xref: /openbsd-src/sys/kern/subr_prf.c (revision c7e8ea31cd41a963f06f0a8ba93948b06aa6b4a4)
1 /*	$OpenBSD: subr_prf.c,v 1.91 2017/04/30 16:45:46 mpi Exp $	*/
2 /*	$NetBSD: subr_prf.c,v 1.45 1997/10/24 18:14:25 chuck Exp $	*/
3 
4 /*-
5  * Copyright (c) 1986, 1988, 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  * (c) UNIX System Laboratories, Inc.
8  * All or some portions of this file are derived from material licensed
9  * to the University of California by American Telephone and Telegraph
10  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
11  * the permission of UNIX System Laboratories, Inc.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/conf.h>
43 #include <sys/reboot.h>
44 #include <sys/msgbuf.h>
45 #include <sys/proc.h>
46 #include <sys/ioctl.h>
47 #include <sys/vnode.h>
48 #include <sys/file.h>
49 #include <sys/tty.h>
50 #include <sys/tprintf.h>
51 #include <sys/syslog.h>
52 #include <sys/malloc.h>
53 #include <sys/pool.h>
54 #include <sys/mutex.h>
55 
56 #include <dev/cons.h>
57 
58 /*
59  * note that stdarg.h and the ansi style va_start macro is used for both
60  * ansi and traditional c compilers.
61  */
62 #include <sys/stdarg.h>
63 
64 #ifdef DDB
65 #include <ddb/db_output.h>	/* db_printf, db_putchar prototypes */
66 #include <ddb/db_var.h>		/* db_log, db_radix */
67 #endif
68 
69 
70 /*
71  * defines
72  */
73 
74 /* flags for kprintf */
75 #define TOCONS		0x01	/* to the console */
76 #define TOTTY		0x02	/* to the process' tty */
77 #define TOLOG		0x04	/* to the kernel message buffer */
78 #define TOBUFONLY	0x08	/* to the buffer (only) [for snprintf] */
79 #define TODDB		0x10	/* to ddb console */
80 #define TOCOUNT		0x20	/* act like [v]snprintf */
81 
82 /* max size buffer kprintf needs to print quad_t [size in base 8 + \0] */
83 #define KPRINTF_BUFSIZE		(sizeof(quad_t) * NBBY / 3 + 2)
84 
85 
86 /*
87  * local prototypes
88  */
89 
90 int	 kprintf(const char *, int, void *, char *, va_list);
91 void	 kputchar(int, int, struct tty *);
92 
93 struct mutex kprintf_mutex =
94     MUTEX_INITIALIZER_FLAGS(IPL_HIGH, "kprintf", MTX_NOWITNESS);
95 
96 /*
97  * globals
98  */
99 
100 extern	int log_open;	/* subr_log: is /dev/klog open? */
101 const	char *panicstr; /* arg to first call to panic (used as a flag
102 			   to indicate that panic has already been called). */
103 #ifdef DDB
104 /*
105  * Enter ddb on panic.
106  */
107 int	db_panic = 1;
108 
109 /*
110  * db_console controls if we can be able to enter ddb by a special key
111  * combination (machine dependent).
112  * If DDB_SAFE_CONSOLE is defined in the kernel configuration it allows
113  * to break into console during boot. It's _really_ useful when debugging
114  * some things in the kernel that can cause init(8) to crash.
115  */
116 #ifdef DDB_SAFE_CONSOLE
117 int	db_console = 1;
118 #else
119 int	db_console = 0;
120 #endif
121 
122 /*
123  * flag to indicate if we are currently in ddb (on some processor)
124  */
125 int db_is_active;
126 #endif
127 
128 /*
129  * panic on spl assertion failure?
130  */
131 int splassert_ctl = 1;
132 
133 /*
134  * v_putc: routine to putc on virtual console
135  *
136  * the v_putc pointer can be used to redirect the console cnputc elsewhere
137  * [e.g. to a "virtual console"].
138  */
139 
140 void (*v_putc)(int) = cnputc;	/* start with cnputc (normal cons) */
141 
142 
143 /*
144  * functions
145  */
146 
147 /*
148  *	Partial support (the failure case) of the assertion facility
149  *	commonly found in userland.
