aboutsummaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/ptrace.c
blob: 581d427148e70f33caebfd685349fb705a49872b (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
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
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
/*
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Derived from "arch/m68k/kernel/ptrace.c"
 *  Copyright (C) 1994 by Hamish Macdonald
 *  Taken from linux/kernel/ptrace.c and modified for M680x0.
 *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
 *
 * Modified by Cort Dougan (cort@hq.fsmlabs.com)
 * and Paul Mackerras (paulus@samba.org).
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file README.legal 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/seccomp.h>
#include <linux/audit.h>
#ifdef CONFIG_PPC32
#include <linux/module.h>
#endif

#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>

/*
 * does not yet catch signals sent when the child dies.
 * in exit.c or in signal.c.
 */

/*
 * Set of msr bits that gdb can change on behalf of a process.
 */
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
#define MSR_DEBUGCHANGE	0
#else
#define MSR_DEBUGCHANGE	(MSR_SE | MSR_BE)
#endif

/*
 * Max register writeable via put_reg
 */
#ifdef CONFIG_PPC32
#define PT_MAX_PUT_REG	PT_MQ
#else
#define PT_MAX_PUT_REG	PT_CCR
#endif

/*
 * Get contents of register REGNO in task TASK.
 */
unsigned long ptrace_get_reg(struct task_struct *task, int regno)
{
	unsigned long tmp = 0;

	if (task->thread.regs == NULL)
		return -EIO;

	if (regno == PT_MSR) {
		tmp = ((unsigned long *)task->thread.regs)[PT_MSR];
		return tmp | task->thread.fpexc_mode;
	}

	if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
		return ((unsigned long *)task->thread.regs)[regno];

	return -EIO;
}

/*
 * Write contents of register REGNO in task TASK.
 */
int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
{
	if (task->thread.regs == NULL)
		return -EIO;

	if (regno <= PT_MAX_PUT_REG || regno == PT_TRAP) {
		if (regno == PT_MSR)
			data = (data & MSR_DEBUGCHANGE)
				| (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
		/* We prevent mucking around with the reserved area of trap
		 * which are used internally by the kernel
		 */
		if (regno == PT_TRAP)
			data &= 0xfff0;
		((unsigned long *)task->thread.regs)[regno] = data;
		return 0;
	}
	return -EIO;
}


static int get_fpregs(void __user *data, struct task_struct *task,
		      int has_fpscr)
{
	unsigned int count = has_fpscr ? 33 : 32;

	if (copy_to_user(data, task->thread.fpr, count * sizeof(double)))
		return -EFAULT;
	return 0;
}

static int set_fpregs(void __user *data, struct task_struct *task,
		      int has_fpscr)
{
	unsigned int count = has_fpscr ? 33 : 32;

	if (copy_from_user(task->thread.fpr, data, count * sizeof(double)))
		return -EFAULT;
	return 0;
}


#ifdef CONFIG_ALTIVEC
/*
 * Get/set all the altivec registers vr0..vr31, vscr, vrsave, in one go.
 * The transfer totals 34 quadword.  Quadwords 0-31 contain the
 * corresponding vector registers.  Quadword 32 contains the vscr as the
 * last word (offset 12) within that quadword.  Quadword 33 contains the
 * vrsave as the first word (offset 0) within the quadword.
 *
 * This definition of the VMX state is compatible with the current PPC32
 * ptrace interface.  This allows signal handling and ptrace to use the
 * same structures.  This also simplifies the implementation of a bi-arch
 * (combined (32- and 64-bit) gdb.
 */

/*
 * Get contents of AltiVec register state in task TASK
 */
static int get_vrregs(unsigned long __user *data, struct task_struct *task)
{
	unsigned long regsize;

	/* copy AltiVec registers VR[0] .. VR[31] */
	regsize = 32 * sizeof(vector128);
	if (copy_to_user(data, task->thread.vr, regsize))
		return -EFAULT;
	data += (regsize / sizeof(unsigned long));

	/* copy VSCR */
	regsize = 1 * sizeof(vector128);
	if (copy_to_user(data, &task->thread.vscr, regsize))
		return -EFAULT;
	data += (regsize / sizeof(unsigned long));

	/* copy VRSAVE */
	if (put_user(task->thread.vrsave, (u32 __user *)data))
		return -EFAULT;

	return 0;
}

/*
 * Write contents of AltiVec register state into task TASK.
 */
static int set_vrregs(struct task_struct *task, unsigned long __user *data)
{
	unsigned long regsize;

