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