sys/kern/subr_prf.c

   1 /*-
   2  * Copyright (c) 1986, 1988, 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  * (c) UNIX System Laboratories, Inc.
   5  * All or some portions of this file are derived from material licensed
   6  * to the University of California by American Telephone and Telegraph
   7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
   8  * the permission of UNIX System Laboratories, Inc.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. 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  * $FreeBSD: src/sys/kern/subr_prf.c,v 1.61.2.5 2002/08/31 18:22:08 dwmalone Exp $
  40  * $DragonFly: src/sys/kern/subr_prf.c,v 1.8 2004/09/13 16:22:36 dillon Exp $
  41  */
  42
  43 #include <sys/param.h>
  44 #include <sys/systm.h>
  45 #include <sys/kernel.h>
  46 #include <sys/msgbuf.h>
  47 #include <sys/malloc.h>
  48 #include <sys/proc.h>
  49 #include <sys/tty.h>
  50 #include <sys/tprintf.h>
  51 #include <sys/syslog.h>
  52 #include <sys/cons.h>
  53 #include <sys/uio.h>
  54 #include <sys/sysctl.h>
  55 #include <sys/lock.h>
  56
  57 /*
  58  * Note that stdarg.h and the ANSI style va_start macro is used for both
  59  * ANSI and traditional C compilers.  We use the __ machine version to stay
  60  * within the kernel header file set.
  61  */
  62 #include <machine/stdarg.h>
  63
  64 #define TOCONS  0x01
  65 #define TOTTY   0x02
  66 #define TOLOG   0x04
  67
  68 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
  69 #define MAXNBUF (sizeof(quad_t) * NBBY + 1)
  70
  71 struct putchar_arg {
  72         int     flags;
  73         int     pri;
  74         struct  tty *tty;
  75 };
  76
  77 struct snprintf_arg {
  78         char    *str;
  79         size_t  remain;
  80 };
  81
  82 extern  int log_open;
  83
  84 struct  tty *constty;                   /* pointer to console "window" tty */
  85
  86 static void (*v_putc)(int) = cnputc;    /* routine to putc on virtual console */
  87 static void  msglogchar(int c, int pri);
  88 static void  msgaddchar(int c, void *dummy);
  89 static void  putchar (int ch, void *arg);
  90 static char *ksprintn (char *nbuf, u_long num, int base, int *len);
  91 static char *ksprintqn (char *nbuf, u_quad_t num, int base, int *len);
  92 static void  snprintf_func (int ch, void *arg);
  93
  94 static int consintr = 1;                /* Ok to handle console interrupts? */
  95 static int msgbufmapped;                /* Set when safe to use msgbuf */
  96 int msgbuftrigger;
  97
  98 static int      log_console_output = 1;
  99 TUNABLE_INT("kern.log_console_output", &log_console_output);
 100 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
 101     &log_console_output, 0, "");
 102
 103 /*
 104  * Warn that a system table is full.
 105  */
 106 void
 107 tablefull(const char *tab)
 108 {
 109
 110         log(LOG_ERR, "%s: table is full\n", tab);
 111 }
 112
 113 /*
 114  * Uprintf prints to the controlling terminal for the current process.
 115  * It may block if the tty queue is overfull.  No message is printed if
 116  * the queue does not clear in a reasonable time.
 117  */
 118 int
 119 uprintf(const char *fmt, ...)
 120 {
 121         struct proc *p = curproc;
 122         __va_list ap;
 123         struct putchar_arg pca;
 124         int retval = 0;
 125
 126         if (p && p->p_flag & P_CONTROLT &&
 127             p->p_session->s_ttyvp) {
 128                 __va_start(ap, fmt);
 129                 pca.tty = p->p_session->s_ttyp;
 130                 pca.flags = TOTTY;
 131
 132                 retval = kvprintf(fmt, putchar, &pca, 10, ap);
 133                 __va_end(ap);
 134         }
 135         return retval;
 136 }
 137
 138 tpr_t
 139 tprintf_open(struct proc *p)
 140 {
 141
 142         if ((p->p_flag & P_CONTROLT) && p->p_session->s_ttyvp) {
 143                 sess_hold(p->p_session);
 144                 return ((tpr_t) p->p_session);
 145         }
 146         return ((tpr_t) NULL);
 147 }
 148
 149 void
 150 tprintf_close(tpr_t sess)
 151 {
 152         if (sess)
 153                 sess_rele((struct session *) sess);
 154 }
 155
 156 /*
 157  * tprintf prints on the controlling terminal associated
 158  * with the given session.
