Commit 2bea33f9 authored by Andrii Nakryiko's avatar Andrii Nakryiko
Browse files

Merge branch 'bpf-add-percpu-map-value-size-check' 

Tao Chen says:

====================
bpf: Add percpu map value size check

Check percpu map value size first and add the test case in selftest.

Change list:
- v2 -> v3:
    - use bpf_map_create API and mv test case in map_percpu_stats.c
- v1 -> v2:
    - round up map value size with 8 bytes in patch 1
    - add selftest case in patch 2
====================

Link: https://lore.kernel.org/r/20240910144111.1464912-1-chen.dylane@gmail.com


Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
parents 300a90b2 7eab3a58

kernel/bpf/arraymap.c

+3 −0
Original line number Diff line number Diff line
@@ -73,6 +73,9 @@ int array_map_alloc_check(union bpf_attr *attr) 
	/* avoid overflow on round_up(map->value_size) */

	if (attr->value_size > INT_MAX)

		return -E2BIG;

	/* percpu map value size is bound by PCPU_MIN_UNIT_SIZE */

	if (percpu && round_up(attr->value_size, 8) > PCPU_MIN_UNIT_SIZE)

		return -E2BIG;



	return 0;

}

kernel/bpf/hashtab.c

+3 −0
Original line number Diff line number Diff line
@@ -462,6 +462,9 @@ static int htab_map_alloc_check(union bpf_attr *attr) 
		 * kmalloc-able later in htab_map_update_elem()

		 */

		return -E2BIG;

	/* percpu map value size is bound by PCPU_MIN_UNIT_SIZE */

	if (percpu && round_up(attr->value_size, 8) > PCPU_MIN_UNIT_SIZE)

		return -E2BIG;



	return 0;

}

tools/testing/selftests/bpf/map_tests/map_percpu_stats.c

+18 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#define MAX_ENTRIES_HASH_OF_MAPS	64

#define N_THREADS			8

#define MAX_MAP_KEY_SIZE		4

#define PCPU_MIN_UNIT_SIZE		32768



static void map_info(int map_fd, struct bpf_map_info *info)

{
@@ -456,6 +457,22 @@ static void map_percpu_stats_hash_of_maps(void) 
	printf("test_%s:PASS\n", __func__);

}



static void map_percpu_stats_map_value_size(void)

{

	int fd;

	int value_sz = PCPU_MIN_UNIT_SIZE + 1;

	struct bpf_map_create_opts opts = { .sz = sizeof(opts) };

	enum bpf_map_type map_types[] = { BPF_MAP_TYPE_PERCPU_ARRAY,

					  BPF_MAP_TYPE_PERCPU_HASH,

					  BPF_MAP_TYPE_LRU_PERCPU_HASH };

	for (int i = 0; i < ARRAY_SIZE(map_types); i++) {

		fd = bpf_map_create(map_types[i], NULL, sizeof(__u32), value_sz, 1, &opts);

		CHECK(fd < 0 && errno != E2BIG, "percpu map value size",

			"error: %s\n", strerror(errno));

	}

	printf("test_%s:PASS\n", __func__);

}



void test_map_percpu_stats(void)

{

	map_percpu_stats_hash();
@@ -467,4 +484,5 @@ void test_map_percpu_stats(void) 
	map_percpu_stats_percpu_lru_hash();

	map_percpu_stats_percpu_lru_hash_no_common();

	map_percpu_stats_hash_of_maps();

	map_percpu_stats_map_value_size();

}