xref: /netbsd-src/sys/kern/subr_prf.c (revision eb961d0e02b7a46a9acfa877b02df48df6637278)
1 /*	$NetBSD: subr_prf.c,v 1.102 2006/01/28 14:37:31 darrenr 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. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)subr_prf.c	8.4 (Berkeley) 5/4/95
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: subr_prf.c,v 1.102 2006/01/28 14:37:31 darrenr Exp $");
41 
42 #include "opt_ddb.h"
43 #include "opt_ipkdb.h"
44 #include "opt_kgdb.h"
45 #include "opt_multiprocessor.h"
46 #include "opt_dump.h"
47 
48 #include <sys/param.h>
49 #include <sys/stdint.h>
50 #include <sys/systm.h>
51 #include <sys/buf.h>
52 #include <sys/reboot.h>
53 #include <sys/msgbuf.h>
54 #include <sys/proc.h>
55 #include <sys/ioctl.h>
56 #include <sys/vnode.h>
57 #include <sys/file.h>
58 #include <sys/tty.h>
59 #include <sys/tprintf.h>
60 #include <sys/syslog.h>
61 #include <sys/malloc.h>
62 #include <sys/lock.h>
63 #include <sys/kprintf.h>
64 
65 #include <dev/cons.h>
66 
67 #ifdef DDB
68 #include <ddb/ddbvar.h>
69 #include <machine/db_machdep.h>
70 #include <ddb/db_command.h>
71 #include <ddb/db_interface.h>
72 #endif
73 
74 #ifdef IPKDB
75 #include <ipkdb/ipkdb.h>
76 #endif
77 
78 #if defined(MULTIPROCESSOR)
79 struct simplelock kprintf_slock = SIMPLELOCK_INITIALIZER;
80 #endif /* MULTIPROCESSOR */
81 
82 /*
83  * note that stdarg.h and the ansi style va_start macro is used for both
84  * ansi and traditional c complers.
85  * XXX: this requires that stdarg.h define: va_alist and va_dcl
86  */
87 #include <machine/stdarg.h>
88 
89 
90 #ifdef KGDB
91 #include <sys/kgdb.h>
92 #include <machine/cpu.h>
93 #endif
94 #ifdef DDB
95 #include <ddb/db_output.h>	/* db_printf, db_putchar prototypes */
96 #endif
97 
98 
99 /*
100  * defines
101  */
102 
103 /* max size buffer kprintf needs to print quad_t [size in base 8 + \0] */
104 #define KPRINTF_BUFSIZE		(sizeof(quad_t) * NBBY / 3 + 2)
105 
106 
107 /*
108  * local prototypes
109  */
110 
111 static void	 putchar(int, int, struct tty *);
112 
113 
114 /*
115  * globals
116  */
117 
118 extern	struct tty *constty;	/* pointer to console "window" tty */
119 extern	int log_open;	/* subr_log: is /dev/klog open? */
120 const	char *panicstr; /* arg to first call to panic (used as a flag
121 			   to indicate that panic has already been called). */
122 long	panicstart, panicend;	/* position in the msgbuf of the start and
123 				   end of the formatted panicstr. */
124 int	doing_shutdown;	/* set to indicate shutdown in progress */
125 
126 #ifndef	DUMP_ON_PANIC
127 #define	DUMP_ON_PANIC	1
128 #endif
129 int	dumponpanic = DUMP_ON_PANIC;
130 
131 /*
132  * v_putc: routine to putc on virtual console
133  *
134  * the v_putc pointer can be used to redirect the console cnputc elsewhere
135  * [e.g. to a "virtual console"].
136  */
137 
138 void (*v_putc)(int) = cnputc;	/* start with cnputc (normal cons) */
139 void (*v_flush)(void) = cnflush;	/* start with cnflush (normal cons) */
140 
141 const char hexdigits[] = "0123456789abcdef";
142 const char HEXDIGITS[] = "0123456789ABCDEF";
143 
144 
145 /*
146  * functions
147  */
148 
149 /*
150  * tablefull: warn that a system table is full
151  */
152 
153 void
154 tablefull(const char *tab, const char *hint)
155 {
156 	if (hint)
157 		log(LOG_ERR, "%s: table is full - %s\n", tab, hint);
158 	else
159 		log(LOG_ERR, "%s: table is full\n", tab);
160 }
161 
162 /*
163  * twiddle: spin a little propellor on the console.
164  */
165 
166 void
167 twiddle(void)
168 {
169 	static const char twiddle_chars[] = "|/-\\";
170 	static int pos;
171 	int s;
172 
173 	KPRINTF_MUTEX_ENTER(s);
174 
175 	putchar(twiddle_chars[pos++ & 3], TOCONS, NULL);
176 	putchar('\b', TOCONS, NULL);
177 
178 	KPRINTF_MUTEX_EXIT(s);
179 }
180 
181 /*
182  * panic: handle an unresolvable fatal error
183  *
184  * prints "panic: <message>" and reboots.   if called twice (i.e. recursive
185  * call) we avoid trying to sync the disk and just reboot (to avoid
186  * recursive panics).
187  */
188 
189 void
190 panic(const char *fmt, ...)
