selftests/bpf: mmap: Use runtime page size

Replace hardcoded 4096 with runtime value in the userspace part of
the test and set bpf table sizes dynamically according to the value.

Do not switch to ASSERT macros, keep CHECK, for consistency with the
rest of the test. Can be a separate cleanup patch.

Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-5-yauheni.kaliuta@redhat.com

2 files changed, 19 insertions, 7 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/mmap.c b/tools/testing/selftests/bpf/prog_tests/mmap.c
index 9c3c5c0f068f..37b002ca1167 100644
--- a/tools/testing/selftests/bpf/prog_tests/mmap.c
+++ b/tools/testing/selftests/bpf/prog_tests/mmap.c
@@ -29,22 +29,36 @@ void test_mmap(void)
 	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"))
+	skel = test_mmap__open();
+	if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
 		return;
 
+	err = bpf_map__set_max_entries(skel->maps.rdonly_map, page_size);
+	if (CHECK(err != 0, "bpf_map__set_max_entries", "bpf_map__set_max_entries failed\n"))
+		goto cleanup;
+
+	/* at least 4 pages of data */
+	err = bpf_map__set_max_entries(skel->maps.data_map,
+				       4 * (page_size / sizeof(u64)));
+	if (CHECK(err != 0, "bpf_map__set_max_entries", "bpf_map__set_max_entries failed\n"))
+		goto cleanup;
+
+	err = test_mmap__load(skel);
+	if (CHECK(err != 0, "skel_load", "skeleton load failed\n"))
+		goto cleanup;
+
 	bss_map = skel->maps.bss;
 	data_map = skel->maps.data_map;
 	data_map_fd = bpf_map__fd(data_map);
 
 	rdmap_fd = bpf_map__fd(skel->maps.rdonly_map);
-	tmp1 = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, rdmap_fd, 0);
+	tmp1 = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, rdmap_fd, 0);
 	if (CHECK(tmp1 != MAP_FAILED, "rdonly_write_mmap", "unexpected success\n")) {
-		munmap(tmp1, 4096);
+		munmap(tmp1, page_size);
 		goto cleanup;
 	}
 	/* now double-check if it's mmap()'able at all */
-	tmp1 = mmap(NULL, 4096, PROT_READ, MAP_SHARED, rdmap_fd, 0);
+	tmp1 = mmap(NULL, page_size, PROT_READ, MAP_SHARED, rdmap_fd, 0);
 	if (CHECK(tmp1 == MAP_FAILED, "rdonly_read_mmap", "failed: %d\n", errno))
 		goto cleanup;
 
diff --git a/tools/testing/selftests/bpf/progs/test_mmap.c b/tools/testing/selftests/bpf/progs/test_mmap.c
index 4eb42cff5fe9..5a5cc19a15bf 100644
--- a/tools/testing/selftests/bpf/progs/test_mmap.c
+++ b/tools/testing/selftests/bpf/progs/test_mmap.c
@@ -9,7 +9,6 @@ char _license[] SEC("license") = "GPL";
 
 struct {
 	__uint(type, BPF_MAP_TYPE_ARRAY);
-	__uint(max_entries, 4096);
 	__uint(map_flags, BPF_F_MMAPABLE | BPF_F_RDONLY_PROG);
 	__type(key, __u32);
 	__type(value, char);
@@ -17,7 +16,6 @@ struct {
 
 struct {
 	__uint(type, BPF_MAP_TYPE_ARRAY);
-	__uint(max_entries, 512 * 4); /* at least 4 pages of data */
 	__uint(map_flags, BPF_F_MMAPABLE);
 	__type(key, __u32);
 	__type(value, __u64);