This is the mail archive of the
gdb@sources.redhat.com
mailing list for the GDB project.
Re: PATCH: Re: [RFHelp] Linux, threads, and regsets in thread_db
- From: Daniel Jacobowitz <drow at mvista dot com>
- To: "H . J . Lu" <hjl at lucon dot org>
- Cc: GDB <gdb at sourceware dot cygnus dot com>
- Date: Thu, 15 Nov 2001 11:48:41 -0500
- Subject: Re: PATCH: Re: [RFHelp] Linux, threads, and regsets in thread_db
- References: <20010924212808.A20851@nevyn.them.org> <20011003170848.A30843@lucon.org> <20011003211007.A12210@nevyn.them.org> <20011114134521.A25645@lucon.org>
On Wed, Nov 14, 2001 at 01:45:21PM -0800, H . J . Lu wrote:
> On Wed, Oct 03, 2001 at 09:10:07PM -0400, Daniel Jacobowitz wrote:
> > > >
> > >
> > > How far have you gone on Linux/mips? I know gdb 5.1 doesn't work with
> > > threads on Linux/mips. Does your change fix it? I'd like to clean up
> > > glibc for mips on this.
> >
> > Yes. Debugging threads works reasonably well. I'm going to do more
> > work about this in the next couple of months too, I think; after I go
> > back to gdbserver for a little while.
>
> I am still having problems with threads on mips. I cannot set break
> point after target has run:
>
> (gdb) run
> ...
> (gdb) b main
> reading register sp (#29): No such process.
>
> The problem is gdb tries to read sp register in thread mode. This patch
> seems to work for me.
This should not be a problem. It works fine for me. I'll step through
it later tonight and try to figure out what the difference is from what
you're seeing.
> Another problem is when I set a break point in a thread function, only
> the first thread stops. I got
>
> (gdb) b process
> Breakpoint 1 at 0x400a38: file Examples/ex1.c, line 14.
> (gdb) r
> Starting program: /export/build/gnu/glibc/build-mipsel-linux/linuxthreads/ex1
> [New Thread 1024 (LWP 26552)]
> [New Thread 2049 (LWP 26569)]
> [New Thread 1026 (LWP 26570)]
> [Switching to Thread 1026 (LWP 26570)]
>
> Breakpoint 1, process (arg=0x1000) at Examples/ex1.c:14
> 14 fprintf (stderr, "Starting process %s\n", (char *) arg);
> ...
> Program received signal SIGTRAP, Trace/breakpoint trap.
> [Switching to Thread 1024 (LWP 26552)]
> 0x2ab8de24 in __syscall_rt_sigsuspend () at soinit.c:56
> 56 soinit.c: No such file or directory.
>
> But it may be a kernel bug.
Something is suspicious here. The process in sigsuspend should have
been stopped with SIGSTOP, not SIGTRAP... is this an example program
from glibc?
> H.J.
> ---
> 2001-11-14 H.J. Lu (hjl@gnu.org)
>
> * mips-tdep.c (heuristic_proc_desc): Read register only when
> target is running.
I can't see why this changes behavior in the way you're seeing. I'm
pretty sure it isn't right.
--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer