e2764a1e30
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
151 lines
3.6 KiB
C
151 lines
3.6 KiB
C
/*
|
|
* linux/arch/x86_64/kernel/i387.c
|
|
*
|
|
* Copyright (C) 1994 Linus Torvalds
|
|
* Copyright (C) 2002 Andi Kleen, SuSE Labs
|
|
*
|
|
* Pentium III FXSR, SSE support
|
|
* General FPU state handling cleanups
|
|
* Gareth Hughes <gareth@valinux.com>, May 2000
|
|
*
|
|
* x86-64 rework 2002 Andi Kleen.
|
|
* Does direct fxsave in and out of user space now for signal handlers.
|
|
* All the FSAVE<->FXSAVE conversion code has been moved to the 32bit emulation,
|
|
* the 64bit user space sees a FXSAVE frame directly.
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/init.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/i387.h>
|
|
#include <asm/sigcontext.h>
|
|
#include <asm/user.h>
|
|
#include <asm/ptrace.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
unsigned int mxcsr_feature_mask __read_mostly = 0xffffffff;
|
|
|
|
void mxcsr_feature_mask_init(void)
|
|
{
|
|
unsigned int mask;
|
|
clts();
|
|
memset(¤t->thread.i387.fxsave, 0, sizeof(struct i387_fxsave_struct));
|
|
asm volatile("fxsave %0" : : "m" (current->thread.i387.fxsave));
|
|
mask = current->thread.i387.fxsave.mxcsr_mask;
|
|
if (mask == 0) mask = 0x0000ffbf;
|
|
mxcsr_feature_mask &= mask;
|
|
stts();
|
|
}
|
|
|
|
/*
|
|
* Called at bootup to set up the initial FPU state that is later cloned
|
|
* into all processes.
|
|
*/
|
|
void __cpuinit fpu_init(void)
|
|
{
|
|
unsigned long oldcr0 = read_cr0();
|
|
extern void __bad_fxsave_alignment(void);
|
|
|
|
if (offsetof(struct task_struct, thread.i387.fxsave) & 15)
|
|
__bad_fxsave_alignment();
|
|
set_in_cr4(X86_CR4_OSFXSR);
|
|
set_in_cr4(X86_CR4_OSXMMEXCPT);
|
|
|
|
write_cr0(oldcr0 & ~((1UL<<3)|(1UL<<2))); /* clear TS and EM */
|
|
|
|
mxcsr_feature_mask_init();
|
|
/* clean state in init */
|
|
current_thread_info()->status = 0;
|
|
clear_used_math();
|
|
}
|
|
|
|
void init_fpu(struct task_struct *child)
|
|
{
|
|
if (tsk_used_math(child)) {
|
|
if (child == current)
|
|
unlazy_fpu(child);
|
|
return;
|
|
}
|
|
memset(&child->thread.i387.fxsave, 0, sizeof(struct i387_fxsave_struct));
|
|
child->thread.i387.fxsave.cwd = 0x37f;
|
|
child->thread.i387.fxsave.mxcsr = 0x1f80;
|
|
/* only the device not available exception or ptrace can call init_fpu */
|
|
set_stopped_child_used_math(child);
|
|
}
|
|
|
|
/*
|
|
* Signal frame handlers.
|
|
*/
|
|
|
|
int save_i387(struct _fpstate __user *buf)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
int err = 0;
|
|
|
|
BUILD_BUG_ON(sizeof(struct user_i387_struct) !=
|
|
sizeof(tsk->thread.i387.fxsave));
|
|
|
|
if ((unsigned long)buf % 16)
|
|
printk("save_i387: bad fpstate %p\n",buf);
|
|
|
|
if (!used_math())
|
|
return 0;
|
|
clear_used_math(); /* trigger finit */
|
|
if (task_thread_info(tsk)->status & TS_USEDFPU) {
|
|
err = save_i387_checking((struct i387_fxsave_struct __user *)buf);
|
|
if (err) return err;
|
|
stts();
|
|
} else {
|
|
if (__copy_to_user(buf, &tsk->thread.i387.fxsave,
|
|
sizeof(struct i387_fxsave_struct)))
|
|
return -1;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* ptrace request handlers.
|
|
*/
|
|
|
|
int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *tsk)
|
|
{
|
|
init_fpu(tsk);
|
|
return __copy_to_user(buf, &tsk->thread.i387.fxsave,
|
|
sizeof(struct user_i387_struct)) ? -EFAULT : 0;
|
|
}
|
|
|
|
int set_fpregs(struct task_struct *tsk, struct user_i387_struct __user *buf)
|
|
{
|
|
if (__copy_from_user(&tsk->thread.i387.fxsave, buf,
|
|
sizeof(struct user_i387_struct)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* FPU state for core dumps.
|
|
*/
|
|
|
|
int dump_fpu( struct pt_regs *regs, struct user_i387_struct *fpu )
|
|
{
|
|
struct task_struct *tsk = current;
|
|
|
|
if (!used_math())
|
|
return 0;
|
|
|
|
unlazy_fpu(tsk);
|
|
memcpy(fpu, &tsk->thread.i387.fxsave, sizeof(struct user_i387_struct));
|
|
return 1;
|
|
}
|
|
|
|
int dump_task_fpu(struct task_struct *tsk, struct user_i387_struct *fpu)
|
|
{
|
|
int fpvalid = !!tsk_used_math(tsk);
|
|
|
|
if (fpvalid) {
|
|
if (tsk == current)
|
|
unlazy_fpu(tsk);
|
|
memcpy(fpu, &tsk->thread.i387.fxsave, sizeof(struct user_i387_struct));
|
|
}
|
|
return fpvalid;
|
|
}
|