[deliverable/linux.git] / arch / m68knommu / kernel / ptrace.c

/*
 *  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 <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;
}

/*
 * 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_SR) & ~(TRACE_BITS << 16);
	put_reg(child, PT_SR, tmp);
}

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

	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: {
			unsigned long tmp;
			
			ret = -EIO;
			if ((addr & 3) || addr < 0 ||
			    addr > sizeof(struct user) - 3)
				break;
			
			tmp = 0;  /* Default return condition */
			addr = addr >> 2; /* temporary hack. */
			ret = -EIO;
			if (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];
#ifdef CONFIG_M68KFPU_EMU
				/* Convert internal fpu reg representation
				 * into long double format
				 */
				if (FPU_IS_EMU && (addr < 45) && !(addr % 3))
					tmp = ((tmp & 0xffff0000) << 15) |
					      ((tmp & 0x0000ffff) << 16);
#endif
			} else if (addr == 49) {
				tmp = child->mm->start_code;
			} else if (addr == 50) {
				tmp = child->mm->start_data;
			} else if (addr == 51) {
				tmp = child->mm->end_code;
			} 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 */
			ret = -EIO;
			if ((addr & 3) || addr < 0 ||
			    addr > sizeof(struct user) - 3)
				break;

			addr = addr >> 2; /* temporary hack. */
			    
			if (addr == PT_SR) {
				data &= SR_MASK;
				data <<= 16;
				data |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
			}
			if (addr < 19) {
				if (put_reg(child, addr, data))
					break;
				ret = 0;
				break;
			}
			if (addr >= 21 && addr < 48)
			{
#ifdef CONFIG_M68KFPU_EMU
				/* 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);
				}
#endif
				child->thread.fp[addr - 21] = data;
				ret = 0;
			}
			break;

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

			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_SR) & ~(TRACE_BITS << 16);
			put_reg(child, PT_SR, tmp);
			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_SR) & ~(TRACE_BITS << 16);
			put_reg(child, PT_SR, tmp);
			wake_up_process(child);
			break;
		}

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

			ret = -EIO;
			if (!valid_signal(data))
				break;
			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
			tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16);
			put_reg(child, PT_SR, tmp);

			child->exit_code = data;
			/* give it a chance to run. */
			wake_up_process(child);
			ret = 0;
			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. */
		  	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, (unsigned long *) data)) {
				ret = -EFAULT;
				break;
			    }
			    data += sizeof(long);
			}
			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, (unsigned long *) data)) {
				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);
			    data += sizeof(long);
			}
			ret = 0;
			break;
		}

#ifdef PTRACE_GETFPREGS
		case PTRACE_GETFPREGS: { /* Get the child FPU state. */
			ret = 0;
			if (copy_to_user((void *)data, &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, (void *)data,
					   sizeof(struct user_m68kfp_struct)))
				ret = -EFAULT;
			break;
		}
#endif

