aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mn10300/kernel/ptrace.c
blob: 5bd58514e739729a7fb5722b39b1704df9f6dfeb (plain) (blame)
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
/* MN10300 Process tracing
 *
 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Modified by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#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/regset.h>
#include <linux/elf.h>
#include <linux/tracehook.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/cacheflush.h>
#include <asm/fpu.h>
#include <asm/asm-offsets.h>

/*
 * translate ptrace register IDs into struct pt_regs offsets
 */
static const u8 ptrace_regid_to_frame[] = {
	[PT_A3 << 2]		= REG_A3,
	[PT_A2 << 2]		= REG_A2,
	[PT_D3 << 2]		= REG_D3,
	[PT_D2 << 2]		= REG_D2,
	[PT_MCVF << 2]		= REG_MCVF,
	[PT_MCRL << 2]		= REG_MCRL,
	[PT_MCRH << 2]		= REG_MCRH,
	[PT_MDRQ << 2]		= REG_MDRQ,
	[PT_E1 << 2]		= REG_E1,
	[PT_E0 << 2]		= REG_E0,
	[PT_E7 << 2]		= REG_E7,
	[PT_E6 << 2]		= REG_E6,
	[PT_E5 << 2]		= REG_E5,
	[PT_E4 << 2]		= REG_E4,
	[PT_E3 << 2]		= REG_E3,
	[PT_E2 << 2]		= REG_E2,
	[PT_SP << 2]		= REG_SP,
	[PT_LAR << 2]		= REG_LAR,
	[PT_LIR << 2]		= REG_LIR,
	[PT_MDR << 2]		= REG_MDR,
	[PT_A1 << 2]		= REG_A1,
	[PT_A0 << 2]		= REG_A0,
	[PT_D1 << 2]		= REG_D1,
	[PT_D0 << 2]		= REG_D0,
	[PT_ORIG_D0 << 2]	= REG_ORIG_D0,
	[PT_EPSW << 2]		= REG_EPSW,
	[PT_PC << 2]		= REG_PC,
};

static inline int get_stack_long(struct task_struct *task, int offset)
{
	return *(unsigned long *)
		((unsigned long) task->thread.uregs + offset);
}

static inline
int put_stack_long(struct task_struct *task, int offset, unsigned long data)
{
	unsigned long stack;

	stack = (unsigned long) task->thread.uregs + offset;
	*(unsigned long *) stack = data;
	return 0;
}

/*
 * retrieve the contents of MN10300 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;

	/* we need to skip regs->next */
	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				  regs, 0, PT_ORIG_D0 * sizeof(long));
	if (ret < 0)
		return ret;

	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				  &regs->orig_d0, PT_ORIG_D0 * sizeof(long),
				  NR_PTREGS * sizeof(long));
	if (ret < 0)
		return ret;

	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
					NR_PTREGS * sizeof(long), -1);
}

/*
 * update the contents of the MN10300 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);
	unsigned long tmp;
	int ret;

	/* we need to skip regs->next */
	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 regs, 0, PT_ORIG_D0 * sizeof(long));
	if (ret < 0)
		return ret;

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &regs->orig_d0, PT_ORIG_D0 * sizeof(long),
				 PT_EPSW * sizeof(long));
	if (ret < 0)
		return ret;

	/* we need to mask off changes to EPSW */
	tmp = regs->epsw;
	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &tmp, PT_EPSW * sizeof(long),
				 PT_PC * sizeof(long));
	tmp &= EPSW_FLAG_V | EPSW_FLAG_C | EPSW_FLAG_N | EPSW_FLAG_Z;
	tmp |= regs->epsw & ~(EPSW_FLAG_V | EPSW_FLAG_C | EPSW_FLAG_N |
			      EPSW_FLAG_Z);
	regs->epsw = tmp;

	if (ret < 0)
		return ret;

	/* and finally load the PC */
	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &regs->pc, PT_PC * sizeof(long),
				 NR_PTREGS * sizeof(long));

	if (ret < 0)
		return ret;

	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
					 NR_PTREGS * sizeof(long), -1);
}

/*
 * retrieve the contents of MN10300 userspace FPU registers
 */
static int fpuregs_get(struct task_struct *target,
		       const struct user_regset *regset,
		       unsigned int pos, unsigned int count,
		       void *kbuf, void __user *ubuf)
{
	const struct fpu_state_struct *fpregs = &target->thread.fpu_state;
	int ret;

	unlazy_fpu(target);

	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				  fpregs, 0, sizeof(*fpregs));
	if (ret < 0)
		return ret;

	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
					sizeof(*fpregs), -1);
}

/*
 * update the contents of the MN10300 userspace FPU registers
 */
static int fpuregs_set(struct task_struct *target,
		       const struct user_regset *regset,
		       unsigned int pos, unsigned int count,
		       const void *kbuf, const void __user *ubuf)
{
	struct fpu_state_struct fpu_state = target->thread.fpu_state;
	int ret;

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &fpu_state, 0, sizeof(fpu_state));
	if (ret < 0)
		return ret;

	fpu_kill_state(target);
	target->thread.fpu_state = fpu_state;
	set_using_fpu(target);

	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
					 sizeof(fpu_state), -1);
}

