1 /* $NetBSD: linux_futex.c,v 1.7 2006/07/24 19:01:49 manu Exp $ */
4 * Copyright (c) 2005 Emmanuel Dreyfus, all rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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
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.
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
37 __KERNEL_RCSID(1, "$NetBSD: linux_futex.c,v 1.7 2006/07/24 19:01:49 manu Exp $");
40 #include "opt_compat.h"
41 #include "opt_kdtrace.h"
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/imgact.h>
46 #include <sys/kernel.h>
49 #include <sys/malloc.h>
50 #include <sys/mutex.h>
53 #include <sys/queue.h>
54 #include <sys/sched.h>
60 #include <machine/../linux32/linux.h>
61 #include <machine/../linux32/linux32_proto.h>
63 #include <machine/../linux/linux.h>
64 #include <machine/../linux/linux_proto.h>
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_util.h>
72 LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
75 * Futex part for the special DTrace module "locks".
77 LIN_SDT_PROBE_DEFINE1(locks, futex_mtx, locked, "struct mtx *");
78 LIN_SDT_PROBE_DEFINE1(locks, futex_mtx, unlock, "struct mtx *");
83 LIN_SDT_PROBE_DEFINE1(futex, futex, create, "struct sx *");
84 LIN_SDT_PROBE_DEFINE1(futex, futex, destroy, "struct sx *");
87 * DTrace probes in this module.
89 LIN_SDT_PROBE_DEFINE2(futex, futex_put, entry, "struct futex *",
90 "struct waiting_proc *");
91 LIN_SDT_PROBE_DEFINE3(futex, futex_put, destroy, "uint32_t *", "uint32_t",
93 LIN_SDT_PROBE_DEFINE3(futex, futex_put, unlock, "uint32_t *", "uint32_t",
95 LIN_SDT_PROBE_DEFINE0(futex, futex_put, return);
96 LIN_SDT_PROBE_DEFINE3(futex, futex_get0, entry, "uint32_t *", "struct futex **",
98 LIN_SDT_PROBE_DEFINE1(futex, futex_get0, umtx_key_get_error, "int");
99 LIN_SDT_PROBE_DEFINE3(futex, futex_get0, shared, "uint32_t *", "uint32_t",
101 LIN_SDT_PROBE_DEFINE1(futex, futex_get0, null, "uint32_t *");
102 LIN_SDT_PROBE_DEFINE3(futex, futex_get0, new, "uint32_t *", "uint32_t", "int");
103 LIN_SDT_PROBE_DEFINE1(futex, futex_get0, return, "int");
104 LIN_SDT_PROBE_DEFINE3(futex, futex_get, entry, "uint32_t *",
105 "struct waiting_proc **", "struct futex **");
106 LIN_SDT_PROBE_DEFINE0(futex, futex_get, error);
107 LIN_SDT_PROBE_DEFINE1(futex, futex_get, return, "int");
108 LIN_SDT_PROBE_DEFINE3(futex, futex_sleep, entry, "struct futex *",
109 "struct waiting_proc **", "int");
110 LIN_SDT_PROBE_DEFINE5(futex, futex_sleep, requeue_error, "int", "uint32_t *",
111 "struct waiting_proc *", "uint32_t *", "uint32_t");
112 LIN_SDT_PROBE_DEFINE3(futex, futex_sleep, sleep_error, "int", "uint32_t *",
113 "struct waiting_proc *");
114 LIN_SDT_PROBE_DEFINE1(futex, futex_sleep, return, "int");
115 LIN_SDT_PROBE_DEFINE3(futex, futex_wake, entry, "struct futex *", "int",
117 LIN_SDT_PROBE_DEFINE3(futex, futex_wake, iterate, "uint32_t",
118 "struct waiting_proc *", "uint32_t");
119 LIN_SDT_PROBE_DEFINE1(futex, futex_wake, wakeup, "struct waiting_proc *");
120 LIN_SDT_PROBE_DEFINE1(futex, futex_wake, return, "int");
121 LIN_SDT_PROBE_DEFINE4(futex, futex_requeue, entry, "struct futex *", "int",
122 "struct futex *", "int");
123 LIN_SDT_PROBE_DEFINE1(futex, futex_requeue, wakeup, "struct waiting_proc *");
124 LIN_SDT_PROBE_DEFINE3(futex, futex_requeue, requeue, "uint32_t *",
125 "struct waiting_proc *", "uint32_t");
126 LIN_SDT_PROBE_DEFINE1(futex, futex_requeue, return, "int");
127 LIN_SDT_PROBE_DEFINE4(futex, futex_wait, entry, "struct futex *",
128 "struct waiting_proc **", "int", "uint32_t");
129 LIN_SDT_PROBE_DEFINE1(futex, futex_wait, sleep_error, "int");
130 LIN_SDT_PROBE_DEFINE1(futex, futex_wait, return, "int");
131 LIN_SDT_PROBE_DEFINE3(futex, futex_atomic_op, entry, "struct thread *",
133 LIN_SDT_PROBE_DEFINE4(futex, futex_atomic_op, decoded_op, "int", "int", "int",
135 LIN_SDT_PROBE_DEFINE0(futex, futex_atomic_op, missing_access_check);
136 LIN_SDT_PROBE_DEFINE1(futex, futex_atomic_op, unimplemented_op, "int");
137 LIN_SDT_PROBE_DEFINE1(futex, futex_atomic_op, unimplemented_cmp, "int");
138 LIN_SDT_PROBE_DEFINE1(futex, futex_atomic_op, return, "int");
139 LIN_SDT_PROBE_DEFINE2(futex, linux_sys_futex, entry, "struct thread *",
140 "struct linux_sys_futex_args *");
141 LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_clockswitch);
142 LIN_SDT_PROBE_DEFINE1(futex, linux_sys_futex, itimerfix_error, "int");
