d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
21e47be25e
freebsd-dev/sys/kern/kern_umtx.c
Konstantin Belousov 30b3018d48 Provide protection against starvation of the ll/sc loops when accessing userpace. 
Casueword(9) on ll/sc architectures must be prepared for userspace
constantly modifying the same cache line as containing the CAS word,
and not loop infinitely.  Otherwise, rogue userspace livelocks the
kernel.

To fix the issue, change casueword(9) interface to return new value 1
indicating that either comparision or store failed, instead of relying
on the oldval == *oldvalp comparison.  The primitive no longer retries
the operation if it failed spuriously.  Modify callers of
casueword(9), all in kern_umtx.c, to handle retries, and react to
stops and requests to terminate between retries.

On x86, despite cmpxchg should not return spurious failures, we can
take advantage of the new interface and just return PSL.ZF.

Reviewed by:	andrew (arm64, previous version), markj
Tested by:	pho
Reported by:	https://xenbits.xen.org/xsa/advisory-295.txt
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D20772
2019-07-12 18:43:24 +00:00

4714 lines
107 KiB
C
Raw Blame History

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2015, 2016 The FreeBSD Foundation
* Copyright (c) 2004, David Xu <davidxu@freebsd.org>
* Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
* All rights reserved.
*
* Portions of this software were developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_umtx_profiling.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mman.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/resource.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.h>
#include <sys/sbuf.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/syscallsubr.h>
#include <sys/taskqueue.h>
#include <sys/time.h>
#include <sys/eventhandler.h>
#include <sys/umtx.h>
#include <security/mac/mac_framework.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <machine/atomic.h>
#include <machine/cpu.h>
#ifdef COMPAT_FREEBSD32
#include <compat/freebsd32/freebsd32_proto.h>
#endif
#define _UMUTEX_TRY 1
#define _UMUTEX_WAIT 2
#ifdef UMTX_PROFILING
#define UPROF_PERC_BIGGER(w, f, sw, sf) \
(((w) > (sw)) || ((w) == (sw) && (f) > (sf)))
#endif
/* Priority inheritance mutex info. */
struct umtx_pi {
/* Owner thread */
struct thread *pi_owner;
/* Reference count */
int pi_refcount;
/* List entry to link umtx holding by thread */
TAILQ_ENTRY(umtx_pi) pi_link;
/* List entry in hash */
TAILQ_ENTRY(umtx_pi) pi_hashlink;
/* List for waiters */
TAILQ_HEAD(,umtx_q) pi_blocked;
/* Identify a userland lock object */
struct umtx_key pi_key;
};
/* A userland synchronous object user. */
struct umtx_q {
/* Linked list for the hash. */
TAILQ_ENTRY(umtx_q) uq_link;
/* Umtx key. */
struct umtx_key uq_key;
/* Umtx flags. */
int uq_flags;
#define UQF_UMTXQ 0x0001
/* The thread waits on. */
struct thread *uq_thread;
/*
* Blocked on PI mutex. read can use chain lock
* or umtx_lock, write must have both chain lock and
* umtx_lock being hold.
*/
struct umtx_pi *uq_pi_blocked;
/* On blocked list */
TAILQ_ENTRY(umtx_q) uq_lockq;
/* Thread contending with us */
TAILQ_HEAD(,umtx_pi) uq_pi_contested;
/* Inherited priority from PP mutex */
u_char uq_inherited_pri;
/* Spare queue ready to be reused */
struct umtxq_queue *uq_spare_queue;
/* The queue we on */
struct umtxq_queue *uq_cur_queue;
};
TAILQ_HEAD(umtxq_head, umtx_q);
/* Per-key wait-queue */
struct umtxq_queue {
struct umtxq_head head;
struct umtx_key key;
LIST_ENTRY(umtxq_queue) link;
int length;
};
LIST_HEAD(umtxq_list, umtxq_queue);
/* Userland lock object's wait-queue chain */
struct umtxq_chain {
/* Lock for this chain. */
struct mtx uc_lock;
/* List of sleep queues. */
struct umtxq_list uc_queue[2];
#define UMTX_SHARED_QUEUE 0
#define UMTX_EXCLUSIVE_QUEUE 1
LIST_HEAD(, umtxq_queue) uc_spare_queue;
/* Busy flag */
char uc_busy;
/* Chain lock waiters */
int uc_waiters;
/* All PI in the list */
TAILQ_HEAD(,umtx_pi) uc_pi_list;
#ifdef UMTX_PROFILING
u_int length;
u_int max_length;
#endif
};
#define UMTXQ_LOCKED_ASSERT(uc) mtx_assert(&(uc)->uc_lock, MA_OWNED)
/*
* Don't propagate time-sharing priority, there is a security reason,
* a user can simply introduce PI-mutex, let thread A lock the mutex,
* and let another thread B block on the mutex, because B is
* sleeping, its priority will be boosted, this causes A's priority to
* be boosted via priority propagating too and will never be lowered even
* if it is using 100%CPU, this is unfair to other processes.
