[Gdb] cannot debug any threaded/fork program

[Ricardo Nabinger Sanchez]

hello,

I'm trying to debug a program which has 3 threads (pthreads).  the main
problem is that gdb doesn't detect the threads, althought it stops if I set
a breakpoint and some of the threads reach it, but then gdb seems to lost
control and the debugging session gets unreliable.

this is my environment:

* Linux kernel 2.4.25
* glibc-2.3.2 (with and without debugging info versions)
* gcc-3.3.4, with posix thread model
* binutils 2.15.90.0.3 20040415
* gdb 6.2 and 5.3
* pthreads 0.10

this is the output of gdb:

---------------------------------------------------------------------------
GNU gdb 6.2
[...]
This GDB was configured as "i486-slackware-linux"...Using host libthread_db
library "/lib/libthread_db.so.1".

(gdb) handle SIG32 nostop noprint pass
Signal        Stop      Print   Pass to program Description
SIG32         No        No      Yes             Real-time event 32
(gdb) r
Starting program: rmon2 
conversor: pid 19303
Servidor está rodando com PID: 19304
fila: pid 19305
---------------------------------------------------------------------------

as you can notice, the 3 "pid" messages are from each new thread.  so I have
3 threads running (they are truly active), and the main process joins them.

I've already tried gdb version 5.3, but without success.  the threads are
not detected, and ``info threads'' gives nothing.  ``thread 1'' gives an
error message, telling that the ID is unknown.

I've also tried some variations: fork() and clone() to create
childs/threads, but even so gdb didn't detected them.

I think both gdb-6.2 and 5.3 have thread support, because they throwned
warnings telling me I wouldn't have thread support when I renamed
libthread_db.

any ideas?

thanks in advance.

Ricardo Nabinger Sanchez