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

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:

quoted

Hi Jason,

Le 12/12/2022 à 19:53, Jason A. Donenfeld a écrit :

quoted

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/ (local)

Jason