linux_futex.c revision 293703
1/* $NetBSD: linux_futex.c,v 1.7 2006/07/24 19:01:49 manu Exp $ */ 2 3/*- 4 * Copyright (c) 2005 Emmanuel Dreyfus, all rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following 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 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by Emmanuel Dreyfus 17 * 4. The name of the author may not be used to endorse or promote 18 * products derived from this software without specific prior written 19 * permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``AS IS'' 22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 23 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS 25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 * POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34#include <sys/cdefs.h> 35__FBSDID("$FreeBSD: stable/10/sys/compat/linux/linux_futex.c 293703 2016-01-11 21:46:37Z glebius $"); 36#if 0 37__KERNEL_RCSID(1, "$NetBSD: linux_futex.c,v 1.7 2006/07/24 19:01:49 manu Exp $"); 38#endif 39 40#include "opt_compat.h" 41#include "opt_kdtrace.h" 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/imgact.h> 46#include <sys/kernel.h> 47#include <sys/ktr.h> 48#include <sys/lock.h> 49#include <sys/malloc.h> 50#include <sys/mutex.h> 51#include <sys/priv.h> 52#include <sys/proc.h> 53#include <sys/queue.h> 54#include <sys/sched.h> 55#include <sys/sdt.h> 56#include <sys/sx.h> 57#include <sys/umtx.h> 58 59#ifdef COMPAT_LINUX32 60#include <machine/../linux32/linux.h> 61#include <machine/../linux32/linux32_proto.h> 62#else 63#include <machine/../linux/linux.h> 64#include <machine/../linux/linux_proto.h> 65#endif 66#include <compat/linux/linux_dtrace.h> 67#include <compat/linux/linux_emul.h> 68#include <compat/linux/linux_futex.h> 69#include <compat/linux/linux_timer.h> 70#include <compat/linux/linux_util.h> 71 72/* DTrace init */ 73LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE); 74 75/** 76 * Futex part for the special DTrace module "locks". 77 */ 78LIN_SDT_PROBE_DEFINE1(locks, futex_mtx, locked, "struct mtx *"); 79LIN_SDT_PROBE_DEFINE1(locks, futex_mtx, unlock, "struct mtx *"); 80 81/** 82 * Per futex probes. 83 */ 84LIN_SDT_PROBE_DEFINE1(futex, futex, create, "struct sx *"); 85LIN_SDT_PROBE_DEFINE1(futex, futex, destroy, "struct sx *"); 86 87/** 88 * DTrace probes in this module. 89 */ 90LIN_SDT_PROBE_DEFINE2(futex, futex_put, entry, "struct futex *", 91 "struct waiting_proc *"); 92LIN_SDT_PROBE_DEFINE3(futex, futex_put, destroy, "uint32_t *", "uint32_t", 93 "int"); 94LIN_SDT_PROBE_DEFINE3(futex, futex_put, unlock, "uint32_t *", "uint32_t", 95 "int"); 96LIN_SDT_PROBE_DEFINE0(futex, futex_put, return); 97LIN_SDT_PROBE_DEFINE3(futex, futex_get0, entry, "uint32_t *", "struct futex **", 98 "uint32_t"); 99LIN_SDT_PROBE_DEFINE1(futex, futex_get0, umtx_key_get_error, "int"); 100LIN_SDT_PROBE_DEFINE3(futex, futex_get0, shared, "uint32_t *", "uint32_t", 101 "int"); 102LIN_SDT_PROBE_DEFINE1(futex, futex_get0, null, "uint32_t *"); 103LIN_SDT_PROBE_DEFINE3(futex, futex_get0, new, "uint32_t *", "uint32_t", "int"); 104LIN_SDT_PROBE_DEFINE1(futex, futex_get0, return, "int"); 105LIN_SDT_PROBE_DEFINE3(futex, futex_get, entry, "uint32_t *", 106 "struct waiting_proc **", "struct futex **"); 107LIN_SDT_PROBE_DEFINE0(futex, futex_get, error); 108LIN_SDT_PROBE_DEFINE1(futex, futex_get, return, "int"); 109LIN_SDT_PROBE_DEFINE3(futex, futex_sleep, entry, "struct futex *", 110 "struct waiting_proc **", "int"); 111LIN_SDT_PROBE_DEFINE5(futex, futex_sleep, requeue_error, "int", "uint32_t *", 112 "struct waiting_proc *", "uint32_t *", "uint32_t"); 113LIN_SDT_PROBE_DEFINE3(futex, futex_sleep, sleep_error, "int", "uint32_t *", 114 "struct waiting_proc *"); 115LIN_SDT_PROBE_DEFINE1(futex, futex_sleep, return, "int"); 116LIN_SDT_PROBE_DEFINE3(futex, futex_wake, entry, "struct futex *", "int", 117 "uint32_t"); 118LIN_SDT_PROBE_DEFINE3(futex, futex_wake, iterate, "uint32_t", 119 "struct waiting_proc *", "uint32_t"); 120LIN_SDT_PROBE_DEFINE1(futex, futex_wake, wakeup, "struct waiting_proc *"); 121LIN_SDT_PROBE_DEFINE1(futex, futex_wake, return, "int"); 122LIN_SDT_PROBE_DEFINE4(futex, futex_requeue, entry, "struct futex *", "int", 123 "struct futex *", "int"); 124LIN_SDT_PROBE_DEFINE1(futex, futex_requeue, wakeup, "struct waiting_proc *"); 125LIN_SDT_PROBE_DEFINE3(futex, futex_requeue, requeue, "uint32_t *", 126 "struct waiting_proc *", "uint32_t"); 127LIN_SDT_PROBE_DEFINE1(futex, futex_requeue, return, "int"); 128LIN_SDT_PROBE_DEFINE4(futex, futex_wait, entry, "struct futex *", 129 "struct waiting_proc **", "int", "uint32_t"); 130LIN_SDT_PROBE_DEFINE1(futex, futex_wait, sleep_error, "int"); 131LIN_SDT_PROBE_DEFINE1(futex, futex_wait, return, "int"); 132LIN_SDT_PROBE_DEFINE3(futex, futex_atomic_op, entry, "struct thread *", 133 "int", "uint32_t"); 134LIN_SDT_PROBE_DEFINE4(futex, futex_atomic_op, decoded_op, "int", "int", "int", 135 "int"); 