1 /* $OpenBSD: subr_log.c,v 1.75 2022/07/02 08:50:42 visa Exp $ */ 2 /* $NetBSD: subr_log.c,v 1.11 1996/03/30 22:24:44 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)subr_log.c 8.1 (Berkeley) 6/10/93 33 */ 34 35 /* 36 * Error log buffer for kernel printf's. 37 */ 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/proc.h> 42 #include <sys/vnode.h> 43 #include <sys/ioctl.h> 44 #include <sys/msgbuf.h> 45 #include <sys/file.h> 46 #include <sys/tty.h> 47 #include <sys/signalvar.h> 48 #include <sys/syslog.h> 49 #include <sys/malloc.h> 50 #include <sys/filedesc.h> 51 #include <sys/socket.h> 52 #include <sys/socketvar.h> 53 #include <sys/fcntl.h> 54 #include <sys/mutex.h> 55 #include <sys/timeout.h> 56 57 #ifdef KTRACE 58 #include <sys/ktrace.h> 59 #endif 60 61 #include <sys/mount.h> 62 #include <sys/syscallargs.h> 63 64 #include <dev/cons.h> 65 66 #define LOG_RDPRI (PZERO + 1) 67 #define LOG_TICK 50 /* log tick interval in msec */ 68 69 #define LOG_ASYNC 0x04 70 #define LOG_RDWAIT 0x08 71 72 /* 73 * Locking: 74 * L log_mtx 75 */ 76 struct logsoftc { 77 int sc_state; /* [L] see above for possibilities */ 78 struct selinfo sc_selp; /* process waiting on select call */ 79 struct sigio_ref sc_sigio; /* async I/O registration */ 80 int sc_need_wakeup; /* if set, wake up waiters */ 81 struct timeout sc_tick; /* wakeup poll timeout */ 82 } logsoftc; 83 84 int log_open; /* also used in log() */ 85 int msgbufmapped; /* is the message buffer mapped */ 86 struct msgbuf *msgbufp; /* the mapped buffer, itself. */ 87 struct msgbuf *consbufp; /* console message buffer. */ 88 89 struct file *syslogf; 90 struct rwlock syslogf_rwlock = RWLOCK_INITIALIZER("syslogf"); 91 92 /* 93 * Lock that serializes access to log message buffers. 94 * This should be kept as a leaf lock in order not to constrain where 95 * printf(9) can be used. 96 */ 97 struct mutex log_mtx = 98 MUTEX_INITIALIZER_FLAGS(IPL_HIGH, "logmtx", MTX_NOWITNESS); 99 100 void filt_logrdetach(struct knote *kn); 101 int filt_logread(struct knote *kn, long hint); 102 103 const struct filterops logread_filtops = { 104 .f_flags = FILTEROP_ISFD, 105 .f_attach = NULL, 106 .f_detach = filt_logrdetach, 107 .f_event = filt_logread, 108 }; 109 110 int dosendsyslog(struct proc *, const char *, size_t, int, enum uio_seg); 111 void logtick(void *); 112 size_t msgbuf_getlen(struct msgbuf *); 113 void msgbuf_putchar_locked(struct msgbuf *, const char); 114 115 void 116 initmsgbuf(caddr_t buf, size_t bufsize) 117 { 118 struct msgbuf *mbp; 119 long new_bufs; 120 121 /* Sanity-check the given size. */ 122 if (bufsize < sizeof(struct msgbuf)) 123 return; 124 125 mbp = msgbufp = (struct msgbuf *)buf; 126 127 new_bufs = bufsize - offsetof(struct msgbuf, msg_bufc); 128 if ((mbp->msg_magic != MSG_MAGIC) || (mbp->msg_bufs != new_bufs) || 129 (mbp->msg_bufr < 0) || (mbp->msg_bufr >= mbp->msg_bufs) || 130 (mbp->msg_bufx < 0) || (mbp->msg_bufx >= mbp->msg_bufs)) { 131 /* 132 * If the buffer magic number is wrong, has changed 133 * size (which shouldn't happen often), or is 134 * internally inconsistent, initialize it. 135 */ 136 137 memset(buf, 0, bufsize); 138 mbp->msg_magic = MSG_MAGIC; 139 mbp->msg_bufs = new_bufs; 140 } 141 142 /* 143 * Always start new buffer data on a new line. 144 * Avoid using log_mtx because mutexes do not work during early boot 145 * on some architectures. 