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/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/umtx.h> 56 #include <sys/limits.h> 57 58 #include <vm/vm_domain.h> 59 60 #include <machine/frame.h> 61 62 #include <security/audit/audit.h> 63 64 static SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0, 65 "thread allocation"); 66 67 static 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; 148 149 /* 150 * Here we copy out tid to two places, one for child and one 151 * for parent, because pthread can create a detached thread, 152 * if parent wants to safely access child tid, it has to provide 153 * its storage, because child thread may exit quickly and 154 * memory is freed before parent thread can access it. 155 */ 156 param = thunk; 157 if ((param->child_tid != NULL && 158 suword_lwpid(param->child_tid, td->td_tid)) || 159 (param->parent_tid != NULL && 160 suword_lwpid(param->parent_tid, td->td_tid))) 161 return (EFAULT); 162 163 /* Set up our machine context. */ 164 stack.ss_sp = param->stack_base; 165 stack.ss_size = param->stack_size; 166 /* Set upcall address to user thread entry function. */ 167 cpu_set_upcall(td, param->start_func, param->arg, &stack); 168 /* Setup user TLS address and TLS pointer register. */ 169 return (cpu_set_user_tls(td, param->tls_base)); 170 } 171 172 int 173 kern_thr_new(struct thread *td, struct thr_param *param) 174 { 175 struct rtprio rtp, *rtpp; 176 int error; 177 178 rtpp = NULL; 179 if (param->rtp != 0) { 180 error = copyin(param->rtp, &rtp, sizeof(struct rtprio)); 181 if (error) 182 return (error); 183 rtpp = &rtp; 184 } 185 return (thread_create(td, rtpp, thr_new_initthr, param)); 186 } 187 188 int 189 thread_create(struct thread *td, struct rtprio *rtp, 190 int (*initialize_thread)(struct thread *, void *), void *thunk) 191 { 192 struct thread *newtd; 193 struct proc *p; 194 int error; 195 196 p = td->td_proc; 197 198 if (rtp != NULL) { 199 switch(rtp->type) { 200 case RTP_PRIO_REALTIME: 201 case RTP_PRIO_FIFO: 202 /* Only root can set scheduler policy */ 203 if (priv_check(td, PRIV_SCHED_SETPOLICY) != 0) 204 return (EPERM); 205 if (rtp->prio > RTP_PRIO_MAX) 206 return (EINVAL); 207 break; 208 case RTP_PRIO_NORMAL: 209 rtp->prio = 0; 210 break; 211 default: 212 return (EINVAL); 213 } 214 } 215 216 #ifdef RACCT 217 if (racct_enable) { 218 PROC_LOCK(p); 219 error = racct_add(p, RACCT_NTHR, 1); 220 PROC_UNLOCK(p); 221 if (error != 0) 222 return (EPROCLIM); 223 } 224 #endif 225 226 /* Initialize our td */ 227 error = kern_thr_alloc(p, 0, &newtd); 228 if (error) 229 goto fail; 230 231 cpu_copy_thread(newtd, td); 232 233 bzero(&newtd->td_startzero, 234 __rangeof(struct thread, td_startzero, td_endzero)); 235 bcopy(&td->td_startcopy, &newtd->td_startcopy, 236 __rangeof(struct thread, td_startcopy, td_endcopy)); 237 newtd->td_proc = td->td_proc; 238 newtd->td_rb_list = newtd->td_rbp_list = newtd->td_rb_inact = 0; 239 thread_cow_get(newtd, td); 240 241 error = initialize_thread(newtd, thunk); 242 if (error != 0) { 243 thread_cow_free(newtd); 244 thread_free(newtd); 245 goto fail; 246 } 247 248 PROC_LOCK(p); 249 p->p_flag |= P_HADTHREADS; 250 thread_link(newtd, p); 251 bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name)); 252 thread_lock(td); 253 /* let the scheduler know about these things. */ 254 sched_fork_thread(td, newtd); 255 thread_unlock(td); 256 if (P_SHOULDSTOP(p)) 257 newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 258 if (p->p_ptevents & PTRACE_LWP) 259 newtd->td_dbgflags |= TDB_BORN; 260 261 /* 262 * Copy the existing thread VM policy into the new thread. 