xref: /linux/kernel/compat.c (revision 776cfebb430c7b22c208b1b17add97f354d97cab)
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 #include <asm/bug.h>
27 
28 int get_compat_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
29 {
30 	return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
31 			__get_user(ts->tv_sec, &cts->tv_sec) ||
32 			__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
33 }
34 
35 int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
36 {
37 	return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
38 			__put_user(ts->tv_sec, &cts->tv_sec) ||
39 			__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
40 }
41 
42 static long compat_nanosleep_restart(struct restart_block *restart)
43 {
44 	unsigned long expire = restart->arg0, now = jiffies;
45 	struct compat_timespec __user *rmtp;
46 
47 	/* Did it expire while we handled signals? */
48 	if (!time_after(expire, now))
49 		return 0;
50 
51 	current->state = TASK_INTERRUPTIBLE;
52 	expire = schedule_timeout(expire - now);
53 	if (expire == 0)
54 		return 0;
55 
56 	rmtp = (struct compat_timespec __user *)restart->arg1;
57 	if (rmtp) {
58 		struct compat_timespec ct;
59 		struct timespec t;
60 
61 		jiffies_to_timespec(expire, &t);
62 		ct.tv_sec = t.tv_sec;
63 		ct.tv_nsec = t.tv_nsec;
64 		if (copy_to_user(rmtp, &ct, sizeof(ct)))
65 			return -EFAULT;
66 	}
67 	/* The 'restart' block is already filled in */
68 	return -ERESTART_RESTARTBLOCK;
69 }
70 
71 asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
72 		struct compat_timespec __user *rmtp)
73 {
74 	struct timespec t;
75 	struct restart_block *restart;
76 	unsigned long expire;
77 
78 	if (get_compat_timespec(&t, rqtp))
79 		return -EFAULT;
80 
81 	if ((t.tv_nsec >= 1000000000L) || (t.tv_nsec < 0) || (t.tv_sec < 0))
82 		return -EINVAL;
83 
84 	expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
85 	current->state = TASK_INTERRUPTIBLE;
86 	expire = schedule_timeout(expire);
87 	if (expire == 0)
88 		return 0;
89 
90 	if (rmtp) {
91 		jiffies_to_timespec(expire, &t);
92 		if (put_compat_timespec(&t, rmtp))
93 			return -EFAULT;
94 	}
95 	restart = &current_thread_info()->restart_block;
96 	restart->fn = compat_nanosleep_restart;
97 	restart->arg0 = jiffies + expire;
98 	restart->arg1 = (unsigned long) rmtp;
99 	return -ERESTART_RESTARTBLOCK;
100 }
101 
102 static inline long get_compat_itimerval(struct itimerval *o,
103 		struct compat_itimerval __user *i)
104 {
105 	return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
106 		(__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
107 		 __get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
108 		 __get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
109 		 __get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
110 }
111 
112 static inline long put_compat_itimerval(struct compat_itimerval __user *o,
113 		struct itimerval *i)
114 {
115 	return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
116 		(__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
117 		 __put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
118 		 __put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
119 		 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
120 }
121 
122 asmlinkage long compat_sys_getitimer(int which,
123 		struct compat_itimerval __user *it)
124 {
125 	struct itimerval kit;
126 	int error;
127 
128 	error = do_getitimer(which, &kit);
129 	if (!error && put_compat_itimerval(it, &kit))
130 		error = -EFAULT;
131 	return error;
132 }
133 
134 asmlinkage long compat_sys_setitimer(int which,
135 		struct compat_itimerval __user *in,
136 		struct compat_itimerval __user *out)
137 {
138 	struct itimerval kin, kout;
139 	int error;
140 
141 	if (in) {
142 		if (get_compat_itimerval(&kin, in))
143 			return -EFAULT;
144 	} else
145 		memset(&kin, 0, sizeof(kin));
146 
147 	error = do_setitimer(which, &kin, out ? &kout : NULL);
148 	if (error || !out)
149 		return error;
150 	if (put_compat_itimerval(out, &kout))
151 		return -EFAULT;
152 	return 0;
153 }
154 
155 asmlinkage long compat_sys_times(struct compat_tms __user *tbuf)
156 {
157 	/*
158 	 *	In the SMP world we might just be unlucky and have one of
159 	 *	the times increment as we use it. Since the value is an
160 	 *	atomically safe type this is just fine. Conceptually its
161 	 *	as if the syscall took an instant longer to occur.
