1 /* $NetBSD: kern_ktrace.c,v 1.178 2021/02/27 13:02:42 simonb Exp $ */ 2 3 /*- 4 * Copyright (c) 2006, 2007, 2008, 2020 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Andrew Doran. 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Copyright (c) 1989, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 3. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)kern_ktrace.c 8.5 (Berkeley) 5/14/95 61 */ 62 63 #include <sys/cdefs.h> 64 __KERNEL_RCSID(0, "$NetBSD: kern_ktrace.c,v 1.178 2021/02/27 13:02:42 simonb Exp $"); 65 66 #include <sys/param.h> 67 #include <sys/systm.h> 68 #include <sys/proc.h> 69 #include <sys/file.h> 70 #include <sys/kernel.h> 71 #include <sys/kthread.h> 72 #include <sys/ktrace.h> 73 #include <sys/kmem.h> 74 #include <sys/syslog.h> 75 #include <sys/filedesc.h> 76 #include <sys/ioctl.h> 77 #include <sys/callout.h> 78 #include <sys/kauth.h> 79 80 #include <sys/mount.h> 81 #include <sys/syscallargs.h> 82 83 /* 84 * TODO: 85 * - need better error reporting? 86 * - userland utility to sort ktrace.out by timestamp. 87 * - keep minimum information in ktrace_entry when rest of alloc failed. 88 * - per trace control of configurable parameters. 89 */ 90 91 struct ktrace_entry { 92 TAILQ_ENTRY(ktrace_entry) kte_list; 93 struct ktr_header kte_kth; 94 void *kte_buf; 95 size_t kte_bufsz; 96 #define KTE_SPACE 32 97 uint8_t kte_space[KTE_SPACE] __aligned(sizeof(register_t)); 98 }; 99 100 struct ktr_desc { 101 TAILQ_ENTRY(ktr_desc) ktd_list; 102 int ktd_flags; 103 #define KTDF_WAIT 0x0001 104 #define KTDF_DONE 0x0002 105 #define KTDF_BLOCKING 0x0004 106 #define KTDF_INTERACTIVE 0x0008 107 int ktd_error; 108 #define KTDE_ENOMEM 0x0001 109 #define KTDE_ENOSPC 0x0002 110 int ktd_errcnt; 111 int ktd_ref; /* # of reference */ 112 int ktd_qcount; /* # of entry in the queue */ 113 114 /* 115 * Params to control behaviour. 116 */ 117 int ktd_delayqcnt; /* # of entry allowed to delay */ 118 int ktd_wakedelay; /* delay of wakeup in *tick* */ 119 int ktd_intrwakdl; /* ditto, but when interactive */ 120 121 file_t *ktd_fp; /* trace output file */ 122 lwp_t *ktd_lwp; /* our kernel thread */ 123 TAILQ_HEAD(, ktrace_entry) ktd_queue; 124 callout_t ktd_wakch; /* delayed wakeup */ 125 kcondvar_t ktd_sync_cv; 126 kcondvar_t ktd_cv; 127 }; 128 129 static void ktrwrite(struct ktr_desc *, struct ktrace_entry *); 130 static int ktrops(lwp_t *, struct proc *, int, int, 131 struct ktr_desc *); 132 static int ktrsetchildren(lwp_t *, struct proc *, int, int, 133 struct ktr_desc *); 134 static int ktrcanset(lwp_t *, struct proc *); 135 static int ktrsamefile(file_t *, file_t *); 136 static void ktr_kmem(lwp_t *, int, const void *, size_t); 137 static void ktr_io(lwp_t *, int, enum uio_rw, struct iovec *, size_t); 138 139 static struct ktr_desc * 140 ktd_lookup(file_t *); 141 static void ktdrel(struct ktr_desc *); 142 static void ktdref(struct ktr_desc *); 143 static void ktefree(struct ktrace_entry *); 144 static void ktd_logerrl(struct ktr_desc *, int); 145 static void ktrace_thread(void *); 146 static int ktrderefall(struct ktr_desc *, int); 147 148 /* 149 * Default values. 150 */ 151 #define KTD_MAXENTRY 1000 /* XXX: tune */ 152 #define KTD_TIMEOUT 5 /* XXX: tune */ 153 #define KTD_DELAYQCNT 100 /* XXX: tune */ 154 #define KTD_WAKEDELAY 5000 /* XXX: tune */ 155 #define KTD_INTRWAKDL 100 /* XXX: tune */ 156 157 /* 158 * Patchable variables. 159 */ 160 int ktd_maxentry = KTD_MAXENTRY; /* max # of entry in the queue */ 161 int ktd_timeout = KTD_TIMEOUT; /* timeout in seconds */ 162 int ktd_delayqcnt = KTD_DELAYQCNT; /* # of entry allowed to delay */ 163 int ktd_wakedelay = KTD_WAKEDELAY; /* delay of wakeup in *ms* */ 164 int ktd_intrwakdl = KTD_INTRWAKDL; /* ditto, but when interactive */ 165 166 kmutex_t ktrace_lock; 167 int ktrace_on; 168 static TAILQ_HEAD(, ktr_desc) ktdq = TAILQ_HEAD_INITIALIZER(ktdq); 169 static pool_cache_t kte_cache; 170 171 static kauth_listener_t ktrace_listener; 172 173 static void 174 ktd_wakeup(struct ktr_desc *ktd) 175 { 176 177 callout_stop(&ktd->ktd_wakch); 178 cv_signal(&ktd->ktd_cv); 179 } 180 181 static void 182 ktd_callout(void *arg) 183 { 184 185 mutex_enter(&ktrace_lock); 186 ktd_wakeup(arg); 