263 */ 264 vm_domain_policy_localcopy(&newtd->td_vm_dom_policy, 265 &td->td_vm_dom_policy); 266 267 PROC_UNLOCK(p); 268 269 tidhash_add(newtd); 270 271 thread_lock(newtd); 272 if (rtp != NULL) { 273 if (!(td->td_pri_class == PRI_TIMESHARE && 274 rtp->type == RTP_PRIO_NORMAL)) { 275 rtp_to_pri(rtp, newtd); 276 sched_prio(newtd, newtd->td_user_pri); 277 } /* ignore timesharing class */ 278 } 279 TD_SET_CAN_RUN(newtd); 280 sched_add(newtd, SRQ_BORING); 281 thread_unlock(newtd); 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 p->p_pendingexits++; 357 td->td_dbgflags |= TDB_EXIT; 358 if (p->p_ptevents & PTRACE_LWP) 359 ptracestop(td, SIGTRAP, NULL); 360 PROC_UNLOCK(p); 361 tidhash_remove(td); 362 PROC_LOCK(p); 363 p->p_pendingexits--; 364 365 /* 366 * The check above should prevent all other threads from this 367 * process from exiting while the PROC_LOCK is dropped, so 368 * there must be at least one other thread other than the 369 * current thread. 370 */ 371 KASSERT(p->p_numthreads > 1, ("too few threads")); 372 racct_sub(p, RACCT_NTHR, 1); 373 tdsigcleanup(td); 374 PROC_SLOCK(p); 375 thread_stopped(p); 376 thread_exit(); 377 /* NOTREACHED */ 378 } 379 380 int 381 sys_thr_kill(struct thread *td, struct thr_kill_args *uap) 382 /* long id, int sig */ 383 { 384 ksiginfo_t ksi; 385 struct thread *ttd; 386 struct proc *p; 387 int error; 388 389 p = td->td_proc; 390 ksiginfo_init(&ksi); 391 ksi.ksi_signo = uap->sig; 392 ksi.ksi_code = SI_LWP; 393 ksi.ksi_pid = p->p_pid; 394 ksi.ksi_uid = td->td_ucred->cr_ruid; 395 if (uap->id == -1) { 396 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) { 397 error = EINVAL; 398 } else { 399 error = ESRCH; 400 PROC_LOCK(p); 401 FOREACH_THREAD_IN_PROC(p, ttd) { 402 if (ttd != td) { 403 error = 0; 404 if (uap->sig == 0) 405 break; 406 tdksignal(ttd, uap->sig, &ksi); 407 } 408 } 409 PROC_UNLOCK(p); 410 } 411 } else { 412 error = 0; 413 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 414 if (ttd == NULL) 415 return (ESRCH); 416 if (uap->sig == 0) 417 ; 418 else if (!_SIG_VALID(uap->sig)) 419 error = EINVAL; 420 else 421 tdksignal(ttd, uap->sig, &ksi); 422 PROC_UNLOCK(ttd->td_proc); 423 } 424 return (error); 425 } 426 427 int 428 sys_thr_kill2(struct thread *td, struct thr_kill2_args *uap) 429 /* pid_t pid, long id, int sig */ 430 { 431 ksiginfo_t ksi; 432 struct thread *ttd; 433 struct proc *p; 434 int error; 435 436 AUDIT_ARG_SIGNUM(uap->sig); 437 438 ksiginfo_init(&ksi); 439 ksi.ksi_signo = uap->sig; 440 ksi.ksi_code = SI_LWP; 441 ksi.ksi_pid = td->td_proc->p_pid; 442 ksi.ksi_uid = td->td_ucred->cr_ruid; 443 if (uap->id == -1) { 444 if ((p = pfind(uap->pid)) == NULL) 445 return (ESRCH); 446 AUDIT_ARG_PROCESS(p); 447 error = p_cansignal(td, p, uap->sig); 448 if (error) { 449 PROC_UNLOCK(p); 450 return (error); 451 } 452 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) { 453 error = EINVAL; 454 } else { 455 error = ESRCH; 456 FOREACH_THREAD_IN_PROC(p, ttd) { 457 if (ttd != td) { 458 error = 0; 459 if (uap->sig == 0) 460 break; 461 tdksignal(ttd, uap->sig, &ksi); 462 } 463 } 464 } 465 PROC_UNLOCK(p); 466 } else { 467 ttd = tdfind((lwpid_t)uap->id, uap->pid); 468 if (ttd == NULL) 469 return (ESRCH); 470 p = ttd->td_proc; 471 AUDIT_ARG_PROCESS(p); 472 error = p_cansignal(td, p, uap->sig); 473 if (uap->sig == 0) 474 ; 475 else if (!