xref: /openbmc/linux/kernel/compat.c (revision 81d67439)
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/migrate.h>
25 #include <linux/posix-timers.h>
26 #include <linux/times.h>
27 #include <linux/ptrace.h>
28 #include <linux/gfp.h>
29 
30 #include <asm/uaccess.h>
31 
32 /*
33  * Note that the native side is already converted to a timespec, because
34  * that's what we want anyway.
35  */
36 static int compat_get_timeval(struct timespec *o,
37 		struct compat_timeval __user *i)
38 {
39 	long usec;
40 
41 	if (get_user(o->tv_sec, &i->tv_sec) ||
42 	    get_user(usec, &i->tv_usec))
43 		return -EFAULT;
44 	o->tv_nsec = usec * 1000;
45 	return 0;
46 }
47 
48 static int compat_put_timeval(struct compat_timeval __user *o,
49 		struct timeval *i)
50 {
51 	return (put_user(i->tv_sec, &o->tv_sec) ||
52 		put_user(i->tv_usec, &o->tv_usec)) ? -EFAULT : 0;
53 }
54 
55 static int compat_get_timex(struct timex *txc, struct compat_timex __user *utp)
56 {
57 	memset(txc, 0, sizeof(struct timex));
58 
59 	if (!access_ok(VERIFY_READ, utp, sizeof(struct compat_timex)) ||
60 			__get_user(txc->modes, &utp->modes) ||
61 			__get_user(txc->offset, &utp->offset) ||
62 			__get_user(txc->freq, &utp->freq) ||
63 			__get_user(txc->maxerror, &utp->maxerror) ||
64 			__get_user(txc->esterror, &utp->esterror) ||
65 			__get_user(txc->status, &utp->status) ||
66 			__get_user(txc->constant, &utp->constant) ||
67 			__get_user(txc->precision, &utp->precision) ||
68 			__get_user(txc->tolerance, &utp->tolerance) ||
69 			__get_user(txc->time.tv_sec, &utp->time.tv_sec) ||
70 			__get_user(txc->time.tv_usec, &utp->time.tv_usec) ||
71 			__get_user(txc->tick, &utp->tick) ||
72 			__get_user(txc->ppsfreq, &utp->ppsfreq) ||
73 			__get_user(txc->jitter, &utp->jitter) ||
74 			__get_user(txc->shift, &utp->shift) ||
75 			__get_user(txc->stabil, &utp->stabil) ||
76 			__get_user(txc->jitcnt, &utp->jitcnt) ||
77 			__get_user(txc->calcnt, &utp->calcnt) ||
78 			__get_user(txc->errcnt, &utp->errcnt) ||
79 			__get_user(txc->stbcnt, &utp->stbcnt))
80 		return -EFAULT;
81 
82 	return 0;
83 }
84 
85 static int compat_put_timex(struct compat_timex __user *utp, struct timex *txc)
86 {
87 	if (!access_ok(VERIFY_WRITE, utp, sizeof(struct compat_timex)) ||
88 			__put_user(txc->modes, &utp->modes) ||
89 			__put_user(txc->offset, &utp->offset) ||
90 			__put_user(txc->freq, &utp->freq) ||
91 			__put_user(txc->maxerror, &utp->maxerror) ||
92 			__put_user(txc->esterror, &utp->esterror) ||
93 			__put_user(txc->status, &utp->status) ||
94 			__put_user(txc->constant, &utp->constant) ||
95 			__put_user(txc->precision, &utp->precision) ||
96 			__put_user(txc->tolerance, &utp->tolerance) ||
97 			__put_user(txc->time.tv_sec, &utp->time.tv_sec) ||
98 			__put_user(txc->time.tv_usec, &utp->time.tv_usec) ||
99 			__put_user(txc->tick, &utp->tick) ||
100 			__put_user(txc->ppsfreq, &utp->ppsfreq) ||
101 			__put_user(txc->jitter, &utp->jitter) ||
102 			__put_user(txc->shift, &utp->shift) ||
103 			__put_user(txc->stabil, &utp->stabil) ||
104 			__put_user(txc->jitcnt, &utp->jitcnt) ||
105 			__put_user(txc->calcnt, &utp->calcnt) ||
106 			__put_user(txc->errcnt, &utp->errcnt) ||
107 			__put_user(txc->stbcnt, &utp->stbcnt) ||
108 			__put_user(txc->tai, &utp->tai))
109 		return -EFAULT;
110 	return 0;
111 }
112 
113 asmlinkage long compat_sys_gettimeofday(struct compat_timeval __user *tv,
114 		struct timezone __user *tz)
115 {
116 	if (tv) {
117 		struct timeval ktv;
118 		do_gettimeofday(&ktv);
119 		if (compat_put_timeval(tv, &ktv))
120 			return -EFAULT;
121 	}
122 	if (tz) {
123 		if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
124 			return -EFAULT;
125 	}
126 
127 	return 0;
128 }
129 
130 asmlinkage long compat_sys_settimeofday(struct compat_timeval __user *tv,
131 		struct timezone __user *tz)
132 {
133 	struct timespec kts;
134 	struct timezone ktz;
135 
136 	if (tv) {
137 		if (compat_get_timeval(&kts, tv))
138 			return -EFAULT;
139 	}
140 	if (tz) {
141 		if (copy_from_user(&ktz, tz, sizeof(ktz)))
142 			return -EFAULT;
143 	}
144 
145 	return do_sys_settimeofday(tv ? &kts : NULL, tz ? &ktz : NULL);
146 }
147 
148 int get_compat_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
149 {
150 	return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
151 			__get_user(ts->tv_sec, &cts->tv_sec) ||
