xref: /netbsd-src/sys/kern/subr_prf.c (revision 21e37cc72a480a47828990a439cde7ac9ffaf0c6)
1 /*	$NetBSD: subr_prf.c,v 1.94 2004/03/23 13:22:04 junyoung 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 1.94 2004/03/23 13:22:04 junyoung 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 
142 /*
143  * functions
144  */
145 
146 /*
147  * tablefull: warn that a system table is full
148  */
149 
150 void
151 tablefull(tab, hint)
152 	const char *tab, *hint;
153 {
154 	if (hint)
155 		log(LOG_ERR, "%s: table is full - %s\n", tab, hint);
156 	else
157 		log(LOG_ERR, "%s: table is full\n", tab);
158 }
159 
160 /*
161  * twiddle: spin a little propellor on the console.
162  */
163 
164 void
165 twiddle(void)
166 {
167 	static const char twiddle_chars[] = "|/-\\";
168 	static int pos;
169 	int s;
170 
171 	KPRINTF_MUTEX_ENTER(s);
172 
173 	putchar(twiddle_chars[pos++ & 3], TOCONS, NULL);
174 	putchar('\b', TOCONS, NULL);
175 
176 	KPRINTF_MUTEX_EXIT(s);
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 panic(const char *fmt, ...)
189 {
190 	int bootopt;
191 	va_list ap;
192 
193 	bootopt = RB_AUTOBOOT;
194 	if (dumponpanic)
195 		bootopt |= RB_DUMP;
196 	if (doing_shutdown)
197 		bootopt |= RB_NOSYNC;
198 	if (!panicstr)
199 		panicstr = fmt;
200 	doing_shutdown = 1;
201 
202 	if (msgbufenabled && msgbufp->msg_magic == MSG_MAGIC)
203 		panicstart = msgbufp->msg_bufx;
204 
205 	va_start(ap, fmt);
206 	printf("panic: ");
207 	vprintf(fmt, ap);
208 	printf("\n");
209 	va_end(ap);
210 
211 	if (msgbufenabled && msgbufp->msg_magic == MSG_MAGIC)
212 		panicend = msgbufp->msg_bufx;
213 
214 #ifdef IPKDB
215 	ipkdb_panic();
216 #endif
217 #ifdef KGDB
218 	kgdb_panic();
219 #endif
220 #ifdef KADB
221 	if (boothowto & RB_KDB)
222 		kdbpanic();
223 #endif
224 #ifdef DDB
225 	if (db_onpanic)
226 		Debugger();
227 	else {
228 		static int intrace = 0;
229 
230 		if (intrace==0) {
231 			intrace=1;
232 			printf("Begin traceback...\n");
233 			db_stack_trace_print(
234 			    (db_expr_t)(intptr_t)__builtin_frame_address(0),
235 			    TRUE, 65535, "", printf);
236 			printf("End traceback...\n");
237 			intrace=0;
238 		} else
239 			printf("Faulted in mid-traceback; aborting...");
240 	}
241 #endif
242 	cpu_reboot(bootopt, NULL);
243 }
244 
245 /*
246  * kernel logging functions: log, logpri, addlog
247  */
248 
249 /*
250  * log: write to the log buffer
251  *
252  * => will not sleep [so safe to call from interrupt]
253  * => will log to console if /dev/klog isn't open
254  */
255 
256 void
257 log(int level, const char *fmt, ...)
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 void
322 klogpri(level)
323 	int level;
324 {
325 	char *p;
326 	char snbuf[KPRINTF_BUFSIZE];
327 
328 	putchar('<', TOLOG, NULL);
329 	snprintf(snbuf, sizeof(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 addlog(const char *fmt, ...)
341 {
342 	int s;
343 	va_list ap;
344 
345 	KPRINTF_MUTEX_ENTER(s);
346 
347 	va_start(ap, fmt);
348 	kprintf(fmt, TOLOG, NULL, NULL, ap);
349 	va_end(ap);
350 	if (!log_open) {
351 		va_start(ap, fmt);
352 		kprintf(fmt, TOCONS, NULL, NULL, ap);
353 		va_end(ap);
354 	}
355 
356 	KPRINTF_MUTEX_EXIT(s);
357 
358 	logwakeup();
359 }
360 
361 
362 /*
363  * putchar: print a single character on console or user terminal.
