Re: [PATCH v2 22/39] mm: Don't allow write GUPs to shadow stack memory

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, 2022-09-30 at 12:16 -0700, Dave Hansen wrote:
> On 9/29/22 15:29, Rick Edgecombe wrote:
> > @@ -1633,6 +1633,9 @@ static inline bool
> > __pte_access_permitted(unsigned long pteval, bool write)
> >   {
> >        unsigned long need_pte_bits = _PAGE_PRESENT|_PAGE_USER;
> >   
> > +     if (write && (pteval & (_PAGE_RW | _PAGE_DIRTY)) ==
> > _PAGE_DIRTY)
> > +             return 0;
> 
> Do we not have a helper for this?  Seems a bit messy to open-code
> these
> shadow-stack permissions.  Definitely at least needs a comment.

It's because pteval is an unsigned long. We could create a pte_t, and
use the helpers, but then we would be using pte_foo() on pmd's, etc. So
probably comment is the better option?




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux