xref: /linux/kernel/compat.c (revision d8327c784b51b57dac2c26cfad87dce0d68dfd98)
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/futex.h>	/* for FUTEX_WAIT */
21 #include <linux/syscalls.h>
22 #include <linux/unistd.h>
23 #include <linux/security.h>
24 
25 #include <asm/uaccess.h>
26 
27 int get_compat_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
28 {
29 	return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
30 			__get_user(ts->tv_sec, &cts->tv_sec) ||
31 			__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
32 }
33 
34 int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
35 {
36 	return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
37 			__put_user(ts->tv_sec, &cts->tv_sec) ||
38 			__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
39 }
40 
41 static long compat_nanosleep_restart(struct restart_block *restart)
42 {
43 	unsigned long expire = restart->arg0, now = jiffies;
44 	struct compat_timespec __user *rmtp;
45 
46 	/* Did it expire while we handled signals? */
47 	if (!time_after(expire, now))
48 		return 0;
49 
50 	expire = schedule_timeout_interruptible(expire - now);
51 	if (expire == 0)
52 		return 0;
53 
54 	rmtp = (struct compat_timespec __user *)restart->arg1;
55 	if (rmtp) {
56 		struct compat_timespec ct;
57 		struct timespec t;
58 
59 		jiffies_to_timespec(expire, &t);
60 		ct.tv_sec = t.tv_sec;
61 		ct.tv_nsec = t.tv_nsec;
62 		if (copy_to_user(rmtp, &ct, sizeof(ct)))
63 			return -EFAULT;
64 	}
65 	/* The 'restart' block is already filled in */
66 	return -ERESTART_RESTARTBLOCK;
67 }
68 
69 asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
70 		struct compat_timespec __user *rmtp)
71 {
72 	struct timespec t;
73 	struct restart_block *restart;
74 	unsigned long expire;
75 
76 	if (get_compat_timespec(&t, rqtp))
77 		return -EFAULT;
78 
79 	if ((t.tv_nsec >= 1000000000L) || (t.tv_nsec < 0) || (t.tv_sec < 0))
80 		return -EINVAL;
81 
82 	expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
83 	expire = schedule_timeout_interruptible(expire);
84 	if (expire == 0)
85 		return 0;
86 
87 	if (rmtp) {
88 		jiffies_to_timespec(expire, &t);
89 		if (put_compat_timespec(&t, rmtp))
90 			return -EFAULT;
91 	}
92 	restart = &current_thread_info()->restart_block;
93 	restart->fn = compat_nanosleep_restart;
94 	restart->arg0 = jiffies + expire;
95 	restart->arg1 = (unsigned long) rmtp;
96 	return -ERESTART_RESTARTBLOCK;
97 }
98 
99 static inline long get_compat_itimerval(struct itimerval *o,
100 		struct compat_itimerval __user *i)
101 {
102 	return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
103 		(__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
104 		 __get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
105 		 __get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
106 		 __get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
107 }
108 
109 static inline long put_compat_itimerval(struct compat_itimerval __user *o,
110 		struct itimerval *i)
111 {
112 	return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
113 		(__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
114 		 __put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
115 		 __put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
116 		 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
117 }
118 
119 asmlinkage long compat_sys_getitimer(int which,
120 		struct compat_itimerval __user *it)
121 {
122 	struct itimerval kit;
123 	int error;
124 
125 	error = do_getitimer(which, &kit);
126 	if (!error && put_compat_itimerval(it, &kit))
127 		error = -EFAULT;
128 	return error;
129 }
130 
131 asmlinkage long compat_sys_setitimer(int which,
132 		struct compat_itimerval __user *in,
133 		struct compat_itimerval __user *out)
134 {
135 	struct itimerval kin, kout;
136 	int error;
137 
138 	if (in) {
139 		if (get_compat_itimerval(&kin, in))
140 			return -EFAULT;
141 	} else
142 		memset(&kin, 0, sizeof(kin));
143 
144 	error = do_setitimer(which, &kin, out ? &kout : NULL);
145 	if (error || !out)
146 		return error;
147 	if (put_compat_itimerval(out, &kout))
148 		return -EFAULT;
149 	return 0;
150 }
151 
152 asmlinkage long compat_sys_times(struct compat_tms __user *tbuf)
153 {
154 	/*
155 	 *	In the SMP world we might just be unlucky and have one of
156 	 *	the times increment as we use it. Since the value is an
157 	 *	atomically safe type this is just fine. Conceptually its
158 	 *	as if the syscall took an instant longer to occur.
