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654d6b2e0b
function do_lock_umutex.
2127 lines
46 KiB
C
2127 lines
46 KiB
C
/*-
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* Copyright (c) 2004, David Xu <davidxu@freebsd.org>
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* Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/limits.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/sched.h>
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#include <sys/sysctl.h>
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#include <sys/sysent.h>
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#include <sys/systm.h>
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#include <sys/sysproto.h>
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#include <sys/eventhandler.h>
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#include <sys/umtx.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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#include <vm/vm_object.h>
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#define TYPE_SIMPLE_LOCK 0
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#define TYPE_SIMPLE_WAIT 1
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#define TYPE_NORMAL_UMUTEX 2
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#define TYPE_PI_UMUTEX 3
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#define TYPE_PP_UMUTEX 4
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#define TYPE_CV 5
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/* Key to represent a unique userland synchronous object */
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struct umtx_key {
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int hash;
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int type;
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int shared;
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union {
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struct {
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vm_object_t object;
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uintptr_t offset;
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} shared;
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struct {
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struct vmspace *vs;
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uintptr_t addr;
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} private;
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struct {
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void *a;
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uintptr_t b;
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} both;
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} info;
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};
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/* Priority inheritance mutex info. */
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struct umtx_pi {
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/* Owner thread */
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struct thread *pi_owner;
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/* Reference count */
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int pi_refcount;
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/* List entry to link umtx holding by thread */
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TAILQ_ENTRY(umtx_pi) pi_link;
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/* List entry in hash */
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TAILQ_ENTRY(umtx_pi) pi_hashlink;
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/* List for waiters */
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TAILQ_HEAD(,umtx_q) pi_blocked;
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/* Identify a userland lock object */
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struct umtx_key pi_key;
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};
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/* A userland synchronous object user. */
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struct umtx_q {
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/* Linked list for the hash. */
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TAILQ_ENTRY(umtx_q) uq_link;
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/* Umtx key. */
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struct umtx_key uq_key;
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/* Umtx flags. */
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int uq_flags;
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#define UQF_UMTXQ 0x0001
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/* The thread waits on. */
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struct thread *uq_thread;
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/*
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* Blocked on PI mutex. read can use chain lock
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* or sched_lock, write must have both chain lock and
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* sched_lock being hold.
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*/
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struct umtx_pi *uq_pi_blocked;
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/* On blocked list */
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TAILQ_ENTRY(umtx_q) uq_lockq;
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/* Thread contending with us */
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TAILQ_HEAD(,umtx_pi) uq_pi_contested;
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/* Inherited priority from PP mutex */
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u_char uq_inherited_pri;
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};
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TAILQ_HEAD(umtxq_head, umtx_q);
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/* Userland lock object's wait-queue chain */
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struct umtxq_chain {
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/* Lock for this chain. */
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struct mtx uc_lock;
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/* List of sleep queues. */
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struct umtxq_head uc_queue;
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/* Busy flag */
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char uc_busy;
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/* Chain lock waiters */
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int uc_waiters;
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/* All PI in the list */
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TAILQ_HEAD(,umtx_pi) uc_pi_list;
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};
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#define UMTXQ_LOCKED_ASSERT(uc) mtx_assert(&(uc)->uc_lock, MA_OWNED)
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/*
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* Don't propagate time-sharing priority, there is a security reason,
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* a user can simply introduce PI-mutex, let thread A lock the mutex,
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* and let another thread B block on the mutex, because B is
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* sleeping, its priority will be boosted, this causes A's priority to
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* be boosted via priority propagating too and will never be lowered even
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* if it is using 100%CPU, this is unfair to other processes.
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*/
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#define UPRI(td) (((td)->td_ksegrp->kg_user_pri >= PRI_MIN_TIMESHARE &&\
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(td)->td_ksegrp->kg_user_pri <= PRI_MAX_TIMESHARE) ?\
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PRI_MAX_TIMESHARE : (td)->td_ksegrp->kg_user_pri)
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#define GOLDEN_RATIO_PRIME 2654404609U
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#define UMTX_CHAINS 128
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#define UMTX_SHIFTS (__WORD_BIT - 7)
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#define THREAD_SHARE 0
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#define PROCESS_SHARE 1
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#define AUTO_SHARE 2
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#define GET_SHARE(flags) \
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(((flags) & USYNC_PROCESS_SHARED) == 0 ? THREAD_SHARE : PROCESS_SHARE)
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static uma_zone_t umtx_pi_zone;
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static struct umtxq_chain umtxq_chains[UMTX_CHAINS];
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static MALLOC_DEFINE(M_UMTX, "umtx", "UMTX queue memory");
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static int umtx_pi_allocated;
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SYSCTL_NODE(_debug, OID_AUTO, umtx, CTLFLAG_RW, 0, "umtx debug");
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SYSCTL_INT(_debug_umtx, OID_AUTO, umtx_pi_allocated, CTLFLAG_RD,
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&umtx_pi_allocated, 0, "Allocated umtx_pi");
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static void umtxq_sysinit(void *);
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static void umtxq_hash(struct umtx_key *key);
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static struct umtxq_chain *umtxq_getchain(struct umtx_key *key);
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static void umtxq_lock(struct umtx_key *key);
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static void umtxq_unlock(struct umtx_key *key);
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static void umtxq_busy(struct umtx_key *key);
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static void umtxq_unbusy(struct umtx_key *key);
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static void umtxq_insert(struct umtx_q *uq);
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static void umtxq_remove(struct umtx_q *uq);
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static int umtxq_sleep(struct umtx_q *uq, const char *wmesg, int timo);
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static int umtxq_count(struct umtx_key *key);
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static int umtxq_signal(struct umtx_key *key, int nr_wakeup);
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static int umtx_key_match(const struct umtx_key *k1, const struct umtx_key *k2);
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static int umtx_key_get(void *addr, int type, int share,
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struct umtx_key *key);
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static void umtx_key_release(struct umtx_key *key);
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static struct umtx_pi *umtx_pi_alloc(void);
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static void umtx_pi_free(struct umtx_pi *pi);
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static int do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags);
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static void umtx_thread_cleanup(struct thread *td);
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static void umtx_exec_hook(void *arg __unused, struct proc *p __unused,
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struct image_params *imgp __unused);
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SYSINIT(umtx, SI_SUB_EVENTHANDLER+1, SI_ORDER_MIDDLE, umtxq_sysinit, NULL);
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static void
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umtxq_sysinit(void *arg __unused)
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{
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int i;
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umtx_pi_zone = uma_zcreate("umtx pi", sizeof(struct umtx_pi),
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NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
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for (i = 0; i < UMTX_CHAINS; ++i) {
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mtx_init(&umtxq_chains[i].uc_lock, "umtxql", NULL,
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MTX_DEF | MTX_DUPOK);
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TAILQ_INIT(&umtxq_chains[i].uc_queue);
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TAILQ_INIT(&umtxq_chains[i].uc_pi_list);
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umtxq_chains[i].uc_busy = 0;
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umtxq_chains[i].uc_waiters = 0;
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}
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EVENTHANDLER_REGISTER(process_exec, umtx_exec_hook, NULL,
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EVENTHANDLER_PRI_ANY);
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}
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struct umtx_q *
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umtxq_alloc(void)
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{
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struct umtx_q *uq;
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uq = malloc(sizeof(struct umtx_q), M_UMTX, M_WAITOK | M_ZERO);
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TAILQ_INIT(&uq->uq_pi_contested);
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uq->uq_inherited_pri = PRI_MAX;
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return (uq);
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}
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void
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umtxq_free(struct umtx_q *uq)
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{
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free(uq, M_UMTX);
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}
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static inline void
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umtxq_hash(struct umtx_key *key)
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{
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unsigned n = (uintptr_t)key->info.both.a + key->info.both.b;
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key->hash = ((n * GOLDEN_RATIO_PRIME) >> UMTX_SHIFTS) % UMTX_CHAINS;
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}
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static inline int
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umtx_key_match(const struct umtx_key *k1, const struct umtx_key *k2)
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{
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return (k1->type == k2->type &&
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k1->info.both.a == k2->info.both.a &&
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k1->info.both.b == k2->info.both.b);
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}
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static inline struct umtxq_chain *
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umtxq_getchain(struct umtx_key *key)
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{
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return (&umtxq_chains[key->hash]);
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}
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/*
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* Set chain to busy state when following operation
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* may be blocked (kernel mutex can not be used).
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*/
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static inline void
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umtxq_busy(struct umtx_key *key)
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{
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struct umtxq_chain *uc;
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uc = umtxq_getchain(key);
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mtx_assert(&uc->uc_lock, MA_OWNED);
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while (uc->uc_busy != 0) {
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uc->uc_waiters++;
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msleep(uc, &uc->uc_lock, 0, "umtxqb", 0);
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uc->uc_waiters--;
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}
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uc->uc_busy = 1;
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}
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/*
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* Unbusy a chain.