152 			__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
153 }
154 
155 int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
156 {
157 	return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
158 			__put_user(ts->tv_sec, &cts->tv_sec) ||
159 			__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
160 }
161 
162 static long compat_nanosleep_restart(struct restart_block *restart)
163 {
164 	struct compat_timespec __user *rmtp;
165 	struct timespec rmt;
166 	mm_segment_t oldfs;
167 	long ret;
168 
169 	restart->nanosleep.rmtp = (struct timespec __user *) &rmt;
170 	oldfs = get_fs();
171 	set_fs(KERNEL_DS);
172 	ret = hrtimer_nanosleep_restart(restart);
173 	set_fs(oldfs);
174 
175 	if (ret) {
176 		rmtp = restart->nanosleep.compat_rmtp;
177 
178 		if (rmtp && put_compat_timespec(&rmt, rmtp))
179 			return -EFAULT;
180 	}
181 
182 	return ret;
183 }
184 
185 asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
186 				     struct compat_timespec __user *rmtp)
187 {
188 	struct timespec tu, rmt;
189 	mm_segment_t oldfs;
190 	long ret;
191 
192 	if (get_compat_timespec(&tu, rqtp))
193 		return -EFAULT;
194 
195 	if (!timespec_valid(&tu))
196 		return -EINVAL;
197 
198 	oldfs = get_fs();
199 	set_fs(KERNEL_DS);
200 	ret = hrtimer_nanosleep(&tu,
201 				rmtp ? (struct timespec __user *)&rmt : NULL,
202 				HRTIMER_MODE_REL, CLOCK_MONOTONIC);
203 	set_fs(oldfs);
204 
205 	if (ret) {
206 		struct restart_block *restart
207 			= &current_thread_info()->restart_block;
208 
209 		restart->fn = compat_nanosleep_restart;
210 		restart->nanosleep.compat_rmtp = rmtp;
211 
212 		if (rmtp && put_compat_timespec(&rmt, rmtp))
213 			return -EFAULT;
214 	}
215 
216 	return ret;
217 }
218 
219 static inline long get_compat_itimerval(struct itimerval *o,
220 		struct compat_itimerval __user *i)
221 {
222 	return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
223 		(__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
224 		 __get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
225 		 __get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
226 		 __get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
227 }
228 
229 static inline long put_compat_itimerval(struct compat_itimerval __user *o,
230 		struct itimerval *i)
231 {
232 	return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
233 		(__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
234 		 __put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
235 		 __put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
236 		 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
237 }
238 
239 asmlinkage long compat_sys_getitimer(int which,
240 		struct compat_itimerval __user *it)
241 {
242 	struct itimerval kit;
243 	int error;
244 
245 	error = do_getitimer(which, &kit);
246 	if (!error && put_compat_itimerval(it, &kit))
247 		error = -EFAULT;
248 	return error;
249 }
250 
251 asmlinkage long compat_sys_setitimer(int which,
252 		struct compat_itimerval __user *in,
253 		struct compat_itimerval __user *out)
254 {
255 	struct itimerval kin, kout;
256 	int error;
257 
258 	if (in) {
259 		if (get_compat_itimerval(&kin, in))
260 			return -EFAULT;
261 	} else
262 		memset(&kin, 0, sizeof(kin));
263 
264 	error = do_setitimer(which, &kin, out ? &kout : NULL);
265 	if (error || !out)
266 		return error;
267 	if (put_compat_itimerval(out, &kout))
268 		return -EFAULT;
269 	return 0;
270 }
271 
272 static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
273 {
274 	return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
275 }
276 
277 asmlinkage long compat_sys_times(struct compat_tms __user *tbuf)
278 {
279 	if (tbuf) {
280 		struct tms tms;
281 		struct compat_tms tmp;
282 
283 		do_sys_times(&tms);
284 		/* Convert our struct tms to the compat version. */
285 		tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
286 		tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
287 		tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
288 		tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
289 		if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
290 			return -EFAULT;
291 	}
292 	force_successful_syscall_return();
293 	return compat_jiffies_to_clock_t(jiffies);
294 }
295 
296 #ifdef __ARCH_WANT_SYS_SIGPENDING
297 
298 /*
299  * Assumption: old_sigset_t and compat_old_sigset_t are both
300  * types that can be passed to put_user()/get_user().
