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/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include "linux/mm.h"
#include "linux/sched.h"
#include "asm/uaccess.h"
#include "skas.h"
extern int arch_switch_tls(struct task_struct *to);
void arch_switch_to(struct task_struct *to)
{
int err = arch_switch_tls(to);
if (!err)
return;
if (err != -EINVAL)
printk(KERN_WARNING "arch_switch_tls failed, errno %d, "
"not EINVAL\n", -err);
else
printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n");
}
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(KERN_ERR "is_syscall : failed to read "
"instruction from 0x%lx\n", addr);
return 1;
}
}
/* int 0x80 or sysenter */
return (instr == 0x80cd) || (instr == 0x340f);
}
/* determines which flags the user has access to. */
/* 1 = access 0 = no access */
#define FLAG_MASK 0x00044dd5
int putreg(struct task_struct *child, int regno, unsigned long value)
{
regno >>= 2;
switch (regno) {
case FS:
if (value && (value & 3) != 3)
return -EIO;
PT_REGS_FS(&child->thread.regs) = value;
return 0;
case GS:
if (value && (value & 3) != 3)
return -EIO;
PT_REGS_GS(&child->thread.regs) = value;
return 0;
case DS:
case ES:
if (value && (value & 3) != 3)
return -EIO;
value &= 0xffff;
break;
case SS:
case CS:
if ((value & 3) != 3)
return -EIO;
value &= 0xffff;
break;
case EFL:
value &= FLAG_MASK;
value |= PT_REGS_EFLAGS(&child->thread.regs);
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;
regno >>= 2;
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);
}
return retval;
}
/* read the word at location addr in the USER area. */
int peek_user(struct task_struct *child, long addr, long data)
{
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 __user *) data);
}
int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
{
int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
struct user_i387_struct fpregs;
err = save_fp_registers(userspace_pid[cpu], (unsigned long *) &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;
struct user_i387_struct fpregs;
n = copy_from_user(&fpregs, buf, sizeof(fpregs));
if (n > 0)
return -EFAULT;
return restore_fp_registers(userspace_pid[cpu],
(unsigned long *) &fpregs);
}
int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
{
int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
struct user_fxsr_struct fpregs;
err = save_fpx_registers(userspace_pid[cpu], (unsigned long *) &fpregs);
if (err)
return err;
n = copy_to_user(buf, &fpregs, sizeof(fpregs));
if(n > 0)
return -EFAULT;
return n;
}
int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
{
int n, cpu = ((struct thread_info *) child->stack)->cpu;
struct user_fxsr_struct fpregs;
n = copy_from_user(&fpregs, buf, sizeof(fpregs));
if (n > 0)
return -EFAULT;
return restore_fpx_registers(userspace_pid[cpu],
(unsigned long *) &fpregs);
}
long subarch_ptrace(struct task_struct *child, long request, long addr,
long data)
{
return -EIO;
}
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