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*/
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static inline void
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umtxq_unbusy(struct umtx_key *key)
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{
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struct umtxq_chain *uc;
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uc = umtxq_getchain(key);
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mtx_assert(&uc->uc_lock, MA_OWNED);
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KASSERT(uc->uc_busy != 0, ("not busy"));
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uc->uc_busy = 0;
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if (uc->uc_waiters)
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wakeup_one(uc);
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}
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/*
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* Lock a chain.
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*/
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static inline void
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umtxq_lock(struct umtx_key *key)
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{
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struct umtxq_chain *uc;
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uc = umtxq_getchain(key);
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mtx_lock(&uc->uc_lock);
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}
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/*
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* Unlock a chain.
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*/
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static inline void
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umtxq_unlock(struct umtx_key *key)
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{
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struct umtxq_chain *uc;
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uc = umtxq_getchain(key);
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mtx_unlock(&uc->uc_lock);
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}
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/*
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* Insert a thread onto the umtx queue.
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*/
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static inline void
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umtxq_insert(struct umtx_q *uq)
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{
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struct umtxq_chain *uc;
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uc = umtxq_getchain(&uq->uq_key);
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UMTXQ_LOCKED_ASSERT(uc);
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TAILQ_INSERT_TAIL(&uc->uc_queue, uq, uq_link);
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uq->uq_flags |= UQF_UMTXQ;
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}
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/*
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* Remove thread from the umtx queue.
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*/
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static inline void
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umtxq_remove(struct umtx_q *uq)
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{
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struct umtxq_chain *uc;
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uc = umtxq_getchain(&uq->uq_key);
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UMTXQ_LOCKED_ASSERT(uc);
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if (uq->uq_flags & UQF_UMTXQ) {
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TAILQ_REMOVE(&uc->uc_queue, uq, uq_link);
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uq->uq_flags &= ~UQF_UMTXQ;
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}
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}
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/*
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* Check if there are multiple waiters
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*/
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static int
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umtxq_count(struct umtx_key *key)
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{
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struct umtxq_chain *uc;
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struct umtx_q *uq;
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int count = 0;
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uc = umtxq_getchain(key);
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UMTXQ_LOCKED_ASSERT(uc);
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TAILQ_FOREACH(uq, &uc->uc_queue, uq_link) {
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if (umtx_key_match(&uq->uq_key, key)) {
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if (++count > 1)
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break;
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}
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}
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return (count);
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}
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/*
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* Check if there are multiple PI waiters and returns first
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* waiter.
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*/
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static int
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umtxq_count_pi(struct umtx_key *key, struct umtx_q **first)
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{
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struct umtxq_chain *uc;
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struct umtx_q *uq;
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int count = 0;
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*first = NULL;
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uc = umtxq_getchain(key);
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UMTXQ_LOCKED_ASSERT(uc);
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TAILQ_FOREACH(uq, &uc->uc_queue, uq_link) {
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if (umtx_key_match(&uq->uq_key, key)) {
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if (++count > 1)
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break;
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*first = uq;
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}
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}
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return (count);
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}
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/*
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* Wake up threads waiting on an userland object.
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*/
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static int
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umtxq_signal(struct umtx_key *key, int n_wake)
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{
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struct umtxq_chain *uc;
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struct umtx_q *uq, *next;
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int ret;
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ret = 0;
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uc = umtxq_getchain(key);
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UMTXQ_LOCKED_ASSERT(uc);
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TAILQ_FOREACH_SAFE(uq, &uc->uc_queue, uq_link, next) {
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if (umtx_key_match(&uq->uq_key, key)) {
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umtxq_remove(uq);
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wakeup(uq);
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if (++ret >= n_wake)
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break;
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}
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}
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return (ret);
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}
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/*
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* Wake up specified thread.
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*/
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static inline void
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umtxq_signal_thread(struct umtx_q *uq)
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{
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struct umtxq_chain *uc;
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uc = umtxq_getchain(&uq->uq_key);
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UMTXQ_LOCKED_ASSERT(uc);
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umtxq_remove(uq);
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wakeup(uq);
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}
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/*
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* Put thread into sleep state, before sleeping, check if
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* thread was removed from umtx queue.
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*/
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static inline int
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umtxq_sleep(struct umtx_q *uq, const char *wmesg, int timo)
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{
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struct umtxq_chain *uc;
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int error;
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uc = umtxq_getchain(&uq->uq_key);
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UMTXQ_LOCKED_ASSERT(uc);
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if (!(uq->uq_flags & UQF_UMTXQ))
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return (0);
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error = msleep(uq, &uc->uc_lock, PCATCH, wmesg, timo);
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if (error == EWOULDBLOCK)
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error = ETIMEDOUT;
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return (error);
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}
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/*
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* Convert userspace address into unique logical address.
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*/
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static int
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umtx_key_get(void *addr, int type, int share, struct umtx_key *key)
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{
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struct thread *td = curthread;
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vm_map_t map;
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vm_map_entry_t entry;
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vm_pindex_t pindex;
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vm_prot_t prot;
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boolean_t wired;
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key->type = type;
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if (share == THREAD_SHARE) {
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key->shared = 0;
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key->info.private.vs = td->td_proc->p_vmspace;
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key->info.private.addr = (uintptr_t)addr;
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} else if (share == PROCESS_SHARE || share == AUTO_SHARE) {
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map = &td->td_proc->p_vmspace->vm_map;
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if (vm_map_lookup(&map, (vm_offset_t)addr, VM_PROT_WRITE,
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&entry, &key->info.shared.object, &pindex, &prot,
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&wired) != KERN_SUCCESS) {
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return EFAULT;
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}
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if ((share == PROCESS_SHARE) ||
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(share == AUTO_SHARE &&
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VM_INHERIT_SHARE == entry->inheritance)) {
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key->shared = 1;
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key->info.shared.offset = entry->offset + entry->start -
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(vm_offset_t)addr;
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vm_object_reference(key->info.shared.object);
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} else {
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key->shared = 0;
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key->info.private.vs = td->td_proc->p_vmspace;
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key->info.private.addr = (uintptr_t)addr;
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}
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vm_map_lookup_done(map, entry);
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}
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umtxq_hash(key);
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return (0);
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|
}
|
|
|
|
/*
|
|
* Release key.
|
|
*/
|
|
static inline void
|
|
umtx_key_release(struct umtx_key *key)
|
|
{
|
|
if (key->shared)
|
|
vm_object_deallocate(key->info.shared.object);
|
|
}
|
|
|
|
/*
|
|
* Lock a umtx object.
|
|
*/
|
|
static int
|
|
_do_lock(struct thread *td, struct umtx *umtx, uintptr_t id, int timo)
|
|
{
|
|
struct umtx_q *uq;
|
|
intptr_t owner;
|
|
intptr_t old;
|
|
int error = 0;
|
|
|
|
uq = td->td_umtxq;
|
|
|
|
/*
|
|
* Care must be exercised when dealing with umtx structure. It
|
|
* can fault on any access.
|
|
*/
|
|
for (;;) {
|
|
/*
|
|
* Try the uncontested case. This should be done in userland.
|
|
*/
|
|
owner = casuptr((intptr_t *)&umtx->u_owner, UMTX_UNOWNED, id);
|
|
|
|
/* The acquire succeeded. */
|
|
if (owner == UMTX_UNOWNED)
|
|
return (0);
|
|
|
|
/* The address was invalid. */
|
|
if (owner == -1)
|
|
return (EFAULT);
|
|
|
|
/* If no one owns it but it is contested try to acquire it. */
|
|
if (owner == UMTX_CONTESTED) {
|
|
owner = casuptr((intptr_t *)&umtx->u_owner,
|
|
UMTX_CONTESTED, id | UMTX_CONTESTED);
|
|
|
|
if (owner == UMTX_CONTESTED)
|
|
return (0);
|
|
|
|
/* The address was invalid. */
|
|
if (owner == -1)
|
|
return (EFAULT);
|
|
|
|
/* If this failed the lock has changed, restart. */
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* If we caught a signal, we have retried and now
|
|
* exit immediately.
|
|
*/
|
|
if (error != 0)
|
|
return (error);
|
|
|
|
if ((error = umtx_key_get(umtx, TYPE_SIMPLE_LOCK,
|
|
AUTO_SHARE, &uq->uq_key)) != 0)
|
|
return (error);
|
|
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_busy(&uq->uq_key);
|
|
umtxq_insert(uq);
|
|
umtxq_unbusy(&uq->uq_key);
|
|
umtxq_unlock(&uq->uq_key);
|
|
|
|
/*
|
|
* Set the contested bit so that a release in user space
|
|
* knows to use the system call for unlock. If this fails
|
|
* either some one else has acquired the lock or it has been
|
|
* released.
