Re: deconflicting new syscall numbers for 6.11

Jason A. Donenfeld
2024-07-06T23:26:17Z

Hi Linus,

On Fri, Jul 05, 2024 at 07:56:03PM -0700, Linus Torvalds wrote:
> On Fri, 5 Jul 2024 at 19:10, Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> >
> > https://git.zx2c4.com/linux-rng/log/
>
> So we already expose VM_WIPEONFORK and VM_DONTDUMP using madvise().
> Exposing them at mmap creation time with MMAP_xyz sounds fine.
>
> However, I do note that both the pre-existing VM_WIPEONFORK - and the
> new VM_DROPPABLE - needs to be limited to anonymous private mappings
> only.
>
> You did that for VM_DROPPABLE, but not for VM_WIPEONFORK.

Good catch, thanks. I'll look over all of that again closely too.

> Anyway, that patch looks largely fine to me apart from that note, but
> I do think you want to check it with the mm people on linux-mm.

They'll certainly be on the list of recipients for the v+1 series when I
post it (hopefully shortly).

> > The selftest code is the largest part of it. There's no more syscall. I
> > think it should be much more to your liking and seems like an alright
> > set of compromises. Hopefully that's a bit closer to the mark.
>
> From a "look through the patches" standpoint, this did look more
> palatable to me, but I also would have had an easier time with looking
> at the patches if the self-tests were separate commits.

Okay, will do. I think you've got some selftest makefile fixes from
John/Shuah that'll be sent your way if they haven't already for 6.10
that I'll rebase on so that there isn't an annoying merge conflict.
https://lore.kernel.org/all/d99a1e3b-1893-4fac-bf05-bcb60ca7f89c@linuxfoundation.org/

Jason