Re: [re] Java executables can abort trying to access a null pointer in a leaf function

[David Daney <ddaney at avtrex dot com>]

tsuraan wrote:
> > Just run the thing under GDB,  Set most signals (other than SIGABRT) to
> > noprint nostop pass.  Then print the trace when gdb stops in the abort.
>
>
> Invoking gdb with
>
> LD_LIBRARY_PATH=/opt/gcc-4.1/lib gdb ./nullpointer
>
> When I run I get
>
> Starting program: /home/tsuraan/java/abort/nullpointer
> Cannot find thread 2: Thread ID=1, generic error
>
> My gdb version is
>
> GNU gdb 6.1.1 [FreeBSD]
> Copyright 2004 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you are
> welcome to change it and/or distribute copies of it under certain conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB.  Type "show warranty" for details.
> This GDB was configured as "i386-marcel-freebsd".
>
> A backtrace of the program that showed me this bug (a python program
> using PyLucene) is:
>
> #0  0x2822f31b in pthread_testcancel () from /usr/lib/libpthread.so.1
> #1  0x28220145 in sigaction () from /usr/lib/libpthread.so.1
> #2  0x2821a1dd in pthread_kill () from /usr/lib/libpthread.so.1
> #3  0x28219bac in raise () from /usr/lib/libpthread.so.1
> #4  0x282eac1b in abort () from /lib/libc.so.5
> #5  0x28e5800c in _Jv_Throw (value=0x8c06ac8)
>     at ../../../gcc-4.1-20051029/libjava/exception.cc:111
                                          ^^^^^^^^^^^^^^^^^^^^
Yeah, I've seen that before.

As aph said it is likley bad DWARF unwinding data.

Someone will need the assembly and/or object file for a small test case 
to examine the DWARF frame data.

David Daney