Mark freed pointer to NULL in wrapper for u_free()

[raveendrapadala]

As u_free is a wrapper function, so i think it would be a good idea to mark the freed pointer to NULL.
The advantages can be:

1. Dangling pointer usage can be caught, if any existing.
2. Unexpected behaviour due to double free can be eradicated. -- manual page for free says "if free(ptr) has already been called before, undefined behavior occurs. If ptr is NULL, no operation is performed."

Fix Description:-
File Name: memory.c
Path: src/lib/u/memory.c
Macro: u_free
/** \brief Wrapper for free(3), sanity checks the supplied pointer */

define u_free(ptr) if(ptr){free(ptr);ptr=NULL;}

[raveendrapadala]

Hi Klaus,

Related to the memory leaks.
we prepared report by writing a wrapper for malloc, calloc, realloc and free to check for memory leaks. Generated report is given at the end.

We are analyzing this report. It would be great if you can help us finding the potential memory leaks.
Each entry in report can be read as: "filename:LineNumber@Number of Times "

Executed a WS-Man command that has one instance and nearly 60 properties:

Entries in Generated Report:
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/wsman-server.c:104@2times
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/list.c:233 : @12times
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/hash.c:372 : @1time
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/hash.c:305 : @2TIMES
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/hash.c:302 : @2TIMES
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/hash.c:375 : @1Times
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/memory.c:32 : @16times
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/iniparser.c:226 : @1Times
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/memory.c:20 : @31times
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/list.c:73 : @22times
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/iniparser.c:221 : @1time
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/iniparser.c:224 : @1time
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/iniparser.c:225 : @1time
/home/Raveendra_Reddy/13G_WAVE3/build-yocto-sh4/tmp/work/sh4-poky-linux/openwsman-2.4.10-r4.0/openwsman-2.4.10/src/lib/u/hash.c:817 : @1time

[kkaempf]

src/lib/wsman-server.c:104@2times looks harmless. That's the plugin initialization at startup. Memory should be freed at teardown. But the operating system will also take care of this when the process exits

[kkaempf]

src/lib/u/list.c:233 - uhm, that's the create function and its purpose is to malloc. It's the callers responsibility to free memory.

You might be better off with using valgrind (http://valgrind.org/) which does a full coverage