arch/blackfin/kernel/ptrace.c - linux - Git at Google

 /*
  * File:         arch/blackfin/kernel/ptrace.c
  * Based on:     Taken from linux/kernel/ptrace.c
  * Author:       linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
  *
  * Created:      1/23/92
  * Description:
  *
  * Modified:
  *               Copyright 2004-2006 Analog Devices Inc.
  *
  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see the file COPYING, or write
  * to the Free Software Foundation, Inc.,
  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */

 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/smp_lock.h>
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <linux/user.h>
 #include <linux/signal.h>
 #include <linux/uaccess.h>

 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include <asm/system.h>
 #include <asm/processor.h>
 #include <asm/asm-offsets.h>
 #include <asm/dma.h>
 #include <asm/fixed_code.h>

 #define MAX_SHARED_LIBS 3
 #define TEXT_OFFSET 0
 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.
  */

 /* determines which bits in the SYSCFG reg the user has access to. */
 /* 1 = access 0 = no access */
 #define SYSCFG_MASK 0x0007	/* SYSCFG reg */
 /* sets the trace bits. */
 #define TRACE_BITS 0x0001

 /* Find the stack offset for a register, relative to thread.esp0. */
 #define PT_REG(reg)	((long)&((struct pt_regs *)0)->reg)

 /*
  * Get the address of the live pt_regs for the specified task.
  * These are saved onto the top kernel stack when the process
  * is not running.
  *
  * Note: if a user thread is execve'd from kernel space, the
  * kernel stack will not be empty on entry to the kernel, so
  * ptracing these tasks will fail.
  */
 static inline struct pt_regs *get_user_regs(struct task_struct *task)
 {
 	return (struct pt_regs *)
 	    ((unsigned long)task_stack_page(task) +
 	     (THREAD_SIZE - sizeof(struct pt_regs)));
 }

 /*
  * Get all user integer registers.
  */
 static inline int ptrace_getregs(struct task_struct *tsk, void __user * uregs)
 {
 	struct pt_regs *regs = get_user_regs(tsk);
 	return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
 }

 /* 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).
  */

 /*
  * Get contents of register REGNO in task TASK.
  */
 static inline long get_reg(struct task_struct *task, int regno)
 {
 	unsigned char *reg_ptr;

 	struct pt_regs *regs =
 	    (struct pt_regs *)((unsigned long)task_stack_page(task) +
 			       (THREAD_SIZE - sizeof(struct pt_regs)));
 	reg_ptr = (char *)regs;

 	switch (regno) {
 	case PT_USP:
 		return task->thread.usp;
 	default:
 		if (regno <= 216)
 			return *(long *)(reg_ptr + regno);
 	}
 	/* slight mystery ... never seems to come here but kernel misbehaves without this code! */

 	printk(KERN_WARNING "Request to get for unknown register %d\n", regno);
 	return 0;
 }

 /*
  * Write contents of register REGNO in task TASK.
  */
 static inline int
 put_reg(struct task_struct *task, int regno, unsigned long data)
 {
 	char *reg_ptr;

 	struct pt_regs *regs =
 	    (struct pt_regs *)((unsigned long)task_stack_page(task) +
 			       (THREAD_SIZE - sizeof(struct pt_regs)));
 	reg_ptr = (char *)regs;

 	switch (regno) {
 	case PT_PC:
 		/*********************************************************************/
 		/* At this point the kernel is most likely in exception.             */
 		/* The RETX register will be used to populate the pc of the process. */
 		/*********************************************************************/
 		regs->retx = data;
 		regs->pc = data;
 		break;
 	case PT_RETX:
 		break;		/* regs->retx = data; break; */
 	case PT_USP:
 		regs->usp = data;
 		task->thread.usp = data;
 		break;
 	default:
 		if (regno <= 216)
 			*(long *)(reg_ptr + regno) = data;
 	}
 	return 0;
 }

