arch/m32r/kernel/ptrace.c - third_party/linux - Git at Google

 /*
  * linux/arch/m32r/kernel/ptrace.c
  *
  * Copyright (C) 2002  Hirokazu Takata, Takeo Takahashi
  * Copyright (C) 2004  Hirokazu Takata, Kei Sakamoto
  *
  * Original x86 implementation:
  *	By Ross Biro 1/23/92
  *	edited by Linus Torvalds
  *
  * Some code taken from sh version:
  *   Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
  * Some code taken from arm version:
  *   Copyright (C) 2000 Russell King
  */

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

 #include <asm/cacheflush.h>
 #include <asm/io.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 #include <asm/processor.h>
 #include <asm/mmu_context.h>

 /*
  * This routine will get a word off of the process kernel stack.
  */
 static inline unsigned long int
 get_stack_long(struct task_struct *task, int offset)
 {
 	unsigned long *stack;

 	stack = (unsigned long *)task_pt_regs(task);

 	return stack[offset];
 }

 /*
  * This routine will put a word on the process kernel stack.
  */
 static inline int
 put_stack_long(struct task_struct *task, int offset, unsigned long data)
 {
 	unsigned long *stack;

 	stack = (unsigned long *)task_pt_regs(task);
 	stack[offset] = data;

 	return 0;
 }

 static int reg_offset[] = {
 	PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5, PT_R6, PT_R7,
 	PT_R8, PT_R9, PT_R10, PT_R11, PT_R12, PT_FP, PT_LR, PT_SPU,
 };

 /*
  * Read the word at offset "off" into the "struct user".  We
  * actually access the pt_regs stored on the kernel stack.
  */
 static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
 			    unsigned long __user *data)
 {
 	unsigned long tmp;
 #ifndef NO_FPU
 	struct user * dummy = NULL;
 #endif

 	if ((off & 3) || off > sizeof(struct user) - 3)
 		return -EIO;

 	off >>= 2;
 	switch (off) {
 	case PT_EVB:
 		__asm__ __volatile__ (
 			"mvfc	%0, cr5 \n\t"
 	 		: "=r" (tmp)
 		);
 		break;
 	case PT_CBR: {
 			unsigned long psw;
 			psw = get_stack_long(tsk, PT_PSW);
 			tmp = ((psw >> 8) & 1);
 		}
 		break;
 	case PT_PSW: {
 			unsigned long psw, bbpsw;
 			psw = get_stack_long(tsk, PT_PSW);
 			bbpsw = get_stack_long(tsk, PT_BBPSW);
 			tmp = ((psw >> 8) & 0xff) | ((bbpsw & 0xff) << 8);
 		}
 		break;
 	case PT_PC:
 		tmp = get_stack_long(tsk, PT_BPC);
 		break;
 	case PT_BPC:
 		off = PT_BBPC;
 		/* fall through */
 	default:
 		if (off < (sizeof(struct pt_regs) >> 2))
 			tmp = get_stack_long(tsk, off);
 #ifndef NO_FPU
 		else if (off >= (long)(&dummy->fpu >> 2) &&
 			 off < (long)(&dummy->u_fpvalid >> 2)) {
 			if (!tsk_used_math(tsk)) {
 				if (off == (long)(&dummy->fpu.fpscr >> 2))
 					tmp = FPSCR_INIT;
 				else
 					tmp = 0;
 			} else
 				tmp = ((long *)(&tsk->thread.fpu >> 2))
 					[off - (long)&dummy->fpu];
 		} else if (off == (long)(&dummy->u_fpvalid >> 2))
 			tmp = !!tsk_used_math(tsk);
 #endif /* not NO_FPU */
 		else
 			tmp = 0;
 	}

 	return put_user(tmp, data);
 }

 static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
 			     unsigned long data)
 {
 	int ret = -EIO;
 #ifndef NO_FPU
 	struct user * dummy = NULL;
 #endif

 	if ((off & 3) || off > sizeof(struct user) - 3)
 		return -EIO;

 	off >>= 2;
 	switch (off) {
 	case PT_EVB:
 	case PT_BPC:
 	case PT_SPI:
 		/* We don't allow to modify evb. */
 		ret = 0;
 		break;
 	case PT_PSW:
 	case PT_CBR: {
 			/* We allow to modify only cbr in psw */
 			unsigned long psw;
 			psw = get_stack_long(tsk, PT_PSW);
 			psw = (psw & ~0x100) | ((data & 1) << 8);
 			ret = put_stack_long(tsk, PT_PSW, psw);
 		}
 		break;
 	case PT_PC:
 		off = PT_BPC;
 		data &= ~1;
 		/* fall through */
 	default:
 		if (off < (sizeof(struct pt_regs) >> 2))
 			ret = put_stack_long(tsk, off, data);
 #ifndef NO_FPU
 		else if (off >= (long)(&dummy->fpu >> 2) &&
 			 off < (long)(&dummy->u_fpvalid >> 2)) {
 			set_stopped_child_used_math(tsk);
 			((long *)&tsk->thread.fpu)
 				[off - (long)&dummy->fpu] = data;
 			ret = 0;
 		} else if (off == (long)(&dummy->u_fpvalid >> 2)) {
 			conditional_stopped_child_used_math(data, tsk);
 			ret = 0;
 		}
 #endif /* not NO_FPU */
 		break;
 	}