187 mutex_exit(&ktrace_lock); 188 } 189 190 static void 191 ktd_logerrl(struct ktr_desc *ktd, int error) 192 { 193 194 ktd->ktd_error |= error; 195 ktd->ktd_errcnt++; 196 } 197 198 #if 0 199 static void 200 ktd_logerr(struct proc *p, int error) 201 { 202 struct ktr_desc *ktd; 203 204 KASSERT(mutex_owned(&ktrace_lock)); 205 206 ktd = p->p_tracep; 207 if (ktd == NULL) 208 return; 209 210 ktd_logerrl(ktd, error); 211 } 212 #endif 213 214 static int 215 ktrace_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 216 void *arg0, void *arg1, void *arg2, void *arg3) 217 { 218 struct proc *p; 219 int result; 220 enum kauth_process_req req; 221 222 result = KAUTH_RESULT_DEFER; 223 p = arg0; 224 225 if (action != KAUTH_PROCESS_KTRACE) 226 return result; 227 228 req = (enum kauth_process_req)(uintptr_t)arg1; 229 230 /* Privileged; secmodel should handle these. */ 231 if (req == KAUTH_REQ_PROCESS_KTRACE_PERSISTENT) 232 return result; 233 234 if ((p->p_traceflag & KTRFAC_PERSISTENT) || 235 (p->p_flag & PK_SUGID)) 236 return result; 237 238 if (kauth_cred_geteuid(cred) == kauth_cred_getuid(p->p_cred) && 239 kauth_cred_getuid(cred) == kauth_cred_getsvuid(p->p_cred) && 240 kauth_cred_getgid(cred) == kauth_cred_getgid(p->p_cred) && 241 kauth_cred_getgid(cred) == kauth_cred_getsvgid(p->p_cred)) 242 result = KAUTH_RESULT_ALLOW; 243 244 return result; 245 } 246 247 /* 248 * Initialise the ktrace system. 249 */ 250 void 251 ktrinit(void) 252 { 253 254 mutex_init(&ktrace_lock, MUTEX_DEFAULT, IPL_NONE); 255 kte_cache = pool_cache_init(sizeof(struct ktrace_entry), 0, 0, 0, 256 "ktrace", &pool_allocator_nointr, IPL_NONE, NULL, NULL, NULL); 257 258 ktrace_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS, 259 ktrace_listener_cb, NULL); 260 } 261 262 /* 263 * Release a reference. Called with ktrace_lock held. 264 */ 265 static void 266 ktdrel(struct ktr_desc *ktd) 267 { 268 269 KASSERT(mutex_owned(&ktrace_lock)); 270 271 KDASSERT(ktd->ktd_ref != 0); 272 KASSERT(ktd->ktd_ref > 0); 273 KASSERT(ktrace_on > 0); 274 ktrace_on--; 275 if (--ktd->ktd_ref <= 0) { 276 ktd->ktd_flags |= KTDF_DONE; 277 cv_signal(&ktd->ktd_cv); 278 } 279 } 280 281 static void 282 ktdref(struct ktr_desc *ktd) 283 { 284 285 KASSERT(mutex_owned(&ktrace_lock)); 286 287 ktd->ktd_ref++; 288 ktrace_on++; 289 } 290 291 static struct ktr_desc * 292 ktd_lookup(file_t *fp) 293 { 294 struct ktr_desc *ktd; 295 296 KASSERT(mutex_owned(&ktrace_lock)); 297 298 for (ktd = TAILQ_FIRST(&ktdq); ktd != NULL; 299 ktd = TAILQ_NEXT(ktd, ktd_list)) { 300 if (ktrsamefile(ktd->ktd_fp, fp)) { 301 ktdref(ktd); 302 break; 303 } 304 } 305 306 return (ktd); 307 } 308 309 void 310 ktraddentry(lwp_t *l, struct ktrace_entry *kte, int flags) 311 { 312 struct proc *p = l->l_proc; 313 struct ktr_desc *ktd; 314 #ifdef DEBUG 315 struct timeval t1, t2; 316 #endif 317 318 mutex_enter(&ktrace_lock); 319 320 if (p->p_traceflag & KTRFAC_TRC_EMUL) { 321 /* Add emulation trace before first entry for this process */ 322 p->p_traceflag &= ~KTRFAC_TRC_EMUL; 323 mutex_exit(&ktrace_lock); 324 ktrexit(l); 325 ktremul(); 326 (void)ktrenter(l); 327 mutex_enter(&ktrace_lock); 328 } 329 330 /* Tracing may have been cancelled. */ 331 ktd = p->p_tracep; 332 if (ktd == NULL) 333 goto freekte; 334 335 /* 336 * Bump reference count so that the object will remain while 337 * we are here. Note that the trace is controlled by other 338 * process. 339 */ 340 ktdref(ktd); 341 342 if (ktd->ktd_flags & KTDF_DONE) 343 goto relktd; 344 345 if (ktd->ktd_qcount > ktd_maxentry) { 346 ktd_logerrl(ktd, KTDE_ENOSPC); 347 goto relktd; 348 } 349 TAILQ_INSERT_TAIL(&ktd->ktd_queue, kte, kte_list); 350 ktd->ktd_qcount++; 351 if (ktd->ktd_flags & KTDF_BLOCKING) 352 goto skip_sync; 353 354 if (flags & KTA_WAITOK && 355 (/* flags & KTA_LARGE */0 || ktd->ktd_flags & KTDF_WAIT || 356 ktd->ktd_qcount > ktd_maxentry >> 1)) 357 /* 358 * Sync with writer thread since we're requesting rather 359 * big one or many requests are pending. 360 */ 361 do { 362 ktd->ktd_flags |= KTDF_WAIT; 363 ktd_wakeup(ktd); 364 #ifdef DEBUG 365 getmicrouptime(&t1); 366 #endif 367 if (cv_timedwait(&ktd->ktd_sync_cv, &ktrace_lock, 368 ktd_timeout * hz) != 0) { 369 ktd->ktd_flags |= KTDF_BLOCKING; 370 /* 371 * Maybe the writer thread is blocking 372 * completely for some reason, but 373 * don't stop target process forever. 