364  *
365  * => if console, then the last MSGBUFS chars are saved in msgbuf
366  *	for inspection later (e.g. dmesg/syslog)
367  * => we must already be in the mutex!
368  */
369 static void
370 putchar(c, flags, tp)
371 	int c;
372 	int flags;
373 	struct tty *tp;
374 {
375 	struct kern_msgbuf *mbp;
376 
377 	if (panicstr)
378 		constty = NULL;
379 	if ((flags & TOCONS) && tp == NULL && constty) {
380 		tp = constty;
381 		flags |= TOTTY;
382 	}
383 	if ((flags & TOTTY) && tp &&
384 	    tputchar(c, flags, tp) < 0 &&
385 	    (flags & TOCONS) && tp == constty)
386 		constty = NULL;
387 	if ((flags & TOLOG) &&
388 	    c != '\0' && c != '\r' && c != 0177 && msgbufenabled) {
389 		mbp = msgbufp;
390 		if (mbp->msg_magic != MSG_MAGIC) {
391 			/*
392 			 * Arguably should panic or somehow notify the
393 			 * user...  but how?  Panic may be too drastic,
394 			 * and would obliterate the message being kicked
395 			 * out (maybe a panic itself), and printf
396 			 * would invoke us recursively.  Silently punt
397 			 * for now.  If syslog is running, it should
398 			 * notice.
399 			 */
400 			msgbufenabled = 0;
401 		} else {
402 			mbp->msg_bufc[mbp->msg_bufx++] = c;
403 			if (mbp->msg_bufx < 0 || mbp->msg_bufx >= mbp->msg_bufs)
404 				mbp->msg_bufx = 0;
405 			/* If the buffer is full, keep the most recent data. */
406 			if (mbp->msg_bufr == mbp->msg_bufx) {
407 				 if (++mbp->msg_bufr >= mbp->msg_bufs)
408 					mbp->msg_bufr = 0;
409 			}
410 		}
411 	}
412 	if ((flags & TOCONS) && constty == NULL && c != '\0')
413 		(*v_putc)(c);
414 #ifdef DDB
415 	if (flags & TODDB)
416 		db_putchar(c);
417 #endif
418 }
419 
420 
421 /*
422  * uprintf: print to the controlling tty of the current process
423  *
424  * => we may block if the tty queue is full
425  * => no message is printed if the queue doesn't clear in a reasonable
426  *	time
427  */
428 
429 void
430 uprintf(const char *fmt, ...)
431 {
432 	struct proc *p = curproc;
433 	va_list ap;
434 
435 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
436 		/* No mutex needed; going to process TTY. */
437 		va_start(ap, fmt);
438 		kprintf(fmt, TOTTY, p->p_session->s_ttyp, NULL, ap);
439 		va_end(ap);
440 	}
441 }
442 
443 /*
444  * tprintf functions: used to send messages to a specific process
445  *
446  * usage:
447  *   get a tpr_t handle on a process "p" by using "tprintf_open(p)"
448  *   use the handle when calling "tprintf"
449  *   when done, do a "tprintf_close" to drop the handle
450  */
451 
452 /*
453  * tprintf_open: get a tprintf handle on a process "p"
454  *
455  * => returns NULL if process can't be printed to
456  */
457 
458 tpr_t
459 tprintf_open(p)
460 	struct proc *p;
461 {
462 
463 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
464 		SESSHOLD(p->p_session);
465 		return ((tpr_t) p->p_session);
466 	}
467 	return ((tpr_t) NULL);
468 }
469 
470 /*
471  * tprintf_close: dispose of a tprintf handle obtained with tprintf_open
472  */
473 
474 void
475 tprintf_close(sess)
476 	tpr_t sess;
477 {
478 
479 	if (sess)
480 		SESSRELE((struct session *) sess);
481 }
482 
483 /*
484  * tprintf: given tprintf handle to a process [obtained with tprintf_open],
485  * send a message to the controlling tty for that process.
486  *
487  * => also sends message to /dev/klog
488  */
489 void
490 tprintf(tpr_t tpr, const char *fmt, ...)
