xref: /openbmc/linux/kernel/compat.c (revision f7d84fa7)
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 
33 static int compat_get_timex(struct timex *txc, struct compat_timex __user *utp)
34 {
35 	memset(txc, 0, sizeof(struct timex));
36 
37 	if (!access_ok(VERIFY_READ, utp, sizeof(struct compat_timex)) ||
38 			__get_user(txc->modes, &utp->modes) ||
39 			__get_user(txc->offset, &utp->offset) ||
40 			__get_user(txc->freq, &utp->freq) ||
41 			__get_user(txc->maxerror, &utp->maxerror) ||
42 			__get_user(txc->esterror, &utp->esterror) ||
43 			__get_user(txc->status, &utp->status) ||
44 			__get_user(txc->constant, &utp->constant) ||
45 			__get_user(txc->precision, &utp->precision) ||
46 			__get_user(txc->tolerance, &utp->tolerance) ||
47 			__get_user(txc->time.tv_sec, &utp->time.tv_sec) ||
48 			__get_user(txc->time.tv_usec, &utp->time.tv_usec) ||
49 			__get_user(txc->tick, &utp->tick) ||
50 			__get_user(txc->ppsfreq, &utp->ppsfreq) ||
51 			__get_user(txc->jitter, &utp->jitter) ||
52 			__get_user(txc->shift, &utp->shift) ||
53 			__get_user(txc->stabil, &utp->stabil) ||
54 			__get_user(txc->jitcnt, &utp->jitcnt) ||
55 			__get_user(txc->calcnt, &utp->calcnt) ||
56 			__get_user(txc->errcnt, &utp->errcnt) ||
57 			__get_user(txc->stbcnt, &utp->stbcnt))
58 		return -EFAULT;
59 
60 	return 0;
61 }
62 
63 static int compat_put_timex(struct compat_timex __user *utp, struct timex *txc)
64 {
65 	if (!access_ok(VERIFY_WRITE, utp, sizeof(struct compat_timex)) ||
66 			__put_user(txc->modes, &utp->modes) ||
67 			__put_user(txc->offset, &utp->offset) ||
68 			__put_user(txc->freq, &utp->freq) ||
69 			__put_user(txc->maxerror, &utp->maxerror) ||
70 			__put_user(txc->esterror, &utp->esterror) ||
71 			__put_user(txc->status, &utp->status) ||
72 			__put_user(txc->constant, &utp->constant) ||
73 			__put_user(txc->precision, &utp->precision) ||
74 			__put_user(txc->tolerance, &utp->tolerance) ||
75 			__put_user(txc->time.tv_sec, &utp->time.tv_sec) ||
76 			__put_user(txc->time.tv_usec, &utp->time.tv_usec) ||
77 			__put_user(txc->tick, &utp->tick) ||
78 			__put_user(txc->ppsfreq, &utp->ppsfreq) ||
79 			__put_user(txc->jitter, &utp->jitter) ||
80 			__put_user(txc->shift, &utp->shift) ||
81 			__put_user(txc->stabil, &utp->stabil) ||
82 			__put_user(txc->jitcnt, &utp->jitcnt) ||
83 			__put_user(txc->calcnt, &utp->calcnt) ||
84 			__put_user(txc->errcnt, &utp->errcnt) ||
85 			__put_user(txc->stbcnt, &utp->stbcnt) ||
86 			__put_user(txc->tai, &utp->tai))
87 		return -EFAULT;
88 	return 0;
89 }
90 
91 COMPAT_SYSCALL_DEFINE2(gettimeofday, struct compat_timeval __user *, tv,
92 		       struct timezone __user *, tz)
93 {
94 	if (tv) {
95 		struct timeval ktv;
96 		do_gettimeofday(&ktv);
97 		if (compat_put_timeval(&ktv, tv))
98 			return -EFAULT;
99 	}
100 	if (tz) {
101 		if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
102 			return -EFAULT;
103 	}
104 
105 	return 0;
106 }
107 
108 COMPAT_SYSCALL_DEFINE2(settimeofday, struct compat_timeval __user *, tv,
109 		       struct timezone __user *, tz)
110 {
111 	struct timespec64 new_ts;
112 	struct timeval user_tv;
113 	struct timezone new_tz;
114 
115 	if (tv) {
116 		if (compat_get_timeval(&user_tv, tv))
117 			return -EFAULT;
118 		new_ts.tv_sec = user_tv.tv_sec;
119 		new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
120 	}
121 	if (tz) {
122 		if (copy_from_user(&new_tz, tz, sizeof(*tz)))
123 			return -EFAULT;
124 	}
125 
126 	return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL);
127 }
128 
129 static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv)
130 {
131 	return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||
132 			__get_user(tv->tv_sec, &ctv->tv_sec) ||
133 			__get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
134 }
135 
136 static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv)
137 {
138 	return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
139 			__put_user(tv->tv_sec, &ctv->tv_sec) ||
140 			__put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
141 }
142 
143 static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