146 */ 147 if (mbp->msg_bufx > 0 && mbp->msg_bufc[mbp->msg_bufx - 1] != '\n') 148 msgbuf_putchar_locked(mbp, '\n'); 149 150 /* mark it as ready for use. */ 151 msgbufmapped = 1; 152 } 153 154 void 155 initconsbuf(void) 156 { 157 /* Set up a buffer to collect /dev/console output */ 158 consbufp = malloc(CONSBUFSIZE, M_TTYS, M_WAITOK | M_ZERO); 159 consbufp->msg_magic = MSG_MAGIC; 160 consbufp->msg_bufs = CONSBUFSIZE - offsetof(struct msgbuf, msg_bufc); 161 } 162 163 void 164 msgbuf_putchar(struct msgbuf *mbp, const char c) 165 { 166 if (mbp->msg_magic != MSG_MAGIC) 167 /* Nothing we can do */ 168 return; 169 170 mtx_enter(&log_mtx); 171 msgbuf_putchar_locked(mbp, c); 172 mtx_leave(&log_mtx); 173 } 174 175 void 176 msgbuf_putchar_locked(struct msgbuf *mbp, const char c) 177 { 178 mbp->msg_bufc[mbp->msg_bufx++] = c; 179 if (mbp->msg_bufx < 0 || mbp->msg_bufx >= mbp->msg_bufs) 180 mbp->msg_bufx = 0; 181 /* If the buffer is full, keep the most recent data. */ 182 if (mbp->msg_bufr == mbp->msg_bufx) { 183 if (++mbp->msg_bufr >= mbp->msg_bufs) 184 mbp->msg_bufr = 0; 185 mbp->msg_bufd++; 186 } 187 } 188 189 size_t 190 msgbuf_getlen(struct msgbuf *mbp) 191 { 192 long len; 193 194 mtx_enter(&log_mtx); 195 len = mbp->msg_bufx - mbp->msg_bufr; 196 if (len < 0) 197 len += mbp->msg_bufs; 198 mtx_leave(&log_mtx); 199 return (len); 200 } 201 202 int 203 logopen(dev_t dev, int flags, int mode, struct proc *p) 204 { 205 if (log_open) 206 return (EBUSY); 207 log_open = 1; 208 sigio_init(&logsoftc.sc_sigio); 209 timeout_set(&logsoftc.sc_tick, logtick, NULL); 210 timeout_add_msec(&logsoftc.sc_tick, LOG_TICK); 211 return (0); 212 } 213 214 int 215 logclose(dev_t dev, int flag, int mode, struct proc *p) 216 { 217 struct file *fp; 218 219 rw_enter_write(&syslogf_rwlock); 220 fp = syslogf; 221 syslogf = NULL; 222 rw_exit(&syslogf_rwlock); 223 224 if (fp) 225 FRELE(fp, p); 226 log_open = 0; 227 timeout_del(&logsoftc.sc_tick); 228 logsoftc.sc_state = 0; 229 sigio_free(&logsoftc.sc_sigio); 230 return (0); 231 } 232 233 int 234 logread(dev_t dev, struct uio *uio, int flag) 235 { 236 struct sleep_state sls; 237 struct msgbuf *mbp = msgbufp; 238 size_t l, rpos; 239 int error = 0; 240 241 mtx_enter(&log_mtx); 242 while (mbp->msg_bufr == mbp->msg_bufx) { 243 if (flag & IO_NDELAY) { 244 error = EWOULDBLOCK; 245 goto out; 246 } 247 logsoftc.sc_state |= LOG_RDWAIT; 248 mtx_leave(&log_mtx); 249 /* 250 * Set up and enter sleep manually instead of using msleep() 251 * to keep log_mtx as a leaf lock. 252 */ 253 sleep_setup(&sls, mbp, LOG_RDPRI | PCATCH, "klog", 0); 254 error = sleep_finish(&sls, logsoftc.sc_state & LOG_RDWAIT); 255 mtx_enter(&log_mtx); 256 if (error) 257 goto out; 258 } 259 260 if (mbp->msg_bufd > 0) { 261 char buf[64]; 262 long ndropped; 263 264 ndropped = mbp->msg_bufd; 265 mtx_leave(&log_mtx); 266 l = snprintf(buf, sizeof(buf), 267 "<%d>klog: dropped %ld byte%s, message buffer full\n", 268 LOG_KERN|LOG_WARNING, ndropped, 269 ndropped == 1 ? "" : "s"); 270 error = uiomove(buf, ulmin(l, sizeof(buf) - 1), uio); 271 mtx_enter(&log_mtx); 272 if (error) 273 goto out; 274 mbp->msg_bufd -= ndropped; 275 } 276 277 while (uio->uio_resid > 0) { 278 if (mbp->msg_bufx >= mbp->msg_bufr) 279 l = mbp->msg_bufx - mbp->msg_bufr; 280 else 281 l = mbp->msg_bufs - mbp->msg_bufr; 282 l = ulmin(l, uio->uio_resid); 283 if (l == 0) 284 break; 285 rpos = mbp->msg_bufr; 286 mtx_leave(&log_mtx); 287 /* Ignore that concurrent readers may consume the same data. */ 288 error = uiomove(&mbp->msg_bufc[rpos], l, uio); 289 mtx_enter(&log_mtx); 290 if (error) 291 break; 292 mbp->msg_bufr += l; 293 if (mbp->msg_bufr < 0 || mbp->msg_bufr >= mbp->msg_bufs) 294 mbp->msg_bufr = 0; 295 } 296 out: 297 mtx_leave(&log_mtx); 298 return (error); 299 } 300 301 int 302 logkqfilter(dev_t dev, struct knote *kn) 303 { 304 struct klist *klist; 305 int s; 306 307 switch (kn->kn_filter) { 308 case EVFILT_READ: 309 klist = &logsoftc.sc_selp.si_note; 310 kn->kn_fop = &logread_filtops; 311 break; 312 default: 313 return (EINVAL); 314 } 315 316 kn->kn_hook = (void *)msgbufp; 317 318 s = splhigh(); 319 klist_insert_locked(klist, kn); 320 splx(s); 321 322 return (0); 323 } 324 325 void 326 filt_logrdetach(struct knote *kn) 327 { 328 int s; 329 330 s = splhigh(); 331 klist_remove_locked(&logsoftc.sc_selp.si_note, kn); 332 splx(s); 333 } 334 335 int 336 filt_logread(struct knote *kn, long hint) 337 { 338 struct msgbuf *mbp = kn->kn_hook; 339 340 kn->kn_data = msgbuf_getlen(mbp); 341 return (kn->kn_data != 0); 342 } 343 344 void 345 logwakeup(void) 346 { 347 /* 348 * The actual wakeup has to be deferred because logwakeup() can be 349 * called in very varied contexts. 350 * Keep the print routines usable in as many situations as possible 351 * by not using locking here. 352 */ 353 354 /* 355 * Ensure that preceding stores become visible to other CPUs 356 * before the flag. 357 */ 358 membar_producer(); 359 360 logsoftc.sc_need_wakeup = 1; 361 } 362 363 void 364 logtick(void *arg) 365 { 366 int state; 367 368 if (!log_open) 369 return; 370 371 if (!logsoftc.sc_need_wakeup) 372 goto out; 373 logsoftc.sc_need_wakeup = 0; 374 375 /* 376 * sc_need_wakeup has to be cleared before handling the wakeup. 377 * Visiting log_mtx ensures the proper order. 