162 	 */
163 	if (tbuf) {
164 		struct compat_tms tmp;
165 		struct task_struct *tsk = current;
166 		struct task_struct *t;
167 		cputime_t utime, stime, cutime, cstime;
168 
169 		read_lock(&tasklist_lock);
170 		utime = tsk->signal->utime;
171 		stime = tsk->signal->stime;
172 		t = tsk;
173 		do {
174 			utime = cputime_add(utime, t->utime);
175 			stime = cputime_add(stime, t->stime);
176 			t = next_thread(t);
177 		} while (t != tsk);
178 
179 		/*
180 		 * While we have tasklist_lock read-locked, no dying thread
181 		 * can be updating current->signal->[us]time.  Instead,
182 		 * we got their counts included in the live thread loop.
183 		 * However, another thread can come in right now and
184 		 * do a wait call that updates current->signal->c[us]time.
185 		 * To make sure we always see that pair updated atomically,
186 		 * we take the siglock around fetching them.
187 		 */
188 		spin_lock_irq(&tsk->sighand->siglock);
189 		cutime = tsk->signal->cutime;
190 		cstime = tsk->signal->cstime;
191 		spin_unlock_irq(&tsk->sighand->siglock);
192 		read_unlock(&tasklist_lock);
193 
194 		tmp.tms_utime = compat_jiffies_to_clock_t(cputime_to_jiffies(utime));
195 		tmp.tms_stime = compat_jiffies_to_clock_t(cputime_to_jiffies(stime));
196 		tmp.tms_cutime = compat_jiffies_to_clock_t(cputime_to_jiffies(cutime));
197 		tmp.tms_cstime = compat_jiffies_to_clock_t(cputime_to_jiffies(cstime));
198 		if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
199 			return -EFAULT;
200 	}
201 	return compat_jiffies_to_clock_t(jiffies);
202 }
203 
204 /*
205  * Assumption: old_sigset_t and compat_old_sigset_t are both
206  * types that can be passed to put_user()/get_user().
207  */
208 
209 asmlinkage long compat_sys_sigpending(compat_old_sigset_t __user *set)
210 {
211 	old_sigset_t s;
212 	long ret;
213 	mm_segment_t old_fs = get_fs();
214 
215 	set_fs(KERNEL_DS);
216 	ret = sys_sigpending((old_sigset_t __user *) &s);
217 	set_fs(old_fs);
218 	if (ret == 0)
219 		ret = put_user(s, set);
220 	return ret;
221 }
222 
223 asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t __user *set,
224 		compat_old_sigset_t __user *oset)
225 {
226 	old_sigset_t s;
227 	long ret;
228 	mm_segment_t old_fs;
229 
230 	if (set && get_user(s, set))
231 		return -EFAULT;
232 	old_fs = get_fs();
233 	set_fs(KERNEL_DS);
234 	ret = sys_sigprocmask(how,
235 			      set ? (old_sigset_t __user *) &s : NULL,
236 			      oset ? (old_sigset_t __user *) &s : NULL);
237 	set_fs(old_fs);
238 	if (ret == 0)
239 		if (oset)
240 			ret = put_user(s, oset);
241 	return ret;
242 }
243 
244 #ifdef CONFIG_FUTEX
245 asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, int val,
246 		struct compat_timespec __user *utime, u32 __user *uaddr2,
247 		int val3)
248 {
249 	struct timespec t;
250 	unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
251 	int val2 = 0;
252 
253 	if ((op == FUTEX_WAIT) && utime) {
254 		if (get_compat_timespec(&t, utime))
255 			return -EFAULT;
256 		timeout = timespec_to_jiffies(&t) + 1;
257 	}
258 	if (op >= FUTEX_REQUEUE)
259 		val2 = (int) (unsigned long) utime;
260 
261 	return do_futex((unsigned long)uaddr, op, val, timeout,
262 			(unsigned long)uaddr2, val2, val3);
263 }
264 #endif
265 
266 asmlinkage long compat_sys_setrlimit(unsigned int resource,
