On Fri, Nov 18, 2022 at 12:09:02PM +0100, Peter Zijlstra wrote:
> On Wed, Nov 16, 2022 at 10:16:34AM -0800, Linus Torvalds wrote:
> > Following the history of it is a big of a mess, because there's a
> > number of renamings and re-organizations, but it seems to go back to
> > 2007 and commit b6a2fe
On Wed, Nov 16, 2022 at 10:16:34AM -0800, Linus Torvalds wrote:
> Following the history of it is a big of a mess, because there's a
> number of renamings and re-organizations, but it seems to go back to
> 2007 and commit b6a2fea39318 ("mm: variable length argument support").
I went back and read p
On Thu, Nov 17, 2022 at 03:20:01PM -0800, Linus Torvalds wrote:
> On Thu, Nov 17, 2022 at 2:58 PM Kees Cook 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, w
On Thu, Nov 17, 2022 at 2:58 PM Kees Cook 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 |
On Wed, Nov 16, 2022 at 10:16:34AM -0800, Linus Torvalds wrote:
> There _are_ also small random cases too, like get_cmdline(). Maybe
> that counts as ptrace, but the execve() case most definitely does not.
Oh, er, why does get_arg_page() even need FOLL_FORCE? This is writing the
new stack contents
On 16.11.22 19:16, Linus Torvalds wrote:
On Wed, Nov 16, 2022 at 2:30 AM David Hildenbrand wrote:
Let's make it clearer that functionality provided by FOLL_FORCE is
really only for ptrace access.
I'm not super-happy about this one.
I do understand the "let's rename the bit so that no new us
On Wed, Nov 16, 2022 at 2:30 AM David Hildenbrand wrote:
>
> Let's make it clearer that functionality provided by FOLL_FORCE is
> really only for ptrace access.
I'm not super-happy about this one.
I do understand the "let's rename the bit so that no new user shows up".
And it's true that the ma
Let's make it clearer that functionality provided by FOLL_FORCE is
really only for ptrace access. Prevent accidental re-use in drivers
by renaming FOLL_FORCE to FOLL_PTRACE:
git grep -l 'FOLL_FORCE' | xargs sed -i 's/FOLL_FORCE/FOLL_PTRACE/g'
In the future, we might want to use a separate set o
