Re: [Y2038] [PATCH 07/23] y2038: vdso: powerpc: avoid timespec references

From: Arnd Bergmann
Date: Wed Nov 27 2019 - 06:03:31 EST


On Thu, Nov 21, 2019 at 5:25 PM Christophe Leroy
<christophe.leroy@xxxxxx> wrote:
> Arnd Bergmann <arnd@xxxxxxxx> a Ãcrit :
> > On Wed, Nov 20, 2019 at 11:43 PM Ben Hutchings
> > <ben.hutchings@xxxxxxxxxxxxxxx> wrote:
> >>
> >> On Fri, 2019-11-08 at 22:07 +0100, Arnd Bergmann wrote:
> >> > @@ -192,7 +190,7 @@ V_FUNCTION_BEGIN(__kernel_time)
> >> > bl __get_datapage@local
> >> > mr r9, r3 /* datapage ptr in r9 */
> >> >
> >> > - lwz r3,STAMP_XTIME+TSPEC_TV_SEC(r9)
> >> > + lwz r3,STAMP_XTIME_SEC+LOWPART(r9)
> >>
> >> "LOWPART" should be "LOPART".
> >>
> >
> > Thanks, fixed both instances in a patch on top now. I considered folding
> > it into the original patch, but as it's close to the merge window I'd
> > rather not rebase it, and this way I also give you credit for
> > finding the bug.
>
> Take care, might conflict with
> https://github.com/linuxppc/linux/commit/5e381d727fe8834ca5a126f510194a7a4ac6dd3a

Sorry for my late reply. I see this commit and no other variant of it has
made it into linux-next by now, so I assume this is not getting sent for v5.5
and it's not stopping me from sending my own pull request.

Please let me know if I missed something and this will cause problems.

On a related note: are you still working on the generic lib/vdso support for
powerpc? Without that, future libc implementations that use 64-bit time_t
will have to use the slow clock_gettime64 syscall instead of the vdso,
which has a significant performance impact.

Arnd