		default:
			ret = -EIO;
			break;
	}
	return ret;
}

asmlinkage void syscall_trace(void)
{
	if (!test_thread_flag(TIF_SYSCALL_TRACE))
		return;
	if (!(current->ptrace & PT_PTRACED))
		return;
	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/m68knommu/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	PT_REG(d1), PT_REG(d2), PT_REG(d3), PT_REG(d4),
	49	PT_REG(d5), SW_REG(d6), SW_REG(d7), PT_REG(a0),
	50	PT_REG(a1), PT_REG(a2), SW_REG(a3), SW_REG(a4),
	51	SW_REG(a5), SW_REG(a6), PT_REG(d0), -1,
	52	PT_REG(orig_d0), PT_REG(sr), PT_REG(pc),
	53	};
	54
	55	/*
	56	* Get contents of register REGNO in task TASK.
	57	*/
	58	static inline long get_reg(struct task_struct *task, int regno)
	59	{
	60	unsigned long *addr;
	61
	62	if (regno == PT_USP)
	63	addr = &task->thread.usp;
bf0059b2	64	else if (regno < ARRAY_SIZE(regoff))
1da177e4 LT	65	addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
	66	else
	67	return 0;
	68	return *addr;
	69	}
	70
	71	/*
	72	* Write contents of register REGNO in task TASK.
	73	*/
	74	static inline int put_reg(struct task_struct *task, int regno,
	75	unsigned long data)
	76	{
	77	unsigned long *addr;
	78
	79	if (regno == PT_USP)
	80	addr = &task->thread.usp;
bf0059b2	81	else if (regno < ARRAY_SIZE(regoff))
1da177e4 LT	82	addr = (unsigned long *) (task->thread.esp0 + regoff[regno]);
	83	else
	84	return -1;
	85	*addr = data;
	86	return 0;
	87	}
	88
	89	/*
	90	* Called by kernel/ptrace.c when detaching..
	91	*
	92	* Make sure the single step bit is not set.
	93	*/
	94	void ptrace_disable(struct task_struct *child)
	95	{
	96	unsigned long tmp;
	97	/* make sure the single step bit is not set. */
	98	tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
	99	put_reg(child, PT_SR, tmp);
	100	}
	101
afc7cd89	102	long arch_ptrace(struct task_struct *child, long request, long addr, long data)
1da177e4	103	{
1da177e4 LT	104	int ret;
1da177e4 LT	105
1da177e4 LT	106	switch (request) {
	107	/* when I and D space are separate, these will need to be fixed. */
	108	case PTRACE_PEEKTEXT: /* read word at location addr. */
76647323 AD	109	case PTRACE_PEEKDATA:
76647323 AD	110	ret = generic_ptrace_peekdata(child, addr, data);
1da177e4	111	break;
1da177e4 LT	112
	113	/* read the word at location addr in the USER area. */
	114	case PTRACE_PEEKUSR: {
	115	unsigned long tmp;
	116
	117	ret = -EIO;
	118	if ((addr & 3) \|\| addr < 0 \|\|
	119	addr > sizeof(struct user) - 3)
	120	break;
	121
	122	tmp = 0; /* Default return condition */
	123	addr = addr >> 2; /* temporary hack. */
	124	ret = -EIO;
	125	if (addr < 19) {
	126	tmp = get_reg(child, addr);
	127	if (addr == PT_SR)
	128	tmp >>= 16;
	129	} else if (addr >= 21 && addr < 49) {
	130	tmp = child->thread.fp[addr - 21];
	131	#ifdef CONFIG_M68KFPU_EMU
	132	/* Convert internal fpu reg representation
	133	* into long double format
	134	*/
	135	if (FPU_IS_EMU && (addr < 45) && !(addr % 3))
	136	tmp = ((tmp & 0xffff0000) << 15) \|
	137	((tmp & 0x0000ffff) << 16);
	138	#endif
	139	} else if (addr == 49) {
	140	tmp = child->mm->start_code;
	141	} else if (addr == 50) {
	142	tmp = child->mm->start_data;
	143	} else if (addr == 51) {
	144	tmp = child->mm->end_code;
	145	} else
	146	break;
	147	ret = put_user(tmp,(unsigned long *) data);
	148	break;
	149	}
	150
	151	/* when I and D space are separate, this will have to be fixed. */
	152	case PTRACE_POKETEXT: /* write the word at location addr. */
	153	case PTRACE_POKEDATA:
f284ce72	154	ret = generic_ptrace_pokedata(child, addr, data);
1da177e4 LT	155	break;
	156
	157	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
	158	ret = -EIO;
	159	if ((addr & 3) \|\| addr < 0 \|\|
	160	addr > sizeof(struct user) - 3)
	161	break;
	162
	163	addr = addr >> 2; /* temporary hack. */
	164
	165	if (addr == PT_SR) {
	166	data &= SR_MASK;
	167	data <<= 16;
	168	data \|= get_reg(child, PT_SR) & ~(SR_MASK << 16);
	169	}
	170	if (addr < 19) {
	171	if (put_reg(child, addr, data))
	172	break;
	173	ret = 0;
	174	break;
	175	}
	176	if (addr >= 21 && addr < 48)
	177	{