378 */ 379 380 mtx_enter(&log_mtx); 381 state = logsoftc.sc_state; 382 if (logsoftc.sc_state & LOG_RDWAIT) 383 logsoftc.sc_state &= ~LOG_RDWAIT; 384 mtx_leave(&log_mtx); 385 386 selwakeup(&logsoftc.sc_selp); 387 if (state & LOG_ASYNC) 388 pgsigio(&logsoftc.sc_sigio, SIGIO, 0); 389 if (state & LOG_RDWAIT) 390 wakeup(msgbufp); 391 out: 392 timeout_add_msec(&logsoftc.sc_tick, LOG_TICK); 393 } 394 395 int 396 logioctl(dev_t dev, u_long com, caddr_t data, int flag, struct proc *p) 397 { 398 struct file *fp, *newfp; 399 int error; 400 401 switch (com) { 402 403 /* return number of characters immediately available */ 404 case FIONREAD: 405 *(int *)data = (int)msgbuf_getlen(msgbufp); 406 break; 407 408 case FIONBIO: 409 break; 410 411 case FIOASYNC: 412 mtx_enter(&log_mtx); 413 if (*(int *)data) 414 logsoftc.sc_state |= LOG_ASYNC; 415 else 416 logsoftc.sc_state &= ~LOG_ASYNC; 417 mtx_leave(&log_mtx); 418 break; 419 420 case FIOSETOWN: 421 case TIOCSPGRP: 422 return (sigio_setown(&logsoftc.sc_sigio, com, data)); 423 424 case FIOGETOWN: 425 case TIOCGPGRP: 426 sigio_getown(&logsoftc.sc_sigio, com, data); 427 break; 428 429 case LIOCSFD: 430 if ((error = suser(p)) != 0) 431 return (error); 432 if ((error = getsock(p, *(int *)data, &newfp)) != 0) 433 return (error); 434 435 rw_enter_write(&syslogf_rwlock); 436 fp = syslogf; 437 syslogf = newfp; 438 rw_exit(&syslogf_rwlock); 439 440 if (fp) 441 FRELE(fp, p); 442 break; 443 444 default: 445 return (ENOTTY); 446 } 447 return (0); 448 } 449 450 /* 451 * If syslogd is not running, temporarily store a limited amount of messages 452 * in kernel. After log stash is full, drop messages and count them. When 453 * syslogd is available again, next log message will flush the stashed 454 * messages and insert a message with drop count. Calls to malloc(9) and 455 * copyin(9) may sleep, protect data structures with rwlock. 456 */ 457 458 #define LOGSTASH_SIZE 100 459 struct logstash_message { 460 char *lgs_buffer; 461 size_t lgs_size; 462 } logstash_messages[LOGSTASH_SIZE]; 463 464 struct logstash_message *logstash_in = &logstash_messages[0]; 465 struct logstash_message *logstash_out = &logstash_messages[0]; 466 467 struct rwlock logstash_rwlock = RWLOCK_INITIALIZER("logstash"); 468 469 int logstash_dropped, logstash_error, logstash_pid; 470 471 int logstash_insert(const char *, size_t, int, pid_t); 472 void logstash_remove(void); 473 int logstash_sendsyslog(struct proc *); 474 475 static inline int 476 logstash_full(void) 477 { 478 rw_assert_anylock(&logstash_rwlock); 479 480 return logstash_out->lgs_buffer != NULL && 481 logstash_in == logstash_out; 482 } 483 484 static inline void 485 logstash_increment(struct logstash_message **msg) 486 { 487 rw_assert_wrlock(&logstash_rwlock); 488 489 KASSERT((*msg) >= &logstash_messages[0]); 490 KASSERT((*msg) < &logstash_messages[LOGSTASH_SIZE]); 491 if ((*msg) == &logstash_messages[LOGSTASH_SIZE - 1]) 492 (*msg) = &logstash_messages[0]; 493 else 494 (*msg)++; 495 } 496 497 int 498 logstash_insert(const char *buf, size_t nbyte, int logerror, pid_t pid) 499 { 500 int error; 501 502 rw_enter_write(&logstash_rwlock); 503 504 if (logstash_full()) { 505 if (logstash_dropped == 0) { 