summaryrefslogtreecommitdiffstats
path: root/arch/sh/kernel/ptrace_32.c
blob: 90a15d29feebdceb4aa019bc7cc8e4f649f08721 (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
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
/*
 * SuperH process tracing
 *
 * Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
 * Copyright (C) 2002 - 2009  Paul Mundt
 *
 * Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#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/security.h>
#include <linux/signal.h>
#include <linux/io.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/tracehook.h>
#include <linux/elf.h>
#include <linux/regset.h>
#include <linux/hw_breakpoint.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>
#include <asm/syscalls.h>
#include <asm/fpu.h>

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

/*
 * This routine will get a word off of the process kernel stack.
 */
static inline int get_stack_long(struct task_struct *task, int offset)
{
	unsigned char *stack;

	stack = (unsigned char *)task_pt_regs(task);
	stack += offset;
	return (*((int *)stack));
}

/*
 * This routine will put a word on the process kernel stack.
 */
static inline int put_stack_long(struct task_struct *task, int offset,
				 unsigned long data)
{
	unsigned char *stack;

	stack = (unsigned char *)task_pt_regs(task);
	stack += offset;
	*(unsigned long *) stack = data;
	return 0;
}

void ptrace_triggered(struct perf_event *bp, int nmi,
		      struct perf_sample_data *data, struct pt_regs *regs)
{
	struct perf_event_attr attr;

	/*
	 * Disable the breakpoint request here since ptrace has defined a
	 * one-shot behaviour for breakpoint exceptions.
	 */
	attr = bp->attr;
	attr.disabled = true;
	modify_user_hw_breakpoint(bp, &attr);
}

static int set_single_step(struct task_struct *tsk, unsigned long addr)
{
	struct thread_struct *thread = &tsk->thread;
	struct perf_event *bp;
	struct perf_event_attr attr;

	bp = thread->ptrace_bps[0];
	if (!bp) {
		ptrace_breakpoint_init(&attr);

		attr.bp_addr = addr;
		attr.bp_len = HW_BREAKPOINT_LEN_2;
		attr.bp_type = HW_BREAKPOINT_R;

		bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk);
		if (IS_ERR(bp))
			return PTR_ERR(bp);

		thread->ptrace_bps[0] = bp;
	} else {
		int err;

		attr = bp->attr;
		attr.bp_addr = addr;
		err = modify_user_hw_breakpoint(bp, &attr);
		if (unlikely(err))
			return err;
	}

	return 0;
}

void user_enable_single_step(struct task_struct *child)
{
	unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc));

	set_tsk_thread_flag(child, TIF_SINGLESTEP);

	set_single_step(child, pc);
}

void user_disable_single_step(struct task_struct *child)
{
	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
	user_disable_single_step(child);
}

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;

	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				  regs->regs,
				  0, 16 * sizeof(unsigned long));
	if (!ret)
		/* PC, PR, SR, GBR, MACH, MACL, TRA */
		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
					  &regs->pc,
					  offsetof(struct pt_regs, pc),
					  sizeof(struct pt_regs));
	if (!ret)
		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
					       sizeof(struct pt_regs), -1);

	return ret;
}

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;

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				 regs->regs,
				 0, 16 * sizeof(unsigned long));
	if (!ret && count > 0)
		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
					 &regs->pc,
					 offsetof(struct pt_regs, pc),
					 sizeof(struct pt_regs));
	if (!ret)
		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
						sizeof(struct pt_regs), -1);

	return ret;
}

#ifdef CONFIG_SH_FPU
int fpregs_get(struct task_struct *target,
	       const struct user_regset *regset,
	       unsigned int pos, unsigned int count,
	       void *kbuf, void __user *ubuf)
{
	int ret;

	ret = init_fpu(target);
	if (ret)
		return ret;

	if ((boot_cpu_data.flags & CPU_HAS_FPU))
		return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
					   &target->thread.xstate->hardfpu, 0, -1);

	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
				   &target->thread.xstate->softfpu, 0, -1);
}

static int fpregs_set(struct task_struct *target,
		       const struct user_regset *regset,
		       unsigned int pos, unsigned int count,
		       const void *kbuf, const void __user *ubuf)
{
	int ret;

	ret = init_fpu(target);
	if (ret)
		return ret;

	set_stopped_child_used_math(target);

	if ((boot_cpu_data.flags & CPU_HAS_FPU))
		return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
					  &target->thread.xstate->hardfpu, 0, -1);

