[linux-2.6-block.git] / arch / m68k / kernel / ptrace.c

/*
 *  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 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[] = {
	[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;
	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;
}

/*
 * 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 << 16);
	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);
}

long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
	unsigned long tmp;
	int i, ret = 0;

	switch (request) {
	/* when I and D space are separate, these will need to be fixed. */
	case PTRACE_PEEKTEXT:	/* read word at location addr. */
	case PTRACE_PEEKDATA:
		ret = generic_ptrace_peekdata(child, addr, data);
		break;

	/* 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);
			if (addr == PT_SR)
				tmp >>= 16;
		} 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
			break;
		ret = put_user(tmp, (unsigned long *)data);
		break;

	/* when I and D space are separate, this will have to be fixed. */
	case PTRACE_POKETEXT:	/* write the word at location addr. */
	case PTRACE_POKEDATA:
		ret = generic_ptrace_pokedata(child, addr, 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 <<= 16;
			data |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
		} else 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_SYSCALL:	/* continue and stop at next (return from) syscall */
	case PTRACE_CONT:	/* restart after signal. */
		if (!valid_signal(data))
			goto out_eio;

		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;
		singlestep_disable(child);
		wake_up_process(child);
		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:
		if (child->exit_state == EXIT_ZOMBIE) /* already dead */
			break;
		child->exit_code = SIGKILL;
		singlestep_disable(child);
		wake_up_process(child);
		break;

	case PTRACE_SINGLESTEP:	/* set the trap flag. */
		if (!valid_signal(data))
			goto out_eio;

		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16);
		put_reg(child, PT_SR, tmp);
		set_tsk_thread_flag(child, TIF_DELAYED_TRACE);

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

	case PTRACE_DETACH:	/* detach a process that was attached. */
		ret = ptrace_detach(child, data);
		break;

	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
		for (i = 0; i < 19; i++) {
			tmp = get_reg(child, i);
			if (i == PT_SR)
				tmp >>= 16;
			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 <<= 16;
				tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
			}
			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;

