summaryrefslogtreecommitdiff
path: root/arch/score/kernel/ptrace.c
blob: 8fe7209355aa448b5f49fa6d3d08462c572c4858 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
/*
 * arch/score/kernel/ptrace.c
 *
 * Score Processor version.
 *
 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
 *  Chen Liqin <liqin.chen@sunplusct.com>
 *  Lennox Wu <lennox.wu@sunplusct.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/kernel.h>
#include <linux/ptrace.h>

#include <asm/uaccess.h>

static int is_16bitinsn(unsigned long insn)
{
	if ((insn & INSN32_MASK) == INSN32_MASK)
		return 0;
	else
		return 1;
}

int
read_tsk_long(struct task_struct *child,
		unsigned long addr, unsigned long *res)
{
	int copied;

	copied = access_process_vm(child, addr, res, sizeof(*res), 0);

	return copied != sizeof(*res) ? -EIO : 0;
}

int
read_tsk_short(struct task_struct *child,
		unsigned long addr, unsigned short *res)
{
	int copied;

	copied = access_process_vm(child, addr, res, sizeof(*res), 0);

	return copied != sizeof(*res) ? -EIO : 0;
}

static int
write_tsk_short(struct task_struct *child,
		unsigned long addr, unsigned short val)
{
	int copied;

	copied = access_process_vm(child, addr, &val, sizeof(val), 1);

	return copied != sizeof(val) ? -EIO : 0;
}

static int
write_tsk_long(struct task_struct *child,
		unsigned long addr, unsigned long val)
{
	int copied;

	copied = access_process_vm(child, addr, &val, sizeof(val), 1);

	return copied != sizeof(val) ? -EIO : 0;
}

void set_single_step(struct task_struct *child)
{
	/* far_epc is the target of branch */
	unsigned int epc, far_epc = 0;
	unsigned long epc_insn, far_epc_insn;
	int ninsn_type;			/* next insn type 0=16b, 1=32b */
	unsigned int tmp, tmp2;
	struct pt_regs *regs = task_pt_regs(child);
	child->thread.single_step = 1;
	child->thread.ss_nextcnt = 1;
	epc = regs->cp0_epc;

	read_tsk_long(child, epc, &epc_insn);

	if (is_16bitinsn(epc_insn)) {
		if ((epc_insn & J16M) == J16) {
			tmp = epc_insn & 0xFFE;
			epc = (epc & 0xFFFFF000) | tmp;
		} else if ((epc_insn & B16M) == B16) {
			child->thread.ss_nextcnt = 2;
			tmp = (epc_insn & 0xFF) << 1;
			tmp = tmp << 23;
			tmp = (unsigned int)((int) tmp >> 23);
			far_epc = epc + tmp;
			epc += 2;
		} else if ((epc_insn & BR16M) == BR16) {
			child->thread.ss_nextcnt = 2;
			tmp = (epc_insn >> 4) & 0xF;
			far_epc = regs->regs[tmp];
			epc += 2;
		} else
			epc += 2;
	} else {
		if ((epc_insn & J32M) == J32) {
			tmp = epc_insn & 0x03FFFFFE;
			tmp2 = tmp & 0x7FFF;
			tmp = (((tmp >> 16) & 0x3FF) << 15) | tmp2;
			epc = (epc & 0xFFC00000) | tmp;
		} else if ((epc_insn & B32M) == B32) {
			child->thread.ss_nextcnt = 2;
			tmp = epc_insn & 0x03FFFFFE;	/* discard LK bit */
			tmp2 = tmp & 0x3FF;
			tmp = (((tmp >> 16) & 0x3FF) << 10) | tmp2; /* 20bit */
			tmp = tmp << 12;
			tmp = (unsigned int)((int) tmp >> 12);
			far_epc = epc + tmp;
			epc += 4;
		} else if ((epc_insn & BR32M) == BR32) {
			child->thread.ss_nextcnt = 2;
			tmp = (epc_insn >> 16) & 0x1F;
			far_epc = regs->regs[tmp];
			epc += 4;
		} else
			epc += 4;
	}

	if (child->thread.ss_nextcnt == 1) {
		read_tsk_long(child, epc, &epc_insn);

		if (is_16bitinsn(epc_insn)) {
			write_tsk_short(child, epc, SINGLESTEP16_INSN);
			ninsn_type = 0;
		} else {
			write_tsk_long(child, epc, SINGLESTEP32_INSN);
			ninsn_type = 1;
		}

		if (ninsn_type == 0) {  /* 16bits */
			child->thread.insn1_type = 0;
			child->thread.addr1 = epc;
			 /* the insn may have 32bit data */
			child->thread.insn1 = (short)epc_insn;
		} else {
			child->thread.insn1_type = 1;
			child->thread.addr1 = epc;
			child->thread.insn1 = epc_insn;
		}
	} else {
		/* branch! have two target child->thread.ss_nextcnt=2 */
		read_tsk_long(child, epc, &epc_insn);
		read_tsk_long(child, far_epc, &far_epc_insn);
		if (is_16bitinsn(epc_insn)) {
			write_tsk_short(child, epc, SINGLESTEP16_INSN);
			ninsn_type = 0;
		} else {
			write_tsk_long(child, epc, SINGLESTEP32_INSN);
			ninsn_type = 1;
		}

