/*
   *  linux/arch/m68knommu/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 <linux/tracehook.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 0x8000
  
  /* 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 int regoff[] = {
  	PT_REG(d1), PT_REG(d2), PT_REG(d3), PT_REG(d4),
  	PT_REG(d5), SW_REG(d6), SW_REG(d7), PT_REG(a0),
  	PT_REG(a1), PT_REG(a2), SW_REG(a3), SW_REG(a4),
  	SW_REG(a5), SW_REG(a6), PT_REG(d0), -1,
  	PT_REG(orig_d0), PT_REG(sr), 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;
  	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;
  	*addr = data;
  	return 0;
  }

  void user_enable_single_step(struct task_struct *task)
  {
  	unsigned long srflags;
  	srflags = get_reg(task, PT_SR) | (TRACE_BITS << 16);
  	put_reg(task, PT_SR, srflags);
  }
  
  void user_disable_single_step(struct task_struct *task)
  {
  	unsigned long srflags;
  	srflags = get_reg(task, PT_SR) & ~(TRACE_BITS << 16);
  	put_reg(task, PT_SR, srflags);
  }

  /*
   * Called by kernel/ptrace.c when detaching..
   *
   * Make sure the single step bit is not set.
   */
  void ptrace_disable(struct task_struct *child)
  {

  	/* make sure the single step bit is not set. */

  	user_disable_single_step(child);

  }

  long arch_ptrace(struct task_struct *child, long request,
  		 unsigned long addr, unsigned long data)

  {

  	int ret;

  	int regno = addr >> 2;
  	unsigned long __user *datap = (unsigned long __user *) data;

  	switch (request) {

  		/* read the word at location addr in the USER area. */
  		case PTRACE_PEEKUSR: {
  			unsigned long tmp;
  			
  			ret = -EIO;

  			if ((addr & 3) || addr > sizeof(struct user) - 3)

  				break;
  			
  			tmp = 0;  /* Default return condition */

  			ret = -EIO;

  			if (regno < 19) {
  				tmp = get_reg(child, regno);
  				if (regno == PT_SR)

  					tmp >>= 16;

  			} else if (regno >= 21 && regno < 49) {
  				tmp = child->thread.fp[regno - 21];
  			} else if (regno == 49) {

  				tmp = child->mm->start_code;

  			} else if (regno == 50) {

  				tmp = child->mm->start_data;

  			} else if (regno == 51) {

  				tmp = child->mm->end_code;
  			} else
  				break;

  			ret = put_user(tmp, datap);

  			break;
  		}

  		case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
  			ret = -EIO;

  			if ((addr & 3) || addr > sizeof(struct user) - 3)

  				break;

  			if (regno == PT_SR) {

  				data &= SR_MASK;
  				data <<= 16;
  				data |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
  			}

  			if (regno < 19) {
  				if (put_reg(child, regno, data))

  					break;
  				ret = 0;
  				break;
  			}

  			if (regno >= 21 && regno < 48)

  			{

  				child->thread.fp[regno - 21] = data;

  				ret = 0;
  			}
  			break;

  		case PTRACE_GETREGS: { /* Get all gp regs from the child. */
  		  	int i;
  			unsigned long tmp;
  			for (i = 0; i < 19; i++) {
  			    tmp = get_reg(child, i);
  			    if (i == PT_SR)
  				tmp >>= 16;

  			    if (put_user(tmp, datap)) {

  				ret = -EFAULT;
  				break;
  			    }

  			    datap++;

  			}
  			ret = 0;
  			break;
  		}
  
  		case PTRACE_SETREGS: { /* Set all gp regs in the child. */
  			int i;
  			unsigned long tmp;
  			for (i = 0; i < 19; i++) {

  			    if (get_user(tmp, datap)) {

  				ret = -EFAULT;
  				break;
  			    }
  			    if (i == PT_SR) {
  				tmp &= SR_MASK;
  				tmp <<= 16;
  				tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
  			    }
  			    put_reg(child, i, tmp);

  			    datap++;

  			}
  			ret = 0;
  			break;
  		}
  
  #ifdef PTRACE_GETFPREGS
  		case PTRACE_GETFPREGS: { /* Get the child FPU state. */
  			ret = 0;

  			if (copy_to_user(datap, &child->thread.fp,

  					 sizeof(struct user_m68kfp_struct)))
  				ret = -EFAULT;
  			break;
  		}
  #endif
  
  #ifdef PTRACE_SETFPREGS
  		case PTRACE_SETFPREGS: { /* Set the child FPU state. */
  			ret = 0;

  			if (copy_from_user(&child->thread.fp, datap,

  					   sizeof(struct user_m68kfp_struct)))
  				ret = -EFAULT;
  			break;
  		}
  #endif

  	case PTRACE_GET_THREAD_AREA:

  		ret = put_user(task_thread_info(child)->tp_value, datap);

  		break;

  		default:

  			ret = ptrace_request(child, request, addr, data);

  			break;
  	}

  	return ret;
  }

  asmlinkage int syscall_trace_enter(void)

  {

  	int ret = 0;
  
  	if (test_thread_flag(TIF_SYSCALL_TRACE))
  		ret = tracehook_report_syscall_entry(task_pt_regs(current));
  	return ret;
  }
  
  asmlinkage void syscall_trace_leave(void)
  {
  	if (test_thread_flag(TIF_SYSCALL_TRACE))
  		tracehook_report_syscall_exit(task_pt_regs(current), 0);

  }