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 1.21 2008/07/17 23:56:23 dillon Exp $ 41 */ 42 43 #include "opt_ddb.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/kernel.h> 48 #include <sys/msgbuf.h> 49 #include <sys/malloc.h> 50 #include <sys/proc.h> 51 #include <sys/priv.h> 52 #include <sys/tty.h> 53 #include <sys/tprintf.h> 54 #include <sys/stdint.h> 55 #include <sys/syslog.h> 56 #include <sys/cons.h> 57 #include <sys/uio.h> 58 #include <sys/sysctl.h> 59 #include <sys/lock.h> 60 #include <sys/ctype.h> 61 #include <sys/eventhandler.h> 62 #include <sys/kthread.h> 63 64 #include <sys/thread2.h> 65 #include <sys/spinlock2.h> 66 67 #ifdef DDB 68 #include <ddb/ddb.h> 69 #endif 70 71 /* 72 * Note that stdarg.h and the ANSI style va_start macro is used for both 73 * ANSI and traditional C compilers. We use the __ machine version to stay 74 * within the kernel header file set. 75 */ 76 #include <machine/stdarg.h> 77 78 #define TOCONS 0x01 79 #define TOTTY 0x02 80 #define TOLOG 0x04 81 #define TOWAKEUP 0x08 82 83 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */ 84 #define MAXNBUF (sizeof(intmax_t) * NBBY + 1) 85 86 struct putchar_arg { 87 int flags; 88 int pri; 89 struct tty *tty; 90 }; 91 92 struct snprintf_arg { 93 char *str; 94 size_t remain; 95 }; 96 97 extern int log_open; 98 99 struct tty *constty; /* pointer to console "window" tty */ 100 101 static void msglogchar(int c, int pri); 102 static void msgaddchar(int c, void *dummy); 103 static void kputchar (int ch, void *arg); 104 static char *ksprintn (char *nbuf, uintmax_t num, int base, int *lenp, 105 int upper); 106 static void snprintf_func (int ch, void *arg); 107 108 static int consintr = 1; /* Ok to handle console interrupts? */ 109 static int msgbufmapped; /* Set when safe to use msgbuf */ 110 static struct spinlock cons_spin = SPINLOCK_INITIALIZER(cons_spin); 111 static thread_t constty_td = NULL; 112 113 int msgbuftrigger; 114 115 static int log_console_output = 1; 116 TUNABLE_INT("kern.log_console_output", &log_console_output); 117 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW, 118 &log_console_output, 0, ""); 119 120 static int unprivileged_read_msgbuf = 1; 121 SYSCTL_INT(_security, OID_AUTO, unprivileged_read_msgbuf, CTLFLAG_RW, 122 &unprivileged_read_msgbuf, 0, 123 "Unprivileged processes may read the kernel message buffer"); 124 125 /* 126 * Warn that a system table is full. 127 */ 128 void 129 tablefull(const char *tab) 130 { 131 132 log(LOG_ERR, "%s: table is full\n", tab); 133 } 134 135 /* 136 * Uprintf prints to the controlling terminal for the current process. 137 */ 138 int 139 uprintf(const char *fmt, ...) 140 { 141 struct proc *p = curproc; 142 __va_list ap; 143 struct putchar_arg pca; 144 int retval = 0; 145 146 if (p && p->p_flag & P_CONTROLT && 147 p->p_session->s_ttyvp) { 148 __va_start(ap, fmt); 149 pca.tty = p->p_session->s_ttyp; 150 pca.flags = TOTTY; 151 152 retval = kvcprintf(fmt, kputchar, &pca, 10, ap); 153 __va_end(ap); 154 } 155 return (retval); 156 } 157 158 tpr_t 159 tprintf_open(struct proc *p) 160 { 161 162 if ((p->p_flag & P_CONTROLT) && p->p_session->s_ttyvp) { 163 sess_hold(p->p_session); 164 return ((tpr_t) p->p_session); 165 } 166 return ((tpr_t) NULL); 167 } 168 169 void 170 tprintf_close(tpr_t sess) 171 { 172 if (sess) 173 sess_rele((struct session *) sess); 174 } 175 176 /* 177 * tprintf prints on the controlling terminal associated 178 * with the given session. 