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