150  */
151 void
152 __assert(const char *t, const char *f, int l, const char *e)
153 {
154 
155 	panic(__KASSERTSTR, t, e, f, l);
156 }
157 
158 /*
159  * tablefull: warn that a system table is full
160  */
161 
162 void
163 tablefull(const char *tab)
164 {
165 	log(LOG_ERR, "%s: table is full\n", tab);
166 }
167 
168 /*
169  * panic: handle an unresolvable fatal error
170  *
171  * prints "panic: <message>" and reboots.   if called twice (i.e. recursive
172  * call) we avoid trying to sync the disk and just reboot (to avoid
173  * recursive panics).
174  */
175 
176 void
177 panic(const char *fmt, ...)
178 {
179 	static char panicbuf[512];
180 	int bootopt;
181 	va_list ap;
182 
183 	/* do not trigger assertions, we know that we are inconsistent */
184 	splassert_ctl = 0;
185 
186 	bootopt = RB_AUTOBOOT | RB_DUMP;
187 	va_start(ap, fmt);
188 	if (panicstr)
189 		bootopt |= RB_NOSYNC;
190 	else {
191 		vsnprintf(panicbuf, sizeof panicbuf, fmt, ap);
192 		panicstr = panicbuf;
193 	}
194 	va_end(ap);
195 
196 	printf("panic: ");
197 	va_start(ap, fmt);
198 	vprintf(fmt, ap);
199 	printf("\n");
200 	va_end(ap);
201 
202 #ifdef DDB
203 	if (db_panic)
204 		db_enter();
205 	else
206 		db_stack_dump();
207 #endif
208 	reboot(bootopt);
209 	/* NOTREACHED */
210 }
211 
212 /*
213  * We print only the function name. The file name is usually very long and
214  * would eat tons of space in the kernel.
215  */
216 void
217 splassert_fail(int wantipl, int haveipl, const char *func)
218 {
219 
220 	printf("splassert: %s: want %d have %d\n", func, wantipl, haveipl);
221 	switch (splassert_ctl) {
222 	case 1:
223 		break;
224 	case 2:
225 #ifdef DDB
226 		db_stack_dump();
227 #endif
228 		break;
229 	case 3:
230 #ifdef DDB
231 		db_stack_dump();
232 		db_enter();
233 #endif
234 		break;
235 	default:
236 		panic("spl assertion failure in %s", func);
237 	}
238 }
239 
240 /*
241  * kernel logging functions: log, logpri, addlog
242  */
243 
244 /*
245  * log: write to the log buffer
246  *
247  * => will not sleep [so safe to call from interrupt]
248  * => will log to console if /dev/klog isn't open
249  */
250 
251 void
252 log(int level, const char *fmt, ...)
253 {
254 	int s;
255 	va_list ap;
256 
257 	s = splhigh();
258 	logpri(level);		/* log the level first */
259 	va_start(ap, fmt);
260 	kprintf(fmt, TOLOG, NULL, NULL, ap);
261 	va_end(ap);
262 	splx(s);
263 	if (!log_open) {
264 		va_start(ap, fmt);
265 		kprintf(fmt, TOCONS, NULL, NULL, ap);
266 		va_end(ap);
267 	}
268 	logwakeup();		/* wake up anyone waiting for log msgs */
269 }
270 
271 /*
272  * logpri: log the priority level to the klog
273  */
274 
275 void
276 logpri(int level)
277 {
278 	char *p;
279 	char snbuf[KPRINTF_BUFSIZE];
280 
281 	kputchar('<', TOLOG, NULL);
282 	snprintf(snbuf, sizeof snbuf, "%d", level);
283 	for (p = snbuf ; *p ; p++)
284 		kputchar(*p, TOLOG, NULL);
285 	kputchar('>', TOLOG, NULL);
286 }
287 
288 /*
289  * addlog: add info to previous log message
290  */
291 
292 int
293 addlog(const char *fmt, ...)
