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. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)subr_prf.c  8.3 (Berkeley) 1/21/94
  35  * $FreeBSD: src/sys/kern/subr_prf.c,v 1.61.2.5 2002/08/31 18:22:08 dwmalone Exp $
  36  */
  37
  38 #include "opt_ddb.h"
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/kernel.h>
  43 #include <sys/msgbuf.h>
  44 #include <sys/malloc.h>
  45 #include <sys/proc.h>
  46 #include <sys/priv.h>
  47 #include <sys/tty.h>
  48 #include <sys/tprintf.h>
  49 #include <sys/stdint.h>
  50 #include <sys/syslog.h>
  51 #include <sys/cons.h>
  52 #include <sys/uio.h>
  53 #include <sys/sysctl.h>
  54 #include <sys/lock.h>
  55 #include <sys/ctype.h>
  56 #include <sys/eventhandler.h>
  57 #include <sys/kthread.h>
  58 #include <sys/cpu_topology.h>
  59
  60 #include <sys/thread2.h>
  61 #include <sys/spinlock2.h>
  62
  63 #ifdef DDB
  64 #include <ddb/ddb.h>
  65 #endif
  66
  67 /*
  68  * Note that stdarg.h and the ANSI style va_start macro is used for both
  69  * ANSI and traditional C compilers.  We use the __ machine version to stay
  70  * within the kernel header file set.
  71  */
  72 #include <machine/stdarg.h>
  73
  74 #define TOCONS          0x01
  75 #define TOTTY           0x02
  76 #define TOLOG           0x04
  77 #define TOWAKEUP        0x08
  78 #define TONOSPIN        0x10    /* avoid serialization */
  79
  80 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
  81 #define MAXNBUF (sizeof(intmax_t) * NBBY + 1)
  82
  83 struct putchar_arg {
  84         int     flags;
  85         int     pri;
  86         struct  tty *tty;
  87 };
  88
  89 struct snprintf_arg {
  90         char    *str;
  91         size_t  remain;
  92 };
  93
  94 extern  int log_open;
  95
  96 struct  tty *constty;                   /* pointer to console "window" tty */
  97
  98 static void  msglogchar(int c, int pri);
  99 static void  msgaddchar(int c, void *dummy);
 100 static void  kputchar (int ch, void *arg);
 101 static char *ksprintn (char *nbuf, uintmax_t num, int base, int *lenp,
 102                        int upper);
 103 static void  snprintf_func (int ch, void *arg);
 104
 105 static int consintr = 1;                /* Ok to handle console interrupts? */
 106 static int msgbufmapped;                /* Set when safe to use msgbuf */
 107 static struct spinlock cons_spin = SPINLOCK_INITIALIZER(cons_spin, "cons_spin");
 108 static thread_t constty_td = NULL;
 109
 110 int msgbuftrigger;
 111
 112 static int      log_console_output = 1;
 113 TUNABLE_INT("kern.log_console_output", &log_console_output);
 114 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
 115     &log_console_output, 0, "");
 116 static int      kprintf_logging = TOLOG | TOCONS;
 117 SYSCTL_INT(_kern, OID_AUTO, kprintf_logging, CTLFLAG_RW,
 118     &kprintf_logging, 0, "");
 119
 120 static int ptr_restrict = 0;
 121 TUNABLE_INT("security.ptr_restrict", &ptr_restrict);
 122 SYSCTL_INT(_security, OID_AUTO, ptr_restrict, CTLFLAG_RW, &ptr_restrict, 0,
 123     "Prevent leaking the kernel pointers back to userland");
 124
 125 static int unprivileged_read_msgbuf = 1;
 126 SYSCTL_INT(_security, OID_AUTO, unprivileged_read_msgbuf, CTLFLAG_RW,
 127     &unprivileged_read_msgbuf, 0,
 128     "Unprivileged processes may read the kernel message buffer");
 129
 130 /*
 131  * Warn that a system table is full.
 132  */
 133 void
 134 tablefull(const char *tab)
 135 {
 136
 137         log(LOG_ERR, "%s: table is full\n", tab);
 138 }
 139
 140 /*
 141  * Uprintf prints to the controlling terminal for the current process.
 142  */
 143 int
 144 uprintf(const char *fmt, ...)
 145 {
 146         struct proc *p = curproc;
 147         __va_list ap;
 148         struct putchar_arg pca;
 149         int retval = 0;
 150
 151         if (p && (p->p_flags & P_CONTROLT) && p->p_session->s_ttyvp) {
 152                 __va_start(ap, fmt);
 153                 pca.tty = p->p_session->s_ttyp;
 154                 pca.flags = TOTTY;
 155
 156                 retval = kvcprintf(fmt, kputchar, &pca, ap);
 157                 __va_end(ap);
 158         }
 159         return (retval);
 160 }
 161
 162 tpr_t
 163 tprintf_open(struct proc *p)
 164 {
 165         if ((p->p_flags & P_CONTROLT) && p->p_session->s_ttyvp) {
 166                 sess_hold(p->p_session);
 167                 return ((tpr_t) p->p_session);
 168         }
 169         return (NULL);
 170 }
 171
 172 void
 173 tprintf_close(tpr_t sess)
 174 {
 175         if (sess)
 176                 sess_rele((struct session *) sess);
 177 }
 178
 179 /*
 180  * tprintf prints on the controlling terminal associated
 181  * with the given session.
 182  */
 183 int
 184 tprintf(tpr_t tpr, const char *fmt, ...)
