kernel/bpf/bpf_local_storage.c

27 static int mem_charge(struct bpf_local_storage_map *smap, void *owner, u32 size)
34 	return map->ops->map_local_storage_charge(smap, owner, size);
37 static void mem_uncharge(struct bpf_local_storage_map *smap, void *owner,
43 		map->ops->map_local_storage_uncharge(smap, owner, size);
47 owner_storage(struct bpf_local_storage_map *smap, void *owner)
51 	return map->ops->map_owner_storage_ptr(owner);
75 bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner,
80 	if (charge_mem && mem_charge(smap, owner, smap->elem_size))
109 		mem_uncharge(smap, owner, smap->elem_size);
259 	void *owner;
262 	owner = local_storage->owner;
264 	/* All uncharging on the owner must be done first.
265 	 * The owner may be freed once the last selem is unlinked
269 		mem_uncharge(smap, owner, smap->elem_size);
274 		mem_uncharge(smap, owner, sizeof(struct bpf_local_storage));
275 		local_storage->owner = NULL;
277 		/* After this RCU_INIT, owner may be freed and cannot be used */
278 		RCU_INIT_POINTER(*owner_storage(smap, owner), NULL);
448 int bpf_local_storage_alloc(void *owner,
457 	err = mem_charge(smap, owner, sizeof(*storage));
478 	storage->owner = owner;
484 		(struct bpf_local_storage **)owner_storage(smap, owner);
485 	/* Publish storage to the owner.
486 	 * Instead of using any lock of the kernel object (i.e. owner),
490 	 * From now on, the owner->storage pointer (e.g. sk->sk_bpf_storage)
492 	 * the owner->storage, the storage->lock must be held before
493 	 * setting owner->storage ptr to NULL.
516 	mem_uncharge(smap, owner, sizeof(*storage));
526 bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap,
545 	local_storage = rcu_dereference_check(*owner_storage(smap, owner),
548 		/* Very first elem for the owner */
553 		selem = bpf_selem_alloc(smap, owner, value, true, gfp_flags);
557 		err = bpf_local_storage_alloc(owner, smap, selem, gfp_flags);
560 			mem_uncharge(smap, owner, smap->elem_size);
587 	alloc_selem = selem = bpf_selem_alloc(smap, owner, value, true, gfp_flags);
633 		mem_uncharge(smap, owner, smap->elem_size);
757  * get a hold of the owner PTR_TO_BTF_ID in any context. eg. bpf_get_current_task_btf.
759  * memory immediately. To be reuse-immediate safe, the owner destruction
843 	 * to the owner->storage or to the map bucket's list.