294 {
295 	int s;
296 	va_list ap;
297 
298 	s = splhigh();
299 	va_start(ap, fmt);
300 	kprintf(fmt, TOLOG, NULL, NULL, ap);
301 	va_end(ap);
302 	splx(s);
303 	if (!log_open) {
304 		va_start(ap, fmt);
305 		kprintf(fmt, TOCONS, NULL, NULL, ap);
306 		va_end(ap);
307 	}
308 	logwakeup();
309 	return(0);
310 }
311 
312 
313 /*
314  * kputchar: print a single character on console or user terminal.
315  *
316  * => if console, then the last MSGBUFS chars are saved in msgbuf
317  *	for inspection later (e.g. dmesg/syslog)
318  */
319 void
320 kputchar(int c, int flags, struct tty *tp)
321 {
322 	extern int msgbufmapped;
323 	int ddb_active = 0;
324 
325 #ifdef DDB
326 	ddb_active = db_is_active;
327 #endif
328 
329 	if (panicstr)
330 		constty = NULL;
331 
332 	if ((flags & TOCONS) && tp == NULL && constty && !ddb_active) {
333 		tp = constty;
334 		flags |= TOTTY;
335 	}
336 	if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
337 	    (flags & TOCONS) && tp == constty)
338 		constty = NULL;
339 	if ((flags & TOLOG) &&
340 	    c != '\0' && c != '\r' && c != 0177 && msgbufmapped)
341 		msgbuf_putchar(msgbufp, c);
342 	if ((flags & TOCONS) && (constty == NULL || ddb_active) && c != '\0')
343 		(*v_putc)(c);
344 #ifdef DDB
345 	if (flags & TODDB)
346 		db_putchar(c);
347 #endif
348 }
349 
350 
351 /*
352  * uprintf: print to the controlling tty of the current process
353  *
354  * => we may block if the tty queue is full
355  * => no message is printed if the queue doesn't clear in a reasonable
356  *	time
357  */
358 
359 void
360 uprintf(const char *fmt, ...)
361 {
362 	struct process *pr = curproc->p_p;
363 	va_list ap;
364 
365 	if (pr->ps_flags & PS_CONTROLT && pr->ps_session->s_ttyvp) {
366 		va_start(ap, fmt);
367 		kprintf(fmt, TOTTY, pr->ps_session->s_ttyp, NULL, ap);
368 		va_end(ap);
369 	}
370 }
371 
372 #if defined(NFSSERVER) || defined(NFSCLIENT)
373 
374 /*
375  * tprintf functions: used to send messages to a specific process
376  *
377  * usage:
378  *   get a tpr_t handle on a process "p" by using "tprintf_open(p)"
379  *   use the handle when calling "tprintf"
380  *   when done, do a "tprintf_close" to drop the handle
381  */
382 
383 /*
384  * tprintf_open: get a tprintf handle on a process "p"
385  * XXX change s/proc/process
386  *
387  * => returns NULL if process can't be printed to
388  */
389 
390 tpr_t
391 tprintf_open(struct proc *p)
392 {
393 	struct process *pr = p->p_p;
394 
395 	if (pr->ps_flags & PS_CONTROLT && pr->ps_session->s_ttyvp) {
396 		SESSHOLD(pr->ps_session);
397 		return ((tpr_t)pr->ps_session);
398 	}
399 	return ((tpr_t) NULL);
400 }
401 
402 /*
403  * tprintf_close: dispose of a tprintf handle obtained with tprintf_open
404  */
405 
406 void
407 tprintf_close(tpr_t sess)
408 {
409 
410 	if (sess)
411 		SESSRELE((struct session *) sess);
412 }
413 
414 /*
415  * tprintf: given tprintf handle to a process [obtained with tprintf_open],
416  * send a message to the controlling tty for that process.
417  *
418  * => also sends message to /dev/klog
419  */
420 void
421 tprintf(tpr_t tpr, const char *fmt, ...)
