xref: /netbsd-src/sys/kern/subr_prf.c (revision fdecd6a253f999ae92b139670d9e15cc9df4497c)
1 /*	$NetBSD: subr_prf.c,v 1.43 1997/06/26 05:17:45 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 1986, 1988, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * (c) UNIX System Laboratories, Inc.
7  * All or some portions of this file are derived from material licensed
8  * to the University of California by American Telephone and Telegraph
9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10  * the permission of UNIX System Laboratories, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Berkeley and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  *
40  *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
41  */
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/buf.h>
46 #include <sys/conf.h>
47 #include <sys/reboot.h>
48 #include <sys/msgbuf.h>
49 #include <sys/proc.h>
50 #include <sys/ioctl.h>
51 #include <sys/vnode.h>
52 #include <sys/file.h>
53 #include <sys/tty.h>
54 #include <sys/tprintf.h>
55 #include <sys/syslog.h>
56 #include <sys/malloc.h>
57 
58 #include <dev/cons.h>
59 
60 /*
61  * Note that stdarg.h and the ANSI style va_start macro is used for both
62  * ANSI and traditional C compilers.
63  * XXX: This requires that stdarg.h defines: va_alist, va_dcl
64  */
65 #include <machine/stdarg.h>
66 
67 #include "ipkdb.h"
68 
69 #ifdef KADB
70 #include <machine/kdbparam.h>
71 #endif
72 #ifdef KGDB
73 #include <sys/kgdb.h>
74 #include <machine/cpu.h>
75 #endif
76 
77 #define TOCONS	0x01
78 #define TOTTY	0x02
79 #define TOLOG	0x04
80 
81 /*
82  * This is the size of the buffer that should be passed to ksnprintn().
83  * It's the length of a long in base 8, plus NULL.
84  */
85 #define KSNPRINTN_BUFSIZE	(sizeof(quad_t) * NBBY / 3 + 2)
86 
87 struct	tty *constty;			/* pointer to console "window" tty */
88 
89 void	(*v_putc) __P((int)) = cnputc;	/* routine to putc on virtual console */
90 
91 static void putchar __P((int, int, struct tty *));
92 static char *ksnprintn __P((u_quad_t, int, int *, char *, size_t));
93 void kprintf __P((const char *, int, struct tty *, va_list));
94 
95 int consintr = 1;			/* Ok to handle console interrupts? */
96 
97 /*
98  * Variable panicstr contains argument to first call to panic; used as flag
99  * to indicate that the kernel has already called panic.
100  */
101 const char *panicstr;
102 
103 /*
104  * Panic is called on unresolvable fatal errors.  It prints "panic: mesg",
105  * and then reboots.  If we are called twice, then we avoid trying to sync
106  * the disks as this often leads to recursive panics.
107  */
108 void
109 #ifdef __STDC__
110 panic(const char *fmt, ...)
111 #else
112 panic(fmt, va_alist)
113 	char *fmt;
114 	va_dcl
115 #endif
116 {
117 	int bootopt;
118 	va_list ap;
119 
120 	bootopt = RB_AUTOBOOT | RB_DUMP;
121 	if (panicstr)
122 		bootopt |= RB_NOSYNC;
123 	else
124 		panicstr = fmt;
125 
126 	va_start(ap, fmt);
127 #ifdef __powerpc__				/* XXX */
128 	printf("panic: ");			/* XXX */
129 	vprintf(fmt, ap);			/* XXX */
130 	printf("\n");				/* XXX */
131 #else						/* XXX */
132 	printf("panic: %:\n", fmt, ap);		/* XXX */
133 #endif						/* XXX */
134 	va_end(ap);
135 
136 #if NIPKDB > 0
137 	ipkdb_panic();
138 #endif
139 #ifdef KGDB
140 	kgdb_panic();
141 #endif
142 #ifdef KADB
143 	if (boothowto & RB_KDB)
144 		kdbpanic();
145 #endif
146 #ifdef DDB
147 	if (db_onpanic)
148 		Debugger();
149 #endif
150 	cpu_reboot(bootopt, NULL);
151 }
152 
153 /*
154  * Warn that a system table is full.
