xref: /netbsd-src/sys/kern/subr_prf.c (revision 404ee5b9334f618040b6cdef96a0ff35a6fc4636)
1 /*	$NetBSD: subr_prf.c,v 1.181 2019/05/21 04:57:02 christos 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 1.181 2019/05/21 04:57:02 christos Exp $");
41 
42 #ifdef _KERNEL_OPT
43 #include "opt_ddb.h"
44 #include "opt_kgdb.h"
45 #include "opt_dump.h"
46 #include "opt_rnd_printf.h"
47 #endif
48 
49 #include <sys/param.h>
50 #include <sys/stdint.h>
51 #include <sys/systm.h>
52 #include <sys/buf.h>
53 #include <sys/device.h>
54 #include <sys/reboot.h>
55 #include <sys/msgbuf.h>
56 #include <sys/proc.h>
57 #include <sys/ioctl.h>
58 #include <sys/vnode.h>
59 #include <sys/file.h>
60 #include <sys/tty.h>
61 #include <sys/tprintf.h>
62 #include <sys/spldebug.h>
63 #include <sys/syslog.h>
64 #include <sys/kprintf.h>
65 #include <sys/atomic.h>
66 #include <sys/kernel.h>
67 #include <sys/cpu.h>
68 #include <sys/sha2.h>
69 #include <sys/rndsource.h>
70 #include <sys/kmem.h>
71 
72 #include <dev/cons.h>
73 
74 #include <net/if.h>
75 
76 static kmutex_t kprintf_mtx;
77 static bool kprintf_inited = false;
78 
79 #ifdef KGDB
80 #include <sys/kgdb.h>
81 #endif
82 
83 #ifdef DDB
84 #include <ddb/ddbvar.h>		/* db_panic */
85 #include <ddb/db_output.h>	/* db_printf, db_putchar prototypes */
86 #endif
87 
88 
89 /*
90  * defines
91  */
92 #define KLOG_PRI	0x80000000
93 
94 
95 /*
96  * local prototypes
97  */
98 
99 static void	 putchar(int, int, struct tty *);
100 
101 
102 /*
103  * globals
104  */
105 
106 extern	struct tty *constty;	/* pointer to console "window" tty */
107 extern	int log_open;	/* subr_log: is /dev/klog open? */
108 extern	krndsource_t	rnd_printf_source;
109 const	char *panicstr; /* arg to first call to panic (used as a flag
110 			   to indicate that panic has already been called). */
111 struct cpu_info *paniccpu;	/* cpu that first paniced */
112 long	panicstart, panicend;	/* position in the msgbuf of the start and
113 				   end of the formatted panicstr. */
114 int	doing_shutdown;	/* set to indicate shutdown in progress */
115 
116 #ifdef RND_PRINTF
117 static bool kprintf_inited_callout = false;
118 static SHA512_CTX kprnd_sha;
119 static uint8_t kprnd_accum[SHA512_DIGEST_LENGTH];
120 static int kprnd_added;
121 
122 static struct callout kprnd_callout;
123 #endif
124 
125 #ifndef	DUMP_ON_PANIC
126 #define	DUMP_ON_PANIC	1
127 #endif
128 int	dumponpanic = DUMP_ON_PANIC;
129 
130 /*
131  * v_putc: routine to putc on virtual console
132  *
133  * the v_putc pointer can be used to redirect the console cnputc elsewhere
134  * [e.g. to a "virtual console"].
135  */
136 
137 void (*v_putc)(int) = cnputc;	/* start with cnputc (normal cons) */
138 void (*v_flush)(void) = cnflush;	/* start with cnflush (normal cons) */
139 
140 const char hexdigits[] = "0123456789abcdef";
141 const char HEXDIGITS[] = "0123456789ABCDEF";
142 
143 
144 /*
145  * functions
146  */
147 
148 #ifdef RND_PRINTF
149 static void kprintf_rnd_get(size_t bytes, void *priv)
150 {
151 	if (kprnd_added)  {
152 		KASSERT(kprintf_inited);
153 		if (mutex_tryenter(&kprintf_mtx)) {
154 			SHA512_Final(kprnd_accum, &kprnd_sha);
155 			rnd_add_data(&rnd_printf_source,
156 				     kprnd_accum, sizeof(kprnd_accum), 0);
157 			kprnd_added = 0;
158 			/* This, we must do, since we called _Final. */
159 			SHA512_Init(&kprnd_sha);
160 			/* This is optional but seems useful. */
161 			SHA512_Update(&kprnd_sha, kprnd_accum,
162 				      sizeof(kprnd_accum));
163 			mutex_exit(&kprintf_mtx);
164 		}
165 	}
166 }
167 
168 static void kprintf_rnd_callout(void *arg)
169 {
170 	kprintf_rnd_get(0, NULL);
171 	callout_schedule(&kprnd_callout, hz);
172 }
173 
174 #endif
175 
176 /*
177  * Locking is inited fairly early in MI bootstrap.  Before that
178  * prints are done unlocked.  But that doesn't really matter,
179  * since nothing can preempt us before interrupts are enabled.
180  */
181 void
182 kprintf_init(void)
183 {
184 
185 	KASSERT(!kprintf_inited && cold); /* not foolproof, but ... */
186 #ifdef RND_PRINTF
187 	SHA512_Init(&kprnd_sha);
188 #endif
189 	mutex_init(&kprintf_mtx, MUTEX_DEFAULT, IPL_HIGH);
190 	kprintf_inited = true;
191 }
192 
193 #ifdef RND_PRINTF
194 void
195 kprintf_init_callout(void)
196 {
197 	KASSERT(!kprintf_inited_callout);
198 	callout_init(&kprnd_callout, CALLOUT_MPSAFE);
199 	callout_setfunc(&kprnd_callout, kprintf_rnd_callout, NULL);
200 	callout_schedule(&kprnd_callout, hz);
201 	kprintf_inited_callout = true;
202 }
203 #endif
204 
205 void
206 kprintf_lock(void)
207 {
208 
209 	if (__predict_true(kprintf_inited))
210 		mutex_enter(&kprintf_mtx);
211 }
212 
213 void
214 kprintf_unlock(void)
215 {
216 
217 	if (__predict_true(kprintf_inited)) {
218 		/* assert kprintf wasn't somehow inited while we were in */
219 		KASSERT(mutex_owned(&kprintf_mtx));
220 		mutex_exit(&kprintf_mtx);
221 	}
222 }
223 
224 /*
225  * twiddle: spin a little propellor on the console.
