projects/linux·blob v4.17 · refs

511 lines · 13.6 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 memset(txc, 0, sizeof(struct timex));
38 if (copy_from_user(&tx32, utp, sizeof(struct compat_timex)))
39 return -EFAULT;
40
41 txc->modes = tx32.modes;
42 txc->offset = tx32.offset;
43 txc->freq = tx32.freq;
44 txc->maxerror = tx32.maxerror;
45 txc->esterror = tx32.esterror;
46 txc->status = tx32.status;
47 txc->constant = tx32.constant;
48 txc->precision = tx32.precision;
49 txc->tolerance = tx32.tolerance;
50 txc->time.tv_sec = tx32.time.tv_sec;
51 txc->time.tv_usec = tx32.time.tv_usec;
52 txc->tick = tx32.tick;
53 txc->ppsfreq = tx32.ppsfreq;
54 txc->jitter = tx32.jitter;
55 txc->shift = tx32.shift;
56 txc->stabil = tx32.stabil;
57 txc->jitcnt = tx32.jitcnt;
58 txc->calcnt = tx32.calcnt;
59 txc->errcnt = tx32.errcnt;
60 txc->stbcnt = tx32.stbcnt;
61
62 return 0;
63}
64
65int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc)
66{
67 struct compat_timex tx32;
68
69 memset(&tx32, 0, sizeof(struct compat_timex));
70 tx32.modes = txc->modes;
71 tx32.offset = txc->offset;
72 tx32.freq = txc->freq;
73 tx32.maxerror = txc->maxerror;
74 tx32.esterror = txc->esterror;
75 tx32.status = txc->status;
76 tx32.constant = txc->constant;
77 tx32.precision = txc->precision;
78 tx32.tolerance = txc->tolerance;
79 tx32.time.tv_sec = txc->time.tv_sec;
80 tx32.time.tv_usec = txc->time.tv_usec;
81 tx32.tick = txc->tick;
82 tx32.ppsfreq = txc->ppsfreq;
83 tx32.jitter = txc->jitter;
84 tx32.shift = txc->shift;
85 tx32.stabil = txc->stabil;
86 tx32.jitcnt = txc->jitcnt;
87 tx32.calcnt = txc->calcnt;
88 tx32.errcnt = txc->errcnt;
89 tx32.stbcnt = txc->stbcnt;
90 tx32.tai = txc->tai;
91 if (copy_to_user(utp, &tx32, sizeof(struct compat_timex)))
92 return -EFAULT;
93 return 0;
94}
95
96static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv)
97{
98 return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||
99 __get_user(tv->tv_sec, &ctv->tv_sec) ||
100 __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
101}
102
103static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv)
104{
105 return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
106 __put_user(tv->tv_sec, &ctv->tv_sec) ||
107 __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
108}
109
110static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
111{
112 return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
113 __get_user(ts->tv_sec, &cts->tv_sec) ||
114 __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
115}
116
117static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
118{
119 return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
120 __put_user(ts->tv_sec, &cts->tv_sec) ||
121 __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
122}
123
124static int __compat_get_timespec64(struct timespec64 *ts64,
125 const struct compat_timespec __user *cts)
126{
127 struct compat_timespec ts;
128 int ret;
129
130 ret = copy_from_user(&ts, cts, sizeof(ts));
131 if (ret)
132 return -EFAULT;
133
134 ts64->tv_sec = ts.tv_sec;
135 ts64->tv_nsec = ts.tv_nsec;
136
137 return 0;
138}
139
140static int __compat_put_timespec64(const struct timespec64 *ts64,
141 struct compat_timespec __user *cts)
142{
143 struct compat_timespec ts = {
144 .tv_sec = ts64->tv_sec,
145 .tv_nsec = ts64->tv_nsec
146 };
147 return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0;
148}
149
150int compat_get_timespec64(struct timespec64 *ts, const void __user *uts)
151{
152 if (COMPAT_USE_64BIT_TIME)
153 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
154 else
155 return __compat_get_timespec64(ts, uts);
156}
157EXPORT_SYMBOL_GPL(compat_get_timespec64);
158
159int compat_put_timespec64(const struct timespec64 *ts, void __user *uts)
160{
161 if (COMPAT_USE_64BIT_TIME)
162 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
163 else
164 return __compat_put_timespec64(ts, uts);
165}
166EXPORT_SYMBOL_GPL(compat_put_timespec64);
167
168int compat_get_timeval(struct timeval *tv, const void __user *utv)
169{
170 if (COMPAT_USE_64BIT_TIME)
171 return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0;
172 else
173 return __compat_get_timeval(tv, utv);
174}
175EXPORT_SYMBOL_GPL(compat_get_timeval);
176
177int compat_put_timeval(const struct timeval *tv, void __user *utv)
178{
179 if (COMPAT_USE_64BIT_TIME)
180 return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0;
181 else
182 return __compat_put_timeval(tv, utv);
183}
184EXPORT_SYMBOL_GPL(compat_put_timeval);
185
186int compat_get_timespec(struct timespec *ts, const void __user *uts)
187{
188 if (COMPAT_USE_64BIT_TIME)