_SIG_VALID(uap->sig)) 476 error = EINVAL; 477 else 478 tdksignal(ttd, uap->sig, &ksi); 479 PROC_UNLOCK(p); 480 } 481 return (error); 482 } 483 484 int 485 sys_thr_suspend(struct thread *td, struct thr_suspend_args *uap) 486 /* const struct timespec *timeout */ 487 { 488 struct timespec ts, *tsp; 489 int error; 490 491 tsp = NULL; 492 if (uap->timeout != NULL) { 493 error = umtx_copyin_timeout(uap->timeout, &ts); 494 if (error != 0) 495 return (error); 496 tsp = &ts; 497 } 498 499 return (kern_thr_suspend(td, tsp)); 500 } 501 502 int 503 kern_thr_suspend(struct thread *td, struct timespec *tsp) 504 { 505 struct proc *p = td->td_proc; 506 struct timeval tv; 507 int error = 0; 508 int timo = 0; 509 510 if (td->td_pflags & TDP_WAKEUP) { 511 td->td_pflags &= ~TDP_WAKEUP; 512 return (0); 513 } 514 515 if (tsp != NULL) { 516 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 517 error = EWOULDBLOCK; 518 else { 519 TIMESPEC_TO_TIMEVAL(&tv, tsp); 520 timo = tvtohz(&tv); 521 } 522 } 523 524 PROC_LOCK(p); 525 if (error == 0 && (td->td_flags & TDF_THRWAKEUP) == 0) 526 error = msleep((void *)td, &p->p_mtx, 527 PCATCH, "lthr", timo); 528 529 if (td->td_flags & TDF_THRWAKEUP) { 530 thread_lock(td); 531 td->td_flags &= ~TDF_THRWAKEUP; 532 thread_unlock(td); 533 PROC_UNLOCK(p); 534 return (0); 535 } 536 PROC_UNLOCK(p); 537 if (error == EWOULDBLOCK) 538 error = ETIMEDOUT; 539 else if (error == ERESTART) { 540 if (timo != 0) 541 error = EINTR; 542 } 543 return (error); 544 } 545 546 int 547 sys_thr_wake(struct thread *td, struct thr_wake_args *uap) 548 /* long id */ 549 { 550 struct proc *p; 551 struct thread *ttd; 552 553 if (uap->id == td->td_tid) { 554 td->td_pflags |= TDP_WAKEUP; 555 return (0); 556 } 557 558 p = td->td_proc; 559 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 560 if (ttd == NULL) 561 return (ESRCH); 562 thread_lock(ttd); 563 ttd->td_flags |= TDF_THRWAKEUP; 564 thread_unlock(ttd); 565 wakeup((void *)ttd); 566 PROC_UNLOCK(p); 567 return (0); 568 } 569 570 int 571 sys_thr_set_name(struct thread *td, struct thr_set_name_args *uap) 572 { 573 struct proc *p; 574 char name[MAXCOMLEN + 1]; 575 struct thread *ttd; 576 int error; 577 578 error = 0; 579 name[0] = '\0'; 580 if (uap->name != NULL) { 581 error = copyinstr(uap->name, name, sizeof(name), NULL); 582 if (error == ENAMETOOLONG) { 583 error = copyin(uap->name, name, sizeof(name) - 1); 584 name[sizeof(name) - 1] = '\0'; 585 } 586 if (error) 587 return (error); 588 } 589 p = td->td_proc; 590 ttd = tdfind((lwpid_t)uap->id, p->p_pid); 591 if (ttd == NULL) 592 return (ESRCH); 593 strcpy(ttd->td_name, name); 594 #ifdef KTR 595 sched_clear_tdname(ttd); 596 #endif 597 PROC_UNLOCK(p); 598 return (error); 599 } 600 601 int 602 kern_thr_alloc(struct proc *p, int pages, struct thread **ntd) 603 { 604 605 /* Have race condition but it is cheap. */ 606 if (p->p_numthreads >= max_threads_per_proc) { 607 ++max_threads_hits; 608 return (EPROCLIM); 609 } 610 611 *ntd = thread_alloc(pages); 612 if (*ntd == NULL) 613 return (ENOMEM); 614 615 return (0); 616 } 617