diff options
| -rw-r--r-- | arch/x86/include/asm/i387.h | 183 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 7 | ||||
| -rw-r--r-- | arch/x86/kernel/i387.c | 58 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 35 |
6 files changed, 86 insertions, 203 deletions
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h index 70f105b352e..4aa2bb3b242 100644 --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -55,6 +55,12 @@ extern int save_i387_xstate_ia32(void __user *buf); extern int restore_i387_xstate_ia32(void __user *buf); #endif +#ifdef CONFIG_MATH_EMULATION +extern void finit_soft_fpu(struct i387_soft_struct *soft); +#else +static inline void finit_soft_fpu(struct i387_soft_struct *soft) {} +#endif + #define X87_FSW_ES (1 << 7) /* Exception Summary */ static __always_inline __pure bool use_xsaveopt(void) @@ -67,6 +73,11 @@ static __always_inline __pure bool use_xsave(void) return static_cpu_has(X86_FEATURE_XSAVE); } +static __always_inline __pure bool use_fxsr(void) +{ + return static_cpu_has(X86_FEATURE_FXSR); +} + extern void __sanitize_i387_state(struct task_struct *); static inline void sanitize_i387_state(struct task_struct *tsk) @@ -77,19 +88,11 @@ static inline void sanitize_i387_state(struct task_struct *tsk) } #ifdef CONFIG_X86_64 - -/* Ignore delayed exceptions from user space */ -static inline void tolerant_fwait(void) -{ - asm volatile("1: fwait\n" - "2:\n" - _ASM_EXTABLE(1b, 2b)); -} - static inline int fxrstor_checking(struct i387_fxsave_struct *fx) { int err; + /* See comment in fxsave() below. */ asm volatile("1: rex64/fxrstor (%[fx])\n\t" "2:\n" ".section .fixup,\"ax\"\n" @@ -98,44 +101,10 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx) ".previous\n" _ASM_EXTABLE(1b, 3b) : [err] "=r" (err) -#if 0 /* See comment in fxsave() below. */ - : [fx] "r" (fx), "m" (*fx), "0" (0)); -#else - : [fx] "cdaSDb" (fx), "m" (*fx), "0" (0)); -#endif + : [fx] "R" (fx), "m" (*fx), "0" (0)); return err; } -/* AMD CPUs don't save/restore FDP/FIP/FOP unless an exception - is pending. Clear the x87 state here by setting it to fixed - values. The kernel data segment can be sometimes 0 and sometimes - new user value. Both should be ok. - Use the PDA as safe address because it should be already in L1. */ -static inline void fpu_clear(struct fpu *fpu) -{ - struct xsave_struct *xstate = &fpu->state->xsave; - struct i387_fxsave_struct *fx = &fpu->state->fxsave; - - /* - * xsave header may indicate the init state of the FP. - */ - if (use_xsave() && - !(xstate->xsave_hdr.xstate_bv & XSTATE_FP)) - return; - - if (unlikely(fx->swd & X87_FSW_ES)) - asm volatile("fnclex"); - alternative_input(ASM_NOP8 ASM_NOP2, - " emms\n" /* clear stack tags */ - " fildl %%gs:0", /* load to clear state */ - X86_FEATURE_FXSAVE_LEAK); -} - -static inline void clear_fpu_state(struct task_struct *tsk) -{ - fpu_clear(&tsk->thread.fpu); -} - static inline int fxsave_user(struct i387_fxsave_struct __user *fx) { int err; @@ -149,6 +118,7 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx) if (unlikely(err)) return -EFAULT; + /* See comment in fxsave() below. */ asm volatile("1: rex64/fxsave (%[fx])\n\t" "2:\n" ".section .fixup,\"ax\"\n" @@ -157,11 +127,7 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx) ".previous\n" _ASM_EXTABLE(1b, 3b) : [err] "=r" (err), "=m" (*fx) -#if 0 /* See comment in fxsave() below. */ - : [fx] "r" (fx), "0" (0)); -#else - : [fx] "cdaSDb" (fx), "0" (0)); -#endif + : [fx] "R" (fx), "0" (0)); if (unlikely(err) && __clear_user(fx, sizeof(struct i387_fxsave_struct))) err = -EFAULT; @@ -175,56 +141,29 @@ static inline void fpu_fxsave(struct fpu *fpu) uses any extended