projects/linux·blob v4.15-rc4 · refs

584 lines · 15.7 KiB

1/*
2 * linux/kernel/compat.c
3 *
4 * Kernel compatibililty routines for e.g. 32 bit syscall support
5 * on 64 bit kernels.
6 *
7 * Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/linkage.h>
15#include <linux/compat.h>
16#include <linux/errno.h>
17#include <linux/time.h>
18#include <linux/signal.h>
19#include <linux/sched.h> /* for MAX_SCHEDULE_TIMEOUT */
20#include <linux/syscalls.h>
21#include <linux/unistd.h>
22#include <linux/security.h>
23#include <linux/timex.h>
24#include <linux/export.h>
25#include <linux/migrate.h>
26#include <linux/posix-timers.h>
27#include <linux/times.h>
28#include <linux/ptrace.h>
29#include <linux/gfp.h>
30
31#include <linux/uaccess.h>
32
33int compat_get_timex(struct timex *txc, const struct compat_timex __user *utp)
34{
35 struct compat_timex tx32;
36
37 if (copy_from_user(&tx32, utp, sizeof(struct compat_timex)))
38 return -EFAULT;
39
40 txc->modes = tx32.modes;
41 txc->offset = tx32.offset;
42 txc->freq = tx32.freq;
43 txc->maxerror = tx32.maxerror;
44 txc->esterror = tx32.esterror;
45 txc->status = tx32.status;
46 txc->constant = tx32.constant;
47 txc->precision = tx32.precision;
48 txc->tolerance = tx32.tolerance;
49 txc->time.tv_sec = tx32.time.tv_sec;
50 txc->time.tv_usec = tx32.time.tv_usec;
51 txc->tick = tx32.tick;
52 txc->ppsfreq = tx32.ppsfreq;
53 txc->jitter = tx32.jitter;
54 txc->shift = tx32.shift;
55 txc->stabil = tx32.stabil;
56 txc->jitcnt = tx32.jitcnt;
57 txc->calcnt = tx32.calcnt;
58 txc->errcnt = tx32.errcnt;
59 txc->stbcnt = tx32.stbcnt;
60
61 return 0;
62}
63
64int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc)
65{
66 struct compat_timex tx32;
67
68 memset(&tx32, 0, sizeof(struct compat_timex));
69 tx32.modes = txc->modes;
70 tx32.offset = txc->offset;
71 tx32.freq = txc->freq;
72 tx32.maxerror = txc->maxerror;
73 tx32.esterror = txc->esterror;
74 tx32.status = txc->status;
75 tx32.constant = txc->constant;
76 tx32.precision = txc->precision;
77 tx32.tolerance = txc->tolerance;
78 tx32.time.tv_sec = txc->time.tv_sec;
79 tx32.time.tv_usec = txc->time.tv_usec;
80 tx32.tick = txc->tick;
81 tx32.ppsfreq = txc->ppsfreq;
82 tx32.jitter = txc->jitter;
83 tx32.shift = txc->shift;
84 tx32.stabil = txc->stabil;
85 tx32.jitcnt = txc->jitcnt;
86 tx32.calcnt = txc->calcnt;
87 tx32.errcnt = txc->errcnt;
88 tx32.stbcnt = txc->stbcnt;
89 tx32.tai = txc->tai;
90 if (copy_to_user(utp, &tx32, sizeof(struct compat_timex)))
91 return -EFAULT;
92 return 0;
93}
94
95static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv)
96{
97 return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||
98 __get_user(tv->tv_sec, &ctv->tv_sec) ||
99 __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
100}
101
102static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv)
103{
104 return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
105 __put_user(tv->tv_sec, &ctv->tv_sec) ||
106 __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
107}
108
109static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
110{
111 return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
112 __get_user(ts->tv_sec, &cts->tv_sec) ||
113 __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
114}
115
116static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
117{
118 return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
119 __put_user(ts->tv_sec, &cts->tv_sec) ||
120 __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
121}
122
123static int __compat_get_timespec64(struct timespec64 *ts64,
124 const struct compat_timespec __user *cts)
125{
126 struct compat_timespec ts;
127 int ret;
128
129 ret = copy_from_user(&ts, cts, sizeof(ts));