191 {
192 	int bootopt;
193 	va_list ap;
194 
195 	bootopt = RB_AUTOBOOT;
196 	if (dumponpanic)
197 		bootopt |= RB_DUMP;
198 	if (doing_shutdown)
199 		bootopt |= RB_NOSYNC;
200 	if (!panicstr)
201 		panicstr = fmt;
202 	doing_shutdown = 1;
203 
204 	if (msgbufenabled && msgbufp->msg_magic == MSG_MAGIC)
205 		panicstart = msgbufp->msg_bufx;
206 
207 	va_start(ap, fmt);
208 	printf("panic: ");
209 	vprintf(fmt, ap);
210 	printf("\n");
211 	va_end(ap);
212 
213 	if (msgbufenabled && msgbufp->msg_magic == MSG_MAGIC)
214 		panicend = msgbufp->msg_bufx;
215 
216 #ifdef IPKDB
217 	ipkdb_panic();
218 #endif
219 #ifdef KGDB
220 	kgdb_panic();
221 #endif
222 #ifdef KADB
223 	if (boothowto & RB_KDB)
224 		kdbpanic();
225 #endif
226 #ifdef DDB
227 	if (db_onpanic == 1)
228 		Debugger();
229 	else if (db_onpanic >= 0) {
230 		static int intrace = 0;
231 
232 		if (intrace == 0) {
233 			intrace = 1;
234 			printf("Begin traceback...\n");
235 			db_stack_trace_print(
236 			    (db_expr_t)(intptr_t)__builtin_frame_address(0),
237 			    TRUE, 65535, "", printf);
238 			printf("End traceback...\n");
239 			intrace = 0;
240 		} else
241 			printf("Faulted in mid-traceback; aborting...");
242 		if (db_onpanic == 2)
243 			Debugger();
244 	}
245 #endif
246 	cpu_reboot(bootopt, NULL);
247 }
248 
249 /*
250  * kernel logging functions: log, logpri, addlog
251  */
252 
253 /*
254  * log: write to the log buffer
255  *
256  * => will not sleep [so safe to call from interrupt]
257  * => will log to console if /dev/klog isn't open
258  */
259 
260 void
261 log(int level, const char *fmt, ...)
262 {
263 	int s;
264 	va_list ap;
265 
266 	KPRINTF_MUTEX_ENTER(s);
267 
268 	klogpri(level);		/* log the level first */
269 	va_start(ap, fmt);
270 	kprintf(fmt, TOLOG, NULL, NULL, ap);
271 	va_end(ap);
272 	if (!log_open) {
273 		va_start(ap, fmt);
274 		kprintf(fmt, TOCONS, NULL, NULL, ap);
275 		va_end(ap);
276 	}
277 
278 	KPRINTF_MUTEX_EXIT(s);
279 
280 	logwakeup();		/* wake up anyone waiting for log msgs */
281 }
282 
283 /*
284  * vlog: write to the log buffer [already have va_alist]
285  */
286 
287 void
288 vlog(int level, const char *fmt, va_list ap)
289 {
290 	int s;
291 
292 	KPRINTF_MUTEX_ENTER(s);
293 
294 	klogpri(level);		/* log the level first */
295 	kprintf(fmt, TOLOG, NULL, NULL, ap);
296 	if (!log_open)
297 		kprintf(fmt, TOCONS, NULL, NULL, ap);
298 
299 	KPRINTF_MUTEX_EXIT(s);
300 
301 	logwakeup();		/* wake up anyone waiting for log msgs */
302 }
303 
304 /*
305  * logpri: log the priority level to the klog
306  */
307 
308 void
309 logpri(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 void
322 klogpri(int level)
323 {
324 	char *p;
325 	char snbuf[KPRINTF_BUFSIZE];
326 
327 	putchar('<', TOLOG, NULL);
328 	snprintf(snbuf, sizeof(snbuf), "%d", level);
329 	for (p = snbuf ; *p ; p++)
330 		putchar(*p, TOLOG, NULL);
331 	putchar('>', TOLOG, NULL);
332 }
333 
334 /*
335  * addlog: add info to previous log message
336  */
337 
338 void
339 addlog(const char *fmt, ...)
340 {
341 	int s;
342 	va_list ap;
343 
344 	KPRINTF_MUTEX_ENTER(s);
345 
346 	va_start(ap, fmt);
347 	kprintf(fmt, TOLOG, NULL, NULL, ap);
348 	va_end(ap);
349 	if (!log_open) {
350 		va_start(ap, fmt);
351 		kprintf(fmt, TOCONS, NULL, NULL, ap);
352 		va_end(ap);
353 	}
354 
355 	KPRINTF_MUTEX_EXIT(s);
356 
357 	logwakeup();
358 }
359 
360 
361 /*
362  * putchar: print a single character on console or user terminal.
363  *
364  * => if console, then the last MSGBUFS chars are saved in msgbuf
365  *	for inspection later (e.g. dmesg/syslog)
366  * => we must already be in the mutex!
367  */
368 static void
369 putchar(int c, int flags, struct tty *tp)
370 {
371 	struct kern_msgbuf *mbp;
372 
373 	if (panicstr)
374 		constty = NULL;
375 	if ((flags & TOCONS) && tp == NULL && constty) {
376 		tp = constty;
377 		flags |= TOTTY;
378 	}
379 	if ((flags & TOTTY) && tp &&
380 	    tputchar(c, flags, tp) < 0 &&
381 	    (flags & TOCONS) && tp == constty)
382 		constty = NULL;
383 	if ((flags & TOLOG) &&
384 	    c != '\0' && c != '\r' && c != 0177 && msgbufenabled) {
385 		mbp = msgbufp;
386 		if (mbp->msg_magic != MSG_MAGIC) {
387 			/*
388 			 * Arguably should panic or somehow notify the
389 			 * user...  but how?  Panic may be too drastic,
390 			 * and would obliterate the message being kicked
391 			 * out (maybe a panic itself), and printf
392 			 * would invoke us recursively.  Silently punt
393 			 * for now.  If syslog is running, it should
394 			 * notice.