374 */ 375 log(LOG_NOTICE, "ktrace timeout\n"); 376 break; 377 } 378 #ifdef DEBUG 379 getmicrouptime(&t2); 380 timersub(&t2, &t1, &t2); 381 if (t2.tv_sec > 0) 382 log(LOG_NOTICE, 383 "ktrace long wait: %lld.%06ld\n", 384 (long long)t2.tv_sec, (long)t2.tv_usec); 385 #endif 386 } while (p->p_tracep == ktd && 387 (ktd->ktd_flags & (KTDF_WAIT | KTDF_DONE)) == KTDF_WAIT); 388 else { 389 /* Schedule delayed wakeup */ 390 if (ktd->ktd_qcount > ktd->ktd_delayqcnt) 391 ktd_wakeup(ktd); /* Wakeup now */ 392 else if (!callout_pending(&ktd->ktd_wakch)) 393 callout_reset(&ktd->ktd_wakch, 394 ktd->ktd_flags & KTDF_INTERACTIVE ? 395 ktd->ktd_intrwakdl : ktd->ktd_wakedelay, 396 ktd_callout, ktd); 397 } 398 399 skip_sync: 400 ktdrel(ktd); 401 mutex_exit(&ktrace_lock); 402 ktrexit(l); 403 return; 404 405 relktd: 406 ktdrel(ktd); 407 408 freekte: 409 mutex_exit(&ktrace_lock); 410 ktefree(kte); 411 ktrexit(l); 412 } 413 414 static void 415 ktefree(struct ktrace_entry *kte) 416 { 417 418 if (kte->kte_buf != kte->kte_space) 419 kmem_free(kte->kte_buf, kte->kte_bufsz); 420 pool_cache_put(kte_cache, kte); 421 } 422 423 /* 424 * "deep" compare of two files for the purposes of clearing a trace. 425 * Returns true if they're the same open file, or if they point at the 426 * same underlying vnode/socket. 427 */ 428 429 static int 430 ktrsamefile(file_t *f1, file_t *f2) 431 { 432 433 return ((f1 == f2) || 434 ((f1 != NULL) && (f2 != NULL) && 435 (f1->f_type == f2->f_type) && 436 (f1->f_data == f2->f_data))); 437 } 438 439 void 440 ktrderef(struct proc *p) 441 { 442 struct ktr_desc *ktd = p->p_tracep; 443 444 KASSERT(mutex_owned(&ktrace_lock)); 445 446 p->p_traceflag = 0; 447 if (ktd == NULL) 448 return; 449 p->p_tracep = NULL; 450 451 cv_broadcast(&ktd->ktd_sync_cv); 452 ktdrel(ktd); 453 } 454 455 void 456 ktradref(struct proc *p) 457 { 458 struct ktr_desc *ktd = p->p_tracep; 459 460 KASSERT(mutex_owned(&ktrace_lock)); 461 462 ktdref(ktd); 463 } 464 465 static int 466 ktrderefall(struct ktr_desc *ktd, int auth) 467 { 468 lwp_t *curl = curlwp; 469 struct proc *p; 470 int error = 0; 471 472 mutex_enter(&proc_lock); 473 PROCLIST_FOREACH(p, &allproc) { 474 if (p->p_tracep != ktd) 475 continue; 476 mutex_enter(p->p_lock); 477 mutex_enter(&ktrace_lock); 478 if (p->p_tracep == ktd) { 479 if (!auth || ktrcanset(curl, p)) 480 ktrderef(p); 481 else 482 error = EPERM; 483 } 484 mutex_exit(&ktrace_lock); 485 mutex_exit(p->p_lock); 486 } 487 mutex_exit(&proc_lock); 488 489 return error; 490 } 491 492 int 493 ktealloc(struct ktrace_entry **ktep, void **bufp, lwp_t *l, int type, 494 size_t sz) 495 { 496 struct proc *p = l->l_proc; 497 struct ktrace_entry *kte; 498 struct ktr_header *kth; 499 void *buf; 500 501 if (ktrenter(l)) 502 return EAGAIN; 503 504 kte = pool_cache_get(kte_cache, PR_WAITOK); 505 if (sz > sizeof(kte->kte_space)) { 506 buf = kmem_alloc(sz, KM_SLEEP); 507 } else 508 buf = kte->kte_space; 509 510 kte->kte_bufsz = sz; 511 kte->kte_buf = buf; 512 513 kth = &kte->kte_kth; 514 (void)memset(kth, 0, sizeof(*kth)); 515 kth->ktr_len = sz; 516 kth->ktr_type = type; 517 kth->ktr_pid = p->p_pid; 518 memcpy(kth->ktr_comm, p->p_comm, MAXCOMLEN); 519 kth->ktr_version = KTRFAC_VERSION(p->p_traceflag); 520 kth->ktr_lid = l->l_lid; 521 nanotime(&kth->ktr_ts); 522 523 *ktep = kte; 524 *bufp = buf; 525 526 return 0; 527 } 528 529 void 530 ktesethdrlen(struct ktrace_entry *kte, size_t l) 531 { 532 kte->kte_kth.ktr_len = l; 533 } 534 535 void 536 ktr_syscall(register_t code, const register_t args[], int narg) 537 { 538 lwp_t *l = curlwp; 539 struct proc *p = l->l_proc; 540 struct ktrace_entry *kte; 541 struct ktr_syscall *ktp; 542 register_t *argp; 543 size_t len; 544 u_int i; 545 546 if (!KTRPOINT(p, KTR_SYSCALL)) 547 return; 548 549 len = sizeof(struct ktr_syscall) + narg * sizeof argp[0]; 550 551 if (ktealloc(&kte, (void *)&ktp, l, KTR_SYSCALL, len)) 552 return; 553 554 ktp->ktr_code = code; 555 ktp->ktr_argsize = narg * sizeof argp[0]; 556 argp = (register_t *)(ktp + 1); 557 for (i = 0; i < narg; i++) 