registers for addressing, a second REX prefix will be generated (to the assembler, rex64 followed by semicolon is a separate instruction), and hence the 64-bitness is lost. */ + #ifdef CONFIG_AS_FXSAVEQ /* Using "fxsaveq %0" would be the ideal choice, but is only supported starting with gas 2.16. */ __asm__ __volatile__("fxsaveq %0" : "=m" (fpu->state->fxsave)); -#elif 0 +#else /* Using, as a workaround, the properly prefixed form below isn't accepted by any binutils version so far released, complaining that the same type of prefix is used twice if an extended register is - needed for addressing (fix submitted to mainline 2005-11-21). */ - __asm__ __volatile__("rex64/fxsave %0" - : "=m" (fpu->state->fxsave)); -#else - /* This, however, we can work around by forcing the compiler to select + needed for addressing (fix submitted to mainline 2005-11-21). + asm volatile("rex64/fxsave %0" + : "=m" (fpu->state->fxsave)); + This, however, we can work around by forcing the compiler to select an addressing mode that doesn't require extended registers. */ - __asm__ __volatile__("rex64/fxsave (%1)" - : "=m" (fpu->state->fxsave) - : "cdaSDb" (&fpu->state->fxsave)); + asm volatile("rex64/fxsave (%[fx])" + : "=m" (fpu->state->fxsave) + : [fx] "R" (&fpu->state->fxsave)); #endif } -static inline void fpu_save_init(struct fpu *fpu) -{ - if (use_xsave()) - fpu_xsave(fpu); - else - fpu_fxsave(fpu); - - fpu_clear(fpu); -} - -static inline void __save_init_fpu(struct task_struct *tsk) -{ - fpu_save_init(&tsk->thread.fpu); - task_thread_info(tsk)->status &= ~TS_USEDFPU; -} - #else /* CONFIG_X86_32 */ -#ifdef CONFIG_MATH_EMULATION -extern void finit_soft_fpu(struct i387_soft_struct *soft); -#else -static inline void finit_soft_fpu(struct i387_soft_struct *soft) {} -#endif - -static inline void tolerant_fwait(void) -{ - asm volatile("fnclex ; fwait"); -} - /* perform fxrstor iff the processor has extended states, otherwise frstor */ static inline int fxrstor_checking(struct i387_fxsave_struct *fx) { @@ -241,6 +180,14 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx) return 0; } +static inline void fpu_fxsave(struct fpu *fpu) +{ + asm volatile("fxsave %[fx]" + : [fx] "=m" (fpu->state->fxsave)); +} + +#endif /* CONFIG_X86_64 */ + /* We need a safe address that is cheap to find and that is already in L1 during context switch. The best choices are unfortunately different for UP and SMP */ @@ -256,47 +203,33 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx) static inline void fpu_save_init(struct fpu *fpu) { if (use_xsave()) { - struct xsave_struct *xstate = &fpu->state->xsave; - struct i387_fxsave_struct *fx = &fpu->state->fxsave; - fpu_xsave(fpu); /* * xsave header may indicate the init state of the FP. */ - if (!(xstate->xsave_hdr.xstate_bv & XSTATE_FP)) - goto end; - - if (unlikely(fx->swd & X87_FSW_ES)) - asm volatile("fnclex"); - - /* - * we can do a simple return here or be paranoid :) - */ - goto clear_state; + if (!(fpu->state->xsave.xsave_hdr.xstate_bv & XSTATE_FP)) + return; + } else if (use_fxsr()) { + fpu_fxsave(fpu); + } else { + asm volatile("fsave %[fx]; fwait" + : [fx] "=m" (fpu->state->fsave)); + return; } - /* Use more nops than strictly needed in case the compiler - varies code */ - alternative_input( - "fnsave %[fx] ;fwait;" GENERIC_NOP8 GENERIC_NOP4, - "fxsave %[fx]\n" - "bt $7,%[fsw] ; jnc 1f ; fnclex\n1:", - X86_FEATURE_FXSR, - [fx] "m" (fpu->state->fxsave), - [fsw] "m" (fpu->state->fxsave.swd) : "memory"); -clear_state: + if (unlikely(fpu->state->fxsave.swd & X87_FSW_ES)) + asm volatile("fnclex"); + /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception is pending. Clear