lkml.org 
[lkml]   [2022]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH mm-unstable v1 20/20] mm: rename FOLL_FORCE to FOLL_PTRACE
On Thu, Nov 17, 2022 at 03:20:01PM -0800, Linus Torvalds wrote:
> On Thu, Nov 17, 2022 at 2:58 PM Kees Cook <keescook@chromium.org> wrote:
> >
> > Oh, er, why does get_arg_page() even need FOLL_FORCE? This is writing the
> > new stack contents to the nascent brpm->vma, which was newly allocated
> > with VM_STACK_FLAGS, which an arch can override, but they all appear to include
> > VM_WRITE | VM_MAYWRITE.
>
> Yeah, it does seem entirely superfluous.
>
> It's been there since the very beginning (although in that original
> commit b6a2fea39318 it was there as a '1' to the 'force' argument to
> get_user_pages()).
>
> I *think* it can be just removed. But as long as it exists, it should
> most definitely not be renamed to FOLL_PTRACE.
>
> There's a slight worry that it currently hides some other setup issue
> that makes it matter, since it's been that way so long, but I can't
> see what it is.

My test system boots happily with it removed. I'll throw it into -next
and see if anything melts...

--
Kees Cook

\
 
 \ /
  Last update: 2022-11-18 01:31    [W:1.253 / U:0.728 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site