 /*
  * check that an address falls within the bounds of the target process's memory mappings
  */
 static inline int is_user_addr_valid(struct task_struct *child,
 				     unsigned long start, unsigned long len)
 {
 	struct vm_list_struct *vml;
 	struct sram_list_struct *sraml;

 	for (vml = child->mm->context.vmlist; vml; vml = vml->next)
 		if (start >= vml->vma->vm_start && start + len <= vml->vma->vm_end)
 			return 0;

 	for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
 		if (start >= (unsigned long)sraml->addr
 		    && start + len <= (unsigned long)sraml->addr + sraml->length)
 			return 0;

 	if (start >= FIXED_CODE_START && start + len <= FIXED_CODE_END)
 		return 0;

 	return -EIO;
 }

 /*
  * Called by kernel/ptrace.c when detaching..
  *
  * Make sure the single step bit is not set.
  */
 void ptrace_disable(struct task_struct *child)
 {
 	unsigned long tmp;
 	/* make sure the single step bit is not set. */
 	tmp = get_reg(child, PT_SYSCFG) & ~TRACE_BITS;
 	put_reg(child, PT_SYSCFG, tmp);
 }

 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 {
 	int ret;
 	int add = 0;
 	unsigned long __user *datap = (unsigned long __user *)data;

 	switch (request) {
 		/* when I and D space are separate, these will need to be fixed. */
 	case PTRACE_PEEKDATA:
 		pr_debug("ptrace: PEEKDATA\n");
 		add = MAX_SHARED_LIBS * 4;	/* space between text and data */
 		/* fall through */
 	case PTRACE_PEEKTEXT:	/* read word at location addr. */
 		{
 			unsigned long tmp = 0;
 			int copied;

 			ret = -EIO;
 			pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + add %d %ld\n", addr, add,
 			         sizeof(data));
 			if (is_user_addr_valid(child, addr + add, sizeof(tmp)) < 0)
 				break;
 			pr_debug("ptrace: user address is valid\n");

 #if L1_CODE_LENGTH != 0
 			if (addr + add >= L1_CODE_START
 			    && addr + add + sizeof(tmp) <= L1_CODE_START + L1_CODE_LENGTH) {
 				safe_dma_memcpy (&tmp, (const void *)(addr + add), sizeof(tmp));
 				copied = sizeof(tmp);
 			} else
 #endif
 #if L1_DATA_A_LENGTH != 0
 			if (addr + add >= L1_DATA_A_START
 			    && addr + add + sizeof(tmp) <= L1_DATA_A_START + L1_DATA_A_LENGTH) {
 				memcpy(&tmp, (const void *)(addr + add), sizeof(tmp));
 				copied = sizeof(tmp);
 			} else
 #endif
 #if L1_DATA_B_LENGTH != 0
 			if (addr + add >= L1_DATA_B_START
 			    && addr + add + sizeof(tmp) <= L1_DATA_B_START + L1_DATA_B_LENGTH) {
 				memcpy(&tmp, (const void *)(addr + add), sizeof(tmp));
 				copied = sizeof(tmp);
 			} else
 #endif
 			if (addr + add >= FIXED_CODE_START
 			    && addr + add + sizeof(tmp) <= FIXED_CODE_END) {
 				memcpy(&tmp, (const void *)(addr + add), sizeof(tmp));
 				copied = sizeof(tmp);
 			} else
 				copied = access_process_vm(child, addr + add, &tmp,
 							   sizeof(tmp), 0);
 			pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
 			if (copied != sizeof(tmp))
 				break;
 			ret = put_user(tmp, datap);
 			break;
 		}