 159  */
 160 int
 161 tprintf(tpr_t tpr, const char *fmt, ...)
 162 {
 163         struct session *sess = (struct session *)tpr;
 164         struct tty *tp = NULL;
 165         int flags = TOLOG;
 166         __va_list ap;
 167         struct putchar_arg pca;
 168         int retval;
 169
 170         if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
 171                 flags |= TOTTY;
 172                 tp = sess->s_ttyp;
 173         }
 174         __va_start(ap, fmt);
 175         pca.tty = tp;
 176         pca.flags = flags;
 177         pca.pri = LOG_INFO;
 178         retval = kvprintf(fmt, putchar, &pca, 10, ap);
 179         __va_end(ap);
 180         msgbuftrigger = 1;
 181         return retval;
 182 }
 183
 184 /*
 185  * Ttyprintf displays a message on a tty; it should be used only by
 186  * the tty driver, or anything that knows the underlying tty will not
 187  * be revoke(2)'d away.  Other callers should use tprintf.
 188  */
 189 int
 190 ttyprintf(struct tty *tp, const char *fmt, ...)
 191 {
 192         __va_list ap;
 193         struct putchar_arg pca;
 194         int retval;
 195
 196         __va_start(ap, fmt);
 197         pca.tty = tp;
 198         pca.flags = TOTTY;
 199         retval = kvprintf(fmt, putchar, &pca, 10, ap);
 200         __va_end(ap);
 201         return retval;
 202 }
 203
 204 /*
 205  * Log writes to the log buffer, and guarantees not to sleep (so can be
 206  * called by interrupt routines).  If there is no process reading the
 207  * log yet, it writes to the console also.
 208  */
 209 int
 210 log(int level, const char *fmt, ...)
 211 {
 212         __va_list ap;
 213         int retval;
 214         struct putchar_arg pca;
 215
 216         pca.tty = NULL;
 217         pca.pri = level;
 218         pca.flags = log_open ? TOLOG : TOCONS;
 219
 220         __va_start(ap, fmt);
 221         retval = kvprintf(fmt, putchar, &pca, 10, ap);
 222         __va_end(ap);
 223
 224         msgbuftrigger = 1;
 225         return (retval);
 226 }
 227
 228 int
 229 addlog(const char *fmt, ...)
 230 {
 231         __va_list ap;
 232         int retval;
 233         struct putchar_arg pca;
 234
 235         pca.tty = NULL;
 236         pca.pri = -1;
 237         pca.flags = log_open ? TOLOG : TOCONS;
 238
 239         __va_start(ap, fmt);
 240         retval = kvprintf(fmt, putchar, &pca, 10, ap);
 241         __va_end(ap);
 242
 243         msgbuftrigger = 1;
 244         return (retval);
 245 }
 246
 247 #define CONSCHUNK 128
 248
 249 void
 250 log_console(struct uio *uio)
 251 {
 252         int c, i, error, iovlen, nl;
 253         struct uio muio;
 254         struct iovec *miov = NULL;
 255         char *consbuffer;
 256         int pri;
 257
 258         if (!log_console_output)
 259                 return;
 260
 261         pri = LOG_INFO | LOG_CONSOLE;
 262         muio = *uio;
 263         iovlen = uio->uio_iovcnt * sizeof (struct iovec);
 264         MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
 265         MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK);
 266         bcopy((caddr_t)muio.uio_iov, (caddr_t)miov, iovlen);
 267         muio.uio_iov = miov;
 268         uio = &muio;
 269
 270         nl = 0;
 271         while (uio->uio_resid > 0) {
 272                 c = imin(uio->uio_resid, CONSCHUNK);
 273                 error = uiomove(consbuffer, c, uio);
 274                 if (error != 0)
 275                         return;
 276                 for (i = 0; i < c; i++) {
 277                         msglogchar(consbuffer[i], pri);
 278                         if (consbuffer[i] == '\n')
 279                                 nl = 1;
 280                         else
 281                                 nl = 0;
 282                 }
 283         }
 284         if (!nl)
 285                 msglogchar('\n', pri);
 286         msgbuftrigger = 1;
 287         FREE(miov, M_TEMP);
 288         FREE(consbuffer, M_TEMP);
 289         return;
 290 }
 291
 292 int
 293 printf(const char *fmt, ...)
