1 /**	$MirOS: src/sys/kern/subr_prf.c,v 1.6 2014/02/09 23:20:02 tg Exp $ */
2 /*	$OpenBSD: subr_prf.c,v 1.61 2005/04/14 21:58:50 krw Exp $	*/
3 /*	$NetBSD: subr_prf.c,v 1.45 1997/10/24 18:14:25 chuck Exp $	*/
4 
5 /*-
6  * Copyright (c) 1986, 1988, 1991, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  * (c) UNIX System Laboratories, Inc.
9  * All or some portions of this file are derived from material licensed
10  * to the University of California by American Telephone and Telegraph
11  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
12  * the permission of UNIX System Laboratories, Inc.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
39  */
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/buf.h>
44 #include <sys/conf.h>
45 #include <sys/reboot.h>
46 #include <sys/msgbuf.h>
47 #include <sys/proc.h>
48 #include <sys/ioctl.h>
49 #include <sys/vnode.h>
50 #include <sys/file.h>
51 #include <sys/tty.h>
52 #include <sys/tprintf.h>
53 #include <sys/syslog.h>
54 #include <sys/malloc.h>
55 #include <sys/pool.h>
56 
57 #include <dev/cons.h>
58 
59 /*
60  * note that stdarg.h and the ansi style va_start macro is used for both
61  * ansi and traditional c compilers.
62  */
63 #include <sys/stdarg.h>
64 
65 #ifdef KGDB
66 #include <sys/kgdb.h>
67 #include <machine/cpu.h>
68 #endif
69 #ifdef DDB
70 #include <ddb/db_output.h>	/* db_printf, db_putchar prototypes */
71 extern	int db_radix;		/* XXX: for non-standard '%r' format */
72 #endif
73 #if defined(UVM_SWAP_ENCRYPT)
74 extern int uvm_doswapencrypt;
75 #endif
76 
77 
78 /*
79  * defines
80  */
81 
82 /* flags for kprintf */
83 #define TOCONS		0x01	/* to the console */
84 #define TOTTY		0x02	/* to the process' tty */
85 #define TOLOG		0x04	/* to the kernel message buffer */
86 #define TOBUFONLY	0x08	/* to the buffer (only) [for sprintf] */
87 #define TODDB		0x10	/* to ddb console */
88 #define TOCOUNT		0x20	/* act like [v]snprintf */
89 
90 /* max size buffer kprintf needs to print quad_t [size in base 8 + \0] */
91 #define KPRINTF_BUFSIZE		(sizeof(quad_t) * NBBY / 3 + 2)
92 
93 
94 /*
95  * local prototypes
96  */
97 
98 int	 kprintf(const char *, int, void *, char *, va_list);
99 void	 kputchar(int, int, struct tty *);
100 
101 /*
102  * globals
103  */
104 
105 extern struct	tty *constty;	/* pointer to console "window" tty */
106 int	consintr = 1;	/* ok to handle console interrupts? */
107 extern	int log_open;	/* subr_log: is /dev/klog open? */
108 const	char *panicstr; /* arg to first call to panic (used as a flag
109 			   to indicate that panic has already been called). */
110 void (*panic_hook)(void) = NULL;
111 void (*panic_hook_display)(void) = NULL;
112 #ifdef DDB
113 /*
114  * Enter ddb on panic.
115  */
116 int	db_panic = 1;
117 
118 /*
119  * db_console controls if we can be able to enter ddb by a special key
120  * combination (machine dependent).
121  * If DDB_SAFE_CONSOLE is defined in the kernel configuration it allows
122  * to break into console during boot. It's _really_ useful when debugging
123  * some things in the kernel that can cause init(8) to crash.
124  */
125 #ifdef DDB_SAFE_CONSOLE
126 int	db_console = 1;
127 #else
128 int	db_console = 0;
129 #endif
130 #endif
131 
132 /*
133  * panic on spl assertion failure?
134  */
135 int splassert_ctl = 0;
136 
137 /*
138  * v_putc: routine to putc on virtual console
139  *
140  * the v_putc pointer can be used to redirect the console cnputc elsewhere
141  * [e.g. to a "virtual console"].
142  */
143 
144 void (*v_putc)(int) = cnputc;	/* start with cnputc (normal cons) */
145 
146 
147 /*
148  * functions
149  */
150 
151 /*
152  *	Partial support (the failure case) of the assertion facility
153  *	commonly found in userland.
