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