[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);
	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
}

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);
3b66a1ed	119	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
1da177e4 LT	120	}
1da177e4 LT	121
481bed45	122	long arch_ptrace(struct task_struct *child, long request, long addr, long data)
1da177e4	123	{
69f447cf RZ	124	unsigned long tmp;
69f447cf RZ	125	int i, ret = 0;
1da177e4	126
1da177e4 LT	127	switch (request) {
1da177e4 LT	128	/* when I and D space are separate, these will need to be fixed. */
b3319f50	129	case PTRACE_PEEKTEXT: /* read word at location addr. */
69f447cf	130	case PTRACE_PEEKDATA:
76647323	131	ret = generic_ptrace_peekdata(child, addr, data);
b3319f50	132	break;
1da177e4 LT	133
1da177e4 LT	134	/* read the word at location addr in the USER area. */
69f447cf RZ	135	case PTRACE_PEEKUSR:
	136	if (addr & 3)
	137	goto out_eio;
	138	addr >>= 2; /* temporary hack. */
1da177e4	139
69f447cf	140	if (addr >= 0 && addr < 19) {
b3319f50 RZ	141	tmp = get_reg(child, addr);
	142	if (addr == PT_SR)
	143	tmp >>= 16;
	144	} else if (addr >= 21 && addr < 49) {
	145	tmp = child->thread.fp[addr - 21];
b3319f50 RZ	146	/* Convert internal fpu reg representation
	147	* into long double format
	148	*/
	149	if (FPU_IS_EMU && (addr < 45) && !(addr % 3))
	150	tmp = ((tmp & 0xffff0000) << 15) \|
	151	((tmp & 0x0000ffff) << 16);
b3319f50	152	} else
1da177e4	153	break;
b3319f50 RZ	154	ret = put_user(tmp, (unsigned long *)data);
b3319f50 RZ	155	break;
1da177e4	156
b3319f50 RZ	157	/* when I and D space are separate, this will have to be fixed. */
	158	case PTRACE_POKETEXT: /* write the word at location addr. */
	159	case PTRACE_POKEDATA:
f284ce72	160	ret = generic_ptrace_pokedata(child, addr, data);
b3319f50	161	break;
1da177e4	162
b3319f50	163	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
69f447cf RZ	164	if (addr & 3)
	165	goto out_eio;
	166	addr >>= 2; /* temporary hack. */
1da177e4	167
b3319f50 RZ	168	if (addr == PT_SR) {
	169	data &= SR_MASK;
	170	data <<= 16;
	171	data \|= get_reg(child, PT_SR) & ~(SR_MASK << 16);
69f447cf	172	} else if (addr >= 0 && addr < 19) {
b3319f50	173	if (put_reg(child, addr, data))
69f447cf RZ	174	goto out_eio;
69f447cf RZ	175	} else if (addr >= 21 && addr < 48) {
b3319f50 RZ	176	/* Convert long double format
	177	* into internal fpu reg representation
	178	*/
	179	if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) {
	180	data = (unsigned long)data << 15;
	181	data = (data & 0xffff0000) \|
	182	((data & 0x0000ffff) >> 1);
	183	}
b3319f50	184	child->thread.fp[addr - 21] = data;
69f447cf RZ	185	} else
69f447cf RZ	186	goto out_eio;
b3319f50	187	break;
1da177e4	188
b3319f50	189	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
69f447cf	190	case PTRACE_CONT: /* restart after signal. */
b3319f50	191	if (!valid_signal(data))
69f447cf RZ	192	goto out_eio;
	193
	194	if (request == PTRACE_SYSCALL)
3b66a1ed	195	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
69f447cf	196	else
3b66a1ed	197	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
b3319f50	198	child->exit_code = data;
69f447cf	199	singlestep_disable(child);
b3319f50	200	wake_up_process(child);
b3319f50	201	break;
1da177e4	202
b3319f50 RZ	203	/*
	204	* make the child exit. Best I can do is send it a sigkill.
