[net-next-2.6.git] / arch / ppc / kernel / ptrace.c

/*
 *  arch/ppc/kernel/ptrace.c
 *
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Derived from "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
 *
 * Modified by Cort Dougan (cort@hq.fsmlabs.com)
 * and Paul Mackerras (paulus@linuxcare.com.au).
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file README.legal 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/smp_lock.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/security.h>

#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>

/*
 * Set of msr bits that gdb can change on behalf of a process.
 */
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
#define MSR_DEBUGCHANGE	0
#else
#define MSR_DEBUGCHANGE	(MSR_SE | MSR_BE)
#endif

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

/*
 * Get contents of register REGNO in task TASK.
 */
static inline unsigned long get_reg(struct task_struct *task, int regno)
{
	if (regno < sizeof(struct pt_regs) / sizeof(unsigned long)
	    && task->thread.regs != NULL)
		return ((unsigned long *)task->thread.regs)[regno];
	return (0);
}

/*
 * Write contents of register REGNO in task TASK.
 */
static inline int put_reg(struct task_struct *task, int regno,
			  unsigned long data)
{
	if (regno <= PT_MQ && task->thread.regs != NULL) {
		if (regno == PT_MSR)
			data = (data & MSR_DEBUGCHANGE)
				| (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
		((unsigned long *)task->thread.regs)[regno] = data;
		return 0;
	}
	return -EIO;
}

#ifdef CONFIG_ALTIVEC
/*
 * Get contents of AltiVec register state in task TASK
 */
static inline int get_vrregs(unsigned long __user *data, struct task_struct *task)
{
	int i, j;

	if (!access_ok(VERIFY_WRITE, data, 133 * sizeof(unsigned long)))
		return -EFAULT;

	/* copy AltiVec registers VR[0] .. VR[31] */
	for (i = 0; i < 32; i++)
		for (j = 0; j < 4; j++, data++)
			if (__put_user(task->thread.vr[i].u[j], data))
				return -EFAULT;

	/* copy VSCR */
	for (i = 0; i < 4; i++, data++)
		if (__put_user(task->thread.vscr.u[i], data))
			return -EFAULT;

        /* copy VRSAVE */
	if (__put_user(task->thread.vrsave, data))
		return -EFAULT;

	return 0;
}

/*
 * Write contents of AltiVec register state into task TASK.
 */
static inline int set_vrregs(struct task_struct *task, unsigned long __user *data)
{
	int i, j;

	if (!access_ok(VERIFY_READ, data, 133 * sizeof(unsigned long)))
		return -EFAULT;

	/* copy AltiVec registers VR[0] .. VR[31] */
	for (i = 0; i < 32; i++)
		for (j = 0; j < 4; j++, data++)
			if (__get_user(task->thread.vr[i].u[j], data))
				return -EFAULT;

	/* copy VSCR */
	for (i = 0; i < 4; i++, data++)
		if (__get_user(task->thread.vscr.u[i], data))
			return -EFAULT;

	/* copy VRSAVE */
	if (__get_user(task->thread.vrsave, data))
		return -EFAULT;

	return 0;
}
#endif

#ifdef CONFIG_SPE

/*
 * For get_evrregs/set_evrregs functions 'data' has the following layout:
 *
 * struct {
 *   u32 evr[32];
 *   u64 acc;
 *   u32 spefscr;
 * }
 */

/*
 * Get contents of SPE register state in task TASK.
 */
static inline int get_evrregs(unsigned long *data, struct task_struct *task)
{
	int i;

	if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(unsigned long)))
		return -EFAULT;

	/* copy SPEFSCR */
	if (__put_user(task->thread.spefscr, &data[34]))
		return -EFAULT;

	/* copy SPE registers EVR[0] .. EVR[31] */
	for (i = 0; i < 32; i++, data++)
		if (__put_user(task->thread.evr[i], data))
			return -EFAULT;

	/* copy ACC */
	if (__put_user64(task->thread.acc, (unsigned long long *)data))
		return -EFAULT;

	return 0;
}

/*
 * Write contents of SPE register state into task TASK.
 */
static inline int set_evrregs(struct task_struct *task, unsigned long *data)
{
	int i;

	if (!access_ok(VERIFY_READ, data, 35 * sizeof(unsigned long)))
		return -EFAULT;

