Messages in this thread | | | From | Sami Tolvanen <> | Date | Thu, 7 Nov 2019 08:26:30 -0800 | Subject | Re: [PATCH v5 11/14] arm64: efi: restore x18 if it was corrupted |
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On Thu, Nov 7, 2019 at 2:51 AM Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > > On Wed, 6 Nov 2019 at 05:46, Miguel Ojeda > <miguel.ojeda.sandonis@gmail.com> wrote: > > > > On Wed, Nov 6, 2019 at 12:56 AM Sami Tolvanen <samitolvanen@google.com> 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
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