155  */
156 void
157 tablefull(tab)
158 	const char *tab;
159 {
160 
161 	log(LOG_ERR, "%s: table is full\n", tab);
162 }
163 
164 /*
165  * Uprintf prints to the controlling terminal for the current process.
166  * It may block if the tty queue is overfull.  No message is printed if
167  * the queue does not clear in a reasonable time.
168  */
169 void
170 #ifdef __STDC__
171 uprintf(const char *fmt, ...)
172 #else
173 uprintf(fmt, va_alist)
174 	char *fmt;
175 	va_dcl
176 #endif
177 {
178 	register struct proc *p = curproc;
179 	va_list ap;
180 
181 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
182 		va_start(ap, fmt);
183 		kprintf(fmt, TOTTY, p->p_session->s_ttyp, ap);
184 		va_end(ap);
185 	}
186 }
187 
188 tpr_t
189 tprintf_open(p)
190 	register struct proc *p;
191 {
192 
193 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
194 		SESSHOLD(p->p_session);
195 		return ((tpr_t) p->p_session);
196 	}
197 	return ((tpr_t) NULL);
198 }
199 
200 void
201 tprintf_close(sess)
202 	tpr_t sess;
203 {
204 
205 	if (sess)
206 		SESSRELE((struct session *) sess);
207 }
208 
209 /*
210  * tprintf prints on the controlling terminal associated
211  * with the given session.
212  */
213 void
214 #ifdef __STDC__
215 tprintf(tpr_t tpr, const char *fmt, ...)
216 #else
217 tprintf(tpr, fmt, va_alist)
218 	tpr_t tpr;
219 	char *fmt;
220 	va_dcl
221 #endif
222 {
223 	register struct session *sess = (struct session *)tpr;
224 	struct tty *tp = NULL;
225 	int flags = TOLOG;
226 	va_list ap;
227 
228 	logpri(LOG_INFO);
229 	if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
230 		flags |= TOTTY;
231 		tp = sess->s_ttyp;
232 	}
233 	va_start(ap, fmt);
234 	kprintf(fmt, flags, tp, ap);
235 	va_end(ap);
236 	logwakeup();
237 }
238 
239 /*
240  * Ttyprintf displays a message on a tty; it should be used only by
241  * the tty driver, or anything that knows the underlying tty will not
242  * be revoke(2)'d away.  Other callers should use tprintf.
243  */
244 void
245 #ifdef __STDC__
246 ttyprintf(struct tty *tp, const char *fmt, ...)
247 #else
248 ttyprintf(tp, fmt, va_alist)
249 	struct tty *tp;
250 	char *fmt;
251 	va_dcl
252 #endif
253 {
254 	va_list ap;
255 
256 	va_start(ap, fmt);
257 	kprintf(fmt, TOTTY, tp, ap);
258 	va_end(ap);
259 }
260 
261 extern	int log_open;
262 
263 /*
264  * Log writes to the log buffer, and guarantees not to sleep (so can be
265  * called by interrupt routines).  If there is no process reading the
266  * log yet, it writes to the console also.
267  */
268 void
269 #ifdef __STDC__
270 log(int level, const char *fmt, ...)
271 #else
272 log(level, fmt, va_alist)
273 	int level;
274 	char *fmt;
275 	va_dcl
276 #endif
277 {
278 	register int s;
279 	va_list ap;
280 
281 	s = splhigh();
282 	logpri(level);
283 	va_start(ap, fmt);
284 	kprintf(fmt, TOLOG, NULL, ap);
285 	splx(s);
286 	va_end(ap);
287 	if (!log_open) {
288 		va_start(ap, fmt);
289 		kprintf(fmt, TOCONS, NULL, ap);
290 		va_end(ap);
291 	}
292 	logwakeup();
293 }
294 
295 void
296 logpri(level)
297 	int level;
298 {
299 	register int ch;
300 	register char *p;
301 	char snbuf[KSNPRINTN_BUFSIZE];
302 
303 	putchar('<', TOLOG, NULL);
304 	for (p = ksnprintn((u_long)level, 10, NULL, snbuf, sizeof(snbuf));
305 	    (ch = *p--) != 0;)
306 		putchar(ch, TOLOG, NULL);
307 	putchar('>', TOLOG, NULL);
308 }
309 
310 void
311 #ifdef __STDC__
312 addlog(const char *fmt, ...)