154  */
155 void
__assert(t,f,l,e)156 __assert(t, f, l, e)
157 	const char *t, *f, *e;
158 	int l;
159 {
160 
161 	panic("kernel %sassertion \"%s\" failed: file \"%s\", line %d",
162 		t, e, f, l);
163 }
164 
165 /*
166  * tablefull: warn that a system table is full
167  */
168 
169 void
tablefull(tab)170 tablefull(tab)
171 	const char *tab;
172 {
173 	log(LOG_ERR, "%s: table is full\n", tab);
174 }
175 
176 /*
177  * panic: handle an unresolvable fatal error
178  *
179  * prints "panic: <message>" and reboots.   if called twice (i.e. recursive
180  * call) we avoid trying to sync the disk and just reboot (to avoid
181  * recursive panics).
182  * A stripped version of this code is at ddb/db_usrreq.c - keep it in sync.
183  */
184 
185 void
panic(const char * fmt,...)186 panic(const char *fmt, ...)
187 {
188 	static char panicbuf[512];
189 	int bootopt;
190 	va_list ap;
191 
192 	bootopt = RB_AUTOBOOT | RB_DUMP;
193 #if defined(UVM_SWAP_ENCRYPT)
194 	if (uvm_doswapencrypt)
195 		bootopt &= ~RB_DUMP;
196 #endif
197 	va_start(ap, fmt);
198 	if (panicstr)
199 		bootopt |= RB_NOSYNC;
200 	else {
201 		vsnprintf(panicbuf, sizeof panicbuf, fmt, ap);
202 		panicstr = panicbuf;
203 	}
204 	va_end(ap);
205 
206 	if (panic_hook) {
207 		void (*tmp_panic_hook)(void) = panic_hook;
208 
209 		panic_hook = NULL;
210 		tmp_panic_hook();
211 	}
212 
213 	printf("panic: ");
214 	va_start(ap, fmt);
215 	vprintf(fmt, ap);
216 	printf("\n");
217 	va_end(ap);
218 
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_panic)
228 		Debugger();
229 	else
230 		db_stack_dump();
231 #endif
232 	boot(bootopt);
233 }
234 
235 /*
236  * We print only the function name. The file name is usually very long and
237  * would eat tons of space in the kernel.
238  */
239 void
splassert_fail(int wantipl,int haveipl,const char * func)240 splassert_fail(int wantipl, int haveipl, const char *func)
241 {
242 
243 	printf("splassert: %s: want %d have %d\n", func, wantipl, haveipl);
244 	switch (splassert_ctl) {
245 	case 1:
246 		break;
247 	case 2:
248 #ifdef DDB
249 		db_stack_dump();
250 #endif
251 		break;
252 	case 3:
253 #ifdef DDB
254 		db_stack_dump();
255 		Debugger();
256 #endif
257 		break;
258 	default:
259 		panic("spl assertion failure in %s", func);
260 	}
261 }
262 
263 /*
264  * kernel logging functions: log, logpri, addlog
265  */
266 
267 /*
268  * log: write to the log buffer
269  *
270  * => will not sleep [so safe to call from interrupt]
271  * => will log to console if /dev/klog isn't open
272  */
273 
274 void
log(int level,const char * fmt,...)275 log(int level, const char *fmt, ...)
276 {
277 	int s;
278 	va_list ap;
279 
280 	s = splhigh();
281 	logpri(level);		/* log the level first */
282 	va_start(ap, fmt);
283 	kprintf(fmt, TOLOG, NULL, NULL, ap);
284 	va_end(ap);
285 	splx(s);
286 	if (!log_open) {
287 		va_start(ap, fmt);
288 		kprintf(fmt, TOCONS, NULL, NULL, ap);
289 		va_end(ap);
290 	}
291 	logwakeup();		/* wake up anyone waiting for log msgs */
292 }
293 
294 /*
295  * logpri: log the priority level to the klog
296  */
297 
298 void
logpri(int level)299 logpri(int level)
300 {
301 	char *p;
302 	char snbuf[KPRINTF_BUFSIZE];
303 
304 	kputchar('<', TOLOG, NULL);
305 	snprintf(snbuf, sizeof snbuf, "%d", level);
306 	for (p = snbuf ; *p ; p++)
307 		kputchar(*p, TOLOG, NULL);
308 	kputchar('>', TOLOG, NULL);
309 }
310 
311 /*
312  * addlog: add info to previous log message
313  */
314 
315 int
addlog(const char * fmt,...)316 addlog(const char *fmt, ...)