267 		struct compat_rlimit __user *rlim)
268 {
269 	struct rlimit r;
270 	int ret;
271 	mm_segment_t old_fs = get_fs ();
272 
273 	if (resource >= RLIM_NLIMITS)
274 		return -EINVAL;
275 
276 	if (!access_ok(VERIFY_READ, rlim, sizeof(*rlim)) ||
277 	    __get_user(r.rlim_cur, &rlim->rlim_cur) ||
278 	    __get_user(r.rlim_max, &rlim->rlim_max))
279 		return -EFAULT;
280 
281 	if (r.rlim_cur == COMPAT_RLIM_INFINITY)
282 		r.rlim_cur = RLIM_INFINITY;
283 	if (r.rlim_max == COMPAT_RLIM_INFINITY)
284 		r.rlim_max = RLIM_INFINITY;
285 	set_fs(KERNEL_DS);
286 	ret = sys_setrlimit(resource, (struct rlimit __user *) &r);
287 	set_fs(old_fs);
288 	return ret;
289 }
290 
291 #ifdef COMPAT_RLIM_OLD_INFINITY
292 
293 asmlinkage long compat_sys_old_getrlimit(unsigned int resource,
294 		struct compat_rlimit __user *rlim)
295 {
296 	struct rlimit r;
297 	int ret;
298 	mm_segment_t old_fs = get_fs();
299 
300 	set_fs(KERNEL_DS);
301 	ret = sys_old_getrlimit(resource, &r);
302 	set_fs(old_fs);
303 
304 	if (!ret) {
305 		if (r.rlim_cur > COMPAT_RLIM_OLD_INFINITY)
306 			r.rlim_cur = COMPAT_RLIM_INFINITY;
307 		if (r.rlim_max > COMPAT_RLIM_OLD_INFINITY)
308 			r.rlim_max = COMPAT_RLIM_INFINITY;
309 
310 		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
311 		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
312 		    __put_user(r.rlim_max, &rlim->rlim_max))
313 			return -EFAULT;
314 	}
315 	return ret;
316 }
317 
318 #endif
319 
320 asmlinkage long compat_sys_getrlimit (unsigned int resource,
321 		struct compat_rlimit __user *rlim)
322 {
323 	struct rlimit r;
324 	int ret;
325 	mm_segment_t old_fs = get_fs();
326 
327 	set_fs(KERNEL_DS);
328 	ret = sys_getrlimit(resource, (struct rlimit __user *) &r);
329 	set_fs(old_fs);
330 	if (!ret) {
331 		if (r.rlim_cur > COMPAT_RLIM_INFINITY)
332 			r.rlim_cur = COMPAT_RLIM_INFINITY;
333 		if (r.rlim_max > COMPAT_RLIM_INFINITY)
334 			r.rlim_max = COMPAT_RLIM_INFINITY;
335 
336 		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
337 		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
338 		    __put_user(r.rlim_max, &rlim->rlim_max))
339 			return -EFAULT;
340 	}
341 	return ret;
342 }
343 
344 int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
345 {
346 	if (!access_ok(VERIFY_WRITE, ru, sizeof(*ru)) ||
347 	    __put_user(r->ru_utime.tv_sec, &ru->ru_utime.tv_sec) ||
348 	    __put_user(r->ru_utime.tv_usec, &ru->ru_utime.tv_usec) ||
349 	    __put_user(r->ru_stime.tv_sec, &ru->ru_stime.tv_sec) ||
350 	    __put_user(r->ru_stime.tv_usec, &ru->ru_stime.tv_usec) ||
351 	    __put_user(r->ru_maxrss, &ru->ru_maxrss) ||
352 	    __put_user(r->ru_ixrss, &ru->ru_ixrss) ||
353 	    __put_user(r->ru_idrss, &ru->ru_idrss) ||
354 	    __put_user(r->ru_isrss, &ru->ru_isrss) ||
355 	    __put_user(r->ru_minflt, &ru->ru_minflt) ||
356 	    __put_user(r->ru_majflt, &ru->ru_majflt) ||
357 	    __put_user(r->ru_nswap, &ru->ru_nswap) ||
358 	    __put_user(r->ru_inblock, &ru->ru_inblock) ||
359 	    __put_user(r->ru_oublock, &ru->ru_oublock) ||
360 	    __put_user(r->ru_msgsnd, &ru->ru_msgsnd) ||
361 	    __put_user(r->ru_msgrcv, &ru->ru_msgrcv) ||
362 	    __put_user(r->ru_nsignals, &ru->ru_nsignals) ||
363 	    __put_user(r->ru_nvcsw, &ru->ru_nvcsw) ||