 		/* read the word at location addr in the USER area. */
 	case PTRACE_PEEKUSR:
 		{
 			unsigned long tmp;
 			ret = -EIO;
 			tmp = 0;
 			if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
 				printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning "
 				                    "0 - %x sizeof(pt_regs) is %lx\n",
 				     (int)addr, sizeof(struct pt_regs));
 				break;
 			}
 			if (addr == sizeof(struct pt_regs)) {
 				/* PT_TEXT_ADDR */
 				tmp = child->mm->start_code + TEXT_OFFSET;
 			} else if (addr == (sizeof(struct pt_regs) + 4)) {
 				/* PT_TEXT_END_ADDR */
 				tmp = child->mm->end_code;
 			} else if (addr == (sizeof(struct pt_regs) + 8)) {
 				/* PT_DATA_ADDR */
 				tmp = child->mm->start_data;
 #ifdef CONFIG_BINFMT_ELF_FDPIC
 			} else if (addr == (sizeof(struct pt_regs) + 12)) {
 				tmp = child->mm->context.exec_fdpic_loadmap;
 			} else if (addr == (sizeof(struct pt_regs) + 16)) {
 				tmp = child->mm->context.interp_fdpic_loadmap;
 #endif
 			} else {
 				tmp = get_reg(child, addr);
 			}
 			ret = put_user(tmp, datap);
 			break;
 		}

 		/* when I and D space are separate, this will have to be fixed. */
 	case PTRACE_POKEDATA:
 		printk(KERN_NOTICE "ptrace: PTRACE_PEEKDATA\n");
 		/* fall through */
 	case PTRACE_POKETEXT:	/* write the word at location addr. */
 		{
 			int copied;

 			ret = -EIO;
 			pr_debug("ptrace: POKETEXT at addr 0x%08lx + add %d %ld bytes %lx\n",
 			         addr, add, sizeof(data), data);
 			if (is_user_addr_valid(child, addr + add, sizeof(data)) < 0)
 				break;
 			pr_debug("ptrace: user address is valid\n");

 #if L1_CODE_LENGTH != 0
 			if (addr + add >= L1_CODE_START
 			    && addr + add + sizeof(data) <= L1_CODE_START + L1_CODE_LENGTH) {
 				safe_dma_memcpy ((void *)(addr + add), &data, sizeof(data));
 				copied = sizeof(data);
 			} else
 #endif
 #if L1_DATA_A_LENGTH != 0
 			if (addr + add >= L1_DATA_A_START
 			    && addr + add + sizeof(data) <= L1_DATA_A_START + L1_DATA_A_LENGTH) {
 				memcpy((void *)(addr + add), &data, sizeof(data));
 				copied = sizeof(data);
 			} else
 #endif
 #if L1_DATA_B_LENGTH != 0
 			if (addr + add >= L1_DATA_B_START
 			    && addr + add + sizeof(data) <= L1_DATA_B_START + L1_DATA_B_LENGTH) {
 				memcpy((void *)(addr + add), &data, sizeof(data));
 				copied = sizeof(data);
 			} else
 #endif
 			if (addr + add >= FIXED_CODE_START
 			    && addr + add + sizeof(data) <= FIXED_CODE_END) {
 				memcpy((void *)(addr + add), &data, sizeof(data));
 				copied = sizeof(data);
 			} else
 				copied = access_process_vm(child, addr + add, &data,
 							   sizeof(data), 1);
 			pr_debug("ptrace: copied size %d\n", copied);
 			if (copied != sizeof(data))
 				break;
 			ret = 0;
 			break;
 		}

 	case PTRACE_POKEUSR:	/* write the word at location addr in the USER area */
 		ret = -EIO;
 		if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
 			printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n");
 			break;
 		}

 		if (addr >= (sizeof(struct pt_regs))) {
 			ret = 0;
 			break;
 		}
 		if (addr == PT_SYSCFG) {
 			data &= SYSCFG_MASK;
 			data |= get_reg(child, PT_SYSCFG);
 		}
 		ret = put_reg(child, addr, data);
 		break;

 	case PTRACE_SYSCALL:	/* continue and stop at next (return from) syscall */
 	case PTRACE_CONT:
 		{		/* restart after signal. */
 			long tmp;

 			pr_debug("ptrace_cont\n");

 			ret = -EIO;
 			if (!valid_signal(data))
 				break;
 			if (request == PTRACE_SYSCALL)
 				set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 			else
 				clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

 			child->exit_code = data;
 			/* make sure the single step bit is not set. */
 			tmp = get_reg(child, PT_SYSCFG) & ~(TRACE_BITS);
 			put_reg(child, PT_SYSCFG, tmp);
 			pr_debug("before wake_up_process\n");
 			wake_up_process(child);
 			ret = 0;
 			break;
 		}