130 if (ret)
131 return -EFAULT;
132
133 ts64->tv_sec = ts.tv_sec;
134 ts64->tv_nsec = ts.tv_nsec;
135
136 return 0;
137}
138
139static int __compat_put_timespec64(const struct timespec64 *ts64,
140 struct compat_timespec __user *cts)
141{
142 struct compat_timespec ts = {
143 .tv_sec = ts64->tv_sec,
144 .tv_nsec = ts64->tv_nsec
145 };
146 return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0;
147}
148
149int compat_get_timespec64(struct timespec64 *ts, const void __user *uts)
150{
151 if (COMPAT_USE_64BIT_TIME)
152 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
153 else
154 return __compat_get_timespec64(ts, uts);
155}
156EXPORT_SYMBOL_GPL(compat_get_timespec64);
157
158int compat_put_timespec64(const struct timespec64 *ts, void __user *uts)
159{
160 if (COMPAT_USE_64BIT_TIME)
161 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
162 else
163 return __compat_put_timespec64(ts, uts);
164}
165EXPORT_SYMBOL_GPL(compat_put_timespec64);
166
167int compat_get_timeval(struct timeval *tv, const void __user *utv)
168{
169 if (COMPAT_USE_64BIT_TIME)
170 return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0;
171 else
172 return __compat_get_timeval(tv, utv);
173}
174EXPORT_SYMBOL_GPL(compat_get_timeval);
175
176int compat_put_timeval(const struct timeval *tv, void __user *utv)
177{
178 if (COMPAT_USE_64BIT_TIME)
179 return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0;
180 else
181 return __compat_put_timeval(tv, utv);
182}
183EXPORT_SYMBOL_GPL(compat_put_timeval);
184
185int compat_get_timespec(struct timespec *ts, const void __user *uts)
186{
187 if (COMPAT_USE_64BIT_TIME)
188 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
189 else
190 return __compat_get_timespec(ts, uts);
191}
192EXPORT_SYMBOL_GPL(compat_get_timespec);
193
194int compat_put_timespec(const struct timespec *ts, void __user *uts)
195{
196 if (COMPAT_USE_64BIT_TIME)
197 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
198 else
199 return __compat_put_timespec(ts, uts);
200}
201EXPORT_SYMBOL_GPL(compat_put_timespec);
202
203int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i)
204{
205 struct compat_itimerval v32;
206
207 if (copy_from_user(&v32, i, sizeof(struct compat_itimerval)))
208 return -EFAULT;
209 o->it_interval.tv_sec = v32.it_interval.tv_sec;
210 o->it_interval.tv_usec = v32.it_interval.tv_usec;
211 o->it_value.tv_sec = v32.it_value.tv_sec;
212 o->it_value.tv_usec = v32.it_value.tv_usec;
213 return 0;
214}
215
216int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i)
217{
218 struct compat_itimerval v32;
219
220 v32.it_interval.tv_sec = i->it_interval.tv_sec;
221 v32.it_interval.tv_usec = i->it_interval.tv_usec;
222 v32.it_value.tv_sec = i->it_value.tv_sec;
223 v32.it_value.tv_usec = i->it_value.tv_usec;
224 return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0;
225}
226
227#ifdef __ARCH_WANT_SYS_SIGPROCMASK
228
229/*
230 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
231 * blocked set of signals to the supplied signal set
232 */
233static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
234{
235 memcpy(blocked->sig, &set, sizeof(set));
236}
237
238COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
239 compat_old_sigset_t __user *, nset,
240 compat_old_sigset_t __user *, oset)
241{
242 old_sigset_t old_set, new_set;
243 sigset_t new_blocked;
244
245 old_set = current->blocked.sig[0];
246
247 if (nset) {
248 if (get_user(new_set, nset))
249 return -EFAULT;
250 new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
251
252 new_blocked = current->blocked;
253
254 switch (how) {
255 case SIG_BLOCK:
256 sigaddsetmask(&new_blocked, new_set);
257 break;
258 case SIG_UNBLOCK:
259 sigdelsetmask(&new_blocked, new_set);
