Issue
I'm trying to do some debugging on a server on an issue that I suspect is related to a buffer overflow, so I tried to compile my code with -fsanitize=address to enable address sanitizing.
It compiled, and the resulting software runs. However, I'm trying to get a core dump when the address sanitizer detects an error since that is pretty much the only way I can get information out of the system due to the setup.
I am calling the software with ASAN_OPTIONS=abort_on_error=1 prepended on the command line (using a shell script to do that), and have checked that ulimit -c gives unlimited as result, but it just won't produce a core dump.
What am I missing?
This is on an ubuntu 14.04 server with gcc version 4.8.4
EDIT: sysctl kernel.core_pattern gives back kernel.core_pattern = |/usr/share/apport/apport %p %s %c %P. This probably means that apport is enabled (at least in some form). However, I have been able to get proper core files on this system from asserts and SIGFPEs in the software (that is where the suspicion of array overruns comes from).
Solution
Let me guess, is this x64 target? Coredumps are disabled there to avoid dumping 16 TB shadow memory (see docs for disable_coredump here for details).
Newer versions of GCC/Clang remove shadow from core by default so that one could do something like
export ASAN_OPTIONS=abort_on_error=1:disable_coredump=0
but I'm afraid 4.8 is too old for this.
As an alternative suggestion, why backtraces are not enough for you? You could use log_path or log_to_syslog to preserve them if you do not have access to programs stderr.
NB: I posted suggestion to enable coredumps on all platforms.
Answered By - yugr Answer Checked By - Pedro (WPSolving Volunteer)