 	/*
 	 * make the child exit.  Best I can do is send it a sigkill.
 	 * perhaps it should be put in the status that it wants to
 	 * exit.
 	 */
 	case PTRACE_KILL:
 		{
 			long tmp;
 			ret = 0;
 			if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
 				break;
 			child->exit_code = SIGKILL;
 			/* make sure the single step bit is not set. */
 			tmp = get_reg(child, PT_SYSCFG) & ~(TRACE_BITS);
 			put_reg(child, PT_SYSCFG, tmp);
 			wake_up_process(child);
 			break;
 		}

 	case PTRACE_SINGLESTEP:
 		{		/* set the trap flag. */
 			long tmp;

 			pr_debug("single step\n");
 			ret = -EIO;
 			if (!valid_signal(data))
 				break;
 			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

 			tmp = get_reg(child, PT_SYSCFG) | (TRACE_BITS);
 			put_reg(child, PT_SYSCFG, tmp);

 			child->exit_code = data;
 			/* give it a chance to run. */
 			wake_up_process(child);
 			ret = 0;
 			break;
 		}

 	case PTRACE_GETREGS:
 		{

 			/* Get all gp regs from the child. */
 			ret = ptrace_getregs(child, datap);
 			break;
 		}

 	case PTRACE_SETREGS:
 		{
 			printk(KERN_NOTICE
 			       "ptrace: SETREGS: **** NOT IMPLEMENTED ***\n");
 			/* Set all gp regs in the child. */
 			ret = 0;
 			break;
 		}
 	default:
 		ret = ptrace_request(child, request, addr, data);
 		break;
 	}

 	return ret;
 }

 asmlinkage void syscall_trace(void)
 {

 	if (!test_thread_flag(TIF_SYSCALL_TRACE))
 		return;

 	if (!(current->ptrace & PT_PTRACED))
 		return;

 	/* the 0x80 provides a way for the tracing parent to distinguish
 	 * between a syscall stop and SIGTRAP delivery
 	 */
 	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;
 	}
 }
	/*
	* File: arch/blackfin/kernel/ptrace.c
	* Based on: Taken from linux/kernel/ptrace.c
	* Author: linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
	*
	* Created: 1/23/92
	* Description:
	*
	* Modified:
	* Copyright 2004-2006 Analog Devices Inc.
	*
	* Bugs: Enter bugs at http://blackfin.uclinux.org/
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see the file COPYING, or write
	* to the Free Software Foundation, Inc.,
	* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#include <linux/kernel.h>
	#include <linux/sched.h>
	#include <linux/mm.h>
	#include <linux/smp.h>
	#include <linux/smp_lock.h>
	#include <linux/errno.h>
	#include <linux/ptrace.h>
	#include <linux/user.h>
	#include <linux/signal.h>
	#include <linux/uaccess.h>

	#include <asm/page.h>
	#include <asm/pgtable.h>
	#include <asm/system.h>
	#include <asm/processor.h>
	#include <asm/asm-offsets.h>
	#include <asm/dma.h>
	#include <asm/fixed_code.h>

	#define MAX_SHARED_LIBS 3
	#define TEXT_OFFSET 0
	/*
	* does not yet catch signals sent when the child dies.
	* in exit.c or in signal.c.
	*/

	/* determines which bits in the SYSCFG reg the user has access to. */
	/* 1 = access 0 = no access */
	#define SYSCFG_MASK 0x0007 /* SYSCFG reg */
	/* sets the trace bits. */
	#define TRACE_BITS 0x0001

	/* Find the stack offset for a register, relative to thread.esp0. */
	#define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)