179 */ 180 int 181 tprintf(tpr_t tpr, const char *fmt, ...) 182 { 183 struct session *sess = (struct session *)tpr; 184 struct tty *tp = NULL; 185 int flags = TOLOG; 186 __va_list ap; 187 struct putchar_arg pca; 188 int retval; 189 190 if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) { 191 flags |= TOTTY; 192 tp = sess->s_ttyp; 193 } 194 __va_start(ap, fmt); 195 pca.tty = tp; 196 pca.flags = flags; 197 pca.pri = LOG_INFO; 198 retval = kvcprintf(fmt, kputchar, &pca, 10, ap); 199 __va_end(ap); 200 msgbuftrigger = 1; 201 return (retval); 202 } 203 204 /* 205 * Ttyprintf displays a message on a tty; it should be used only by 206 * the tty driver, or anything that knows the underlying tty will not 207 * be revoke(2)'d away. Other callers should use tprintf. 208 */ 209 int 210 ttyprintf(struct tty *tp, const char *fmt, ...) 211 { 212 __va_list ap; 213 struct putchar_arg pca; 214 int retval; 215 216 __va_start(ap, fmt); 217 pca.tty = tp; 218 pca.flags = TOTTY; 219 retval = kvcprintf(fmt, kputchar, &pca, 10, ap); 220 __va_end(ap); 221 return (retval); 222 } 223 224 /* 225 * Log writes to the log buffer, and guarantees not to sleep (so can be 226 * called by interrupt routines). If there is no process reading the 227 * log yet, it writes to the console also. 228 */ 229 int 230 log(int level, const char *fmt, ...) 231 { 232 __va_list ap; 233 int retval; 234 struct putchar_arg pca; 235 236 pca.tty = NULL; 237 pca.pri = level; 238 pca.flags = log_open ? TOLOG : TOCONS; 239 240 __va_start(ap, fmt); 241 retval = kvcprintf(fmt, kputchar, &pca, 10, ap); 242 __va_end(ap); 243 244 msgbuftrigger = 1; 245 return (retval); 246 } 247 248 #define CONSCHUNK 128 249 250 void 251 log_console(struct uio *uio) 252 { 253 int c, i, error, iovlen, nl; 254 struct uio muio; 255 struct iovec *miov = NULL; 256 char *consbuffer; 257 int pri; 258 259 if (!log_console_output) 260 return; 261 262 pri = LOG_INFO | LOG_CONSOLE; 263 muio = *uio; 264 iovlen = uio->uio_iovcnt * sizeof (struct iovec); 265 MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 266 MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK); 267 bcopy((caddr_t)muio.uio_iov, (caddr_t)miov, iovlen); 268 muio.uio_iov = miov; 269 uio = &muio; 270 271 nl = 0; 272 while (uio->uio_resid > 0) { 273 c = (int)szmin(uio->uio_resid, CONSCHUNK); 274 error = uiomove(consbuffer, (size_t)c, uio); 275 if (error != 0) 276 break; 277 for (i = 0; i < c; i++) { 278 msglogchar(consbuffer[i], pri); 279 if (consbuffer[i] == '\n') 280 nl = 1; 281 else 282 nl = 0; 283 } 284 } 285 if (!nl) 286 msglogchar('\n', pri); 287 msgbuftrigger = 1; 288 FREE(miov, M_TEMP); 289 FREE(consbuffer, M_TEMP); 290 return; 291 } 292 293 /* 294 * Output to the console. 295 */ 296 int 297 kprintf(const char *fmt, ...) 