Memory Debugging on (Open)Solaris

We know there are many commercial tools to debug memory on Solaris systems as Dynamic Suite and Purify. But I prefer to use open source tools always it is possible.

Well, Linux has many open source tools and the best in my opinion is Valgrind, but Valgrind will not be ported to sparc architecture as well to (open)solaris. Then, what tool I should use ?

(Open)Solaris has useful tools to debug memory, the most known is DTrace, but I’ll talk of two important and easiest tools to use: libumem and watchmalloc (equivalent to MALLOC_CHECK from linux).

Using libumem

It’s not need to recompile your application. The library is loaded dynamically by LD_PRELOAD environment variable.

• Prepare your environment

$ setenv UMEM_DEBUG default

$ setenv UMEM_LOGGING transaction

$ setenv LD_PRELOAD libumem.so.1

• Run the application normally

 $ ./myapp

• After the program has passed by all fluxes, generate a core to analyze with mdb

$ gcore `pgrep myapp`

• mdb means Solaris Modular Debugger

$ mdb myapp core.pid

• With mdb opened, just run a simple command (findleaks):

> ::findleaks -dvf
CACHE     LEAKED   BUFCTL CALLER
0014f12f       1 00067000 libumem.so.1`malloc+0x0
----------------------------------------------------------------------
 Total       1 buffer, 48 bytes

Using watchmalloc

Watchmalloc is the linux equivalent to MALLOC_CHECK. The use is most simple than libumem. See it:

• Prepare your environment

$ setenv MALLOC_DEBUG=WATCH,RW

$ setenv LD_PRELOAD watchmalloc.so.1

• Run the application normally

$ ./myapp

• When a leakage happens the program will generate a core dumped and will be possibly to analyze with gdb.