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

/*
 * linux/arch/sh/kernel/ptrace.c
 *
 * Original x86 implementation:
 *	By Ross Biro 1/23/92
 *	edited by Linus Torvalds
 *
 * SuperH version:   Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
 *
 */
#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/slab.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/io.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>

/*
 * does not yet catch signals sent when the child dies.
 * in exit.c or in signal.c.
 */

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

	stack = (unsigned char *)task_pt_regs(task);
	stack += offset;
	return (*((int *)stack));
}

/*
 * 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 char *stack;

	stack = (unsigned char *)task_pt_regs(task);
	stack += offset;
	*(unsigned long *) stack = data;
	return 0;
}

static void ptrace_disable_singlestep(struct task_struct *child)
{
	clear_tsk_thread_flag(child, TIF_SINGLESTEP);

	/*
	 * Ensure the UBC is not programmed at the next context switch.
	 *
	 * Normally this is not needed but there are sequences such as
	 * singlestep, signal delivery, and continue that leave the
	 * ubc_pc non-zero leading to spurious SIGTRAPs.
	 */
	if (child->thread.ubc_pc != 0) {
		ubc_usercnt -= 1;
		child->thread.ubc_pc = 0;
	}
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
	ptrace_disable_singlestep(child);
}

long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
	struct user * dummy = NULL;
	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);

	/* 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;

		if (addr < sizeof(struct pt_regs))
			tmp = get_stack_long(child, addr);
		else if (addr >= (long) &dummy->fpu &&
			 addr < (long) &dummy->u_fpvalid) {
			if (!tsk_used_math(child)) {
				if (addr == (long)&dummy->fpu.fpscr)
					tmp = FPSCR_INIT;
				else
					tmp = 0;
			} else
				tmp = ((long *)&child->thread.fpu)
					[(addr - (long)&dummy->fpu) >> 2];
		} else if (addr == (long) &dummy->u_fpvalid)
			tmp = !!tsk_used_math(child);
		else
			tmp = 0;
		ret = put_user(tmp, (unsigned long __user *)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;

		if (addr < sizeof(struct pt_regs))
			ret = put_stack_long(child, addr, data);
		else if (addr >= (long) &dummy->fpu &&
			 addr < (long) &dummy->u_fpvalid) {
			set_stopped_child_used_math(child);
			((long *)&child->thread.fpu)
				[(addr - (long)&dummy->fpu) >> 2] = data;
			ret = 0;
		} else if (addr == (long) &dummy->u_fpvalid) {
			conditional_stopped_child_used_math(data, child);
			ret = 0;
		}
		break;

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

		ptrace_disable_singlestep(child);

		child->exit_code = data;
		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: {
		ret = 0;
		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
			break;
		ptrace_disable_singlestep(child);
		child->exit_code = SIGKILL;
		wake_up_process(child);
		break;
	}

	case PTRACE_SINGLESTEP: {  /* set the trap flag. */
		long pc;
		struct pt_regs *regs = NULL;

		ret = -EIO;
		if (!valid_signal(data))
			break;
		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		if ((child->ptrace & PT_DTRACE) == 0) {
			/* Spurious delayed TF traps may occur */
			child->ptrace |= PT_DTRACE;
		}

		pc = get_stack_long(child, (long)&regs->pc);

		/* Next scheduling will set up UBC */
		if (child->thread.ubc_pc == 0)
			ubc_usercnt += 1;
		child->thread.ubc_pc = pc;

		set_tsk_thread_flag(child, TIF_SINGLESTEP);
		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;

#ifdef CONFIG_SH_DSP
	case PTRACE_GETDSPREGS: {
		unsigned long dp;

		ret = -EIO;
		dp = ((unsigned long) child) + THREAD_SIZE -
			 sizeof(struct pt_dspregs);
		if (*((int *) (dp - 4)) == SR_FD) {
			copy_to_user(addr, (void *) dp,
				sizeof(struct pt_dspregs));
			ret = 0;
		}
		break;
	}

	case PTRACE_SETDSPREGS: {
		unsigned long dp;

		ret = -EIO;
		dp = ((unsigned long) child) + THREAD_SIZE -
			 sizeof(struct pt_dspregs);
		if (*((int *) (dp - 4)) == SR_FD) {
			copy_from_user((void *) dp, addr,
				sizeof(struct pt_dspregs));
			ret = 0;
		}
		break;
	}
#endif
	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}

	return ret;
}

asmlinkage void do_syscall_trace(void)
{
	struct task_struct *tsk = current;