159 	 */
160 	if (tbuf) {
161 		struct compat_tms tmp;
162 		struct task_struct *tsk = current;
163 		struct task_struct *t;
164 		cputime_t utime, stime, cutime, cstime;
165 
166 		read_lock(&tasklist_lock);
167 		utime = tsk->signal->utime;
168 		stime = tsk->signal->stime;
169 		t = tsk;
170 		do {
171 			utime = cputime_add(utime, t->utime);
172 			stime = cputime_add(stime, t->stime);
173 			t = next_thread(t);
174 		} while (t != tsk);
175 
176 		/*
177 		 * While we have tasklist_lock read-locked, no dying thread
178 		 * can be updating current->signal->[us]time.  Instead,
179 		 * we got their counts included in the live thread loop.
180 		 * However, another thread can come in right now and
181 		 * do a wait call that updates current->signal->c[us]time.
182 		 * To make sure we always see that pair updated atomically,
183 		 * we take the siglock around fetching them.
184 		 */
185 		spin_lock_irq(&tsk->sighand->siglock);
186 		cutime = tsk->signal->cutime;
187 		cstime = tsk->signal->cstime;
188 		spin_unlock_irq(&tsk->sighand->siglock);
189 		read_unlock(&tasklist_lock);
190 
191 		tmp.tms_utime = compat_jiffies_to_clock_t(cputime_to_jiffies(utime));
192 		tmp.tms_stime = compat_jiffies_to_clock_t(cputime_to_jiffies(stime));
193 		tmp.tms_cutime = compat_jiffies_to_clock_t(cputime_to_jiffies(cutime));
194 		tmp.tms_cstime = compat_jiffies_to_clock_t(cputime_to_jiffies(cstime));
195 		if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
196 			return -EFAULT;
197 	}
198 	return compat_jiffies_to_clock_t(jiffies);
199 }
200 
201 /*
202  * Assumption: old_sigset_t and compat_old_sigset_t are both
203  * types that can be passed to put_user()/get_user().
204  */
205 
206 asmlinkage long compat_sys_sigpending(compat_old_sigset_t __user *set)
207 {
208 	old_sigset_t s;
209 	long ret;
210 	mm_segment_t old_fs = get_fs();
211 
212 	set_fs(KERNEL_DS);
213 	ret = sys_sigpending((old_sigset_t __user *) &s);
214 	set_fs(old_fs);
215 	if (ret == 0)
216 		ret = put_user(s, set);
217 	return ret;
218 }
219 
220 asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t __user *set,
221 		compat_old_sigset_t __user *oset)
222 {
223 	old_sigset_t s;
224 	long ret;
225 	mm_segment_t old_fs;
226 
227 	if (set && get_user(s, set))
228 		return -EFAULT;
229 	old_fs = get_fs();
230 	set_fs(KERNEL_DS);
231 	ret = sys_sigprocmask(how,
232 			      set ? (old_sigset_t __user *) &s : NULL,
233 			      oset ? (old_sigset_t __user *) &s : NULL);
234 	set_fs(old_fs);
