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 "opt_posix.h" 30 #include "opt_hwpmc_hooks.h" 31 32 #include <sys/systm.h> 33 #include <sys/kernel.h> 34 #include <sys/limits.h> 35 #include <sys/lock.h> 36 #include <sys/mutex.h> 37 #include <sys/priv.h> 38 #include <sys/proc.h> 39 #include <sys/posix4.h> 40 #include <sys/ptrace.h> 41 #include <sys/racct.h> 42 #include <sys/resourcevar.h> 43 #include <sys/rtprio.h> 44 #include <sys/rwlock.h> 45 #include <sys/sched.h> 46 #include <sys/sysctl.h> 47 #include <sys/smp.h> 48 #include <sys/syscallsubr.h> 49 #include <sys/sysent.h> 50 #include <sys/sysproto.h> 51 #include <sys/signalvar.h> 52 #include <sys/sysctl.h> 53 #include <sys/thr.h> 54 #include <sys/ucontext.h> 55 #include <sys/umtxvar.h> 56 #ifdef HWPMC_HOOKS 57 #include <sys/pmckern.h> 58 #endif 59 60 #include <machine/frame.h> 61 62 #include <security/audit/audit.h> 63 64 static SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 65 "thread allocation"); 66 67 int max_threads_per_proc = 1500; 68 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW, 69 &max_threads_per_proc, 0, "Limit on threads per proc"); 70 71 static int max_threads_hits; 72 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD, 73 &max_threads_hits, 0, "kern.threads.max_threads_per_proc hit count"); 74 75 #ifdef COMPAT_FREEBSD32 76 77 static inline int 78 suword_lwpid(void *addr, lwpid_t lwpid) 79 { 80 int error; 81 82 if (SV_CURPROC_FLAG(SV_LP64)) 83 error = suword(addr, lwpid); 84 else 85 error = suword32(addr, lwpid); 86 return (error); 87 } 88 89 #else 90 #define suword_lwpid suword 91 #endif 92 93 /* 94 * System call interface. 95 */ 96 97 struct thr_create_initthr_args { 98 ucontext_t ctx; 99 long *tid; 100 }; 101 102 static int 103 thr_create_initthr(struct thread *td, void *thunk) 104 { 105 struct thr_create_initthr_args *args; 106 107 /* Copy out the child tid. */ 108 args = thunk; 109 if (args->tid != NULL && suword_lwpid(args->tid, td->td_tid)) 110 return (EFAULT); 111 112 return (set_mcontext(td, &args->ctx.uc_mcontext)); 113 } 114 115 int 116 sys_thr_create(struct thread *td, struct thr_create_args *uap) 117 /* ucontext_t *ctx, long *id, int flags */ 118 { 119 struct thr_create_initthr_args args; 120 int error; 121 122 if ((error = copyin(uap->ctx, &args.ctx, sizeof(args.ctx)))) 123 return (error); 124 args.tid = uap->id; 125 return (thread_create(td, NULL, thr_create_initthr, &args)); 126 } 127 128 int 129 sys_thr_new(struct thread *td, struct thr_new_args *uap) 130 /* struct thr_param * */ 131 { 132 struct thr_param param; 133 int error; 134 135 if (uap->param_size < 0 || uap->param_size > sizeof(param)) 136 return (EINVAL); 137 bzero(¶m, sizeof(param)); 138 if ((error = copyin(uap->param, ¶m, uap->param_size))) 139 return (error); 140 return (kern_thr_new(td, ¶m)); 141 } 142 143 static int 144 thr_new_initthr(struct thread *td, void *thunk) 145 { 146 stack_t stack; 147 struct thr_param *param; 148 int