xref: /freebsd/sys/i386/linux/linux_machdep.c (revision eac7052fdebb90caf2f653e06187bdbca837b9c7)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2000 Marcel Moolenaar
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/capsicum.h>
34 #include <sys/fcntl.h>
35 #include <sys/file.h>
36 #include <sys/imgact.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/mman.h>
40 #include <sys/mutex.h>
41 #include <sys/priv.h>
42 #include <sys/proc.h>
43 #include <sys/queue.h>
44 #include <sys/resource.h>
45 #include <sys/resourcevar.h>
46 #include <sys/sched.h>
47 #include <sys/signalvar.h>
48 #include <sys/syscallsubr.h>
49 #include <sys/sysproto.h>
50 #include <sys/systm.h>
51 #include <sys/sx.h>
52 #include <sys/unistd.h>
53 #include <sys/wait.h>
54 
55 #include <machine/frame.h>
56 #include <machine/psl.h>
57 #include <machine/segments.h>
58 #include <machine/sysarch.h>
59 
60 #include <vm/pmap.h>
61 #include <vm/vm.h>
62 #include <vm/vm_map.h>
63 
64 #include <i386/linux/linux.h>
65 #include <i386/linux/linux_proto.h>
66 #include <compat/linux/linux_emul.h>
67 #include <compat/linux/linux_ipc.h>
68 #include <compat/linux/linux_misc.h>
69 #include <compat/linux/linux_mmap.h>
70 #include <compat/linux/linux_signal.h>
71 #include <compat/linux/linux_util.h>
72 
73 #include <i386/include/pcb.h>			/* needed for pcb definition in linux_set_thread_area */
74 
75 #include "opt_posix.h"
76 
77 extern struct sysentvec elf32_freebsd_sysvec;	/* defined in i386/i386/elf_machdep.c */
78 
79 struct l_descriptor {
80 	l_uint		entry_number;
81 	l_ulong		base_addr;
82 	l_uint		limit;
83 	l_uint		seg_32bit:1;
84 	l_uint		contents:2;
85 	l_uint		read_exec_only:1;
86 	l_uint		limit_in_pages:1;
87 	l_uint		seg_not_present:1;
88 	l_uint		useable:1;
89 };
90 
91 struct l_old_select_argv {
92 	l_int		nfds;
93 	l_fd_set	*readfds;
94 	l_fd_set	*writefds;
95 	l_fd_set	*exceptfds;
96 	struct l_timeval	*timeout;
97 };
98 
99 int
100 linux_execve(struct thread *td, struct linux_execve_args *args)
101 {
102 	struct image_args eargs;
103 	char *newpath;
104 	int error;
105 
106 	if (!LUSECONVPATH(td)) {
107 		error = exec_copyin_args(&eargs, args->path, UIO_USERSPACE,
108 		    args->argp, args->envp);
109 	} else {
110 		LCONVPATHEXIST(td, args->path, &newpath);
111 		error = exec_copyin_args(&eargs, newpath, UIO_SYSSPACE,
112 		    args->argp, args->envp);
113 		LFREEPATH(newpath);
114 	}
115 	if (error == 0)
116 		error = linux_common_execve(td, &eargs);
117 	return (error);
118 }
119 
120 struct l_ipc_kludge {
121 	struct l_msgbuf *msgp;
122 	l_long msgtyp;
123 };
124 
125 int
126 linux_ipc(struct thread *td, struct linux_ipc_args *args)
127 {
128 
129 	switch (args->what & 0xFFFF) {
130 	case LINUX_SEMOP: {
131 		struct linux_semop_args a;
132 
133 		a.semid = args->arg1;
134 		a.tsops = PTRIN(args->ptr);
135 		a.nsops = args->arg2;
136 		return (linux_semop(td, &a));
137 	}
138 	case LINUX_SEMGET: {
139 		struct linux_semget_args a;
140 
141 		a.key = args->arg1;
142 		a.nsems = args->arg2;
143 		a.semflg = args->arg3;
144 		return (linux_semget(td, &a));
145 	}
146 	case LINUX_SEMCTL: {
