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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"
extern int arch_switch_tls(struct task_struct *from, struct task_struct *to);
void arch_switch_to(struct task_struct *from, struct task_struct *to)
{
int err = arch_switch_tls(from, 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);
}
static inline int convert_fxsr_to_user(struct _fpstate __user *buf,
struct pt_regs *regs)
{
return 0;
}
static inline int convert_fxsr_from_user(struct pt_regs *regs,
struct _fpstate __user *buf)
{
return 0;
}
int get_fpregs(unsigned long buf, struct task_struct *child)
{
int err;
err = convert_fxsr_to_user((struct _fpstate __user *) buf,
&child->thread.regs);
if (err)
return -EFAULT;
return 0;
}
int set_fpregs(unsigned long buf, struct task_struct *child)
{
int err;
err = convert_fxsr_from_user(&child->thread.regs,
(struct _fpstate __user *) buf);
if (err)
return -EFAULT;
return 0;
}
int get_fpxregs(unsigned long buf, struct task_struct *tsk)
{
return 0;
}
int set_fpxregs(unsigned long buf, struct task_struct *tsk)
{
return 0;
}
#ifdef notdef
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
fpu->cwd = (((SC_FP_CW(PT_REGS_SC(regs)) & 0xffff) << 16) |
(SC_FP_SW(PT_REGS_SC(regs)) & 0xffff));
fpu->swd = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
fpu->twd = SC_FP_IPOFF(PT_REGS_SC(regs));
fpu->fip = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff;
fpu->fcs = SC_FP_DATAOFF(PT_REGS_SC(regs));
fpu->foo = SC_FP_DATASEL(PT_REGS_SC(regs));
fpu->fos = 0;
memcpy(fpu->st_space, (void *) SC_FP_ST(PT_REGS_SC(regs)),
sizeof(fpu->st_space));
return 1;
}
#endif
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu )
{
return 1;
}
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