From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31864 invoked by alias); 27 Aug 2004 03:25:00 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 31836 invoked from network); 27 Aug 2004 03:24:59 -0000 Received: from unknown (HELO mx1.redhat.com) (66.187.233.31) by sourceware.org with SMTP; 27 Aug 2004 03:24:59 -0000 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx1.redhat.com (8.12.10/8.12.10) with ESMTP id i7R3OxS0005175 for ; Thu, 26 Aug 2004 23:24:59 -0400 Received: from potter.sfbay.redhat.com (potter.sfbay.redhat.com [172.16.27.15]) by int-mx2.corp.redhat.com (8.11.6/8.11.6) with ESMTP id i7R3Oq726335; Thu, 26 Aug 2004 23:24:52 -0400 Received: from redhat.com (dhcp-172-16-25-160.sfbay.redhat.com [172.16.25.160]) by potter.sfbay.redhat.com (8.11.6/8.11.6) with ESMTP id i7R3OTV05471; Thu, 26 Aug 2004 20:24:41 -0700 Message-ID: <412EA96D.8010307@redhat.com> Date: Fri, 27 Aug 2004 03:25:00 -0000 From: Michael Snyder Organization: Red Hat, Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; es-ES; rv:1.4.2) Gecko/20040301 MIME-Version: 1.0 To: Manoj Iyer CC: Andrew Cagney , gilliam@us.ibm.com, gdb-patches@sources.redhat.com Subject: Re: [RFC] New thread testcase. References: <4117F82B.nail1N111PN0T@mindspring.com> <41187827.nailB8H1E9AWV@mindspring.com> <4118E61B.3060902@gnu.org> <411930DF.30401@gnu.org> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2004-08/txt/msg00722.txt.bz2 Manoj, It sounds from your eplanation like the "step" part of your test is not required, since your bug shows up without it. I explained in my previous msg why I was concerned about that test. What would you think of removing the step? Michael Manoj Iyer wrote: > oh! sorry abt that... got confused btwn 'bugs'... > > The kernel bug was causing gdb to fail when passing a 32bit address to the > kernel. this was causing 32 bit gdb to fail in linux_test_for_tracefork() > by always returning second_pid = 0 in the PTRACE_GETEVENTMSG call. > > this resulted in linux_enable_event_reporting() not setting the PTRACE > fork options for the pid and then the thread never received a SIGSTOP. > > John Engel, kernel developer, debugged and fixed this problem in the > kernel after we reported this GDB problem to him... > > So, when you debug a multi-threaded app with 32bit GDB on a PPC64 system, > and you set a break point at the thread function and tried to step, you > get the message "reading register pc (#64): No such process." for example: > > Breakpoint 1, main (argc=1, argv=0xffffe464) at tbug.c:31 > 31 for (n = 0; n < N; ++n) > (gdb) cont > Continuing. > [New Thread 1078217504 (LWP 26708)] > tf(0): begin > [New Thread 1082411808 (LWP 26709)] > after create > tf(1): begin > tf(0): end > [Thread 1078217504 (LWP 26708) exited] > tf(1): end > [Thread 1082411808 (LWP 26709) exited] > after join > > Program exited normally. > (gdb) clear main > Deleted breakpoint 1 > (gdb) break tf > Breakpoint 2 at 0x10000594: file tbug.c, line 15. > (gdb) run > Starting program: /home/public/test-tools/gdb/tbug > [Thread debugging using libthread_db enabled] > [New Thread 1074020384 (LWP 26710)] > reading register pc (#64): No such process. > (gdb) cont > Continuing. > reading register pc (#64): No such process. > > Thanks > ----- ---- > Manoj Iyer > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > + Cognito ergo sum + > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > On Tue, 10 Aug 2004, Andrew Cagney wrote: > > >>>>Manoj, >>>> >>>>>You've got me curious. Do any of the existing tests exercise this bug >>>>>(manythreads.exp comes to mind)? Oh, and what is the bug? :-) >>>>> >>> >>> >>>This is a generic kernel bug (in ptrace() )that causes ptrace to fail on >>>Power 64 systems. Please look at PR#1712 for details. >> >>Unfortunatly 1712 doesn't answer my question. What is the bug? What >>causes ptrace to fail? >> >>Andrew >> >> >> > >