error; 149 150 /* 151 * Here we copy out tid to two places, one for child and one 152 * for parent, because pthread can create a detached thread, 153 * if parent wants to safely access child tid, it has to provide 154 * its storage, because child thread may exit quickly and 155 * memory is freed before parent thread can access it. 156 */ 157 param = thunk; 158 if ((param->child_tid != NULL && 159 suword_lwpid(param->child_tid, td->td_tid)) || 160 (param->parent_tid != NULL && 161 suword_lwpid(param->parent_tid, td->td_tid))) 162 return (EFAULT); 163 164 /* Set up our machine context. */ 165 stack.ss_sp = param->stack_base; 166 stack.ss_size = param->stack_size; 167 /* Set upcall address to user thread entry function. */ 168 error = cpu_set_upcall(td, param->start_func, param->arg, &stack); 169 if (error != 0) 170 return (error); 171 /* Setup user TLS address and TLS pointer register. */ 172 return (cpu_set_user_tls(td, param->tls_base, param->flags)); 173 } 174 175 int 176 kern_thr_new(struct thread *td, struct thr_param *param) 177 { 178 struct rtprio rtp, *rtpp; 179 int error; 180 181 if ((param->flags & ~(THR_SUSPENDED | THR_SYSTEM_SCOPE | 182 THR_C_RUNTIME)) != 0) 183 return (EINVAL); 184 rtpp = NULL; 185 if (param->rtp != 0) { 186 error = copyin(param->rtp, &rtp, sizeof(struct rtprio)); 187 if (error) 188 return (error); 189 rtpp = &rtp; 190 } 191 return (thread_create(td, rtpp, thr_new_initthr, param)); 192 } 193 194 int 195 thread_create(struct thread *td, struct rtprio *rtp, 196 int (*initialize_thread)(struct thread *, void *), void *thunk) 197 { 198 struct thread *newtd; 199 struct proc *p; 200 int error; 201 202 p = td->td_proc; 203 204 if (rtp != NULL) { 205 switch(rtp->type) { 206 case RTP_PRIO_REALTIME: 207 case RTP_PRIO_FIFO: 208 /* Only root can set scheduler policy */ 209 if (priv_check(td, PRIV_SCHED_SETPOLICY) != 0) 210 return (EPERM); 211 if (rtp->prio > RTP_PRIO_MAX) 212 return (EINVAL); 213 break; 214 case RTP_PRIO_NORMAL: 215 rtp->prio = 0; 216 break; 217 default: 218 return (EINVAL); 219 } 220 } 221 222 #ifdef RACCT 223 if (racct_enable) { 224 PROC_LOCK(p); 225 error = racct_add(p, RACCT_NTHR, 1); 226 PROC_UNLOCK(p); 227 if (error != 0) 228 return (EPROCLIM); 229 } 230 #endif 231 232 /* Initialize our td */ 233 error = kern_thr_alloc(p, 0, &newtd); 234 if (error) 235 goto fail; 236 237 bzero(&newtd->td_startzero, 238 __rangeof(struct thread, td_startzero, td_endzero)); 239 bcopy(&td->td_startcopy, &newtd->td_startcopy, 240 __rangeof(struct thread, td_startcopy, td_endcopy)); 241 newtd->td_proc = td->td_proc; 242 newtd->td_rb_list = newtd->td_rbp_list = newtd->td_rb_inact = 0; 243 thread_cow_get(newtd, td); 244 245 cpu_copy_thread(newtd, td); 246 247 error = initialize_thread(newtd, thunk); 248 if (error != 0) { 249 thread_cow_free(newtd); 250 thread_free(newtd); 251 goto fail; 252 } 253 254 PROC_LOCK(p); 255 p->p_flag |= P_HADTHREADS; 256 thread_link(newtd, p); 257 bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name)); 258 thread_lock(td); 259 /* let the scheduler know about these things. */ 260 sched_fork_thread(td, newtd); 261 thread_unlock(td); 262 if (P_SHOULDSTOP(p)) 263 ast_sched(newtd, TDA_SUSPEND); 264 if (p->p_ptevents & PTRACE_LWP) 265 newtd->td_dbgflags |= TDB_BORN; 266 267 PROC_UNLOCK(p); 268 #ifdef HWPMC_HOOKS 269 if (PMC_PROC_IS_USING_PMCS(p)) 270 PMC_CALL_HOOK(newtd, PMC_FN_THR_CREATE, NULL); 271 else if (PMC_SYSTEM_SAMPLING_ACTIVE()) 272 PMC_CALL_HOOK_UNLOCKED(newtd, PMC_FN_THR_CREATE_LOG, NULL); 273 #endif 274 275 tidhash_add(newtd); 276 277 /* ignore timesharing class */ 278 if (rtp != NULL && !(td->td_pri_class == PRI_TIMESHARE && 279 rtp->type == RTP_PRIO_NORMAL)) 280 rtp_to_pri(rtp, newtd); 281 282 thread_lock(newtd); 283 TD_SET_CAN_RUN(newtd); 284 sched_add(newtd, SRQ_BORING); 285 286 return (0); 287 288 fail: 289 #ifdef RACCT 290 if (racct_enable) { 291 PROC_LOCK(p); 292 racct_sub(p, RACCT_NTHR, 1); 293 PROC_UNLOCK(p); 294 } 295 #endif 296 return (error); 297 } 298 299 int 300 sys_thr_self(struct thread *td, struct thr_self_args *uap) 301 /* long *id */ 302 { 303 int error; 304 305 error = suword_lwpid(uap->id, (unsigned)td->td_tid); 306 if (error == -1) 307 return (EFAULT); 308 return (0); 309 } 310 311 int 312 sys_thr_exit(struct thread *td, struct thr_exit_args *uap) 313 /* long *state */ 314 { 315 316 umtx_thread_exit(td); 317 318 /* Signal userland that it can free the stack. */ 319 if ((void *)uap->state != NULL) { 320 (void)suword_lwpid(uap->state, 1); 321 (void)kern_umtx_wake(td, uap->state, INT_MAX, 0); 322 } 323 324 return (kern_thr_exit(td)); 325 } 326 327 int 328 kern_thr_exit(struct thread *td) 329 { 330 struct proc *p; 331 332 p = td->td_proc; 333 334 /* 335 * If all of the threads in a process call this routine to 336 * exit (e.g. all threads call pthread_exit()), exactly one 337 * thread should return to the caller to terminate the process 338 * instead of the thread. 339 * 340 * Checking p_numthreads alone is not sufficient since threads 341 * might be committed to terminating while the PROC_LOCK is 342 * dropped in either ptracestop() or while removing this thread 343 * from the tidhash. Instead, the p_pendingexits field holds 344 * the count of threads in either of those states and a thread 345 * is considered the "last" thread if all of the other threads 346 * in a process are already terminating. 347 */ 348 PROC_LOCK(p); 349 if (p->p_numthreads == p->p_pendingexits + 1) { 350 /* 351 * Ignore attempts to shut down last thread in the 352 * proc. This will actually call _exit(2) in the 353 * usermode trampoline when it returns. 354 */ 355 PROC_UNLOCK(p); 356 return (0); 357 } 358 359 if (p->p_sysent->sv_ontdexit != NULL) 360 p->p_sysent->sv_ontdexit(td); 361 362 td->td_dbgflags |= TDB_EXIT; 363 if (p->p_ptevents & PTRACE_LWP) { 364 p->p_pendingexits++; 365 ptracestop(td, SIGTRAP, NULL); 366 p->p_pendingexits--; 367 } 368 tidhash_remove(td); 369 370 /* 371 * The check above should prevent all other threads from this 372 * process from exiting while the PROC_LOCK is dropped, so 373 * there must be at least one other thread other than the 374 * current thread. 