 	return ret;
 }

 /*
  * Get all user integer registers.
  */
 static int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
 {
 	struct pt_regs *regs = task_pt_regs(tsk);

 	return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
 }

 /*
  * Set all user integer registers.
  */
 static int ptrace_setregs(struct task_struct *tsk, void __user *uregs)
 {
 	struct pt_regs newregs;
 	int ret;

 	ret = -EFAULT;
 	if (copy_from_user(&newregs, uregs, sizeof(struct pt_regs)) == 0) {
 		struct pt_regs *regs = task_pt_regs(tsk);
 		*regs = newregs;
 		ret = 0;
 	}

 	return ret;
 }


 static inline int
 check_condition_bit(struct task_struct *child)
 {
 	return (int)((get_stack_long(child, PT_PSW) >> 8) & 1);
 }

 static int
 check_condition_src(unsigned long op, unsigned long regno1,
 		    unsigned long regno2, struct task_struct *child)
 {
 	unsigned long reg1, reg2;

 	reg2 = get_stack_long(child, reg_offset[regno2]);

 	switch (op) {
 	case 0x0: /* BEQ */
 		reg1 = get_stack_long(child, reg_offset[regno1]);
 		return reg1 == reg2;
 	case 0x1: /* BNE */
 		reg1 = get_stack_long(child, reg_offset[regno1]);
 		return reg1 != reg2;
 	case 0x8: /* BEQZ */
 		return reg2 == 0;
 	case 0x9: /* BNEZ */
 		return reg2 != 0;
 	case 0xa: /* BLTZ */
 		return (int)reg2 < 0;
 	case 0xb: /* BGEZ */
 		return (int)reg2 >= 0;
 	case 0xc: /* BLEZ */
 		return (int)reg2 <= 0;
 	case 0xd: /* BGTZ */
 		return (int)reg2 > 0;
 	default:
 		/* never reached */
 		return 0;
 	}
 }

 static void
 compute_next_pc_for_16bit_insn(unsigned long insn, unsigned long pc,
 			       unsigned long *next_pc,
 			       struct task_struct *child)
 {
 	unsigned long op, op2, op3;
 	unsigned long disp;
 	unsigned long regno;
 	int parallel = 0;

 	if (insn & 0x00008000)
 		parallel = 1;
 	if (pc & 3)
 		insn &= 0x7fff;	/* right slot */
 	else
 		insn >>= 16;	/* left slot */

 	op = (insn >> 12) & 0xf;
 	op2 = (insn >> 8) & 0xf;
 	op3 = (insn >> 4) & 0xf;

 	if (op == 0x7) {
 		switch (op2) {
 		case 0xd: /* BNC */
 		case 0x9: /* BNCL */
 			if (!check_condition_bit(child)) {
 				disp = (long)(insn << 24) >> 22;
 				*next_pc = (pc & ~0x3) + disp;
 				return;
 			}
 			break;
 		case 0x8: /* BCL */
 		case 0xc: /* BC */
 			if (check_condition_bit(child)) {
 				disp = (long)(insn << 24) >> 22;
 				*next_pc = (pc & ~0x3) + disp;
 				return;
 			}
 			break;
 		case 0xe: /* BL */
 		case 0xf: /* BRA */
 			disp = (long)(insn << 24) >> 22;
 			*next_pc = (pc & ~0x3) + disp;
 			return;
 			break;
 		}
 	} else if (op == 0x1) {
 		switch (op2) {
 		case 0x0:
 			if (op3 == 0xf) { /* TRAP */
 #if 1
 				/* pass through */
 #else
  				/* kernel space is not allowed as next_pc */
 				unsigned long evb;
 				unsigned long trapno;
 				trapno = insn & 0xf;
 				__asm__ __volatile__ (
 					"mvfc %0, cr5\n"
 		 			:"=r"(evb)
 		 			:
 				);
 				*next_pc = evb + (trapno << 2);
 				return;
 #endif
 			} else if (op3 == 0xd) { /* RTE */
 				*next_pc = get_stack_long(child, PT_BPC);
 				return;
 			}
 			break;
 		case 0xc: /* JC */
 			if (op3 == 0xc && check_condition_bit(child)) {
 				regno = insn & 0xf;
 				*next_pc = get_stack_long(child,
 							  reg_offset[regno]);
 				return;
 			}
 			break;
 		case 0xd: /* JNC */
 			if (op3 == 0xc && !check_condition_bit(child)) {
 				regno = insn & 0xf;
 				*next_pc = get_stack_long(child,
 							  reg_offset[regno]);
 				return;
 			}
 			break;
 		case 0xe: /* JL */
 		case 0xf: /* JMP */
 			if (op3 == 0xc) { /* JMP */
 				regno = insn & 0xf;
 				*next_pc = get_stack_long(child,
 							  reg_offset[regno]);
 				return;
 			}
 			break;
 		}
 	}
 	if (parallel)
 		*next_pc = pc + 4;
 	else
 		*next_pc = pc + 2;
 }