144 {
145 	return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
146 			__get_user(ts->tv_sec, &cts->tv_sec) ||
147 			__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
148 }
149 
150 static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
151 {
152 	return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
153 			__put_user(ts->tv_sec, &cts->tv_sec) ||
154 			__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
155 }
156 
157 int compat_get_timeval(struct timeval *tv, const void __user *utv)
158 {
159 	if (COMPAT_USE_64BIT_TIME)
160 		return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0;
161 	else
162 		return __compat_get_timeval(tv, utv);
163 }
164 EXPORT_SYMBOL_GPL(compat_get_timeval);
165 
166 int compat_put_timeval(const struct timeval *tv, void __user *utv)
167 {
168 	if (COMPAT_USE_64BIT_TIME)
169 		return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0;
170 	else
171 		return __compat_put_timeval(tv, utv);
172 }
173 EXPORT_SYMBOL_GPL(compat_put_timeval);
174 
175 int compat_get_timespec(struct timespec *ts, const void __user *uts)
176 {
177 	if (COMPAT_USE_64BIT_TIME)
178 		return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
179 	else
180 		return __compat_get_timespec(ts, uts);
181 }
182 EXPORT_SYMBOL_GPL(compat_get_timespec);
183 
184 int compat_put_timespec(const struct timespec *ts, void __user *uts)
185 {
186 	if (COMPAT_USE_64BIT_TIME)
187 		return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
188 	else
189 		return __compat_put_timespec(ts, uts);
190 }
191 EXPORT_SYMBOL_GPL(compat_put_timespec);
192 
193 int compat_convert_timespec(struct timespec __user **kts,
194 			    const void __user *cts)
195 {
196 	struct timespec ts;
197 	struct timespec __user *uts;
198 
199 	if (!cts || COMPAT_USE_64BIT_TIME) {
200 		*kts = (struct timespec __user *)cts;
201 		return 0;
202 	}
203 
204 	uts = compat_alloc_user_space(sizeof(ts));
205 	if (!uts)
206 		return -EFAULT;
207 	if (compat_get_timespec(&ts, cts))
208 		return -EFAULT;
209 	if (copy_to_user(uts, &ts, sizeof(ts)))
210 		return -EFAULT;
211 
212 	*kts = uts;
213 	return 0;
214 }
215 
216 static long compat_nanosleep_restart(struct restart_block *restart)
217 {
218 	struct compat_timespec __user *rmtp;
219 	struct timespec rmt;
220 	mm_segment_t oldfs;
221 	long ret;
222 
223 	restart->nanosleep.rmtp = (struct timespec __user *) &rmt;
224 	oldfs = get_fs();
225 	set_fs(KERNEL_DS);
226 	ret = hrtimer_nanosleep_restart(restart);
227 	set_fs(oldfs);
228 
229 	if (ret == -ERESTART_RESTARTBLOCK) {
230 		rmtp = restart->nanosleep.compat_rmtp;
231 
232 		if (rmtp && compat_put_timespec(&rmt, rmtp))
233 			return -EFAULT;
234 	}
235 
236 	return ret;
237 }
238 
239 COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
240 		       struct compat_timespec __user *, rmtp)
241 {
242 	struct timespec tu, rmt;
243 	struct timespec64 tu64;
244 	mm_segment_t oldfs;
245 	long ret;
246 
247 	if (compat_get_timespec(&tu, rqtp))
248 		return -EFAULT;
249 
250 	tu64 = timespec_to_timespec64(tu);
251 	if (!timespec64_valid(&tu64))
252 		return -EINVAL;
253 
254 	oldfs = get_fs();
255 	set_fs(KERNEL_DS);
256 	ret = hrtimer_nanosleep(&tu64,
257 				rmtp ? (struct timespec __user *)&rmt : NULL,
258 				HRTIMER_MODE_REL, CLOCK_MONOTONIC);
259 	set_fs(oldfs);
260 
261 	/*
262 	 * hrtimer_nanosleep() can only return 0 or
263 	 * -ERESTART_RESTARTBLOCK here because:
264 	 *
265 	 * - we call it with HRTIMER_MODE_REL and therefor exclude the
266 	 *   -ERESTARTNOHAND return path.
267 	 *
268 	 * - we supply the rmtp argument from the task stack (due to
269 	 *   the necessary compat conversion. So the update cannot
270 	 *   fail, which excludes the -EFAULT return path as well. If
271 	 *   it fails nevertheless we have a bigger problem and wont
272 	 *   reach this place anymore.
273 	 *
274 	 * - if the return value is 0, we do not have to update rmtp
275 	 *    because there is no remaining time.
276 	 *
277 	 * We check for -ERESTART_RESTARTBLOCK nevertheless if the
278 	 * core implementation decides to return random nonsense.
