1 files changed, 31 insertions, 1 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0a4924a0a8da..fe23dc5a3ec4 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -27,6 +27,7 @@
 #include <linux/cred.h>
 #include <linux/timekeeping.h>
 #include <linux/ctype.h>
+#include <linux/btf.h>
 
 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
                            (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
@@ -251,6 +252,7 @@ static void bpf_map_free_deferred(struct work_struct *work)
 
         bpf_map_uncharge_memlock(map);
         security_bpf_map_free(map);
+        btf_put(map->btf);
         /* implementation dependent freeing */
         map->ops->map_free(map);
 }
@@ -416,7 +418,7 @@ static int bpf_obj_name_cpy(char *dst, const char *src)
         return 0;
 }
 
-#define BPF_MAP_CREATE_LAST_FIELD map_ifindex
+#define BPF_MAP_CREATE_LAST_FIELD btf_value_id
 /* called via syscall */
 static int map_create(union bpf_attr *attr)
 {
@@ -450,6 +452,33 @@ static int map_create(union bpf_attr *attr)
         atomic_set(&map->refcnt, 1);
         atomic_set(&map->usercnt, 1);
 
+        if (bpf_map_support_seq_show(map) &&
+            (attr->btf_key_id || attr->btf_value_id)) {
+                struct btf *btf;
+
+                if (!attr->btf_key_id || !attr->btf_value_id) {
+                        err = -EINVAL;
+                        goto free_map_nouncharge;
+                }
+
+                btf = btf_get_by_fd(attr->btf_fd);
+                if (IS_ERR(btf)) {
+                        err = PTR_ERR(btf);
+                        goto free_map_nouncharge;
+                }
+
+                err = map->ops->map_check_btf(map, btf, attr->btf_key_id,
+                                              attr->btf_value_id);
+                if (err) {
+                        btf_put(btf);
+                        goto free_map_nouncharge;
+                }
+
+                map->btf = btf;
+                map->btf_key_id = attr->btf_key_id;
+                map->btf_value_id = attr->btf_value_id;
+        }
+
         err = security_bpf_map_alloc(map);
         if (err)
                 goto free_map_nouncharge;
@@ -482,6 +511,7 @@ free_map:
 free_map_sec:
         security_bpf_map_free(map);
 free_map_nouncharge:
+        btf_put(map->btf);
         map->ops->map_free(map);
         return err;
 }