147 		struct linux_semctl_args a;
148 		int error;
149 
150 		a.semid = args->arg1;
151 		a.semnum = args->arg2;
152 		a.cmd = args->arg3;
153 		error = copyin(PTRIN(args->ptr), &a.arg, sizeof(a.arg));
154 		if (error)
155 			return (error);
156 		return (linux_semctl(td, &a));
157 	}
158 	case LINUX_MSGSND: {
159 		struct linux_msgsnd_args a;
160 
161 		a.msqid = args->arg1;
162 		a.msgp = PTRIN(args->ptr);
163 		a.msgsz = args->arg2;
164 		a.msgflg = args->arg3;
165 		return (linux_msgsnd(td, &a));
166 	}
167 	case LINUX_MSGRCV: {
168 		struct linux_msgrcv_args a;
169 
170 		a.msqid = args->arg1;
171 		a.msgsz = args->arg2;
172 		a.msgflg = args->arg3;
173 		if ((args->what >> 16) == 0) {
174 			struct l_ipc_kludge tmp;
175 			int error;
176 
177 			if (args->ptr == 0)
178 				return (EINVAL);
179 			error = copyin(PTRIN(args->ptr), &tmp, sizeof(tmp));
180 			if (error)
181 				return (error);
182 			a.msgp = PTRIN(tmp.msgp);
183 			a.msgtyp = tmp.msgtyp;
184 		} else {
185 			a.msgp = PTRIN(args->ptr);
186 			a.msgtyp = args->arg5;
187 		}
188 		return (linux_msgrcv(td, &a));
189 	}
190 	case LINUX_MSGGET: {
191 		struct linux_msgget_args a;
192 
193 		a.key = args->arg1;
194 		a.msgflg = args->arg2;
195 		return (linux_msgget(td, &a));
196 	}
197 	case LINUX_MSGCTL: {
198 		struct linux_msgctl_args a;
199 
200 		a.msqid = args->arg1;
201 		a.cmd = args->arg2;
202 		a.buf = PTRIN(args->ptr);
203 		return (linux_msgctl(td, &a));
204 	}
205 	case LINUX_SHMAT: {
206 		struct linux_shmat_args a;
207 		l_uintptr_t addr;
208 		int error;
209 
210 		a.shmid = args->arg1;
211 		a.shmaddr = PTRIN(args->ptr);
212 		a.shmflg = args->arg2;
213 		error = linux_shmat(td, &a);
214 		if (error != 0)
215 			return (error);
216 		addr = td->td_retval[0];
217 		error = copyout(&addr, PTRIN(args->arg3), sizeof(addr));
218 		td->td_retval[0] = 0;
219 		return (error);
220 	}
221 	case LINUX_SHMDT: {
222 		struct linux_shmdt_args a;
223 
224 		a.shmaddr = PTRIN(args->ptr);
225 		return (linux_shmdt(td, &a));
226 	}
227 	case LINUX_SHMGET: {
228 		struct linux_shmget_args a;
229 
230 		a.key = args->arg1;
231 		a.size = args->arg2;
232 		a.shmflg = args->arg3;
233 		return (linux_shmget(td, &a));
234 	}
235 	case LINUX_SHMCTL: {
236 		struct linux_shmctl_args a;
237 
238 		a.shmid = args->arg1;
239 		a.cmd = args->arg2;
240 		a.buf = PTRIN(args->ptr);
241 		return (linux_shmctl(td, &a));
242 	}
243 	default:
244 		break;
245 	}
246 
247 	return (EINVAL);
248 }
249 
250 int
251 linux_old_select(struct thread *td, struct linux_old_select_args *args)
252 {
253 	struct l_old_select_argv linux_args;
254 	struct linux_select_args newsel;
255 	int error;
256 
257 	error = copyin(args->ptr, &linux_args, sizeof(linux_args));
258 	if (error)
259 		return (error);
260 
261 	newsel.nfds = linux_args.nfds;
262 	newsel.readfds = linux_args.readfds;
263 	newsel.writefds = linux_args.writefds;
264 	newsel.exceptfds = linux_args.exceptfds;
265 	newsel.timeout = linux_args.timeout;
266 	return (linux_select(td, &newsel));
267 }
268 
269 int
270 linux_set_cloned_tls(struct thread *td, void *desc)
271 {