136LIN_SDT_PROBE_DEFINE0(futex, futex_atomic_op, missing_access_check); 137LIN_SDT_PROBE_DEFINE1(futex, futex_atomic_op, unimplemented_op, "int"); 138LIN_SDT_PROBE_DEFINE1(futex, futex_atomic_op, unimplemented_cmp, "int"); 139LIN_SDT_PROBE_DEFINE1(futex, futex_atomic_op, return, "int"); 140LIN_SDT_PROBE_DEFINE2(futex, linux_sys_futex, entry, "struct thread *", 141 "struct linux_sys_futex_args *"); 142LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_clockswitch); 143LIN_SDT_PROBE_DEFINE1(futex, linux_sys_futex, itimerfix_error, "int"); 144LIN_SDT_PROBE_DEFINE1(futex, linux_sys_futex, copyin_error, "int"); 145LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, invalid_cmp_requeue_use); 146LIN_SDT_PROBE_DEFINE3(futex, linux_sys_futex, debug_wait, "uint32_t *", 147 "uint32_t", "uint32_t"); 148LIN_SDT_PROBE_DEFINE4(futex, linux_sys_futex, debug_wait_value_neq, 149 "uint32_t *", "uint32_t", "int", "uint32_t"); 150LIN_SDT_PROBE_DEFINE3(futex, linux_sys_futex, debug_wake, "uint32_t *", 151 "uint32_t", "uint32_t"); 152LIN_SDT_PROBE_DEFINE5(futex, linux_sys_futex, debug_cmp_requeue, "uint32_t *", 153 "uint32_t", "uint32_t", "uint32_t *", "struct l_timespec *"); 154LIN_SDT_PROBE_DEFINE2(futex, linux_sys_futex, debug_cmp_requeue_value_neq, 155 "uint32_t", "int"); 156LIN_SDT_PROBE_DEFINE5(futex, linux_sys_futex, debug_wake_op, "uint32_t *", 157 "int", "uint32_t", "uint32_t *", "uint32_t"); 158LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unhandled_efault); 159LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_lock_pi); 160LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_unlock_pi); 161LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_trylock_pi); 162LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, deprecated_requeue); 163LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_wait_requeue_pi); 164LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_cmp_requeue_pi); 165LIN_SDT_PROBE_DEFINE1(futex, linux_sys_futex, unknown_operation, "int"); 166LIN_SDT_PROBE_DEFINE1(futex, linux_sys_futex, return, "int"); 167LIN_SDT_PROBE_DEFINE2(futex, linux_set_robust_list, entry, "struct thread *", 168 "struct linux_set_robust_list_args *"); 169LIN_SDT_PROBE_DEFINE0(futex, linux_set_robust_list, size_error); 170LIN_SDT_PROBE_DEFINE1(futex, linux_set_robust_list, return, "int"); 171LIN_SDT_PROBE_DEFINE2(futex, linux_get_robust_list, entry, "struct thread *", 172 "struct linux_get_robust_list_args *"); 173LIN_SDT_PROBE_DEFINE1(futex, linux_get_robust_list, copyout_error, "int"); 174LIN_SDT_PROBE_DEFINE1(futex, linux_get_robust_list, return, "int"); 175LIN_SDT_PROBE_DEFINE3(futex, handle_futex_death, entry, 176 "struct linux_emuldata *", "uint32_t *", "unsigned int"); 177LIN_SDT_PROBE_DEFINE1(futex, handle_futex_death, copyin_error, "int"); 178LIN_SDT_PROBE_DEFINE1(futex, handle_futex_death, return, "int"); 179LIN_SDT_PROBE_DEFINE3(futex, fetch_robust_entry, entry, 180 "struct linux_robust_list **", "struct linux_robust_list **", 181 "unsigned int *"); 182LIN_SDT_PROBE_DEFINE1(futex, fetch_robust_entry, copyin_error, "int"); 183LIN_SDT_PROBE_DEFINE1(futex, fetch_robust_entry, return, "int"); 184LIN_SDT_PROBE_DEFINE2(futex, release_futexes, entry, "struct thread *", 185 "struct linux_emuldata *"); 186LIN_SDT_PROBE_DEFINE1(futex, release_futexes, copyin_error, "int"); 187LIN_SDT_PROBE_DEFINE0(futex, release_futexes, return); 188 189struct futex; 190 191struct waiting_proc { 192 uint32_t wp_flags; 193 struct futex *wp_futex; 194 TAILQ_ENTRY(waiting_proc) wp_list; 195}; 196 197struct futex { 198 struct sx f_lck; 199 uint32_t *f_uaddr; /* user-supplied value, for debug */ 200 struct umtx_key f_key; 201 uint32_t f_refcount; 202 uint32_t f_bitset; 203 LIST_ENTRY(futex) f_list; 204 TAILQ_HEAD(lf_waiting_proc, waiting_proc) f_waiting_proc; 205}; 206 207struct futex_list futex_list; 208 209#define FUTEX_LOCK(f) sx_xlock(&(f)->f_lck) 210#define FUTEX_UNLOCK(f) sx_xunlock(&(f)->f_lck) 211#define FUTEX_INIT(f) do { \ 212 sx_init_flags(&(f)->f_lck, "ftlk", \ 213 SX_DUPOK); \ 214 LIN_SDT_PROBE1(futex, futex, create, \ 215 &(f)->f_lck); \ 216 } while (0) 217#define FUTEX_DESTROY(f) do { \ 218 LIN_SDT_PROBE1(futex, futex, destroy, \ 219 &(f)->f_lck); \ 220 sx_destroy(&(f)->f_lck); \ 221 } while (0) 222#define FUTEX_ASSERT_LOCKED(f) sx_assert(&(f)->f_lck, SA_XLOCKED) 223 224struct mtx futex_mtx; /* protects the futex list */ 225#define FUTEXES_LOCK do { \ 226 mtx_lock(&futex_mtx); \ 227 LIN_SDT_PROBE1(locks, futex_mtx, \ 228 locked, &futex_mtx); \ 229 } while (0) 230#define FUTEXES_UNLOCK do { \ 231 LIN_SDT_PROBE1(locks, futex_mtx, \ 232 unlock, &futex_mtx); \ 233 mtx_unlock(&futex_mtx); \ 234 } while (0) 235 236/* flags for futex_get() */ 237#define FUTEX_CREATE_WP 0x1 /* create waiting_proc */ 238#define FUTEX_DONTCREATE 0x2 /* don't create futex if not exists */ 239#define FUTEX_DONTEXISTS 0x4 /* return EINVAL if futex exists */ 240#define FUTEX_SHARED 0x8 /* shared futex */ 241 242/* wp_flags */ 243#define FUTEX_WP_REQUEUED 0x1 /* wp requeued - wp moved from wp_list 244 * of futex where thread sleep to wp_list 245 * of another futex. 