I am running Linux RedHat ES 4 and I have a question regarding gdb (version
6.3.0.0).
When doing a backtrace of some threads I get the following:

#0 0x0031f7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2
#1 0x0026bcf6 in pthread_cond_wait@@GLIBC_2.3.2 () from
/lib/tls/libpthread.so.0
#2 0x0055fcd7 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/libc.so.6
#3 0x085281d4 in LSemaphore::Wait (this=0x877d1b8, inMilliSeconds=-1)
at ../../Threads/LSemaphore.cp:139
#4 0x080c800a in DataBase::Run (this=0x877d160) at
.../../Database/MySQL/DataBase.cp:167
#5 0x08528728 in threadEntry (args=0x877d160) at
.../../Threads/LThread.cp:77
#6 0x002693cc in start_thread () from /lib/tls/libpthread.so.0
#7 0x005531ae in clone () from /lib/tls/libc.so.6
(gdb) thread 57
[Switching to thread 57 (Thread 111045536 (LWP 6449))]#0 0x0031f7a2 in
_dl_sysinfo_int80
() from /lib/ld-linux.so.2
(gdb) bt
#0 0x0031f7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2
#1 0x0026e3de in __lll_mutex_lock_wait () from /lib/tls/libpthread.so.0
#2 0x0026b017 in _L_mutex_lock_182 () from /lib/tls/libpthread.so.0
#3 0x069e60a8 in ?? ()
#4 0x005b1ff4 in ?? () from /lib/tls/libc.so.6
#5 0x069e6200 in ?? ()
#6 0x00000000 in ?? ()
(gdb)

For the thread 57 I don't see all the backtrace, only until frame 6 in
0x00000000. Why is that address null? Why do I not see all the backtrace? Is
the stack corrupted? If yes, any idea/tool how to find who did corrupt the
stack?

Thank you.
CÚdric