375 */ 376 KASSERT(p->p_numthreads > 1, ("too few threads")); 377 racct_sub(p, RACCT_NTHR, 1); 378 tdsigcleanup(td); 379 380 #ifdef AUDIT 381 AUDIT_SYSCALL_EXIT(0, td); 382 #endif 383 384 PROC_SLOCK(p); 385 thread_stopped(p); 386 thread_exit(); 387 /* NOTREACHED */ 388 } 389 390 int 391 sys_thr_kill(struct thread *td, struct thr_kill_args *uap) 392 /* long id, int sig */ 393 { 394 ksiginfo_t ksi; 395 struct thread *ttd; 396 struct proc *p; 397 int error; 398 399 p = td->td_proc; 400 ksiginfo_init(&ksi); 401 ksi.ksi_signo = uap->sig; 402 ksi.ksi_code = SI_LWP; 403 ksi.ksi_pid = p->p_pid; 404 ksi.ksi_uid = td->td_ucred->cr_ruid; 405 if (uap->id == -1) { 406 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) { 407 error = EINVAL; 408 } else { 409 error = ESRCH; 410 PROC_LOCK(p); 411 FOREACH_THREAD_IN_PROC(p, ttd) { 412 if (ttd != td) { 413 error = 0; 414 if (uap->sig == 0) 415 break; 416 tdksignal(ttd, uap->sig, &ksi); 417 } 418 } 419 PROC_UNLOCK(p); 420 } 421 } else { 422 error = 0; 423 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 424 if (ttd == NULL) 425 return (ESRCH); 426 if (uap->sig == 0) 427 ; 428 else if (!_SIG_VALID(uap->sig)) 429 error = EINVAL; 430 else 431 tdksignal(ttd, uap->sig, &ksi); 432 PROC_UNLOCK(ttd->td_proc); 433 } 434 return (error); 435 } 436 437 int 438 sys_thr_kill2(struct thread *td, struct thr_kill2_args *uap) 439 /* pid_t pid, long id, int sig */ 440 { 441 ksiginfo_t ksi; 442 struct thread *ttd; 443 struct proc *p; 444 int error; 445 446 AUDIT_ARG_SIGNUM(uap->sig); 447 448 ksiginfo_init(&ksi); 449 ksi.ksi_signo = uap->sig; 450 ksi.ksi_code = SI_LWP; 451 ksi.ksi_pid = td->td_proc->p_pid; 452 ksi.ksi_uid = td->td_ucred->cr_ruid; 453 if (uap->id == -1) { 454 if ((p = pfind(uap->pid)) == NULL) 455 return (ESRCH); 456 AUDIT_ARG_PROCESS(p); 457 error = p_cansignal(td, p, uap->sig); 458 if (error) { 459 PROC_UNLOCK(p); 460 return (error); 461 } 462 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) { 463 error = EINVAL; 464 } else { 465 error = ESRCH; 466 FOREACH_THREAD_IN_PROC(p, ttd) { 467 if (ttd != td) { 468 error = 0; 469 if (uap->sig == 0) 470 break; 471 tdksignal(ttd, uap->sig, &ksi); 472 } 473 } 474 } 475 PROC_UNLOCK(p); 476 } else { 477 ttd = tdfind((lwpid_t)uap->id, uap->pid); 478 if (ttd == NULL) 479 return (ESRCH); 480 p = ttd->td_proc; 481 AUDIT_ARG_PROCESS(p); 482 error = p_cansignal(td, p, uap->sig); 483 if (uap->sig == 0) 484 ; 485 else if (!