226  */
227 
228 void
229 twiddle(void)
230 {
231 	static const char twiddle_chars[] = "|/-\\";
232 	static int pos;
233 
234 	kprintf_lock();
235 
236 	putchar(twiddle_chars[pos++ & 3], TOCONS|NOTSTAMP, NULL);
237 	putchar('\b', TOCONS|NOTSTAMP, NULL);
238 
239 	kprintf_unlock();
240 }
241 
242 /*
243  * panic: handle an unresolvable fatal error
244  *
245  * prints "panic: <message>" and reboots.   if called twice (i.e. recursive
246  * call) we avoid trying to dump and just reboot (to avoid recursive panics).
247  */
248 
249 void
250 panic(const char *fmt, ...)
251 {
252 	va_list ap;
253 
254 	va_start(ap, fmt);
255 	vpanic(fmt, ap);
256 	va_end(ap);
257 }
258 
259 void
260 vpanic(const char *fmt, va_list ap)
261 {
262 	CPU_INFO_ITERATOR cii;
263 	struct cpu_info *ci, *oci;
264 	int bootopt;
265 	static char scratchstr[384]; /* stores panic message */
266 
267 	spldebug_stop();
268 
269 	if (lwp0.l_cpu && curlwp) {
270 		/*
271 		 * Disable preemption.  If already panicing on another CPU, sit
272 		 * here and spin until the system is rebooted.  Allow the CPU that
273 		 * first paniced to panic again.
274 		 */
275 		kpreempt_disable();
276 		ci = curcpu();
277 		oci = atomic_cas_ptr((void *)&paniccpu, NULL, ci);
278 		if (oci != NULL && oci != ci) {
279 			/* Give interrupts a chance to try and prevent deadlock. */
280 			for (;;) {
281 #ifndef _RUMPKERNEL /* XXXpooka: temporary build fix, see kern/40505 */
282 				DELAY(10);
283 #endif /* _RUMPKERNEL */
284 			}
285 		}
286 
287 		/*
288 		 * Convert the current thread to a bound thread and prevent all
289 		 * CPUs from scheduling unbound jobs.  Do so without taking any
290 		 * locks.
291 		 */
292 		curlwp->l_pflag |= LP_BOUND;
293 		for (CPU_INFO_FOREACH(cii, ci)) {
294 			ci->ci_schedstate.spc_flags |= SPCF_OFFLINE;
295 		}
296 	}
297 
298 	bootopt = RB_AUTOBOOT | RB_NOSYNC;
299 	if (!doing_shutdown) {
300 		if (dumponpanic)
301 			bootopt |= RB_DUMP;
302 	} else
303 		printf("Skipping crash dump on recursive panic\n");
304 
305 	doing_shutdown = 1;
306 
307 	if (logenabled(msgbufp))
308 		panicstart = msgbufp->msg_bufx;
309 
310 	printf("panic: ");
311 	if (panicstr == NULL) {
312 		/* first time in panic - store fmt first for precaution */
313 		panicstr = fmt;
314 
315 		vsnprintf(scratchstr, sizeof(scratchstr), fmt, ap);
316 		printf("%s", scratchstr);
317 		panicstr = scratchstr;
318 	} else {
319 		vprintf(fmt, ap);
320 	}
321 	printf("\n");
322 
323 	if (logenabled(msgbufp))
324 		panicend = msgbufp->msg_bufx;
325 
326 #ifdef KGDB
327 	kgdb_panic();
328 #endif
329 #ifdef KADB
330 	if (boothowto & RB_KDB)
331 		kdbpanic();
332 #endif
333 #ifdef DDB
334 	db_panic();
335 #endif
336 	cpu_reboot(bootopt, NULL);
337 }
338 
339 /*
340  * kernel logging functions: log, logpri, addlog
341  */
342 
343 /*
344  * log: write to the log buffer
345  *
346  * => will not sleep [so safe to call from interrupt]
347  * => will log to console if /dev/klog isn't open
348  */
349 
350 void
351 log(int level, const char *fmt, ...)
352 {
353 	va_list ap;
354 
355 	kprintf_lock();
356 
357 	klogpri(level);		/* log the level first */
358 	va_start(ap, fmt);
359 	kprintf(fmt, TOLOG, NULL, NULL, ap);
360 	va_end(ap);
361 	if (!log_open) {
362 		va_start(ap, fmt);
363 		kprintf(fmt, TOCONS, NULL, NULL, ap);
364 		va_end(ap);
365 	}
366 
367 	kprintf_unlock();
368 
369 	logwakeup();		/* wake up anyone waiting for log msgs */
370 }
371 
372 /*
373  * vlog: write to the log buffer [already have va_list]
374  */
375 
376 void
377 vlog(int level, const char *fmt, va_list ap)
378 {
379 	va_list cap;
380 
381 	va_copy(cap, ap);
382 	kprintf_lock();
383 
384 	klogpri(level);		/* log the level first */
385 	kprintf(fmt, TOLOG, NULL, NULL, ap);
386 	if (!log_open)
387 		kprintf(fmt, TOCONS, NULL, NULL, cap);
388 
389 	kprintf_unlock();
390 	va_end(cap);
391 
392 	logwakeup();		/* wake up anyone waiting for log msgs */
393 }
394 
395 /*
396  * logpri: log the priority level to the klog
397  */
398 
399 void
400 logpri(int level)
401 {
402 
403 	kprintf_lock();
404 	klogpri(level);
405 	kprintf_unlock();
406 }
407 
408 /*
409  * Note: we must be in the mutex here!
410  */
411 void
412 klogpri(int level)
413 {
414 	KASSERT((level & KLOG_PRI) == 0);
415 
416 	putchar(level | KLOG_PRI, TOLOG, NULL);
417 }
418 
419 /*
420  * addlog: add info to previous log message
421  */
422 
423 void
424 addlog(const char *fmt, ...)
