Memory leak in a shared library plugin

[Cason, Kenny]

Howdy:

I need help determining why memory continuously increases for a process that calls a shared library. Several sets of eyes have scanned the code for many months without success in stopping the memory leakage, if that's what it is. Your input on tools and/or advice are desperately needed.

BTW: because the plugin described below does not run from the command line I have not had practical success with valgrind nor gdb. Purify is installed but hasn't been helpful either. I've heard rumors there might be a switch on the gcc compiler that will help but, if so, it's been elusive.

Situation:

Linux 2.6.9-89.0.9.ELsmp #1 SMP Wed Aug 19 08:07:15 EDT 2009 i686 i686 i386 GNU/Linux
gcc/g++ 3.4.6

Daemon A:
  1) uses pPlugin B
  2) is owned by a vendor and I have no source code
  3) shows increasing memory usage when calling Plugin B, but not otherwise


Plugin B:
  1) written in-house so I have all the source code
  2) is compiled and linked as a shared library
  3) does not run from the command line so use of gdb and breakpoints is of little value

The memory usage of Daemon A continuously increases while repeatedly calling Plugin B, which leads me to believe there is either a memory leak in Plugin B or in the mechanism used by Daemon A to call it. Using the command: ps -efl | grep <process> the memory size (SZ) shown every 5 seconds like this:

F S UID        PID  PPID  C PRI  NI ADDR SZ WCHAN  STIME TTY          TIME CMD
4 S root     23129     1  0  78   0 - 59079 -      13:28 ?        00:00:39
4 S root     23129     1  0  78   0 - 59747 -      13:28 ?        00:00:40
4 S root     23129     1  0  78   0 - 59817 -      13:28 ?        00:00:40
4 S root     23129     1  0  78   0 - 59935 -      13:28 ?        00:00:41
4 S root     23129     1  0  78   0 - 60575 -      13:28 ?        00:00:42
4 S root     23129     1  0  78   0 - 60735 -      13:28 ?        00:00:44
4 S root     23129     1  0  78   0 - 61106 -      13:28 ?        00:00:45
4 S root     23129     1  0  78   0 - 61213 -      13:28 ?        00:00:46
4 S root     23129     1  0  78   0 - 61296 -      13:28 ?        00:00:47
4 S root     23129     1  0  78   0 - 61683 -      13:28 ?        00:00:48
4 S root     23129     1  0  78   0 - 61774 -      13:28 ?        00:00:49
4 S root     23129     1  0  78   0 - 61875 -      13:28 ?        00:00:50
4 S root     23129     1  0  78   0 - 61902 -      13:28 ?        00:00:51

Target:

Determine why the memory continuously increases (memory leak?) for Daemon A. If it's a memory leak is it in Daemon A or Plugin B.


Proposed Solution:

This is where I need someone smarter than me to elucidate the path to a solution. Please!!!
As it is I have no visibility to where the memory is being eaten up nor why other than the "ps" command above.


Thanks,

-Kenny

Information Security - Identity Management & Authorization Controls
kenny.cason@boeing.com
206-550-0049