491 {
492 	struct session *sess = (struct session *)tpr;
493 	struct tty *tp = NULL;
494 	int s, flags = TOLOG;
495 	va_list ap;
496 
497 	if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
498 		flags |= TOTTY;
499 		tp = sess->s_ttyp;
500 	}
501 
502 	KPRINTF_MUTEX_ENTER(s);
503 
504 	klogpri(LOG_INFO);
505 	va_start(ap, fmt);
506 	kprintf(fmt, flags, tp, NULL, ap);
507 	va_end(ap);
508 
509 	KPRINTF_MUTEX_EXIT(s);
510 
511 	logwakeup();
512 }
513 
514 
515 /*
516  * ttyprintf: send a message to a specific tty
517  *
518  * => should be used only by tty driver or anything that knows the
519  *    underlying tty will not be revoked(2)'d away.  [otherwise,
520  *    use tprintf]
521  */
522 void
523 ttyprintf(struct tty *tp, const char *fmt, ...)
524 {
525 	va_list ap;
526 
527 	/* No mutex needed; going to process TTY. */
528 	va_start(ap, fmt);
529 	kprintf(fmt, TOTTY, tp, NULL, ap);
530 	va_end(ap);
531 }
532 
533 #ifdef DDB
534 
535 /*
536  * db_printf: printf for DDB (via db_putchar)
537  */
538 
539 void
540 db_printf(const char *fmt, ...)
541 {
542 	va_list ap;
543 
544 	/* No mutex needed; DDB pauses all processors. */
545 	va_start(ap, fmt);
546 	kprintf(fmt, TODDB, NULL, NULL, ap);
547 	va_end(ap);
548 }
549 
550 void
551 db_vprintf(fmt, ap)
552 	const char *fmt;
553 	va_list ap;
554 {
555 
556 	/* No mutex needed; DDB pauses all processors. */
557 	kprintf(fmt, TODDB, 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(fmt, ap)
759 	const char *fmt;
760 	va_list ap;
761 {
762 	int s;
763 
764 	KPRINTF_MUTEX_ENTER(s);
765 
766 	kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
767 
768 	KPRINTF_MUTEX_EXIT(s);
769 
770 	if (!panicstr)
771 		logwakeup();
772 }
773 
774 /*
775  * sprintf: print a message to a buffer
776  */
777 int
778 sprintf(char *buf, const char *fmt, ...)
779 {
780 	int retval;
781 	va_list ap;
782 
783 	va_start(ap, fmt);
784 	retval = kprintf(fmt, TOBUFONLY, NULL, buf, ap);
785 	va_end(ap);
786 	*(buf + retval) = 0;	/* null terminate */
787 	return(retval);
788 }
789 
790 /*
791  * vsprintf: print a message to a buffer [already have va_alist]
792  */
793 
794 int
795 vsprintf(buf, fmt, ap)
796 	char *buf;
797 	const char *fmt;
798 	va_list ap;
799 {
800 	int retval;
801 
802 	retval = kprintf(fmt, TOBUFONLY, NULL, buf, ap);
803 	*(buf + retval) = 0;	/* null terminate */
804 	return (retval);
805 }
806 
807 /*
808  * snprintf: print a message to a buffer
809  */
810 int
811 snprintf(char *buf, size_t size, const char *fmt, ...)
812 {
813 	int retval;
814 	va_list ap;
815 	char *p;
816 
817 	if (size < 1)
818 		return (-1);
819 	p = buf + size - 1;
820 	va_start(ap, fmt);
821 	retval = kprintf(fmt, TOBUFONLY, &p, buf, ap);
822 	va_end(ap);
823 	*(p) = 0;	/* null terminate */
824 	return(retval);
825 }
826 
827 /*
828  * vsnprintf: print a message to a buffer [already have va_alist]
829  */
830 int
831 vsnprintf(buf, size, fmt, ap)
832         char *buf;
833         size_t size;
834         const char *fmt;
835         va_list ap;
836 {
837 	int retval;
838 	char *p;
839 
840 	if (size < 1)
841 		return (-1);
842 	p = buf + size - 1;
843 	retval = kprintf(fmt, TOBUFONLY, &p, buf, ap);
844 	*(p) = 0;	/* null terminate */
845 	return(retval);
846 }
847 
848 /*
849  * bitmask_snprintf: print an interpreted bitmask to a buffer
850  *
851  * => returns pointer to the buffer
852  */
853 char *
854 bitmask_snprintf(val, p, buf, buflen)
855 	u_quad_t val;
856 	const char *p;
857 	char *buf;
858 	size_t buflen;
859 {
860 	char *bp, *q;
861 	size_t left;
862 	char *sbase, snbuf[KPRINTF_BUFSIZE];
863 	int base, bit, ch, len, sep;
864 	u_quad_t field;
865 
866 	bp = buf;
867 	memset(buf, 0, buflen);
868 
869 	/*
870 	 * Always leave room for the trailing NULL.