313 #else
314 addlog(fmt, va_alist)
315 	char *fmt;
316 	va_dcl
317 #endif
318 {
319 	register int s;
320 	va_list ap;
321 
322 	s = splhigh();
323 	va_start(ap, fmt);
324 	kprintf(fmt, TOLOG, NULL, ap);
325 	splx(s);
326 	va_end(ap);
327 	if (!log_open) {
328 		va_start(ap, fmt);
329 		kprintf(fmt, TOCONS, NULL, ap);
330 		va_end(ap);
331 	}
332 	logwakeup();
333 }
334 
335 void
336 #ifdef __STDC__
337 printf(const char *fmt, ...)
338 #else
339 printf(fmt, va_alist)
340 	char *fmt;
341 	va_dcl
342 #endif
343 {
344 	va_list ap;
345 	register int savintr;
346 
347 	savintr = consintr;		/* disable interrupts */
348 	consintr = 0;
349 	va_start(ap, fmt);
350 	kprintf(fmt, TOCONS | TOLOG, NULL, ap);
351 	va_end(ap);
352 	if (!panicstr)
353 		logwakeup();
354 	consintr = savintr;		/* reenable interrupts */
355 }
356 
357 #ifdef __powerpc__			/* XXX XXX XXX */
358 void
359 vprintf(fmt, ap)
360 	const char *fmt;
361 	va_list ap;
362 {
363 	register int savintr;
364 
365 	savintr = consintr;		/* disable interrupts */
366 	consintr = 0;
367 	kprintf(fmt, TOCONS | TOLOG, NULL, ap);
368 	if (!panicstr)
369 		logwakeup();
370 	consintr = savintr;		/* reenable interrupts */
371 }
372 #endif /* __powerpc__ */		/* XXX XXX XXX */
373 
374 /*
375  * Scaled down version of printf(3).
376  *
377  * Two additional formats:
378  *
379  * The format %b is supported to decode error registers.
380  * Its usage is:
381  *
382  *	printf("reg=%b\n", regval, "<base><arg>*");
383  *
384  * where <base> is the output base expressed as a control character, e.g.
385  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
386  * the first of which gives the bit number to be inspected (origin 1), and
387  * the next characters (up to a control character, i.e. a character <= 32),
388  * give the name of the register.  Thus:
389  *
390  *	kprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
391  *
392  * would produce output:
393  *
394  *	reg=3<BITTWO,BITONE>
395  *
396  * The format %: passes an additional format string and argument list
397  * recursively.  Its usage is:
398  *
399  * fn(char *fmt, ...)
400  * {
401  *	va_list ap;
402  *	va_start(ap, fmt);
403  *	printf("prefix: %: suffix\n", fmt, ap);
404  *	va_end(ap);
405  * }
406  *
407  * Space or zero padding and a field width are supported for the numeric
408  * formats only.