	/* copy SPEFSCR */
	if (__get_user(task->thread.spefscr, &data[34]))
		return -EFAULT;

	/* copy SPE registers EVR[0] .. EVR[31] */
	for (i = 0; i < 32; i++, data++)
		if (__get_user(task->thread.evr[i], data))
			return -EFAULT;
	/* copy ACC */
	if (__get_user64(task->thread.acc, (unsigned long long*)data))
		return -EFAULT;

	return 0;
}
#endif /* CONFIG_SPE */

static inline void
set_single_step(struct task_struct *task)
{
	struct pt_regs *regs = task->thread.regs;

	if (regs != NULL) {
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
		task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC;
		regs->msr |= MSR_DE;
#else
		regs->msr |= MSR_SE;
#endif
	}
}

static inline void
clear_single_step(struct task_struct *task)
{
	struct pt_regs *regs = task->thread.regs;

	if (regs != NULL) {
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
		task->thread.dbcr0 = 0;
		regs->msr &= ~MSR_DE;
#else
		regs->msr &= ~MSR_SE;
#endif
	}
}

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

int sys_ptrace(long request, long pid, long addr, long data)
{
	struct task_struct *child;
	int ret = -EPERM;

	lock_kernel();
	if (request == PTRACE_TRACEME) {
		/* are we already being traced? */
		if (current->ptrace & PT_PTRACED)
			goto out;
		ret = security_ptrace(current->parent, current);
		if (ret)
			goto out;
		/* set the ptrace bit in the process flags. */
		current->ptrace |= PT_PTRACED;
		ret = 0;
		goto out;
	}
	ret = -ESRCH;
	read_lock(&tasklist_lock);
	child = find_task_by_pid(pid);
	if (child)
		get_task_struct(child);
	read_unlock(&tasklist_lock);
	if (!child)
		goto out;

	ret = -EPERM;
	if (pid == 1)		/* you may not mess with init */
		goto out_tsk;

	if (request == PTRACE_ATTACH) {
		ret = ptrace_attach(child);
		goto out_tsk;
	}

	ret = ptrace_check_attach(child, request == PTRACE_KILL);
	if (ret < 0)
		goto out_tsk;

	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: {
		unsigned long tmp;
		int copied;

		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
		ret = -EIO;
		if (copied != sizeof(tmp))
			break;
		ret = put_user(tmp,(unsigned long __user *) data);
		break;
	}

	/* read the word at location addr in the USER area. */
	/* XXX this will need fixing for 64-bit */
	case PTRACE_PEEKUSR: {
		unsigned long index, tmp;

		ret = -EIO;
		/* convert to index and check */
		index = (unsigned long) addr >> 2;
		if ((addr & 3) || index > PT_FPSCR
		    || child->thread.regs == NULL)
			break;

		CHECK_FULL_REGS(child->thread.regs);
		if (index < PT_FPR0) {
			tmp = get_reg(child, (int) index);
		} else {
			preempt_disable();
			if (child->thread.regs->msr & MSR_FP)
				giveup_fpu(child);
			preempt_enable();
			tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
		}
		ret = put_user(tmp,(unsigned long __user *) data);
		break;
	}

	/* If 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;

	/* write the word at location addr in the USER area */
	case PTRACE_POKEUSR: {
		unsigned long index;

		ret = -EIO;
		/* convert to index and check */
		index = (unsigned long) addr >> 2;
		if ((addr & 3) || index > PT_FPSCR
		    || child->thread.regs == NULL)
			break;

		CHECK_FULL_REGS(child->thread.regs);
		if (index == PT_ORIG_R3)
			break;
		if (index < PT_FPR0) {
			ret = put_reg(child, index, data);
		} else {
			preempt_disable();
			if (child->thread.regs->msr & MSR_FP)
				giveup_fpu(child);
			preempt_enable();
			((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
			ret = 0;
		}
		break;
	}

