyn.them.org with local (Exim 4.54) id 1GP55i-0000cW-CC; Sun, 17 Sep 2006 18:26:22 -0400 Date: Sun, 17 Sep 2006 22:26:00 -0000 From: Daniel Jacobowitz To: Jan Kratochvil Cc: gdb-patches@sourceware.org Subject: Re: [patch] Fix attaching to Linux stopped processes Message-ID: <20060917222622.GA2150@nevyn.them.org> Mail-Followup-To: Jan Kratochvil , gdb-patches@sourceware.org References: <20060917221228.GA17263@host0.dyn.jankratochvil.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060917221228.GA17263@host0.dyn.jankratochvil.net> User-Agent: Mutt/1.5.13 (2006-08-11) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2006-09/txt/msg00093.txt.bz2 On Mon, Sep 18, 2006 at 12:12:28AM +0200, Jan Kratochvil wrote: > Hi, > > sleep 1h& pid=$!; kill -STOP $pid; gdb sleep $pid > -> > Attaching to program: /bin/sleep, process 20768 > ../../gdb/linux-nat.c:1057: internal-error: linux_nat_attach: Assertion `pid == GET_PID (inferior_ptid) && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP' failed. > + /* Do not check `WSTOPSIG (status) == SIGSTOP' as the status may be > + arbitrary - depending on the signal that stopped the processes. > + If the process was running we get SIGSTOP, if it was already stopped > + by SIGSTOP we get 0. The value gets used for `PTRACE_CONT'. */ That's a very strange behavior. It doesn't make much sense to me, and it isn't familiar - which is strange because I've been all over the kernel code for this. So I checked. Sure enough, on my 2.6.18-rc4 installation, this is _not_ what happens. Instead, the traditional thing happens: wait hangs and no new event is returned. Is this new in kernel.org? Or is it a Red Hat kernel patch? Where did it come from? -- Daniel Jacobowitz CodeSourcery