|
|
*/
|
|
old = casuptr((intptr_t *)&umtx->u_owner, owner,
|
|
owner | UMTX_CONTESTED);
|
|
|
|
/* The address was invalid. */
|
|
if (old == -1) {
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_remove(uq);
|
|
umtxq_unlock(&uq->uq_key);
|
|
umtx_key_release(&uq->uq_key);
|
|
return (EFAULT);
|
|
}
|
|
|
|
/*
|
|
* We set the contested bit, sleep. Otherwise the lock changed
|
|
* and we need to retry or we lost a race to the thread
|
|
* unlocking the umtx.
|
|
*/
|
|
umtxq_lock(&uq->uq_key);
|
|
if (old == owner)
|
|
error = umtxq_sleep(uq, "umtx", timo);
|
|
umtxq_remove(uq);
|
|
umtxq_unlock(&uq->uq_key);
|
|
umtx_key_release(&uq->uq_key);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Lock a umtx object.
|
|
*/
|
|
static int
|
|
do_lock(struct thread *td, struct umtx *umtx, uintptr_t id,
|
|
struct timespec *timeout)
|
|
{
|
|
struct timespec ts, ts2, ts3;
|
|
struct timeval tv;
|
|
int error;
|
|
|
|
if (timeout == NULL) {
|
|
error = _do_lock(td, umtx, id, 0);
|
|
/* Mutex locking is restarted if it is interrupted. */
|
|
if (error == EINTR)
|
|
error = ERESTART;
|
|
} else {
|
|
getnanouptime(&ts);
|
|
timespecadd(&ts, timeout);
|
|
TIMESPEC_TO_TIMEVAL(&tv, timeout);
|
|
for (;;) {
|
|
error = _do_lock(td, umtx, id, tvtohz(&tv));
|
|
if (error != ETIMEDOUT)
|
|
break;
|
|
getnanouptime(&ts2);
|
|
if (timespeccmp(&ts2, &ts, >=)) {
|
|
error = ETIMEDOUT;
|
|
break;
|
|
}
|
|
ts3 = ts;
|
|
timespecsub(&ts3, &ts2);
|
|
TIMESPEC_TO_TIMEVAL(&tv, &ts3);
|
|
}
|
|
/* Timed-locking is not restarted. */
|
|
if (error == ERESTART)
|
|
error = EINTR;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Unlock a umtx object.
|
|
*/
|
|
static int
|
|
do_unlock(struct thread *td, struct umtx *umtx, uintptr_t id)
|
|
{
|
|
struct umtx_key key;
|
|
intptr_t owner;
|
|
intptr_t old;
|
|
int error;
|
|
int count;
|
|
|
|
/*
|
|
* Make sure we own this mtx.
|
|
*
|
|
* XXX Need a {fu,su}ptr this is not correct on arch where
|
|
* sizeof(intptr_t) != sizeof(long).
|
|
*/
|
|
owner = fuword(&umtx->u_owner);
|
|
if (owner == -1)
|
|
return (EFAULT);
|
|
|
|
if ((owner & ~UMTX_CONTESTED) != id)
|
|
return (EPERM);
|
|
|
|
/* This should be done in userland */
|
|
if ((owner & UMTX_CONTESTED) == 0) {
|
|
old = casuptr((intptr_t *)&umtx->u_owner, owner,
|
|
UMTX_UNOWNED);
|
|
if (old == -1)
|
|
return (EFAULT);
|
|
if (old == owner)
|
|
return (0);
|
|
owner = old;
|
|
}
|
|
|
|
/* We should only ever be in here for contested locks */
|
|
if ((error = umtx_key_get(umtx, TYPE_SIMPLE_LOCK, AUTO_SHARE,
|
|
&key)) != 0)
|
|
return (error);
|
|
|
|
umtxq_lock(&key);
|
|
umtxq_busy(&key);
|
|
count = umtxq_count(&key);
|
|
umtxq_unlock(&key);
|
|
|
|
/*
|
|
* When unlocking the umtx, it must be marked as unowned if
|
|
* there is zero or one thread only waiting for it.
|
|
* Otherwise, it must be marked as contested.
|
|
*/
|
|
old = casuptr((intptr_t *)&umtx->u_owner, owner,
|
|
count <= 1 ? UMTX_UNOWNED : UMTX_CONTESTED);
|
|
umtxq_lock(&key);
|
|
umtxq_signal(&key,1);
|
|
umtxq_unbusy(&key);
|
|
umtxq_unlock(&key);
|
|
umtx_key_release(&key);
|
|
if (old == -1)
|
|
return (EFAULT);
|
|
if (old != owner)
|
|
return (EINVAL);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Fetch and compare value, sleep on the address if value is not changed.
|
|
*/
|
|
static int
|
|
do_wait(struct thread *td, struct umtx *umtx, uintptr_t id, struct timespec *timeout)
|
|
{
|
|
struct umtx_q *uq;
|
|
struct timespec ts, ts2, ts3;
|
|
struct timeval tv;
|
|
uintptr_t tmp;
|
|
int error = 0;
|
|
|
|
uq = td->td_umtxq;
|
|
if ((error = umtx_key_get(umtx, TYPE_SIMPLE_WAIT, AUTO_SHARE,
|
|
&uq->uq_key)) != 0)
|
|
return (error);
|
|
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_insert(uq);
|
|
umtxq_unlock(&uq->uq_key);
|
|
tmp = fuword(&umtx->u_owner);
|
|
if (tmp != id) {
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_remove(uq);
|
|
umtxq_unlock(&uq->uq_key);
|
|
} else if (timeout == NULL) {
|
|
umtxq_lock(&uq->uq_key);
|
|
error = umtxq_sleep(uq, "ucond", 0);
|
|
umtxq_remove(uq);
|
|
umtxq_unlock(&uq->uq_key);
|
|
} else {
|
|
getnanouptime(&ts);
|
|
timespecadd(&ts, timeout);
|
|
TIMESPEC_TO_TIMEVAL(&tv, timeout);
|
|
umtxq_lock(&uq->uq_key);
|
|
for (;;) {
|
|
error = umtxq_sleep(uq, "ucond", tvtohz(&tv));
|
|
if (!(uq->uq_flags & UQF_UMTXQ))
|
|
break;
|
|
if (error != ETIMEDOUT)
|
|
break;
|
|
umtxq_unlock(&uq->uq_key);
|
|
getnanouptime(&ts2);
|
|
if (timespeccmp(&ts2, &ts, >=)) {
|
|
error = ETIMEDOUT;
|
|
umtxq_lock(&uq->uq_key);
|
|
break;
|
|
}
|
|
ts3 = ts;
|
|
timespecsub(&ts3, &ts2);
|
|
TIMESPEC_TO_TIMEVAL(&tv, &ts3);
|
|
umtxq_lock(&uq->uq_key);
|
|
}
|
|
umtxq_remove(uq);
|
|
umtxq_unlock(&uq->uq_key);
|
|
}
|
|
umtx_key_release(&uq->uq_key);
|
|
if (error == ERESTART)
|
|
error = EINTR;
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Wake up threads sleeping on the specified address.
|
|
*/
|
|
int
|
|
kern_umtx_wake(struct thread *td, void *uaddr, int n_wake)
|
|
{
|
|
struct umtx_key key;
|
|
int ret;
|
|
|
|
if ((ret = umtx_key_get(uaddr, TYPE_SIMPLE_WAIT, AUTO_SHARE,
|
|
&key)) != 0)
|
|
return (ret);
|
|
umtxq_lock(&key);
|
|
ret = umtxq_signal(&key, n_wake);
|
|
umtxq_unlock(&key);
|
|
umtx_key_release(&key);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Lock PTHREAD_PRIO_NONE protocol POSIX mutex.
|
|
*/
|
|
static int
|
|
_do_lock_normal(struct thread *td, struct umutex *m, uint32_t flags, int timo,
|
|
int try)
|
|
{
|
|
struct umtx_q *uq;
|
|
uint32_t owner, old, id;
|
|
int error = 0;
|
|
|
|
id = td->td_tid;
|
|
uq = td->td_umtxq;
|
|
|
|
/*
|
|
* Care must be exercised when dealing with umtx structure. It
|
|
* can fault on any access.
|
|
*/
|
|
for (;;) {
|
|
/*
|
|
* Try the uncontested case. This should be done in userland.
|
|
*/
|
|
owner = casuword32(&m->m_owner, UMUTEX_UNOWNED, id);
|
|
|
|
/* The acquire succeeded. */
|
|
if (owner == UMUTEX_UNOWNED)
|
|
return (0);
|
|
|
|
/* The address was invalid. */
|
|
if (owner == -1)
|
|
return (EFAULT);
|
|
|
|
/* If no one owns it but it is contested try to acquire it. */
|
|
if (owner == UMUTEX_CONTESTED) {
|
|
owner = casuword32(&m->m_owner,
|
|
UMUTEX_CONTESTED, id | UMUTEX_CONTESTED);
|
|
|
|
if (owner == UMUTEX_CONTESTED)
|
|
return (0);
|
|
|
|
/* The address was invalid. */
|
|
if (owner == -1)
|
|
return (EFAULT);
|
|
|
|
/* If this failed the lock has changed, restart. */
|
|
continue;
|
|
}
|
|
|
|
if ((flags & UMUTEX_ERROR_CHECK) != 0 &&
|
|
(owner & ~UMUTEX_CONTESTED) == id)
|
|
return (EDEADLK);
|
|
|
|
if (try != 0)
|
|
return (EBUSY);
|
|
|
|
/*
|
|
* If we caught a signal, we have retried and now
|
|
* exit immediately.