409  */
410 #define	LONGINT		0x010		/* long integer */
411 #define	QUADINT		0x020		/* quad integer */
412 #define	SARG() \
413 	(flags&QUADINT ? va_arg(ap, quad_t) : \
414 	    flags&LONGINT ? va_arg(ap, long) : \
415 	    (long)va_arg(ap, int))
416 #define	UARG() \
417 	(flags&QUADINT ? va_arg(ap, u_quad_t) : \
418 	    flags&LONGINT ? va_arg(ap, u_long) : \
419 	    (u_long)va_arg(ap, u_int))
420 void
421 kprintf(fmt, oflags, tp, ap)
422 	register const char *fmt;
423 	int oflags;
424 	struct tty *tp;
425 	va_list ap;
426 {
427 	register char *p, *q;
428 	register int ch, n;
429 	u_quad_t ul;
430 	int base, flags, tmp, width;
431 	char padc, snbuf[KSNPRINTN_BUFSIZE];
432 
433 	for (;;) {
434 		padc = ' ';
435 		width = 0;
436 		while ((ch = *(const u_char *)fmt++) != '%') {
437 			if (ch == '\0')
438 				return;
439 			putchar(ch, oflags, tp);
440 		}
441 		flags = 0;
442 reswitch:	switch (ch = *(const u_char *)fmt++) {
443 		case '\0':
444 			/* XXX Print the last format character? */
445 			return;
446 		case '0':
447 		case '.':
448 			padc = '0';
449 			goto reswitch;
450 		case '1': case '2': case '3': case '4':
451 		case '5': case '6': case '7': case '8': case '9':
452 			for (width = 0;; ++fmt) {
453 				width = width * 10 + ch - '0';
454 				ch = *fmt;
455 				if (ch < '0' || ch > '9')
456 					break;
457 			}
458 			goto reswitch;
459 		case 'l':
460 			flags |= LONGINT;
461 			goto reswitch;
462 		case 'q':
463 			flags |= QUADINT;
464 			goto reswitch;
465 		case 'b':
466 			ul = va_arg(ap, int);
467 			p = va_arg(ap, char *);
468 			for (q = ksnprintn(ul, *p++, NULL, snbuf,
469 			    sizeof(snbuf)); (ch = *q--) != 0;)
470 				putchar(ch, oflags, tp);
471 
472 			if (!ul)
473 				break;
474 
475 			for (tmp = 0; (n = *p++) != 0;) {
476 				if (ul & (1 << (n - 1))) {
477 					putchar(tmp ? ',' : '<', oflags, tp);
478 					for (; (n = *p) > ' '; ++p)
479 						putchar(n, oflags, tp);
480 					tmp = 1;
481 				} else
482 					for (; *p > ' '; ++p)
483 						continue;
484 			}
485 			if (tmp)
486 				putchar('>', oflags, tp);
487 			break;
488 		case 'c':
489 			putchar(va_arg(ap, int), oflags, tp);
490 			break;
491 #ifndef __powerpc__			/* XXX XXX XXX */
492 		case ':':
493 			p = va_arg(ap, char *);
494 			kprintf(p, oflags, tp, va_arg(ap, va_list));
495 			break;
496 #endif /* __powerpc__ */		/* XXX XXX XXX */
497 		case 's':
498 			if ((p = va_arg(ap, char *)) == NULL)
499 				p = "(null)";
500 			while ((ch = *p++) != 0)
501 				putchar(ch, oflags, tp);
502 			break;
503 		case 'd':
504 		        ul = SARG();
505 			if ((quad_t)ul < 0) {
506 				putchar('-', oflags, tp);
507 				ul = -ul;
508 			}
509 			base = 10;
510 			goto number;
511 		case 'o':
512 			ul = UARG();
513 			base = 8;
514 			goto number;
515 		case 'u':
516 			ul = UARG();
517 			base = 10;
518 			goto number;
519 		case 'p':
520 			putchar('0', oflags, tp);
521 			putchar('x', oflags, tp);
522 			ul = (u_long)va_arg(ap, void *);
523 			base = 16;
524 			goto number;
525 		case 'x':
526 			ul = UARG();
527 			base = 16;
528 number:			p = ksnprintn(ul, base, &tmp, snbuf, sizeof(snbuf));
529 			if (width && (width -= tmp) > 0)
530 				while (width--)
531 					putchar(padc, oflags, tp);
532 			while ((ch = *p--) != 0)
533 				putchar(ch, oflags, tp);
534 			break;
535 		default:
536 			putchar('%', oflags, tp);
537 		        /* flags??? */
538 			/* FALLTHROUGH */
539 		case '%':
540 			putchar(ch, oflags, tp);
541 		}
542 	}
543 }
544 
545 /*
546  * Print a character on console or users terminal.  If destination is
547  * the console then the last MSGBUFS characters are saved in msgbuf for
548  * inspection later.