279 	 */
280 	if (ret == -ERESTART_RESTARTBLOCK) {
281 		struct restart_block *restart = &current->restart_block;
282 
283 		restart->fn = compat_nanosleep_restart;
284 		restart->nanosleep.compat_rmtp = rmtp;
285 
286 		if (rmtp && compat_put_timespec(&rmt, rmtp))
287 			return -EFAULT;
288 	}
289 	return ret;
290 }
291 
292 static inline long get_compat_itimerval(struct itimerval *o,
293 		struct compat_itimerval __user *i)
294 {
295 	return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
296 		(__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
297 		 __get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
298 		 __get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
299 		 __get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
300 }
301 
302 static inline long put_compat_itimerval(struct compat_itimerval __user *o,
303 		struct itimerval *i)
304 {
305 	return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
306 		(__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
307 		 __put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
308 		 __put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
309 		 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
310 }
311 
312 asmlinkage long sys_ni_posix_timers(void);
313 
314 COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
315 		struct compat_itimerval __user *, it)
316 {
317 	struct itimerval kit;
318 	int error;
319 
320 	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
321 		return sys_ni_posix_timers();
322 
323 	error = do_getitimer(which, &kit);
324 	if (!error && put_compat_itimerval(it, &kit))
325 		error = -EFAULT;
326 	return error;
327 }
328 
329 COMPAT_SYSCALL_DEFINE3(setitimer, int, which,
330 		struct compat_itimerval __user *, in,
331 		struct compat_itimerval __user *, out)
332 {
333 	struct itimerval kin, kout;
334 	int error;
335 
336 	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
337 		return sys_ni_posix_timers();
338 
339 	if (in) {
340 		if (get_compat_itimerval(&kin, in))
341 			return -EFAULT;
342 	} else
343 		memset(&kin, 0, sizeof(kin));
344 
345 	error = do_setitimer(which, &kin, out ? &kout : NULL);
346 	if (error || !out)
347 		return error;
348 	if (put_compat_itimerval(out, &kout))
349 		return -EFAULT;
350 	return 0;
351 }
352 
353 static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
354 {
355 	return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
356 }
357 
358 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
359 {
360 	if (tbuf) {
361 		struct tms tms;
362 		struct compat_tms tmp;
363 
364 		do_sys_times(&tms);
365 		/* Convert our struct tms to the compat version. */
366 		tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
367 		tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
368 		tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
369 		tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
370 		if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
371 			return -EFAULT;
372 	}
373 	force_successful_syscall_return();
374 	return compat_jiffies_to_clock_t(jiffies);
375 }
376 
377 #ifdef __ARCH_WANT_SYS_SIGPENDING
378 
379 /*
380  * Assumption: old_sigset_t and compat_old_sigset_t are both
381  * types that can be passed to put_user()/get_user().
382  */
383 
384 COMPAT_SYSCALL_DEFINE1(sigpending, compat_old_sigset_t __user *, set)
385 {
386 	old_sigset_t s;
387 	long ret;
388 	mm_segment_t old_fs = get_fs();
389 
390 	set_fs(KERNEL_DS);
391 	ret = sys_sigpending((old_sigset_t __user *) &s);
392 	set_fs(old_fs);
393 	if (ret == 0)
394 		ret = put_user(s, set);
395 	return ret;
396 }
397 
398 #endif
399 
400 #ifdef __ARCH_WANT_SYS_SIGPROCMASK
401 
402 /*
403  * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
404  * blocked set of signals to the supplied signal set
405  */
406 static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
407 {
408 	memcpy(blocked->sig, &set, sizeof(set));
409 }
410 
411 COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
412 		       compat_old_sigset_t __user *, nset,
413 		       compat_old_sigset_t __user *, oset)
414 {
415 	old_sigset_t old_set, new_set;
416 	sigset_t new_blocked;
417 
418 	old_set = current->blocked.sig[0];
419 
420 	if (nset) {
