xref: /openbmc/linux/kernel/compat.c (revision 4ed91d48259d9ddd378424d008f2e6559f7e78f8)
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 timeval user_tv;
112 	struct timespec	new_ts;
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_settimeofday(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 	mm_segment_t oldfs;
244 	long ret;
245 
246 	if (compat_get_timespec(&tu, rqtp))
247 		return -EFAULT;
248 
249 	if (!timespec_valid(&tu))
250 		return -EINVAL;
251 
252 	oldfs = get_fs();
253 	set_fs(KERNEL_DS);
254 	ret = hrtimer_nanosleep(&tu,
255 				rmtp ? (struct timespec __user *)&rmt : NULL,
256 				HRTIMER_MODE_REL, CLOCK_MONOTONIC);
257 	set_fs(oldfs);
258 
259 	/*
260 	 * hrtimer_nanosleep() can only return 0 or
261 	 * -ERESTART_RESTARTBLOCK here because:
262 	 *
263 	 * - we call it with HRTIMER_MODE_REL and therefor exclude the
264 	 *   -ERESTARTNOHAND return path.
265 	 *
266 	 * - we supply the rmtp argument from the task stack (due to
267 	 *   the necessary compat conversion. So the update cannot
268 	 *   fail, which excludes the -EFAULT return path as well. If
269 	 *   it fails nevertheless we have a bigger problem and wont
270 	 *   reach this place anymore.
271 	 *
272 	 * - if the return value is 0, we do not have to update rmtp
273 	 *    because there is no remaining time.
274 	 *
275 	 * We check for -ERESTART_RESTARTBLOCK nevertheless if the
276 	 * core implementation decides to return random nonsense.
277 	 */
278 	if (ret == -ERESTART_RESTARTBLOCK) {
279 		struct restart_block *restart = &current->restart_block;
280 
281 		restart->fn = compat_nanosleep_restart;
282 		restart->nanosleep.compat_rmtp = rmtp;
283 
284 		if (rmtp && compat_put_timespec(&rmt, rmtp))
285 			return -EFAULT;
286 	}
287 	return ret;
288 }
289 
290 static inline long get_compat_itimerval(struct itimerval *o,
291 		struct compat_itimerval __user *i)
292 {
293 	return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
294 		(__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
295 		 __get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
296 		 __get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
297 		 __get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
298 }
299 
300 static inline long put_compat_itimerval(struct compat_itimerval __user *o,
301 		struct itimerval *i)
302 {
303 	return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
304 		(__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
305 		 __put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
306 		 __put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
307 		 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
308 }
309 
310 asmlinkage long sys_ni_posix_timers(void);
311 
312 COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
313 		struct compat_itimerval __user *, it)
314 {
315 	struct itimerval kit;
316 	int error;
317 
318 	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
319 		return sys_ni_posix_timers();
320 
321 	error = do_getitimer(which, &kit);
322 	if (!error && put_compat_itimerval(it, &kit))
323 		error = -EFAULT;
324 	return error;
325 }
326 
327 COMPAT_SYSCALL_DEFINE3(setitimer, int, which,
328 		struct compat_itimerval __user *, in,
329 		struct compat_itimerval __user *, out)
330 {
331 	struct itimerval kin, kout;
332 	int error;
333 
334 	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
335 		return sys_ni_posix_timers();
336 
337 	if (in) {
338 		if (get_compat_itimerval(&kin, in))
339 			return -EFAULT;
340 	} else
341 		memset(&kin, 0, sizeof(kin));
342 
343 	error = do_setitimer(which, &kin, out ? &kout : NULL);
344 	if (error || !out)
345 		return error;
346 	if (put_compat_itimerval(out, &kout))
347 		return -EFAULT;
348 	return 0;
349 }
350 
351 static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
352 {
353 	return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
354 }
355 
356 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
357 {
358 	if (tbuf) {
359 		struct tms tms;
360 		struct compat_tms tmp;
361 
362 		do_sys_times(&tms);
363 		/* Convert our struct tms to the compat version. */
364 		tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
365 		tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
366 		tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
367 		tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
368 		if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
369 			return -EFAULT;
370 	}
371 	force_successful_syscall_return();
372 	return compat_jiffies_to_clock_t(jiffies);
373 }
374 
375 #ifdef __ARCH_WANT_SYS_SIGPENDING
376 
377 /*
378  * Assumption: old_sigset_t and compat_old_sigset_t are both
379  * types that can be passed to put_user()/get_user().
