Re: [PATCH] selftests: memcg: uninitialized variable in test_memcg_reclaim()

[Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>]

On Tue, Jul 19, 2022 at 10:27:36AM -0700, Yosry Ahmed wrote:
> 
> Nit: keep the cleanup_* naming for labels to make it obvious and to be
> consistent with the rest of the file (e.g. cleanup_free,
> cleanup_memcg, cleanup_file/cleanup_all). See
> test_memcg_subtree_control().
> 
> I would honestly have one label to cleanup the memcg. Calling
> cg_destroy() on a non-existent memcg should be fine. rmdir() will just
> fail silently. All other tests do this and it's easier to read when we
> have fewer return paths. My advice would be cleanup_file and
> cleanup_memcg labels.

One error label handling is very bug prone.  You always end up freeing
things which have not been initialized/allocated.  Or dereferencing
pointers which are NULL.  Or, since most kernel functions clean up
after themselves, you end up double freeing things.

regards,
dan carpenter