317 {
318 	int s;
319 	va_list ap;
320 
321 	s = splhigh();
322 	va_start(ap, fmt);
323 	kprintf(fmt, TOLOG, NULL, NULL, ap);
324 	va_end(ap);
325 	splx(s);
326 	if (!log_open) {
327 		va_start(ap, fmt);
328 		kprintf(fmt, TOCONS, NULL, NULL, ap);
329 		va_end(ap);
330 	}
331 	logwakeup();
332 	return(0);
333 }
334 
335 
336 /*
337  * kputchar: print a single character on console or user terminal.
338  *
339  * => if console, then the last MSGBUFS chars are saved in msgbuf
340  *	for inspection later (e.g. dmesg/syslog)
341  */
342 void
kputchar(int c,int flags,struct tty * tp)343 kputchar(int c, int flags, struct tty *tp)
344 {
345 	extern int msgbufmapped;
346 
347 	if (panicstr)
348 		constty = NULL;
349 	if ((flags & TOCONS) && tp == NULL && constty) {
350 		tp = constty;
351 		flags |= TOTTY;
352 	}
353 	if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
354 	    (flags & TOCONS) && tp == constty)
355 		constty = NULL;
356 	if ((flags & TOLOG) &&
357 	    c != '\0' && c != '\r' && c != 0177 && msgbufmapped)
358 		msgbuf_putchar(c);
359 	if ((flags & TOCONS) && constty == NULL && c != '\0')
360 		(*v_putc)(c);
361 #ifdef DDB
362 	if (flags & TODDB)
363 		db_putchar(c);
364 #endif
365 }
366 
367 
368 /*
369  * uprintf: print to the controlling tty of the current process
370  *
371  * => we may block if the tty queue is full
372  * => no message is printed if the queue doesn't clear in a reasonable
373  *	time
374  */
375 
376 void
uprintf(const char * fmt,...)377 uprintf(const char *fmt, ...)
378 {
379 	struct proc *p = curproc;
380 	va_list ap;
381 
382 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
383 		va_start(ap, fmt);
384 		kprintf(fmt, TOTTY, p->p_session->s_ttyp, NULL, ap);
385 		va_end(ap);
386 	}
387 }
388 
389 /*
390  * tprintf functions: used to send messages to a specific process
391  *
392  * usage:
393  *   get a tpr_t handle on a process "p" by using "tprintf_open(p)"
394  *   use the handle when calling "tprintf"
395  *   when done, do a "tprintf_close" to drop the handle
396  */
397 
398 /*
399  * tprintf_open: get a tprintf handle on a process "p"
400  *
401  * => returns NULL if process can't be printed to
402  */
403 
404 tpr_t
tprintf_open(struct proc * p)405 tprintf_open(struct proc *p)
406 {
407 
408 	if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
409 		SESSHOLD(p->p_session);
410 		return ((tpr_t) p->p_session);
411 	}
412 	return ((tpr_t) NULL);
413 }
414 
415 /*
416  * tprintf_close: dispose of a tprintf handle obtained with tprintf_open
417  */
418 
419 void
tprintf_close(tpr_t sess)420 tprintf_close(tpr_t sess)
421 {
422 
423 	if (sess)
424 		SESSRELE((struct session *) sess);
425 }
426 
427 /*
428  * tprintf: given tprintf handle to a process [obtained with tprintf_open],
429  * send a message to the controlling tty for that process.
430  *
431  * => also sends message to /dev/klog
432  */
433 void
tprintf(tpr_t tpr,const char * fmt,...)434 tprintf(tpr_t tpr, const char *fmt, ...)
435 {
436 	struct session *sess = (struct session *)tpr;
437 	struct tty *tp = NULL;
438 	int flags = TOLOG;
439 	va_list ap;
440 
441 	logpri(LOG_INFO);
442 	if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
443 		flags |= TOTTY;
444 		tp = sess->s_ttyp;
445 	}
446 	va_start(ap, fmt);
447 	kprintf(fmt, flags, tp, NULL, ap);
448 	va_end(ap);
449 	logwakeup();
450 }
451 
452 
453 /*
454  * ttyprintf: send a message to a specific tty
455  *
456  * => should be used only by tty driver or anything that knows the
457  *	underlying tty will not be revoked(2)'d away.  [otherwise,
458  *	use tprintf]
459  */
460 void
ttyprintf(struct tty * tp,const char * fmt,...)461 ttyprintf(struct tty *tp, const char *fmt, ...)