*/
#define UPRI(td) (((td)->td_user_pri >= PRI_MIN_TIMESHARE &&\
(td)->td_user_pri <= PRI_MAX_TIMESHARE) ?\
PRI_MAX_TIMESHARE : (td)->td_user_pri)
#define GOLDEN_RATIO_PRIME 2654404609U
#ifndef UMTX_CHAINS
#define UMTX_CHAINS 512
#endif
#define UMTX_SHIFTS (__WORD_BIT - 9)
#define GET_SHARE(flags) \
(((flags) & USYNC_PROCESS_SHARED) == 0 ? THREAD_SHARE : PROCESS_SHARE)
#define BUSY_SPINS 200
struct abs_timeout {
int clockid;
bool is_abs_real; /* TIMER_ABSTIME && CLOCK_REALTIME* */
struct timespec cur;
struct timespec end;
};
#ifdef COMPAT_FREEBSD32
struct umutex32 {
volatile __lwpid_t m_owner; /* Owner of the mutex */
__uint32_t m_flags; /* Flags of the mutex */
__uint32_t m_ceilings[2]; /* Priority protect ceiling */
__uint32_t m_rb_lnk; /* Robust linkage */
__uint32_t m_pad;
__uint32_t m_spare[2];
};
_Static_assert(sizeof(struct umutex) == sizeof(struct umutex32), "umutex32");
_Static_assert(__offsetof(struct umutex, m_spare[0]) ==
__offsetof(struct umutex32, m_spare[0]), "m_spare32");
#endif
int umtx_shm_vnobj_persistent = 0;
SYSCTL_INT(_kern_ipc, OID_AUTO, umtx_vnode_persistent, CTLFLAG_RWTUN,
&umtx_shm_vnobj_persistent, 0,
"False forces destruction of umtx attached to file, on last close");
static int umtx_max_rb = 1000;
SYSCTL_INT(_kern_ipc, OID_AUTO, umtx_max_robust, CTLFLAG_RWTUN,
&umtx_max_rb, 0,
"");
static uma_zone_t umtx_pi_zone;
static struct umtxq_chain umtxq_chains[2][UMTX_CHAINS];
static MALLOC_DEFINE(M_UMTX, "umtx", "UMTX queue memory");
static int umtx_pi_allocated;
static SYSCTL_NODE(_debug, OID_AUTO, umtx, CTLFLAG_RW, 0, "umtx debug");
SYSCTL_INT(_debug_umtx, OID_AUTO, umtx_pi_allocated, CTLFLAG_RD,
&umtx_pi_allocated, 0, "Allocated umtx_pi");
static int umtx_verbose_rb = 1;
SYSCTL_INT(_debug_umtx, OID_AUTO, robust_faults_verbose, CTLFLAG_RWTUN,
&umtx_verbose_rb, 0,
"");
#ifdef UMTX_PROFILING
static long max_length;
SYSCTL_LONG(_debug_umtx, OID_AUTO, max_length, CTLFLAG_RD, &max_length, 0, "max_length");
static SYSCTL_NODE(_debug_umtx, OID_AUTO, chains, CTLFLAG_RD, 0, "umtx chain stats");
#endif
static void abs_timeout_update(struct abs_timeout *timo);
static void umtx_shm_init(void);
static void umtxq_sysinit(void *);
static void umtxq_hash(struct umtx_key *key);
static struct umtxq_chain *umtxq_getchain(struct umtx_key *key);
static void umtxq_lock(struct umtx_key *key);
static void umtxq_unlock(struct umtx_key *key);
static void umtxq_busy(struct umtx_key *key);
static void umtxq_unbusy(struct umtx_key *key);
static void umtxq_insert_queue(struct umtx_q *uq, int q);
static void umtxq_remove_queue(struct umtx_q *uq, int q);
static int umtxq_sleep(struct umtx_q *uq, const char *wmesg, struct abs_timeout *);
static int umtxq_count(struct umtx_key *key);
static struct umtx_pi *umtx_pi_alloc(int);
static void umtx_pi_free(struct umtx_pi *pi);
static int do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags,