|
|
*/
|
|
if (error != 0)
|
|
return (error);
|
|
|
|
if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX,
|
|
GET_SHARE(flags), &uq->uq_key)) != 0)
|
|
return (error);
|
|
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_busy(&uq->uq_key);
|
|
umtxq_insert(uq);
|
|
umtxq_unbusy(&uq->uq_key);
|
|
umtxq_unlock(&uq->uq_key);
|
|
|
|
/*
|
|
* Set the contested bit so that a release in user space
|
|
* knows to use the system call for unlock. If this fails
|
|
* either some one else has acquired the lock or it has been
|
|
* released.
|
|
*/
|
|
old = casuword32(&m->m_owner, owner, owner | UMUTEX_CONTESTED);
|
|
|
|
/* The address was invalid. */
|
|
if (old == -1) {
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_remove(uq);
|
|
umtxq_unlock(&uq->uq_key);
|
|
umtx_key_release(&uq->uq_key);
|
|
return (EFAULT);
|
|
}
|
|
|
|
/*
|
|
* We set the contested bit, sleep. Otherwise the lock changed
|
|
* and we need to retry or we lost a race to the thread
|
|
* unlocking the umtx.
|
|
*/
|
|
umtxq_lock(&uq->uq_key);
|
|
if (old == owner)
|
|
error = umtxq_sleep(uq, "umtxn", timo);
|
|
umtxq_remove(uq);
|
|
umtxq_unlock(&uq->uq_key);
|
|
umtx_key_release(&uq->uq_key);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Lock PTHREAD_PRIO_NONE protocol POSIX mutex.
|
|
*/
|
|
/*
|
|
* Unlock PTHREAD_PRIO_NONE protocol POSIX mutex.
|
|
*/
|
|
static int
|
|
do_unlock_normal(struct thread *td, struct umutex *m, uint32_t flags)
|
|
{
|
|
struct umtx_key key;
|
|
uint32_t owner, old, id;
|
|
int error;
|
|
int count;
|
|
|
|
id = td->td_tid;
|
|
/*
|
|
* Make sure we own this mtx.
|
|
*/
|
|
owner = fuword32(&m->m_owner);
|
|
if (owner == -1)
|
|
return (EFAULT);
|
|
|
|
if ((owner & ~UMUTEX_CONTESTED) != id)
|
|
return (EPERM);
|
|
|
|
/* This should be done in userland */
|
|
if ((owner & UMUTEX_CONTESTED) == 0) {
|
|
old = casuword32(&m->m_owner, owner, UMUTEX_UNOWNED);
|
|
if (old == -1)
|
|
return (EFAULT);
|
|
if (old == owner)
|
|
return (0);
|
|
owner = old;
|
|
}
|
|
|
|
/* We should only ever be in here for contested locks */
|
|
if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags),
|
|
&key)) != 0)
|
|
return (error);
|
|
|
|
umtxq_lock(&key);
|
|
umtxq_busy(&key);
|
|
count = umtxq_count(&key);
|
|
umtxq_unlock(&key);
|
|
|
|
/*
|
|
* When unlocking the umtx, it must be marked as unowned if
|
|
* there is zero or one thread only waiting for it.
|
|
* Otherwise, it must be marked as contested.
|
|
*/
|
|
old = casuword32(&m->m_owner, owner,
|
|
count <= 1 ? UMUTEX_UNOWNED : UMUTEX_CONTESTED);
|
|
umtxq_lock(&key);
|
|
umtxq_signal(&key,1);
|
|
umtxq_unbusy(&key);
|
|
umtxq_unlock(&key);
|
|
umtx_key_release(&key);
|
|
if (old == -1)
|
|
return (EFAULT);
|
|
if (old != owner)
|
|
return (EINVAL);
|
|
return (0);
|
|
}
|
|
|
|
static inline struct umtx_pi *
|
|
umtx_pi_alloc(void)
|
|
{
|
|
struct umtx_pi *pi;
|
|
|
|
pi = uma_zalloc(umtx_pi_zone, M_ZERO | M_WAITOK);
|
|
TAILQ_INIT(&pi->pi_blocked);
|
|
atomic_add_int(&umtx_pi_allocated, 1);
|
|
return (pi);
|
|
}
|
|
|
|
static inline void
|
|
umtx_pi_free(struct umtx_pi *pi)
|
|
{
|
|
uma_zfree(umtx_pi_zone, pi);
|
|
atomic_add_int(&umtx_pi_allocated, -1);
|
|
}
|
|
|
|
/*
|
|
* Adjust the thread's position on a pi_state after its priority has been
|
|
* changed.
|
|
*/
|
|
static int
|
|
umtx_pi_adjust_thread(struct umtx_pi *pi, struct thread *td)
|
|
{
|
|
struct umtx_q *uq, *uq1, *uq2;
|
|
struct thread *td1;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
if (pi == NULL)
|
|
return (0);
|
|
|
|
uq = td->td_umtxq;
|
|
|
|
/*
|
|
* Check if the thread needs to be moved on the blocked chain.
|
|
* It needs to be moved if either its priority is lower than
|
|
* the previous thread or higher than the next thread.
|
|
*/
|
|
uq1 = TAILQ_PREV(uq, umtxq_head, uq_lockq);
|
|
uq2 = TAILQ_NEXT(uq, uq_lockq);
|
|
if ((uq1 != NULL && UPRI(td) < UPRI(uq1->uq_thread)) ||
|
|
(uq2 != NULL && UPRI(td) > UPRI(uq2->uq_thread))) {
|
|
/*
|
|
* Remove thread from blocked chain and determine where
|
|
* it should be moved to.
|
|
*/
|
|
TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq);
|
|
TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) {
|
|
td1 = uq1->uq_thread;
|
|
MPASS(td1->td_proc->p_magic == P_MAGIC);
|
|
if (UPRI(td1) > UPRI(td))
|
|
break;
|
|
}
|
|
|
|
if (uq1 == NULL)
|
|
TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq);
|
|
else
|
|
TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq);
|
|
}
|
|
return (1);
|
|
}
|
|
|
|
/*
|
|
* Propagate priority when a thread is blocked on POSIX
|
|
* PI mutex.
|
|
*/
|
|
static void
|
|
umtx_propagate_priority(struct thread *td)
|
|
{
|
|
struct umtx_q *uq;
|
|
struct umtx_pi *pi;
|
|
int pri;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
pri = UPRI(td);
|
|
uq = td->td_umtxq;
|
|
pi = uq->uq_pi_blocked;
|
|
if (pi == NULL)
|
|
return;
|
|
|
|
for (;;) {
|
|
td = pi->pi_owner;
|
|
if (td == NULL)
|
|
return;
|
|
|
|
MPASS(td->td_proc != NULL);
|
|
MPASS(td->td_proc->p_magic == P_MAGIC);
|
|
|
|
if (UPRI(td) <= pri)
|
|
return;
|
|
|
|
sched_lend_user_prio(td, pri);
|
|
|
|
/*
|
|
* Pick up the lock that td is blocked on.
|
|
*/
|
|
uq = td->td_umtxq;
|
|
pi = uq->uq_pi_blocked;
|
|
/* Resort td on the list if needed. */
|
|
if (!umtx_pi_adjust_thread(pi, td))
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Unpropagate priority for a PI mutex when a thread blocked on
|
|
* it is interrupted by signal or resumed by others.
|
|
*/
|
|
static void
|
|
umtx_unpropagate_priority(struct umtx_pi *pi)
|
|
{
|
|
struct umtx_q *uq, *uq_owner;
|
|
struct umtx_pi *pi2;
|
|
int pri;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
|
|
while (pi != NULL && pi->pi_owner != NULL) {
|
|
pri = PRI_MAX;
|
|
uq_owner = pi->pi_owner->td_umtxq;
|
|
|
|
TAILQ_FOREACH(pi2, &uq_owner->uq_pi_contested, pi_link) {
|
|
uq = TAILQ_FIRST(&pi2->pi_blocked);
|
|
if (uq != NULL) {
|
|
if (pri > UPRI(uq->uq_thread))
|
|
pri = UPRI(uq->uq_thread);
|
|
}
|
|
}
|
|
|
|
if (pri > uq_owner->uq_inherited_pri)
|
|
pri = uq_owner->uq_inherited_pri;
|
|
sched_unlend_user_prio(pi->pi_owner, pri);
|
|
pi = uq_owner->uq_pi_blocked;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Insert a PI mutex into owned list.
