linux_pipe.c revision 1.2
1/*	$NetBSD: linux_pipe.c,v 1.2 1995/03/05 23:23:41 fvdl Exp $	*/
2
3/*
4 * Copyright (c) 1995 Frank van der Linden
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 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *      This product includes software developed for the NetBSD Project
18 *      by Frank van der Linden
19 * 4. The name of the author may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34/*
35 * Linux compatibility module. Try to deal with various Linux system calls.
36 */
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/namei.h>
41#include <sys/proc.h>
42#include <sys/dir.h>
43#include <sys/file.h>
44#include <sys/stat.h>
45#include <sys/filedesc.h>
46#include <sys/ioctl.h>
47#include <sys/kernel.h>
48#include <sys/malloc.h>
49#include <sys/mbuf.h>
50#include <sys/mman.h>
51#include <sys/mount.h>
52#include <sys/ptrace.h>
53#include <sys/resource.h>
54#include <sys/resourcevar.h>
55#include <sys/signal.h>
56#include <sys/signalvar.h>
57#include <sys/socket.h>
58#include <sys/time.h>
59#include <sys/times.h>
60#include <sys/vnode.h>
61#include <sys/uio.h>
62#include <sys/wait.h>
63#include <sys/utsname.h>
64#include <sys/unistd.h>
65
66#include <sys/syscallargs.h>
67
68#include <vm/vm.h>
69#include <vm/vm_param.h>
70
71#include <compat/linux/linux_types.h>
72#include <compat/linux/linux_fcntl.h>
73#include <compat/linux/linux_mmap.h>
74#include <compat/linux/linux_syscallargs.h>
75#include <compat/linux/linux_util.h>
76#include <compat/linux/linux_dirent.h>
77
78/*
79 * The information on a terminated (or stopped) process needs
80 * to be converted in order for Linux binaries to get a valid signal
81 * number out of it.
82 */
83static int
84bsd_to_linux_wstat(status)
85	int *status;
86{
87	if (WIFSIGNALED(*status))
88		*status = (*status & ~0177) |
89		    bsd_to_linux_sig(WTERMSIG(*status));
90	else if (WIFSTOPPED(*status))
91		*status = (*status & ~0xff00) |
92		    (bsd_to_linux_sig(WSTOPSIG(*status)) << 8);
93}
94
95/*
96 * waitpid(2). Passed on to the NetBSD call, surrounded by code to
97 * reserve some space for a NetBSD-style wait status, and converting
98 * it to what Linux wants.
99 */
100int
101linux_waitpid(p, uap, retval)
102	struct proc *p;
103	struct linux_waitpid_args /* {
104		syscallarg(int) pid;
105		syscallarg(int *) status;
106		syscallarg(int) options;
107	} */ *uap;
108	register_t *retval;
109{
110	struct wait4_args w4a;
111	int error, *status, tstat;
112	caddr_t sg;
113
114	sg = stackgap_init();
115	status = (int *) stackgap_alloc(&sg, sizeof status);
116
117	SCARG(&w4a, pid) = SCARG(uap, pid);
118	SCARG(&w4a, status) = status;
119	SCARG(&w4a, options) = SCARG(uap, options);
120	SCARG(&w4a, rusage) = NULL;
121
122	if ((error = wait4(p, &w4a, retval)))
123		return error;
124
125	if ((error = copyin(status, &tstat, sizeof tstat)))
126		return error;
127
128	bsd_to_linux_wstat(&tstat);
129
130	return copyout(&tstat, SCARG(uap, status), sizeof tstat);
131}
132
133/*
134 * This is very much the same as waitpid()
135 */
136int
137linux_wait4(p, uap, retval)
138	struct proc *p;
139	struct linux_wait4_args /* {
140		syscallarg(int) pid;
141		syscallarg(int *) status;
142		syscallarg(int) options;
143		syscallarg(struct rusage *) rusage;
144	} */ *uap;
145	register_t *retval;
146{
147	struct wait4_args w4a;
148	int error, *status, tstat;
149	caddr_t sg;
150
151	sg = stackgap_init();
152	status = (int *) stackgap_alloc(&sg, sizeof status);
153
154	SCARG(&w4a, pid) = SCARG(uap, pid);
155	SCARG(&w4a, status) = status;
156	SCARG(&w4a, options) = SCARG(uap, options);
157	SCARG(&w4a, rusage) = SCARG(uap, rusage);
158
159	if ((error = wait4(p, &w4a, retval)))
160		return error;
161
162	if ((error = copyin(status, &tstat, sizeof tstat)))
163		return error;
164
165	bsd_to_linux_wstat(&tstat);
166
167	return copyout(&tstat, SCARG(uap, status), sizeof tstat);
168}
169
170/*
171 * This is the old brk(2) call. I don't think anything in the Linux
172 * world uses this anymore
173 */
174int
175linux_break(p, uap, retval)
176	struct proc *p;
177	struct linux_brk_args /* {
178		syscallarg(char *) nsize;
179	} */ *uap;
180	register_t *retval;
181{
182	return ENOSYS;
183}
184
185/*
186 * Linux brk(2). The check if the new address is >= the old one is
187 * done in the kernel in Linux. NetBSD does it in the library.