422 {
423 	struct session *sess = (struct session *)tpr;
424 	struct tty *tp = NULL;
425 	int flags = TOLOG;
426 	va_list ap;
427 
428 	logpri(LOG_INFO);
429 	if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
430 		flags |= TOTTY;
431 		tp = sess->s_ttyp;
432 	}
433 	va_start(ap, fmt);
434 	kprintf(fmt, flags, tp, NULL, ap);
435 	va_end(ap);
436 	logwakeup();
437 }
438 
439 #endif	/* NFSSERVER || NFSCLIENT */
440 
441 
442 /*
443  * ttyprintf: send a message to a specific tty
444  *
445  * => should be used only by tty driver or anything that knows the
446  *	underlying tty will not be revoked(2)'d away.  [otherwise,
447  *	use tprintf]
448  */
449 void
450 ttyprintf(struct tty *tp, const char *fmt, ...)
451 {
452 	va_list ap;
453 
454 	va_start(ap, fmt);
455 	kprintf(fmt, TOTTY, tp, NULL, ap);
456 	va_end(ap);
457 }
458 
459 #ifdef DDB
460 
461 /*
462  * db_printf: printf for DDB (via db_putchar)
463  */
464 
465 int
466 db_printf(const char *fmt, ...)
467 {
468 	va_list ap;
469 	int retval;
470 
471 	va_start(ap, fmt);
472 	retval = db_vprintf(fmt, ap);
473 	va_end(ap);
474 	return(retval);
475 }
476 
477 int
478 db_vprintf(const char *fmt, va_list ap)
479 {
480 	int flags;
481 
482 	flags = TODDB;
483 	if (db_log)
484 		flags |= TOLOG;
485 	return (kprintf(fmt, flags, NULL, NULL, ap));
486 }
487 #endif /* DDB */
488 
489 
490 /*
491  * normal kernel printf functions: printf, vprintf, snprintf
492  */
493 
494 /*
495  * printf: print a message to the console and the log
496  */
497 int
498 printf(const char *fmt, ...)
499 {
500 	va_list ap;
501 	int retval;
502 
503 	mtx_enter(&kprintf_mutex);
504 
505 	va_start(ap, fmt);
506 	retval = kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
507 	va_end(ap);
508 	if (!panicstr)
509 		logwakeup();
510 
511 	mtx_leave(&kprintf_mutex);
512 
513 	return(retval);
514 }
515 
516 /*
517  * vprintf: print a message to the console and the log [already have a
518  *	va_list]
519  */
520 
521 int
522 vprintf(const char *fmt, va_list ap)
523 {
524 	int retval;
525 
526 	mtx_enter(&kprintf_mutex);
527 
528 	retval = kprintf(fmt, TOCONS | TOLOG, NULL, NULL, ap);
529 	if (!panicstr)
530 		logwakeup();
531 
532 	mtx_leave(&kprintf_mutex);
533 
534 	return (retval);
535 }
536 
537 /*
538  * snprintf: print a message to a buffer
539  */
540 int
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
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  * The additional format %b is supported to decode error registers.
583  * Its usage is:
584  *
585  *	printf("reg=%b\n", regval, "<base><arg>*");
586  *
587  * where <base> is the output base expressed as a control character, e.g.
588  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
589  * the first of which gives the bit number to be inspected (origin 1), and
590  * the next characters (up to a control character, i.e. a character <= 32),
591  * give the name of the register.  Thus:
592  *
593  *	kprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
594  *
595  * would produce output:
596  *
597  *	reg=3<BITTWO,BITONE>
598  *
599  * To support larger integers (> 32 bits), %b formatting will also accept
600  * control characters in the region 0x80 - 0xff.  0x80 refers to bit 0,
601  * 0x81 refers to bit 1, and so on.  The equivalent string to the above is:
602  *
603  *	kprintf("reg=%b\n", 3, "\10\201BITTWO\200BITONE\n");
604  *
605  * and would produce the same output.
606  *
607  * Like the rest of printf, %b can be prefixed to handle various size
608  * modifiers, eg. %b is for "int", %lb is for "long", and %llb supports
609  * "long long".
610  *
611  * This code is large and complicated...
612  */
613 
614 /*
615  * macros for converting digits to letters and vice versa
616  */
617 #define	to_digit(c)	((c) - '0')
618 #define is_digit(c)	((unsigned)to_digit(c) <= 9)
619 #define	to_char(n)	((n) + '0')
620 
621 /*
622  * flags used during conversion.