235 	if (ret == 0)
236 		if (oset)
237 			ret = put_user(s, oset);
238 	return ret;
239 }
240 
241 #ifdef CONFIG_FUTEX
242 asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, int val,
243 		struct compat_timespec __user *utime, u32 __user *uaddr2,
244 		int val3)
245 {
246 	struct timespec t;
247 	unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
248 	int val2 = 0;
249 
250 	if ((op == FUTEX_WAIT) && utime) {
251 		if (get_compat_timespec(&t, utime))
252 			return -EFAULT;
253 		timeout = timespec_to_jiffies(&t) + 1;
254 	}
255 	if (op >= FUTEX_REQUEUE)
256 		val2 = (int) (unsigned long) utime;
257 
258 	return do_futex((unsigned long)uaddr, op, val, timeout,
259 			(unsigned long)uaddr2, val2, val3);
260 }
261 #endif
262 
263 asmlinkage long compat_sys_setrlimit(unsigned int resource,
264 		struct compat_rlimit __user *rlim)
265 {
266 	struct rlimit r;
267 	int ret;
268 	mm_segment_t old_fs = get_fs ();
269 
270 	if (resource >= RLIM_NLIMITS)
271 		return -EINVAL;
272 
273 	if (!access_ok(VERIFY_READ, rlim, sizeof(*rlim)) ||
274 	    __get_user(r.rlim_cur, &rlim->rlim_cur) ||
275 	    __get_user(r.rlim_max, &rlim->rlim_max))
276 		return -EFAULT;
277 
278 	if (r.rlim_cur == COMPAT_RLIM_INFINITY)
279 		r.rlim_cur = RLIM_INFINITY;
280 	if (r.rlim_max == COMPAT_RLIM_INFINITY)
281 		r.rlim_max = RLIM_INFINITY;
282 	set_fs(KERNEL_DS);
283 	ret = sys_setrlimit(resource, (struct rlimit __user *) &r);
284 	set_fs(old_fs);
285 	return ret;
286 }
287 
288 #ifdef COMPAT_RLIM_OLD_INFINITY
289 
290 asmlinkage long compat_sys_old_getrlimit(unsigned int resource,
291 		struct compat_rlimit __user *rlim)
292 {
293 	struct rlimit r;
294 	int ret;
295 	mm_segment_t old_fs = get_fs();
296 
297 	set_fs(KERNEL_DS);
298 	ret = sys_old_getrlimit(resource, &r);
299 	set_fs(old_fs);
300 
301 	if (!ret) {
302 		if (r.rlim_cur > COMPAT_RLIM_OLD_INFINITY)
303 			r.rlim_cur = COMPAT_RLIM_INFINITY;
304 		if (r.rlim_max > COMPAT_RLIM_OLD_INFINITY)
305 			r.rlim_max = COMPAT_RLIM_INFINITY;
306 
307 		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
308 		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
309 		    __put_user(r.rlim_max, &rlim->rlim_max))
310 			return -EFAULT;
311 	}
312 	return ret;
313 }
314 
315 #endif
316 
317 asmlinkage long compat_sys_getrlimit (unsigned int resource,
318 		struct compat_rlimit __user *rlim)
319 {
320 	struct rlimit r;
321 	int ret;
322 	mm_segment_t old_fs = get_fs();
323 
324 	set_fs(KERNEL_DS);
