Compile and Using MariaDB with AddressSanitizer (ASAN)
Contents
What is AddressSanitizer (ASAN)
AddressSanitizer (aka ASan) is a memory error detector for C/C++. It finds a lot of the same things as valgrind, but with a lot less overhead.
- Use after free (dangling pointer dereference)
- Heap buffer overflow
- Stack buffer overflow
- Global buffer overflow
- Use after return
- Use after scope
- Initialization order bugs
- Memory leaks
To use ASAN you need a gcc version that supports ASAN. gcc 4.8.5 and up are known to work.
How to Compile MariaDB for ASAN
ASAN is supported in MariaDB 10.1 and up.
You can use one of the two following build commands:
cmake . -DWITH_ASAN=ON
or from MariaDB 10.2 and up:
./BUILD/compile-pentium64-asan-max
Running an ASAN Build
To run mysqld with instrumentation you have to set the ASAN_OPTIONS environment variable before starting mysqld. Either in your shell or in your mysqld_safe script.
export ASAN_OPTIONS=abort_on_error=1
The above command will abort any instrumented executable if any errors are found, which is good for debugging. If you set abort_on_error=0 all server errors are logged to your error log file (mysqld.err).
To catch errors for other processes than the server, you can set more options, like this:
export ASAN_OPTIONS=abort_on_error=1:log_path=/tmp/asan
If you are seeing an incomplete stack trace for a memory allocation, you may rerun the failing test with
export ASAN_OPTIONS=abort_on_error=1:log_path=/tmp/asan:fast_unwind_on_malloc=0
To get core dumps of failures:
export ASAN_OPTIONS=abort_on_error=1:disable_coredump=0
To see all the options (or to check if an executable is instrumented), you may try the following:
ASAN_OPTIONS=help=1 extra/perror 0
Using Valgrind
The MariaDB test system can use Valgrind for finding memory leaks and wrong memory accesses. Valgrind is an instrumentation framework for building dynamic analysis tools. If Valgrind is installed on your system, you can simply use mysql-test-run --valgrind to run the test under Valgrind.
