mm: kfence: fix objcgs vector allocation
authorMuchun Song <songmuchun@bytedance.com>
Fri, 1 Apr 2022 18:28:36 +0000 (11:28 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 1 Apr 2022 18:46:09 +0000 (11:46 -0700)
commit8f0b36497303487d5a32c75789c77859cc2ee895
tree232415b951aae1b938d87e1739f99117bddf476f
parentadb11e78c5dc5e26774acb05f983da36447f7911
mm: kfence: fix objcgs vector allocation

If the kfence object is allocated to be used for objects vector, then
this slot of the pool eventually being occupied permanently since the
vector is never freed.  The solutions could be (1) freeing vector when
the kfence object is freed or (2) allocating all vectors statically.

Since the memory consumption of object vectors is low, it is better to
chose (2) to fix the issue and it is also can reduce overhead of vectors
allocating in the future.

Link: https://lkml.kernel.org/r/20220328132843.16624-1-songmuchun@bytedance.com
Fixes: d3fb45f370d9 ("mm, kfence: insert KFENCE hooks for SLAB")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/kfence/core.c
mm/kfence/kfence.h