summaryrefslogtreecommitdiffstats
path: root/kernel/compat.c
blob: 3247fe761f6018ef61ecb37124720f3fa092d441 (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
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
/*
 *  linux/kernel/compat.c
 *
 *  Kernel compatibililty routines for e.g. 32 bit syscall support
 *  on 64 bit kernels.
 *
 *  Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */

#include <linux/linkage.h>
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/signal.h>
#include <linux/sched.h>	/* for MAX_SCHEDULE_TIMEOUT */
#include <linux/syscalls.h>
#include <linux/unistd.h>
#include <linux/security.h>
#include <linux/timex.h>
#include <linux/export.h>
#include <linux/migrate.h>
#include <linux/posix-timers.h>
#include <linux/times.h>
#include <linux/ptrace.h>
#include <linux/gfp.h>

#include <linux/uaccess.h>

int compat_get_timex(struct timex *txc, const struct compat_timex __user *utp)
{
	struct compat_timex tx32;

	if (copy_from_user(&tx32, utp, sizeof(struct compat_timex)))
		return -EFAULT;

	txc->modes = tx32.modes;
	txc->offset = tx32.offset;
	txc->freq = tx32.freq;
	txc->maxerror = tx32.maxerror;
	txc->esterror = tx32.esterror;
	txc->status = tx32.status;
	txc->constant = tx32.constant;
	txc->precision = tx32.precision;
	txc->tolerance = tx32.tolerance;
	txc->time.tv_sec = tx32.time.tv_sec;
	txc->time.tv_usec = tx32.time.tv_usec;
	txc->tick = tx32.tick;
	txc->ppsfreq = tx32.ppsfreq;
	txc->jitter = tx32.jitter;
	txc->shift = tx32.shift;
	txc->stabil = tx32.stabil;
	txc->jitcnt = tx32.jitcnt;
	txc->calcnt = tx32.calcnt;
	txc->errcnt = tx32.errcnt;
	txc->stbcnt = tx32.stbcnt;

	return 0;
}

int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc)
{
	struct compat_timex tx32;

	memset(&tx32, 0, sizeof(struct compat_timex));
	tx32.modes = txc->modes;
	tx32.offset = txc->offset;
	tx32.freq = txc->freq;
	tx32.maxerror = txc->maxerror;
	tx32.esterror = txc->esterror;
	tx32.status = txc->status;
	tx32.constant = txc->constant;
	tx32.precision = txc->precision;
	tx32.tolerance = txc->tolerance;
	tx32.time.tv_sec = txc->time.tv_sec;
	tx32.time.tv_usec = txc->time.tv_usec;
	tx32.tick = txc->tick;
	tx32.ppsfreq = txc->ppsfreq;
	tx32.jitter = txc->jitter;
	tx32.shift = txc->shift;
	tx32.stabil = txc->stabil;
	tx32.jitcnt = txc->jitcnt;
	tx32.calcnt = txc->calcnt;
	tx32.errcnt = txc->errcnt;
	tx32.stbcnt = txc->stbcnt;
	tx32.tai = txc->tai;
	if (copy_to_user(utp, &tx32, sizeof(struct compat_timex)))
		return -EFAULT;
	return 0;
}

static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv)
{
	return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||
			__get_user(tv->tv_sec, &ctv->tv_sec) ||
			__get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
}

static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv)
{
	return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
			__put_user(tv->tv_sec, &ctv->tv_sec) ||
			__put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
}

static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
{
	return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
			__get_user(ts->tv_sec, &cts->tv_sec) ||
			__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
}

static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
{
	return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
			__put_user(ts->tv_sec, &cts->tv_sec) ||
			__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
}

static int __compat_get_timespec64(struct timespec64 *ts64,
				   const struct compat_timespec __user *cts)
{
	struct compat_timespec ts;
	int ret;

	ret = copy_from_user(&ts, cts, sizeof(ts));
	if (ret)
		return -EFAULT;

	ts64->tv_sec = ts.tv_sec;
	ts64->tv_nsec = ts.tv_nsec;