301  */
302 
303 asmlinkage long compat_sys_sigpending(compat_old_sigset_t __user *set)
304 {
305 	old_sigset_t s;
306 	long ret;
307 	mm_segment_t old_fs = get_fs();
308 
309 	set_fs(KERNEL_DS);
310 	ret = sys_sigpending((old_sigset_t __user *) &s);
311 	set_fs(old_fs);
312 	if (ret == 0)
313 		ret = put_user(s, set);
314 	return ret;
315 }
316 
317 #endif
318 
319 #ifdef __ARCH_WANT_SYS_SIGPROCMASK
320 
321 asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t __user *set,
322 		compat_old_sigset_t __user *oset)
323 {
324 	old_sigset_t s;
325 	long ret;
326 	mm_segment_t old_fs;
327 
328 	if (set && get_user(s, set))
329 		return -EFAULT;
330 	old_fs = get_fs();
331 	set_fs(KERNEL_DS);
332 	ret = sys_sigprocmask(how,
333 			      set ? (old_sigset_t __user *) &s : NULL,
334 			      oset ? (old_sigset_t __user *) &s : NULL);
335 	set_fs(old_fs);
336 	if (ret == 0)
337 		if (oset)
338 			ret = put_user(s, oset);
339 	return ret;
340 }
341 
342 #endif
343 
344 asmlinkage long compat_sys_setrlimit(unsigned int resource,
345 		struct compat_rlimit __user *rlim)
346 {
347 	struct rlimit r;
348 
349 	if (!access_ok(VERIFY_READ, rlim, sizeof(*rlim)) ||
350 	    __get_user(r.rlim_cur, &rlim->rlim_cur) ||
351 	    __get_user(r.rlim_max, &rlim->rlim_max))
352 		return -EFAULT;
353 
354 	if (r.rlim_cur == COMPAT_RLIM_INFINITY)
355 		r.rlim_cur = RLIM_INFINITY;
356 	if (r.rlim_max == COMPAT_RLIM_INFINITY)
357 		r.rlim_max = RLIM_INFINITY;
358 	return do_prlimit(current, resource, &r, NULL);
359 }
360 
361 #ifdef COMPAT_RLIM_OLD_INFINITY
362 
363 asmlinkage long compat_sys_old_getrlimit(unsigned int resource,
364 		struct compat_rlimit __user *rlim)
365 {
366 	struct rlimit r;
367 	int ret;
368 	mm_segment_t old_fs = get_fs();
369 
370 	set_fs(KERNEL_DS);
371 	ret = sys_old_getrlimit(resource, &r);
372 	set_fs(old_fs);
373 
374 	if (!ret) {
375 		if (r.rlim_cur > COMPAT_RLIM_OLD_INFINITY)
376 			r.rlim_cur = COMPAT_RLIM_INFINITY;
377 		if (r.rlim_max > COMPAT_RLIM_OLD_INFINITY)
378 			r.rlim_max = COMPAT_RLIM_INFINITY;
379 
380 		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
381 		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
382 		    __put_user(r.rlim_max, &rlim->rlim_max))
383 			return -EFAULT;
384 	}
385 	return ret;
386 }
387 
388 #endif
389 
390 asmlinkage long compat_sys_getrlimit(unsigned int resource,
391 		struct compat_rlimit __user *rlim)
392 {
393 	struct rlimit r;
394 	int ret;
395 
396 	ret = do_prlimit(current, resource, NULL, &r);
397 	if (!ret) {
398 		if (r.rlim_cur > COMPAT_RLIM_INFINITY)
399 			r.rlim_cur = COMPAT_RLIM_INFINITY;
400 		if (r.rlim_max > COMPAT_RLIM_INFINITY)
401 			r.rlim_max = COMPAT_RLIM_INFINITY;
402 
403 		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
404 		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
405 		    __put_user(r.rlim_max, &rlim->rlim_max))
406 			return -EFAULT;
407 	}
408 	return ret;
409 }
410 
411 int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
412 {
413 	if (!access_ok(VERIFY_WRITE, ru, sizeof(*ru)) ||
414 	    __put_user(r->ru_utime.tv_sec, &ru->ru_utime.tv_sec) ||
415 	    __put_user(r->ru_utime.tv_usec, &ru->ru_utime.tv_usec) ||
416 	    __put_user(r->ru_stime.tv_sec, &ru->ru_stime.tv_sec) ||
417 	    __put_user(r->ru_stime.tv_usec, &ru->ru_stime.tv_usec) ||
418 	    __put_user(r->ru_maxrss, &ru->ru_maxrss) ||
419 	    __put_user(r->ru_ixrss, &ru->ru_ixrss) ||
420 	    __put_user(r->ru_idrss, &ru->ru_idrss) ||
421 	    __put_user(r->ru_isrss, &ru->ru_isrss) ||
422 	    __put_user(r->ru_minflt, &ru->ru_minflt) ||
423 	    __put_user(r->ru_majflt, &ru->ru_majflt) ||
424 	    __put_user(r->ru_nswap, &ru->ru_nswap) ||
425 	    __put_user(r->ru_inblock, &ru->ru_inblock) ||
426 	    __put_user(r->ru_oublock, &ru->ru_oublock) ||
427 	    __put_user(r->ru_msgsnd, &ru->ru_msgsnd) ||
428 	    __put_user(r->ru_msgrcv, &ru->ru_msgrcv) ||
429 	    __put_user(r->ru_nsignals, &ru->ru_nsignals) ||
430 	    __put_user(r->ru_nvcsw, &ru->ru_nvcsw) ||