558 *argp++ = args[i]; 559 560 ktraddentry(l, kte, KTA_WAITOK); 561 } 562 563 void 564 ktr_sysret(register_t code, int error, register_t *retval) 565 { 566 lwp_t *l = curlwp; 567 struct ktrace_entry *kte; 568 struct ktr_sysret *ktp; 569 570 if (!KTRPOINT(l->l_proc, KTR_SYSRET)) 571 return; 572 573 if (ktealloc(&kte, (void *)&ktp, l, KTR_SYSRET, 574 sizeof(struct ktr_sysret))) 575 return; 576 577 ktp->ktr_code = code; 578 ktp->ktr_eosys = 0; /* XXX unused */ 579 ktp->ktr_error = error; 580 ktp->ktr_retval = retval && error == 0 ? retval[0] : 0; 581 ktp->ktr_retval_1 = retval && error == 0 ? retval[1] : 0; 582 583 ktraddentry(l, kte, KTA_WAITOK); 584 } 585 586 void 587 ktr_namei(const char *path, size_t pathlen) 588 { 589 lwp_t *l = curlwp; 590 591 if (!KTRPOINT(l->l_proc, KTR_NAMEI)) 592 return; 593 594 ktr_kmem(l, KTR_NAMEI, path, pathlen); 595 } 596 597 void 598 ktr_namei2(const char *eroot, size_t erootlen, 599 const char *path, size_t pathlen) 600 { 601 lwp_t *l = curlwp; 602 struct ktrace_entry *kte; 603 void *buf; 604 605 if (!KTRPOINT(l->l_proc, KTR_NAMEI)) 606 return; 607 608 if (ktealloc(&kte, &buf, l, KTR_NAMEI, erootlen + pathlen)) 609 return; 610 memcpy(buf, eroot, erootlen); 611 buf = (char *)buf + erootlen; 612 memcpy(buf, path, pathlen); 613 ktraddentry(l, kte, KTA_WAITOK); 614 } 615 616 void 617 ktr_emul(void) 618 { 619 lwp_t *l = curlwp; 620 const char *emul = l->l_proc->p_emul->e_name; 621 622 if (!KTRPOINT(l->l_proc, KTR_EMUL)) 623 return; 624 625 ktr_kmem(l, KTR_EMUL, emul, strlen(emul)); 626 } 627 628 void 629 ktr_execarg(const void *bf, size_t len) 630 { 631 lwp_t *l = curlwp; 632 633 if (!KTRPOINT(l->l_proc, KTR_EXEC_ARG)) 634 return; 635 636 ktr_kmem(l, KTR_EXEC_ARG, bf, len); 637 } 638 639 void 640 ktr_execenv(const void *bf, size_t len) 641 { 642 lwp_t *l = curlwp; 643 644 if (!KTRPOINT(l->l_proc, KTR_EXEC_ENV)) 645 return; 646 647 ktr_kmem(l, KTR_EXEC_ENV, bf, len); 648 } 649 650 void 651 ktr_execfd(int fd, u_int dtype) 652 { 653 struct ktrace_entry *kte; 654 struct ktr_execfd* ktp; 655 656 lwp_t *l = curlwp; 657 658 if (!KTRPOINT(l->l_proc, KTR_EXEC_FD)) 659 return; 660 661 if (ktealloc(&kte, (void *)&ktp, l, KTR_EXEC_FD, sizeof(*ktp))) 662 return; 663 664 ktp->ktr_fd = fd; 665 ktp->ktr_dtype = dtype; 666 ktraddentry(l, kte, KTA_WAITOK); 667 } 668 669 static void 670 ktr_kmem(lwp_t *l, int type, const void *bf, size_t len) 671 { 672 struct ktrace_entry *kte; 673 void *buf; 674 675 if (ktealloc(&kte, &buf, l, type, len)) 676 return; 677 memcpy(buf, bf, len); 678 ktraddentry(l, kte, KTA_WAITOK); 679 } 680 681 static void 682 ktr_io(lwp_t *l, int fd, enum uio_rw rw, struct iovec *iov, size_t len) 683 { 684 struct ktrace_entry *kte; 685 struct ktr_genio *ktp; 686 size_t resid = len, cnt, buflen; 687 char *cp; 688 689 next: 690 buflen = uimin(PAGE_SIZE, resid + sizeof(struct ktr_genio)); 691 692 if (ktealloc(&kte, (void *)&ktp, l, KTR_GENIO, buflen)) 693 return; 694 695 ktp->ktr_fd = fd; 696 ktp->ktr_rw = rw; 697 698 cp = (void *)(ktp + 1); 699 buflen -= sizeof(struct ktr_genio); 700 kte->kte_kth.ktr_len = sizeof(struct ktr_genio); 701 702 while (buflen > 0) { 703 cnt = uimin(iov->iov_len, buflen); 704 if (copyin(iov->iov_base, cp, cnt) != 0) 705 goto out; 706 kte->kte_kth.ktr_len += cnt; 707 cp += cnt; 708 buflen -= cnt; 709 resid -= cnt; 710 iov->iov_len -= cnt; 711 if (iov->iov_len == 0) 712 iov++; 713 else 714 iov->iov_base = (char *)iov->iov_base + cnt; 715 } 716 717 /* 718 * Don't push so many entry at once. It will cause kmem map 719 * shortage. 720 */ 721 ktraddentry(l, kte, KTA_WAITOK | KTA_LARGE); 722 if (resid > 0) { 723 if (preempt_needed()) { 724 (void)ktrenter(l); 725 preempt(); 726 ktrexit(l); 727 } 728 729 goto next; 730 } 731 732 return; 733 734 out: 735 ktefree(kte); 736 ktrexit(l); 737 } 738 739 void 740 ktr_genio(int fd, enum uio_rw rw, const void *addr, size_t len, int error) 741 { 742 lwp_t *l = curlwp; 743 struct iovec iov; 744 745 if (!KTRPOINT(l->l_proc, KTR_GENIO) || error != 0) 746 return; 747 iov.iov_base = __UNCONST(addr); 748 iov.iov_len = len; 749 ktr_io(l, fd, rw, &iov, len); 750 } 751 752 void 753 ktr_geniov(int fd, enum uio_rw rw, struct iovec *iov, size_t