On Thu, Nov 7, 2019 at 2:51 AM Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: > > On Wed, 6 Nov 2019 at 05:46, Miguel Ojeda > <miguel.ojeda.sandonis@xxxxxxxxx> wrote: > > > > On Wed, Nov 6, 2019 at 12:56 AM Sami Tolvanen <samitolvanen@xxxxxxxxxx> wrote: > > > > > > If we detect a corrupted x18 and SCS is enabled, restore the register > > > before jumping back to instrumented code. This is safe, because the > > > wrapper is called with preemption disabled and a separate shadow stack > > > is used for interrupt handling. > > > > In case you do v6: I think putting the explanation about why this is > > safe in the existing comment would be best given it is justifying a > > subtlety of the code rather than the change itself. Ard? > > > > Agreed, but only if you have to respin for other reasons. Sure, sounds good to me. I'll update the comment if other changes are needed. Sami
