xref: /netbsd-src/sys/miscfs/procfs/procfs_linux.c (revision e656d3b0f67ff865d95b4ddb842cc19f893475e6)
1 /*      $NetBSD: procfs_linux.c,v 1.61 2011/09/04 17:32:10 jmcneill Exp $      */
2 
3 /*
4  * Copyright (c) 2001 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Frank van der Linden for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: procfs_linux.c,v 1.61 2011/09/04 17:32:10 jmcneill Exp $");
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/time.h>
44 #include <sys/kernel.h>
45 #include <sys/proc.h>
46 #include <sys/vnode.h>
47 #include <sys/exec.h>
48 #include <sys/resource.h>
49 #include <sys/resourcevar.h>
50 #include <sys/signal.h>
51 #include <sys/signalvar.h>
52 #include <sys/tty.h>
53 #include <sys/malloc.h>
54 #include <sys/mount.h>
55 #include <sys/conf.h>
56 #include <sys/sysctl.h>
57 
58 #include <miscfs/procfs/procfs.h>
59 
60 #include <compat/linux/common/linux_exec.h>
61 #include <compat/linux32/common/linux32_sysctl.h>
62 
63 #include <uvm/uvm_extern.h>
64 #include <uvm/uvm.h>
65 
66 extern struct devsw_conv *devsw_conv;
67 extern int max_devsw_convs;
68 
69 #define PGTOB(p)	((unsigned long)(p) << PAGE_SHIFT)
70 #define PGTOKB(p)	((unsigned long)(p) << (PAGE_SHIFT - 10))
71 
72 #define LBFSZ (8 * 1024)
73 
74 static void
75 get_proc_size_info(struct lwp *l, unsigned long *stext, unsigned long *etext, unsigned long *sstack)
76 {
77 	struct proc *p = l->l_proc;
78 	struct vmspace *vm;
79 	struct vm_map *map;
80 	struct vm_map_entry *entry;
81 
82 	*stext = 0;
83 	*etext = 0;
84 	*sstack = 0;
85 
86 	proc_vmspace_getref(p, &vm);
87 	map = &vm->vm_map;
88 	vm_map_lock_read(map);
89 
90 	for (entry = map->header.next; entry != &map->header;
91 	    entry = entry->next) {
92 		if (UVM_ET_ISSUBMAP(entry))
93 			continue;
94 		/* assume text is the first entry */
95 		if (*stext == *etext) {
96 			*stext = entry->start;
97 			*etext = entry->end;
98 			break;
99 		}
100 	}
101 #if defined(LINUX_USRSTACK32) && defined(USRSTACK32)
102 	if (strcmp(p->p_emul->e_name, "linux32") == 0 &&
103 	    LINUX_USRSTACK32 < USRSTACK32)
104 		*sstack = (unsigned long)LINUX_USRSTACK32;
105 	else
106 #endif
107 #ifdef LINUX_USRSTACK
108 	if (strcmp(p->p_emul->e_name, "linux") == 0 &&
109 	    LINUX_USRSTACK < USRSTACK)
110 		*sstack = (unsigned long)LINUX_USRSTACK;
111 	else
112 #endif
113 #ifdef	USRSTACK32
114 	if (strstr(p->p_emul->e_name, "32") != NULL)
115 		*sstack = (unsigned long)USRSTACK32;
116 	else
117 #endif
118 		*sstack = (unsigned long)USRSTACK;
119 
120 	/*
121 	 * jdk 1.6 compares low <= addr && addr < high
122 	 * if we put addr == high, then the test fails
123 	 * so eat one page.
124 	 */
125 	*sstack -= PAGE_SIZE;
126 
127 	vm_map_unlock_read(map);
128 	uvmspace_free(vm);
129 }
130 
131 /*
132  * Linux compatible /proc/meminfo. Only active when the -o linux
133  * mountflag is used.
