[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 = 0;
		if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
			break;
		ret = -EIO;
		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:
	129	ret = 0;
	130	if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
	131	break;
	132	ret = -EIO;
	133	break;
	134
	135	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
	136	ret = -EIO;
9432f968	137	if ((addr & 3) \|\| addr < 0 \|\|
1da177e4 LT	138	addr > sizeof(struct user) - 3)
	139	break;
	140
	141	if (addr < sizeof(struct pt_regs))
	142	ret = put_stack_long(child, addr, data);
	143	else if (addr >= (long) &dummy->fpu &&
	144	addr < (long) &dummy->u_fpvalid) {
	145	set_stopped_child_used_math(child);
	146	((long *)&child->thread.fpu)
	147	[(addr - (long)&dummy->fpu) >> 2] = data;
	148	ret = 0;
	149	} else if (addr == (long) &dummy->u_fpvalid) {
	150	conditional_stopped_child_used_math(data, child);
	151	ret = 0;
	152	}
	153	break;
	154
	155	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	156	case PTRACE_CONT: { /* restart after signal. */
	157	ret = -EIO;
7ed20e1a	158	if (!valid_signal(data))
1da177e4 LT	159	break;
	160	if (request == PTRACE_SYSCALL)
	161	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	162	else
	163	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
9432f968 SM	164
	165	ptrace_disable_singlestep(child);
	166
1da177e4 LT	167	child->exit_code = data;
	168	wake_up_process(child);
	169	ret = 0;
	170	break;
	171	}
	172
	173	/*
9432f968 SM	174	* make the child exit. Best I can do is send it a sigkill.
9432f968 SM	175	* perhaps it should be put in the status that it wants to
1da177e4 LT	176	* exit.
	177	*/
	178	case PTRACE_KILL: {
	179	ret = 0;
	180	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
	181	break;
9432f968	182	ptrace_disable_singlestep(child);
1da177e4 LT	183	child->exit_code = SIGKILL;
	184	wake_up_process(child);
	185	break;
	186	}
	187
	188	case PTRACE_SINGLESTEP: { /* set the trap flag. */
	189	long pc;
e08f457c	190	struct pt_regs *regs = NULL;
1da177e4 LT	191
1da177e4 LT	192	ret = -EIO;
7ed20e1a	193	if (!valid_signal(data))
1da177e4 LT	194	break;
	195	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	196	if ((child->ptrace & PT_DTRACE) == 0) {
	197	/* Spurious delayed TF traps may occur */
	198	child->ptrace \|= PT_DTRACE;
	199	}
	200
e08f457c	201	pc = get_stack_long(child, (long)&regs->pc);
1da177e4 LT	202
	203	/* Next scheduling will set up UBC */
	204	if (child->thread.ubc_pc == 0)
	205	ubc_usercnt += 1;
	206	child->thread.ubc_pc = pc;
	207
9432f968	208	set_tsk_thread_flag(child, TIF_SINGLESTEP);
1da177e4 LT	209	child->exit_code = data;
	210	/* give it a chance to run. */
	211	wake_up_process(child);
	212	ret = 0;
	213	break;
	214	}
	215
	216	case PTRACE_DETACH: /* detach a process that was attached. */
	217	ret = ptrace_detach(child, data);
	218	break;
	219
	220	#ifdef CONFIG_SH_DSP
	221	case PTRACE_GETDSPREGS: {
	222	unsigned long dp;
	223
	224	ret = -EIO;
	225	dp = ((unsigned long) child) + THREAD_SIZE -
	226	sizeof(struct pt_dspregs);
	227	if (((int ) (dp - 4)) == SR_FD) {
	228	copy_to_user(addr, (void *) dp,
	229	sizeof(struct pt_dspregs));
	230	ret = 0;
	231	}
	232	break;
	233	}
	234
	235	case PTRACE_SETDSPREGS: {
	236	unsigned long dp;
1da177e4 LT	237
	238	ret = -EIO;
	239	dp = ((unsigned long) child) + THREAD_SIZE -
	240	sizeof(struct pt_dspregs);
	241	if (((int ) (dp - 4)) == SR_FD) {
	242	copy_from_user((void *) dp, addr,
	243	sizeof(struct pt_dspregs));
	244	ret = 0;
	245	}
	246	break;
	247	}
	248	#endif
	249	default:
	250	ret = ptrace_request(child, request, addr, data);
	251	break;
	252	}
481bed45	253
1da177e4 LT	254	return ret;
	255	}
	256
	257	asmlinkage void do_syscall_trace(void)
	258	{
	259	struct task_struct *tsk = current;
	260
9432f968 SM	261	if (!test_thread_flag(TIF_SYSCALL_TRACE) &&
9432f968 SM	262	!test_thread_flag(TIF_SINGLESTEP))
1da177e4 LT	263	return;
	264	if (!(tsk->ptrace & PT_PTRACED))
	265	return;
	266	/* the 0x80 provides a way for the tracing parent to distinguish
	267	between a syscall stop and SIGTRAP delivery */
9432f968 SM	268	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD) &&
9432f968 SM	269	!test_thread_flag(TIF_SINGLESTEP) ? 0x80 : 0));
1da177e4 LT	270
	271	/*
	272	* this isn't the same as continuing with a signal, but it will do
	273	* for normal use. strace only continues with a signal if the
	274	* stopping signal is not SIGTRAP. -brl
	275	*/
	276	if (tsk->exit_code) {
	277	send_sig(tsk->exit_code, tsk, 1);
	278	tsk->exit_code = 0;
	279	}
	280	}