462 {
463 	va_list ap;
464 
465 	va_start(ap, fmt);
466 	kprintf(fmt, TOTTY, tp, NULL, ap);
467 	va_end(ap);
468 }
469 
470 #ifdef DDB
471 
472 /*
473  * db_printf: printf for DDB (via db_putchar)
474  */
475 
476 int
db_printf(const char * fmt,...)477 db_printf(const char *fmt, ...)
478 {
479 	va_list ap;
480 	int flags, retval;
481 
482 	flags = TODDB;
483 	if (db_log)
484 		flags |= TOLOG;
485 	va_start(ap, fmt);
486 	retval = kprintf(fmt, flags, NULL, NULL, ap);
487 	va_end(ap);
488 	return(retval);
489 }
490 
491 #endif /* DDB */
492 
493 
494 /*
495  * normal kernel printf functions: printf, vprintf, sprintf
496  */
497 
498 /*
499  * printf: print a message to the console and the log
500  */
501 int
printf(const char * fmt,...)502 printf(const char *fmt, ...)
503 {
504 	va_list ap;
505 	int savintr, retval;
506 
507 	savintr = consintr;		/* disable interrupts */
508 	consintr = 0;
509 	va_start(ap, fmt);
510 	retval = kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
511 	va_end(ap);
512 	if (!panicstr)
513 		logwakeup();
514 	consintr = savintr;		/* reenable interrupts */
515 	return(retval);
516 }
517 
518 /*
519  * vprintf: print a message to the console and the log [already have a
520  *	va_list]
521  */
522 
523 int
vprintf(const char * fmt,va_list ap)524 vprintf(const char *fmt, va_list ap)
525 {
526 	int savintr, retval;
527 
528 	savintr = consintr;		/* disable interrupts */
529 	consintr = 0;
530 	retval = kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
531 	if (!panicstr)
532 		logwakeup();
533 	consintr = savintr;		/* reenable interrupts */
534 	return (retval);
535 }
536 
537 /*
538  * snprintf: print a message to a buffer
539  */
540 int
snprintf(char * buf,size_t size,const char * fmt,...)541 snprintf(char *buf, size_t size, const char *fmt, ...)
542 {
543 	int retval;
544 	va_list ap;
545 	char *p;
546 
547 	p = buf + size - 1;
548 	if (size < 1)
549 		p = buf;
550 	va_start(ap, fmt);
551 	retval = kprintf(fmt, TOBUFONLY | TOCOUNT, &p, buf, ap);
552 	va_end(ap);
553 	if (size > 0)
554 		*(p) = 0;	/* null terminate */
555 	return(retval);
556 }
557 
558 /*
559  * vsnprintf: print a message to a buffer [already have va_alist]
560  */
561 int
vsnprintf(char * buf,size_t size,const char * fmt,va_list ap)562 vsnprintf(char *buf, size_t size, const char *fmt, va_list ap)
563 {
564 	int retval;
565 	char *p;
566 
567 	p = buf + size - 1;
568 	if (size < 1)
569 		p = buf;
570 	retval = kprintf(fmt, TOBUFONLY | TOCOUNT, &p, buf, ap);
571 	if (size > 0)
572 		*(p) = 0;	/* null terminate */
573 	return(retval);
574 }
575 
576 /*
577  * kprintf: scaled down version of printf(3).
578  *
579  * this version based on vfprintf() from libc which was derived from
580  * software contributed to Berkeley by Chris Torek.
581  *
582  * Two additional formats:
583  *
584  * The format %b is supported to decode error registers.
585  * Its usage is:
586  *
587  *	printf("reg=%b\n", regval, "<base><arg>*");
588  *
589  * where <base> is the output base expressed as a control character, e.g.
590  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
591  * the first of which gives the bit number to be inspected (origin 1), and
592  * the next characters (up to a control character, i.e. a character <= 32),
593  * give the name of the register.  Thus:
594  *
595  *	kprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
596  *
597  * would produce output:
598  *
599  *	reg=3<BITTWO,BITONE>
600  *
601  * This code is large and complicated...