	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	case PTRACE_CONT: { /* restart after signal. */
		ret = -EIO;
		if ((unsigned long) data > _NSIG)
			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. */
		clear_single_step(child);
		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;
		child->exit_code = SIGKILL;
		/* make sure the single step bit is not set. */
		clear_single_step(child);
		wake_up_process(child);
		break;
	}

	case PTRACE_SINGLESTEP: {  /* set the trap flag. */
		ret = -EIO;
		if ((unsigned long) data > _NSIG)
			break;
		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		set_single_step(child);
		child->exit_code = data;
		/* give it a chance to run. */
		wake_up_process(child);
		ret = 0;
		break;
	}

	case PTRACE_DETACH:
		ret = ptrace_detach(child, data);
		break;

#ifdef CONFIG_ALTIVEC
	case PTRACE_GETVRREGS:
		/* Get the child altivec register state. */
		preempt_disable();
		if (child->thread.regs->msr & MSR_VEC)
			giveup_altivec(child);
		preempt_enable();
		ret = get_vrregs((unsigned long __user *)data, child);
		break;

	case PTRACE_SETVRREGS:
		/* Set the child altivec register state. */
		/* this is to clear the MSR_VEC bit to force a reload
		 * of register state from memory */
		preempt_disable();
		if (child->thread.regs->msr & MSR_VEC)
			giveup_altivec(child);
		preempt_enable();
		ret = set_vrregs(child, (unsigned long __user *)data);
		break;
#endif
#ifdef CONFIG_SPE
	case PTRACE_GETEVRREGS:
		/* Get the child spe register state. */
		if (child->thread.regs->msr & MSR_SPE)
			giveup_spe(child);
		ret = get_evrregs((unsigned long __user *)data, child);
		break;

	case PTRACE_SETEVRREGS:
		/* Set the child spe register state. */
		/* this is to clear the MSR_SPE bit to force a reload
		 * of register state from memory */
		if (child->thread.regs->msr & MSR_SPE)
			giveup_spe(child);
		ret = set_evrregs(child, (unsigned long __user *)data);
		break;
#endif

	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}
out_tsk:
	put_task_struct(child);
out:
	unlock_kernel();
	return ret;
}