143 LIN_SDT_PROBE_DEFINE1(futex, linux_sys_futex, copyin_error, "int");
144 LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, invalid_cmp_requeue_use);
145 LIN_SDT_PROBE_DEFINE3(futex, linux_sys_futex, debug_wait, "uint32_t *",
146 "uint32_t", "uint32_t");
147 LIN_SDT_PROBE_DEFINE4(futex, linux_sys_futex, debug_wait_value_neq,
148 "uint32_t *", "uint32_t", "int", "uint32_t");
149 LIN_SDT_PROBE_DEFINE3(futex, linux_sys_futex, debug_wake, "uint32_t *",
150 "uint32_t", "uint32_t");
151 LIN_SDT_PROBE_DEFINE5(futex, linux_sys_futex, debug_cmp_requeue, "uint32_t *",
152 "uint32_t", "uint32_t", "uint32_t *", "struct l_timespec *");
153 LIN_SDT_PROBE_DEFINE2(futex, linux_sys_futex, debug_cmp_requeue_value_neq,
155 LIN_SDT_PROBE_DEFINE5(futex, linux_sys_futex, debug_wake_op, "uint32_t *",
156 "int", "uint32_t", "uint32_t *", "uint32_t");
157 LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unhandled_efault);
158 LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_lock_pi);
159 LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_unlock_pi);
160 LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_trylock_pi);
161 LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, deprecated_requeue);
162 LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_wait_requeue_pi);
163 LIN_SDT_PROBE_DEFINE0(futex, linux_sys_futex, unimplemented_cmp_requeue_pi);
164 LIN_SDT_PROBE_DEFINE1(futex, linux_sys_futex, unknown_operation, "int");
165 LIN_SDT_PROBE_DEFINE1(futex, linux_sys_futex, return, "int");
166 LIN_SDT_PROBE_DEFINE2(futex, linux_set_robust_list, entry, "struct thread *",
167 "struct linux_set_robust_list_args *");
168 LIN_SDT_PROBE_DEFINE0(futex, linux_set_robust_list, size_error);
169 LIN_SDT_PROBE_DEFINE1(futex, linux_set_robust_list, return, "int");
170 LIN_SDT_PROBE_DEFINE2(futex, linux_get_robust_list, entry, "struct thread *",
171 "struct linux_get_robust_list_args *");
172 LIN_SDT_PROBE_DEFINE1(futex, linux_get_robust_list, copyout_error, "int");
173 LIN_SDT_PROBE_DEFINE1(futex, linux_get_robust_list, return, "int");
174 LIN_SDT_PROBE_DEFINE3(futex, handle_futex_death, entry,
175 "struct linux_emuldata *", "uint32_t *", "unsigned int");
176 LIN_SDT_PROBE_DEFINE1(futex, handle_futex_death, copyin_error, "int");
177 LIN_SDT_PROBE_DEFINE1(futex, handle_futex_death, return, "int");
178 LIN_SDT_PROBE_DEFINE3(futex, fetch_robust_entry, entry,
179 "struct linux_robust_list **", "struct linux_robust_list **",
181 LIN_SDT_PROBE_DEFINE1(futex, fetch_robust_entry, copyin_error, "int");
182 LIN_SDT_PROBE_DEFINE1(futex, fetch_robust_entry, return, "int");
183 LIN_SDT_PROBE_DEFINE2(futex, release_futexes, entry, "struct thread *",
184 "struct linux_emuldata *");
185 LIN_SDT_PROBE_DEFINE1(futex, release_futexes, copyin_error, "int");
186 LIN_SDT_PROBE_DEFINE0(futex, release_futexes, return);
190 struct waiting_proc {
192 struct futex *wp_futex;
193 TAILQ_ENTRY(waiting_proc) wp_list;
198 uint32_t *f_uaddr; /* user-supplied value, for debug */
199 struct umtx_key f_key;
202 LIST_ENTRY(futex) f_list;
203 TAILQ_HEAD(lf_waiting_proc, waiting_proc) f_waiting_proc;
206 struct futex_list futex_list;
208 #define FUTEX_LOCK(f) sx_xlock(&(f)->f_lck)
209 #define FUTEX_UNLOCK(f) sx_xunlock(&(f)->f_lck)
210 #define FUTEX_INIT(f) do { \
211 sx_init_flags(&(f)->f_lck, "ftlk", \
213 LIN_SDT_PROBE1(futex, futex, create, \
216 #define FUTEX_DESTROY(f) do { \
217 LIN_SDT_PROBE1(futex, futex, destroy, \
219 sx_destroy(&(f)->f_lck); \
221 #define FUTEX_ASSERT_LOCKED(f) sx_assert(&(f)->f_lck, SA_XLOCKED)
223 struct mtx futex_mtx; /* protects the futex list */
224 #define FUTEXES_LOCK do { \
225 mtx_lock(&futex_mtx); \
226 LIN_SDT_PROBE1(locks, futex_mtx, \
227 locked, &futex_mtx); \
229 #define FUTEXES_UNLOCK do { \
230 LIN_SDT_PROBE1(locks, futex_mtx, \
231 unlock, &futex_mtx); \
232 mtx_unlock(&futex_mtx); \
235 /* flags for futex_get() */
236 #define FUTEX_CREATE_WP 0x1 /* create waiting_proc */
237 #define FUTEX_DONTCREATE 0x2 /* don't create futex if not exists */
238 #define FUTEX_DONTEXISTS 0x4 /* return EINVAL if futex exists */
239 #define FUTEX_SHARED 0x8 /* shared futex */
242 #define FUTEX_WP_REQUEUED 0x1 /* wp requeued - wp moved from wp_list
243 * of futex where thread sleep to wp_list
246 #define FUTEX_WP_REMOVED 0x2 /* wp is woken up and removed from futex
247 * wp_list to prevent double wakeup.