325 	ret = sys_getrlimit(resource, (struct rlimit __user *) &r);
326 	set_fs(old_fs);
327 	if (!ret) {
328 		if (r.rlim_cur > COMPAT_RLIM_INFINITY)
329 			r.rlim_cur = COMPAT_RLIM_INFINITY;
330 		if (r.rlim_max > COMPAT_RLIM_INFINITY)
331 			r.rlim_max = COMPAT_RLIM_INFINITY;
332 
333 		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
334 		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
335 		    __put_user(r.rlim_max, &rlim->rlim_max))
336 			return -EFAULT;
337 	}
338 	return ret;
339 }
340 
341 int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
342 {
343 	if (!access_ok(VERIFY_WRITE, ru, sizeof(*ru)) ||
344 	    __put_user(r->ru_utime.tv_sec, &ru->ru_utime.tv_sec) ||
345 	    __put_user(r->ru_utime.tv_usec, &ru->ru_utime.tv_usec) ||
346 	    __put_user(r->ru_stime.tv_sec, &ru->ru_stime.tv_sec) ||
347 	    __put_user(r->ru_stime.tv_usec, &ru->ru_stime.tv_usec) ||
348 	    __put_user(r->ru_maxrss, &ru->ru_maxrss) ||
349 	    __put_user(r->ru_ixrss, &ru->ru_ixrss) ||
350 	    __put_user(r->ru_idrss, &ru->ru_idrss) ||
351 	    __put_user(r->ru_isrss, &ru->ru_isrss) ||
352 	    __put_user(r->ru_minflt, &ru->ru_minflt) ||
353 	    __put_user(r->ru_majflt, &ru->ru_majflt) ||
354 	    __put_user(r->ru_nswap, &ru->ru_nswap) ||
355 	    __put_user(r->ru_inblock, &ru->ru_inblock) ||
356 	    __put_user(r->ru_oublock, &ru->ru_oublock) ||
357 	    __put_user(r->ru_msgsnd, &ru->ru_msgsnd) ||
358 	    __put_user(r->ru_msgrcv, &ru->ru_msgrcv) ||
359 	    __put_user(r->ru_nsignals, &ru->ru_nsignals) ||
360 	    __put_user(r->ru_nvcsw, &ru->ru_nvcsw) ||
361 	    __put_user(r->ru_nivcsw, &ru->ru_nivcsw))
362 		return -EFAULT;
363 	return 0;
364 }
365 
366 asmlinkage long compat_sys_getrusage(int who, struct compat_rusage __user *ru)
367 {
368 	struct rusage r;
369 	int ret;
370 	mm_segment_t old_fs = get_fs();
371 
372 	set_fs(KERNEL_DS);
373 	ret = sys_getrusage(who, (struct rusage __user *) &r);
374 	set_fs(old_fs);
375 
376 	if (ret)
377 		return ret;
378 
379 	if (put_compat_rusage(&r, ru))
380 		return -EFAULT;
381 
382 	return 0;
383 }
384 
385 asmlinkage long
386 compat_sys_wait4(compat_pid_t pid, compat_uint_t __user *stat_addr, int options,
387 	struct compat_rusage __user *ru)
388 {
389 	if (!ru) {
390 		return sys_wait4(pid, stat_addr, options, NULL);
391 	} else {
392 		struct rusage r;
393 		int ret;
394 		unsigned int status;
395 		mm_segment_t old_fs = get_fs();
396 
397 		set_fs (KERNEL_DS);
398 		ret = sys_wait4(pid,
399 				(stat_addr ?