|
|
*/
|
|
static void
|
|
umtx_pi_setowner(struct umtx_pi *pi, struct thread *owner)
|
|
{
|
|
struct umtx_q *uq_owner;
|
|
|
|
uq_owner = owner->td_umtxq;
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
if (pi->pi_owner != NULL)
|
|
panic("pi_ower != NULL");
|
|
pi->pi_owner = owner;
|
|
TAILQ_INSERT_TAIL(&uq_owner->uq_pi_contested, pi, pi_link);
|
|
}
|
|
|
|
/*
|
|
* Claim ownership of a PI mutex.
|
|
*/
|
|
static int
|
|
umtx_pi_claim(struct umtx_pi *pi, struct thread *owner)
|
|
{
|
|
struct umtx_q *uq, *uq_owner;
|
|
|
|
uq_owner = owner->td_umtxq;
|
|
mtx_lock_spin(&sched_lock);
|
|
if (pi->pi_owner == owner) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
return (0);
|
|
}
|
|
|
|
if (pi->pi_owner != NULL) {
|
|
/*
|
|
* userland may have already messed the mutex, sigh.
|
|
*/
|
|
mtx_unlock_spin(&sched_lock);
|
|
return (EPERM);
|
|
}
|
|
umtx_pi_setowner(pi, owner);
|
|
uq = TAILQ_FIRST(&pi->pi_blocked);
|
|
if (uq != NULL) {
|
|
int pri;
|
|
|
|
pri = UPRI(uq->uq_thread);
|
|
if (pri < UPRI(owner))
|
|
sched_lend_user_prio(owner, pri);
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Adjust a thread's order position in its blocked PI mutex,
|
|
* this may result new priority propagating process.
|
|
*/
|
|
void
|
|
umtx_pi_adjust(struct thread *td, u_char oldpri)
|
|
{
|
|
struct umtx_q *uq;
|
|
struct umtx_pi *pi;
|
|
|
|
uq = td->td_umtxq;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
MPASS(TD_ON_UPILOCK(td));
|
|
|
|
/*
|
|
* Pick up the lock that td is blocked on.
|
|
*/
|
|
pi = uq->uq_pi_blocked;
|
|
MPASS(pi != NULL);
|
|
|
|
/* Resort the turnstile on the list. */
|
|
if (!umtx_pi_adjust_thread(pi, td))
|
|
return;
|
|
|
|
/*
|
|
* If our priority was lowered and we are at the head of the
|
|
* turnstile, then propagate our new priority up the chain.
|
|
*/
|
|
if (uq == TAILQ_FIRST(&pi->pi_blocked) && UPRI(td) < oldpri)
|
|
umtx_propagate_priority(td);
|
|
}
|
|
|
|
/*
|
|
* Sleep on a PI mutex.
|
|
*/
|
|
static int
|
|
umtxq_sleep_pi(struct umtx_q *uq, struct umtx_pi *pi,
|
|
uint32_t owner, const char *wmesg, int timo)
|
|
{
|
|
struct umtxq_chain *uc;
|
|
struct thread *td, *td1;
|
|
struct umtx_q *uq1;
|
|
int pri;
|
|
int error = 0;
|
|
|
|
td = uq->uq_thread;
|
|
KASSERT(td == curthread, ("inconsistent uq_thread"));
|
|
uc = umtxq_getchain(&uq->uq_key);
|
|
UMTXQ_LOCKED_ASSERT(uc);
|
|
umtxq_insert(uq);
|
|
if (pi->pi_owner == NULL) {
|
|
/* XXX
|
|
* Current, We only support process private PI-mutex,
|
|
* non-contended PI-mutexes are locked in userland.
|
|
* Process shared PI-mutex should always be initialized
|
|
* by kernel and be registered in kernel, locking should
|
|
* always be done by kernel to avoid security problems.
|
|
* For process private PI-mutex, we can find owner
|
|
* thread and boost its priority safely.
|
|
*/
|
|
PROC_LOCK(curproc);
|
|
td1 = thread_find(curproc, owner);
|
|
mtx_lock_spin(&sched_lock);
|
|
if (td1 != NULL && pi->pi_owner == NULL) {
|
|
uq1 = td1->td_umtxq;
|
|
umtx_pi_setowner(pi, td1);
|
|
}
|
|
PROC_UNLOCK(curproc);
|
|
} else {
|
|
mtx_lock_spin(&sched_lock);
|
|
}
|
|
|
|
TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) {
|
|
pri = UPRI(uq1->uq_thread);
|
|
if (pri > UPRI(td))
|
|
break;
|
|
}
|
|
|
|
if (uq1 != NULL)
|
|
TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq);
|
|
else
|
|
TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq);
|
|
|
|
uq->uq_pi_blocked = pi;
|
|
td->td_flags |= TDF_UPIBLOCKED;
|
|
mtx_unlock_spin(&sched_lock);
|
|
umtxq_unlock(&uq->uq_key);
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
umtx_propagate_priority(td);
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
umtxq_lock(&uq->uq_key);
|
|
if (uq->uq_flags & UQF_UMTXQ) {
|
|
error = msleep(uq, &uc->uc_lock, PCATCH, wmesg, timo);
|
|
if (error == EWOULDBLOCK)
|
|
error = ETIMEDOUT;
|
|
if (uq->uq_flags & UQF_UMTXQ) {
|
|
umtxq_busy(&uq->uq_key);
|
|
umtxq_remove(uq);
|
|
umtxq_unbusy(&uq->uq_key);
|
|
}
|
|
}
|
|
umtxq_unlock(&uq->uq_key);
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
uq->uq_pi_blocked = NULL;
|
|
td->td_flags &= ~TDF_UPIBLOCKED;
|
|
TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq);
|
|
umtx_unpropagate_priority(pi);
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
umtxq_lock(&uq->uq_key);
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Add reference count for a PI mutex.
|
|
*/
|
|
static void
|
|
umtx_pi_ref(struct umtx_pi *pi)
|
|
{
|
|
struct umtxq_chain *uc;
|
|
|
|
uc = umtxq_getchain(&pi->pi_key);
|
|
UMTXQ_LOCKED_ASSERT(uc);
|
|
pi->pi_refcount++;
|
|
}
|
|
|
|
/*
|
|
* Decrease reference count for a PI mutex, if the counter
|
|
* is decreased to zero, its memory space is freed.
|
|
*/
|
|
static void
|
|
umtx_pi_unref(struct umtx_pi *pi)
|
|
{
|
|
struct umtxq_chain *uc;
|
|
int free = 0;
|
|
|
|
uc = umtxq_getchain(&pi->pi_key);
|
|
UMTXQ_LOCKED_ASSERT(uc);
|
|
KASSERT(pi->pi_refcount > 0, ("invalid reference count"));
|
|
if (--pi->pi_refcount == 0) {
|
|
mtx_lock_spin(&sched_lock);
|
|
if (pi->pi_owner != NULL) {
|
|
TAILQ_REMOVE(&pi->pi_owner->td_umtxq->uq_pi_contested,
|
|
pi, pi_link);
|
|
pi->pi_owner = NULL;
|
|
}
|
|
KASSERT(TAILQ_EMPTY(&pi->pi_blocked),
|
|
("blocked queue not empty"));
|
|
mtx_unlock_spin(&sched_lock);
|
|
TAILQ_REMOVE(&uc->uc_pi_list, pi, pi_hashlink);
|
|
free = 1;
|
|
}
|
|
if (free)
|
|
umtx_pi_free(pi);
|
|
}
|
|
|
|
/*
|
|
* Find a PI mutex in hash table.
|
|
*/
|
|
static struct umtx_pi *
|
|
umtx_pi_lookup(struct umtx_key *key)
|
|
{
|
|
struct umtxq_chain *uc;
|
|
struct umtx_pi *pi;
|
|
|
|
uc = umtxq_getchain(key);
|
|
UMTXQ_LOCKED_ASSERT(uc);
|
|
|
|
TAILQ_FOREACH(pi, &uc->uc_pi_list, pi_hashlink) {
|
|
if (umtx_key_match(&pi->pi_key, key)) {
|
|
return (pi);
|
|
}
|
|
}
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* Insert a PI mutex into hash table.
|
|
*/
|
|
static inline void
|
|
umtx_pi_insert(struct umtx_pi *pi)
|
|
{
|
|
struct umtxq_chain *uc;
|
|
|
|
uc = umtxq_getchain(&pi->pi_key);
|
|
UMTXQ_LOCKED_ASSERT(uc);
|
|
TAILQ_INSERT_TAIL(&uc->uc_pi_list, pi, pi_hashlink);
|
|
}
|
|
|
|
/*
|
|
* Lock a PI mutex.