364 	    __put_user(r->ru_nivcsw, &ru->ru_nivcsw))
365 		return -EFAULT;
366 	return 0;
367 }
368 
369 asmlinkage long compat_sys_getrusage(int who, struct compat_rusage __user *ru)
370 {
371 	struct rusage r;
372 	int ret;
373 	mm_segment_t old_fs = get_fs();
374 
375 	set_fs(KERNEL_DS);
376 	ret = sys_getrusage(who, (struct rusage __user *) &r);
377 	set_fs(old_fs);
378 
379 	if (ret)
380 		return ret;
381 
382 	if (put_compat_rusage(&r, ru))
383 		return -EFAULT;
384 
385 	return 0;
386 }
387 
388 asmlinkage long
389 compat_sys_wait4(compat_pid_t pid, compat_uint_t __user *stat_addr, int options,
390 	struct compat_rusage __user *ru)
391 {
392 	if (!ru) {
393 		return sys_wait4(pid, stat_addr, options, NULL);
394 	} else {
395 		struct rusage r;
396 		int ret;
397 		unsigned int status;
398 		mm_segment_t old_fs = get_fs();
399 
400 		set_fs (KERNEL_DS);
401 		ret = sys_wait4(pid,
402 				(stat_addr ?
403 				 (unsigned int __user *) &status : NULL),
404 				options, (struct rusage __user *) &r);
405 		set_fs (old_fs);
406 
407 		if (ret > 0) {
408 			if (put_compat_rusage(&r, ru))
409 				return -EFAULT;
410 			if (stat_addr && put_user(status, stat_addr))
411 				return -EFAULT;
412 		}
413 		return ret;
414 	}
415 }
416 
417 asmlinkage long compat_sys_waitid(int which, compat_pid_t pid,
418 		struct compat_siginfo __user *uinfo, int options,
419 		struct compat_rusage __user *uru)
420 {
421 	siginfo_t info;
422 	struct rusage ru;
423 	long ret;
424 	mm_segment_t old_fs = get_fs();
425 
426 	memset(&info, 0, sizeof(info));
427 
428 	set_fs(KERNEL_DS);
429 	ret = sys_waitid(which, pid, (siginfo_t __user *)&info, options,
430 			 uru ? (struct rusage __user *)&ru : NULL);
431 	set_fs(old_fs);
432 
433 	if ((ret < 0) || (info.si_signo == 0))
434 		return ret;
435 
436 	if (uru) {
437 		ret = put_compat_rusage(&ru, uru);
438 		if (ret)
439 			return ret;
440 	}
441 
442 	BUG_ON(info.si_code & __SI_MASK);
443 	info.si_code |= __SI_CHLD;
444 	return copy_siginfo_to_user32(uinfo, &info);
445 }
446 
447 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
448 				    unsigned len, cpumask_t *new_mask)
449 {
450 	unsigned long *k;
451 
452 	if (len < sizeof(cpumask_t))
453 		memset(new_mask, 0, sizeof(cpumask_t));
454 	else if (len > sizeof(cpumask_t))
455 		len = sizeof(cpumask_t);
456 
457 	k = cpus_addr(*new_mask);
458 	return compat_get_bitmap(k, user_mask_ptr, len * 8);
459 }
460 
461 asmlinkage long compat_sys_sched_setaffinity(compat_pid_t pid,
462 					     unsigned int len,
463 					     compat_ulong_t __user *user_mask_ptr)
464 {
465 	cpumask_t new_mask;
466 	int retval;
467 
468 	retval = compat_get_user_cpu_mask(user_mask_ptr, len, &new_mask);
469 	if (retval)
470 		return retval;
471 
472 	return sched_setaffinity(pid, new_mask);
473 }
474 
475 asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len,
476 					     compat_ulong_t __user *user_mask_ptr)
477 {
478 	int ret;
479 	cpumask_t mask;
480 	unsigned long *k;
481 	unsigned int min_length = sizeof(cpumask_t);
482 
483 	if (NR_CPUS <= BITS_PER_COMPAT_LONG)
484 		min_length = sizeof(compat_ulong_t);
485 
486 	if (len < min_length)
487 		return -EINVAL;
488 
489 	ret = sched_getaffinity(pid, &mask);
490 	if (ret < 0)
491 		return ret;
492 
493 	k = cpus_addr(mask);