549  */
550 static void
551 putchar(c, flags, tp)
552 	register int c;
553 	int flags;
554 	struct tty *tp;
555 {
556 	extern int msgbufmapped;
557 	register struct msgbuf *mbp;
558 
559 	if (panicstr)
560 		constty = NULL;
561 	if ((flags & TOCONS) && tp == NULL && constty) {
562 		tp = constty;
563 		flags |= TOTTY;
564 	}
565 	if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
566 	    (flags & TOCONS) && tp == constty)
567 		constty = NULL;
568 	if ((flags & TOLOG) &&
569 	    c != '\0' && c != '\r' && c != 0177 && msgbufmapped) {
570 		mbp = msgbufp;
571 		if (mbp->msg_magic != MSG_MAGIC) {
572 			bzero((caddr_t)mbp, sizeof(*mbp));
573 			mbp->msg_magic = MSG_MAGIC;
574 		}
575 		mbp->msg_bufc[mbp->msg_bufx++] = c;
576 		if (mbp->msg_bufx < 0 || mbp->msg_bufx >= MSG_BSIZE)
577 			mbp->msg_bufx = 0;
578 	}
579 	if ((flags & TOCONS) && constty == NULL && c != '\0')
580 		(*v_putc)(c);
581 }
582 
583 /*
584  * Scaled down version of sprintf(3).
585  */
586 int
587 #ifdef __STDC__
588 sprintf(char *buf, const char *cfmt, ...)
589 #else
590 sprintf(buf, cfmt, va_alist)
591 	char *buf;
592 	const char *cfmt;
593 	va_dcl
594 #endif
595 {
596 	register const char *fmt = cfmt;
597 	register char *p, *bp;
598 	register int ch, base;
599 	u_quad_t ul;
600 	int flags, tmp, width;
601 	va_list ap;
602 	char padc, snbuf[KSNPRINTN_BUFSIZE];
603 
604 	va_start(ap, cfmt);
605 	for (bp = buf; ; ) {
606 		padc = ' ';
607 		width = 0;
608 		while ((ch = *(const u_char *)fmt++) != '%')
609 			if ((*bp++ = ch) == '\0')
610 				return ((bp - buf) - 1);
611 
612 		flags = 0;
613 reswitch:	switch (ch = *(const u_char *)fmt++) {
614 		case '\0':
615 			/* XXX Store the last format character? */
616 			*bp++ = '\0';
617 			return ((bp - buf) - 1);
618 		case '0':
619 			padc = '0';
620 			goto reswitch;
621 		case '1': case '2': case '3': case '4':
622 		case '5': case '6': case '7': case '8': case '9':
623 			for (width = 0;; ++fmt) {
624 				width = width * 10 + ch - '0';
625 				ch = *fmt;
626 				if (ch < '0' || ch > '9')
627 					break;
628 			}
629 			goto reswitch;
630 		case 'l':
631 			flags |= LONGINT;
632 			goto reswitch;
633 		case 'q':
634 			flags |= QUADINT;
635 			goto reswitch;
636 		/* case 'b': ... break; XXX */
637 		case 'c':
638 			*bp++ = va_arg(ap, int);
639 			break;
640 		/* case 'r': ... break; XXX */
641 		case 's':
642 			p = va_arg(ap, char *);
643 			while ((*bp++ = *p++) != 0)
644 				continue;
645 			--bp;
646 			break;
647 		case 'd':
648 		        ul = SARG();
649 			if ((quad_t)ul < 0) {
650 				*bp++ = '-';
651 				ul = -ul;
652 			}
653 			base = 10;
654 			goto number;
655 		case 'o':
656 			ul = UARG();
657 			base = 8;
658 			goto number;
659 		case 'u':
660 			ul = UARG();
661 			base = 10;
662 			goto number;
663 		case 'p':
664 			*bp++ = '0';
665 			*bp++ = 'x';
666 			ul = (u_long)va_arg(ap, void *);
667 			base = 16;
668 			goto number;
669 		case 'x':
670 			ul = UARG();
671 			base = 16;
672 number:			p = ksnprintn(ul, base, &tmp, snbuf, sizeof(snbuf));
673 			if (width && (width -= tmp) > 0)
674 				while (width--)
675 					*bp++ = padc;
676 			while ((ch = *p--) != 0)
677 				*bp++ = ch;
678 			break;
679 		default:
680 			*bp++ = '%';
681 		        /* flags??? */
682 			/* FALLTHROUGH */
683 		case '%':
684 			*bp++ = ch;
685 		}
686 	}
687 	va_end(ap);
688 }
689 
690 /*
691  * Put a number (base <= 16) in a buffer in reverse order; return an
692  * optional length and a pointer to the NULL terminated (preceded?)
