xref: /netbsd-src/sys/kern/subr_prf.c (revision 5aefcfdc06931dd97e76246d2fe0302f7b3fe094)
1 /*	$NetBSD: subr_prf.c,v 1.76 2000/08/09 10:22:31 tv 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	8.4 (Berkeley) 5/4/95
41  */
42 
43 #include "opt_ddb.h"
44 #include "opt_ipkdb.h"
45 #include "opt_multiprocessor.h"
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/buf.h>
50 #include <sys/reboot.h>
51 #include <sys/msgbuf.h>
52 #include <sys/proc.h>
53 #include <sys/ioctl.h>
54 #include <sys/vnode.h>
55 #include <sys/file.h>
56 #include <sys/tty.h>
57 #include <sys/tprintf.h>
58 #include <sys/syslog.h>
59 #include <sys/malloc.h>
60 #include <sys/lock.h>
61 
62 #include <dev/cons.h>
63 
64 #ifdef DDB
65 #include <ddb/ddbvar.h>
66 #include <machine/db_machdep.h>
67 #include <ddb/db_command.h>
68 #include <ddb/db_interface.h>
69 #endif
70 
71 #ifdef IPKDB
72 #include <ipkdb/ipkdb.h>
73 #endif
74 
75 #if defined(MULTIPROCESSOR)
76 struct simplelock kprintf_slock = SIMPLELOCK_INITIALIZER;
77 
78 /*
79  * Use cpu_simple_lock() and cpu_simple_unlock().  These are the actual
80  * atomic locking operations, and never attempt to print debugging
81  * information.
82  */
83 #define	KPRINTF_MUTEX_ENTER(s)						\
84 do {									\
85 	(s) = splhigh();						\
86 	__cpu_simple_lock(&kprintf_slock.lock_data);			\
87 } while (0)
88 
89 #define	KPRINTF_MUTEX_EXIT(s)						\
90 do {									\
91 	__cpu_simple_unlock(&kprintf_slock.lock_data);			\
92 	splx((s));							\
93 } while (0)
94 #else /* ! MULTIPROCESSOR */
95 #define	KPRINTF_MUTEX_ENTER(s)	(s) = splhigh()
96 #define	KPRINTF_MUTEX_EXIT(s)	splx((s))
97 #endif /* MULTIPROCESSOR */
98 
99 /*
100  * note that stdarg.h and the ansi style va_start macro is used for both
101  * ansi and traditional c complers.
102  * XXX: this requires that stdarg.h define: va_alist and va_dcl
103  */
104 #include <machine/stdarg.h>
105 
106 
107 #ifdef KGDB
108 #include <sys/kgdb.h>
109 #include <machine/cpu.h>
110 #endif
111 #ifdef DDB
112 #include <ddb/db_output.h>	/* db_printf, db_putchar prototypes */
113 #endif
114 
115 
116 /*
117  * defines
118  */
119 
120 /* flags for kprintf */
121 #define TOCONS		0x01	/* to the console */
122 #define TOTTY		0x02	/* to the process' tty */
123 #define TOLOG		0x04	/* to the kernel message buffer */
124 #define TOBUFONLY	0x08	/* to the buffer (only) [for snprintf] */
125 #define TODDB		0x10	/* to ddb console */
126 
127 /* max size buffer kprintf needs to print quad_t [size in base 8 + \0] */
128 #define KPRINTF_BUFSIZE		(sizeof(quad_t) * NBBY / 3 + 2)
129 
130 
131 /*
132  * local prototypes
133  */
134 
135 static int	 kprintf __P((const char *, int, void *,
136 				char *, va_list));
137 static void	 putchar __P((int, int, struct tty *));
138 static void	 klogpri __P((int));
139 
140 
141 /*
142  * globals
143  */
144 
145 struct	tty *constty;	/* pointer to console "window" tty */
146 extern	int log_open;	/* subr_log: is /dev/klog open? */
147 const	char *panicstr; /* arg to first call to panic (used as a flag
148 			   to indicate that panic has already been called). */
149 int	doing_shutdown;	/* set to indicate shutdown in progress */
150 
151 /*
152  * v_putc: routine to putc on virtual console
153  *
154  * the v_putc pointer can be used to redirect the console cnputc elsewhere
155  * [e.g. to a "virtual console"].
156  */
157 
158 void (*v_putc) __P((int)) = cnputc;	/* start with cnputc (normal cons) */
159 
160 
161 /*
162  * functions
163  */
164 
165 /*
166  * tablefull: warn that a system table is full
167  */
168 
169 void
170 tablefull(tab, hint)
171 	const char *tab, *hint;
172 {
173 	if (hint)
174 		log(LOG_ERR, "%s: table is full - %s\n", tab, hint);
175 	else
176 		log(LOG_ERR, "%s: table is full\n", tab);
177 }
178 
179 /*
180  * panic: handle an unresolvable fatal error
181  *
182  * prints "panic: <message>" and reboots.   if called twice (i.e. recursive
183  * call) we avoid trying to sync the disk and just reboot (to avoid
184  * recursive panics).