602  */
603 
604 /*
605  * macros for converting digits to letters and vice versa
606  */
607 #define	to_digit(c)	((c) - '0')
608 #define is_digit(c)	((unsigned)to_digit(c) <= 9)
609 #define	to_char(n)	((n) + '0')
610 
611 /*
612  * flags used during conversion.
613  */
614 #define	ALT		0x001		/* alternate form */
615 #define	HEXPREFIX	0x002		/* add 0x or 0X prefix */
616 #define	LADJUST		0x004		/* left adjustment */
617 /*#define LONGDBL	0x008		 * long double; unimplemented */
618 #define	LONGINT		0x010		/* long integer */
619 #define	QUADINT		0x020		/* quad integer */
620 #define	SHORTINT	0x040		/* short integer */
621 #define	ZEROPAD		0x080		/* zero (as opposed to blank) pad */
622 #define FPT		0x100		/* Floating point number */
623 
624 	/*
625 	 * To extend shorts properly, we need both signed and unsigned
626 	 * argument extraction methods.
627 	 */
628 #define	SARG() \
629 	(flags&QUADINT ? va_arg(ap, quad_t) : \
630 	    flags&LONGINT ? va_arg(ap, long) : \
631 	    flags&SHORTINT ? (long)(short)va_arg(ap, int) : \
632 	    (long)va_arg(ap, int))
633 #define	UARG() \
634 	(flags&QUADINT ? va_arg(ap, u_quad_t) : \
635 	    flags&LONGINT ? va_arg(ap, u_long) : \
636 	    flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \
637 	    (u_long)va_arg(ap, u_int))
638 
639 #define KPRINTF_PUTCHAR(C) do {					\
640 	int chr = (C);							\
641 	ret += 1;							\
642 	if (oflags & TOBUFONLY) {					\
643 		if ((vp != NULL) && (sbuf == tailp)) {			\
644 			if (!(oflags & TOCOUNT))				\
645 				goto overflow;				\
646 		} else							\
647 			*sbuf++ = chr;					\
648 	} else {							\
649 		kputchar(chr, oflags, (struct tty *)vp);			\
650 	}								\
651 } while(0)
652 
653 int
kprintf(const char * fmt0,int oflags,void * vp,char * sbuf,va_list ap)654 kprintf(const char *fmt0, int oflags, void *vp, char *sbuf, va_list ap)
655 {
656 	char *fmt;		/* format string */
657 	int ch;			/* character from fmt */
658 	int n;			/* handy integer (short term usage) */
659 	char *cp = NULL;	/* handy char pointer (short term usage) */
660 	int flags;		/* flags as above */
661 	int ret;		/* return value accumulator */
662 	int width;		/* width from format (%8d), or 0 */
663 	int prec;		/* precision from format (%.3d), or -1 */
664 	char sign;		/* sign prefix (' ', '+', '-', or \0) */
665 
666 	u_quad_t _uquad;	/* integer arguments %[diouxX] */
667 	enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
668 	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
669 	int realsz;		/* field size expanded by dprec */
670 	int size = 0;		/* size of converted field or string */
671 	char *xdigs = NULL;	/* digits for [xX] conversion */
672 	char buf[KPRINTF_BUFSIZE]; /* space for %c, %[diouxX] */
673 	char *tailp = NULL;	/* tail pointer for snprintf */
674 
675 	if ((oflags & TOBUFONLY) && (vp != NULL))
676 		tailp = *(char **)vp;
677 
678 	fmt = (char *)fmt0;
679 	ret = 0;
680 
681 	/*
682 	 * Scan the format for conversions (`%' character).