871 	 */
872 	left = buflen - 1;
873 
874 	/*
875 	 * Print the value into the buffer.  Abort if there's not
876 	 * enough room.
877 	 */
878 	if (buflen < KPRINTF_BUFSIZE)
879 		return (buf);
880 
881 	ch = *p++;
882 	base = ch != '\177' ? ch : *p++;
883 	sbase = base == 8 ? "%qo" : base == 10 ? "%qd" : base == 16 ? "%qx" : 0;
884 	if (sbase == 0)
885 		return (buf);	/* punt if not oct, dec, or hex */
886 
887 	snprintf(snbuf, sizeof(snbuf), sbase, val);
888 	for (q = snbuf ; *q ; q++) {
889 		*bp++ = *q;
890 		left--;
891 	}
892 
893 	/*
894 	 * If the value we printed was 0 and we're using the old-style format,
895 	 * or if we don't have room for "<x>", we're done.
896 	 */
897 	if (((val == 0) && (ch != '\177')) || left < 3)
898 		return (buf);
899 
900 #define PUTBYTE(b, c, l) do {	\
901 	*(b)++ = (c);		\
902 	if (--(l) == 0)		\
903 		goto out;	\
904 } while (/*CONSTCOND*/ 0)
905 #define PUTSTR(b, p, l) do {		\
906 	int c;				\
907 	while ((c = *(p)++) != 0) {	\
908 		*(b)++ = c;		\
909 		if (--(l) == 0)		\
910 			goto out;	\
911 	}				\
912 } while (/*CONSTCOND*/ 0)
913 
914 	/*
915 	 * Chris Torek's new bitmask format is identified by a leading \177
916 	 */
917 	sep = '<';
918 	if (ch != '\177') {
919 		/* old (standard) format. */
920 		for (;(bit = *p++) != 0;) {
921 			if (val & (1 << (bit - 1))) {
922 				PUTBYTE(bp, sep, left);
923 				for (; (ch = *p) > ' '; ++p) {
924 					PUTBYTE(bp, ch, left);
925 				}
926 				sep = ',';
927 			} else
928 				for (; *p > ' '; ++p)
929 					continue;
930 		}
931 	} else {
932 		/* new quad-capable format; also does fields. */
933 		field = val;
934 		while ((ch = *p++) != '\0') {
935 			bit = *p++;	/* now 0-origin */
936 			switch (ch) {
937 			case 'b':
938 				if (((u_int)(val >> bit) & 1) == 0)
939 					goto skip;
940 				PUTBYTE(bp, sep, left);
941 				PUTSTR(bp, p, left);
942 				sep = ',';
943 				break;
944 			case 'f':
945 			case 'F':
946 				len = *p++;	/* field length */
947 				field = (val >> bit) & ((1ULL << len) - 1);
948 				if (ch == 'F')	/* just extract */
949 					break;
950 				PUTBYTE(bp, sep, left);
951 				sep = ',';
952 				PUTSTR(bp, p, left);
953 				PUTBYTE(bp, '=', left);
954 				sprintf(snbuf, sbase, field);
955 				q = snbuf; PUTSTR(bp, q, left);
956 				break;
957 			case '=':
958 			case ':':
959 				/*
960 				 * Here "bit" is actually a value instead,
961 				 * to be compared against the last field.
962 				 * This only works for values in [0..255],
963 				 * of course.
964 				 */
965 				if ((int)field != bit)
966 					goto skip;
967 				if (ch == '=')
968 					PUTBYTE(bp, '=', left);
969 				PUTSTR(bp, p, left);
970 				break;
971 			default:
972 			skip:
973 				while (*p++ != '\0')
974 					continue;
975 				break;
976 			}
977 		}
978 	}
979 	if (sep != '<')
980 		PUTBYTE(bp, '>', left);
981 
982 out:
983 	return (buf);
984 
985 #undef PUTBYTE
986 #undef PUTSTR
987 }
988 
989 /*
990  * kprintf: scaled down version of printf(3).