185  */
186 
187 void
188 #ifdef __STDC__
189 panic(const char *fmt, ...)
190 #else
191 panic(fmt, va_alist)
192 	char *fmt;
193 	va_dcl
194 #endif
195 {
196 	int bootopt;
197 	va_list ap;
198 
199 	bootopt = RB_AUTOBOOT | RB_DUMP;
200 	if (doing_shutdown)
201 		bootopt |= RB_NOSYNC;
202 	if (!panicstr)
203 		panicstr = fmt;
204 	doing_shutdown = 1;
205 
206 	va_start(ap, fmt);
207 	printf("panic: ");
208 	vprintf(fmt, ap);
209 	printf("\n");
210 	va_end(ap);
211 
212 #ifdef IPKDB
213 	ipkdb_panic();
214 #endif
215 #ifdef KGDB
216 	kgdb_panic();
217 #endif
218 #ifdef KADB
219 	if (boothowto & RB_KDB)
220 		kdbpanic();
221 #endif
222 #ifdef DDB
223 	if (db_onpanic)
224 		Debugger();
225 	else {
226 		static int intrace = 0;
227 
228 		if (intrace==0) {
229 			intrace=1;
230 			printf("Begin traceback...\n");
231 			db_stack_trace_print(
232 			    (db_expr_t)__builtin_frame_address(0),
233 			    TRUE, 65535, "", printf);
234 			printf("End traceback...\n");
235 			intrace=0;
236 		} else
237 			printf("Faulted in mid-traceback; aborting...");
238 	}
239 #endif
240 	cpu_reboot(bootopt, NULL);
241 }
242 
243 /*
244  * kernel logging functions: log, logpri, addlog
245  */
246 
247 /*
248  * log: write to the log buffer
249  *
250  * => will not sleep [so safe to call from interrupt]
251  * => will log to console if /dev/klog isn't open
252  */
253 
254 void
255 #ifdef __STDC__
256 log(int level, const char *fmt, ...)
257 #else
258 log(level, fmt, va_alist)
259 	int level;
260 	char *fmt;
261 	va_dcl
262 #endif
263 {
264 	int s;
265 	va_list ap;
266 
267 	KPRINTF_MUTEX_ENTER(s);
268 
269 	klogpri(level);		/* log the level first */
270 	va_start(ap, fmt);
271 	kprintf(fmt, TOLOG, NULL, NULL, ap);
272 	va_end(ap);
273 	if (!log_open) {
274 		va_start(ap, fmt);
275 		kprintf(fmt, TOCONS, NULL, NULL, ap);
276 		va_end(ap);
277 	}
278 
279 	KPRINTF_MUTEX_EXIT(s);
280 
281 	logwakeup();		/* wake up anyone waiting for log msgs */
282 }
283 
284 /*
285  * vlog: write to the log buffer [already have va_alist]
286  */
287 
288 void
289 vlog(level, fmt, ap)
290 	int level;
291 	const char *fmt;
292 	va_list ap;
293 {
294 	int s;
295 
296 	KPRINTF_MUTEX_ENTER(s);
297 
298 	klogpri(level);		/* log the level first */
299 	kprintf(fmt, TOLOG, NULL, NULL, ap);
300 	if (!log_open)
301 		kprintf(fmt, TOCONS, NULL, NULL, ap);
302 
303 	KPRINTF_MUTEX_EXIT(s);
304 
305 	logwakeup();		/* wake up anyone waiting for log msgs */
306 }
307 
308 /*
309  * logpri: log the priority level to the klog
310  */
311 
312 void
313 logpri(level)
314 	int level;
315 {
316 	int s;
317 
318 	KPRINTF_MUTEX_ENTER(s);
319 	klogpri(level);
320 	KPRINTF_MUTEX_EXIT(s);
321 }
322 
323 /*
324  * Note: we must be in the mutex here!
325  */
326 static void
327 klogpri(level)
328 	int level;
329 {
330 	char *p;
331 	char snbuf[KPRINTF_BUFSIZE];
332 
333 	putchar('<', TOLOG, NULL);
334 	snprintf(snbuf, sizeof(snbuf), "%d", level);
335 	for (p = snbuf ; *p ; p++)
336 		putchar(*p, TOLOG, NULL);
337 	putchar('>', TOLOG, NULL);
338 }
339 
340 /*
341  * addlog: add info to previous log message
342  */
343 
344 void
345 #ifdef __STDC__
346 addlog(const char *fmt, ...)
347 #else
348 addlog(fmt, va_alist)
349 	char *fmt;
350 	va_dcl
351 #endif
352 {
353 	int s;
354 	va_list ap;
355 
356 	KPRINTF_MUTEX_ENTER(s);
357 
358 	va_start(ap, fmt);
359 	kprintf(fmt, TOLOG, NULL, NULL, ap);
360 	va_end(ap);
361 	if (!log_open) {
362 		va_start(ap, fmt);
363 		kprintf(fmt, TOCONS, NULL, NULL, ap);
364 		va_end(ap);
365 	}
366 
367 	KPRINTF_MUTEX_EXIT(s);
368 
369 	logwakeup();
370 }
371 
372 
373 /*
374  * putchar: print a single character on console or user terminal.
