diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/i387.h | 19 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 14 |
3 files changed, 16 insertions, 22 deletions
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h index 86974c72d0d0..01b115d86770 100644 --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -211,15 +211,6 @@ static inline void fpu_fxsave(struct fpu *fpu) #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 */ -#ifdef CONFIG_SMP -#define safe_address (__per_cpu_offset[0]) -#else -#define safe_address (__get_cpu_var(kernel_cpustat).cpustat[CPUTIME_USER]) -#endif - /* * These must be called with preempt disabled */ @@ -243,16 +234,6 @@ static inline void fpu_save_init(struct fpu *fpu) 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( - ASM_NOP8 ASM_NOP2, - "emms\n\t" /* clear stack tags */ - "fildl %P[addr]", /* set F?P to defined value */ - X86_FEATURE_FXSAVE_LEAK, - [addr] "m" (safe_address)); } static inline void __save_init_fpu(struct task_struct *tsk) diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 992b4e542bc3..753e803f7197 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -387,6 +387,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) struct tss_struct *tss = &per_cpu(init_tss, cpu); unsigned fsindex, gsindex; + __unlazy_fpu(prev_p); + /* * Reload esp0, LDT and the page table pointer: */ @@ -415,9 +417,6 @@ __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); - /* * Leave lazy mode, flushing any hypercalls made here. * This must be done before restoring TLS segments so diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 5afe824c66e5..4d42300dcd2c 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -585,6 +585,10 @@ void math_state_restore(void) struct thread_info *thread = current_thread_info(); struct task_struct *tsk = thread->task; + /* We need a safe address that is cheap to find and that is already + in L1. We just brought in "thread->task", so use that */ +#define safe_address (thread->task) + if (!tsk_used_math(tsk)) { local_irq_enable(); /* @@ -602,6 +606,16 @@ void math_state_restore(void) __thread_fpu_begin(thread); + /* 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( + ASM_NOP8 ASM_NOP2, + "emms\n\t" /* clear stack tags */ + "fildl %P[addr]", /* set F?P to defined value */ + X86_FEATURE_FXSAVE_LEAK, + [addr] "m" (safe_address)); + /* * Paranoid restore. send a SIGSEGV if we fail to restore the state. */ |