void do_syscall_trace(void)
{
        if (!test_thread_flag(TIF_SYSCALL_TRACE)
	    || !(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	* arch/ppc/kernel/ptrace.c
	3	*
	4	* PowerPC version
	5	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
	6	*
	7	* Derived from "arch/m68k/kernel/ptrace.c"
	8	* Copyright (C) 1994 by Hamish Macdonald
	9	* Taken from linux/kernel/ptrace.c and modified for M680x0.
	10	* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
	11	*
	12	* Modified by Cort Dougan (cort@hq.fsmlabs.com)
	13	* and Paul Mackerras (paulus@linuxcare.com.au).
	14	*
	15	* This file is subject to the terms and conditions of the GNU General
	16	* Public License. See the file README.legal in the main directory of
	17	* this archive for more details.
	18	*/
	19
	20	#include <linux/kernel.h>
	21	#include <linux/sched.h>
	22	#include <linux/mm.h>
	23	#include <linux/smp.h>
	24	#include <linux/smp_lock.h>
	25	#include <linux/errno.h>
	26	#include <linux/ptrace.h>
	27	#include <linux/user.h>
	28	#include <linux/security.h>
	29
	30	#include <asm/uaccess.h>
	31	#include <asm/page.h>
	32	#include <asm/pgtable.h>
	33	#include <asm/system.h>
	34
	35	/*
	36	* Set of msr bits that gdb can change on behalf of a process.
	37	*/
	38	#if defined(CONFIG_40x) \|\| defined(CONFIG_BOOKE)
	39	#define MSR_DEBUGCHANGE 0
	40	#else
	41	#define MSR_DEBUGCHANGE (MSR_SE \| MSR_BE)
	42	#endif
	43
	44	/*
	45	* does not yet catch signals sent when the child dies.
	46	* in exit.c or in signal.c.
	47	*/
	48
	49	/*
	50	* Get contents of register REGNO in task TASK.
	51	*/
	52	static inline unsigned long get_reg(struct task_struct *task, int regno)
	53	{
	54	if (regno < sizeof(struct pt_regs) / sizeof(unsigned long)
	55	&& task->thread.regs != NULL)
	56	return ((unsigned long *)task->thread.regs)[regno];
	57	return (0);
	58	}
	59
	60	/*
	61	* Write contents of register REGNO in task TASK.
	62	*/
	63	static inline int put_reg(struct task_struct *task, int regno,
	64	unsigned long data)
65	{
66	if (regno <= PT_MQ && task->thread.regs != NULL) {
67	if (regno == PT_MSR)
68	data = (data & MSR_DEBUGCHANGE)
69	\| (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
70	((unsigned long *)task->thread.regs)[regno] = data;
71	return 0;
72	}
73	return -EIO;
74	}
75
76	#ifdef CONFIG_ALTIVEC
77	/*
78	* Get contents of AltiVec register state in task TASK
79	*/
80	static inline int get_vrregs(unsigned long __user data, struct task_struct task)
81	{
82	int i, j;
83
84	if (!access_ok(VERIFY_WRITE, data, 133 * sizeof(unsigned long)))
85	return -EFAULT;
86
87	/* copy AltiVec registers VR[0] .. VR[31] */
88	for (i = 0; i < 32; i++)
89	for (j = 0; j < 4; j++, data++)
90	if (__put_user(task->thread.vr[i].u[j], data))
91	return -EFAULT;
92
93	/* copy VSCR */
94	for (i = 0; i < 4; i++, data++)
95	if (__put_user(task->thread.vscr.u[i], data))
96	return -EFAULT;
97
98	/* copy VRSAVE */
99	if (__put_user(task->thread.vrsave, data))
100	return -EFAULT;
101
102	return 0;
103	}
104
105	/*
106	* Write contents of AltiVec register state into task TASK.
107	*/
108	static inline int set_vrregs(struct task_struct task, unsigned long __user data)
109	{
110	int i, j;
111
112	if (!access_ok(VERIFY_READ, data, 133 * sizeof(unsigned long)))
113	return -EFAULT;
114
115	/* copy AltiVec registers VR[0] .. VR[31] */
116	for (i = 0; i < 32; i++)
117	for (j = 0; j < 4; j++, data++)
118	if (__get_user(task->thread.vr[i].u[j], data))
119	return -EFAULT;
120
121	/* copy VSCR */
122	for (i = 0; i < 4; i++, data++)
123	if (__get_user(task->thread.vscr.u[i], data))
124	return -EFAULT;
125
126	/* copy VRSAVE */
127	if (__get_user(task->thread.vrsave, data))
128	return -EFAULT;
129
130	return 0;
131	}
132	#endif
133
134	#ifdef CONFIG_SPE
135
136	/*
137	* For get_evrregs/set_evrregs functions 'data' has the following layout:
138	*
139	* struct {
140	* u32 evr[32];
141	* u64 acc;
142	* u32 spefscr;
143	* }
144	*/
145
146	/*
147	* Get contents of SPE register state in task TASK.
148	*/
149	static inline int get_evrregs(unsigned long data, struct task_struct task)
150	{
151	int i;
152
153	if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(unsigned long)))
