From 4daab7132731ac5ec9384c8a070cdb9607dc38c8 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 2 Sep 2020 16:53:41 -0700 Subject: selftests/bpf: Add bpf_{update, delete}_map_elem in hashmap iter program Added bpf_{updata,delete}_map_elem to the very map element the iter program is visiting. Due to rcu protection, the visited map elements, although stale, should still contain correct values. $ ./test_progs -n 4/18 #4/18 bpf_hash_map:OK #4 bpf_iter:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200902235341.2001534-1-yhs@fb.com --- tools/testing/selftests/bpf/progs/bpf_iter_bpf_hash_map.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_bpf_hash_map.c b/tools/testing/selftests/bpf/progs/bpf_iter_bpf_hash_map.c index 07ddbfdbcab7..6dfce3fd68bc 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_bpf_hash_map.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_bpf_hash_map.c @@ -47,7 +47,10 @@ int dump_bpf_hash_map(struct bpf_iter__bpf_map_elem *ctx) __u32 seq_num = ctx->meta->seq_num; struct bpf_map *map = ctx->map; struct key_t *key = ctx->key; + struct key_t tmp_key; __u64 *val = ctx->value; + __u64 tmp_val = 0; + int ret; if (in_test_mode) { /* test mode is used by selftests to @@ -61,6 +64,18 @@ int dump_bpf_hash_map(struct bpf_iter__bpf_map_elem *ctx) if (key == (void *)0 || val == (void *)0) return 0; + /* update the value and then delete the pair. + * it should not impact the existing 'val' which is still + * accessible under rcu. + */ + __builtin_memcpy(&tmp_key, key, sizeof(struct key_t)); + ret = bpf_map_update_elem(&hashmap1, &tmp_key, &tmp_val, 0); + if (ret) + return 0; + ret = bpf_map_delete_elem(&hashmap1, &tmp_key); + if (ret) + return 0; + key_sum_a += key->a; key_sum_b += key->b; key_sum_c += key->c; -- cgit