summaryrefslogtreecommitdiffstats
path: root/arch/arc/kernel/ptrace.c
blob: e0c233c178b1aec3ea5e6fe3be9cac851839684c (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
 */

#include <linux/ptrace.h>
#include <linux/sched/task_stack.h>
#include <linux/regset.h>
#include <linux/unistd.h>
#include <linux/elf.h>

#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>

struct pt_regs_offset {
	const char *name;
	int offset;
};

#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
#define REG_OFFSET_END {.name = NULL, .offset = 0}

#ifdef CONFIG_ISA_ARCOMPACT
static const struct pt_regs_offset regoffset_table[] = {
	REG_OFFSET_NAME(bta),
	REG_OFFSET_NAME(lp_start),
	REG_OFFSET_NAME(lp_end),
	REG_OFFSET_NAME(lp_count),
	REG_OFFSET_NAME(status32),
	REG_OFFSET_NAME(ret),
	REG_OFFSET_NAME(blink),
	REG_OFFSET_NAME(fp),
	REG_OFFSET_NAME(r26),
	REG_OFFSET_NAME(r12),
	REG_OFFSET_NAME(r11),
	REG_OFFSET_NAME(r10),
	REG_OFFSET_NAME(r9),
	REG_OFFSET_NAME(r8),
	REG_OFFSET_NAME(r7),
	REG_OFFSET_NAME(r6),
	REG_OFFSET_NAME(r5),
	REG_OFFSET_NAME(r4),
	REG_OFFSET_NAME(r3),
	REG_OFFSET_NAME(r2),
	REG_OFFSET_NAME(r1),
	REG_OFFSET_NAME(r0),
	REG_OFFSET_NAME(sp),
	REG_OFFSET_NAME(orig_r0),
	REG_OFFSET_NAME(ecr),
	REG_OFFSET_END,
};

#else

static const struct pt_regs_offset regoffset_table[] = {
	REG_OFFSET_NAME(orig_r0),
	REG_OFFSET_NAME(ecr),
	REG_OFFSET_NAME(bta),
	REG_OFFSET_NAME(r26),
	REG_OFFSET_NAME(fp),
	REG_OFFSET_NAME(sp),
	REG_OFFSET_NAME(r12),
	REG_OFFSET_NAME(r30),
#ifdef CONFIG_ARC_HAS_ACCL_REGS
	REG_OFFSET_NAME(r58),
	REG_OFFSET_NAME(r59),
#endif
#ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
	REG_OFFSET_NAME(DSP_CTRL),
#endif
	REG_OFFSET_NAME(r0),
	REG_OFFSET_NAME(r1),
	REG_OFFSET_NAME(r2),
	REG_OFFSET_NAME(r3),
	REG_OFFSET_NAME(r4),
	REG_OFFSET_NAME(r5),
	REG_OFFSET_NAME(r6),
	REG_OFFSET_NAME(r7),
	REG_OFFSET_NAME(r8),
	REG_OFFSET_NAME(r9),
	REG_OFFSET_NAME(r10),
	REG_OFFSET_NAME(r11),
	REG_OFFSET_NAME(blink),
	REG_OFFSET_NAME(lp_end),
	REG_OFFSET_NAME(lp_start),
	REG_OFFSET_NAME(lp_count),
	REG_OFFSET_NAME(ei),
	REG_OFFSET_NAME(ldi),
	REG_OFFSET_NAME(jli),
	REG_OFFSET_NAME(ret),
	REG_OFFSET_NAME(status32),
	REG_OFFSET_END,
};
#endif

static struct callee_regs *task_callee_regs(struct task_struct *tsk)
{
	struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
	return tmp;
}

static int genregs_get(struct task_struct *target,
		       const struct user_regset *regset,
		       struct membuf to)
{
	const struct pt_regs *ptregs = task_pt_regs(target);
	const struct callee_regs *cregs = task_callee_regs(target);
	unsigned int stop_pc_val;