 static void
 compute_next_pc_for_32bit_insn(unsigned long insn, unsigned long pc,
 			       unsigned long *next_pc,
 			       struct task_struct *child)
 {
 	unsigned long op;
 	unsigned long op2;
 	unsigned long disp;
 	unsigned long regno1, regno2;

 	op = (insn >> 28) & 0xf;
 	if (op == 0xf) { 	/* branch 24-bit relative */
 		op2 = (insn >> 24) & 0xf;
 		switch (op2) {
 		case 0xd:	/* BNC */
 		case 0x9:	/* BNCL */
 			if (!check_condition_bit(child)) {
 				disp = (long)(insn << 8) >> 6;
 				*next_pc = (pc & ~0x3) + disp;
 				return;
 			}
 			break;
 		case 0x8:	/* BCL */
 		case 0xc:	/* BC */
 			if (check_condition_bit(child)) {
 				disp = (long)(insn << 8) >> 6;
 				*next_pc = (pc & ~0x3) + disp;
 				return;
 			}
 			break;
 		case 0xe:	/* BL */
 		case 0xf:	/* BRA */
 			disp = (long)(insn << 8) >> 6;
 			*next_pc = (pc & ~0x3) + disp;
 			return;
 		}
 	} else if (op == 0xb) { /* branch 16-bit relative */
 		op2 = (insn >> 20) & 0xf;
 		switch (op2) {
 		case 0x0: /* BEQ */
 		case 0x1: /* BNE */
 		case 0x8: /* BEQZ */
 		case 0x9: /* BNEZ */
 		case 0xa: /* BLTZ */
 		case 0xb: /* BGEZ */
 		case 0xc: /* BLEZ */
 		case 0xd: /* BGTZ */
 			regno1 = ((insn >> 24) & 0xf);
 			regno2 = ((insn >> 16) & 0xf);
 			if (check_condition_src(op2, regno1, regno2, child)) {
 				disp = (long)(insn << 16) >> 14;
 				*next_pc = (pc & ~0x3) + disp;
 				return;
 			}
 			break;
 		}
 	}
 	*next_pc = pc + 4;
 }

 static inline void
 compute_next_pc(unsigned long insn, unsigned long pc,
 		unsigned long *next_pc, struct task_struct *child)
 {
 	if (insn & 0x80000000)
 		compute_next_pc_for_32bit_insn(insn, pc, next_pc, child);
 	else
 		compute_next_pc_for_16bit_insn(insn, pc, next_pc, child);
 }

 static int
 register_debug_trap(struct task_struct *child, unsigned long next_pc,
 	unsigned long next_insn, unsigned long *code)
 {
 	struct debug_trap *p = &child->thread.debug_trap;
 	unsigned long addr = next_pc & ~3;

 	if (p->nr_trap == MAX_TRAPS) {
 		printk("kernel BUG at %s %d: p->nr_trap = %d\n",
 					__FILE__, __LINE__, p->nr_trap);
 		return -1;
 	}
 	p->addr[p->nr_trap] = addr;
 	p->insn[p->nr_trap] = next_insn;
 	p->nr_trap++;
 	if (next_pc & 3) {
 		*code = (next_insn & 0xffff0000) | 0x10f1;
 		/* xxx --> TRAP1 */
 	} else {
 		if ((next_insn & 0x80000000) || (next_insn & 0x8000)) {
 			*code = 0x10f17000;
 			/* TRAP1 --> NOP */
 		} else {
 			*code = (next_insn & 0xffff) | 0x10f10000;
 			/* TRAP1 --> xxx */
 		}
 	}
 	return 0;
 }

 static int
 unregister_debug_trap(struct task_struct *child, unsigned long addr,
 		      unsigned long *code)
 {
 	struct debug_trap *p = &child->thread.debug_trap;
         int i;

 	/* Search debug trap entry. */
 	for (i = 0; i < p->nr_trap; i++) {
 		if (p->addr[i] == addr)
 			break;
 	}
 	if (i >= p->nr_trap) {
 		/* The trap may be requested from debugger.
 		 * ptrace should do nothing in this case.
 		 */
 		return 0;
 	}

 	/* Recover original instruction code. */
 	*code = p->insn[i];