380  */
381 
382 COMPAT_SYSCALL_DEFINE1(sigpending, compat_old_sigset_t __user *, set)
383 {
384 	old_sigset_t s;
385 	long ret;
386 	mm_segment_t old_fs = get_fs();
387 
388 	set_fs(KERNEL_DS);
389 	ret = sys_sigpending((old_sigset_t __user *) &s);
390 	set_fs(old_fs);
391 	if (ret == 0)
392 		ret = put_user(s, set);
393 	return ret;
394 }
395 
396 #endif
397 
398 #ifdef __ARCH_WANT_SYS_SIGPROCMASK
399 
400 /*
401  * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
402  * blocked set of signals to the supplied signal set
403  */
404 static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
405 {
406 	memcpy(blocked->sig, &set, sizeof(set));
407 }
408 
409 COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
410 		       compat_old_sigset_t __user *, nset,
411 		       compat_old_sigset_t __user *, oset)
412 {
413 	old_sigset_t old_set, new_set;
414 	sigset_t new_blocked;
415 
416 	old_set = current->blocked.sig[0];
417 
418 	if (nset) {
419 		if (get_user(new_set, nset))
420 			return -EFAULT;
421 		new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
422 
423 		new_blocked = current->blocked;
424 
425 		switch (how) {
426 		case SIG_BLOCK:
427 			sigaddsetmask(&new_blocked, new_set);
428 			break;
429 		case SIG_UNBLOCK:
430 			sigdelsetmask(&new_blocked, new_set);
431 			break;
432 		case SIG_SETMASK:
433 			compat_sig_setmask(&new_blocked, new_set);
434 			break;
435 		default:
436 			return -EINVAL;
437 		}
438 
439 		set_current_blocked(&new_blocked);
440 	}
441 
442 	if (oset) {
443 		if (put_user(old_set, oset))
444 			return -EFAULT;
445 	}
446 
447 	return 0;
448 }
449 
450 #endif
451 
452 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
453 		       struct compat_rlimit __user *, rlim)
454 {
455 	struct rlimit r;
456 
457 	if (!access_ok(VERIFY_READ, rlim, sizeof(*rlim)) ||
458 	    __get_user(r.rlim_cur, &rlim->rlim_cur) ||
459 	    __get_user(r.rlim_max, &rlim->rlim_max))
460 		return -EFAULT;
461 
462 	if (r.rlim_cur == COMPAT_RLIM_INFINITY)
463 		r.rlim_cur = RLIM_INFINITY;
464 	if (r.rlim_max == COMPAT_RLIM_INFINITY)
465 		r.rlim_max = RLIM_INFINITY;
466 	return do_prlimit(current, resource, &r, NULL);
467 }
468 
469 #ifdef COMPAT_RLIM_OLD_INFINITY
470 
471 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
472 		       struct compat_rlimit __user *, rlim)
473 {
474 	struct rlimit r;
475 	int ret;
476 	mm_segment_t old_fs = get_fs();
477 
478 	set_fs(KERNEL_DS);
479 	ret = sys_old_getrlimit(resource, (struct rlimit __user *)&r);
480 	set_fs(old_fs);
481 
482 	if (!ret) {
483 		if (r.rlim_cur > COMPAT_RLIM_OLD_INFINITY)
