On Fri, Jun 14, 2019 at 01:51:37PM +0200, Peter Zijlstra wrote:
> On Wed, May 08, 2019 at 05:44:05PM +0300, Kirill A. Shutemov wrote:
snip
> > /*
> > - * When pkey==NO_KEY we get legacy mprotect behavior here.
> > + * do_mprotect_ext() supports the legacy mprotect behavior plus extensions
> > + * for Protection Keys and Memory Encryption Keys. These extensions are
> > + * mutually exclusive and the behavior is:
> > + * (pkey==NO_KEY && keyid==NO_KEY) ==> legacy mprotect
> > + * (pkey is valid) ==> legacy mprotect plus Protection Key extensions
> > + * (keyid is valid) ==> legacy mprotect plus Encryption Key extensions
> > */
> > static int do_mprotect_ext(unsigned long start, size_t len,
> > - unsigned long prot, int pkey)
> > + unsigned long prot, int pkey, int keyid)
> > {
snip
>
> I've missed the part where pkey && keyid results in a WARN or error or
> whatever.
>
I wasn't so sure about that since do_mprotect_ext()
is the call 'behind' the system calls.
legacy mprotect always calls with: NO_KEY, NO_KEY
pkey_mprotect always calls with: pkey, NO_KEY
encrypt_mprotect always calls with NO_KEY, keyid
Would a check on those arguments be debug only
to future proof this?