272 	struct segment_descriptor sd;
273 	struct l_user_desc info;
274 	int idx, error;
275 	int a[2];
276 
277 	error = copyin(desc, &info, sizeof(struct l_user_desc));
278 	if (error) {
279 		linux_msg(td, "set_cloned_tls copyin failed!");
280 	} else {
281 		idx = info.entry_number;
282 
283 		/*
284 		 * looks like we're getting the idx we returned
285 		 * in the set_thread_area() syscall
286 		 */
287 		if (idx != 6 && idx != 3) {
288 			linux_msg(td, "set_cloned_tls resetting idx!");
289 			idx = 3;
290 		}
291 
292 		/* this doesnt happen in practice */
293 		if (idx == 6) {
294 			/* we might copy out the entry_number as 3 */
295 			info.entry_number = 3;
296 			error = copyout(&info, desc, sizeof(struct l_user_desc));
297 			if (error)
298 				linux_msg(td, "set_cloned_tls copyout failed!");
299 		}
300 
301 		a[0] = LINUX_LDT_entry_a(&info);
302 		a[1] = LINUX_LDT_entry_b(&info);
303 
304 		memcpy(&sd, &a, sizeof(a));
305 		/* set %gs */
306 		td->td_pcb->pcb_gsd = sd;
307 		td->td_pcb->pcb_gs = GSEL(GUGS_SEL, SEL_UPL);
308 	}
309 
310 	return (error);
311 }
312 
313 int
314 linux_set_upcall_kse(struct thread *td, register_t stack)
315 {
316 
317 	if (stack)
318 		td->td_frame->tf_esp = stack;
319 
320 	/*
321 	 * The newly created Linux thread returns
322 	 * to the user space by the same path that a parent do.
323 	 */
324 	td->td_frame->tf_eax = 0;
325 	return (0);
326 }
327 
328 int
329 linux_mmap2(struct thread *td, struct linux_mmap2_args *args)
330 {
331 
332 	return (linux_mmap_common(td, args->addr, args->len, args->prot,
333 		args->flags, args->fd, (uint64_t)(uint32_t)args->pgoff *
334 		PAGE_SIZE));
335 }
336 
337 int
338 linux_mmap(struct thread *td, struct linux_mmap_args *args)
339 {
340 	int error;
341 	struct l_mmap_argv linux_args;
342 
343 	error = copyin(args->ptr, &linux_args, sizeof(linux_args));
344 	if (error)
345 		return (error);
346 
347 	return (linux_mmap_common(td, linux_args.addr, linux_args.len,
348 	    linux_args.prot, linux_args.flags, linux_args.fd,
349 	    (uint32_t)linux_args.pgoff));
350 }
351 
352 int
353 linux_mprotect(struct thread *td, struct linux_mprotect_args *uap)
354 {
355 
356 	return (linux_mprotect_common(td, PTROUT(uap->addr), uap->len, uap->prot));
357 }
358 
359 int
360 linux_madvise(struct thread *td, struct linux_madvise_args *uap)
361 {
362 
363 	return (linux_madvise_common(td, PTROUT(uap->addr), uap->len, uap->behav));
364 }
365 
366 int
367 linux_ioperm(struct thread *td, struct linux_ioperm_args *args)
368 {
369 	int error;
370 	struct i386_ioperm_args iia;
371 
372 	iia.start = args->start;
373 	iia.length = args->length;
374 	iia.enable = args->enable;
375 	error = i386_set_ioperm(td, &iia);
376 	return (error);
377 }
378 
379 int
380 linux_iopl(struct thread *td, struct linux_iopl_args *args)
381 {
382 	int error;
383 
384 	if (args->level < 0 || args->level > 3)
385 		return (EINVAL);
386 	if ((error = priv_check(td, PRIV_IO)) != 0)
387 		return (error);
388 	if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
389 		return (error);
390 	td->td_frame->tf_eflags = (td->td_frame->tf_eflags & ~PSL_IOPL) |