484 			r.rlim_cur = COMPAT_RLIM_INFINITY;
485 		if (r.rlim_max > COMPAT_RLIM_OLD_INFINITY)
486 			r.rlim_max = COMPAT_RLIM_INFINITY;
487 
488 		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
489 		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
490 		    __put_user(r.rlim_max, &rlim->rlim_max))
491 			return -EFAULT;
492 	}
493 	return ret;
494 }
495 
496 #endif
497 
498 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
499 		       struct compat_rlimit __user *, rlim)
500 {
501 	struct rlimit r;
502 	int ret;
503 
504 	ret = do_prlimit(current, resource, NULL, &r);
505 	if (!ret) {
506 		if (r.rlim_cur > COMPAT_RLIM_INFINITY)
507 			r.rlim_cur = COMPAT_RLIM_INFINITY;
508 		if (r.rlim_max > COMPAT_RLIM_INFINITY)
509 			r.rlim_max = COMPAT_RLIM_INFINITY;
510 
511 		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
512 		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
513 		    __put_user(r.rlim_max, &rlim->rlim_max))
514 			return -EFAULT;
515 	}
516 	return ret;
517 }
518 
519 int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
520 {
521 	if (!access_ok(VERIFY_WRITE, ru, sizeof(*ru)) ||
522 	    __put_user(r->ru_utime.tv_sec, &ru->ru_utime.tv_sec) ||
523 	    __put_user(r->ru_utime.tv_usec, &ru->ru_utime.tv_usec) ||
524 	    __put_user(r->ru_stime.tv_sec, &ru->ru_stime.tv_sec) ||
525 	    __put_user(r->ru_stime.tv_usec, &ru->ru_stime.tv_usec) ||
526 	    __put_user(r->ru_maxrss, &ru->ru_maxrss) ||
527 	    __put_user(r->ru_ixrss, &ru->ru_ixrss) ||
528 	    __put_user(r->ru_idrss, &ru->ru_idrss) ||
529 	    __put_user(r->ru_isrss, &ru->ru_isrss) ||
530 	    __put_user(r->ru_minflt, &ru->ru_minflt) ||
531 	    __put_user(r->ru_majflt, &ru->ru_majflt) ||
532 	    __put_user(r->ru_nswap, &ru->ru_nswap) ||
533 	    __put_user(r->ru_inblock, &ru->ru_inblock) ||
534 	    __put_user(r->ru_oublock, &ru->ru_oublock) ||
535 	    __put_user(r->ru_msgsnd, &ru->ru_msgsnd) ||
536 	    __put_user(r->ru_msgrcv, &ru->ru_msgrcv) ||
537 	    __put_user(r->ru_nsignals, &ru->ru_nsignals) ||
538 	    __put_user(r->ru_nvcsw, &ru->ru_nvcsw) ||
539 	    __put_user(r->ru_nivcsw, &ru->ru_nivcsw))
540 		return -EFAULT;
541 	return 0;
542 }
543 
544 COMPAT_SYSCALL_DEFINE4(wait4,
545 	compat_pid_t, pid,
546 	compat_uint_t __user *, stat_addr,
547 	int, options,
548 	struct compat_rusage __user *, ru)
549 {
550 	if (!ru) {
551 		return sys_wait4(pid, stat_addr, options, NULL);
552 	} else {
553 		struct rusage r;
554 		int ret;
555 		unsigned int status;
556 		mm_segment_t old_fs = get_fs();
557 
558 		set_fs (KERNEL_DS);
559 		ret = sys_wait4(pid,
560 				(stat_addr ?