425 {
426 	va_list ap;
427 
428 	kprintf_lock();
429 
430 	va_start(ap, fmt);
431 	kprintf(fmt, TOLOG, NULL, NULL, ap);
432 	va_end(ap);
433 	if (!log_open) {
434 		va_start(ap, fmt);
435 		kprintf(fmt, TOCONS, NULL, NULL, ap);
436 		va_end(ap);
437 	}
438 
439 	kprintf_unlock();
440 
441 	logwakeup();
442 }
443 
444 static void
445 putone(int c, int flags, struct tty *tp)
446 {
447 	if (panicstr)
448 		constty = NULL;
449 
450 	if ((flags & TOCONS) && tp == NULL && constty) {
451 		tp = constty;
452 		flags |= TOTTY;
453 	}
454 	if ((flags & TOTTY) && tp &&
455 	    tputchar(c, flags, tp) < 0 &&
456 	    (flags & TOCONS) && tp == constty)
457 		constty = NULL;
458 	if ((flags & TOLOG) &&
459 	    c != '\0' && c != '\r' && c != 0177)
460 	    	logputchar(c);
461 	if ((flags & TOCONS) && constty == NULL && c != '\0')
462 		(*v_putc)(c);
463 }
464 
465 static void
466 putlogpri(int level)
467 {
468 	char *p;
469 	char snbuf[KPRINTF_BUFSIZE];
470 
471 	putone('<', TOLOG, NULL);
472 	snprintf(snbuf, sizeof(snbuf), "%d", level);
473 	for (p = snbuf ; *p ; p++)
474 		putone(*p, TOLOG, NULL);
475 	putone('>', TOLOG, NULL);
476 }
477 
478 #ifndef KLOG_NOTIMESTAMP
479 static int needtstamp = 1;
480 int log_ts_prec = 7;
481 
482 static void
483 addtstamp(int flags, struct tty *tp)
484 {
485 	char buf[64];
486 	struct timespec ts;
487 	int n, prec;
488 	long fsec;
489 
490 	prec = log_ts_prec;
491 	if (prec < 0) {
492 		prec = 0;
493 		log_ts_prec = prec;
494 	} else if (prec > 9) {
495 		prec = 9;
496 		log_ts_prec = prec;
497 	}
498 
499 	getnanouptime(&ts);
500 
501 	for (n = prec, fsec = ts.tv_nsec; n < 8; n++)
502 		fsec /= 10;
503 	if (n < 9)
504 		fsec = (fsec / 10) + ((fsec % 10) >= 5);
505 
506 	n = snprintf(buf, sizeof(buf), "[% 4jd.%.*ld] ",
507 	    (intmax_t)ts.tv_sec, prec, fsec);
508 
509 	for (int i = 0; i < n; i++)
510 		putone(buf[i], flags, tp);
511 }
512 #endif
513 
514 /*
515  * putchar: print a single character on console or user terminal.
516  *
517  * => if console, then the last MSGBUFS chars are saved in msgbuf
518  *	for inspection later (e.g. dmesg/syslog)
519  * => we must already be in the mutex!
520  */
521 static void
522 putchar(int c, int flags, struct tty *tp)
523 {
524 	if (c & KLOG_PRI) {
525 		putlogpri(c & ~KLOG_PRI);
526 		return;
527 	}
528 
529 #ifndef KLOG_NOTIMESTAMP
530 	if (c != '\0' && c != '\n' && needtstamp && (flags & NOTSTAMP) == 0) {
531 		addtstamp(flags, tp);
532 		needtstamp = 0;
533 	}
534 
535 	if (c == '\n')
536 		needtstamp = 1;
537 #endif
538 	putone(c, flags, tp);
539 
540 #ifdef DDB
541 	if (flags & TODDB) {
542 		db_putchar(c);
543 		return;
544 	}
545 #endif
546 
547 #ifdef RND_PRINTF
548 	if (__predict_true(kprintf_inited)) {
549 		static uint8_t rbuf[SHA512_BLOCK_LENGTH];
550 		static int cursor;
551 
552 		rbuf[cursor] = c;
553 		if (cursor == sizeof(rbuf) - 1) {
554 			SHA512_Update(&kprnd_sha, rbuf, sizeof(rbuf));
555 			kprnd_added++;
556 			cursor = 0;
557 		} else {
558 			cursor++;
559 		}
560 	}
561 #endif
562 }
563 
564 /*
565  * tablefull: warn that a system table is full
566  */
567 
568 void
569 tablefull(const char *tab, const char *hint)
570 {
571 	if (hint)
572 		log(LOG_ERR, "%s: table is full - %s\n", tab, hint);
573 	else
574 		log(LOG_ERR, "%s: table is full\n", tab);
575 }
576 
577 
578 /*
579  * uprintf: print to the controlling tty of the current process
580  *
581  * => we may block if the tty queue is full
582  * => no message is printed if the queue doesn't clear in a reasonable
583  *	time
584  */
585 
586 void
587 uprintf(const char *fmt, ...)
588 {
589 	struct proc *p = curproc;
590 	va_list ap;
591 
592 	/* mutex_enter(proc_lock); XXXSMP */
593 
594 	if (p->p_lflag & PL_CONTROLT && p->p_session->s_ttyvp) {
595 		/* No mutex needed; going to process TTY. */
596 		va_start(ap, fmt);
597 		kprintf(fmt, TOTTY, p->p_session->s_ttyp, NULL, ap);
598 		va_end(ap);
599 	}
600 
601 	/* mutex_exit(proc_lock); XXXSMP */
602 }
603 
604 void
605 uprintf_locked(const char *fmt, ...)
606 {
607 	struct proc *p = curproc;
608 	va_list ap;
609 
610 	if (p->p_lflag & PL_CONTROLT && p->p_session->s_ttyvp) {
611 		/* No mutex needed; going to process TTY. */
612 		va_start(ap, fmt);
613 		kprintf(fmt, TOTTY, p->p_session->s_ttyp, NULL, ap);
614 		va_end(ap);
615 	}
616 }
617 
618 /*
619  * tprintf functions: used to send messages to a specific process
620  *
621  * usage:
622  *   get a tpr_t handle on a process "p" by using "tprintf_open(p)"
623  *   use the handle when calling "tprintf"
624  *   when done, do a "tprintf_close" to drop the handle
625  */
626 
627 /*
628  * tprintf_open: get a tprintf handle on a process "p"
629  *
630  * => returns NULL if process can't be printed to
631  */
632 
633 tpr_t
634 tprintf_open(struct proc *p)
635 {
636 	tpr_t cookie;
637 
638 	cookie = NULL;
639 
640 	mutex_enter(proc_lock);
641 	if (p->p_lflag & PL_CONTROLT && p->p_session->s_ttyvp) {
642 		proc_sesshold(p->p_session);
643 		cookie = (tpr_t)p->p_session;
644 	}
645 	mutex_exit(proc_lock);
646 
647 	return cookie;
648 }
649 
650 /*
651  * tprintf_close: dispose of a tprintf handle obtained with tprintf_open
652  */
653 
654 void
655 tprintf_close(tpr_t sess)
656 {
657 
658 	if (sess) {
659 		mutex_enter(proc_lock);
660 		/* Releases proc_lock. */
661 		proc_sessrele((struct session *)sess);
662 	}
663 }
664 
665 /*
666  * tprintf: given tprintf handle to a process [obtained with tprintf_open],
667  * send a message to the controlling tty for that process.