189 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
190 else
191 return __compat_get_timespec(ts, uts);
192}
193EXPORT_SYMBOL_GPL(compat_get_timespec);
194
195int compat_put_timespec(const struct timespec *ts, void __user *uts)
196{
197 if (COMPAT_USE_64BIT_TIME)
198 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
199 else
200 return __compat_put_timespec(ts, uts);
201}
202EXPORT_SYMBOL_GPL(compat_put_timespec);
203
204int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i)
205{
206 struct compat_itimerval v32;
207
208 if (copy_from_user(&v32, i, sizeof(struct compat_itimerval)))
209 return -EFAULT;
210 o->it_interval.tv_sec = v32.it_interval.tv_sec;
211 o->it_interval.tv_usec = v32.it_interval.tv_usec;
212 o->it_value.tv_sec = v32.it_value.tv_sec;
213 o->it_value.tv_usec = v32.it_value.tv_usec;
214 return 0;
215}
216
217int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i)
218{
219 struct compat_itimerval v32;
220
221 v32.it_interval.tv_sec = i->it_interval.tv_sec;
222 v32.it_interval.tv_usec = i->it_interval.tv_usec;
223 v32.it_value.tv_sec = i->it_value.tv_sec;
224 v32.it_value.tv_usec = i->it_value.tv_usec;
225 return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0;
226}
227
228#ifdef __ARCH_WANT_SYS_SIGPROCMASK
229
230/*
231 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
232 * blocked set of signals to the supplied signal set
233 */
234static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
235{
236 memcpy(blocked->sig, &set, sizeof(set));
237}
238
239COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
240 compat_old_sigset_t __user *, nset,
241 compat_old_sigset_t __user *, oset)
242{
243 old_sigset_t old_set, new_set;
244 sigset_t new_blocked;
245
246 old_set = current->blocked.sig[0];
247
248 if (nset) {
249 if (get_user(new_set, nset))
250 return -EFAULT;
251 new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
252
253 new_blocked = current->blocked;
254
255 switch (how) {
256 case SIG_BLOCK:
257 sigaddsetmask(&new_blocked, new_set);
258 break;
259 case SIG_UNBLOCK:
260 sigdelsetmask(&new_blocked, new_set);
261 break;
262 case SIG_SETMASK:
263 compat_sig_setmask(&new_blocked, new_set);
264 break;
265 default:
266 return -EINVAL;
267 }
268
269 set_current_blocked(&new_blocked);
270 }
271
272 if (oset) {
273 if (put_user(old_set, oset))
274 return -EFAULT;
275 }
276
277 return 0;
278}
279
280#endif
281
282int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
283{
284 struct compat_rusage r32;
285 memset(&r32, 0, sizeof(r32));
286 r32.ru_utime.tv_sec = r->ru_utime.tv_sec;
287 r32.ru_utime.tv_usec = r->ru_utime.tv_usec;
288 r32.ru_stime.tv_sec = r->ru_stime.tv_sec;
289 r32.ru_stime.tv_usec = r->ru_stime.tv_usec;
290 r32.ru_maxrss = r->ru_maxrss;
291 r32.ru_ixrss = r->ru_ixrss;
292 r32.ru_idrss = r->ru_idrss;
293 r32.ru_isrss = r->ru_isrss;
294 r32.ru_minflt = r->ru_minflt;
295 r32.ru_majflt = r->ru_majflt;
296 r32.ru_nswap = r->ru_nswap;
297 r32.ru_inblock = r->ru_inblock;
298 r32.ru_oublock = r->ru_oublock;
299 r32.ru_msgsnd = r->ru_msgsnd;
300 r32.ru_msgrcv = r->ru_msgrcv;
301 r32.ru_nsignals = r->ru_nsignals;
302 r32.ru_nvcsw = r->ru_nvcsw;
303 r32.ru_nivcsw = r->ru_nivcsw;
304 if (copy_to_user(ru, &r32, sizeof(r32)))
305 return -EFAULT;
306 return 0;
307}
308
309static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
310 unsigned len, struct cpumask *new_mask)
311{
312 unsigned long *k;
313
314 if (len < cpumask_size())
315 memset(new_mask, 0, cpumask_size());
316 else if (len > cpumask_size())
317 len = cpumask_size();
318
319 k = cpumask_bits(new_mask);
320 return compat_get_bitmap(k, user_mask_ptr, len * 8);
321}
322
323COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
324 unsigned int, len,
325 compat_ulong_t __user *, user_mask_ptr)
326{
327 cpumask_var_t new_mask;
328 int retval;
329
330 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
331 return -ENOMEM;
332
333 retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
334 if (retval)
335 goto out;
336
337 retval = sched_setaffinity(pid, new_mask);
338out:
339 free_cpumask_var(new_mask);
340 return retval;
341}
342
343COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len,
344 compat_ulong_t __user *, user_mask_ptr)
345{
346 int ret;
347 cpumask_var_t mask;
348
349 if ((len * BITS_PER_BYTE) < nr_cpu_ids)
350 return -EINVAL;
351 if (len & (sizeof(compat_ulong_t)-1))
352 return -EINVAL;
353
354 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
355 return -ENOMEM;
356
357 ret = sched_getaffinity(pid, mask);
358 if (ret == 0) {
359 unsigned int retlen = min(len, cpumask_size());
360