561 				 (unsigned int __user *) &status : NULL),
562 				options, (struct rusage __user *) &r);
563 		set_fs (old_fs);
564 
565 		if (ret > 0) {
566 			if (put_compat_rusage(&r, ru))
567 				return -EFAULT;
568 			if (stat_addr && put_user(status, stat_addr))
569 				return -EFAULT;
570 		}
571 		return ret;
572 	}
573 }
574 
575 COMPAT_SYSCALL_DEFINE5(waitid,
576 		int, which, compat_pid_t, pid,
577 		struct compat_siginfo __user *, uinfo, int, options,
578 		struct compat_rusage __user *, uru)
579 {
580 	siginfo_t info;
581 	struct rusage ru;
582 	long ret;
583 	mm_segment_t old_fs = get_fs();
584 
585 	memset(&info, 0, sizeof(info));
586 
587 	set_fs(KERNEL_DS);
588 	ret = sys_waitid(which, pid, (siginfo_t __user *)&info, options,
589 			 uru ? (struct rusage __user *)&ru : NULL);
590 	set_fs(old_fs);
591 
592 	if ((ret < 0) || (info.si_signo == 0))
593 		return ret;
594 
595 	if (uru) {
596 		/* sys_waitid() overwrites everything in ru */
597 		if (COMPAT_USE_64BIT_TIME)
598 			ret = copy_to_user(uru, &ru, sizeof(ru));
599 		else
600 			ret = put_compat_rusage(&ru, uru);
601 		if (ret)
602 			return -EFAULT;
603 	}
604 
605 	BUG_ON(info.si_code & __SI_MASK);
606 	info.si_code |= __SI_CHLD;
607 	return copy_siginfo_to_user32(uinfo, &info);
608 }
609 
610 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
611 				    unsigned len, struct cpumask *new_mask)
612 {
613 	unsigned long *k;
614 
615 	if (len < cpumask_size())
616 		memset(new_mask, 0, cpumask_size());
617 	else if (len > cpumask_size())
618 		len = cpumask_size();
619 
620 	k = cpumask_bits(new_mask);
621 	return compat_get_bitmap(k, user_mask_ptr, len * 8);
622 }
623 
624 COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
625 		       unsigned int, len,
626 		       compat_ulong_t __user *, user_mask_ptr)
627 {
628 	cpumask_var_t new_mask;
629 	int retval;
630 
631 	if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
632 		return -ENOMEM;
633 
634 	retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
635 	if (retval)
636 		goto out;
637 
638 	retval = sched_setaffinity(pid, new_mask);
639 out:
640 	free_cpumask_var(new_mask);
641 	return retval;
642 }
643 
644 COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t,  pid, unsigned int, len,
645 		       compat_ulong_t __user *, user_mask_ptr)
646 {
647 	int ret;
648 	cpumask_var_t mask;
649 
650 	if ((len * BITS_PER_BYTE) < nr_cpu_ids)
651 		return -EINVAL;
652 	if (len & (sizeof(compat_ulong_t)-1))
653 		return -EINVAL;
654 
655 	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
656 		return -ENOMEM;
657 
658 	ret = sched_getaffinity(pid, mask);
659 	if (ret == 0) {
660 		size_t retlen = min_t(size_t, len, cpumask_size());
661 
662 		if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
663 			ret = -EFAULT;
664 		else
665 			ret = retlen;
666 	}
667 	free_cpumask_var(mask);
668 
669 	return ret;
670 }
671 
672 int get_compat_itimerspec(struct itimerspec *dst,
673 			  const struct compat_itimerspec __user *src)
674 {
675 	if (__compat_get_timespec(&dst->it_interval, &src->it_interval) ||
676 	    __compat_get_timespec(&dst->it_value, &src->it_value))
677 		return -EFAULT;
678 	return 0;
679 }
680 
681 int put_compat_itimerspec(struct compat_itimerspec __user *dst,
682 			  const struct itimerspec *src)
683 {
684 	if (__compat_put_timespec(&src->it_interval, &dst->it_interval) ||
685 	    __compat_put_timespec(&src->it_value, &dst->it_value))