250 static void futex_put(struct futex *, struct waiting_proc *);
251 static int futex_get0(uint32_t *, struct futex **f, uint32_t);
252 static int futex_get(uint32_t *, struct waiting_proc **, struct futex **,
254 static int futex_sleep(struct futex *, struct waiting_proc *, int);
255 static int futex_wake(struct futex *, int, uint32_t);
256 static int futex_requeue(struct futex *, int, struct futex *, int);
257 static int futex_wait(struct futex *, struct waiting_proc *, int,
259 static int futex_atomic_op(struct thread *, int, uint32_t *);
260 static int handle_futex_death(struct linux_emuldata *, uint32_t *,
262 static int fetch_robust_entry(struct linux_robust_list **,
263 struct linux_robust_list **, unsigned int *);
266 int futex_xchgl(int oparg, uint32_t *uaddr, int *oldval);
267 int futex_addl(int oparg, uint32_t *uaddr, int *oldval);
268 int futex_orl(int oparg, uint32_t *uaddr, int *oldval);
269 int futex_andl(int oparg, uint32_t *uaddr, int *oldval);
270 int futex_xorl(int oparg, uint32_t *uaddr, int *oldval);
274 futex_put(struct futex *f, struct waiting_proc *wp)
276 LIN_SDT_PROBE2(futex, futex_put, entry, f, wp);
278 FUTEX_ASSERT_LOCKED(f);
280 if ((wp->wp_flags & FUTEX_WP_REMOVED) == 0)
281 TAILQ_REMOVE(&f->f_waiting_proc, wp, wp_list);
282 free(wp, M_FUTEX_WP);
286 if (--f->f_refcount == 0) {
287 LIST_REMOVE(f, f_list);
291 LIN_SDT_PROBE3(futex, futex_put, destroy, f->f_uaddr,
292 f->f_refcount, f->f_key.shared);
293 LINUX_CTR3(sys_futex, "futex_put destroy uaddr %p ref %d "
294 "shared %d", f->f_uaddr, f->f_refcount, f->f_key.shared);
295 umtx_key_release(&f->f_key);
299 LIN_SDT_PROBE0(futex, futex_put, return);
303 LIN_SDT_PROBE3(futex, futex_put, unlock, f->f_uaddr, f->f_refcount,
305 LINUX_CTR3(sys_futex, "futex_put uaddr %p ref %d shared %d",
306 f->f_uaddr, f->f_refcount, f->f_key.shared);
310 LIN_SDT_PROBE0(futex, futex_put, return);
314 futex_get0(uint32_t *uaddr, struct futex **newf, uint32_t flags)
316 struct futex *f, *tmpf;
320 LIN_SDT_PROBE3(futex, futex_get0, entry, uaddr, newf, flags);
324 error = umtx_key_get(uaddr, TYPE_FUTEX, (flags & FUTEX_SHARED) ?
325 AUTO_SHARE : THREAD_SHARE, &key);
327 LIN_SDT_PROBE1(futex, futex_get0, umtx_key_get_error, error);
328 LIN_SDT_PROBE1(futex, futex_get0, return, error);
333 LIST_FOREACH(f, &futex_list, f_list) {
334 if (umtx_key_match(&f->f_key, &key)) {
340 if (flags & FUTEX_DONTEXISTS) {
342 umtx_key_release(&key);
344 LIN_SDT_PROBE1(futex, futex_get0, return,
350 * Increment refcount of the found futex to
351 * prevent it from deallocation before FUTEX_LOCK()
355 umtx_key_release(&key);
359 LIN_SDT_PROBE3(futex, futex_get0, shared, uaddr,
360 f->f_refcount, f->f_key.shared);
361 LINUX_CTR3(sys_futex, "futex_get uaddr %p ref %d shared %d",
362 uaddr, f->f_refcount, f->f_key.shared);
364 LIN_SDT_PROBE1(futex, futex_get0, return, 0);
369 if (flags & FUTEX_DONTCREATE) {
371 umtx_key_release(&key);
372 LIN_SDT_PROBE1(futex, futex_get0, null, uaddr);
373 LINUX_CTR1(sys_futex, "futex_get uaddr %p null", uaddr);
375 LIN_SDT_PROBE1(futex, futex_get0, return, 0);
381 tmpf = malloc(sizeof(*tmpf), M_FUTEX, M_WAITOK | M_ZERO);
382 tmpf->f_uaddr = uaddr;
384 tmpf->f_refcount = 1;
385 tmpf->f_bitset = FUTEX_BITSET_MATCH_ANY;
387 TAILQ_INIT(&tmpf->f_waiting_proc);
390 * Lock the new futex before an insert into the futex_list
391 * to prevent futex usage by other.