_SIG_VALID(uap->sig)) 486 error = EINVAL; 487 else 488 tdksignal(ttd, uap->sig, &ksi); 489 PROC_UNLOCK(p); 490 } 491 return (error); 492 } 493 494 int 495 sys_thr_suspend(struct thread *td, struct thr_suspend_args *uap) 496 /* const struct timespec *timeout */ 497 { 498 struct timespec ts, *tsp; 499 int error; 500 501 tsp = NULL; 502 if (uap->timeout != NULL) { 503 error = umtx_copyin_timeout(uap->timeout, &ts); 504 if (error != 0) 505 return (error); 506 tsp = &ts; 507 } 508 509 return (kern_thr_suspend(td, tsp)); 510 } 511 512 int 513 kern_thr_suspend(struct thread *td, struct timespec *tsp) 514 { 515 struct proc *p = td->td_proc; 516 struct timeval tv; 517 int error = 0; 518 int timo = 0; 519 520 if (td->td_pflags & TDP_WAKEUP) { 521 td->td_pflags &= ~TDP_WAKEUP; 522 return (0); 523 } 524 525 if (tsp != NULL) { 526 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 527 error = EWOULDBLOCK; 528 else { 529 TIMESPEC_TO_TIMEVAL(&tv, tsp); 530 timo = tvtohz(&tv); 531 } 532 } 533 534 PROC_LOCK(p); 535 if (error == 0 && (td->td_flags & TDF_THRWAKEUP) == 0) 536 error = msleep((void *)td, &p->p_mtx, 537 PCATCH, "lthr", timo); 538 539 if (td->td_flags & TDF_THRWAKEUP) { 540 thread_lock(td); 541 td->td_flags &= ~TDF_THRWAKEUP; 542 thread_unlock(td); 543 PROC_UNLOCK(p); 544 return (0); 545 } 546 PROC_UNLOCK(p); 547 if (error == EWOULDBLOCK) 548 error = ETIMEDOUT; 549 else if (error == ERESTART) { 550 if (timo != 0) 551 error = EINTR; 552 } 553 return (error); 554 } 555 556 int 557 sys_thr_wake(struct thread *td, struct thr_wake_args *uap) 558 /* long id */ 559 { 560 struct proc *p; 561 struct thread *ttd; 562 563 if (uap->id == td->td_tid) { 564 td->td_pflags |= TDP_WAKEUP; 565 return (0); 566 } 567 568 p = td->td_proc; 569 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 570 if (ttd == NULL) 571 return (ESRCH); 572 thread_lock(ttd); 573 ttd->td_flags |= TDF_THRWAKEUP; 574 thread_unlock(ttd); 575 wakeup((void *)ttd); 576 PROC_UNLOCK(p); 577 return (0); 578 } 579 580 int 581 sys_thr_set_name(struct thread *td, struct thr_set_name_args *uap) 582 { 583 struct proc *p; 584 char name[MAXCOMLEN + 1]; 585 struct thread *ttd; 586 int error; 587 588 error = 0; 589 name[0] = '\0'; 590 if (uap->name != NULL) { 591 error = copyinstr(uap->name, name, sizeof(name), NULL); 592 if (error == ENAMETOOLONG) { 593 error = copyin(uap->name, name, sizeof(name) - 1); 594 name[sizeof(name) - 1] = '\0'; 595 } 596 if (error) 597 return (error); 598 } 599 p = td->td_proc; 600 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 601 if (ttd == NULL) 602 return (ESRCH); 603 strcpy(ttd->td_name, name); 604 #ifdef HWPMC_HOOKS 605 if (PMC_PROC_IS_USING_PMCS(p) || PMC_SYSTEM_SAMPLING_ACTIVE()) 606 PMC_CALL_HOOK_UNLOCKED(ttd, PMC_FN_THR_CREATE_LOG, NULL); 607 #endif 608 #ifdef KTR 609 sched_clear_tdname(ttd); 610 #endif 611 PROC_UNLOCK(p); 612 return (error); 613 } 614 615 int 616 kern_thr_alloc(struct proc *p, int pages, struct thread **ntd) 617 { 618 619 /* Have race condition but it is cheap. */ 620 if (p->p_numthreads >= max_threads_per_proc) { 621 ++max_threads_hits; 622 return (EPROCLIM); 623 } 624 625 *ntd = thread_alloc(pages); 626 if (*ntd == NULL) 627 return (ENOMEM); 628 629 return (0); 630 } 631