xref: /netbsd-src/sys/kern/subr_prf.c (revision 4472dbe5e3bd91ef2540bada7a7ca7384627ff9b)
1 /*	$NetBSD: subr_prf.c,v 1.73 2000/05/29 23:10:03 jhawk 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 sprintf] */
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 
150 /*
151  * v_putc: routine to putc on virtual console
152  *
153  * the v_putc pointer can be used to redirect the console cnputc elsewhere
154  * [e.g. to a "virtual console"].
155  */
156 
157 void (*v_putc) __P((int)) = cnputc;	/* start with cnputc (normal cons) */
158 
159 
160 /*
161  * functions
162  */
163 
164 /*
165  * tablefull: warn that a system table is full
166  */
167 
168 void
169 tablefull(tab)
170 	const char *tab;
171 {
172 	log(LOG_ERR, "%s: table is full\n", tab);
173 }
174 
175 /*
176  * panic: handle an unresolvable fatal error
177  *
178  * prints "panic: <message>" and reboots.   if called twice (i.e. recursive
179  * call) we avoid trying to sync the disk and just reboot (to avoid
180  * recursive panics).
181  */
182 
183 void
184 #ifdef __STDC__
185 panic(const char *fmt, ...)
186 #else
187 panic(fmt, va_alist)
188 	char *fmt;
189 	va_dcl
190 #endif
191 {
192 	int bootopt;
193 	va_list ap;
194 
195 	bootopt = RB_AUTOBOOT | RB_DUMP;
196 	if (panicstr)
197 		bootopt |= RB_NOSYNC;
198 	else
199 		panicstr = fmt;
200 
201 	va_start(ap, fmt);
202 	printf("panic: ");
203 	vprintf(fmt, ap);
204 	printf("\n");
205 	va_end(ap);
206 
207 #ifdef IPKDB
208 	ipkdb_panic();
209 #endif
210 #ifdef KGDB
211 	kgdb_panic();
212 #endif
213 #ifdef KADB
214 	if (boothowto & RB_KDB)
215 		kdbpanic();
216 #endif
217 #ifdef DDB
218 	if (db_onpanic)
219 		Debugger();
220 	else {
221 		static int intrace = 0;
222 
223 		if (intrace==0) {
224 			intrace=1;
225 			printf("Begin traceback...\n");
226 			db_stack_trace_print(
227 			    (db_expr_t)__builtin_frame_address(0),
228 			    TRUE, 65535, "", printf);
229 			printf("End traceback...\n");
230 			intrace=0;
231 		} else
232 			printf("Faulted in mid-traceback; aborting...");
233 	}
234 #endif
235 	cpu_reboot(bootopt, NULL);
236 }
237 
238 /*
239  * kernel logging functions: log, logpri, addlog
240  */
241 
242 /*
243  * log: write to the log buffer
244  *
245  * => will not sleep [so safe to call from interrupt]
246  * => will log to console if /dev/klog isn't open
247  */
248 
249 void
250 #ifdef __STDC__
251 log(int level, const char *fmt, ...)
252 #else
253 log(level, fmt, va_alist)
254 	int level;
255 	char *fmt;
256 	va_dcl
257 #endif
258 {
259 	int s;
260 	va_list ap;
261 
262 	KPRINTF_MUTEX_ENTER(s);
263 
264 	klogpri(level);		/* log the level first */
265 	va_start(ap, fmt);
266 	kprintf(fmt, TOLOG, NULL, NULL, ap);
267 	va_end(ap);
268 	if (!log_open) {
269 		va_start(ap, fmt);
270 		kprintf(fmt, TOCONS, NULL, NULL, ap);
271 		va_end(ap);
272 	}
273 
274 	KPRINTF_MUTEX_EXIT(s);
275 
276 	logwakeup();		/* wake up anyone waiting for log msgs */
277 }
278 
279 /*
280  * vlog: write to the log buffer [already have va_alist]
281  */
282 
283 void
284 vlog(level, fmt, ap)
285 	int level;
286 	const char *fmt;
287 	va_list ap;
288 {
289 	int s;
290 
291 	KPRINTF_MUTEX_ENTER(s);
292 
293 	klogpri(level);		/* log the level first */
294 	kprintf(fmt, TOLOG, NULL, NULL, ap);
295 	if (!log_open)
296 		kprintf(fmt, TOCONS, NULL, NULL, ap);
297 
298 	KPRINTF_MUTEX_EXIT(s);
299 
300 	logwakeup();		/* wake up anyone waiting for log msgs */
301 }
302 
303 /*
304  * logpri: log the priority level to the klog
305  */
306 
307 void
308 logpri(level)
309 	int level;
310 {
311 	int s;
312 
313 	KPRINTF_MUTEX_ENTER(s);
314 	klogpri(level);
315 	KPRINTF_MUTEX_EXIT(s);
316 }
317 
318 /*
319  * Note: we must be in the mutex here!
