Commit 9c651127445c ("selftests/btf: add initial BTF dedup tests") added dedup tests in test_btf.c. It broke the raw test: BTF raw test[71] (func proto (Bad arg name_off)): btf_raw_create:2905:FAIL Error getting string #65535, strs_cnt:1
The test itself encodes invalid func_proto parameter name offset 0xffffFFFF as a negative test for the kernel. The above commit changed the meaning of that offset and resulted in a user space error. #define NAME_NTH(N) (0xffff0000 | N) #define IS_NAME_NTH(X) ((X & 0xffff0000) == 0xffff0000) #define GET_NAME_NTH_IDX(X) (X & 0x0000ffff) Currently, the kernel permits maximum name offset 0xffff. Set the test name off as 0x0fffFFFF to trigger the kernel verification failure. Cc: Andrii Nakryiko <andr...@fb.com> Fixes: 9c651127445c ("selftests/btf: add initial BTF dedup tests") Signed-off-by: Yonghong Song <y...@fb.com> --- tools/testing/selftests/bpf/test_btf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index 30c3edde7e07..447acc34db94 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -1978,7 +1978,7 @@ static struct btf_raw_test raw_tests[] = { /* void (*)(int a, unsigned int <bad_name_off>) */ BTF_FUNC_PROTO_ENC(0, 2), /* [3] */ BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), - BTF_FUNC_PROTO_ARG_ENC(0xffffffff, 2), + BTF_FUNC_PROTO_ARG_ENC(0x0fffffff, 2), BTF_END_RAW, }, .str_sec = "\0a", -- 2.17.1