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| author | Martin KaFai Lau <kafai@fb.com> | 2017-06-28 08:08:34 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-06-29 19:13:25 +0200 |
| commit | 14dc6f04f49dc12614d7e90928b495b8d73cd471 (patch) | |
| tree | 159ebddef04be2ae417c503ab46593be570c680f /kernel/bpf/syscall.c | |
| parent | net: stmmac: Add additional registers for dwmac1000_dma ethtool (diff) | |
| download | linux-14dc6f04f49dc12614d7e90928b495b8d73cd471.tar.xz linux-14dc6f04f49dc12614d7e90928b495b8d73cd471.zip | |
bpf: Add syscall lookup support for fd array and htab
This patch allows userspace to do BPF_MAP_LOOKUP_ELEM on
BPF_MAP_TYPE_PROG_ARRAY,
BPF_MAP_TYPE_ARRAY_OF_MAPS and
BPF_MAP_TYPE_HASH_OF_MAPS.
The lookup returns a prog-id or map-id to the userspace.
The userspace can then use the BPF_PROG_GET_FD_BY_ID
or BPF_MAP_GET_FD_BY_ID to get a fd.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
| -rw-r--r-- | kernel/bpf/syscall.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 8942c820d620..4409ccca8831 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -24,6 +24,13 @@ #include <linux/kernel.h> #include <linux/idr.h> +#define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \ + (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ + (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ + (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) +#define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) +#define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map)) + DEFINE_PER_CPU(int, bpf_prog_active); static DEFINE_IDR(prog_idr); static DEFINE_SPINLOCK(prog_idr_lock); @@ -411,6 +418,8 @@ static int map_lookup_elem(union bpf_attr *attr) map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) value_size = round_up(map->value_size, 8) * num_possible_cpus(); + else if (IS_FD_MAP(map)) + value_size = sizeof(u32); else value_size = map->value_size; @@ -426,9 +435,10 @@ static int map_lookup_elem(union bpf_attr *attr) err = bpf_percpu_array_copy(map, key, value); } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { err = bpf_stackmap_copy(map, key, value); - } else if (map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS || - map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { - err = -ENOTSUPP; + } else if (IS_FD_ARRAY(map)) { + err = bpf_fd_array_map_lookup_elem(map, key, value); + } else if (IS_FD_HASH(map)) { + err = bpf_fd_htab_map_lookup_elem(map, key, value); } else { rcu_read_lock(); ptr = map->ops->map_lookup_elem(map, key); |