 294 {
 295         __va_list ap;
 296         int savintr;
 297         struct putchar_arg pca;
 298         int retval;
 299
 300         savintr = consintr;             /* disable interrupts */
 301         consintr = 0;
 302         __va_start(ap, fmt);
 303         pca.tty = NULL;
 304         pca.flags = TOCONS | TOLOG;
 305         pca.pri = -1;
 306         cons_lock();
 307         retval = kvprintf(fmt, putchar, &pca, 10, ap);
 308         cons_unlock();
 309         __va_end(ap);
 310         if (!panicstr)
 311                 msgbuftrigger = 1;
 312         consintr = savintr;             /* reenable interrupts */
 313         return retval;
 314 }
 315
 316 int
 317 vprintf(const char *fmt, __va_list ap)
 318 {
 319         int savintr;
 320         struct putchar_arg pca;
 321         int retval;
 322
 323         savintr = consintr;             /* disable interrupts */
 324         consintr = 0;
 325         pca.tty = NULL;
 326         pca.flags = TOCONS | TOLOG;
 327         pca.pri = -1;
 328         cons_lock();
 329         retval = kvprintf(fmt, putchar, &pca, 10, ap);
 330         cons_unlock();
 331         if (!panicstr)
 332                 msgbuftrigger = 1;
 333         consintr = savintr;             /* reenable interrupts */
 334         return retval;
 335 }
 336
 337 /*
 338  * Print a character on console or users terminal.  If destination is
 339  * the console then the last bunch of characters are saved in msgbuf for
 340  * inspection later.
 341  */
 342 static void
 343 putchar(int c, void *arg)
 344 {
 345         struct putchar_arg *ap = (struct putchar_arg*) arg;
 346         int flags = ap->flags;
 347         struct tty *tp = ap->tty;
 348         if (panicstr)
 349                 constty = NULL;
 350         if ((flags & TOCONS) && tp == NULL && constty) {
 351                 tp = constty;
 352                 flags |= TOTTY;
 353         }
 354         if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
 355             (flags & TOCONS) && tp == constty)
 356                 constty = NULL;
 357         if ((flags & TOLOG))
 358                 msglogchar(c, ap->pri);
 359         if ((flags & TOCONS) && constty == NULL && c != '\0')
 360                 (*v_putc)(c);
 361 }
 362
 363 /*
 364  * Scaled down version of sprintf(3).
 365  */
 366 int
 367 sprintf(char *buf, const char *cfmt, ...)
 368 {
 369         int retval;
 370         __va_list ap;
 371
 372         __va_start(ap, cfmt);
 373         retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
 374         buf[retval] = '\0';
 375         __va_end(ap);
 376         return retval;
 377 }
 378
 379 /*
 380  * Scaled down version of vsprintf(3).
 381  */
 382 int
 383 vsprintf(char *buf, const char *cfmt, __va_list ap)
 384 {
 385         int retval;
 386
 387         retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
 388         buf[retval] = '\0';
 389         return retval;
 390 }
 391
 392 /*
 393  * Scaled down version of snprintf(3).
 394  */
 395 int
 396 snprintf(char *str, size_t size, const char *format, ...)
 397 {
 398         int retval;
 399         __va_list ap;
 400
 401         __va_start(ap, format);
 402         retval = vsnprintf(str, size, format, ap);
 403         __va_end(ap);
 404         return(retval);
 405 }
 406
 407 /*
 408  * Scaled down version of vsnprintf(3).
