summaryrefslogtreecommitdiffstats
path: root/arch/score/kernel/ptrace.c
blob: d8455e60bce06cec81fc60f832ff0e0105050126 (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
/*
 * 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/elf.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/ptrace.h>
#include <linux/regset.h>
#include <linux/sched/task_stack.h>

#include <linux/uaccess.h>

/*
 * retrieve the contents of SCORE userspace general registers
 */
static int genregs_get(struct task_struct *target,
		       const struct user_regset *regset,
		       unsigned int pos, unsigned int count,
		       void *kbuf, void __user *ubuf)
{
	const struct pt_regs *regs = task_pt_regs(target);
	int ret;

	/* skip 9 * sizeof(unsigned long) not use for pt_regs */
	ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
					0, offsetof(struct pt_regs, regs));

	/* r0 - r31, cel, ceh, sr0, sr1, sr2, epc, ema, psr, ecr, condition */
	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				  regs->regs,
				  offsetof(struct pt_regs, regs),
				  offsetof(struct pt_regs, cp0_condition));

	if (!ret)
		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
						sizeof(struct pt_regs), -1);

	return ret;
}

/*
 * update the contents of the SCORE userspace general registers
 */
static int genregs_set(struct task_struct *target,
		       const struct user_regset *regset,
		       unsigned int pos, unsigned int count,
		       const void *kbuf, const void __user *ubuf)
{
	struct pt_regs *regs = task_pt_regs(target);
	int ret;

	/* skip 9 * sizeof(unsigned long) */
	ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
					0, offsetof(struct pt_regs, regs));

	/* r0 - r31, cel, ceh, sr0, sr1, sr2, epc, ema, psr, ecr, condition */
	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				  regs->regs,
				  offsetof(struct pt_regs, regs),
				  offsetof(struct pt_regs, cp0_condition));

	if (!ret)
		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
						sizeof(struct pt_regs), -1);

	return ret;
}

/*
 * Define the register sets available on the score7 under Linux
 */
enum score7_regset {
	REGSET_GENERAL,
};

static const struct user_regset score7_regsets[] = {
	[REGSET_GENERAL] = {
		.core_note_type	= NT_PRSTATUS,
		.n		= ELF_NGREG,
		.size		= sizeof(long),
		.align		= sizeof(long),
		.get		= genregs_get,
		.set		= genregs_set,
	},
};

static const struct user_regset_view user_score_native_view = {
	.name		= "score7",
	.e_machine	= EM_SCORE7,
	.regsets	= score7_regsets,
	.n		= ARRAY_SIZE(score7_regsets),
};

const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
	return &user_score_native_view;
}

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), FOLL_FORCE);

	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), FOLL_FORCE);

	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),
			FOLL_FORCE | FOLL_WRITE);

	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),
			FOLL_FORCE | FOLL_WRITE);

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

void user_enable_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 user_disable_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)
{
	user_disable_single_step(child);
}

long
arch_ptrace(struct task_struct *child, long request,
	    unsigned long addr, unsigned long data)
{
	int ret;
	unsigned long __user *datap = (void __user *)data;

	switch (request) {
	case PTRACE_GETREGS:
		ret = copy_regset_to_user(child, &user_score_native_view,
						REGSET_GENERAL,
						0, sizeof(struct pt_regs),
						datap);
		break;

	case PTRACE_SETREGS:
		ret = copy_regset_from_user(child, &user_score_native_view,
						REGSET_GENERAL,
						0, sizeof(struct pt_regs),
						datap);
		break;

	default:
		ret = ptrace_request(child, request, addr, data);
		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;
	}
}