glibc

malloc tracer `mtrace(3)`

Trace memory allocation and de-allocation to detect memory leaks. -Need to call mtrace(3) to install the tracing hooks.

If we can't modify the binary to call mtrace we can create a small shared -library and pre-load it.

// libmtrace.c
-#include <mcheck.h>
-__attribute__((constructor))  static void init_mtrace() { mtrace(); }
-

Compile as:

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

To generate the trace file run:

export MALLOC_TRACE=<file>
-LD_PRELOAD=./libmtrace.so <binary>
-

Note: If MALLOC_TRACE is not set mtrace won't install tracing hooks.

To get the results of the trace file:

mtrace <binary> $MALLOC_TRACE
-

malloc check `mallopt(3)`

Configure action when glibc detects memory error.

export MALLOC_CHECK_=<N>
-

Useful values:

1   print detailed error & continue
-3   print detailed error + stack trace + memory mappings & abort
-7   print simple error message + stack trace + memory mappings & abort
-

- -

Notes

glibc

malloc tracer mtrace(3)

malloc check mallopt(3)

malloc tracer `mtrace(3)`

malloc check `mallopt(3)`