/*
* linux/arch/m68k/kernel/ptrace.c
*
* Copyright (C) 1994 by Hamish Macdonald
* Taken from linux/kernel/ptrace.c and modified for M680x0.
* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of
* this archive for more details.
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/signal.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/* determines which bits in the SR the user has access to. */
/* 1 = access 0 = no access */
#define SR_MASK 0x001f
/* sets the trace bits. */
#define TRACE_BITS 0xC000
#define T1_BIT 0x8000
#define T0_BIT 0x4000
/* Find the stack offset for a register, relative to thread.esp0. */
#define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
#define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \
- sizeof(struct switch_stack))
/* Mapping from PT_xxx to the stack offset at which the register is
saved. Notice that usp has no stack-slot and needs to be treated
specially (see get_reg/put_reg below). */
static const int regoff[] = {
[0] = PT_REG(d1),
[1] = PT_REG(d2),
[2] = PT_REG(d3),
[3] = PT_REG(d4),
[4] = PT_REG(d5),
[5] = SW_REG(d6),
[6] = SW_REG(d7),
[7] = PT_REG(a0),
[8] = PT_REG(a1),
[9] = PT_REG(a2),
[10] = SW_REG(a3),
[11] = SW_REG(a4),
[12] = SW_REG(a5),
[13] = SW_REG(a6),
[14] = PT_REG(d0),
[15] = -1,
[16] = PT_REG(orig_d0),
[17] = PT_REG(sr),
[18] = PT_REG(pc),
};
/*
* Get contents of register REGNO in task TASK.
*/
static inline long get_reg(struct task_struct *task, int regno)
{
unsigned long *addr;
if (regno == PT_USP)
addr = &task->thread.usp;
else if (regno < ARRAY_SIZE(regoff))
addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
else
return 0;
/* Need to take stkadj into account. */
if (regno == PT_SR || regno == PT_PC) {
long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));
addr = (unsigned long *) ((unsigned long)addr + stkadj);
/* The sr is actually a 16 bit register. */
if (regno == PT_SR)
return *(unsigned short *)addr;
}
return *addr;
}
/*
* Write contents of register REGNO in task TASK.
*/
static inline int put_reg(struct task_struct *task, int regno,
unsigned long data)
{
unsigned long *addr;
if (regno == PT_USP)
addr = &task->thread.usp;
else if (regno < ARRAY_SIZE(regoff))
addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
else
return -1;
/* Need to take stkadj into account. */
if (regno == PT_SR || regno == PT_PC) {
long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));
addr = (unsigned long *) ((unsigned long)addr + stkadj);
/* The sr is actually a 16 bit register. */
if (regno == PT_SR) {
*(unsigned short *)addr = data;
return 0;
}
}
*addr = data;
return 0;
}
/*
* Make sure the single step bit is not set.
*/
static inline void singlestep_disable(struct task_struct *child)
{
unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
put_reg(child, PT_SR, tmp);
clear_tsk_thread_flag(child, TIF_DELAYED_TRACE);
}
/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
{
singlestep_disable(child);
}
void user_enable_single_step(struct task_struct *child)
{
unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
put_reg(child, PT_SR, tmp | T1_BIT);
set_tsk_thread_flag(child, TIF_DELAYED_TRACE);
}
void user_enable_block_step(struct task_struct *child)
{
unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
put_reg(child, PT_SR, tmp | T0_BIT);
}
void user_disable_single_step(struct task_struct *child)
{
singlestep_disable(child);
}
long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
unsigned long tmp;
int i, ret = 0;
switch (request) {
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR:
if (addr & 3)
goto out_eio;
addr >>= 2; /* temporary hack. */
if (addr >= 0 && addr < 19) {
tmp = get_reg(child, addr);
} else if (addr >= 21 && addr < 49) {
tmp = child->thread.fp[addr - 21];
/* Convert internal fpu reg representation
* into long double format
*/
if (FPU_IS_EMU && (addr < 45) && !(addr % 3))
tmp = ((tmp & 0xffff0000) << 15) |
((tmp & 0x0000ffff) << 16);
} else
goto out_eio;
ret = put_user(tmp, (unsigned long *)data);
break;
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
if (addr & 3)
goto out_eio;
addr >>= 2; /* temporary hack. */
if (addr == PT_SR) {
data &= SR_MASK;
data |= get_reg(child, PT_SR) & ~SR_MASK;
}
if (addr >= 0 && addr < 19) {
if (put_reg(child, addr, data))
goto out_eio;
} else if (addr >= 21 && addr < 48) {
/* Convert long double format
* into internal fpu reg representation
*/
if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) {
data = (unsigned long)data << 15;
data = (data & 0xffff0000) |
((data & 0x0000ffff) >> 1);
}
child->thread.fp[addr - 21] = data;
} else
goto out_eio;
break;
case PTRACE_GETREGS: /* Get all gp regs from the child. */
for (i = 0; i < 19; i++) {
tmp = get_reg(child, i);
ret = put_user(tmp, (unsigned long *)data);
if (ret)
break;
data += sizeof(long);
}
break;
case PTRACE_SETREGS: /* Set all gp regs in the child. */
for (i = 0; i < 19; i++) {
ret = get_user(tmp, (unsigned long *)data);
if (ret)
break;
if (i == PT_SR) {
tmp &= SR_MASK;
tmp |= get_reg(child, PT_SR) & ~SR_MASK;
}
put_reg(child, i, tmp);
data += sizeof(long);
}
break;
case PTRACE_GETFPREGS: /* Get the child FPU state. */
if (copy_to_user((void *)data, &child->thread.fp,
sizeof(struct user_m68kfp_struct)))
ret = -EFAULT;
break;
case PTRACE_SETFPREGS: /* Set the child FPU state. */
if (copy_from_user(&child->thread.fp, (void *)data,
sizeof(struct user_m68kfp_struct)))
ret = -EFAULT;
break;
case PTRACE_GET_THREAD_AREA:
ret = put_user(task_thread_info(child)->tp_value,
(unsigned long __user *)data);
break;
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
out_eio:
return -EIO;
}
asmlinkage void syscall_trace(void)
{
ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
? 0x80 : 0));
/*
* this isn't the same as continuing with a signal, but it will do
* for normal use. strace only continues with a signal if the
* stopping signal is not SIGTRAP. -brl
*/
if (current->exit_code) {
send_sig(current->exit_code, current, 1);
current->exit_code = 0;
}
}