506 logstash_error = logerror; 507 logstash_pid = pid; 508 } 509 logstash_dropped++; 510 511 rw_exit(&logstash_rwlock); 512 return (0); 513 } 514 515 logstash_in->lgs_buffer = malloc(nbyte, M_LOG, M_WAITOK); 516 error = copyin(buf, logstash_in->lgs_buffer, nbyte); 517 if (error) { 518 free(logstash_in->lgs_buffer, M_LOG, nbyte); 519 logstash_in->lgs_buffer = NULL; 520 521 rw_exit(&logstash_rwlock); 522 return (error); 523 } 524 logstash_in->lgs_size = nbyte; 525 logstash_increment(&logstash_in); 526 527 rw_exit(&logstash_rwlock); 528 return (0); 529 } 530 531 void 532 logstash_remove(void) 533 { 534 rw_assert_wrlock(&logstash_rwlock); 535 536 KASSERT(logstash_out->lgs_buffer != NULL); 537 free(logstash_out->lgs_buffer, M_LOG, logstash_out->lgs_size); 538 logstash_out->lgs_buffer = NULL; 539 logstash_increment(&logstash_out); 540 541 /* Insert dropped message in sequence where messages were dropped. */ 542 if (logstash_dropped) { 543 size_t l, nbyte; 544 char buf[80]; 545 546 l = snprintf(buf, sizeof(buf), 547 "<%d>sendsyslog: dropped %d message%s, error %d, pid %d", 548 LOG_KERN|LOG_WARNING, logstash_dropped, 549 logstash_dropped == 1 ? "" : "s", 550 logstash_error, logstash_pid); 551 logstash_dropped = 0; 552 logstash_error = 0; 553 logstash_pid = 0; 554 555 /* Cannot fail, we have just freed a slot. */ 556 KASSERT(!logstash_full()); 557 nbyte = ulmin(l, sizeof(buf) - 1); 558 logstash_in->lgs_buffer = malloc(nbyte, M_LOG, M_WAITOK); 559 memcpy(logstash_in->lgs_buffer, buf, nbyte); 560 logstash_in->lgs_size = nbyte; 561 logstash_increment(&logstash_in); 562 } 563 } 564 565 int 566 logstash_sendsyslog(struct proc *p) 567 { 568 int error; 569 570 rw_enter_write(&logstash_rwlock); 571 572 while (logstash_out->lgs_buffer != NULL) { 573 error = dosendsyslog(p, logstash_out->lgs_buffer, 574 logstash_out->lgs_size, 0, UIO_SYSSPACE); 575 if (error) { 576 rw_exit(&logstash_rwlock); 577 return (error); 578 } 579 logstash_remove(); 580 } 581 582 rw_exit(&logstash_rwlock); 583 return (0); 584 } 585 586 /* 587 * Send syslog(3) message from userland to socketpair(2) created by syslogd(8). 588 * Store message in kernel log stash for later if syslogd(8) is not available 589 * or sending fails. Send to console if LOG_CONS is set and syslogd(8) socket 590 * does not exist. 591 */ 592 593 int 594 sys_sendsyslog(struct proc *p, void *v, register_t *retval) 595 { 596 struct sys_sendsyslog_args /* { 597 syscallarg(const char *) buf; 598 syscallarg(size_t) nbyte; 599 syscallarg(int) flags; 600 } */ *uap = v; 601 size_t nbyte; 602 int error; 603 604 nbyte = SCARG(uap, nbyte); 605 if (nbyte > LOG_MAXLINE) 606 nbyte = LOG_MAXLINE; 607 608 logstash_sendsyslog(p); 609 error = dosendsyslog(p, SCARG(uap, buf), nbyte, SCARG(uap, flags), 610 UIO_USERSPACE); 611 if (error && error != EFAULT) 612 logstash_insert(SCARG(uap, buf), nbyte, error, p->p_p->ps_pid); 613 return (error); 614 } 615 616 int 617 dosendsyslog(struct proc *p, const