 185 {
 186         struct session *sess = (struct session *)tpr;
 187         struct tty *tp = NULL;
 188         int flags = TOLOG;
 189         __va_list ap;
 190         struct putchar_arg pca;
 191         int retval;
 192
 193         if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
 194                 flags |= TOTTY;
 195                 tp = sess->s_ttyp;
 196         }
 197         __va_start(ap, fmt);
 198         pca.tty = tp;
 199         pca.flags = flags;
 200         pca.pri = LOG_INFO;
 201         retval = kvcprintf(fmt, kputchar, &pca, ap);
 202         __va_end(ap);
 203         msgbuftrigger = 1;
 204         return (retval);
 205 }
 206
 207 /*
 208  * Ttyprintf displays a message on a tty; it should be used only by
 209  * the tty driver, or anything that knows the underlying tty will not
 210  * be revoke(2)'d away.  Other callers should use tprintf.
 211  */
 212 int
 213 ttyprintf(struct tty *tp, const char *fmt, ...)
 214 {
 215         __va_list ap;
 216         struct putchar_arg pca;
 217         int retval;
 218
 219         __va_start(ap, fmt);
 220         pca.tty = tp;
 221         pca.flags = TOTTY;
 222         retval = kvcprintf(fmt, kputchar, &pca, ap);
 223         __va_end(ap);
 224         return (retval);
 225 }
 226
 227 /*
 228  * Log writes to the log buffer, and guarantees not to sleep (so can be
 229  * called by interrupt routines).  If there is no process reading the
 230  * log yet, it writes to the console also.
 231  */
 232 int
 233 log(int level, const char *fmt, ...)
 234 {
 235         __va_list ap;
 236         int retval;
 237         struct putchar_arg pca;
 238
 239         pca.tty = NULL;
 240         pca.pri = level;
 241         if ((kprintf_logging & TOCONS) == 0 || log_open)
 242                 pca.flags = TOLOG;
 243         else
 244                 pca.flags = TOCONS;
 245
 246         __va_start(ap, fmt);
 247         retval = kvcprintf(fmt, kputchar, &pca, ap);
 248         __va_end(ap);
 249
 250         msgbuftrigger = 1;
 251         return (retval);
 252 }
 253
 254 #define CONSCHUNK 128
 255
 256 void
 257 log_console(struct uio *uio)
 258 {
 259         int c, i, error, iovlen, nl;
 260         struct uio muio;
 261         struct iovec *miov = NULL;
 262         char *consbuffer;
 263         int pri;
 264
 265         if (!log_console_output)
 266                 return;
 267
 268         pri = LOG_INFO | LOG_CONSOLE;
 269         muio = *uio;
 270         iovlen = uio->uio_iovcnt * sizeof (struct iovec);
 271         miov = kmalloc(iovlen, M_TEMP, M_WAITOK);
 272         consbuffer = kmalloc(CONSCHUNK, M_TEMP, M_WAITOK);
 273         bcopy((caddr_t)muio.uio_iov, (caddr_t)miov, iovlen);
 274         muio.uio_iov = miov;
 275         uio = &muio;
 276
 277         nl = 0;
 278         while (uio->uio_resid > 0) {
 279                 c = (int)szmin(uio->uio_resid, CONSCHUNK);
 280                 error = uiomove(consbuffer, (size_t)c, uio);
 281                 if (error != 0)
 282                         break;
 283                 for (i = 0; i < c; i++) {
 284                         msglogchar(consbuffer[i], pri);
 285                         if (consbuffer[i] == '\n')
 286                                 nl = 1;
 287                         else
 288                                 nl = 0;
 289                 }
 290         }
 291         if (!nl)
 292                 msglogchar('\n', pri);
 293         msgbuftrigger = 1;
 294         kfree(miov, M_TEMP);
 295         kfree(consbuffer, M_TEMP);
 296         return;
 297 }
 298
 299 /*
 300  * Output to the console.
 301  */
 302 int
 303 kprintf(const char *fmt, ...)
 304 {
 305         __va_list ap;
 306         int savintr;
 307         struct putchar_arg pca;
 308         int retval;
 309
 310         savintr = consintr;             /* disable interrupts */
 311         consintr = 0;
 312         __va_start(ap, fmt);
 313         pca.tty = NULL;
 314         pca.flags = kprintf_logging & ~TOTTY;
 315         pca.pri = -1;
 316         retval = kvcprintf(fmt, kputchar, &pca, ap);
 317         __va_end(ap);
 318         if (!panicstr)
 319                 msgbuftrigger = 1;
 320         consintr = savintr;             /* reenable interrupts */
 321         return (retval);
 322 }
 323
 324 int
 325 kvprintf(const char *fmt, __va_list ap)
 326 {
 327         int savintr;
 328         struct putchar_arg pca;
 329         int retval;
 330
 331         savintr = consintr;             /* disable interrupts */
 332         consintr = 0;
 333         pca.tty = NULL;
 334         pca.flags = kprintf_logging & ~TOTTY;
 335         pca.pri = -1;
 336         retval = kvcprintf(fmt, kputchar, &pca, ap);
 337         if (!panicstr)
 338                 msgbuftrigger = 1;
 339         consintr = savintr;             /* reenable interrupts */
 340         return (retval);
 341 }
 342
 343 /*
 344  * Limited rate kprintf.  The passed rate structure must be initialized
 345  * with the desired reporting frequency.  A frequency of 0 will result in
 346  * no output.
 347  *
 348  * count may be initialized to a negative number to allow an initial
 349  * burst.
