1 /*- 2 * Copyright (c) 2003, Jeffrey Roberson <jeff@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_compat.h" 31 #include "opt_posix.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/racct.h> 40 #include <sys/resourcevar.h> 41 #include <sys/rwlock.h> 42 #include <sys/sched.h> 43 #include <sys/sysctl.h> 44 #include <sys/smp.h> 45 #include <sys/syscallsubr.h> 46 #include <sys/sysent.h> 47 #include <sys/systm.h> 48 #include <sys/sysproto.h> 49 #include <sys/signalvar.h> 50 #include <sys/sysctl.h> 51 #include <sys/ucontext.h> 52 #include <sys/thr.h> 53 #include <sys/rtprio.h> 54 #include <sys/umtx.h> 55 #include <sys/limits.h> 56 57 #include <vm/vm_domain.h> 58 59 #include <machine/frame.h> 60 61 #include <security/audit/audit.h> 62 63 static SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0, 64 "thread allocation"); 65 66 static int max_threads_per_proc = 1500; 67 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW, 68 &max_threads_per_proc, 0, "Limit on threads per proc"); 69 70 static int max_threads_hits; 71 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD, 72 &max_threads_hits, 0, "kern.threads.max_threads_per_proc hit count"); 73 74 #ifdef COMPAT_FREEBSD32 75 76 static inline int 77 suword_lwpid(void *addr, lwpid_t lwpid) 78 { 79 int error; 80 81 if (SV_CURPROC_FLAG(SV_LP64)) 82 error = suword(addr, lwpid); 83 else 84 error = suword32(addr, lwpid); 85 return (error); 86 } 87 88 #else 89 #define suword_lwpid suword 90 #endif 91 92 /* 93 * System call interface. 94 */ 95 96 struct thr_create_initthr_args { 97 ucontext_t ctx; 98 long *tid; 99 }; 100 101 static int 102 thr_create_initthr(struct thread *td, void *thunk) 103 { 104 struct thr_create_initthr_args *args; 105 106 /* Copy out the child tid. */ 107 args = thunk; 108 if (args->tid != NULL && suword_lwpid(args->tid, td->td_tid)) 109 return (EFAULT); 110 111 return (set_mcontext(td, &args->ctx.uc_mcontext)); 112 } 113 114 int 115 sys_thr_create(struct thread *td, struct thr_create_args *uap) 116 /* ucontext_t *ctx, long *id, int flags */ 117 { 118 struct thr_create_initthr_args args; 119 int error; 120 121 if ((error = copyin(uap->ctx, &args.ctx, sizeof(args.ctx)))) 122 return (error); 123 args.tid = uap->id; 124 return (thread_create(td, NULL, thr_create_initthr, &args)); 125 } 126 127 int 128 sys_thr_new(struct thread *td, struct thr_new_args *uap) 129 /* struct thr_param * */ 130 { 131 struct thr_param param; 132 int error; 133 134 if (uap->param_size < 0 || uap->param_size > sizeof(param)) 135 return (EINVAL); 136 bzero(¶m, sizeof(param)); 137 if ((error = copyin(uap->param, ¶m, uap->param_size))) 138 return (error); 139 return (kern_thr_new(td, ¶m)); 140 } 141 142 static int 143 thr_new_initthr(struct thread *td, void *thunk) 144 { 145 stack_t stack; 146 struct thr_param *param; 147 148 /* 149 * Here we copy out tid to two places, one for child and one 150 * for parent, because pthread can create a detached thread, 151 * if parent wants to safely access child tid, it has to provide 152 * its storage, because child thread may exit quickly and 153 * memory is freed before parent thread can access it. 154 */ 155 param = thunk; 156 if ((param->child_tid != NULL && 157 suword_lwpid(param->child_tid, td->td_tid)) || 158 (param->parent_tid != NULL && 159 suword_lwpid(param->parent_tid, td->td_tid))) 160 return (EFAULT); 161 162 /* Set up our machine context. */ 163 stack.ss_sp = param->stack_base; 164 stack.ss_size = param->stack_size; 165 /* Set upcall address to