375  *
376  * => if console, then the last MSGBUFS chars are saved in msgbuf
377  *	for inspection later (e.g. dmesg/syslog)
378  * => we must already be in the mutex!
379  */
380 static void
381 putchar(c, flags, tp)
382 	int c;
383 	int flags;
384 	struct tty *tp;
385 {
386 	struct kern_msgbuf *mbp;
387 
388 	if (panicstr)
389 		constty = NULL;
390 	if ((flags & TOCONS) && tp == NULL && constty) {
391 		tp = constty;
392 		flags |= TOTTY;
393 	}
394 	if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
395 	    (flags & TOCONS) && tp == constty)
396 		constty = NULL;
397 	if ((flags & TOLOG) &&
398 	    c != '\0' && c != '\r' && c != 0177 && msgbufenabled) {
399 		mbp = msgbufp;
400 		if (mbp->msg_magic != MSG_MAGIC) {
401 			/*
402 			 * Arguably should panic or somehow notify the
403 			 * user...  but how?  Panic may be too drastic,
404 			 * and would obliterate the message being kicked
405 			 * out (maybe a panic itself), and printf
406 			 * would invoke us recursively.  Silently punt
407 			 * for now.  If syslog is running, it should
408 			 * notice.
409 			 */
410 			msgbufenabled = 0;
411 		} else {
412 			mbp->msg_bufc[mbp->msg_bufx++] = c;
413 			if (mbp->msg_bufx < 0 || mbp->msg_bufx >= mbp->msg_bufs)
414 				mbp->msg_bufx = 0;
415 			/* If the buffer is full, keep the most recent data. */
416 			if (mbp->msg_bufr == mbp->msg_bufx) {
417 				 if (++mbp->msg_bufr >= mbp->msg_bufs)
418 					mbp->msg_bufr = 0;
419 			}
420 		}
421 	}
422 	if ((flags & TOCONS) && constty == NULL && c != '\0')
423 		(*v_putc)(c);
424 #ifdef DDB
425 	if (flags & TODDB)
426 		db_putchar(c);
427 #endif
428 }
429 
430 
431 /*
432  * uprintf: print to the controlling tty of the current process
433  *
434  * => we may block if the tty queue is full
435  * => no message is printed if the queue doesn't clear in a reasonable
436  *	time
437  */
438 
439 void
440 #ifdef __STDC__
441 uprintf(const char *fmt, ...)
442 #else
443 uprintf(fmt, va_alist)
444 	char *fmt;
445 	va_dcl
446 #endif
447 {
448 	struct proc *p = curproc;
449 	va_list ap;
450 
451 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
452 		/* No mutex needed; going to process TTY. */
453 		va_start(ap, fmt);
454 		kprintf(fmt, TOTTY, p->p_session->s_ttyp, NULL, ap);
455 		va_end(ap);
456 	}
457 }
458 
459 /*
460  * tprintf functions: used to send messages to a specific process
461  *
462  * usage:
463  *   get a tpr_t handle on a process "p" by using "tprintf_open(p)"
464  *   use the handle when calling "tprintf"
465  *   when done, do a "tprintf_close" to drop the handle
466  */
467 
468 /*
469  * tprintf_open: get a tprintf handle on a process "p"
470  *
471  * => returns NULL if process can't be printed to
472  */
473 
474 tpr_t
475 tprintf_open(p)
476 	struct proc *p;
477 {
478 
479 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
480 		SESSHOLD(p->p_session);
481 		return ((tpr_t) p->p_session);
482 	}
483 	return ((tpr_t) NULL);
484 }
485 
486 /*
487  * tprintf_close: dispose of a tprintf handle obtained with tprintf_open
488  */
489 
490 void
491 tprintf_close(sess)
492 	tpr_t sess;
493 {
494 
495 	if (sess)
496 		SESSRELE((struct session *) sess);
497 }
498 
499 /*
500  * tprintf: given tprintf handle to a process [obtained with tprintf_open],
501  * send a message to the controlling tty for that process.
502  *
503  * => also sends message to /dev/klog
504  */
505 void
506 #ifdef __STDC__
507 tprintf(tpr_t tpr, const char *fmt, ...)