623  */
624 #define	ALT		0x001		/* alternate form */
625 #define	HEXPREFIX	0x002		/* add 0x or 0X prefix */
626 #define	LADJUST		0x004		/* left adjustment */
627 #define	LONGDBL		0x008		/* long double; unimplemented */
628 #define	LONGINT		0x010		/* long integer */
629 #define	QUADINT		0x020		/* quad integer */
630 #define	SHORTINT	0x040		/* short integer */
631 #define	ZEROPAD		0x080		/* zero (as opposed to blank) pad */
632 #define FPT		0x100		/* Floating point number */
633 #define SIZEINT		0x200		/* (signed) size_t */
634 
635 	/*
636 	 * To extend shorts properly, we need both signed and unsigned
637 	 * argument extraction methods.
638 	 */
639 #define	SARG() \
640 	(flags&QUADINT ? va_arg(ap, quad_t) : \
641 	    flags&LONGINT ? va_arg(ap, long) : \
642 	    flags&SIZEINT ? va_arg(ap, ssize_t) : \
643 	    flags&SHORTINT ? (long)(short)va_arg(ap, int) : \
644 	    (long)va_arg(ap, int))
645 #define	UARG() \
646 	(flags&QUADINT ? va_arg(ap, u_quad_t) : \
647 	    flags&LONGINT ? va_arg(ap, u_long) : \
648 	    flags&SIZEINT ? va_arg(ap, size_t) : \
649 	    flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \
650 	    (u_long)va_arg(ap, u_int))
651 
652 #define KPRINTF_PUTCHAR(C) do {					\
653 	int chr = (C);							\
654 	ret += 1;							\
655 	if (oflags & TOBUFONLY) {					\
656 		if ((vp != NULL) && (sbuf == tailp)) {			\
657 			if (!(oflags & TOCOUNT))				\
658 				goto overflow;				\
659 		} else							\
660 			*sbuf++ = chr;					\
661 	} else {							\
662 		kputchar(chr, oflags, (struct tty *)vp);			\
663 	}								\
664 } while(0)
665 
666 int
667 kprintf(const char *fmt0, int oflags, void *vp, char *sbuf, va_list ap)
668 {
669 	char *fmt;		/* format string */
670 	int ch;			/* character from fmt */
671 	int n;			/* handy integer (short term usage) */
672 	char *cp = NULL;	/* handy char pointer (short term usage) */
673 	int flags;		/* flags as above */
674 	int ret;		/* return value accumulator */
675 	int width;		/* width from format (%8d), or 0 */
676 	int prec;		/* precision from format (%.3d), or -1 */
677 	char sign;		/* sign prefix (' ', '+', '-', or \0) */
678 
679 	u_quad_t _uquad;	/* integer arguments %[diouxX] */
680 	enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
681 	int dprec;		/* a copy of prec if [diouxX], 0 otherwise */
682 	int realsz;		/* field size expanded by dprec */
683 	int size = 0;		/* size of converted field or string */
684 	char *xdigs = NULL;	/* digits for [xX] conversion */
685 	char buf[KPRINTF_BUFSIZE]; /* space for %c, %[diouxX] */
686 	char *tailp = NULL;	/* tail pointer for snprintf */
687 
688 	if ((oflags & TOBUFONLY) && (vp != NULL))
689 		tailp = *(char **)vp;
690 
691 	fmt = (char *)fmt0;
692 	ret = 0;
693 
694 	/*
695 	 * Scan the format for conversions (`%' character).
