[PATCH] fix broken lib/genalloc.c

genalloc improperly stores the sizes of freed chunks, allocates overlapping
memory regions, and oopses after its in-band data is overwritten.

Signed-off-by: Chris Humbert <mahadri-kernel@drigon.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>