summaryrefslogtreecommitdiffstats
path: root/arch/loongarch/kernel/ptrace.c
blob: dc2b82ea894cd26c1c3d662e488145d82d1fba0d (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
// SPDX-License-Identifier: GPL-2.0
/*
 * Author: Hanlu Li <lihanlu@loongson.cn>
 *         Huacai Chen <chenhuacai@loongson.cn>
 *
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 *
 * Derived from MIPS:
 * Copyright (C) 1992 Ross Biro
 * Copyright (C) Linus Torvalds
 * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
 * Copyright (C) 1996 David S. Miller
 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 1999 MIPS Technologies, Inc.
 * Copyright (C) 2000 Ulf Carlsson
 */
#include <linux/kernel.h>
#include <linux/audit.h>
#include <linux/compiler.h>
#include <linux/context_tracking.h>
#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/ptrace.h>
#include <linux/regset.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/security.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/seccomp.h>
#include <linux/uaccess.h>

#include <asm/byteorder.h>
#include <asm/cpu.h>
#include <asm/cpu-info.h>
#include <asm/fpu.h>
#include <asm/loongarch.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/reg.h>
#include <asm/syscall.h>

static void init_fp_ctx(struct task_struct *target)
{
	/* The target already has context */
	if (tsk_used_math(target))
		return;

	/* Begin with data registers set to all 1s... */
	memset(&target->thread.fpu.fpr, ~0, sizeof(target->thread.fpu.fpr));
	set_stopped_child_used_math(target);
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
	/* Don't load the watchpoint registers for the ex-child. */
	clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
}

/* regset get/set implementations */

static int gpr_get(struct task_struct *target,
		   const struct user_regset *regset,
		   struct membuf to)
{
	int r;
	struct pt_regs *regs = task_pt_regs(target);

	r = membuf_write(&to, &regs->regs, sizeof(u64) * GPR_NUM);
	r = membuf_write(&to, &regs->orig_a0, sizeof(u64));
	r = membuf_write(&to, &regs->csr_era, sizeof(u64));
	r = membuf_write(&to, &regs->csr_badvaddr, sizeof(u64));

	return r;
}

static int gpr_set(struct task_struct *target,
		   const struct user_regset *regset,
		   unsigned int pos, unsigned int count,
		   const void *kbuf, const void __user *ubuf)
{
	int err;
	int a0_start = sizeof(u64) * GPR_NUM;
	int era_start = a0_start + sizeof(u64);
	int badvaddr_start = era_start + sizeof(u64);
	struct pt_regs *regs = task_pt_regs(target);

	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &regs->regs,
				 0, a0_start);
	err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &regs->orig_a0,
				 a0_start, a0_start + sizeof(u64));
	err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &regs->csr_era,
				 era_start, era_start + sizeof(u64));
	err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 &regs->csr_badvaddr,
				 badvaddr_start, badvaddr_start + sizeof(u64));

	return err;
}


/*
 * Get the general floating-point registers.
 */
static int gfpr_get(struct task_struct *target, struct membuf *to)
{
	return membuf_write(to, &target->thread.fpu.fpr,
			    sizeof(elf_fpreg_t) * NUM_FPU_REGS);
}

static int gfpr_get_simd(struct task_struct *target, struct membuf *to)
{
	int i, r;
	u64 fpr_val;

	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
	for (i = 0; i < NUM_FPU_REGS; i++) {
		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
		r = membuf_write(to, &fpr_val, sizeof(elf_fpreg_t));
	}

	return r;
}

/*
 * Choose the appropriate helper for general registers, and then copy
 * the FCC and FCSR registers separately.
 */
static int fpr_get(struct task_struct *target,
		   const struct user_regset *regset,
		   struct membuf to)
{
	int r;