260 break;
261 case SIG_SETMASK:
262 compat_sig_setmask(&new_blocked, new_set);
263 break;
264 default:
265 return -EINVAL;
266 }
267
268 set_current_blocked(&new_blocked);
269 }
270
271 if (oset) {
272 if (put_user(old_set, oset))
273 return -EFAULT;
274 }
275
276 return 0;
277}
278
279#endif
280
281int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
282{
283 struct compat_rusage r32;
284 memset(&r32, 0, sizeof(r32));
285 r32.ru_utime.tv_sec = r->ru_utime.tv_sec;
286 r32.ru_utime.tv_usec = r->ru_utime.tv_usec;
287 r32.ru_stime.tv_sec = r->ru_stime.tv_sec;
288 r32.ru_stime.tv_usec = r->ru_stime.tv_usec;
289 r32.ru_maxrss = r->ru_maxrss;
290 r32.ru_ixrss = r->ru_ixrss;
291 r32.ru_idrss = r->ru_idrss;
292 r32.ru_isrss = r->ru_isrss;
293 r32.ru_minflt = r->ru_minflt;
294 r32.ru_majflt = r->ru_majflt;
295 r32.ru_nswap = r->ru_nswap;
296 r32.ru_inblock = r->ru_inblock;
297 r32.ru_oublock = r->ru_oublock;
298 r32.ru_msgsnd = r->ru_msgsnd;
299 r32.ru_msgrcv = r->ru_msgrcv;
300 r32.ru_nsignals = r->ru_nsignals;
301 r32.ru_nvcsw = r->ru_nvcsw;
302 r32.ru_nivcsw = r->ru_nivcsw;
303 if (copy_to_user(ru, &r32, sizeof(r32)))
304 return -EFAULT;
305 return 0;
306}
307
308static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
309 unsigned len, struct cpumask *new_mask)
310{
311 unsigned long *k;
312
313 if (len < cpumask_size())
314 memset(new_mask, 0, cpumask_size());
315 else if (len > cpumask_size())
316 len = cpumask_size();
317
318 k = cpumask_bits(new_mask);
319 return compat_get_bitmap(k, user_mask_ptr, len * 8);
320}
321
322COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
323 unsigned int, len,
324 compat_ulong_t __user *, user_mask_ptr)
325{
326 cpumask_var_t new_mask;
327 int retval;
328
329 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
330 return -ENOMEM;
331
332 retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
333 if (retval)
334 goto out;
335
336 retval = sched_setaffinity(pid, new_mask);
337out:
338 free_cpumask_var(new_mask);
339 return retval;
340}
341
342COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len,
343 compat_ulong_t __user *, user_mask_ptr)
344{
345 int ret;
346 cpumask_var_t mask;
347
348 if ((len * BITS_PER_BYTE) < nr_cpu_ids)
349 return -EINVAL;
350 if (len & (sizeof(compat_ulong_t)-1))
351 return -EINVAL;
352
353 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
354 return -ENOMEM;
355
356 ret = sched_getaffinity(pid, mask);
357 if (ret == 0) {
358 size_t retlen = min_t(size_t, len, cpumask_size());
359
360 if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
361 ret = -EFAULT;
362 else
363 ret = retlen;
364 }
365 free_cpumask_var(mask);
366
367 return ret;
368}
369
370int get_compat_itimerspec64(struct itimerspec64 *its,
371 const struct compat_itimerspec __user *uits)
372{
373
374 if (__compat_get_timespec64(&its->it_interval, &uits->it_interval) ||
375 __compat_get_timespec64(&its->it_value, &uits->it_value))
376 return -EFAULT;
377 return 0;
378}
379EXPORT_SYMBOL_GPL(get_compat_itimerspec64);
380
381int put_compat_itimerspec64(const struct itimerspec64 *its,
382 struct compat_itimerspec __user *uits)
383{
384 if (__compat_put_timespec64(&its->it_interval, &uits->it_interval) ||
385 __compat_put_timespec64(&its->it_value, &uits->it_value))
386 return -EFAULT;
387 return 0;
388}
389EXPORT_SYMBOL_GPL(put_compat_itimerspec64);
390
391/*
392 * We currently only need the following fields from the sigevent
393 * structure: sigev_value, sigev_signo, sig_notify and (sometimes
394 * sigev_notify_thread_id). The others are handled in user mode.
395 * We also assume that copying sigev_value.sival_int is sufficient
396 * to keep all the bits of sigev_value.sival_ptr intact.