668  *
669  * => also sends message to /dev/klog
670  */
671 void
672 tprintf(tpr_t tpr, const char *fmt, ...)
673 {
674 	struct session *sess = (struct session *)tpr;
675 	struct tty *tp = NULL;
676 	int flags = TOLOG;
677 	va_list ap;
678 
679 	/* mutex_enter(proc_lock); XXXSMP */
680 	if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
681 		flags |= TOTTY;
682 		tp = sess->s_ttyp;
683 	}
684 
685 	kprintf_lock();
686 
687 	klogpri(LOG_INFO);
688 	va_start(ap, fmt);
689 	kprintf(fmt, flags, tp, NULL, ap);
690 	va_end(ap);
691 
692 	kprintf_unlock();
693 	/* mutex_exit(proc_lock);	XXXSMP */
694 
695 	logwakeup();
696 }
697 
698 
699 /*
700  * ttyprintf: send a message to a specific tty
701  *
702  * => should be used only by tty driver or anything that knows the
703  *    underlying tty will not be revoked(2)'d away.  [otherwise,
704  *    use tprintf]
705  */
706 void
707 ttyprintf(struct tty *tp, const char *fmt, ...)
708 {
709 	va_list ap;
710 
711 	/* No mutex needed; going to process TTY. */
712 	va_start(ap, fmt);
713 	kprintf(fmt, TOTTY, tp, NULL, ap);
714 	va_end(ap);
715 }
716 
717 #ifdef DDB
718 
719 /*
720  * db_printf: printf for DDB (via db_putchar)
721  */
722 
723 void
724 db_printf(const char *fmt, ...)
725 {
726 	va_list ap;
727 
728 	/* No mutex needed; DDB pauses all processors. */
729 	va_start(ap, fmt);
730 	kprintf(fmt, TODDB, NULL, NULL, ap);
731 	va_end(ap);
732 
733 	if (db_tee_msgbuf) {
734 		va_start(ap, fmt);
735 		kprintf(fmt, TOLOG, NULL, NULL, ap);
736 		va_end(ap);
737 	}
738 }
739 
740 void
741 db_vprintf(const char *fmt, va_list ap)
742 {
743 	va_list cap;
744 
745 	va_copy(cap, ap);
746 	/* No mutex needed; DDB pauses all processors. */
747 	kprintf(fmt, TODDB, NULL, NULL, ap);
748 	if (db_tee_msgbuf)
749 		kprintf(fmt, TOLOG, NULL, NULL, cap);
750 	va_end(cap);
751 }
752 
753 #endif /* DDB */
754 
755 static void
756 kprintf_internal(const char *fmt, int oflags, void *vp, char *sbuf, ...)
757 {
758 	va_list ap;
759 
760 	va_start(ap, sbuf);
761 	(void)kprintf(fmt, oflags, vp, sbuf, ap);
762 	va_end(ap);
763 }
764 
765 /*
766  * Device autoconfiguration printf routines.  These change their
767  * behavior based on the AB_* flags in boothowto.  If AB_SILENT
768  * is set, messages never go to the console (but they still always
769  * go to the log).  AB_VERBOSE overrides AB_SILENT.
770  */
771 
772 /*
773  * aprint_normal: Send to console unless AB_QUIET.  Always goes
774  * to the log.
775  */
776 static void
777 aprint_normal_internal(const char *prefix, const char *fmt, va_list ap)
778 {
779 	int flags = TOLOG;
780 
781 	if ((boothowto & (AB_SILENT|AB_QUIET)) == 0 ||
782 	    (boothowto & AB_VERBOSE) != 0)
783 		flags |= TOCONS;
784 
785 	kprintf_lock();
786 
787 	if (prefix)
788 		kprintf_internal("%s: ", flags, NULL, NULL, prefix);
789 	kprintf(fmt, flags, NULL, NULL, ap);
790 
791 	kprintf_unlock();
792 
793 	if (!panicstr)
794 		logwakeup();
795 }
796 
797 void
798 aprint_normal(const char *fmt, ...)
799 {
800 	va_list ap;
801 
802 	va_start(ap, fmt);
803 	aprint_normal_internal(NULL, fmt, ap);
804 	va_end(ap);
805 }
806 
807 void
808 aprint_normal_dev(device_t dv, const char *fmt, ...)
809 {
810 	va_list ap;
811 
812 	KASSERT(dv != NULL);
813 
814 	va_start(ap, fmt);
815 	aprint_normal_internal(device_xname(dv), fmt, ap);
816 	va_end(ap);
817 }
818 
819 void
820 aprint_normal_ifnet(struct ifnet *ifp, const char *fmt, ...)
821 {
822 	va_list ap;
823 
824 	KASSERT(ifp != NULL);
825 
826 	va_start(ap, fmt);
827 	aprint_normal_internal(ifp->if_xname, fmt, ap);
828 	va_end(ap);
829 }
830 
831 /*
832  * aprint_error: Send to console unless AB_QUIET.  Always goes
833  * to the log.  Also counts the number of times called so other
834  * parts of the kernel can report the number of errors during a
835  * given phase of system startup.
836  */
837 static int aprint_error_count;
838 
839 int
840 aprint_get_error_count(void)
841 {
842 	int count;
843 
844 	kprintf_lock();
845 
846 	count = aprint_error_count;
847 	aprint_error_count = 0;
848 
849 	kprintf_unlock();
850 
851 	return (count);
852 }
853 
854 static void
855 aprint_error_internal(const char *prefix, const char *fmt, va_list ap)
856 {
857 	int flags = TOLOG;
858 
859 	if ((boothowto & (AB_SILENT|AB_QUIET)) == 0 ||
860 	    (boothowto & AB_VERBOSE) != 0)
861 		flags |= TOCONS;
862 
863 	kprintf_lock();
864 
865 	aprint_error_count++;
866 
867 	if (prefix)
868 		kprintf_internal("%s: ", flags, NULL, NULL, prefix);
869 	kprintf_internal("autoconfiguration error: ", TOLOG, NULL, NULL);
870 	kprintf(fmt, flags, NULL, NULL, ap);
871 
872 	kprintf_unlock();
873 
874 	if (!panicstr)
875 		logwakeup();
876 }
877 
878 void
879 aprint_error(const char *fmt, ...)
880 {
881 	va_list ap;
882 
883 	va_start(ap, fmt);
884 	aprint_error_internal(NULL, fmt, ap);
885 	va_end(ap);
886 }
887 
888 void
889 aprint_error_dev(device_t dv, const char *fmt, ...)