421 		if (get_user(new_set, nset))
422 			return -EFAULT;
423 		new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
424 
425 		new_blocked = current->blocked;
426 
427 		switch (how) {
428 		case SIG_BLOCK:
429 			sigaddsetmask(&new_blocked, new_set);
430 			break;
431 		case SIG_UNBLOCK:
432 			sigdelsetmask(&new_blocked, new_set);
433 			break;
434 		case SIG_SETMASK:
435 			compat_sig_setmask(&new_blocked, new_set);
436 			break;
437 		default:
438 			return -EINVAL;
439 		}
440 
441 		set_current_blocked(&new_blocked);
442 	}
443 
444 	if (oset) {
445 		if (put_user(old_set, oset))
446 			return -EFAULT;
447 	}
448 
449 	return 0;
450 }
451 
452 #endif
453 
454 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
455 		       struct compat_rlimit __user *, rlim)
456 {
457 	struct rlimit r;
458 
459 	if (!access_ok(VERIFY_READ, rlim, sizeof(*rlim)) ||
460 	    __get_user(r.rlim_cur, &rlim->rlim_cur) ||
461 	    __get_user(r.rlim_max, &rlim->rlim_max))
462 		return -EFAULT;
463 
464 	if (r.rlim_cur == COMPAT_RLIM_INFINITY)
465 		r.rlim_cur = RLIM_INFINITY;
466 	if (r.rlim_max == COMPAT_RLIM_INFINITY)
467 		r.rlim_max = RLIM_INFINITY;
468 	return do_prlimit(current, resource, &r, NULL);
469 }
470 
471 #ifdef COMPAT_RLIM_OLD_INFINITY
472 
473 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
474 		       struct compat_rlimit __user *, rlim)
475 {
476 	struct rlimit r;
477 	int ret;
478 	mm_segment_t old_fs = get_fs();
479 
480 	set_fs(KERNEL_DS);
481 	ret = sys_old_getrlimit(resource, (struct rlimit __user *)&r);
482 	set_fs(old_fs);
483 
484 	if (!ret) {
485 		if (r.rlim_cur > COMPAT_RLIM_OLD_INFINITY)
486 			r.rlim_cur = COMPAT_RLIM_INFINITY;
487 		if (r.rlim_max > COMPAT_RLIM_OLD_INFINITY)
488 			r.rlim_max = COMPAT_RLIM_INFINITY;
489 
490 		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
491 		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
492 		    __put_user(r.rlim_max, &rlim->rlim_max))
493 			return -EFAULT;
494 	}
495 	return ret;
496 }
497 
498 #endif
499 
500 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
501 		       struct compat_rlimit __user *, rlim)
502 {
503 	struct rlimit r;
504 	int ret;
505 
506 	ret = do_prlimit(current, resource, NULL, &r);
507 	if (!ret) {
508 		if (r.rlim_cur > COMPAT_RLIM_INFINITY)
509 			r.rlim_cur = COMPAT_RLIM_INFINITY;
510 		if (r.rlim_max > COMPAT_RLIM_INFINITY)
511 			r.rlim_max = COMPAT_RLIM_INFINITY;
512 
513 		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
514 		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
515 		    __put_user(r.rlim_max, &rlim->rlim_max))
516 			return -EFAULT;
517 	}
518 	return ret;
519 }
520 
521 int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
522 {
523 	if (!access_ok(VERIFY_WRITE, ru, sizeof(*ru)) ||
524 	    __put_user(r->ru_utime.tv_sec, &ru->ru_utime.tv_sec) ||
525 	    __put_user(r->ru_utime.tv_usec, &ru->ru_utime.tv_usec) ||
526 	    __put_user(r->ru_stime.tv_sec, &ru->ru_stime.tv_sec) ||
527 	    __put_user(r->ru_stime.tv_usec, &ru->ru_stime.tv_usec) ||
528 	    __put_user(r->ru_maxrss, &ru->ru_maxrss) ||
529 	    __put_user(r->ru_ixrss, &ru->ru_ixrss) ||
530 	    __put_user(r->ru_idrss, &ru->ru_idrss) ||
531 	    __put_user(r->ru_isrss, &ru->ru_isrss) ||
532 	    __put_user(r->ru_minflt, &ru->ru_minflt) ||
533 	    __put_user(r->ru_majflt, &ru->ru_majflt) ||
534 	    __put_user(r->ru_nswap, &ru->ru_nswap) ||
535 	    __put_user(r->ru_inblock, &ru->ru_inblock) ||
536 	    __put_user(r->ru_oublock, &ru->ru_oublock) ||
537 	    __put_user(r->ru_msgsnd, &ru->ru_msgsnd) ||
538 	    __put_user(r->ru_msgrcv, &ru->ru_msgrcv) ||
539 	    __put_user(r->ru_nsignals, &ru->ru_nsignals) ||
540 	    __put_user(r->ru_nvcsw, &ru->ru_nvcsw) ||
541 	    __put_user(r->ru_nivcsw, &ru->ru_nivcsw))
542 		return -EFAULT;
543 	return 0;
544 }
545 
546 COMPAT_SYSCALL_DEFINE4(wait4,
547 	compat_pid_t, pid,
548 	compat_uint_t __user *, stat_addr,
549 	int, options,
550 	struct compat_rusage __user *, ru)
551 {
552 	if (!ru) {
553 		return sys_wait4(pid, stat_addr, options, NULL);
554 	} else {
555 		struct rusage r;
556 		int ret;
557 		unsigned int status;
558 		mm_segment_t old_fs = get_fs();
559 
560 		set_fs (KERNEL_DS);
561 		ret = sys_wait4(pid,
562 				(stat_addr ?