320  */
321 static void
322 klogpri(level)
323 	int level;
324 {
325 	char *p;
326 	char snbuf[KPRINTF_BUFSIZE];
327 
328 	putchar('<', TOLOG, NULL);
329 	sprintf(snbuf, "%d", level);
330 	for (p = snbuf ; *p ; p++)
331 		putchar(*p, TOLOG, NULL);
332 	putchar('>', TOLOG, NULL);
333 }
334 
335 /*
336  * addlog: add info to previous log message
337  */
338 
339 void
340 #ifdef __STDC__
341 addlog(const char *fmt, ...)
342 #else
343 addlog(fmt, va_alist)
344 	char *fmt;
345 	va_dcl
346 #endif
347 {
348 	int s;
349 	va_list ap;
350 
351 	KPRINTF_MUTEX_ENTER(s);
352 
353 	va_start(ap, fmt);
354 	kprintf(fmt, TOLOG, NULL, NULL, ap);
355 	va_end(ap);
356 	if (!log_open) {
357 		va_start(ap, fmt);
358 		kprintf(fmt, TOCONS, NULL, NULL, ap);
359 		va_end(ap);
360 	}
361 
362 	KPRINTF_MUTEX_EXIT(s);
363 
364 	logwakeup();
365 }
366 
367 
368 /*
369  * putchar: print a single character on console or user terminal.
370  *
371  * => if console, then the last MSGBUFS chars are saved in msgbuf
372  *	for inspection later (e.g. dmesg/syslog)
373  * => we must already be in the mutex!
374  */
375 static void
376 putchar(c, flags, tp)
377 	int c;
378 	int flags;
379 	struct tty *tp;
380 {
381 	struct kern_msgbuf *mbp;
382 
383 	if (panicstr)
384 		constty = NULL;
385 	if ((flags & TOCONS) && tp == NULL && constty) {
386 		tp = constty;
387 		flags |= TOTTY;
388 	}
389 	if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
390 	    (flags & TOCONS) && tp == constty)
391 		constty = NULL;
392 	if ((flags & TOLOG) &&
393 	    c != '\0' && c != '\r' && c != 0177 && msgbufenabled) {
394 		mbp = msgbufp;
395 		if (mbp->msg_magic != MSG_MAGIC) {
396 			/*
397 			 * Arguably should panic or somehow notify the
398 			 * user...  but how?  Panic may be too drastic,
399 			 * and would obliterate the message being kicked
400 			 * out (maybe a panic itself), and printf
401 			 * would invoke us recursively.  Silently punt
402 			 * for now.  If syslog is running, it should
403 			 * notice.
404 			 */
405 			msgbufenabled = 0;
406 		} else {
407 			mbp->msg_bufc[mbp->msg_bufx++] = c;
408 			if (mbp->msg_bufx < 0 || mbp->msg_bufx >= mbp->msg_bufs)
409 				mbp->msg_bufx = 0;
410 			/* If the buffer is full, keep the most recent data. */
411 			if (mbp->msg_bufr == mbp->msg_bufx) {
412 				 if (++mbp->msg_bufr >= mbp->msg_bufs)
413 					mbp->msg_bufr = 0;
414 			}
415 		}
416 	}
417 	if ((flags & TOCONS) && constty == NULL && c != '\0')
418 		(*v_putc)(c);
419 #ifdef DDB
420 	if (flags & TODDB)
421 		db_putchar(c);
422 #endif
423 }
424 
425 
426 /*
427  * uprintf: print to the controlling tty of the current process
428  *
429  * => we may block if the tty queue is full
430  * => no message is printed if the queue doesn't clear in a reasonable
431  *	time
432  */
433 
434 void
435 #ifdef __STDC__
436 uprintf(const char *fmt, ...)
437 #else
438 uprintf(fmt, va_alist)
439 	char *fmt;
440 	va_dcl
441 #endif
442 {
443 	struct proc *p = curproc;
444 	va_list ap;
445 
446 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
447 		/* No mutex needed; going to process TTY. */
448 		va_start(ap, fmt);
449 		kprintf(fmt, TOTTY, p->p_session->s_ttyp, NULL, ap);
450 		va_end(ap);
451 	}
452 }
453 
454 /*
455  * tprintf functions: used to send messages to a specific process
456  *
457  * usage:
458  *   get a tpr_t handle on a process "p" by using "tprintf_open(p)"
459  *   use the handle when calling "tprintf"
460  *   when done, do a "tprintf_close" to drop the handle
461  */
462 
463 /*
464  * tprintf_open: get a tprintf handle on a process "p"
465  *
466  * => returns NULL if process can't be printed to
467  */
468 
469 tpr_t
470 tprintf_open(p)
471 	struct proc *p;
472 {
473 
474 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
475 		SESSHOLD(p->p_session);
476 		return ((tpr_t) p->p_session);
477 	}
478 	return ((tpr_t) NULL);
479 }
480 
481 /*
482  * tprintf_close: dispose of a tprintf handle obtained with tprintf_open
483  */
484 
485 void
486 tprintf_close(sess)
487 	tpr_t sess;
488 {
489 
490 	if (sess)
491 		SESSRELE((struct session *) sess);
492 }
493 
494 /*
495  * tprintf: given tprintf handle to a process [obtained with tprintf_open],
496  * send a message to the controlling tty for that process.