134  */
135 int
136 procfs_domeminfo(struct lwp *curl, struct proc *p,
137     struct pfsnode *pfs, struct uio *uio)
138 {
139 	char *bf;
140 	int len;
141 	int error = 0;
142 
143 	bf = malloc(LBFSZ, M_TEMP, M_WAITOK);
144 
145 	len = snprintf(bf, LBFSZ,
146 		"        total:    used:    free:  shared: buffers: cached:\n"
147 		"Mem:  %8lu %8lu %8lu %8lu %8lu %8lu\n"
148 		"Swap: %8lu %8lu %8lu\n"
149 		"MemTotal:  %8lu kB\n"
150 		"MemFree:   %8lu kB\n"
151 		"MemShared: %8lu kB\n"
152 		"Buffers:   %8lu kB\n"
153 		"Cached:    %8lu kB\n"
154 		"SwapTotal: %8lu kB\n"
155 		"SwapFree:  %8lu kB\n",
156 		PGTOB(uvmexp.npages),
157 		PGTOB(uvmexp.npages - uvmexp.free),
158 		PGTOB(uvmexp.free),
159 		0L,
160 		PGTOB(uvmexp.filepages),
161 		PGTOB(uvmexp.anonpages + uvmexp.filepages + uvmexp.execpages),
162 		PGTOB(uvmexp.swpages),
163 		PGTOB(uvmexp.swpginuse),
164 		PGTOB(uvmexp.swpages - uvmexp.swpginuse),
165 		PGTOKB(uvmexp.npages),
166 		PGTOKB(uvmexp.free),
167 		0L,
168 		PGTOKB(uvmexp.filepages),
169 		PGTOKB(uvmexp.anonpages + uvmexp.filepages + uvmexp.execpages),
170 		PGTOKB(uvmexp.swpages),
171 		PGTOKB(uvmexp.swpages - uvmexp.swpginuse));
172 
173 	if (len == 0)
174 		goto out;
175 
176 	error = uiomove_frombuf(bf, len, uio);
177 out:
178 	free(bf, M_TEMP);
179 	return error;
180 }
181 
182 /*
183  * Linux compatible /proc/devices. Only active when the -o linux
184  * mountflag is used.
185  */
186 int
187 procfs_dodevices(struct lwp *curl, struct proc *p,
188     struct pfsnode *pfs, struct uio *uio)
189 {
190 	char *bf;
191 	int offset = 0;
192 	int i, error = ENAMETOOLONG;
193 
194 	/* XXX elad - may need filtering. */
195 
196 	bf = malloc(LBFSZ, M_TEMP, M_WAITOK);
197 
198 	offset += snprintf(&bf[offset], LBFSZ - offset, "Character devices:\n");
199 	if (offset >= LBFSZ)
200 		goto out;
201 
202 	mutex_enter(&device_lock);
203 	for (i = 0; i < max_devsw_convs; i++) {
204 		if ((devsw_conv[i].d_name == NULL) ||
205 		    (devsw_conv[i].d_cmajor == -1))
206 			continue;
207 
208 		offset += snprintf(&bf[offset], LBFSZ - offset,
209 		    "%3d %s\n", devsw_conv[i].d_cmajor, devsw_conv[i].d_name);
210 		if (offset >= LBFSZ) {
211 			mutex_exit(&device_lock);
212 			goto out;
213 		}
214 	}
215 
216 	offset += snprintf(&bf[offset], LBFSZ - offset, "\nBlock devices:\n");
217 	if (offset >= LBFSZ) {
218 		mutex_exit(&device_lock);
219 		goto out;
220 	}
221 
222 	for (i = 0; i < max_devsw_convs; i++) {
223 		if ((devsw_conv[i].d_name == NULL) ||
224 		    (devsw_conv[i].d_bmajor == -1))
225 			continue;
226 
227 		offset += snprintf(&bf[offset], LBFSZ - offset,
228 		    "%3d %s\n", devsw_conv[i].d_bmajor, devsw_conv[i].d_name);
229 		if (offset >= LBFSZ) {
230 			mutex_exit(&device_lock);
231 			goto out;
232 		}
233 	}
234 	mutex_exit(&device_lock);
235 
236 	error = uiomove_frombuf(bf, offset, uio);
237 out:
238 	free(bf, M_TEMP);
239 	return error;
240 }
241 
242 /*
243  * Linux compatible /proc/stat. Only active when the -o linux
244  * mountflag is used.
