1 files changed, 50 insertions, 1 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 4ca46df19c9a..fe23dc5a3ec4 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -11,6 +11,7 @@
  */
 #include <linux/bpf.h>
 #include <linux/bpf_trace.h>
+#include <linux/btf.h>
 #include <linux/syscalls.h>
 #include <linux/slab.h>
 #include <linux/sched/signal.h>
@@ -26,6 +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 || \
@@ -250,6 +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);
 }
@@ -415,7 +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)
 {
@@ -449,6 +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;
@@ -481,6 +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;
 }
@@ -2016,6 +2047,8 @@ static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
         else if (f.file->f_op == &bpf_map_fops)
                 err = bpf_map_get_info_by_fd(f.file->private_data, attr,
                                              uattr);
+        else if (f.file->f_op == &btf_fops)
+                err = btf_get_info_by_fd(f.file->private_data, attr, uattr);
         else
                 err = -EINVAL;
 
@@ -2023,6 +2056,19 @@ static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
         return err;
 }
 
+#define BPF_BTF_LOAD_LAST_FIELD btf_log_level
+
+static int bpf_btf_load(const union bpf_attr *attr)
+{
+        if (CHECK_ATTR(BPF_BTF_LOAD))
+                return -EINVAL;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        return btf_new_fd(attr);
+}
+
 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
 {
         union bpf_attr attr = {};
@@ -2103,6 +2149,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
         case BPF_RAW_TRACEPOINT_OPEN:
                 err = bpf_raw_tracepoint_open(&attr);
                 break;
+        case BPF_BTF_LOAD:
+                err = bpf_btf_load(&attr);
+                break;
         default:
                 err = -EINVAL;
                 break;