497  *
498  * => also sends message to /dev/klog
499  */
500 void
501 #ifdef __STDC__
502 tprintf(tpr_t tpr, const char *fmt, ...)
503 #else
504 tprintf(tpr, fmt, va_alist)
505 	tpr_t tpr;
506 	char *fmt;
507 	va_dcl
508 #endif
509 {
510 	struct session *sess = (struct session *)tpr;
511 	struct tty *tp = NULL;
512 	int s, flags = TOLOG;
513 	va_list ap;
514 
515 	if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
516 		flags |= TOTTY;
517 		tp = sess->s_ttyp;
518 	}
519 
520 	KPRINTF_MUTEX_ENTER(s);
521 
522 	klogpri(LOG_INFO);
523 	va_start(ap, fmt);
524 	kprintf(fmt, flags, tp, NULL, ap);
525 	va_end(ap);
526 
527 	KPRINTF_MUTEX_EXIT(s);
528 
529 	logwakeup();
530 }
531 
532 
533 /*
534  * ttyprintf: send a message to a specific tty
535  *
536  * => should be used only by tty driver or anything that knows the
537  *    underlying tty will not be revoked(2)'d away.  [otherwise,
538  *    use tprintf]
539  */
540 void
541 #ifdef __STDC__
542 ttyprintf(struct tty *tp, const char *fmt, ...)
543 #else
544 ttyprintf(tp, fmt, va_alist)
545 	struct tty *tp;
546 	char *fmt;
547 	va_dcl
548 #endif
549 {
550 	va_list ap;
551 
552 	/* No mutex needed; going to process TTY. */
553 	va_start(ap, fmt);
554 	kprintf(fmt, TOTTY, tp, NULL, ap);
555 	va_end(ap);
556 }
557 
558 #ifdef DDB
559 
560 /*
561  * db_printf: printf for DDB (via db_putchar)
562  */
563 
564 void
565 #ifdef __STDC__
566 db_printf(const char *fmt, ...)
567 #else
568 db_printf(fmt, va_alist)
569 	char *fmt;
570 	va_dcl
571 #endif
572 {
573 	va_list ap;
574 
575 	/* No mutex needed; DDB pauses all processors. */
576 	va_start(ap, fmt);
577 	kprintf(fmt, TODDB, NULL, NULL, ap);
578 	va_end(ap);
579 }
580 
581 #endif /* DDB */
582 
583 
584 /*
585  * normal kernel printf functions: printf, vprintf, sprintf
586  */
587 
588 /*
589  * printf: print a message to the console and the log
590  */
591 void
592 #ifdef __STDC__
593 printf(const char *fmt, ...)
594 #else
595 printf(fmt, va_alist)
596 	char *fmt;
597 	va_dcl
598 #endif
599 {
600 	va_list ap;
601 	int s;
602 
603 	KPRINTF_MUTEX_ENTER(s);
604 
605 	va_start(ap, fmt);
606 	kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
607 	va_end(ap);
608 
609 	KPRINTF_MUTEX_EXIT(s);
610 
611 	if (!panicstr)
612 		logwakeup();
613 }
614 
615 /*
616  * vprintf: print a message to the console and the log [already have
617  *	va_alist]
618  */
619 
620 void
621 vprintf(fmt, ap)
622 	const char *fmt;
623 	va_list ap;
624 {
625 	int s;
626 
627 	KPRINTF_MUTEX_ENTER(s);
628 
629 	kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
630 
631 	KPRINTF_MUTEX_EXIT(s);
632 
633 	if (!panicstr)
634 		logwakeup();
635 }
636 
637 /*
638  * sprintf: print a message to a buffer
639  */
640 int
641 #ifdef __STDC__
642 sprintf(char *buf, const char *fmt, ...)
643 #else
644 sprintf(buf, fmt, va_alist)
645         char *buf;
646         const char *cfmt;
647         va_dcl
648 #endif
649 {
650 	int retval;
651 	va_list ap;
652 
653 	va_start(ap, fmt);
654 	retval = kprintf(fmt, TOBUFONLY, NULL, buf, ap);
655 	va_end(ap);
656 	*(buf + retval) = 0;	/* null terminate */
657 	return(retval);
658 }
659 
660 /*
661  * vsprintf: print a message to a buffer [already have va_alist]
662  */
663 
664 int
665 vsprintf(buf, fmt, ap)
666 	char *buf;
667 	const char *fmt;
668 	va_list ap;
669 {
670 	int retval;
671 
672 	retval = kprintf(fmt, TOBUFONLY, NULL, buf, ap);
673 	*(buf + retval) = 0;	/* null terminate */
674 	return (retval);
675 }
676 
677 /*
678  * snprintf: print a message to a buffer
679  */
680 int
681 #ifdef __STDC__
682 snprintf(char *buf, size_t size, const char *fmt, ...)
