[deliverable/linux.git] / arch / sh64 / kernel / ptrace.c

/*
 * 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.
 *
 * arch/sh64/kernel/ptrace.c
 *
 * Copyright (C) 2000, 2001  Paolo Alberelli
 * Copyright (C) 2003  Paul Mundt
 *
 * Started from SH3/4 version:
 *   SuperH version:   Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
 *
 *   Original x86 implementation:
 *	By Ross Biro 1/23/92
 *	edited by Linus Torvalds
 *
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/rwsem.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 <asm/io.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>

/* This mask defines the bits of the SR which the user is not allowed to
   change, which are everything except S, Q, M, PR, SZ, FR. */
#define SR_MASK      (0xffff8cfd)

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

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

	stack = (unsigned char *)(task->thread.uregs);
	stack += offset;
	return (*((int *)stack));
}

static inline unsigned long
get_fpu_long(struct task_struct *task, unsigned long addr)
{
	unsigned long tmp;
	struct pt_regs *regs;
	regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;

	if (!tsk_used_math(task)) {
		if (addr == offsetof(struct user_fpu_struct, fpscr)) {
			tmp = FPSCR_INIT;
		} else {
			tmp = 0xffffffffUL; /* matches initial value in fpu.c */
		}
		return tmp;
	}

	if (last_task_used_math == task) {
		grab_fpu();
		fpsave(&task->thread.fpu.hard);
		release_fpu();
		last_task_used_math = 0;
		regs->sr |= SR_FD;
	}

	tmp = ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)];
	return tmp;
}

/*
 * This routine will put a word into the user area in 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->thread.uregs);
	stack += offset;
	*(unsigned long *) stack = data;
	return 0;
}

static inline int
put_fpu_long(struct task_struct *task, unsigned long addr, unsigned long data)
{
	struct pt_regs *regs;

	regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;

	if (!tsk_used_math(task)) {
		fpinit(&task->thread.fpu.hard);
		set_stopped_child_used_math(task);
	} else if (last_task_used_math == task) {
		grab_fpu();
		fpsave(&task->thread.fpu.hard);
		release_fpu();
		last_task_used_math = 0;
		regs->sr |= SR_FD;
	}

	((long *)&task->thread.fpu)[addr / sizeof(unsigned long)] = data;
	return 0;
}

asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
{
	struct task_struct *child;
	extern void poke_real_address_q(unsigned long long addr, unsigned long long data);
#define WPC_DBRMODE 0x0d104008
	static int first_call = 1;
	int ret;

	lock_kernel();

	if (first_call) {
		/* Set WPC.DBRMODE to 0.  This makes all debug events get
		 * delivered through RESVEC, i.e. into the handlers in entry.S.
		 * (If the kernel was downloaded using a remote gdb, WPC.DBRMODE
		 * would normally be left set to 1, which makes debug events get
		 * delivered through DBRVEC, i.e. into the remote gdb's
		 * handlers.  This prevents ptrace getting them, and confuses
		 * the remote gdb.) */
		printk("DBRMODE set to 0 to permit native debugging\n");
		poke_real_address_q(WPC_DBRMODE, 0);
		first_call = 0;
	}

	ret = -EPERM;
	if (request == PTRACE_TRACEME) {
		/* are we already being traced? */
		if (current->ptrace & PT_PTRACED)
			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 *) 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)
			break;

		if (addr < sizeof(struct pt_regs))
			tmp = get_stack_long(child, addr);
		else if ((addr >= offsetof(struct user, fpu)) &&
			 (addr <  offsetof(struct user, u_fpvalid))) {
			tmp = get_fpu_long(child, addr - offsetof(struct user, fpu));
		} else if (addr == offsetof(struct user, u_fpvalid)) {
			tmp = !!tsk_used_math(child);
		} 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 = 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. We must
                   disallow any changes to certain SR bits or u_fpvalid, since
                   this could crash the kernel or result in a security
                   loophole. */
		ret = -EIO;
		if ((addr & 3) || addr < 0)
			break;

		if (addr < sizeof(struct pt_regs)) {
			/* Ignore change of top 32 bits of SR */
			if (addr == offsetof (struct pt_regs, sr)+4)
			{
				ret = 0;
				break;
			}
			/* If lower 32 bits of SR, ignore non-user bits */
			if (addr == offsetof (struct pt_regs, sr))
			{
				long cursr = get_stack_long(child, addr);
				data &= ~(SR_MASK);
				data |= (cursr & SR_MASK);
			}
			ret = put_stack_long(child, addr, data);
		}
		else if ((addr >= offsetof(struct user, fpu)) &&
			 (addr <  offsetof(struct user, u_fpvalid))) {
			ret = put_fpu_long(child, addr - offsetof(struct user, fpu), data);
		}
		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;
		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;
		wake_up_process(child);
		break;
	}

	case PTRACE_SINGLESTEP: {  /* set the trap flag. */
		struct pt_regs *regs;

		ret = -EIO;
		if ((unsigned long) data > _NSIG)
			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;
		}

		regs = child->thread.uregs;

		regs->sr |= SR_SSTEP;	/* auto-resetting upon exception */

		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;