696 	 */
697 	for (;;) {
698 		while (*fmt != '%' && *fmt) {
699 			KPRINTF_PUTCHAR(*fmt++);
700 		}
701 		if (*fmt == 0)
702 			goto done;
703 
704 		fmt++;		/* skip over '%' */
705 
706 		flags = 0;
707 		dprec = 0;
708 		width = 0;
709 		prec = -1;
710 		sign = '\0';
711 
712 rflag:		ch = *fmt++;
713 reswitch:	switch (ch) {
714 		/* XXX: non-standard '%b' format */
715 		case 'b': {
716 			char *b, *z;
717 			int tmp;
718 			_uquad = UARG();
719 			b = va_arg(ap, char *);
720 			if (*b == 8)
721 				snprintf(buf, sizeof buf, "%llo", _uquad);
722 			else if (*b == 10)
723 				snprintf(buf, sizeof buf, "%lld", _uquad);
724 			else if (*b == 16)
725 				snprintf(buf, sizeof buf, "%llx", _uquad);
726 			else
727 				break;
728 			b++;
729 
730 			z = buf;
731 			while (*z) {
732 				KPRINTF_PUTCHAR(*z++);
733 			}
734 
735 			if (_uquad) {
736 				tmp = 0;
737 				while ((n = *b++) != 0) {
738 					if (n & 0x80)
739 						n &= 0x7f;
740 					else if (n <= ' ')
741 						n = n - 1;
742 					if (_uquad & (1LL << n)) {
743 						KPRINTF_PUTCHAR(tmp ? ',':'<');
744 						while (*b > ' ' &&
745 						    (*b & 0x80) == 0) {
746 							KPRINTF_PUTCHAR(*b);
747 							b++;
748 						}
749 						tmp = 1;
750 					} else {
751 						while (*b > ' ' &&
752 						    (*b & 0x80) == 0)
753 							b++;
754 					}
755 				}
756 				if (tmp) {
757 					KPRINTF_PUTCHAR('>');
758 				}
759 			}
760 			continue;	/* no output */
761 		}
762 
763 		case ' ':
764 			/*
765 			 * ``If the space and + flags both appear, the space
766 			 * flag will be ignored.''
767 			 *	-- ANSI X3J11
768 			 */
769 			if (!sign)
770 				sign = ' ';
771 			goto rflag;
772 		case '#':
773 			flags |= ALT;
774 			goto rflag;
775 		case '*':
776 			/*
777 			 * ``A negative field width argument is taken as a
778 			 * - flag followed by a positive field width.''
779 			 *	-- ANSI X3J11
780 			 * They don't exclude field widths read from args.
781 			 */
782 			if ((width = va_arg(ap, int)) >= 0)
783 				goto rflag;
784 			width = -width;
785 			/* FALLTHROUGH */
786 		case '-':
787 			flags |= LADJUST;
788 			goto rflag;
789 		case '+':
790 			sign = '+';
791 			goto rflag;
792 		case '.':
793 			if ((ch = *fmt++) == '*') {
794 				n = va_arg(ap, int);
795 				prec = n < 0 ? -1 : n;
796 				goto rflag;
797 			}
798 			n = 0;
799 			while (is_digit(ch)) {
800 				n = 10 * n + to_digit(ch);
801 				ch = *fmt++;
802 			}
803 			prec = n < 0 ? -1 : n;
804 			goto reswitch;
805 		case '0':
806 			/*
807 			 * ``Note that 0 is taken as a flag, not as the
808 			 * beginning of a field width.''
809 			 *	-- ANSI X3J11
810 			 */
811 			flags |= ZEROPAD;
812 			goto rflag;
813 		case '1': case '2': case '3': case '4':
814 		case '5': case '6': case '7': case '8': case '9':
815 			n = 0;
816 			do {
817 				n = 10 * n + to_digit(ch);
818 				ch = *fmt++;
819 			} while (is_digit(ch));
820 			width = n;
821 			goto reswitch;
822 		case 'h':
823 			flags |= SHORTINT;
824 			goto rflag;
825 		case 'l':
826 			if (*fmt == 'l') {
827 				fmt++;
828 				flags |= QUADINT;
829 			} else {
830 				flags |= LONGINT;
831 			}
832 			goto rflag;
833 		case 'q':
834 			flags |= QUADINT;
835 			goto rflag;
836 		case 'z':
837 			flags |= SIZEINT;
838 			goto rflag;
839 		case 'c':
840 			*(cp = buf) = va_arg(ap, int);
841 			size = 1;
842 			sign = '\0';
843 			break;
844 		case 't':
845 			/* ptrdiff_t */
846 			/* FALLTHROUGH */
847 		case 'D':
848 			flags |= LONGINT;
849 			/*FALLTHROUGH*/
850 		case 'd':
851 		case 'i':
852 			_uquad = SARG();
853 			if ((quad_t)_uquad < 0) {
854 				_uquad = -_uquad;
855 				sign = '-';
856 			}
857 			base = DEC;
858 			goto number;
859 		case 'n':
860 			/* %n is unsupported in the kernel; just skip it */
861 			if (flags & QUADINT)
862 				(void)va_arg(ap, quad_t *);
863 			else if (flags & LONGINT)
864 				(void)va_arg(ap, long *);
865 			else if (flags & SHORTINT)
866 				(void)va_arg(ap, short *);
867 			else if (flags & SIZEINT)
868 				(void)va_arg(ap, ssize_t *);
869 			else
870 				(void)va_arg(ap, int *);
871 			continue;	/* no output */
872 		case 'O':
873 			flags |= LONGINT;
874 			/*FALLTHROUGH*/
875 		case 'o':
876 			_uquad = UARG();
877 			base = OCT;
878 			goto nosign;
879 		case 'p':
880 			/*
881 			 * ``The argument shall be a pointer to void.  The
882 			 * value of the pointer is converted to a sequence
883 			 * of printable characters, in an implementation-
884 			 * defined manner.''