188 */
189int
190linux_brk(p, uap, retval)
191	struct proc *p;
192	struct linux_brk_args /* {
193		syscallarg(char *) nsize;
194	} */ *uap;
195	register_t *retval;
196{
197	char *nbrk = SCARG(uap, nsize);
198	struct obreak_args oba;
199	struct vmspace *vm = p->p_vmspace;
200	int error = 0;
201	caddr_t oldbrk, newbrk;
202
203	oldbrk = vm->vm_daddr + ctob(vm->vm_dsize);
204	/*
205	 * XXX inconsistent.. Linux always returns at least the old
206	 * brk value, but it will be page-aligned if this fails,
207	 * and possibly not page aligned if it succeeds (the user
208	 * supplied pointer is returned).
209	 */
210	SCARG(&oba, nsize) = nbrk;
211
212	if ((caddr_t) nbrk > vm->vm_daddr && obreak(p, &oba, retval) == 0)
213		retval[0] = (register_t) nbrk;
214	else
215		retval[0] = (register_t) oldbrk;
216
217	return 0;
218}
219
220/*
221 * I wonder why Linux has gettimeofday() _and_ time().. Still, we
222 * need to deal with it.
223 */
224int
225linux_time(p, uap, retval)
226	struct proc *p;
227	struct linux_time_args /* {
228		linux_time_t *t;
229	} */ *uap;
230	register_t *retval;
231{
232	struct timeval atv;
233	linux_time_t tt;
234	int error;
235
236	microtime(&atv);
237
238	tt = atv.tv_sec;
239	if (SCARG(uap, t) && (error = copyout(&tt, SCARG(uap, t), sizeof tt)))
240		return error;
241
242	retval[0] = tt;
243	return 0;
244}
245
246/*
247 * Convert BSD statfs structure to Linux statfs structure.
248 * The Linux structure has less fields, and it also wants
249 * the length of a name in a dir entry in a field, which
250 * we fake (probably the wrong way).
251 */
252static void
253bsd_to_linux_statfs(bsp, lsp)
254	struct statfs *bsp;
255	struct linux_statfs *lsp;
256{
257	lsp->l_ftype = bsp->f_type;
258	lsp->l_fbsize = bsp->f_bsize;
259	lsp->l_fblocks = bsp->f_blocks;
260	lsp->l_fbfree = bsp->f_bfree;
261	lsp->l_fbavail = bsp->f_bavail;
262	lsp->l_ffiles = bsp->f_files;
263	lsp->l_fffree = bsp->f_ffree;
264	lsp->l_ffsid.val[0] = bsp->f_fsid.val[0];
265	lsp->l_ffsid.val[1] = bsp->f_fsid.val[1];
266	lsp->l_fnamelen = MAXNAMLEN;	/* XXX */
267}
268
269/*
270 * Implement the fs stat functions. Straightforward.