395 			 */
396 			msgbufenabled = 0;
397 		} else {
398 			mbp->msg_bufc[mbp->msg_bufx++] = c;
399 			if (mbp->msg_bufx < 0 || mbp->msg_bufx >= mbp->msg_bufs)
400 				mbp->msg_bufx = 0;
401 			/* If the buffer is full, keep the most recent data. */
402 			if (mbp->msg_bufr == mbp->msg_bufx) {
403 				 if (++mbp->msg_bufr >= mbp->msg_bufs)
404 					mbp->msg_bufr = 0;
405 			}
406 		}
407 	}
408 	if ((flags & TOCONS) && constty == NULL && c != '\0')
409 		(*v_putc)(c);
410 #ifdef DDB
411 	if (flags & TODDB)
412 		db_putchar(c);
413 #endif
414 }
415 
416 
417 /*
418  * uprintf: print to the controlling tty of the current process
419  *
420  * => we may block if the tty queue is full
421  * => no message is printed if the queue doesn't clear in a reasonable
422  *	time
423  */
424 
425 void
426 uprintf(const char *fmt, ...)
427 {
428 	struct proc *p = curproc;
429 	va_list ap;
430 
431 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
432 		/* No mutex needed; going to process TTY. */
433 		va_start(ap, fmt);
434 		kprintf(fmt, TOTTY, p->p_session->s_ttyp, NULL, ap);
435 		va_end(ap);
436 	}
437 }
438 
439 /*
440  * tprintf functions: used to send messages to a specific process
441  *
442  * usage:
443  *   get a tpr_t handle on a process "p" by using "tprintf_open(p)"
444  *   use the handle when calling "tprintf"
445  *   when done, do a "tprintf_close" to drop the handle
446  */
447 
448 /*
449  * tprintf_open: get a tprintf handle on a process "p"
450  *
451  * => returns NULL if process can't be printed to
452  */
453 
454 tpr_t
455 tprintf_open(struct proc *p)
456 {
457 
458 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
459 		SESSHOLD(p->p_session);
460 		return ((tpr_t) p->p_session);
461 	}
462 	return ((tpr_t) NULL);
463 }
464 
465 /*
466  * tprintf_close: dispose of a tprintf handle obtained with tprintf_open
467  */
468 
469 void
470 tprintf_close(tpr_t sess)
471 {
472 
473 	if (sess)
474 		SESSRELE((struct session *) sess);
475 }
476 
477 /*
478  * tprintf: given tprintf handle to a process [obtained with tprintf_open],
479  * send a message to the controlling tty for that process.
480  *
481  * => also sends message to /dev/klog
482  */
483 void
484 tprintf(tpr_t tpr, const char *fmt, ...)
485 {
486 	struct session *sess = (struct session *)tpr;
487 	struct tty *tp = NULL;
488 	int s, flags = TOLOG;
489 	va_list ap;
490 
491 	if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
492 		flags |= TOTTY;
493 		tp = sess->s_ttyp;
494 	}
495 
496 	KPRINTF_MUTEX_ENTER(s);
497 
498 	klogpri(LOG_INFO);
499 	va_start(ap, fmt);
500 	kprintf(fmt, flags, tp, NULL, ap);
501 	va_end(ap);
502 
503 	KPRINTF_MUTEX_EXIT(s);
504 
505 	logwakeup();
506 }
507 
508 
509 /*
510  * ttyprintf: send a message to a specific tty
511  *
512  * => should be used only by tty driver or anything that knows the
513  *    underlying tty will not be revoked(2)'d away.  [otherwise,
514  *    use tprintf]
515  */
516 void
517 ttyprintf(struct tty *tp, const char *fmt, ...)
518 {
519 	va_list ap;
520 
521 	/* No mutex needed; going to process TTY. */
522 	va_start(ap, fmt);
523 	kprintf(fmt, TOTTY, tp, NULL, ap);
524 	va_end(ap);
525 }
526 
527 #ifdef DDB
528 
529 /*
530  * db_printf: printf for DDB (via db_putchar)
531  */
532 
533 void
534 db_printf(const char *fmt, ...)
535 {
536 	va_list ap;
537 
538 	/* No mutex needed; DDB pauses all processors. */
539 	va_start(ap, fmt);
540 	kprintf(fmt, TODDB, NULL, NULL, ap);
541 	va_end(ap);
542 
543 	if (db_tee_msgbuf) {
544 		va_start(ap, fmt);
545 		kprintf(fmt, TOLOG, NULL, NULL, ap);
546 		va_end(ap);
547 	};
548 }
549 
550 void
551 db_vprintf(const char *fmt, va_list ap)
552 {
553 
554 	/* No mutex needed; DDB pauses all processors. */
555 	kprintf(fmt, TODDB, NULL, NULL, ap);
556 	if (db_tee_msgbuf)
557 		kprintf(fmt, TOLOG, NULL, NULL, ap);
558 }
559 
560 #endif /* DDB */
561 
562 /*
563  * Device autoconfiguration printf routines.  These change their
564  * behavior based on the AB_* flags in boothowto.  If AB_SILENT
565  * is set, messages never go to the console (but they still always
566  * go to the log).  AB_VERBOSE overrides AB_SILENT.
567  */
568 
569 /*
570  * aprint_normal: Send to console unless AB_QUIET.  Always goes
571  * to the log.
572  */
573 void
574 aprint_normal(const char *fmt, ...)