bool rb);
static void umtx_thread_cleanup(struct thread *td);
static void umtx_exec_hook(void *arg __unused, struct proc *p __unused,
struct image_params *imgp __unused);
SYSINIT(umtx, SI_SUB_EVENTHANDLER+1, SI_ORDER_MIDDLE, umtxq_sysinit, NULL);
#define umtxq_signal(key, nwake) umtxq_signal_queue((key), (nwake), UMTX_SHARED_QUEUE)
#define umtxq_insert(uq) umtxq_insert_queue((uq), UMTX_SHARED_QUEUE)
#define umtxq_remove(uq) umtxq_remove_queue((uq), UMTX_SHARED_QUEUE)
static struct mtx umtx_lock;
#ifdef UMTX_PROFILING
static void
umtx_init_profiling(void)
{
struct sysctl_oid *chain_oid;
char chain_name[10];
int i;
for (i = 0; i < UMTX_CHAINS; ++i) {
snprintf(chain_name, sizeof(chain_name), "%d", i);
chain_oid = SYSCTL_ADD_NODE(NULL,
SYSCTL_STATIC_CHILDREN(_debug_umtx_chains), OID_AUTO,
chain_name, CTLFLAG_RD, NULL, "umtx hash stats");
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO,
"max_length0", CTLFLAG_RD, &umtxq_chains[0][i].max_length, 0, NULL);
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO,
"max_length1", CTLFLAG_RD, &umtxq_chains[1][i].max_length, 0, NULL);
}
}
static int
sysctl_debug_umtx_chains_peaks(SYSCTL_HANDLER_ARGS)
{
char buf[512];
struct sbuf sb;
struct umtxq_chain *uc;
u_int fract, i, j, tot, whole;
u_int sf0, sf1, sf2, sf3, sf4;
u_int si0, si1, si2, si3, si4;
u_int sw0, sw1, sw2, sw3, sw4;
sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
for (i = 0; i < 2; i++) {
tot = 0;
for (j = 0; j < UMTX_CHAINS; ++j) {
uc = &umtxq_chains[i][j];
mtx_lock(&uc->uc_lock);
tot += uc->max_length;
mtx_unlock(&uc->uc_lock);
}
if (tot == 0)
sbuf_printf(&sb, "%u) Empty ", i);
else {
sf0 = sf1 = sf2 = sf3 = sf4 = 0;
si0 = si1 = si2 = si3 = si4 = 0;
sw0 = sw1 = sw2 = sw3 = sw4 = 0;
for (j = 0; j < UMTX_CHAINS; j++) {
uc = &umtxq_chains[i][j];
mtx_lock(&uc->uc_lock);
whole = uc->max_length * 100;
mtx_unlock(&uc->uc_lock);
fract = (whole % tot) * 100;
if (UPROF_PERC_BIGGER(whole, fract, sw0, sf0)) {
sf0 = fract;
si0 = j;
sw0 = whole;
} else if (UPROF_PERC_BIGGER(whole, fract, sw1,
sf1)) {
sf1 = fract;
si1 = j;
sw1 = whole;
} else if (UPROF_PERC_BIGGER(whole, fract, sw2,
sf2)) {
sf2 = fract;
si2 = j;
sw2 = whole;
} else if (UPROF_PERC_BIGGER(whole, fract, sw3,
sf3)) {
sf3 = fract;
si3 = j;
sw3 = whole;
} else if (UPROF_PERC_BIGGER(whole, fract, sw4,
sf4)) {
sf4 = fract;
si4 = j;
sw4 = whole;
}
}
sbuf_printf(&sb, "queue %u:\n", i);
sbuf_printf(&sb, "1st: %u.%u%% idx: %u\n", sw0 / tot,
sf0 / tot, si0);
sbuf_printf(&sb, "2nd: %u.%u%% idx: %u\n", sw1 / tot,
sf1 / tot, si1);
sbuf_printf(&sb, "3rd: %u.%u%% idx: %u\n", sw2 / tot,
sf2 / tot, si2);
sbuf_printf(&sb, "4th: %u.%u%% idx: %u\n", sw3 / tot,
sf3 / tot, si3);
sbuf_printf(&sb, "5th: %u.%u%% idx: %u\n", sw4 / tot,
sf4 / tot, si4);
}
}
sbuf_trim(&sb);
sbuf_finish(&sb);
sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
sbuf_delete(&sb);
return (0);
}