char *buf, size_t nbyte, int flags, 618 enum uio_seg sflg) 619 { 620 #ifdef KTRACE 621 struct iovec ktriov; 622 #endif 623 struct file *fp; 624 char pri[6], *kbuf; 625 struct iovec aiov; 626 struct uio auio; 627 size_t i, len; 628 int error; 629 630 /* Global variable syslogf may change during sleep, use local copy. */ 631 rw_enter_read(&syslogf_rwlock); 632 fp = syslogf; 633 if (fp) 634 FREF(fp); 635 rw_exit(&syslogf_rwlock); 636 637 if (fp == NULL) { 638 if (!ISSET(flags, LOG_CONS)) 639 return (ENOTCONN); 640 /* 641 * Strip off syslog priority when logging to console. 642 * LOG_PRIMASK | LOG_FACMASK is 0x03ff, so at most 4 643 * decimal digits may appear in priority as <1023>. 644 */ 645 len = MIN(nbyte, sizeof(pri)); 646 if (sflg == UIO_USERSPACE) { 647 if ((error = copyin(buf, pri, len))) 648 return (error); 649 } else 650 memcpy(pri, buf, len); 651 if (0 < len && pri[0] == '<') { 652 for (i = 1; i < len; i++) { 653 if (pri[i] < '0' || pri[i] > '9') 654 break; 655 } 656 if (i < len && pri[i] == '>') { 657 i++; 658 /* There must be at least one digit <0>. */ 659 if (i >= 3) { 660 buf += i; 661 nbyte -= i; 662 } 663 } 664 } 665 } 666 667 aiov.iov_base = (char *)buf; 668 aiov.iov_len = nbyte; 669 auio.uio_iov = &aiov; 670 auio.uio_iovcnt = 1; 671 auio.uio_segflg = sflg; 672 auio.uio_rw = UIO_WRITE; 673 auio.uio_procp = p; 674 auio.uio_offset = 0; 675 auio.uio_resid = aiov.iov_len; 676 #ifdef KTRACE 677 if (sflg == UIO_USERSPACE && KTRPOINT(p, KTR_GENIO)) 678 ktriov = aiov; 679 else 680 ktriov.iov_len = 0; 681 #endif 682 683 len = auio.uio_resid; 684 if (fp) { 685 int flags = (fp->f_flag & FNONBLOCK) ? MSG_DONTWAIT : 0; 686 error = sosend(fp->f_data, NULL, &auio, NULL, NULL, flags); 687 if (error == 0) 688 len -= auio.uio_resid; 689 } else { 690 KERNEL_LOCK(); 691 if (constty || cn_devvp) { 692 error = cnwrite(0, &auio, 0); 693 if (error == 0) 694 len -= auio.uio_resid; 695 aiov.iov_base = "\r\n"; 696 aiov.iov_len = 2; 697 auio.uio_iov = &aiov; 698 auio.uio_iovcnt = 1; 699 auio.uio_segflg = UIO_SYSSPACE; 700 auio.uio_rw = UIO_WRITE; 701 auio.uio_procp = p; 702 auio.uio_offset = 0; 703 auio.uio_resid = aiov.iov_len; 704 cnwrite(0, &auio, 0); 705 } else { 706 /* XXX console redirection breaks down... */ 707 if (sflg == UIO_USERSPACE) { 708 kbuf = malloc(len, M_TEMP, M_WAITOK); 709 error = copyin(aiov.iov_base, kbuf, len); 710 } else { 711 kbuf = aiov.iov_base; 712 error = 0; 713 } 714 if (error == 0) 715 for (i = 0; i < len; i++) { 716 if (kbuf[i] == '\0') 717 break; 718 cnputc(kbuf[i]); 719 auio.uio_resid--; 720 } 721 if (sflg == UIO_USERSPACE) 722 free(kbuf, M_TEMP, len); 723 if (error == 0) 724 len -= auio.uio_resid; 725 cnputc('\n'); 726 } 727 KERNEL_UNLOCK(); 728 } 729 730 #ifdef KTRACE 731 if (error == 0 && ktriov.iov_len != 0) 732 ktrgenio(p, -1, UIO_WRITE, &ktriov, len); 733 #endif 734 if (fp) 735 FRELE(fp, p); 736 else if (error != EFAULT) 737 error = ENOTCONN; 738 return (error); 739 } 740