the x87 state here by setting it to fixed values. safe_address is a random variable that should be in L1 */ alternative_input( - GENERIC_NOP8 GENERIC_NOP2, + ASM_NOP8 ASM_NOP2, "emms\n\t" /* clear stack tags */ - "fildl %[addr]", /* set F?P to defined value */ + "fildl %P[addr]", /* set F?P to defined value */ X86_FEATURE_FXSAVE_LEAK, [addr] "m" (safe_address)); -end: - ; } static inline void __save_init_fpu(struct task_struct *tsk) @@ -305,9 +238,6 @@ static inline void __save_init_fpu(struct task_struct *tsk) task_thread_info(tsk)->status &= ~TS_USEDFPU; } - -#endif /* CONFIG_X86_64 */ - static inline int fpu_fxrstor_checking(struct fpu *fpu) { return fxrstor_checking(&fpu->state->fxsave); @@ -344,7 +274,10 @@ static inline void __unlazy_fpu(struct task_struct *tsk) static inline void __clear_fpu(struct task_struct *tsk) { if (task_thread_info(tsk)->status & TS_USEDFPU) { - tolerant_fwait(); + /* Ignore delayed exceptions from user space */ + asm volatile("1: fwait\n" + "2:\n" + _ASM_EXTABLE(1b, 2b)); task_thread_info(tsk)->status &= ~TS_USEDFPU; stts(); } @@ -405,19 +338,6 @@ static inline void irq_ts_restore(int TS_state) stts(); } -#ifdef CONFIG_X86_64 - -static inline void save_init_fpu(struct task_struct *tsk) -{ - __save_init_fpu(tsk); - stts(); -} - -#define unlazy_fpu __unlazy_fpu -#define clear_fpu __clear_fpu - -#else /* CONFIG_X86_32 */ - /* * These disable preemption on their own and are safe */ @@ -443,8 +363,6 @@ static inline void clear_fpu(struct task_struct *tsk) preempt_enable(); } -#endif /* CONFIG_X86_64 */ - /* * i387 state interaction */ @@ -508,7 +426,4 @@ extern void fpu_finit(struct fpu *fpu); #endif /* __ASSEMBLY__ */ -#define PSHUFB_XMM5_XMM0 .byte 0x66, 0x0f, 0x38, 0x00, 0xc5 -#define PSHUFB_XMM5_XMM6 .byte 0x66, 0x0f, 0x38, 0x00, 0xf5 - #endif /* _ASM_X86_I387_H */ diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 69e80c2ec6c..a668d66301f 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -604,7 +604,7 @@ extern unsigned long mmu_cr4_features; static inline void set_in_cr4(unsigned long mask) { - unsigned cr4; + unsigned long cr4; mmu_cr4_features |= mask; cr4 = read_cr4(); @@ -614,7 +614,7 @@ static inline void set_in_cr4(unsigned long mask) static inline void clear_in_cr4(unsigned long mask) { - unsigned cr4; + unsigned long cr4; mmu_cr4_features &= ~mask; cr4 = read_cr4(); diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 92af7b420ab..4b68bda3093 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1269,13 +1269,6 @@ void __cpuinit cpu_init(void) clear_all_debug_regs(); dbg_restore_debug_regs(); - /* - * Force FPU initialization: - */ - current_thread_info()->status = 0; - clear_used_math(); - mxcsr_feature_mask_init(); - fpu_init(); xsave_init(); } diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index a46cb3522c0..58bb239a2fd 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -68,19 +68,22 @@ static void __cpuinit init_thread_xstate(void) */ if (!HAVE_HWFP) { + /* + * Disable xsave as we do not support it if i387 + * emulation is enabled. + */ + setup_clear_cpu_cap(X86_FEATURE_XSAVE); + setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); xstate_size = sizeof(struct i387_soft_struct); return; } if (cpu_has_fxsr) xstate_size = sizeof(struct i387_fxsave_struct); -#ifdef CONFIG_X86_32 else xstate_size = sizeof(struct i387_fsave_struct); -#endif } -#ifdef CONFIG_X86_64 /* * Called at bootup to set up the initial FPU state that is later cloned * into all processes. @@ -88,12 +91,21 @@ static void __cpuinit init_thread_xstate(void) void __cpuinit fpu_init(void) { - unsigned long oldcr0 = read_cr0(); - - set_in_cr4(X86_CR4_OSFXSR); - set_in_cr4(X86_CR4_OSXMMEXCPT); + unsigned long cr0; + unsigned long cr4_mask = 0; - write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */ + if (cpu_has_fxsr) + cr4_mask |= X86_CR4_OSFXSR; + if (cpu_has_xmm) + cr4_mask |= X86_CR4_OSXMMEXCPT; + if (cr4_mask) + set_in_cr4(cr4_mask); + + cr0 = read_cr0(); + cr0 &= ~(X86_CR0_TS|X86_CR0_EM); /* clear TS and EM */ + if (!HAVE_HWFP) + cr0 |= X86_CR0_EM; + write_cr0(cr0); if (!smp_processor_id()) init_thread_xstate(); @@ -104,24 +116,12 @@ void __cpuinit fpu_init(void) clear_used_math(); } -#else /* CONFIG_X86_64 */ - -void __cpuinit fpu_init(void) -{ - if (!smp_processor_id()) - init_thread_xstate(); -} - -#endif /* CONFIG_X86_32 */ - void fpu_finit(struct fpu *fpu) { -#ifdef CONFIG_X86_32 if (!HAVE_HWFP) { finit_soft_fpu(&fpu->state->soft); return; } -#endif if (cpu_has_fxsr) { struct i387_fxsave_struct *fx = &fpu->state->fxsave; @@ -386,19 +386,17 @@ convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk) #ifdef CONFIG_X86_64 env->fip = fxsave->rip; env->foo = fxsave->rdp; + /* + * should be actually ds/cs at fpu exception time, but + * that information is not available in 64bit mode. + */ + env->fcs = task_pt_regs(tsk)->cs; if (tsk == current) { - /* - * should be actually ds/cs at fpu exception time, but - * that information is not available in 64bit mode. - */ - asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos)); - asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs)); + savesegment(ds, env->fos); } else { - struct pt_regs *regs = task_pt_regs(tsk); - - env->fos = 0xffff0000 | tsk->thread.ds; - env->fcs = regs->cs; + env->fos = tsk->thread.ds; } + env->fos |= 0xffff0000; #else env->fip = fxsave->fip; env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 3d9ea531ddd..b3d7a3a04f3 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -424,7 +424,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) load_TLS(next, cpu); /* Must be after DS reload */ - unlazy_fpu(prev_p); + __unlazy_fpu(prev_p); /* Make sure cpu is ready for new context */ if (preload_fpu) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 60788dee0f8..d43968503dd 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -776,21 +776,10 @@ asmlinkage void math_state_restore(void) } EXPORT_SYMBOL_GPL(math_state_restore); -#ifndef CONFIG_MATH_EMULATION -void math_emulate(struct math_emu_info *info) -{ - printk(KERN_EMERG - "math-emulation not enabled and no coprocessor found.\n"); - printk(KERN_EMERG "killing %s.\n", current->comm); - force_sig(SIGFPE, current); - schedule(); -} -#endif /* CONFIG_MATH_EMULATION */ - dotraplinkage void __kprobes do_device_not_available(struct pt_regs *regs, long error_code) { -#ifdef CONFIG_X86_32 +#ifdef CONFIG_MATH_EMULATION if (read_cr0() & X86_CR0_EM) { struct math_emu_info info = { }; @@ -798,12 +787,12 @@ do_device_not_available(struct pt_regs *regs, long error_code) info.regs = regs; math_emulate(&info); - } else { - math_state_restore(); /* interrupts still off */ - conditional_sti(regs); + return; } -#else - math_state_restore(); +#endif + math_state_restore(); /* interrupts still off */ +#ifdef CONFIG_X86_32 + conditional_sti(regs); #endif } @@ -881,18 +870,6 @@ void __init trap_init(void) #endif #ifdef CONFIG_X86_32 - if (cpu_has_fxsr) { - printk(KERN_INFO "Enabling fast FPU save and restore... "); - set_in_cr4(X86_CR4_OSFXSR); - printk("done.\n"); - } - if (cpu_has_xmm) { - printk(KERN_INFO - "Enabling unmasked SIMD FPU exception support... "); - set_in_cr4(X86_CR4_OSXMMEXCPT); - printk("done.\n"); - } - set_system_trap_gate(SYSCALL_VECTOR, &system_call); set_bit(SYSCALL_VECTOR, used_vectors); #endif |