Add a test to verify that the tailing padding 4 bytes are checked in syscall.c::__sys_bpf() using bpf_check_uarg_tail_zero().
Without the fix, the test fails with: test_common_attr_padding:FAIL:syscall unexpected syscall: actual 4 >= expected 0 #213/12 map_create_failure/common_attr_padding:FAIL Signed-off-by: Leon Hwang <[email protected]> --- .../selftests/bpf/prog_tests/map_init.c | 26 +++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/map_init.c b/tools/testing/selftests/bpf/prog_tests/map_init.c index b0b902d5783d..c804c3ce9be9 100644 --- a/tools/testing/selftests/bpf/prog_tests/map_init.c +++ b/tools/testing/selftests/bpf/prog_tests/map_init.c @@ -353,6 +353,30 @@ static void test_excl_prog_hash_size_2(void) test_map_create_array(&opts, msg); } +static void test_common_attr_padding(void) +{ + struct bpf_common_attr_fake { + __u8 attrs[offsetofend(struct bpf_common_attr, log_true_size)]; + __u32 pad; + } attr_common = { + .pad = 1, + }; + union bpf_attr attr = { + .map_type = BPF_MAP_TYPE_ARRAY, + .key_size = 4, + .value_size = 4, + .max_entries = 1, + }; + int fd; + + fd = syscall(__NR_bpf, BPF_MAP_CREATE | BPF_COMMON_ATTRS, &attr, sizeof(attr), &attr_common, + sizeof(attr_common)); + if (!ASSERT_LT(fd, 0, "syscall")) + close(fd); + else + ASSERT_EQ(errno, E2BIG, "errno"); +} + void test_map_create_failure(void) { if (test__start_subtest("invalid_vmlinux_value_type_id_struct_ops")) @@ -377,4 +401,6 @@ void test_map_create_failure(void) test_excl_prog_hash_size_1(); if (test__start_subtest("invalid_excl_prog_hash_size_2")) test_excl_prog_hash_size_2(); + if (test__start_subtest("common_attr_padding")) + test_common_attr_padding(); } -- 2.54.0