683 #else
684 snprintf(buf, size, fmt, va_alist)
685         char *buf;
686         size_t size;
687         const char *cfmt;
688         va_dcl
689 #endif
690 {
691 	int retval;
692 	va_list ap;
693 	char *p;
694 
695 	if (size < 1)
696 		return (-1);
697 	p = buf + size - 1;
698 	va_start(ap, fmt);
699 	retval = kprintf(fmt, TOBUFONLY, &p, buf, ap);
700 	va_end(ap);
701 	*(p) = 0;	/* null terminate */
702 	return(retval);
703 }
704 
705 /*
706  * vsnprintf: print a message to a buffer [already have va_alist]
707  */
708 int
709 vsnprintf(buf, size, fmt, ap)
710         char *buf;
711         size_t size;
712         const char *fmt;
713         va_list ap;
714 {
715 	int retval;
716 	char *p;
717 
718 	if (size < 1)
719 		return (-1);
720 	p = buf + size - 1;
721 	retval = kprintf(fmt, TOBUFONLY, &p, buf, ap);
722 	*(p) = 0;	/* null terminate */
723 	return(retval);
724 }
725 
726 /*
727  * bitmask_snprintf: print a kernel-printf "%b" message to a buffer
728  *
729  * => returns pointer to the buffer
730  * => XXX: useful vs. kernel %b?
731  */
732 char *
733 bitmask_snprintf(val, p, buf, buflen)
734 	u_quad_t val;
735 	const char *p;
736 	char *buf;
737 	size_t buflen;
738 {
739 	char *bp, *q;
740 	size_t left;
741 	char *sbase, snbuf[KPRINTF_BUFSIZE];
742 	int base, bit, ch, len, sep;
743 	u_quad_t field;
744 
745 	bp = buf;
746 	memset(buf, 0, buflen);
747 
748 	/*
749 	 * Always leave room for the trailing NULL.
750 	 */
751 	left = buflen - 1;
752 
753 	/*
754 	 * Print the value into the buffer.  Abort if there's not
755 	 * enough room.
756 	 */
757 	if (buflen < KPRINTF_BUFSIZE)
758 		return (buf);
759 
760 	ch = *p++;
761 	base = ch != '\177' ? ch : *p++;
762 	sbase = base == 8 ? "%qo" : base == 10 ? "%qd" : base == 16 ? "%qx" : 0;
763 	if (sbase == 0)
764 		return (buf);	/* punt if not oct, dec, or hex */
765 
766 	sprintf(snbuf, sbase, val);
767 	for (q = snbuf ; *q ; q++) {
768 		*bp++ = *q;
769 		left--;
770 	}
771 
772 	/*
773 	 * If the value we printed was 0 and we're using the old-style format,
774 	 * or if we don't have room for "<x>", we're done.
775 	 */
776 	if (((val == 0) && (ch != '\177')) || left < 3)
777 		return (buf);
778 
779 #define PUTBYTE(b, c, l)	\
780 	*(b)++ = (c);		\
781 	if (--(l) == 0)		\
782 		goto out;
783 #define PUTSTR(b, p, l) do {		\
784 	int c;				\
785 	while ((c = *(p)++) != 0) {	\
786 		*(b)++ = c;		\
787 		if (--(l) == 0)		\
788 			goto out;	\
789 	}				\
790 } while (0)
791 
792 	/*
793 	 * Chris Torek's new style %b format is identified by a leading \177
794 	 */
795 	sep = '<';
796 	if (ch != '\177') {
797 		/* old (standard) %b format. */
798 		for (;(bit = *p++) != 0;) {
799 			if (val & (1 << (bit - 1))) {
800 				PUTBYTE(bp, sep, left);
801 				for (; (ch = *p) > ' '; ++p) {
802 					PUTBYTE(bp, ch, left);
803 				}
804 				sep = ',';
805 			} else
806 				for (; *p > ' '; ++p)
807 					continue;
808 		}
809 	} else {
810 		/* new quad-capable %b format; also does fields. */
811 		field = val;
812 		while ((ch = *p++) != '\0') {
813 			bit = *p++;	/* now 0-origin */
814 			switch (ch) {
815 			case 'b':
816 				if (((u_int)(val >> bit) & 1) == 0)
817 					goto skip;
818 				PUTBYTE(bp, sep, left);
819 				PUTSTR(bp, p, left);
820 				sep = ',';
821 				break;
822 			case 'f':
823 			case 'F':
824 				len = *p++;	/* field length */
825 				field = (val >> bit) & ((1ULL << len) - 1);
826 				if (ch == 'F')	/* just extract */
827 					break;
828 				PUTBYTE(bp, sep, left);
829 				sep = ',';
830 				PUTSTR(bp, p, left);
831 				PUTBYTE(bp, '=', left);
832 				sprintf(snbuf, sbase, field);
833 				q = snbuf; PUTSTR(bp, q, left);
834 				break;
835 			case '=':
836 			case ':':
837 				/*
838 				 * Here "bit" is actually a value instead,
839 				 * to be compared against the last field.
840 				 * This only works for values in [0..255],
841 				 * of course.
