Re: [PATCH v14 03/26] x86/fpu/xstate: Introduce CET MSR XSAVES supervisor states
From: Cyrill Gorcunov <hidden>
Date: 2020-10-12 19:58:14
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linux-arch, linux-doc, linux-mm, lkml
On Mon, Oct 12, 2020 at 08:38:27AM -0700, Yu-cheng Yu wrote: ...
quoted hunk ↗ jump to hunk
/* * x86-64 Task Priority Register, CR8diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 038e19c0019e..705fd9b94e31 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c@@ -38,6 +38,9 @@ static const char *xfeature_names[] = "Processor Trace (unused)" , "Protection Keys User registers", "unknown xstate feature" , + "Control-flow User registers" , + "Control-flow Kernel registers" , + "unknown xstate feature" , }; static short xsave_cpuid_features[] __initdata = {@@ -51,6 +54,9 @@ static short xsave_cpuid_features[] __initdata = { X86_FEATURE_AVX512F, X86_FEATURE_INTEL_PT, X86_FEATURE_PKU, + -1, /* Unused */ + X86_FEATURE_SHSTK, /* XFEATURE_CET_USER */ + X86_FEATURE_SHSTK, /* XFEATURE_CET_KERNEL */ };
Why do you need "-1" here in the array? The only 1:1 mapping is between the names itselves and values, not indices of arrays so i don't understand why we need this unused value. Sorry if it is a dumb questions and been discussed already.