From 8fe45924387be6b5c1be59a7eb330790c61d5d10 Mon Sep 17 00:00:00 2001 From: Teng Qin Date: Mon, 24 Apr 2017 19:00:37 -0700 Subject: bpf: map_get_next_key to return first key on NULL When iterating through a map, we need to find a key that does not exist in the map so map_get_next_key will give us the first key of the map. This often requires a lot of guessing in production systems. This patch makes map_get_next_key return the first key when the key pointer in the parameter is NULL. Signed-off-by: Teng Qin Signed-off-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- tools/testing/selftests/bpf/test_maps.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c index 20f1871874df..a977c4f7b0ce 100644 --- a/tools/testing/selftests/bpf/test_maps.c +++ b/tools/testing/selftests/bpf/test_maps.c @@ -28,7 +28,7 @@ static int map_flags; static void test_hashmap(int task, void *data) { - long long key, next_key, value; + long long key, next_key, first_key, value; int fd; fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value), @@ -89,10 +89,13 @@ static void test_hashmap(int task, void *data) assert(bpf_map_delete_elem(fd, &key) == -1 && errno == ENOENT); /* Iterate over two elements. */ + assert(bpf_map_get_next_key(fd, NULL, &first_key) == 0 && + (first_key == 1 || first_key == 2)); assert(bpf_map_get_next_key(fd, &key, &next_key) == 0 && - (next_key == 1 || next_key == 2)); + (next_key == first_key)); assert(bpf_map_get_next_key(fd, &next_key, &next_key) == 0 && - (next_key == 1 || next_key == 2)); + (next_key == 1 || next_key == 2) && + (next_key != first_key)); assert(bpf_map_get_next_key(fd, &next_key, &next_key) == -1 && errno == ENOENT); @@ -105,6 +108,8 @@ static void test_hashmap(int task, void *data) key = 0; /* Check that map is empty. */ + assert(bpf_map_get_next_key(fd, NULL, &next_key) == -1 && + errno == ENOENT); assert(bpf_map_get_next_key(fd, &key, &next_key) == -1 && errno == ENOENT); @@ -133,7 +138,7 @@ static void test_hashmap_percpu(int task, void *data) { unsigned int nr_cpus = bpf_num_possible_cpus(); long long value[nr_cpus]; - long long key, next_key; + long long key, next_key, first_key; int expected_key_mask = 0; int fd, i; @@ -193,7 +198,13 @@ static void test_hashmap_percpu(int task, void *data) assert(bpf_map_delete_elem(fd, &key) == -1 && errno == ENOENT); /* Iterate over two elements. */ + assert(bpf_map_get_next_key(fd, NULL, &first_key) == 0 && + ((expected_key_mask & first_key) == first_key)); while (!bpf_map_get_next_key(fd, &key, &next_key)) { + if (first_key) { + assert(next_key == first_key); + first_key = 0; + } assert((expected_key_mask & next_key) == next_key); expected_key_mask &= ~next_key; @@ -219,6 +230,8 @@ static void test_hashmap_percpu(int task, void *data) key = 0; /* Check that map is empty. */ + assert(bpf_map_get_next_key(fd, NULL, &next_key) == -1 && + errno == ENOENT); assert(bpf_map_get_next_key(fd, &key, &next_key) == -1 && errno == ENOENT); @@ -264,6 +277,8 @@ static void test_arraymap(int task, void *data) assert(bpf_map_lookup_elem(fd, &key, &value) == -1 && errno == ENOENT); /* Iterate over two elements. */ + assert(bpf_map_get_next_key(fd, NULL, &next_key) == 0 && + next_key == 0); assert(bpf_map_get_next_key(fd, &key, &next_key) == 0 && next_key == 0); assert(bpf_map_get_next_key(fd, &next_key, &next_key) == 0 && @@ -319,6 +334,8 @@ static void test_arraymap_percpu(int task, void *data) assert(bpf_map_lookup_elem(fd, &key, values) == -1 && errno == ENOENT); /* Iterate over two elements. */ + assert(bpf_map_get_next_key(fd, NULL, &next_key) == 0 && + next_key == 0); assert(bpf_map_get_next_key(fd, &key, &next_key) == 0 && next_key == 0); assert(bpf_map_get_next_key(fd, &next_key, &next_key) == 0 && @@ -400,6 +417,8 @@ static void test_map_large(void) errno == E2BIG); /* Iterate through all elements. */ + assert(bpf_map_get_next_key(fd, NULL, &key) == 0); + key.c = -1; for (i = 0; i < MAP_SIZE; i++) assert(bpf_map_get_next_key(fd, &key, &key) == 0); assert(bpf_map_get_next_key(fd, &key, &key) == -1 && errno == ENOENT); @@ -499,6 +518,7 @@ static void test_map_parallel(void) errno == EEXIST); /* Check that all elements were inserted. */ + assert(bpf_map_get_next_key(fd, NULL, &key) == 0); key = -1; for (i = 0; i < MAP_SIZE; i++) assert(bpf_map_get_next_key(fd, &key, &key) == 0); @@ -518,6 +538,7 @@ static void test_map_parallel(void) /* Nothing should be left. */ key = -1; + assert(bpf_map_get_next_key(fd, NULL, &key) == -1 && errno == ENOENT); assert(bpf_map_get_next_key(fd, &key, &key) == -1 && errno == ENOENT); } -- cgit v1.2.3-58-ga151