Commit baa8fdec authored by Hou Tao's avatar Hou Tao Committed by Alexei Starovoitov
Browse files

bpf: Re-enable unit_size checking for global per-cpu allocator 



With pcpu_alloc_size() in place, check whether or not the size of
the dynamic per-cpu area is matched with unit_size.

Signed-off-by: default avatarHou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-4-houtao@huaweicloud.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent b460bc83

kernel/bpf/memalloc.c

+12 −10
Original line number Diff line number Diff line
@@ -491,21 +491,17 @@ static int check_obj_size(struct bpf_mem_cache *c, unsigned int idx) 
	struct llist_node *first;

	unsigned int obj_size;



	/* For per-cpu allocator, the size of free objects in free list doesn't

	 * match with unit_size and now there is no way to get the size of

	 * per-cpu pointer saved in free object, so just skip the checking.

	 */

	if (c->percpu_size)

		return 0;



	first = c->free_llist.first;

	if (!first)

		return 0;



	if (c->percpu_size)

		obj_size = pcpu_alloc_size(((void **)first)[1]);

	else

		obj_size = ksize(first);

	if (obj_size != c->unit_size) {

		WARN_ONCE(1, "bpf_mem_cache[%u]: unexpected object size %u, expect %u\n",

			  idx, obj_size, c->unit_size);

		WARN_ONCE(1, "bpf_mem_cache[%u]: percpu %d, unexpected object size %u, expect %u\n",

			  idx, c->percpu_size, obj_size, c->unit_size);

		return -EINVAL;

	}

	return 0;
@@ -973,6 +969,12 @@ void notrace *bpf_mem_cache_alloc_flags(struct bpf_mem_alloc *ma, gfp_t flags) 
	return !ret ? NULL : ret + LLIST_NODE_SZ;

}



/* The alignment of dynamic per-cpu area is 8, so c->unit_size and the

 * actual size of dynamic per-cpu area will always be matched and there is

 * no need to adjust size_index for per-cpu allocation. However for the

 * simplicity of the implementation, use an unified size_index for both

 * kmalloc and per-cpu allocation.

 */

static __init int bpf_mem_cache_adjust_size(void)

{

	unsigned int size;