 350  */
 351 void
 352 krateprintf(struct krate *rate, const char *fmt, ...)
 353 {
 354         __va_list ap;
 355
 356         if (rate->ticks != (int)time_uptime) {
 357                 rate->ticks = (int)time_uptime;
 358                 if (rate->count > 0)
 359                         rate->count = 0;
 360         }
 361         if (rate->count < rate->freq) {
 362                 ++rate->count;
 363                 __va_start(ap, fmt);
 364                 kvprintf(fmt, ap);
 365                 __va_end(ap);
 366         }
 367 }
 368
 369 /*
 370  * Print a character to the dmesg log, the console, and/or the user's
 371  * terminal.
 372  *
 373  * NOTE: TOTTY does not require nonblocking operation, but TOCONS
 374  *       and TOLOG do.  When we have a constty we still output to
 375  *       the real console but we have a monitoring thread which
 376  *       we wakeup which tracks the log.
 377  */
 378 static void
 379 kputchar(int c, void *arg)
 380 {
 381         struct putchar_arg *ap = (struct putchar_arg*) arg;
 382         int flags = ap->flags;
 383         struct tty *tp = ap->tty;
 384
 385         if (panicstr)
 386                 constty = NULL;
 387         if ((flags & TOCONS) && tp == NULL && constty)
 388                 flags |= TOLOG | TOWAKEUP;
 389         if ((flags & TOTTY) && tputchar(c, tp) < 0)
 390                 ap->flags &= ~TOTTY;
 391         if ((flags & TOLOG))
 392                 msglogchar(c, ap->pri);
 393         if ((flags & TOCONS) && c)
 394                 cnputc(c);
 395         if (flags & TOWAKEUP)
 396                 wakeup(constty_td);
 397 }
 398
 399 /*
 400  * Scaled down version of sprintf(3).
 401  */
 402 int
 403 ksprintf(char *buf, const char *cfmt, ...)
 404 {
 405         int retval;
 406         __va_list ap;
 407
 408         __va_start(ap, cfmt);
 409         retval = kvcprintf(cfmt, NULL, buf, ap);
 410         buf[retval] = '\0';
 411         __va_end(ap);
 412         return (retval);
 413 }
 414
 415 /*
 416  * Scaled down version of vsprintf(3).
 417  */
 418 int
 419 kvsprintf(char *buf, const char *cfmt, __va_list ap)
 420 {
 421         int retval;
 422
 423         retval = kvcprintf(cfmt, NULL, buf, ap);
 424         buf[retval] = '\0';
 425         return (retval);
 426 }
 427
 428 /*
 429  * Scaled down version of snprintf(3).
 430  */
 431 int
 432 ksnprintf(char *str, size_t size, const char *format, ...)
 433 {
 434         int retval;
 435         __va_list ap;
 436
 437         __va_start(ap, format);
 438         retval = kvsnprintf(str, size, format, ap);
 439         __va_end(ap);
 440         return(retval);
 441 }
 442
 443 /*
 444  * Scaled down version of vsnprintf(3).
 445  */
 446 int
 447 kvsnprintf(char *str, size_t size, const char *format, __va_list ap)
 448 {
 449         struct snprintf_arg info;
 450         int retval;
 451
 452         info.str = str;
 453         info.remain = size;
 454         retval = kvcprintf(format, snprintf_func, &info, ap);
 455         if (info.remain >= 1)
 456                 *info.str++ = '\0';
 457         return (retval);
 458 }
 459
 460 int
 461 kvasnprintf(char **strp, size_t size, const char *format, __va_list ap)
 462 {
 463         struct snprintf_arg info;
 464         int retval;
 465
 466         *strp = kmalloc(size, M_TEMP, M_WAITOK);
 467         info.str = *strp;
 468         info.remain = size;
 469         retval = kvcprintf(format, snprintf_func, &info, ap);
 470         if (info.remain >= 1)
 471                 *info.str++ = '\0';
 472         return (retval);
 473 }
 474
 475 void
 476 kvasfree(char **strp)
 477 {
 478         if (*strp) {
 479                 kfree(*strp, M_TEMP);
 480                 *strp = NULL;
 481         }
 482 }
 483
 484 static void
 485 snprintf_func(int ch, void *arg)
 486 {
 487         struct snprintf_arg *const info = arg;
 488
 489         if (info->remain >= 2) {
 490                 *info->str++ = ch;
 491                 info->remain--;
 492         }
 493 }
 494
 495 /*
 496  * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
 497  * order; return an optional length and a pointer to the last character
 498  * written in the buffer (i.e., the first character of the string).
 499  * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
 500  */
 501 static char *
 502 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
 503 {
 504         char *p, c;
 505
 506         p = nbuf;
 507         *p = '\0';
 508         do {
 509                 c = hex2ascii(num % base);
 510                 *++p = upper ? toupper(c) : c;
 511         } while (num /= base);
 512         if (lenp)
 513                 *lenp = p - nbuf;
 514         return (p);
 515 }
 516
 517 /*
 518  * Scaled down version of printf(3).
 519  *
 520  * Two additional formats:
 521  *
 522  * The format %pb%i is supported to decode error registers.
 523  * Its usage is:
 524  *
 525  *      kprintf("reg=%pb%i\n", "<base><arg>*", regval);
 526  *
 527  * where <base> is the output base expressed as a control character, e.g.