	/*
	* Get the address of the live pt_regs for the specified task.
	* These are saved onto the top kernel stack when the process
	* is not running.
	*
	* Note: if a user thread is execve'd from kernel space, the
	* kernel stack will not be empty on entry to the kernel, so
	* ptracing these tasks will fail.
	*/
	static inline struct pt_regs get_user_regs(struct task_struct task)
	{
	return (struct pt_regs *)
	((unsigned long)task_stack_page(task) +
	(THREAD_SIZE - sizeof(struct pt_regs)));
	}

	/*
	* Get all user integer registers.
	*/
	static inline int ptrace_getregs(struct task_struct tsk, void __user uregs)
	{
	struct pt_regs *regs = get_user_regs(tsk);
	return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
	}

	/* 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).
	*/

	/*
	* Get contents of register REGNO in task TASK.
	*/
	static inline long get_reg(struct task_struct *task, int regno)
	{
	unsigned char *reg_ptr;

	struct pt_regs *regs =
	(struct pt_regs *)((unsigned long)task_stack_page(task) +
	(THREAD_SIZE - sizeof(struct pt_regs)));
	reg_ptr = (char *)regs;

	switch (regno) {
	case PT_USP:
	return task->thread.usp;
	default:
	if (regno <= 216)
	return (long )(reg_ptr + regno);
	}
	/* slight mystery ... never seems to come here but kernel misbehaves without this code! */

	printk(KERN_WARNING "Request to get for unknown register %d\n", regno);
	return 0;
	}

	/*
	* Write contents of register REGNO in task TASK.
	*/
	static inline int
	put_reg(struct task_struct *task, int regno, unsigned long data)
	{
	char *reg_ptr;

	struct pt_regs *regs =
	(struct pt_regs *)((unsigned long)task_stack_page(task) +
	(THREAD_SIZE - sizeof(struct pt_regs)));
	reg_ptr = (char *)regs;

	switch (regno) {
	case PT_PC:
	/*********************************************************************/
	/* At this point the kernel is most likely in exception. */
	/* The RETX register will be used to populate the pc of the process. */
	/*********************************************************************/
	regs->retx = data;
	regs->pc = data;
	break;
	case PT_RETX:
	break; /* regs->retx = data; break; */
	case PT_USP:
	regs->usp = data;
	task->thread.usp = data;
	break;
	default:
	if (regno <= 216)
	(long )(reg_ptr + regno) = data;
	}
	return 0;
	}

	/*
	* check that an address falls within the bounds of the target process's memory mappings
	*/
	static inline int is_user_addr_valid(struct task_struct *child,
	unsigned long start, unsigned long len)
	{
	struct vm_list_struct *vml;
	struct sram_list_struct *sraml;

	for (vml = child->mm->context.vmlist; vml; vml = vml->next)
	if (start >= vml->vma->vm_start && start + len <= vml->vma->vm_end)
	return 0;

	for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
	if (start >= (unsigned long)sraml->addr
	&& start + len <= (unsigned long)sraml->addr + sraml->length)
	return 0;

	if (start >= FIXED_CODE_START && start + len <= FIXED_CODE_END)
	return 0;

	return -EIO;
	}

	/*
	* Called by kernel/ptrace.c when detaching..
	*
	* Make sure the single step bit is not set.
	*/
	void ptrace_disable(struct task_struct *child)
	{
	unsigned long tmp;
	/* make sure the single step bit is not set. */
	tmp = get_reg(child, PT_SYSCFG) & ~TRACE_BITS;
	put_reg(child, PT_SYSCFG, tmp);
	}

	long arch_ptrace(struct task_struct *child, long request, long addr, long data)
	{
	int ret;
	int add = 0;
	unsigned long __user datap = (unsigned long __user )data;

	switch (request) {
	/* when I and D space are separate, these will need to be fixed. */
	case PTRACE_PEEKDATA:
	pr_debug("ptrace: PEEKDATA\n");
	add = MAX_SHARED_LIBS * 4; /* space between text and data */
	/* fall through */
	case PTRACE_PEEKTEXT: /* read word at location addr. */
	{
	unsigned long tmp = 0;
	int copied;

	ret = -EIO;
	pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + add %d %ld\n", addr, add,
	sizeof(data));
	if (is_user_addr_valid(child, addr + add, sizeof(tmp)) < 0)
	break;
	pr_debug("ptrace: user address is valid\n");

