1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2003, Jeffrey Roberson <jeff@freebsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice unmodified, this list of conditions, and the following 12 * 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 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 #include "opt_posix.h" 31 #include "opt_hwpmc_hooks.h" 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/lock.h> 35 #include <sys/mutex.h> 36 #include <sys/priv.h> 37 #include <sys/proc.h> 38 #include <sys/posix4.h> 39 #include <sys/ptrace.h> 40 #include <sys/racct.h> 41 #include <sys/resourcevar.h> 42 #include <sys/rwlock.h> 43 #include <sys/sched.h> 44 #include <sys/sysctl.h> 45 #include <sys/smp.h> 46 #include <sys/syscallsubr.h> 47 #include <sys/sysent.h> 48 #include <sys/systm.h> 49 #include <sys/sysproto.h> 50 #include <sys/signalvar.h> 51 #include <sys/sysctl.h> 52 #include <sys/ucontext.h> 53 #include <sys/thr.h> 54 #include <sys/rtprio.h> 55 #include <sys/umtxvar.h> 56 #include <sys/limits.h> 57 #ifdef HWPMC_HOOKS 58 #include <sys/pmckern.h> 59 #endif 60 61 #include <machine/frame.h> 62 63 #include <security/audit/audit.h> 64 65 static SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 66 "thread allocation"); 67 68 int max_threads_per_proc = 1500; 69 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW, 70 &max_threads_per_proc, 0, "Limit on threads per proc"); 71 72 static int max_threads_hits; 73 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD, 74 &max_threads_hits, 0, "kern.threads.max_threads_per_proc hit count"); 75 76 #ifdef COMPAT_FREEBSD32 77 78 static inline int 79 suword_lwpid(void *addr, lwpid_t lwpid) 80 { 81 int error; 82 83 if (SV_CURPROC_FLAG(SV_LP64)) 84 error = suword(addr, lwpid); 85 else 86 error = suword32(addr, lwpid); 87 return (error); 88 } 89 90 #else 91 #define suword_lwpid suword 92 #endif 93 94 /* 95 * System call interface. 96 */ 97 98 struct thr_create_initthr_args { 99 ucontext_t ctx; 100 long *tid; 101 }; 102 103 static int 104 thr_create_initthr(struct thread *td, void *thunk) 105 { 106 struct thr_create_initthr_args *args; 107 108 /* Copy out the child tid. */ 109 args = thunk; 110 if (args->tid != NULL && suword_lwpid(args->tid, td->td_tid)) 111 return (EFAULT); 112 113 return (set_mcontext(td, &args->ctx.uc_mcontext)); 114 } 115 116 int 117 sys_thr_create(struct thread *td, struct thr_create_args *uap) 118 /* ucontext_t *ctx, long *id, int flags */ 119 { 120 struct thr_create_initthr_args args; 121 int error; 122 123 if ((error = copyin(uap->ctx, &args.ctx, sizeof(args.ctx)))) 124 return (error); 125 args.tid = uap->id; 126 return (thread_create(td, NULL, thr_create_initthr, &args)); 127 } 128 129 int 130 sys_thr_new(struct thread *td, struct thr_new_args *uap) 131 /* struct thr_param * */ 132 { 133 struct thr_param param; 134 int error; 135 136 if (uap->param_size < 0 || uap->param_size > sizeof(param)) 137 return (EINVAL); 138 bzero(¶m, sizeof(param)); 139 if ((error = copyin(uap->param, ¶m, uap->param_size))) 140 return (error); 141 return (kern_thr_new(td, ¶m)); 142 } 143 144 static int 145 thr_new_initthr(struct thread *td, void *thunk) 146 { 147 stack_t stack; 148 struct thr_param *param; 149 int error; 150 151 /* 152 * Here we copy out tid to two places, one for child and one 153 * for parent, because pthread can create a detached thread, 154 * if parent wants to safely access child tid, it has to provide 155 * its storage, because child thread may exit quickly and 156 * memory is freed before parent thread can access it. 157 */ 158 param = thunk; 159 if ((param->child_tid != NULL && 160 suword_lwpid(param->child_tid, td->td_tid)) || 161 (param->parent_tid != NULL && 162 suword_lwpid(param->parent_tid, td->td_tid))) 163 return (EFAULT); 164 165 /* Set up our machine context. */ 166 stack.ss_sp = param->stack_base; 167 stack.ss_size = param->stack_size; 168 /* Set upcall address to user thread entry function. */ 169 error = cpu_set_upcall(td, param->start_func, param->arg, &stack); 170 if (error != 0) 171 return (error); 172 /* Setup user TLS address and TLS pointer register. */ 173 return (cpu_set_user_tls(td, param->tls_base)); 174 } 175 176 int 177 kern_thr_new(struct thread *td, struct thr_param *param) 178 { 179 struct rtprio rtp, *rtpp; 180 int error; 181 182 rtpp = NULL; 183 if (param->rtp != 0) { 184 error = copyin(param->rtp, &rtp, sizeof(struct rtprio)); 185 if (error) 186 return (error); 187 rtpp = &rtp; 188 } 189 return (thread_create(td, rtpp, thr_new_initthr, param)); 190 } 191 192 int 193 thread_create(struct thread *td, struct rtprio *rtp, 194 int (*initialize_thread)(struct thread *, void *), void *thunk) 195 { 196 struct thread *newtd; 197 struct proc *p; 198 int error; 199 200 p = td->td_proc; 201 202 if (rtp != NULL) { 203 switch(rtp->type) { 204 case RTP_PRIO_REALTIME: 205 case RTP_PRIO_FIFO: 206 /* Only root can set scheduler policy */ 207 if (priv_check(td, PRIV_SCHED_SETPOLICY) != 0) 208 return (EPERM); 209 if (rtp->prio > RTP_PRIO_MAX) 210 return (EINVAL); 211 break; 212 case RTP_PRIO_NORMAL: 213 rtp->prio = 0; 214 break; 215 default: 216 return (EINVAL); 217 } 218 } 219 220 #ifdef RACCT 221 if (racct_enable) { 222 PROC_LOCK(p); 223 error = racct_add(p, RACCT_NTHR, 1); 224 PROC_UNLOCK(p); 225 if (error != 0) 226 return (EPROCLIM); 227 } 228 #endif 229 230 /* Initialize our td */ 231 error = kern_thr_alloc(p, 0, &newtd); 232 if (error) 233 goto fail; 234 235 bzero(&newtd->td_startzero, 236 __rangeof(struct thread, td_startzero, td_endzero)); 237 bcopy(&td->td_startcopy, &newtd->td_startcopy, 238 __rangeof(struct thread, td_startcopy, td_endcopy)); 239 newtd->td_proc = td->td_proc; 240 newtd->td_rb_list = newtd->td_rbp_list = newtd->td_rb_inact = 0; 241 thread_cow_get(newtd, td); 242 243 cpu_copy_thread(newtd, td); 244 245 error = initialize_thread(newtd, thunk); 246 if (error != 0) { 247 thread_cow_free(newtd); 248 thread_free(newtd); 249 goto fail; 250 } 