 528  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
 529  * the first of which gives the bit number to be inspected (origin 1), and
 530  * the next characters (up to a control character, i.e. a character <= 32),
 531  * give the name of the register.  Thus:
 532  *
 533  *      kvcprintf("reg=%pb%i\n", "\10\2BITTWO\1BITONE\n", 3);
 534  *
 535  * would produce output:
 536  *
 537  *      reg=3<BITTWO,BITONE>
 538  */
 539
 540 #define PCHAR(c) {int cc=(c); if(func) (*func)(cc,arg); else *d++=cc; retval++;}
 541
 542 int
 543 kvcprintf(char const *fmt, void (*func)(int, void*), void *arg, __va_list ap)
 544 {
 545         char nbuf[MAXNBUF];
 546         char *d;
 547         const char *p, *percent, *q;
 548         int ch, n;
 549         uintmax_t num;
 550         int base, tmp, width, ladjust, sharpflag, spaceflag, neg, sign, dot;
 551         int cflag, hflag, jflag, lflag, qflag, tflag, zflag;
 552         int dwidth, upper;
 553         char padc;
 554         int retval = 0, stop = 0;
 555         int usespin;
 556         int ddb_active;
 557
 558         /*
 559          * Make a supreme effort to avoid reentrant panics or deadlocks.
 560          *
 561          * NOTE!  Do nothing that would access mycpu/gd/fs unless the
 562          *        function is the normal kputchar(), which allows us to
 563          *        use this function for very early debugging with a special
 564          *        function.
 565          */
 566         if (func == kputchar) {
 567                 if (mycpu->gd_flags & GDF_KPRINTF)
 568                         return(0);
 569                 atomic_set_long(&mycpu->gd_flags, GDF_KPRINTF);
 570         }
 571
 572 #ifdef DDB
 573         ddb_active = db_active;
 574 #else
 575         ddb_active = 0;
 576 #endif
 577
 578         num = 0;
 579         if (!func)
 580                 d = (char *) arg;
 581         else
 582                 d = NULL;
 583
 584         if (fmt == NULL)
 585                 fmt = "(fmt null)\n";
 586
 587         usespin = (func == kputchar &&
 588                    (kprintf_logging & TONOSPIN) == 0 &&
 589                    panic_cpu_gd != mycpu &&
 590                    (((struct putchar_arg *)arg)->flags & TOTTY) == 0);
 591         if (usespin) {
 592                 crit_enter_hard();
 593                 spin_lock(&cons_spin);
 594         }
 595
 596         for (;;) {
 597                 padc = ' ';
 598                 width = 0;
 599                 while ((ch = (u_char)*fmt++) != '%' || stop) {
 600                         if (ch == '\0')
 601                                 goto done;
 602                         PCHAR(ch);
 603                 }
 604                 percent = fmt - 1;
 605                 dot = dwidth = ladjust = neg = sharpflag = sign = upper = 0;
 606                 spaceflag = 0;
 607                 cflag = hflag = jflag = lflag = qflag = tflag = zflag = 0;
 608
 609 reswitch:
 610                 switch (ch = (u_char)*fmt++) {
 611                 case ' ':
 612                         spaceflag = 1;
 613                         goto reswitch;
 614                 case '.':
 615                         dot = 1;
 616                         goto reswitch;
 617                 case '#':
 618                         sharpflag = 1;
 619                         goto reswitch;
 620                 case '+':
 621                         sign = 1;
 622                         goto reswitch;
 623                 case '-':
 624                         ladjust = 1;
 625                         goto reswitch;
 626                 case '%':
 627                         PCHAR(ch);
 628                         break;
 629                 case '*':
 630                         if (!dot) {
 631                                 width = __va_arg(ap, int);
 632                                 if (width < 0) {
 633                                         ladjust = !ladjust;
 634                                         width = -width;
 635                                 }
 636                         } else {
 637                                 dwidth = __va_arg(ap, int);
 638                         }
 639                         goto reswitch;
 640                 case '0':
 641                         if (!dot) {
 642                                 padc = '0';
 643                                 goto reswitch;
 644                         }
 645                 case '1': case '2': case '3': case '4':
 646                 case '5': case '6': case '7': case '8': case '9':
 647                                 for (n = 0;; ++fmt) {
 648                                         n = n * 10 + ch - '0';
 649                                         ch = *fmt;
 650                                         if (ch < '0' || ch > '9')
 651                                                 break;
 652                                 }
 653                         if (dot)
 654                                 dwidth = n;
 655                         else
 656                                 width = n;
 657                         goto reswitch;
 658                 case 'c':
 659                         PCHAR(__va_arg(ap, int));
 660                         break;
 661                 case 'd':
 662                 case 'i':
 663                         base = 10;
 664                         sign = 1;
 665                         goto handle_sign;
 666                 case 'h':
 667                         if (hflag) {
 668                                 hflag = 0;
 669                                 cflag = 1;
 670                         } else
 671                                 hflag = 1;
 672                         goto reswitch;
 673                 case 'j':
 674                         jflag = 1;
 675                         goto reswitch;
 676                 case 'l':
 677                         if (lflag) {
 678                                 lflag = 0;
 679                                 qflag = 1;
 680                         } else
 681                                 lflag = 1;
 682                         goto reswitch;
 683                 case 'n':
 684                         if (cflag)
 685                                 *(__va_arg(ap, char *)) = retval;
 686                         else if (hflag)
 687                                 *(__va_arg(ap, short *)) = retval;
 688                         else if (jflag)
 689                                 *(__va_arg(ap, intmax_t *)) = retval;
 690                         else if (lflag)
 691                                 *(__va_arg(ap, long *)) = retval;
 692                         else if (qflag)
 693                                 *(__va_arg(ap, quad_t *)) = retval;
 694                         else
 695                                 *(__va_arg(ap, int *)) = retval;
 696                         break;
 697                 case 'o':
 698                         base = 8;
 699                         goto handle_nosign;
 700                 case 'p':
 701                         /* peek if this is a /b/ hiding as /p/ or not */
 702                         if (fmt[0] == 'b' && fmt[1] == '%' && fmt[2] == 'i') {
 703                                 fmt += 3; /* consume "b%i" */
 704                                 p = __va_arg(ap, char *);
 705                                 num = (u_int)__va_arg(ap, int);
 706                                 for (q = ksprintn(nbuf, num, *p++, NULL, 0);*q;)
 707                                         PCHAR(*q--);
 708
 709                                 if (num == 0)
 710                                         break;
 711
 712                                 for (tmp = 0; *p;) {
