Re: [PATCH] tst-process_madvise: Check process_madvise-syscall support.

[Stefan Liebler <stli@linux.ibm.com>]

On 11/08/2022 10:37, Florian Weimer wrote:
> * Stefan Liebler via Libc-alpha:
> 
>> So far this test checks if pidfd_open-syscall is supported,
>> which was introduced with linux 5.3.
>>
>> The process_madvise-syscall was introduced with linux 5.10.
>> Thus you'll get FAILs if you are running a kernel in between.
>>
>> This patch adds a check if the first process_madvise-syscall
>> returns ENOSYS and in this case will fail with UNSUPPORTED.
>> ---
>>  sysdeps/unix/sysv/linux/tst-process_madvise.c | 8 ++++++--
>>  1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/sysdeps/unix/sysv/linux/tst-process_madvise.c b/sysdeps/unix/sysv/linux/tst-process_madvise.c
>> index a674e80b76..6fe5a79b1d 100644
>> --- a/sysdeps/unix/sysv/linux/tst-process_madvise.c
>> +++ b/sysdeps/unix/sysv/linux/tst-process_madvise.c
>> @@ -101,8 +101,12 @@ do_test (void)
>>  
>>      /* We expect this to succeed in the target process because the mapping
>>         is valid.  */
>> -    TEST_COMPARE (process_madvise (pidfd, &iv, 1, MADV_COLD, 0),
>> -		  2 * page_size);
>> +    errno = 0;
>> +    ssize_t ret = process_madvise (pidfd, &iv, 1, MADV_COLD, 0);
>> +    if (ret == -1 && errno == ENOSYS)
>> +      FAIL_UNSUPPORTED ("kernel does not support process_madvise, skipping"
>> +			"test");
>> +    TEST_COMPARE (ret, 2 * page_size);
>>    }
>>  
>>    {
> 
> Assigning 0 to errno should not be necessary here.  But the patch looks
> good otherwise.
> 
> Reviewed-by: Florian Weimer <fweimer@redhat.com>
> 
> Thanks,
> Florian
> 
Hi Florian,

yes you are right. I've just committed it without the assignment.

Thanks,
Stefan