user thread entry function. */ 166 cpu_set_upcall_kse(td, param->start_func, param->arg, &stack); 167 /* Setup user TLS address and TLS pointer register. */ 168 return (cpu_set_user_tls(td, param->tls_base)); 169 } 170 171 int 172 kern_thr_new(struct thread *td, struct thr_param *param) 173 { 174 struct rtprio rtp, *rtpp; 175 int error; 176 177 rtpp = NULL; 178 if (param->rtp != 0) { 179 error = copyin(param->rtp, &rtp, sizeof(struct rtprio)); 180 if (error) 181 return (error); 182 rtpp = &rtp; 183 } 184 return (thread_create(td, rtpp, thr_new_initthr, param)); 185 } 186 187 int 188 thread_create(struct thread *td, struct rtprio *rtp, 189 int (*initialize_thread)(struct thread *, void *), void *thunk) 190 { 191 struct thread *newtd; 192 struct proc *p; 193 int error; 194 195 p = td->td_proc; 196 197 if (rtp != NULL) { 198 switch(rtp->type) { 199 case RTP_PRIO_REALTIME: 200 case RTP_PRIO_FIFO: 201 /* Only root can set scheduler policy */ 202 if (priv_check(td, PRIV_SCHED_SETPOLICY) != 0) 203 return (EPERM); 204 if (rtp->prio > RTP_PRIO_MAX) 205 return (EINVAL); 206 break; 207 case RTP_PRIO_NORMAL: 208 rtp->prio = 0; 209 break; 210 default: 211 return (EINVAL); 212 } 213 } 214 215 #ifdef RACCT 216 if (racct_enable) { 217 PROC_LOCK(p); 218 error = racct_add(p, RACCT_NTHR, 1); 219 PROC_UNLOCK(p); 220 if (error != 0) 221 return (EPROCLIM); 222 } 223 #endif 224 225 /* Initialize our td */ 226 error = kern_thr_alloc(p, 0, &newtd); 227 if (error) 228 goto fail; 229 230 cpu_set_upcall(newtd, td); 231 232 bzero(&newtd->td_startzero, 233 __rangeof(struct thread, td_startzero, td_endzero)); 234 bcopy(&td->td_startcopy, &newtd->td_startcopy, 235 __rangeof(struct thread, td_startcopy, td_endcopy)); 236 newtd->td_proc = td->td_proc; 237 thread_cow_get(newtd, td); 238 239 error = initialize_thread(newtd, thunk); 240 if (error != 0) { 241 thread_cow_free(newtd); 242 thread_free(newtd); 243 goto fail; 244 } 245 246 PROC_LOCK(p); 247 p->p_flag |= P_HADTHREADS; 248 thread_link(newtd, p); 249 bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name)); 250 thread_lock(td); 251 /* let the scheduler know about these things. */ 252 sched_fork_thread(td, newtd); 253 thread_unlock(td); 254 if (P_SHOULDSTOP(p)) 255 newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 256 if (p->p_flag2 & P2_LWP_EVENTS) 257 newtd->td_dbgflags |= TDB_BORN; 258 259 /* 260 * Copy the existing thread VM policy into the new thread. 261 */ 262 vm_domain_policy_localcopy(&newtd->td_vm_dom_policy, 263 &td->td_vm_dom_policy); 264 265 PROC_UNLOCK(p); 266 267 tidhash_add(newtd); 268 269 thread_lock(newtd); 270 if (rtp != NULL) { 271 if (!(td->td_pri_class == PRI_TIMESHARE && 272 rtp->type == RTP_PRIO_NORMAL)) { 273 rtp_to_pri(rtp, newtd); 274 sched_prio(newtd, newtd->td_user_pri); 275 } /* ignore timesharing class */ 276 } 277 TD_SET_CAN_RUN(newtd); 278 sched_add(newtd, SRQ_BORING); 279 thread_unlock(newtd); 280 281 return (0); 282 283 fail: 284 #ifdef RACCT 285 if (racct_enable) { 286 PROC_LOCK(p); 287 racct_sub(p, RACCT_NTHR, 1); 288 PROC_UNLOCK(p); 289 } 290 #endif 291 return (error); 292 } 293 294 int 295 sys_thr_self(struct thread *td, struct thr_self_args *uap) 296 /* long *id */ 297 { 298 int error; 299 300 error = suword_lwpid(uap->id, (unsigned)td->td_tid); 301 if (error == -1) 302 return (EFAULT); 303 return (0); 304 } 305 306 int 307 sys_thr_exit(struct thread *td, struct thr_exit_args *uap) 308 /* long *state */ 309 { 310 311 umtx_thread_exit(td); 312 313 /* Signal userland that it can free the stack. */ 314 if ((void *)uap->state != NULL) { 315 suword_lwpid(uap->state, 1); 316 kern_umtx_wake(td, uap->state, INT_MAX, 0); 317 } 318 319 return (kern_thr_exit(td)); 320 } 321 322 int 323 kern_thr_exit(struct thread *td) 324 { 325 struct proc *p; 326 327 p = td->td_proc; 328 329 /* 330 * If all of the threads in a process call this routine to 331 * exit (e.g. all threads call pthread_exit()), exactly one 332 * thread should return to the caller to terminate the process 333 * instead of the thread. 