	if (!test_thread_flag(TIF_SYSCALL_TRACE) &&
	    !test_thread_flag(TIF_SINGLESTEP))
		return;
	if (!(tsk->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) &&
				 !test_thread_flag(TIF_SINGLESTEP) ? 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 (tsk->exit_code) {
		send_sig(tsk->exit_code, tsk, 1);
		tsk->exit_code = 0;
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/sh/kernel/ptrace.c
	3	*
	4	* Original x86 implementation:
	5	* By Ross Biro 1/23/92
	6	* edited by Linus Torvalds
	7	*
	8	* SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
	9	*
	10	*/
1da177e4 LT	11	#include <linux/kernel.h>
	12	#include <linux/sched.h>
	13	#include <linux/mm.h>
	14	#include <linux/smp.h>
1da177e4 LT	15	#include <linux/errno.h>
	16	#include <linux/ptrace.h>
	17	#include <linux/user.h>
	18	#include <linux/slab.h>
	19	#include <linux/security.h>
7ed20e1a	20	#include <linux/signal.h>
9432f968	21	#include <linux/io.h>
1da177e4 LT	22	#include <asm/uaccess.h>
	23	#include <asm/pgtable.h>
	24	#include <asm/system.h>
	25	#include <asm/processor.h>
	26	#include <asm/mmu_context.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	/*
	34	* This routine will get a word off of the process kernel stack.
	35	*/
	36	static inline int get_stack_long(struct task_struct *task, int offset)
	37	{
	38	unsigned char *stack;
	39
3cf0f4ec	40	stack = (unsigned char *)task_pt_regs(task);
1da177e4 LT	41	stack += offset;
	42	return (((int )stack));
	43	}
	44
	45	/*
	46	* This routine will put a word on the process kernel stack.
	47	*/
	48	static inline int put_stack_long(struct task_struct *task, int offset,
	49	unsigned long data)
	50	{
	51	unsigned char *stack;
	52
3cf0f4ec	53	stack = (unsigned char *)task_pt_regs(task);
1da177e4 LT	54	stack += offset;
	55	(unsigned long ) stack = data;
	56	return 0;
	57	}
	58
9432f968 SM	59	static void ptrace_disable_singlestep(struct task_struct *child)
	60	{
	61	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
	62
	63	/*
	64	* Ensure the UBC is not programmed at the next context switch.
	65	*
	66	* Normally this is not needed but there are sequences such as
	67	* singlestep, signal delivery, and continue that leave the
	68	* ubc_pc non-zero leading to spurious SIGTRAPs.
	69	*/
	70	if (child->thread.ubc_pc != 0) {
	71	ubc_usercnt -= 1;
	72	child->thread.ubc_pc = 0;
	73	}
	74	}
	75
1da177e4 LT	76	/*
	77	* Called by kernel/ptrace.c when detaching..
	78	*
	79	* Make sure single step bits etc are not set.
	80	*/
	81	void ptrace_disable(struct task_struct *child)
	82	{
9432f968	83	ptrace_disable_singlestep(child);
1da177e4 LT	84	}
1da177e4 LT	85
481bed45	86	long arch_ptrace(struct task_struct *child, long request, long addr, long data)
1da177e4	87	{
1da177e4 LT	88	struct user * dummy = NULL;
	89	int ret;
	90
1da177e4 LT	91	switch (request) {
1da177e4 LT	92	/* when I and D space are separate, these will need to be fixed. */
9432f968	93	case PTRACE_PEEKTEXT: /* read word at location addr. */
76647323 AD	94	case PTRACE_PEEKDATA:
76647323 AD	95	ret = generic_ptrace_peekdata(child, addr, data);
1da177e4 LT	96
	97	/* read the word at location addr in the USER area. */
	98	case PTRACE_PEEKUSR: {
	99	unsigned long tmp;
	100
	101	ret = -EIO;
9432f968	102	if ((addr & 3) \|\| addr < 0 \|\|
1da177e4 LT	103	addr > sizeof(struct user) - 3)
	104	break;
	105
	106	if (addr < sizeof(struct pt_regs))
	107	tmp = get_stack_long(child, addr);
	108	else if (addr >= (long) &dummy->fpu &&
	109	addr < (long) &dummy->u_fpvalid) {
	110	if (!tsk_used_math(child)) {
	111	if (addr == (long)&dummy->fpu.fpscr)
	112	tmp = FPSCR_INIT;
	113	else
	114	tmp = 0;
	115	} else
	116	tmp = ((long *)&child->thread.fpu)
	117	[(addr - (long)&dummy->fpu) >> 2];
	118	} else if (addr == (long) &dummy->u_fpvalid)
	119	tmp = !!tsk_used_math(child);
	120	else
	121	tmp = 0;
e08f457c	122	ret = put_user(tmp, (unsigned long __user *)data);
1da177e4 LT	123	break;
	124	}
	125
	126	/* when I and D space are separate, this will have to be fixed. */
	127	case PTRACE_POKETEXT: /* write the word at location addr. */
	128	case PTRACE_POKEDATA:
f284ce72	129	ret = generic_ptrace_pokedata(child, addr, data);
1da177e4 LT	130	break;
	131
