arch/powerpc/kernel/cacheinfo.c: Possible null pointer dereference

Hello there,

I just tried out cppcheck-1.47 on the linux-2.6.38-rc4 source code.

It said

[arch/powerpc/kernel/cacheinfo.c:380]: (error) Possible null pointer dereference: cache - otherwise it is redundant to check if cache is null at line 382

The source code is

    WARN_ONCE(cache && cache->level != level,
          "cache level mismatch on lookup (got %d, expected %d)\n",
          cache->level, level);

    if (!cache)

I agree with cppcheck. Suggest code rework.

Regards

David Binderman

 		 	   		  

On Sat, 2011-02-12 at 10:08 +0000, David Binderman wrote:

Hello there,

I just tried out cppcheck-1.47 on the linux-2.6.38-rc4 source code.

It said

[arch/powerpc/kernel/cacheinfo.c:380]: (error) Possible null pointer
dereference: cache - otherwise it is redundant to check if cache is
null at line 382

The source code is

    WARN_ONCE(cache && cache->level != level,
          "cache level mismatch on lookup (got %d, expected %d)\n",
          cache->level, level);

    if (!cache)

I agree with cppcheck. Suggest code rework.

It's wrong.

The code is essentially:

if (cache && cache->level != level)
	printf("cache level mismatch on lookup (got %d, expected %d)\n", cache->level, level);

if (!cache)
	cache = cache_do_one_devnode(node, level);


Which looks fine to me?

cheers