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Subject[patch 6/8] x86/fpu: Mop up xfeatures_mask_uabi()
Date
Use the new fpu_user_cfg to retrieve the information instead of
xfeatures_mask_uabi() which will be not longer correct when dynamically
enabled features become available.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/include/asm/fpu/xstate.h | 9 ---------
arch/x86/kernel/fpu/core.c | 4 ++--
arch/x86/kernel/fpu/signal.c | 2 +-
arch/x86/kernel/fpu/xstate.c | 6 +++---
4 files changed, 6 insertions(+), 15 deletions(-)

--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -84,15 +84,6 @@ static inline u64 xfeatures_mask_supervi
}

/*
- * The xfeatures which are enabled in XCR0 and expected to be in ptrace
- * buffers and signal frames.
- */
-static inline u64 xfeatures_mask_uabi(void)
-{
- return fpu_kernel_cfg.max_features & XFEATURE_MASK_USER_SUPPORTED;
-}
-
-/*
* The xfeatures which are restored by the kernel when returning to user
* mode. This is not necessarily the same as xfeatures_mask_uabi() as the
* kernel does not manage all XCR0 enabled features via xsave/xrstor as
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -237,7 +237,7 @@ int fpu_copy_kvm_uabi_to_fpstate(struct
}

/* Ensure that XCOMP_BV is set up for XSAVES */
- xstate_init_xcomp_bv(&kstate->regs.xsave, xfeatures_mask_uabi());
+ xstate_init_xcomp_bv(&kstate->regs.xsave, fpu_user_cfg.max_features);
return 0;
}
EXPORT_SYMBOL_GPL(fpu_copy_kvm_uabi_to_fpstate);
@@ -333,7 +333,7 @@ void fpstate_init_user(struct fpstate *f
return;
}

- xstate_init_xcomp_bv(&fpstate->regs.xsave, xfeatures_mask_uabi());
+ xstate_init_xcomp_bv(&fpstate->regs.xsave, fpu_user_cfg.max_features);

if (cpu_feature_enabled(X86_FEATURE_FXSR))
fpstate_init_fxstate(fpstate);
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -530,7 +530,7 @@ void __init fpu__init_prepare_fx_sw_fram

fx_sw_reserved.magic1 = FP_XSTATE_MAGIC1;
fx_sw_reserved.extended_size = size;
- fx_sw_reserved.xfeatures = xfeatures_mask_uabi();
+ fx_sw_reserved.xfeatures = fpu_user_cfg.default_features;
fx_sw_reserved.xstate_size = fpu_user_cfg.default_size;

if (IS_ENABLED(CONFIG_IA32_EMULATION) ||
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -770,7 +770,7 @@ void __init fpu__init_system_xstate(unsi
cpuid_count(XSTATE_CPUID, 1, &eax, &ebx, &ecx, &edx);
fpu_kernel_cfg.max_features |= ecx + ((u64)edx << 32);

- if ((xfeatures_mask_uabi() & XFEATURE_MASK_FPSSE) != XFEATURE_MASK_FPSSE) {
+ if ((fpu_kernel_cfg.max_features & XFEATURE_MASK_FPSSE) != XFEATURE_MASK_FPSSE) {
/*
* This indicates that something really unexpected happened
* with the enumeration. Disable XSAVE and try to continue
@@ -815,7 +815,7 @@ void __init fpu__init_system_xstate(unsi
* supervisor xstates:
*/
update_regset_xstate_info(fpu_user_cfg.max_size,
- xfeatures_mask_uabi());
+ fpu_user_cfg.max_features);

fpu__init_prepare_fx_sw_frame();
setup_init_fpu_buf();
@@ -853,7 +853,7 @@ void fpu__resume_cpu(void)
* Restore XCR0 on xsave capable CPUs:
*/
if (cpu_feature_enabled(X86_FEATURE_XSAVE))
- xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask_uabi());
+ xsetbv(XCR_XFEATURE_ENABLED_MASK, fpu_user_cfg.max_features);

/*
* Restore IA32_XSS. The same CPUID bit enumerates support
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