static int
sysctl_debug_umtx_chains_clear(SYSCTL_HANDLER_ARGS)
{
struct umtxq_chain *uc;
u_int i, j;
int clear, error;
clear = 0;
error = sysctl_handle_int(oidp, &clear, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (clear != 0) {
for (i = 0; i < 2; ++i) {
for (j = 0; j < UMTX_CHAINS; ++j) {
uc = &umtxq_chains[i][j];
mtx_lock(&uc->uc_lock);
uc->length = 0;
uc->max_length = 0;
mtx_unlock(&uc->uc_lock);
}
}
}
return (0);
}
SYSCTL_PROC(_debug_umtx_chains, OID_AUTO, clear,
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
sysctl_debug_umtx_chains_clear, "I", "Clear umtx chains statistics");
SYSCTL_PROC(_debug_umtx_chains, OID_AUTO, peaks,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
sysctl_debug_umtx_chains_peaks, "A", "Highest peaks in chains max length");
#endif
static void
umtxq_sysinit(void *arg __unused)
{
int i, j;
umtx_pi_zone = uma_zcreate("umtx pi", sizeof(struct umtx_pi),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
for (i = 0; i < 2; ++i) {
for (j = 0; j < UMTX_CHAINS; ++j) {
mtx_init(&umtxq_chains[i][j].uc_lock, "umtxql", NULL,
MTX_DEF | MTX_DUPOK);
LIST_INIT(&umtxq_chains[i][j].uc_queue[0]);
LIST_INIT(&umtxq_chains[i][j].uc_queue[1]);
LIST_INIT(&umtxq_chains[i][j].uc_spare_queue);
TAILQ_INIT(&umtxq_chains[i][j].uc_pi_list);
umtxq_chains[i][j].uc_busy = 0;
umtxq_chains[i][j].uc_waiters = 0;
#ifdef UMTX_PROFILING
umtxq_chains[i][j].length = 0;
umtxq_chains[i][j].max_length = 0;
#endif
}
}
#ifdef UMTX_PROFILING
umtx_init_profiling();
#endif
mtx_init(&umtx_lock, "umtx lock", NULL, MTX_DEF);
EVENTHANDLER_REGISTER(process_exec, umtx_exec_hook, NULL,
EVENTHANDLER_PRI_ANY);
umtx_shm_init();
}
struct umtx_q *
umtxq_alloc(void)
{
struct umtx_q *uq;
uq = malloc(sizeof(struct umtx_q), M_UMTX, M_WAITOK | M_ZERO);
uq->uq_spare_queue = malloc(sizeof(struct umtxq_queue), M_UMTX,
M_WAITOK | M_ZERO);
TAILQ_INIT(&uq->uq_spare_queue->head);
TAILQ_INIT(&uq->uq_pi_contested);
uq->uq_inherited_pri = PRI_MAX;
return (uq);
}
void
umtxq_free(struct umtx_q *uq)
{
MPASS(uq->uq_spare_queue != NULL);
free(uq->uq_spare_queue, M_UMTX);
free(uq, M_UMTX);
}
static inline void
umtxq_hash(struct umtx_key *key)
{
unsigned n;
n = (uintptr_t)key->info.both.a + key->info.both.b;
key->hash = ((n * GOLDEN_RATIO_PRIME) >> UMTX_SHIFTS) % UMTX_CHAINS;
}
static inline struct umtxq_chain *
umtxq_getchain(struct umtx_key *key)
{
if (key->type <= TYPE_SEM)
return (&umtxq_chains[1][key->hash]);
return (&umtxq_chains[0][key->hash]);
}
/*
* Lock a chain.
*/
static inline void
umtxq_lock(struct umtx_key *key)
{
struct umtxq_chain *uc;
uc = umtxq_getchain(key);
mtx_lock(&uc->uc_lock);
}
/*
* Unlock a chain.
*/
static inline void
umtxq_unlock(struct umtx_key *key)
{
struct umtxq_chain *uc;
uc = umtxq_getchain(key);
mtx_unlock(&uc->uc_lock);
}
/*
* Set chain to busy state when following operation
* may be blocked (kernel mutex can not be used).
