Messages in this thread | | | From | Sami Tolvanen <> | Date | Thu, 31 Oct 2019 10:42:17 -0700 | Subject | Re: [PATCH v3 13/17] arm64: preserve x18 when CPU is suspended |
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On Thu, Oct 31, 2019 at 10:35 AM Nick Desaulniers <ndesaulniers@google.com> wrote: > > On Thu, Oct 31, 2019 at 10:27 AM Sami Tolvanen <samitolvanen@google.com> wrote: > > > > On Thu, Oct 31, 2019 at 10:18 AM Nick Desaulniers > > <ndesaulniers@google.com> wrote: > > > > +#ifdef CONFIG_SHADOW_CALL_STACK > > > > + ldr x18, [x0, #96] > > > > + str xzr, [x0, #96] > > > > > > How come we zero out x0+#96, but not for other offsets? Is this str necessary? > > > > It clears the shadow stack pointer from the sleep state buffer, which > > is not strictly speaking necessary, but leaves one fewer place to find > > it. > > That sounds like a good idea. Consider adding comments or to the > commit message so that the str doesn't get removed accidentally in the > future.
Sure, I'll add a comment in the next version.
Sami
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