563 				 (unsigned int __user *) &status : NULL),
564 				options, (struct rusage __user *) &r);
565 		set_fs (old_fs);
566 
567 		if (ret > 0) {
568 			if (put_compat_rusage(&r, ru))
569 				return -EFAULT;
570 			if (stat_addr && put_user(status, stat_addr))
571 				return -EFAULT;
572 		}
573 		return ret;
574 	}
575 }
576 
577 COMPAT_SYSCALL_DEFINE5(waitid,
578 		int, which, compat_pid_t, pid,
579 		struct compat_siginfo __user *, uinfo, int, options,
580 		struct compat_rusage __user *, uru)
581 {
582 	siginfo_t info;
583 	struct rusage ru;
584 	long ret;
585 	mm_segment_t old_fs = get_fs();
586 
587 	memset(&info, 0, sizeof(info));
588 
589 	set_fs(KERNEL_DS);
590 	ret = sys_waitid(which, pid, (siginfo_t __user *)&info, options,
591 			 uru ? (struct rusage __user *)&ru : NULL);
592 	set_fs(old_fs);
593 
594 	if ((ret < 0) || (info.si_signo == 0))
595 		return ret;
596 
597 	if (uru) {
598 		/* sys_waitid() overwrites everything in ru */
599 		if (COMPAT_USE_64BIT_TIME)
600 			ret = copy_to_user(uru, &ru, sizeof(ru));
601 		else
602 			ret = put_compat_rusage(&ru, uru);
603 		if (ret)
604 			return -EFAULT;
605 	}
606 
607 	BUG_ON(info.si_code & __SI_MASK);
608 	info.si_code |= __SI_CHLD;
609 	return copy_siginfo_to_user32(uinfo, &info);
610 }
611 
612 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
613 				    unsigned len, struct cpumask *new_mask)
614 {
615 	unsigned long *k;
616 
617 	if (len < cpumask_size())
618 		memset(new_mask, 0, cpumask_size());
619 	else if (len > cpumask_size())
620 		len = cpumask_size();
621 
622 	k = cpumask_bits(new_mask);
623 	return compat_get_bitmap(k, user_mask_ptr, len * 8);
624 }
625 
626 COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
627 		       unsigned int, len,
628 		       compat_ulong_t __user *, user_mask_ptr)
629 {
630 	cpumask_var_t new_mask;
631 	int retval;
632 
633 	if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
634 		return -ENOMEM;
635 
636 	retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
637 	if (retval)
638 		goto out;
639 
640 	retval = sched_setaffinity(pid, new_mask);
641 out:
642 	free_cpumask_var(new_mask);
643 	return retval;
644 }
645 
646 COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t,  pid, unsigned int, len,
647 		       compat_ulong_t __user *, user_mask_ptr)
648 {
649 	int ret;
650 	cpumask_var_t mask;
651 
652 	if ((len * BITS_PER_BYTE) < nr_cpu_ids)
653 		return -EINVAL;
654 	if (len & (sizeof(compat_ulong_t)-1))
655 		return -EINVAL;
656 
657 	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
658 		return -ENOMEM;
659 
660 	ret = sched_getaffinity(pid, mask);
661 	if (ret == 0) {
662 		size_t retlen = min_t(size_t, len, cpumask_size());
663 
664 		if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
665 			ret = -EFAULT;
666 		else
667 			ret = retlen;
668 	}
669 	free_cpumask_var(mask);
670 
671 	return ret;
672 }
673 
674 int get_compat_itimerspec(struct itimerspec *dst,
675 			  const struct compat_itimerspec __user *src)
676 {
677 	if (__compat_get_timespec(&dst->it_interval, &src->it_interval) ||
678 	    __compat_get_timespec(&dst->it_value, &src->it_value))
679 		return -EFAULT;
680 	return 0;
681 }
682 
683 int put_compat_itimerspec(struct compat_itimerspec __user *dst,
684 			  const struct itimerspec *src)
685 {
686 	if (__compat_put_timespec(&src->it_interval, &dst->it_interval) ||
687 	    __compat_put_timespec(&src->it_value, &dst->it_value))
688 		return -EFAULT;
689 	return 0;
690 }
691 
692 COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock,
693 		       struct compat_sigevent __user *, timer_event_spec,
694 		       timer_t __user *, created_timer_id)
695 {
696 	struct sigevent __user *event = NULL;
697 
698 	if (timer_event_spec) {
699 		struct sigevent kevent;
700 
701 		event = compat_alloc_user_space(sizeof(*event));
702 		if (get_compat_sigevent(&kevent, timer_event_spec) ||
703 		    copy_to_user(event, &kevent, sizeof(*event)))
704 			return -EFAULT;
705 	}
706 
707 	return sys_timer_create(which_clock, event, created_timer_id);
708 }
709 
710 COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
711 		       struct compat_itimerspec __user *, new,
712 		       struct compat_itimerspec __user *, old)
713 {
714 	long err;
715 	mm_segment_t oldfs;
716 	struct itimerspec newts, oldts;
717 
718 	if (!new)
719 		return -EINVAL;
720 	if (get_compat_itimerspec(&newts, new))
721 		return -EFAULT;