 	/* Shift debug trap entries. */
 	while (i < p->nr_trap - 1) {
 		p->insn[i] = p->insn[i + 1];
 		p->addr[i] = p->addr[i + 1];
 		i++;
 	}
 	p->nr_trap--;
 	return 1;
 }

 static void
 unregister_all_debug_traps(struct task_struct *child)
 {
 	struct debug_trap *p = &child->thread.debug_trap;
 	int i;

 	for (i = 0; i < p->nr_trap; i++)
 		access_process_vm(child, p->addr[i], &p->insn[i], sizeof(p->insn[i]),
 				FOLL_FORCE | FOLL_WRITE);
 	p->nr_trap = 0;
 }

 static inline void
 invalidate_cache(void)
 {
 #if defined(CONFIG_CHIP_M32700) || defined(CONFIG_CHIP_OPSP)

 	_flush_cache_copyback_all();

 #else	/* ! CONFIG_CHIP_M32700 */

 	/* Invalidate cache */
 	__asm__ __volatile__ (
                 "ldi    r0, #-1					\n\t"
                 "ldi    r1, #0					\n\t"
                 "stb    r1, @r0		; cache off		\n\t"
                 ";						\n\t"
                 "ldi    r0, #-2					\n\t"
                 "ldi    r1, #1					\n\t"
                 "stb    r1, @r0		; cache invalidate	\n\t"
                 ".fillinsn					\n"
                 "0:						\n\t"
                 "ldb    r1, @r0		; invalidate check	\n\t"
                 "bnez   r1, 0b					\n\t"
                 ";						\n\t"
                 "ldi    r0, #-1					\n\t"
                 "ldi    r1, #1					\n\t"
                 "stb    r1, @r0		; cache on		\n\t"
 		: : : "r0", "r1", "memory"
 	);
 	/* FIXME: copying-back d-cache and invalidating i-cache are needed.
 	 */
 #endif	/* CONFIG_CHIP_M32700 */
 }

 /* Embed a debug trap (TRAP1) code */
 static int
 embed_debug_trap(struct task_struct *child, unsigned long next_pc)
 {
 	unsigned long next_insn, code;
 	unsigned long addr = next_pc & ~3;

 	if (access_process_vm(child, addr, &next_insn, sizeof(next_insn),
 			FOLL_FORCE)
 	    != sizeof(next_insn)) {
 		return -1; /* error */
 	}

 	/* Set a trap code. */
 	if (register_debug_trap(child, next_pc, next_insn, &code)) {
 		return -1; /* error */
 	}
 	if (access_process_vm(child, addr, &code, sizeof(code),
 			FOLL_FORCE | FOLL_WRITE)
 	    != sizeof(code)) {
 		return -1; /* error */
 	}
 	return 0; /* success */
 }

 void
 withdraw_debug_trap(struct pt_regs *regs)
 {
 	unsigned long addr;
 	unsigned long code;

  	addr = (regs->bpc - 2) & ~3;
 	regs->bpc -= 2;
 	if (unregister_debug_trap(current, addr, &code)) {
 	    access_process_vm(current, addr, &code, sizeof(code),
 		    FOLL_FORCE | FOLL_WRITE);
 	    invalidate_cache();
 	}
 }

 void
 init_debug_traps(struct task_struct *child)
 {
 	struct debug_trap *p = &child->thread.debug_trap;
 	int i;
 	p->nr_trap = 0;
 	for (i = 0; i < MAX_TRAPS; i++) {
 		p->addr[i] = 0;
 		p->insn[i] = 0;
 	}
 }

 void user_enable_single_step(struct task_struct *child)
 {
 	unsigned long next_pc;
 	unsigned long pc, insn;

 	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

 	/* Compute next pc.  */
 	pc = get_stack_long(child, PT_BPC);

 	if (access_process_vm(child, pc&~3, &insn, sizeof(insn),
 			FOLL_FORCE)
 	    != sizeof(insn))
 		return;

 	compute_next_pc(insn, pc, &next_pc, child);
 	if (next_pc & 0x80000000)
 		return;

 	if (embed_debug_trap(child, next_pc))
 		return;

 	invalidate_cache();
 }

 void user_disable_single_step(struct task_struct *child)
 {
 	unregister_all_debug_traps(child);
 	invalidate_cache();
 }

 /*
  * Called by kernel/ptrace.c when detaching..
  *
  * Make sure single step bits etc are not set.
  */
 void ptrace_disable(struct task_struct *child)
 {
 	/* nothing to do.. */
 }

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

 	switch (request) {
 	/*
 	 * read word at location "addr" in the child process.
 	 */
 	case PTRACE_PEEKTEXT:
 	case PTRACE_PEEKDATA:
 		ret = generic_ptrace_peekdata(child, addr, data);
 		break;

 	/*
 	 * read the word at location addr in the USER area.
 	 */
 	case PTRACE_PEEKUSR:
 		ret = ptrace_read_user(child, addr, datap);
 		break;

 	/*
 	 * write the word at location addr.
 	 */
 	case PTRACE_POKETEXT:
 	case PTRACE_POKEDATA:
 		ret = generic_ptrace_pokedata(child, addr, data);
 		if (ret == 0 && request == PTRACE_POKETEXT)
 			invalidate_cache();
 		break;