334 * 335 * Checking p_numthreads alone is not sufficient since threads 336 * might be committed to terminating while the PROC_LOCK is 337 * dropped in either ptracestop() or while removing this thread 338 * from the tidhash. Instead, the p_pendingexits field holds 339 * the count of threads in either of those states and a thread 340 * is considered the "last" thread if all of the other threads 341 * in a process are already terminating. 342 */ 343 PROC_LOCK(p); 344 if (p->p_numthreads == p->p_pendingexits + 1) { 345 /* 346 * Ignore attempts to shut down last thread in the 347 * proc. This will actually call _exit(2) in the 348 * usermode trampoline when it returns. 349 */ 350 PROC_UNLOCK(p); 351 return (0); 352 } 353 354 p->p_pendingexits++; 355 td->td_dbgflags |= TDB_EXIT; 356 if (p->p_flag & P_TRACED && p->p_flag2 & P2_LWP_EVENTS) 357 ptracestop(td, SIGTRAP); 358 PROC_UNLOCK(p); 359 tidhash_remove(td); 360 PROC_LOCK(p); 361 p->p_pendingexits--; 362 363 /* 364 * The check above should prevent all other threads from this 365 * process from exiting while the PROC_LOCK is dropped, so 366 * there must be at least one other thread other than the 367 * current thread. 368 */ 369 KASSERT(p->p_numthreads > 1, ("too few threads")); 370 racct_sub(p, RACCT_NTHR, 1); 371 tdsigcleanup(td); 372 PROC_SLOCK(p); 373 thread_stopped(p); 374 thread_exit(); 375 /* NOTREACHED */ 376 } 377 378 int 379 sys_thr_kill(struct thread *td, struct thr_kill_args *uap) 380 /* long id, int sig */ 381 { 382 ksiginfo_t ksi; 383 struct thread *ttd; 384 struct proc *p; 385 int error; 386 387 p = td->td_proc; 388 ksiginfo_init(&ksi); 389 ksi.ksi_signo = uap->sig; 390 ksi.ksi_code = SI_LWP; 391 ksi.ksi_pid = p->p_pid; 392 ksi.ksi_uid = td->td_ucred->cr_ruid; 393 if (uap->id == -1) { 394 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) { 395 error = EINVAL; 396 } else { 397 error = ESRCH; 398 PROC_LOCK(p); 399 FOREACH_THREAD_IN_PROC(p, ttd) { 400 if (ttd != td) { 401 error = 0; 402 if (uap->sig == 0) 403 break; 404 tdksignal(ttd, uap->sig, &ksi); 405 } 406 } 407 PROC_UNLOCK(p); 408 } 409 } else { 410 error = 0; 411 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 412 if (ttd == NULL) 413 return (ESRCH); 414 if (uap->sig == 0) 415 ; 416 else if (!_SIG_VALID(uap->sig)) 417 error = EINVAL; 418 else 419 tdksignal(ttd, uap->sig, &ksi); 420 PROC_UNLOCK(ttd->td_proc); 421 } 422 return (error); 423 } 424 425 int 426 sys_thr_kill2(struct thread *td, struct thr_kill2_args *uap) 427 /* pid_t pid, long id, int sig */ 428 { 429 ksiginfo_t ksi; 430 struct thread *ttd; 431 struct proc *p; 432 int error; 433 434 AUDIT_ARG_SIGNUM(uap->sig); 435 436 ksiginfo_init(&ksi); 437 ksi.ksi_signo = uap->sig; 438 ksi.ksi_code = SI_LWP; 439 ksi.ksi_pid = td->td_proc->p_pid; 440 ksi.ksi_uid = td->td_ucred->cr_ruid; 441 if (uap->id == -1) { 442 if ((p = pfind(uap->pid)) == NULL) 443 return (ESRCH); 444 AUDIT_ARG_PROCESS(p); 445 error = p_cansignal(td, p, uap->sig); 446 if (error) { 447 