/*
* 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
static const int reg_offsets[] =
{
[R8 >> 3] = HOST_R8,
[R9 >> 3] = HOST_R9,
[R10 >> 3] = HOST_R10,
[R11 >> 3] = HOST_R11,
[R12 >> 3] = HOST_R12,
[R13 >> 3] = HOST_R13,
[R14 >> 3] = HOST_R14,
[R15 >> 3] = HOST_R15,
[RIP >> 3] = HOST_IP,
[RSP >> 3] = HOST_SP,
[RAX >> 3] = HOST_AX,
[RBX >> 3] = HOST_BX,
[RCX >> 3] = HOST_CX,
[RDX >> 3] = HOST_DX,
[RSI >> 3] = HOST_SI,
[RDI >> 3] = HOST_DI,
[RBP >> 3] = HOST_BP,
[CS >> 3] = HOST_CS,
[SS >> 3] = HOST_SS,
[FS_BASE >> 3] = HOST_FS_BASE,
[GS_BASE >> 3] = HOST_GS_BASE,
[DS >> 3] = HOST_DS,
[ES >> 3] = HOST_ES,
[FS >> 3] = HOST_FS,
[GS >> 3] = HOST_GS,
[EFLAGS >> 3] = HOST_EFLAGS,
[ORIG_RAX >> 3] = HOST_ORIG_AX,
};
int putreg(struct task_struct *child, int regno, unsigned long value)
{
#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 R8:
case R9:
case R10:
case R11:
case R12:
case R13:
case R14:
case R15:
case RIP:
case RSP:
case RAX:
case RBX:
case RCX:
case RDX:
case RSI:
case RDI:
case RBP:
case ORIG_RAX:
break;
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;
child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
return 0;
default:
panic("Bad register in putreg(): %d\n", regno);
}
child->thread.regs.regs.gp[reg_offsets[regno >> 3]] = 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 mask = ~0UL;
#ifdef TIF_IA32
if (test_tsk_thread_flag(child, TIF_IA32))
mask = 0xffffffff;
#endif
switch (regno) {
case R8:
case R9:
case R10:
case R11:
case R12:
case R13:
case R14:
case R15:
case RIP:
case RSP:
case RAX:
case RBX:
case RCX:
case RDX:
case RSI:
case RDI:
case RBP:
case ORIG_RAX:
case EFLAGS:
case FS_BASE:
case GS_BASE:
break;
case FS:
case GS:
case DS:
case ES:
case SS:
case CS:
mask = 0xffff;
break;
default:
panic("Bad register in getreg: %d\n", regno);
}
return mask & child->thread.regs.regs.gp[reg_offsets[regno >> 3]];
}
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;
}
static 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;
}
static 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;
void __user *datap = (void __user *) data;
switch (request) {
case PTRACE_GETFPREGS: /* Get the child FPU state. */
ret = get_fpregs(datap, child);
break;
case PTRACE_SETFPREGS: /* Set the child FPU state. */
ret = set_fpregs(datap, child);
break;
case PTRACE_ARCH_PRCTL:
/* XXX Calls ptrace on the host - needs some SMP thinking */
ret = arch_prctl(child, data, (void __user *) addr);
break;
}
return ret;
}
