From ea7c24c78551c8b3e6a7e9824e5ad8ba6224f5fe 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 commit 8fe45924387be6b5c1be59a7eb330790c61d5d10 upstream. 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 Signed-off-by: Chenbo Feng Cc: Lorenzo Colitti Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/arraymap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/bpf/arraymap.c') diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 3608fa1aec8a..0eb11b4ac4c7 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -102,7 +102,7 @@ static void *array_map_lookup_elem(struct bpf_map *map, void *key) static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key) { struct bpf_array *array = container_of(map, struct bpf_array, map); - u32 index = *(u32 *)key; + u32 index = key ? *(u32 *)key : U32_MAX; u32 *next = (u32 *)next_key; if (index >= array->map.max_entries) { -- cgit v1.2.3