# Re: \[PATCH v2 16/17\] selftests: vdso: Make VDSO function call more generic

- From: LEROY Christophe \<hidden\>
- Date: 2024-08-26 07:48:38 
- List: linux-trace-kernel
- Page: https://ratatoskr.run/linux-trace-kernel/2024/08/290077
- Thread: https://ratatoskr.run/linuxppc-dev/2024/08/289625/t.md

```text


Le 26/08/2024 à 09:37, Jason A. Donenfeld a écrit :
> On Thu, Aug 22, 2024 at 09:13:24AM +0200, Christophe Leroy wrote:
>> On powerpc, a call to a VDSO function is not a standard C function
>> call. Unlike x86 that returns a negated error code in case of an
>> error, powerpc sets CR[SO] and returns the error code as a
>> positive value.
>>
>> So use a macro called VDSO_CALL() which takes a pointer to the
>> function to call, the number of arguments and the arguments.
>   
> You'll probably want to move to VDSO_CALL() for the whole test suite,
> not just the getrandom one, right?

Yes indeed, the following needs it as well:

vdso_test_abi.c
vdso_test_getcpu.c
vdso_test_gettimeofday.c
vdso_test_correctness.c

Christophe
```