885 			 *	-- ANSI X3J11
886 			 */
887 			_uquad = (u_long)va_arg(ap, void *);
888 			base = HEX;
889 			xdigs = "0123456789abcdef";
890 			flags |= HEXPREFIX;
891 			ch = 'x';
892 			goto nosign;
893 		case 's':
894 			if ((cp = va_arg(ap, char *)) == NULL)
895 				cp = "(null)";
896 			if (prec >= 0) {
897 				/*
898 				 * can't use strlen; can only look for the
899 				 * NUL in the first `prec' characters, and
900 				 * strlen() will go further.
901 				 */
902 				char *p = memchr(cp, 0, prec);
903 
904 				if (p != NULL) {
905 					size = p - cp;
906 					if (size > prec)
907 						size = prec;
908 				} else
909 					size = prec;
910 			} else
911 				size = strlen(cp);
912 			sign = '\0';
913 			break;
914 		case 'U':
915 			flags |= LONGINT;
916 			/*FALLTHROUGH*/
917 		case 'u':
918 			_uquad = UARG();
919 			base = DEC;
920 			goto nosign;
921 		case 'X':
922 			xdigs = "0123456789ABCDEF";
923 			goto hex;
924 		case 'x':
925 			xdigs = "0123456789abcdef";
926 hex:			_uquad = UARG();
927 			base = HEX;
928 			/* leading 0x/X only if non-zero */
929 			if (flags & ALT && _uquad != 0)
930 				flags |= HEXPREFIX;
931 
932 			/* unsigned conversions */
933 nosign:			sign = '\0';
934 			/*
935 			 * ``... diouXx conversions ... if a precision is
936 			 * specified, the 0 flag will be ignored.''
937 			 *	-- ANSI X3J11
938 			 */
939 number:			if ((dprec = prec) >= 0)
940 				flags &= ~ZEROPAD;
941 
942 			/*
943 			 * ``The result of converting a zero value with an
944 			 * explicit precision of zero is no characters.''
945 			 *	-- ANSI X3J11
946 			 */
947 			cp = buf + KPRINTF_BUFSIZE;
948 			if (_uquad != 0 || prec != 0) {
949 				/*
950 				 * Unsigned mod is hard, and unsigned mod
951 				 * by a constant is easier than that by
952 				 * a variable; hence this switch.