 409  */
 410 int
 411 vsnprintf(char *str, size_t size, const char *format, __va_list ap)
 412 {
 413         struct snprintf_arg info;
 414         int retval;
 415
 416         info.str = str;
 417         info.remain = size;
 418         retval = kvprintf(format, snprintf_func, &info, 10, ap);
 419         if (info.remain >= 1)
 420                 *info.str++ = '\0';
 421         return retval;
 422 }
 423
 424 static void
 425 snprintf_func(int ch, void *arg)
 426 {
 427         struct snprintf_arg *const info = arg;
 428
 429         if (info->remain >= 2) {
 430                 *info->str++ = ch;
 431                 info->remain--;
 432         }
 433 }
 434
 435 /*
 436  * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
 437  * order; return an optional length and a pointer to the last character
 438  * written in the buffer (i.e., the first character of the string).
 439  * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
 440  */
 441 static char *
 442 ksprintn(nbuf, ul, base, lenp)
 443         char *nbuf;
 444         u_long ul;
 445         int base, *lenp;
 446 {
 447         char *p;
 448
 449         p = nbuf;
 450         *p = '\0';
 451         do {
 452                 *++p = hex2ascii(ul % base);
 453         } while (ul /= base);
 454         if (lenp)
 455                 *lenp = p - nbuf;
 456         return (p);
 457 }
 458 /* ksprintn, but for a quad_t. */
 459 static char *
 460 ksprintqn(nbuf, uq, base, lenp)
 461         char *nbuf;
 462         u_quad_t uq;
 463         int base, *lenp;
 464 {
 465         char *p;
 466
 467         p = nbuf;
 468         *p = '\0';
 469         do {
 470                 *++p = hex2ascii(uq % base);
 471         } while (uq /= base);
 472         if (lenp)
 473                 *lenp = p - nbuf;
 474         return (p);
 475 }
 476
 477 /*
 478  * Scaled down version of printf(3).
 479  *
 480  * Two additional formats:
 481  *
 482  * The format %b is supported to decode error registers.
 483  * Its usage is:
 484  *
 485  *      printf("reg=%b\n", regval, "<base><arg>*");
 486  *
 487  * where <base> is the output base expressed as a control character, e.g.
 488  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
 489  * the first of which gives the bit number to be inspected (origin 1), and
 490  * the next characters (up to a control character, i.e. a character <= 32),
 491  * give the name of the register.  Thus:
 492  *
 493  *      kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
 494  *
 495  * would produce output:
 496  *
 497  *      reg=3<BITTWO,BITONE>
 498  *
 499  * XXX:  %D  -- Hexdump, takes pointer and separator string:
 500  *              ("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
 501  *              ("%*D", len, ptr, " " -> XX XX XX XX ...
 502  */
 503 int
 504 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, __va_list ap)
 505 {
 506 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
 507         char nbuf[MAXNBUF];
 508         char *p, *q, *d;
 509         u_char *up;
 510         int ch, n;
 511         u_long ul;
 512         u_quad_t uq;
 513         int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
 514         int dwidth;
 515         char padc;
 516         int retval = 0;
 517
 518         ul = 0;
 519         uq = 0;
 520         if (!func)
 521                 d = (char *) arg;
 522         else
 523                 d = NULL;
 524
 525         if (fmt == NULL)
 526                 fmt = "(fmt null)\n";
 527
 528         if (radix < 2 || radix > 36)
 529                 radix = 10;
 530
 531         for (;;) {
 532                 padc = ' ';
 533                 width = 0;
 534                 while ((ch = (u_char)*fmt++) != '%') {
 535                         if (ch == '\0')
 536                                 return retval;
 537                         PCHAR(ch);
 538                 }
 539                 qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
 540                 sign = 0; dot = 0; dwidth = 0;
 541 reswitch:       switch (ch = (u_char)*fmt++) {
 542                 case '.':
 543                         dot = 1;
 544                         goto reswitch;
 545                 case '#':
 546                         sharpflag = 1;
 547                         goto reswitch;
 548                 case '+':
 549                         sign = 1;
 550                         goto reswitch;
 551                 case '-':
 552                         ladjust = 1;
 553                         goto reswitch;
 554                 case '%':
 555                         PCHAR(ch);
 556                         break;
 557                 case '*':
 558                         if (!dot) {
 559                                 width = __va_arg(ap, int);
 560                                 if (width < 0) {
 561                                         ladjust = !ladjust;
 562                                         width = -width;