271 */
272int
273linux_statfs(p, uap, retval)
274	struct proc *p;
275	struct linux_statfs_args /* {
276		syscallarg(char *) path;
277		syscallarg(struct linux_statfs *) sp;
278	} */ *uap;
279	register_t *retval;
280{
281	struct statfs btmp, *bsp;
282	struct linux_statfs ltmp;
283	struct statfs_args bsa;
284	caddr_t sg;
285	int error;
286
287	sg = stackgap_init();
288	bsp = (struct statfs *) stackgap_alloc(&sg, sizeof (struct statfs));
289
290	CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
291
292	SCARG(&bsa, path) = SCARG(uap, path);
293	SCARG(&bsa, buf) = bsp;
294
295	if ((error = statfs(p, &bsa, retval)))
296		return error;
297
298	if ((error = copyin((caddr_t) bsp, (caddr_t) &btmp, sizeof btmp)))
299		return error;
300
301	bsd_to_linux_statfs(&btmp, &ltmp);
302
303	return copyout((caddr_t) &ltmp, (caddr_t) SCARG(uap, sp), sizeof ltmp);
304}
305
306int
307linux_fstatfs(p, uap, retval)
308	struct proc *p;
309	struct linux_fstatfs_args /* {
310		syscallarg(int) fd;
311		syscallarg(struct linux_statfs *) sp;
312	} */ *uap;
313	register_t *retval;
314{
315	struct statfs btmp, *bsp;
316	struct linux_statfs ltmp;
317	struct fstatfs_args bsa;
318	caddr_t sg;
319	int error;
320
321	sg = stackgap_init();
322	bsp = (struct statfs *) stackgap_alloc(&sg, sizeof (struct statfs));
323
324	SCARG(&bsa, fd) = SCARG(uap, fd);
325	SCARG(&bsa, buf) = bsp;
326
327	if ((error = statfs(p, &bsa, retval)))
328		return error;
329
330	if ((error = copyin((caddr_t) bsp, (caddr_t) &btmp, sizeof btmp)))
331		return error;
332
333	bsd_to_linux_statfs(&btmp, &ltmp);
334
335	return copyout((caddr_t) &ltmp, (caddr_t) SCARG(uap, sp), sizeof ltmp);
336}
337
338/*
339 * uname(). Just copy the info from the various strings stored in the
340 * kernel, and put it in the Linux utsname structure. That structure
341 * is almost the same as the NetBSD one, only it has fields 65 characters
342 * long, and an extra domainname field.
343 */
344int
345linux_uname(p, uap, retval)
346	struct proc *p;
347	struct linux_uname_args /* {
348		syscallarg(struct linux_utsname *) up;
349	} */ *uap;
350	register_t *retval;
351{
352	extern char ostype[], osrelease[], version[], hostname[], domainname[];
353	extern char machine[];
354	struct linux_utsname tluts;
355	int len;
356	char *cp;
357
358	strncpy(tluts.l_sysname, ostype, sizeof (tluts.l_sysname));
359	strncpy(tluts.l_nodename, hostname, sizeof (tluts.l_nodename));
360	strncpy(tluts.l_release, osrelease, sizeof (tluts.l_release));
361	strncpy(tluts.l_machine, machine, sizeof (tluts.l_machine));
362	strncpy(tluts.l_domainname, domainname, sizeof (tluts.l_domainname));
363	strncpy(tluts.l_version, version, sizeof (tluts.l_version));
364
365	/* This part taken from the the uname() in libc */
366	len = sizeof (tluts.l_version);
367	for (cp = tluts.l_version; len--; ++cp)
368		if (*cp == '\n' || *cp == '\t')
369			if (len > 1)
370				*cp = ' ';
371			else
372				*cp = '\0';
373
374	return copyout(&tluts, SCARG(uap, up), sizeof tluts);
375}
376
377/*
378 * Linux wants to pass everything to a syscall in registers. However,
379 * mmap() has 6 of them. Oops: out of register error. They just pass
380 * everything in a structure.
381 */
382int
383linux_mmap(p, uap, retval)
384	struct proc *p;
385	struct linux_mmap_args /* {
386		syscallarg(struct linux_mmap *) lmp;
387	} */ *uap;
388	register_t *retval;
389{
390	struct linux_mmap lmap;
391	struct mmap_args cma;
392	int error, flags;
393
394	if ((error = copyin(SCARG(uap, lmp), &lmap, sizeof lmap)))
395		return error;
396
397	flags = 0;
398	flags |= cvtto_bsd_mask(lmap.lm_flags, LINUX_MAP_SHARED, MAP_SHARED);
399	flags |= cvtto_bsd_mask(lmap.lm_flags, LINUX_MAP_PRIVATE, MAP_PRIVATE);
400	flags |= cvtto_bsd_mask(lmap.lm_flags, LINUX_MAP_FIXED, MAP_FIXED);
401	flags |= cvtto_bsd_mask(lmap.lm_flags, LINUX_MAP_ANON, MAP_ANON);
402
403	SCARG(&cma,addr) = lmap.lm_addr;
404	SCARG(&cma,len) = lmap.lm_len;
405 	SCARG(&cma,prot) = lmap.lm_prot;
406	SCARG(&cma,flags) = flags;
407	SCARG(&cma,fd) = lmap.lm_fd;
408	SCARG(&cma,pad) = 0;
409	SCARG(&cma,pos) = lmap.lm_pos;
410
411	return mmap(p, &cma, retval);
412}
413
414/*
415 * Linux doesn't use the retval[1] value to determine whether
416 * we are the child or parent.