	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
		r = gfpr_get(target, &to);
	else
		r = gfpr_get_simd(target, &to);

	r = membuf_write(&to, &target->thread.fpu.fcc, sizeof(target->thread.fpu.fcc));
	r = membuf_write(&to, &target->thread.fpu.fcsr, sizeof(target->thread.fpu.fcsr));

	return r;
}

static int gfpr_set(struct task_struct *target,
		    unsigned int *pos, unsigned int *count,
		    const void **kbuf, const void __user **ubuf)
{
	return user_regset_copyin(pos, count, kbuf, ubuf,
				  &target->thread.fpu.fpr,
				  0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
}

static int gfpr_set_simd(struct task_struct *target,
		       unsigned int *pos, unsigned int *count,
		       const void **kbuf, const void __user **ubuf)
{
	int i, err;
	u64 fpr_val;

	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
	for (i = 0; i < NUM_FPU_REGS && *count > 0; i++) {
		err = user_regset_copyin(pos, count, kbuf, ubuf,
					 &fpr_val, i * sizeof(elf_fpreg_t),
					 (i + 1) * sizeof(elf_fpreg_t));
		if (err)
			return err;
		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
	}

	return 0;
}

/*
 * Choose the appropriate helper for general registers, and then copy
 * the FCC register separately.
 */
static int fpr_set(struct task_struct *target,
		   const struct user_regset *regset,
		   unsigned int pos, unsigned int count,
		   const void *kbuf, const void __user *ubuf)
{
	const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t);
	const int fcsr_start = fcc_start + sizeof(u64);
	int err;

	BUG_ON(count % sizeof(elf_fpreg_t));
	if (pos + count > sizeof(elf_fpregset_t))
		return -EIO;

	init_fp_ctx(target);

	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
		err = gfpr_set(target, &pos, &count, &kbuf, &ubuf);
	else
		err = gfpr_set_simd(target, &pos, &count, &kbuf, &ubuf);
	if (err)
		return err;

	err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				  &target->thread.fpu.fcc, fcc_start,
				  fcc_start + sizeof(u64));
	err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				  &target->thread.fpu.fcsr, fcsr_start,
				  fcsr_start + sizeof(u32));

	return err;
}

static int cfg_get(struct task_struct *target,
		   const struct user_regset *regset,
		   struct membuf to)
{
	int i, r;
	u32 cfg_val;

	i = 0;
	while (to.left > 0) {
		cfg_val = read_cpucfg(i++);
		r = membuf_write(&to, &cfg_val, sizeof(u32));
	}

	return r;
}

/*
 * CFG registers are read-only.
 */
static int cfg_set(struct task_struct *target,
		   const struct user_regset *regset,
		   unsigned int pos, unsigned int count,
		   const void *kbuf, const void __user *ubuf)
{
	return 0;
}

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

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

static const struct pt_regs_offset regoffset_table[] = {
	REG_OFFSET_NAME(r0, regs[0]),
	REG_OFFSET_NAME(r1, regs[1]),
	REG_OFFSET_NAME(r2, regs[2]),
	REG_OFFSET_NAME(r3, regs[3]),
	REG_OFFSET_NAME(r4, regs[4]),
	REG_OFFSET_NAME(r5, regs[5]),
	REG_OFFSET_NAME(r6, regs[6]),
	REG_OFFSET_NAME(r7, regs[7]),
	REG_OFFSET_NAME(r8, regs[8]),
	REG_OFFSET_NAME(r9, regs[9]),
	REG_OFFSET_NAME(r10, regs[10]),
	REG_OFFSET_NAME(r11, regs[11]),
	REG_OFFSET_NAME(r12, regs[12]),
	REG_OFFSET_NAME(r13, regs[13]),
	REG_OFFSET_NAME(r14, regs[14]),
	REG_OFFSET_NAME(r15, regs[15]),
	REG_OFFSET_NAME(r16, regs[16]),
	REG_OFFSET_NAME(r17, regs[17]),
	REG_OFFSET_NAME(r18, regs[18]),
	REG_OFFSET_NAME(r19, regs[19]),
	REG_OFFSET_NAME(r20, regs[20]),
	REG_OFFSET_NAME(r21, regs[21]),
	REG_OFFSET_NAME(r22, regs[22]),
	REG_OFFSET_NAME(r23, regs[23]),
	REG_OFFSET_NAME(r24, regs[24]),
	REG_OFFSET_NAME(r25, regs[25]),
	REG_OFFSET_NAME(r26, regs[26]),
	REG_OFFSET_NAME(r27, regs[27]),
	REG_OFFSET_NAME(r28, regs[28]),
	REG_OFFSET_NAME(r29, regs[29]),
	REG_OFFSET_NAME(r30, regs[30]),
	REG_OFFSET_NAME(r31, regs[31]),
	REG_OFFSET_NAME(orig_a0, orig_a0),
	REG_OFFSET_NAME(csr_era, csr_era),
	REG_OFFSET_NAME(csr_badvaddr, csr_badvaddr),
	REG_OFFSET_NAME(csr_crmd, csr_crmd),
	REG_OFFSET_NAME(csr_prmd, csr_prmd),
	REG_OFFSET_NAME(csr_euen, csr_euen),
	REG_OFFSET_NAME(csr_ecfg, csr_ecfg),
	REG_OFFSET_NAME(csr_estat, csr_estat),
	REG_OFFSET_END,
};