 563                                 }
 564                         } else {
 565                                 dwidth = __va_arg(ap, int);
 566                         }
 567                         goto reswitch;
 568                 case '0':
 569                         if (!dot) {
 570                                 padc = '0';
 571                                 goto reswitch;
 572                         }
 573                 case '1': case '2': case '3': case '4':
 574                 case '5': case '6': case '7': case '8': case '9':
 575                                 for (n = 0;; ++fmt) {
 576                                         n = n * 10 + ch - '0';
 577                                         ch = *fmt;
 578                                         if (ch < '0' || ch > '9')
 579                                                 break;
 580                                 }
 581                         if (dot)
 582                                 dwidth = n;
 583                         else
 584                                 width = n;
 585                         goto reswitch;
 586                 case 'b':
 587                         ul = __va_arg(ap, int);
 588                         p = __va_arg(ap, char *);
 589                         for (q = ksprintn(nbuf, ul, *p++, NULL); *q;)
 590                                 PCHAR(*q--);
 591
 592                         if (!ul)
 593                                 break;
 594
 595                         for (tmp = 0; *p;) {
 596                                 n = *p++;
 597                                 if (ul & (1 << (n - 1))) {
 598                                         PCHAR(tmp ? ',' : '<');
 599                                         for (; (n = *p) > ' '; ++p)
 600                                                 PCHAR(n);
 601                                         tmp = 1;
 602                                 } else
 603                                         for (; *p > ' '; ++p)
 604                                                 continue;
 605                         }
 606                         if (tmp)
 607                                 PCHAR('>');
 608                         break;
 609                 case 'c':
 610                         PCHAR(__va_arg(ap, int));
 611                         break;
 612                 case 'D':
 613                         up = __va_arg(ap, u_char *);
 614                         p = __va_arg(ap, char *);
 615                         if (!width)
 616                                 width = 16;
 617                         while(width--) {
 618                                 PCHAR(hex2ascii(*up >> 4));
 619                                 PCHAR(hex2ascii(*up & 0x0f));
 620                                 up++;
 621                                 if (width)
 622                                         for (q=p;*q;q++)
 623                                                 PCHAR(*q);
 624                         }
 625                         break;
 626                 case 'd':
 627                         if (qflag)
 628                                 uq = __va_arg(ap, quad_t);
 629                         else if (lflag)
 630                                 ul = __va_arg(ap, long);
 631                         else
 632                                 ul = __va_arg(ap, int);
 633                         sign = 1;
 634                         base = 10;
 635                         goto number;
 636                 case 'l':
 637                         if (lflag) {
 638                                 lflag = 0;
 639                                 qflag = 1;
 640                         } else
 641                                 lflag = 1;
 642                         goto reswitch;
 643                 case 'o':
 644                         if (qflag)
 645                                 uq = __va_arg(ap, u_quad_t);
 646                         else if (lflag)
 647                                 ul = __va_arg(ap, u_long);
 648                         else
 649                                 ul = __va_arg(ap, u_int);
 650                         base = 8;
 651                         goto nosign;
 652                 case 'p':
 653                         ul = (uintptr_t)__va_arg(ap, void *);
 654                         base = 16;
 655                         sharpflag = (width == 0);
 656                         goto nosign;
 657                 case 'q':
 658                         qflag = 1;
 659                         goto reswitch;
 660                 case 'n':
 661                 case 'r':
 662                         if (qflag)
 663                                 uq = __va_arg(ap, u_quad_t);
 664                         else if (lflag)
 665                                 ul = __va_arg(ap, u_long);
 666                         else
 667                                 ul = sign ?