400 				 (unsigned int __user *) &status : NULL),
401 				options, (struct rusage __user *) &r);
402 		set_fs (old_fs);
403 
404 		if (ret > 0) {
405 			if (put_compat_rusage(&r, ru))
406 				return -EFAULT;
407 			if (stat_addr && put_user(status, stat_addr))
408 				return -EFAULT;
409 		}
410 		return ret;
411 	}
412 }
413 
414 asmlinkage long compat_sys_waitid(int which, compat_pid_t pid,
415 		struct compat_siginfo __user *uinfo, int options,
416 		struct compat_rusage __user *uru)
417 {
418 	siginfo_t info;
419 	struct rusage ru;
420 	long ret;
421 	mm_segment_t old_fs = get_fs();
422 
423 	memset(&info, 0, sizeof(info));
424 
425 	set_fs(KERNEL_DS);
426 	ret = sys_waitid(which, pid, (siginfo_t __user *)&info, options,
427 			 uru ? (struct rusage __user *)&ru : NULL);
428 	set_fs(old_fs);
429 
430 	if ((ret < 0) || (info.si_signo == 0))
431 		return ret;
432 
433 	if (uru) {
434 		ret = put_compat_rusage(&ru, uru);
435 		if (ret)
436 			return ret;
437 	}
438 
439 	BUG_ON(info.si_code & __SI_MASK);
440 	info.si_code |= __SI_CHLD;
441 	return copy_siginfo_to_user32(uinfo, &info);
442 }
443 
444 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
445 				    unsigned len, cpumask_t *new_mask)
446 {
447 	unsigned long *k;
448 
449 	if (len < sizeof(cpumask_t))
450 		memset(new_mask, 0, sizeof(cpumask_t));
451 	else if (len > sizeof(cpumask_t))
452 		len = sizeof(cpumask_t);
453 
454 	k = cpus_addr(*new_mask);
455 	return compat_get_bitmap(k, user_mask_ptr, len * 8);
456 }
457 
458 asmlinkage long compat_sys_sched_setaffinity(compat_pid_t pid,
459 					     unsigned int len,
460 					     compat_ulong_t __user *user_mask_ptr)
461 {
462 	cpumask_t new_mask;
463 	int retval;
464 
465 	retval = compat_get_user_cpu_mask(user_mask_ptr, len, &new_mask);
466 	if (retval)
467 		return retval;
468 
469 	return sched_setaffinity(pid, new_mask);
470 }
471 
472 asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len,
473 					     compat_ulong_t __user *user_mask_ptr)
474 {
475 	int ret;
476 	cpumask_t mask;
477 	unsigned long *k;
478 	unsigned int min_length = sizeof(cpumask_t);
479 
480 	if (NR_CPUS <= BITS_PER_COMPAT_LONG)
481 		min_length = sizeof(compat_ulong_t);
482 
483 	if (len < min_length)
484 		return -EINVAL;
485 
486 	ret = sched_getaffinity(pid, &mask);
487 	if (ret < 0)
488 		return ret;
489 
490 	k = cpus_addr(mask);
491 	ret = compat_put_bitmap(user_mask_ptr, k, min_length * 8);
492 	if (ret)
493 		return ret;
494 
495 	return min_length;
496 }
497 
498 static int get_compat_itimerspec(struct itimerspec *dst,
499 				 struct compat_itimerspec __user *src)
500 {
501 	if (get_compat_timespec(&dst->it_interval, &src->it_interval) ||
502 	    get_compat_timespec(&dst->it_value, &src->it_value))
503 		return -EFAULT;
504 	return 0;
505 }
506 
507 static int put_compat_itimerspec(struct compat_itimerspec __user *dst,
508 				 struct itimerspec *src)
509 {
510 	if (put_compat_timespec(&src->it_interval, &dst->it_interval) ||
511 	    put_compat_timespec(&src->it_value, &dst->it_value))
512 		return -EFAULT;
513 	return 0;
514 }
515 
516 long compat_sys_timer_create(clockid_t which_clock,
517 			struct compat_sigevent __user *timer_event_spec,
518 			timer_t __user *created_timer_id)
519 {
520 	struct sigevent __user *event = NULL;
521 
522 	if (timer_event_spec) {
523 		struct sigevent kevent;
524 
525 		event = compat_alloc_user_space(sizeof(*event));
526 		if (get_compat_sigevent(&kevent, timer_event_spec) ||
527 		    copy_to_user(event, &kevent, sizeof(*event)))
