From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26666 invoked by alias); 18 Jul 2010 22:09:04 -0000 Received: (qmail 26656 invoked by uid 22791); 18 Jul 2010 22:09:03 -0000 X-SWARE-Spam-Status: No, hits=-5.9 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 18 Jul 2010 22:08:59 +0000 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o6IM8vsv029602 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sun, 18 Jul 2010 18:08:58 -0400 Received: from host1.dyn.jankratochvil.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o6IM8ti6021953 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sun, 18 Jul 2010 18:08:57 -0400 Received: from host1.dyn.jankratochvil.net (localhost [127.0.0.1]) by host1.dyn.jankratochvil.net (8.14.4/8.14.4) with ESMTP id o6IM8sRl003049 for ; Mon, 19 Jul 2010 00:08:54 +0200 Received: (from jkratoch@localhost) by host1.dyn.jankratochvil.net (8.14.4/8.14.4/Submit) id o6IM8r1Z003043 for gdb-patches@sourceware.org; Mon, 19 Jul 2010 00:08:53 +0200 Date: Sun, 18 Jul 2010 22:09:00 -0000 From: Jan Kratochvil To: gdb-patches@sourceware.org Subject: [patch] Fix linux-nat.c new_lp dropped status Message-ID: <20100718220853.GA3011@host1.dyn.jankratochvil.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-12-10) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2010-07/txt/msg00272.txt.bz2 Hi, while reading the code it seems to me it can drop non-SIGSTOP status in this case. It can happen only during some racy case while creating a thread, I have not tried to exploit it. Does the patch make sense? I have no dependency on it, I just have seen it. No regressions on {x86_64,x86_64-m32,i686}-fedora12-linux-gnu. Thanks, Jan --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -2288,6 +2288,23 @@ linux_handle_extended_wait (struct lwp_info *lp, int status, linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid), 0, signo); } + else + { + if (status != 0) + { + /* We created NEW_LP so it cannot yet contain STATUS. */ + gdb_assert (new_lp->status == 0); + + /* Save the wait status to report later. */ + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "LHEW: waitpid of new LWP %ld, " + "saving status %s\n", + (long) GET_LWP (new_lp->ptid), + status_to_str (status)); + new_lp->status = status; + } + } if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog,