diff options
Diffstat (limited to 'arch/x86/include/asm/fpu/internal.h')
| -rw-r--r-- | arch/x86/include/asm/fpu/internal.h | 50 |
1 files changed, 18 insertions, 32 deletions
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 8d33ad80704f..16bf4d4a8159 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -204,6 +204,14 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu) asm volatile("fxsaveq %[fx]" : [fx] "=m" (fpu->state.fxsave)); } +static inline void fxsave(struct fxregs_state *fx) +{ + if (IS_ENABLED(CONFIG_X86_32)) + asm volatile( "fxsave %[fx]" : [fx] "=m" (*fx)); + else + asm volatile("fxsaveq %[fx]" : [fx] "=m" (*fx)); +} + /* These macros all use (%edi)/(%rdi) as the single memory argument. */ #define XSAVE ".byte " REX_PREFIX "0x0f,0xae,0x27" #define XSAVEOPT ".byte " REX_PREFIX "0x0f,0xae,0x37" @@ -272,28 +280,6 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu) * This function is called only during boot time when x86 caps are not set * up and alternative can not be used yet. */ -static inline void copy_xregs_to_kernel_booting(struct xregs_state *xstate) -{ - u64 mask = xfeatures_mask_all; - u32 lmask = mask; - u32 hmask = mask >> 32; - int err; - - WARN_ON(system_state != SYSTEM_BOOTING); - - if (boot_cpu_has(X86_FEATURE_XSAVES)) - XSTATE_OP(XSAVES, xstate, lmask, hmask, err); - else - XSTATE_OP(XSAVE, xstate, lmask, hmask, err); - - /* We should never fault when copying to a kernel buffer: */ - WARN_ON_FPU(err); -} - -/* - * This function is called only during boot time when x86 caps are not set - * up and alternative can not be used yet. - */ static inline void copy_kernel_to_xregs_booting(struct xregs_state *xstate) { u64 mask = -1; @@ -578,19 +564,19 @@ static inline void switch_fpu_finish(struct fpu *new_fpu) * PKRU state is switched eagerly because it needs to be valid before we * return to userland e.g. for a copy_to_user() operation. */ - if (current->mm) { + if (!(current->flags & PF_KTHREAD)) { + /* + * If the PKRU bit in xsave.header.xfeatures is not set, + * then the PKRU component was in init state, which means + * XRSTOR will set PKRU to 0. If the bit is not set then + * get_xsave_addr() will return NULL because the PKRU value + * in memory is not valid. This means pkru_val has to be + * set to 0 and not to init_pkru_value. + */ pk = get_xsave_addr(&new_fpu->state.xsave, XFEATURE_PKRU); - if (pk) - pkru_val = pk->pkru; + pkru_val = pk ? pk->pkru : 0; } __write_pkru(pkru_val); - - /* - * Expensive PASID MSR write will be avoided in update_pasid() because - * TIF_NEED_FPU_LOAD was set. And the PASID state won't be updated - * unless it's different from mm->pasid to reduce overhead. - */ - update_pasid(); } #endif /* _ASM_X86_FPU_INTERNAL_H */ |