	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
				  &target->thread.xstate->softfpu, 0, -1);
}

static int fpregs_active(struct task_struct *target,
			 const struct user_regset *regset)
{
	return tsk_used_math(target) ? regset->n : 0;
}
#endif

#ifdef CONFIG_SH_DSP
static int dspregs_get(struct task_struct *target,
		       const struct user_regset *regset,
		       unsigned int pos, unsigned int count,
		       void *kbuf, void __user *ubuf)
{
	const struct pt_dspregs *regs =
		(struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
	int ret;

	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
				  0, sizeof(struct pt_dspregs));
	if (!ret)
		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
					       sizeof(struct pt_dspregs), -1);

	return ret;
}

static int dspregs_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_dspregs *regs =
		(struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
	int ret;

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
				 0, sizeof(struct pt_dspregs));
	if (!ret)
		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
						sizeof(struct pt_dspregs), -1);

	return ret;
}

static int dspregs_active(struct task_struct *target,
			  const struct user_regset *regset)
{
	struct pt_regs *regs = task_pt_regs(target);

	return regs->sr & SR_DSP ? regset->n : 0;
}
#endif

const struct pt_regs_offset regoffset_table[] = {
	REGS_OFFSET_NAME(0),
	REGS_OFFSET_NAME(1),
	REGS_OFFSET_NAME(2),
	REGS_OFFSET_NAME(3),
	REGS_OFFSET_NAME(4),
	REGS_OFFSET_NAME(5),
	REGS_OFFSET_NAME(6),
	REGS_OFFSET_NAME(7),
	REGS_OFFSET_NAME(8),
	REGS_OFFSET_NAME(9),
	REGS_OFFSET_NAME(10),
	REGS_OFFSET_NAME(11),
	REGS_OFFSET_NAME(12),
	REGS_OFFSET_NAME(13),
	REGS_OFFSET_NAME(14),
	REGS_OFFSET_NAME(15),
	REG_OFFSET_NAME(pc),
	REG_OFFSET_NAME(pr),
	REG_OFFSET_NAME(sr),
	REG_OFFSET_NAME(gbr),
	REG_OFFSET_NAME(mach),
	REG_OFFSET_NAME(macl),
	REG_OFFSET_NAME(tra),
	REG_OFFSET_END,
};

/*
 * These are our native regset flavours.
 */
enum sh_regset {
	REGSET_GENERAL,
#ifdef CONFIG_SH_FPU
	REGSET_FPU,
#endif
#ifdef CONFIG_SH_DSP
	REGSET_DSP,
#endif
};

static const struct user_regset sh_regsets[] = {
	/*
	 * Format is:
	 *	R0 --> R15
	 *	PC, PR, SR, GBR, MACH, MACL, TRA
	 */
	[REGSET_GENERAL] = {
		.core_note_type	= NT_PRSTATUS,
		.n		= ELF_NGREG,
		.size		= sizeof(long),
		.align		= sizeof(long),
		.get		= genregs_get,
		.set		= genregs_set,
	},

#ifdef CONFIG_SH_FPU
	[REGSET_FPU] = {
		.core_note_type	= NT_PRFPREG,
		.n		= sizeof(struct user_fpu_struct) / sizeof(long),
		.size		= sizeof(long),
		.align		= sizeof(long),
		.get		= fpregs_get,
		.set		= fpregs_set,
		.active		= fpregs_active,
	},
#endif

#ifdef CONFIG_SH_DSP
	[REGSET_DSP] = {
		.n		= sizeof(struct pt_dspregs) / sizeof(long),
		.size		= sizeof(long),
		.align		= sizeof(long),
		.get		= dspregs_get,
		.set		= dspregs_set,
		.active		= dspregs_active,
	},
#endif
};

static const struct user_regset_view user_sh_native_view = {
	.name		= "sh",
	.e_machine	= EM_SH,
	.regsets	= sh_regsets,
	.n		= ARRAY_SIZE(sh_regsets),
};