683 	 */
684 	for (;;) {
685 		while (*fmt != '%' && *fmt) {
686 			KPRINTF_PUTCHAR(*fmt++);
687 		}
688 		if (*fmt == 0)
689 			goto done;
690 
691 		fmt++;		/* skip over '%' */
692 
693 		flags = 0;
694 		dprec = 0;
695 		width = 0;
696 		prec = -1;
697 		sign = '\0';
698 
699 rflag:		ch = *fmt++;
700 reswitch:	switch (ch) {
701 		/* XXX: non-standard '%b' format */
702 		case 'b': {
703 			char *b, *z;
704 			int tmp;
705 			_uquad = va_arg(ap, u_int);
706 			b = va_arg(ap, char *);
707 			if (*b == 8)
708 				snprintf(buf, sizeof buf, "%llo", _uquad);
709 			else if (*b == 10)
710 				snprintf(buf, sizeof buf, "%lld", _uquad);
711 			else if (*b == 16)
712 				snprintf(buf, sizeof buf, "%llx", _uquad);
713 			else
714 				break;
715 			b++;
716 
717 			z = buf;
718 			while (*z) {
719 				KPRINTF_PUTCHAR(*z++);
720 			}
721 
722 			if (_uquad) {
723 				tmp = 0;
724 				while ((n = *b++) != 0) {
725 					if (_uquad & (1 << (n - 1))) {
726 						KPRINTF_PUTCHAR(tmp ? ',':'<');
727 						while ((n = *b) > ' ') {
728 							KPRINTF_PUTCHAR(n);
729 							b++;
730 						}
731 						tmp = 1;
732 					} else {
733 						while(*b > ' ')
734 							b++;
735 					}
736 				}
737 				if (tmp) {
738 					KPRINTF_PUTCHAR('>');
739 				}
740 			}
741 			continue;	/* no output */
742 		}
743 
744 #ifdef DDB
745 		/* XXX: non-standard '%r' format (print int in db_radix) */
746 		case 'r':
747 			if ((oflags & TODDB) == 0)
748 				goto default_case;
749 
750 			if (db_radix == 16)
751 				goto case_z;	/* signed hex */
752 			_uquad = SARG();
753 			if ((quad_t)_uquad < 0) {
754 				_uquad = -_uquad;
755 				sign = '-';
756 			}
757 			base = (db_radix == 8) ? OCT : DEC;
758 			goto number;
759 
760 
761 		/* XXX: non-standard '%z' format ("signed hex", a "hex %i")*/
762 		case 'z':
763 		case_z:
764 			if ((oflags & TODDB) == 0)
765 				goto default_case;
766 
767 			xdigs = "0123456789abcdef";
768 			ch = 'x';	/* the 'x' in '0x' (below) */
769 			_uquad = SARG();
770 			base = HEX;
771 			/* leading 0x/X only if non-zero */
772 			if (flags & ALT && _uquad != 0)
773 				flags |= HEXPREFIX;
774 			if ((quad_t)_uquad < 0) {
775 				_uquad = -_uquad;
776 				sign = '-';
777 			}
778 			goto number;
779 #endif
780 
781 		case ' ':
782 			/*
783 			 * ``If the space and + flags both appear, the space
784 			 * flag will be ignored.''
785 			 *	-- ANSI X3J11
786 			 */
787 			if (!sign)
788 				sign = ' ';
789 			goto rflag;
790 		case '#':
791 			flags |= ALT;
792 			goto rflag;
793 		case '*':
794 			/*
795 			 * ``A negative field width argument is taken as a
796 			 * - flag followed by a positive field width.''
797 			 *	-- ANSI X3J11
798 			 * They don't exclude field widths read from args.
799 			 */
800 			if ((width = va_arg(ap, int)) >= 0)
801 				goto rflag;
802 			width = -width;
803 			/* FALLTHROUGH */
804 		case '-':
805 			flags |= LADJUST;
806 			goto rflag;
807 		case '+':
808 			sign = '+';
809 			goto rflag;
810 		case '.':
811 			if ((ch = *fmt++) == '*') {
812 				n = va_arg(ap, int);
813 				prec = n < 0 ? -1 : n;
814 				goto rflag;
815 			}
816 			n = 0;
817 			while (is_digit(ch)) {
818 				n = 10 * n + to_digit(ch);
819 				ch = *fmt++;
820 			}
821 			prec = n < 0 ? -1 : n;
822 			goto reswitch;
823 		case '0':
824 			/*
825 			 * ``Note that 0 is taken as a flag, not as the
826 			 * beginning of a field width.''