431 	    __put_user(r->ru_nivcsw, &ru->ru_nivcsw))
432 		return -EFAULT;
433 	return 0;
434 }
435 
436 asmlinkage long compat_sys_getrusage(int who, struct compat_rusage __user *ru)
437 {
438 	struct rusage r;
439 	int ret;
440 	mm_segment_t old_fs = get_fs();
441 
442 	set_fs(KERNEL_DS);
443 	ret = sys_getrusage(who, (struct rusage __user *) &r);
444 	set_fs(old_fs);
445 
446 	if (ret)
447 		return ret;
448 
449 	if (put_compat_rusage(&r, ru))
450 		return -EFAULT;
451 
452 	return 0;
453 }
454 
455 asmlinkage long
456 compat_sys_wait4(compat_pid_t pid, compat_uint_t __user *stat_addr, int options,
457 	struct compat_rusage __user *ru)
458 {
459 	if (!ru) {
460 		return sys_wait4(pid, stat_addr, options, NULL);
461 	} else {
462 		struct rusage r;
463 		int ret;
464 		unsigned int status;
465 		mm_segment_t old_fs = get_fs();
466 
467 		set_fs (KERNEL_DS);
468 		ret = sys_wait4(pid,
469 				(stat_addr ?
470 				 (unsigned int __user *) &status : NULL),
471 				options, (struct rusage __user *) &r);
472 		set_fs (old_fs);
473 
474 		if (ret > 0) {
475 			if (put_compat_rusage(&r, ru))
476 				return -EFAULT;
477 			if (stat_addr && put_user(status, stat_addr))
478 				return -EFAULT;
479 		}
480 		return ret;
481 	}
482 }
483 
484 asmlinkage long compat_sys_waitid(int which, compat_pid_t pid,
485 		struct compat_siginfo __user *uinfo, int options,
486 		struct compat_rusage __user *uru)
487 {
488 	siginfo_t info;
489 	struct rusage ru;
490 	long ret;
491 	mm_segment_t old_fs = get_fs();
492 
493 	memset(&info, 0, sizeof(info));
494 
495 	set_fs(KERNEL_DS);
496 	ret = sys_waitid(which, pid, (siginfo_t __user *)&info, options,
497 			 uru ? (struct rusage __user *)&ru : NULL);
498 	set_fs(old_fs);
499 
500 	if ((ret < 0) || (info.si_signo == 0))
501 		return ret;
502 
503 	if (uru) {
504 		ret = put_compat_rusage(&ru, uru);
505 		if (ret)
506 			return ret;
507 	}
508 
509 	BUG_ON(info.si_code & __SI_MASK);
510 	info.si_code |= __SI_CHLD;
511 	return copy_siginfo_to_user32(uinfo, &info);
512 }
513 
514 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
515 				    unsigned len, struct cpumask *new_mask)
516 {
517 	unsigned long *k;
518 
519 	if (len < cpumask_size())
520 		memset(new_mask, 0, cpumask_size());
521 	else if (len > cpumask_size())
522 		len = cpumask_size();
523 
524 	k = cpumask_bits(new_mask);
525 	return compat_get_bitmap(k, user_mask_ptr, len * 8);
526 }
527 
528 asmlinkage long compat_sys_sched_setaffinity(compat_pid_t pid,
529 					     unsigned int len,
530 					     compat_ulong_t __user *user_mask_ptr)
531 {
532 	cpumask_var_t new_mask;
533 	int retval;
534 
535 	if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
536 		return -ENOMEM;
537 
538 	retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
539 	if (retval)
540 		goto out;
541 
542 	retval = sched_setaffinity(pid, new_mask);
543 out:
544 	free_cpumask_var(new_mask);
545 	return retval;
546 }
547 
548 asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len,
549 					     compat_ulong_t __user *user_mask_ptr)
550 {
551 	int ret;
552 	cpumask_var_t mask;
553 
554 	if ((len * BITS_PER_BYTE) < nr_cpu_ids)
555 		return -EINVAL;
556 	if (len & (sizeof(compat_ulong_t)-1))
557 		return -EINVAL;
558 
559 	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
560 		return -ENOMEM;
561 
562 	ret = sched_getaffinity(pid, mask);
563 	if (ret == 0) {
564 		size_t retlen = min_t(size_t, len, cpumask_size());
565 
566 		if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
567 			ret = -EFAULT;
568 		else
569 			ret = retlen;
570 	}
571 	free_cpumask_var(mask);
572 
573 	return ret;
574 }
575 
576 int get_compat_itimerspec(struct itimerspec *dst,
577 			  const struct compat_itimerspec __user *src)
578 {
579 	if (get_compat_timespec(&dst->it_interval, &src->it_interval) ||
580 	    get_compat_timespec(&dst->it_value, &src->it_value))
581 		return -EFAULT;
582 	return 0;
583 }
584 
585 int put_compat_itimerspec(struct compat_itimerspec __user *dst,
