fork problem in multithreaded process -- segmentation fault seen

[dev nath <dev_wip_bms at yahoo dot com>]

> Hi *, 
> 
> I am facing a seg fault with the backtrace as below. Not
> sure if this is a kernel problem or glibc problem or
> something in the application.
>  
> This problem is similar to the one listed in the below URL
> http://lkml.indiana.edu/hypermail/linux/kernel/9908.0/0486.html
>  
> Explanation of the scenario:
> ----------------------------
> A multiple threaded process tries to fork another process
> and the application crashes at fork () api.?
> glibc-2.3.3 is used. I have ensured that the application is
> not doing anything between fork() and exec() api. In the
> pthread_mutex_init call the mutex variable seems NULL and
> not sure if this is something related to streams. 
>  
> Please help me with the problem.
>  
>  
>  
>  
> Loaded symbols for
> /opt/montavista/pro/devkit/ppc/7xx/target/lib/libnss_files.so.2
> #0? *__GI___pthread_mutex_init (mutex=0x0,
> mutex_attr=0x257ffe78) at spinlock.h:102
> 102? ???spinlock.h: No such file or
> directory.
> ? ? ? ? in spinlock.h
> (gdb) bt
> #0? *__GI___pthread_mutex_init (mutex=0x0,
> mutex_attr=0x257ffe78) at spinlock.h:102
> #1? 0x0f9af820 in __fresetlockfiles () at
> lockfile.c:77
> #2? 0x0f9ad59c in __pthread_fork (b=0xfb4eef8) at
> ptfork.c:51
> #3? 0x0faaaa20 in __libc_fork () at
> ../linuxthreads/sysdeps/unix/sysv/linux/fork.c:39
> #4? 0x100e8f80 in pn_exec_XXXX () at
> XXXX_pim_msgq_YYY_thread.c:714
> #5? 0x100131bc in PN_PI_ThreadStarter (theArg=0x0) at
> pn_pi.c:377
> #6? 0x0f9abd48 in pthread_start_thread (arg=0x0) at
> manager.c:310
> #7? 0x0fadc228 in ?? () at
> ../sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S:94
> ???from
> /opt/montavista/pro/devkit/ppc/777/target/lib/libc.so.6
> warning: Previous frame inner to this frame (corrupt
> stack?)
> (gdb) frame 0
> #0? *__GI___pthread_mutex_init (mutex=0x0,
> mutex_attr=0x257ffe78) at spinlock.h:102
> 102? ???in spinlock.h
> (gdb) frame 1
> #1? 0x0f9af820 in __fresetlockfiles () at
> lockfile.c:77
> 77? ? ? lockfile.c: No such file or
> directory.
> ? ? ? ? in lockfile.c
> (gdb) list
> 72? ? ? in lockfile.c
> (gdb) p *attr
> Structure has no component named operator*.
> (gdb) p attr
> $1 = {__mutexkind = 1}
> (gdb) p i
> $2 = 0x224ee690
> (gdb) p *i
> $3 = {_flags = -72503612, _IO_read_ptr = 0x238f1000 "",
> _IO_read_end = 0x238f1000 "",
> ? _IO_read_base = 0x238f1000 "", _IO_write_base =
> 0x238f1000 "", _IO_write_ptr = 0x238f1000 "",
> ? _IO_write_end = 0x238f1000 "", _IO_buf_base =
> 0x238f1000 "",
> ? _IO_buf_end = 0x238f2000 <Address 0x238f2000 out
> of bounds>, _IO_save_base = 0x0,
> ? _IO_backup_base = 0x0, _IO_save_end = 0x0, _markers
> = 0x0, _chain = 0x10270708, _fileno = 48,
> ? _flags2 = 0, _old_offset = 0, _cur_column = 0,
> _vtable_offset = 0 '\0', _shortbuf = "",
> ? _lock = 0x0, _offset = -1, _codecvt = 0x0,
> _wide_data = 0x224ee730, _mode = -1,
> ? _unused2 = '\0' <repeats 40 times>,
> "\"Nè°\000\000\000\001\020\000\000"}
> 
> 
> 
>