953 				 */
954 				switch (base) {
955 				case OCT:
956 					do {
957 						*--cp = to_char(_uquad & 7);
958 						_uquad >>= 3;
959 					} while (_uquad);
960 					/* handle octal leading 0 */
961 					if (flags & ALT && *cp != '0')
962 						*--cp = '0';
963 					break;
964 
965 				case DEC:
966 					/* many numbers are 1 digit */
967 					while (_uquad >= 10) {
968 						*--cp = to_char(_uquad % 10);
969 						_uquad /= 10;
970 					}
971 					*--cp = to_char(_uquad);
972 					break;
973 
974 				case HEX:
975 					do {
976 						*--cp = xdigs[_uquad & 15];
977 						_uquad >>= 4;
978 					} while (_uquad);
979 					break;
980 
981 				default:
982 					cp = "bug in kprintf: bad base";
983 					size = strlen(cp);
984 					goto skipsize;
985 				}
986 			}
987 			size = buf + KPRINTF_BUFSIZE - cp;
988 		skipsize:
989 			break;
990 		default:	/* "%?" prints ?, unless ? is NUL */
991 			if (ch == '\0')
992 				goto done;
993 			/* pretend it was %c with argument ch */
994 			cp = buf;
995 			*cp = ch;
996 			size = 1;
997 			sign = '\0';
998 			break;
999 		}
1000 
1001 		/*
1002 		 * All reasonable formats wind up here.  At this point, `cp'
1003 		 * points to a string which (if not flags&LADJUST) should be
1004 		 * padded out to `width' places.  If flags&ZEROPAD, it should
1005 		 * first be prefixed by any sign or other prefix; otherwise,
1006 		 * it should be blank padded before the prefix is emitted.
1007 		 * After any left-hand padding and prefixing, emit zeroes
1008 		 * required by a decimal [diouxX] precision, then print the
1009 		 * string proper, then emit zeroes required by any leftover
1010 		 * floating precision; finally, if LADJUST, pad with blanks.
1011 		 *
1012 		 * Compute actual size, so we know how much to pad.
1013 		 * size excludes decimal prec; realsz includes it.
1014 		 */
1015 		realsz = dprec > size ? dprec : size;
1016 		if (sign)
1017 			realsz++;
1018 		else if (flags & HEXPREFIX)
1019 			realsz+= 2;
1020 
1021 		/* right-adjusting blank padding */
1022 		if ((flags & (LADJUST|ZEROPAD)) == 0) {
1023 			n = width - realsz;
1024 			while (n-- > 0)
1025 				KPRINTF_PUTCHAR(' ');
1026 		}
1027 
1028 		/* prefix */
1029 		if (sign) {
1030 			KPRINTF_PUTCHAR(sign);
1031 		} else if (flags & HEXPREFIX) {
1032 			KPRINTF_PUTCHAR('0');
1033 			KPRINTF_PUTCHAR(ch);
1034 		}
1035 
1036 		/* right-adjusting zero padding */
1037 		if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) {
1038 			n = width - realsz;
1039 			while (n-- > 0)
1040 				KPRINTF_PUTCHAR('0');
1041 		}
1042 
1043 		/* leading zeroes from decimal precision */
1044 		n = dprec - size;
1045 		while (n-- > 0)
1046 			KPRINTF_PUTCHAR('0');
1047 
1048 		/* the string or number proper */
1049 		while (size--)
1050 			KPRINTF_PUTCHAR(*cp++);
1051 		/* left-adjusting padding (always blank) */
1052 		if (flags & LADJUST) {
1053 			n = width - realsz;
1054 			while (n-- > 0)
1055 				KPRINTF_PUTCHAR(' ');
1056 		}
1057 	}
1058 
1059 done:
1060 	if ((oflags & TOBUFONLY) && (vp != NULL))
1061 		*(char **)vp = sbuf;
1062 overflow:
1063 	return (ret);
1064 	/* NOTREACHED */
1065 }
1066 
1067 #if __GNUC_PREREQ__(2,96)
1068 /*
1069  * XXX - these functions shouldn't be in the kernel, but gcc 3.X feels like
1070  *       translating some printf calls to puts and since it doesn't seem
1071  *       possible to just turn off parts of those optimizations (some of
1072  *       them are really useful), we have to provide a dummy puts and putchar
1073  *	 that are wrappers around printf.
1074  */
1075 int	puts(const char *);
1076 int	putchar(int c);
1077 
1078 int
1079 puts(const char *str)
1080 {
1081 	printf("%s\n", str);
1082 
1083 	return (0);
1084 }
1085 
1086 int
1087 putchar(int c)
1088 {
1089 	printf("%c", c);
1090 
1091 	return (c);
1092 }
1093 
1094 
1095 #endif
1096