245  */
246 int
247 procfs_docpustat(struct lwp *curl, struct proc *p,
248     struct pfsnode *pfs, struct uio *uio)
249 {
250 	char		*bf;
251 	int	 	 error;
252 	int	 	 len;
253 #if defined(MULTIPROCESSOR)
254         struct cpu_info *ci;
255         CPU_INFO_ITERATOR cii;
256 #endif
257 	int	 	 i;
258 	uint64_t	nintr;
259 	uint64_t	nswtch;
260 
261 	error = ENAMETOOLONG;
262 	bf = malloc(LBFSZ, M_TEMP, M_WAITOK);
263 
264 	len = snprintf(bf, LBFSZ,
265 		"cpu %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64 "\n",
266 		curcpu()->ci_schedstate.spc_cp_time[CP_USER],
267 		curcpu()->ci_schedstate.spc_cp_time[CP_NICE],
268 		curcpu()->ci_schedstate.spc_cp_time[CP_SYS] /*+ [CP_INTR]*/,
269 		curcpu()->ci_schedstate.spc_cp_time[CP_IDLE]);
270 	if (len == 0)
271 		goto out;
272 
273 #if defined(MULTIPROCESSOR)
274 #define ALLCPUS	CPU_INFO_FOREACH(cii, ci)
275 #define CPUNAME	ci
276 #else
277 #define ALLCPUS	; i < 1 ;
278 #define CPUNAME	curcpu()
279 #endif
280 
281 	i = 0;
282 	nintr = 0;
283 	nswtch = 0;
284 	for (ALLCPUS) {
285 		len += snprintf(&bf[len], LBFSZ - len,
286 			"cpu%d %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64
287 			"\n", i,
288 			CPUNAME->ci_schedstate.spc_cp_time[CP_USER],
289 			CPUNAME->ci_schedstate.spc_cp_time[CP_NICE],
290 			CPUNAME->ci_schedstate.spc_cp_time[CP_SYS],
291 			CPUNAME->ci_schedstate.spc_cp_time[CP_IDLE]);
292 		if (len >= LBFSZ)
293 			goto out;
294 		i += 1;
295 		nintr += CPUNAME->ci_data.cpu_nintr;
296 		nswtch += CPUNAME->ci_data.cpu_nswtch;
297 	}
298 
299 	len += snprintf(&bf[len], LBFSZ - len,
300 			"disk 0 0 0 0\n"
301 			"page %u %u\n"
302 			"swap %u %u\n"
303 			"intr %"PRIu64"\n"
304 			"ctxt %"PRIu64"\n"
305 			"btime %"PRId64"\n",
306 			uvmexp.pageins, uvmexp.pdpageouts,
307 			uvmexp.pgswapin, uvmexp.pgswapout,
308 			nintr,
309 			nswtch,
310 			boottime.tv_sec);
311 	if (len >= LBFSZ)
312 		goto out;
313 
314 	error = uiomove_frombuf(bf, len, uio);
315 out:
316 	free(bf, M_TEMP);
317 	return error;
318 }
319 
320 /*
321  * Linux compatible /proc/loadavg. Only active when the -o linux
322  * mountflag is used.