575 {
576 	va_list ap;
577 	int s, flags = TOLOG;
578 
579 	if ((boothowto & (AB_SILENT|AB_QUIET)) == 0 ||
580 	    (boothowto & AB_VERBOSE) != 0)
581 		flags |= TOCONS;
582 
583 	KPRINTF_MUTEX_ENTER(s);
584 
585 	va_start(ap, fmt);
586 	kprintf(fmt, flags, NULL, NULL, ap);
587 	va_end(ap);
588 
589 	KPRINTF_MUTEX_EXIT(s);
590 
591 	if (!panicstr)
592 		logwakeup();
593 }
594 
595 /*
596  * aprint_error: Send to console unless AB_QUIET.  Always goes
597  * to the log.  Also counts the number of times called so other
598  * parts of the kernel can report the number of errors during a
599  * given phase of system startup.
600  */
601 static int aprint_error_count;
602 
603 int
604 aprint_get_error_count(void)
605 {
606 	int count, s;
607 
608 	KPRINTF_MUTEX_ENTER(s);
609 
610 	count = aprint_error_count;
611 	aprint_error_count = 0;
612 
613 	KPRINTF_MUTEX_EXIT(s);
614 
615 	return (count);
616 }
617 
618 void
619 aprint_error(const char *fmt, ...)
620 {
621 	va_list ap;
622 	int s, flags = TOLOG;
623 
624 	if ((boothowto & (AB_SILENT|AB_QUIET)) == 0 ||
625 	    (boothowto & AB_VERBOSE) != 0)
626 		flags |= TOCONS;
627 
628 	KPRINTF_MUTEX_ENTER(s);
629 
630 	aprint_error_count++;
631 
632 	va_start(ap, fmt);
633 	kprintf(fmt, flags, NULL, NULL, ap);
634 	va_end(ap);
635 
636 	KPRINTF_MUTEX_EXIT(s);
637 
638 	if (!panicstr)
639 		logwakeup();
640 }
641 
642 /*
643  * aprint_naive: Send to console only if AB_QUIET.  Never goes
644  * to the log.
645  */
646 void
647 aprint_naive(const char *fmt, ...)
648 {
649 	va_list ap;
650 	int s;
651 
652 	if ((boothowto & (AB_QUIET|AB_SILENT|AB_VERBOSE)) == AB_QUIET) {
653 		KPRINTF_MUTEX_ENTER(s);
654 
655 		va_start(ap, fmt);
656 		kprintf(fmt, TOCONS, NULL, NULL, ap);
657 		va_end(ap);
658 
659 		KPRINTF_MUTEX_EXIT(s);
660 	}
661 }
662 
663 /*
664  * aprint_verbose: Send to console only if AB_VERBOSE.  Always
665  * goes to the log.
666  */
667 void
668 aprint_verbose(const char *fmt, ...)
669 {
670 	va_list ap;
671 	int s, flags = TOLOG;
672 
673 	if (boothowto & AB_VERBOSE)
674 		flags |= TOCONS;
675 
676 	KPRINTF_MUTEX_ENTER(s);
677 
678 	va_start(ap, fmt);
679 	kprintf(fmt, flags, NULL, NULL, ap);
680 	va_end(ap);
681 
682 	KPRINTF_MUTEX_EXIT(s);
683 
684 	if (!panicstr)
685 		logwakeup();
686 }
687 
688 /*
689  * aprint_debug: Send to console and log only if AB_DEBUG.
690  */
691 void
692 aprint_debug(const char *fmt, ...)
693 {
694 	va_list ap;
695 	int s;
696 
697 	if (boothowto & AB_DEBUG) {
698 		KPRINTF_MUTEX_ENTER(s);
699 
700 		va_start(ap, fmt);
701 		kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
702 		va_end(ap);
703 
704 		KPRINTF_MUTEX_EXIT(s);
705 	}
706 }
707 
708 /*
709  * printf_nolog: Like printf(), but does not send message to the log.
710  */
711 
712 void
713 printf_nolog(const char *fmt, ...)
714 {
715 	va_list ap;
716 	int s;
717 
718 	KPRINTF_MUTEX_ENTER(s);
719 
720 	va_start(ap, fmt);
721 	kprintf(fmt, TOCONS, NULL, NULL, ap);
722 	va_end(ap);
723 
724 	KPRINTF_MUTEX_EXIT(s);
725 }
726 
727 /*
728  * normal kernel printf functions: printf, vprintf, snprintf, vsnprintf
729  */
730 
731 /*
732  * printf: print a message to the console and the log
733  */
734 void
735 printf(const char *fmt, ...)
736 {
737 	va_list ap;
738 	int s;
739 
740 	KPRINTF_MUTEX_ENTER(s);
741 
742 	va_start(ap, fmt);
743 	kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
744 	va_end(ap);
745 
746 	KPRINTF_MUTEX_EXIT(s);
747 
748 	if (!panicstr)
749 		logwakeup();
750 }
751 
752 /*
753  * vprintf: print a message to the console and the log [already have
754  *	va_alist]
755  */
756 
757 void
758 vprintf(const char *fmt, va_list ap)
759 {
760 	int s;
761 
762 	KPRINTF_MUTEX_ENTER(s);
763 
764 	kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
765 
766 	KPRINTF_MUTEX_EXIT(s);
767 
768 	if (!panicstr)
769 		logwakeup();
770 }
771 
772 /*
773  * sprintf: print a message to a buffer
774  */
775 int
776 sprintf(char *bf, const char *fmt, ...)