417 */
418int
419linux_fork(p, uap, retval)
420	struct proc *p;
421	void *uap;
422	register_t *retval;
423{
424	int error;
425
426	if ((error = fork(p, uap, retval)))
427		return error;
428
429	if (retval[1] == 1)
430		retval[0] = 0;
431
432	return 0;
433}
434
435/*
436 * This code is partly stolen from src/lib/libc/compat-43/times.c
437 * XXX - CLK_TCK isn't declared in /sys, just in <time.h>, done here
438 */
439
440#define CLK_TCK 100
441#define	CONVTCK(r)	(r.tv_sec * CLK_TCK + r.tv_usec / (1000000 / CLK_TCK))
442
443int
444linux_times(p, uap, retval)
445	struct proc *p;
446	struct linux_times_args /* {
447		syscallarg(struct times *) tms;
448	} */ *uap;
449	register_t *retval;
450{
451	struct timeval t;
452	struct linux_tms ltms;
453	struct rusage ru;
454	int error;
455
456	calcru(p, &ru.ru_utime, &ru.ru_stime, NULL);
457	ltms.ltms_utime = CONVTCK(ru.ru_utime);
458	ltms.ltms_stime = CONVTCK(ru.ru_stime);
459
460	ltms.ltms_cutime = CONVTCK(p->p_stats->p_cru.ru_utime);
461	ltms.ltms_cstime = CONVTCK(p->p_stats->p_cru.ru_stime);
462
463	if ((error = copyout(&ltms, SCARG(uap, tms), sizeof ltms)))
464		return error;
465
466	microtime(&t);
467
468	retval[0] = ((linux_clock_t)(CONVTCK(t)));
469	return 0;
470}
471
472/*
473 * NetBSD passes fd[0] in retval[0], and fd[1] in retval[1].
474 * Linux directly passes the pointer.
475 */
476int
477linux_pipe(p, uap, retval)
478	struct proc *p;
479	struct linux_pipe_args /* {
480		syscallarg(int *) pfds;
481	} */ *uap;
482	register_t *retval;
483{
484	int error;
485
486	if ((error = pipe(p, 0, retval)))
487		return error;
488
489	/* Assumes register_t is an int */
490
491	if ((error = copyout(retval, SCARG(uap, pfds), 2 * sizeof (int))))
492		return error;
493
494	retval[0] = 0;
495	return 0;
496}
497
498/*
499 * Alarm. This is a libc call which used setitimer(2) in NetBSD.
500 * Fiddle with the timers to make it work.
501 */
502int
503linux_alarm(p, uap, retval)
504	struct proc *p;
505	struct linux_alarm_args /* {
506		syscallarg(unsigned int) secs;
507	} */ *uap;
508	register_t *retval;
509{
510	int error, s;
511	struct itimerval *itp, it;
512
513	itp = &p->p_realtimer;
514	s = splclock();
515	/*
516	 * Clear any pending timer alarms.
517	 */
518	untimeout(realitexpire, p);
519	timerclear(&itp->it_interval);
520	if (timerisset(&itp->it_value) &&
521	    timercmp(&itp->it_value, &time, >))
522		__timersub(&itp->it_value, &time);
523	/*
524	 * Return how many seconds were left (rounded up)
525	 */
526	retval[0] = itp->it_value.tv_sec;
527	if (itp->it_value.tv_usec)
528		retval[0]++;
529
530	/*
531	 * alarm(0) just resets the timer.