|
|
*/
|
|
static int
|
|
_do_lock_pi(struct thread *td, struct umutex *m, uint32_t flags, int timo,
|
|
int try)
|
|
{
|
|
struct umtx_q *uq;
|
|
struct umtx_pi *pi, *new_pi;
|
|
uint32_t id, owner, old;
|
|
int error;
|
|
|
|
id = td->td_tid;
|
|
uq = td->td_umtxq;
|
|
|
|
if ((error = umtx_key_get(m, TYPE_PI_UMUTEX, GET_SHARE(flags),
|
|
&uq->uq_key)) != 0)
|
|
return (error);
|
|
for (;;) {
|
|
pi = NULL;
|
|
umtxq_lock(&uq->uq_key);
|
|
pi = umtx_pi_lookup(&uq->uq_key);
|
|
if (pi == NULL) {
|
|
umtxq_unlock(&uq->uq_key);
|
|
new_pi = umtx_pi_alloc();
|
|
new_pi->pi_key = uq->uq_key;
|
|
umtxq_lock(&uq->uq_key);
|
|
pi = umtx_pi_lookup(&uq->uq_key);
|
|
if (pi != NULL)
|
|
umtx_pi_free(new_pi);
|
|
else {
|
|
umtx_pi_insert(new_pi);
|
|
pi = new_pi;
|
|
}
|
|
}
|
|
|
|
umtx_pi_ref(pi);
|
|
umtxq_unlock(&uq->uq_key);
|
|
|
|
/*
|
|
* Care must be exercised when dealing with umtx structure. It
|
|
* can fault on any access.
|
|
*/
|
|
|
|
/*
|
|
* Try the uncontested case. This should be done in userland.
|
|
*/
|
|
owner = casuword32(&m->m_owner, UMUTEX_UNOWNED, id);
|
|
|
|
/* The acquire succeeded. */
|
|
if (owner == UMUTEX_UNOWNED) {
|
|
error = 0;
|
|
break;
|
|
}
|
|
|
|
/* The address was invalid. */
|
|
if (owner == -1) {
|
|
error = EFAULT;
|
|
break;
|
|
}
|
|
|
|
/* If no one owns it but it is contested try to acquire it. */
|
|
if (owner == UMUTEX_CONTESTED) {
|
|
owner = casuword32(&m->m_owner,
|
|
UMUTEX_CONTESTED, id | UMUTEX_CONTESTED);
|
|
|
|
if (owner == UMUTEX_CONTESTED) {
|
|
umtxq_lock(&uq->uq_key);
|
|
error = umtx_pi_claim(pi, td);
|
|
umtxq_unlock(&uq->uq_key);
|
|
break;
|
|
}
|
|
|
|
/* The address was invalid. */
|
|
if (owner == -1) {
|
|
error = EFAULT;
|
|
break;
|
|
}
|
|
|
|
/* If this failed the lock has changed, restart. */
|
|
umtxq_lock(&uq->uq_key);
|
|
umtx_pi_unref(pi);
|
|
umtxq_unlock(&uq->uq_key);
|
|
pi = NULL;
|
|
continue;
|
|
}
|
|
|
|
if ((flags & UMUTEX_ERROR_CHECK) != 0 &&
|
|
(owner & ~UMUTEX_CONTESTED) == id) {
|
|
error = EDEADLK;
|
|
break;
|
|
}
|
|
|
|
if (try != 0) {
|
|
error = EBUSY;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If we caught a signal, we have retried and now
|
|
* exit immediately.
|
|
*/
|
|
if (error != 0)
|
|
break;
|
|
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_busy(&uq->uq_key);
|
|
umtxq_unlock(&uq->uq_key);
|
|
|
|
/*
|
|
* Set the contested bit so that a release in user space
|
|
* knows to use the system call for unlock. If this fails
|
|
* either some one else has acquired the lock or it has been
|
|
* released.
|
|
*/
|
|
old = casuword32(&m->m_owner, owner, owner | UMUTEX_CONTESTED);
|
|
|
|
/* The address was invalid. */
|
|
if (old == -1) {
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_unbusy(&uq->uq_key);
|
|
umtxq_unlock(&uq->uq_key);
|
|
error = EFAULT;
|
|
break;
|
|
}
|
|
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_unbusy(&uq->uq_key);
|
|
/*
|
|
* We set the contested bit, sleep. Otherwise the lock changed
|
|
* and we need to retry or we lost a race to the thread
|
|
* unlocking the umtx.
|
|
*/
|
|
if (old == owner)
|
|
error = umtxq_sleep_pi(uq, pi, owner & ~UMUTEX_CONTESTED,
|
|
"umtxpi", timo);
|
|
umtx_pi_unref(pi);
|
|
umtxq_unlock(&uq->uq_key);
|
|
pi = NULL;
|
|
}
|
|
|
|
if (pi != NULL) {
|
|
umtxq_lock(&uq->uq_key);
|
|
umtx_pi_unref(pi);
|
|
umtxq_unlock(&uq->uq_key);
|
|
}
|
|
|
|
umtx_key_release(&uq->uq_key);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Unlock a PI mutex.
|
|
*/
|
|
static int
|
|
do_unlock_pi(struct thread *td, struct umutex *m, uint32_t flags)
|
|
{
|
|
struct umtx_key key;
|
|
struct umtx_q *uq_first, *uq_first2, *uq_me;
|
|
struct umtx_pi *pi, *pi2;
|
|
uint32_t owner, old, id;
|
|
int error;
|
|
int count;
|
|
int pri;
|
|
|
|
id = td->td_tid;
|
|
/*
|
|
* Make sure we own this mtx.
|
|
*/
|
|
owner = fuword32(&m->m_owner);
|
|
if (owner == -1)
|
|
return (EFAULT);
|
|
|
|
if ((owner & ~UMUTEX_CONTESTED) != id)
|
|
return (EPERM);
|
|
|
|
/* This should be done in userland */
|
|
if ((owner & UMUTEX_CONTESTED) == 0) {
|
|
old = casuword32(&m->m_owner, owner, UMUTEX_UNOWNED);
|
|
if (old == -1)
|
|
return (EFAULT);
|
|
if (old == owner)
|
|
return (0);
|
|
owner = old;
|
|
}
|
|
|
|
/* We should only ever be in here for contested locks */
|
|
if ((error = umtx_key_get(m, TYPE_PI_UMUTEX, GET_SHARE(flags),
|
|
&key)) != 0)
|
|
return (error);
|
|
|
|
umtxq_lock(&key);
|
|
umtxq_busy(&key);
|
|
count = umtxq_count_pi(&key, &uq_first);
|
|
if (uq_first != NULL) {
|
|
pi = uq_first->uq_pi_blocked;
|
|
if (pi->pi_owner != curthread) {
|
|
umtxq_unbusy(&key);
|
|
umtxq_unlock(&key);
|
|
/* userland messed the mutex */
|
|
return (EPERM);
|
|
}
|
|
uq_me = curthread->td_umtxq;
|
|
mtx_lock_spin(&sched_lock);
|
|
pi->pi_owner = NULL;
|
|
TAILQ_REMOVE(&uq_me->uq_pi_contested, pi, pi_link);
|
|
uq_first = TAILQ_FIRST(&pi->pi_blocked);
|
|
pri = PRI_MAX;
|
|
TAILQ_FOREACH(pi2, &uq_me->uq_pi_contested, pi_link) {
|
|
uq_first2 = TAILQ_FIRST(&pi2->pi_blocked);
|
|
if (uq_first2 != NULL) {
|
|
if (pri > UPRI(uq_first2->uq_thread))
|
|
pri = UPRI(uq_first2->uq_thread);
|
|
}
|
|
}
|
|
sched_unlend_user_prio(curthread, pri);
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
umtxq_unlock(&key);
|
|
|
|
/*
|
|
* When unlocking the umtx, it must be marked as unowned if
|
|
* there is zero or one thread only waiting for it.
|
|
* Otherwise, it must be marked as contested.
|
|
*/
|
|
old = casuword32(&m->m_owner, owner,
|
|
count <= 1 ? UMUTEX_UNOWNED : UMUTEX_CONTESTED);
|
|
|
|
umtxq_lock(&key);
|
|
if (uq_first != NULL)
|
|
umtxq_signal_thread(uq_first);
|
|
umtxq_unbusy(&key);
|
|
umtxq_unlock(&key);
|
|
umtx_key_release(&key);
|
|
if (old == -1)
|
|
return (EFAULT);
|
|
if (old != owner)
|
|
return (EINVAL);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Lock a PP mutex.