361 if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
362 ret = -EFAULT;
363 else
364 ret = retlen;
365 }
366 free_cpumask_var(mask);
367
368 return ret;
369}
370
371int get_compat_itimerspec64(struct itimerspec64 *its,
372 const struct compat_itimerspec __user *uits)
373{
374
375 if (__compat_get_timespec64(&its->it_interval, &uits->it_interval) ||
376 __compat_get_timespec64(&its->it_value, &uits->it_value))
377 return -EFAULT;
378 return 0;
379}
380EXPORT_SYMBOL_GPL(get_compat_itimerspec64);
381
382int put_compat_itimerspec64(const struct itimerspec64 *its,
383 struct compat_itimerspec __user *uits)
384{
385 if (__compat_put_timespec64(&its->it_interval, &uits->it_interval) ||
386 __compat_put_timespec64(&its->it_value, &uits->it_value))
387 return -EFAULT;
388 return 0;
389}
390EXPORT_SYMBOL_GPL(put_compat_itimerspec64);
391
392/*
393 * We currently only need the following fields from the sigevent
394 * structure: sigev_value, sigev_signo, sig_notify and (sometimes
395 * sigev_notify_thread_id). The others are handled in user mode.
396 * We also assume that copying sigev_value.sival_int is sufficient
397 * to keep all the bits of sigev_value.sival_ptr intact.
398 */
399int get_compat_sigevent(struct sigevent *event,
400 const struct compat_sigevent __user *u_event)
401{
402 memset(event, 0, sizeof(*event));
403 return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
404 __get_user(event->sigev_value.sival_int,
405 &u_event->sigev_value.sival_int) ||
406 __get_user(event->sigev_signo, &u_event->sigev_signo) ||
407 __get_user(event->sigev_notify, &u_event->sigev_notify) ||
408 __get_user(event->sigev_notify_thread_id,
409 &u_event->sigev_notify_thread_id))
410 ? -EFAULT : 0;
411}
412
413long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
414 unsigned long bitmap_size)
415{
416 unsigned long nr_compat_longs;
417
418 /* align bitmap up to nearest compat_long_t boundary */
419 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
420 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
421
422 if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
423 return -EFAULT;
424
425 user_access_begin();
426 while (nr_compat_longs > 1) {
427 compat_ulong_t l1, l2;
428 unsafe_get_user(l1, umask++, Efault);
429 unsafe_get_user(l2, umask++, Efault);
430 *mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1;
431 nr_compat_longs -= 2;
432 }
433 if (nr_compat_longs)
434 unsafe_get_user(*mask, umask++, Efault);
435 user_access_end();
436 return 0;
437
438Efault:
439 user_access_end();
440 return -EFAULT;
441}
442
443long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
444 unsigned long bitmap_size)
445{
446 unsigned long nr_compat_longs;
447
448 /* align bitmap up to nearest compat_long_t boundary */
449 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
450 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
451
452 if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
453 return -EFAULT;
454
455 user_access_begin();
456 while (nr_compat_longs > 1) {
457 unsigned long m = *mask++;
458 unsafe_put_user((compat_ulong_t)m, umask++, Efault);
459 unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault);
460 nr_compat_longs -= 2;
461 }
462 if (nr_compat_longs)
463 unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
464 user_access_end();
465 return 0;
466Efault:
467 user_access_end();
468 return -EFAULT;
469}
470
471int
472get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
473{
474#ifdef __BIG_ENDIAN
475 compat_sigset_t v;
476 if (copy_from_user(&v, compat, sizeof(compat_sigset_t)))
477 return -EFAULT;
478 switch (_NSIG_WORDS) {
479 case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
480 case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
481 case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
482 case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
483 }
484#else
485 if (copy_from_user(set, compat, sizeof(compat_sigset_t)))
486 return -EFAULT;
487#endif
488 return 0;
489}
490EXPORT_SYMBOL_GPL(get_compat_sigset);
491
492/*
493 * Allocate user-space memory for the duration of a single system call,
494 * in order to marshall parameters inside a compat thunk.
495 */
496void __user *compat_alloc_user_space(unsigned long len)
497{
498 void __user *ptr;
499
500 /* If len would occupy more than half of the entire compat space... */
501 if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
502 return NULL;
503
504 ptr = arch_compat_alloc_user_space(len);
505
506 if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
507 return NULL;
508
509 return ptr;
510}
511EXPORT_SYMBOL_GPL(compat_alloc_user_space);