	membuf_zero(&to, 4);	// pad
	membuf_store(&to, ptregs->bta);
	membuf_store(&to, ptregs->lp_start);
	membuf_store(&to, ptregs->lp_end);
	membuf_store(&to, ptregs->lp_count);
	membuf_store(&to, ptregs->status32);
	membuf_store(&to, ptregs->ret);
	membuf_store(&to, ptregs->blink);
	membuf_store(&to, ptregs->fp);
	membuf_store(&to, ptregs->r26);	// gp
	membuf_store(&to, ptregs->r12);
	membuf_store(&to, ptregs->r11);
	membuf_store(&to, ptregs->r10);
	membuf_store(&to, ptregs->r9);
	membuf_store(&to, ptregs->r8);
	membuf_store(&to, ptregs->r7);
	membuf_store(&to, ptregs->r6);
	membuf_store(&to, ptregs->r5);
	membuf_store(&to, ptregs->r4);
	membuf_store(&to, ptregs->r3);
	membuf_store(&to, ptregs->r2);
	membuf_store(&to, ptregs->r1);
	membuf_store(&to, ptregs->r0);
	membuf_store(&to, ptregs->sp);
	membuf_zero(&to, 4);	// pad2
	membuf_store(&to, cregs->r25);
	membuf_store(&to, cregs->r24);
	membuf_store(&to, cregs->r23);
	membuf_store(&to, cregs->r22);
	membuf_store(&to, cregs->r21);
	membuf_store(&to, cregs->r20);
	membuf_store(&to, cregs->r19);
	membuf_store(&to, cregs->r18);
	membuf_store(&to, cregs->r17);
	membuf_store(&to, cregs->r16);
	membuf_store(&to, cregs->r15);
	membuf_store(&to, cregs->r14);
	membuf_store(&to, cregs->r13);
	membuf_store(&to, target->thread.fault_address); // efa

	if (in_brkpt_trap(ptregs)) {
		stop_pc_val = target->thread.fault_address;
		pr_debug("\t\tstop_pc (brk-pt)\n");
	} else {
		stop_pc_val = ptregs->ret;
		pr_debug("\t\tstop_pc (others)\n");
	}

	return membuf_store(&to, stop_pc_val); // stop_pc
}

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)
{
	const struct pt_regs *ptregs = task_pt_regs(target);
	const struct callee_regs *cregs = task_callee_regs(target);
	int ret = 0;

#define REG_IN_CHUNK(FIRST, NEXT, PTR)	\
	if (!ret)			\
		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
			(void *)(PTR), \
			offsetof(struct user_regs_struct, FIRST), \
			offsetof(struct user_regs_struct, NEXT));

#define REG_IN_ONE(LOC, PTR)		\
	if (!ret)			\
		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
			(void *)(PTR), \
			offsetof(struct user_regs_struct, LOC), \
			offsetof(struct user_regs_struct, LOC) + 4);

#define REG_IGNORE_ONE(LOC)		\
	if (!ret)			\
		user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
			offsetof(struct user_regs_struct, LOC), \
			offsetof(struct user_regs_struct, LOC) + 4);

	REG_IGNORE_ONE(pad);

	REG_IN_ONE(scratch.bta, &ptregs->bta);
	REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
	REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
	REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);

	REG_IGNORE_ONE(scratch.status32);

	REG_IN_ONE(scratch.ret, &ptregs->ret);
	REG_IN_ONE(scratch.blink, &ptregs->blink);
	REG_IN_ONE(scratch.fp, &ptregs->fp);
	REG_IN_ONE(scratch.gp, &ptregs->r26);
	REG_IN_ONE(scratch.r12, &ptregs->r12);
	REG_IN_ONE(scratch.r11, &ptregs->r11);
	REG_IN_ONE(scratch.r10, &ptregs->r10);
	REG_IN_ONE(scratch.r9, &ptregs->r9);
	REG_IN_ONE(scratch.r8, &ptregs->r8);
	REG_IN_ONE(scratch.r7, &ptregs->r7);
	REG_IN_ONE(scratch.r6, &ptregs->r6);
	REG_IN_ONE(scratch.r5, &ptregs->r5);
	REG_IN_ONE(scratch.r4, &ptregs->r4);
	REG_IN_ONE(scratch.r3, &ptregs->r3);
	REG_IN_ONE(scratch.r2, &ptregs->r2);
	REG_IN_ONE(scratch.r1, &ptregs->r1);
	REG_IN_ONE(scratch.r0, &ptregs->r0);
	REG_IN_ONE(scratch.sp, &ptregs->sp);

	REG_IGNORE_ONE(pad2);