397 */
398int get_compat_sigevent(struct sigevent *event,
399 const struct compat_sigevent __user *u_event)
400{
401 memset(event, 0, sizeof(*event));
402 return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
403 __get_user(event->sigev_value.sival_int,
404 &u_event->sigev_value.sival_int) ||
405 __get_user(event->sigev_signo, &u_event->sigev_signo) ||
406 __get_user(event->sigev_notify, &u_event->sigev_notify) ||
407 __get_user(event->sigev_notify_thread_id,
408 &u_event->sigev_notify_thread_id))
409 ? -EFAULT : 0;
410}
411
412long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
413 unsigned long bitmap_size)
414{
415 unsigned long nr_compat_longs;
416
417 /* align bitmap up to nearest compat_long_t boundary */
418 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
419 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
420
421 if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
422 return -EFAULT;
423
424 user_access_begin();
425 while (nr_compat_longs > 1) {
426 compat_ulong_t l1, l2;
427 unsafe_get_user(l1, umask++, Efault);
428 unsafe_get_user(l2, umask++, Efault);
429 *mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1;
430 nr_compat_longs -= 2;
431 }
432 if (nr_compat_longs)
433 unsafe_get_user(*mask, umask++, Efault);
434 user_access_end();
435 return 0;
436
437Efault:
438 user_access_end();
439 return -EFAULT;
440}
441
442long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
443 unsigned long bitmap_size)
444{
445 unsigned long nr_compat_longs;
446
447 /* align bitmap up to nearest compat_long_t boundary */
448 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
449 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
450
451 if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
452 return -EFAULT;
453
454 user_access_begin();
455 while (nr_compat_longs > 1) {
456 unsigned long m = *mask++;
457 unsafe_put_user((compat_ulong_t)m, umask++, Efault);
458 unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault);
459 nr_compat_longs -= 2;
460 }
461 if (nr_compat_longs)
462 unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
463 user_access_end();
464 return 0;
465Efault:
466 user_access_end();
467 return -EFAULT;
468}
469
470int
471get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
472{
473#ifdef __BIG_ENDIAN
474 compat_sigset_t v;
475 if (copy_from_user(&v, compat, sizeof(compat_sigset_t)))
476 return -EFAULT;
477 switch (_NSIG_WORDS) {
478 case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
479 case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
480 case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
481 case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
482 }
483#else
484 if (copy_from_user(set, compat, sizeof(compat_sigset_t)))
485 return -EFAULT;
486#endif
487 return 0;
488}
489EXPORT_SYMBOL_GPL(get_compat_sigset);
490
491int
492put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set,
493 unsigned int size)
494{
495 /* size <= sizeof(compat_sigset_t) <= sizeof(sigset_t) */
496#ifdef __BIG_ENDIAN
497 compat_sigset_t v;
498 switch (_NSIG_WORDS) {
499 case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
500 case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
501 case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
502 case 1: v.sig[1] = (set->sig[0] >> 32); v.sig[0] = set->sig[0];
503 }
504 return copy_to_user(compat, &v, size) ? -EFAULT : 0;
505#else
506 return copy_to_user(compat, set, size) ? -EFAULT : 0;
507#endif
508}
509
510#ifdef CONFIG_NUMA
511COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
512 compat_uptr_t __user *, pages32,
513 const int __user *, nodes,
514 int __user *, status,
515 int, flags)
516{
517 const void __user * __user *pages;
518 int i;
519
520 pages = compat_alloc_user_space(nr_pages * sizeof(void *));
521 for (i = 0; i < nr_pages; i++) {
522 compat_uptr_t p;
523
524 if (get_user(p, pages32 + i) ||
525 put_user(compat_ptr(p), pages + i))
526 return -EFAULT;
527 }
528 return sys_move_pages(pid, nr_pages, pages, nodes, status, flags);
529}
530
531COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
532 compat_ulong_t, maxnode,
533 const compat_ulong_t __user *, old_nodes,
534 const compat_ulong_t __user *, new_nodes)
535{
536 unsigned long __user *old = NULL;
537 unsigned long __user *new = NULL;
538 nodemask_t tmp_mask;
539 unsigned long nr_bits;
540 unsigned long size;
541
542 nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
543 size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
544 if (old_nodes) {
545 if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
546 return -EFAULT;
547 old = compat_alloc_user_space(new_nodes ? size * 2 : size);
548 if (new_nodes)
549 new = old + size / sizeof(unsigned long);
550 if (copy_to_user(old, nodes_addr(tmp_mask), size))
551 return -EFAULT;
552 }
553 if (new_nodes) {
554 if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
555 return -EFAULT;
556 if (new == NULL)
557 new = compat_alloc_user_space(size);
558 if (copy_to_user(new, nodes_addr(tmp_mask), size))
559 return -EFAULT;
560 }
561 return sys_migrate_pages(pid, nr_bits + 1, old, new);
562}
563#endif
564
565/*
566 * Allocate user-space memory for the duration of a single system call,
567 * in order to marshall parameters inside a compat thunk.
568 */
569void __user *compat_alloc_user_space(unsigned long len)
570{
571 void __user *ptr;
572
573 /* If len would occupy more than half of the entire compat space... */
574 if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
575 return NULL;
576
577 ptr = arch_compat_alloc_user_space(len);
578
579 if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
580 return NULL;
581
582 return ptr;
583}
584EXPORT_SYMBOL_GPL(compat_alloc_user_space);