323  */
324 int
325 procfs_doloadavg(struct lwp *curl, struct proc *p,
326     struct pfsnode *pfs, struct uio *uio)
327 {
328 	char	*bf;
329 	int 	 error;
330 	int 	 len;
331 
332 	error = ENAMETOOLONG;
333 	bf = malloc(LBFSZ, M_TEMP, M_WAITOK);
334 
335 	averunnable.fscale = FSCALE;
336 	len = snprintf(bf, LBFSZ,
337 	        "%d.%02d %d.%02d %d.%02d %d/%d %d\n",
338 		(int)(averunnable.ldavg[0] / averunnable.fscale),
339 		(int)(averunnable.ldavg[0] * 100 / averunnable.fscale % 100),
340 		(int)(averunnable.ldavg[1] / averunnable.fscale),
341 		(int)(averunnable.ldavg[1] * 100 / averunnable.fscale % 100),
342 		(int)(averunnable.ldavg[2] / averunnable.fscale),
343 		(int)(averunnable.ldavg[2] * 100 / averunnable.fscale % 100),
344 		1,		/* number of ONPROC processes */
345 		nprocs,
346 		30000);		/* last pid */
347 	if (len == 0)
348 		goto out;
349 
350 	error = uiomove_frombuf(bf, len, uio);
351 out:
352 	free(bf, M_TEMP);
353 	return error;
354 }
355 
356 /*
357  * Linux compatible /proc/<pid>/statm. Only active when the -o linux
358  * mountflag is used.
359  */
360 int
361 procfs_do_pid_statm(struct lwp *curl, struct lwp *l,
362     struct pfsnode *pfs, struct uio *uio)
363 {
364 	struct vmspace	*vm;
365 	struct proc	*p = l->l_proc;
366 	struct rusage	*ru = &p->p_stats->p_ru;
367 	char		*bf;
368 	int	 	 error;
369 	int	 	 len;
370 
371 	error = ENAMETOOLONG;
372 	bf = malloc(LBFSZ, M_TEMP, M_WAITOK);
373 
374 	/* XXX - we use values from vmspace, since dsl says that ru figures
375 	   are always 0 except for zombies. See kvm_proc.c::kvm_getproc2() */
376 	if ((error = proc_vmspace_getref(p, &vm)) != 0) {
377 		goto out;
378 	}
379 
380 	len = snprintf(bf, LBFSZ,
381 	        "%lu %lu %lu %lu %lu %lu %lu\n",
382 		(unsigned long)(vm->vm_tsize + vm->vm_dsize + vm->vm_ssize), /* size */
383 		(unsigned long)(vm->vm_rssize),	/* resident */
384 		(unsigned long)(ru->ru_ixrss),	/* shared */
385 		(unsigned long)(vm->vm_tsize),	/* text size in pages */
386 		(unsigned long)(vm->vm_dsize),	/* data size in pages */
387 		(unsigned long)(vm->vm_ssize),	/* stack size in pages */
388 		(unsigned long) 0);
389 
390 	uvmspace_free(vm);
391 
392 	if (len == 0)
393 		goto out;
394 
395 	error = uiomove_frombuf(bf, len, uio);
396 out:
397 	free(bf, M_TEMP);
398 	return error;
399 }
400 
401 #define USEC_2_TICKS(x)		((x) / 10000)
402 
403 /*
404  * Linux compatible /proc/<pid>/stat. Only active when the -o linux
405  * mountflag is used.