391 	    (args->level * (PSL_IOPL / 3));
392 	return (0);
393 }
394 
395 int
396 linux_modify_ldt(struct thread *td, struct linux_modify_ldt_args *uap)
397 {
398 	int error;
399 	struct i386_ldt_args ldt;
400 	struct l_descriptor ld;
401 	union descriptor desc;
402 	int size, written;
403 
404 	switch (uap->func) {
405 	case 0x00: /* read_ldt */
406 		ldt.start = 0;
407 		ldt.descs = uap->ptr;
408 		ldt.num = uap->bytecount / sizeof(union descriptor);
409 		error = i386_get_ldt(td, &ldt);
410 		td->td_retval[0] *= sizeof(union descriptor);
411 		break;
412 	case 0x02: /* read_default_ldt = 0 */
413 		size = 5*sizeof(struct l_desc_struct);
414 		if (size > uap->bytecount)
415 			size = uap->bytecount;
416 		for (written = error = 0; written < size && error == 0; written++)
417 			error = subyte((char *)uap->ptr + written, 0);
418 		td->td_retval[0] = written;
419 		break;
420 	case 0x01: /* write_ldt */
421 	case 0x11: /* write_ldt */
422 		if (uap->bytecount != sizeof(ld))
423 			return (EINVAL);
424 
425 		error = copyin(uap->ptr, &ld, sizeof(ld));
426 		if (error)
427 			return (error);
428 
429 		ldt.start = ld.entry_number;
430 		ldt.descs = &desc;
431 		ldt.num = 1;
432 		desc.sd.sd_lolimit = (ld.limit & 0x0000ffff);
433 		desc.sd.sd_hilimit = (ld.limit & 0x000f0000) >> 16;
434 		desc.sd.sd_lobase = (ld.base_addr & 0x00ffffff);
435 		desc.sd.sd_hibase = (ld.base_addr & 0xff000000) >> 24;
436 		desc.sd.sd_type = SDT_MEMRO | ((ld.read_exec_only ^ 1) << 1) |
437 			(ld.contents << 2);
438 		desc.sd.sd_dpl = 3;
439 		desc.sd.sd_p = (ld.seg_not_present ^ 1);
440 		desc.sd.sd_xx = 0;
441 		desc.sd.sd_def32 = ld.seg_32bit;
442 		desc.sd.sd_gran = ld.limit_in_pages;
443 		error = i386_set_ldt(td, &ldt, &desc);
444 		break;
445 	default:
446 		error = ENOSYS;
447 		break;
448 	}
449 
450 	if (error == EOPNOTSUPP) {
451 		linux_msg(td, "modify_ldt needs kernel option USER_LDT");
452 		error = ENOSYS;
453 	}
454 
455 	return (error);
456 }
457 
458 int
459 linux_sigaction(struct thread *td, struct linux_sigaction_args *args)
460 {
461 	l_osigaction_t osa;
462 	l_sigaction_t act, oact;
463 	int error;
464 
465 	if (args->nsa != NULL) {
466 		error = copyin(args->nsa, &osa, sizeof(l_osigaction_t));
467 		if (error)
468 			return (error);
469 		act.lsa_handler = osa.lsa_handler;
470 		act.lsa_flags = osa.lsa_flags;
471 		act.lsa_restorer = osa.lsa_restorer;
472 		LINUX_SIGEMPTYSET(act.lsa_mask);
473 		act.lsa_mask.__mask = osa.lsa_mask;
474 	}
475 
476 	error = linux_do_sigaction(td, args->sig, args->nsa ? &act : NULL,
477 	    args->osa ? &oact : NULL);
478 
479 	if (args->osa != NULL && !error) {
480 		osa.lsa_handler = oact.lsa_handler;
481 		osa.lsa_flags = oact.lsa_flags;
482 		osa.lsa_restorer = oact.lsa_restorer;
483 		osa.lsa_mask = oact.lsa_mask.__mask;
484 		error = copyout(&osa, args->osa, sizeof(l_osigaction_t));
485 	}
486 
487 	return (error);
488 }
489 
490 /*
491  * Linux has two extra args, restart and oldmask.  We dont use these,
492  * but it seems that "restart" is actually a context pointer that
493  * enables the signal to happen with a different register set.