246 */ 247#define FUTEX_WP_REMOVED 0x2 /* wp is woken up and removed from futex 248 * wp_list to prevent double wakeup. 249 */ 250 251static void futex_put(struct futex *, struct waiting_proc *); 252static int futex_get0(uint32_t *, struct futex **f, uint32_t); 253static int futex_get(uint32_t *, struct waiting_proc **, struct futex **, 254 uint32_t); 255static int futex_sleep(struct futex *, struct waiting_proc *, int); 256static int futex_wake(struct futex *, int, uint32_t); 257static int futex_requeue(struct futex *, int, struct futex *, int); 258static int futex_wait(struct futex *, struct waiting_proc *, int, 259 uint32_t); 260static int futex_atomic_op(struct thread *, int, uint32_t *); 261static int handle_futex_death(struct linux_emuldata *, uint32_t *, 262 unsigned int); 263static int fetch_robust_entry(struct linux_robust_list **, 264 struct linux_robust_list **, unsigned int *); 265 266/* support.s */ 267int futex_xchgl(int oparg, uint32_t *uaddr, int *oldval); 268int futex_addl(int oparg, uint32_t *uaddr, int *oldval); 269int futex_orl(int oparg, uint32_t *uaddr, int *oldval); 270int futex_andl(int oparg, uint32_t *uaddr, int *oldval); 271int futex_xorl(int oparg, uint32_t *uaddr, int *oldval); 272 273 274static void 275futex_put(struct futex *f, struct waiting_proc *wp) 276{ 277 LIN_SDT_PROBE2(futex, futex_put, entry, f, wp); 278 279 FUTEX_ASSERT_LOCKED(f); 280 if (wp != NULL) { 281 if ((wp->wp_flags & FUTEX_WP_REMOVED) == 0) 282 TAILQ_REMOVE(&f->f_waiting_proc, wp, wp_list); 283 free(wp, M_FUTEX_WP); 284 } 285 286 FUTEXES_LOCK; 287 if (--f->f_refcount == 0) { 288 LIST_REMOVE(f, f_list); 289 FUTEXES_UNLOCK; 290 FUTEX_UNLOCK(f); 291 292 LIN_SDT_PROBE3(futex, futex_put, destroy, f->f_uaddr, 293 f->f_refcount, f->f_key.shared); 294 LINUX_CTR3(sys_futex, "futex_put destroy uaddr %p ref %d " 295 "shared %d", f->f_uaddr, f->f_refcount, f->f_key.shared); 296 umtx_key_release(&f->f_key); 297 FUTEX_DESTROY(f); 298 free(f, M_FUTEX); 299 300 LIN_SDT_PROBE0(futex, futex_put, return); 301 return; 302 } 303 304 LIN_SDT_PROBE3(futex, futex_put, unlock, f->f_uaddr, f->f_refcount, 305 f->f_key.shared); 306 LINUX_CTR3(sys_futex, "futex_put uaddr %p ref %d shared %d", 307 f->f_uaddr, f->f_refcount, f->f_key.shared); 308 FUTEXES_UNLOCK; 309 FUTEX_UNLOCK(f); 310 311 LIN_SDT_PROBE0(futex, futex_put, return); 312} 313 314static int 315futex_get0(uint32_t *uaddr, struct futex **newf, uint32_t flags) 316{ 317 struct futex *f, *tmpf; 318 struct umtx_key key; 319 int error; 320 321 LIN_SDT_PROBE3(futex, futex_get0, entry, uaddr, newf, flags); 322 323 *newf = tmpf = NULL; 324 325 error = umtx_key_get(uaddr, TYPE_FUTEX, (flags & FUTEX_SHARED) ? 326 AUTO_SHARE : THREAD_SHARE, &key); 327 if (error) { 328 LIN_SDT_PROBE1(futex, futex_get0, umtx_key_get_error, error); 329 LIN_SDT_PROBE1(futex, futex_get0, return, error); 330 return (error); 331 } 332retry: 333 FUTEXES_LOCK; 334 LIST_FOREACH(f, &futex_list, f_list) { 335 if (umtx_key_match(&f->f_key, &key)) { 336 if (tmpf != NULL) { 337 FUTEX_UNLOCK(tmpf); 338 FUTEX_DESTROY(tmpf); 339 free(tmpf, M_FUTEX); 340 } 341 if (flags & FUTEX_DONTEXISTS) { 342 FUTEXES_UNLOCK; 343 umtx_key_release(&key); 344 345 LIN_SDT_PROBE1(futex, futex_get0, return, 346 EINVAL); 347 return (EINVAL); 348 } 349 350 /* 351 * Increment refcount of the found futex to 352 * prevent it from deallocation before FUTEX_LOCK() 353 */ 354 ++f->f_refcount; 355 FUTEXES_UNLOCK; 356 umtx_key_release(&key); 357 358 FUTEX_LOCK(f); 359 *newf = f; 360 LIN_SDT_PROBE3(futex, futex_get0, shared, uaddr, 361 f->f_refcount, f->f_key.shared); 362 LINUX_CTR3(sys_futex, "futex_get uaddr %p ref %d shared %d", 363 uaddr, f->f_refcount, f->f_key.shared); 364 365 LIN_SDT_PROBE1(futex, futex_get0, return, 0); 366 return (0); 367 } 368 } 369 370 if (flags & FUTEX_DONTCREATE) { 371 FUTEXES_UNLOCK; 372 umtx_key_release(&key); 373 LIN_SDT_PROBE1(futex, futex_get0, null, uaddr); 374 LINUX_CTR1(sys_futex, "futex_get uaddr %p null", uaddr); 375 376 LIN_SDT_PROBE1(futex, futex_get0, return, 0); 377 return (0); 378 } 379 380 if (tmpf == NULL) { 381 FUTEXES_UNLOCK; 382 tmpf = malloc(sizeof(*tmpf), M_FUTEX, M_WAITOK | M_ZERO); 383 tmpf->f_uaddr = uaddr; 384 tmpf->f_key = key; 385 tmpf->f_refcount = 1; 386 tmpf->f_bitset = FUTEX_BITSET_MATCH_ANY; 387 FUTEX_INIT(tmpf); 388 TAILQ_INIT(&tmpf->f_waiting_proc); 389 390 /* 391 * Lock the new futex before an insert into the futex_list 392 * to prevent futex usage by other. 