	/* copy AltiVec registers VR[0] .. VR[31] */
	regsize = 32 * sizeof(vector128);
	if (copy_from_user(task->thread.vr, data, regsize))
		return -EFAULT;
	data += (regsize / sizeof(unsigned long));

	/* copy VSCR */
	regsize = 1 * sizeof(vector128);
	if (copy_from_user(&task->thread.vscr, data, regsize))
		return -EFAULT;
	data += (regsize / sizeof(unsigned long));

	/* copy VRSAVE */
	if (get_user(task->thread.vrsave, (u32 __user *)data))
		return -EFAULT;

	return 0;
}
#endif /* CONFIG_ALTIVEC */

#ifdef CONFIG_SPE

/*
 * For get_evrregs/set_evrregs functions 'data' has the following layout:
 *
 * struct {
 *   u32 evr[32];
 *   u64 acc;
 *   u32 spefscr;
 * }
 */

/*
 * Get contents of SPE register state in task TASK.
 */
static int get_evrregs(unsigned long *data, struct task_struct *task)
{
	int i;

	if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(unsigned long)))
		return -EFAULT;

	/* copy SPEFSCR */
	if (__put_user(task->thread.spefscr, &data[34]))
		return -EFAULT;

	/* copy SPE registers EVR[0] .. EVR[31] */
	for (i = 0; i < 32; i++, data++)
		if (__put_user(task->thread.evr[i], data))
			return -EFAULT;

	/* copy ACC */
	if (__put_user64(task->thread.acc, (unsigned long long *)data))
		return -EFAULT;

	return 0;
}

/*
 * Write contents of SPE register state into task TASK.
 */
static int set_evrregs(struct task_struct *task, unsigned long *data)
{
	int i;

	if (!access_ok(VERIFY_READ, data, 35 * sizeof(unsigned long)))
		return -EFAULT;

	/* copy SPEFSCR */
	if (__get_user(task->thread.spefscr, &data[34]))
		return -EFAULT;

	/* copy SPE registers EVR[0] .. EVR[31] */
	for (i = 0; i < 32; i++, data++)
		if (__get_user(task->thread.evr[i], data))
			return -EFAULT;
	/* copy ACC */
	if (__get_user64(task->thread.acc, (unsigned long long*)data))
		return -EFAULT;

	return 0;
}
#endif /* CONFIG_SPE */


static void set_single_step(struct task_struct *task)
{
	struct pt_regs *regs = task->thread.regs;

	if (regs != NULL) {
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
		task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC;
		regs->msr |= MSR_DE;
#else
		regs->msr |= MSR_SE;
#endif
	}
	set_tsk_thread_flag(task, TIF_SINGLESTEP);
}

static void clear_single_step(struct task_struct *task)
{
	struct pt_regs *regs = task->thread.regs;

	if (regs != NULL) {
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
		task->thread.dbcr0 = 0;
		regs->msr &= ~MSR_DE;
#else
		regs->msr &= ~MSR_SE;
#endif
	}
	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
}

static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
			       unsigned long data)
{
	/* We only support one DABR and no IABRS at the moment */
	if (addr > 0)
		return -EINVAL;

	/* The bottom 3 bits are flags */
	if ((data & ~0x7UL) >= TASK_SIZE)
		return -EIO;

	/* Ensure translation is on */
	if (data && !(data & DABR_TRANSLATION))
		return -EIO;

	task->thread.dabr = data;
	return 0;
}

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

/*
 * Here are the old "legacy" powerpc specific getregs/setregs ptrace calls,
 * we mark them as obsolete now, they will be removed in a future version
 */
static long arch_ptrace_old(struct task_struct *child, long request, long addr,
			    long data)
{
	int ret = -EPERM;

	switch(request) {
	case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
		int i;
		unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
		unsigned long __user *tmp = (unsigned long __user *)addr;

		for (i = 0; i < 32; i++) {
			ret = put_user(*reg, tmp);
			if (ret)
				break;
			reg++;
			tmp++;
		}
		break;
	}

	case PPC_PTRACE_SETREGS: { /* Set GPRs 0 - 31. */
		int i;
		unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
		unsigned long __user *tmp = (unsigned long __user *)addr;

		for (i = 0; i < 32; i++) {
			ret = get_user(*reg, tmp);
			if (ret)
				break;
			reg++;
			tmp++;
		}
		break;
	}

	case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
		flush_fp_to_thread(child);
		ret = get_fpregs((void __user *)addr, child, 0);
		break;
	}

	case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
		flush_fp_to_thread(child);
		ret = set_fpregs((void __user *)addr, child, 0);
		break;
	}