	#if L1_CODE_LENGTH != 0
	if (addr + add >= L1_CODE_START
	&& addr + add + sizeof(tmp) <= L1_CODE_START + L1_CODE_LENGTH) {
	safe_dma_memcpy (&tmp, (const void *)(addr + add), sizeof(tmp));
	copied = sizeof(tmp);
	} else
	#endif
	#if L1_DATA_A_LENGTH != 0
	if (addr + add >= L1_DATA_A_START
	&& addr + add + sizeof(tmp) <= L1_DATA_A_START + L1_DATA_A_LENGTH) {
	memcpy(&tmp, (const void *)(addr + add), sizeof(tmp));
	copied = sizeof(tmp);
	} else
	#endif
	#if L1_DATA_B_LENGTH != 0
	if (addr + add >= L1_DATA_B_START
	&& addr + add + sizeof(tmp) <= L1_DATA_B_START + L1_DATA_B_LENGTH) {
	memcpy(&tmp, (const void *)(addr + add), sizeof(tmp));
	copied = sizeof(tmp);
	} else
	#endif
	if (addr + add >= FIXED_CODE_START
	&& addr + add + sizeof(tmp) <= FIXED_CODE_END) {
	memcpy(&tmp, (const void *)(addr + add), sizeof(tmp));
	copied = sizeof(tmp);
	} else
	copied = access_process_vm(child, addr + add, &tmp,
	sizeof(tmp), 0);
	pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
	if (copied != sizeof(tmp))
	break;
	ret = put_user(tmp, datap);
	break;
	}

	/* read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR:
	{
	unsigned long tmp;
	ret = -EIO;
	tmp = 0;
	if ((addr & 3) \|\| (addr > (sizeof(struct pt_regs) + 16))) {
	printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning "
	"0 - %x sizeof(pt_regs) is %lx\n",
	(int)addr, sizeof(struct pt_regs));
	break;
	}
	if (addr == sizeof(struct pt_regs)) {
	/* PT_TEXT_ADDR */
	tmp = child->mm->start_code + TEXT_OFFSET;
	} else if (addr == (sizeof(struct pt_regs) + 4)) {
	/* PT_TEXT_END_ADDR */
	tmp = child->mm->end_code;
	} else if (addr == (sizeof(struct pt_regs) + 8)) {
	/* PT_DATA_ADDR */
	tmp = child->mm->start_data;
	#ifdef CONFIG_BINFMT_ELF_FDPIC
	} else if (addr == (sizeof(struct pt_regs) + 12)) {
	tmp = child->mm->context.exec_fdpic_loadmap;
	} else if (addr == (sizeof(struct pt_regs) + 16)) {
	tmp = child->mm->context.interp_fdpic_loadmap;
	#endif
	} else {
	tmp = get_reg(child, addr);
	}
	ret = put_user(tmp, datap);
	break;
	}

	/* when I and D space are separate, this will have to be fixed. */
	case PTRACE_POKEDATA:
	printk(KERN_NOTICE "ptrace: PTRACE_PEEKDATA\n");
	/* fall through */
	case PTRACE_POKETEXT: /* write the word at location addr. */
	{
	int copied;

	ret = -EIO;
	pr_debug("ptrace: POKETEXT at addr 0x%08lx + add %d %ld bytes %lx\n",
	addr, add, sizeof(data), data);
	if (is_user_addr_valid(child, addr + add, sizeof(data)) < 0)
	break;
	pr_debug("ptrace: user address is valid\n");