393 */ 394 FUTEX_LOCK(tmpf); 395 goto retry; 396 } 397 398 LIST_INSERT_HEAD(&futex_list, tmpf, f_list); 399 FUTEXES_UNLOCK; 400 401 LIN_SDT_PROBE3(futex, futex_get0, new, uaddr, tmpf->f_refcount, 402 tmpf->f_key.shared); 403 LINUX_CTR3(sys_futex, "futex_get uaddr %p ref %d shared %d new", 404 uaddr, tmpf->f_refcount, tmpf->f_key.shared); 405 *newf = tmpf; 406 407 LIN_SDT_PROBE1(futex, futex_get0, return, 0); 408 return (0); 409} 410 411static int 412futex_get(uint32_t *uaddr, struct waiting_proc **wp, struct futex **f, 413 uint32_t flags) 414{ 415 int error; 416 417 LIN_SDT_PROBE3(futex, futex_get, entry, uaddr, wp, f); 418 419 if (flags & FUTEX_CREATE_WP) { 420 *wp = malloc(sizeof(struct waiting_proc), M_FUTEX_WP, M_WAITOK); 421 (*wp)->wp_flags = 0; 422 } 423 error = futex_get0(uaddr, f, flags); 424 if (error) { 425 LIN_SDT_PROBE0(futex, futex_get, error); 426 427 if (flags & FUTEX_CREATE_WP) 428 free(*wp, M_FUTEX_WP); 429 430 LIN_SDT_PROBE1(futex, futex_get, return, error); 431 return (error); 432 } 433 if (flags & FUTEX_CREATE_WP) { 434 TAILQ_INSERT_HEAD(&(*f)->f_waiting_proc, *wp, wp_list); 435 (*wp)->wp_futex = *f; 436 } 437 438 LIN_SDT_PROBE1(futex, futex_get, return, error); 439 return (error); 440} 441 442static int 443futex_sleep(struct futex *f, struct waiting_proc *wp, int timeout) 444{ 445 int error; 446 447 FUTEX_ASSERT_LOCKED(f); 448 LIN_SDT_PROBE3(futex, futex_sleep, entry, f, wp, timeout); 449 LINUX_CTR4(sys_futex, "futex_sleep enter uaddr %p wp %p timo %d ref %d", 450 f->f_uaddr, wp, timeout, f->f_refcount); 451 error = sx_sleep(wp, &f->f_lck, PCATCH, "futex", timeout); 452 if (wp->wp_flags & FUTEX_WP_REQUEUED) { 453 KASSERT(f != wp->wp_futex, ("futex != wp_futex")); 454 455 if (error) { 456 LIN_SDT_PROBE5(futex, futex_sleep, requeue_error, error, 457 f->f_uaddr, wp, wp->wp_futex->f_uaddr, 458 wp->wp_futex->f_refcount); 459 } 460 461 LINUX_CTR5(sys_futex, "futex_sleep out error %d uaddr %p wp" 462 " %p requeued uaddr %p ref %d", 463 error, f->f_uaddr, wp, wp->wp_futex->f_uaddr, 464 wp->wp_futex->f_refcount); 465 futex_put(f, NULL); 466 f = wp->wp_futex; 467 FUTEX_LOCK(f); 468 } else { 469 if (error) { 470 LIN_SDT_PROBE3(futex, futex_sleep, sleep_error, error, 471 f->f_uaddr, wp); 472 } 473 LINUX_CTR3(sys_futex, "futex_sleep out error %d uaddr %p wp %p", 474 error, f->f_uaddr, wp); 475 } 476 477 futex_put(f, wp); 478 479 LIN_SDT_PROBE1(futex, futex_sleep, return, error); 480 return (error); 481} 482 483static int 484futex_wake(struct futex *f, int n, uint32_t bitset) 485{ 486 struct waiting_proc *wp, *wpt; 487 int count = 0; 488 489 LIN_SDT_PROBE3(futex, futex_wake, entry, f, n, bitset); 490 491 if (bitset == 0) { 492 LIN_SDT_PROBE1(futex, futex_wake, return, EINVAL); 493 return (EINVAL); 494 } 495 496 FUTEX_ASSERT_LOCKED(f); 497 TAILQ_FOREACH_SAFE(wp, &f->f_waiting_proc, wp_list, wpt) { 498 LIN_SDT_PROBE3(futex, futex_wake, iterate, f->f_uaddr, wp, 499 f->f_refcount); 500 LINUX_CTR3(sys_futex, "futex_wake uaddr %p wp %p ref %d", 501 f->f_uaddr, wp, f->f_refcount); 502 /* 503 * Unless we find a matching bit in 504 * the bitset, continue searching. 505 */ 506 if (!(wp->wp_futex->f_bitset & bitset)) 507 continue; 508 509 wp->wp_flags |= FUTEX_WP_REMOVED; 510 TAILQ_REMOVE(&f->f_waiting_proc, wp, wp_list); 511 LIN_SDT_PROBE1(futex, futex_wake, wakeup, wp); 512 wakeup_one(wp); 513 if (++count == n) 514 break; 515 } 516 517 LIN_SDT_PROBE1(futex, futex_wake, return, count); 518 return (count); 519} 520 521static int 522futex_requeue(struct futex *f, int n, struct futex *f2, int n2) 523{ 524 struct waiting_proc *wp, *wpt; 525 int count = 0; 526 527 LIN_SDT_PROBE4(futex, futex_requeue, entry, f, n, f2, n2); 528 529 FUTEX_ASSERT_LOCKED(f); 530 FUTEX_ASSERT_LOCKED(f2); 531 532 TAILQ_FOREACH_SAFE(wp, &f->f_waiting_proc, wp_list, wpt) { 533 if (++count <= n) { 534 LINUX_CTR2(sys_futex, "futex_req_wake uaddr %p wp %p", 535 f->f_uaddr, wp); 536 wp->wp_flags |= FUTEX_WP_REMOVED; 537 TAILQ_REMOVE(&f->f_waiting_proc, wp, wp_list); 538 LIN_SDT_PROBE1(futex, futex_requeue, wakeup, wp); 539 wakeup_one(wp); 540 } else { 541 LIN_SDT_PROBE3(futex, futex_requeue, requeue, 542 f->f_uaddr, wp, f2->f_uaddr); 543 LINUX_CTR3(sys_futex, "futex_requeue uaddr %p wp %p to %p", 544 f->f_uaddr, wp, f2->f_uaddr); 545 wp->wp_flags |= FUTEX_WP_REQUEUED; 546 /* Move wp to wp_list of f2 futex */ 547 TAILQ_REMOVE(&f->f_waiting_proc, wp, wp_list); 548 TAILQ_INSERT_HEAD(&f2->f_waiting_proc, wp, wp_list); 549 550 /* 551 * Thread which sleeps on wp after waking should 552 * acquire f2 lock, so increment refcount of f2 to 553 * prevent it from premature deallocation. 