298 { 299 __va_list ap; 300 int savintr; 301 struct putchar_arg pca; 302 int retval; 303 304 savintr = consintr; /* disable interrupts */ 305 consintr = 0; 306 __va_start(ap, fmt); 307 pca.tty = NULL; 308 pca.flags = TOCONS | TOLOG; 309 pca.pri = -1; 310 retval = kvcprintf(fmt, kputchar, &pca, 10, ap); 311 __va_end(ap); 312 if (!panicstr) 313 msgbuftrigger = 1; 314 consintr = savintr; /* reenable interrupts */ 315 return (retval); 316 } 317 318 int 319 kvprintf(const char *fmt, __va_list ap) 320 { 321 int savintr; 322 struct putchar_arg pca; 323 int retval; 324 325 savintr = consintr; /* disable interrupts */ 326 consintr = 0; 327 pca.tty = NULL; 328 pca.flags = TOCONS | TOLOG; 329 pca.pri = -1; 330 retval = kvcprintf(fmt, kputchar, &pca, 10, ap); 331 if (!panicstr) 332 msgbuftrigger = 1; 333 consintr = savintr; /* reenable interrupts */ 334 return (retval); 335 } 336 337 /* 338 * Limited rate kprintf. The passed rate structure must be initialized 339 * with the desired reporting frequency. A frequency of 0 will result in 340 * no output. 341 * 342 * count may be initialized to a negative number to allow an initial 343 * burst. 344 */ 345 void 346 krateprintf(struct krate *rate, const char *fmt, ...) 347 { 348 __va_list ap; 349 350 if (rate->ticks != (int)time_second) { 351 rate->ticks = (int)time_second; 352 if (rate->count > 0) 353 rate->count = 0; 354 } 355 if (rate->count < rate->freq) { 356 ++rate->count; 357 __va_start(ap, fmt); 358 kvprintf(fmt, ap); 359 __va_end(ap); 360 } 361 } 362 363 /* 364 * Print a character to the dmesg log, the console, and/or the user's 365 * terminal. 366 * 367 * NOTE: TOTTY does not require nonblocking operation, but TOCONS 368 * and TOLOG do. When we have a constty we still output to 369 * the real console but we have a monitoring thread which 370 * we wakeup which tracks the log. 371 */ 372 static void 373 kputchar(int c, void *arg) 374 { 375 struct putchar_arg *ap = (struct putchar_arg*) arg; 376 int flags = ap->flags; 377 struct tty *tp = ap->tty; 378 379 if (panicstr) 380 constty = NULL; 381 if ((flags & TOCONS) && tp == NULL && constty) 382 flags |= TOLOG | TOWAKEUP; 383 if ((flags & TOLOG)) 384 msglogchar(c, ap->pri); 385 if ((flags & TOCONS) && c) 386 cnputc(c); 387 if (flags & TOWAKEUP) 388 wakeup(constty_td); 389 } 390 391 /* 392 * Scaled down version of sprintf(3). 393 */ 394 int 395 ksprintf(char *buf, const char *cfmt, ...) 396 { 397 int retval; 398 __va_list ap; 399 400 __va_start(ap, cfmt); 401 retval = kvcprintf(cfmt, NULL, (void *)buf, 10, ap); 402 buf[retval] = '\0'; 403 __va_end(ap); 404 return (retval); 405 } 406 407 /* 408 * Scaled down version of vsprintf(3). 409 */ 410 int 411 kvsprintf(char *buf, const char *cfmt, __va_list ap) 412 { 413 int retval; 414 415 retval = kvcprintf(cfmt, NULL, (void *)buf, 10, ap); 416 buf[retval] = '\0'; 417 return (retval); 418 } 419 420 /* 421 * Scaled down version of snprintf(3). 422 */ 423 int 424 ksnprintf(char *str, size_t size, const char *format, ...) 425 { 426 int retval; 427 __va_list ap; 428 429 __va_start(ap, format); 430 retval = kvsnprintf(str, size, format, ap); 431 __va_end(ap); 432 return(retval); 433 } 434 435 /* 436 * Scaled down version of vsnprintf(3). 437 */ 438 int 439 kvsnprintf(char *str, size_t size, const char *format, __va_list ap) 440 { 441 struct snprintf_arg info; 442 int retval; 443 444 info.str = str; 445 info.remain = size; 446 retval = kvcprintf(format, snprintf_func, &info, 10, ap); 447 if (info.remain >= 1) 448 *info.str++ = '\0'; 449 return (retval); 450 } 451 452 int 453 ksnrprintf(char *str, size_t size, int radix, const char *format, ...) 