*/
static inline void
umtxq_busy(struct umtx_key *key)
{
struct umtxq_chain *uc;
uc = umtxq_getchain(key);
mtx_assert(&uc->uc_lock, MA_OWNED);
if (uc->uc_busy) {
#ifdef SMP
if (smp_cpus > 1) {
int count = BUSY_SPINS;
if (count > 0) {
umtxq_unlock(key);
while (uc->uc_busy && --count > 0)
cpu_spinwait();
umtxq_lock(key);
}
}
#endif
while (uc->uc_busy) {
uc->uc_waiters++;
msleep(uc, &uc->uc_lock, 0, "umtxqb", 0);
uc->uc_waiters--;
}
}
uc->uc_busy = 1;
}
/*
* Unbusy a chain.
*/
static inline void
umtxq_unbusy(struct umtx_key *key)
{
struct umtxq_chain *uc;
uc = umtxq_getchain(key);
mtx_assert(&uc->uc_lock, MA_OWNED);
KASSERT(uc->uc_busy != 0, ("not busy"));
uc->uc_busy = 0;
if (uc->uc_waiters)
wakeup_one(uc);
}
static inline void
umtxq_unbusy_unlocked(struct umtx_key *key)
{
umtxq_lock(key);
umtxq_unbusy(key);
umtxq_unlock(key);
}
static struct umtxq_queue *
umtxq_queue_lookup(struct umtx_key *key, int q)
{
struct umtxq_queue *uh;
struct umtxq_chain *uc;
uc = umtxq_getchain(key);
UMTXQ_LOCKED_ASSERT(uc);
LIST_FOREACH(uh, &uc->uc_queue[q], link) {
if (umtx_key_match(&uh->key, key))
return (uh);
}
return (NULL);
}
static inline void
umtxq_insert_queue(struct umtx_q *uq, int q)
{
struct umtxq_queue *uh;
struct umtxq_chain *uc;
uc = umtxq_getchain(&uq->uq_key);
UMTXQ_LOCKED_ASSERT(uc);
KASSERT((uq->uq_flags & UQF_UMTXQ) == 0, ("umtx_q is already on queue"));
uh = umtxq_queue_lookup(&uq->uq_key, q);
if (uh != NULL) {
LIST_INSERT_HEAD(&uc->uc_spare_queue, uq->uq_spare_queue, link);
} else {
uh = uq->uq_spare_queue;
uh->key = uq->uq_key;
LIST_INSERT_HEAD(&uc->uc_queue[q], uh, link);
#ifdef UMTX_PROFILING
uc->length++;
if (uc->length > uc->max_length) {
uc->max_length = uc->length;
if (uc->max_length > max_length)
max_length = uc->max_length;
}
#endif
}
uq->uq_spare_queue = NULL;
TAILQ_INSERT_TAIL(&uh->head, uq, uq_link);
uh->length++;
uq->uq_flags |= UQF_UMTXQ;
uq->uq_cur_queue = uh;
return;
}
static inline void
umtxq_remove_queue(struct umtx_q *uq, int q)
{
struct umtxq_chain *uc;
struct umtxq_queue *uh;
uc = umtxq_getchain(&uq->uq_key);
UMTXQ_LOCKED_ASSERT(uc);
if (uq->uq_flags & UQF_UMTXQ) {
uh = uq->uq_cur_queue;
TAILQ_REMOVE(&uh->head, uq, uq_link);
uh->length--;
uq->uq_flags &= ~UQF_UMTXQ;
if (TAILQ_EMPTY(&uh->head)) {
KASSERT(uh->length == 0,
("inconsistent umtxq_queue length"));
#ifdef UMTX_PROFILING
uc->length--;
#endif
LIST_REMOVE(uh, link);
} else {
uh = LIST_FIRST(&uc->uc_spare_queue);
KASSERT(uh != NULL, ("uc_spare_queue is empty"));
LIST_REMOVE(uh, link);
}
uq->uq_spare_queue = uh;
uq->uq_cur_queue = NULL;
}
}
/*
* Check if there are multiple waiters
*/
static int
umtxq_count(struct umtx_key *key)
{
struct umtxq_queue *uh;
UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
if (uh != NULL)
return (uh->length);
return (0);
}
/*
* Check if there are multiple PI waiters and returns first
* waiter.