827 			 *	-- ANSI X3J11
828 			 */
829 			flags |= ZEROPAD;
830 			goto rflag;
831 		case '1': case '2': case '3': case '4':
832 		case '5': case '6': case '7': case '8': case '9':
833 			n = 0;
834 			do {
835 				n = 10 * n + to_digit(ch);
836 				ch = *fmt++;
837 			} while (is_digit(ch));
838 			width = n;
839 			goto reswitch;
840 		case 'h':
841 			flags |= SHORTINT;
842 			goto rflag;
843 		case 'l':
844 			if (*fmt == 'l') {
845 				fmt++;
846 				flags |= QUADINT;
847 			} else {
848 				flags |= LONGINT;
849 			}
850 			goto rflag;
851 		case 'q':
852 			flags |= QUADINT;
853 			goto rflag;
854 		case 'c':
855 			*(cp = buf) = va_arg(ap, int);
856 			size = 1;
857 			sign = '\0';
858 			break;
859 		case 'D':
860 			flags |= LONGINT;
861 			/*FALLTHROUGH*/
862 		case 'd':
863 		case 'i':
864 			_uquad = SARG();
865 			if ((quad_t)_uquad < 0) {
866 				_uquad = -_uquad;
867 				sign = '-';
868 			}
869 			base = DEC;
870 			goto number;
871 		case 'n':
872 #ifdef DDB
873 		/* XXX: non-standard '%n' format */
874 		/*
875 		 * XXX: HACK!   DDB wants '%n' to be a '%u' printed
876 		 * in db_radix format.   this should die since '%n'
877 		 * is already defined in standard printf to write
878 		 * the number of chars printed so far to the arg (which
879 		 * should be a pointer.
880 		 */
881 			if (oflags & TODDB) {
882 				if (db_radix == 16)
883 					ch = 'x';	/* convert to %x */
884 				else if (db_radix == 8)
885 					ch = 'o';	/* convert to %o */
886 				else
887 					ch = 'u';	/* convert to %u */
888 
889 				/* ... and start again */
890 				goto reswitch;
891 			}
892 
893 #endif
894 			if (flags & QUADINT)
895 				*va_arg(ap, quad_t *) = ret;
896 			else if (flags & LONGINT)
897 				*va_arg(ap, long *) = ret;
898 			else if (flags & SHORTINT)
899 				*va_arg(ap, short *) = ret;
900 			else
901 				*va_arg(ap, int *) = ret;
902 			continue;	/* no output */
903 		case 'O':
904 			flags |= LONGINT;
905 			/*FALLTHROUGH*/
906 		case 'o':
907 			_uquad = UARG();
908 			base = OCT;
909 			goto nosign;
910 		case 'p':
911 			/*
912 			 * ``The argument shall be a pointer to void.  The
913 			 * value of the pointer is converted to a sequence
914 			 * of printable characters, in an implementation-
915 			 * defined manner.''
916 			 *	-- ANSI X3J11
917 			 */
918 			/* NOSTRICT */
919 			_uquad = (u_long)va_arg(ap, void *);
920 			base = HEX;
921 			xdigs = "0123456789abcdef";
922 			flags |= HEXPREFIX;
923 			ch = 'x';
924 			goto nosign;
925 		case 's':
926 			if ((cp = va_arg(ap, char *)) == NULL)
927 				cp = "(null)";
928 			if (prec >= 0) {
929 				/*
930 				 * can't use strlen; can only look for the
931 				 * NUL in the first `prec' characters, and
932 				 * strlen() will go further.
933 				 */
934 				char *p = memchr(cp, 0, prec);
935 
936 				if (p != NULL) {
937 					size = p - cp;
938 					if (size > prec)
939 						size = prec;
940 				} else
941 					size = prec;
942 			} else
943 				size = strlen(cp);
944 			sign = '\0';
945 			break;
946 		case 'U':
947 			flags |= LONGINT;
948 			/*FALLTHROUGH*/
949 		case 'u':
950 			_uquad = UARG();
951 			base = DEC;
952 			goto nosign;
953 		case 'X':
954 			xdigs = "0123456789ABCDEF";
955 			goto hex;
956 		case 'x':
957 			xdigs = "0123456789abcdef";
958 hex:			_uquad = UARG();
959 			base = HEX;
960 			/* leading 0x/X only if non-zero */
961 			if (flags & ALT && _uquad != 0)
962 				flags |= HEXPREFIX;
963 
964 			/* unsigned conversions */
965 nosign:			sign = '\0';
966 			/*
967 			 * ``... diouXx conversions ... if a precision is
968 			 * specified, the 0 flag will be ignored.''
969 			 *	-- ANSI X3J11
970 			 */
971 number:			if ((dprec = prec) >= 0)
972 				flags &= ~ZEROPAD;
973 
974 			/*
975 			 * ``The result of converting a zero value with an
976 			 * explicit precision of zero is no characters.''