890 {
891 	va_list ap;
892 
893 	KASSERT(dv != NULL);
894 
895 	va_start(ap, fmt);
896 	aprint_error_internal(device_xname(dv), fmt, ap);
897 	va_end(ap);
898 }
899 
900 void
901 aprint_error_ifnet(struct ifnet *ifp, const char *fmt, ...)
902 {
903 	va_list ap;
904 
905 	KASSERT(ifp != NULL);
906 
907 	va_start(ap, fmt);
908 	aprint_error_internal(ifp->if_xname, fmt, ap);
909 	va_end(ap);
910 }
911 
912 /*
913  * aprint_naive: Send to console only if AB_QUIET.  Never goes
914  * to the log.
915  */
916 static void
917 aprint_naive_internal(const char *prefix, const char *fmt, va_list ap)
918 {
919 	if ((boothowto & (AB_QUIET|AB_SILENT|AB_VERBOSE)) != AB_QUIET)
920 		return;
921 
922 	kprintf_lock();
923 
924 	if (prefix)
925 		kprintf_internal("%s: ", TOCONS, NULL, NULL, prefix);
926 	kprintf(fmt, TOCONS, NULL, NULL, ap);
927 
928 	kprintf_unlock();
929 }
930 
931 void
932 aprint_naive(const char *fmt, ...)
933 {
934 	va_list ap;
935 
936 	va_start(ap, fmt);
937 	aprint_naive_internal(NULL, fmt, ap);
938 	va_end(ap);
939 }
940 
941 void
942 aprint_naive_dev(device_t dv, const char *fmt, ...)
943 {
944 	va_list ap;
945 
946 	KASSERT(dv != NULL);
947 
948 	va_start(ap, fmt);
949 	aprint_naive_internal(device_xname(dv), fmt, ap);
950 	va_end(ap);
951 }
952 
953 void
954 aprint_naive_ifnet(struct ifnet *ifp, const char *fmt, ...)
955 {
956 	va_list ap;
957 
958 	KASSERT(ifp != NULL);
959 
960 	va_start(ap, fmt);
961 	aprint_naive_internal(ifp->if_xname, fmt, ap);
962 	va_end(ap);
963 }
964 
965 /*
966  * aprint_verbose: Send to console only if AB_VERBOSE.  Always
967  * goes to the log.
968  */
969 static void
970 aprint_verbose_internal(const char *prefix, const char *fmt, va_list ap)
971 {
972 	int flags = TOLOG;
973 
974 	if (boothowto & AB_VERBOSE)
975 		flags |= TOCONS;
976 
977 	kprintf_lock();
978 
979 	if (prefix)
980 		kprintf_internal("%s: ", flags, NULL, NULL, prefix);
981 	kprintf(fmt, flags, NULL, NULL, ap);
982 
983 	kprintf_unlock();
984 
985 	if (!panicstr)
986 		logwakeup();
987 }
988 
989 void
990 aprint_verbose(const char *fmt, ...)
991 {
992 	va_list ap;
993 
994 	va_start(ap, fmt);
995 	aprint_verbose_internal(NULL, fmt, ap);
996 	va_end(ap);
997 }
998 
999 void
1000 aprint_verbose_dev(device_t dv, const char *fmt, ...)
1001 {
1002 	va_list ap;
1003 
1004 	KASSERT(dv != NULL);
1005 
1006 	va_start(ap, fmt);
1007 	aprint_verbose_internal(device_xname(dv), fmt, ap);
1008 	va_end(ap);
1009 }
1010 
1011 void
1012 aprint_verbose_ifnet(struct ifnet *ifp, const char *fmt, ...)
1013 {
1014 	va_list ap;
1015 
1016 	KASSERT(ifp != NULL);
1017 
1018 	va_start(ap, fmt);
1019 	aprint_verbose_internal(ifp->if_xname, fmt, ap);
1020 	va_end(ap);
1021 }
1022 
1023 /*
1024  * aprint_debug: Send to console and log only if AB_DEBUG.
1025  */
1026 static void
1027 aprint_debug_internal(const char *prefix, const char *fmt, va_list ap)
1028 {
1029 	if ((boothowto & AB_DEBUG) == 0)
1030 		return;
1031 
1032 	kprintf_lock();
1033 
1034 	if (prefix)
1035 		kprintf_internal("%s: ", TOCONS | TOLOG, NULL, NULL, prefix);
1036 	kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
1037 
1038 	kprintf_unlock();
1039 }
1040 
1041 void
1042 aprint_debug(const char *fmt, ...)
1043 {
1044 	va_list ap;
1045 
1046 	va_start(ap, fmt);
1047 	aprint_debug_internal(NULL, fmt, ap);
1048 	va_end(ap);
1049 }
1050 
1051 void
1052 aprint_debug_dev(device_t dv, const char *fmt, ...)
1053 {
1054 	va_list ap;
1055 
1056 	KASSERT(dv != NULL);
1057 
1058 	va_start(ap, fmt);
1059 	aprint_debug_internal(device_xname(dv), fmt, ap);
1060 	va_end(ap);
1061 }
1062 
1063 void
1064 aprint_debug_ifnet(struct ifnet *ifp, const char *fmt, ...)
1065 {
1066 	va_list ap;
1067 
1068 	KASSERT(ifp != NULL);
1069 
1070 	va_start(ap, fmt);
1071 	aprint_debug_internal(ifp->if_xname, fmt, ap);
1072 	va_end(ap);
1073 }
1074 
1075 void
1076 vprintf_flags(int flags, const char *fmt, va_list ap)
1077 {
1078 	kprintf_lock();
1079 	kprintf(fmt, flags, NULL, NULL, ap);
1080 	kprintf_unlock();
1081 }
1082 
1083 void
1084 printf_flags(int flags, const char *fmt, ...)
1085 {
1086 	va_list ap;
1087 
1088 	va_start(ap, fmt);
1089 	vprintf_flags(flags, fmt, ap);
1090 	va_end(ap);
1091 }
1092 
1093 void
1094 printf_tolog(const char *fmt, ...)
1095 {
1096 	va_list ap;
1097 
1098 	va_start(ap, fmt);
1099 	vprintf_flags(TOLOG, fmt, ap);
1100 	va_end(ap);
1101 }
1102 
1103 /*
1104  * printf_nolog: Like printf(), but does not send message to the log.
1105  */
1106 
1107 void
1108 printf_nolog(const char *fmt, ...)