686 		return -EFAULT;
687 	return 0;
688 }
689 
690 COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock,
691 		       struct compat_sigevent __user *, timer_event_spec,
692 		       timer_t __user *, created_timer_id)
693 {
694 	struct sigevent __user *event = NULL;
695 
696 	if (timer_event_spec) {
697 		struct sigevent kevent;
698 
699 		event = compat_alloc_user_space(sizeof(*event));
700 		if (get_compat_sigevent(&kevent, timer_event_spec) ||
701 		    copy_to_user(event, &kevent, sizeof(*event)))
702 			return -EFAULT;
703 	}
704 
705 	return sys_timer_create(which_clock, event, created_timer_id);
706 }
707 
708 COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
709 		       struct compat_itimerspec __user *, new,
710 		       struct compat_itimerspec __user *, old)
711 {
712 	long err;
713 	mm_segment_t oldfs;
714 	struct itimerspec newts, oldts;
715 
716 	if (!new)
717 		return -EINVAL;
718 	if (get_compat_itimerspec(&newts, new))
719 		return -EFAULT;
720 	oldfs = get_fs();
721 	set_fs(KERNEL_DS);
722 	err = sys_timer_settime(timer_id, flags,
723 				(struct itimerspec __user *) &newts,
724 				(struct itimerspec __user *) &oldts);
725 	set_fs(oldfs);
726 	if (!err && old && put_compat_itimerspec(old, &oldts))
727 		return -EFAULT;
728 	return err;
729 }
730 
731 COMPAT_SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
732 		       struct compat_itimerspec __user *, setting)
733 {
734 	long err;
735 	mm_segment_t oldfs;
736 	struct itimerspec ts;
737 
738 	oldfs = get_fs();
739 	set_fs(KERNEL_DS);
740 	err = sys_timer_gettime(timer_id,
741 				(struct itimerspec __user *) &ts);
742 	set_fs(oldfs);
743 	if (!err && put_compat_itimerspec(setting, &ts))
744 		return -EFAULT;
745 	return err;
746 }
747 
748 COMPAT_SYSCALL_DEFINE2(clock_settime, clockid_t, which_clock,
749 		       struct compat_timespec __user *, tp)
750 {
751 	long err;
752 	mm_segment_t oldfs;
753 	struct timespec ts;
754 
755 	if (compat_get_timespec(&ts, tp))
756 		return -EFAULT;
757 	oldfs = get_fs();
758 	set_fs(KERNEL_DS);
759 	err = sys_clock_settime(which_clock,
760 				(struct timespec __user *) &ts);
761 	set_fs(oldfs);
762 	return err;
763 }
764 
765 COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
766 		       struct compat_timespec __user *, tp)
767 {
768 	long err;
769 	mm_segment_t oldfs;
770 	struct timespec ts;
771 
772 	oldfs = get_fs();
773 	set_fs(KERNEL_DS);
774 	err = sys_clock_gettime(which_clock,
775 				(struct timespec __user *) &ts);
776 	set_fs(oldfs);
777 	if (!err && compat_put_timespec(&ts, tp))
778 		return -EFAULT;
779 	return err;
780 }
781 
782 COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock,
783 		       struct compat_timex __user *, utp)
784 {
785 	struct timex txc;
786 	mm_segment_t oldfs;
787 	int err, ret;
788 
789 	err = compat_get_timex(&txc, utp);
790 	if (err)
791 		return err;
792 
793 	oldfs = get_fs();
794 	set_fs(KERNEL_DS);
795 	ret = sys_clock_adjtime(which_clock, (struct timex __user *) &txc);
796 	set_fs(oldfs);
797 
798 	err = compat_put_timex(utp, &txc);
799 	if (err)
800 		return err;
801 
802 	return ret;
803 }
804 
805 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
806 		       struct compat_timespec __user *, tp)
807 {
808 	long err;
809 	mm_segment_t oldfs;
810 	struct timespec ts;
811 
812 	oldfs = get_fs();
813 	set_fs(KERNEL_DS);
814 	err = sys_clock_getres(which_clock,
815 			       (struct timespec __user *) &ts);