586 			  const struct itimerspec *src)
587 {
588 	if (put_compat_timespec(&src->it_interval, &dst->it_interval) ||
589 	    put_compat_timespec(&src->it_value, &dst->it_value))
590 		return -EFAULT;
591 	return 0;
592 }
593 
594 long compat_sys_timer_create(clockid_t which_clock,
595 			struct compat_sigevent __user *timer_event_spec,
596 			timer_t __user *created_timer_id)
597 {
598 	struct sigevent __user *event = NULL;
599 
600 	if (timer_event_spec) {
601 		struct sigevent kevent;
602 
603 		event = compat_alloc_user_space(sizeof(*event));
604 		if (get_compat_sigevent(&kevent, timer_event_spec) ||
605 		    copy_to_user(event, &kevent, sizeof(*event)))
606 			return -EFAULT;
607 	}
608 
609 	return sys_timer_create(which_clock, event, created_timer_id);
610 }
611 
612 long compat_sys_timer_settime(timer_t timer_id, int flags,
613 			  struct compat_itimerspec __user *new,
614 			  struct compat_itimerspec __user *old)
615 {
616 	long err;
617 	mm_segment_t oldfs;
618 	struct itimerspec newts, oldts;
619 
620 	if (!new)
621 		return -EINVAL;
622 	if (get_compat_itimerspec(&newts, new))
623 		return -EFAULT;
624 	oldfs = get_fs();
625 	set_fs(KERNEL_DS);
626 	err = sys_timer_settime(timer_id, flags,
627 				(struct itimerspec __user *) &newts,
628 				(struct itimerspec __user *) &oldts);
629 	set_fs(oldfs);
630 	if (!err && old && put_compat_itimerspec(old, &oldts))
631 		return -EFAULT;
632 	return err;
633 }
634 
635 long compat_sys_timer_gettime(timer_t timer_id,
636 		struct compat_itimerspec __user *setting)
637 {
638 	long err;
639 	mm_segment_t oldfs;
640 	struct itimerspec ts;
641 
642 	oldfs = get_fs();
643 	set_fs(KERNEL_DS);
644 	err = sys_timer_gettime(timer_id,
645 				(struct itimerspec __user *) &ts);
646 	set_fs(oldfs);
647 	if (!err && put_compat_itimerspec(setting, &ts))
648 		return -EFAULT;
649 	return err;
650 }
651 
652 long compat_sys_clock_settime(clockid_t which_clock,
653 		struct compat_timespec __user *tp)
654 {
655 	long err;
656 	mm_segment_t oldfs;
657 	struct timespec ts;
658 
659 	if (get_compat_timespec(&ts, tp))
660 		return -EFAULT;
661 	oldfs = get_fs();
662 	set_fs(KERNEL_DS);
663 	err = sys_clock_settime(which_clock,
664 				(struct timespec __user *) &ts);
665 	set_fs(oldfs);
666 	return err;
667 }
668 
669 long compat_sys_clock_gettime(clockid_t which_clock,
670 		struct compat_timespec __user *tp)
671 {
672 	long err;
673 	mm_segment_t oldfs;
674 	struct timespec ts;
675 
676 	oldfs = get_fs();
677 	set_fs(KERNEL_DS);
678 	err = sys_clock_gettime(which_clock,
679 				(struct timespec __user *) &ts);
680 	set_fs(oldfs);
681 	if (!err && put_compat_timespec(&ts, tp))
682 		return -EFAULT;
683 	return err;
684 }
685 
686 long compat_sys_clock_adjtime(clockid_t which_clock,
687 		struct compat_timex __user *utp)
688 {
689 	struct timex txc;
690 	mm_segment_t oldfs;
691 	int err, ret;
692 
693 	err = compat_get_timex(&txc, utp);
694 	if (err)
695 		return err;
696 
697 	oldfs = get_fs();
698 	set_fs(KERNEL_DS);
699 	ret = sys_clock_adjtime(which_clock, (struct timex __user *) &txc);
700 	set_fs(oldfs);
701 
702 	err = compat_put_timex(utp, &txc);
703 	if (err)
704 		return err;
705 
706 	return ret;
707 }
708 
709 long compat_sys_clock_getres(clockid_t which_clock,
710 		struct compat_timespec __user *tp)
711 {
712 	long err;
713 	mm_segment_t oldfs;
714 	struct timespec ts;
715 
716 	oldfs = get_fs();
717 	set_fs(KERNEL_DS);
718 	err = sys_clock_getres(which_clock,
719 			       (struct timespec __user *) &ts);
720 	set_fs(oldfs);
721 	if (!err && tp && put_compat_timespec(&ts, tp))
722 		return -EFAULT;
723 	return err;
724 }
725 
726 static long compat_clock_nanosleep_restart(struct restart_block *restart)
727 {
728 	long err;
729 	mm_segment_t oldfs;
730 	struct timespec tu;
731 	struct compat_timespec *rmtp = restart->nanosleep.compat_rmtp;
732 
733 	restart->nanosleep.rmtp = (struct timespec __user *) &tu;
734 	oldfs = get_fs();
735 	set_fs(KERNEL_DS);