842 				 */
843 				if ((int)field != bit)
844 					goto skip;
845 				if (ch == '=')
846 					PUTBYTE(bp, '=', left);
847 				PUTSTR(bp, p, left);
848 				break;
849 			default:
850 			skip:
851 				while (*p++ != '\0')
852 					continue;
853 				break;
854 			}
855 		}
856 	}
857 	if (sep != '<')
858 		PUTBYTE(bp, '>', left);
859 
860 out:
861 	return (buf);
862 
863 #undef PUTBYTE
864 #undef PUTSTR
865 }
866 
867 /*
868  * kprintf: scaled down version of printf(3).
869  *
870  * this version based on vfprintf() from libc which was derived from
871  * software contributed to Berkeley by Chris Torek.
872  *
873  * Two additional formats:
874  *
875  * The format %b is supported to decode error registers.
876  * Its usage is:
877  *
878  *	printf("reg=%b\n", regval, "<base><arg>*");
879  *
880  * where <base> is the output base expressed as a control character, e.g.
881  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
882  * the first of which gives the bit number to be inspected (origin 1), and
883  * the next characters (up to a control character, i.e. a character <= 32),
884  * give the name of the register.  Thus:
885  *
886  *	kprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
887  *
888  * would produce output:
889  *
890  *	reg=3<BITTWO,BITONE>
891  *
892  * The format %: passes an additional format string and argument list
893  * recursively.  Its usage is:
894  *
895  * fn(char *fmt, ...)
896  * {
897  *	va_list ap;
898  *	va_start(ap, fmt);
899  *	printf("prefix: %: suffix\n", fmt, ap);
900  *	va_end(ap);
901  * }
902  *
903  * this is the actual printf innards
904  *
905  * This code is large and complicated...
906  *
907  * NOTE: The kprintf mutex must be held of we're going TOBUF or TOCONS!
908  */
909 
910 /*
911  * macros for converting digits to letters and vice versa
912  */
913 #define	to_digit(c)	((c) - '0')
914 #define is_digit(c)	((unsigned)to_digit(c) <= 9)
915 #define	to_char(n)	((n) + '0')
916 
917 /*
918  * flags used during conversion.
919  */
920 #define	ALT		0x001		/* alternate form */
921 #define	HEXPREFIX	0x002		/* add 0x or 0X prefix */
922 #define	LADJUST		0x004		/* left adjustment */
923 #define	LONGDBL		0x008		/* long double; unimplemented */
924 #define	LONGINT		0x010		/* long integer */
925 #define	QUADINT		0x020		/* quad integer */
926 #define	SHORTINT	0x040		/* short integer */
927 #define	ZEROPAD		0x080		/* zero (as opposed to blank) pad */
928 #define FPT		0x100		/* Floating point number */
929 
930 	/*
931 	 * To extend shorts properly, we need both signed and unsigned
932 	 * argument extraction methods.
933 	 */
934 #define	SARG() \
935 	(flags&QUADINT ? va_arg(ap, quad_t) : \
936 	    flags&LONGINT ? va_arg(ap, long) : \
937 	    flags&SHORTINT ? (long)(short)va_arg(ap, int) : \
938 	    (long)va_arg(ap, int))
939 #define	UARG() \
940 	(flags&QUADINT ? va_arg(ap, u_quad_t) : \
941 	    flags&LONGINT ? va_arg(ap, u_long) : \
942 	    flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \
943 	    (u_long)va_arg(ap, u_int))
944 
945 #define KPRINTF_PUTCHAR(C) {						\
946 	if (oflags == TOBUFONLY) {					\
947 		if ((vp != NULL) && (sbuf == tailp)) {			\
948 			ret += 1;		/* indicate error */	\
949 			goto overflow;					\
950 		}							\
951 		*sbuf++ = (C);						\
952 	} else {							\
953 		putchar((C), oflags, (struct tty *)vp);			\
954 	}								\
955 }
956 
957 /*
958  * Guts of kernel printf.  Note, we already expect to be in a mutex!
959  */
960 static int
961 kprintf(fmt0, oflags, vp, sbuf, ap)
962 	const char *fmt0;
963 	int oflags;
964 	void *vp;
965 	char *sbuf;
966 	va_list ap;
967 {
968 	char *fmt;		/* format string */
969 	int ch;			/* character from fmt */
970 	int n;			/* handy integer (short term usage) */
971 	char *cp;		/* handy char pointer (short term usage) */
972 	int flags;		/* flags as above */
973 	int ret;		/* return value accumulator */
974 	int width;		/* width from format (%8d), or 0 */
975 	int prec;		/* precision from format (%.3d), or -1 */
976 	char sign;		/* sign prefix (' ', '+', '-', or \0) */
977 
978 	u_quad_t _uquad;	/* integer arguments %[diouxX] */
979 	enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
980 	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
981 	int realsz;		/* field size expanded by dprec */
982 	int size;		/* size of converted field or string */
983 	char *xdigs;		/* digits for [xX] conversion */
984 	char buf[KPRINTF_BUFSIZE]; /* space for %c, %[diouxX] */
985 	char *tailp;		/* tail pointer for snprintf */
986 
987 	tailp = NULL;	/* XXX: shutup gcc */
988 	if (oflags == TOBUFONLY && (vp != NULL))
989 		tailp = *(char **)vp;
990 
991 	cp = NULL;	/* XXX: shutup gcc */
992 	size = 0;	/* XXX: shutup gcc */
993 
994 	fmt = (char *)fmt0;
995 	ret = 0;
996 
997 	xdigs = NULL;		/* XXX: shut up gcc warning */
998 
999 	/*
1000 	 * Scan the format for conversions (`%' character).