 713                                         n = *p++;
 714                                         if (num & (1 << (n - 1))) {
 715                                                 PCHAR(tmp ? ',' : '<');
 716                                                 for (; (n = *p) > ' '; ++p)
 717                                                         PCHAR(n);
 718                                                 tmp = 1;
 719                                         } else {
 720                                                 for (; *p > ' '; ++p)
 721                                                         continue;
 722                                         }
 723                                 }
 724                                 if (tmp)
 725                                         PCHAR('>');
 726                                 break;
 727                         }
 728                         base = 16;
 729                         sharpflag = (width == 0);
 730                         sign = 0;
 731                         num = (uintptr_t)__va_arg(ap, void *);
 732                         if (ptr_restrict && fmt[0] != 'x' &&
 733                             !(panicstr || dumping || ddb_active)) {
 734                                 if (ptr_restrict == 1) {
 735                                         /* zero out upper bits */
 736                                         num &= 0xffffffUL;
 737                                 } else {
 738                                         num = 0xc0ffee;
 739                                 }
 740                         }
 741                         goto number;
 742                 case 'q':
 743                         qflag = 1;
 744                         goto reswitch;
 745                 case 's':
 746                         p = __va_arg(ap, char *);
 747                         if (p == NULL)
 748                                 p = "(null)";
 749                         if (!dot)
 750                                 n = strlen (p);
 751                         else
 752                                 for (n = 0; n < dwidth && p[n]; n++)
 753                                         continue;
 754
 755                         width -= n;
 756
 757                         if (!ladjust && width > 0)
 758                                 while (width--)
 759                                         PCHAR(padc);
 760                         while (n--)
 761                                 PCHAR(*p++);
 762                         if (ladjust && width > 0)
 763                                 while (width--)
 764                                         PCHAR(padc);
 765                         break;
 766                 case 't':
 767                         tflag = 1;
 768                         goto reswitch;
 769                 case 'u':
 770                         base = 10;
 771                         goto handle_nosign;
 772                 case 'X':
 773                         upper = 1;
 774                         /* FALLTHROUGH */
 775                 case 'x':
 776                         base = 16;
 777                         goto handle_nosign;
 778                 case 'z':
 779                         zflag = 1;
 780                         goto reswitch;
 781 handle_nosign:
 782                         sign = 0;
 783                         if (cflag)
 784                                 num = (u_char)__va_arg(ap, int);
 785                         else if (hflag)
 786                                 num = (u_short)__va_arg(ap, int);
 787                         else if (jflag)
 788                                 num = __va_arg(ap, uintmax_t);
 789                         else if (lflag)
 790                                 num = __va_arg(ap, u_long);
 791                         else if (qflag)
 792                                 num = __va_arg(ap, u_quad_t);
 793                         else if (tflag)
 794                                 num = __va_arg(ap, ptrdiff_t);
 795                         else if (zflag)
 796                                 num = __va_arg(ap, size_t);
 797                         else
 798                                 num = __va_arg(ap, u_int);
 799                         goto number;
 800 handle_sign:
 801                         if (cflag)
 802                                 num = (char)__va_arg(ap, int);
 803                         else if (hflag)
 804                                 num = (short)__va_arg(ap, int);
 805                         else if (jflag)
 806                                 num = __va_arg(ap, intmax_t);
 807                         else if (lflag)
 808                                 num = __va_arg(ap, long);
 809                         else if (qflag)
 810                                 num = __va_arg(ap, quad_t);
 811                         else if (tflag)
 812                                 num = __va_arg(ap, ptrdiff_t);
 813                         else if (zflag)
 814                                 num = __va_arg(ap, ssize_t);
 815                         else
 816                                 num = __va_arg(ap, int);
 817 number:
 818                         if (sign && (intmax_t)num < 0) {
 819                                 neg = 1;
 820                                 num = -(intmax_t)num;
 821                         }
 822                         p = ksprintn(nbuf, num, base, &n, upper);
 823                         tmp = 0;
 824                         if (sharpflag && num != 0) {
 825                                 if (base == 8)
 826                                         tmp++;
 827                                 else if (base == 16)
 828                                         tmp += 2;
 829                         }
 830                         if (neg || (sign && spaceflag))
 831                                 tmp++;
 832
 833                         if (!ladjust && padc == '0')
 834                                 dwidth = width - tmp;
 835                         width -= tmp + imax(dwidth, n);
 836                         dwidth -= n;
 837                         if (!ladjust)
 838                                 while (width-- > 0)
 839                                         PCHAR(' ');
 840                         if (neg) {
 841                                 PCHAR('-');
 842                         } else if (sign && spaceflag) {
 843                                 PCHAR(' ');
 844                         }
 845                         if (sharpflag && num != 0) {
 846                                 if (base == 8) {
 847                                         PCHAR('0');
 848                                 } else if (base == 16) {
 849                                         PCHAR('0');
 850                                         PCHAR('x');
 851                                 }
 852                         }
 853                         while (dwidth-- > 0)
 854                                 PCHAR('0');
 855
 856                         while (*p)
 857                                 PCHAR(*p--);
 858
 859                         if (ladjust)
 860                                 while (width-- > 0)
 861                                         PCHAR(' ');
 862
 863                         break;
 864                 default:
 865                         while (percent < fmt)
 866                                 PCHAR(*percent++);
 867                         /*
 868                          * Since we ignore an formatting argument it is no
 869                          * longer safe to obey the remaining formatting
 870                          * arguments as the arguments will no longer match
 871                          * the format specs.