 668                                     (u_long)__va_arg(ap, int) : __va_arg(ap, u_int);
 669                         base = radix;
 670                         goto number;
 671                 case 's':
 672                         p = __va_arg(ap, char *);
 673                         if (p == NULL)
 674                                 p = "(null)";
 675                         if (!dot)
 676                                 n = strlen (p);
 677                         else
 678                                 for (n = 0; n < dwidth && p[n]; n++)
 679                                         continue;
 680
 681                         width -= n;
 682
 683                         if (!ladjust && width > 0)
 684                                 while (width--)
 685                                         PCHAR(padc);
 686                         while (n--)
 687                                 PCHAR(*p++);
 688                         if (ladjust && width > 0)
 689                                 while (width--)
 690                                         PCHAR(padc);
 691                         break;
 692                 case 'u':
 693                         if (qflag)
 694                                 uq = __va_arg(ap, u_quad_t);
 695                         else if (lflag)
 696                                 ul = __va_arg(ap, u_long);
 697                         else
 698                                 ul = __va_arg(ap, u_int);
 699                         base = 10;
 700                         goto nosign;
 701                 case 'x':
 702                 case 'X':
 703                         if (qflag)
 704                                 uq = __va_arg(ap, u_quad_t);
 705                         else if (lflag)
 706                                 ul = __va_arg(ap, u_long);
 707                         else
 708                                 ul = __va_arg(ap, u_int);
 709                         base = 16;
 710                         goto nosign;
 711                 case 'z':
 712                         if (qflag)
 713                                 uq = __va_arg(ap, u_quad_t);
 714                         else if (lflag)
 715                                 ul = __va_arg(ap, u_long);
 716                         else
 717                                 ul = sign ?
 718                                     (u_long)__va_arg(ap, int) : __va_arg(ap, u_int);
 719                         base = 16;
 720                         goto number;
 721 nosign:                 sign = 0;
 722 number:
 723                         if (qflag) {
 724                                 if (sign && (quad_t)uq < 0) {
 725                                         neg = 1;
 726                                         uq = -(quad_t)uq;
 727                                 }
 728                                 p = ksprintqn(nbuf, uq, base, &tmp);
 729                         } else {
 730                                 if (sign && (long)ul < 0) {
 731                                         neg = 1;
 732                                         ul = -(long)ul;
 733                                 }
 734                                 p = ksprintn(nbuf, ul, base, &tmp);
 735                         }
 736                         if (sharpflag && (qflag ? uq != 0 : ul != 0)) {
 737                                 if (base == 8)
 738                                         tmp++;
 739                                 else if (base == 16)
 740                                         tmp += 2;
 741                         }
 742                         if (neg)
 743                                 tmp++;
 744
 745                         if (!ladjust && width && (width -= tmp) > 0)
 746                                 while (width--)
 747                                         PCHAR(padc);
 748                         if (neg)
 749                                 PCHAR('-');
 750                         if (sharpflag && (qflag ? uq != 0 : ul != 0)) {
 751                                 if (base == 8) {
 752                                         PCHAR('0');
 753                                 } else if (base == 16) {
 754                                         PCHAR('0');
 755                                         PCHAR('x');
 756                                 }
 757                         }
 758
 759                         while (*p)
 760                                 PCHAR(*p--);
 761
 762                         if (ladjust && width && (width -= tmp) > 0)
 763                                 while (width--)
 764                                         PCHAR(padc);
 765
 766                         break;
 767                 default:
 768                         PCHAR('%');
 769                         if (lflag)
 770                                 PCHAR('l');
 771                         PCHAR(ch);
 772                         break;
 773                 }
 774         }
 775 #undef PCHAR
 776 }
 777
 778 /*
 779  * Put character in log buffer with a particular priority.