*/
static int
umtxq_count_pi(struct umtx_key *key, struct umtx_q **first)
{
struct umtxq_queue *uh;
*first = NULL;
UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
if (uh != NULL) {
*first = TAILQ_FIRST(&uh->head);
return (uh->length);
}
return (0);
}
/*
* Check for possible stops and suspensions while executing a umtx
* locking operation.
*
* The sleep argument controls whether the function can handle a stop
* request itself or it should return ERESTART and the request is
* proceed at the kernel/user boundary in ast.
*
* Typically, when retrying due to casueword(9) failure (rv == 1), we
* should handle the stop requests there, with exception of cases when
* the thread busied the umtx key, or when functions return
* immediately if umtxq_check_susp() returned non-zero. On the other
* hand, retrying the whole lock operation, we better not stop there
* but delegate the handling to ast.
*
* If the request is for thread termination P_SINGLE_EXIT, we cannot
* handle it at all, and simply return EINTR.
*/
static int
umtxq_check_susp(struct thread *td, bool sleep)
{
struct proc *p;
int error;
/*
* The check for TDF_NEEDSUSPCHK is racy, but it is enough to
* eventually break the lockstep loop.
*/
if ((td->td_flags & TDF_NEEDSUSPCHK) == 0)
return (0);
error = 0;
p = td->td_proc;
PROC_LOCK(p);
if (P_SHOULDSTOP(p) ||
((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_SUSPEND))) {
if (p->p_flag & P_SINGLE_EXIT)
error = EINTR;
else
error = sleep ? thread_suspend_check(0) : ERESTART;
}
PROC_UNLOCK(p);
return (error);
}
/*
* Wake up threads waiting on an userland object.
*/
static int
umtxq_signal_queue(struct umtx_key *key, int n_wake, int q)
{
struct umtxq_queue *uh;
struct umtx_q *uq;
int ret;
ret = 0;
UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
uh = umtxq_queue_lookup(key, q);
if (uh != NULL) {
while ((uq = TAILQ_FIRST(&uh->head)) != NULL) {
umtxq_remove_queue(uq, q);
wakeup(uq);
if (++ret >= n_wake)
return (ret);
}
}
return (ret);
}
/*
* Wake up specified thread.
*/
static inline void
umtxq_signal_thread(struct umtx_q *uq)
{
UMTXQ_LOCKED_ASSERT(umtxq_getchain(&uq->uq_key));
umtxq_remove(uq);
wakeup(uq);
}
static inline int
tstohz(const struct timespec *tsp)
{
struct timeval tv;
TIMESPEC_TO_TIMEVAL(&tv, tsp);
return tvtohz(&tv);
}
static void
abs_timeout_init(struct abs_timeout *timo, int clockid, int absolute,
const struct timespec *timeout)
{
timo->clockid = clockid;
if (!absolute) {
timo->is_abs_real = false;
abs_timeout_update(timo);
timespecadd(&timo->cur, timeout, &timo->end);
} else {
timo->end = *timeout;
timo->is_abs_real = clockid == CLOCK_REALTIME ||
clockid == CLOCK_REALTIME_FAST ||
clockid == CLOCK_REALTIME_PRECISE;
/*
* If is_abs_real, umtxq_sleep will read the clock
* after setting td_rtcgen; otherwise, read it here.
*/
if (!timo->is_abs_real) {
abs_timeout_update(timo);
}
}
}
static void
abs_timeout_init2(struct abs_timeout *timo, const struct _umtx_time *umtxtime)
{
abs_timeout_init(timo, umtxtime->_clockid,
(umtxtime->_flags & UMTX_ABSTIME) != 0, &umtxtime->_timeout);
}
static inline void
abs_timeout_update(struct abs_timeout *timo)
{
kern_clock_gettime(curthread, timo->clockid, &timo->cur);
}
static int
abs_timeout_gethz(struct abs_timeout *timo)
{
struct timespec tts;
if (timespeccmp(&timo->end, &timo->cur, <=))
return (-1);
timespecsub(&timo->end, &timo->cur, &tts);
return (tstohz(&tts));
}
static uint32_t
umtx_unlock_val(uint32_t flags, bool rb)
{
if (rb)
return (UMUTEX_RB_OWNERDEAD);
else if ((flags & UMUTEX_NONCONSISTENT) != 0)
return (UMUTEX_RB_NOTRECOV);
else
return (UMUTEX_UNOWNED);
}
/*
* Put thread into sleep state, before sleeping, check if
* thread was removed from umtx queue.