1001 	 */
1002 	for (;;) {
1003 		while (*fmt != '%' && *fmt) {
1004 			ret++;
1005 			KPRINTF_PUTCHAR(*fmt++);
1006 		}
1007 		if (*fmt == 0)
1008 			goto done;
1009 
1010 		fmt++;		/* skip over '%' */
1011 
1012 		flags = 0;
1013 		dprec = 0;
1014 		width = 0;
1015 		prec = -1;
1016 		sign = '\0';
1017 
1018 rflag:		ch = *fmt++;
1019 reswitch:	switch (ch) {
1020 		/* XXX: non-standard '%:' format */
1021 #ifndef __powerpc__
1022 		case ':':
1023 			if (oflags != TOBUFONLY) {
1024 				cp = va_arg(ap, char *);
1025 				kprintf(cp, oflags, vp,
1026 					NULL, va_arg(ap, va_list));
1027 			}
1028 			continue;	/* no output */
1029 #endif
1030 		/* XXX: non-standard '%b' format */
1031 		case 'b': {
1032 			char *b, *z;
1033 			int tmp;
1034 			_uquad = va_arg(ap, int);
1035 			b = va_arg(ap, char *);
1036 			if (*b == 8)
1037 				sprintf(buf, "%qo", (unsigned long long)_uquad);
1038 			else if (*b == 10)
1039 				sprintf(buf, "%qd", (unsigned long long)_uquad);
1040 			else if (*b == 16)
1041 				sprintf(buf, "%qx", (unsigned long long)_uquad);
1042 			else
1043 				break;
1044 			b++;
1045 
1046 			z = buf;
1047 			while (*z) {
1048 				ret++;
1049 				KPRINTF_PUTCHAR(*z++);
1050 			}
1051 
1052 			if (_uquad) {
1053 				tmp = 0;
1054 				while ((n = *b++) != 0) {
1055 					if (_uquad & (1 << (n - 1))) {
1056 						ret++;
1057 						KPRINTF_PUTCHAR(tmp ? ',':'<');
1058 						while ((n = *b) > ' ') {
1059 							ret++;
1060 							KPRINTF_PUTCHAR(n);
1061 							b++;
1062 						}
1063 						tmp = 1;
1064 					} else {
1065 						while(*b > ' ')
1066 							b++;
1067 					}
1068 				}
1069 				if (tmp) {
1070 					ret++;
1071 					KPRINTF_PUTCHAR('>');
1072 				}
1073 			}
1074 			continue;	/* no output */
1075 		}
1076 
1077 #ifdef DDB
1078 		/* XXX: non-standard '%r' format (print int in db_radix) */
1079 		case 'r':
1080 			if (db_radix == 16)
1081 				goto case_z;	/* signed hex */
1082 			_uquad = SARG();
1083 			if ((quad_t)_uquad < 0) {
1084 				_uquad = -_uquad;
1085 				sign = '-';
1086 			}
1087 			base = (db_radix == 8) ? OCT : DEC;
1088 			goto number;
1089 
1090 
1091 		/* XXX: non-standard '%z' format ("signed hex", a "hex %i")*/
1092 		case 'z':
1093 		case_z:
1094 			xdigs = "0123456789abcdef";
1095 			ch = 'x';	/* the 'x' in '0x' (below) */
1096 			_uquad = SARG();
1097 			base = HEX;
1098 			/* leading 0x/X only if non-zero */
1099 			if (flags & ALT && _uquad != 0)
1100 				flags |= HEXPREFIX;
1101 			if ((quad_t)_uquad < 0) {
1102 				_uquad = -_uquad;
1103 				sign = '-';
1104 			}
1105 			goto number;
1106 #endif
1107 
1108 		case ' ':
1109 			/*
1110 			 * ``If the space and + flags both appear, the space
1111 			 * flag will be ignored.''
1112 			 *	-- ANSI X3J11
1113 			 */
1114 			if (!sign)
1115 				sign = ' ';
1116 			goto rflag;
1117 		case '#':
1118 			flags |= ALT;
1119 			goto rflag;
1120 		case '*':
1121 			/*
1122 			 * ``A negative field width argument is taken as a
1123 			 * - flag followed by a positive field width.''
1124 			 *	-- ANSI X3J11
1125 			 * They don't exclude field widths read from args.
1126 			 */
1127 			if ((width = va_arg(ap, int)) >= 0)
1128 				goto rflag;
1129 			width = -width;
1130 			/* FALLTHROUGH */
1131 		case '-':
1132 			flags |= LADJUST;
1133 			goto rflag;
1134 		case '+':
1135 			sign = '+';
1136 			goto rflag;
1137 		case '.':
1138 			if ((ch = *fmt++) == '*') {
1139 				n = va_arg(ap, int);
1140 				prec = n < 0 ? -1 : n;
1141 				goto rflag;
1142 			}
1143 			n = 0;
1144 			while (is_digit(ch)) {
1145 				n = 10 * n + to_digit(ch);
1146 				ch = *fmt++;
1147 			}
1148 			prec = n < 0 ? -1 : n;
1149 			goto reswitch;
1150 		case '0':
1151 			/*
1152 			 * ``Note that 0 is taken as a flag, not as the
1153 			 * beginning of a field width.''
