Re: [PATCHv3 11/11] arm64: docs: document pointer authentication

From: Pavel Machek
Date: Sun Apr 22 2018 - 05:00:22 EST


On Sun 2018-04-22 09:47:29, Marc Zyngier wrote:
> On Sun, 22 Apr 2018 09:05:21 +0100,
> Pavel Machek wrote:
> >
> > Hi!
> >
> > > @@ -205,6 +205,14 @@ Before jumping into the kernel, the following conditions must be met:
> > > ICC_SRE_EL2.SRE (bit 0) must be initialised to 0b0.
> > > - The DT or ACPI tables must describe a GICv2 interrupt controller.
> > >
> > > + For CPUs with pointer authentication functionality:
> > > + - If EL3 is present:
> > > + SCR_EL3.APK (bit 16) must be initialised to 0b1
> > > + SCR_EL3.API (bit 17) must be initialised to 0b1
> > > + - If the kernel is entered at EL1:
> > > + HCR_EL2.APK (bit 40) must be initialised to 0b1
> > > + HCR_EL2.API (bit 41) must be initialised to 0b1
> > > +
> >
> > 0b1 is quite confusing way to write 1.
>
> Do you find 0x1 equally confusing?

It is slightly better. Still I'd not use it for describing single bit.

> 0bx is a pretty common way of describing bit-fields of a hardware
> register. It is also consistent with the rest of this document.

...and inconsistent with rest of the world :-).
Pavel
--
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