528 			return -EFAULT;
529 	}
530 
531 	return sys_timer_create(which_clock, event, created_timer_id);
532 }
533 
534 long compat_sys_timer_settime(timer_t timer_id, int flags,
535 			  struct compat_itimerspec __user *new,
536 			  struct compat_itimerspec __user *old)
537 {
538 	long err;
539 	mm_segment_t oldfs;
540 	struct itimerspec newts, oldts;
541 
542 	if (!new)
543 		return -EINVAL;
544 	if (get_compat_itimerspec(&newts, new))
545 		return -EFAULT;
546 	oldfs = get_fs();
547 	set_fs(KERNEL_DS);
548 	err = sys_timer_settime(timer_id, flags,
549 				(struct itimerspec __user *) &newts,
550 				(struct itimerspec __user *) &oldts);
551 	set_fs(oldfs);
552 	if (!err && old && put_compat_itimerspec(old, &oldts))
553 		return -EFAULT;
554 	return err;
555 }
556 
557 long compat_sys_timer_gettime(timer_t timer_id,
558 		struct compat_itimerspec __user *setting)
559 {
560 	long err;
561 	mm_segment_t oldfs;
562 	struct itimerspec ts;
563 
564 	oldfs = get_fs();
565 	set_fs(KERNEL_DS);
566 	err = sys_timer_gettime(timer_id,
567 				(struct itimerspec __user *) &ts);
568 	set_fs(oldfs);
569 	if (!err && put_compat_itimerspec(setting, &ts))
570 		return -EFAULT;
571 	return err;
572 }
573 
574 long compat_sys_clock_settime(clockid_t which_clock,
575 		struct compat_timespec __user *tp)
576 {
577 	long err;
578 	mm_segment_t oldfs;
579 	struct timespec ts;
580 
581 	if (get_compat_timespec(&ts, tp))
582 		return -EFAULT;
583 	oldfs = get_fs();
584 	set_fs(KERNEL_DS);
585 	err = sys_clock_settime(which_clock,
586 				(struct timespec __user *) &ts);
587 	set_fs(oldfs);
588 	return err;
589 }
590 
591 long compat_sys_clock_gettime(clockid_t which_clock,
592 		struct compat_timespec __user *tp)
593 {
594 	long err;
595 	mm_segment_t oldfs;
596 	struct timespec ts;
597 
598 	oldfs = get_fs();
599 	set_fs(KERNEL_DS);
600 	err = sys_clock_gettime(which_clock,
601 				(struct timespec __user *) &ts);
602 	set_fs(oldfs);
603 	if (!err && put_compat_timespec(&ts, tp))
604 		return -EFAULT;
605 	return err;
606 }
607 
608 long compat_sys_clock_getres(clockid_t which_clock,
609 		struct compat_timespec __user *tp)
610 {
611 	long err;
612 	mm_segment_t oldfs;
613 	struct timespec ts;
614 
615 	oldfs = get_fs();
616 	set_fs(KERNEL_DS);
617 	err = sys_clock_getres(which_clock,
618 			       (struct timespec __user *) &ts);
619 	set_fs(oldfs);
620 	if (!err && tp && put_compat_timespec(&ts, tp))
621 		return -EFAULT;
622 	return err;
623 }
624 
625 long compat_sys_clock_nanosleep(clockid_t which_clock, int flags,
626 			    struct compat_timespec __user *rqtp,
627 			    struct compat_timespec __user *rmtp)
628 {
629 	long err;
630 	mm_segment_t oldfs;
631 	struct timespec in, out;
632 
633 	if (get_compat_timespec(&in, rqtp))
634 		return -EFAULT;
635 
636 	oldfs = get_fs();
637 	set_fs(KERNEL_DS);
638 	err = sys_clock_nanosleep(which_clock, flags,
639 				  (struct timespec __user *) &in,
640 				  (struct timespec __user *) &out);
641 	set_fs(oldfs);
642 	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
643 	    put_compat_timespec(&out, rmtp))
644 		return -EFAULT;
645 	return err;
646 }
647 
648 /*
649  * We currently only need the following fields from the sigevent
650  * structure: sigev_value, sigev_signo, sig_notify and (sometimes
651  * sigev_notify_thread_id).  The others are handled in user mode.
652  * We also assume that copying sigev_value.sival_int is sufficient
653  * to keep all the bits of sigev_value.sival_ptr intact.