|
|
*/
|
|
static int
|
|
_do_lock_pp(struct thread *td, struct umutex *m, uint32_t flags, int timo,
|
|
int try)
|
|
{
|
|
struct umtx_q *uq, *uq2;
|
|
struct umtx_pi *pi;
|
|
uint32_t ceiling;
|
|
uint32_t owner, id;
|
|
int error, pri, old_inherited_pri, su;
|
|
|
|
id = td->td_tid;
|
|
uq = td->td_umtxq;
|
|
if ((error = umtx_key_get(m, TYPE_PP_UMUTEX, GET_SHARE(flags),
|
|
&uq->uq_key)) != 0)
|
|
return (error);
|
|
su = (suser(td) == 0);
|
|
for (;;) {
|
|
old_inherited_pri = uq->uq_inherited_pri;
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_busy(&uq->uq_key);
|
|
umtxq_unlock(&uq->uq_key);
|
|
|
|
ceiling = RTP_PRIO_MAX - fuword32(&m->m_ceilings[0]);
|
|
if (ceiling > RTP_PRIO_MAX) {
|
|
error = EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
if (UPRI(td) < PRI_MIN_REALTIME + ceiling) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
error = EINVAL;
|
|
goto out;
|
|
}
|
|
if (su && PRI_MIN_REALTIME + ceiling < uq->uq_inherited_pri) {
|
|
uq->uq_inherited_pri = PRI_MIN_REALTIME + ceiling;
|
|
if (uq->uq_inherited_pri < UPRI(td))
|
|
sched_lend_user_prio(td, uq->uq_inherited_pri);
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
owner = casuword32(&m->m_owner,
|
|
UMUTEX_CONTESTED, id | UMUTEX_CONTESTED);
|
|
|
|
if (owner == UMUTEX_CONTESTED) {
|
|
error = 0;
|
|
break;
|
|
}
|
|
|
|
/* The address was invalid. */
|
|
if (owner == -1) {
|
|
error = EFAULT;
|
|
break;
|
|
}
|
|
|
|
if ((flags & UMUTEX_ERROR_CHECK) != 0 &&
|
|
(owner & ~UMUTEX_CONTESTED) == id) {
|
|
error = EDEADLK;
|
|
break;
|
|
}
|
|
|
|
if (try != 0) {
|
|
error = EBUSY;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If we caught a signal, we have retried and now
|
|
* exit immediately.
|
|
*/
|
|
if (error != 0)
|
|
break;
|
|
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_insert(uq);
|
|
umtxq_unbusy(&uq->uq_key);
|
|
error = umtxq_sleep(uq, "umtxpp", timo);
|
|
umtxq_remove(uq);
|
|
umtxq_unlock(&uq->uq_key);
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
uq->uq_inherited_pri = old_inherited_pri;
|
|
pri = PRI_MAX;
|
|
TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
|
|
uq2 = TAILQ_FIRST(&pi->pi_blocked);
|
|
if (uq2 != NULL) {
|
|
if (pri > UPRI(uq2->uq_thread))
|
|
pri = UPRI(uq2->uq_thread);
|
|
}
|
|
}
|
|
if (pri > uq->uq_inherited_pri)
|
|
pri = uq->uq_inherited_pri;
|
|
sched_unlend_user_prio(td, pri);
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
|
|
if (error != 0) {
|
|
mtx_lock_spin(&sched_lock);
|
|
uq->uq_inherited_pri = old_inherited_pri;
|
|
pri = PRI_MAX;
|
|
TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
|
|
uq2 = TAILQ_FIRST(&pi->pi_blocked);
|
|
if (uq2 != NULL) {
|
|
if (pri > UPRI(uq2->uq_thread))
|
|
pri = UPRI(uq2->uq_thread);
|
|
}
|
|
}
|
|
if (pri > uq->uq_inherited_pri)
|
|
pri = uq->uq_inherited_pri;
|
|
sched_unlend_user_prio(td, pri);
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
|
|
out:
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_unbusy(&uq->uq_key);
|
|
umtxq_unlock(&uq->uq_key);
|
|
umtx_key_release(&uq->uq_key);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Unlock a PP mutex.
|
|
*/
|
|
static int
|
|
do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags)
|
|
{
|
|
struct umtx_key key;
|
|
struct umtx_q *uq, *uq2;
|
|
struct umtx_pi *pi;
|
|
uint32_t owner, id;
|
|
uint32_t rceiling;
|
|
int error, pri, new_inherited_pri, su;
|
|
|
|
id = td->td_tid;
|
|
uq = td->td_umtxq;
|
|
su = (suser(td) == 0);
|
|
|
|
/*
|
|
* Make sure we own this mtx.
|
|
*/
|
|
owner = fuword32(&m->m_owner);
|
|
if (owner == -1)
|
|
return (EFAULT);
|
|
|
|
if ((owner & ~UMUTEX_CONTESTED) != id)
|
|
return (EPERM);
|
|
|
|
error = copyin(&m->m_ceilings[1], &rceiling, sizeof(uint32_t));
|
|
if (error != 0)
|
|
return (error);
|
|
|
|
if (rceiling == -1)
|
|
new_inherited_pri = PRI_MAX;
|
|
else {
|
|
rceiling = RTP_PRIO_MAX - rceiling;
|
|
if (rceiling > RTP_PRIO_MAX)
|
|
return (EINVAL);
|
|
new_inherited_pri = PRI_MIN_REALTIME + rceiling;
|
|
}
|
|
|
|
if ((error = umtx_key_get(m, TYPE_PP_UMUTEX, GET_SHARE(flags),
|
|
&key)) != 0)
|
|
return (error);
|
|
umtxq_lock(&key);
|
|
umtxq_busy(&key);
|
|
umtxq_unlock(&key);
|
|
/*
|
|
* For priority protected mutex, always set unlocked state
|
|
* to UMUTEX_CONTESTED, so that userland always enters kernel
|
|
* to lock the mutex, it is necessary because thread priority
|
|
* has to be adjusted for such mutex.
|
|
*/
|
|
error = suword32(&m->m_owner, UMUTEX_CONTESTED);
|
|
|
|
umtxq_lock(&key);
|
|
if (error == 0)
|
|
umtxq_signal(&key, 1);
|
|
umtxq_unbusy(&key);
|
|
umtxq_unlock(&key);
|
|
|
|
if (error == -1)
|
|
error = EFAULT;
|
|
else {
|
|
mtx_lock_spin(&sched_lock);
|
|
if (su != 0)
|
|
uq->uq_inherited_pri = new_inherited_pri;
|
|
pri = PRI_MAX;
|
|
TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
|
|
uq2 = TAILQ_FIRST(&pi->pi_blocked);
|
|
if (uq2 != NULL) {
|
|
if (pri > UPRI(uq2->uq_thread))
|
|
pri = UPRI(uq2->uq_thread);
|
|
}
|
|
}
|
|
if (pri > uq->uq_inherited_pri)
|
|
pri = uq->uq_inherited_pri;
|
|
sched_unlend_user_prio(td, pri);
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
umtx_key_release(&key);
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
do_set_ceiling(struct thread *td, struct umutex *m, uint32_t ceiling,
|
|
uint32_t *old_ceiling)
|
|
{
|
|
struct umtx_q *uq;
|
|
uint32_t save_ceiling;
|
|
uint32_t owner, id;
|
|
uint32_t flags;
|
|
int error;
|
|
|
|
flags = fuword32(&m->m_flags);
|
|
if ((flags & UMUTEX_PRIO_PROTECT) == 0)
|
|
return (EINVAL);
|
|
if (ceiling > RTP_PRIO_MAX)
|
|
return (EINVAL);
|
|
id = td->td_tid;
|
|
uq = td->td_umtxq;
|
|
if ((error = umtx_key_get(m, TYPE_PP_UMUTEX, GET_SHARE(flags),
|
|
&uq->uq_key)) != 0)
|
|
return (error);
|
|
for (;;) {
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_busy(&uq->uq_key);
|
|
umtxq_unlock(&uq->uq_key);
|
|
|
|
save_ceiling = fuword32(&m->m_ceilings[0]);
|
|
|
|
owner = casuword32(&m->m_owner,
|
|
UMUTEX_CONTESTED, id | UMUTEX_CONTESTED);
|
|
|
|
if (owner == UMUTEX_CONTESTED) {
|
|
suword32(&m->m_ceilings[0], ceiling);
|
|
suword32(&m->m_owner, UMUTEX_CONTESTED);
|
|
error = 0;
|
|
break;
|
|
}
|
|
|
|
/* The address was invalid. */
|
|
if (owner == -1) {
|
|
error = EFAULT;
|
|
break;
|
|
}
|
|
|
|
if ((owner & ~UMUTEX_CONTESTED) == id) {
|
|
suword32(&m->m_ceilings[0], ceiling);
|
|
error = 0;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If we caught a signal, we have retried and now
|
|
* exit immediately.
|
|
*/
|
|
if (error != 0)
|
|
break;
|
|
|
|
/*
|
|
* We set the contested bit, sleep. Otherwise the lock changed
|
|
* and we need to retry or we lost a race to the thread
|
|
* unlocking the umtx.