722 	oldfs = get_fs();
723 	set_fs(KERNEL_DS);
724 	err = sys_timer_settime(timer_id, flags,
725 				(struct itimerspec __user *) &newts,
726 				(struct itimerspec __user *) &oldts);
727 	set_fs(oldfs);
728 	if (!err && old && put_compat_itimerspec(old, &oldts))
729 		return -EFAULT;
730 	return err;
731 }
732 
733 COMPAT_SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
734 		       struct compat_itimerspec __user *, setting)
735 {
736 	long err;
737 	mm_segment_t oldfs;
738 	struct itimerspec ts;
739 
740 	oldfs = get_fs();
741 	set_fs(KERNEL_DS);
742 	err = sys_timer_gettime(timer_id,
743 				(struct itimerspec __user *) &ts);
744 	set_fs(oldfs);
745 	if (!err && put_compat_itimerspec(setting, &ts))
746 		return -EFAULT;
747 	return err;
748 }
749 
750 COMPAT_SYSCALL_DEFINE2(clock_settime, clockid_t, which_clock,
751 		       struct compat_timespec __user *, tp)
752 {
753 	long err;
754 	mm_segment_t oldfs;
755 	struct timespec ts;
756 
757 	if (compat_get_timespec(&ts, tp))
758 		return -EFAULT;
759 	oldfs = get_fs();
760 	set_fs(KERNEL_DS);
761 	err = sys_clock_settime(which_clock,
762 				(struct timespec __user *) &ts);
763 	set_fs(oldfs);
764 	return err;
765 }
766 
767 COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
768 		       struct compat_timespec __user *, tp)
769 {
770 	long err;
771 	mm_segment_t oldfs;
772 	struct timespec ts;
773 
774 	oldfs = get_fs();
775 	set_fs(KERNEL_DS);
776 	err = sys_clock_gettime(which_clock,
777 				(struct timespec __user *) &ts);
778 	set_fs(oldfs);
779 	if (!err && compat_put_timespec(&ts, tp))
780 		return -EFAULT;
781 	return err;
782 }
783 
784 COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock,
785 		       struct compat_timex __user *, utp)
786 {
787 	struct timex txc;
788 	mm_segment_t oldfs;
789 	int err, ret;
790 
791 	err = compat_get_timex(&txc, utp);
792 	if (err)
793 		return err;
794 
795 	oldfs = get_fs();
796 	set_fs(KERNEL_DS);
797 	ret = sys_clock_adjtime(which_clock, (struct timex __user *) &txc);
798 	set_fs(oldfs);
799 
800 	err = compat_put_timex(utp, &txc);
801 	if (err)
802 		return err;
803 
804 	return ret;
805 }
806 
807 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
808 		       struct compat_timespec __user *, tp)
809 {
810 	long err;
811 	mm_segment_t oldfs;
812 	struct timespec ts;
813 
814 	oldfs = get_fs();
815 	set_fs(KERNEL_DS);
816 	err = sys_clock_getres(which_clock,
817 			       (struct timespec __user *) &ts);
818 	set_fs(oldfs);
819 	if (!err && tp && compat_put_timespec(&ts, tp))
820 		return -EFAULT;
821 	return err;
822 }
823 
824 static long compat_clock_nanosleep_restart(struct restart_block *restart)
825 {
826 	long err;
827 	mm_segment_t oldfs;
828 	struct timespec tu;
829 	struct compat_timespec __user *rmtp = restart->nanosleep.compat_rmtp;
830 
831 	restart->nanosleep.rmtp = (struct timespec __user *) &tu;
832 	oldfs = get_fs();
833 	set_fs(KERNEL_DS);
834 	err = clock_nanosleep_restart(restart);
835 	set_fs(oldfs);
836 
837 	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
838 	    compat_put_timespec(&tu, rmtp))
839 		return -EFAULT;
840 
841 	if (err == -ERESTART_RESTARTBLOCK) {
842 		restart->fn = compat_clock_nanosleep_restart;
843 		restart->nanosleep.compat_rmtp = rmtp;
844 	}
845 	return err;
846 }
847 
848 COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
849 		       struct compat_timespec __user *, rqtp,
850 		       struct compat_timespec __user *, rmtp)
851 {
852 	long err;
853 	mm_segment_t oldfs;
854 	struct timespec in, out;
855 	struct restart_block *restart;
856 
857 	if (compat_get_timespec(&in, rqtp))
858 		return -EFAULT;
859 
860 	oldfs = get_fs();
861 	set_fs(KERNEL_DS);
862 	err = sys_clock_nanosleep(which_clock, flags,
863 				  (struct timespec __user *) &in,
864 				  (struct timespec __user *) &out);
865 	set_fs(oldfs);
866 
867 	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
868 	    compat_put_timespec(&out, rmtp))
869 		return -EFAULT;
870 
871 	if (err == -ERESTART_RESTARTBLOCK) {
872 		restart = &current->restart_block;
873 		restart->fn = compat_clock_nanosleep_restart;
874 		restart->nanosleep.compat_rmtp = rmtp;
875 	}
876 	return err;
877 }
878 
879 /*
880  * We currently only need the following fields from the sigevent
881  * structure: sigev_value, sigev_signo, sig_notify and (sometimes
882  * sigev_notify_thread_id).  The others are handled in user mode.