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

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

	if (!test_thread_flag(TIF_SYSCALL_TRACE))
		return;
	if (!(tsk->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 (tsk->exit_code) {
		send_sig(tsk->exit_code, tsk, 1);
		tsk->exit_code = 0;
	}
}

/* Called with interrupts disabled */
asmlinkage void do_single_step(unsigned long long vec, struct pt_regs *regs)
{
	/* This is called after a single step exception (DEBUGSS).
	   There is no need to change the PC, as it is a post-execution
	   exception, as entry.S does not do anything to the PC for DEBUGSS.
	   We need to clear the Single Step setting in SR to avoid
	   continually stepping. */
	local_irq_enable();
	regs->sr &= ~SR_SSTEP;
	force_sig(SIGTRAP, current);
}

/* Called with interrupts disabled */
asmlinkage void do_software_break_point(unsigned long long vec,
					struct pt_regs *regs)
{
	/* We need to forward step the PC, to counteract the backstep done
	   in signal.c. */
	local_irq_enable();
	force_sig(SIGTRAP, current);
	regs->pc += 4;
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
        /* nothing to do.. */
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This file is subject to the terms and conditions of the GNU General Public
	3	* License. See the file "COPYING" in the main directory of this archive
	4	* for more details.
	5	*
	6	* arch/sh64/kernel/ptrace.c
	7	*
	8	* Copyright (C) 2000, 2001 Paolo Alberelli
	9	* Copyright (C) 2003 Paul Mundt
	10	*
	11	* Started from SH3/4 version:
	12	* SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
	13	*
	14	* Original x86 implementation:
	15	* By Ross Biro 1/23/92
	16	* edited by Linus Torvalds
	17	*
	18	*/
	19
	20	#include <linux/config.h>
	21	#include <linux/kernel.h>
	22	#include <linux/rwsem.h>
	23	#include <linux/sched.h>
	24	#include <linux/mm.h>
	25	#include <linux/smp.h>
	26	#include <linux/smp_lock.h>
	27	#include <linux/errno.h>
	28	#include <linux/ptrace.h>
	29	#include <linux/user.h>
	30
	31	#include <asm/io.h>
	32	#include <asm/uaccess.h>
	33	#include <asm/pgtable.h>
	34	#include <asm/system.h>
	35	#include <asm/processor.h>
	36	#include <asm/mmu_context.h>
	37
	38	/* This mask defines the bits of the SR which the user is not allowed to
	39	change, which are everything except S, Q, M, PR, SZ, FR. */
	40	#define SR_MASK (0xffff8cfd)
	41
	42	/*
	43	* does not yet catch signals sent when the child dies.
	44	* in exit.c or in signal.c.
	45	*/
	46
	47	/*
	48	* This routine will get a word from the user area in the process kernel stack.
	49	*/
	50	static inline int get_stack_long(struct task_struct *task, int offset)
	51	{
	52	unsigned char *stack;
	53
	54	stack = (unsigned char *)(task->thread.uregs);
	55	stack += offset;
	56	return (((int )stack));
	57	}
	58
	59	static inline unsigned long
	60	get_fpu_long(struct task_struct *task, unsigned long addr)
	61	{
	62	unsigned long tmp;
	63	struct pt_regs *regs;
	64	regs = (struct pt_regs)((unsigned char )task + THREAD_SIZE) - 1;
65
66	if (!tsk_used_math(task)) {
67	if (addr == offsetof(struct user_fpu_struct, fpscr)) {
68	tmp = FPSCR_INIT;
69	} else {
70	tmp = 0xffffffffUL; /* matches initial value in fpu.c */
71	}
72	return tmp;
73	}
74
75	if (last_task_used_math == task) {
76	grab_fpu();
77	fpsave(&task->thread.fpu.hard);
78	release_fpu();
79	last_task_used_math = 0;
80	regs->sr \|= SR_FD;
81	}
82
83	tmp = ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)];
84	return tmp;
85	}
86
87	/*
88	* This routine will put a word into the user area in the process kernel stack.
89	*/
90	static inline int put_stack_long(struct task_struct *task, int offset,
91	unsigned long data)
92	{
93	unsigned char *stack;
94
95	stack = (unsigned char *)(task->thread.uregs);
96	stack += offset;
97	(unsigned long ) stack = data;
98	return 0;
99	}
100