406  */
407 int
408 procfs_do_pid_stat(struct lwp *curl, struct lwp *l,
409     struct pfsnode *pfs, struct uio *uio)
410 {
411 	char *bf;
412 	struct proc *p = l->l_proc;
413 	int len;
414 	struct tty *tty = p->p_session->s_ttyp;
415 	struct rusage *ru = &p->p_stats->p_ru;
416 	struct rusage *cru = &p->p_stats->p_cru;
417 	unsigned long stext = 0, etext = 0, sstack = 0;
418 	struct timeval rt;
419 	struct vmspace	*vm;
420 	int error = 0;
421 
422 	bf = malloc(LBFSZ, M_TEMP, M_WAITOK);
423 
424 	if ((error = proc_vmspace_getref(p, &vm)) != 0) {
425 		goto out;
426 	}
427 
428 	get_proc_size_info(l, &stext, &etext, &sstack);
429 
430 	mutex_enter(proc_lock);
431 	mutex_enter(p->p_lock);
432 
433 	calcru(p, NULL, NULL, NULL, &rt);
434 
435 	len = snprintf(bf, LBFSZ,
436 	    "%d (%s) %c %d %d %d %lld %d "
437 	    "%u "
438 	    "%lu %lu %lu %lu %lu %lu %lu %lu "
439 	    "%d %d %d "
440 	    "%lld %lld %lu %lu %" PRIu64 " "
441 	    "%lu %lu %lu "
442 	    "%u %u "
443 	    "%u %u %u %u "
444 	    "%lu %lu %lu %d %d\n",
445 
446 	    p->p_pid,
447 	    p->p_comm,
448 	    "0IR3SZD"[(p->p_stat > 6) ? 0 : (int)p->p_stat],
449 	    (p->p_pptr != NULL) ? p->p_pptr->p_pid : 0,
450 
451 	    p->p_pgid,
452 	    p->p_session->s_sid,
453 	    (unsigned long long)(tty ? tty->t_dev : 0),
454 	    (tty && tty->t_pgrp) ? tty->t_pgrp->pg_id : 0,
455 
456 	    p->p_flag,
457 
458 	    ru->ru_minflt,
459 	    cru->ru_minflt,
460 	    ru->ru_majflt,
461 	    cru->ru_majflt,
462 	    (long)USEC_2_TICKS(ru->ru_utime.tv_usec),
463 	    (long)USEC_2_TICKS(ru->ru_stime.tv_usec),
464 	    (long)USEC_2_TICKS(cru->ru_utime.tv_usec),
465 	    (long)USEC_2_TICKS(cru->ru_stime.tv_usec),
466 
467 	    l->l_priority,				/* XXX: priority */
468 	    p->p_nice - 20,
469 	    0,
470 
471 	    (long long)rt.tv_sec,
472 	    (long long)p->p_stats->p_start.tv_sec,
473 	    (unsigned long)(vm->vm_tsize + vm->vm_dsize + vm->vm_ssize), /* size */
474 	    (unsigned long)(vm->vm_rssize),	/* resident */
475 	    p->p_rlimit[RLIMIT_RSS].rlim_cur,
476 
477 	    stext,					/* start code */
478 	    etext,					/* end code */
479 	    sstack,					/* mm start stack */
480 	    0,						/* XXX: pc */
481 	    0,						/* XXX: sp */
482 	    p->p_sigpend.sp_set.__bits[0],		/* XXX: pending */
483 	    0,						/* XXX: held */
484 	    p->p_sigctx.ps_sigignore.__bits[0],		/* ignored */
485 	    p->p_sigctx.ps_sigcatch.__bits[0],		/* caught */
486 
487 	    (unsigned long)(intptr_t)l->l_wchan,
488 	    ru->ru_nvcsw,
489 	    ru->ru_nivcsw,
490 	    p->p_exitsig,
491 	    0);						/* XXX: processor */
492 
493 	mutex_exit(p->p_lock);
494 	mutex_exit(proc_lock);
495 
496 	uvmspace_free(vm);
497 
498 	if (len == 0)
499 		goto out;
500 
501 	error = uiomove_frombuf(bf, len, uio);
502 out:
503 	free(bf, M_TEMP);
504 	return error;
505 }
506 
507 int
