Lightweight memory leak debugging on linux

I would like to advertise my just announced heaptrack utility, which should be just what you where looking for back then. You can find more information here: http://milianw.de/blog/heaptrack-a-heap-memory-profiler-for-linux

Compared to your heapwatch tool, the performance should be far better, as I use libunwind and later libbacktrace to delay the annotation of the backtrace with DWARF debug information.

I'd love to get more feedback on it, so try it out!

memleax should work for you.

It debugs memory leak of a running process by attaching it, without recompiling program or restarting target process. It's very convenient and suitable for production environment.

It TRAPs only for malloc/free() calls, so it should bring less performace impact than Vagrild.

It works on GNU/Linux-x86_64 and FreeBSD-amd64.

NOTE: I'm the author, any suggestion is welcomed

GNU libc has built-in malloc debugging:

http://www.gnu.org/software/libc/manual/html_node/Allocation-Debugging.html

Use LD_PRELOAD to call mtrace() from your own .so:

#include <mcheck.h>
static void prepare(void) __attribute__((constructor));
static void prepare(void)
{
    mtrace();
}

Compile it with:

gcc -shared -fPIC dbg.c -o dbg.so

Run it with:

export MALLOC_TRACE=out.txt
LD_PRELOAD=./dbg.so ./my-leaky-program

Later inspect the output file:

mtrace ./my-leaky-program out.txt

And you will get something like:

Memory not freed:
-----------------
           Address     Size     Caller
0x0000000001bda460     0x96  at /tmp/test/src/test.c:7

Of course, feel free to write your own malloc hooks that dump the entire stack (calling backtrace() if you think that's going to help).

Lines numbers and/or function names will be obtainable if you kept debug info for the binary somewhere (e.g. the binary has some debug info built in, or you did objcopy --only-keep-debug my-leaky-program my-leaky-program.debug).

---

Also, you could try Boehm's GC, it works as a leak detector too:

http://www.hpl.hp.com/personal/Hans_Boehm/gc/leak.html