1109 {
1110 	va_list ap;
1111 
1112 	va_start(ap, fmt);
1113 	vprintf_flags(TOCONS, fmt, ap);
1114 	va_end(ap);
1115 }
1116 
1117 /*
1118  * normal kernel printf functions: printf, vprintf, snprintf, vsnprintf
1119  */
1120 
1121 /*
1122  * printf: print a message to the console and the log
1123  */
1124 void
1125 printf(const char *fmt, ...)
1126 {
1127 	va_list ap;
1128 
1129 	va_start(ap, fmt);
1130 	vprintf_flags(TOCONS | TOLOG, fmt, ap);
1131 	va_end(ap);
1132 }
1133 
1134 /*
1135  * vprintf: print a message to the console and the log [already have
1136  *	va_list]
1137  */
1138 
1139 void
1140 vprintf(const char *fmt, va_list ap)
1141 {
1142 	vprintf_flags(TOCONS | TOLOG, fmt, ap);
1143 
1144 	if (!panicstr)
1145 		logwakeup();
1146 }
1147 
1148 /*
1149  * snprintf: print a message to a buffer
1150  */
1151 int
1152 snprintf(char *bf, size_t size, const char *fmt, ...)
1153 {
1154 	int retval;
1155 	va_list ap;
1156 
1157 	va_start(ap, fmt);
1158 	retval = vsnprintf(bf, size, fmt, ap);
1159 	va_end(ap);
1160 
1161 	return retval;
1162 }
1163 
1164 /*
1165  * vsnprintf: print a message to a buffer [already have va_list]
1166  */
1167 int
1168 vsnprintf(char *bf, size_t size, const char *fmt, va_list ap)
1169 {
1170 	int retval;
1171 	char *p;
1172 
1173 	p = bf + size;
1174 	retval = kprintf(fmt, TOBUFONLY, &p, bf, ap);
1175 	if (bf && size > 0) {
1176 		/* nul terminate */
1177 		if (size <= (size_t)retval)
1178 			bf[size - 1] = '\0';
1179 		else
1180 			bf[retval] = '\0';
1181 	}
1182 	return retval;
1183 }
1184 
1185 int
1186 vasprintf(char **bf, const char *fmt, va_list ap)
1187 {
1188 	int retval;
1189 	va_list cap;
1190 
1191 	va_copy(cap, ap);
1192 	retval = kprintf(fmt, TOBUFONLY, NULL, NULL, cap) + 1;
1193 	va_end(cap);
1194 	*bf = kmem_alloc(retval, KM_SLEEP);
1195 	return vsnprintf(*bf, retval, fmt, ap);
1196 }
1197 
1198 /*
1199  * kprintf: scaled down version of printf(3).
1200  *
1201  * this version based on vfprintf() from libc which was derived from
1202  * software contributed to Berkeley by Chris Torek.
1203  *
1204  * NOTE: The kprintf mutex must be held if we're going TOBUF or TOCONS!
1205  */
1206 
1207 /*
1208  * macros for converting digits to letters and vice versa
1209  */
1210 #define	to_digit(c)	((c) - '0')
1211 #define is_digit(c)	((unsigned)to_digit(c) <= 9)
1212 #define	to_char(n)	((n) + '0')
1213 
1214 /*
1215  * flags used during conversion.
1216  */
1217 #define	ALT		0x001		/* alternate form */
1218 #define	HEXPREFIX	0x002		/* add 0x or 0X prefix */
1219 #define	LADJUST		0x004		/* left adjustment */
1220 #define	LONGDBL		0x008		/* long double; unimplemented */
1221 #define	LONGINT		0x010		/* long integer */
1222 #define	QUADINT		0x020		/* quad integer */
1223 #define	SHORTINT	0x040		/* short integer */
1224 #define	MAXINT		0x080		/* intmax_t */
1225 #define	PTRINT		0x100		/* intptr_t */
1226 #define	SIZEINT		0x200		/* size_t */
1227 #define	ZEROPAD		0x400		/* zero (as opposed to blank) pad */
1228 #define FPT		0x800		/* Floating point number */
1229 
1230 	/*
1231 	 * To extend shorts properly, we need both signed and unsigned
1232 	 * argument extraction methods.
1233 	 */
1234 #define	SARG() \
1235 	(flags&MAXINT ? va_arg(ap, intmax_t) : \
1236 	    flags&PTRINT ? va_arg(ap, intptr_t) : \
1237 	    flags&SIZEINT ? va_arg(ap, ssize_t) : /* XXX */ \
1238 	    flags&QUADINT ? va_arg(ap, quad_t) : \
1239 	    flags&LONGINT ? va_arg(ap, long) : \
1240 	    flags&SHORTINT ? (long)(short)va_arg(ap, int) : \
1241 	    (long)va_arg(ap, int))
1242 #define	UARG() \
1243 	(flags&MAXINT ? va_arg(ap, uintmax_t) : \
1244 	    flags&PTRINT ? va_arg(ap, uintptr_t) : \
1245 	    flags&SIZEINT ? va_arg(ap, size_t) : \
1246 	    flags&QUADINT ? va_arg(ap, u_quad_t) : \
1247 	    flags&LONGINT ? va_arg(ap, u_long) : \
1248 	    flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \
1249 	    (u_long)va_arg(ap, u_int))
1250 
1251 #define KPRINTF_PUTCHAR(C) {						\
1252 	if (oflags == TOBUFONLY) {					\
1253 		if (sbuf && ((vp == NULL) || (sbuf < tailp))) 		\
1254 			*sbuf++ = (C);					\
1255 	} else {							\
1256 		putchar((C), oflags, vp);				\
1257 	}								\
1258 }
1259 
1260 void
1261 device_printf(device_t dev, const char *fmt, ...)
1262 {
1263 	va_list ap;
1264 
1265 	va_start(ap, fmt);
1266 	printf("%s: ", device_xname(dev));
1267 	vprintf(fmt, ap);
1268 	va_end(ap);
1269 	return;
1270 }
1271 
1272 /*
1273  * Guts of kernel printf.  Note, we already expect to be in a mutex!