 872                          */
 873                         stop = 1;
 874                         break;
 875                 }
 876         }
 877 done:
 878         /*
 879          * Cleanup reentrancy issues.
 880          */
 881         if (func == kputchar)
 882                 atomic_clear_long(&mycpu->gd_flags, GDF_KPRINTF);
 883         if (usespin) {
 884                 spin_unlock(&cons_spin);
 885                 crit_exit_hard();
 886         }
 887         return (retval);
 888 }
 889
 890 #undef PCHAR
 891
 892 /*
 893  * Called from the panic code to try to get the console working
 894  * again in case we paniced inside a kprintf().
 895  */
 896 void
 897 kvcreinitspin(void)
 898 {
 899         spin_init(&cons_spin, "kvcre");
 900         atomic_clear_long(&mycpu->gd_flags, GDF_KPRINTF);
 901 }
 902
 903 /*
 904  * Console support thread for constty intercepts.  This is needed because
 905  * console tty intercepts can block.  Instead of having kputchar() attempt
 906  * to directly write to the console intercept we just force it to log
 907  * and wakeup this baby to track and dump the log to constty.
 908  */
 909 static void
 910 constty_daemon(void)
 911 {
 912         u_int rindex;
 913         u_int xindex;
 914         u_int n;
 915         struct msgbuf *mbp;
 916         struct tty *tp;
 917
 918         EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_kproc,
 919                               constty_td, SHUTDOWN_PRI_FIRST);
 920         constty_td->td_flags |= TDF_SYSTHREAD;
 921
 922         mbp = msgbufp;
 923         rindex = mbp->msg_bufr;         /* persistent loop variable */
 924         xindex = mbp->msg_bufx - 1;     /* anything different than bufx */
 925         cpu_ccfence();
 926
 927         for (;;) {
 928                 kproc_suspend_loop();
 929
 930                 crit_enter();
 931                 if (mbp != msgbufp)
 932                         mbp = msgbufp;
 933                 if (xindex == mbp->msg_bufx ||
 934                     mbp == NULL ||
 935                     msgbufmapped == 0) {
 936                         tsleep(constty_td, 0, "waiting", hz*60);
 937                         crit_exit();
 938                         continue;
 939                 }
 940                 crit_exit();
 941
 942                 /*
 943                  * Get message buf FIFO indices.  rindex is tracking.
 944                  */
 945                 xindex = mbp->msg_bufx;
 946                 cpu_ccfence();
 947                 if ((tp = constty) == NULL) {
 948                         rindex = xindex;
 949                         continue;
 950                 }
 951
 952                 /*
 953                  * Check if the calculated bytes has rolled the whole
 954                  * message buffer.
 955                  */
 956                 n = xindex - rindex;
 957                 if (n > mbp->msg_size - 1024) {
 958                         rindex = xindex - mbp->msg_size + 2048;
 959                         n = xindex - rindex;
 960                 }
 961
 962                 /*
 963                  * And dump it.  If constty gets stuck will give up.
 964                  */
 965                 while (rindex != xindex) {
 966                         u_int ri = rindex % mbp->msg_size;
 967                         if (tputchar((uint8_t)mbp->msg_ptr[ri], tp) < 0) {
 968                                 constty = NULL;
 969                                 rindex = xindex;
 970                                 break;
 971                         }
 972                         if (tp->t_outq.c_cc >= tp->t_ohiwat) {
 973                                 tsleep(constty_daemon, 0, "blocked", hz / 10);
 974                                 if (tp->t_outq.c_cc >= tp->t_ohiwat) {
 975                                         rindex = xindex;
 976                                         break;
 977                                 }
 978                         }
 979                         ++rindex;
 980                 }
 981         }
 982 }
 983
 984 static struct kproc_desc constty_kp = {
 985         "consttyd",
 986         constty_daemon,
 987         &constty_td
 988 };
 989 SYSINIT(bufdaemon, SI_SUB_KTHREAD_UPDATE, SI_ORDER_ANY,
 990         kproc_start, &constty_kp);
 991
 992 /*
 993  * Put character in log buffer with a particular priority.
