1 files changed, 167 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c b/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c
new file mode 100644
index 000000000000..f81d08d429a2
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/err.h>
+#include <string.h>
+#include <bpf/btf.h>
+#include <bpf/libbpf.h>
+#include <linux/btf.h>
+#include <linux/kernel.h>
+#define CONFIG_DEBUG_INFO_BTF
+#include <linux/btf_ids.h>
+#include "test_progs.h"
+
+static int duration;
+
+struct symbol {
+	const char	*name;
+	int		 type;
+	int		 id;
+};
+
+struct symbol test_symbols[] = {
+	{ "unused",  BTF_KIND_UNKN,     0 },
+	{ "S",       BTF_KIND_TYPEDEF, -1 },
+	{ "T",       BTF_KIND_TYPEDEF, -1 },
+	{ "U",       BTF_KIND_TYPEDEF, -1 },
+	{ "S",       BTF_KIND_STRUCT,  -1 },
+	{ "U",       BTF_KIND_UNION,   -1 },
+	{ "func",    BTF_KIND_FUNC,    -1 },
+};
+
+/* Align the .BTF_ids section to 4 bytes */
+asm (
+".pushsection " BTF_IDS_SECTION " ,\"a\"; \n"
+".balign 4, 0;                            \n"
+".popsection;                             \n");
+
+BTF_ID_LIST(test_list_local)
+BTF_ID_UNUSED
+BTF_ID(typedef, S)
+BTF_ID(typedef, T)
+BTF_ID(typedef, U)
+BTF_ID(struct,  S)
+BTF_ID(union,   U)
+BTF_ID(func,    func)
+
+extern __u32 test_list_global[];
+BTF_ID_LIST_GLOBAL(test_list_global, 1)
+BTF_ID_UNUSED
+BTF_ID(typedef, S)
+BTF_ID(typedef, T)
+BTF_ID(typedef, U)
+BTF_ID(struct,  S)
+BTF_ID(union,   U)
+BTF_ID(func,    func)
+
+BTF_SET_START(test_set)
+BTF_ID(typedef, S)
+BTF_ID(typedef, T)
+BTF_ID(typedef, U)
+BTF_ID(struct,  S)
+BTF_ID(union,   U)
+BTF_ID(func,    func)
+BTF_SET_END(test_set)
+
+static int
+__resolve_symbol(struct btf *btf, int type_id)
+{
+	const struct btf_type *type;
+	const char *str;
+	unsigned int i;
+
+	type = btf__type_by_id(btf, type_id);
+	if (!type) {
+		PRINT_FAIL("Failed to get type for ID %d\n", type_id);
+		return -1;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(test_symbols); i++) {
+		if (test_symbols[i].id >= 0)
+			continue;
+
+		if (BTF_INFO_KIND(type->info) != test_symbols[i].type)
+			continue;
+
+		str = btf__name_by_offset(btf, type->name_off);
+		if (!str) {
+			PRINT_FAIL("Failed to get name for BTF ID %d\n", type_id);
+			return -1;
+		}
+
+		if (!strcmp(str, test_symbols[i].name))
+			test_symbols[i].id = type_id;
+	}
+
+	return 0;
+}
+
+static int resolve_symbols(void)
+{
+	struct btf *btf;
+	int type_id;
+	__u32 nr;
+
+	btf = btf__parse_elf("btf_data.bpf.o", NULL);
+	if (CHECK(libbpf_get_error(btf), "resolve",
+		  "Failed to load BTF from btf_data.o\n"))
+		return -1;
+
+	nr = btf__type_cnt(btf);
+
+	for (type_id = 1; type_id < nr; type_id++) {
+		if (__resolve_symbol(btf, type_id))
+			break;
+	}
+
+	btf__free(btf);
+	return 0;
+}
+
+void test_resolve_btfids(void)
+{
+	__u32 *test_list, *test_lists[] = { test_list_local, test_list_global };
+	unsigned int i, j;
+	int ret = 0;
+
+	if (resolve_symbols())
+		return;
+
+	/* Check BTF_ID_LIST(test_list_local) and
+	 * BTF_ID_LIST_GLOBAL(test_list_global) IDs
+	 */
+	for (j = 0; j < ARRAY_SIZE(test_lists); j++) {
+		test_list = test_lists[j];
+		for (i = 0; i < ARRAY_SIZE(test_symbols); i++) {
+			ret = CHECK(test_list[i] != test_symbols[i].id,
+				    "id_check",
+				    "wrong ID for %s (%d != %d)\n",
+				    test_symbols[i].name,
+				    test_list[i], test_symbols[i].id);
+			if (ret)
+				return;
+		}
+	}
+
+	/* Check BTF_SET_START(test_set) IDs */
+	for (i = 0; i < test_set.cnt; i++) {
+		bool found = false;
+
+		for (j = 0; j < ARRAY_SIZE(test_symbols); j++) {
+			if (test_symbols[j].id != test_set.ids[i])
+				continue;
+			found = true;
+			break;
+		}
+
+		ret = CHECK(!found, "id_check",
+			    "ID %d not found in test_symbols\n",
+			    test_set.ids[i]);
+		if (ret)
+			break;
+
+		if (i > 0) {
+			if (!ASSERT_LE(test_set.ids[i - 1], test_set.ids[i], "sort_check"))
+				return;
+		}
+	}
+}