Re: [PATCH 6/6] mm: Forbid splitting special mappings

[Will Deacon]

On Fri, Jan 22, 2021 at 12:58:58PM +0000, Will Deacon wrote:
> On Tue, Oct 13, 2020 at 02:34:16AM +0100, Dmitry Safonov wrote:
> > Don't allow splitting of vm_special_mapping's.
> > It affects vdso/vvar areas. Uprobes have only one page in xol_area so
> > they aren't affected.
> > 
> > Those restrictions were enforced by checks in .mremap() callbacks.
> > Restrict resizing with generic .split() callback.
> > 
> > Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
> > ---
> >  arch/arm/kernel/vdso.c    |  9 ---------
> >  arch/arm64/kernel/vdso.c  | 41 +++------------------------------------
> >  arch/mips/vdso/genvdso.c  |  4 ----
> >  arch/s390/kernel/vdso.c   | 11 +----------
> >  arch/x86/entry/vdso/vma.c | 17 ----------------
> >  mm/mmap.c                 | 12 ++++++++++++
> >  6 files changed, 16 insertions(+), 78 deletions(-)
> 
> For arm64:
> 
> Acked-by: Will Deacon <will@xxxxxxxxxx>

Wait -- this got merged ages ago! Why am I reading such old email?

Will