Debugging a crash

[Boris Samorodov]

30.06.2013 19:53, Fernando Apesteguía пишет:
> On Sun, Jun 30, 2013 at 5:36 PM, Boris Samorodov <bsam at passap.ru> wrote:
> 
>> Hi All,
>>
>> I get an application crashing. Build some libs with debug symbols.
>> Here is the gdb log:
>> -----
>> Program received signal SIGSEGV, Segmentation fault.
>> [Switching to Thread 809806400 (LWP 101133/photoprint)]
>> strtol_l (nptr=0x0, endptr=0x0, base=10, locale=<value optimized out>)
>> at /usr/src/lib/libc/stdlib/strtol.c:73
>> 73              } while (isspace_l((unsigned char)c, locale));
>> Current language:  auto; currently minimal
>> (gdb) bt
>> #0  strtol_l (nptr=0x0, endptr=0x0, base=10, locale=<value optimized
> 
>                         ^^^^
> It seems you are passing a NULL str to strtol.

OK. So how to proceed in debugging it?

>> out>) at /usr/src/lib/libc/stdlib/strtol.c:73
>> #1  0x00000008017d951c in ps_parameters (v=0x809d0dc00, name=0x80996c120
>> "JCLBOXHOLDTYPE", description=0x7fffffffd0a8) at print-ps.c:380
>> #2  0x00000008017996df in stp_describe_parameter (v=0x809d0dc00,
>> name=0x80996c120 "JCLBOXHOLDTYPE", description=0x7fffffffd0a8) at
>> print-vars.c:1687
>> #3  0x000000000046cfd2 in ?? ()
>> #4  0x00000000004627a1 in ?? ()
>> #5  0x0000000000461da4 in ?? ()
>> #6  0x00000000004657fe in ?? ()
>> #7  0x0000000000422863 in ?? ()
>> #8  0x0000000000421f45 in ?? ()
>> #9  0x000000000041054f in ?? ()
>> #10 0x0000000800719000 in ?? ()
>> #11 0x0000000000000000 in ?? ()
>> (gdb) fr 0
>> #0  strtol_l (nptr=0x0, endptr=0x0, base=10, locale=<value optimized
>> out>) at /usr/src/lib/libc/stdlib/strtol.c:73
>> 73              } while (isspace_l((unsigned char)c, locale));
>> (gdb) fr 1
>> #1  0x00000008017d951c in ps_parameters (v=0x809d0dc00, name=0x80996c120
>> "JCLBOXHOLDTYPE", description=0x7fffffffd0a8) at print-ps.c:380
>> 380       num_choices = atoi(stp_mxmlElementGetAttr(option,
>> "num_choices"));
>> (gdb) fr 2
>> #2  0x00000008017996df in stp_describe_parameter (v=0x809d0dc00,
>> name=0x80996c120 "JCLBOXHOLDTYPE", description=0x7fffffffd0a8) at
>> print-vars.c:1687
>> 1687      stp_printer_describe_parameter(v, name, description);
>> (gdb)
>> -----
>>
>> How should I proceed with debugging? Thanks!

-- 
WBR, Boris Samorodov (bsam)
FreeBSD Committer, http://www.FreeBSD.org The Power To Serve