Commit d937bc34 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

bpf: make uniform use of array->elem_size everywhere in arraymap.c 



BPF_MAP_TYPE_ARRAY is rounding value_size to closest multiple of 8 and
stores that as array->elem_size for various memory allocations and
accesses.

But the code tends to re-calculate round_up(map->value_size, 8) in
multiple places instead of using array->elem_size. Cleaning this up and
making sure we always use array->size to avoid duplication of this
(admittedly simple) logic for consistency.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220715053146.1291891-3-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 87ac0d60

kernel/bpf/arraymap.c

+8 −6
Original line number Diff line number Diff line
@@ -208,7 +208,7 @@ static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) 
{

	struct bpf_array *array = container_of(map, struct bpf_array, map);

	struct bpf_insn *insn = insn_buf;

	u32 elem_size = round_up(map->value_size, 8);

	u32 elem_size = array->elem_size;

	const int ret = BPF_REG_0;

	const int map_ptr = BPF_REG_1;

	const int index = BPF_REG_2;
@@ -277,7 +277,7 @@ int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value) 
	 * access 'value_size' of them, so copying rounded areas

	 * will not leak any kernel data

	 */

	size = round_up(map->value_size, 8);

	size = array->elem_size;

	rcu_read_lock();

	pptr = array->pptrs[index & array->index_mask];

	for_each_possible_cpu(cpu) {
@@ -381,7 +381,7 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, 
	 * returned or zeros which were zero-filled by percpu_alloc,

	 * so no kernel data leaks possible

	 */

	size = round_up(map->value_size, 8);

	size = array->elem_size;

	rcu_read_lock();

	pptr = array->pptrs[index & array->index_mask];

	for_each_possible_cpu(cpu) {
@@ -587,6 +587,7 @@ static int __bpf_array_map_seq_show(struct seq_file *seq, void *v) 
	struct bpf_iter_seq_array_map_info *info = seq->private;

	struct bpf_iter__bpf_map_elem ctx = {};

	struct bpf_map *map = info->map;

	struct bpf_array *array = container_of(map, struct bpf_array, map);

	struct bpf_iter_meta meta;

	struct bpf_prog *prog;

	int off = 0, cpu = 0;
@@ -607,7 +608,7 @@ static int __bpf_array_map_seq_show(struct seq_file *seq, void *v) 
			ctx.value = v;

		} else {

			pptr = v;

			size = round_up(map->value_size, 8);

			size = array->elem_size;

			for_each_possible_cpu(cpu) {

				bpf_long_memcpy(info->percpu_value_buf + off,

						per_cpu_ptr(pptr, cpu),
@@ -637,11 +638,12 @@ static int bpf_iter_init_array_map(void *priv_data, 
{

	struct bpf_iter_seq_array_map_info *seq_info = priv_data;

	struct bpf_map *map = aux->map;

	struct bpf_array *array = container_of(map, struct bpf_array, map);

	void *value_buf;

	u32 buf_size;



	if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {

		buf_size = round_up(map->value_size, 8) * num_possible_cpus();

		buf_size = array->elem_size * num_possible_cpus();

		value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);

		if (!value_buf)

			return -ENOMEM;
@@ -1326,7 +1328,7 @@ static int array_of_map_gen_lookup(struct bpf_map *map, 
				   struct bpf_insn *insn_buf)

{

	struct bpf_array *array = container_of(map, struct bpf_array, map);

	u32 elem_size = round_up(map->value_size, 8);

	u32 elem_size = array->elem_size;

	struct bpf_insn *insn = insn_buf;

	const int ret = BPF_REG_0;

	const int map_ptr = BPF_REG_1;