654  */
655 int get_compat_sigevent(struct sigevent *event,
656 		const struct compat_sigevent __user *u_event)
657 {
658 	memset(event, 0, sizeof(*event));
659 	return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
660 		__get_user(event->sigev_value.sival_int,
661 			&u_event->sigev_value.sival_int) ||
662 		__get_user(event->sigev_signo, &u_event->sigev_signo) ||
663 		__get_user(event->sigev_notify, &u_event->sigev_notify) ||
664 		__get_user(event->sigev_notify_thread_id,
665 			&u_event->sigev_notify_thread_id))
666 		? -EFAULT : 0;
667 }
668 
669 long compat_get_bitmap(unsigned long *mask, compat_ulong_t __user *umask,
670 		       unsigned long bitmap_size)
671 {
672 	int i, j;
673 	unsigned long m;
674 	compat_ulong_t um;
675 	unsigned long nr_compat_longs;
676 
677 	/* align bitmap up to nearest compat_long_t boundary */
678 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
679 
680 	if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
681 		return -EFAULT;
682 
683 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
684 
685 	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
686 		m = 0;
687 
688 		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
689 			/*
690 			 * We dont want to read past the end of the userspace
691 			 * bitmap. We must however ensure the end of the
692 			 * kernel bitmap is zeroed.
693 			 */
694 			if (nr_compat_longs-- > 0) {
695 				if (__get_user(um, umask))
696 					return -EFAULT;
697 			} else {
698 				um = 0;
699 			}
700 
701 			umask++;
702 			m |= (long)um << (j * BITS_PER_COMPAT_LONG);
703 		}
704 		*mask++ = m;
705 	}
706 
707 	return 0;
708 }
709 
710 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
711 		       unsigned long bitmap_size)
712 {
713 	int i, j;
714 	unsigned long m;
715 	compat_ulong_t um;
716 	unsigned long nr_compat_longs;
717 
718 	/* align bitmap up to nearest compat_long_t boundary */
719 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
720 
721 	if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
722 		return -EFAULT;
723 
724 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
725 
726 	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
727 		m = *mask++;
728 
729 		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
730 			um = m;
731 
732 			/*
733 			 * We dont want to write past the end of the userspace
734 			 * bitmap.
735 			 */
736 			if (nr_compat_longs-- > 0) {
737 				if (__put_user(um, umask))
738 					return -EFAULT;
739 			}
740 
741 			umask++;
742 			m >>= 4*sizeof(um);
743 			m >>= 4*sizeof(um);
744 		}
745 	}
746 
747 	return 0;
748 }
749 
750 void
751 sigset_from_compat (sigset_t *set, compat_sigset_t *compat)
752 {
753 	switch (_NSIG_WORDS) {
754 #if defined (__COMPAT_ENDIAN_SWAP__)
755 	case 4: set->sig[3] = compat->sig[7] | (((long)compat->sig[6]) << 32 );
756 	case 3: set->sig[2] = compat->sig[5] | (((long)compat->sig[4]) << 32 );
757 	case 2: set->sig[1] = compat->sig[3] | (((long)compat->sig[2]) << 32 );
758 	case 1: set->sig[0] = compat->sig[1] | (((long)compat->sig[0]) << 32 );
759 #else
760 	case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
761 	case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 );
762 	case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 );
763 	case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 );
764 #endif
765 	}
766 }
767 
768 asmlinkage long
769 compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese,
770 		struct compat_siginfo __user *uinfo,