 	/*
 	 * write the word at location addr in the USER area.
 	 */
 	case PTRACE_POKEUSR:
 		ret = ptrace_write_user(child, addr, data);
 		break;

 	case PTRACE_GETREGS:
 		ret = ptrace_getregs(child, datap);
 		break;

 	case PTRACE_SETREGS:
 		ret = ptrace_setregs(child, datap);
 		break;

 	default:
 		ret = ptrace_request(child, request, addr, data);
 		break;
 	}

 	return ret;
 }

 /* notification of system call entry/exit
  * - triggered by current->work.syscall_trace
  */
 void do_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;
 	}
 }
	/*
	* linux/arch/m32r/kernel/ptrace.c
	*
	* Copyright (C) 2002 Hirokazu Takata, Takeo Takahashi
	* Copyright (C) 2004 Hirokazu Takata, Kei Sakamoto
	*
	* Original x86 implementation:
	* By Ross Biro 1/23/92
	* edited by Linus Torvalds
	*
	* Some code taken from sh version:
	* Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
	* Some code taken from arm version:
	* Copyright (C) 2000 Russell King
	*/

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

	#include <asm/cacheflush.h>
	#include <asm/io.h>
	#include <asm/uaccess.h>
	#include <asm/pgtable.h>
	#include <asm/processor.h>
	#include <asm/mmu_context.h>

	/*
	* This routine will get a word off of the process kernel stack.
	*/
	static inline unsigned long int
	get_stack_long(struct task_struct *task, int offset)
	{
	unsigned long *stack;

	stack = (unsigned long *)task_pt_regs(task);

	return stack[offset];
	}

	/*
	* This routine will put a word on the process kernel stack.
	*/
	static inline int
	put_stack_long(struct task_struct *task, int offset, unsigned long data)
	{
	unsigned long *stack;

	stack = (unsigned long *)task_pt_regs(task);
	stack[offset] = data;

	return 0;
	}

	static int reg_offset[] = {
	PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5, PT_R6, PT_R7,
	PT_R8, PT_R9, PT_R10, PT_R11, PT_R12, PT_FP, PT_LR, PT_SPU,
	};

	/*
	* Read the word at offset "off" into the "struct user". We
	* actually access the pt_regs stored on the kernel stack.
	*/
	static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
	unsigned long __user *data)
	{
	unsigned long tmp;
	#ifndef NO_FPU
	struct user * dummy = NULL;
	#endif

	if ((off & 3) \|\| off > sizeof(struct user) - 3)
	return -EIO;

	off >>= 2;
	switch (off) {
	case PT_EVB:
	__asm__ __volatile__ (
	"mvfc %0, cr5 \n\t"
	: "=r" (tmp)
	);
	break;
	case PT_CBR: {
	unsigned long psw;
	psw = get_stack_long(tsk, PT_PSW);
	tmp = ((psw >> 8) & 1);
	}
	break;
	case PT_PSW: {
	unsigned long psw, bbpsw;
	psw = get_stack_long(tsk, PT_PSW);
	bbpsw = get_stack_long(tsk, PT_BBPSW);
	tmp = ((psw >> 8) & 0xff) \| ((bbpsw & 0xff) << 8);
	}
	break;
	case PT_PC:
	tmp = get_stack_long(tsk, PT_BPC);
	break;
	case PT_BPC:
	off = PT_BBPC;
	/* fall through */
	default:
	if (off < (sizeof(struct pt_regs) >> 2))
	tmp = get_stack_long(tsk, off);
	#ifndef NO_FPU
	else if (off >= (long)(&dummy->fpu >> 2) &&
	off < (long)(&dummy->u_fpvalid >> 2)) {
	if (!tsk_used_math(tsk)) {
	if (off == (long)(&dummy->fpu.fpscr >> 2))
	tmp = FPSCR_INIT;
	else
	tmp = 0;
	} else
	tmp = ((long *)(&tsk->thread.fpu >> 2))
	[off - (long)&dummy->fpu];
	} else if (off == (long)(&dummy->u_fpvalid >> 2))
	tmp = !!tsk_used_math(tsk);
	#endif /* not NO_FPU */
	else
	tmp = 0;
	}

	return put_user(tmp, data);
	}

	static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
	unsigned long data)
	{
	int ret = -EIO;
	#ifndef NO_FPU
	struct user * dummy = NULL;
	#endif

	if ((off & 3) \|\| off > sizeof(struct user) - 3)
	return -EIO;