508 #else
509 tprintf(tpr, fmt, va_alist)
510 	tpr_t tpr;
511 	char *fmt;
512 	va_dcl
513 #endif
514 {
515 	struct session *sess = (struct session *)tpr;
516 	struct tty *tp = NULL;
517 	int s, flags = TOLOG;
518 	va_list ap;
519 
520 	if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
521 		flags |= TOTTY;
522 		tp = sess->s_ttyp;
523 	}
524 
525 	KPRINTF_MUTEX_ENTER(s);
526 
527 	klogpri(LOG_INFO);
528 	va_start(ap, fmt);
529 	kprintf(fmt, flags, tp, NULL, ap);
530 	va_end(ap);
531 
532 	KPRINTF_MUTEX_EXIT(s);
533 
534 	logwakeup();
535 }
536 
537 
538 /*
539  * ttyprintf: send a message to a specific tty
540  *
541  * => should be used only by tty driver or anything that knows the
542  *    underlying tty will not be revoked(2)'d away.  [otherwise,
543  *    use tprintf]
544  */
545 void
546 #ifdef __STDC__
547 ttyprintf(struct tty *tp, const char *fmt, ...)
548 #else
549 ttyprintf(tp, fmt, va_alist)
550 	struct tty *tp;
551 	char *fmt;
552 	va_dcl
553 #endif
554 {
555 	va_list ap;
556 
557 	/* No mutex needed; going to process TTY. */
558 	va_start(ap, fmt);
559 	kprintf(fmt, TOTTY, tp, NULL, ap);
560 	va_end(ap);
561 }
562 
563 #ifdef DDB
564 
565 /*
566  * db_printf: printf for DDB (via db_putchar)
567  */
568 
569 void
570 #ifdef __STDC__
571 db_printf(const char *fmt, ...)
572 #else
573 db_printf(fmt, va_alist)
574 	char *fmt;
575 	va_dcl
576 #endif
577 {
578 	va_list ap;
579 
580 	/* No mutex needed; DDB pauses all processors. */
581 	va_start(ap, fmt);
582 	kprintf(fmt, TODDB, NULL, NULL, ap);
583 	va_end(ap);
584 }
585 
586 #endif /* DDB */
587 
588 
589 /*
590  * normal kernel printf functions: printf, vprintf, snprintf, vsnprintf
591  */
592 
593 /*
594  * printf: print a message to the console and the log
595  */
596 void
597 #ifdef __STDC__
598 printf(const char *fmt, ...)
599 #else
600 printf(fmt, va_alist)
601 	char *fmt;
602 	va_dcl
603 #endif
604 {
605 	va_list ap;
606 	int s;
607 
608 	KPRINTF_MUTEX_ENTER(s);
609 
610 	va_start(ap, fmt);
611 	kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
612 	va_end(ap);
613 
614 	KPRINTF_MUTEX_EXIT(s);
615 
616 	if (!panicstr)
617 		logwakeup();
618 }
619 
620 /*
621  * vprintf: print a message to the console and the log [already have
622  *	va_alist]
623  */
624 
625 void
626 vprintf(fmt, ap)
627 	const char *fmt;
628 	va_list ap;
629 {
630 	int s;
631 
632 	KPRINTF_MUTEX_ENTER(s);
633 
634 	kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
635 
636 	KPRINTF_MUTEX_EXIT(s);
637 
638 	if (!panicstr)
639 		logwakeup();
640 }
641 
642 /*
643  * sprintf: print a message to a buffer
644  */
645 int
646 #ifdef __STDC__
647 sprintf(char *buf, const char *fmt, ...)
648 #else
649 sprintf(buf, fmt, va_alist)
650         char *buf;
651         const char *cfmt;
652         va_dcl
653 #endif
654 {
655 	int retval;
656 	va_list ap;
657 
658 	va_start(ap, fmt);
659 	retval = kprintf(fmt, TOBUFONLY, NULL, buf, ap);
660 	va_end(ap);
661 	*(buf + retval) = 0;	/* null terminate */
662 	return(retval);
663 }
664 
665 /*
666  * vsprintf: print a message to a buffer [already have va_alist]
667  */
668 
669 int
670 vsprintf(buf, fmt, ap)
671 	char *buf;
672 	const char *fmt;
673 	va_list ap;
674 {
675 	int retval;
676 
677 	retval = kprintf(fmt, TOBUFONLY, NULL, buf, ap);
678 	*(buf + retval) = 0;	/* null terminate */
679 	return (retval);
680 }
681 
682 /*
683  * snprintf: print a message to a buffer
684  */
685 int
686 #ifdef __STDC__
687 snprintf(char *buf, size_t size, const char *fmt, ...)