991  *
992  * this version based on vfprintf() from libc which was derived from
993  * software contributed to Berkeley by Chris Torek.
994  *
995  * NOTE: The kprintf mutex must be held if we're going TOBUF or TOCONS!
996  */
997 
998 /*
999  * macros for converting digits to letters and vice versa
1000  */
1001 #define	to_digit(c)	((c) - '0')
1002 #define is_digit(c)	((unsigned)to_digit(c) <= 9)
1003 #define	to_char(n)	((n) + '0')
1004 
1005 /*
1006  * flags used during conversion.
1007  */
1008 #define	ALT		0x001		/* alternate form */
1009 #define	HEXPREFIX	0x002		/* add 0x or 0X prefix */
1010 #define	LADJUST		0x004		/* left adjustment */
1011 #define	LONGDBL		0x008		/* long double; unimplemented */
1012 #define	LONGINT		0x010		/* long integer */
1013 #define	QUADINT		0x020		/* quad integer */
1014 #define	SHORTINT	0x040		/* short integer */
1015 #define	MAXINT		0x080		/* intmax_t */
1016 #define	PTRINT		0x100		/* intptr_t */
1017 #define	SIZEINT		0x200		/* size_t */
1018 #define	ZEROPAD		0x400		/* zero (as opposed to blank) pad */
1019 #define FPT		0x800		/* Floating point number */
1020 
1021 	/*
1022 	 * To extend shorts properly, we need both signed and unsigned
1023 	 * argument extraction methods.
1024 	 */
1025 #define	SARG() \
1026 	(flags&MAXINT ? va_arg(ap, intmax_t) : \
1027 	    flags&PTRINT ? va_arg(ap, intptr_t) : \
1028 	    flags&SIZEINT ? va_arg(ap, ssize_t) : /* XXX */ \
1029 	    flags&QUADINT ? va_arg(ap, quad_t) : \
1030 	    flags&LONGINT ? va_arg(ap, long) : \
1031 	    flags&SHORTINT ? (long)(short)va_arg(ap, int) : \
1032 	    (long)va_arg(ap, int))
1033 #define	UARG() \
1034 	(flags&MAXINT ? va_arg(ap, uintmax_t) : \
1035 	    flags&PTRINT ? va_arg(ap, uintptr_t) : \
1036 	    flags&SIZEINT ? va_arg(ap, size_t) : \
1037 	    flags&QUADINT ? va_arg(ap, u_quad_t) : \
1038 	    flags&LONGINT ? va_arg(ap, u_long) : \
1039 	    flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \
1040 	    (u_long)va_arg(ap, u_int))
1041 
1042 #define KPRINTF_PUTCHAR(C) {						\
1043 	if (oflags == TOBUFONLY) {					\
1044 		if ((vp != NULL) && (sbuf == tailp)) {			\
1045 			ret += 1;		/* indicate error */	\
1046 			goto overflow;					\
1047 		}							\
1048 		*sbuf++ = (C);						\
1049 	} else {							\
1050 		putchar((C), oflags, (struct tty *)vp);			\
1051 	}								\
1052 }
1053 
1054 /*
1055  * Guts of kernel printf.  Note, we already expect to be in a mutex!