554 */ 555 wp->wp_futex = f2; 556 FUTEXES_LOCK; 557 ++f2->f_refcount; 558 FUTEXES_UNLOCK; 559 if (count - n >= n2) 560 break; 561 } 562 } 563 564 LIN_SDT_PROBE1(futex, futex_requeue, return, count); 565 return (count); 566} 567 568static int 569futex_wait(struct futex *f, struct waiting_proc *wp, int timeout_hz, 570 uint32_t bitset) 571{ 572 int error; 573 574 LIN_SDT_PROBE4(futex, futex_wait, entry, f, wp, timeout_hz, bitset); 575 576 if (bitset == 0) { 577 LIN_SDT_PROBE1(futex, futex_wait, return, EINVAL); 578 return (EINVAL); 579 } 580 581 f->f_bitset = bitset; 582 error = futex_sleep(f, wp, timeout_hz); 583 if (error) 584 LIN_SDT_PROBE1(futex, futex_wait, sleep_error, error); 585 if (error == EWOULDBLOCK) 586 error = ETIMEDOUT; 587 588 LIN_SDT_PROBE1(futex, futex_wait, return, error); 589 return (error); 590} 591 592static int 593futex_atomic_op(struct thread *td, int encoded_op, uint32_t *uaddr) 594{ 595 int op = (encoded_op >> 28) & 7; 596 int cmp = (encoded_op >> 24) & 15; 597 int oparg = (encoded_op << 8) >> 20; 598 int cmparg = (encoded_op << 20) >> 20; 599 int oldval = 0, ret; 600 601 LIN_SDT_PROBE3(futex, futex_atomic_op, entry, td, encoded_op, uaddr); 602 603 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) 604 oparg = 1 << oparg; 605 606 LIN_SDT_PROBE4(futex, futex_atomic_op, decoded_op, op, cmp, oparg, 607 cmparg); 608 609 /* XXX: Linux verifies access here and returns EFAULT */ 610 LIN_SDT_PROBE0(futex, futex_atomic_op, missing_access_check); 611 612 switch (op) { 613 case FUTEX_OP_SET: 614 ret = futex_xchgl(oparg, uaddr, &oldval); 615 break; 616 case FUTEX_OP_ADD: 617 ret = futex_addl(oparg, uaddr, &oldval); 618 break; 619 case FUTEX_OP_OR: 620 ret = futex_orl(oparg, uaddr, &oldval); 621 break; 622 case FUTEX_OP_ANDN: 623 ret = futex_andl(~oparg, uaddr, &oldval); 624 break; 625 case FUTEX_OP_XOR: 626 ret = futex_xorl(oparg, uaddr, &oldval); 627 break; 628 default: 629 LIN_SDT_PROBE1(futex, futex_atomic_op, unimplemented_op, op); 630 ret = -ENOSYS; 631 break; 632 } 633 634 if (ret) { 635 LIN_SDT_PROBE1(futex, futex_atomic_op, return, ret); 636 return (ret); 637 } 638 639 switch (cmp) { 640 case FUTEX_OP_CMP_EQ: 641 ret = (oldval == cmparg); 642 break; 643 case FUTEX_OP_CMP_NE: 644 ret = (oldval != cmparg); 645 break; 646 case FUTEX_OP_CMP_LT: 647 ret = (oldval < cmparg); 648 break; 649 case FUTEX_OP_CMP_GE: 650 ret = (oldval >= cmparg); 651 break; 652 case FUTEX_OP_CMP_LE: 653 ret = (oldval <= cmparg); 654 break; 655 case FUTEX_OP_CMP_GT: 656 ret = (oldval > cmparg); 657 break; 658 default: 659 LIN_SDT_PROBE1(futex, futex_atomic_op, unimplemented_cmp, cmp); 660 ret = -ENOSYS; 661 } 662 663 LIN_SDT_PROBE1(futex, futex_atomic_op, return, ret); 664 return (ret); 665} 666 667int 668linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args) 669{ 670 int clockrt, nrwake, op_ret, ret; 671 struct linux_pemuldata *pem; 672 struct waiting_proc *wp; 673 struct futex *f, *f2; 674 struct l_timespec ltimeout; 675 struct timespec timeout; 676 struct timeval utv, ctv; 677 int timeout_hz; 678 int error; 679 uint32_t flags, val; 680 681 LIN_SDT_PROBE2(futex, linux_sys_futex, entry, td, args); 682 683 if (args->op & LINUX_FUTEX_PRIVATE_FLAG) { 684 flags = 0; 685 args->op &= ~LINUX_FUTEX_PRIVATE_FLAG; 686 } else 687 flags = FUTEX_SHARED; 688 689 /* 690 * Currently support for switching between CLOCK_MONOTONIC and 691 * CLOCK_REALTIME is not present. However Linux forbids the use of 692 * FUTEX_CLOCK_REALTIME with any op except FUTEX_WAIT_BITSET and 693 * FUTEX_WAIT_REQUEUE_PI. 694 */ 695 clockrt = args->op & LINUX_FUTEX_CLOCK_REALTIME; 696 args->op = args->op & ~LINUX_FUTEX_CLOCK_REALTIME; 697 if (clockrt && args->op != LINUX_FUTEX_WAIT_BITSET && 698 args->op != LINUX_FUTEX_WAIT_REQUEUE_PI) { 699 LIN_SDT_PROBE0(futex, linux_sys_futex, 700 unimplemented_clockswitch); 701 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS); 702 return (ENOSYS); 703 } 704 705 error = 0; 706 f = f2 = NULL; 707 708 switch (args->op) { 709 case LINUX_FUTEX_WAIT: 710 args->val3 = FUTEX_BITSET_MATCH_ANY; 711 /* FALLTHROUGH */ 712 713 case LINUX_FUTEX_WAIT_BITSET: 714 LIN_SDT_PROBE3(futex, linux_sys_futex, debug_wait, args->uaddr, 715 args->val, args->val3); 716 LINUX_CTR3(sys_futex, "WAIT uaddr %p val 0x%x bitset 0x%x", 717 args->uaddr, args->val, args->val3); 718 719 if (args->timeout != NULL) { 720 error = copyin(args->timeout, <imeout, sizeof(ltimeout)); 721 if (error) { 722 LIN_SDT_PROBE1(futex, linux_sys_futex, copyin_error, 723 error); 724 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 725 return (error); 726 } 727 error = linux_to_native_timespec(&timeout, <imeout); 728 if (error) 729 return (error); 730 TIMESPEC_TO_TIMEVAL(&utv, &timeout); 731 error = itimerfix(&utv); 732 if (error) { 733 LIN_SDT_PROBE1(futex, linux_sys_futex, itimerfix_error, 734 error); 735 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 736 return (error); 737 } 738 if (clockrt) { 739 microtime(&ctv); 740 timevalsub(&utv, &ctv); 741 } else if (args->op == LINUX_FUTEX_WAIT_BITSET) { 742 microuptime(&ctv); 743 timevalsub(&utv, &ctv); 744 } 745 if (utv.tv_sec < 0) 746 timevalclear(&utv); 747 timeout_hz = tvtohz(&utv); 748 } else 749 timeout_hz = 0; 750 751 error = futex_get(args->uaddr, &wp, &f, 752 flags | FUTEX_CREATE_WP); 753 if (error) { 754 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 755 return (error); 756 } 757 758 error = copyin(args->uaddr, &val, sizeof(val)); 759 if (error) { 760 LIN_SDT_PROBE1(futex, linux_sys_futex, copyin_error, 