 994  *
 995  * MPSAFE
 996  */
 997 static void
 998 msglogchar(int c, int pri)
 999 {
1000         static int lastpri = -1;
1001         static int dangling;
1002         char nbuf[MAXNBUF];
1003         char *p;
1004
1005         if (!msgbufmapped)
1006                 return;
1007         if (c == '\0' || c == '\r')
1008                 return;
1009         if (pri != -1 && pri != lastpri) {
1010                 if (dangling) {
1011                         msgaddchar('\n', NULL);
1012                         dangling = 0;
1013                 }
1014                 msgaddchar('<', NULL);
1015                 for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
1016                         msgaddchar(*p--, NULL);
1017                 msgaddchar('>', NULL);
1018                 lastpri = pri;
1019         }
1020         msgaddchar(c, NULL);
1021         if (c == '\n') {
1022                 dangling = 0;
1023                 lastpri = -1;
1024         } else {
1025                 dangling = 1;
1026         }
1027 }
1028
1029 /*
1030  * Put char in log buffer.   Make sure nothing blows up beyond repair if
1031  * we have an MP race.
1032  *
1033  * MPSAFE.
1034  */
1035 static void
1036 msgaddchar(int c, void *dummy)
1037 {
1038         struct msgbuf *mbp;
1039         u_int lindex;
1040         u_int rindex;
1041         u_int xindex;
1042         u_int n;
1043
1044         if (!msgbufmapped)
1045                 return;
1046         mbp = msgbufp;
1047         lindex = mbp->msg_bufl;
1048         rindex = mbp->msg_bufr;
1049         xindex = mbp->msg_bufx++;       /* Allow SMP race */
1050         cpu_ccfence();
1051
1052         mbp->msg_ptr[xindex % mbp->msg_size] = c;
1053         n = xindex - lindex;
1054         if (n > mbp->msg_size - 1024) {
1055                 lindex = xindex - mbp->msg_size + 2048;
1056                 cpu_ccfence();
1057                 mbp->msg_bufl = lindex;
1058         }
1059         n = xindex - rindex;
1060         if (n > mbp->msg_size - 1024) {
1061                 rindex = xindex - mbp->msg_size + 2048;
1062                 cpu_ccfence();
1063                 mbp->msg_bufr = rindex;
1064         }
1065 }
1066
1067 static void
1068 msgbufcopy(struct msgbuf *oldp)
1069 {
1070         u_int rindex;
1071         u_int xindex;
1072         u_int n;
1073
1074         rindex = oldp->msg_bufr;
1075         xindex = oldp->msg_bufx;
1076         cpu_ccfence();
1077
1078         n = xindex - rindex;
1079         if (n > oldp->msg_size - 1024)
1080                 rindex = xindex - oldp->msg_size + 2048;
1081         while (rindex != xindex) {
1082                 msglogchar(oldp->msg_ptr[rindex % oldp->msg_size], -1);
1083                 ++rindex;
1084         }
1085 }
1086
1087 void
1088 msgbufinit(void *ptr, size_t size)
1089 {
1090         char *cp;
1091         static struct msgbuf *oldp = NULL;
1092
1093         size -= sizeof(*msgbufp);
1094         cp = (char *)ptr;
1095         msgbufp = (struct msgbuf *) (cp + size);
1096         if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size) {
1097                 bzero(cp, size);
1098                 bzero(msgbufp, sizeof(*msgbufp));
1099                 msgbufp->msg_magic = MSG_MAGIC;
1100                 msgbufp->msg_size = (char *)msgbufp - cp;
1101         }
1102         msgbufp->msg_ptr = cp;
1103         if (msgbufmapped && oldp != msgbufp)
1104                 msgbufcopy(oldp);
1105         cpu_mfence();
1106         msgbufmapped = 1;
1107         oldp = msgbufp;
1108 }
1109
1110 /* Sysctls for accessing/clearing the msgbuf */
1111
1112 static int
1113 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
1114 {
1115         struct msgbuf *mbp;
1116         struct ucred *cred;
1117         int error;
1118         u_int rindex_modulo;
1119         u_int xindex_modulo;
1120         u_int rindex;
1121         u_int xindex;
1122         u_int n;
1123
1124         /*
1125          * Only wheel or root can access the message log.
1126          */
1127         if (unprivileged_read_msgbuf == 0) {
1128                 KKASSERT(req->td->td_proc);
1129                 cred = req->td->td_proc->p_ucred;
1130
1131                 if ((cred->cr_prison || groupmember(0, cred) == 0) &&
1132                     priv_check(req->td, PRIV_ROOT) != 0
1133                 ) {
1134                         return (EPERM);
1135                 }
1136         }
1137
1138         /*
1139          * Unwind the buffer, so that it's linear (possibly starting with
1140          * some initial nulls).
1141          *
1142          * We don't push the entire buffer like we did before because
1143          * bufr (and bufl) now advance in chunks when the fifo is full,
1144          * rather than one character.
1145          */
1146         mbp = msgbufp;
1147         rindex = mbp->msg_bufr;
1148         xindex = mbp->msg_bufx;
1149         n = xindex - rindex;
1150         if (n > mbp->msg_size - 1024) {
1151                 rindex = xindex - mbp->msg_size + 2048;
1152                 n = xindex - rindex;
1153         }
1154         rindex_modulo = rindex % mbp->msg_size;
1155         xindex_modulo = xindex % mbp->msg_size;
1156
1157         if (rindex_modulo < xindex_modulo) {
1158                 /*
1159                  * Can handle in one linear section.
1160                  */
1161                 error = sysctl_handle_opaque(oidp,
1162                                              mbp->msg_ptr + rindex_modulo,
1163                                              xindex_modulo - rindex_modulo,
1164                                              req);
1165         } else if (rindex_modulo == xindex_modulo) {
1166                 /*
1167                  * Empty buffer, just return a single newline
1168                  */
1169                 error = sysctl_handle_opaque(oidp, "\n", 1, req);
1170         } else if (n <= mbp->msg_size - rindex_modulo) {
1171                 /*
1172                  * Can handle in one linear section.