1154 			 *	-- ANSI X3J11
1155 			 */
1156 			flags |= ZEROPAD;
1157 			goto rflag;
1158 		case '1': case '2': case '3': case '4':
1159 		case '5': case '6': case '7': case '8': case '9':
1160 			n = 0;
1161 			do {
1162 				n = 10 * n + to_digit(ch);
1163 				ch = *fmt++;
1164 			} while (is_digit(ch));
1165 			width = n;
1166 			goto reswitch;
1167 		case 'h':
1168 			flags |= SHORTINT;
1169 			goto rflag;
1170 		case 'l':
1171 			if (*fmt == 'l') {
1172 				fmt++;
1173 				flags |= QUADINT;
1174 			} else {
1175 				flags |= LONGINT;
1176 			}
1177 			goto rflag;
1178 		case 'q':
1179 			flags |= QUADINT;
1180 			goto rflag;
1181 		case 'c':
1182 			*(cp = buf) = va_arg(ap, int);
1183 			size = 1;
1184 			sign = '\0';
1185 			break;
1186 		case 'D':
1187 			flags |= LONGINT;
1188 			/*FALLTHROUGH*/
1189 		case 'd':
1190 		case 'i':
1191 			_uquad = SARG();
1192 			if ((quad_t)_uquad < 0) {
1193 				_uquad = -_uquad;
1194 				sign = '-';
1195 			}
1196 			base = DEC;
1197 			goto number;
1198 		case 'n':
1199 #ifdef DDB
1200 		/* XXX: non-standard '%n' format */
1201 		/*
1202 		 * XXX: HACK!   DDB wants '%n' to be a '%u' printed
1203 		 * in db_radix format.   this should die since '%n'
1204 		 * is already defined in standard printf to write
1205 		 * the number of chars printed so far to the arg (which
1206 		 * should be a pointer.
1207 		 */
1208 			if (oflags & TODDB) {
1209 				if (db_radix == 16)
1210 					ch = 'x';	/* convert to %x */
1211 				else if (db_radix == 8)
1212 					ch = 'o';	/* convert to %o */
1213 				else
1214 					ch = 'u';	/* convert to %u */
1215 
1216 				/* ... and start again */
1217 				goto reswitch;
1218 			}
1219 
1220 #endif
1221 			if (flags & QUADINT)
1222 				*va_arg(ap, quad_t *) = ret;
1223 			else if (flags & LONGINT)
1224 				*va_arg(ap, long *) = ret;
1225 			else if (flags & SHORTINT)
1226 				*va_arg(ap, short *) = ret;
1227 			else
1228 				*va_arg(ap, int *) = ret;
1229 			continue;	/* no output */
1230 		case 'O':
1231 			flags |= LONGINT;
1232 			/*FALLTHROUGH*/
1233 		case 'o':
1234 			_uquad = UARG();
1235 			base = OCT;
1236 			goto nosign;
1237 		case 'p':
1238 			/*
1239 			 * ``The argument shall be a pointer to void.  The
1240 			 * value of the pointer is converted to a sequence
1241 			 * of printable characters, in an implementation-
1242 			 * defined manner.''
1243 			 *	-- ANSI X3J11
1244 			 */
1245 			/* NOSTRICT */
1246 			_uquad = (u_long)va_arg(ap, void *);
1247 			base = HEX;
1248 			xdigs = "0123456789abcdef";
1249 			flags |= HEXPREFIX;
1250 			ch = 'x';
1251 			goto nosign;
1252 		case 's':
1253 			if ((cp = va_arg(ap, char *)) == NULL)
1254 				cp = "(null)";
1255 			if (prec >= 0) {
1256 				/*
1257 				 * can't use strlen; can only look for the
1258 				 * NUL in the first `prec' characters, and
1259 				 * strlen() will go further.
1260 				 */
1261 				char *p = memchr(cp, 0, prec);
1262 
1263 				if (p != NULL) {
1264 					size = p - cp;
1265 					if (size > prec)
1266 						size = prec;
1267 				} else
1268 					size = prec;
1269 			} else
1270 				size = strlen(cp);
1271 			sign = '\0';
1272 			break;
1273 		case 'U':
1274 			flags |= LONGINT;
1275 			/*FALLTHROUGH*/
1276 		case 'u':
1277 			_uquad = UARG();
1278 			base = DEC;
1279 			goto nosign;
1280 		case 'X':
1281 			xdigs = "0123456789ABCDEF";
1282 			goto hex;
1283 		case 'x':
1284 			xdigs = "0123456789abcdef";
1285 hex:			_uquad = UARG();
1286 			base = HEX;
1287 			/* leading 0x/X only if non-zero */
1288 			if (flags & ALT && _uquad != 0)
1289 				flags |= HEXPREFIX;
1290 
1291 			/* unsigned conversions */
1292 nosign:			sign = '\0';
1293 			/*
1294 			 * ``... diouXx conversions ... if a precision is
1295 			 * specified, the 0 flag will be ignored.''
