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Commit ad5b177b authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by David S. Miller
Browse files

bpf: Add map_name to bpf_map_info 



This patch allows userspace to specify a name for a map
during BPF_MAP_CREATE.

The map's name can later be exported to user space
via BPF_OBJ_GET_INFO_BY_FD.

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Acked-by: default avatarAlexei Starovoitov <ast@fb.com>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cb4d2b3f

include/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ struct bpf_map { 
	struct work_struct work;

	atomic_t usercnt;

	struct bpf_map *inner_map_meta;

	u8 name[BPF_OBJ_NAME_LEN];

};



/* function argument constraints */

include/uapi/linux/bpf.h

+2 −0
Original line number Diff line number Diff line
@@ -190,6 +190,7 @@ union bpf_attr { 
		__u32	numa_node;	/* numa node (effective only if

					 * BPF_F_NUMA_NODE is set).

					 */

		__u8	map_name[BPF_OBJ_NAME_LEN];

	};



	struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
@@ -829,6 +830,7 @@ struct bpf_map_info { 
	__u32 value_size;

	__u32 max_entries;

	__u32 map_flags;

	__u8  name[BPF_OBJ_NAME_LEN];

} __attribute__((aligned(8)));



/* User bpf_sock_ops struct to access socket values and specify request ops

kernel/bpf/syscall.c

+6 −1
Original line number Diff line number Diff line
@@ -339,7 +339,7 @@ static int bpf_obj_name_cpy(char *dst, const char *src) 
	return 0;

}



#define BPF_MAP_CREATE_LAST_FIELD numa_node

#define BPF_MAP_CREATE_LAST_FIELD map_name

/* called via syscall */

static int map_create(union bpf_attr *attr)

{
@@ -361,6 +361,10 @@ static int map_create(union bpf_attr *attr) 
	if (IS_ERR(map))

		return PTR_ERR(map);



	err = bpf_obj_name_cpy(map->name, attr->map_name);

	if (err)

		goto free_map_nouncharge;



	atomic_set(&map->refcnt, 1);

	atomic_set(&map->usercnt, 1);
@@ -1462,6 +1466,7 @@ static int bpf_map_get_info_by_fd(struct bpf_map *map, 
	info.value_size = map->value_size;

	info.max_entries = map->max_entries;

	info.map_flags = map->map_flags;

	memcpy(info.name, map->name, sizeof(map->name));



	if (copy_to_user(uinfo, &info, info_len) ||

	    put_user(info_len, &uattr->info.info_len))