454 { 455 int retval; 456 __va_list ap; 457 458 __va_start(ap, format); 459 retval = kvsnrprintf(str, size, radix, format, ap); 460 __va_end(ap); 461 return(retval); 462 } 463 464 int 465 kvsnrprintf(char *str, size_t size, int radix, const char *format, __va_list ap) 466 { 467 struct snprintf_arg info; 468 int retval; 469 470 info.str = str; 471 info.remain = size; 472 retval = kvcprintf(format, snprintf_func, &info, radix, ap); 473 if (info.remain >= 1) 474 *info.str++ = '\0'; 475 return (retval); 476 } 477 478 int 479 kvasnrprintf(char **strp, size_t size, int radix, 480 const char *format, __va_list ap) 481 { 482 struct snprintf_arg info; 483 int retval; 484 485 *strp = kmalloc(size, M_TEMP, M_WAITOK); 486 info.str = *strp; 487 info.remain = size; 488 retval = kvcprintf(format, snprintf_func, &info, radix, ap); 489 if (info.remain >= 1) 490 *info.str++ = '\0'; 491 return (retval); 492 } 493 494 void 495 kvasfree(char **strp) 496 { 497 if (*strp) { 498 kfree(*strp, M_TEMP); 499 *strp = NULL; 500 } 501 } 502 503 static void 504 snprintf_func(int ch, void *arg) 505 { 506 struct snprintf_arg *const info = arg; 507 508 if (info->remain >= 2) { 509 *info->str++ = ch; 510 info->remain--; 511 } 512 } 513 514 /* 515 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse 516 * order; return an optional length and a pointer to the last character 517 * written in the buffer (i.e., the first character of the string). 518 * The buffer pointed to by `nbuf' must have length >= MAXNBUF. 519 */ 520 static char * 521 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper) 522 { 523 char *p, c; 524 525 p = nbuf; 526 *p = '\0'; 527 do { 528 c = hex2ascii(num % base); 529 *++p = upper ? toupper(c) : c; 530 } while (num /= base); 531 if (lenp) 532 *lenp = p - nbuf; 533 return (p); 534 } 535 536 /* 537 * Scaled down version of printf(3). 538 * 539 * Two additional formats: 540 * 541 * The format %b is supported to decode error registers. 542 * Its usage is: 543 * 544 * kprintf("reg=%b\n", regval, "<base><arg>*"); 545 * 546 * where <base> is the output base expressed as a control character, e.g. 547 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters, 548 * the first of which gives the bit number to be inspected (origin 1), and 549 * the next characters (up to a control character, i.e. a character <= 32), 550 * give the name of the register. Thus: 551 * 552 * kvcprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n"); 553 * 554 * would produce output: 555 * 556 * reg=3<BITTWO,BITONE> 557 * 558 * XXX: %D -- Hexdump, takes pointer and separator string: 559 * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX 560 * ("%*D", len, ptr, " " -> XX XX XX XX ... 561 */ 562 563 #define PCHAR(c) {int cc=(c); if(func) (*func)(cc,arg); else *d++=cc; retval++;} 564 565 int 566 kvcprintf(char const *fmt, void (*func)(int, void*), void *arg, 567 int radix, __va_list ap) 568 { 569 char nbuf[MAXNBUF]; 570 char *d; 571 const char *p, *percent, *q; 572 u_char *up; 573 int ch, n; 574 uintmax_t num; 575 int base, tmp, width, ladjust, sharpflag, neg, sign, dot; 576 int cflag, hflag, jflag, lflag, qflag, tflag, zflag; 577 int dwidth, upper; 578 char padc; 579 int retval = 0, stop = 0; 580 int usespin; 581 582 /* 583 * Make a supreme effort to avoid reentrant panics or deadlocks. 