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/*
* Copyright 2003 PathScale, Inc.
* Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*
* Licensed under the GPL
*/
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/errno.h>
#define __FRAME_OFFSETS
#include <asm/ptrace.h>
#include <asm/uaccess.h>
/*
* determines which flags the user has access to.
* 1 = access 0 = no access
*/
#define FLAG_MASK 0x44dd5UL
int putreg(struct task_struct *child, int regno, unsigned long value)
{
unsigned long tmp;
#ifdef TIF_IA32
/*
* Some code in the 64bit emulation may not be 64bit clean.
* Don't take any chances.
*/
if (test_tsk_thread_flag(child, TIF_IA32))
value &= 0xffffffff;
#endif
switch (regno) {
case FS:
case GS:
case DS:
case ES:
case SS:
case CS:
if (value && (value & 3) != 3)
return -EIO;
value &= 0xffff;
break;
case FS_BASE:
case GS_BASE:
if (!((value >> 48) == 0 || (value >> 48) == 0xffff))
return -EIO;
break;
case EFLAGS:
value &= FLAG_MASK;
tmp = PT_REGS_EFLAGS(&child->thread.regs) & ~FLAG_MASK;
value |= tmp;
break;
}
PT_REGS_SET(&child->thread.regs, regno, value);
return 0;
}
int poke_user(struct task_struct *child, long addr, long data)
{
if ((addr & 3) || addr < 0)
return -EIO;
if (addr < MAX_REG_OFFSET)
return putreg(child, addr, data);
else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
(addr <= offsetof(struct user, u_debugreg[7]))) {
addr -= offsetof(struct user, u_debugreg[0]);
addr = addr >> 2;
if ((addr == 4) || (addr == 5))
return -EIO;
child->thread.arch.debugregs[addr] = data;
return 0;
}
return -EIO;
}
unsigned long getreg(struct task_struct *child, int regno)
{
unsigned long retval = ~0UL;
switch (regno) {
case FS:
case GS:
case DS:
case ES:
case SS:
case CS:
retval = 0xffff;
/* fall through */
default:
retval &= PT_REG(&child->thread.regs, regno);
#ifdef TIF_IA32
if (test_tsk_thread_flag(child, TIF_IA32))
retval &= 0xffffffff;
#endif
}
return retval;
}
int peek_user(struct task_struct *child, long addr, long data)
{
/* read the word at location addr in the USER area. */
unsigned long tmp;
if ((addr & 3) || addr < 0)
return -EIO;
tmp = 0; /* Default return condition */
if (addr < MAX_REG_OFFSET)
tmp = getreg(child, addr);
else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
(addr <= offsetof(struct user, u_debugreg[7]))) {
addr -= offsetof(struct user, u_debugreg[0]);
addr = addr >> 2;
tmp = child->thread.arch.debugregs[addr];
}
return put_user(tmp, (unsigned long *) data);
}
/* XXX Mostly copied from sys-i386 */
int is_syscall(unsigned long addr)
{
unsigned short instr;
int n;
n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
if (n) {
/*
* access_process_vm() grants access to vsyscall and stub,
* while copy_from_user doesn't. Maybe access_process_vm is
* slow, but that doesn't matter, since it will be called only
* in case of singlestepping, if copy_from_user failed.
*/
n = access_process_vm(current, addr, &instr, sizeof(instr), 0);
if (n != sizeof(instr)) {
printk("is_syscall : failed to read instruction from "
"0x%lx\n", addr);
return 1;
}
}
/* sysenter */
return instr == 0x050f;
}
int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
{
int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
long fpregs[HOST_FP_SIZE];
BUG_ON(sizeof(*buf) != sizeof(fpregs));
err = save_fp_registers(userspace_pid[cpu], fpregs);
if (err)
return err;
n = copy_to_user(buf, fpregs, sizeof(fpregs));
if (n > 0)
return -EFAULT;
return n;
}
int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
{
int n, cpu = ((struct thread_info *) child->stack)->cpu;
long fpregs[HOST_FP_SIZE];
BUG_ON(sizeof(*buf) != sizeof(fpregs));
n = copy_from_user(fpregs, buf, sizeof(fpregs));
if (n > 0)
return -EFAULT;
return restore_fp_registers(userspace_pid[cpu], fpregs);
}
long subarch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
int ret = -EIO;
switch (request) {
case PTRACE_GETFPXREGS: /* Get the child FPU state. */
ret = get_fpregs((struct user_i387_struct __user *) data,
child);
break;
case PTRACE_SETFPXREGS: /* Set the child FPU state. */
ret = set_fpregs((struct user_i387_struct __user *) data,
child);
break;
}
return ret;
}
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