diff options
| -rw-r--r-- | include/linux/bpf.h | 3 | ||||
| -rw-r--r-- | kernel/bpf/arraymap.c | 27 | ||||
| -rw-r--r-- | kernel/bpf/hashtab.c | 21 | ||||
| -rw-r--r-- | kernel/bpf/map_in_map.c | 5 | ||||
| -rw-r--r-- | kernel/bpf/map_in_map.h | 1 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 16 |
6 files changed, 70 insertions, 3 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index deca4e7f2845..5175729270d7 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -36,6 +36,7 @@ struct bpf_map_ops { int fd); void (*map_fd_put_ptr)(void *ptr); u32 (*map_gen_lookup)(struct bpf_map *map, struct bpf_insn *insn_buf); + u32 (*map_fd_sys_lookup_elem)(void *ptr); }; struct bpf_map { @@ -288,9 +289,11 @@ int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value); int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, void *key, void *value, u64 map_flags); +int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); void bpf_fd_array_map_clear(struct bpf_map *map); int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file, void *key, void *value, u64 map_flags); +int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); /* memcpy that is used with 8-byte aligned pointers, power-of-8 size and * forced to use 'long' read/writes to try to atomically copy long counters. diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index ecb43542246e..d771a3872500 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -335,6 +335,26 @@ static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key) } /* only called from syscall */ +int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value) +{ + void **elem, *ptr; + int ret = 0; + + if (!map->ops->map_fd_sys_lookup_elem) + return -ENOTSUPP; + + rcu_read_lock(); + elem = array_map_lookup_elem(map, key); + if (elem && (ptr = READ_ONCE(*elem))) + *value = map->ops->map_fd_sys_lookup_elem(ptr); + else + ret = -ENOENT; + rcu_read_unlock(); + + return ret; +} + +/* only called from syscall */ int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, void *key, void *value, u64 map_flags) { @@ -400,6 +420,11 @@ static void prog_fd_array_put_ptr(void *ptr) bpf_prog_put(ptr); } +static u32 prog_fd_array_sys_lookup_elem(void *ptr) +{ + return ((struct bpf_prog *)ptr)->aux->id; +} + /* decrement refcnt of all bpf_progs that are stored in this map */ void bpf_fd_array_map_clear(struct bpf_map *map) { @@ -418,6 +443,7 @@ const struct bpf_map_ops prog_array_map_ops = { .map_delete_elem = fd_array_map_delete_elem, .map_fd_get_ptr = prog_fd_array_get_ptr, .map_fd_put_ptr = prog_fd_array_put_ptr, + .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem, }; static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file, @@ -585,4 +611,5 @@ const struct bpf_map_ops array_of_maps_map_ops = { .map_delete_elem = fd_array_map_delete_elem, .map_fd_get_ptr = bpf_map_fd_get_ptr, .map_fd_put_ptr = bpf_map_fd_put_ptr, + .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem, }; diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 004334ea13ba..4fb463172aa8 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -1244,6 +1244,26 @@ static void fd_htab_map_free(struct bpf_map *map) } /* only called from syscall */ +int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value) +{ + void **ptr; + int ret = 0; + + if (!map->ops->map_fd_sys_lookup_elem) + return -ENOTSUPP; + + rcu_read_lock(); + ptr = htab_map_lookup_elem(map, key); + if (ptr) + *value = map->ops->map_fd_sys_lookup_elem(READ_ONCE(*ptr)); + else + ret = -ENOENT; + rcu_read_unlock(); + + return ret; +} + +/* only called from syscall */ int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file, void *key, void *value, u64 map_flags) { @@ -1305,4 +1325,5 @@ const struct bpf_map_ops htab_of_maps_map_ops = { .map_delete_elem = htab_map_delete_elem, .map_fd_get_ptr = bpf_map_fd_get_ptr, .map_fd_put_ptr = bpf_map_fd_put_ptr, + .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem, }; diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c index 59bcdf821ae4..1da574612bea 100644 --- a/kernel/bpf/map_in_map.c +++ b/kernel/bpf/map_in_map.c @@ -95,3 +95,8 @@ void bpf_map_fd_put_ptr(void *ptr) */ bpf_map_put(ptr); } + +u32 bpf_map_fd_sys_lookup_elem(void *ptr) +{ + return ((struct bpf_map *)ptr)->id; +} diff --git a/kernel/bpf/map_in_map.h b/kernel/bpf/map_in_map.h index 177fadb689dc..6183db9ec08c 100644 --- a/kernel/bpf/map_in_map.h +++ b/kernel/bpf/map_in_map.h @@ -19,5 +19,6 @@ bool bpf_map_meta_equal(const struct bpf_map *meta0, void *bpf_map_fd_get_ptr(struct bpf_map *map, struct file *map_file, int ufd); void bpf_map_fd_put_ptr(void *ptr); +u32 bpf_map_fd_sys_lookup_elem(void *ptr); #endif 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); |