1173                  */
1174                 error = sysctl_handle_opaque(oidp,
1175                                              mbp->msg_ptr + rindex_modulo,
1176                                              n - rindex_modulo,
1177                                              req);
1178         } else {
1179                 /*
1180                  * Glue together two linear sections into one contiguous
1181                  * output.
1182                  */
1183                 error = sysctl_handle_opaque(oidp,
1184                                              mbp->msg_ptr + rindex_modulo,
1185                                              mbp->msg_size - rindex_modulo,
1186                                              req);
1187                 n -= mbp->msg_size - rindex_modulo;
1188                 if (error == 0)
1189                         error = sysctl_handle_opaque(oidp, mbp->msg_ptr,
1190                                                      n, req);
1191         }
1192         return (error);
1193 }
1194
1195 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
1196     0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
1197
1198 static int msgbuf_clear;
1199
1200 static int
1201 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
1202 {
1203         int error;
1204         error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1205         if (!error && req->newptr) {
1206                 /* Clear the buffer and reset write pointer */
1207                 msgbufp->msg_bufr = msgbufp->msg_bufx;
1208                 msgbufp->msg_bufl = msgbufp->msg_bufx;
1209                 bzero(msgbufp->msg_ptr, msgbufp->msg_size);
1210                 msgbuf_clear = 0;
1211         }
1212         return (error);
1213 }
1214
1215 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
1216     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0,
1217     sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
1218
1219 #ifdef DDB
1220
1221 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
1222 {
1223         u_int rindex;
1224         u_int i;
1225         u_int j;
1226
1227         if (!msgbufmapped) {
1228                 db_printf("msgbuf not mapped yet\n");
1229                 return;
1230         }
1231         db_printf("msgbufp = %p\n", msgbufp);
1232         db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p\n",
1233                   msgbufp->msg_magic, msgbufp->msg_size,
1234                   msgbufp->msg_bufr % msgbufp->msg_size,
1235                   msgbufp->msg_bufx % msgbufp->msg_size,
1236                   msgbufp->msg_ptr);
1237
1238         rindex = msgbufp->msg_bufr;
1239         for (i = 0; i < msgbufp->msg_size; i++) {
1240                 j = (i + rindex) % msgbufp->msg_size;
1241                 db_printf("%c", msgbufp->msg_ptr[j]);
1242         }
1243         db_printf("\n");
1244 }
1245
1246 #endif /* DDB */
1247
1248
1249 void
1250 hexdump(const void *ptr, int length, const char *hdr, int flags)
1251 {
1252         int i, j, k;
1253         int cols;
1254         const unsigned char *cp;
1255         char delim;
1256
1257         if ((flags & HD_DELIM_MASK) != 0)
1258                 delim = (flags & HD_DELIM_MASK) >> 8;
1259         else
1260                 delim = ' ';
1261
1262         if ((flags & HD_COLUMN_MASK) != 0)
1263                 cols = flags & HD_COLUMN_MASK;
1264         else
1265                 cols = 16;
1266
1267         cp = ptr;
1268         for (i = 0; i < length; i+= cols) {
1269                 if (hdr != NULL)
1270                         kprintf("%s", hdr);
1271
1272                 if ((flags & HD_OMIT_COUNT) == 0)
1273                         kprintf("%04x  ", i);
1274
1275                 if ((flags & HD_OMIT_HEX) == 0) {
1276                         for (j = 0; j < cols; j++) {
1277                                 k = i + j;
1278                                 if (k < length)
1279                                         kprintf("%c%02x", delim, cp[k]);
1280                                 else
1281                                         kprintf("   ");
1282                         }
1283                 }
1284
1285                 if ((flags & HD_OMIT_CHARS) == 0) {
1286                         kprintf("  |");
1287                         for (j = 0; j < cols; j++) {
1288                                 k = i + j;
1289                                 if (k >= length)
1290                                         kprintf(" ");
1291                                 else if (cp[k] >= ' ' && cp[k] <= '~')
1292                                         kprintf("%c", cp[k]);
1293                                 else
1294                                         kprintf(".");
1295                         }
1296                         kprintf("|");
1297                 }
1298                 kprintf("\n");
1299         }
1300 }
1301
1302 void
1303 kprint_cpuset(cpumask_t *mask)
1304 {
1305         int i;
1306         int b = -1;
1307         int e = -1;
1308         int more = 0;
1309
1310         kprintf("cpus(");
1311         CPUSET_FOREACH(i, *mask) {
1312                 if (b < 0) {
1313                         b = i;
1314                         e = b + 1;
1315                         continue;
1316                 }
1317                 if (e == i) {
1318                         ++e;
1319                         continue;
1320                 }
1321                 if (more)
1322                         kprintf(", ");
1323                 if (b == e - 1) {
1324                         kprintf("%d", b);
1325                 } else {
1326                         kprintf("%d-%d", b, e - 1);
1327                 }
1328                 more = 1;
1329                 b = i;
1330                 e = b + 1;
1331         }
1332         if (more)
1333                 kprintf(", ");
1334         if (b >= 0) {
1335                 if (b == e - 1) {
1336                         kprintf("%d", b);
1337                 } else {
1338                         kprintf("%d-%d", b, e - 1);
1339                 }
1340         }
1341         kprintf(") ");
1342 }