532	 */
533	if (SCARG(uap, secs) == 0) {
534		timerclear(&itp->it_value);
535		splx(s);
536		return 0;
537	}
538
539	/*
540	 * Check the new alarm time for sanity, and set it.
541	 */
542	timerclear(&it.it_interval);
543	it.it_value.tv_sec = SCARG(uap, secs);
544	it.it_value.tv_usec = 0;
545	if (itimerfix(&it.it_value) || itimerfix(&it.it_interval)) {
546		splx(s);
547		return (EINVAL);
548	}
549
550	if (timerisset(&it.it_value)) {
551		__timeradd(&it.it_value, &time);
552		timeout(realitexpire, p, hzto(&it.it_value));
553	}
554	p->p_realtimer = it;
555	splx(s);
556
557	return 0;
558}
559
560/*
561 * utime(). Do conversion to things that utimes() understands,
562 * and pass it on.
563 */
564int
565linux_utime(p, uap, retval)
566	struct proc *p;
567	struct linux_utime_args /* {
568		syscallarg(char *) path;
569		syscallarg(struct linux_utimbuf *)times;
570	} */ *uap;
571	register_t *retval;
572{
573	caddr_t sg;
574	int error;
575	struct utimes_args ua;
576	struct timeval tv[2], *tvp;
577	struct linux_utimbuf lut;
578
579	sg = stackgap_init();
580	CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
581
582	SCARG(&ua, path) = SCARG(uap, path);
583
584	if (SCARG(uap, times) != NULL) {
585		if ((error = copyin(SCARG(uap, times), &lut, sizeof lut)))
586			return error;
587		tv[0].tv_usec = tv[1].tv_usec = 0;
588		tv[0].tv_sec = lut.l_actime;
589		tv[1].tv_sec = lut.l_modtime;
590		tvp = (struct timeval *) stackgap_alloc(sizeof tv);
591		if ((error = copyout(tv, tvp, sizeof tv)))
592			return error;
593		SCARG(&ua, tptr) = tvp;
594	}
595	else
596		SCARG(&ua, tptr) = NULL;
597
598	return utimes(p, uap, retval);
599}
600
601/*
602 * Linux 'readdir' call. This code is mostly taken from the
603 * SunOS getdents call (see compat/sunos/sunos_misc.c), though
604 * an attempt has been made to keep it a little cleaner (failing
605 * miserably, because of the cruft needed if count 1 is passed).
606 *
607 * Read in BSD-style entries, convert them, and copy them out.
608 * Note that the Linux d_reclen is actually the name length,
609 * and d_off is the reclen.
610 *
611 * Note that this doesn't handle union-mounted filesystems.
612 */
613int
614linux_readdir(p, uap, retval)
615	struct proc *p;
616	struct linux_readdir_args /* {
617		syscallarg(int) fd;
618		syscallarg(struct linux_dirent *) dent;
619		syscallarg(unsigned int) count;
620	} */ *uap;
621	register_t *retval;
622{
623	register struct dirent *bdp;
624	struct vnode *vp;
625	caddr_t	inp, buf;	/* BSD-format */
626	int len, reclen;	/* BSD-format */
627	caddr_t outp;		/* Linux-format */
628	int resid, linuxreclen;	/* Linux-format */
629	struct file *fp;
630	struct uio auio;
631	struct iovec aiov;
632	struct linux_dirent idb;
633	off_t off;		/* true file offset */
634	linux_off_t soff;	/* Linux file offset */
635	int buflen, error, eofflag, nbytes, justone;
636	struct vattr va;
637
638	if ((error = getvnode(p->p_fd, SCARG(uap, fd), &fp)) != 0)
639		return (error);
640
641	if ((fp->f_flag & FREAD) == 0)
642		return (EBADF);
643
644	vp = (struct vnode *) fp->f_data;
645
646	if (vp->v_type != VDIR)	/* XXX  vnode readdir op should do this */
647		return (EINVAL);
648
649	if ((error = VOP_GETATTR(vp, &va, p->p_ucred, p)))
650		return error;
651
652	nbytes = SCARG(uap, count);
653	if (nbytes == 1) {	/* Need this for older Linux libs, apparently */
654		nbytes = sizeof (struct linux_dirent);
655		justone = 1;
656	}
657	else
658		justone = 0;
659
660	buflen = max(va.va_blocksize, nbytes);
661	buf = malloc(buflen, M_TEMP, M_WAITOK);
662	VOP_LOCK(vp);
663	off = fp->f_offset;
664again:
665	aiov.iov_base = buf;
666	aiov.iov_len = buflen;
667	auio.uio_iov = &aiov;
668	auio.uio_iovcnt = 1;
669	auio.uio_rw = UIO_READ;
670	auio.uio_segflg = UIO_SYSSPACE;
671	auio.uio_procp = p;
672	auio.uio_resid = buflen;
673	auio.uio_offset = off;
674	/*
675         * First we read into the malloc'ed buffer, then
676         * we massage it into user space, one record at a time.