736 	err = clock_nanosleep_restart(restart);
737 	set_fs(oldfs);
738 
739 	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
740 	    put_compat_timespec(&tu, rmtp))
741 		return -EFAULT;
742 
743 	if (err == -ERESTART_RESTARTBLOCK) {
744 		restart->fn = compat_clock_nanosleep_restart;
745 		restart->nanosleep.compat_rmtp = rmtp;
746 	}
747 	return err;
748 }
749 
750 long compat_sys_clock_nanosleep(clockid_t which_clock, int flags,
751 			    struct compat_timespec __user *rqtp,
752 			    struct compat_timespec __user *rmtp)
753 {
754 	long err;
755 	mm_segment_t oldfs;
756 	struct timespec in, out;
757 	struct restart_block *restart;
758 
759 	if (get_compat_timespec(&in, rqtp))
760 		return -EFAULT;
761 
762 	oldfs = get_fs();
763 	set_fs(KERNEL_DS);
764 	err = sys_clock_nanosleep(which_clock, flags,
765 				  (struct timespec __user *) &in,
766 				  (struct timespec __user *) &out);
767 	set_fs(oldfs);
768 
769 	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
770 	    put_compat_timespec(&out, rmtp))
771 		return -EFAULT;
772 
773 	if (err == -ERESTART_RESTARTBLOCK) {
774 		restart = &current_thread_info()->restart_block;
775 		restart->fn = compat_clock_nanosleep_restart;
776 		restart->nanosleep.compat_rmtp = rmtp;
777 	}
778 	return err;
779 }
780 
781 /*
782  * We currently only need the following fields from the sigevent
783  * structure: sigev_value, sigev_signo, sig_notify and (sometimes
784  * sigev_notify_thread_id).  The others are handled in user mode.
785  * We also assume that copying sigev_value.sival_int is sufficient
786  * to keep all the bits of sigev_value.sival_ptr intact.
787  */
788 int get_compat_sigevent(struct sigevent *event,
789 		const struct compat_sigevent __user *u_event)
790 {
791 	memset(event, 0, sizeof(*event));
792 	return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
793 		__get_user(event->sigev_value.sival_int,
794 			&u_event->sigev_value.sival_int) ||
795 		__get_user(event->sigev_signo, &u_event->sigev_signo) ||
796 		__get_user(event->sigev_notify, &u_event->sigev_notify) ||
797 		__get_user(event->sigev_notify_thread_id,
798 			&u_event->sigev_notify_thread_id))
799 		? -EFAULT : 0;
800 }
801 
802 long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
803 		       unsigned long bitmap_size)
804 {
805 	int i, j;
806 	unsigned long m;
807 	compat_ulong_t um;
808 	unsigned long nr_compat_longs;
809 
810 	/* align bitmap up to nearest compat_long_t boundary */
811 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
812 
813 	if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
814 		return -EFAULT;
815 
816 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
817 
818 	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
819 		m = 0;
820 
821 		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
822 			/*
823 			 * We dont want to read past the end of the userspace
824 			 * bitmap. We must however ensure the end of the
825 			 * kernel bitmap is zeroed.
826 			 */
827 			if (nr_compat_longs-- > 0) {
828 				if (__get_user(um, umask))
829 					return -EFAULT;
830 			} else {
831 				um = 0;
832 			}
833 
834 			umask++;
835 			m |= (long)um << (j * BITS_PER_COMPAT_LONG);
836 		}
837 		*mask++ = m;
838 	}
839 
840 	return 0;
841 }
842 
843 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
844 		       unsigned long bitmap_size)
845 {
846 	int i, j;
847 	unsigned long m;
848 	compat_ulong_t um;
849 	unsigned long nr_compat_longs;
850 
851 	/* align bitmap up to nearest compat_long_t boundary */
852 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
853 
854 	if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
855 		return -EFAULT;
856 
857 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
858 
859 	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
860 		m = *mask++;
861 
862 		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
863 			um = m;
864 
865 			/*
866 			 * We dont want to write past the end of the userspace
867 			 * bitmap.