1274  */
1275 int
1276 kprintf(const char *fmt0, int oflags, void *vp, char *sbuf, va_list ap)
1277 {
1278 	const char *fmt;	/* format string */
1279 	int ch;			/* character from fmt */
1280 	int n;			/* handy integer (short term usage) */
1281 	char *cp;		/* handy char pointer (short term usage) */
1282 	int flags;		/* flags as above */
1283 	int ret;		/* return value accumulator */
1284 	int width;		/* width from format (%8d), or 0 */
1285 	int prec;		/* precision from format (%.3d), or -1 */
1286 	char sign;		/* sign prefix (' ', '+', '-', or \0) */
1287 
1288 	u_quad_t _uquad;	/* integer arguments %[diouxX] */
1289 	enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
1290 	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
1291 	int realsz;		/* field size expanded by dprec */
1292 	int size;		/* size of converted field or string */
1293 	const char *xdigs;	/* digits for [xX] conversion */
1294 	char bf[KPRINTF_BUFSIZE]; /* space for %c, %[diouxX] */
1295 	char *tailp;		/* tail pointer for snprintf */
1296 
1297 	if (oflags == TOBUFONLY && (vp != NULL))
1298 		tailp = *(char **)vp;
1299 	else
1300 		tailp = NULL;
1301 
1302 	cp = NULL;	/* XXX: shutup gcc */
1303 	size = 0;	/* XXX: shutup gcc */
1304 
1305 	fmt = fmt0;
1306 	ret = 0;
1307 
1308 	xdigs = NULL;		/* XXX: shut up gcc warning */
1309 
1310 	/*
1311 	 * Scan the format for conversions (`%' character).
1312 	 */
1313 	for (;;) {
1314 		for (; *fmt != '%' && *fmt; fmt++) {
1315 			ret++;
1316 			KPRINTF_PUTCHAR(*fmt);
1317 		}
1318 		if (*fmt == 0)
1319 			goto done;
1320 
1321 		fmt++;		/* skip over '%' */
1322 
1323 		flags = 0;
1324 		dprec = 0;
1325 		width = 0;
1326 		prec = -1;
1327 		sign = '\0';
1328 
1329 rflag:		ch = *fmt++;
1330 reswitch:	switch (ch) {
1331 		case ' ':
1332 			/*
1333 			 * ``If the space and + flags both appear, the space
1334 			 * flag will be ignored.''
1335 			 *	-- ANSI X3J11
1336 			 */
1337 			if (!sign)
1338 				sign = ' ';
1339 			goto rflag;
1340 		case '#':
1341 			flags |= ALT;
1342 			goto rflag;
1343 		case '*':
1344 			/*
1345 			 * ``A negative field width argument is taken as a
1346 			 * - flag followed by a positive field width.''
1347 			 *	-- ANSI X3J11
1348 			 * They don't exclude field widths read from args.
1349 			 */
1350 			if ((width = va_arg(ap, int)) >= 0)
1351 				goto rflag;
1352 			width = -width;
1353 			/* FALLTHROUGH */
1354 		case '-':
1355 			flags |= LADJUST;
1356 			goto rflag;
1357 		case '+':
1358 			sign = '+';
1359 			goto rflag;
1360 		case '.':
1361 			if ((ch = *fmt++) == '*') {
1362 				n = va_arg(ap, int);
1363 				prec = n < 0 ? -1 : n;
1364 				goto rflag;
1365 			}
1366 			n = 0;
1367 			while (is_digit(ch)) {
1368 				n = 10 * n + to_digit(ch);
1369 				ch = *fmt++;
1370 			}
1371 			prec = n < 0 ? -1 : n;
1372 			goto reswitch;
1373 		case '0':
1374 			/*
1375 			 * ``Note that 0 is taken as a flag, not as the
1376 			 * beginning of a field width.''
1377 			 *	-- ANSI X3J11
1378 			 */
1379 			flags |= ZEROPAD;
1380 			goto rflag;
1381 		case '1': case '2': case '3': case '4':
1382 		case '5': case '6': case '7': case '8': case '9':
1383 			n = 0;
1384 			do {
1385 				n = 10 * n + to_digit(ch);
1386 				ch = *fmt++;
1387 			} while (is_digit(ch));
1388 			width = n;
1389 			goto reswitch;
1390 		case 'h':
1391 			flags |= SHORTINT;
1392 			goto rflag;
1393 		case 'j':
1394 			flags |= MAXINT;
1395 			goto rflag;
1396 		case 'l':
1397 			if (*fmt == 'l') {
1398 				fmt++;
1399 				flags |= QUADINT;
1400 			} else {
1401 				flags |= LONGINT;
1402 			}
1403 			goto rflag;
1404 		case 'q':
1405 			flags |= QUADINT;
1406 			goto rflag;
1407 		case 't':
1408 			flags |= PTRINT;
1409 			goto rflag;
1410 		case 'z':
1411 			flags |= SIZEINT;
1412 			goto rflag;
1413 		case 'c':
1414 			*(cp = bf) = va_arg(ap, int);
1415 			size = 1;
1416 			sign = '\0';
1417 			break;
1418 		case 'D':
1419 			flags |= LONGINT;
1420 			/*FALLTHROUGH*/
1421 		case 'd':
1422 		case 'i':
1423 			_uquad = SARG();
1424 			if ((quad_t)_uquad < 0) {
1425 				_uquad = -_uquad;
1426 				sign = '-';
1427 			}
1428 			base = DEC;
1429 			goto number;
1430 		case 'n':
1431 			if (flags & MAXINT)
1432 				*va_arg(ap, intmax_t *) = ret;
1433 			else if (flags & PTRINT)
1434 				*va_arg(ap, intptr_t *) = ret;
1435 			else if (flags & SIZEINT)
1436 				*va_arg(ap, ssize_t *) = ret;
1437 			else if (flags & QUADINT)
1438 				*va_arg(ap, quad_t *) = ret;
1439 			else if (flags & LONGINT)
1440 				*va_arg(ap, long *) = ret;
1441 			else if (flags & SHORTINT)
1442 				*va_arg(ap, short *) = ret;
1443 			else
1444 				*va_arg(ap, int *) = ret;
1445 			continue;	/* no output */
1446 		case 'O':
1447 			flags |= LONGINT;
1448 			/*FALLTHROUGH*/
1449 		case 'o':
1450 			_uquad = UARG();
1451 			base = OCT;
1452 			goto nosign;
1453 		case 'p':
1454 			/*
1455 			 * ``The argument shall be a pointer to void.  The
1456 			 * value of the pointer is converted to a sequence
1457 			 * of printable characters, in an implementation-
1458 			 * defined manner.''
1459 			 *	-- ANSI X3J11
1460 			 */
1461 			/* NOSTRICT */
1462 			_uquad = (u_long)va_arg(ap, void *);
1463 			base = HEX;
1464 			xdigs = hexdigits;
1465 			flags |= HEXPREFIX;
1466 			ch = 'x';
1467 			goto nosign;
1468 		case 's':
1469 			if ((cp = va_arg(ap, char *)) == NULL)
1470 				/*XXXUNCONST*/
1471 				cp = __UNCONST("(null)");
1472 			if (prec >= 0) {
1473 				/*
1474 				 * can't use strlen; can only look for the
1475 				 * NUL in the first `prec' characters, and
1476 				 * strlen() will go further.