	}
	return ret;
}

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

	switch (request) {
	/* when I and D space are separate, these will need to be fixed. */
	case PTRACE_PEEKTEXT: /* read word at location addr. */
	case PTRACE_PEEKDATA:
		ret = generic_ptrace_peekdata(child, addr, data);
		break;

	/* read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR: {
		unsigned long index, tmp;

		ret = -EIO;
		/* convert to index and check */
#ifdef CONFIG_PPC32
		index = (unsigned long) addr >> 2;
		if ((addr & 3) || (index > PT_FPSCR)
		    || (child->thread.regs == NULL))
#else
		index = (unsigned long) addr >> 3;
		if ((addr & 7) || (index > PT_FPSCR))
#endif
			break;

		CHECK_FULL_REGS(child->thread.regs);
		if (index < PT_FPR0) {
			tmp = ptrace_get_reg(child, (int) index);
		} else {
			flush_fp_to_thread(child);
			tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
		}
		ret = put_user(tmp,(unsigned long __user *) data);
		break;
	}

	/* If I and D space are separate, this will have to be fixed. */
	case PTRACE_POKETEXT: /* write the word at location addr. */
	case PTRACE_POKEDATA:
		ret = 0;
		if (access_process_vm(child, addr, &data, sizeof(data), 1)
				== sizeof(data))
			break;
		ret = -EIO;
		break;

	/* write the word at location addr in the USER area */
	case PTRACE_POKEUSR: {
		unsigned long index;

		ret = -EIO;
		/* convert to index and check */
#ifdef CONFIG_PPC32
		index = (unsigned long) addr >> 2;
		if ((addr & 3) || (index > PT_FPSCR)
		    || (child->thread.regs == NULL))
#else
		index = (unsigned long) addr >> 3;
		if ((addr & 7) || (index > PT_FPSCR))
#endif
			break;

		CHECK_FULL_REGS(child->thread.regs);
		if (index < PT_FPR0) {
			ret = ptrace_put_reg(child, index, data);
		} else {
			flush_fp_to_thread(child);
			((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
			ret = 0;
		}
		break;
	}

	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	case PTRACE_CONT: { /* restart after signal. */
		ret = -EIO;
		if (!valid_signal(data))
			break;
		if (request == PTRACE_SYSCALL)
			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		else
			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		child->exit_code = data;
		/* make sure the single step bit is not set. */
		clear_single_step(child);
		wake_up_process(child);
		ret = 0;
		break;
	}

/*
 * make the child exit.  Best I can do is send it a sigkill.
 * perhaps it should be put in the status that it wants to
 * exit.
 */
	case PTRACE_KILL: {
		ret = 0;
		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
			break;
		child->exit_code = SIGKILL;
		/* make sure the single step bit is not set. */
		clear_single_step(child);
		wake_up_process(child);
		break;
	}

	case PTRACE_SINGLESTEP: {  /* set the trap flag. */
		ret = -EIO;
		if (!valid_signal(data))
			break;
		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		set_single_step(child);
		child->exit_code = data;
		/* give it a chance to run. */
		wake_up_process(child);
		ret = 0;
		break;
	}

	case PTRACE_GET_DEBUGREG: {
		ret = -EINVAL;
		/* We only support one DABR and no IABRS at the moment */
		if (addr > 0)
			break;
		ret = put_user(child->thread.dabr,
			       (unsigned long __user *)data);
		break;
	}

	case PTRACE_SET_DEBUGREG:
		ret = ptrace_set_debugreg(child, addr, data);
		break;

	case PTRACE_DETACH:
		ret = ptrace_detach(child, data);
		break;

#ifdef CONFIG_PPC64
	case PTRACE_GETREGS64:
#endif
	case PTRACE_GETREGS: { /* Get all pt_regs from the child. */
		int ui;
	  	if (!access_ok(VERIFY_WRITE, (void __user *)data,
			       sizeof(struct pt_regs))) {
			ret = -EIO;
			break;
		}
		ret = 0;
		for (ui = 0; ui < PT_REGS_COUNT; ui ++) {
			ret |= __put_user(ptrace_get_reg(child, ui),
					  (unsigned long __user *) data);
			data += sizeof(long);
		}
		break;
	}