868 			 */
869 			if (nr_compat_longs-- > 0) {
870 				if (__put_user(um, umask))
871 					return -EFAULT;
872 			}
873 
874 			umask++;
875 			m >>= 4*sizeof(um);
876 			m >>= 4*sizeof(um);
877 		}
878 	}
879 
880 	return 0;
881 }
882 
883 void
884 sigset_from_compat (sigset_t *set, compat_sigset_t *compat)
885 {
886 	switch (_NSIG_WORDS) {
887 	case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
888 	case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 );
889 	case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 );
890 	case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 );
891 	}
892 }
893 EXPORT_SYMBOL_GPL(sigset_from_compat);
894 
895 asmlinkage long
896 compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese,
897 		struct compat_siginfo __user *uinfo,
898 		struct compat_timespec __user *uts, compat_size_t sigsetsize)
899 {
900 	compat_sigset_t s32;
901 	sigset_t s;
902 	struct timespec t;
903 	siginfo_t info;
904 	long ret;
905 
906 	if (sigsetsize != sizeof(sigset_t))
907 		return -EINVAL;
908 
909 	if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
910 		return -EFAULT;
911 	sigset_from_compat(&s, &s32);
912 
913 	if (uts) {
914 		if (get_compat_timespec(&t, uts))
915 			return -EFAULT;
916 	}
917 
918 	ret = do_sigtimedwait(&s, &info, uts ? &t : NULL);
919 
920 	if (ret > 0 && uinfo) {
921 		if (copy_siginfo_to_user32(uinfo, &info))
922 			ret = -EFAULT;
923 	}
924 
925 	return ret;
926 
927 }
928 
929 asmlinkage long
930 compat_sys_rt_tgsigqueueinfo(compat_pid_t tgid, compat_pid_t pid, int sig,
931 			     struct compat_siginfo __user *uinfo)
932 {
933 	siginfo_t info;
934 
935 	if (copy_siginfo_from_user32(&info, uinfo))
936 		return -EFAULT;
937 	return do_rt_tgsigqueueinfo(tgid, pid, sig, &info);
938 }
939 
940 #ifdef __ARCH_WANT_COMPAT_SYS_TIME
941 
942 /* compat_time_t is a 32 bit "long" and needs to get converted. */
943 
944 asmlinkage long compat_sys_time(compat_time_t __user * tloc)
945 {
946 	compat_time_t i;
947 	struct timeval tv;
948 
949 	do_gettimeofday(&tv);
950 	i = tv.tv_sec;
951 
952 	if (tloc) {
953 		if (put_user(i,tloc))
954 			return -EFAULT;
955 	}
956 	force_successful_syscall_return();
957 	return i;
958 }
959 
960 asmlinkage long compat_sys_stime(compat_time_t __user *tptr)
961 {
962 	struct timespec tv;
963 	int err;
964 
965 	if (get_user(tv.tv_sec, tptr))
966 		return -EFAULT;
967 
968 	tv.tv_nsec = 0;
969 
970 	err = security_settime(&tv, NULL);
971 	if (err)
972 		return err;
973 
974 	do_settimeofday(&tv);
975 	return 0;
976 }
977 
978 #endif /* __ARCH_WANT_COMPAT_SYS_TIME */
979 
980 #ifdef __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND
981 asmlinkage long compat_sys_rt_sigsuspend(compat_sigset_t __user *unewset, compat_size_t sigsetsize)
982 {
983 	sigset_t newset;
984 	compat_sigset_t newset32;
985 
986 	/* XXX: Don't preclude handling different sized sigset_t's.  */
987 	if (sigsetsize != sizeof(sigset_t))
988 		return -EINVAL;
989 
990 	if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t)))
991 		return -EFAULT;
992 	sigset_from_compat(&newset, &newset32);
993 	sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP));
994 
995 	spin_lock_irq(&current->sighand->siglock);
996 	current->saved_sigmask = current->blocked;
997 	current->blocked = newset;
998 	recalc_sigpending();
999 	spin_unlock_irq(&current->sighand->siglock);
1000 
1001 	current->state = TASK_INTERRUPTIBLE;
1002 	schedule();
1003 	set_restore_sigmask();
1004 	return -ERESTARTNOHAND;
1005 }
1006 #endif /* __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND */
1007 
1008 asmlinkage long compat_sys_adjtimex(struct compat_timex __user *utp)
1009 {
1010 	struct timex txc;
1011 	int err, ret;
1012 
1013 	err = compat_get_timex(&txc, utp);
1014 	if (err)
1015 		return err;
1016 
1017 	ret = do_adjtimex(&txc);
1018 
1019 	err = compat_put_timex(utp, &txc);
1020 	if (err)
1021 		return err;
1022 
1023 	return ret;
1024 }
1025 
1026 #ifdef CONFIG_NUMA
1027 asmlinkage long compat_sys_move_pages(pid_t pid, unsigned long nr_pages,
1028 		compat_uptr_t __user *pages32,
1029 		const int __user *nodes,
1030 		int __user *status,