688 #else
689 snprintf(buf, size, fmt, va_alist)
690         char *buf;
691         size_t size;
692         const char *cfmt;
693         va_dcl
694 #endif
695 {
696 	int retval;
697 	va_list ap;
698 	char *p;
699 
700 	if (size < 1)
701 		return (-1);
702 	p = buf + size - 1;
703 	va_start(ap, fmt);
704 	retval = kprintf(fmt, TOBUFONLY, &p, buf, ap);
705 	va_end(ap);
706 	*(p) = 0;	/* null terminate */
707 	return(retval);
708 }
709 
710 /*
711  * vsnprintf: print a message to a buffer [already have va_alist]
712  */
713 int
714 vsnprintf(buf, size, fmt, ap)
715         char *buf;
716         size_t size;
717         const char *fmt;
718         va_list ap;
719 {
720 	int retval;
721 	char *p;
722 
723 	if (size < 1)
724 		return (-1);
725 	p = buf + size - 1;
726 	retval = kprintf(fmt, TOBUFONLY, &p, buf, ap);
727 	*(p) = 0;	/* null terminate */
728 	return(retval);
729 }
730 
731 /*
732  * bitmask_snprintf: print an interpreted bitmask to a buffer
733  *
734  * => returns pointer to the buffer
735  */
736 char *
737 bitmask_snprintf(val, p, buf, buflen)
738 	u_quad_t val;
739 	const char *p;
740 	char *buf;
741 	size_t buflen;
742 {
743 	char *bp, *q;
744 	size_t left;
745 	char *sbase, snbuf[KPRINTF_BUFSIZE];
746 	int base, bit, ch, len, sep;
747 	u_quad_t field;
748 
749 	bp = buf;
750 	memset(buf, 0, buflen);
751 
752 	/*
753 	 * Always leave room for the trailing NULL.
754 	 */
755 	left = buflen - 1;
756 
757 	/*
758 	 * Print the value into the buffer.  Abort if there's not
759 	 * enough room.
760 	 */
761 	if (buflen < KPRINTF_BUFSIZE)
762 		return (buf);
763 
764 	ch = *p++;
765 	base = ch != '\177' ? ch : *p++;
766 	sbase = base == 8 ? "%qo" : base == 10 ? "%qd" : base == 16 ? "%qx" : 0;
767 	if (sbase == 0)
768 		return (buf);	/* punt if not oct, dec, or hex */
769 
770 	snprintf(snbuf, sizeof(snbuf), sbase, val);
771 	for (q = snbuf ; *q ; q++) {
772 		*bp++ = *q;
773 		left--;
774 	}
775 
776 	/*
777 	 * If the value we printed was 0 and we're using the old-style format,
778 	 * or if we don't have room for "<x>", we're done.
779 	 */
780 	if (((val == 0) && (ch != '\177')) || left < 3)
781 		return (buf);
782 
783 #define PUTBYTE(b, c, l)	\
784 	*(b)++ = (c);		\
785 	if (--(l) == 0)		\
786 		goto out;
787 #define PUTSTR(b, p, l) do {		\
788 	int c;				\
789 	while ((c = *(p)++) != 0) {	\
790 		*(b)++ = c;		\
791 		if (--(l) == 0)		\
792 			goto out;	\
793 	}				\
794 } while (0)
795 
796 	/*
797 	 * Chris Torek's new bitmask format is identified by a leading \177
798 	 */
799 	sep = '<';
800 	if (ch != '\177') {
801 		/* old (standard) format. */
802 		for (;(bit = *p++) != 0;) {
803 			if (val & (1 << (bit - 1))) {
804 				PUTBYTE(bp, sep, left);
805 				for (; (ch = *p) > ' '; ++p) {
806 					PUTBYTE(bp, ch, left);
807 				}
808 				sep = ',';
809 			} else
810 				for (; *p > ' '; ++p)
811 					continue;
812 		}
813 	} else {
814 		/* new quad-capable format; also does fields. */
815 		field = val;
816 		while ((ch = *p++) != '\0') {
817 			bit = *p++;	/* now 0-origin */
818 			switch (ch) {
819 			case 'b':
820 				if (((u_int)(val >> bit) & 1) == 0)
821 					goto skip;
822 				PUTBYTE(bp, sep, left);
823 				PUTSTR(bp, p, left);
824 				sep = ',';
825 				break;
826 			case 'f':
827 			case 'F':
828 				len = *p++;	/* field length */
829 				field = (val >> bit) & ((1ULL << len) - 1);
830 				if (ch == 'F')	/* just extract */
831 					break;
832 				PUTBYTE(bp, sep, left);
833 				sep = ',';
834 				PUTSTR(bp, p, left);
835 				PUTBYTE(bp, '=', left);
836 				sprintf(snbuf, sbase, field);
837 				q = snbuf; PUTSTR(bp, q, left);
838 				break;
839 			case '=':
840 			case ':':
841 				/*
842 				 * Here "bit" is actually a value instead,
843 				 * to be compared against the last field.
844 				 * This only works for values in [0..255],
845 				 * of course.
846 				 */
847 				if ((int)field != bit)
848 					goto skip;
849 				if (ch == '=')
850 					PUTBYTE(bp, '=', left);
851 				PUTSTR(bp, p, left);
852 				break;
853 			default:
854 			skip:
855 				while (*p++ != '\0')
856 					continue;
857 				break;
858 			}
859 		}
860 	}
861 	if (sep != '<')
862 		PUTBYTE(bp, '>', left);
863 
864 out:
865 	return (buf);
866 
867 #undef PUTBYTE
868 #undef PUTSTR
869 }
870 
871 /*
872  * kprintf: scaled down version of printf(3).
873  *
874  * this version based on vfprintf() from libc which was derived from
875  * software contributed to Berkeley by Chris Torek.