397 LIST_INSERT_HEAD(&futex_list, tmpf, f_list);
400 LIN_SDT_PROBE3(futex, futex_get0, new, uaddr, tmpf->f_refcount,
402 LINUX_CTR3(sys_futex, "futex_get uaddr %p ref %d shared %d new",
403 uaddr, tmpf->f_refcount, tmpf->f_key.shared);
406 LIN_SDT_PROBE1(futex, futex_get0, return, 0);
411 futex_get(uint32_t *uaddr, struct waiting_proc **wp, struct futex **f,
416 LIN_SDT_PROBE3(futex, futex_get, entry, uaddr, wp, f);
418 if (flags & FUTEX_CREATE_WP) {
419 *wp = malloc(sizeof(struct waiting_proc), M_FUTEX_WP, M_WAITOK);
422 error = futex_get0(uaddr, f, flags);
424 LIN_SDT_PROBE0(futex, futex_get, error);
426 if (flags & FUTEX_CREATE_WP)
427 free(*wp, M_FUTEX_WP);
429 LIN_SDT_PROBE1(futex, futex_get, return, error);
432 if (flags & FUTEX_CREATE_WP) {
433 TAILQ_INSERT_HEAD(&(*f)->f_waiting_proc, *wp, wp_list);
434 (*wp)->wp_futex = *f;
437 LIN_SDT_PROBE1(futex, futex_get, return, error);
442 futex_sleep(struct futex *f, struct waiting_proc *wp, int timeout)
446 FUTEX_ASSERT_LOCKED(f);
447 LIN_SDT_PROBE3(futex, futex_sleep, entry, f, wp, timeout);
448 LINUX_CTR4(sys_futex, "futex_sleep enter uaddr %p wp %p timo %d ref %d",
449 f->f_uaddr, wp, timeout, f->f_refcount);
450 error = sx_sleep(wp, &f->f_lck, PCATCH, "futex", timeout);
451 if (wp->wp_flags & FUTEX_WP_REQUEUED) {
452 KASSERT(f != wp->wp_futex, ("futex != wp_futex"));
455 LIN_SDT_PROBE5(futex, futex_sleep, requeue_error, error,
456 f->f_uaddr, wp, wp->wp_futex->f_uaddr,
457 wp->wp_futex->f_refcount);
460 LINUX_CTR5(sys_futex, "futex_sleep out error %d uaddr %p wp"
461 " %p requeued uaddr %p ref %d",
462 error, f->f_uaddr, wp, wp->wp_futex->f_uaddr,
463 wp->wp_futex->f_refcount);
469 LIN_SDT_PROBE3(futex, futex_sleep, sleep_error, error,
472 LINUX_CTR3(sys_futex, "futex_sleep out error %d uaddr %p wp %p",
473 error, f->f_uaddr, wp);
478 LIN_SDT_PROBE1(futex, futex_sleep, return, error);
483 futex_wake(struct futex *f, int n, uint32_t bitset)
485 struct waiting_proc *wp, *wpt;
488 LIN_SDT_PROBE3(futex, futex_wake, entry, f, n, bitset);
491 LIN_SDT_PROBE1(futex, futex_wake, return, EINVAL);
495 FUTEX_ASSERT_LOCKED(f);
496 TAILQ_FOREACH_SAFE(wp, &f->f_waiting_proc, wp_list, wpt) {
497 LIN_SDT_PROBE3(futex, futex_wake, iterate, f->f_uaddr, wp,
499 LINUX_CTR3(sys_futex, "futex_wake uaddr %p wp %p ref %d",
500 f->f_uaddr, wp, f->f_refcount);
502 * Unless we find a matching bit in
503 * the bitset, continue searching.