584 */ 585 if (func == kputchar) { 586 if (mycpu->gd_flags & GDF_KPRINTF) 587 return(0); 588 atomic_set_long(&mycpu->gd_flags, GDF_KPRINTF); 589 } 590 591 num = 0; 592 if (!func) 593 d = (char *) arg; 594 else 595 d = NULL; 596 597 if (fmt == NULL) 598 fmt = "(fmt null)\n"; 599 600 if (radix < 2 || radix > 36) 601 radix = 10; 602 603 usespin = (panic_cpu_gd != mycpu && 604 func == kputchar && 605 (((struct putchar_arg *)arg)->flags & TOTTY) == 0); 606 if (usespin) { 607 crit_enter_hard(); 608 spin_lock(&cons_spin); 609 } 610 611 for (;;) { 612 padc = ' '; 613 width = 0; 614 while ((ch = (u_char)*fmt++) != '%' || stop) { 615 if (ch == '\0') 616 goto done; 617 PCHAR(ch); 618 } 619 percent = fmt - 1; 620 dot = dwidth = ladjust = neg = sharpflag = sign = upper = 0; 621 cflag = hflag = jflag = lflag = qflag = tflag = zflag = 0; 622 623 reswitch: 624 switch (ch = (u_char)*fmt++) { 625 case '.': 626 dot = 1; 627 goto reswitch; 628 case '#': 629 sharpflag = 1; 630 goto reswitch; 631 case '+': 632 sign = 1; 633 goto reswitch; 634 case '-': 635 ladjust = 1; 636 goto reswitch; 637 case '%': 638 PCHAR(ch); 639 break; 640 case '*': 641 if (!dot) { 642 width = __va_arg(ap, int); 643 if (width < 0) { 644 ladjust = !ladjust; 645 width = -width; 646 } 647 } else { 648 dwidth = __va_arg(ap, int); 649 } 650 goto reswitch; 651 case '0': 652 if (!dot) { 653 padc = '0'; 654 goto reswitch; 655 } 656 case '1': case '2': case '3': case '4': 657 case '5': case '6': case '7': case '8': case '9': 658 for (n = 0;; ++fmt) { 659 n = n * 10 + ch - '0'; 660 ch = *fmt; 661 if (ch < '0' || ch > '9') 662 break; 663 } 664 if (dot) 665 dwidth = n; 666 else 667 width = n; 668 goto reswitch; 669 case 'b': 670 num = (u_int)__va_arg(ap, int); 671 p = __va_arg(ap, char *); 672 for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;) 673 PCHAR(*q--); 674 675 if (num == 0) 676 break; 677 678 for (tmp = 0; *p;) { 679 n = *p++; 680 if (num & (1 << (n - 1))) { 681 PCHAR(tmp ? ',' : '<'); 682 for (; (n = *p) > ' '; ++p) 683 PCHAR(n); 684 tmp = 1; 685 } else 686 for (; *p > ' '; ++p) 687 continue; 688 } 689 if (tmp) 690 PCHAR('>'); 691 break; 692 case 'c': 693 PCHAR(__va_arg(ap, int)); 694 break; 695 case 'D': 696 up = __va_arg(ap, u_char *); 697 p = __va_arg(ap, char *); 698 if (!width) 699 width = 16; 700 while(width--) { 701 PCHAR(hex2ascii(*up >> 4)); 702 PCHAR(hex2ascii(*up & 0x0f)); 703 up++; 704 if (width) 705 for (q=p;*q;q++) 706 PCHAR(*q); 707 } 708 break; 709 case 'd': 710 case 'i': 711 base = 10; 712 sign = 1; 713 goto handle_sign; 714 case 'h': 715 if (hflag) { 716 hflag = 0; 717 cflag = 1; 718 } else 719 hflag = 1; 720 goto reswitch; 721 case 'j': 722 jflag = 1; 723 goto reswitch; 724 case 'l': 725 if (lflag) { 726 lflag = 0; 727 qflag = 1; 728 } else 729 lflag = 1; 730 goto reswitch; 731 case 'n': 732 if (cflag) 733 *(__va_arg(ap, char *)) = retval; 734 else if (hflag) 735 *(__va_arg(ap, short *)) = retval; 736 else if (jflag) 737 *(__va_arg(ap, intmax_t *)) = retval; 738 else if (lflag) 739 *(__va_arg(ap, long *)) = retval; 740 else if (qflag) 741 *(__va_arg(ap, quad_t *)) = retval; 742 else 743 *(__va_arg(ap, int *)) = retval; 744 break; 745 case 'o': 746 base = 8; 747 goto handle_nosign; 748 case 'p': 749 base = 16; 750 sharpflag = (width == 0); 751 sign = 0; 752 num = (uintptr_t)__va_arg(ap, void *); 753 goto number; 754 case 'q': 755 qflag = 1; 756 goto reswitch; 757 case 'r': 758 base = radix; 759 if (sign) 760 goto handle_sign; 761 goto handle_nosign; 762 case 's': 763 p = __va_arg(ap, char *); 764 if (p == NULL) 765 p = "(null)"; 766 if (!dot) 767 n = strlen (p); 768 else 769 for (n = 0; n < dwidth && p[n]; n++) 770 continue; 771 772 width -= n; 773 774 if (!ladjust && width > 0) 775 while (width--) 776 PCHAR(padc); 777 while (n--) 778 PCHAR(*p++); 779 if (ladjust && width > 0) 780 while (width--) 781 PCHAR(padc); 782 break; 783 case 't': 784 tflag = 1; 785 goto reswitch; 786 case 'u': 787 base = 10; 788 goto handle_nosign; 789 case 'X': 790 upper = 1; 791 /* FALLTHROUGH */ 792 case 'x': 793 base = 16; 794 goto handle_nosign; 795 case 'z': 796 zflag = 1; 797 goto reswitch; 798 handle_nosign: 799 sign = 0; 800 if (cflag) 801 num = (u_char)__va_arg(ap, int); 802 else if (hflag) 803 num = (u_short)__va_arg(ap, int); 804 else if (jflag) 805 num = __va_arg(ap, uintmax_t); 806 else if (lflag) 807 num = __va_arg(ap, u_long); 808 else if (qflag) 809 num = __va_arg(ap, u_quad_t); 810 else if (tflag) 811 num = __va_arg(ap, ptrdiff_t); 812 else if (zflag) 813 num = __va_arg(ap, size_t); 814 else 815 num = __va_arg(ap, u_int); 816 goto number; 817 handle_sign: 818 if (cflag) 819 num = (char)__va_arg(ap, int); 820 else if (hflag) 821 num = (short)__va_arg(ap, int); 822 else if (jflag) 823 num = __va_arg(ap, intmax_t); 824 else if (lflag) 825 num = __va_arg(ap, long); 826 else if (qflag) 827 num = __va_arg(ap, quad_t); 828 else if (tflag) 829 num = __va_arg(ap, ptrdiff_t); 830 else if (zflag) 831 num = __va_arg(ap, ssize_t); 832 else 833 num = __va_arg(ap, int); 834 number: 835 if (sign && (intmax_t)num < 0) { 836 neg = 1; 837 num = -(intmax_t)num; 838 } 839 p = ksprintn(nbuf, num, base, &tmp, upper); 840 if (sharpflag && num != 0) { 841 if (base == 8) 842 tmp++; 843 else if (base == 16) 844 tmp += 2; 845 } 846 if (neg) 847 tmp++; 848 849 if (!ladjust && padc != '0' && width && 850 (width -= tmp) > 0) { 851 while (width--) 852 PCHAR(padc); 853 } 854 if (neg) 855 PCHAR('-'); 856 if (sharpflag && num != 0) { 857 if (base == 8) { 858 PCHAR('0'); 859 } else if (base == 16) { 860 PCHAR('0'); 861 PCHAR('x'); 862 } 863 } 864 if (!ladjust && width && (width -= tmp) > 0) 865 while (width--) 866 PCHAR(padc); 867 868 while (*p) 869 PCHAR(*p--); 870 871 if (ladjust && width && (width -= tmp) > 0) 872 while (width--) 873 PCHAR(padc); 874 875 break; 876 default: 877 while (percent < fmt) 878 PCHAR(*percent++); 879 /* 880 * Since we ignore an formatting argument it is no 881 * longer safe to obey the remaining formatting 882 * arguments as the arguments will no longer match 883 * the format specs. 884 */ 885 stop = 1; 886 break; 887 } 888 } 889 done: 890 /* 891 * Cleanup reentrancy issues. 892 */ 893 if (func == kputchar) 894 atomic_clear_long(&mycpu->gd_flags, GDF_KPRINTF); 895 if (usespin) { 896 spin_unlock(&cons_spin); 897 crit_exit_hard(); 898 } 899 return (retval); 900 } 901 902 #undef PCHAR 903 904 /* 905 * Called from the panic code to try to get the console working 906 * again in case we paniced inside a kprintf(). 