251 252 PROC_LOCK(p); 253 p->p_flag |= P_HADTHREADS; 254 thread_link(newtd, p); 255 bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name)); 256 thread_lock(td); 257 /* let the scheduler know about these things. */ 258 sched_fork_thread(td, newtd); 259 thread_unlock(td); 260 if (P_SHOULDSTOP(p)) 261 ast_sched(newtd, TDA_SUSPEND); 262 if (p->p_ptevents & PTRACE_LWP) 263 newtd->td_dbgflags |= TDB_BORN; 264 265 PROC_UNLOCK(p); 266 #ifdef HWPMC_HOOKS 267 if (PMC_PROC_IS_USING_PMCS(p)) 268 PMC_CALL_HOOK(newtd, PMC_FN_THR_CREATE, NULL); 269 else if (PMC_SYSTEM_SAMPLING_ACTIVE()) 270 PMC_CALL_HOOK_UNLOCKED(newtd, PMC_FN_THR_CREATE_LOG, NULL); 271 #endif 272 273 tidhash_add(newtd); 274 275 /* ignore timesharing class */ 276 if (rtp != NULL && !(td->td_pri_class == PRI_TIMESHARE && 277 rtp->type == RTP_PRIO_NORMAL)) 278 rtp_to_pri(rtp, newtd); 279 280 thread_lock(newtd); 281 TD_SET_CAN_RUN(newtd); 282 sched_add(newtd, SRQ_BORING); 283 284 return (0); 285 286 fail: 287 #ifdef RACCT 288 if (racct_enable) { 289 PROC_LOCK(p); 290 racct_sub(p, RACCT_NTHR, 1); 291 PROC_UNLOCK(p); 292 } 293 #endif 294 return (error); 295 } 296 297 int 298 sys_thr_self(struct thread *td, struct thr_self_args *uap) 299 /* long *id */ 300 { 301 int error; 302 303 error = suword_lwpid(uap->id, (unsigned)td->td_tid); 304 if (error == -1) 305 return (EFAULT); 306 return (0); 307 } 308 309 int 310 sys_thr_exit(struct thread *td, struct thr_exit_args *uap) 311 /* long *state */ 312 { 313 314 umtx_thread_exit(td); 315 316 /* Signal userland that it can free the stack. */ 317 if ((void *)uap->state != NULL) { 318 (void)suword_lwpid(uap->state, 1); 319 (void)kern_umtx_wake(td, uap->state, INT_MAX, 0); 320 } 321 322 return (kern_thr_exit(td)); 323 } 324 325 int 326 kern_thr_exit(struct thread *td) 327 { 328 struct proc *p; 329 330 p = td->td_proc; 331 332 /* 333 * If all of the threads in a process call this routine to 334 * exit (e.g. all threads call pthread_exit()), exactly one 335 * thread should return to the caller to terminate the process 336 * instead of the thread. 337 * 338 * Checking p_numthreads alone is not sufficient since threads 339 * might be committed to terminating while the PROC_LOCK is 340 * dropped in either ptracestop() or while removing this thread 341 * from the tidhash. Instead, the p_pendingexits field holds 342 * the count of threads in either of those states and a thread 343 * is considered the "last" thread if all of the other threads 344 * in a process are already terminating. 345 */ 346 PROC_LOCK(p); 347 if (p->p_numthreads == p->p_pendingexits + 1) { 348 /* 349 * Ignore attempts to shut down last thread in the 350 * proc. This will actually call _exit(2) in the 351 * usermode trampoline when it returns. 