	return 0;
}

static int __compat_put_timespec64(const struct timespec64 *ts64,
				   struct compat_timespec __user *cts)
{
	struct compat_timespec ts = {
		.tv_sec = ts64->tv_sec,
		.tv_nsec = ts64->tv_nsec
	};
	return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0;
}

int compat_get_timespec64(struct timespec64 *ts, const void __user *uts)
{
	if (COMPAT_USE_64BIT_TIME)
		return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
	else
		return __compat_get_timespec64(ts, uts);
}
EXPORT_SYMBOL_GPL(compat_get_timespec64);

int compat_put_timespec64(const struct timespec64 *ts, void __user *uts)
{
	if (COMPAT_USE_64BIT_TIME)
		return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
	else
		return __compat_put_timespec64(ts, uts);
}
EXPORT_SYMBOL_GPL(compat_put_timespec64);

int compat_get_timeval(struct timeval *tv, const void __user *utv)
{
	if (COMPAT_USE_64BIT_TIME)
		return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0;
	else
		return __compat_get_timeval(tv, utv);
}
EXPORT_SYMBOL_GPL(compat_get_timeval);

int compat_put_timeval(const struct timeval *tv, void __user *utv)
{
	if (COMPAT_USE_64BIT_TIME)
		return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0;
	else
		return __compat_put_timeval(tv, utv);
}
EXPORT_SYMBOL_GPL(compat_put_timeval);

int compat_get_timespec(struct timespec *ts, const void __user *uts)
{
	if (COMPAT_USE_64BIT_TIME)
		return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
	else
		return __compat_get_timespec(ts, uts);
}
EXPORT_SYMBOL_GPL(compat_get_timespec);

int compat_put_timespec(const struct timespec *ts, void __user *uts)
{
	if (COMPAT_USE_64BIT_TIME)
		return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
	else
		return __compat_put_timespec(ts, uts);
}
EXPORT_SYMBOL_GPL(compat_put_timespec);

int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i)
{
	struct compat_itimerval v32;

	if (copy_from_user(&v32, i, sizeof(struct compat_itimerval)))
		return -EFAULT;
	o->it_interval.tv_sec = v32.it_interval.tv_sec;
	o->it_interval.tv_usec = v32.it_interval.tv_usec;
	o->it_value.tv_sec = v32.it_value.tv_sec;
	o->it_value.tv_usec = v32.it_value.tv_usec;
	return 0;
}

int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i)
{
	struct compat_itimerval v32;

	v32.it_interval.tv_sec = i->it_interval.tv_sec;
	v32.it_interval.tv_usec = i->it_interval.tv_usec;
	v32.it_value.tv_sec = i->it_value.tv_sec;
	v32.it_value.tv_usec = i->it_value.tv_usec;
	return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0;
}

#ifdef __ARCH_WANT_SYS_SIGPROCMASK

/*
 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
 * blocked set of signals to the supplied signal set
 */
static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
{
	memcpy(blocked->sig, &set, sizeof(set));
}

COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
		       compat_old_sigset_t __user *, nset,
		       compat_old_sigset_t __user *, oset)
{
	old_sigset_t old_set, new_set;
	sigset_t new_blocked;

	old_set = current->blocked.sig[0];

	if (nset) {
		if (get_user(new_set, nset))
			return -EFAULT;
		new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));

		new_blocked = current->blocked;

		switch (how) {
		case SIG_BLOCK:
			sigaddsetmask(&new_blocked, new_set);
			break;
		case SIG_UNBLOCK:
			sigdelsetmask(&new_blocked, new_set);
			break;
		case SIG_SETMASK:
			compat_sig_setmask(&new_blocked, new_set);
			break;
		default:
			return -EINVAL;
		}