907 */ 908 void 909 kvcreinitspin(void) 910 { 911 spin_init(&cons_spin); 912 atomic_clear_long(&mycpu->gd_flags, GDF_KPRINTF); 913 } 914 915 /* 916 * Console support thread for constty intercepts. This is needed because 917 * console tty intercepts can block. Instead of having kputchar() attempt 918 * to directly write to the console intercept we just force it to log 919 * and wakeup this baby to track and dump the log to constty. 920 */ 921 static void 922 constty_daemon(void) 923 { 924 int rindex = -1; 925 int windex = -1; 926 struct msgbuf *mbp; 927 struct tty *tp; 928 929 EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_kproc, 930 constty_td, SHUTDOWN_PRI_FIRST); 931 constty_td->td_flags |= TDF_SYSTHREAD; 932 933 for (;;) { 934 kproc_suspend_loop(); 935 936 crit_enter(); 937 mbp = msgbufp; 938 if (mbp == NULL || msgbufmapped == 0 || 939 windex == mbp->msg_bufx) { 940 tsleep(constty_td, 0, "waiting", hz*60); 941 crit_exit(); 942 continue; 943 } 944 windex = mbp->msg_bufx; 945 crit_exit(); 946 947 /* 948 * Get message buf FIFO indices. rindex is tracking. 949 */ 950 if ((tp = constty) == NULL) { 951 rindex = mbp->msg_bufx; 952 continue; 953 } 954 955 /* 956 * Don't blow up if the message buffer is broken 957 */ 958 if (windex < 0 || windex >= mbp->msg_size) 959 continue; 960 if (rindex < 0 || rindex >= mbp->msg_size) 961 rindex = windex; 962 963 /* 964 * And dump it. If constty gets stuck will give up. 965 */ 966 while (rindex != windex) { 967 if (tputchar((uint8_t)mbp->msg_ptr[rindex], tp) < 0) { 968 constty = NULL; 969 rindex = mbp->msg_bufx; 970 break; 971 } 972 if (++rindex >= mbp->msg_size) 973 rindex = 0; 974 if (tp->t_outq.c_cc >= tp->t_ohiwat) { 975 tsleep(constty_daemon, 0, "blocked", hz / 10); 976 if (tp->t_outq.c_cc >= tp->t_ohiwat) { 977 rindex = windex; 978 break; 979 } 980 } 981 } 982 } 983 } 984 985 static struct kproc_desc constty_kp = { 986 "consttyd", 987 constty_daemon, 988 &constty_td 989 }; 990 SYSINIT(bufdaemon, SI_SUB_KTHREAD_UPDATE, SI_ORDER_ANY, 991 kproc_start, &constty_kp) 992 993 /* 994 * Put character in log buffer with a particular priority. 995 * 996 * MPSAFE 997 */ 998 static void 999 msglogchar(int c, int pri) 1000 { 1001 static int lastpri = -1; 1002 static int dangling; 1003 char nbuf[MAXNBUF]; 1004 char *p; 1005 1006 if (!msgbufmapped) 1007 return; 1008 if (c == '\0' || c == '\r') 1009 return; 1010 if (pri != -1 && pri != lastpri) { 1011 if (dangling) { 1012 msgaddchar('\n', NULL); 1013 dangling = 0; 1014 } 1015 msgaddchar('<', NULL); 1016 for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;) 1017 msgaddchar(*p--, NULL); 1018 msgaddchar('>', NULL); 1019 lastpri = pri; 1020 } 1021 msgaddchar(c, NULL); 1022 if (c == '\n') { 1023 dangling = 0; 1024 lastpri = -1; 1025 } else { 1026 dangling = 1; 1027 } 1028 } 1029 1030 /* 1031 * Put char in log buffer. Make sure nothing blows up beyond repair if 1032 * we have an MP race. 1033 * 1034 * MPSAFE. 