352 */ 353 PROC_UNLOCK(p); 354 return (0); 355 } 356 357 if (p->p_sysent->sv_ontdexit != NULL) 358 p->p_sysent->sv_ontdexit(td); 359 360 td->td_dbgflags |= TDB_EXIT; 361 if (p->p_ptevents & PTRACE_LWP) { 362 p->p_pendingexits++; 363 ptracestop(td, SIGTRAP, NULL); 364 p->p_pendingexits--; 365 } 366 tidhash_remove(td); 367 368 /* 369 * The check above should prevent all other threads from this 370 * process from exiting while the PROC_LOCK is dropped, so 371 * there must be at least one other thread other than the 372 * current thread. 373 */ 374 KASSERT(p->p_numthreads > 1, ("too few threads")); 375 racct_sub(p, RACCT_NTHR, 1); 376 tdsigcleanup(td); 377 378 #ifdef AUDIT 379 AUDIT_SYSCALL_EXIT(0, td); 380 #endif 381 382 PROC_SLOCK(p); 383 thread_stopped(p); 384 thread_exit(); 385 /* NOTREACHED */ 386 } 387 388 int 389 sys_thr_kill(struct thread *td, struct thr_kill_args *uap) 390 /* long id, int sig */ 391 { 392 ksiginfo_t ksi; 393 struct thread *ttd; 394 struct proc *p; 395 int error; 396 397 p = td->td_proc; 398 ksiginfo_init(&ksi); 399 ksi.ksi_signo = uap->sig; 400 ksi.ksi_code = SI_LWP; 401 ksi.ksi_pid = p->p_pid; 402 ksi.ksi_uid = td->td_ucred->cr_ruid; 403 if (uap->id == -1) { 404 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) { 405 error = EINVAL; 406 } else { 407 error = ESRCH; 408 PROC_LOCK(p); 409 FOREACH_THREAD_IN_PROC(p, ttd) { 410 if (ttd != td) { 411 error = 0; 412 if (uap->sig == 0) 413 break; 414 tdksignal(ttd, uap->sig, &ksi); 415 } 416 } 417 PROC_UNLOCK(p); 418 } 419 } else { 420 error = 0; 421 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 422 if (ttd == NULL) 423 return (ESRCH); 424 if (uap->sig == 0) 425 ; 426 else if (!_SIG_VALID(uap->sig)) 427 error = EINVAL; 428 else 429 tdksignal(ttd, uap->sig, &ksi); 430 PROC_UNLOCK(ttd->td_proc); 431 } 432 return (error); 433 } 434 435 int 436 sys_thr_kill2(struct thread *td, struct thr_kill2_args *uap) 437 /* pid_t pid, long id, int sig */ 438 { 439 ksiginfo_t ksi; 440 struct thread *ttd; 441 struct proc *p; 442 int error; 443 444 AUDIT_ARG_SIGNUM(uap->sig); 445 446 ksiginfo_init(&ksi); 447 ksi.ksi_signo = uap->sig; 448 ksi.ksi_code = SI_LWP; 449 ksi.ksi_pid = td->td_proc->p_pid; 450 ksi.ksi_uid = td->td_ucred->cr_ruid; 451 if (uap->id == -1) { 452 if ((p = pfind(uap->pid)) == NULL) 453 return (ESRCH); 454 AUDIT_ARG_PROCESS(p); 455 error = p_cansignal(td, p, uap->sig); 456 if (error) { 457 PROC_UNLOCK(p); 458 return (error); 459 } 460 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) { 461 error = EINVAL; 462 } else { 463 error = ESRCH; 464 FOREACH_THREAD_IN_PROC(p, ttd) { 465 if (ttd != td) { 466 error = 0; 467 if (uap->sig == 0) 468 break; 469 tdksignal(ttd, uap->sig, &ksi); 470 } 471 } 472 } 473 PROC_UNLOCK(p); 474 } else { 475 ttd = tdfind((lwpid_t)uap->id, uap->pid); 476 if (ttd == NULL) 477 return (ESRCH); 478 p = ttd->td_proc; 479 AUDIT_ARG_PROCESS(p); 480 error = p_cansignal(td, p, uap->sig); 481 if (uap->sig == 0) 482 ; 483 else if (!