		set_current_blocked(&new_blocked);
	}

	if (oset) {
		if (put_user(old_set, oset))
			return -EFAULT;
	}

	return 0;
}

#endif

int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
{
	struct compat_rusage r32;
	memset(&r32, 0, sizeof(r32));
	r32.ru_utime.tv_sec = r->ru_utime.tv_sec;
	r32.ru_utime.tv_usec = r->ru_utime.tv_usec;
	r32.ru_stime.tv_sec = r->ru_stime.tv_sec;
	r32.ru_stime.tv_usec = r->ru_stime.tv_usec;
	r32.ru_maxrss = r->ru_maxrss;
	r32.ru_ixrss = r->ru_ixrss;
	r32.ru_idrss = r->ru_idrss;
	r32.ru_isrss = r->ru_isrss;
	r32.ru_minflt = r->ru_minflt;
	r32.ru_majflt = r->ru_majflt;
	r32.ru_nswap = r->ru_nswap;
	r32.ru_inblock = r->ru_inblock;
	r32.ru_oublock = r->ru_oublock;
	r32.ru_msgsnd = r->ru_msgsnd;
	r32.ru_msgrcv = r->ru_msgrcv;
	r32.ru_nsignals = r->ru_nsignals;
	r32.ru_nvcsw = r->ru_nvcsw;
	r32.ru_nivcsw = r->ru_nivcsw;
	if (copy_to_user(ru, &r32, sizeof(r32)))
		return -EFAULT;
	return 0;
}

static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
				    unsigned len, struct cpumask *new_mask)
{
	unsigned long *k;

	if (len < cpumask_size())
		memset(new_mask, 0, cpumask_size());
	else if (len > cpumask_size())
		len = cpumask_size();

	k = cpumask_bits(new_mask);
	return compat_get_bitmap(k, user_mask_ptr, len * 8);
}

COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
		       unsigned int, len,
		       compat_ulong_t __user *, user_mask_ptr)
{
	cpumask_var_t new_mask;
	int retval;

	if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
		return -ENOMEM;

	retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
	if (retval)
		goto out;

	retval = sched_setaffinity(pid, new_mask);
out:
	free_cpumask_var(new_mask);
	return retval;
}

COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t,  pid, unsigned int, len,
		       compat_ulong_t __user *, user_mask_ptr)
{
	int ret;
	cpumask_var_t mask;

	if ((len * BITS_PER_BYTE) < nr_cpu_ids)
		return -EINVAL;
	if (len & (sizeof(compat_ulong_t)-1))
		return -EINVAL;

	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
		return -ENOMEM;

	ret = sched_getaffinity(pid, mask);
	if (ret == 0) {
		unsigned int retlen = min(len, cpumask_size());

		if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
			ret = -EFAULT;
		else
			ret = retlen;
	}
	free_cpumask_var(mask);

	return ret;
}

int get_compat_itimerspec64(struct itimerspec64 *its,
			const struct compat_itimerspec __user *uits)
{

	if (__compat_get_timespec64(&its->it_interval, &uits->it_interval) ||
	    __compat_get_timespec64(&its->it_value, &uits->it_value))
		return -EFAULT;
	return 0;
}
EXPORT_SYMBOL_GPL(get_compat_itimerspec64);

int put_compat_itimerspec64(const struct itimerspec64 *its,
			struct compat_itimerspec __user *uits)
{
	if (__compat_put_timespec64(&its->it_interval, &uits->it_interval) ||
	    __compat_put_timespec64(&its->it_value, &uits->it_value))
		return -EFAULT;
	return 0;
}
EXPORT_SYMBOL_GPL(put_compat_itimerspec64);

/*
 * We currently only need the following fields from the sigevent
 * structure: sigev_value, sigev_signo, sig_notify and (sometimes
 * sigev_notify_thread_id).  The others are handled in user mode.
 * We also assume that copying sigev_value.sival_int is sufficient
 * to keep all the bits of sigev_value.sival_ptr intact.
 */
int get_compat_sigevent(struct sigevent *event,
		const struct compat_sigevent __user *u_event)
{
	memset(event, 0, sizeof(*event));
	return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
		__get_user(event->sigev_value.sival_int,
			&u_event->sigev_value.sival_int) ||
		__get_user(event->sigev_signo, &u_event->sigev_signo) ||
		__get_user(event->sigev_notify, &u_event->sigev_notify) ||
		__get_user(event->sigev_notify_thread_id,
			&u_event->sigev_notify_thread_id))
		? -EFAULT : 0;
}

long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
		       unsigned long bitmap_size)
{
	unsigned long nr_compat_longs;