761 error); 762 LINUX_CTR1(sys_futex, "WAIT copyin failed %d", 763 error); 764 futex_put(f, wp); 765 766 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 767 return (error); 768 } 769 if (val != args->val) { 770 LIN_SDT_PROBE4(futex, linux_sys_futex, 771 debug_wait_value_neq, args->uaddr, args->val, val, 772 args->val3); 773 LINUX_CTR3(sys_futex, 774 "WAIT uaddr %p val 0x%x != uval 0x%x", 775 args->uaddr, args->val, val); 776 futex_put(f, wp); 777 778 LIN_SDT_PROBE1(futex, linux_sys_futex, return, 779 EWOULDBLOCK); 780 return (EWOULDBLOCK); 781 } 782 783 error = futex_wait(f, wp, timeout_hz, args->val3); 784 break; 785 786 case LINUX_FUTEX_WAKE: 787 args->val3 = FUTEX_BITSET_MATCH_ANY; 788 /* FALLTHROUGH */ 789 790 case LINUX_FUTEX_WAKE_BITSET: 791 LIN_SDT_PROBE3(futex, linux_sys_futex, debug_wake, args->uaddr, 792 args->val, args->val3); 793 LINUX_CTR3(sys_futex, "WAKE uaddr %p nrwake 0x%x bitset 0x%x", 794 args->uaddr, args->val, args->val3); 795 796 error = futex_get(args->uaddr, NULL, &f, 797 flags | FUTEX_DONTCREATE); 798 if (error) { 799 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 800 return (error); 801 } 802 803 if (f == NULL) { 804 td->td_retval[0] = 0; 805 806 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 807 return (error); 808 } 809 td->td_retval[0] = futex_wake(f, args->val, args->val3); 810 futex_put(f, NULL); 811 break; 812 813 case LINUX_FUTEX_CMP_REQUEUE: 814 LIN_SDT_PROBE5(futex, linux_sys_futex, debug_cmp_requeue, 815 args->uaddr, args->val, args->val3, args->uaddr2, 816 args->timeout); 817 LINUX_CTR5(sys_futex, "CMP_REQUEUE uaddr %p " 818 "nrwake 0x%x uval 0x%x uaddr2 %p nrequeue 0x%x", 819 args->uaddr, args->val, args->val3, args->uaddr2, 820 args->timeout); 821 822 /* 823 * Linux allows this, we would not, it is an incorrect 824 * usage of declared ABI, so return EINVAL. 825 */ 826 if (args->uaddr == args->uaddr2) { 827 LIN_SDT_PROBE0(futex, linux_sys_futex, 828 invalid_cmp_requeue_use); 829 LIN_SDT_PROBE1(futex, linux_sys_futex, return, EINVAL); 830 return (EINVAL); 831 } 832 833 error = futex_get(args->uaddr, NULL, &f, flags); 834 if (error) { 835 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 836 return (error); 837 } 838 839 /* 840 * To avoid deadlocks return EINVAL if second futex 841 * exists at this time. 842 * 843 * Glibc fall back to FUTEX_WAKE in case of any error 844 * returned by FUTEX_CMP_REQUEUE. 845 */ 846 error = futex_get(args->uaddr2, NULL, &f2, 847 flags | FUTEX_DONTEXISTS); 848 if (error) { 849 futex_put(f, NULL); 850 851 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 852 return (error); 853 } 854 error = copyin(args->uaddr, &val, sizeof(val)); 855 if (error) { 856 LIN_SDT_PROBE1(futex, linux_sys_futex, copyin_error, 857 error); 858 LINUX_CTR1(sys_futex, "CMP_REQUEUE copyin failed %d", 859 error); 860 futex_put(f2, NULL); 861 futex_put(f, NULL); 862 863 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 864 return (error); 865 } 866 if (val != args->val3) { 867 LIN_SDT_PROBE2(futex, linux_sys_futex, 868 debug_cmp_requeue_value_neq, args->val, val); 869 LINUX_CTR2(sys_futex, "CMP_REQUEUE val 0x%x != uval 0x%x", 870 args->val, val); 871 futex_put(f2, NULL); 872 futex_put(f, NULL); 873 874 LIN_SDT_PROBE1(futex, linux_sys_futex, return, EAGAIN); 875 return (EAGAIN); 876 } 877 878 nrwake = (int)(unsigned long)args->timeout; 879 td->td_retval[0] = futex_requeue(f, args->val, f2, nrwake); 880 futex_put(f2, NULL); 881 futex_put(f, NULL); 882 break; 883 884 case LINUX_FUTEX_WAKE_OP: 885 LIN_SDT_PROBE5(futex, linux_sys_futex, debug_wake_op, 886 args->uaddr, args->op, args->val, args->uaddr2, args->val3); 887 LINUX_CTR5(sys_futex, "WAKE_OP " 888 "uaddr %p nrwake 0x%x uaddr2 %p op 0x%x nrwake2 0x%x", 889 args->uaddr, args->val, args->uaddr2, args->val3, 890 args->timeout); 891 892 error = futex_get(args->uaddr, NULL, &f, flags); 893 if (error) { 894 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 895 return (error); 896 } 897 898 if (args->uaddr != args->uaddr2) 899 error = futex_get(args->uaddr2, NULL, &f2, flags); 900 if (error) { 901 futex_put(f, NULL); 902 903 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 904 return (error); 905 } 906 907 /* 908 * This function returns positive number as results and 909 * negative as errors 910 */ 911 op_ret = futex_atomic_op(td, args->val3, args->uaddr2); 912 913 LINUX_CTR2(sys_futex, "WAKE_OP atomic_op uaddr %p ret 0x%x", 914 args->uaddr, op_ret); 915 916 if (op_ret < 0) { 917 /* XXX: We don't handle the EFAULT yet. */ 918 if (op_ret != -EFAULT) { 919 if (f2 != NULL) 920 futex_put(f2, NULL); 921 futex_put(f, NULL); 922 923 LIN_SDT_PROBE1(futex, linux_sys_futex, return, 924 -op_ret); 925 return (-op_ret); 926 } else { 927 LIN_SDT_PROBE0(futex, linux_sys_futex, 928 unhandled_efault); 929 } 930 if (f2 != NULL) 931 futex_put(f2, NULL); 932 futex_put(f, NULL); 933 934 LIN_SDT_PROBE1(futex, linux_sys_futex, return, EFAULT); 