508 procfs_docpuinfo(struct lwp *curl, struct proc *p,
509     struct pfsnode *pfs, struct uio *uio)
510 {
511 	int len = LBFSZ;
512 	char *bf = malloc(len, M_TEMP, M_WAITOK);
513 	int error;
514 
515 	if (procfs_getcpuinfstr(bf, &len) < 0) {
516 		error = ENOSPC;
517 		goto done;
518 	}
519 
520 	if (len == 0) {
521 		error = 0;
522 		goto done;
523 	}
524 
525 	error = uiomove_frombuf(bf, len, uio);
526 done:
527 	free(bf, M_TEMP);
528 	return error;
529 }
530 
531 int
532 procfs_douptime(struct lwp *curl, struct proc *p,
533     struct pfsnode *pfs, struct uio *uio)
534 {
535 	char *bf;
536 	int len;
537 	struct timeval runtime;
538 	u_int64_t idle;
539 	int error = 0;
540 
541 	bf = malloc(LBFSZ, M_TEMP, M_WAITOK);
542 
543 	microuptime(&runtime);
544 	idle = curcpu()->ci_schedstate.spc_cp_time[CP_IDLE];
545 	len = snprintf(bf, LBFSZ,
546 	    "%lld.%02lu %" PRIu64 ".%02" PRIu64 "\n",
547 	    (long long)runtime.tv_sec, (long)runtime.tv_usec / 10000,
548 	    idle / hz, (((idle % hz) * 100) / hz) % 100);
549 
550 	if (len == 0)
551 		goto out;
552 
553 	error = uiomove_frombuf(bf, len, uio);
554 out:
555 	free(bf, M_TEMP);
556 	return error;
557 }
558 
559 int
560 procfs_domounts(struct lwp *curl, struct proc *p,
561     struct pfsnode *pfs, struct uio *uio)
562 {
563 	char *bf, *mtab = NULL;
564 	const char *fsname;
565 	size_t len, mtabsz = 0;
566 	struct mount *mp, *nmp;
567 	struct statvfs *sfs;
568 	int error = 0;
569 
570 	bf = malloc(LBFSZ, M_TEMP, M_WAITOK);
571 	mutex_enter(&mountlist_lock);
572 	for (mp = CIRCLEQ_FIRST(&mountlist); mp != (void *)&mountlist;
573 	     mp = nmp) {
574 		if (vfs_busy(mp, &nmp)) {
575 			continue;
576 		}
577 
578 		sfs = &mp->mnt_stat;
579 
580 		/* Linux uses different names for some filesystems */
581 		fsname = sfs->f_fstypename;
582 		if (strcmp(fsname, "procfs") == 0)
583 			fsname = "proc";
584 		else if (strcmp(fsname, "ext2fs") == 0)
585 			fsname = "ext2";
586 
587 		len = snprintf(bf, LBFSZ, "%s %s %s %s%s%s%s%s%s 0 0\n",
588 			sfs->f_mntfromname,
589 			sfs->f_mntonname,
590 			fsname,
591 			(mp->mnt_flag & MNT_RDONLY) ? "ro" : "rw",
592 			(mp->mnt_flag & MNT_NOSUID) ? ",nosuid" : "",
593 			(mp->mnt_flag & MNT_NOEXEC) ? ",noexec" : "",
594 			(mp->mnt_flag & MNT_NODEV) ? ",nodev" : "",
595 			(mp->mnt_flag & MNT_SYNCHRONOUS) ? ",sync" : "",
596 			(mp->mnt_flag & MNT_NOATIME) ? ",noatime" : ""
597 			);
598 
599 		mtab = realloc(mtab, mtabsz + len, M_TEMP, M_WAITOK);
600 		memcpy(mtab + mtabsz, bf, len);
601 		mtabsz += len;
602 
603 		vfs_unbusy(mp, false, &nmp);
604 	}
605 	mutex_exit(&mountlist_lock);
606 	free(bf, M_TEMP);
607 
608 	if (mtabsz > 0) {
609 		error = uiomove_frombuf(mtab, mtabsz, uio);
610 		free(mtab, M_TEMP);
611 	}
612 
613 	return error;
614 }
615 
616 /*
617  * Linux compatible /proc/version. Only active when the -o linux
618  * mountflag is used.