693  * buffer.
694  */
695 static char *
696 ksnprintn(ul, base, lenp, buf, buflen)
697 	register u_quad_t ul;
698 	register int base, *lenp;
699 	char *buf;
700 	size_t buflen;
701 {
702 	register char *p;
703 
704 	p = buf;
705 	*p = '\0';			/* ensure NULL `termination' */
706 
707 	/*
708 	 * Don't even bother of the buffer's not big enough.  No
709 	 * value at all is better than a wrong value, and we
710 	 * have a lot of control over the buffer that's passed
711 	 * to this function, since it's not exported.
712 	 */
713 	if (buflen < KSNPRINTN_BUFSIZE)
714 		return (p);
715 
716 	do {
717 		*++p = "0123456789abcdef"[ul % base];
718 	} while (ul /= base);
719 	if (lenp)
720 		*lenp = p - buf;
721 	return (p);
722 }
723 
724 /*
725  * Print a bitmask into the provided buffer, and return a pointer
726  * to that buffer.
727  */
728 char *
729 bitmask_snprintf(ul, p, buf, buflen)
730 	u_long ul;
731 	const char *p;
732 	char *buf;
733 	size_t buflen;
734 {
735 	char *bp, *q;
736 	size_t left;
737 	register int n;
738 	int ch, tmp;
739 	char snbuf[KSNPRINTN_BUFSIZE];
740 
741 	bp = buf;
742 	bzero(buf, buflen);
743 
744 	/*
745 	 * Always leave room for the trailing NULL.
746 	 */
747 	left = buflen - 1;
748 
749 	/*
750 	 * Print the value into the buffer.  Abort if there's not
751 	 * enough room.
752 	 */
753 	if (buflen < KSNPRINTN_BUFSIZE)
754 		return (buf);
755 
756 	for (q = ksnprintn(ul, *p++, NULL, snbuf, sizeof(snbuf));
757 	    (ch = *q--) != 0;) {
758 		*bp++ = ch;
759 		left--;
760 	}
761 
762 	/*
763 	 * If the value we printed was 0, or if we don't have room for
764 	 * "<x>", we're done.
765 	 */
766 	if (ul == 0 || left < 3)
767 		return (buf);
768 
769 #define PUTBYTE(b, c, l)	\
770 	*(b)++ = (c);		\
771 	if (--(l) == 0)		\
772 		goto out;
773 
774 	for (tmp = 0; (n = *p++) != 0;) {
775 		if (ul & (1 << (n - 1))) {
776 			PUTBYTE(bp, tmp ? ',' : '<', left);
777 				for (; (n = *p) > ' '; ++p) {
778 					PUTBYTE(bp, n, left);
779 				}
780 				tmp = 1;
781 		} else
782 			for (; *p > ' '; ++p)
783 				continue;
784 	}
785 	if (tmp)
786 		*bp = '>';
787 
788 #undef PUTBYTE
789 
790  out:
791 	return (buf);
792 }
793