505 if (!(wp->wp_futex->f_bitset & bitset))
508 wp->wp_flags |= FUTEX_WP_REMOVED;
509 TAILQ_REMOVE(&f->f_waiting_proc, wp, wp_list);
510 LIN_SDT_PROBE1(futex, futex_wake, wakeup, wp);
516 LIN_SDT_PROBE1(futex, futex_wake, return, count);
521 futex_requeue(struct futex *f, int n, struct futex *f2, int n2)
523 struct waiting_proc *wp, *wpt;
526 LIN_SDT_PROBE4(futex, futex_requeue, entry, f, n, f2, n2);
528 FUTEX_ASSERT_LOCKED(f);
529 FUTEX_ASSERT_LOCKED(f2);
531 TAILQ_FOREACH_SAFE(wp, &f->f_waiting_proc, wp_list, wpt) {
533 LINUX_CTR2(sys_futex, "futex_req_wake uaddr %p wp %p",
535 wp->wp_flags |= FUTEX_WP_REMOVED;
536 TAILQ_REMOVE(&f->f_waiting_proc, wp, wp_list);
537 LIN_SDT_PROBE1(futex, futex_requeue, wakeup, wp);
540 LIN_SDT_PROBE3(futex, futex_requeue, requeue,
541 f->f_uaddr, wp, f2->f_uaddr);
542 LINUX_CTR3(sys_futex, "futex_requeue uaddr %p wp %p to %p",
543 f->f_uaddr, wp, f2->f_uaddr);
544 wp->wp_flags |= FUTEX_WP_REQUEUED;
545 /* Move wp to wp_list of f2 futex */
546 TAILQ_REMOVE(&f->f_waiting_proc, wp, wp_list);
547 TAILQ_INSERT_HEAD(&f2->f_waiting_proc, wp, wp_list);
550 * Thread which sleeps on wp after waking should
551 * acquire f2 lock, so increment refcount of f2 to
552 * prevent it from premature deallocation.
563 LIN_SDT_PROBE1(futex, futex_requeue, return, count);
568 futex_wait(struct futex *f, struct waiting_proc *wp, int timeout_hz,
573 LIN_SDT_PROBE4(futex, futex_wait, entry, f, wp, timeout_hz, bitset);
576 LIN_SDT_PROBE1(futex, futex_wait, return, EINVAL);
580 f->f_bitset = bitset;
581 error = futex_sleep(f, wp, timeout_hz);
583 LIN_SDT_PROBE1(futex, futex_wait, sleep_error, error);
584 if (error == EWOULDBLOCK)
587 LIN_SDT_PROBE1(futex, futex_wait, return, error);
592 futex_atomic_op(struct thread *td, int encoded_op, uint32_t *uaddr)
594 int op = (encoded_op >> 28) & 7;
595 int cmp = (encoded_op >> 24) & 15;
596 int oparg = (encoded_op << 8) >> 20;
597 int cmparg = (encoded_op << 20) >> 20;
600 LIN_SDT_PROBE3(futex, futex_atomic_op, entry, td, encoded_op, uaddr);
602 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
605 LIN_SDT_PROBE4(futex, futex_atomic_op, decoded_op, op, cmp, oparg,
608 /* XXX: Linux verifies access here and returns EFAULT */
609 LIN_SDT_PROBE0(futex, futex_atomic_op, missing_access_check);
613 ret = futex_xchgl(oparg, uaddr, &oldval);
616 ret = futex_addl(oparg, uaddr, &oldval);
619 ret = futex_orl(oparg, uaddr, &oldval);
622 ret = futex_andl(~oparg, uaddr, &oldval);
625 ret = futex_xorl(oparg, uaddr, &oldval);
628 LIN_SDT_PROBE1(futex, futex_atomic_op, unimplemented_op, op);
634 LIN_SDT_PROBE1(futex, futex_atomic_op, return, ret);
639 case FUTEX_OP_CMP_EQ:
640 ret = (oldval == cmparg);
642 case FUTEX_OP_CMP_NE:
643 ret = (oldval != cmparg);
645 case FUTEX_OP_CMP_LT:
646 ret = (oldval < cmparg);
648 case FUTEX_OP_CMP_GE:
649 ret = (oldval >= cmparg);
651 case FUTEX_OP_CMP_LE:
652 ret = (oldval <= cmparg);
654 case FUTEX_OP_CMP_GT:
655 ret = (oldval > cmparg);
658 LIN_SDT_PROBE1(futex, futex_atomic_op, unimplemented_cmp, cmp);
662 LIN_SDT_PROBE1(futex, futex_atomic_op, return, ret);
667 linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
669 int clockrt, nrwake, op_ret, ret;
670 struct linux_pemuldata *pem;
671 struct waiting_proc *wp;
672 struct futex *f, *f2;
673 struct l_timespec timeout;
674 struct timeval utv, ctv;
679 LIN_SDT_PROBE2(futex, linux_sys_futex, entry, td, args);
681 if (args->op & LINUX_FUTEX_PRIVATE_FLAG) {
683 args->op &= ~LINUX_FUTEX_PRIVATE_FLAG;
685 flags = FUTEX_SHARED;
688 * Currently support for switching between CLOCK_MONOTONIC and
689 * CLOCK_REALTIME is not present. However Linux forbids the use of
690 * FUTEX_CLOCK_REALTIME with any op except FUTEX_WAIT_BITSET and
691 * FUTEX_WAIT_REQUEUE_PI.