#ifdef CONFIG_PPC64
	case PTRACE_SETREGS64:
#endif
	case PTRACE_SETREGS: { /* Set all gp regs in the child. */
		unsigned long tmp;
		int ui;
	  	if (!access_ok(VERIFY_READ, (void __user *)data,
			       sizeof(struct pt_regs))) {
			ret = -EIO;
			break;
		}
		ret = 0;
		for (ui = 0; ui < PT_REGS_COUNT; ui ++) {
			ret = __get_user(tmp, (unsigned long __user *) data);
			if (ret)
				break;
			ptrace_put_reg(child, ui, tmp);
			data += sizeof(long);
		}
		break;
	}

	case PTRACE_GETFPREGS: { /* Get the child FPU state (FPR0...31 + FPSCR) */
		flush_fp_to_thread(child);
		ret = get_fpregs((void __user *)data, child, 1);
		break;
	}

	case PTRACE_SETFPREGS: { /* Set the child FPU state (FPR0...31 + FPSCR) */
		flush_fp_to_thread(child);
		ret = set_fpregs((void __user *)data, child, 1);
		break;
	}

#ifdef CONFIG_ALTIVEC
	case PTRACE_GETVRREGS:
		/* Get the child altivec register state. */
		flush_altivec_to_thread(child);
		ret = get_vrregs((unsigned long __user *)data, child);
		break;

	case PTRACE_SETVRREGS:
		/* Set the child altivec register state. */
		flush_altivec_to_thread(child);
		ret = set_vrregs(child, (unsigned long __user *)data);
		break;
#endif
#ifdef CONFIG_SPE
	case PTRACE_GETEVRREGS:
		/* Get the child spe register state. */
		if (child->thread.regs->msr & MSR_SPE)
			giveup_spe(child);
		ret = get_evrregs((unsigned long __user *)data, child);
		break;

	case PTRACE_SETEVRREGS:
		/* Set the child spe register state. */
		/* this is to clear the MSR_SPE bit to force a reload
		 * of register state from memory */
		if (child->thread.regs->msr & MSR_SPE)
			giveup_spe(child);
		ret = set_evrregs(child, (unsigned long __user *)data);
		break;
#endif

	/* Old reverse args ptrace callss */
	case PPC_PTRACE_GETREGS: /* Get GPRs 0 - 31. */
	case PPC_PTRACE_SETREGS: /* Set GPRs 0 - 31. */
	case PPC_PTRACE_GETFPREGS: /* Get FPRs 0 - 31. */
	case PPC_PTRACE_SETFPREGS: /* Get FPRs 0 - 31. */
		ret = arch_ptrace_old(child, request, addr, data);
		break;

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

static void do_syscall_trace(void)
{
	/* 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;
	}
}

void do_syscall_trace_enter(struct pt_regs *regs)
{
	secure_computing(regs->gpr[0]);

	if (test_thread_flag(TIF_SYSCALL_TRACE)
	    && (current->ptrace & PT_PTRACED))
		do_syscall_trace();

	if (unlikely(current->audit_context)) {
#ifdef CONFIG_PPC64
		if (!test_thread_flag(TIF_32BIT))
			audit_syscall_entry(AUDIT_ARCH_PPC64,
					    regs->gpr[0],
					    regs->gpr[3], regs->gpr[4],
					    regs->gpr[5], regs->gpr[6]);
		else
#endif
			audit_syscall_entry(AUDIT_ARCH_PPC,
					    regs->gpr[0],
					    regs->gpr[3] & 0xffffffff,
					    regs->gpr[4] & 0xffffffff,
					    regs->gpr[5] & 0xffffffff,
					    regs->gpr[6] & 0xffffffff);
	}
}

void do_syscall_trace_leave(struct pt_regs *regs)
{
	if (unlikely(current->audit_context))
		audit_syscall_exit((regs->ccr&0x10000000)?AUDITSC_FAILURE:AUDITSC_SUCCESS,
				   regs->result);

	if ((test_thread_flag(TIF_SYSCALL_TRACE)
	     || test_thread_flag(TIF_SINGLESTEP))
	    && (current->ptrace & PT_PTRACED))
		do_syscall_trace();
}