	#if L1_CODE_LENGTH != 0
	if (addr + add >= L1_CODE_START
	&& addr + add + sizeof(data) <= L1_CODE_START + L1_CODE_LENGTH) {
	safe_dma_memcpy ((void *)(addr + add), &data, sizeof(data));
	copied = sizeof(data);
	} else
	#endif
	#if L1_DATA_A_LENGTH != 0
	if (addr + add >= L1_DATA_A_START
	&& addr + add + sizeof(data) <= L1_DATA_A_START + L1_DATA_A_LENGTH) {
	memcpy((void *)(addr + add), &data, sizeof(data));
	copied = sizeof(data);
	} else
	#endif
	#if L1_DATA_B_LENGTH != 0
	if (addr + add >= L1_DATA_B_START
	&& addr + add + sizeof(data) <= L1_DATA_B_START + L1_DATA_B_LENGTH) {
	memcpy((void *)(addr + add), &data, sizeof(data));
	copied = sizeof(data);
	} else
	#endif
	if (addr + add >= FIXED_CODE_START
	&& addr + add + sizeof(data) <= FIXED_CODE_END) {
	memcpy((void *)(addr + add), &data, sizeof(data));
	copied = sizeof(data);
	} else
	copied = access_process_vm(child, addr + add, &data,
	sizeof(data), 1);
	pr_debug("ptrace: copied size %d\n", copied);
	if (copied != sizeof(data))
	break;
	ret = 0;
	break;
	}

	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
	ret = -EIO;
	if ((addr & 3) \|\| (addr > (sizeof(struct pt_regs) + 16))) {
	printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n");
	break;
	}

	if (addr >= (sizeof(struct pt_regs))) {
	ret = 0;
	break;
	}
	if (addr == PT_SYSCFG) {
	data &= SYSCFG_MASK;
	data \|= get_reg(child, PT_SYSCFG);
	}
	ret = put_reg(child, addr, data);
	break;

	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	case PTRACE_CONT:
	{ /* restart after signal. */
	long tmp;

	pr_debug("ptrace_cont\n");

	ret = -EIO;
	if (!valid_signal(data))
	break;
	if (request == PTRACE_SYSCALL)
	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	else
	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

	child->exit_code = data;
	/* make sure the single step bit is not set. */
	tmp = get_reg(child, PT_SYSCFG) & ~(TRACE_BITS);
	put_reg(child, PT_SYSCFG, tmp);
	pr_debug("before wake_up_process\n");
	wake_up_process(child);
	ret = 0;
	break;
	}

	/*
	* make the child exit. Best I can do is send it a sigkill.
	* perhaps it should be put in the status that it wants to
	* exit.
	*/
	case PTRACE_KILL:
	{
	long tmp;
	ret = 0;
	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
	break;
	child->exit_code = SIGKILL;
	/* make sure the single step bit is not set. */
	tmp = get_reg(child, PT_SYSCFG) & ~(TRACE_BITS);
	put_reg(child, PT_SYSCFG, tmp);
	wake_up_process(child);
	break;
	}

	case PTRACE_SINGLESTEP:
	{ /* set the trap flag. */
	long tmp;

	pr_debug("single step\n");
	ret = -EIO;
	if (!valid_signal(data))
	break;
	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

	tmp = get_reg(child, PT_SYSCFG) \| (TRACE_BITS);
	put_reg(child, PT_SYSCFG, tmp);

	child->exit_code = data;
	/* give it a chance to run. */
	wake_up_process(child);
	ret = 0;
	break;
	}

	case PTRACE_GETREGS:
	{

	/* Get all gp regs from the child. */
	ret = ptrace_getregs(child, datap);
	break;
	}

	case PTRACE_SETREGS:
	{
	printk(KERN_NOTICE
	"ptrace: SETREGS: ** NOT IMPLEMENTED *\n");
	/* Set all gp regs in the child. */
	ret = 0;
	break;
	}
	default:
	ret = ptrace_request(child, request, addr, data);
	break;
	}

	return ret;
	}

	asmlinkage void syscall_trace(void)
	{

	if (!test_thread_flag(TIF_SYSCALL_TRACE))
	return;

	if (!(current->ptrace & PT_PTRACED))
	return;

	/* the 0x80 provides a way for the tracing parent to distinguish
	* between a syscall stop and SIGTRAP delivery
	*/
	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;
	}
	}