Lightweight memory leak debugging on linux

Question

I looked for existing answers first and saw that Valgrind is everyone’s favorite tool for memory leak debugging on linux. Unfortunately Valgrind does not seem

Answer 1

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

Answer 2

MemoryScape would meet your needs. This is the dynamic memory debugging tool that comes with the TotalView debugger.

http://www.roguewave.com/products/memoryscape.aspx

Answer 3

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!

Answer 4

Surprisingly, I was unable to find anything like Microsoft's UMDH in open-source domain or available for immediate download. (I also looked at Google Heap Leak Checker but it is more like Valgrind rather than to UMDH). So I ended up writing the tool myself using malloc instrumentation project as a reference point:

https://github.com/glagolig/heapwatch

The tool has number of limitations, but it worked just fine for my purposes.

Answer 5

There is a free, open source tool called chap that will do most of what you want. It specifically will not give you stack traces, but it is an extremely light weight tool because it doesn't require any instrumentation at all. All you need is to be able to grab a live core of the process in question, at a point at which you believe the process has already exhibited the bug (so you believe that it has leaked or is too large or whatever).

For details, see https://github.com/vmware/chap

Answer 6

@glagolig,

Yes, MemoryScape can group allocations by stack location.

Were you able to get the evaluation version? Assuming you used an email address that doesn't look like a bot you should have heard back from us pretty quickly. If not, or if you are having technical trouble with it give me a shout or reach out to our tech support team.

Chris Gottbrath

Principal Product Manager for TotalView at Rogue Wave Software

email: Firstname . Lastname (at) roguewave . com