Re: How to catch GDB crash

Dr. Rolf Jansen
2008-06-23T20:50:30Z

Hi,

Here comes a poor mans approach.

1. add in the file gdb/main.c at line 661 the
following code:

#if defined (POOR_MAN_DEBUG)
printf_filtered ("[GDB PID %d]\n", getpid());
t0 = time(NULL);
while ((diff = difftime(time(NULL), t0)) <= 60);
#endif

and at line 43

#if defined (POOR_MAN_DEBUG)
#include <sys/time.h>
double diff;
time_t t0 = time(NULL);
#endif

2. issue before the configure command:
export CFLAGS="-g -O0 -DPOOR_MAN_DEBUG"
export CXXFLAGS=$CFLAGS

3. configure and make your cross-686-pc-cygwin/arm-elf-gdb

4. start the cross-debugging session

5. now you have 60 seconds to attach your host-gdb
to the just printed PID of your cross-gdb, and to
set a reasonable breakpoint somewhere near to the
location where you expect the crash to happen.

6. after 60 s the cross-gdb will continue running and
your host-gdb shall stop the cross-gdb at the
breakpoint that you set.

7. Now step through until the crash occurs.

Hopefully this helps.

Best regards

Rolf Jansen

Am 23.06.2008 um 23:31 schrieb Dmitry Smirnov:

> Hi,
>
> I've encountered the very annoying problem with GDB. While
> debugging, it crashes for some reason and I cannot catch this
> moment. I have a possibility to attach to the running process with
> another GDB, but it does not help. Perhaps, there is some way to
> catch some system exception or something similar?
>
> I'm using a litle bit complex setup, so there is no much freedom (at
> least I cannot simplify the situation). First, I'm debugging from
> Eclipse (and it looks this crash happens only while running from
> Eclipse, I've tried from commad line - there is no crash). The
> debugger I'm using is cross-compiled arm-elf-gdb. It is compiled on
> windows (i686) platform:
> GNU gdb (GDB) 6.8.50.20080620
> ...
> This GDB was configured as "--host=i686-pc-cygwin --target=arm-elf".
>
> I doubt this can be linked to GDB version. I recall I've seen this
> crash earlier with arm-elf-gdb 6.5 from GNUARM. I was just skipped
> this crash somehow but now I cannot continue my job.
>
> This arm-elf-gdb is running against skyeye simulator as a remote
> target.
>
> As you can see there are many possibilities for mailfunctioning
> software (Eclipse, GDB, skyeye). But the only way I can find the
> root cause is to debug the crash in arm-elf-gdb. While crashing it
> attempts to create the crashdump file, but it is incomplete and
> Cygwin gdb cannot recognize it. Typically it contains just three
> lines:
>
> Stack trace:
> Frame Function Args
> 0022E268 7C802532 (00000058
>
> If attached, Cygwin GDB just reporting me:
> Program exited with code 037777777777.
>
> Is there any way to stop arm-elf-gdb on some critical error?
>
> Dmitry
>
>