bpf: sockmap: Call sock_map_update_elem directly

Don't go via map->ops to call sock_map_update_elem, since we know
what function to call in bpf_map_update_value. Since we currently
don't allow calling map_update_elem from BPF context, we can remove
ops->map_update_elem and rename the function to sock_map_update_elem_sys.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200821102948.21918-4-lmb@cloudflare.com

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 30c144af894a740a19c1d29f4df4481fb91e5dba..81f38e2fda786fea4119d4f5e2138ece5a138fee 100644 (file)
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1648,6 +1648,7 @@ int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
                         struct bpf_prog *old, u32 which);
 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog);
 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype);
+int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, u64 flags);
 void sock_map_unhash(struct sock *sk);
 void sock_map_close(struct sock *sk, long timeout);
 #else
@@ -1669,6 +1670,12 @@ static inline int sock_map_prog_detach(const union bpf_attr *attr,
 {
        return -EOPNOTSUPP;
 }
+
+static inline int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
+                                          u64 flags)
+{
+       return -EOPNOTSUPP;
+}
 #endif /* CONFIG_BPF_STREAM_PARSER */
 
 #if defined(CONFIG_INET) && defined(CONFIG_BPF_SYSCALL)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 689d736b69041a9735630c5383dd3840e6580e86..b46e973faee934ef7e378e313c117cbc2ebe87b0 100644 (file)
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -157,10 +157,11 @@ static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
        if (bpf_map_is_dev_bound(map)) {
                return bpf_map_offload_update_elem(map, key, value, flags);
        } else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
-                  map->map_type == BPF_MAP_TYPE_SOCKHASH ||
-                  map->map_type == BPF_MAP_TYPE_SOCKMAP ||
                   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
                return map->ops->map_update_elem(map, key, value, flags);
+       } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
+                  map->map_type == BPF_MAP_TYPE_SOCKMAP) {
+               return sock_map_update_elem_sys(map, key, value, flags);
        } else if (IS_FD_PROG_ARRAY(map)) {
                return bpf_fd_array_map_update_elem(map, f.file, key, value,
                                                    flags);

diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 905e2dd765aaca3137c6518c2eca71495a49fafa..48e83f93ee66fd49ec8cc32ef7a78037d1babd95 100644 (file)
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -562,8 +562,8 @@ static bool sock_map_sk_state_allowed(const struct sock *sk)
 static int sock_hash_update_common(struct bpf_map *map, void *key,
                                   struct sock *sk, u64 flags);
 
-static int sock_map_update_elem(struct bpf_map *map, void *key,
-                               void *value, u64 flags)
+int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
+                            u64 flags)
 {
        struct socket *sock;
        struct sock *sk;
@@ -687,7 +687,6 @@ const struct bpf_map_ops sock_map_ops = {
        .map_free               = sock_map_free,
        .map_get_next_key       = sock_map_get_next_key,
        .map_lookup_elem_sys_only = sock_map_lookup_sys,
-       .map_update_elem        = sock_map_update_elem,
        .map_delete_elem        = sock_map_delete_elem,
        .map_lookup_elem        = sock_map_lookup,
        .map_release_uref       = sock_map_release_progs,
@@ -1181,7 +1180,6 @@ const struct bpf_map_ops sock_hash_ops = {
        .map_alloc              = sock_hash_alloc,
        .map_free               = sock_hash_free,
        .map_get_next_key       = sock_hash_get_next_key,
-       .map_update_elem        = sock_map_update_elem,
        .map_delete_elem        = sock_hash_delete_elem,
        .map_lookup_elem        = sock_hash_lookup,
        .map_lookup_elem_sys_only = sock_hash_lookup_sys,