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

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

	switch (request) {
	/* read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR: {
		unsigned long tmp;

		ret = -EIO;
		if ((addr & 3) || addr < 0 ||
		    addr > sizeof(struct user) - 3)
			break;

		if (addr < sizeof(struct pt_regs))
			tmp = get_stack_long(child, addr);
		else if (addr >= offsetof(struct user, fpu) &&
			 addr < offsetof(struct user, u_fpvalid)) {
			if (!tsk_used_math(child)) {
				if (addr == offsetof(struct user, fpu.fpscr))
					tmp = FPSCR_INIT;
				else
					tmp = 0;
			} else {
				unsigned long index;
				index = addr - offsetof(struct user, fpu);
				tmp = ((unsigned long *)child->thread.xstate)
					[index >> 2];
			}
		} else if (addr == offsetof(struct user, u_fpvalid))
			tmp = !!tsk_used_math(child);
		else if (addr == PT_TEXT_ADDR)
			tmp = child->mm->start_code;
		else if (addr == PT_DATA_ADDR)
			tmp = child->mm->start_data;
		else if (addr == PT_TEXT_END_ADDR)
			tmp = child->mm->end_code;
		else if (addr == PT_TEXT_LEN)
			tmp = child->mm->end_code - child->mm->start_code;
		else
			tmp = 0;
		ret = put_user(tmp, datap);
		break;
	}

	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
		ret = -EIO;
		if ((addr & 3) || addr < 0 ||
		    addr > sizeof(struct user) - 3)
			break;

		if (addr < sizeof(struct pt_regs))
			ret = put_stack_long(child, addr, data);
		else if (addr >= offsetof(struct user, fpu) &&
			 addr < offsetof(struct user, u_fpvalid)) {
			unsigned long index;
			index = addr - offsetof(struct user, fpu);
			set_stopped_child_used_math(child);
			((unsigned long *)child->thread.xstate)
				[index >> 2] = data;
			ret = 0;
		} else if (addr == offsetof(struct user, u_fpvalid)) {
			conditional_stopped_child_used_math(data, child);
			ret = 0;
		}
		break;

	case PTRACE_GETREGS:
		return copy_regset_to_user(child, &user_sh_native_view,
					   REGSET_GENERAL,
					   0, sizeof(struct pt_regs),
					   datap);
	case PTRACE_SETREGS:
		return copy_regset_from_user(child, &user_sh_native_view,
					     REGSET_GENERAL,
					     0, sizeof(struct pt_regs),
					     datap);
#ifdef CONFIG_SH_FPU
	case PTRACE_GETFPREGS:
		return copy_regset_to_user(child, &user_sh_native_view,
					   REGSET_FPU,
					   0, sizeof(struct user_fpu_struct),
					   datap);
	case PTRACE_SETFPREGS:
		return copy_regset_from_user(child, &user_sh_native_view,
					     REGSET_FPU,
					     0, sizeof(struct user_fpu_struct),
					     datap);
#endif
#ifdef CONFIG_SH_DSP
	case PTRACE_GETDSPREGS:
		return copy_regset_to_user(child, &user_sh_native_view,
					   REGSET_DSP,
					   0, sizeof(struct pt_dspregs),
					   datap);
	case PTRACE_SETDSPREGS:
		return copy_regset_from_user(child, &user_sh_native_view,
					     REGSET_DSP,
					     0, sizeof(struct pt_dspregs),
					     datap);
#endif
	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}

	return ret;
}

static inline int audit_arch(void)
{
	int arch = EM_SH;

#ifdef CONFIG_CPU_LITTLE_ENDIAN
	arch |= __AUDIT_ARCH_LE;
#endif

	return arch;
}

asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
{
	long ret = 0;

	secure_computing(regs->regs[0]);

	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
	    tracehook_report_syscall_entry(regs))
		/*
		 * Tracing decided this syscall should not happen.
		 * We'll return a bogus call number to get an ENOSYS
		 * error, but leave the original number in regs->regs[0].
		 */
		ret = -1L;

	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
		trace_sys_enter(regs, regs->regs[0]);

	if (unlikely(current->audit_context))
		audit_syscall_entry(audit_arch(), regs->regs[3],
				    regs->regs[4], regs->regs[5],
				    regs->regs[6], regs->regs[7]);

	return ret ?: regs->regs[0];
}

asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
{
	int step;

	if (unlikely(current->audit_context))
		audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
				   regs->regs[0]);

	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
		trace_sys_exit(regs, regs->regs[0]);

	step = test_thread_flag(TIF_SINGLESTEP);
	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
		tracehook_report_syscall_exit(regs, step);
}