1477 				 */
1478 				char *p = memchr(cp, 0, prec);
1479 
1480 				if (p != NULL) {
1481 					size = p - cp;
1482 					if (size > prec)
1483 						size = prec;
1484 				} else
1485 					size = prec;
1486 			} else
1487 				size = strlen(cp);
1488 			sign = '\0';
1489 			break;
1490 		case 'U':
1491 			flags |= LONGINT;
1492 			/*FALLTHROUGH*/
1493 		case 'u':
1494 			_uquad = UARG();
1495 			base = DEC;
1496 			goto nosign;
1497 		case 'X':
1498 			xdigs = HEXDIGITS;
1499 			goto hex;
1500 		case 'x':
1501 			xdigs = hexdigits;
1502 hex:			_uquad = UARG();
1503 			base = HEX;
1504 			/* leading 0x/X only if non-zero */
1505 			if (flags & ALT && _uquad != 0)
1506 				flags |= HEXPREFIX;
1507 
1508 			/* unsigned conversions */
1509 nosign:			sign = '\0';
1510 			/*
1511 			 * ``... diouXx conversions ... if a precision is
1512 			 * specified, the 0 flag will be ignored.''
1513 			 *	-- ANSI X3J11
1514 			 */
1515 number:			if ((dprec = prec) >= 0)
1516 				flags &= ~ZEROPAD;
1517 
1518 			/*
1519 			 * ``The result of converting a zero value with an
1520 			 * explicit precision of zero is no characters.''
1521 			 *	-- ANSI X3J11
1522 			 */
1523 			cp = bf + KPRINTF_BUFSIZE;
1524 			if (_uquad != 0 || prec != 0) {
1525 				/*
1526 				 * Unsigned mod is hard, and unsigned mod
1527 				 * by a constant is easier than that by
1528 				 * a variable; hence this switch.
1529 				 */
1530 				switch (base) {
1531 				case OCT:
1532 					do {
1533 						*--cp = to_char(_uquad & 7);
1534 						_uquad >>= 3;
1535 					} while (_uquad);
1536 					/* handle octal leading 0 */
1537 					if (flags & ALT && *cp != '0')
1538 						*--cp = '0';
1539 					break;
1540 
1541 				case DEC:
1542 					/* many numbers are 1 digit */
1543 					while (_uquad >= 10) {
1544 						*--cp = to_char(_uquad % 10);
1545 						_uquad /= 10;
1546 					}
1547 					*--cp = to_char(_uquad);
1548 					break;
1549 
1550 				case HEX:
1551 					do {
1552 						*--cp = xdigs[_uquad & 15];
1553 						_uquad >>= 4;
1554 					} while (_uquad);
1555 					break;
1556 
1557 				default:
1558 					/*XXXUNCONST*/
1559 					cp = __UNCONST("bug in kprintf: bad base");
1560 					size = strlen(cp);
1561 					goto skipsize;
1562 				}
1563 			}
1564 			size = bf + KPRINTF_BUFSIZE - cp;
1565 		skipsize:
1566 			break;
1567 		default:	/* "%?" prints ?, unless ? is NUL */
1568 			if (ch == '\0')
1569 				goto done;
1570 			/* pretend it was %c with argument ch */
1571 			cp = bf;
1572 			*cp = ch;
1573 			size = 1;
1574 			sign = '\0';
1575 			break;
1576 		}
1577 
1578 		/*
1579 		 * All reasonable formats wind up here.  At this point, `cp'
1580 		 * points to a string which (if not flags&LADJUST) should be
1581 		 * padded out to `width' places.  If flags&ZEROPAD, it should
1582 		 * first be prefixed by any sign or other prefix; otherwise,
1583 		 * it should be blank padded before the prefix is emitted.
1584 		 * After any left-hand padding and prefixing, emit zeroes
1585 		 * required by a decimal [diouxX] precision, then print the
1586 		 * string proper, then emit zeroes required by any leftover
1587 		 * floating precision; finally, if LADJUST, pad with blanks.
1588 		 *
1589 		 * Compute actual size, so we know how much to pad.
1590 		 * size excludes decimal prec; realsz includes it.
1591 		 */
1592 		realsz = dprec > size ? dprec : size;
1593 		if (sign)
1594 			realsz++;
1595 		else if (flags & HEXPREFIX)
1596 			realsz+= 2;
1597 
1598 		/* adjust ret */
1599 		ret += width > realsz ? width : realsz;
1600 
1601 		/* right-adjusting blank padding */
1602 		if ((flags & (LADJUST|ZEROPAD)) == 0) {
1603 			n = width - realsz;
1604 			while (n-- > 0)
1605 				KPRINTF_PUTCHAR(' ');
1606 		}
1607 
1608 		/* prefix */
1609 		if (sign) {
1610 			KPRINTF_PUTCHAR(sign);
1611 		} else if (flags & HEXPREFIX) {
1612 			KPRINTF_PUTCHAR('0');
1613 			KPRINTF_PUTCHAR(ch);
1614 		}
1615 
1616 		/* right-adjusting zero padding */
1617 		if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) {
1618 			n = width - realsz;
1619 			while (n-- > 0)
1620 				KPRINTF_PUTCHAR('0');
1621 		}
1622 
1623 		/* leading zeroes from decimal precision */
1624 		n = dprec - size;
1625 		while (n-- > 0)
1626 			KPRINTF_PUTCHAR('0');
1627 
1628 		/* the string or number proper */
1629 		for (; size--; cp++)
1630 			KPRINTF_PUTCHAR(*cp);
1631 		/* left-adjusting padding (always blank) */
1632 		if (flags & LADJUST) {
1633 			n = width - realsz;
1634 			while (n-- > 0)
1635 				KPRINTF_PUTCHAR(' ');
1636 		}
1637 	}
1638 
1639 done:
1640 	if ((oflags == TOBUFONLY) && (vp != NULL))
1641 		*(char **)vp = sbuf;
1642 	(*v_flush)();
1643 
1644 #ifdef RND_PRINTF
1645 	if (!cold) {
1646 		struct timespec ts;
1647 		(void)nanotime(&ts);
1648 		SHA512_Update(&kprnd_sha, (char *)&ts, sizeof(ts));
1649 	}
1650 #endif
1651 	return ret;
1652 }
1653