*/
static inline int
umtxq_sleep(struct umtx_q *uq, const char *wmesg, struct abs_timeout *abstime)
{
struct umtxq_chain *uc;
int error, timo;
if (abstime != NULL && abstime->is_abs_real) {
curthread->td_rtcgen = atomic_load_acq_int(&rtc_generation);
abs_timeout_update(abstime);
}
uc = umtxq_getchain(&uq->uq_key);
UMTXQ_LOCKED_ASSERT(uc);
for (;;) {
if (!(uq->uq_flags & UQF_UMTXQ)) {
error = 0;
break;
}
if (abstime != NULL) {
timo = abs_timeout_gethz(abstime);
if (timo < 0) {
error = ETIMEDOUT;
break;
}
} else
timo = 0;
error = msleep(uq, &uc->uc_lock, PCATCH | PDROP, wmesg, timo);
if (error == EINTR || error == ERESTART) {
umtxq_lock(&uq->uq_key);
break;
}
if (abstime != NULL) {
if (abstime->is_abs_real)
curthread->td_rtcgen =
atomic_load_acq_int(&rtc_generation);
abs_timeout_update(abstime);
}
umtxq_lock(&uq->uq_key);
}
curthread->td_rtcgen = 0;
return (error);
}
/*
* Convert userspace address into unique logical address.
*/
int
umtx_key_get(const void *addr, int type, int share, struct umtx_key *key)
{
struct thread *td = curthread;
vm_map_t map;
vm_map_entry_t entry;
vm_pindex_t pindex;
vm_prot_t prot;
boolean_t wired;
key->type = type;
if (share == THREAD_SHARE) {
key->shared = 0;
key->info.private.vs = td->td_proc->p_vmspace;
key->info.private.addr = (uintptr_t)addr;
} else {
MPASS(share == PROCESS_SHARE || share == AUTO_SHARE);
map = &td->td_proc->p_vmspace->vm_map;
if (vm_map_lookup(&map, (vm_offset_t)addr, VM_PROT_WRITE,
&entry, &key->info.shared.object, &pindex, &prot,
&wired) != KERN_SUCCESS) {
return (EFAULT);
}
if ((share == PROCESS_SHARE) ||
(share == AUTO_SHARE &&
VM_INHERIT_SHARE == entry->inheritance)) {
key->shared = 1;
key->info.shared.offset = (vm_offset_t)addr -
entry->start + entry->offset;
vm_object_reference(key->info.shared.object);
} else {
key->shared = 0;
key->info.private.vs = td->td_proc->p_vmspace;
key->info.private.addr = (uintptr_t)addr;
}
vm_map_lookup_done(map, entry);
}
umtxq_hash(key);
return (0);
}
/*
* Release key.
*/
void
umtx_key_release(struct umtx_key *key)
{
if (key->shared)
vm_object_deallocate(key->info.shared.object);
}
/*
* Fetch and compare value, sleep on the address if value is not changed.
*/
static int
do_wait(struct thread *td, void *addr, u_long id,
struct _umtx_time *timeout, int compat32, int is_private)
{
struct abs_timeout timo;
struct umtx_q *uq;
u_long tmp;
uint32_t tmp32;
int error = 0;
uq = td->td_umtxq;
if ((error = umtx_key_get(addr, TYPE_SIMPLE_WAIT,
is_private ? THREAD_SHARE : AUTO_SHARE, &uq->uq_key)) != 0)
return (error);
if (timeout != NULL)
abs_timeout_init2(&timo, timeout);
umtxq_lock(&uq->uq_key);
umtxq_insert(uq);
umtxq_unlock(&uq->uq_key);
if (compat32 == 0) {
error = fueword(addr, &tmp);
if (error != 0)
error = EFAULT;
} else {
error = fueword32(addr, &tmp32);
if (error == 0)
tmp = tmp32;
else
error = EFAULT;
}
umtxq_lock(&uq->uq_key);
if (error == 0) {
if (tmp == id)
error = umtxq_sleep(uq, "uwait", timeout == NULL ?
