Hi Helge,
If you link the test with -static, you should be able to set
breaks in your test application and determine why _exit isn't
called.
I'm in the process of moving homes, so I don't have much time
to investigate myself.
Dave
> On 01/08/2010 10:44 PM, Carlos O'Donell wrote:
> > On Fri, Jan 8, 2010 at 4:18 PM, Helge Deller<deller@xxxxxx> wrote:
> >>> I now think this probably is a glibc bug. The kernel uses this value
> >>> when the CLONE_PARENT_SETTID flag is passed.
> >>
> >>
> >> Maybe we have a futex problem in glibc on hppa?
> >> In glibc nptl/pthread_mutex_trylock.c we check the return value of a futex
> >> syscall against EWOULDBLOCK.
> >> Since on parisc - in contrast to all other architectures - we have
> >> EWOULDBLOCK!=EAGAIN, we maybe missed a check?
> >
> > That's a bug. [...]
>
> Carlos, Dave,
>
> I'm wondering if we have another bug in glibc...?
>
> When running strace, I noticed that a thread which returns with "return 0",
> exits the process on hppa with exit(0):
> [pid 1875] write(1, "Thread OK.\n", 11) = 11
> [pid 1875] exit(0)
>
> On my x86_64 I see:
> [pid 8154] write(1, "Thread OK.\n", 11) = 11
> [pid 8154] _exit(0) =
>
> In ports/sysdeps/unix/sysv/linux/hppa/clone.S (line 170) I do see:
> /* The call to _exit needs saved r19. */
> bl _exit, %rp
> copy %ret0, %arg0
>
> This coding seems to indicate that we call _exit(), but we aren't (as
> you see above in the strace).
> So I'm wondering if the "bl _exit,%rp" needs changing.
> Something with HIDDEN_JUMPTARGET(_exit) or similar, so that
> _exit() instead of exit() is called?
>
> Actually I did tested this with the minifail test program, and changed
> thread_run() to call _exit(0) at the end instead of "return 0":
> void* thread_run(void* arg) {
> ...
> /* return (void *)&status; */
> _exit(0);
> }
> With strace I then suddenly got exit_group() which seems more correct:
> [pid 1910] write(1, "Thread OK.\n", 11) = 11
> [pid 1910] exit_group(0) = ?
>
> Helge
>
--
J. David Anglin dave.anglin@xxxxxxxxxxxxxx
National Research Council of Canada (613) 990-0752 (FAX: 952-6602)
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