| /* |
| * 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/config.h> |
| #include <linux/sched.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> |
| |
| extern int exception_trace; |
| |
| void init_fpu(struct task_struct *child) |
| { |
| if (child->used_math) { |
| 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; |
| child->used_math = 1; |
| } |
| |
| /* |
| * Signal frame handlers. |
| */ |
| |
| int save_i387(struct _fpstate *buf) |
| { |
| struct task_struct *tsk = current; |
| int err = 0; |
| |
| { |
| extern void bad_user_i387_struct(void); |
| if (sizeof(struct user_i387_struct) != sizeof(tsk->thread.i387.fxsave)) |
| bad_user_i387_struct(); |
| } |
| |
| if (!tsk->used_math) |
| return 0; |
| tsk->used_math = 0; /* trigger finit */ |
| if (tsk->flags & PF_USEDFPU) { |
| err = save_i387_checking((struct i387_fxsave_struct *)buf); |
| if (err) { |
| if (exception_trace) |
| printk("%s[%d] unaligned signal floating point context %p\n", |
| tsk->comm, tsk->pid, buf); |
| 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 *buf, struct task_struct *tsk) |
| { |
| init_fpu(tsk); |
| return __copy_to_user((void *)buf, &tsk->thread.i387.fxsave, |
| sizeof(struct user_i387_struct)) ? -EFAULT : 0; |
| } |
| |
| int set_fpregs(struct task_struct *tsk, struct user_i387_struct *buf) |
| { |
| if (__copy_from_user(&tsk->thread.i387.fxsave, buf, |
| sizeof(struct user_i387_struct))) |
| return -EFAULT; |
| /* mxcsr bit 6 and 31-16 must be zero for security reasons. */ |
| tsk->thread.i387.fxsave.mxcsr &= 0xffbf; |
| 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 (!tsk->used_math) |
| return 0; |
| unlazy_fpu(tsk); |
| |
| memcpy(fpu, &tsk->thread.i387.fxsave, sizeof(struct user_i387_struct)); |
| return 1; |
| } |