Re: [PATCH v12 0/6] implement getrandom() in vDSO

Eric Biggers
2022-12-21T20:48:46Z

On Wed, Dec 21, 2022 at 03:25:49PM +0100, Jason A. Donenfeld wrote:
> On Tue, Dec 20, 2022 at 08:13:14PM +0000, Eric Biggers wrote:
> > On Tue, Dec 20, 2022 at 05:17:52PM +0000, Christophe Leroy wrote:
> > > Hi Jason,
> > >
> > > Le 12/12/2022 à 19:53, Jason A. Donenfeld a écrit :
> > > > Changes v11->v12:
> > > > ----------------
> > > > - In order to avoid mlock()ing pages, and the related rlimit and fork
> > > > inheritance issues there, Introduce VM_DROPPABLE to prevent swapping
> > > > while meeting the cache-like requirements of vDSO getrandom().
> > > >
> > > > This has some tenticles in mm/ and arch/x86/ code, so I've marked the
> > > > two patches for that as still RFC, while the rest of the series is not
> > > > RFC.
> > > >
> > > > - Mandate that opaque state blobs don't straddle page boundaries, so
> > > > that VM_DROPPABLE can work on page-level granularity rather than
> > > > allocation-level granularity.
> > > >
> > > > - Add compiler barriers to vDSO getrandom() to prevent theoretical
> > > > reordering potential.
> > > >
> > > > - Initialize the trials loop counter in the chacha test.
> > >
> > > I would have liked to give it a try on powerpc, but the series
> > > conflicts. I tried both on v6.1 and on linus/master from now:
> > >
> >
> > Same here, I can't figure out how to apply this series.
>
> Rebased v13 posted: https://lore.kernel.org/all/20221221142327.126451-1-Jason@zx2c4.com/
>

Thanks, it is always good to give the *actual* base commit though, preferably
with the --base option to git format-patch. "Latest random.git master branch"
changes over time.

- Eric