Commit abbdd081 authored by Roman Gushchin's avatar Roman Gushchin Committed by Alexei Starovoitov
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bpf: Eliminate rlimit-based memory accounting for bpf ringbuffer 



Do not use rlimit-based memory accounting for bpf ringbuffer.
It has been replaced with the memcg-based memory accounting.

bpf_ringbuf_alloc() can't return anything except ERR_PTR(-ENOMEM)
and a valid pointer, so to simplify the code make it return NULL
in the first case. This allows to drop a couple of lines in
ringbuf_map_alloc() and also makes it look similar to other memory
allocating function like kmalloc().

Signed-off-by: default avatarRoman Gushchin <guro@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-28-guro@fb.com
parent db54330d

kernel/bpf/ringbuf.c

+4 −20
Original line number Diff line number Diff line
@@ -48,7 +48,6 @@ struct bpf_ringbuf { 


struct bpf_ringbuf_map {

	struct bpf_map map;

	struct bpf_map_memory memory;

	struct bpf_ringbuf *rb;

};
@@ -131,7 +130,7 @@ static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node) 


	rb = bpf_ringbuf_area_alloc(data_sz, numa_node);

	if (!rb)

		return ERR_PTR(-ENOMEM);

		return NULL;



	spin_lock_init(&rb->spinlock);

	init_waitqueue_head(&rb->waitq);
@@ -147,8 +146,6 @@ static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node) 
static struct bpf_map *ringbuf_map_alloc(union bpf_attr *attr)

{

	struct bpf_ringbuf_map *rb_map;

	u64 cost;

	int err;



	if (attr->map_flags & ~RINGBUF_CREATE_FLAG_MASK)

		return ERR_PTR(-EINVAL);
@@ -170,26 +167,13 @@ static struct bpf_map *ringbuf_map_alloc(union bpf_attr *attr) 


	bpf_map_init_from_attr(&rb_map->map, attr);



	cost = sizeof(struct bpf_ringbuf_map) +

	       sizeof(struct bpf_ringbuf) +

	       attr->max_entries;

	err = bpf_map_charge_init(&rb_map->map.memory, cost);

	if (err)

		goto err_free_map;



	rb_map->rb = bpf_ringbuf_alloc(attr->max_entries, rb_map->map.numa_node);

	if (IS_ERR(rb_map->rb)) {

		err = PTR_ERR(rb_map->rb);

		goto err_uncharge;

	if (!rb_map->rb) {

		kfree(rb_map);

		return ERR_PTR(-ENOMEM);

	}



	return &rb_map->map;



err_uncharge:

	bpf_map_charge_finish(&rb_map->map.memory);

err_free_map:

	kfree(rb_map);

	return ERR_PTR(err);

}



static void bpf_ringbuf_free(struct bpf_ringbuf *rb)