777 {
778 	int retval;
779 	va_list ap;
780 
781 	va_start(ap, fmt);
782 	retval = kprintf(fmt, TOBUFONLY, NULL, bf, ap);
783 	va_end(ap);
784 	*(bf + retval) = 0;	/* null terminate */
785 	return(retval);
786 }
787 
788 /*
789  * vsprintf: print a message to a buffer [already have va_alist]
790  */
791 
792 int
793 vsprintf(char *bf, const char *fmt, va_list ap)
794 {
795 	int retval;
796 
797 	retval = kprintf(fmt, TOBUFONLY, NULL, bf, ap);
798 	*(bf + retval) = 0;	/* null terminate */
799 	return (retval);
800 }
801 
802 /*
803  * snprintf: print a message to a buffer
804  */
805 int
806 snprintf(char *bf, size_t size, const char *fmt, ...)
807 {
808 	int retval;
809 	va_list ap;
810 	char *p;
811 
812 	if (size < 1)
813 		return (-1);
814 	p = bf + size - 1;
815 	va_start(ap, fmt);
816 	retval = kprintf(fmt, TOBUFONLY, &p, bf, ap);
817 	va_end(ap);
818 	*(p) = 0;	/* null terminate */
819 	return(retval);
820 }
821 
822 /*
823  * vsnprintf: print a message to a buffer [already have va_alist]
824  */
825 int
826 vsnprintf(char *bf, size_t size, const char *fmt, va_list ap)
827 {
828 	int retval;
829 	char *p;
830 
831 	if (size < 1)
832 		return (-1);
833 	p = bf + size - 1;
834 	retval = kprintf(fmt, TOBUFONLY, &p, bf, ap);
835 	*(p) = 0;	/* null terminate */
836 	return(retval);
837 }
838 
839 /*
840  * bitmask_snprintf: print an interpreted bitmask to a buffer
841  *
842  * => returns pointer to the buffer
843  */
844 char *
845 bitmask_snprintf(u_quad_t val, const char *p, char *bf, size_t buflen)
846 {
847 	char *bp, *q;
848 	size_t left;
849 	const char *sbase;
850 	char snbuf[KPRINTF_BUFSIZE];
851 	int base, bit, ch, len, sep;
852 	u_quad_t field;
853 
854 	bp = bf;
855 	memset(bf, 0, buflen);
856 
857 	/*
858 	 * Always leave room for the trailing NULL.
859 	 */
860 	left = buflen - 1;
861 
862 	/*
863 	 * Print the value into the buffer.  Abort if there's not
864 	 * enough room.
865 	 */
866 	if (buflen < KPRINTF_BUFSIZE)
867 		return (bf);
868 
869 	ch = *p++;
870 	base = ch != '\177' ? ch : *p++;
871 	sbase = base == 8 ? "%qo" : base == 10 ? "%qd" : base == 16 ? "%qx" : 0;
872 	if (sbase == 0)
873 		return (bf);	/* punt if not oct, dec, or hex */
874 
875 	snprintf(snbuf, sizeof(snbuf), sbase, val);
876 	for (q = snbuf ; *q ; q++) {
877 		*bp++ = *q;
878 		left--;
879 	}
880 
881 	/*
882 	 * If the value we printed was 0 and we're using the old-style format,
883 	 * or if we don't have room for "<x>", we're done.
884 	 */
885 	if (((val == 0) && (ch != '\177')) || left < 3)
886 		return (bf);
887 
888 #define PUTBYTE(b, c, l) do {	\
889 	*(b)++ = (c);		\
890 	if (--(l) == 0)		\
891 		goto out;	\
892 } while (/*CONSTCOND*/ 0)
893 #define PUTSTR(b, p, l) do {		\
894 	int c;				\
895 	while ((c = *(p)++) != 0) {	\
896 		*(b)++ = c;		\
897 		if (--(l) == 0)		\
898 			goto out;	\
899 	}				\
900 } while (/*CONSTCOND*/ 0)
901 
902 	/*
903 	 * Chris Torek's new bitmask format is identified by a leading \177
904 	 */
905 	sep = '<';
906 	if (ch != '\177') {
907 		/* old (standard) format. */
908 		for (;(bit = *p++) != 0;) {
909 			if (val & (1 << (bit - 1))) {
910 				PUTBYTE(bp, sep, left);
911 				for (; (ch = *p) > ' '; ++p) {
912 					PUTBYTE(bp, ch, left);
913 				}
914 				sep = ',';
915 			} else
916 				for (; *p > ' '; ++p)
917 					continue;
918 		}
919 	} else {
920 		/* new quad-capable format; also does fields. */
921 		field = val;
922 		while ((ch = *p++) != '\0') {
923 			bit = *p++;	/* now 0-origin */
924 			switch (ch) {
925 			case 'b':
926 				if (((u_int)(val >> bit) & 1) == 0)
927 					goto skip;
928 				PUTBYTE(bp, sep, left);
929 				PUTSTR(bp, p, left);
930 				sep = ',';
931 				break;
932 			case 'f':
933 			case 'F':
934 				len = *p++;	/* field length */
935 				field = (val >> bit) & ((1ULL << len) - 1);
936 				if (ch == 'F')	/* just extract */
937 					break;
938 				PUTBYTE(bp, sep, left);
939 				sep = ',';
940 				PUTSTR(bp, p, left);
941 				PUTBYTE(bp, '=', left);
942 				sprintf(snbuf, sbase, field);
943 				q = snbuf; PUTSTR(bp, q, left);
944 				break;
945 			case '=':
946 			case ':':
947 				/*
948 				 * Here "bit" is actually a value instead,
949 				 * to be compared against the last field.
950 				 * This only works for values in [0..255],
951 				 * of course.