816 	set_fs(oldfs);
817 	if (!err && tp && compat_put_timespec(&ts, tp))
818 		return -EFAULT;
819 	return err;
820 }
821 
822 static long compat_clock_nanosleep_restart(struct restart_block *restart)
823 {
824 	long err;
825 	mm_segment_t oldfs;
826 	struct timespec tu;
827 	struct compat_timespec __user *rmtp = restart->nanosleep.compat_rmtp;
828 
829 	restart->nanosleep.rmtp = (struct timespec __user *) &tu;
830 	oldfs = get_fs();
831 	set_fs(KERNEL_DS);
832 	err = clock_nanosleep_restart(restart);
833 	set_fs(oldfs);
834 
835 	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
836 	    compat_put_timespec(&tu, rmtp))
837 		return -EFAULT;
838 
839 	if (err == -ERESTART_RESTARTBLOCK) {
840 		restart->fn = compat_clock_nanosleep_restart;
841 		restart->nanosleep.compat_rmtp = rmtp;
842 	}
843 	return err;
844 }
845 
846 COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
847 		       struct compat_timespec __user *, rqtp,
848 		       struct compat_timespec __user *, rmtp)
849 {
850 	long err;
851 	mm_segment_t oldfs;
852 	struct timespec in, out;
853 	struct restart_block *restart;
854 
855 	if (compat_get_timespec(&in, rqtp))
856 		return -EFAULT;
857 
858 	oldfs = get_fs();
859 	set_fs(KERNEL_DS);
860 	err = sys_clock_nanosleep(which_clock, flags,
861 				  (struct timespec __user *) &in,
862 				  (struct timespec __user *) &out);
863 	set_fs(oldfs);
864 
865 	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
866 	    compat_put_timespec(&out, rmtp))
867 		return -EFAULT;
868 
869 	if (err == -ERESTART_RESTARTBLOCK) {
870 		restart = &current->restart_block;
871 		restart->fn = compat_clock_nanosleep_restart;
872 		restart->nanosleep.compat_rmtp = rmtp;
873 	}
874 	return err;
875 }
876 
877 /*
878  * We currently only need the following fields from the sigevent
879  * structure: sigev_value, sigev_signo, sig_notify and (sometimes
880  * sigev_notify_thread_id).  The others are handled in user mode.
881  * We also assume that copying sigev_value.sival_int is sufficient
882  * to keep all the bits of sigev_value.sival_ptr intact.
883  */
884 int get_compat_sigevent(struct sigevent *event,
885 		const struct compat_sigevent __user *u_event)
886 {
887 	memset(event, 0, sizeof(*event));
888 	return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
889 		__get_user(event->sigev_value.sival_int,
890 			&u_event->sigev_value.sival_int) ||
891 		__get_user(event->sigev_signo, &u_event->sigev_signo) ||
892 		__get_user(event->sigev_notify, &u_event->sigev_notify) ||
893 		__get_user(event->sigev_notify_thread_id,
894 			&u_event->sigev_notify_thread_id))
895 		? -EFAULT : 0;
896 }
897 
898 long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
899 		       unsigned long bitmap_size)
900 {
901 	int i, j;
902 	unsigned long m;
903 	compat_ulong_t um;
904 	unsigned long nr_compat_longs;
905 
906 	/* align bitmap up to nearest compat_long_t boundary */
907 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
908 
909 	if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
910 		return -EFAULT;
911 
912 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
913 
914 	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
915 		m = 0;
916 
917 		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
918 			/*
919 			 * We dont want to read past the end of the userspace
920 			 * bitmap. We must however ensure the end of the
921 			 * kernel bitmap is zeroed.
