Re: [PATCH v2 0/4] kselftest: Extend vDSO tests

From: Arnd Bergmann
Date: Tue May 05 2020 - 11:07:26 EST


On Tue, May 5, 2020 at 5:03 PM Vincenzo Frascino
<vincenzo.frascino@xxxxxxx> wrote:
> On 5/5/20 3:50 PM, Arnd Bergmann wrote:
> > On Wed, Apr 29, 2020 at 1:34 PM Vincenzo Frascino <vincenzo.frascino@xxxxxxx> wrote:
> >
> > Not sure if you are aware of the recent bug report about clock_gettime64()
> > returning invalid times on some arm32 kernels:
> > https://github.com/raspberrypi/linux/issues/3579
> >
>
> No, I was not aware of the problem. There has been no mention on the arm list
> (unless I missed it). I can try to have a look at it as soon as I get some time.

Right, it was on only on the musl list, and I had pinged you on IRC, but you
must have been offline.

> > Regardless of when that gets fixed or by whom, I wonder if kselftest should
> > also check for consistency, i.e. call both the vdso and the syscall version of
> > clock_gettime() and clock_gettime64() and check that the results are always
> > in sequence.
> >
>
> The test #4 partially does that: it calls syscall-vdso-syscall and verifies that
> the sequencing is correct. I reused the x86 code for that. I could extend it to
> clock_gettime64() and make sure it builds on all the platforms.

Sounds good to me.

Arnd