952 				 */
953 				if ((int)field != bit)
954 					goto skip;
955 				if (ch == '=')
956 					PUTBYTE(bp, '=', left);
957 				PUTSTR(bp, p, left);
958 				break;
959 			default:
960 			skip:
961 				while (*p++ != '\0')
962 					continue;
963 				break;
964 			}
965 		}
966 	}
967 	if (sep != '<')
968 		PUTBYTE(bp, '>', left);
969 
970 out:
971 	return (bf);
972 
973 #undef PUTBYTE
974 #undef PUTSTR
975 }
976 
977 /*
978  * kprintf: scaled down version of printf(3).
979  *
980  * this version based on vfprintf() from libc which was derived from
981  * software contributed to Berkeley by Chris Torek.
982  *
983  * NOTE: The kprintf mutex must be held if we're going TOBUF or TOCONS!
984  */
985 
986 /*
987  * macros for converting digits to letters and vice versa
988  */
989 #define	to_digit(c)	((c) - '0')
990 #define is_digit(c)	((unsigned)to_digit(c) <= 9)
991 #define	to_char(n)	((n) + '0')
992 
993 /*
994  * flags used during conversion.
995  */
996 #define	ALT		0x001		/* alternate form */
997 #define	HEXPREFIX	0x002		/* add 0x or 0X prefix */
998 #define	LADJUST		0x004		/* left adjustment */
999 #define	LONGDBL		0x008		/* long double; unimplemented */
1000 #define	LONGINT		0x010		/* long integer */
1001 #define	QUADINT		0x020		/* quad integer */
1002 #define	SHORTINT	0x040		/* short integer */
1003 #define	MAXINT		0x080		/* intmax_t */
1004 #define	PTRINT		0x100		/* intptr_t */
1005 #define	SIZEINT		0x200		/* size_t */
1006 #define	ZEROPAD		0x400		/* zero (as opposed to blank) pad */
1007 #define FPT		0x800		/* Floating point number */
1008 
1009 	/*
1010 	 * To extend shorts properly, we need both signed and unsigned
1011 	 * argument extraction methods.
1012 	 */
1013 #define	SARG() \
1014 	(flags&MAXINT ? va_arg(ap, intmax_t) : \
1015 	    flags&PTRINT ? va_arg(ap, intptr_t) : \
1016 	    flags&SIZEINT ? va_arg(ap, ssize_t) : /* XXX */ \
1017 	    flags&QUADINT ? va_arg(ap, quad_t) : \
1018 	    flags&LONGINT ? va_arg(ap, long) : \
1019 	    flags&SHORTINT ? (long)(short)va_arg(ap, int) : \
1020 	    (long)va_arg(ap, int))
1021 #define	UARG() \
1022 	(flags&MAXINT ? va_arg(ap, uintmax_t) : \
1023 	    flags&PTRINT ? va_arg(ap, uintptr_t) : \
1024 	    flags&SIZEINT ? va_arg(ap, size_t) : \
1025 	    flags&QUADINT ? va_arg(ap, u_quad_t) : \
1026 	    flags&LONGINT ? va_arg(ap, u_long) : \
1027 	    flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \
1028 	    (u_long)va_arg(ap, u_int))
1029 
1030 #define KPRINTF_PUTCHAR(C) {						\
1031 	if (oflags == TOBUFONLY) {					\
1032 		if ((vp != NULL) && (sbuf == tailp)) {			\
1033 			ret += 1;		/* indicate error */	\
1034 			goto overflow;					\
1035 		}							\
1036 		*sbuf++ = (C);						\
1037 	} else {							\
1038 		putchar((C), oflags, (struct tty *)vp);			\
1039 	}								\
1040 }
1041 
1042 /*
1043  * Guts of kernel printf.  Note, we already expect to be in a mutex!
1044  */
1045 int
1046 kprintf(const char *fmt0, int oflags, void *vp, char *sbuf, va_list ap)
1047 {
1048 	const char *fmt;	/* format string */
1049 	int ch;			/* character from fmt */
1050 	int n;			/* handy integer (short term usage) */
1051 	char *cp;		/* handy char pointer (short term usage) */
1052 	int flags;		/* flags as above */
1053 	int ret;		/* return value accumulator */
1054 	int width;		/* width from format (%8d), or 0 */
1055 	int prec;		/* precision from format (%.3d), or -1 */
1056 	char sign;		/* sign prefix (' ', '+', '-', or \0) */
1057 
1058 	u_quad_t _uquad;	/* integer arguments %[diouxX] */
1059 	enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
1060 	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
1061 	int realsz;		/* field size expanded by dprec */
1062 	int size;		/* size of converted field or string */
1063 	const char *xdigs;	/* digits for [xX] conversion */
1064 	char bf[KPRINTF_BUFSIZE]; /* space for %c, %[diouxX] */
1065 	char *tailp;		/* tail pointer for snprintf */
1066 
1067 	tailp = NULL;	/* XXX: shutup gcc */
1068 	if (oflags == TOBUFONLY && (vp != NULL))
1069 		tailp = *(char **)vp;
1070 
1071 	cp = NULL;	/* XXX: shutup gcc */
1072 	size = 0;	/* XXX: shutup gcc */
1073 
1074 	fmt = fmt0;
1075 	ret = 0;
1076 
1077 	xdigs = NULL;		/* XXX: shut up gcc warning */
1078 
1079 	/*
1080 	 * Scan the format for conversions (`%' character).
1081 	 */
1082 	for (;;) {
1083 		while (*fmt != '%' && *fmt) {
1084 			ret++;
1085 			KPRINTF_PUTCHAR(*fmt++);
1086 		}
1087 		if (*fmt == 0)
1088 			goto done;
1089 
1090 		fmt++;		/* skip over '%' */
1091 
1092 		flags = 0;
1093 		dprec = 0;
1094 		width = 0;
1095 		prec = -1;
1096 		sign = '\0';
1097 
1098 rflag:		ch = *fmt++;
1099 reswitch:	switch (ch) {
1100 		case ' ':
1101 			/*
1102 			 * ``If the space and + flags both appear, the space
1103 			 * flag will be ignored.''