1035 */ 1036 static void 1037 msgaddchar(int c, void *dummy) 1038 { 1039 struct msgbuf *mbp; 1040 int rindex; 1041 int windex; 1042 1043 if (!msgbufmapped) 1044 return; 1045 mbp = msgbufp; 1046 windex = mbp->msg_bufx; 1047 mbp->msg_ptr[windex] = c; 1048 if (++windex >= mbp->msg_size) 1049 windex = 0; 1050 rindex = mbp->msg_bufr; 1051 if (windex == rindex) { 1052 rindex += 32; 1053 if (rindex >= mbp->msg_size) 1054 rindex -= mbp->msg_size; 1055 mbp->msg_bufr = rindex; 1056 } 1057 mbp->msg_bufx = windex; 1058 } 1059 1060 static void 1061 msgbufcopy(struct msgbuf *oldp) 1062 { 1063 int pos; 1064 1065 pos = oldp->msg_bufr; 1066 while (pos != oldp->msg_bufx) { 1067 msglogchar(oldp->msg_ptr[pos], -1); 1068 if (++pos >= oldp->msg_size) 1069 pos = 0; 1070 } 1071 } 1072 1073 void 1074 msgbufinit(void *ptr, size_t size) 1075 { 1076 char *cp; 1077 static struct msgbuf *oldp = NULL; 1078 1079 size -= sizeof(*msgbufp); 1080 cp = (char *)ptr; 1081 msgbufp = (struct msgbuf *) (cp + size); 1082 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size || 1083 msgbufp->msg_bufx >= size || msgbufp->msg_bufr >= size) { 1084 bzero(cp, size); 1085 bzero(msgbufp, sizeof(*msgbufp)); 1086 msgbufp->msg_magic = MSG_MAGIC; 1087 msgbufp->msg_size = (char *)msgbufp - cp; 1088 } 1089 msgbufp->msg_ptr = cp; 1090 if (msgbufmapped && oldp != msgbufp) 1091 msgbufcopy(oldp); 1092 msgbufmapped = 1; 1093 oldp = msgbufp; 1094 } 1095 1096 /* Sysctls for accessing/clearing the msgbuf */ 1097 1098 static int 1099 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS) 1100 { 1101 struct ucred *cred; 1102 int error; 1103 1104 /* 1105 * Only wheel or root can access the message log. 1106 */ 1107 if (unprivileged_read_msgbuf == 0) { 1108 KKASSERT(req->td->td_proc); 1109 cred = req->td->td_proc->p_ucred; 1110 1111 if ((cred->cr_prison || groupmember(0, cred) == 0) && 1112 priv_check(req->td, PRIV_ROOT) != 0 1113 ) { 1114 return (EPERM); 1115 } 1116 } 1117 1118 /* 1119 * Unwind the buffer, so that it's linear (possibly starting with 1120 * some initial nulls). 1121 */ 1122 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx, 1123 msgbufp->msg_size - msgbufp->msg_bufx, req); 1124 if (error) 1125 return (error); 1126 if (msgbufp->msg_bufx > 0) { 1127 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr, 1128 msgbufp->msg_bufx, req); 1129 } 1130 return (error); 1131 } 1132 1133 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD, 1134 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer"); 1135 1136 static int msgbuf_clear; 1137 1138 static int 1139 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS) 1140 { 1141 int error; 1142 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 1143 if (!error && req->newptr) { 1144 /* Clear the buffer and reset write pointer */ 1145 bzero(msgbufp->msg_ptr, msgbufp->msg_size); 1146 msgbufp->msg_bufr = msgbufp->msg_bufx = 0; 1147 msgbuf_clear = 0; 1148 } 1149 return (error); 1150 } 1151 1152 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear, 1153 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0, 1154 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer"); 1155 1156 #ifdef DDB 1157 1158 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf) 1159 { 1160 int i, j; 1161 1162 if (!msgbufmapped) { 1163 db_printf("msgbuf not mapped yet\n"); 1164 return; 1165 } 1166 db_printf("msgbufp = %p\n", msgbufp); 1167 db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p\n", 1168 msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr, 1169 msgbufp->msg_bufx, msgbufp->msg_ptr); 1170 for (i = 0; i < msgbufp->msg_size; i++) { 1171 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size; 1172 db_printf("%c", msgbufp->msg_ptr[j]); 1173 } 1174 db_printf("\n"); 1175 } 1176 1177 #endif /* DDB */ 1178