494 	ret = compat_put_bitmap(user_mask_ptr, k, min_length * 8);
495 	if (ret)
496 		return ret;
497 
498 	return min_length;
499 }
500 
501 static int get_compat_itimerspec(struct itimerspec *dst,
502 				 struct compat_itimerspec __user *src)
503 {
504 	if (get_compat_timespec(&dst->it_interval, &src->it_interval) ||
505 	    get_compat_timespec(&dst->it_value, &src->it_value))
506 		return -EFAULT;
507 	return 0;
508 }
509 
510 static int put_compat_itimerspec(struct compat_itimerspec __user *dst,
511 				 struct itimerspec *src)
512 {
513 	if (put_compat_timespec(&src->it_interval, &dst->it_interval) ||
514 	    put_compat_timespec(&src->it_value, &dst->it_value))
515 		return -EFAULT;
516 	return 0;
517 }
518 
519 long compat_sys_timer_settime(timer_t timer_id, int flags,
520 			  struct compat_itimerspec __user *new,
521 			  struct compat_itimerspec __user *old)
522 {
523 	long err;
524 	mm_segment_t oldfs;
525 	struct itimerspec newts, oldts;
526 
527 	if (!new)
528 		return -EINVAL;
529 	if (get_compat_itimerspec(&newts, new))
530 		return -EFAULT;
531 	oldfs = get_fs();
532 	set_fs(KERNEL_DS);
533 	err = sys_timer_settime(timer_id, flags,
534 				(struct itimerspec __user *) &newts,
535 				(struct itimerspec __user *) &oldts);
536 	set_fs(oldfs);
537 	if (!err && old && put_compat_itimerspec(old, &oldts))
538 		return -EFAULT;
539 	return err;
540 }
541 
542 long compat_sys_timer_gettime(timer_t timer_id,
543 		struct compat_itimerspec __user *setting)
544 {
545 	long err;
546 	mm_segment_t oldfs;
547 	struct itimerspec ts;
548 
549 	oldfs = get_fs();
550 	set_fs(KERNEL_DS);
551 	err = sys_timer_gettime(timer_id,
552 				(struct itimerspec __user *) &ts);
553 	set_fs(oldfs);
554 	if (!err && put_compat_itimerspec(setting, &ts))
555 		return -EFAULT;
556 	return err;
557 }
558 
559 long compat_sys_clock_settime(clockid_t which_clock,
560 		struct compat_timespec __user *tp)
561 {
562 	long err;
563 	mm_segment_t oldfs;
564 	struct timespec ts;
565 
566 	if (get_compat_timespec(&ts, tp))
567 		return -EFAULT;
568 	oldfs = get_fs();
569 	set_fs(KERNEL_DS);
570 	err = sys_clock_settime(which_clock,
571 				(struct timespec __user *) &ts);
572 	set_fs(oldfs);
573 	return err;
574 }
575 
576 long compat_sys_clock_gettime(clockid_t which_clock,
577 		struct compat_timespec __user *tp)
578 {
579 	long err;
580 	mm_segment_t oldfs;
581 	struct timespec ts;
582 
583 	oldfs = get_fs();
584 	set_fs(KERNEL_DS);
585 	err = sys_clock_gettime(which_clock,
586 				(struct timespec __user *) &ts);
587 	set_fs(oldfs);
588 	if (!err && put_compat_timespec(&ts, tp))
589 		return -EFAULT;
590 	return err;
591 }
592 
593 long compat_sys_clock_getres(clockid_t which_clock,
594 		struct compat_timespec __user *tp)
595 {
596 	long err;
597 	mm_segment_t oldfs;
598 	struct timespec ts;
599 
600 	oldfs = get_fs();
601 	set_fs(KERNEL_DS);
602 	err = sys_clock_getres(which_clock,
603 			       (struct timespec __user *) &ts);
604 	set_fs(oldfs);
605 	if (!err && tp && put_compat_timespec(&ts, tp))
606 		return -EFAULT;
607 	return err;
608 }
609 
610 long compat_sys_clock_nanosleep(clockid_t which_clock, int flags,
611 			    struct compat_timespec __user *rqtp,
612 			    struct compat_timespec __user *rmtp)
613 {
614 	long err;
615 	mm_segment_t oldfs;