922 			 */
923 			if (nr_compat_longs) {
924 				nr_compat_longs--;
925 				if (__get_user(um, umask))
926 					return -EFAULT;
927 			} else {
928 				um = 0;
929 			}
930 
931 			umask++;
932 			m |= (long)um << (j * BITS_PER_COMPAT_LONG);
933 		}
934 		*mask++ = m;
935 	}
936 
937 	return 0;
938 }
939 
940 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
941 		       unsigned long bitmap_size)
942 {
943 	int i, j;
944 	unsigned long m;
945 	compat_ulong_t um;
946 	unsigned long nr_compat_longs;
947 
948 	/* align bitmap up to nearest compat_long_t boundary */
949 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
950 
951 	if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
952 		return -EFAULT;
953 
954 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
955 
956 	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
957 		m = *mask++;
958 
959 		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
960 			um = m;
961 
962 			/*
963 			 * We dont want to write past the end of the userspace
964 			 * bitmap.
965 			 */
966 			if (nr_compat_longs) {
967 				nr_compat_longs--;
968 				if (__put_user(um, umask))
969 					return -EFAULT;
970 			}
971 
972 			umask++;
973 			m >>= 4*sizeof(um);
974 			m >>= 4*sizeof(um);
975 		}
976 	}
977 
978 	return 0;
979 }
980 
981 void
982 sigset_from_compat(sigset_t *set, const compat_sigset_t *compat)
983 {
984 	switch (_NSIG_WORDS) {
985 	case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
986 	case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 );
987 	case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 );
988 	case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 );
989 	}
990 }
991 EXPORT_SYMBOL_GPL(sigset_from_compat);
992 
993 void
994 sigset_to_compat(compat_sigset_t *compat, const sigset_t *set)
995 {
996 	switch (_NSIG_WORDS) {
997 	case 4: compat->sig[7] = (set->sig[3] >> 32); compat->sig[6] = set->sig[3];
998 	case 3: compat->sig[5] = (set->sig[2] >> 32); compat->sig[4] = set->sig[2];
999 	case 2: compat->sig[3] = (set->sig[1] >> 32); compat->sig[2] = set->sig[1];
1000 	case 1: compat->sig[1] = (set->sig[0] >> 32); compat->sig[0] = set->sig[0];
1001 	}
1002 }
1003 
1004 COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
1005 		struct compat_siginfo __user *, uinfo,
1006 		struct compat_timespec __user *, uts, compat_size_t, sigsetsize)
1007 {
1008 	compat_sigset_t s32;
1009 	sigset_t s;
1010 	struct timespec t;
1011 	siginfo_t info;
1012 	long ret;
1013 
1014 	if (sigsetsize != sizeof(sigset_t))
1015 		return -EINVAL;
1016 
1017 	if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
1018 		return -EFAULT;
1019 	sigset_from_compat(&s, &s32);
1020 
1021 	if (uts) {
1022 		if (compat_get_timespec(&t, uts))
1023 			return -EFAULT;
1024 	}
1025 
1026 	ret = do_sigtimedwait(&s, &info, uts ? &t : NULL);
1027 
1028 	if (ret > 0 && uinfo) {
1029 		if (copy_siginfo_to_user32(uinfo, &info))
1030 			ret = -EFAULT;
1031 	}
1032 
1033 	return ret;
1034 }
1035 
1036 #ifdef __ARCH_WANT_COMPAT_SYS_TIME
1037 
1038 /* compat_time_t is a 32 bit "long" and needs to get converted. */
1039 
1040 COMPAT_SYSCALL_DEFINE1(time, compat_time_t __user *, tloc)
1041 {
1042 	compat_time_t i;
1043 	struct timeval tv;
1044 
1045 	do_gettimeofday(&tv);
1046 	i = tv.tv_sec;
1047 
1048 	if (tloc) {
1049 		if (put_user(i,tloc))
1050 			return -EFAULT;
1051 	}
1052 	force_successful_syscall_return();
1053 	return i;
1054 }
1055 
1056 COMPAT_SYSCALL_DEFINE1(stime, compat_time_t __user *, tptr)
1057 {
1058 	struct timespec tv;
1059 	int err;
1060 