619  */
620 int
621 procfs_doversion(struct lwp *curl, struct proc *p,
622     struct pfsnode *pfs, struct uio *uio)
623 {
624 	char *bf;
625 	char lostype[20], losrelease[20], lversion[80];
626 	const char *postype, *posrelease, *pversion;
627 	const char *emulname = curlwp->l_proc->p_emul->e_name;
628 	int len;
629 	int error = 0;
630 	int nm[4];
631 	size_t buflen;
632 
633 	CTASSERT(EMUL_LINUX_KERN_OSTYPE == EMUL_LINUX32_KERN_OSTYPE);
634 	CTASSERT(EMUL_LINUX_KERN_OSRELEASE == EMUL_LINUX32_KERN_OSRELEASE);
635 	CTASSERT(EMUL_LINUX_KERN_VERSION == EMUL_LINUX32_KERN_VERSION);
636 
637 	bf = malloc(LBFSZ, M_TEMP, M_WAITOK);
638 
639 	sysctl_lock(false);
640 
641 	if (strncmp(emulname, "linux", 5) == 0) {
642 		/*
643 		 * Lookup the emulation ostype, osrelease, and version.
644 		 * Since compat_linux and compat_linux32 can be built as
645 		 * modules, we use sysctl to obtain the values instead of
646 		 * using the symbols directly.
647 		 */
648 
649 		if (strcmp(emulname, "linux32") == 0) {
650 			nm[0] = CTL_EMUL;
651 			nm[1] = EMUL_LINUX32;
652 			nm[2] = EMUL_LINUX32_KERN;
653 		} else {
654 			nm[0] = CTL_EMUL;
655 			nm[1] = EMUL_LINUX;
656 			nm[2] = EMUL_LINUX_KERN;
657 		}
658 
659 		nm[3] = EMUL_LINUX_KERN_OSTYPE;
660 		buflen = sizeof(lostype);
661 		error = sysctl_dispatch(nm, __arraycount(nm),
662 		    lostype, &buflen,
663 		    NULL, 0, NULL, NULL, NULL);
664 		if (error)
665 			goto out;
666 
667 		nm[3] = EMUL_LINUX_KERN_OSRELEASE;
668 		buflen = sizeof(losrelease);
669 		error = sysctl_dispatch(nm, __arraycount(nm),
670 		    losrelease, &buflen,
671 		    NULL, 0, NULL, NULL, NULL);
672 		if (error)
673 			goto out;
674 
675 		nm[3] = EMUL_LINUX_KERN_VERSION;
676 		buflen = sizeof(lversion);
677 		error = sysctl_dispatch(nm, __arraycount(nm),
678 		    lversion, &buflen,
679 		    NULL, 0, NULL, NULL, NULL);
680 		if (error)
681 			goto out;
682 
683 		postype = lostype;
684 		posrelease = losrelease;
685 		pversion = lversion;
686 	} else {
687 		postype = ostype;
688 		posrelease = osrelease;
689 		strlcpy(lversion, version, sizeof(lversion));
690 		if (strchr(lversion, '\n'))
691 			*strchr(lversion, '\n') = '\0';
692 		pversion = lversion;
693 	}
694 
695 	len = snprintf(bf, LBFSZ,
696 		"%s version %s (%s@localhost) (gcc version %s) %s\n",
697 		postype, posrelease, emulname,
698 #ifdef __VERSION__
699 		__VERSION__,
700 #else
701 		"unknown",
702 #endif
703 		pversion);
704 
705 	if (len == 0)
706 		goto out;
707 
708 	error = uiomove_frombuf(bf, len, uio);
709 out:
710 	free(bf, M_TEMP);
711 	sysctl_unlock();
712 	return error;
713 }
714