len, int error) 754 { 755 lwp_t *l = curlwp; 756 757 if (!KTRPOINT(l->l_proc, KTR_GENIO) || error != 0) 758 return; 759 ktr_io(l, fd, rw, iov, len); 760 } 761 762 void 763 ktr_mibio(int fd, enum uio_rw rw, const void *addr, size_t len, int error) 764 { 765 lwp_t *l = curlwp; 766 struct iovec iov; 767 768 if (!KTRPOINT(l->l_proc, KTR_MIB) || error != 0) 769 return; 770 iov.iov_base = __UNCONST(addr); 771 iov.iov_len = len; 772 ktr_io(l, fd, rw, &iov, len); 773 } 774 775 void 776 ktr_psig(int sig, sig_t action, const sigset_t *mask, 777 const ksiginfo_t *ksi) 778 { 779 struct ktrace_entry *kte; 780 lwp_t *l = curlwp; 781 struct { 782 struct ktr_psig kp; 783 siginfo_t si; 784 } *kbuf; 785 786 if (!KTRPOINT(l->l_proc, KTR_PSIG)) 787 return; 788 789 if (ktealloc(&kte, (void *)&kbuf, l, KTR_PSIG, sizeof(*kbuf))) 790 return; 791 792 kbuf->kp.signo = (char)sig; 793 kbuf->kp.action = action; 794 kbuf->kp.mask = *mask; 795 796 if (ksi) { 797 kbuf->kp.code = KSI_TRAPCODE(ksi); 798 (void)memset(&kbuf->si, 0, sizeof(kbuf->si)); 799 kbuf->si._info = ksi->ksi_info; 800 kte->kte_kth.ktr_len = sizeof(*kbuf); 801 } else { 802 kbuf->kp.code = 0; 803 kte->kte_kth.ktr_len = sizeof(struct ktr_psig); 804 } 805 806 ktraddentry(l, kte, KTA_WAITOK); 807 } 808 809 void 810 ktr_csw(int out, int user) 811 { 812 lwp_t *l = curlwp; 813 struct proc *p = l->l_proc; 814 struct ktrace_entry *kte; 815 struct ktr_csw *kc; 816 817 if (!KTRPOINT(p, KTR_CSW)) 818 return; 819 820 /* 821 * Don't record context switches resulting from blocking on 822 * locks; it's too easy to get duff results. 823 */ 824 if (l->l_syncobj == &mutex_syncobj || l->l_syncobj == &rw_syncobj) 825 return; 826 827 /* 828 * We can't sleep if we're already going to sleep (if original 829 * condition is met during sleep, we hang up). 830 * 831 * XXX This is not ideal: it would be better to maintain a pool 832 * of ktes and actually push this to the kthread when context 833 * switch happens, however given the points where we are called 834 * from that is difficult to do. 835 */ 836 if (out) { 837 if (ktrenter(l)) 838 return; 839 840 nanotime(&l->l_ktrcsw); 841 l->l_pflag |= LP_KTRCSW; 842 if (user) 843 l->l_pflag |= LP_KTRCSWUSER; 844 else 845 l->l_pflag &= ~LP_KTRCSWUSER; 846 847 ktrexit(l); 848 return; 849 } 850 851 /* 852 * On the way back in, we need to record twice: once for entry, and 853 * once for exit. 854 */ 855 if ((l->l_pflag & LP_KTRCSW) != 0) { 856 struct timespec *ts; 857 l->l_pflag &= ~LP_KTRCSW; 858 859 if (ktealloc(&kte, (void *)&kc, l, KTR_CSW, sizeof(*kc))) 860 return; 861 862 kc->out = 1; 863 kc->user = ((l->l_pflag & LP_KTRCSWUSER) != 0); 864 865 ts = &l->l_ktrcsw; 866 switch (KTRFAC_VERSION(p->p_traceflag)) { 867 case 0: 868 kte->kte_kth.ktr_otv.tv_sec = ts->tv_sec; 869 kte->kte_kth.ktr_otv.tv_usec = ts->tv_nsec / 1000; 870 break; 871 case 1: 872 kte->kte_kth.ktr_ots.tv_sec = ts->tv_sec; 873 kte->kte_kth.ktr_ots.tv_nsec = ts->tv_nsec; 874 break; 875 case 2: 876 kte->kte_kth.ktr_ts.tv_sec = ts->tv_sec; 877 kte->kte_kth.ktr_ts.tv_nsec = ts->tv_nsec; 878 break; 879 default: 880 break; 881 } 882 883 ktraddentry(l, kte, KTA_WAITOK); 884 } 885 886 if (ktealloc(&kte, (void *)&kc, l, KTR_CSW, sizeof(*kc))) 887 return; 888 889 kc->out = 0; 890 kc->user = user; 891 892 ktraddentry(l, kte, KTA_WAITOK); 893 } 894 895 bool 896 ktr_point(int fac_bit) 897 { 898 return curlwp->l_proc->p_traceflag & fac_bit; 899 } 900 901 int 902 ktruser(const char *id, void *addr, size_t len, int ustr) 903 { 904 struct ktrace_entry *kte; 905 struct ktr_user *ktp; 906 lwp_t *l = curlwp; 907 void *user_dta; 908 int error; 909 910 if (!KTRPOINT(l->l_proc, KTR_USER)) 911 return 0; 912 913 if (len > KTR_USER_MAXLEN) 914 return ENOSPC; 915 916 error = ktealloc(&kte, (void *)&ktp, l, KTR_USER, sizeof(*ktp) + len); 917 if (error != 0) 918 return error; 919 920 if (ustr) { 921 if (copyinstr(id, ktp->ktr_id, KTR_USER_MAXIDLEN, NULL) != 0) 922 ktp->ktr_id[0] = '\0'; 923 } else 924 strncpy(ktp->ktr_id, id, KTR_USER_MAXIDLEN); 925 ktp->ktr_id[KTR_USER_MAXIDLEN-1] = '\0'; 926 927 user_dta = (void *)(ktp + 1); 928 if ((error = copyin(addr, user_dta, len)) != 0) 929 kte->kte_kth.ktr_len = 0; 930 931 