From 079ec41b22b952cdf3126527d735e373c9125f6d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 15 Oct 2021 03:16:41 +0200 Subject: [PATCH] x86/fpu: Provide a proper function for ex_handler_fprestore() To make upcoming changes for support of dynamically enabled features simpler, provide a proper function for the exception handler which removes exposure of FPU internals. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20211015011540.053515012@linutronix.de --- arch/x86/include/asm/fpu/api.h | 4 +--- arch/x86/kernel/fpu/core.c | 5 +++++ arch/x86/kernel/fpu/internal.h | 2 ++ arch/x86/mm/extable.c | 5 ++--- 4 files changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index c691f079a56ed..9263d708dff9a 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -113,6 +113,7 @@ static inline void update_pasid(void) { } /* Trap handling */ extern int fpu__exception_code(struct fpu *fpu, int trap_nr); extern void fpu_sync_fpstate(struct fpu *fpu); +extern void fpu_reset_from_exception_fixup(void); /* Boot, hotplug and resume */ extern void fpu__init_cpu(void); @@ -129,9 +130,6 @@ static inline void fpstate_init_soft(struct swregs_state *soft) {} /* State tracking */ DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx); -/* fpstate */ -extern union fpregs_state init_fpstate; - /* fpstate-related functions which are exported to KVM */ extern void fpu_init_fpstate_user(struct fpu *fpu); diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 9bb0c1c45e27f..79f2e8ddd10cb 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -155,6 +155,11 @@ void restore_fpregs_from_fpstate(union fpregs_state *fpstate, u64 mask) } } +void fpu_reset_from_exception_fixup(void) +{ + restore_fpregs_from_fpstate(&init_fpstate, xfeatures_mask_fpstate()); +} + #if IS_ENABLED(CONFIG_KVM) void fpu_swap_kvm_fpu(struct fpu *save, struct fpu *rstor, u64 restore_mask) { diff --git a/arch/x86/kernel/fpu/internal.h b/arch/x86/kernel/fpu/internal.h index bd7f813242dd7..479f2db6e1606 100644 --- a/arch/x86/kernel/fpu/internal.h +++ b/arch/x86/kernel/fpu/internal.h @@ -2,6 +2,8 @@ #ifndef __X86_KERNEL_FPU_INTERNAL_H #define __X86_KERNEL_FPU_INTERNAL_H +extern union fpregs_state init_fpstate; + /* CPU feature check wrappers */ static __always_inline __pure bool use_xsave(void) { diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 79c2e30d93ae6..5cd2a88930a90 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -4,8 +4,7 @@ #include #include -#include -#include +#include #include #include #include @@ -48,7 +47,7 @@ static bool ex_handler_fprestore(const struct exception_table_entry *fixup, WARN_ONCE(1, "Bad FPU state detected at %pB, reinitializing FPU registers.", (void *)instruction_pointer(regs)); - restore_fpregs_from_fpstate(&init_fpstate, xfeatures_mask_fpstate()); + fpu_reset_from_exception_fixup(); return true; } -- 2.49.0