1296 			 *	-- ANSI X3J11
1297 			 */
1298 number:			if ((dprec = prec) >= 0)
1299 				flags &= ~ZEROPAD;
1300 
1301 			/*
1302 			 * ``The result of converting a zero value with an
1303 			 * explicit precision of zero is no characters.''
1304 			 *	-- ANSI X3J11
1305 			 */
1306 			cp = buf + KPRINTF_BUFSIZE;
1307 			if (_uquad != 0 || prec != 0) {
1308 				/*
1309 				 * Unsigned mod is hard, and unsigned mod
1310 				 * by a constant is easier than that by
1311 				 * a variable; hence this switch.
1312 				 */
1313 				switch (base) {
1314 				case OCT:
1315 					do {
1316 						*--cp = to_char(_uquad & 7);
1317 						_uquad >>= 3;
1318 					} while (_uquad);
1319 					/* handle octal leading 0 */
1320 					if (flags & ALT && *cp != '0')
1321 						*--cp = '0';
1322 					break;
1323 
1324 				case DEC:
1325 					/* many numbers are 1 digit */
1326 					while (_uquad >= 10) {
1327 						*--cp = to_char(_uquad % 10);
1328 						_uquad /= 10;
1329 					}
1330 					*--cp = to_char(_uquad);
1331 					break;
1332 
1333 				case HEX:
1334 					do {
1335 						*--cp = xdigs[_uquad & 15];
1336 						_uquad >>= 4;
1337 					} while (_uquad);
1338 					break;
1339 
1340 				default:
1341 					cp = "bug in kprintf: bad base";
1342 					size = strlen(cp);
1343 					goto skipsize;
1344 				}
1345 			}
1346 			size = buf + KPRINTF_BUFSIZE - cp;
1347 		skipsize:
1348 			break;
1349 		default:	/* "%?" prints ?, unless ? is NUL */
1350 			if (ch == '\0')
1351 				goto done;
1352 			/* pretend it was %c with argument ch */
1353 			cp = buf;
1354 			*cp = ch;
1355 			size = 1;
1356 			sign = '\0';
1357 			break;
1358 		}
1359 
1360 		/*
1361 		 * All reasonable formats wind up here.  At this point, `cp'
1362 		 * points to a string which (if not flags&LADJUST) should be
1363 		 * padded out to `width' places.  If flags&ZEROPAD, it should
1364 		 * first be prefixed by any sign or other prefix; otherwise,
1365 		 * it should be blank padded before the prefix is emitted.
1366 		 * After any left-hand padding and prefixing, emit zeroes
1367 		 * required by a decimal [diouxX] precision, then print the
1368 		 * string proper, then emit zeroes required by any leftover
1369 		 * floating precision; finally, if LADJUST, pad with blanks.
1370 		 *
1371 		 * Compute actual size, so we know how much to pad.
1372 		 * size excludes decimal prec; realsz includes it.
1373 		 */
1374 		realsz = dprec > size ? dprec : size;
1375 		if (sign)
1376 			realsz++;
1377 		else if (flags & HEXPREFIX)
1378 			realsz+= 2;
1379 
1380 		/* adjust ret */
1381 		ret += width > realsz ? width : realsz;
1382 
1383 		/* right-adjusting blank padding */
1384 		if ((flags & (LADJUST|ZEROPAD)) == 0) {
1385 			n = width - realsz;
1386 			while (n-- > 0)
1387 				KPRINTF_PUTCHAR(' ');
1388 		}
1389 
1390 		/* prefix */
1391 		if (sign) {
1392 			KPRINTF_PUTCHAR(sign);
1393 		} else if (flags & HEXPREFIX) {
1394 			KPRINTF_PUTCHAR('0');
1395 			KPRINTF_PUTCHAR(ch);
1396 		}
1397 
1398 		/* right-adjusting zero padding */
1399 		if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) {
1400 			n = width - realsz;
1401 			while (n-- > 0)
1402 				KPRINTF_PUTCHAR('0');
1403 		}
1404 
1405 		/* leading zeroes from decimal precision */
1406 		n = dprec - size;
1407 		while (n-- > 0)
1408 			KPRINTF_PUTCHAR('0');
1409 
1410 		/* the string or number proper */
1411 		while (size--)
1412 			KPRINTF_PUTCHAR(*cp++);
1413 		/* left-adjusting padding (always blank) */
1414 		if (flags & LADJUST) {
1415 			n = width - realsz;
1416 			while (n-- > 0)
1417 				KPRINTF_PUTCHAR(' ');
1418 		}
1419 	}
1420 
1421 done:
1422 	if ((oflags == TOBUFONLY) && (vp != NULL))
1423 		*(char **)vp = sbuf;
1424 overflow:
1425 	return (ret);
1426 	/* NOTREACHED */
1427 }
1428