selftests/bpf: Validate frozen map contents stays frozen (642c1654) · Commits · 戴 / test

tools/testing/selftests/bpf/prog_tests/mmap.c

+60 −2

Original line number	Diff line number	Diff line
		@@ -19,15 +19,16 @@ void test_mmap(void)
		const size_t map_sz = roundup_page(sizeof(struct map_data));
		const int zero = 0, one = 1, two = 2, far = 1500;
		const long page_size = sysconf(_SC_PAGE_SIZE);
		int err, duration = 0, i, data_map_fd;
		int err, duration = 0, i, data_map_fd, data_map_id, tmp_fd;
		struct bpf_map data_map, bss_map;
		void bss_mmaped = NULL, map_mmaped = NULL, tmp1, tmp2;
		struct test_mmap__bss *bss_data;
		struct bpf_map_info map_info;
		__u32 map_info_sz = sizeof(map_info);
		struct map_data *map_data;
		struct test_mmap *skel;
		__u64 val = 0;


		skel = test_mmap__open_and_load();
		if (CHECK(!skel, "skel_open_and_load", "skeleton open/load failed\n"))
		return;
		@@ -36,6 +37,14 @@ void test_mmap(void)
		data_map = skel->maps.data_map;
		data_map_fd = bpf_map__fd(data_map);

		/* get map's ID */
		memset(&map_info, 0, map_info_sz);
		err = bpf_obj_get_info_by_fd(data_map_fd, &map_info, &map_info_sz);
		if (CHECK(err, "map_get_info", "failed %d\n", errno))
		goto cleanup;
		data_map_id = map_info.id;

		/* mmap BSS map */
		bss_mmaped = mmap(NULL, bss_sz, PROT_READ \| PROT_WRITE, MAP_SHARED,
		bpf_map__fd(bss_map), 0);
		if (CHECK(bss_mmaped == MAP_FAILED, "bss_mmap",
		@@ -98,6 +107,10 @@ void test_mmap(void)
		"data_map freeze succeeded: err=%d, errno=%d\n", err, errno))
		goto cleanup;

		err = mprotect(map_mmaped, map_sz, PROT_READ);
		if (CHECK(err, "mprotect_ro", "mprotect to r/o failed %d\n", errno))
		goto cleanup;

		/* unmap R/W mapping */
		err = munmap(map_mmaped, map_sz);
		map_mmaped = NULL;
		@@ -111,6 +124,12 @@ void test_mmap(void)
		map_mmaped = NULL;
		goto cleanup;
		}
		err = mprotect(map_mmaped, map_sz, PROT_WRITE);
		if (CHECK(!err, "mprotect_wr", "mprotect() succeeded unexpectedly!\n"))
		goto cleanup;
		err = mprotect(map_mmaped, map_sz, PROT_EXEC);
		if (CHECK(!err, "mprotect_ex", "mprotect() succeeded unexpectedly!\n"))
		goto cleanup;
		map_data = map_mmaped;

		/* map/unmap in a loop to test ref counting */
		@@ -197,6 +216,45 @@ void test_mmap(void)
		CHECK_FAIL(map_data->val[far] != 3 * 321);

		munmap(tmp2, 4 * page_size);

		tmp1 = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0);
		if (CHECK(tmp1 == MAP_FAILED, "last_mmap", "failed %d\n", errno))
		goto cleanup;

		test_mmap__destroy(skel);
		skel = NULL;
		CHECK_FAIL(munmap(bss_mmaped, bss_sz));
		bss_mmaped = NULL;
		CHECK_FAIL(munmap(map_mmaped, map_sz));
		map_mmaped = NULL;

		/* map should be still held by active mmap */
		tmp_fd = bpf_map_get_fd_by_id(data_map_id);
		if (CHECK(tmp_fd < 0, "get_map_by_id", "failed %d\n", errno)) {
		munmap(tmp1, map_sz);
		goto cleanup;
		}
		close(tmp_fd);

		/* this should release data map finally */
		munmap(tmp1, map_sz);

		/* we need to wait for RCU grace period */
		for (i = 0; i < 10000; i++) {
		__u32 id = data_map_id - 1;
		if (bpf_map_get_next_id(id, &id) \|\| id > data_map_id)
		break;
		usleep(1);
		}

		/* should fail to get map FD by non-existing ID */
		tmp_fd = bpf_map_get_fd_by_id(data_map_id);
		if (CHECK(tmp_fd >= 0, "get_map_by_id_after",
		"unexpectedly succeeded %d\n", tmp_fd)) {
		close(tmp_fd);
		goto cleanup;
		}

		cleanup:
		if (bss_mmaped)
		CHECK_FAIL(munmap(bss_mmaped, bss_sz));

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