1061 	if (get_user(tv.tv_sec, tptr))
1062 		return -EFAULT;
1063 
1064 	tv.tv_nsec = 0;
1065 
1066 	err = security_settime(&tv, NULL);
1067 	if (err)
1068 		return err;
1069 
1070 	do_settimeofday(&tv);
1071 	return 0;
1072 }
1073 
1074 #endif /* __ARCH_WANT_COMPAT_SYS_TIME */
1075 
1076 COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp)
1077 {
1078 	struct timex txc;
1079 	int err, ret;
1080 
1081 	err = compat_get_timex(&txc, utp);
1082 	if (err)
1083 		return err;
1084 
1085 	ret = do_adjtimex(&txc);
1086 
1087 	err = compat_put_timex(utp, &txc);
1088 	if (err)
1089 		return err;
1090 
1091 	return ret;
1092 }
1093 
1094 #ifdef CONFIG_NUMA
1095 COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
1096 		       compat_uptr_t __user *, pages32,
1097 		       const int __user *, nodes,
1098 		       int __user *, status,
1099 		       int, flags)
1100 {
1101 	const void __user * __user *pages;
1102 	int i;
1103 
1104 	pages = compat_alloc_user_space(nr_pages * sizeof(void *));
1105 	for (i = 0; i < nr_pages; i++) {
1106 		compat_uptr_t p;
1107 
1108 		if (get_user(p, pages32 + i) ||
1109 			put_user(compat_ptr(p), pages + i))
1110 			return -EFAULT;
1111 	}
1112 	return sys_move_pages(pid, nr_pages, pages, nodes, status, flags);
1113 }
1114 
1115 COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
1116 		       compat_ulong_t, maxnode,
1117 		       const compat_ulong_t __user *, old_nodes,
1118 		       const compat_ulong_t __user *, new_nodes)
1119 {
1120 	unsigned long __user *old = NULL;
1121 	unsigned long __user *new = NULL;
1122 	nodemask_t tmp_mask;
1123 	unsigned long nr_bits;
1124 	unsigned long size;
1125 
1126 	nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
1127 	size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1128 	if (old_nodes) {
1129 		if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
1130 			return -EFAULT;
1131 		old = compat_alloc_user_space(new_nodes ? size * 2 : size);
1132 		if (new_nodes)
1133 			new = old + size / sizeof(unsigned long);
1134 		if (copy_to_user(old, nodes_addr(tmp_mask), size))
1135 			return -EFAULT;
1136 	}
1137 	if (new_nodes) {
1138 		if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
1139 			return -EFAULT;
1140 		if (new == NULL)
1141 			new = compat_alloc_user_space(size);
1142 		if (copy_to_user(new, nodes_addr(tmp_mask), size))
1143 			return -EFAULT;
1144 	}
1145 	return sys_migrate_pages(pid, nr_bits + 1, old, new);
1146 }
1147 #endif
1148 
1149 COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
1150 		       compat_pid_t, pid,
1151 		       struct compat_timespec __user *, interval)
1152 {
1153 	struct timespec t;
1154 	int ret;
1155 	mm_segment_t old_fs = get_fs();
1156 
1157 	set_fs(KERNEL_DS);
1158 	ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t);
1159 	set_fs(old_fs);
1160 	if (compat_put_timespec(&t, interval))
1161 		return -EFAULT;
1162 	return ret;
1163 }
1164 
1165 /*
1166  * Allocate user-space memory for the duration of a single system call,
1167  * in order to marshall parameters inside a compat thunk.
1168  */
1169 void __user *compat_alloc_user_space(unsigned long len)
1170 {
1171 	void __user *ptr;
1172 
1173 	/* If len would occupy more than half of the entire compat space... */
1174 	if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
1175 		return NULL;
1176 
1177 	ptr = arch_compat_alloc_user_space(len);
1178 
1179 	if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
1180 		return NULL;
1181 
1182 	return ptr;
1183 }
1184 EXPORT_SYMBOL_GPL(compat_alloc_user_space);
1185