1031 		int flags)
1032 {
1033 	const void __user * __user *pages;
1034 	int i;
1035 
1036 	pages = compat_alloc_user_space(nr_pages * sizeof(void *));
1037 	for (i = 0; i < nr_pages; i++) {
1038 		compat_uptr_t p;
1039 
1040 		if (get_user(p, pages32 + i) ||
1041 			put_user(compat_ptr(p), pages + i))
1042 			return -EFAULT;
1043 	}
1044 	return sys_move_pages(pid, nr_pages, pages, nodes, status, flags);
1045 }
1046 
1047 asmlinkage long compat_sys_migrate_pages(compat_pid_t pid,
1048 			compat_ulong_t maxnode,
1049 			const compat_ulong_t __user *old_nodes,
1050 			const compat_ulong_t __user *new_nodes)
1051 {
1052 	unsigned long __user *old = NULL;
1053 	unsigned long __user *new = NULL;
1054 	nodemask_t tmp_mask;
1055 	unsigned long nr_bits;
1056 	unsigned long size;
1057 
1058 	nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
1059 	size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1060 	if (old_nodes) {
1061 		if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
1062 			return -EFAULT;
1063 		old = compat_alloc_user_space(new_nodes ? size * 2 : size);
1064 		if (new_nodes)
1065 			new = old + size / sizeof(unsigned long);
1066 		if (copy_to_user(old, nodes_addr(tmp_mask), size))
1067 			return -EFAULT;
1068 	}
1069 	if (new_nodes) {
1070 		if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
1071 			return -EFAULT;
1072 		if (new == NULL)
1073 			new = compat_alloc_user_space(size);
1074 		if (copy_to_user(new, nodes_addr(tmp_mask), size))
1075 			return -EFAULT;
1076 	}
1077 	return sys_migrate_pages(pid, nr_bits + 1, old, new);
1078 }
1079 #endif
1080 
1081 struct compat_sysinfo {
1082 	s32 uptime;
1083 	u32 loads[3];
1084 	u32 totalram;
1085 	u32 freeram;
1086 	u32 sharedram;
1087 	u32 bufferram;
1088 	u32 totalswap;
1089 	u32 freeswap;
1090 	u16 procs;
1091 	u16 pad;
1092 	u32 totalhigh;
1093 	u32 freehigh;
1094 	u32 mem_unit;
1095 	char _f[20-2*sizeof(u32)-sizeof(int)];
1096 };
1097 
1098 asmlinkage long
1099 compat_sys_sysinfo(struct compat_sysinfo __user *info)
1100 {
1101 	struct sysinfo s;
1102 
1103 	do_sysinfo(&s);
1104 
1105 	/* Check to see if any memory value is too large for 32-bit and scale
1106 	 *  down if needed
1107 	 */
1108 	if ((s.totalram >> 32) || (s.totalswap >> 32)) {
1109 		int bitcount = 0;
1110 
1111 		while (s.mem_unit < PAGE_SIZE) {
1112 			s.mem_unit <<= 1;
1113 			bitcount++;
1114 		}
1115 
1116 		s.totalram >>= bitcount;
1117 		s.freeram >>= bitcount;
1118 		s.sharedram >>= bitcount;
1119 		s.bufferram >>= bitcount;
1120 		s.totalswap >>= bitcount;
1121 		s.freeswap >>= bitcount;
1122 		s.totalhigh >>= bitcount;
1123 		s.freehigh >>= bitcount;
1124 	}
1125 
1126 	if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
1127 	    __put_user (s.uptime, &info->uptime) ||
1128 	    __put_user (s.loads[0], &info->loads[0]) ||
1129 	    __put_user (s.loads[1], &info->loads[1]) ||
1130 	    __put_user (s.loads[2], &info->loads[2]) ||
1131 	    __put_user (s.totalram, &info->totalram) ||
1132 	    __put_user (s.freeram, &info->freeram) ||
1133 	    __put_user (s.sharedram, &info->sharedram) ||
1134 	    __put_user (s.bufferram, &info->bufferram) ||
1135 	    __put_user (s.totalswap, &info->totalswap) ||
1136 	    __put_user (s.freeswap, &info->freeswap) ||
1137 	    __put_user (s.procs, &info->procs) ||
1138 	    __put_user (s.totalhigh, &info->totalhigh) ||
1139 	    __put_user (s.freehigh, &info->freehigh) ||
1140 	    __put_user (s.mem_unit, &info->mem_unit))
1141 		return -EFAULT;
1142 
1143 	return 0;
1144 }
1145 
1146 /*
1147  * Allocate user-space memory for the duration of a single system call,
1148  * in order to marshall parameters inside a compat thunk.
1149  */
1150 void __user *compat_alloc_user_space(unsigned long len)
1151 {
1152 	void __user *ptr;
1153 
1154 	/* If len would occupy more than half of the entire compat space... */
1155 	if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
1156 		return NULL;
1157 
1158 	ptr = arch_compat_alloc_user_space(len);
1159 
1160 	if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
1161 		return NULL;
1162 
1163 	return ptr;
1164 }
1165 EXPORT_SYMBOL_GPL(compat_alloc_user_space);
1166