	/* align bitmap up to nearest compat_long_t boundary */
	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);

	if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
		return -EFAULT;

	user_access_begin();
	while (nr_compat_longs > 1) {
		compat_ulong_t l1, l2;
		unsafe_get_user(l1, umask++, Efault);
		unsafe_get_user(l2, umask++, Efault);
		*mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1;
		nr_compat_longs -= 2;
	}
	if (nr_compat_longs)
		unsafe_get_user(*mask, umask++, Efault);
	user_access_end();
	return 0;

Efault:
	user_access_end();
	return -EFAULT;
}

long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
		       unsigned long bitmap_size)
{
	unsigned long nr_compat_longs;

	/* align bitmap up to nearest compat_long_t boundary */
	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);

	if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
		return -EFAULT;

	user_access_begin();
	while (nr_compat_longs > 1) {
		unsigned long m = *mask++;
		unsafe_put_user((compat_ulong_t)m, umask++, Efault);
		unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault);
		nr_compat_longs -= 2;
	}
	if (nr_compat_longs)
		unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
	user_access_end();
	return 0;
Efault:
	user_access_end();
	return -EFAULT;
}

int
get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
{
#ifdef __BIG_ENDIAN
	compat_sigset_t v;
	if (copy_from_user(&v, compat, sizeof(compat_sigset_t)))
		return -EFAULT;
	switch (_NSIG_WORDS) {
	case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
	case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
	case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
	case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
	}
#else
	if (copy_from_user(set, compat, sizeof(compat_sigset_t)))
		return -EFAULT;
#endif
	return 0;
}
EXPORT_SYMBOL_GPL(get_compat_sigset);

int
put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set,
		  unsigned int size)
{
	/* size <= sizeof(compat_sigset_t) <= sizeof(sigset_t) */
#ifdef __BIG_ENDIAN
	compat_sigset_t v;
	switch (_NSIG_WORDS) {
	case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
	case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
	case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
	case 1: v.sig[1] = (set->sig[0] >> 32); v.sig[0] = set->sig[0];
	}
	return copy_to_user(compat, &v, size) ? -EFAULT : 0;
#else
	return copy_to_user(compat, set, size) ? -EFAULT : 0;
#endif
}

#ifdef CONFIG_NUMA
COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
		       compat_uptr_t __user *, pages32,
		       const int __user *, nodes,
		       int __user *, status,
		       int, flags)
{
	const void __user * __user *pages;
	int i;

	pages = compat_alloc_user_space(nr_pages * sizeof(void *));
	for (i = 0; i < nr_pages; i++) {
		compat_uptr_t p;

		if (get_user(p, pages32 + i) ||
			put_user(compat_ptr(p), pages + i))
			return -EFAULT;
	}
	return sys_move_pages(pid, nr_pages, pages, nodes, status, flags);
}

COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
		       compat_ulong_t, maxnode,
		       const compat_ulong_t __user *, old_nodes,
		       const compat_ulong_t __user *, new_nodes)
{
	unsigned long __user *old = NULL;
	unsigned long __user *new = NULL;
	nodemask_t tmp_mask;
	unsigned long nr_bits;
	unsigned long size;

	nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
	size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
	if (old_nodes) {
		if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
			return -EFAULT;
		old = compat_alloc_user_space(new_nodes ? size * 2 : size);
		if (new_nodes)
			new = old + size / sizeof(unsigned long);
		if (copy_to_user(old, nodes_addr(tmp_mask), size))
			return -EFAULT;
	}
	if (new_nodes) {
		if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
			return -EFAULT;
		if (new == NULL)
			new = compat_alloc_user_space(size);
		if (copy_to_user(new, nodes_addr(tmp_mask), size))
			return -EFAULT;
	}
	return sys_migrate_pages(pid, nr_bits + 1, old, new);
}
#endif

/*
 * Allocate user-space memory for the duration of a single system call,
 * in order to marshall parameters inside a compat thunk.
 */
void __user *compat_alloc_user_space(unsigned long len)
{
	void __user *ptr;

	/* If len would occupy more than half of the entire compat space... */
	if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
		return NULL;

	ptr = arch_compat_alloc_user_space(len);

	if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
		return NULL;

	return ptr;
}
EXPORT_SYMBOL_GPL(compat_alloc_user_space);
OpenPOWER on IntegriCloud