	off >>= 2;
	switch (off) {
	case PT_EVB:
	case PT_BPC:
	case PT_SPI:
	/* We don't allow to modify evb. */
	ret = 0;
	break;
	case PT_PSW:
	case PT_CBR: {
	/* We allow to modify only cbr in psw */
	unsigned long psw;
	psw = get_stack_long(tsk, PT_PSW);
	psw = (psw & ~0x100) \| ((data & 1) << 8);
	ret = put_stack_long(tsk, PT_PSW, psw);
	}
	break;
	case PT_PC:
	off = PT_BPC;
	data &= ~1;
	/* fall through */
	default:
	if (off < (sizeof(struct pt_regs) >> 2))
	ret = put_stack_long(tsk, off, data);
	#ifndef NO_FPU
	else if (off >= (long)(&dummy->fpu >> 2) &&
	off < (long)(&dummy->u_fpvalid >> 2)) {
	set_stopped_child_used_math(tsk);
	((long *)&tsk->thread.fpu)
	[off - (long)&dummy->fpu] = data;
	ret = 0;
	} else if (off == (long)(&dummy->u_fpvalid >> 2)) {
	conditional_stopped_child_used_math(data, tsk);
	ret = 0;
	}
	#endif /* not NO_FPU */
	break;
	}

	return ret;
	}

	/*
	* Get all user integer registers.
	*/
	static int ptrace_getregs(struct task_struct tsk, void __user uregs)
	{
	struct pt_regs *regs = task_pt_regs(tsk);

	return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
	}

	/*
	* Set all user integer registers.
	*/
	static int ptrace_setregs(struct task_struct tsk, void __user uregs)
	{
	struct pt_regs newregs;
	int ret;

	ret = -EFAULT;
	if (copy_from_user(&newregs, uregs, sizeof(struct pt_regs)) == 0) {
	struct pt_regs *regs = task_pt_regs(tsk);
	*regs = newregs;
	ret = 0;
	}

	return ret;
	}


	static inline int
	check_condition_bit(struct task_struct *child)
	{
	return (int)((get_stack_long(child, PT_PSW) >> 8) & 1);
	}

	static int
	check_condition_src(unsigned long op, unsigned long regno1,
	unsigned long regno2, struct task_struct *child)
	{
	unsigned long reg1, reg2;

	reg2 = get_stack_long(child, reg_offset[regno2]);

	switch (op) {
	case 0x0: /* BEQ */
	reg1 = get_stack_long(child, reg_offset[regno1]);
	return reg1 == reg2;
	case 0x1: /* BNE */
	reg1 = get_stack_long(child, reg_offset[regno1]);
	return reg1 != reg2;
	case 0x8: /* BEQZ */
	return reg2 == 0;
	case 0x9: /* BNEZ */
	return reg2 != 0;
	case 0xa: /* BLTZ */
	return (int)reg2 < 0;
	case 0xb: /* BGEZ */
	return (int)reg2 >= 0;
	case 0xc: /* BLEZ */
	return (int)reg2 <= 0;
	case 0xd: /* BGTZ */
	return (int)reg2 > 0;
	default:
	/* never reached */
	return 0;
	}
	}

	static void
	compute_next_pc_for_16bit_insn(unsigned long insn, unsigned long pc,
	unsigned long *next_pc,
	struct task_struct *child)
	{
	unsigned long op, op2, op3;
	unsigned long disp;
	unsigned long regno;
	int parallel = 0;

	if (insn & 0x00008000)
	parallel = 1;
	if (pc & 3)
	insn &= 0x7fff; /* right slot */
	else
	insn >>= 16; /* left slot */

	op = (insn >> 12) & 0xf;
	op2 = (insn >> 8) & 0xf;
	op3 = (insn >> 4) & 0xf;

	if (op == 0x7) {
	switch (op2) {
	case 0xd: /* BNC */
	case 0x9: /* BNCL */
	if (!check_condition_bit(child)) {
	disp = (long)(insn << 24) >> 22;
	*next_pc = (pc & ~0x3) + disp;
	return;
	}
	break;
	case 0x8: /* BCL */
	case 0xc: /* BC */
	if (check_condition_bit(child)) {
	disp = (long)(insn << 24) >> 22;
	*next_pc = (pc & ~0x3) + disp;
	return;
	}
	break;
	case 0xe: /* BL */
	case 0xf: /* BRA */
	disp = (long)(insn << 24) >> 22;
	*next_pc = (pc & ~0x3) + disp;
	return;
	break;
	}
	} else if (op == 0x1) {
	switch (op2) {
	case 0x0:
	if (op3 == 0xf) { /* TRAP */
	#if 1
	/* pass through */
	#else
	/* kernel space is not allowed as next_pc */
	unsigned long evb;
	unsigned long trapno;
	trapno = insn & 0xf;
	__asm__ __volatile__ (
	"mvfc %0, cr5\n"
	:"=r"(evb)
	:
	);
	*next_pc = evb + (trapno << 2);
	return;
	#endif
	} else if (op3 == 0xd) { /* RTE */
	*next_pc = get_stack_long(child, PT_BPC);
	return;
	}
	break;
	case 0xc: /* JC */
	if (op3 == 0xc && check_condition_bit(child)) {
	regno = insn & 0xf;
	*next_pc = get_stack_long(child,
	reg_offset[regno]);
	return;
	}
	break;
	case 0xd: /* JNC */
	if (op3 == 0xc && !check_condition_bit(child)) {
	regno = insn & 0xf;
	*next_pc = get_stack_long(child,
	reg_offset[regno]);
	return;
	}
	break;
	case 0xe: /* JL */
	case 0xf: /* JMP */
	if (op3 == 0xc) { /* JMP */
	regno = insn & 0xf;
	*next_pc = get_stack_long(child,
	reg_offset[regno]);
	return;
	}
	break;
	}
	}
	if (parallel)
	*next_pc = pc + 4;
	else
	*next_pc = pc + 2;
	}