876  *
877  * NOTE: The kprintf mutex must be held if we're going TOBUF or TOCONS!
878  */
879 
880 /*
881  * macros for converting digits to letters and vice versa
882  */
883 #define	to_digit(c)	((c) - '0')
884 #define is_digit(c)	((unsigned)to_digit(c) <= 9)
885 #define	to_char(n)	((n) + '0')
886 
887 /*
888  * flags used during conversion.
889  */
890 #define	ALT		0x001		/* alternate form */
891 #define	HEXPREFIX	0x002		/* add 0x or 0X prefix */
892 #define	LADJUST		0x004		/* left adjustment */
893 #define	LONGDBL		0x008		/* long double; unimplemented */
894 #define	LONGINT		0x010		/* long integer */
895 #define	QUADINT		0x020		/* quad integer */
896 #define	SHORTINT	0x040		/* short integer */
897 #define	ZEROPAD		0x080		/* zero (as opposed to blank) pad */
898 #define FPT		0x100		/* Floating point number */
899 
900 	/*
901 	 * To extend shorts properly, we need both signed and unsigned
902 	 * argument extraction methods.
903 	 */
904 #define	SARG() \
905 	(flags&QUADINT ? va_arg(ap, quad_t) : \
906 	    flags&LONGINT ? va_arg(ap, long) : \
907 	    flags&SHORTINT ? (long)(short)va_arg(ap, int) : \
908 	    (long)va_arg(ap, int))
909 #define	UARG() \
910 	(flags&QUADINT ? va_arg(ap, u_quad_t) : \
911 	    flags&LONGINT ? va_arg(ap, u_long) : \
912 	    flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \
913 	    (u_long)va_arg(ap, u_int))
914 
915 #define KPRINTF_PUTCHAR(C) {						\
916 	if (oflags == TOBUFONLY) {					\
917 		if ((vp != NULL) && (sbuf == tailp)) {			\
918 			ret += 1;		/* indicate error */	\
919 			goto overflow;					\
920 		}							\
921 		*sbuf++ = (C);						\
922 	} else {							\
923 		putchar((C), oflags, (struct tty *)vp);			\
924 	}								\
925 }
926 
927 /*
928  * Guts of kernel printf.  Note, we already expect to be in a mutex!
929  */
930 static int
931 kprintf(fmt0, oflags, vp, sbuf, ap)
932 	const char *fmt0;
933 	int oflags;
934 	void *vp;
935 	char *sbuf;
936 	va_list ap;
937 {
938 	char *fmt;		/* format string */
939 	int ch;			/* character from fmt */
940 	int n;			/* handy integer (short term usage) */
941 	char *cp;		/* handy char pointer (short term usage) */
942 	int flags;		/* flags as above */
943 	int ret;		/* return value accumulator */
944 	int width;		/* width from format (%8d), or 0 */
945 	int prec;		/* precision from format (%.3d), or -1 */
946 	char sign;		/* sign prefix (' ', '+', '-', or \0) */
947 
948 	u_quad_t _uquad;	/* integer arguments %[diouxX] */
949 	enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
950 	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
951 	int realsz;		/* field size expanded by dprec */
952 	int size;		/* size of converted field or string */
953 	char *xdigs;		/* digits for [xX] conversion */
954 	char buf[KPRINTF_BUFSIZE]; /* space for %c, %[diouxX] */
955 	char *tailp;		/* tail pointer for snprintf */
956 
957 	tailp = NULL;	/* XXX: shutup gcc */
958 	if (oflags == TOBUFONLY && (vp != NULL))
959 		tailp = *(char **)vp;
960 
961 	cp = NULL;	/* XXX: shutup gcc */
962 	size = 0;	/* XXX: shutup gcc */
963 
964 	fmt = (char *)fmt0;
965 	ret = 0;
966 
967 	xdigs = NULL;		/* XXX: shut up gcc warning */
968 
969 	/*
970 	 * Scan the format for conversions (`%' character).
971 	 */
972 	for (;;) {
973 		while (*fmt != '%' && *fmt) {
974 			ret++;
975 			KPRINTF_PUTCHAR(*fmt++);
976 		}
977 		if (*fmt == 0)
978 			goto done;
979 
980 		fmt++;		/* skip over '%' */
981 
982 		flags = 0;
983 		dprec = 0;
984 		width = 0;
985 		prec = -1;
986 		sign = '\0';
987 
988 rflag:		ch = *fmt++;
989 reswitch:	switch (ch) {
990 		case ' ':
991 			/*
992 			 * ``If the space and + flags both appear, the space
993 			 * flag will be ignored.''
994 			 *	-- ANSI X3J11
995 			 */
996 			if (!sign)
997 				sign = ' ';
998 			goto rflag;
999 		case '#':
1000 			flags |= ALT;
1001 			goto rflag;
1002 		case '*':
1003 			/*
1004 			 * ``A negative field width argument is taken as a
1005 			 * - flag followed by a positive field width.''
1006 			 *	-- ANSI X3J11
1007 			 * They don't exclude field widths read from args.
