Messages in this thread | | | Subject | Re: [PATCHv4 05/10] arm64/cpufeature: detect pointer authentication | From | Suzuki K Poulose <> | Date | Wed, 23 May 2018 09:48:28 +0100 |
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Mark,
On 03/05/18 14:20, Mark Rutland wrote: > So that we can dynamically handle the presence of pointer authentication > functionality, wire up probing code in cpufeature.c. > > From ARMv8.3 onwards, ID_AA64ISAR1 is no longer entirely RES0, and now > has four fields describing the presence of pointer authentication > functionality: > > * APA - address authentication present, using an architected algorithm > * API - address authentication present, using an IMP DEF algorithm > * GPA - generic authentication present, using an architected algorithm > * GPI - generic authentication present, using an IMP DEF algorithm > > For the moment we only care about address authentication, so we only > need to check APA and API. It is assumed that if all CPUs support an IMP > DEF algorithm, the same algorithm is used across all CPUs. > > Note that when we implement KVM support, we will also need to ensure > that CPUs have uniform support for GPA and GPI. > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Suzuki K Poulose <suzuki.poulose@arm.com> > Cc: Will Deacon <will.deacon@arm.com> > --- > arch/arm64/include/asm/cpucaps.h | 5 ++++- > arch/arm64/kernel/cpufeature.c | 47 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 51 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h > index bc51b72fafd4..9dcb4d1b14f5 100644 > --- a/arch/arm64/include/asm/cpucaps.h > +++ b/arch/arm64/include/asm/cpucaps.h > @@ -48,7 +48,10 @@ > #define ARM64_HAS_CACHE_IDC 27 > #define ARM64_HAS_CACHE_DIC 28 > #define ARM64_HW_DBM 29 > +#define ARM64_HAS_ADDRESS_AUTH_ARCH 30 > +#define ARM64_HAS_ADDRESS_AUTH_IMP_DEF 31
Where are these caps used ? I couldn't find anything in the series that uses them. Otherwise looks good to me.
Cheers
Suzuki
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