| Date | Tue, 22 Jun 2021 16:15:47 +0200 | From | Borislav Petkov <> | Subject | Re: [patch V3 41/66] x86/cpu: Sanitize X86_FEATURE_OSPKE |
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On Fri, Jun 18, 2021 at 04:19:04PM +0200, Thomas Gleixner wrote: > X86_FEATURE_OSPKE is enabled first on the boot CPU and the feature flag is > set. Secondary CPUs have to enable CR4.PKE as well and set their per CPU > feature flag. That's ineffective because all call sites have checks for > boot_cpu_data. > > Make it smarter and force the feature flag when PKU is enabled on the boot > cpu which allows then to use cpu_feature_enabled(X86_FEATURE_OSPKE) all > over the place. That either compiles the code out when PKEY support is > disabled in Kconfig or uses a static_cpu_has() for the feature check which > makes a significant difference in hotpathes, e.g. context switch.
"hotpaths"
> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > --- > arch/x86/include/asm/pkeys.h | 8 ++++---- > arch/x86/include/asm/pkru.h | 4 ++-- > arch/x86/kernel/cpu/common.c | 24 +++++++++++------------- > arch/x86/kernel/fpu/core.c | 2 +- > arch/x86/kernel/fpu/xstate.c | 2 +- > arch/x86/kernel/process_64.c | 2 +- > arch/x86/mm/fault.c | 2 +- > 7 files changed, 21 insertions(+), 23 deletions(-)
Other than that:
Reviewed-by: Borislav Petkov <bp@suse.de>
-- Regards/Gruss, Boris.
SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 36809, AG Nürnberg
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