1008 			 */
1009 			if ((width = va_arg(ap, int)) >= 0)
1010 				goto rflag;
1011 			width = -width;
1012 			/* FALLTHROUGH */
1013 		case '-':
1014 			flags |= LADJUST;
1015 			goto rflag;
1016 		case '+':
1017 			sign = '+';
1018 			goto rflag;
1019 		case '.':
1020 			if ((ch = *fmt++) == '*') {
1021 				n = va_arg(ap, int);
1022 				prec = n < 0 ? -1 : n;
1023 				goto rflag;
1024 			}
1025 			n = 0;
1026 			while (is_digit(ch)) {
1027 				n = 10 * n + to_digit(ch);
1028 				ch = *fmt++;
1029 			}
1030 			prec = n < 0 ? -1 : n;
1031 			goto reswitch;
1032 		case '0':
1033 			/*
1034 			 * ``Note that 0 is taken as a flag, not as the
1035 			 * beginning of a field width.''
1036 			 *	-- ANSI X3J11
1037 			 */
1038 			flags |= ZEROPAD;
1039 			goto rflag;
1040 		case '1': case '2': case '3': case '4':
1041 		case '5': case '6': case '7': case '8': case '9':
1042 			n = 0;
1043 			do {
1044 				n = 10 * n + to_digit(ch);
1045 				ch = *fmt++;
1046 			} while (is_digit(ch));
1047 			width = n;
1048 			goto reswitch;
1049 		case 'h':
1050 			flags |= SHORTINT;
1051 			goto rflag;
1052 		case 'l':
1053 			if (*fmt == 'l') {
1054 				fmt++;
1055 				flags |= QUADINT;
1056 			} else {
1057 				flags |= LONGINT;
1058 			}
1059 			goto rflag;
1060 		case 'q':
1061 			flags |= QUADINT;
1062 			goto rflag;
1063 		case 'c':
1064 			*(cp = buf) = va_arg(ap, int);
1065 			size = 1;
1066 			sign = '\0';
1067 			break;
1068 		case 'D':
1069 			flags |= LONGINT;
1070 			/*FALLTHROUGH*/
1071 		case 'd':
1072 		case 'i':
1073 			_uquad = SARG();
1074 			if ((quad_t)_uquad < 0) {
1075 				_uquad = -_uquad;
1076 				sign = '-';
1077 			}
1078 			base = DEC;
1079 			goto number;
1080 		case 'n':
1081 			if (flags & QUADINT)
1082 				*va_arg(ap, quad_t *) = ret;
1083 			else if (flags & LONGINT)
1084 				*va_arg(ap, long *) = ret;
1085 			else if (flags & SHORTINT)
1086 				*va_arg(ap, short *) = ret;
1087 			else
1088 				*va_arg(ap, int *) = ret;
1089 			continue;	/* no output */
1090 		case 'O':
1091 			flags |= LONGINT;
1092 			/*FALLTHROUGH*/
1093 		case 'o':
1094 			_uquad = UARG();
1095 			base = OCT;
1096 			goto nosign;
1097 		case 'p':
1098 			/*
1099 			 * ``The argument shall be a pointer to void.  The
1100 			 * value of the pointer is converted to a sequence
1101 			 * of printable characters, in an implementation-
1102 			 * defined manner.''
1103 			 *	-- ANSI X3J11
1104 			 */
1105 			/* NOSTRICT */
1106 			_uquad = (u_long)va_arg(ap, void *);
1107 			base = HEX;
1108 			xdigs = "0123456789abcdef";
1109 			flags |= HEXPREFIX;
1110 			ch = 'x';
1111 			goto nosign;
1112 		case 's':
1113 			if ((cp = va_arg(ap, char *)) == NULL)
1114 				cp = "(null)";
1115 			if (prec >= 0) {
1116 				/*
1117 				 * can't use strlen; can only look for the
1118 				 * NUL in the first `prec' characters, and
1119 				 * strlen() will go further.
1120 				 */
1121 				char *p = memchr(cp, 0, prec);
1122 
1123 				if (p != NULL) {
1124 					size = p - cp;
1125 					if (size > prec)
1126 						size = prec;
1127 				} else
1128 					size = prec;
1129 			} else
1130 				size = strlen(cp);
1131 			sign = '\0';
1132 			break;
1133 		case 'U':
1134 			flags |= LONGINT;
1135 			/*FALLTHROUGH*/
1136 		case 'u':
1137 			_uquad = UARG();
1138 			base = DEC;
1139 			goto nosign;
1140 		case 'X':
1141 			xdigs = "0123456789ABCDEF";
1142 			goto hex;
1143 		case 'x':
1144 			xdigs = "0123456789abcdef";
1145 hex:			_uquad = UARG();
1146 			base = HEX;
1147 			/* leading 0x/X only if non-zero */
1148 			if (flags & ALT && _uquad != 0)
1149 				flags |= HEXPREFIX;
1150 
1151 			/* unsigned conversions */
1152 nosign:			sign = '\0';
1153 			/*
1154 			 * ``... diouXx conversions ... if a precision is
1155 			 * specified, the 0 flag will be ignored.''
