Re: [mp2] Segmentation faults with threaded worker-mpm

[Torsten Foertsch]

On Wednesday 06 June 2007 10:55, Jani M. wrote:
> (gdb) btt 4
> [Switching to thread 4 (process 2133)]#0  0xb77eb15a in
> modperl_mgv_as_string (my_perl=0x8662c58, symbol=0x8178190, p=0x8938438,
>      package=0) at modperl_mgv.c:399
> 399     modperl_mgv.c: No such file or directory.
>          in modperl_mgv.c
> #0  0xb77eb15a in modperl_mgv_as_string (my_perl=0x8662c58,
> symbol=0x8178190, p=0x8938438, package=0) at modperl_mgv.c:399
> #1  0xb77df146 in modperl_callback (my_perl=0x8662c58,
> handler=0x8939ee8, p=0x8938438, r=0x8938470, s=0x80a88c8, args=0x870c29c)
>      at modperl_callback.c:85
> #2  0xb77dfb79 in modperl_callback_run_handlers (idx=5, type=4,
> r=0x8938470, c=0x0, s=0x80a88c8, pconf=0x0, plog=0x0, ptemp=0x0,
>      run_mode=MP_HOOK_RUN_ALL) at modperl_callback.c:263
> #3  0xb77e00aa in modperl_callback_per_dir (idx=5, r=0x8938470,
> run_mode=MP_HOOK_RUN_ALL) at modperl_callback.c:370
> #4  0xb77feb63 in modperl_fixup_handler (r=0x8938470) at modperl_hooks.c:57
> #5  0x0806ff29 in ap_run_fixups ()
> #6  0x08084528 in ap_process_request ()
> #7  0x080817de in ap_register_input_filter ()
> #8  0x0807b507 in ap_run_process_connection ()
> #9  0x0808914b in ap_graceful_stop_signalled ()
> #10 0xb7d10316 in apr_proc_detach () from /usr/lib/libapr-1.so.0
> #11 0xb7cad0bd in start_thread () from /lib/tls/libpthread.so.0
> #12 0xb7c3c9ee in clone () from /lib/tls/libc.so.6
...
> (gdb) btt 9
> [Switching to thread 9 (process 2125)]#0  0xb7b99d51 in kill () from
> /lib/tls/libc.so.6
> #0  0xb7b99d51 in kill () from /lib/tls/libc.so.6
> #1  0x0807c9bb in ap_fatal_signal_child_setup ()
> #2  <signal handler called>
> #3  0xb77eb15a in modperl_mgv_as_string (my_perl=0x85bc758,
> symbol=0x8178190, p=0x88ad7f8, package=0) at modperl_mgv.c:399
> #4  0xb77df146 in modperl_callback (my_perl=0x85bc758,
> handler=0x88af2a8, p=0x88ad7f8, r=0x88ad830, s=0x80a88c8, args=0x86eaf0c)
>      at modperl_callback.c:85
> #5  0xb77dfb79 in modperl_callback_run_handlers (idx=5, type=4,
> r=0x88ad830, c=0x0, s=0x80a88c8, pconf=0x0, plog=0x0, ptemp=0x0,
>      run_mode=MP_HOOK_RUN_ALL) at modperl_callback.c:263
> #6  0xb77e00aa in modperl_callback_per_dir (idx=5, r=0x88ad830,
> run_mode=MP_HOOK_RUN_ALL) at modperl_callback.c:370
> #7  0xb77feb63 in modperl_fixup_handler (r=0x88ad830) at modperl_hooks.c:57
> #8  0x0806ff29 in ap_run_fixups ()
> #9  0x08084528 in ap_process_request ()
> #10 0x080817de in ap_register_input_filter ()
> #11 0x0807b507 in ap_run_process_connection ()
> #12 0x0808914b in ap_graceful_stop_signalled ()
> #13 0xb7d10316 in apr_proc_detach () from /usr/lib/libapr-1.so.0
> #14 0xb7cad0bd in start_thread () from /lib/tls/libpthread.so.0
> #15 0xb7c3c9ee in clone () from /lib/tls/libc.so.6

Interesting both threads are at exactly the same line of code:

    ptr = string = apr_palloc(p, len+1);

    for (mgv = symbol; (package ? mgv->next : mgv); mgv = mgv->next) {
==>     Copy(mgv->name, ptr, mgv->len, char);
        ptr += mgv->len;
    }

I suspect mgv has been corrupted. The question is who is the culprit?

Try "PerlInterpScope request" and see if the coredumps disappear. Further 
check if it's always this place.

Torsten

pgpp0cPsBazKa.pgp
Description: PGP signature