bpf: add support for btf_* fields in BPF_MAP_CREATE

* bpf_attr.h (struct BPF_MAP_CREATE_struct): Add btf_fd,
btf_key_type_id, and btf_value_type_id fields.
* bpf.c (BEGIN_BPF_CMD_DECODER(BPF_MAP_CREATE)): Decode btf_fd,
btf_key_type_id, and btf_value_type_id fields introduced by Linux
commits v4.18-rc1~114^2~417^2~1^2~3 and v4.18-rc1~114^2~148^2~7^2~2.
* tests/bpf.c (BPF_MAP_CREATE_checks): Check it.
* tests/bpf-obj_get_info_by_fd.c (print_map_create): Update expected
output.

diff --git a/bpf.c b/bpf.c
index 6fb4c2c2bc51ee4873c2b66d09d00cec6a70f5e2..bf7cd6ca881e3c296cdec90c65966057ce7bdb16 100644 (file)
--- a/bpf.c
+++ b/bpf.c
@@ -212,6 +212,16 @@ BEGIN_BPF_CMD_DECODER(BPF_MAP_CREATE)
        if (len <= offsetof(struct BPF_MAP_CREATE_struct, map_ifindex))
                break;
        PRINT_FIELD_IFINDEX(", ", attr, map_ifindex);
+
+       /*
+        * The following three fields were introduced by Linux commits
+        * v4.18-rc1~114^2~417^2~1^2~3 and v4.18-rc1~114^2~148^2~7^2~2.
+        */
+       if (len <= offsetof(struct BPF_MAP_CREATE_struct, btf_fd))
+               break;
+       PRINT_FIELD_FD(", ", attr, btf_fd, tcp);
+       PRINT_FIELD_U(", ", attr, btf_key_type_id);
+       PRINT_FIELD_U(", ", attr, btf_value_type_id);
 }
 END_BPF_CMD_DECODER(RVAL_DECODED | RVAL_FD)
 

diff --git a/bpf_attr.h b/bpf_attr.h
index cb4989631ac723f11f8ff0081a6df94d41526829..a789d10a08ae9520e7f542e0dd10add093e82fde 100644 (file)
--- a/bpf_attr.h
+++ b/bpf_attr.h
@@ -45,11 +45,14 @@ struct BPF_MAP_CREATE_struct {
        uint32_t numa_node;
        char     map_name[BPF_OBJ_NAME_LEN];
        uint32_t map_ifindex;
+       uint32_t btf_fd;
+       uint32_t btf_key_type_id;
+       uint32_t btf_value_type_id;
 };
 
 # define BPF_MAP_CREATE_struct_size \
        sizeof(struct BPF_MAP_CREATE_struct)
-# define expected_BPF_MAP_CREATE_struct_size 48
+# define expected_BPF_MAP_CREATE_struct_size 60
 
 struct BPF_MAP_LOOKUP_ELEM_struct {
        uint32_t map_fd;

diff --git a/tests/bpf-obj_get_info_by_fd.c b/tests/bpf-obj_get_info_by_fd.c
index ff06e27dc27e096d7729c1767b13c001912f28e7..02d14e5e81bae9d795da080b75f79447c0a4edf4 100644 (file)
--- a/tests/bpf-obj_get_info_by_fd.c
+++ b/tests/bpf-obj_get_info_by_fd.c
@@ -84,6 +84,10 @@ print_map_create(void *attr_void, size_t size, long rc)
                printf(", map_name=\"test_map\"");
        if (size > offsetof(struct BPF_MAP_CREATE_struct, map_ifindex))
                printf(", map_ifindex=0");
+       if (size > offsetof(struct BPF_MAP_CREATE_struct, btf_fd)) {
+               printf(", btf_fd=0</dev/null>"
+                      ", btf_key_type_id=0, btf_value_type_id=0");
+       }
        printf("}, %zu) = ", size);
        if (rc >= 0)
                printf("%ld<anon_inode:bpf-map>\n", rc);

diff --git a/tests/bpf.c b/tests/bpf.c
index cfed31913627fa3afea20688a8b4f558d9f5adbd..b18a056e1871c8e1d62385e51d2f111c969685f8 100644 (file)
--- a/tests/bpf.c
+++ b/tests/bpf.c
@@ -400,6 +400,26 @@ static struct bpf_attr_check BPF_MAP_CREATE_checks[] = {
                       ", map_ifindex=" IFINDEX_LO_STR,
                .init_fn = init_BPF_MAP_CREATE_attr7,
        },
+       { /* 8 */
+               .data = { .BPF_MAP_CREATE_data = {
+                       .btf_fd = 0xbadc0ded,
+                       .btf_key_type_id = 0xfacefeed,
+                       .btf_value_type_id = 0xcafef00d
+               } },
+               .size = offsetofend(struct BPF_MAP_CREATE_struct,
+                                   btf_value_type_id),
+               .str = "map_type=BPF_MAP_TYPE_UNSPEC"
+                      ", key_size=0"
+                      ", value_size=0"
+                      ", max_entries=0"
+                      ", map_flags=0"
+                      ", inner_map_fd=0"
+                      ", map_name=\"\""
+                      ", map_ifindex=0"
+                      ", btf_fd=-1159983635"
+                      ", btf_key_type_id=4207869677"
+                      ", btf_value_type_id=3405705229"
+       },
 };
 
 static const struct bpf_attr_check BPF_MAP_LOOKUP_ELEM_checks[] = {