	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;
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/m68k/kernel/ptrace.c
	3	*
	4	* Copyright (C) 1994 by Hamish Macdonald
	5	* Taken from linux/kernel/ptrace.c and modified for M680x0.
	6	* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
	7	*
	8	* This file is subject to the terms and conditions of the GNU General
	9	* Public License. See the file COPYING in the main directory of
	10	* this archive for more details.
	11	*/
	12
	13	#include <linux/kernel.h>
	14	#include <linux/sched.h>
	15	#include <linux/mm.h>
	16	#include <linux/smp.h>
1da177e4 LT	17	#include <linux/errno.h>
	18	#include <linux/ptrace.h>
	19	#include <linux/user.h>
7ed20e1a	20	#include <linux/signal.h>
1da177e4 LT	21
	22	#include <asm/uaccess.h>
	23	#include <asm/page.h>
	24	#include <asm/pgtable.h>
	25	#include <asm/system.h>
	26	#include <asm/processor.h>
	27
	28	/*
	29	* does not yet catch signals sent when the child dies.
	30	* in exit.c or in signal.c.
	31	*/
	32
	33	/* determines which bits in the SR the user has access to. */
	34	/* 1 = access 0 = no access */
	35	#define SR_MASK 0x001f
	36
	37	/* sets the trace bits. */
	38	#define TRACE_BITS 0x8000
	39
	40	/* Find the stack offset for a register, relative to thread.esp0. */
	41	#define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
	42	#define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \
	43	- sizeof(struct switch_stack))
	44	/* Mapping from PT_xxx to the stack offset at which the register is
	45	saved. Notice that usp has no stack-slot and needs to be treated
	46	specially (see get_reg/put_reg below). */
	47	static int regoff[] = {
	48	[0] = PT_REG(d1),
	49	[1] = PT_REG(d2),
	50	[2] = PT_REG(d3),
	51	[3] = PT_REG(d4),
	52	[4] = PT_REG(d5),
	53	[5] = SW_REG(d6),
	54	[6] = SW_REG(d7),
	55	[7] = PT_REG(a0),
	56	[8] = PT_REG(a1),
	57	[9] = PT_REG(a2),
	58	[10] = SW_REG(a3),
	59	[11] = SW_REG(a4),
	60	[12] = SW_REG(a5),
	61	[13] = SW_REG(a6),
	62	[14] = PT_REG(d0),
	63	[15] = -1,
	64	[16] = PT_REG(orig_d0),
	65	[17] = PT_REG(sr),
	66	[18] = PT_REG(pc),
	67	};
	68
	69	/*
	70	* Get contents of register REGNO in task TASK.
	71	*/
	72	static inline long get_reg(struct task_struct *task, int regno)
	73	{
	74	unsigned long *addr;
	75
	76	if (regno == PT_USP)
	77	addr = &task->thread.usp;
ea5e1a82	78	else if (regno < ARRAY_SIZE(regoff))
1da177e4 LT	79	addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
	80	else
	81	return 0;
	82	return *addr;
	83	}
	84
	85	/*
	86	* Write contents of register REGNO in task TASK.
	87	*/
	88	static inline int put_reg(struct task_struct *task, int regno,
	89	unsigned long data)
	90	{
	91	unsigned long *addr;
	92
	93	if (regno == PT_USP)
	94	addr = &task->thread.usp;
ea5e1a82	95	else if (regno < ARRAY_SIZE(regoff))
b3319f50	96	addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
1da177e4 LT	97	else
	98	return -1;
	99	*addr = data;
	100	return 0;
	101	}
	102
	103	/*
1da177e4 LT	104	* Make sure the single step bit is not set.
1da177e4 LT	105	*/
69f447cf	106	static inline void singlestep_disable(struct task_struct *child)
1da177e4	107	{
69f447cf	108	unsigned long tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
1da177e4	109	put_reg(child, PT_SR, tmp);
3b66a1ed	110	clear_tsk_thread_flag(child, TIF_DELAYED_TRACE);
69f447cf RZ	111	}
	112
	113	/*
	114	* Called by kernel/ptrace.c when detaching..
	115	*/
	116	void ptrace_disable(struct task_struct *child)
	117	{
	118	singlestep_disable(child);
1da177e4 LT	119	}
1da177e4 LT	120
481bed45	121	long arch_ptrace(struct task_struct *child, long request, long addr, long data)
1da177e4	122	{
69f447cf RZ	123	unsigned long tmp;
69f447cf RZ	124	int i, ret = 0;
1da177e4	125
1da177e4 LT	126	switch (request) {
1da177e4 LT	127	/* when I and D space are separate, these will need to be fixed. */
b3319f50	128	case PTRACE_PEEKTEXT: /* read word at location addr. */
69f447cf	129	case PTRACE_PEEKDATA:
76647323	130	ret = generic_ptrace_peekdata(child, addr, data);
b3319f50	131	break;
1da177e4 LT	132
1da177e4 LT	133	/* read the word at location addr in the USER area. */
69f447cf RZ	134	case PTRACE_PEEKUSR:
	135	if (addr & 3)
	136	goto out_eio;
	137	addr >>= 2; /* temporary hack. */
1da177e4	138
69f447cf	139	if (addr >= 0 && addr < 19) {
b3319f50 RZ	140	tmp = get_reg(child, addr);
	141	if (addr == PT_SR)
	142	tmp >>= 16;
	143	} else if (addr >= 21 && addr < 49) {
	144	tmp = child->thread.fp[addr - 21];
b3319f50 RZ	145	/* Convert internal fpu reg representation
	146	* into long double format
	147	*/
	148	if (FPU_IS_EMU && (addr < 45) && !(addr % 3))
	149	tmp = ((tmp & 0xffff0000) << 15) \|
	150	((tmp & 0x0000ffff) << 16);
b3319f50	151	} else
1da177e4	152	break;
b3319f50 RZ	153	ret = put_user(tmp, (unsigned long *)data);
b3319f50 RZ	154	break;