1104 			 *	-- ANSI X3J11
1105 			 */
1106 			if (!sign)
1107 				sign = ' ';
1108 			goto rflag;
1109 		case '#':
1110 			flags |= ALT;
1111 			goto rflag;
1112 		case '*':
1113 			/*
1114 			 * ``A negative field width argument is taken as a
1115 			 * - flag followed by a positive field width.''
1116 			 *	-- ANSI X3J11
1117 			 * They don't exclude field widths read from args.
1118 			 */
1119 			if ((width = va_arg(ap, int)) >= 0)
1120 				goto rflag;
1121 			width = -width;
1122 			/* FALLTHROUGH */
1123 		case '-':
1124 			flags |= LADJUST;
1125 			goto rflag;
1126 		case '+':
1127 			sign = '+';
1128 			goto rflag;
1129 		case '.':
1130 			if ((ch = *fmt++) == '*') {
1131 				n = va_arg(ap, int);
1132 				prec = n < 0 ? -1 : n;
1133 				goto rflag;
1134 			}
1135 			n = 0;
1136 			while (is_digit(ch)) {
1137 				n = 10 * n + to_digit(ch);
1138 				ch = *fmt++;
1139 			}
1140 			prec = n < 0 ? -1 : n;
1141 			goto reswitch;
1142 		case '0':
1143 			/*
1144 			 * ``Note that 0 is taken as a flag, not as the
1145 			 * beginning of a field width.''
1146 			 *	-- ANSI X3J11
1147 			 */
1148 			flags |= ZEROPAD;
1149 			goto rflag;
1150 		case '1': case '2': case '3': case '4':
1151 		case '5': case '6': case '7': case '8': case '9':
1152 			n = 0;
1153 			do {
1154 				n = 10 * n + to_digit(ch);
1155 				ch = *fmt++;
1156 			} while (is_digit(ch));
1157 			width = n;
1158 			goto reswitch;
1159 		case 'h':
1160 			flags |= SHORTINT;
1161 			goto rflag;
1162 		case 'j':
1163 			flags |= MAXINT;
1164 			goto rflag;
1165 		case 'l':
1166 			if (*fmt == 'l') {
1167 				fmt++;
1168 				flags |= QUADINT;
1169 			} else {
1170 				flags |= LONGINT;
1171 			}
1172 			goto rflag;
1173 		case 'q':
1174 			flags |= QUADINT;
1175 			goto rflag;
1176 		case 't':
1177 			flags |= PTRINT;
1178 			goto rflag;
1179 		case 'z':
1180 			flags |= SIZEINT;
1181 			goto rflag;
1182 		case 'c':
1183 			*(cp = bf) = va_arg(ap, int);
1184 			size = 1;
1185 			sign = '\0';
1186 			break;
1187 		case 'D':
1188 			flags |= LONGINT;
1189 			/*FALLTHROUGH*/
1190 		case 'd':
1191 		case 'i':
1192 			_uquad = SARG();
1193 			if ((quad_t)_uquad < 0) {
1194 				_uquad = -_uquad;
1195 				sign = '-';
1196 			}
1197 			base = DEC;
1198 			goto number;
1199 		case 'n':
1200 			if (flags & MAXINT)
1201 				*va_arg(ap, intmax_t *) = ret;
1202 			else if (flags & PTRINT)
1203 				*va_arg(ap, intptr_t *) = ret;
1204 			else if (flags & SIZEINT)
1205 				*va_arg(ap, ssize_t *) = ret;
1206 			else if (flags & QUADINT)
1207 				*va_arg(ap, quad_t *) = ret;
1208 			else if (flags & LONGINT)
1209 				*va_arg(ap, long *) = ret;
1210 			else if (flags & SHORTINT)
1211 				*va_arg(ap, short *) = ret;
1212 			else
1213 				*va_arg(ap, int *) = ret;
1214 			continue;	/* no output */
1215 		case 'O':
1216 			flags |= LONGINT;
1217 			/*FALLTHROUGH*/
1218 		case 'o':
1219 			_uquad = UARG();
1220 			base = OCT;
1221 			goto nosign;
1222 		case 'p':
1223 			/*
1224 			 * ``The argument shall be a pointer to void.  The
1225 			 * value of the pointer is converted to a sequence
1226 			 * of printable characters, in an implementation-
1227 			 * defined manner.''
1228 			 *	-- ANSI X3J11
1229 			 */
1230 			/* NOSTRICT */
1231 			_uquad = (u_long)va_arg(ap, void *);
1232 			base = HEX;
1233 			xdigs = hexdigits;
1234 			flags |= HEXPREFIX;
1235 			ch = 'x';
1236 			goto nosign;
1237 		case 's':
1238 			if ((cp = va_arg(ap, char *)) == NULL)
1239 				/*XXXUNCONST*/
1240 				cp = __UNCONST("(null)");
1241 			if (prec >= 0) {
1242 				/*
1243 				 * can't use strlen; can only look for the
1244 				 * NUL in the first `prec' characters, and
1245 				 * strlen() will go further.
