commit ad5b177bd73f5107d97c36f56395c4281fb6f089
author Martin KaFai Lau <kafai@fb.com> Wed Sep 27 14:37:53 2017 -0700
committer David S. Miller <davem@davemloft.net> Fri Sep 29 06:17:05 2017 +0100
tree 90f03bf2a9ce3370d0979524a10784bce7714042
parent cb4d2b3f03d8eed90be3a194e5b54b734ec4bbe9

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: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

kernel/bpf/syscall.c

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 45970df..11a7f82 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -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))