883  * We also assume that copying sigev_value.sival_int is sufficient
884  * to keep all the bits of sigev_value.sival_ptr intact.
885  */
886 int get_compat_sigevent(struct sigevent *event,
887 		const struct compat_sigevent __user *u_event)
888 {
889 	memset(event, 0, sizeof(*event));
890 	return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
891 		__get_user(event->sigev_value.sival_int,
892 			&u_event->sigev_value.sival_int) ||
893 		__get_user(event->sigev_signo, &u_event->sigev_signo) ||
894 		__get_user(event->sigev_notify, &u_event->sigev_notify) ||
895 		__get_user(event->sigev_notify_thread_id,
896 			&u_event->sigev_notify_thread_id))
897 		? -EFAULT : 0;
898 }
899 
900 long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
901 		       unsigned long bitmap_size)
902 {
903 	int i, j;
904 	unsigned long m;
905 	compat_ulong_t um;
906 	unsigned long nr_compat_longs;
907 
908 	/* align bitmap up to nearest compat_long_t boundary */
909 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
910 
911 	if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
912 		return -EFAULT;
913 
914 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
915 
916 	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
917 		m = 0;
918 
919 		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
920 			/*
921 			 * We dont want to read past the end of the userspace
922 			 * bitmap. We must however ensure the end of the
923 			 * kernel bitmap is zeroed.
924 			 */
925 			if (nr_compat_longs) {
926 				nr_compat_longs--;
927 				if (__get_user(um, umask))
928 					return -EFAULT;
929 			} else {
930 				um = 0;
931 			}
932 
933 			umask++;
934 			m |= (long)um << (j * BITS_PER_COMPAT_LONG);
935 		}
936 		*mask++ = m;
937 	}
938 
939 	return 0;
940 }
941 
942 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
943 		       unsigned long bitmap_size)
944 {
945 	int i, j;
946 	unsigned long m;
947 	compat_ulong_t um;
948 	unsigned long nr_compat_longs;
949 
950 	/* align bitmap up to nearest compat_long_t boundary */
951 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
952 
953 	if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
954 		return -EFAULT;
955 
956 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
957 
958 	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
959 		m = *mask++;
960 
961 		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
962 			um = m;
963 
964 			/*
965 			 * We dont want to write past the end of the userspace
966 			 * bitmap.
967 			 */
968 			if (nr_compat_longs) {
969 				nr_compat_longs--;
970 				if (__put_user(um, umask))
971 					return -EFAULT;
972 			}
973 
974 			umask++;
975 			m >>= 4*sizeof(um);
976 			m >>= 4*sizeof(um);
977 		}
978 	}
979 
980 	return 0;
981 }
982 
983 void
984 sigset_from_compat(sigset_t *set, const compat_sigset_t *compat)
985 {
986 	switch (_NSIG_WORDS) {
987 	case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
988 	case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 );
989 	case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 );
990 	case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 );
991 	}
992 }
993 EXPORT_SYMBOL_GPL(sigset_from_compat);
994 
995 void
996 sigset_to_compat(compat_sigset_t *compat, const sigset_t *set)
997 {
998 	switch (_NSIG_WORDS) {
999 	case 4: compat->sig[7] = (set->sig[3] >> 32); compat->sig[6] = set->sig[3];
1000 	case 3: compat->sig[5] = (set->sig[2] >> 32); compat->sig[4] = set->sig[2];
1001 	case 2: compat->sig[3] = (set->sig[1] >> 32); compat->sig[2] = set->sig[1];
1002 	case 1: compat->sig[1] = (set->sig[0] >> 32); compat->sig[0] = set->sig[0];
1003 	}
1004 }
1005 
1006 COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
1007 		struct compat_siginfo __user *, uinfo,
1008 		struct compat_timespec __user *, uts, compat_size_t, sigsetsize)
1009 {
1010 	compat_sigset_t s32;
1011 	sigset_t s;
1012 	struct timespec t;
1013 	siginfo_t info;
1014 	long ret;
1015 
1016 	if (sigsetsize != sizeof(sigset_t))
1017 		return -EINVAL;
1018 
1019 	if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
1020 		return -EFAULT;
1021 	sigset_from_compat(&s, &s32);
1022 
1023 	if (uts) {
1024 		if (compat_get_timespec(&t, uts))
1025 			return -EFAULT;
1026 	}
1027 
1028 	ret = do_sigtimedwait(&s, &info, uts ? &t : NULL);