	205	* perhaps it should be put in the status that it wants to
	206	* exit.
	207	*/
69f447cf	208	case PTRACE_KILL:
b3319f50	209	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
1da177e4	210	break;
b3319f50	211	child->exit_code = SIGKILL;
69f447cf	212	singlestep_disable(child);
b3319f50 RZ	213	wake_up_process(child);
b3319f50 RZ	214	break;
1da177e4	215
69f447cf	216	case PTRACE_SINGLESTEP: /* set the trap flag. */
b3319f50	217	if (!valid_signal(data))
69f447cf RZ	218	goto out_eio;
69f447cf RZ	219
3b66a1ed	220	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
b3319f50 RZ	221	tmp = get_reg(child, PT_SR) \| (TRACE_BITS << 16);
b3319f50 RZ	222	put_reg(child, PT_SR, tmp);
3b66a1ed	223	set_tsk_thread_flag(child, TIF_DELAYED_TRACE);
b3319f50 RZ	224
	225	child->exit_code = data;
	226	/* give it a chance to run. */
	227	wake_up_process(child);
b3319f50	228	break;
b3319f50 RZ	229
	230	case PTRACE_DETACH: /* detach a process that was attached. */
	231	ret = ptrace_detach(child, data);
	232	break;
1da177e4	233
69f447cf	234	case PTRACE_GETREGS: /* Get all gp regs from the child. */
b3319f50 RZ	235	for (i = 0; i < 19; i++) {
	236	tmp = get_reg(child, i);
	237	if (i == PT_SR)
1da177e4	238	tmp >>= 16;
69f447cf RZ	239	ret = put_user(tmp, (unsigned long *)data);
69f447cf RZ	240	if (ret)
1da177e4	241	break;
b3319f50	242	data += sizeof(long);
1da177e4	243	}
b3319f50	244	break;
1da177e4	245
69f447cf	246	case PTRACE_SETREGS: /* Set all gp regs in the child. */
b3319f50	247	for (i = 0; i < 19; i++) {
69f447cf RZ	248	ret = get_user(tmp, (unsigned long *)data);
69f447cf RZ	249	if (ret)
1da177e4	250	break;
b3319f50	251	if (i == PT_SR) {
1da177e4 LT	252	tmp &= SR_MASK;
	253	tmp <<= 16;
	254	tmp \|= get_reg(child, PT_SR) & ~(SR_MASK << 16);
1da177e4	255	}
b3319f50 RZ	256	put_reg(child, i, tmp);
b3319f50 RZ	257	data += sizeof(long);
1da177e4	258	}
b3319f50	259	break;
1da177e4	260
69f447cf	261	case PTRACE_GETFPREGS: /* Get the child FPU state. */
b3319f50 RZ	262	if (copy_to_user((void *)data, &child->thread.fp,
	263	sizeof(struct user_m68kfp_struct)))
	264	ret = -EFAULT;
	265	break;
1da177e4	266
69f447cf	267	case PTRACE_SETFPREGS: /* Set the child FPU state. */
b3319f50 RZ	268	if (copy_from_user(&child->thread.fp, (void *)data,
	269	sizeof(struct user_m68kfp_struct)))
	270	ret = -EFAULT;
	271	break;
1da177e4	272
b3319f50 RZ	273	default:
	274	ret = ptrace_request(child, request, addr, data);
	275	break;
1da177e4	276	}
481bed45	277
1da177e4	278	return ret;
69f447cf	279	out_eio:
481bed45	280	return -EIO;
1da177e4 LT	281	}
	282
	283	asmlinkage void syscall_trace(void)
	284	{
1da177e4 LT	285	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD)
	286	? 0x80 : 0));
	287	/*
	288	* this isn't the same as continuing with a signal, but it will do
	289	* for normal use. strace only continues with a signal if the
	290	* stopping signal is not SIGTRAP. -brl
	291	*/
	292	if (current->exit_code) {
	293	send_sig(current->exit_code, current, 1);
	294	current->exit_code = 0;
	295	}
	296	}