Re: [PATCH] powerpc/vdso: Separate vvar vma from vdso

[Michael Ellerman]

On Fri, 26 Mar 2021 19:17:20 +0000, Dmitry Safonov wrote:
> Since commit 511157ab641e ("powerpc/vdso: Move vdso datapage up front")
> VVAR page is in front of the VDSO area. In result it breaks CRIU
> (Checkpoint Restore In Userspace) [1], where CRIU expects that "[vdso]"
> from /proc/../maps points at ELF/vdso image, rather than at VVAR data page.
> Laurent made a patch to keep CRIU working (by reading aux vector).
> But I think it still makes sence to separate two mappings into different
> VMAs. It will also make ppc64 less "special" for userspace and as
> a side-bonus will make VVAR page un-writable by debugger (which previously
> would COW page and can be unexpected).
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc/vdso: Separate vvar vma from vdso
      https://git.kernel.org/powerpc/c/1c4bce6753857dc409a0197342d18764e7f4b741

cheers