ktraddentry(l, kte, KTA_WAITOK); 932 return error; 933 } 934 935 void 936 ktr_kuser(const char *id, const void *addr, size_t len) 937 { 938 struct ktrace_entry *kte; 939 struct ktr_user *ktp; 940 lwp_t *l = curlwp; 941 int error; 942 943 if (!KTRPOINT(l->l_proc, KTR_USER)) 944 return; 945 946 if (len > KTR_USER_MAXLEN) 947 return; 948 949 error = ktealloc(&kte, (void *)&ktp, l, KTR_USER, sizeof(*ktp) + len); 950 if (error != 0) 951 return; 952 953 strlcpy(ktp->ktr_id, id, KTR_USER_MAXIDLEN); 954 955 memcpy(ktp + 1, addr, len); 956 957 ktraddentry(l, kte, KTA_WAITOK); 958 } 959 960 void 961 ktr_mib(const int *name, u_int namelen) 962 { 963 struct ktrace_entry *kte; 964 int *namep; 965 size_t size; 966 lwp_t *l = curlwp; 967 968 if (!KTRPOINT(l->l_proc, KTR_MIB)) 969 return; 970 971 size = namelen * sizeof(*name); 972 973 if (ktealloc(&kte, (void *)&namep, l, KTR_MIB, size)) 974 return; 975 976 (void)memcpy(namep, name, namelen * sizeof(*name)); 977 978 ktraddentry(l, kte, KTA_WAITOK); 979 } 980 981 /* Interface and common routines */ 982 983 int 984 ktrace_common(lwp_t *curl, int ops, int facs, int pid, file_t **fpp) 985 { 986 struct proc *p; 987 struct pgrp *pg; 988 struct ktr_desc *ktd = NULL, *nktd; 989 file_t *fp = *fpp; 990 int ret = 0; 991 int error = 0; 992 int descend; 993 994 descend = ops & KTRFLAG_DESCEND; 995 facs = facs & ~((unsigned) KTRFAC_PERSISTENT); 996 997 (void)ktrenter(curl); 998 999 switch (KTROP(ops)) { 1000 1001 case KTROP_CLEARFILE: 1002 /* 1003 * Clear all uses of the tracefile 1004 */ 1005 mutex_enter(&ktrace_lock); 1006 ktd = ktd_lookup(fp); 1007 mutex_exit(&ktrace_lock); 1008 if (ktd == NULL) 1009 goto done; 1010 error = ktrderefall(ktd, 1); 1011 goto done; 1012 1013 case KTROP_SET: 1014 mutex_enter(&ktrace_lock); 1015 ktd = ktd_lookup(fp); 1016 mutex_exit(&ktrace_lock); 1017 if (ktd == NULL) { 1018 nktd = kmem_alloc(sizeof(*nktd), KM_SLEEP); 1019 TAILQ_INIT(&nktd->ktd_queue); 1020 callout_init(&nktd->ktd_wakch, CALLOUT_MPSAFE); 1021 cv_init(&nktd->ktd_cv, "ktrwait"); 1022 cv_init(&nktd->ktd_sync_cv, "ktrsync"); 1023 nktd->ktd_flags = 0; 1024 nktd->ktd_qcount = 0; 1025 nktd->ktd_error = 0; 1026 nktd->ktd_errcnt = 0; 1027 nktd->ktd_delayqcnt = ktd_delayqcnt; 1028 nktd->ktd_wakedelay = mstohz(ktd_wakedelay); 1029 nktd->ktd_intrwakdl = mstohz(ktd_intrwakdl); 1030 nktd->ktd_ref = 0; 1031 nktd->ktd_fp = fp; 1032 mutex_enter(&ktrace_lock); 1033 ktdref(nktd); 1034 mutex_exit(&ktrace_lock); 1035 1036 /* 1037 * XXX: not correct. needs an way to detect 1038 * whether ktruss or ktrace. 1039 */ 1040 if (fp->f_type == DTYPE_PIPE) 1041 nktd->ktd_flags |= KTDF_INTERACTIVE; 1042 1043 mutex_enter(&fp->f_lock); 1044 fp->f_count++; 1045 mutex_exit(&fp->f_lock); 1046 error = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, 1047 ktrace_thread, nktd, &nktd->ktd_lwp, "ktrace"); 1048 if (error != 0) { 1049 kmem_free(nktd, sizeof(*nktd)); 1050 nktd = NULL; 1051 mutex_enter(&fp->f_lock); 1052 fp->f_count--; 1053 mutex_exit(&fp->f_lock); 1054 goto done; 1055 } 1056 1057 mutex_enter(&ktrace_lock); 1058 ktd = ktd_lookup(fp); 1059 if (ktd != NULL) { 1060 ktdrel(nktd); 1061 nktd = NULL; 1062 } else { 1063 TAILQ_INSERT_TAIL(&ktdq, nktd, ktd_list); 1064 ktd = nktd; 1065 } 1066 mutex_exit(&ktrace_lock); 1067 } 1068 break; 1069 1070 case KTROP_CLEAR: 1071 break; 1072 } 1073 1074 /* 1075 * need something to (un)trace (XXX - why is this here?) 1076 */ 1077 if (!facs) { 1078 error = EINVAL; 1079 *fpp = NULL; 1080 goto done; 1081 } 1082 1083 /* 1084 * do it 1085 */ 1086 mutex_enter(&proc_lock); 1087 if (pid < 0) { 1088 /* 1089 * by process group 1090 */ 1091 pg = pgrp_find(-pid); 1092 if (pg == NULL) 1093 error = ESRCH; 1094 else { 1095 LIST_FOREACH(p, &pg->pg_members, p_pglist) { 1096 if (descend) 1097 ret |= ktrsetchildren(curl, p, ops, 1098 facs, ktd); 1099 else 1100 ret |= ktrops(curl, p, ops, facs, 1101 ktd); 1102 } 1103 } 1104 1105 } else { 1106 /* 1107 * by pid 1108 */ 1109 p = proc_find(pid); 1110 if (p == NULL) 1111 error = ESRCH; 1112 else if (descend) 1113 ret |= ktrsetchildren(curl, p, ops, facs, ktd); 1114 else 1115 ret |= ktrops(curl, p, ops, facs, ktd); 1116 } 1117 mutex_exit(&proc_lock); 1118 if (error == 0 && !ret) 1119 error = EPERM; 1120 *fpp = NULL; 1121 done: 1122 if (ktd != NULL) { 1123 mutex_enter(&ktrace_lock); 1124 if (error != 0) { 1125 /* 1126 * Wakeup the thread so that it can be die if we 1127 * can't trace any process. 