154	return -EFAULT;
155
156	/* copy SPEFSCR */
157	if (__put_user(task->thread.spefscr, &data[34]))
158	return -EFAULT;
159
160	/* copy SPE registers EVR[0] .. EVR[31] */
161	for (i = 0; i < 32; i++, data++)
162	if (__put_user(task->thread.evr[i], data))
163	return -EFAULT;
164
165	/* copy ACC */
166	if (__put_user64(task->thread.acc, (unsigned long long *)data))
167	return -EFAULT;
168
169	return 0;
170	}
171
172	/*
173	* Write contents of SPE register state into task TASK.
174	*/
175	static inline int set_evrregs(struct task_struct task, unsigned long data)
176	{
177	int i;
178
179	if (!access_ok(VERIFY_READ, data, 35 * sizeof(unsigned long)))
180	return -EFAULT;
181
182	/* copy SPEFSCR */
183	if (__get_user(task->thread.spefscr, &data[34]))
184	return -EFAULT;
185
186	/* copy SPE registers EVR[0] .. EVR[31] */
187	for (i = 0; i < 32; i++, data++)
188	if (__get_user(task->thread.evr[i], data))
189	return -EFAULT;
190	/* copy ACC */
191	if (__get_user64(task->thread.acc, (unsigned long long*)data))
192	return -EFAULT;
193
194	return 0;
195	}
196	#endif /* CONFIG_SPE */
197
198	static inline void
199	set_single_step(struct task_struct *task)
200	{
201	struct pt_regs *regs = task->thread.regs;
202
203	if (regs != NULL) {
204	#if defined(CONFIG_40x) \|\| defined(CONFIG_BOOKE)
205	task->thread.dbcr0 = DBCR0_IDM \| DBCR0_IC;
206	regs->msr \|= MSR_DE;
207	#else
208	regs->msr \|= MSR_SE;
209	#endif
210	}
211	}
212
213	static inline void
214	clear_single_step(struct task_struct *task)
215	{
216	struct pt_regs *regs = task->thread.regs;
217
218	if (regs != NULL) {
219	#if defined(CONFIG_40x) \|\| defined(CONFIG_BOOKE)
220	task->thread.dbcr0 = 0;
221	regs->msr &= ~MSR_DE;
222	#else
223	regs->msr &= ~MSR_SE;
224	#endif
225	}
226	}
227
228	/*
229	* Called by kernel/ptrace.c when detaching..
230	*
231	* Make sure single step bits etc are not set.
232	*/
233	void ptrace_disable(struct task_struct *child)
234	{
235	/* make sure the single step bit is not set. */
236	clear_single_step(child);
237	}
238
239	int sys_ptrace(long request, long pid, long addr, long data)
240	{
241	struct task_struct *child;
242	int ret = -EPERM;
243
244	lock_kernel();
245	if (request == PTRACE_TRACEME) {
246	/* are we already being traced? */
247	if (current->ptrace & PT_PTRACED)
248	goto out;
249	ret = security_ptrace(current->parent, current);
250	if (ret)
251	goto out;
252	/* set the ptrace bit in the process flags. */
253	current->ptrace \|= PT_PTRACED;
254	ret = 0;
255	goto out;
256	}
257	ret = -ESRCH;
258	read_lock(&tasklist_lock);
259	child = find_task_by_pid(pid);
260	if (child)
261	get_task_struct(child);
262	read_unlock(&tasklist_lock);
263	if (!child)
264	goto out;
265
266	ret = -EPERM;
267	if (pid == 1) /* you may not mess with init */
268	goto out_tsk;
269
270	if (request == PTRACE_ATTACH) {
271	ret = ptrace_attach(child);
272	goto out_tsk;
273	}
274
275	ret = ptrace_check_attach(child, request == PTRACE_KILL);
276	if (ret < 0)
277	goto out_tsk;
278
279	switch (request) {
280	/* when I and D space are separate, these will need to be fixed. */
281	case PTRACE_PEEKTEXT: /* read word at location addr. */
282	case PTRACE_PEEKDATA: {
283	unsigned long tmp;
284	int copied;
285
286	copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
287	ret = -EIO;
288	if (copied != sizeof(tmp))
289	break;
290	ret = put_user(tmp,(unsigned long __user *) data);
291	break;
292	}
293
294	/* read the word at location addr in the USER area. */
295	/* XXX this will need fixing for 64-bit */
296	case PTRACE_PEEKUSR: {
297	unsigned long index, tmp;
298
299	ret = -EIO;
300	/* convert to index and check */
301	index = (unsigned long) addr >> 2;
302	if ((addr & 3) \|\| index > PT_FPSCR
303	\|\| child->thread.regs == NULL)
304	break;
305
306	CHECK_FULL_REGS(child->thread.regs);
307	if (index < PT_FPR0) {
308	tmp = get_reg(child, (int) index);
309	} else {
310	preempt_disable();
311	if (child->thread.regs->msr & MSR_FP)
312	giveup_fpu(child);
313	preempt_enable();
314	tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
315	}
316	ret = put_user(tmp,(unsigned long __user *) data);
317	break;
318	}
319
320	/* If I and D space are separate, this will have to be fixed. */