 780  */
 781 static void
 782 msglogchar(int c, int pri)
 783 {
 784         static int lastpri = -1;
 785         static int dangling;
 786         char nbuf[MAXNBUF];
 787         char *p;
 788
 789         if (!msgbufmapped)
 790                 return;
 791         if (c == '\0' || c == '\r')
 792                 return;
 793         if (pri != -1 && pri != lastpri) {
 794                 if (dangling) {
 795                         msgaddchar('\n', NULL);
 796                         dangling = 0;
 797                 }
 798                 msgaddchar('<', NULL);
 799                 for (p = ksprintn(nbuf, (u_long)pri, 10, NULL); *p;)
 800                         msgaddchar(*p--, NULL);
 801                 msgaddchar('>', NULL);
 802                 lastpri = pri;
 803         }
 804         msgaddchar(c, NULL);
 805         if (c == '\n') {
 806                 dangling = 0;
 807                 lastpri = -1;
 808         } else {
 809                 dangling = 1;
 810         }
 811 }
 812
 813 /*
 814  * Put char in log buffer
 815  */
 816 static void
 817 msgaddchar(int c, void *dummy)
 818 {
 819         struct msgbuf *mbp;
 820
 821         if (!msgbufmapped)
 822                 return;
 823         mbp = msgbufp;
 824         mbp->msg_ptr[mbp->msg_bufx++] = c;
 825         if (mbp->msg_bufx >= mbp->msg_size)
 826                 mbp->msg_bufx = 0;
 827         /* If the buffer is full, keep the most recent data. */
 828         if (mbp->msg_bufr == mbp->msg_bufx) {
 829                 if (++mbp->msg_bufr >= mbp->msg_size)
 830                         mbp->msg_bufr = 0;
 831         }
 832 }
 833
 834 static void
 835 msgbufcopy(struct msgbuf *oldp)
 836 {
 837         int pos;
 838
 839         pos = oldp->msg_bufr;
 840         while (pos != oldp->msg_bufx) {
 841                 msglogchar(oldp->msg_ptr[pos], -1);
 842                 if (++pos >= oldp->msg_size)
 843                         pos = 0;
 844         }
 845 }
 846
 847 void
 848 msgbufinit(void *ptr, size_t size)
 849 {
 850         char *cp;
 851         static struct msgbuf *oldp = NULL;
 852
 853         size -= sizeof(*msgbufp);
 854         cp = (char *)ptr;
 855         msgbufp = (struct msgbuf *) (cp + size);
 856         if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size ||
 857             msgbufp->msg_bufx >= size || msgbufp->msg_bufr >= size) {
 858                 bzero(cp, size);
 859                 bzero(msgbufp, sizeof(*msgbufp));
 860                 msgbufp->msg_magic = MSG_MAGIC;
 861                 msgbufp->msg_size = (char *)msgbufp - cp;
 862         }
 863         msgbufp->msg_ptr = cp;
 864         if (msgbufmapped && oldp != msgbufp)
 865                 msgbufcopy(oldp);
 866         msgbufmapped = 1;
 867         oldp = msgbufp;
 868 }
 869
 870 /* Sysctls for accessing/clearing the msgbuf */
 871 static int
 872 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
 873 {
 874         int error;
 875
 876         /*
 877          * Unwind the buffer, so that it's linear (possibly starting with
 878          * some initial nulls).
 879          */
 880         error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx,
 881             msgbufp->msg_size - msgbufp->msg_bufx, req);
 882         if (error)
 883                 return (error);
 884         if (msgbufp->msg_bufx > 0) {
 885                 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr,
 886                     msgbufp->msg_bufx, req);
 887         }
 888         return (error);
 889 }
 890
 891 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
 892     0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
 893
 894 static int msgbuf_clear;
 895
 896 static int
 897 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
 898 {
 899         int error;
 900         error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
 901         if (!error && req->newptr) {
 902                 /* Clear the buffer and reset write pointer */
 903                 bzero(msgbufp->msg_ptr, msgbufp->msg_size);
 904                 msgbufp->msg_bufr = msgbufp->msg_bufx = 0;
 905                 msgbuf_clear = 0;
 906         }
 907         return (error);
 908 }
 909
 910 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
 911     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0,
 912     sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
 913
 914 #include "opt_ddb.h"
 915 #ifdef DDB
 916 #include <ddb/ddb.h>
 917
 918 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
 919 {
 920         int i, j;
 921
 922         if (!msgbufmapped) {
 923                 db_printf("msgbuf not mapped yet\n");
 924                 return;
 925         }
 926         db_printf("msgbufp = %p\n", msgbufp);
 927         db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p\n",
 928             msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr,
 929             msgbufp->msg_bufx, msgbufp->msg_ptr);
 930         for (i = 0; i < msgbufp->msg_size; i++) {
 931                 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size;
 932                 db_printf("%c", msgbufp->msg_ptr[j]);
 933         }
 934         db_printf("\n");
 935 }
 936
 937 #endif /* DDB */