693 clockrt = args->op & LINUX_FUTEX_CLOCK_REALTIME;
694 args->op = args->op & ~LINUX_FUTEX_CLOCK_REALTIME;
695 if (clockrt && args->op != LINUX_FUTEX_WAIT_BITSET &&
696 args->op != LINUX_FUTEX_WAIT_REQUEUE_PI) {
697 LIN_SDT_PROBE0(futex, linux_sys_futex,
698 unimplemented_clockswitch);
699 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS);
707 case LINUX_FUTEX_WAIT:
708 args->val3 = FUTEX_BITSET_MATCH_ANY;
711 case LINUX_FUTEX_WAIT_BITSET:
712 LIN_SDT_PROBE3(futex, linux_sys_futex, debug_wait, args->uaddr,
713 args->val, args->val3);
714 LINUX_CTR3(sys_futex, "WAIT uaddr %p val 0x%x bitset 0x%x",
715 args->uaddr, args->val, args->val3);
717 error = futex_get(args->uaddr, &wp, &f,
718 flags | FUTEX_CREATE_WP);
720 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
724 error = copyin(args->uaddr, &val, sizeof(val));
726 LIN_SDT_PROBE1(futex, linux_sys_futex, copyin_error,
728 LINUX_CTR1(sys_futex, "WAIT copyin failed %d",
732 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
735 if (val != args->val) {
736 LIN_SDT_PROBE4(futex, linux_sys_futex,
737 debug_wait_value_neq, args->uaddr, args->val, val,
739 LINUX_CTR3(sys_futex,
740 "WAIT uaddr %p val 0x%x != uval 0x%x",
741 args->uaddr, args->val, val);
744 LIN_SDT_PROBE1(futex, linux_sys_futex, return,
746 return (EWOULDBLOCK);
749 if (args->timeout != NULL) {
750 error = copyin(args->timeout, &timeout, sizeof(timeout));
752 LIN_SDT_PROBE1(futex, linux_sys_futex, copyin_error,
754 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
758 TIMESPEC_TO_TIMEVAL(&utv, &timeout);
759 error = itimerfix(&utv);
761 LIN_SDT_PROBE1(futex, linux_sys_futex, itimerfix_error,
763 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
769 timevalsub(&utv, &ctv);
770 } else if (args->op == LINUX_FUTEX_WAIT_BITSET) {
772 timevalsub(&utv, &ctv);
776 timeout_hz = tvtohz(&utv);
780 error = futex_wait(f, wp, timeout_hz, args->val3);
783 case LINUX_FUTEX_WAKE:
784 args->val3 = FUTEX_BITSET_MATCH_ANY;
787 case LINUX_FUTEX_WAKE_BITSET:
788 LIN_SDT_PROBE3(futex, linux_sys_futex, debug_wake, args->uaddr,
789 args->val, args->val3);
790 LINUX_CTR3(sys_futex, "WAKE uaddr %p nrwake 0x%x bitset 0x%x",
791 args->uaddr, args->val, args->val3);
793 error = futex_get(args->uaddr, NULL, &f,
794 flags | FUTEX_DONTCREATE);
796 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
801 td->td_retval[0] = 0;
803 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
806 td->td_retval[0] = futex_wake(f, args->val, args->val3);
810 case LINUX_FUTEX_CMP_REQUEUE:
811 LIN_SDT_PROBE5(futex, linux_sys_futex, debug_cmp_requeue,
812 args->uaddr, args->val, args->val3, args->uaddr2,
814 LINUX_CTR5(sys_futex, "CMP_REQUEUE uaddr %p "
815 "nrwake 0x%x uval 0x%x uaddr2 %p nrequeue 0x%x",
816 args->uaddr, args->val, args->val3, args->uaddr2,
820 * Linux allows this, we would not, it is an incorrect
821 * usage of declared ABI, so return EINVAL.
823 if (args->uaddr == args->uaddr2) {
824 LIN_SDT_PROBE0(futex, linux_sys_futex,
825 invalid_cmp_requeue_use);
826 LIN_SDT_PROBE1(futex, linux_sys_futex, return, EINVAL);
830 error = futex_get(args->uaddr, NULL, &f, flags);
832 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
837 * To avoid deadlocks return EINVAL if second futex
838 * exists at this time.
840 * Glibc fall back to FUTEX_WAKE in case of any error
841 * returned by FUTEX_CMP_REQUEUE.
843 error = futex_get(args->uaddr2, NULL, &f2,
844 flags | FUTEX_DONTEXISTS);
848 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
851 error = copyin(args->uaddr, &val, sizeof(val));
853 LIN_SDT_PROBE1(futex, linux_sys_futex, copyin_error,
855 LINUX_CTR1(sys_futex, "CMP_REQUEUE copyin failed %d",
860 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
863 if (val != args->val3) {
864 LIN_SDT_PROBE2(futex, linux_sys_futex,
865 debug_cmp_requeue_value_neq, args->val, val);
866 LINUX_CTR2(sys_futex, "CMP_REQUEUE val 0x%x != uval 0x%x",
871 LIN_SDT_PROBE1(futex, linux_sys_futex, return, EAGAIN);
875 nrwake = (int)(unsigned long)args->timeout;
876 td->td_retval[0] = futex_requeue(f, args->val, f2, nrwake);
881 case LINUX_FUTEX_WAKE_OP:
882 LIN_SDT_PROBE5(futex, linux_sys_futex, debug_wake_op,
883 args->uaddr, args->op, args->val, args->uaddr2, args->val3);
884 LINUX_CTR5(sys_futex, "WAKE_OP "
885 "uaddr %p nrwake 0x%x uaddr2 %p op 0x%x nrwake2 0x%x",
886 args->uaddr, args->val, args->uaddr2, args->val3,
889 error = futex_get(args->uaddr, NULL, &f, flags);
891 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
895 if (args->uaddr != args->uaddr2)
896 error = futex_get(args->uaddr2, NULL, &f2, flags);
900 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
905 * This function returns positive number as results and
908 op_ret = futex_atomic_op(td, args->val3, args->uaddr2);
910 LINUX_CTR2(sys_futex, "WAKE_OP atomic_op uaddr %p ret 0x%x",
911 args->uaddr, op_ret);
914 /* XXX: We don't handle the EFAULT yet. */
915 if (op_ret != -EFAULT) {
920 LIN_SDT_PROBE1(futex, linux_sys_futex, return,
924 LIN_SDT_PROBE0(futex, linux_sys_futex,
931 LIN_SDT_PROBE1(futex, linux_sys_futex, return, EFAULT);
935 ret = futex_wake(f, args->val, args->val3);
939 nrwake = (int)(unsigned long)args->timeout;
942 op_ret += futex_wake(f2, nrwake, args->val3);
944 op_ret += futex_wake(f, nrwake, args->val3);
951 td->td_retval[0] = ret;
954 case LINUX_FUTEX_LOCK_PI:
955 /* not yet implemented */
956 pem = pem_find(td->td_proc);
957 if ((pem->flags & LINUX_XUNSUP_FUTEXPIOP) == 0) {
960 "unsupported futex_pi op\n");
961 pem->flags |= LINUX_XUNSUP_FUTEXPIOP;
962 LIN_SDT_PROBE0(futex, linux_sys_futex,
963 unimplemented_lock_pi);
965 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS);
968 case LINUX_FUTEX_UNLOCK_PI:
969 /* not yet implemented */
970 pem = pem_find(td->td_proc);
971 if ((pem->flags & LINUX_XUNSUP_FUTEXPIOP) == 0) {
974 "unsupported futex_pi op\n");
975 pem->flags |= LINUX_XUNSUP_FUTEXPIOP;
976 LIN_SDT_PROBE0(futex, linux_sys_futex,
977 unimplemented_unlock_pi);
979 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS);
982 case LINUX_FUTEX_TRYLOCK_PI:
983 /* not yet implemented */
984 pem = pem_find(td->td_proc);
985 if ((pem->flags & LINUX_XUNSUP_FUTEXPIOP) == 0) {
988 "unsupported futex_pi op\n");
989 pem->flags |= LINUX_XUNSUP_FUTEXPIOP;
990 LIN_SDT_PROBE0(futex, linux_sys_futex,
991 unimplemented_trylock_pi);
993 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS);
996 case LINUX_FUTEX_REQUEUE:
999 * Glibc does not use this operation since version 2.3.3,
1000 * as it is racy and replaced by FUTEX_CMP_REQUEUE operation.
1001 * Glibc versions prior to 2.3.3 fall back to FUTEX_WAKE when
1002 * FUTEX_REQUEUE returned EINVAL.
1004 pem = pem_find(td->td_proc);
1005 if ((pem->flags & LINUX_XDEPR_REQUEUEOP) == 0) {
1008 "unsupported futex_requeue op\n");
1009 pem->flags |= LINUX_XDEPR_REQUEUEOP;
1010 LIN_SDT_PROBE0(futex, linux_sys_futex,
1011 deprecated_requeue);
1014 LIN_SDT_PROBE1(futex, linux_sys_futex, return, EINVAL);
1017 case LINUX_FUTEX_WAIT_REQUEUE_PI:
1018 /* not yet implemented */
1019 pem = pem_find(td->td_proc);
1020 if ((pem->flags & LINUX_XUNSUP_FUTEXPIOP) == 0) {
1023 "unsupported futex_pi op\n");
1024 pem->flags |= LINUX_XUNSUP_FUTEXPIOP;
1025 LIN_SDT_PROBE0(futex, linux_sys_futex,
1026 unimplemented_wait_requeue_pi);
1028 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS);
1031 case LINUX_FUTEX_CMP_REQUEUE_PI:
1032 /* not yet implemented */
1033 pem = pem_find(td->td_proc);
1034 if ((pem->flags & LINUX_XUNSUP_FUTEXPIOP) == 0) {
1037 "unsupported futex_pi op\n");
1038 pem->flags |= LINUX_XUNSUP_FUTEXPIOP;
1039 LIN_SDT_PROBE0(futex, linux_sys_futex,
1040 unimplemented_cmp_requeue_pi);
1042 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS);
1047 "linux_sys_futex: unknown op %d\n", args->op);
1048 LIN_SDT_PROBE1(futex, linux_sys_futex, unknown_operation,
1050 LIN_SDT_PROBE1(futex, linux_sys_futex, return, ENOSYS);
1054 LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
1059 linux_set_robust_list(struct thread *td, struct linux_set_robust_list_args *args)
1061 struct linux_emuldata *em;
1063 LIN_SDT_PROBE2(futex, linux_set_robust_list, entry, td, args);
1065 if (args->len != sizeof(struct linux_robust_list_head)) {
1066 LIN_SDT_PROBE0(futex, linux_set_robust_list, size_error);