1056  */
1057 int
1058 kprintf(fmt0, oflags, vp, sbuf, ap)
1059 	const char *fmt0;
1060 	int oflags;
1061 	void *vp;
1062 	char *sbuf;
1063 	va_list ap;
1064 {
1065 	char *fmt;		/* format string */
1066 	int ch;			/* character from fmt */
1067 	int n;			/* handy integer (short term usage) */
1068 	char *cp;		/* handy char pointer (short term usage) */
1069 	int flags;		/* flags as above */
1070 	int ret;		/* return value accumulator */
1071 	int width;		/* width from format (%8d), or 0 */
1072 	int prec;		/* precision from format (%.3d), or -1 */
1073 	char sign;		/* sign prefix (' ', '+', '-', or \0) */
1074 
1075 	u_quad_t _uquad;	/* integer arguments %[diouxX] */
1076 	enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
1077 	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
1078 	int realsz;		/* field size expanded by dprec */
1079 	int size;		/* size of converted field or string */
1080 	char *xdigs;		/* digits for [xX] conversion */
1081 	char buf[KPRINTF_BUFSIZE]; /* space for %c, %[diouxX] */
1082 	char *tailp;		/* tail pointer for snprintf */
1083 
1084 	tailp = NULL;	/* XXX: shutup gcc */
1085 	if (oflags == TOBUFONLY && (vp != NULL))
1086 		tailp = *(char **)vp;
1087 
1088 	cp = NULL;	/* XXX: shutup gcc */
1089 	size = 0;	/* XXX: shutup gcc */
1090 
1091 	fmt = (char *)fmt0;
1092 	ret = 0;
1093 
1094 	xdigs = NULL;		/* XXX: shut up gcc warning */
1095 
1096 	/*
1097 	 * Scan the format for conversions (`%' character).
1098 	 */
1099 	for (;;) {
1100 		while (*fmt != '%' && *fmt) {
1101 			ret++;
1102 			KPRINTF_PUTCHAR(*fmt++);
1103 		}
1104 		if (*fmt == 0)
1105 			goto done;
1106 
1107 		fmt++;		/* skip over '%' */
1108 
1109 		flags = 0;
1110 		dprec = 0;
1111 		width = 0;
1112 		prec = -1;
1113 		sign = '\0';
1114 
1115 rflag:		ch = *fmt++;
1116 reswitch:	switch (ch) {
1117 		case ' ':
1118 			/*
1119 			 * ``If the space and + flags both appear, the space
1120 			 * flag will be ignored.''
1121 			 *	-- ANSI X3J11
1122 			 */
1123 			if (!sign)
1124 				sign = ' ';
1125 			goto rflag;
1126 		case '#':
1127 			flags |= ALT;
1128 			goto rflag;
1129 		case '*':
1130 			/*
1131 			 * ``A negative field width argument is taken as a
1132 			 * - flag followed by a positive field width.''
1133 			 *	-- ANSI X3J11
1134 			 * They don't exclude field widths read from args.
1135 			 */
1136 			if ((width = va_arg(ap, int)) >= 0)
1137 				goto rflag;
1138 			width = -width;
1139 			/* FALLTHROUGH */
1140 		case '-':
1141 			flags |= LADJUST;
1142 			goto rflag;
1143 		case '+':
1144 			sign = '+';
1145 			goto rflag;
1146 		case '.':
1147 			if ((ch = *fmt++) == '*') {
1148 				n = va_arg(ap, int);
1149 				prec = n < 0 ? -1 : n;
1150 				goto rflag;
1151 			}
1152 			n = 0;
1153 			while (is_digit(ch)) {
1154 				n = 10 * n + to_digit(ch);
1155 				ch = *fmt++;
1156 			}
1157 			prec = n < 0 ? -1 : n;
1158 			goto reswitch;
1159 		case '0':
1160 			/*
1161 			 * ``Note that 0 is taken as a flag, not as the
1162 			 * beginning of a field width.''