101	static inline int
102	put_fpu_long(struct task_struct *task, unsigned long addr, unsigned long data)
103	{
104	struct pt_regs *regs;
105
106	regs = (struct pt_regs)((unsigned char )task + THREAD_SIZE) - 1;
107
108	if (!tsk_used_math(task)) {
109	fpinit(&task->thread.fpu.hard);
110	set_stopped_child_used_math(task);
111	} else if (last_task_used_math == task) {
112	grab_fpu();
113	fpsave(&task->thread.fpu.hard);
114	release_fpu();
115	last_task_used_math = 0;
116	regs->sr \|= SR_FD;
117	}
118
119	((long *)&task->thread.fpu)[addr / sizeof(unsigned long)] = data;
120	return 0;
121	}
122
123	asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
124	{
125	struct task_struct *child;
126	extern void poke_real_address_q(unsigned long long addr, unsigned long long data);
127	#define WPC_DBRMODE 0x0d104008
128	static int first_call = 1;
129	int ret;
130
131	lock_kernel();
132
133	if (first_call) {
134	/* Set WPC.DBRMODE to 0. This makes all debug events get
135	* delivered through RESVEC, i.e. into the handlers in entry.S.
136	* (If the kernel was downloaded using a remote gdb, WPC.DBRMODE
137	* would normally be left set to 1, which makes debug events get
138	* delivered through DBRVEC, i.e. into the remote gdb's
139	* handlers. This prevents ptrace getting them, and confuses
140	* the remote gdb.) */
141	printk("DBRMODE set to 0 to permit native debugging\n");
142	poke_real_address_q(WPC_DBRMODE, 0);
143	first_call = 0;
144	}
145
146	ret = -EPERM;
147	if (request == PTRACE_TRACEME) {
148	/* are we already being traced? */
149	if (current->ptrace & PT_PTRACED)
150	goto out;
151	/* set the ptrace bit in the process flags. */
152	current->ptrace \|= PT_PTRACED;
153	ret = 0;
154	goto out;
155	}
156	ret = -ESRCH;
157	read_lock(&tasklist_lock);
158	child = find_task_by_pid(pid);
159	if (child)
160	get_task_struct(child);
161	read_unlock(&tasklist_lock);
162	if (!child)
163	goto out;
164
165	ret = -EPERM;
166	if (pid == 1) /* you may not mess with init */
167	goto out_tsk;
168
169	if (request == PTRACE_ATTACH) {
170	ret = ptrace_attach(child);
171	goto out_tsk;
172	}
173
174	ret = ptrace_check_attach(child, request == PTRACE_KILL);
175	if (ret < 0)
176	goto out_tsk;
177
178	switch (request) {
179	/* when I and D space are separate, these will need to be fixed. */
180	case PTRACE_PEEKTEXT: /* read word at location addr. */
181	case PTRACE_PEEKDATA: {
182	unsigned long tmp;
183	int copied;
184
185	copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
186	ret = -EIO;
187	if (copied != sizeof(tmp))
188	break;
189	ret = put_user(tmp,(unsigned long *) data);
190	break;
191	}
192
193	/* read the word at location addr in the USER area. */
194	case PTRACE_PEEKUSR: {
195	unsigned long tmp;
196
197	ret = -EIO;
198	if ((addr & 3) \|\| addr < 0)
199	break;
200
201	if (addr < sizeof(struct pt_regs))
202	tmp = get_stack_long(child, addr);
203	else if ((addr >= offsetof(struct user, fpu)) &&
204	(addr < offsetof(struct user, u_fpvalid))) {
205	tmp = get_fpu_long(child, addr - offsetof(struct user, fpu));
206	} else if (addr == offsetof(struct user, u_fpvalid)) {
207	tmp = !!tsk_used_math(child);
208	} else {
209	break;
210	}
211	ret = put_user(tmp, (unsigned long *)data);
212	break;
213	}
214
215	/* when I and D space are separate, this will have to be fixed. */
216	case PTRACE_POKETEXT: /* write the word at location addr. */
217	case PTRACE_POKEDATA:
218	ret = 0;
219	if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
220	break;
221	ret = -EIO;
222	break;
223
224	case PTRACE_POKEUSR:
225	/* write the word at location addr in the USER area. We must
226	disallow any changes to certain SR bits or u_fpvalid, since
227	this could crash the kernel or result in a security
228	loophole. */
229	ret = -EIO;
230	if ((addr & 3) \|\| addr < 0)
231	break;
232
233	if (addr < sizeof(struct pt_regs)) {