1128 */ 1129 ktd_wakeup(ktd); 1130 } 1131 if (KTROP(ops) == KTROP_SET || KTROP(ops) == KTROP_CLEARFILE) 1132 ktdrel(ktd); 1133 mutex_exit(&ktrace_lock); 1134 } 1135 ktrexit(curl); 1136 return (error); 1137 } 1138 1139 /* 1140 * fktrace system call 1141 */ 1142 /* ARGSUSED */ 1143 int 1144 sys_fktrace(struct lwp *l, const struct sys_fktrace_args *uap, 1145 register_t *retval) 1146 { 1147 /* { 1148 syscallarg(int) fd; 1149 syscallarg(int) ops; 1150 syscallarg(int) facs; 1151 syscallarg(int) pid; 1152 } */ 1153 file_t *fp; 1154 int error, fd; 1155 1156 fd = SCARG(uap, fd); 1157 if ((fp = fd_getfile(fd)) == NULL) 1158 return (EBADF); 1159 if ((fp->f_flag & FWRITE) == 0) 1160 error = EBADF; 1161 else 1162 error = ktrace_common(l, SCARG(uap, ops), 1163 SCARG(uap, facs), SCARG(uap, pid), &fp); 1164 fd_putfile(fd); 1165 return error; 1166 } 1167 1168 static int 1169 ktrops(lwp_t *curl, struct proc *p, int ops, int facs, 1170 struct ktr_desc *ktd) 1171 { 1172 int vers = ops & KTRFAC_VER_MASK; 1173 int error = 0; 1174 1175 mutex_enter(p->p_lock); 1176 mutex_enter(&ktrace_lock); 1177 1178 if (!ktrcanset(curl, p)) 1179 goto out; 1180 1181 switch (vers) { 1182 case KTRFACv0: 1183 case KTRFACv1: 1184 case KTRFACv2: 1185 break; 1186 default: 1187 error = EINVAL; 1188 goto out; 1189 } 1190 1191 if (KTROP(ops) == KTROP_SET) { 1192 if (p->p_tracep != ktd) { 1193 /* 1194 * if trace file already in use, relinquish 1195 */ 1196 ktrderef(p); 1197 p->p_tracep = ktd; 1198 ktradref(p); 1199 } 1200 p->p_traceflag |= facs; 1201 if (kauth_authorize_process(curl->l_cred, KAUTH_PROCESS_KTRACE, 1202 p, KAUTH_ARG(KAUTH_REQ_PROCESS_KTRACE_PERSISTENT), NULL, 1203 NULL) == 0) 1204 p->p_traceflag |= KTRFAC_PERSISTENT; 1205 } else { 1206 /* KTROP_CLEAR */ 1207 if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) { 1208 /* no more tracing */ 1209 ktrderef(p); 1210 } 1211 } 1212 1213 if (p->p_traceflag) 1214 p->p_traceflag |= vers; 1215 /* 1216 * Emit an emulation record, every time there is a ktrace 1217 * change/attach request. 1218 */ 1219 if (KTRPOINT(p, KTR_EMUL)) 1220 p->p_traceflag |= KTRFAC_TRC_EMUL; 1221 1222 p->p_trace_enabled = trace_is_enabled(p); 1223 #ifdef __HAVE_SYSCALL_INTERN 1224 (*p->p_emul->e_syscall_intern)(p); 1225 #endif 1226 1227 out: 1228 mutex_exit(&ktrace_lock); 1229 mutex_exit(p->p_lock); 1230 1231 return error ? 0 : 1; 1232 } 1233 1234 static int 1235 ktrsetchildren(lwp_t *curl, struct proc *top, int ops, int facs, 1236 struct ktr_desc *ktd) 1237 { 1238 struct proc *p; 1239 int ret = 0; 1240 1241 KASSERT(mutex_owned(&proc_lock)); 1242 1243 p = top; 1244 for (;;) { 1245 ret |= ktrops(curl, p, ops, facs, ktd); 1246 /* 1247 * If this process has children, descend to them next, 1248 * otherwise do any siblings, and if done with this level, 1249 * follow back up the tree (but not past top). 1250 */ 1251 if (LIST_FIRST(&p->p_children) != NULL) { 1252 p = LIST_FIRST(&p->p_children); 1253 continue; 1254 } 1255 for (;;) { 1256 if (p == top) 1257 return (ret); 1258 if (LIST_NEXT(p, p_sibling) != NULL) { 1259 p = LIST_NEXT(p, p_sibling); 1260 break; 1261 } 1262 p = p->p_pptr; 1263 } 1264 } 1265 /*NOTREACHED*/ 1266 } 1267 1268 static void 1269 ktrwrite(struct ktr_desc *ktd, struct ktrace_entry *kte) 1270 { 1271 size_t hlen; 1272 struct uio auio; 1273 struct iovec aiov[64], *iov; 1274 struct ktrace_entry *top = kte; 1275 struct ktr_header *kth; 1276 file_t *fp = ktd->ktd_fp; 1277 int error; 1278 next: 1279 auio.uio_iov = iov = &aiov[0]; 1280 auio.uio_offset = 0; 1281 auio.uio_rw = UIO_WRITE; 1282 auio.uio_resid = 0; 1283 auio.uio_iovcnt = 0; 1284 UIO_SETUP_SYSSPACE(&auio); 1285 do { 1286 struct timespec ts; 1287 lwpid_t lid; 1288 kth = &kte->kte_kth; 1289 1290 hlen = sizeof(struct ktr_header); 1291 switch (kth->ktr_version) { 1292 case 0: 1293 ts = kth->ktr_time; 1294 1295 kth->ktr_otv.tv_sec = ts.tv_sec; 1296 kth->ktr_otv.tv_usec = ts.tv_nsec / 1000; 1297 kth->ktr_unused = NULL; 1298 hlen -= sizeof(kth->_v) - 1299 MAX(sizeof(kth->_v._v0), sizeof(kth->_v._v1)); 1300 break; 1301 case 1: 1302 ts = kth->ktr_time; 1303 lid = kth->ktr_lid; 1304 1305 kth->ktr_ots.tv_sec = ts.tv_sec; 1306 kth->ktr_ots.tv_nsec = ts.tv_nsec; 1307 kth->ktr_olid = lid; 1308 hlen -= sizeof(kth->_v) - 1309 MAX(sizeof(kth->_v._v0), sizeof(kth->_v._v1)); 1310 break; 1311 } 1312 iov->iov_base = (void *)kth; 1313 iov++->iov_len = hlen; 1314 auio.uio_resid += hlen; 1315 auio.uio_iovcnt++; 1316 if (kth->ktr_len > 0) { 1317 iov->iov_base = kte->kte_buf; 1318 iov++->iov_len = kth->ktr_len; 1319 auio.uio_resid += kth->ktr_len; 1320 auio.uio_iovcnt++; 1321 } 1322 } while ((kte = TAILQ_NEXT(kte, kte_list)) != NULL && 1323 auio.uio_iovcnt < sizeof(aiov) / sizeof(aiov[0]) - 1); 1324 1325 again: 1326 error = (*fp->f_ops->fo_write)(fp, &fp->f_offset, &auio, 1327 fp->f_cred, FOF_UPDATE_OFFSET); 1328 switch (error) { 1329 1330 case 0: 1331 if (auio.uio_resid > 0) 1332 goto again; 1333 if (kte != NULL) 1334 goto next; 1335 break; 1336 1337 case EWOULDBLOCK: 1338 kpause("ktrzzz", false, 1, NULL); 1339 goto again; 1340 1341 default: 1342 /* 1343 * If error encountered, give up tracing on this 1344 * vnode. Don't report EPIPE as this can easily 1345 * happen with fktrace()/ktruss. 1346 */ 1347 #ifndef DEBUG 1348 if (error != EPIPE) 1349 #endif 1350 log(LOG_NOTICE, 1351 "ktrace write failed, errno %d, tracing stopped\n", 1352 error); 1353 (void)ktrderefall(ktd, 0); 1354 } 1355 1356 while ((kte = top) != NULL) { 1357 top = TAILQ_NEXT(top, kte_list); 1358 ktefree(kte); 1359 } 1360 } 1361 1362 static void 1363 ktrace_thread(void *arg) 1364 { 1365 struct ktr_desc *ktd = arg; 1366 file_t *fp = ktd->ktd_fp; 1367 struct ktrace_entry *kte; 1368 int ktrerr, errcnt; 1369 1370 mutex_enter(&ktrace_lock); 1371 for (;;) { 1372 kte = TAILQ_FIRST(&ktd->ktd_queue); 1373 if (kte == NULL) { 1374 if (ktd->ktd_flags & KTDF_WAIT) { 1375 ktd->ktd_flags &= ~(KTDF_WAIT | KTDF_BLOCKING); 1376 cv_broadcast(&ktd->ktd_sync_cv); 1377 } 1378 if (ktd->ktd_ref == 0) 1379 break; 1380 cv_wait(&ktd->ktd_cv, &ktrace_lock); 1381 continue; 1382 } 1383 TAILQ_INIT(&ktd->ktd_queue); 1384 ktd->ktd_qcount = 0; 1385 ktrerr = ktd->ktd_error; 1386 errcnt = ktd->ktd_errcnt; 1387 ktd->ktd_error = ktd->ktd_errcnt = 0; 1388 mutex_exit(&ktrace_lock); 1389 1390 if (ktrerr) { 1391 log(LOG_NOTICE, 1392 "ktrace failed, fp %p, error 0x%x, total %d\n", 1393 fp, ktrerr, errcnt); 1394 } 1395 ktrwrite(ktd, kte); 1396 mutex_enter(&ktrace_lock); 1397 } 1398 1399 TAILQ_REMOVE(&ktdq, ktd, ktd_list); 1400 1401 callout_halt(&ktd->ktd_wakch, &ktrace_lock); 1402 callout_destroy(&ktd->ktd_wakch); 1403 mutex_exit(&ktrace_lock); 1404 1405 /* 1406 * ktrace file descriptor can't be watched (are not visible to 1407 * userspace), so no kqueue stuff here 1408 * XXX: The above comment is wrong, because the fktrace file 1409 * descriptor is available in userland. 1410 */ 1411 closef(fp); 1412 1413 cv_destroy(&ktd->ktd_sync_cv); 1414 cv_destroy(&ktd->ktd_cv); 1415 1416 kmem_free(ktd, sizeof(*ktd)); 1417 1418 kthread_exit(0); 1419 } 1420 1421 /* 1422 * Return true if caller has permission to set the ktracing state 1423 * of target. Essentially, the target can't possess any 1424 * more permissions than the caller. KTRFAC_PERSISTENT signifies that 1425 * the tracing will persist on sugid processes during exec; it is only 1426 * settable by a process with appropriate credentials. 1427 * 1428 * TODO: check groups. use caller effective gid. 1429 */ 1430 static int 1431 ktrcanset(lwp_t *calll, struct proc *targetp) 1432 { 1433 KASSERT(mutex_owned(targetp->p_lock)); 1434 KASSERT(mutex_owned(&ktrace_lock)); 1435 1436 if (kauth_authorize_process(calll->l_cred, KAUTH_PROCESS_KTRACE, 1437 targetp, NULL, NULL, NULL) == 0) 1438 return (1); 1439 1440 return (0); 1441 } 1442 1443 /* 1444 * Put user defined entry to ktrace records. 1445 */ 1446 int 1447 sys_utrace(struct lwp *l, const struct sys_utrace_args *uap, register_t *retval) 1448 { 1449 /* { 1450 syscallarg(const char *) label; 1451 syscallarg(void *) addr; 1452 syscallarg(size_t) len; 1453 } */ 1454 1455 return ktruser(SCARG(uap, label), SCARG(uap, addr), 1456 SCARG(uap, len), 1); 1457 } 1458