771 		struct compat_timespec __user *uts, compat_size_t sigsetsize)
772 {
773 	compat_sigset_t s32;
774 	sigset_t s;
775 	int sig;
776 	struct timespec t;
777 	siginfo_t info;
778 	long ret, timeout = 0;
779 
780 	if (sigsetsize != sizeof(sigset_t))
781 		return -EINVAL;
782 
783 	if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
784 		return -EFAULT;
785 	sigset_from_compat(&s, &s32);
786 	sigdelsetmask(&s,sigmask(SIGKILL)|sigmask(SIGSTOP));
787 	signotset(&s);
788 
789 	if (uts) {
790 		if (get_compat_timespec (&t, uts))
791 			return -EFAULT;
792 		if (t.tv_nsec >= 1000000000L || t.tv_nsec < 0
793 				|| t.tv_sec < 0)
794 			return -EINVAL;
795 	}
796 
797 	spin_lock_irq(&current->sighand->siglock);
798 	sig = dequeue_signal(current, &s, &info);
799 	if (!sig) {
800 		timeout = MAX_SCHEDULE_TIMEOUT;
801 		if (uts)
802 			timeout = timespec_to_jiffies(&t)
803 				+(t.tv_sec || t.tv_nsec);
804 		if (timeout) {
805 			current->real_blocked = current->blocked;
806 			sigandsets(&current->blocked, &current->blocked, &s);
807 
808 			recalc_sigpending();
809 			spin_unlock_irq(&current->sighand->siglock);
810 
811 			timeout = schedule_timeout_interruptible(timeout);
812 
813 			spin_lock_irq(&current->sighand->siglock);
814 			sig = dequeue_signal(current, &s, &info);
815 			current->blocked = current->real_blocked;
816 			siginitset(&current->real_blocked, 0);
817 			recalc_sigpending();
818 		}
819 	}
820 	spin_unlock_irq(&current->sighand->siglock);
821 
822 	if (sig) {
823 		ret = sig;
824 		if (uinfo) {
825 			if (copy_siginfo_to_user32(uinfo, &info))
826 				ret = -EFAULT;
827 		}
828 	}else {
829 		ret = timeout?-EINTR:-EAGAIN;
830 	}
831 	return ret;
832 
833 }
834 
835 #ifdef __ARCH_WANT_COMPAT_SYS_TIME
836 
837 /* compat_time_t is a 32 bit "long" and needs to get converted. */
838 
839 asmlinkage long compat_sys_time(compat_time_t __user * tloc)
840 {
841 	compat_time_t i;
842 	struct timeval tv;
843 
844 	do_gettimeofday(&tv);
845 	i = tv.tv_sec;
846 
847 	if (tloc) {
848 		if (put_user(i,tloc))
849 			i = -EFAULT;
850 	}
851 	return i;
852 }
853 
854 asmlinkage long compat_sys_stime(compat_time_t __user *tptr)
855 {
856 	struct timespec tv;
857 	int err;
858 
859 	if (get_user(tv.tv_sec, tptr))
860 		return -EFAULT;
861 
862 	tv.tv_nsec = 0;
863 
864 	err = security_settime(&tv, NULL);
865 	if (err)
866 		return err;
867 
868 	do_settimeofday(&tv);
869 	return 0;
870 }
871 
872 #endif /* __ARCH_WANT_COMPAT_SYS_TIME */
873 
874 #ifdef __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND
875 asmlinkage long compat_sys_rt_sigsuspend(compat_sigset_t __user *unewset, compat_size_t sigsetsize)
876 {
877 	sigset_t newset;
878 	compat_sigset_t newset32;
879 
880 	/* XXX: Don't preclude handling different sized sigset_t's.  */
881 	if (sigsetsize != sizeof(sigset_t))
882 		return -EINVAL;
883 
884 	if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t)))
885 		return -EFAULT;
886 	sigset_from_compat(&newset, &newset32);
887 	sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP));
888 
889 	spin_lock_irq(&current->sighand->siglock);
890 	current->saved_sigmask = current->blocked;
891 	current->blocked = newset;
892 	recalc_sigpending();
893 	spin_unlock_irq(&current->sighand->siglock);
894 
895 	current->state = TASK_INTERRUPTIBLE;
896 	schedule();
897 	set_thread_flag(TIF_RESTORE_SIGMASK);
898 	return -ERESTARTNOHAND;
899 }
900 #endif /* __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND */
901