321	case PTRACE_POKETEXT: /* write the word at location addr. */
322	case PTRACE_POKEDATA:
323	ret = 0;
324	if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
325	break;
326	ret = -EIO;
327	break;
328
329	/* write the word at location addr in the USER area */
330	case PTRACE_POKEUSR: {
331	unsigned long index;
332
333	ret = -EIO;
334	/* convert to index and check */
335	index = (unsigned long) addr >> 2;
336	if ((addr & 3) \|\| index > PT_FPSCR
337	\|\| child->thread.regs == NULL)
338	break;
339
340	CHECK_FULL_REGS(child->thread.regs);
341	if (index == PT_ORIG_R3)
342	break;
343	if (index < PT_FPR0) {
344	ret = put_reg(child, index, data);
345	} else {
346	preempt_disable();
347	if (child->thread.regs->msr & MSR_FP)
348	giveup_fpu(child);
349	preempt_enable();
350	((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
351	ret = 0;
352	}
353	break;
354	}
355
356	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
357	case PTRACE_CONT: { /* restart after signal. */
358	ret = -EIO;
359	if ((unsigned long) data > _NSIG)
360	break;
361	if (request == PTRACE_SYSCALL) {
362	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
363	} else {
364	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
365	}
366	child->exit_code = data;
367	/* make sure the single step bit is not set. */
368	clear_single_step(child);
369	wake_up_process(child);
370	ret = 0;
371	break;
372	}
373
374	/*
375	* make the child exit. Best I can do is send it a sigkill.
376	* perhaps it should be put in the status that it wants to
377	* exit.
378	*/
379	case PTRACE_KILL: {
380	ret = 0;
381	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
382	break;
383	child->exit_code = SIGKILL;
384	/* make sure the single step bit is not set. */
385	clear_single_step(child);
386	wake_up_process(child);
387	break;
388	}
389
390	case PTRACE_SINGLESTEP: { /* set the trap flag. */
391	ret = -EIO;
392	if ((unsigned long) data > _NSIG)
393	break;
394	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
395	set_single_step(child);
396	child->exit_code = data;
397	/* give it a chance to run. */
398	wake_up_process(child);
399	ret = 0;
400	break;
401	}
402
403	case PTRACE_DETACH:
404	ret = ptrace_detach(child, data);
405	break;
406
407	#ifdef CONFIG_ALTIVEC
408	case PTRACE_GETVRREGS:
409	/* Get the child altivec register state. */
410	preempt_disable();
411	if (child->thread.regs->msr & MSR_VEC)
412	giveup_altivec(child);
413	preempt_enable();
414	ret = get_vrregs((unsigned long __user *)data, child);
415	break;
416
417	case PTRACE_SETVRREGS:
418	/* Set the child altivec register state. */
419	/* this is to clear the MSR_VEC bit to force a reload
420	* of register state from memory */
421	preempt_disable();
422	if (child->thread.regs->msr & MSR_VEC)
423	giveup_altivec(child);
424	preempt_enable();
425	ret = set_vrregs(child, (unsigned long __user *)data);
426	break;
427	#endif
428	#ifdef CONFIG_SPE
429	case PTRACE_GETEVRREGS:
430	/* Get the child spe register state. */
431	if (child->thread.regs->msr & MSR_SPE)
432	giveup_spe(child);
433	ret = get_evrregs((unsigned long __user *)data, child);
434	break;
435
436	case PTRACE_SETEVRREGS:
437	/* Set the child spe register state. */
438	/* this is to clear the MSR_SPE bit to force a reload
439	* of register state from memory */
440	if (child->thread.regs->msr & MSR_SPE)
441	giveup_spe(child);
442	ret = set_evrregs(child, (unsigned long __user *)data);
443	break;
444	#endif
445
446	default:
447	ret = ptrace_request(child, request, addr, data);
448	break;
449	}
450	out_tsk:
451	put_task_struct(child);
452	out:
453	unlock_kernel();
454	return ret;
455	}
456
457	void do_syscall_trace(void)
458	{
459	if (!test_thread_flag(TIF_SYSCALL_TRACE)
460	\|\| !(current->ptrace & PT_PTRACED))
461	return;
462	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD)
463	? 0x80 : 0));
464
465	/*
466	* this isn't the same as continuing with a signal, but it will do
467	* for normal use. strace only continues with a signal if the
468	* stopping signal is not SIGTRAP. -brl
469	*/
470	if (current->exit_code) {
471	send_sig(current->exit_code, current, 1);
472	current->exit_code = 0;
473	}
474	}