1da177e4	155
b3319f50 RZ	156	/* when I and D space are separate, this will have to be fixed. */
	157	case PTRACE_POKETEXT: /* write the word at location addr. */
	158	case PTRACE_POKEDATA:
f284ce72	159	ret = generic_ptrace_pokedata(child, addr, data);
b3319f50	160	break;
1da177e4	161
b3319f50	162	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
69f447cf RZ	163	if (addr & 3)
	164	goto out_eio;
	165	addr >>= 2; /* temporary hack. */
1da177e4	166
b3319f50 RZ	167	if (addr == PT_SR) {
	168	data &= SR_MASK;
	169	data <<= 16;
	170	data \|= get_reg(child, PT_SR) & ~(SR_MASK << 16);
69f447cf	171	} else if (addr >= 0 && addr < 19) {
b3319f50	172	if (put_reg(child, addr, data))
69f447cf RZ	173	goto out_eio;
69f447cf RZ	174	} else if (addr >= 21 && addr < 48) {
b3319f50 RZ	175	/* Convert long double format
	176	* into internal fpu reg representation
	177	*/
	178	if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) {
	179	data = (unsigned long)data << 15;
	180	data = (data & 0xffff0000) \|
	181	((data & 0x0000ffff) >> 1);
	182	}
b3319f50	183	child->thread.fp[addr - 21] = data;
69f447cf RZ	184	} else
69f447cf RZ	185	goto out_eio;
b3319f50	186	break;
1da177e4	187
b3319f50	188	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
69f447cf	189	case PTRACE_CONT: /* restart after signal. */
b3319f50	190	if (!valid_signal(data))
69f447cf RZ	191	goto out_eio;
	192
	193	if (request == PTRACE_SYSCALL)
3b66a1ed	194	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
69f447cf	195	else
3b66a1ed	196	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
b3319f50	197	child->exit_code = data;
69f447cf	198	singlestep_disable(child);
b3319f50	199	wake_up_process(child);
b3319f50	200	break;
1da177e4	201
b3319f50 RZ	202	/*
	203	* make the child exit. Best I can do is send it a sigkill.
	204	* perhaps it should be put in the status that it wants to
	205	* exit.
	206	*/
69f447cf	207	case PTRACE_KILL:
b3319f50	208	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
1da177e4	209	break;
b3319f50	210	child->exit_code = SIGKILL;
69f447cf	211	singlestep_disable(child);
b3319f50 RZ	212	wake_up_process(child);
b3319f50 RZ	213	break;
1da177e4	214
69f447cf	215	case PTRACE_SINGLESTEP: /* set the trap flag. */
b3319f50	216	if (!valid_signal(data))
69f447cf RZ	217	goto out_eio;
69f447cf RZ	218
3b66a1ed	219	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
b3319f50 RZ	220	tmp = get_reg(child, PT_SR) \| (TRACE_BITS << 16);
b3319f50 RZ	221	put_reg(child, PT_SR, tmp);
3b66a1ed	222	set_tsk_thread_flag(child, TIF_DELAYED_TRACE);
b3319f50 RZ	223
	224	child->exit_code = data;
	225	/* give it a chance to run. */
	226	wake_up_process(child);
b3319f50	227	break;
b3319f50 RZ	228
	229	case PTRACE_DETACH: /* detach a process that was attached. */
	230	ret = ptrace_detach(child, data);
	231	break;
1da177e4	232
69f447cf	233	case PTRACE_GETREGS: /* Get all gp regs from the child. */
b3319f50 RZ	234	for (i = 0; i < 19; i++) {
	235	tmp = get_reg(child, i);
	236	if (i == PT_SR)
1da177e4	237	tmp >>= 16;
69f447cf RZ	238	ret = put_user(tmp, (unsigned long *)data);
69f447cf RZ	239	if (ret)
1da177e4	240	break;
b3319f50	241	data += sizeof(long);
1da177e4	242	}
b3319f50	243	break;
1da177e4	244
69f447cf	245	case PTRACE_SETREGS: /* Set all gp regs in the child. */
b3319f50	246	for (i = 0; i < 19; i++) {
69f447cf RZ	247	ret = get_user(tmp, (unsigned long *)data);
69f447cf RZ	248	if (ret)
1da177e4	249	break;
b3319f50	250	if (i == PT_SR) {
1da177e4 LT	251	tmp &= SR_MASK;
	252	tmp <<= 16;
	253	tmp \|= get_reg(child, PT_SR) & ~(SR_MASK << 16);
1da177e4	254	}
b3319f50 RZ	255	put_reg(child, i, tmp);
b3319f50 RZ	256	data += sizeof(long);
1da177e4	257	}
b3319f50	258	break;
1da177e4	259
69f447cf	260	case PTRACE_GETFPREGS: /* Get the child FPU state. */
b3319f50 RZ	261	if (copy_to_user((void *)data, &child->thread.fp,
	262	sizeof(struct user_m68kfp_struct)))
	263	ret = -EFAULT;
	264	break;
1da177e4	265
69f447cf	266	case PTRACE_SETFPREGS: /* Set the child FPU state. */
b3319f50 RZ	267	if (copy_from_user(&child->thread.fp, (void *)data,
	268	sizeof(struct user_m68kfp_struct)))
	269	ret = -EFAULT;
	270	break;
1da177e4	271
b3319f50 RZ	272	default:
	273	ret = ptrace_request(child, request, addr, data);
	274	break;
1da177e4	275	}
481bed45	276
1da177e4	277	return ret;
69f447cf	278	out_eio:
481bed45	279	return -EIO;
1da177e4 LT	280	}
	281
	282	asmlinkage void syscall_trace(void)
	283	{
1da177e4 LT	284	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD)
	285	? 0x80 : 0));
	286	/*
	287	* this isn't the same as continuing with a signal, but it will do
	288	* for normal use. strace only continues with a signal if the
	289	* stopping signal is not SIGTRAP. -brl
	290	*/
	291	if (current->exit_code) {
	292	send_sig(current->exit_code, current, 1);
	293	current->exit_code = 0;
	294	}
	295	}