977 			 *	-- ANSI X3J11
978 			 */
979 			cp = buf + KPRINTF_BUFSIZE;
980 			if (_uquad != 0 || prec != 0) {
981 				/*
982 				 * Unsigned mod is hard, and unsigned mod
983 				 * by a constant is easier than that by
984 				 * a variable; hence this switch.
985 				 */
986 				switch (base) {
987 				case OCT:
988 					do {
989 						*--cp = to_char(_uquad & 7);
990 						_uquad >>= 3;
991 					} while (_uquad);
992 					/* handle octal leading 0 */
993 					if (flags & ALT && *cp != '0')
994 						*--cp = '0';
995 					break;
996 
997 				case DEC:
998 					/* many numbers are 1 digit */
999 					while (_uquad >= 10) {
1000 						*--cp = to_char(_uquad % 10);
1001 						_uquad /= 10;
1002 					}
1003 					*--cp = to_char(_uquad);
1004 					break;
1005 
1006 				case HEX:
1007 					do {
1008 						*--cp = xdigs[_uquad & 15];
1009 						_uquad >>= 4;
1010 					} while (_uquad);
1011 					break;
1012 
1013 				default:
1014 					cp = "bug in kprintf: bad base";
1015 					size = strlen(cp);
1016 					goto skipsize;
1017 				}
1018 			}
1019 			size = buf + KPRINTF_BUFSIZE - cp;
1020 		skipsize:
1021 			break;
1022 		default:	/* "%?" prints ?, unless ? is NUL */
1023 #ifdef DDB
1024 		default_case:	/* DDB */
1025 #endif
1026 			if (ch == '\0')
1027 				goto done;
1028 			/* pretend it was %c with argument ch */
1029 			cp = buf;
1030 			*cp = ch;
1031 			size = 1;
1032 			sign = '\0';
1033 			break;
1034 		}
1035 
1036 		/*
1037 		 * All reasonable formats wind up here.  At this point, `cp'
1038 		 * points to a string which (if not flags&LADJUST) should be
1039 		 * padded out to `width' places.  If flags&ZEROPAD, it should
1040 		 * first be prefixed by any sign or other prefix; otherwise,
1041 		 * it should be blank padded before the prefix is emitted.
1042 		 * After any left-hand padding and prefixing, emit zeroes
1043 		 * required by a decimal [diouxX] precision, then print the
1044 		 * string proper, then emit zeroes required by any leftover
1045 		 * floating precision; finally, if LADJUST, pad with blanks.
1046 		 *
1047 		 * Compute actual size, so we know how much to pad.
1048 		 * size excludes decimal prec; realsz includes it.
1049 		 */
1050 		realsz = dprec > size ? dprec : size;
1051 		if (sign)
1052 			realsz++;
1053 		else if (flags & HEXPREFIX)
1054 			realsz+= 2;
1055 
1056 		/* right-adjusting blank padding */
1057 		if ((flags & (LADJUST|ZEROPAD)) == 0) {
1058 			n = width - realsz;
1059 			while (n-- > 0)
1060 				KPRINTF_PUTCHAR(' ');
1061 		}
1062 
1063 		/* prefix */
1064 		if (sign) {
1065 			KPRINTF_PUTCHAR(sign);
1066 		} else if (flags & HEXPREFIX) {
1067 			KPRINTF_PUTCHAR('0');
1068 			KPRINTF_PUTCHAR(ch);
1069 		}
1070 
1071 		/* right-adjusting zero padding */
1072 		if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) {
1073 			n = width - realsz;
1074 			while (n-- > 0)
1075 				KPRINTF_PUTCHAR('0');
1076 		}
1077 
1078 		/* leading zeroes from decimal precision */
1079 		n = dprec - size;
1080 		while (n-- > 0)
1081 			KPRINTF_PUTCHAR('0');
1082 
1083 		/* the string or number proper */
1084 		while (size--)
1085 			KPRINTF_PUTCHAR(*cp++);
1086 		/* left-adjusting padding (always blank) */
1087 		if (flags & LADJUST) {
1088 			n = width - realsz;
1089 			while (n-- > 0)
1090 				KPRINTF_PUTCHAR(' ');
1091 		}
1092 	}
1093 
1094 done:
1095 	if ((oflags & TOBUFONLY) && (vp != NULL))
1096 		*(char **)vp = sbuf;
1097 overflow:
1098 	return (ret);
1099 	/* NOTREACHED */
1100 }
1101