494  */
495 int
496 linux_sigsuspend(struct thread *td, struct linux_sigsuspend_args *args)
497 {
498 	sigset_t sigmask;
499 	l_sigset_t mask;
500 
501 	LINUX_SIGEMPTYSET(mask);
502 	mask.__mask = args->mask;
503 	linux_to_bsd_sigset(&mask, &sigmask);
504 	return (kern_sigsuspend(td, sigmask));
505 }
506 
507 int
508 linux_rt_sigsuspend(struct thread *td, struct linux_rt_sigsuspend_args *uap)
509 {
510 	l_sigset_t lmask;
511 	sigset_t sigmask;
512 	int error;
513 
514 	if (uap->sigsetsize != sizeof(l_sigset_t))
515 		return (EINVAL);
516 
517 	error = copyin(uap->newset, &lmask, sizeof(l_sigset_t));
518 	if (error)
519 		return (error);
520 
521 	linux_to_bsd_sigset(&lmask, &sigmask);
522 	return (kern_sigsuspend(td, sigmask));
523 }
524 
525 int
526 linux_pause(struct thread *td, struct linux_pause_args *args)
527 {
528 	struct proc *p = td->td_proc;
529 	sigset_t sigmask;
530 
531 	PROC_LOCK(p);
532 	sigmask = td->td_sigmask;
533 	PROC_UNLOCK(p);
534 	return (kern_sigsuspend(td, sigmask));
535 }
536 
537 int
538 linux_sigaltstack(struct thread *td, struct linux_sigaltstack_args *uap)
539 {
540 	stack_t ss, oss;
541 	l_stack_t lss;
542 	int error;
543 
544 	if (uap->uss != NULL) {
545 		error = copyin(uap->uss, &lss, sizeof(l_stack_t));
546 		if (error)
547 			return (error);
548 
549 		ss.ss_sp = lss.ss_sp;
550 		ss.ss_size = lss.ss_size;
551 		ss.ss_flags = linux_to_bsd_sigaltstack(lss.ss_flags);
552 	}
553 	error = kern_sigaltstack(td, (uap->uss != NULL) ? &ss : NULL,
554 	    (uap->uoss != NULL) ? &oss : NULL);
555 	if (!error && uap->uoss != NULL) {
556 		lss.ss_sp = oss.ss_sp;
557 		lss.ss_size = oss.ss_size;
558 		lss.ss_flags = bsd_to_linux_sigaltstack(oss.ss_flags);
559 		error = copyout(&lss, uap->uoss, sizeof(l_stack_t));
560 	}
561 
562 	return (error);
563 }
564 
565 int
566 linux_set_thread_area(struct thread *td, struct linux_set_thread_area_args *args)
567 {
568 	struct l_user_desc info;
569 	int error;
570 	int idx;
571 	int a[2];
572 	struct segment_descriptor sd;
573 
574 	error = copyin(args->desc, &info, sizeof(struct l_user_desc));
575 	if (error)
576 		return (error);
577 
578 	idx = info.entry_number;
579 	/*
580 	 * Semantics of Linux version: every thread in the system has array of
581 	 * 3 tls descriptors. 1st is GLIBC TLS, 2nd is WINE, 3rd unknown. This
582 	 * syscall loads one of the selected tls decriptors with a value and
583 	 * also loads GDT descriptors 6, 7 and 8 with the content of the
584 	 * per-thread descriptors.
585 	 *
586 	 * Semantics of FreeBSD version: I think we can ignore that Linux has 3
587 	 * per-thread descriptors and use just the 1st one. The tls_array[]
588 	 * is used only in set/get-thread_area() syscalls and for loading the
589 	 * GDT descriptors. In FreeBSD we use just one GDT descriptor for TLS
590 	 * so we will load just one.
591 	 *
592 	 * XXX: this doesn't work when a user space process tries to use more
593 	 * than 1 TLS segment. Comment in the Linux sources says wine might do
594 	 * this.
595 	 */
596 
597 	/*
598 	 * we support just GLIBC TLS now
599 	 * we should let 3 proceed as well because we use this segment so
600 	 * if code does two subsequent calls it should succeed
601 	 */
602 	if (idx != 6 && idx != -1 && idx != 3)
603 		return (EINVAL);
604 
605 	/*
606 	 * we have to copy out the GDT entry we use
607 	 * FreeBSD uses GDT entry #3 for storing %gs so load that
608 	 *
609 	 * XXX: what if a user space program doesn't check this value and tries
610 	 * to use 6, 7 or 8?
