Re: [Libunwind-devel] [PATCH 2/2] coredump: add test

[Arun Sharma]

On Tue, May 22, 2012 at 2:51 AM, Martin Milata <address@hidden> wrote:
> Program test-coredump-unwind was modified to map backing files based on
> virtual addresses instead of segment numbers.
>
> The crasher.c is a program that calls some functions and then writes to
> invalid address causing a crash.
>
> The test itself is a shell script, which runs the program. The script
> then tries to determine the virtual addresses based on output of 'ldd'
> and 'readelf' and then runs test-coredump-unwind to check whether the
> stack trace obtained from the dump roughly corresponds to what it should
> look like.

You probably want to check for  /proc/sys/kernel/randomize_va_space
being non-zero and warn.

Even after that I'm getting a test failure:
Segmentation fault (core dumped)
lt-test-coredump-unwind: Can't add backing file
'/lib/x86_64-linux-gnu/libc.so.6'

Also a few compile warnings with gcc-4.6.3:

test-coredump-unwind.c: In function ‘handle_sigsegv’:
test-coredump-unwind.c:208:15: warning: variable ‘uc’ set but not used
[-Wunused-but-set-variable]
test-coredump-unwind.c: In function ‘verror_msg_helper’:
test-coredump-unwind.c:138:12: warning: ignoring return value of
‘write’, declared with attribute warn_unused_result [-Wunused-result]
test-coredump-unwind.c: In function ‘handle_sigsegv’:
test-coredump-unwind.c:222:10: warning: ‘ip’ is used uninitialized in
this function [-Wuninitialized]

The other patch looks good. I applied it to the 'coredump2' branch,
merged it into master. It should show up on savannah shortly.

 -Arun