935 return (EFAULT); 936 } 937 938 ret = futex_wake(f, args->val, args->val3); 939 940 if (op_ret > 0) { 941 op_ret = 0; 942 nrwake = (int)(unsigned long)args->timeout; 943 944 if (f2 != NULL) 945 op_ret += futex_wake(f2, nrwake, args->val3); 946 else 947 op_ret += futex_wake(f, nrwake, args->val3); 948 ret += op_ret; 949 950 } 951 if (f2 != NULL) 952 futex_put(f2, NULL); 953 futex_put(f, NULL); 954 td->td_retval[0] = ret; 955 break; 956 957 case LINUX_FUTEX_LOCK_PI: 958 /* not yet implemented */ 959 pem = pem_find(td->td_proc); 960 if ((pem->flags & LINUX_XUNSUP_FUTEXPIOP) == 0) { 961 linux_msg(td, 962 "linux_sys_futex: " 963 "unsupported futex_pi op\n"); 964 pem->flags |= LINUX_XUNSUP_FUTEXPIOP; 965 LIN_SDT_PROBE0(futex, linux_sys_futex, 966 unimplemented_lock_pi); 967 } 968 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS); 969 return (ENOSYS); 970 971 case LINUX_FUTEX_UNLOCK_PI: 972 /* not yet implemented */ 973 pem = pem_find(td->td_proc); 974 if ((pem->flags & LINUX_XUNSUP_FUTEXPIOP) == 0) { 975 linux_msg(td, 976 "linux_sys_futex: " 977 "unsupported futex_pi op\n"); 978 pem->flags |= LINUX_XUNSUP_FUTEXPIOP; 979 LIN_SDT_PROBE0(futex, linux_sys_futex, 980 unimplemented_unlock_pi); 981 } 982 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS); 983 return (ENOSYS); 984 985 case LINUX_FUTEX_TRYLOCK_PI: 986 /* not yet implemented */ 987 pem = pem_find(td->td_proc); 988 if ((pem->flags & LINUX_XUNSUP_FUTEXPIOP) == 0) { 989 linux_msg(td, 990 "linux_sys_futex: " 991 "unsupported futex_pi op\n"); 992 pem->flags |= LINUX_XUNSUP_FUTEXPIOP; 993 LIN_SDT_PROBE0(futex, linux_sys_futex, 994 unimplemented_trylock_pi); 995 } 996 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS); 997 return (ENOSYS); 998 999 case LINUX_FUTEX_REQUEUE: 1000 1001 /* 1002 * Glibc does not use this operation since version 2.3.3, 1003 * as it is racy and replaced by FUTEX_CMP_REQUEUE operation. 1004 * Glibc versions prior to 2.3.3 fall back to FUTEX_WAKE when 1005 * FUTEX_REQUEUE returned EINVAL. 1006 */ 1007 pem = pem_find(td->td_proc); 1008 if ((pem->flags & LINUX_XDEPR_REQUEUEOP) == 0) { 1009 linux_msg(td, 1010 "linux_sys_futex: " 1011 "unsupported futex_requeue op\n"); 1012 pem->flags |= LINUX_XDEPR_REQUEUEOP; 1013 LIN_SDT_PROBE0(futex, linux_sys_futex, 1014 deprecated_requeue); 1015 } 1016 1017 LIN_SDT_PROBE1(futex, linux_sys_futex, return, EINVAL); 1018 return (EINVAL); 1019 1020 case LINUX_FUTEX_WAIT_REQUEUE_PI: 1021 /* not yet implemented */ 1022 pem = pem_find(td->td_proc); 1023 if ((pem->flags & LINUX_XUNSUP_FUTEXPIOP) == 0) { 1024 linux_msg(td, 1025 "linux_sys_futex: " 1026 "unsupported futex_pi op\n"); 1027 pem->flags |= LINUX_XUNSUP_FUTEXPIOP; 1028 LIN_SDT_PROBE0(futex, linux_sys_futex, 1029 unimplemented_wait_requeue_pi); 1030 } 1031 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS); 1032 return (ENOSYS); 1033 1034 case LINUX_FUTEX_CMP_REQUEUE_PI: 1035 /* not yet implemented */ 1036 pem = pem_find(td->td_proc); 1037 if ((pem->flags & LINUX_XUNSUP_FUTEXPIOP) == 0) { 1038 linux_msg(td, 1039 "linux_sys_futex: " 1040 "unsupported futex_pi op\n"); 1041 pem->flags |= LINUX_XUNSUP_FUTEXPIOP; 1042 LIN_SDT_PROBE0(futex, linux_sys_futex, 1043 unimplemented_cmp_requeue_pi); 1044 } 1045 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS); 1046 return (ENOSYS); 1047 1048 default: 1049 linux_msg(td, 1050 "linux_sys_futex: unknown op %d\n", args->op); 1051 LIN_SDT_PROBE1(futex, linux_sys_futex, unknown_operation, 1052 args->op); 1053 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS); 1054 return (ENOSYS); 1055 } 1056 1057 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error); 1058 return (error); 1059} 1060 1061int 1062linux_set_robust_list(struct thread *td, struct linux_set_robust_list_args *args) 1063{ 1064 struct linux_emuldata *em; 1065 1066 LIN_SDT_PROBE2(futex, linux_set_robust_list, entry, td, args); 1067 1068 if (args->len != sizeof(struct linux_robust_list_head)) { 1069 LIN_SDT_PROBE0(futex, linux_set_robust_list, size_error); 1070 LIN_SDT_PROBE1(futex, linux_set_robust_list, return, EINVAL); 1071 return (EINVAL); 1072 } 1073 1074 em = em_find(td); 1075 em->robust_futexes = args->head; 1076 1077 LIN_SDT_PROBE1(futex, linux_set_robust_list, return, 0); 1078 return (0); 1079} 1080 1081int 1082linux_get_robust_list(struct thread *td, struct linux_get_robust_list_args *args) 1083{ 1084 struct linux_emuldata *em; 1085 struct linux_robust_list_head *head; 1086 l_size_t len = sizeof(struct linux_robust_list_head); 1087 struct thread *td2; 1088 int error = 0; 1089 1090 LIN_SDT_PROBE2(futex, linux_get_robust_list, entry, td, args); 1091 1092 if (!args->pid) { 1093 em = em_find(td); 1094 KASSERT(em != NULL, ("get_robust_list: emuldata notfound.