	static void
	compute_next_pc_for_32bit_insn(unsigned long insn, unsigned long pc,
	unsigned long *next_pc,
	struct task_struct *child)
	{
	unsigned long op;
	unsigned long op2;
	unsigned long disp;
	unsigned long regno1, regno2;

	op = (insn >> 28) & 0xf;
	if (op == 0xf) { /* branch 24-bit relative */
	op2 = (insn >> 24) & 0xf;
	switch (op2) {
	case 0xd: /* BNC */
	case 0x9: /* BNCL */
	if (!check_condition_bit(child)) {
	disp = (long)(insn << 8) >> 6;
	*next_pc = (pc & ~0x3) + disp;
	return;
	}
	break;
	case 0x8: /* BCL */
	case 0xc: /* BC */
	if (check_condition_bit(child)) {
	disp = (long)(insn << 8) >> 6;
	*next_pc = (pc & ~0x3) + disp;
	return;
	}
	break;
	case 0xe: /* BL */
	case 0xf: /* BRA */
	disp = (long)(insn << 8) >> 6;
	*next_pc = (pc & ~0x3) + disp;
	return;
	}
	} else if (op == 0xb) { /* branch 16-bit relative */
	op2 = (insn >> 20) & 0xf;
	switch (op2) {
	case 0x0: /* BEQ */
	case 0x1: /* BNE */
	case 0x8: /* BEQZ */
	case 0x9: /* BNEZ */
	case 0xa: /* BLTZ */
	case 0xb: /* BGEZ */
	case 0xc: /* BLEZ */
	case 0xd: /* BGTZ */
	regno1 = ((insn >> 24) & 0xf);
	regno2 = ((insn >> 16) & 0xf);
	if (check_condition_src(op2, regno1, regno2, child)) {
	disp = (long)(insn << 16) >> 14;
	*next_pc = (pc & ~0x3) + disp;
	return;
	}
	break;
	}
	}
	*next_pc = pc + 4;
	}

	static inline void
	compute_next_pc(unsigned long insn, unsigned long pc,
	unsigned long next_pc, struct task_struct child)
	{
	if (insn & 0x80000000)
	compute_next_pc_for_32bit_insn(insn, pc, next_pc, child);
	else
	compute_next_pc_for_16bit_insn(insn, pc, next_pc, child);
	}

	static int
	register_debug_trap(struct task_struct *child, unsigned long next_pc,
	unsigned long next_insn, unsigned long *code)
	{
	struct debug_trap *p = &child->thread.debug_trap;
	unsigned long addr = next_pc & ~3;

	if (p->nr_trap == MAX_TRAPS) {
	printk("kernel BUG at %s %d: p->nr_trap = %d\n",
	__FILE__, __LINE__, p->nr_trap);
	return -1;
	}
	p->addr[p->nr_trap] = addr;
	p->insn[p->nr_trap] = next_insn;
	p->nr_trap++;
	if (next_pc & 3) {
	*code = (next_insn & 0xffff0000) \| 0x10f1;
	/* xxx --> TRAP1 */
	} else {
	if ((next_insn & 0x80000000) \|\| (next_insn & 0x8000)) {
	*code = 0x10f17000;
	/* TRAP1 --> NOP */
	} else {
	*code = (next_insn & 0xffff) \| 0x10f10000;
	/* TRAP1 --> xxx */
	}
	}
	return 0;
	}

	static int
	unregister_debug_trap(struct task_struct *child, unsigned long addr,
	unsigned long *code)
	{
	struct debug_trap *p = &child->thread.debug_trap;
	int i;

	/* Search debug trap entry. */
	for (i = 0; i < p->nr_trap; i++) {
	if (p->addr[i] == addr)
	break;
	}
	if (i >= p->nr_trap) {
	/* The trap may be requested from debugger.
	* ptrace should do nothing in this case.
	*/
	return 0;
	}

	/* Recover original instruction code. */
	*code = p->insn[i];

	/* Shift debug trap entries. */
	while (i < p->nr_trap - 1) {
	p->insn[i] = p->insn[i + 1];
	p->addr[i] = p->addr[i + 1];
	i++;
	}
	p->nr_trap--;
	return 1;
	}

	static void
	unregister_all_debug_traps(struct task_struct *child)
	{
	struct debug_trap *p = &child->thread.debug_trap;
	int i;

	for (i = 0; i < p->nr_trap; i++)
	access_process_vm(child, p->addr[i], &p->insn[i], sizeof(p->insn[i]),
	FOLL_FORCE \| FOLL_WRITE);
	p->nr_trap = 0;
	}

	static inline void
	invalidate_cache(void)
	{
	#if defined(CONFIG_CHIP_M32700) \|\| defined(CONFIG_CHIP_OPSP)