	132	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
	133	ret = -EIO;
9432f968	134	if ((addr & 3) \|\| addr < 0 \|\|
1da177e4 LT	135	addr > sizeof(struct user) - 3)
	136	break;
	137
	138	if (addr < sizeof(struct pt_regs))
	139	ret = put_stack_long(child, addr, data);
	140	else if (addr >= (long) &dummy->fpu &&
	141	addr < (long) &dummy->u_fpvalid) {
	142	set_stopped_child_used_math(child);
	143	((long *)&child->thread.fpu)
	144	[(addr - (long)&dummy->fpu) >> 2] = data;
	145	ret = 0;
	146	} else if (addr == (long) &dummy->u_fpvalid) {
	147	conditional_stopped_child_used_math(data, child);
	148	ret = 0;
	149	}
	150	break;
	151
	152	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	153	case PTRACE_CONT: { /* restart after signal. */
	154	ret = -EIO;
7ed20e1a	155	if (!valid_signal(data))
1da177e4 LT	156	break;
	157	if (request == PTRACE_SYSCALL)
	158	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	159	else
	160	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
9432f968 SM	161
	162	ptrace_disable_singlestep(child);
	163
1da177e4 LT	164	child->exit_code = data;
	165	wake_up_process(child);
	166	ret = 0;
	167	break;
	168	}
	169
	170	/*
9432f968 SM	171	* make the child exit. Best I can do is send it a sigkill.
9432f968 SM	172	* perhaps it should be put in the status that it wants to
1da177e4 LT	173	* exit.
	174	*/
	175	case PTRACE_KILL: {
	176	ret = 0;
	177	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
	178	break;
9432f968	179	ptrace_disable_singlestep(child);
1da177e4 LT	180	child->exit_code = SIGKILL;
	181	wake_up_process(child);
	182	break;
	183	}
	184
	185	case PTRACE_SINGLESTEP: { /* set the trap flag. */
	186	long pc;
e08f457c	187	struct pt_regs *regs = NULL;
1da177e4 LT	188
1da177e4 LT	189	ret = -EIO;
7ed20e1a	190	if (!valid_signal(data))
1da177e4 LT	191	break;
	192	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	193	if ((child->ptrace & PT_DTRACE) == 0) {
	194	/* Spurious delayed TF traps may occur */
	195	child->ptrace \|= PT_DTRACE;
	196	}
	197
e08f457c	198	pc = get_stack_long(child, (long)&regs->pc);
1da177e4 LT	199
	200	/* Next scheduling will set up UBC */
	201	if (child->thread.ubc_pc == 0)
	202	ubc_usercnt += 1;
	203	child->thread.ubc_pc = pc;
	204
9432f968	205	set_tsk_thread_flag(child, TIF_SINGLESTEP);
1da177e4 LT	206	child->exit_code = data;
	207	/* give it a chance to run. */
	208	wake_up_process(child);
	209	ret = 0;
	210	break;
	211	}
	212
	213	case PTRACE_DETACH: /* detach a process that was attached. */
	214	ret = ptrace_detach(child, data);
	215	break;
	216
	217	#ifdef CONFIG_SH_DSP
	218	case PTRACE_GETDSPREGS: {
	219	unsigned long dp;
	220
	221	ret = -EIO;
	222	dp = ((unsigned long) child) + THREAD_SIZE -
	223	sizeof(struct pt_dspregs);
	224	if (((int ) (dp - 4)) == SR_FD) {
	225	copy_to_user(addr, (void *) dp,
	226	sizeof(struct pt_dspregs));
	227	ret = 0;
	228	}
	229	break;
	230	}
	231
	232	case PTRACE_SETDSPREGS: {
	233	unsigned long dp;
1da177e4 LT	234
	235	ret = -EIO;
	236	dp = ((unsigned long) child) + THREAD_SIZE -
	237	sizeof(struct pt_dspregs);
	238	if (((int ) (dp - 4)) == SR_FD) {
	239	copy_from_user((void *) dp, addr,
	240	sizeof(struct pt_dspregs));
	241	ret = 0;
	242	}
	243	break;
	244	}
	245	#endif
	246	default:
	247	ret = ptrace_request(child, request, addr, data);
	248	break;
	249	}
481bed45	250
1da177e4 LT	251	return ret;
	252	}
	253
	254	asmlinkage void do_syscall_trace(void)
	255	{
	256	struct task_struct *tsk = current;
	257
9432f968 SM	258	if (!test_thread_flag(TIF_SYSCALL_TRACE) &&
9432f968 SM	259	!test_thread_flag(TIF_SINGLESTEP))
1da177e4 LT	260	return;
	261	if (!(tsk->ptrace & PT_PTRACED))
	262	return;
	263	/* the 0x80 provides a way for the tracing parent to distinguish
	264	between a syscall stop and SIGTRAP delivery */
9432f968 SM	265	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD) &&
9432f968 SM	266	!test_thread_flag(TIF_SINGLESTEP) ? 0x80 : 0));
1da177e4 LT	267
	268	/*
	269	* this isn't the same as continuing with a signal, but it will do
	270	* for normal use. strace only continues with a signal if the
	271	* stopping signal is not SIGTRAP. -brl
	272	*/
	273	if (tsk->exit_code) {
	274	send_sig(tsk->exit_code, tsk, 1);
	275	tsk->exit_code = 0;
	276	}
	277	}