Re: How to catch GDB crash

["Dr. Rolf Jansen" <rj at surtec dot com>]

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