\n")); 1095 head = em->robust_futexes; 1096 } else { 1097 td2 = tdfind(args->pid, -1); 1098 if (td2 == NULL) { 1099 LIN_SDT_PROBE1(futex, linux_get_robust_list, return, 1100 ESRCH); 1101 return (ESRCH); 1102 } 1103 if (SV_PROC_ABI(td2->td_proc) != SV_ABI_LINUX) { 1104 LIN_SDT_PROBE1(futex, linux_get_robust_list, return, 1105 EPERM); 1106 PROC_UNLOCK(td2->td_proc); 1107 return (EPERM); 1108 } 1109 1110 em = em_find(td2); 1111 KASSERT(em != NULL, ("get_robust_list: emuldata notfound.\n")); 1112 /* XXX: ptrace? */ 1113 if (priv_check(td, PRIV_CRED_SETUID) || 1114 priv_check(td, PRIV_CRED_SETEUID) || 1115 p_candebug(td, td2->td_proc)) { 1116 PROC_UNLOCK(td2->td_proc); 1117 1118 LIN_SDT_PROBE1(futex, linux_get_robust_list, return, 1119 EPERM); 1120 return (EPERM); 1121 } 1122 head = em->robust_futexes; 1123 1124 PROC_UNLOCK(td2->td_proc); 1125 } 1126 1127 error = copyout(&len, args->len, sizeof(l_size_t)); 1128 if (error) { 1129 LIN_SDT_PROBE1(futex, linux_get_robust_list, copyout_error, 1130 error); 1131 LIN_SDT_PROBE1(futex, linux_get_robust_list, return, EFAULT); 1132 return (EFAULT); 1133 } 1134 1135 error = copyout(head, args->head, sizeof(struct linux_robust_list_head)); 1136 if (error) { 1137 LIN_SDT_PROBE1(futex, linux_get_robust_list, copyout_error, 1138 error); 1139 } 1140 1141 LIN_SDT_PROBE1(futex, linux_get_robust_list, return, error); 1142 return (error); 1143} 1144 1145static int 1146handle_futex_death(struct linux_emuldata *em, uint32_t *uaddr, 1147 unsigned int pi) 1148{ 1149 uint32_t uval, nval, mval; 1150 struct futex *f; 1151 int error; 1152 1153 LIN_SDT_PROBE3(futex, handle_futex_death, entry, em, uaddr, pi); 1154 1155retry: 1156 error = copyin(uaddr, &uval, 4); 1157 if (error) { 1158 LIN_SDT_PROBE1(futex, handle_futex_death, copyin_error, error); 1159 LIN_SDT_PROBE1(futex, handle_futex_death, return, EFAULT); 1160 return (EFAULT); 1161 } 1162 if ((uval & FUTEX_TID_MASK) == em->em_tid) { 1163 mval = (uval & FUTEX_WAITERS) | FUTEX_OWNER_DIED; 1164 nval = casuword32(uaddr, uval, mval); 1165 1166 if (nval == -1) { 1167 LIN_SDT_PROBE1(futex, handle_futex_death, return, 1168 EFAULT); 1169 return (EFAULT); 1170 } 1171 1172 if (nval != uval) 1173 goto retry; 1174 1175 if (!pi && (uval & FUTEX_WAITERS)) { 1176 error = futex_get(uaddr, NULL, &f, 1177 FUTEX_DONTCREATE | FUTEX_SHARED); 1178 if (error) { 1179 LIN_SDT_PROBE1(futex, handle_futex_death, 1180 return, error); 1181 return (error); 1182 } 1183 if (f != NULL) { 1184 futex_wake(f, 1, FUTEX_BITSET_MATCH_ANY); 1185 futex_put(f, NULL); 1186 } 1187 } 1188 } 1189 1190 LIN_SDT_PROBE1(futex, handle_futex_death, return, 0); 1191 return (0); 1192} 1193 1194static int 1195fetch_robust_entry(struct linux_robust_list **entry, 1196 struct linux_robust_list **head, unsigned int *pi) 1197{ 1198 l_ulong uentry; 1199 int error; 1200 1201 LIN_SDT_PROBE3(futex, fetch_robust_entry, entry, entry, head, pi); 1202 1203 error = copyin((const void *)head, &uentry, sizeof(l_ulong)); 1204 if (error) { 1205 LIN_SDT_PROBE1(futex, fetch_robust_entry, copyin_error, error); 1206 LIN_SDT_PROBE1(futex, fetch_robust_entry, return, EFAULT); 1207 return (EFAULT); 1208 } 1209 1210 *entry = (void *)(uentry & ~1UL); 1211 *pi = uentry & 1; 1212 1213 LIN_SDT_PROBE1(futex, fetch_robust_entry, return, 0); 1214 return (0); 1215} 1216 1217/* This walks the list of robust futexes releasing them. */ 1218void 1219release_futexes(struct thread *td, struct linux_emuldata *em) 1220{ 1221 struct linux_robust_list_head *head = NULL; 1222 struct linux_robust_list *entry, *next_entry, *pending; 1223 unsigned int limit = 2048, pi, next_pi, pip; 1224 l_long futex_offset; 1225 int rc, error; 1226 1227 LIN_SDT_PROBE2(futex, release_futexes, entry, td, em); 1228 1229 head = em->robust_futexes; 1230 1231 if (head == NULL) { 1232 LIN_SDT_PROBE0(futex, release_futexes, return); 1233 return; 1234 } 1235 1236 if (fetch_robust_entry(&entry, PTRIN(&head->list.next), &pi)) { 1237 LIN_SDT_PROBE0(futex, release_futexes, return); 1238 return; 1239 } 1240 1241 error = copyin(&head->futex_offset, &futex_offset, 1242 sizeof(futex_offset)); 1243 if (error) { 1244 LIN_SDT_PROBE1(futex, release_futexes, copyin_error, error); 1245 LIN_SDT_PROBE0(futex, release_futexes, return); 1246 return; 1247 } 1248 1249 if (fetch_robust_entry(&pending, PTRIN(&head->pending_list), &pip)) { 1250 LIN_SDT_PROBE0(futex, release_futexes, return); 1251 return; 1252 } 1253 1254 while (entry != &head->list) { 1255 rc = fetch_robust_entry(&next_entry, PTRIN(&entry->next), &next_pi); 1256 1257 if (entry != pending) 1258 if (handle_futex_death(em, 1259 (uint32_t *)((caddr_t)entry + futex_offset), pi)) { 1260 LIN_SDT_PROBE0(futex, release_futexes, return); 1261 return; 1262 } 1263 if (rc) { 1264 LIN_SDT_PROBE0(futex, release_futexes, return); 1265 return; 1266 } 1267 1268 entry = next_entry; 1269 pi = next_pi; 1270 1271 if (!--limit) 1272 break; 1273 1274 sched_relinquish(curthread); 1275 } 1276 1277 if (pending) 1278 handle_futex_death(em, (uint32_t *)((caddr_t)pending + futex_offset), pip); 1279 1280 LIN_SDT_PROBE0(futex, release_futexes, return); 1281} 1282