	REG_IN_ONE(callee.r25, &cregs->r25);
	REG_IN_ONE(callee.r24, &cregs->r24);
	REG_IN_ONE(callee.r23, &cregs->r23);
	REG_IN_ONE(callee.r22, &cregs->r22);
	REG_IN_ONE(callee.r21, &cregs->r21);
	REG_IN_ONE(callee.r20, &cregs->r20);
	REG_IN_ONE(callee.r19, &cregs->r19);
	REG_IN_ONE(callee.r18, &cregs->r18);
	REG_IN_ONE(callee.r17, &cregs->r17);
	REG_IN_ONE(callee.r16, &cregs->r16);
	REG_IN_ONE(callee.r15, &cregs->r15);
	REG_IN_ONE(callee.r14, &cregs->r14);
	REG_IN_ONE(callee.r13, &cregs->r13);

	REG_IGNORE_ONE(efa);			/* efa update invalid */
	REG_IGNORE_ONE(stop_pc);		/* PC updated via @ret */

	return ret;
}

#ifdef CONFIG_ISA_ARCV2
static int arcv2regs_get(struct task_struct *target,
		       const struct user_regset *regset,
		       struct membuf to)
{
	const struct pt_regs *regs = task_pt_regs(target);

	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
		/*
		 * itemized copy not needed like above as layout of regs (r30,r58,r59)
		 * is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
		 */
		return membuf_write(&to, &regs->r30, sizeof(struct user_regs_arcv2));


	membuf_write(&to, &regs->r30, 4); /* r30 only */
	return membuf_zero(&to, sizeof(struct user_regs_arcv2) - 4);
}

static int arcv2regs_set(struct task_struct *target,
		       const struct user_regset *regset,
		       unsigned int pos, unsigned int count,
		       const void *kbuf, const void __user *ubuf)
{
	const struct pt_regs *regs = task_pt_regs(target);
	int ret, copy_sz;

	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
		copy_sz = sizeof(struct user_regs_arcv2);
	else
		copy_sz = 4;	/* r30 only */

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
				  0, copy_sz);

	return ret;
}

#endif

enum arc_getset {
	REGSET_CMN,
	REGSET_ARCV2,
};

static const struct user_regset arc_regsets[] = {
	[REGSET_CMN] = {
	       .core_note_type = NT_PRSTATUS,
	       .n = ELF_NGREG,
	       .size = sizeof(unsigned long),
	       .align = sizeof(unsigned long),
	       .regset_get = genregs_get,
	       .set = genregs_set,
	},
#ifdef CONFIG_ISA_ARCV2
	[REGSET_ARCV2] = {
	       .core_note_type = NT_ARC_V2,
	       .n = ELF_ARCV2REG,
	       .size = sizeof(unsigned long),
	       .align = sizeof(unsigned long),
	       .regset_get = arcv2regs_get,
	       .set = arcv2regs_set,
	},
#endif
};

static const struct user_regset_view user_arc_view = {
	.name		= "arc",
	.e_machine	= EM_ARC_INUSE,
	.regsets	= arc_regsets,
	.n		= ARRAY_SIZE(arc_regsets)
};

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

void ptrace_disable(struct task_struct *child)
{
}

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

	pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);

	switch (request) {
	case PTRACE_GET_THREAD_AREA:
		ret = put_user(task_thread_info(child)->thr_ptr,
			       (unsigned long __user *)data);
		break;
	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}

	return ret;
}

asmlinkage int syscall_trace_enter(struct pt_regs *regs)
{
	if (test_thread_flag(TIF_SYSCALL_TRACE))
		if (ptrace_report_syscall_entry(regs))
			return ULONG_MAX;

#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
		trace_sys_enter(regs, syscall_get_nr(current, regs));
#endif

	return regs->r8;
}

asmlinkage void syscall_trace_exit(struct pt_regs *regs)
{
	if (test_thread_flag(TIF_SYSCALL_TRACE))
		ptrace_report_syscall_exit(regs, 0);

#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
		trace_sys_exit(regs, regs_return_value(regs));
#endif
}

int regs_query_register_offset(const char *name)
{
	const struct pt_regs_offset *roff;

	for (roff = regoffset_table; roff->name != NULL; roff++)
		if (!strcmp(roff->name, name))
			return roff->offset;
	return -EINVAL;
}

const char *regs_query_register_name(unsigned int offset)
{
	const struct pt_regs_offset *roff;
	for (roff = regoffset_table; roff->name != NULL; roff++)
		if (roff->offset == offset)
			return roff->name;
	return NULL;
}

bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
{
	return (addr & ~(THREAD_SIZE - 1))  ==
		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
}

unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
{
	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);

	addr += n;
	if (regs_within_kernel_stack(regs, (unsigned long)addr))
		return *addr;
	else
		return 0;
}