234	/* Ignore change of top 32 bits of SR */
235	if (addr == offsetof (struct pt_regs, sr)+4)
236	{
237	ret = 0;
238	break;
239	}
240	/* If lower 32 bits of SR, ignore non-user bits */
241	if (addr == offsetof (struct pt_regs, sr))
242	{
243	long cursr = get_stack_long(child, addr);
244	data &= ~(SR_MASK);
245	data \|= (cursr & SR_MASK);
246	}
247	ret = put_stack_long(child, addr, data);
248	}
249	else if ((addr >= offsetof(struct user, fpu)) &&
250	(addr < offsetof(struct user, u_fpvalid))) {
251	ret = put_fpu_long(child, addr - offsetof(struct user, fpu), data);
252	}
253	break;
254
255	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
256	case PTRACE_CONT: { /* restart after signal. */
257	ret = -EIO;
258	if ((unsigned long) data > _NSIG)
259	break;
260	if (request == PTRACE_SYSCALL)
261	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
262	else
263	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
264	child->exit_code = data;
265	wake_up_process(child);
266	ret = 0;
267	break;
268	}
269
270	/*
271	* make the child exit. Best I can do is send it a sigkill.
272	* perhaps it should be put in the status that it wants to
273	* exit.
274	*/
275	case PTRACE_KILL: {
276	ret = 0;
277	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
278	break;
279	child->exit_code = SIGKILL;
280	wake_up_process(child);
281	break;
282	}
283
284	case PTRACE_SINGLESTEP: { /* set the trap flag. */
285	struct pt_regs *regs;
286
287	ret = -EIO;
288	if ((unsigned long) data > _NSIG)
289	break;
290	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
291	if ((child->ptrace & PT_DTRACE) == 0) {
292	/* Spurious delayed TF traps may occur */
293	child->ptrace \|= PT_DTRACE;
294	}
295
296	regs = child->thread.uregs;
297
298	regs->sr \|= SR_SSTEP; /* auto-resetting upon exception */
299
300	child->exit_code = data;
301	/* give it a chance to run. */
302	wake_up_process(child);
303	ret = 0;
304	break;
305	}
306
307	case PTRACE_DETACH: /* detach a process that was attached. */
308	ret = ptrace_detach(child, data);
309	break;
310
311	default:
312	ret = ptrace_request(child, request, addr, data);
313	break;
314	}
315	out_tsk:
316	put_task_struct(child);
317	out:
318	unlock_kernel();
319	return ret;
320	}
321
322	asmlinkage void syscall_trace(void)
323	{
324	struct task_struct *tsk = current;
325
326	if (!test_thread_flag(TIF_SYSCALL_TRACE))
327	return;
328	if (!(tsk->ptrace & PT_PTRACED))
329	return;
330
331	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD)
332	? 0x80 : 0));
333	/*
334	* this isn't the same as continuing with a signal, but it will do
335	* for normal use. strace only continues with a signal if the
336	* stopping signal is not SIGTRAP. -brl
337	*/
338	if (tsk->exit_code) {
339	send_sig(tsk->exit_code, tsk, 1);
340	tsk->exit_code = 0;
341	}
342	}
343
344	/* Called with interrupts disabled */
345	asmlinkage void do_single_step(unsigned long long vec, struct pt_regs *regs)
346	{
347	/* This is called after a single step exception (DEBUGSS).
348	There is no need to change the PC, as it is a post-execution
349	exception, as entry.S does not do anything to the PC for DEBUGSS.
350	We need to clear the Single Step setting in SR to avoid
351	continually stepping. */
352	local_irq_enable();
353	regs->sr &= ~SR_SSTEP;
354	force_sig(SIGTRAP, current);
355	}
356
357	/* Called with interrupts disabled */
358	asmlinkage void do_software_break_point(unsigned long long vec,
359	struct pt_regs *regs)
360	{
361	/* We need to forward step the PC, to counteract the backstep done
362	in signal.c. */
363	local_irq_enable();
364	force_sig(SIGTRAP, current);
365	regs->pc += 4;
366	}
367
368	/*
369	* Called by kernel/ptrace.c when detaching..
370	*
371	* Make sure single step bits etc are not set.
372	*/
373	void ptrace_disable(struct task_struct *child)
374	{
375	/* nothing to do.. */
376	}