1156 			 *	-- ANSI X3J11
1157 			 */
1158 number:			if ((dprec = prec) >= 0)
1159 				flags &= ~ZEROPAD;
1160 
1161 			/*
1162 			 * ``The result of converting a zero value with an
1163 			 * explicit precision of zero is no characters.''
1164 			 *	-- ANSI X3J11
1165 			 */
1166 			cp = buf + KPRINTF_BUFSIZE;
1167 			if (_uquad != 0 || prec != 0) {
1168 				/*
1169 				 * Unsigned mod is hard, and unsigned mod
1170 				 * by a constant is easier than that by
1171 				 * a variable; hence this switch.
1172 				 */
1173 				switch (base) {
1174 				case OCT:
1175 					do {
1176 						*--cp = to_char(_uquad & 7);
1177 						_uquad >>= 3;
1178 					} while (_uquad);
1179 					/* handle octal leading 0 */
1180 					if (flags & ALT && *cp != '0')
1181 						*--cp = '0';
1182 					break;
1183 
1184 				case DEC:
1185 					/* many numbers are 1 digit */
1186 					while (_uquad >= 10) {
1187 						*--cp = to_char(_uquad % 10);
1188 						_uquad /= 10;
1189 					}
1190 					*--cp = to_char(_uquad);
1191 					break;
1192 
1193 				case HEX:
1194 					do {
1195 						*--cp = xdigs[_uquad & 15];
1196 						_uquad >>= 4;
1197 					} while (_uquad);
1198 					break;
1199 
1200 				default:
1201 					cp = "bug in kprintf: bad base";
1202 					size = strlen(cp);
1203 					goto skipsize;
1204 				}
1205 			}
1206 			size = buf + KPRINTF_BUFSIZE - cp;
1207 		skipsize:
1208 			break;
1209 		default:	/* "%?" prints ?, unless ? is NUL */
1210 			if (ch == '\0')
1211 				goto done;
1212 			/* pretend it was %c with argument ch */
1213 			cp = buf;
1214 			*cp = ch;
1215 			size = 1;
1216 			sign = '\0';
1217 			break;
1218 		}
1219 
1220 		/*
1221 		 * All reasonable formats wind up here.  At this point, `cp'
1222 		 * points to a string which (if not flags&LADJUST) should be
1223 		 * padded out to `width' places.  If flags&ZEROPAD, it should
1224 		 * first be prefixed by any sign or other prefix; otherwise,
1225 		 * it should be blank padded before the prefix is emitted.
1226 		 * After any left-hand padding and prefixing, emit zeroes
1227 		 * required by a decimal [diouxX] precision, then print the
1228 		 * string proper, then emit zeroes required by any leftover
1229 		 * floating precision; finally, if LADJUST, pad with blanks.
1230 		 *
1231 		 * Compute actual size, so we know how much to pad.
1232 		 * size excludes decimal prec; realsz includes it.
1233 		 */
1234 		realsz = dprec > size ? dprec : size;
1235 		if (sign)
1236 			realsz++;
1237 		else if (flags & HEXPREFIX)
1238 			realsz+= 2;
1239 
1240 		/* adjust ret */
1241 		ret += width > realsz ? width : realsz;
1242 
1243 		/* right-adjusting blank padding */
1244 		if ((flags & (LADJUST|ZEROPAD)) == 0) {
1245 			n = width - realsz;
1246 			while (n-- > 0)
1247 				KPRINTF_PUTCHAR(' ');
1248 		}
1249 
1250 		/* prefix */
1251 		if (sign) {
1252 			KPRINTF_PUTCHAR(sign);
1253 		} else if (flags & HEXPREFIX) {
1254 			KPRINTF_PUTCHAR('0');
1255 			KPRINTF_PUTCHAR(ch);
1256 		}
1257 
1258 		/* right-adjusting zero padding */
1259 		if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) {
1260 			n = width - realsz;
1261 			while (n-- > 0)
1262 				KPRINTF_PUTCHAR('0');
1263 		}
1264 
1265 		/* leading zeroes from decimal precision */
1266 		n = dprec - size;
1267 		while (n-- > 0)
1268 			KPRINTF_PUTCHAR('0');
1269 
1270 		/* the string or number proper */
1271 		while (size--)
1272 			KPRINTF_PUTCHAR(*cp++);
1273 		/* left-adjusting padding (always blank) */
1274 		if (flags & LADJUST) {
1275 			n = width - realsz;
1276 			while (n-- > 0)
1277 				KPRINTF_PUTCHAR(' ');
1278 		}
1279 	}
1280 
1281 done:
1282 	if ((oflags == TOBUFONLY) && (vp != NULL))
1283 		*(char **)vp = sbuf;
1284 overflow:
1285 	return (ret);
1286 	/* NOTREACHED */
1287 }
1288