616 	struct timespec in, out;
617 
618 	if (get_compat_timespec(&in, rqtp))
619 		return -EFAULT;
620 
621 	oldfs = get_fs();
622 	set_fs(KERNEL_DS);
623 	err = sys_clock_nanosleep(which_clock, flags,
624 				  (struct timespec __user *) &in,
625 				  (struct timespec __user *) &out);
626 	set_fs(oldfs);
627 	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
628 	    put_compat_timespec(&out, rmtp))
629 		return -EFAULT;
630 	return err;
631 }
632 
633 /*
634  * We currently only need the following fields from the sigevent
635  * structure: sigev_value, sigev_signo, sig_notify and (sometimes
636  * sigev_notify_thread_id).  The others are handled in user mode.
637  * We also assume that copying sigev_value.sival_int is sufficient
638  * to keep all the bits of sigev_value.sival_ptr intact.
639  */
640 int get_compat_sigevent(struct sigevent *event,
641 		const struct compat_sigevent __user *u_event)
642 {
643 	memset(event, 0, sizeof(*event));
644 	return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
645 		__get_user(event->sigev_value.sival_int,
646 			&u_event->sigev_value.sival_int) ||
647 		__get_user(event->sigev_signo, &u_event->sigev_signo) ||
648 		__get_user(event->sigev_notify, &u_event->sigev_notify) ||
649 		__get_user(event->sigev_notify_thread_id,
650 			&u_event->sigev_notify_thread_id))
651 		? -EFAULT : 0;
652 }
653 
654 /* timer_create is architecture specific because it needs sigevent conversion */
655 
656 long compat_get_bitmap(unsigned long *mask, compat_ulong_t __user *umask,
657 		       unsigned long bitmap_size)
658 {
659 	int i, j;
660 	unsigned long m;
661 	compat_ulong_t um;
662 	unsigned long nr_compat_longs;
663 
664 	/* align bitmap up to nearest compat_long_t boundary */
665 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
666 
667 	if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
668 		return -EFAULT;
669 
670 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
671 
672 	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
673 		m = 0;
674 
675 		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
676 			/*
677 			 * We dont want to read past the end of the userspace
678 			 * bitmap. We must however ensure the end of the
679 			 * kernel bitmap is zeroed.
680 			 */
681 			if (nr_compat_longs-- > 0) {
682 				if (__get_user(um, umask))
683 					return -EFAULT;
684 			} else {
685 				um = 0;
686 			}
687 
688 			umask++;
689 			m |= (long)um << (j * BITS_PER_COMPAT_LONG);
690 		}
691 		*mask++ = m;
692 	}
693 
694 	return 0;
695 }
696 
697 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
698 		       unsigned long bitmap_size)
699 {
700 	int i, j;
701 	unsigned long m;
702 	compat_ulong_t um;
703 	unsigned long nr_compat_longs;
704 
705 	/* align bitmap up to nearest compat_long_t boundary */
706 	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
707 
708 	if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
709 		return -EFAULT;
710 
711 	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
712 
713 	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
714 		m = *mask++;
715 
716 		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
717 			um = m;
718 
719 			/*
720 			 * We dont want to write past the end of the userspace
721 			 * bitmap.