1067 LIN_SDT_PROBE1(futex, linux_set_robust_list, return, EINVAL);
1072 em->robust_futexes = args->head;
1074 LIN_SDT_PROBE1(futex, linux_set_robust_list, return, 0);
1079 linux_get_robust_list(struct thread *td, struct linux_get_robust_list_args *args)
1081 struct linux_emuldata *em;
1082 struct linux_robust_list_head *head;
1083 l_size_t len = sizeof(struct linux_robust_list_head);
1087 LIN_SDT_PROBE2(futex, linux_get_robust_list, entry, td, args);
1091 KASSERT(em != NULL, ("get_robust_list: emuldata notfound.\n"));
1092 head = em->robust_futexes;
1094 td2 = tdfind(args->pid, -1);
1096 LIN_SDT_PROBE1(futex, linux_get_robust_list, return,
1102 KASSERT(em != NULL, ("get_robust_list: emuldata notfound.\n"));
1104 if (priv_check(td, PRIV_CRED_SETUID) ||
1105 priv_check(td, PRIV_CRED_SETEUID) ||
1106 p_candebug(td, td2->td_proc)) {
1107 PROC_UNLOCK(td2->td_proc);
1109 LIN_SDT_PROBE1(futex, linux_get_robust_list, return,
1113 head = em->robust_futexes;
1115 PROC_UNLOCK(td2->td_proc);
1118 error = copyout(&len, args->len, sizeof(l_size_t));
1120 LIN_SDT_PROBE1(futex, linux_get_robust_list, copyout_error,
1122 LIN_SDT_PROBE1(futex, linux_get_robust_list, return, EFAULT);
1126 error = copyout(head, args->head, sizeof(struct linux_robust_list_head));
1128 LIN_SDT_PROBE1(futex, linux_get_robust_list, copyout_error,
1132 LIN_SDT_PROBE1(futex, linux_get_robust_list, return, error);
1137 handle_futex_death(struct linux_emuldata *em, uint32_t *uaddr,
1140 uint32_t uval, nval, mval;
1144 LIN_SDT_PROBE3(futex, handle_futex_death, entry, em, uaddr, pi);
1147 error = copyin(uaddr, &uval, 4);
1149 LIN_SDT_PROBE1(futex, handle_futex_death, copyin_error, error);
1150 LIN_SDT_PROBE1(futex, handle_futex_death, return, EFAULT);
1153 if ((uval & FUTEX_TID_MASK) == em->em_tid) {
1154 mval = (uval & FUTEX_WAITERS) | FUTEX_OWNER_DIED;
1155 nval = casuword32(uaddr, uval, mval);
1158 LIN_SDT_PROBE1(futex, handle_futex_death, return,
1166 if (!pi && (uval & FUTEX_WAITERS)) {
1167 error = futex_get(uaddr, NULL, &f,
1168 FUTEX_DONTCREATE | FUTEX_SHARED);
1170 LIN_SDT_PROBE1(futex, handle_futex_death,
1175 futex_wake(f, 1, FUTEX_BITSET_MATCH_ANY);
1181 LIN_SDT_PROBE1(futex, handle_futex_death, return, 0);
1186 fetch_robust_entry(struct linux_robust_list **entry,
1187 struct linux_robust_list **head, unsigned int *pi)
1192 LIN_SDT_PROBE3(futex, fetch_robust_entry, entry, entry, head, pi);
1194 error = copyin((const void *)head, &uentry, sizeof(l_ulong));
1196 LIN_SDT_PROBE1(futex, fetch_robust_entry, copyin_error, error);
1197 LIN_SDT_PROBE1(futex, fetch_robust_entry, return, EFAULT);
1201 *entry = (void *)(uentry & ~1UL);
1204 LIN_SDT_PROBE1(futex, fetch_robust_entry, return, 0);
1208 /* This walks the list of robust futexes releasing them. */
1210 release_futexes(struct thread *td, struct linux_emuldata *em)
1212 struct linux_robust_list_head *head = NULL;
1213 struct linux_robust_list *entry, *next_entry, *pending;
1214 unsigned int limit = 2048, pi, next_pi, pip;
1215 l_long futex_offset;
1218 LIN_SDT_PROBE2(futex, release_futexes, entry, td, em);
1220 head = em->robust_futexes;
1223 LIN_SDT_PROBE0(futex, release_futexes, return);
1227 if (fetch_robust_entry(&entry, PTRIN(&head->list.next), &pi)) {
1228 LIN_SDT_PROBE0(futex, release_futexes, return);
1232 error = copyin(&head->futex_offset, &futex_offset,
1233 sizeof(futex_offset));
1235 LIN_SDT_PROBE1(futex, release_futexes, copyin_error, error);
1236 LIN_SDT_PROBE0(futex, release_futexes, return);
1240 if (fetch_robust_entry(&pending, PTRIN(&head->pending_list), &pip)) {
1241 LIN_SDT_PROBE0(futex, release_futexes, return);
1245 while (entry != &head->list) {
1246 rc = fetch_robust_entry(&next_entry, PTRIN(&entry->next), &next_pi);
1248 if (entry != pending)
1249 if (handle_futex_death(em,
1250 (uint32_t *)((caddr_t)entry + futex_offset), pi)) {
1251 LIN_SDT_PROBE0(futex, release_futexes, return);
1255 LIN_SDT_PROBE0(futex, release_futexes, return);
1265 sched_relinquish(curthread);
1269 handle_futex_death(em, (uint32_t *)((caddr_t)pending + futex_offset), pip);
1271 LIN_SDT_PROBE0(futex, release_futexes, return);