Commit 8175383f authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: btf: Ensure t->type == 0 for BTF_KIND_FWD 



The t->type in BTF_KIND_FWD is not used.  It must be 0.
This patch ensures that and also adds a test case in test_btf.c

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent b9308ae6

kernel/bpf/btf.c

+20 −1
Original line number Diff line number Diff line
@@ -1286,8 +1286,27 @@ static struct btf_kind_operations ptr_ops = { 
	.seq_show = btf_ptr_seq_show,

};



static s32 btf_fwd_check_meta(struct btf_verifier_env *env,

			      const struct btf_type *t,

			      u32 meta_left)

{

	if (btf_type_vlen(t)) {

		btf_verifier_log_type(env, t, "vlen != 0");

		return -EINVAL;

	}



	if (t->type) {

		btf_verifier_log_type(env, t, "type != 0");

		return -EINVAL;

	}



	btf_verifier_log_type(env, t, NULL);



	return 0;

}



static struct btf_kind_operations fwd_ops = {

	.check_meta = btf_ref_type_check_meta,

	.check_meta = btf_fwd_check_meta,

	.resolve = btf_df_resolve,

	.check_member = btf_df_check_member,

	.log_details = btf_ref_type_log,

tools/testing/selftests/bpf/test_btf.c

+22 −0
Original line number Diff line number Diff line
@@ -1242,6 +1242,28 @@ static struct btf_raw_test raw_tests[] = { 
	.err_str = "Invalid btf_info",

},



{

	.descr = "fwd test. t->type != 0\"",

	.raw_types = {

		/* int */				/* [1] */

		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),

		/* fwd type */				/* [2] */

		BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FWD, 0, 0), 1),

		BTF_END_RAW,

	},

	.str_sec = "",

	.str_sec_size = sizeof(""),

	.map_type = BPF_MAP_TYPE_ARRAY,

	.map_name = "fwd_test_map",

	.key_size = sizeof(int),

	.value_size = sizeof(int),

	.key_type_id = 1,

	.value_type_id = 1,

	.max_entries = 4,

	.btf_load_err = true,

	.err_str = "type != 0",

},



}; /* struct btf_raw_test raw_tests[] */



static const char *get_next_str(const char *start, const char *end)