/**
 * regs_query_register_offset() - query register offset from its name
 * @name:       the name of a register
 *
 * regs_query_register_offset() returns the offset of a register in struct
 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 */
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;
}

enum loongarch_regset {
	REGSET_GPR,
	REGSET_FPR,
	REGSET_CPUCFG,
};

static const struct user_regset loongarch64_regsets[] = {
	[REGSET_GPR] = {
		.core_note_type	= NT_PRSTATUS,
		.n		= ELF_NGREG,
		.size		= sizeof(elf_greg_t),
		.align		= sizeof(elf_greg_t),
		.regset_get	= gpr_get,
		.set		= gpr_set,
	},
	[REGSET_FPR] = {
		.core_note_type	= NT_PRFPREG,
		.n		= ELF_NFPREG,
		.size		= sizeof(elf_fpreg_t),
		.align		= sizeof(elf_fpreg_t),
		.regset_get	= fpr_get,
		.set		= fpr_set,
	},
	[REGSET_CPUCFG] = {
		.core_note_type	= NT_LOONGARCH_CPUCFG,
		.n		= 64,
		.size		= sizeof(u32),
		.align		= sizeof(u32),
		.regset_get	= cfg_get,
		.set		= cfg_set,
	},
};

static const struct user_regset_view user_loongarch64_view = {
	.name		= "loongarch64",
	.e_machine	= ELF_ARCH,
	.regsets	= loongarch64_regsets,
	.n		= ARRAY_SIZE(loongarch64_regsets),
};


const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
	return &user_loongarch64_view;
}

static inline int read_user(struct task_struct *target, unsigned long addr,
			    unsigned long __user *data)
{
	unsigned long tmp = 0;

	switch (addr) {
	case 0 ... 31:
		tmp = task_pt_regs(target)->regs[addr];
		break;
	case ARG0:
		tmp = task_pt_regs(target)->orig_a0;
		break;
	case PC:
		tmp = task_pt_regs(target)->csr_era;
		break;
	case BADVADDR:
		tmp = task_pt_regs(target)->csr_badvaddr;
		break;
	default:
		return -EIO;
	}

	return put_user(tmp, data);
}

static inline int write_user(struct task_struct *target, unsigned long addr,
			    unsigned long data)
{
	switch (addr) {
	case 0 ... 31:
		task_pt_regs(target)->regs[addr] = data;
		break;
	case ARG0:
		task_pt_regs(target)->orig_a0 = data;
		break;
	case PC:
		task_pt_regs(target)->csr_era = data;
		break;
	case BADVADDR:
		task_pt_regs(target)->csr_badvaddr = data;
		break;
	default:
		return -EIO;
	}

	return 0;
}

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_PEEKUSR:
		ret = read_user(child, addr, datap);
		break;

	case PTRACE_POKEUSR:
		ret = write_user(child, addr, data);
		break;

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

	return ret;
}