Messages in this thread | | | Date | Wed, 25 Jul 2018 09:56:04 +0100 | From | Dave Martin <> | Subject | Re: [PATCH] arm64: Check for errata before evaluating cpu features |
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On Wed, Jul 25, 2018 at 09:51:53AM +0100, Suzuki K Poulose wrote: > On 07/25/2018 09:35 AM, Dirk Mueller wrote: > >Since commit d3aec8a28be3b8 ("arm64: capabilities: Restrict KPTI > >detection to boot-time CPUs") we rely on errata flags being already > >populated during feature enumeration. The order of errata and > >features was flipped as part of commit ed478b3f9e4a ("arm64: > >capabilities: Group handling of features and errata workarounds"). > > > >Return to the orginal order of errata and feature evaluation to > >ensure errata flags are present during feature evaluation. > > > >Fixes: d3aec8a28be3b8 ("arm64: capabilities: Restrict KPTI > >detection to boot-time CPUs") > >CC: Suzuki K Poulose <suzuki.poulose@arm.com> > >CC: Marc Zyngier <marc.zyngier@arm.com> > >Signed-off-by: Dirk Mueller <dmueller@suse.com> > > It would be good to add "Fixes: ed478b3f9e4a" (instead), just to make > sure this gets fixed everywhere the original problem appears. > > >--- > > arch/arm64/kernel/cpufeature.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > >diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > >index f24892a40d2c..c6d80743f4ed 100644 > >--- a/arch/arm64/kernel/cpufeature.c > >+++ b/arch/arm64/kernel/cpufeature.c > >@@ -1351,9 +1351,9 @@ static void __update_cpu_capabilities(const struct arm64_cpu_capabilities *caps, > > static void update_cpu_capabilities(u16 scope_mask) > > { > >- __update_cpu_capabilities(arm64_features, scope_mask, "detected:"); > > __update_cpu_capabilities(arm64_errata, scope_mask, > > "enabling workaround for"); > >+ __update_cpu_capabilities(arm64_features, scope_mask, "detected:"); > > } > > static int __enable_cpu_capability(void *arg) > >@@ -1408,8 +1408,8 @@ __enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps, > > static void __init enable_cpu_capabilities(u16 scope_mask) > > { > >- __enable_cpu_capabilities(arm64_features, scope_mask); > > __enable_cpu_capabilities(arm64_errata, scope_mask); > >+ __enable_cpu_capabilities(arm64_features, scope_mask);
I forget why these were originally reordered in ed478b3f9e4a. Was there any real reason for it?
I also notice in that commit that after the detection pass, we set things up (in update_cpu_capabilities(), enable_cpu_capabilities()) in the order errata, features. Does this matter for anything?
Cheers ---Dave
> > Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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