611 	 */
612 	idx = info.entry_number = 3;
613 	error = copyout(&info, args->desc, sizeof(struct l_user_desc));
614 	if (error)
615 		return (error);
616 
617 	if (LINUX_LDT_empty(&info)) {
618 		a[0] = 0;
619 		a[1] = 0;
620 	} else {
621 		a[0] = LINUX_LDT_entry_a(&info);
622 		a[1] = LINUX_LDT_entry_b(&info);
623 	}
624 
625 	memcpy(&sd, &a, sizeof(a));
626 	/* this is taken from i386 version of cpu_set_user_tls() */
627 	critical_enter();
628 	/* set %gs */
629 	td->td_pcb->pcb_gsd = sd;
630 	PCPU_GET(fsgs_gdt)[1] = sd;
631 	load_gs(GSEL(GUGS_SEL, SEL_UPL));
632 	critical_exit();
633 
634 	return (0);
635 }
636 
637 int
638 linux_get_thread_area(struct thread *td, struct linux_get_thread_area_args *args)
639 {
640 
641 	struct l_user_desc info;
642 	int error;
643 	int idx;
644 	struct l_desc_struct desc;
645 	struct segment_descriptor sd;
646 
647 	error = copyin(args->desc, &info, sizeof(struct l_user_desc));
648 	if (error)
649 		return (error);
650 
651 	idx = info.entry_number;
652 	/* XXX: I am not sure if we want 3 to be allowed too. */
653 	if (idx != 6 && idx != 3)
654 		return (EINVAL);
655 
656 	idx = 3;
657 
658 	memset(&info, 0, sizeof(info));
659 
660 	sd = PCPU_GET(fsgs_gdt)[1];
661 
662 	memcpy(&desc, &sd, sizeof(desc));
663 
664 	info.entry_number = idx;
665 	info.base_addr = LINUX_GET_BASE(&desc);
666 	info.limit = LINUX_GET_LIMIT(&desc);
667 	info.seg_32bit = LINUX_GET_32BIT(&desc);
668 	info.contents = LINUX_GET_CONTENTS(&desc);
669 	info.read_exec_only = !LINUX_GET_WRITABLE(&desc);
670 	info.limit_in_pages = LINUX_GET_LIMIT_PAGES(&desc);
671 	info.seg_not_present = !LINUX_GET_PRESENT(&desc);
672 	info.useable = LINUX_GET_USEABLE(&desc);
673 
674 	error = copyout(&info, args->desc, sizeof(struct l_user_desc));
675 	if (error)
676 		return (EFAULT);
677 
678 	return (0);
679 }
680 
681 /* XXX: this wont work with module - convert it */
682 int
683 linux_mq_open(struct thread *td, struct linux_mq_open_args *args)
684 {
685 #ifdef P1003_1B_MQUEUE
686 	return (sys_kmq_open(td, (struct kmq_open_args *)args));
687 #else
688 	return (ENOSYS);
689 #endif
690 }
691 
692 int
693 linux_mq_unlink(struct thread *td, struct linux_mq_unlink_args *args)
694 {
695 #ifdef P1003_1B_MQUEUE
696 	return (sys_kmq_unlink(td, (struct kmq_unlink_args *)args));
697 #else
698 	return (ENOSYS);
699 #endif
700 }
701 
702 int
703 linux_mq_timedsend(struct thread *td, struct linux_mq_timedsend_args *args)
704 {
705 #ifdef P1003_1B_MQUEUE
706 	return (sys_kmq_timedsend(td, (struct kmq_timedsend_args *)args));
707 #else
708 	return (ENOSYS);
709 #endif
710 }
711 
712 int
713 linux_mq_timedreceive(struct thread *td, struct linux_mq_timedreceive_args *args)
714 {
715 #ifdef P1003_1B_MQUEUE
716 	return (sys_kmq_timedreceive(td, (struct kmq_timedreceive_args *)args));
717 #else
718 	return (ENOSYS);
719 #endif
720 }
721 
722 int
723 linux_mq_notify(struct thread *td, struct linux_mq_notify_args *args)
724 {
725 #ifdef P1003_1B_MQUEUE
726 	return (sys_kmq_notify(td, (struct kmq_notify_args *)args));
727 #else
728 	return (ENOSYS);
729 #endif
730 }
731 
732 int
733 linux_mq_getsetattr(struct thread *td, struct linux_mq_getsetattr_args *args)
734 {
735 #ifdef P1003_1B_MQUEUE
736 	return (sys_kmq_setattr(td, (struct kmq_setattr_args *)args));
737 #else
738 	return (ENOSYS);
739 #endif
740 }
741