722 			 */
723 			if (nr_compat_longs-- > 0) {
724 				if (__put_user(um, umask))
725 					return -EFAULT;
726 			}
727 
728 			umask++;
729 			m >>= 4*sizeof(um);
730 			m >>= 4*sizeof(um);
731 		}
732 	}
733 
734 	return 0;
735 }
736 
737 void
738 sigset_from_compat (sigset_t *set, compat_sigset_t *compat)
739 {
740 	switch (_NSIG_WORDS) {
741 #if defined (__COMPAT_ENDIAN_SWAP__)
742 	case 4: set->sig[3] = compat->sig[7] | (((long)compat->sig[6]) << 32 );
743 	case 3: set->sig[2] = compat->sig[5] | (((long)compat->sig[4]) << 32 );
744 	case 2: set->sig[1] = compat->sig[3] | (((long)compat->sig[2]) << 32 );
745 	case 1: set->sig[0] = compat->sig[1] | (((long)compat->sig[0]) << 32 );
746 #else
747 	case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
748 	case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 );
749 	case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 );
750 	case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 );
751 #endif
752 	}
753 }
754 
755 asmlinkage long
756 compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese,
757 		struct compat_siginfo __user *uinfo,
758 		struct compat_timespec __user *uts, compat_size_t sigsetsize)
759 {
760 	compat_sigset_t s32;
761 	sigset_t s;
762 	int sig;
763 	struct timespec t;
764 	siginfo_t info;
765 	long ret, timeout = 0;
766 
767 	if (sigsetsize != sizeof(sigset_t))
768 		return -EINVAL;
769 
770 	if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
771 		return -EFAULT;
772 	sigset_from_compat(&s, &s32);
773 	sigdelsetmask(&s,sigmask(SIGKILL)|sigmask(SIGSTOP));
774 	signotset(&s);
775 
776 	if (uts) {
777 		if (get_compat_timespec (&t, uts))
778 			return -EFAULT;
779 		if (t.tv_nsec >= 1000000000L || t.tv_nsec < 0
780 				|| t.tv_sec < 0)
781 			return -EINVAL;
782 	}
783 
784 	spin_lock_irq(&current->sighand->siglock);
785 	sig = dequeue_signal(current, &s, &info);
786 	if (!sig) {
787 		timeout = MAX_SCHEDULE_TIMEOUT;
788 		if (uts)
789 			timeout = timespec_to_jiffies(&t)
790 				+(t.tv_sec || t.tv_nsec);
791 		if (timeout) {
792 			current->real_blocked = current->blocked;
793 			sigandsets(&current->blocked, &current->blocked, &s);
794 
795 			recalc_sigpending();
796 			spin_unlock_irq(&current->sighand->siglock);
797 
798 			current->state = TASK_INTERRUPTIBLE;
799 			timeout = schedule_timeout(timeout);
800 
801 			spin_lock_irq(&current->sighand->siglock);
802 			sig = dequeue_signal(current, &s, &info);
803 			current->blocked = current->real_blocked;
804 			siginitset(&current->real_blocked, 0);
805 			recalc_sigpending();
806 		}
807 	}
808 	spin_unlock_irq(&current->sighand->siglock);
809 
810 	if (sig) {
811 		ret = sig;
812 		if (uinfo) {
813 			if (copy_siginfo_to_user32(uinfo, &info))
814 				ret = -EFAULT;
815 		}
816 	}else {
817 		ret = timeout?-EINTR:-EAGAIN;
818 	}
819 	return ret;
820 
821 }
822 
823 #ifdef __ARCH_WANT_COMPAT_SYS_TIME
824 
825 /* compat_time_t is a 32 bit "long" and needs to get converted. */
826 
827 asmlinkage long compat_sys_time(compat_time_t __user * tloc)
828 {
829 	compat_time_t i;
830 	struct timeval tv;
831 
832 	do_gettimeofday(&tv);
833 	i = tv.tv_sec;
834 
835 	if (tloc) {
836 		if (put_user(i,tloc))
837 			i = -EFAULT;
838 	}
839 	return i;
840 }
841 
842 asmlinkage long compat_sys_stime(compat_time_t __user *tptr)
843 {
844 	struct timespec tv;
845 	int err;
846 
847 	if (get_user(tv.tv_sec, tptr))
848 		return -EFAULT;
849 
850 	tv.tv_nsec = 0;
851 
852 	err = security_settime(&tv, NULL);
853 	if (err)
854 		return err;
855 
856 	do_settimeofday(&tv);
857 	return 0;
858 }
859 
860 #endif /* __ARCH_WANT_COMPAT_SYS_TIME */
861