		if (ninsn_type == 0) {  /* 16bits */
			child->thread.insn1_type = 0;
			child->thread.addr1 = epc;
			 /* the insn may have 32bit data */
			child->thread.insn1 = (short)epc_insn;
		} else {
			child->thread.insn1_type = 1;
			child->thread.addr1 = epc;
			child->thread.insn1 = epc_insn;
		}

		if (is_16bitinsn(far_epc_insn)) {
			write_tsk_short(child, far_epc, SINGLESTEP16_INSN);
			ninsn_type = 0;
		} else {
			write_tsk_long(child, far_epc, SINGLESTEP32_INSN);
			ninsn_type = 1;
		}

		if (ninsn_type == 0) {  /* 16bits */
			child->thread.insn2_type = 0;
			child->thread.addr2 = far_epc;
			 /* the insn may have 32bit data */
			child->thread.insn2 = (short)far_epc_insn;
		} else {
			child->thread.insn2_type = 1;
			child->thread.addr2 = far_epc;
			child->thread.insn2 = far_epc_insn;
		}
	}
}

void clear_single_step(struct task_struct *child)
{
	if (child->thread.insn1_type == 0)
		write_tsk_short(child, child->thread.addr1,
				child->thread.insn1);

	if (child->thread.insn1_type == 1)
		write_tsk_long(child, child->thread.addr1,
				child->thread.insn1);

	if (child->thread.ss_nextcnt == 2) {	/* branch */
		if (child->thread.insn1_type == 0)
			write_tsk_short(child, child->thread.addr1,
					child->thread.insn1);
		if (child->thread.insn1_type == 1)
			write_tsk_long(child, child->thread.addr1,
					child->thread.insn1);
		if (child->thread.insn2_type == 0)
			write_tsk_short(child, child->thread.addr2,
					child->thread.insn2);
		if (child->thread.insn2_type == 1)
			write_tsk_long(child, child->thread.addr2,
					child->thread.insn2);
	}

	child->thread.single_step = 0;
	child->thread.ss_nextcnt = 0;
}


void ptrace_disable(struct task_struct *child) {}

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

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

		/* set the ptrace bit in the process flags. */
		current->ptrace |= PT_PTRACED;
		return 0;
	}

	ret = -ESRCH;
	if (!child)
		return ret;

	ret = -EPERM;

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

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

	switch (request) {
	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);
		return ret;
	}

	/* Read the word at location addr in the USER area.  */
	case PTRACE_PEEKUSR: {
		struct pt_regs *regs;
		unsigned long tmp;

		regs = task_pt_regs(child);

		tmp = 0;  /* Default return value. */
		switch (addr) {
		case 0 ... 31:
			tmp = regs->regs[addr];
			break;
		case PC:
			tmp = regs->cp0_epc;
			break;
		case ECR:
			tmp = regs->cp0_ecr;
			break;
		case EMA:
			tmp = regs->cp0_ema;
			break;
		case CEH:
			tmp = regs->ceh;
			break;
		case CEL:
			tmp = regs->cel;
			break;
		case CONDITION:
			tmp = regs->cp0_condition;
			break;
		case PSR:
			tmp = regs->cp0_psr;
			break;
		case COUNTER:
			tmp = regs->sr0;
			break;
		case LDCR:
			tmp = regs->sr1;
			break;
		case STCR:
			tmp = regs->sr2;
			break;
		default:
			tmp = 0;
			return -EIO;
		}

		ret = put_user(tmp, (unsigned long *) data);
		return ret;
	}

	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;
		return ret;

	case PTRACE_POKEUSR: {
		struct pt_regs *regs;
		ret = 0;
		regs = task_pt_regs(child);

		switch (addr) {
		case 0 ... 31:
			regs->regs[addr] = data;
			break;
		case PC:
			regs->cp0_epc = data;
			break;
		case CEH:
			regs->ceh = data;
			break;
		case CEL:
			regs->cel = data;
			break;
		case CONDITION:
			regs->cp0_condition = data;
			break;
		case PSR:
		case COUNTER:
		case STCR:
		case LDCR:
			break; /* user can't write the reg */
		default:
			/* The rest are not allowed. */
			ret = -EIO;
			break;
		}
		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);

		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->state == EXIT_ZOMBIE)	/* already dead. */
			break;
		child->exit_code = SIGKILL;
		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: /* detach a process that was attached. */
		ret = ptrace_detach(child, data);
		break;

	case PTRACE_SETOPTIONS:
		if (data & PTRACE_O_TRACESYSGOOD)
			child->ptrace |= PT_TRACESYSGOOD;
		else
			child->ptrace &= ~PT_TRACESYSGOOD;
		ret = 0;
		break;

	default:
		ret = -EIO;
		break;
	}

	return ret;
}

/*
 * Notification of system call entry/exit
 * - triggered by current->work.syscall_trace
 */
asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
{
	if (!(current->ptrace & PT_PTRACED))
		return;

	if (!test_thread_flag(TIF_SYSCALL_TRACE))
		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) ?
			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;
	}
}