/*
 * determine if the FPU registers have actually been used
 */
static int fpuregs_active(struct task_struct *target,
			  const struct user_regset *regset)
{
	return is_using_fpu(target) ? regset->n : 0;
}

/*
 * Define the register sets available on the MN10300 under Linux
 */
enum mn10300_regset {
	REGSET_GENERAL,
	REGSET_FPU,
};

static const struct user_regset mn10300_regsets[] = {
	/*
	 * General register format is:
	 *	A3, A2, D3, D2, MCVF, MCRL, MCRH, MDRQ
	 *	E1, E0, E7...E2, SP, LAR, LIR, MDR
	 *	A1, A0, D1, D0, ORIG_D0, EPSW, PC
	 */
	[REGSET_GENERAL] = {
		.core_note_type	= NT_PRSTATUS,
		.n		= ELF_NGREG,
		.size		= sizeof(long),
		.align		= sizeof(long),
		.get		= genregs_get,
		.set		= genregs_set,
	},
	/*
	 * FPU register format is:
	 *	FS0-31, FPCR
	 */
	[REGSET_FPU] = {
		.core_note_type	= NT_PRFPREG,
		.n		= sizeof(struct fpu_state_struct) / sizeof(long),
		.size		= sizeof(long),
		.align		= sizeof(long),
		.get		= fpuregs_get,
		.set		= fpuregs_set,
		.active		= fpuregs_active,
	},
};

static const struct user_regset_view user_mn10300_native_view = {
	.name		= "mn10300",
	.e_machine	= EM_MN10300,
	.regsets	= mn10300_regsets,
	.n		= ARRAY_SIZE(mn10300_regsets),
};

const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
	return &user_mn10300_native_view;
}

/*
 * set the single-step bit
 */
void user_enable_single_step(struct task_struct *child)
{
#ifndef CONFIG_MN10300_USING_JTAG
	struct user *dummy = NULL;
	long tmp;

	tmp = get_stack_long(child, (unsigned long) &dummy->regs.epsw);
	tmp |= EPSW_T;
	put_stack_long(child, (unsigned long) &dummy->regs.epsw, tmp);
#endif
}

/*
 * make sure the single-step bit is not set
 */
void user_disable_single_step(struct task_struct *child)
{
#ifndef CONFIG_MN10300_USING_JTAG
	struct user *dummy = NULL;
	long tmp;

	tmp = get_stack_long(child, (unsigned long) &dummy->regs.epsw);
	tmp &= ~EPSW_T;
	put_stack_long(child, (unsigned long) &dummy->regs.epsw, tmp);
#endif
}

void ptrace_disable(struct task_struct *child)
{
	user_disable_single_step(child);
}

/*
 * handle the arch-specific side of process tracing
 */
long arch_ptrace(struct task_struct *child, long request,
		 unsigned long addr, unsigned long data)
{
	unsigned long tmp;
	int ret;
	unsigned long __user *datap = (unsigned long __user *) data;

	switch (request) {
	/* read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR:
		ret = -EIO;
		if ((addr & 3) || addr > sizeof(struct user) - 3)
			break;

		tmp = 0;  /* Default return condition */
		if (addr < NR_PTREGS << 2)
			tmp = get_stack_long(child,
					     ptrace_regid_to_frame[addr]);
		ret = put_user(tmp, datap);
		break;

		/* write the word at location addr in the USER area */
	case PTRACE_POKEUSR:
		ret = -EIO;
		if ((addr & 3) || addr > sizeof(struct user) - 3)
			break;

		ret = 0;
		if (addr < NR_PTREGS << 2)
			ret = put_stack_long(child, ptrace_regid_to_frame[addr],
					     data);
		break;

	case PTRACE_GETREGS:	/* Get all integer regs from the child. */
		return copy_regset_to_user(child, &user_mn10300_native_view,
					   REGSET_GENERAL,
					   0, NR_PTREGS * sizeof(long),
					   datap);

	case PTRACE_SETREGS:	/* Set all integer regs in the child. */
		return copy_regset_from_user(child, &user_mn10300_native_view,
					     REGSET_GENERAL,
					     0, NR_PTREGS * sizeof(long),
					     datap);

	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
		return copy_regset_to_user(child, &user_mn10300_native_view,
					   REGSET_FPU,
					   0, sizeof(struct fpu_state_struct),
					   datap);

	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
		return copy_regset_from_user(child, &user_mn10300_native_view,
					     REGSET_FPU,
					     0, sizeof(struct fpu_state_struct),
					     datap);

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

	return ret;
}

/*
 * handle tracing of system call entry
 * - return the revised system call number or ULONG_MAX to cause ENOSYS
 */
asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs)
{
	if (tracehook_report_syscall_entry(regs))
		/* tracing decided this syscall should not happen, so
		 * We'll return a bogus call number to get an ENOSYS
		 * error, but leave the original number in
		 * regs->orig_d0
		 */
		return ULONG_MAX;

	return regs->orig_d0;
}

/*
 * handle tracing of system call exit
 */
asmlinkage void syscall_trace_exit(struct pt_regs *regs)
{
	tracehook_report_syscall_exit(regs, 0);
}