PROC_UNLOCK(p); 448 return (error); 449 } 450 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) { 451 error = EINVAL; 452 } else { 453 error = ESRCH; 454 FOREACH_THREAD_IN_PROC(p, ttd) { 455 if (ttd != td) { 456 error = 0; 457 if (uap->sig == 0) 458 break; 459 tdksignal(ttd, uap->sig, &ksi); 460 } 461 } 462 } 463 PROC_UNLOCK(p); 464 } else { 465 ttd = tdfind((lwpid_t)uap->id, uap->pid); 466 if (ttd == NULL) 467 return (ESRCH); 468 p = ttd->td_proc; 469 AUDIT_ARG_PROCESS(p); 470 error = p_cansignal(td, p, uap->sig); 471 if (uap->sig == 0) 472 ; 473 else if (!_SIG_VALID(uap->sig)) 474 error = EINVAL; 475 else 476 tdksignal(ttd, uap->sig, &ksi); 477 PROC_UNLOCK(p); 478 } 479 return (error); 480 } 481 482 int 483 sys_thr_suspend(struct thread *td, struct thr_suspend_args *uap) 484 /* const struct timespec *timeout */ 485 { 486 struct timespec ts, *tsp; 487 int error; 488 489 tsp = NULL; 490 if (uap->timeout != NULL) { 491 error = umtx_copyin_timeout(uap->timeout, &ts); 492 if (error != 0) 493 return (error); 494 tsp = &ts; 495 } 496 497 return (kern_thr_suspend(td, tsp)); 498 } 499 500 int 501 kern_thr_suspend(struct thread *td, struct timespec *tsp) 502 { 503 struct proc *p = td->td_proc; 504 struct timeval tv; 505 int error = 0; 506 int timo = 0; 507 508 if (td->td_pflags & TDP_WAKEUP) { 509 td->td_pflags &= ~TDP_WAKEUP; 510 return (0); 511 } 512 513 if (tsp != NULL) { 514 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 515 error = EWOULDBLOCK; 516 else { 517 TIMESPEC_TO_TIMEVAL(&tv, tsp); 518 timo = tvtohz(&tv); 519 } 520 } 521 522 PROC_LOCK(p); 523 if (error == 0 && (td->td_flags & TDF_THRWAKEUP) == 0) 524 error = msleep((void *)td, &p->p_mtx, 525 PCATCH, "lthr", timo); 526 527 if (td->td_flags & TDF_THRWAKEUP) { 528 thread_lock(td); 529 td->td_flags &= ~TDF_THRWAKEUP; 530 thread_unlock(td); 531 PROC_UNLOCK(p); 532 return (0); 533 } 534 PROC_UNLOCK(p); 535 if (error == EWOULDBLOCK) 536 error = ETIMEDOUT; 537 else if (error == ERESTART) { 538 if (timo != 0) 539 error = EINTR; 540 } 541 return (error); 542 } 543 544 int 545 sys_thr_wake(struct thread *td, struct thr_wake_args *uap) 546 /* long id */ 547 { 548 struct proc *p; 549 struct thread *ttd; 550 551 if (uap->id == td->td_tid) { 552 td->td_pflags |= TDP_WAKEUP; 553 return (0); 554 } 555 556 p = td->td_proc; 557 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 558 if (ttd == NULL) 559 return (ESRCH); 560 thread_lock(ttd); 561 ttd->td_flags |= TDF_THRWAKEUP; 562 thread_unlock(ttd); 563 wakeup((void *)ttd); 564 PROC_UNLOCK(p); 565 return (0); 566 } 567 568 int 569 sys_thr_set_name(struct thread *td, struct thr_set_name_args *uap) 570 { 571 struct proc *p; 572 char name[MAXCOMLEN + 1]; 573 struct thread *ttd; 574 int error; 575 576 error = 0; 577 name[0] = '\0'; 578 if (uap->name != NULL) { 579 error = copyinstr(uap->name, name, sizeof(name), 580 NULL); 581 if (error) 582 return (error); 583 } 584 p = td->td_proc; 585 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 586 if (ttd == NULL) 587 return (ESRCH); 588 strcpy(ttd->td_name, name); 589 #ifdef KTR 590 sched_clear_tdname(ttd); 591 #endif 592 PROC_UNLOCK(p); 593 return (error); 594 } 595 596 int 597 kern_thr_alloc(struct proc *p, int pages, struct thread **ntd) 598 { 599 600 /* Have race condition but it is cheap. */ 601 if (p->p_numthreads >= max_threads_per_proc) { 602 ++max_threads_hits; 603 return (EPROCLIM); 604 } 605 606 *ntd = thread_alloc(pages); 607 if (*ntd == NULL) 608 return (ENOMEM); 609 610 return (0); 611 } 612