677         */
678	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, (u_long *) 0, 0);
679	if (error)
680		goto out;
681
682	inp = buf;
683	outp = (caddr_t) SCARG(uap, dent);
684	resid = nbytes;
685	if ((len = buflen - auio.uio_resid) == 0)
686		goto eof;
687
688	for (; len > 0; len -= reclen) {
689		reclen = ((struct dirent *) inp)->d_reclen;
690		if (reclen & 3)
691			panic("linux_readdir");
692		off += reclen;	/* each entry points to next */
693		bdp = (struct dirent *) inp;
694		if (bdp->d_fileno == 0) {
695			inp += reclen;	/* it is a hole; squish it out */
696			continue;
697		}
698		linuxreclen = LINUX_RECLEN(&idb, bdp->d_namlen);
699		if (reclen > len || resid < linuxreclen) {
700			/* entry too big for buffer, so just stop */
701			outp++;
702			break;
703		}
704		/*
705		 * Massage in place to make a Linux-shaped dirent (otherwise
706		 * we have to worry about touching user memory outside of
707		 * the copyout() call).
708		 */
709		idb.l_dino = (long) bdp->d_fileno;
710		idb.l_doff = (linux_off_t) linuxreclen;
711		idb.l_dreclen = (u_short) bdp->d_namlen;	/* sigh */
712		strcpy(idb.l_dname, bdp->d_name);
713		if ((error = copyout((caddr_t)&idb, outp, linuxreclen)))
714			goto out;
715		/* advance past this real entry */
716		inp += reclen;
717		/* advance output past Linux-shaped entry */
718		outp += linuxreclen;
719		resid -= linuxreclen;
720		if (justone)
721			break;
722	}
723
724	/* if we squished out the whole block, try again */
725	if (outp == (caddr_t) SCARG(uap, dent))
726		goto again;
727	fp->f_offset = off;	/* update the vnode offset */
728
729	if (justone)
730		nbytes = resid + linuxreclen;
731
732eof:
733	*retval = nbytes - resid;
734out:
735	VOP_UNLOCK(vp);
736	free(buf, M_TEMP);
737	return error;
738}
739
740/*
741 * Out of register error once more.. Apart from that, no difference.
742 */
743int
744linux_select(p, uap, retval)
745	struct proc *p;
746	struct linux_select_args /* {
747		syscallarg(struct linux_select *) lsp;
748	} */ *uap;
749	register_t *retval;
750{
751	struct linux_select ls;
752	struct select_args bsa;
753	int error;
754
755	if ((error = copyin(SCARG(uap, lsp), (caddr_t) &ls, sizeof ls)))
756		return error;
757
758	SCARG(&bsa, nd) = ls.nfds;
759	SCARG(&bsa, in) = ls.readfds;
760	SCARG(&bsa, ou) = ls.writefds;
761	SCARG(&bsa, ex) = ls.exceptfds;
762	SCARG(&bsa, tv) = ls.timeout;
763
764	return select(p, &bsa, retval);
765}
766
767/*
768 * Get the process group of a certain process. Look it up
769 * and return the value.
770 */
771int
772linux_getpgid(p, uap, retval)
773	struct proc *p;
774	struct linux_getpgid_args /* {
775		syscallarg(int) pid;
776	} */ *uap;
777	register_t *retval;
778{
779	struct proc *targp;
780
781	if (SCARG(uap, pid) != 0 && SCARG(uap, pid) != p->p_pid)
782		if ((targp = pfind(SCARG(uap, pid))) == 0)
783			return ESRCH;
784	else
785		targp = p;
786
787	retval[0] = targp->p_pgid;
788	return 0;
789}
790