[PATCH -next] selftests/landlock: Fix selftest ptrace_test run fail

[limin]

I run test on Linux ubuntu2204 6.1.0-next-20221116

I did't use yama.

you can reproduce by this step:

cd kernel_src

cd tools/testing/selftests/landlock/
make
./ptrace_test




On 2022/11/29 3:44, Mickaël Salaün wrote:
> This patch changes the test semantic and then cannot work on my test 
> environment. On which kernel did you run test? Do you use Yama or 
> something similar?
>
> On 28/11/2022 03:04, limin wrote:
>> Tests PTRACE_ATTACH and PTRACE_MODE_READ on the parent,
>> trace parent return -1 when child== 0
>> How to reproduce warning:
>> $ make -C tools/testing/selftests TARGETS=landlock run_tests
>>
>> Signed-off-by: limin <limin100 at huawei.com>
>> ---
>>   tools/testing/selftests/landlock/ptrace_test.c | 5 ++---
>>   1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/tools/testing/selftests/landlock/ptrace_test.c 
>> b/tools/testing/selftests/landlock/ptrace_test.c
>> index c28ef98ff3ac..88c4dc63eea0 100644
>> --- a/tools/testing/selftests/landlock/ptrace_test.c
>> +++ b/tools/testing/selftests/landlock/ptrace_test.c
>> @@ -267,12 +267,11 @@ TEST_F(hierarchy, trace)
>>           /* Tests PTRACE_ATTACH and PTRACE_MODE_READ on the parent. */
>>           err_proc_read = test_ptrace_read(parent);
>>           ret = ptrace(PTRACE_ATTACH, parent, NULL, 0);
>> +        EXPECT_EQ(-1, ret);
>> +        EXPECT_EQ(EPERM, errno);
>>           if (variant->domain_child) {
>> -            EXPECT_EQ(-1, ret);
>> -            EXPECT_EQ(EPERM, errno);
>>               EXPECT_EQ(EACCES, err_proc_read);
>>           } else {
>> -            EXPECT_EQ(0, ret);
>>               EXPECT_EQ(0, err_proc_read);
>>           }
>>           if (ret == 0) {