1163 			 *	-- ANSI X3J11
1164 			 */
1165 			flags |= ZEROPAD;
1166 			goto rflag;
1167 		case '1': case '2': case '3': case '4':
1168 		case '5': case '6': case '7': case '8': case '9':
1169 			n = 0;
1170 			do {
1171 				n = 10 * n + to_digit(ch);
1172 				ch = *fmt++;
1173 			} while (is_digit(ch));
1174 			width = n;
1175 			goto reswitch;
1176 		case 'h':
1177 			flags |= SHORTINT;
1178 			goto rflag;
1179 		case 'j':
1180 			flags |= MAXINT;
1181 			goto rflag;
1182 		case 'l':
1183 			if (*fmt == 'l') {
1184 				fmt++;
1185 				flags |= QUADINT;
1186 			} else {
1187 				flags |= LONGINT;
1188 			}
1189 			goto rflag;
1190 		case 'q':
1191 			flags |= QUADINT;
1192 			goto rflag;
1193 		case 't':
1194 			flags |= PTRINT;
1195 			goto rflag;
1196 		case 'z':
1197 			flags |= SIZEINT;
1198 			goto rflag;
1199 		case 'c':
1200 			*(cp = buf) = va_arg(ap, int);
1201 			size = 1;
1202 			sign = '\0';
1203 			break;
1204 		case 'D':
1205 			flags |= LONGINT;
1206 			/*FALLTHROUGH*/
1207 		case 'd':
1208 		case 'i':
1209 			_uquad = SARG();
1210 			if ((quad_t)_uquad < 0) {
1211 				_uquad = -_uquad;
1212 				sign = '-';
1213 			}
1214 			base = DEC;
1215 			goto number;
1216 		case 'n':
1217 			if (flags & MAXINT)
1218 				*va_arg(ap, intmax_t *) = ret;
1219 			else if (flags & PTRINT)
1220 				*va_arg(ap, intptr_t *) = ret;
1221 			else if (flags & SIZEINT)
1222 				*va_arg(ap, ssize_t *) = ret;
1223 			else if (flags & QUADINT)
1224 				*va_arg(ap, quad_t *) = ret;
1225 			else if (flags & LONGINT)
1226 				*va_arg(ap, long *) = ret;
1227 			else if (flags & SHORTINT)
1228 				*va_arg(ap, short *) = ret;
1229 			else
1230 				*va_arg(ap, int *) = ret;
1231 			continue;	/* no output */
1232 		case 'O':
1233 			flags |= LONGINT;
1234 			/*FALLTHROUGH*/
1235 		case 'o':
1236 			_uquad = UARG();
1237 			base = OCT;
1238 			goto nosign;
1239 		case 'p':
1240 			/*
1241 			 * ``The argument shall be a pointer to void.  The
1242 			 * value of the pointer is converted to a sequence
1243 			 * of printable characters, in an implementation-
1244 			 * defined manner.''
1245 			 *	-- ANSI X3J11
1246 			 */
1247 			/* NOSTRICT */
1248 			_uquad = (u_long)va_arg(ap, void *);
1249 			base = HEX;
1250 			xdigs = "0123456789abcdef";
1251 			flags |= HEXPREFIX;
1252 			ch = 'x';
1253 			goto nosign;
1254 		case 's':
1255 			if ((cp = va_arg(ap, char *)) == NULL)
1256 				cp = "(null)";
1257 			if (prec >= 0) {
1258 				/*
1259 				 * can't use strlen; can only look for the
1260 				 * NUL in the first `prec' characters, and
1261 				 * strlen() will go further.
1262 				 */
1263 				char *p = memchr(cp, 0, prec);
1264 
1265 				if (p != NULL) {
1266 					size = p - cp;
1267 					if (size > prec)
1268 						size = prec;
1269 				} else
1270 					size = prec;
1271 			} else
1272 				size = strlen(cp);
1273 			sign = '\0';
1274 			break;
1275 		case 'U':
1276 			flags |= LONGINT;
1277 			/*FALLTHROUGH*/
1278 		case 'u':
1279 			_uquad = UARG();
1280 			base = DEC;
1281 			goto nosign;
1282 		case 'X':
1283 			xdigs = "0123456789ABCDEF";
1284 			goto hex;
1285 		case 'x':
1286 			xdigs = "0123456789abcdef";
1287 hex:			_uquad = UARG();
1288 			base = HEX;
1289 			/* leading 0x/X only if non-zero */
1290 			if (flags & ALT && _uquad != 0)
1291 				flags |= HEXPREFIX;
1292 
1293 			/* unsigned conversions */
1294 nosign:			sign = '\0';
1295 			/*
1296 			 * ``... diouXx conversions ... if a precision is
1297 			 * specified, the 0 flag will be ignored.''
1298 			 *	-- ANSI X3J11
1299 			 */
1300 number:			if ((dprec = prec) >= 0)
1301 				flags &= ~ZEROPAD;
1302 
1303 			/*
1304 			 * ``The result of converting a zero value with an
1305 			 * explicit precision of zero is no characters.''
1306 			 *	-- ANSI X3J11
1307 			 */
1308 			cp = buf + KPRINTF_BUFSIZE;
1309 			if (_uquad != 0 || prec != 0) {
1310 				/*
1311 				 * Unsigned mod is hard, and unsigned mod
1312 				 * by a constant is easier than that by
1313 				 * a variable; hence this switch.