1029 
1030 	if (ret > 0 && uinfo) {
1031 		if (copy_siginfo_to_user32(uinfo, &info))
1032 			ret = -EFAULT;
1033 	}
1034 
1035 	return ret;
1036 }
1037 
1038 #ifdef __ARCH_WANT_COMPAT_SYS_TIME
1039 
1040 /* compat_time_t is a 32 bit "long" and needs to get converted. */
1041 
1042 COMPAT_SYSCALL_DEFINE1(time, compat_time_t __user *, tloc)
1043 {
1044 	compat_time_t i;
1045 	struct timeval tv;
1046 
1047 	do_gettimeofday(&tv);
1048 	i = tv.tv_sec;
1049 
1050 	if (tloc) {
1051 		if (put_user(i,tloc))
1052 			return -EFAULT;
1053 	}
1054 	force_successful_syscall_return();
1055 	return i;
1056 }
1057 
1058 COMPAT_SYSCALL_DEFINE1(stime, compat_time_t __user *, tptr)
1059 {
1060 	struct timespec tv;
1061 	int err;
1062 
1063 	if (get_user(tv.tv_sec, tptr))
1064 		return -EFAULT;
1065 
1066 	tv.tv_nsec = 0;
1067 
1068 	err = security_settime(&tv, NULL);
1069 	if (err)
1070 		return err;
1071 
1072 	do_settimeofday(&tv);
1073 	return 0;
1074 }
1075 
1076 #endif /* __ARCH_WANT_COMPAT_SYS_TIME */
1077 
1078 COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp)
1079 {
1080 	struct timex txc;
1081 	int err, ret;
1082 
1083 	err = compat_get_timex(&txc, utp);
1084 	if (err)
1085 		return err;
1086 
1087 	ret = do_adjtimex(&txc);
1088 
1089 	err = compat_put_timex(utp, &txc);
1090 	if (err)
1091 		return err;
1092 
1093 	return ret;
1094 }
1095 
1096 #ifdef CONFIG_NUMA
1097 COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
1098 		       compat_uptr_t __user *, pages32,
1099 		       const int __user *, nodes,
1100 		       int __user *, status,
1101 		       int, flags)
1102 {
1103 	const void __user * __user *pages;
1104 	int i;
1105 
1106 	pages = compat_alloc_user_space(nr_pages * sizeof(void *));
1107 	for (i = 0; i < nr_pages; i++) {
1108 		compat_uptr_t p;
1109 
1110 		if (get_user(p, pages32 + i) ||
1111 			put_user(compat_ptr(p), pages + i))
1112 			return -EFAULT;
1113 	}
1114 	return sys_move_pages(pid, nr_pages, pages, nodes, status, flags);
1115 }
1116 
1117 COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
1118 		       compat_ulong_t, maxnode,
1119 		       const compat_ulong_t __user *, old_nodes,
1120 		       const compat_ulong_t __user *, new_nodes)
1121 {
1122 	unsigned long __user *old = NULL;
1123 	unsigned long __user *new = NULL;
1124 	nodemask_t tmp_mask;
1125 	unsigned long nr_bits;
1126 	unsigned long size;
1127 
1128 	nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
1129 	size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1130 	if (old_nodes) {
1131 		if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
1132 			return -EFAULT;
1133 		old = compat_alloc_user_space(new_nodes ? size * 2 : size);
1134 		if (new_nodes)
1135 			new = old + size / sizeof(unsigned long);
1136 		if (copy_to_user(old, nodes_addr(tmp_mask), size))
1137 			return -EFAULT;
1138 	}
1139 	if (new_nodes) {
1140 		if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
1141 			return -EFAULT;
1142 		if (new == NULL)
1143 			new = compat_alloc_user_space(size);
1144 		if (copy_to_user(new, nodes_addr(tmp_mask), size))
1145 			return -EFAULT;
1146 	}
1147 	return sys_migrate_pages(pid, nr_bits + 1, old, new);
1148 }
1149 #endif
1150 
1151 COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
1152 		       compat_pid_t, pid,
1153 		       struct compat_timespec __user *, interval)
1154 {
1155 	struct timespec t;
1156 	int ret;
1157 	mm_segment_t old_fs = get_fs();
1158 
1159 	set_fs(KERNEL_DS);
1160 	ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t);
1161 	set_fs(old_fs);
1162 	if (compat_put_timespec(&t, interval))
1163 		return -EFAULT;
1164 	return ret;
1165 }
1166 
1167 /*
1168  * Allocate user-space memory for the duration of a single system call,
1169  * in order to marshall parameters inside a compat thunk.
1170  */
1171 void __user *compat_alloc_user_space(unsigned long len)
1172 {
1173 	void __user *ptr;
1174 
1175 	/* If len would occupy more than half of the entire compat space... */
1176 	if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
1177 		return NULL;
1178 
1179 	ptr = arch_compat_alloc_user_space(len);
1180 
1181 	if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
1182 		return NULL;
1183 
1184 	return ptr;
1185 }
1186 EXPORT_SYMBOL_GPL(compat_alloc_user_space);
1187