1246 				 */
1247 				char *p = memchr(cp, 0, prec);
1248 
1249 				if (p != NULL) {
1250 					size = p - cp;
1251 					if (size > prec)
1252 						size = prec;
1253 				} else
1254 					size = prec;
1255 			} else
1256 				size = strlen(cp);
1257 			sign = '\0';
1258 			break;
1259 		case 'U':
1260 			flags |= LONGINT;
1261 			/*FALLTHROUGH*/
1262 		case 'u':
1263 			_uquad = UARG();
1264 			base = DEC;
1265 			goto nosign;
1266 		case 'X':
1267 			xdigs = hexdigits;
1268 			goto hex;
1269 		case 'x':
1270 			xdigs = hexdigits;
1271 hex:			_uquad = UARG();
1272 			base = HEX;
1273 			/* leading 0x/X only if non-zero */
1274 			if (flags & ALT && _uquad != 0)
1275 				flags |= HEXPREFIX;
1276 
1277 			/* unsigned conversions */
1278 nosign:			sign = '\0';
1279 			/*
1280 			 * ``... diouXx conversions ... if a precision is
1281 			 * specified, the 0 flag will be ignored.''
1282 			 *	-- ANSI X3J11
1283 			 */
1284 number:			if ((dprec = prec) >= 0)
1285 				flags &= ~ZEROPAD;
1286 
1287 			/*
1288 			 * ``The result of converting a zero value with an
1289 			 * explicit precision of zero is no characters.''
1290 			 *	-- ANSI X3J11
1291 			 */
1292 			cp = bf + KPRINTF_BUFSIZE;
1293 			if (_uquad != 0 || prec != 0) {
1294 				/*
1295 				 * Unsigned mod is hard, and unsigned mod
1296 				 * by a constant is easier than that by
1297 				 * a variable; hence this switch.
1298 				 */
1299 				switch (base) {
1300 				case OCT:
1301 					do {
1302 						*--cp = to_char(_uquad & 7);
1303 						_uquad >>= 3;
1304 					} while (_uquad);
1305 					/* handle octal leading 0 */
1306 					if (flags & ALT && *cp != '0')
1307 						*--cp = '0';
1308 					break;
1309 
1310 				case DEC:
1311 					/* many numbers are 1 digit */
1312 					while (_uquad >= 10) {
1313 						*--cp = to_char(_uquad % 10);
1314 						_uquad /= 10;
1315 					}
1316 					*--cp = to_char(_uquad);
1317 					break;
1318 
1319 				case HEX:
1320 					do {
1321 						*--cp = xdigs[_uquad & 15];
1322 						_uquad >>= 4;
1323 					} while (_uquad);
1324 					break;
1325 
1326 				default:
1327 					/*XXXUNCONST*/
1328 					cp = __UNCONST("bug in kprintf: bad base");
1329 					size = strlen(cp);
1330 					goto skipsize;
1331 				}
1332 			}
1333 			size = bf + KPRINTF_BUFSIZE - cp;
1334 		skipsize:
1335 			break;
1336 		default:	/* "%?" prints ?, unless ? is NUL */
1337 			if (ch == '\0')
1338 				goto done;
1339 			/* pretend it was %c with argument ch */
1340 			cp = bf;
1341 			*cp = ch;
1342 			size = 1;
1343 			sign = '\0';
1344 			break;
1345 		}
1346 
1347 		/*
1348 		 * All reasonable formats wind up here.  At this point, `cp'
1349 		 * points to a string which (if not flags&LADJUST) should be
1350 		 * padded out to `width' places.  If flags&ZEROPAD, it should
1351 		 * first be prefixed by any sign or other prefix; otherwise,
1352 		 * it should be blank padded before the prefix is emitted.
1353 		 * After any left-hand padding and prefixing, emit zeroes
1354 		 * required by a decimal [diouxX] precision, then print the
1355 		 * string proper, then emit zeroes required by any leftover
1356 		 * floating precision; finally, if LADJUST, pad with blanks.
1357 		 *
1358 		 * Compute actual size, so we know how much to pad.
1359 		 * size excludes decimal prec; realsz includes it.
1360 		 */
1361 		realsz = dprec > size ? dprec : size;
1362 		if (sign)
1363 			realsz++;
1364 		else if (flags & HEXPREFIX)
1365 			realsz+= 2;
1366 
1367 		/* adjust ret */
1368 		ret += width > realsz ? width : realsz;
1369 
1370 		/* right-adjusting blank padding */
1371 		if ((flags & (LADJUST|ZEROPAD)) == 0) {
1372 			n = width - realsz;
1373 			while (n-- > 0)
1374 				KPRINTF_PUTCHAR(' ');
1375 		}
1376 
1377 		/* prefix */
1378 		if (sign) {
1379 			KPRINTF_PUTCHAR(sign);
1380 		} else if (flags & HEXPREFIX) {
1381 			KPRINTF_PUTCHAR('0');
1382 			KPRINTF_PUTCHAR(ch);
1383 		}
1384 
1385 		/* right-adjusting zero padding */
1386 		if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) {
1387 			n = width - realsz;
1388 			while (n-- > 0)
1389 				KPRINTF_PUTCHAR('0');
1390 		}
1391 
1392 		/* leading zeroes from decimal precision */
1393 		n = dprec - size;
1394 		while (n-- > 0)
1395 			KPRINTF_PUTCHAR('0');
1396 
1397 		/* the string or number proper */
1398 		while (size--)
1399 			KPRINTF_PUTCHAR(*cp++);
1400 		/* left-adjusting padding (always blank) */
1401 		if (flags & LADJUST) {
1402 			n = width - realsz;
1403 			while (n-- > 0)
1404 				KPRINTF_PUTCHAR(' ');
1405 		}
1406 	}
1407 
1408 done:
1409 	if ((oflags == TOBUFONLY) && (vp != NULL))
1410 		*(char **)vp = sbuf;
1411 	(*v_flush)();
1412 overflow:
1413 	return (ret);
1414 	/* NOTREACHED */
1415 }
1416