wrong backtrace / __JCR_LIST__ instead of real function name

wrong backtrace / __JCR_LIST__ instead of real function name

[Kremer Markus (MPI/SFR)]

Hello,
i am using gcc 3.2 and gdb 5.3.
One thread of my programm calls
pthread_start_thread->wrapper_routine->acom_loop->acom->acom_read->select.

When i debug my application i get strange backtraces.
instead of acom_read() __JCR_LIST__() is displayed in frame #1.

I had similar problems at other places in my code.
When i used gcc 2.9x and gdb 5.2 i had the same problems.

Any clues what went wrong?
....
pressing CTRL-C
....
Program received signal SIGINT, Interrupt.
[Switching to Thread 3076 (LWP 26480)]
0x401ad6ae in select () from
//app/i33tools/gcc/gcc-3.2c/i386-linux/lib/libc.so.6
(gdb) bt
#0  0x401ad6ae in select () from
//app/i33tools/gcc/gcc-3.2c/i386-linux/lib/libc.so.6
#1  0x0805e9cc in __JCR_LIST__ ()
#2  0x0804ca76 in acom (fd=16, text=0x8062704 "ABCDEABCDE", len=10,
timeout=3)
    at
/net/fr145117/tux_snv/choral.km82fr.linux-snv/vobs/choral/software/RemoteV24
/src/handler_acom.c:182
#3  0x0804cc92 in acom_loop (arg=0x80627b0)
    at
/net/fr145117/tux_snv/choral.km82fr.linux-snv/vobs/choral/software/RemoteV24
/src/handler_acom.c:282
#4  0x08053ff3 in wrapper_routine (data=0xbfffe8d0)
    at
/net/fr145117/tux_snv/choral.km82fr.linux-snv/vobs/choral/software/RemoteV24
/src/mytools.c:1051
#5  0x400ccba3 in pthread_start_thread () from
//app/i33tools/gcc/gcc-3.2c/i386-linux/lib/libpthread.so.0
#6  0x400cd66e in pthread_start_thread_event () from
//app/i33tools/gcc/gcc-3.2c/i386-linux/lib/libpthread.so.0
(gdb) up
#1  0x0805e9cc in __JCR_LIST__ ()
(gdb) up
#2  0x0804ca76 in acom (fd=16, text=0x8062704 "ABCDEABCDE", len=10,
timeout=3)
    at
/net/fr145117/tux_snv/choral.km82fr.linux-snv/vobs/choral/software/RemoteV24
/src/handler_acom.c:182
182                 r = acom_read (fd, timeout);
(gdb) list
177                     acom_send (fd, text, len);
178                     s = state_repeat1;
179                 };
180                 break;
181             case state_repeat1:
182                 r = acom_read (fd, timeout);
183                 if (r == ACK)
184                 {
185                     result = V24_OK;
186                     s = state_end;
(gdb) p acom_read
$1 = {char (int, int)} 0x804c850 <acom_read>

best regards 
Markus

Re: wrong backtrace / __JCR_LIST__ instead of real function name

[Daniel Jacobowitz]

On Tue, Oct 21, 2003 at 01:05:34PM +0200, Kremer Markus (MPI/SFR) wrote:
> Hello,
> i am using gcc 3.2 and gdb 5.3.
> One thread of my programm calls
> pthread_start_thread->wrapper_routine->acom_loop->acom->acom_read->select.
> 
> When i debug my application i get strange backtraces.
> instead of acom_read() __JCR_LIST__() is displayed in frame #1.
> 
> I had similar problems at other places in my code.
> When i used gcc 2.9x and gdb 5.2 i had the same problems.
> 
> Any clues what went wrong?
> ....
> pressing CTRL-C
> ....
> Program received signal SIGINT, Interrupt.
> [Switching to Thread 3076 (LWP 26480)]
> 0x401ad6ae in select () from
> //app/i33tools/gcc/gcc-3.2c/i386-linux/lib/libc.so.6
> (gdb) bt
> #0  0x401ad6ae in select () from
> //app/i33tools/gcc/gcc-3.2c/i386-linux/lib/libc.so.6
> #1  0x0805e9cc in __JCR_LIST__ ()

This means GDB couldn't figure out how to backtrace from select.  It's
an assembly wrapper, so it's hard to manually figure out the frame
location.

Recent versions of gdb and binutils support annotating assembly
functions to describe the backtrace.  Most libc functions will
eventually be annotated, since NPTL uses this information also.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

Re: wrong backtrace / __JCR_LIST__ instead of real function name

[Michael Elizabeth Chastain]

Hello,

Try gdb 6.0, which has improved backtracing in system calls.

Michael C
GDB QA Guy