Re: [PATCH] mm: larger stack guard gap, between vmas

From: Willy Tarreau
Date: Thu Jun 22 2017 - 09:11:11 EST


On Thu, Jun 22, 2017 at 01:58:11PM +0100, Ben Hutchings wrote:
> On Thu, 2017-06-22 at 14:46 +0200, Willy Tarreau wrote:
> > On Thu, Jun 22, 2017 at 01:30:45PM +0100, Ben Hutchings wrote:
> > > Here's my attempt at a backport to 3.2.  This is only tested on
> > > x86_64 and I think I should introduce local variables for
> > > vma_start_gap() in a few places.  I had to cherry-pick commit
> > > 09884964335e "mm: do not grow the stack vma just because of an overrun
> > > on preceding vma" before this one (which was a clean cherry-pick).
> >
> > Ben, I can't apply it on top of 3.2.89 + the patch above, do you have
> > any other patch in your local branch ? For example the patch tries to
> > modify a hunk starting at line 183 of arch/arm/mm/mmap.c while the one
> > I'm having here ends at line 159.
>
> Sorry, yes, I did this on top of the Debian 3.2 branch and that *does*
> have a patch to arch/arm/mm/mmap.c that I had forgotten about (commit
> 7dbaa466780a "ARM: 7169/1: topdown mmap support"). I think you can
> just drop the changes in ARM's arch_get_unmapped_area_topdown().

Thanks, I've just applied this one and it's building now. I'll run the
same checks I did for 3.10.

Willy