	178	#ifdef CONFIG_M68KFPU_EMU
	179	/* Convert long double format
	180	* into internal fpu reg representation
	181	*/
	182	if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) {
	183	data = (unsigned long)data << 15;
	184	data = (data & 0xffff0000) \|
	185	((data & 0x0000ffff) >> 1);
	186	}
	187	#endif
	188	child->thread.fp[addr - 21] = data;
	189	ret = 0;
	190	}
	191	break;
	192
	193	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	194	case PTRACE_CONT: { /* restart after signal. */
	195	long tmp;
	196
	197	ret = -EIO;
7ed20e1a	198	if (!valid_signal(data))
1da177e4 LT	199	break;
	200	if (request == PTRACE_SYSCALL)
	201	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	202	else
	203	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	204	child->exit_code = data;
	205	/* make sure the single step bit is not set. */
	206	tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
	207	put_reg(child, PT_SR, tmp);
	208	wake_up_process(child);
	209	ret = 0;
	210	break;
	211	}
	212
	213	/*
	214	* make the child exit. Best I can do is send it a sigkill.
	215	* perhaps it should be put in the status that it wants to
	216	* exit.
	217	*/
	218	case PTRACE_KILL: {
	219	long tmp;
	220
	221	ret = 0;
	222	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
	223	break;
	224	child->exit_code = SIGKILL;
	225	/* make sure the single step bit is not set. */
	226	tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
	227	put_reg(child, PT_SR, tmp);
	228	wake_up_process(child);
	229	break;
	230	}
	231
	232	case PTRACE_SINGLESTEP: { /* set the trap flag. */
	233	long tmp;
	234
	235	ret = -EIO;
7ed20e1a	236	if (!valid_signal(data))
1da177e4 LT	237	break;
	238	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	239	tmp = get_reg(child, PT_SR) \| (TRACE_BITS << 16);
	240	put_reg(child, PT_SR, tmp);
	241
	242	child->exit_code = data;
	243	/* give it a chance to run. */
	244	wake_up_process(child);
	245	ret = 0;
	246	break;
	247	}
	248
	249	case PTRACE_DETACH: /* detach a process that was attached. */
	250	ret = ptrace_detach(child, data);
	251	break;
	252
	253	case PTRACE_GETREGS: { /* Get all gp regs from the child. */
	254	int i;
	255	unsigned long tmp;
	256	for (i = 0; i < 19; i++) {
	257	tmp = get_reg(child, i);
	258	if (i == PT_SR)
	259	tmp >>= 16;
	260	if (put_user(tmp, (unsigned long *) data)) {
	261	ret = -EFAULT;
	262	break;
	263	}
	264	data += sizeof(long);
	265	}
	266	ret = 0;
	267	break;
	268	}
	269
	270	case PTRACE_SETREGS: { /* Set all gp regs in the child. */
	271	int i;
	272	unsigned long tmp;
	273	for (i = 0; i < 19; i++) {
	274	if (get_user(tmp, (unsigned long *) data)) {
	275	ret = -EFAULT;
	276	break;
	277	}
	278	if (i == PT_SR) {
	279	tmp &= SR_MASK;
	280	tmp <<= 16;
	281	tmp \|= get_reg(child, PT_SR) & ~(SR_MASK << 16);
	282	}
	283	put_reg(child, i, tmp);
	284	data += sizeof(long);
	285	}
	286	ret = 0;
	287	break;
	288	}
	289
	290	#ifdef PTRACE_GETFPREGS
	291	case PTRACE_GETFPREGS: { /* Get the child FPU state. */
	292	ret = 0;
	293	if (copy_to_user((void *)data, &child->thread.fp,
	294	sizeof(struct user_m68kfp_struct)))
	295	ret = -EFAULT;
	296	break;
	297	}
	298	#endif
	299
	300	#ifdef PTRACE_SETFPREGS
301	case PTRACE_SETFPREGS: { /* Set the child FPU state. */
302	ret = 0;
303	if (copy_from_user(&child->thread.fp, (void *)data,
304	sizeof(struct user_m68kfp_struct)))
305	ret = -EFAULT;
306	break;
307	}
308	#endif
309
310	default:
311	ret = -EIO;
312	break;
313	}
1da177e4 LT	314	return ret;
	315	}
	316
	317	asmlinkage void syscall_trace(void)
	318	{
	319	if (!test_thread_flag(TIF_SYSCALL_TRACE))
	320	return;
	321	if (!(current->ptrace & PT_PTRACED))
	322	return;
	323	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD)
	324	? 0x80 : 0));
	325	/*
	326	* this isn't the same as continuing with a signal, but it will do
	327	* for normal use. strace only continues with a signal if the
	328	* stopping signal is not SIGTRAP. -brl
	329	*/
	330	if (current->exit_code) {
	331	send_sig(current->exit_code, current, 1);
	332	current->exit_code = 0;
	333	}
	334	}