|
|
*/
|
|
umtxq_lock(&uq->uq_key);
|
|
umtxq_insert(uq);
|
|
umtxq_unbusy(&uq->uq_key);
|
|
error = umtxq_sleep(uq, "umtxpp", 0);
|
|
umtxq_remove(uq);
|
|
umtxq_unlock(&uq->uq_key);
|
|
}
|
|
umtxq_lock(&uq->uq_key);
|
|
if (error == 0)
|
|
umtxq_signal(&uq->uq_key, INT_MAX);
|
|
umtxq_unbusy(&uq->uq_key);
|
|
umtxq_unlock(&uq->uq_key);
|
|
umtx_key_release(&uq->uq_key);
|
|
if (error == 0 && old_ceiling != NULL)
|
|
suword32(old_ceiling, save_ceiling);
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
_do_lock_umutex(struct thread *td, struct umutex *m, int flags, int timo,
|
|
int try)
|
|
{
|
|
switch(flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) {
|
|
case 0:
|
|
return (_do_lock_normal(td, m, flags, timo, try));
|
|
case UMUTEX_PRIO_INHERIT:
|
|
return (_do_lock_pi(td, m, flags, timo, try));
|
|
case UMUTEX_PRIO_PROTECT:
|
|
return (_do_lock_pp(td, m, flags, timo, try));
|
|
}
|
|
return (EINVAL);
|
|
}
|
|
|
|
/*
|
|
* Lock a userland POSIX mutex.
|
|
*/
|
|
static int
|
|
do_lock_umutex(struct thread *td, struct umutex *m,
|
|
struct timespec *timeout, int try)
|
|
{
|
|
struct timespec ts, ts2, ts3;
|
|
struct timeval tv;
|
|
uint32_t flags;
|
|
int error;
|
|
|
|
flags = fuword32(&m->m_flags);
|
|
if (flags == -1)
|
|
return (EFAULT);
|
|
|
|
if (timeout == NULL) {
|
|
error = _do_lock_umutex(td, m, flags, 0, try);
|
|
/* Mutex locking is restarted if it is interrupted. */
|
|
if (error == EINTR)
|
|
error = ERESTART;
|
|
} else {
|
|
getnanouptime(&ts);
|
|
timespecadd(&ts, timeout);
|
|
TIMESPEC_TO_TIMEVAL(&tv, timeout);
|
|
for (;;) {
|
|
error = _do_lock_umutex(td, m, flags, tvtohz(&tv), try);
|
|
if (error != ETIMEDOUT)
|
|
break;
|
|
getnanouptime(&ts2);
|
|
if (timespeccmp(&ts2, &ts, >=)) {
|
|
error = ETIMEDOUT;
|
|
break;
|
|
}
|
|
ts3 = ts;
|
|
timespecsub(&ts3, &ts2);
|
|
TIMESPEC_TO_TIMEVAL(&tv, &ts3);
|
|
}
|
|
/* Timed-locking is not restarted. */
|
|
if (error == ERESTART)
|
|
error = EINTR;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Unlock a userland POSIX mutex.
|
|
*/
|
|
static int
|
|
do_unlock_umutex(struct thread *td, struct umutex *m)
|
|
{
|
|
uint32_t flags;
|
|
|
|
flags = fuword32(&m->m_flags);
|
|
if (flags == -1)
|
|
return (EFAULT);
|
|
|
|
switch(flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) {
|
|
case 0:
|
|
return (do_unlock_normal(td, m, flags));
|
|
case UMUTEX_PRIO_INHERIT:
|
|
return (do_unlock_pi(td, m, flags));
|
|
case UMUTEX_PRIO_PROTECT:
|
|
return (do_unlock_pp(td, m, flags));
|
|
}
|
|
|
|
return (EINVAL);
|
|
}
|
|
|
|
int
|
|
_umtx_lock(struct thread *td, struct _umtx_lock_args *uap)
|
|
/* struct umtx *umtx */
|
|
{
|
|
return _do_lock(td, uap->umtx, td->td_tid, 0);
|
|
}
|
|
|
|
int
|
|
_umtx_unlock(struct thread *td, struct _umtx_unlock_args *uap)
|
|
/* struct umtx *umtx */
|
|
{
|
|
return do_unlock(td, uap->umtx, td->td_tid);
|
|
}
|
|
|
|
int
|
|
_umtx_op(struct thread *td, struct _umtx_op_args *uap)
|
|
{
|
|
struct timespec timeout;
|
|
struct timespec *ts;
|
|
int error;
|
|
|
|
switch(uap->op) {
|
|
case UMTX_OP_MUTEX_LOCK:
|
|
/* Allow a null timespec (wait forever). */
|
|
if (uap->uaddr2 == NULL)
|
|
ts = NULL;
|
|
else {
|
|
error = copyin(uap->uaddr2, &timeout, sizeof(timeout));
|
|
if (error != 0)
|
|
break;
|
|
if (timeout.tv_nsec >= 1000000000 ||
|
|
timeout.tv_nsec < 0) {
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
ts = &timeout;
|
|
}
|
|
error = do_lock_umutex(td, uap->obj, ts, 0);
|
|
break;
|
|
case UMTX_OP_MUTEX_UNLOCK:
|
|
error = do_unlock_umutex(td, uap->obj);
|
|
break;
|
|
case UMTX_OP_LOCK:
|
|
/* Allow a null timespec (wait forever). */
|
|
if (uap->uaddr2 == NULL)
|
|
ts = NULL;
|
|
else {
|
|
error = copyin(uap->uaddr2, &timeout, sizeof(timeout));
|
|
if (error != 0)
|
|
break;
|
|
if (timeout.tv_nsec >= 1000000000 ||
|
|
timeout.tv_nsec < 0) {
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
ts = &timeout;
|
|
}
|
|
error = do_lock(td, uap->obj, uap->val, ts);
|
|
break;
|
|
case UMTX_OP_UNLOCK:
|
|
error = do_unlock(td, uap->obj, uap->val);
|
|
break;
|
|
case UMTX_OP_WAIT:
|
|
/* Allow a null timespec (wait forever). */
|
|
if (uap->uaddr2 == NULL)
|
|
ts = NULL;
|
|
else {
|
|
error = copyin(uap->uaddr2, &timeout, sizeof(timeout));
|
|
if (error != 0)
|
|
break;
|
|
if (timeout.tv_nsec >= 1000000000 ||
|
|
timeout.tv_nsec < 0) {
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
ts = &timeout;
|
|
}
|
|
error = do_wait(td, uap->obj, uap->val, ts);
|
|
break;
|
|
case UMTX_OP_WAKE:
|
|
error = kern_umtx_wake(td, uap->obj, uap->val);
|
|
break;
|
|
case UMTX_OP_MUTEX_TRYLOCK:
|
|
error = do_lock_umutex(td, uap->obj, NULL, 1);
|
|
break;
|
|
case UMTX_OP_SET_CEILING:
|
|
error = do_set_ceiling(td, uap->obj, uap->val, uap->uaddr1);
|
|
break;
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
void
|
|
umtx_thread_init(struct thread *td)
|
|
{
|
|
td->td_umtxq = umtxq_alloc();
|
|
td->td_umtxq->uq_thread = td;
|
|
}
|
|
|
|
void
|
|
umtx_thread_fini(struct thread *td)
|
|
{
|
|
umtxq_free(td->td_umtxq);
|
|
}
|
|
|
|
/*
|
|
* It will be called when new thread is created, e.g fork().
|
|
*/
|
|
void
|
|
umtx_thread_alloc(struct thread *td)
|
|
{
|
|
struct umtx_q *uq;
|
|
|
|
uq = td->td_umtxq;
|
|
uq->uq_inherited_pri = PRI_MAX;
|
|
|
|
KASSERT(uq->uq_flags == 0, ("uq_flags != 0"));
|
|
KASSERT(uq->uq_thread == td, ("uq_thread != td"));
|
|
KASSERT(uq->uq_pi_blocked == NULL, ("uq_pi_blocked != NULL"));
|
|
KASSERT(TAILQ_EMPTY(&uq->uq_pi_contested), ("uq_pi_contested is not empty"));
|
|
}
|
|
|
|
/*
|
|
* exec() hook.
|
|
*/
|
|
static void
|
|
umtx_exec_hook(void *arg __unused, struct proc *p __unused,
|
|
struct image_params *imgp __unused)
|
|
{
|
|
umtx_thread_cleanup(curthread);
|
|
}
|
|
|
|
/*
|
|
* thread_exit() hook.
|
|
*/
|
|
void
|
|
umtx_thread_exit(struct thread *td)
|
|
{
|
|
umtx_thread_cleanup(td);
|
|
}
|
|
|
|
/*
|
|
* clean up umtx data.
|
|
*/
|
|
static void
|
|
umtx_thread_cleanup(struct thread *td)
|
|
{
|
|
struct umtx_q *uq;
|
|
struct umtx_pi *pi;
|
|
|
|
if ((uq = td->td_umtxq) == NULL)
|
|
return;
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
uq->uq_inherited_pri = PRI_MAX;
|
|
while ((pi = TAILQ_FIRST(&uq->uq_pi_contested)) != NULL) {
|
|
pi->pi_owner = NULL;
|
|
TAILQ_REMOVE(&uq->uq_pi_contested, pi, pi_link);
|
|
}
|
|
td->td_flags &= ~TDF_UBORROWING;
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|