_SIG_VALID(uap->sig)) 484 error = EINVAL; 485 else 486 tdksignal(ttd, uap->sig, &ksi); 487 PROC_UNLOCK(p); 488 } 489 return (error); 490 } 491 492 int 493 sys_thr_suspend(struct thread *td, struct thr_suspend_args *uap) 494 /* const struct timespec *timeout */ 495 { 496 struct timespec ts, *tsp; 497 int error; 498 499 tsp = NULL; 500 if (uap->timeout != NULL) { 501 error = umtx_copyin_timeout(uap->timeout, &ts); 502 if (error != 0) 503 return (error); 504 tsp = &ts; 505 } 506 507 return (kern_thr_suspend(td, tsp)); 508 } 509 510 int 511 kern_thr_suspend(struct thread *td, struct timespec *tsp) 512 { 513 struct proc *p = td->td_proc; 514 struct timeval tv; 515 int error = 0; 516 int timo = 0; 517 518 if (td->td_pflags & TDP_WAKEUP) { 519 td->td_pflags &= ~TDP_WAKEUP; 520 return (0); 521 } 522 523 if (tsp != NULL) { 524 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 525 error = EWOULDBLOCK; 526 else { 527 TIMESPEC_TO_TIMEVAL(&tv, tsp); 528 timo = tvtohz(&tv); 529 } 530 } 531 532 PROC_LOCK(p); 533 if (error == 0 && (td->td_flags & TDF_THRWAKEUP) == 0) 534 error = msleep((void *)td, &p->p_mtx, 535 PCATCH, "lthr", timo); 536 537 if (td->td_flags & TDF_THRWAKEUP) { 538 thread_lock(td); 539 td->td_flags &= ~TDF_THRWAKEUP; 540 thread_unlock(td); 541 PROC_UNLOCK(p); 542 return (0); 543 } 544 PROC_UNLOCK(p); 545 if (error == EWOULDBLOCK) 546 error = ETIMEDOUT; 547 else if (error == ERESTART) { 548 if (timo != 0) 549 error = EINTR; 550 } 551 return (error); 552 } 553 554 int 555 sys_thr_wake(struct thread *td, struct thr_wake_args *uap) 556 /* long id */ 557 { 558 struct proc *p; 559 struct thread *ttd; 560 561 if (uap->id == td->td_tid) { 562 td->td_pflags |= TDP_WAKEUP; 563 return (0); 564 } 565 566 p = td->td_proc; 567 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 568 if (ttd == NULL) 569 return (ESRCH); 570 thread_lock(ttd); 571 ttd->td_flags |= TDF_THRWAKEUP; 572 thread_unlock(ttd); 573 wakeup((void *)ttd); 574 PROC_UNLOCK(p); 575 return (0); 576 } 577 578 int 579 sys_thr_set_name(struct thread *td, struct thr_set_name_args *uap) 580 { 581 struct proc *p; 582 char name[MAXCOMLEN + 1]; 583 struct thread *ttd; 584 int error; 585 586 error = 0; 587 name[0] = '\0'; 588 if (uap->name != NULL) { 589 error = copyinstr(uap->name, name, sizeof(name), NULL); 590 if (error == ENAMETOOLONG) { 591 error = copyin(uap->name, name, sizeof(name) - 1); 592 name[sizeof(name) - 1] = '\0'; 593 } 594 if (error) 595 return (error); 596 } 597 p = td->td_proc; 598 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 599 if (ttd == NULL) 600 return (ESRCH); 601 strcpy(ttd->td_name, name); 602 #ifdef HWPMC_HOOKS 603 if (PMC_PROC_IS_USING_PMCS(p) || PMC_SYSTEM_SAMPLING_ACTIVE()) 604 PMC_CALL_HOOK_UNLOCKED(ttd, PMC_FN_THR_CREATE_LOG, NULL); 605 #endif 606 #ifdef KTR 607 sched_clear_tdname(ttd); 608 #endif 609 PROC_UNLOCK(p); 610 return (error); 611 } 612 613 int 614 kern_thr_alloc(struct proc *p, int pages, struct thread **ntd) 615 { 616 617 /* Have race condition but it is cheap. */ 618 if (p->p_numthreads >= max_threads_per_proc) { 619 ++max_threads_hits; 620 return (EPROCLIM); 621 } 622 623 *ntd = thread_alloc(pages); 624 if (*ntd == NULL) 625 return (ENOMEM); 626 627 return (0); 628 } 629