	_flush_cache_copyback_all();

	#else /* ! CONFIG_CHIP_M32700 */

	/* Invalidate cache */
	__asm__ __volatile__ (
	"ldi r0, #-1 \n\t"
	"ldi r1, #0 \n\t"
	"stb r1, @r0 ; cache off \n\t"
	"; \n\t"
	"ldi r0, #-2 \n\t"
	"ldi r1, #1 \n\t"
	"stb r1, @r0 ; cache invalidate \n\t"
	".fillinsn \n"
	"0: \n\t"
	"ldb r1, @r0 ; invalidate check \n\t"
	"bnez r1, 0b \n\t"
	"; \n\t"
	"ldi r0, #-1 \n\t"
	"ldi r1, #1 \n\t"
	"stb r1, @r0 ; cache on \n\t"
	: : : "r0", "r1", "memory"
	);
	/* FIXME: copying-back d-cache and invalidating i-cache are needed.
	*/
	#endif /* CONFIG_CHIP_M32700 */
	}

	/* Embed a debug trap (TRAP1) code */
	static int
	embed_debug_trap(struct task_struct *child, unsigned long next_pc)
	{
	unsigned long next_insn, code;
	unsigned long addr = next_pc & ~3;

	if (access_process_vm(child, addr, &next_insn, sizeof(next_insn),
	FOLL_FORCE)
	!= sizeof(next_insn)) {
	return -1; /* error */
	}

	/* Set a trap code. */
	if (register_debug_trap(child, next_pc, next_insn, &code)) {
	return -1; /* error */
	}
	if (access_process_vm(child, addr, &code, sizeof(code),
	FOLL_FORCE \| FOLL_WRITE)
	!= sizeof(code)) {
	return -1; /* error */
	}
	return 0; /* success */
	}

	void
	withdraw_debug_trap(struct pt_regs *regs)
	{
	unsigned long addr;
	unsigned long code;

	addr = (regs->bpc - 2) & ~3;
	regs->bpc -= 2;
	if (unregister_debug_trap(current, addr, &code)) {
	access_process_vm(current, addr, &code, sizeof(code),
	FOLL_FORCE \| FOLL_WRITE);
	invalidate_cache();
	}
	}

	void
	init_debug_traps(struct task_struct *child)
	{
	struct debug_trap *p = &child->thread.debug_trap;
	int i;
	p->nr_trap = 0;
	for (i = 0; i < MAX_TRAPS; i++) {
	p->addr[i] = 0;
	p->insn[i] = 0;
	}
	}

	void user_enable_single_step(struct task_struct *child)
	{
	unsigned long next_pc;
	unsigned long pc, insn;

	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

	/* Compute next pc. */
	pc = get_stack_long(child, PT_BPC);

	if (access_process_vm(child, pc&~3, &insn, sizeof(insn),
	FOLL_FORCE)
	!= sizeof(insn))
	return;

	compute_next_pc(insn, pc, &next_pc, child);
	if (next_pc & 0x80000000)
	return;

	if (embed_debug_trap(child, next_pc))
	return;

	invalidate_cache();
	}

	void user_disable_single_step(struct task_struct *child)
	{
	unregister_all_debug_traps(child);
	invalidate_cache();
	}

	/*
	* Called by kernel/ptrace.c when detaching..
	*
	* Make sure single step bits etc are not set.
	*/
	void ptrace_disable(struct task_struct *child)
	{
	/* nothing to do.. */
	}

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

	switch (request) {
	/*
	* read word at location "addr" in the child process.
	*/
	case PTRACE_PEEKTEXT:
	case PTRACE_PEEKDATA:
	ret = generic_ptrace_peekdata(child, addr, data);
	break;

	/*
	* read the word at location addr in the USER area.
	*/
	case PTRACE_PEEKUSR:
	ret = ptrace_read_user(child, addr, datap);
	break;

	/*
	* write the word at location addr.
	*/
	case PTRACE_POKETEXT:
	case PTRACE_POKEDATA:
	ret = generic_ptrace_pokedata(child, addr, data);
	if (ret == 0 && request == PTRACE_POKETEXT)
	invalidate_cache();
	break;

	/*
	* write the word at location addr in the USER area.
	*/
	case PTRACE_POKEUSR:
	ret = ptrace_write_user(child, addr, data);
	break;

	case PTRACE_GETREGS:
	ret = ptrace_getregs(child, datap);
	break;

	case PTRACE_SETREGS:
	ret = ptrace_setregs(child, datap);
	break;

	default:
	ret = ptrace_request(child, request, addr, data);
	break;
	}

	return ret;
	}

	/* notification of system call entry/exit
	* - triggered by current->work.syscall_trace
	*/
	void do_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;
	}
	}