1314 				 */
1315 				switch (base) {
1316 				case OCT:
1317 					do {
1318 						*--cp = to_char(_uquad & 7);
1319 						_uquad >>= 3;
1320 					} while (_uquad);
1321 					/* handle octal leading 0 */
1322 					if (flags & ALT && *cp != '0')
1323 						*--cp = '0';
1324 					break;
1325 
1326 				case DEC:
1327 					/* many numbers are 1 digit */
1328 					while (_uquad >= 10) {
1329 						*--cp = to_char(_uquad % 10);
1330 						_uquad /= 10;
1331 					}
1332 					*--cp = to_char(_uquad);
1333 					break;
1334 
1335 				case HEX:
1336 					do {
1337 						*--cp = xdigs[_uquad & 15];
1338 						_uquad >>= 4;
1339 					} while (_uquad);
1340 					break;
1341 
1342 				default:
1343 					cp = "bug in kprintf: bad base";
1344 					size = strlen(cp);
1345 					goto skipsize;
1346 				}
1347 			}
1348 			size = buf + KPRINTF_BUFSIZE - cp;
1349 		skipsize:
1350 			break;
1351 		default:	/* "%?" prints ?, unless ? is NUL */
1352 			if (ch == '\0')
1353 				goto done;
1354 			/* pretend it was %c with argument ch */
1355 			cp = buf;
1356 			*cp = ch;
1357 			size = 1;
1358 			sign = '\0';
1359 			break;
1360 		}
1361 
1362 		/*
1363 		 * All reasonable formats wind up here.  At this point, `cp'
1364 		 * points to a string which (if not flags&LADJUST) should be
1365 		 * padded out to `width' places.  If flags&ZEROPAD, it should
1366 		 * first be prefixed by any sign or other prefix; otherwise,
1367 		 * it should be blank padded before the prefix is emitted.
1368 		 * After any left-hand padding and prefixing, emit zeroes
1369 		 * required by a decimal [diouxX] precision, then print the
1370 		 * string proper, then emit zeroes required by any leftover
1371 		 * floating precision; finally, if LADJUST, pad with blanks.
1372 		 *
1373 		 * Compute actual size, so we know how much to pad.
1374 		 * size excludes decimal prec; realsz includes it.
1375 		 */
1376 		realsz = dprec > size ? dprec : size;
1377 		if (sign)
1378 			realsz++;
1379 		else if (flags & HEXPREFIX)
1380 			realsz+= 2;
1381 
1382 		/* adjust ret */
1383 		ret += width > realsz ? width : realsz;
1384 
1385 		/* right-adjusting blank padding */
1386 		if ((flags & (LADJUST|ZEROPAD)) == 0) {
1387 			n = width - realsz;
1388 			while (n-- > 0)
1389 				KPRINTF_PUTCHAR(' ');
1390 		}
1391 
1392 		/* prefix */
1393 		if (sign) {
1394 			KPRINTF_PUTCHAR(sign);
1395 		} else if (flags & HEXPREFIX) {
1396 			KPRINTF_PUTCHAR('0');
1397 			KPRINTF_PUTCHAR(ch);
1398 		}
1399 
1400 		/* right-adjusting zero padding */
1401 		if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) {
1402 			n = width - realsz;
1403 			while (n-- > 0)
1404 				KPRINTF_PUTCHAR('0');
1405 		}
1406 
1407 		/* leading zeroes from decimal precision */
1408 		n = dprec - size;
1409 		while (n-- > 0)
1410 			KPRINTF_PUTCHAR('0');
1411 
1412 		/* the string or number proper */
1413 		while (size--)
1414 			KPRINTF_PUTCHAR(*cp++);
1415 		/* left-adjusting padding (always blank) */
1416 		if (flags & LADJUST) {
1417 			n = width - realsz;
1418 			while (n-- > 0)
1419 				KPRINTF_PUTCHAR(' ');
1420 		}
1421 	}
1422 
1423 done:
1424 	if ((oflags == TOBUFONLY) && (vp != NULL))
1425 		*(char **)vp = sbuf;
1426 	(*v_flush)();
1427 overflow:
1428 	return (ret);
1429 	/* NOTREACHED */
1430 }
1431