NULL : &timo);
if ((uq->uq_flags & UQF_UMTXQ) == 0)
error = 0;
else
umtxq_remove(uq);
} else if ((uq->uq_flags & UQF_UMTXQ) != 0) {
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, int is_private)
{
struct umtx_key key;
int ret;
if ((ret = umtx_key_get(uaddr, TYPE_SIMPLE_WAIT,
is_private ? THREAD_SHARE : AUTO_SHARE, &key)) != 0)
return (ret);
umtxq_lock(&key);
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,
struct _umtx_time *timeout, int mode)
{
struct abs_timeout timo;
struct umtx_q *uq;
uint32_t owner, old, id;
int error, rv;
id = td->td_tid;
uq = td->td_umtxq;
error = 0;
if (timeout != NULL)
abs_timeout_init2(&timo, timeout);
/*
* Care must be exercised when dealing with umtx structure. It
* can fault on any access.
*/
for (;;) {
rv = fueword32(&m->m_owner, &owner);
if (rv == -1)
return (EFAULT);
if (mode == _UMUTEX_WAIT) {
if (owner == UMUTEX_UNOWNED ||
owner == UMUTEX_CONTESTED ||
owner == UMUTEX_RB_OWNERDEAD ||
owner == UMUTEX_RB_NOTRECOV)
return (0);
} else {
/*
* Robust mutex terminated. Kernel duty is to
* return EOWNERDEAD to the userspace. The
* umutex.m_flags UMUTEX_NONCONSISTENT is set
* by the common userspace code.
*/
if (owner == UMUTEX_RB_OWNERDEAD) {
rv = casueword32(&m->m_owner,
UMUTEX_RB_OWNERDEAD, &owner,
id | UMUTEX_CONTESTED);
if (rv == -1)
return (EFAULT);
if (rv == 0) {
MPASS(owner == UMUTEX_RB_OWNERDEAD);
return (EOWNERDEAD); /* success */
}
MPASS(rv == 1);
rv = umtxq_check_susp(td, false);
if (rv != 0)
return (rv);
continue;
}
if (owner == UMUTEX_RB_NOTRECOV)
return (ENOTRECOVERABLE);
/*
* Try the uncontested case. This should be
* done in userland.
*/
rv = casueword32(&m->m_owner, UMUTEX_UNOWNED,
&owner, id);
/* The address was invalid. */
if (rv == -1)
return (EFAULT);
/* The acquire succeeded. */
if (rv == 0) {
MPASS(owner == UMUTEX_UNOWNED);
return (0);
}
/*
* If no one owns it but it is contested try
* to acquire it.
*/
MPASS(rv == 1);
if (owner == UMUTEX_CONTESTED) {
rv = casueword32(&m->m_owner,
UMUTEX_CONTESTED, &owner,
id | UMUTEX_CONTESTED);
/* The address was invalid. */
if (rv == -1)
return (EFAULT);
if (rv == 0) {
MPASS(owner == UMUTEX_CONTESTED);
return (0);
}
if (rv == 1) {
rv = umtxq_check_susp(td, false);
if (rv != 0)
return (rv);
}
/*
* If this failed the lock has
* changed, restart.
*/
continue;
}
/* rv == 1 but not contested, likely store failure */
rv = umtxq_check_susp(td, false);
if (rv != 0)
return (rv);
}
if (mode == _UMUTEX_TRY)
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_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.
*/
rv = casueword32(&m->m_owner, owner, &old,
owner | UMUTEX_CONTESTED);
/* The address was invalid or casueword failed to store. */
if (rv == -1 || rv == 1) {
umtxq_lock(&uq->uq_key);
umtxq_remove(uq);
umtxq_unbusy(&uq->uq_key);
umtxq_unlock(&uq->uq_key);
umtx_key_release(&uq->uq_key);
if (rv == -1)
return (EFAULT);
if (rv == 1) {
rv = umtxq_check_susp(td, false);
if (rv != 0)
return (rv);
}
continue;
}
/*
* 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_unbusy(&uq->uq_key);
MPASS(old == owner);
error = umtxq_sleep(uq, "umtxn", timeout == NULL ?
NULL : &timo);
umtxq_remove(uq);
umtxq_unlock(&uq->uq_key);
umtx_key_release(&uq->uq_key);
if (error == 0)
error = umtxq_check_susp(td, false);
}
return (0);
}
/*
* Unlock PTHREAD_PRIO_NONE protocol POSIX mutex.
*/
static int
do_unlock_normal(struct thread *td, struct umutex *m, uint32_t flags, bool rb)
{
struct umtx_key key;
uint32_t owner, old, id, newlock;
int error, count;
id = td->td_tid;
again:
/*
* Make sure we own this mtx.
*/
error = fueword32(&m->m_owner, &owner);
if (error == -1)
return (EFAULT);
if ((owner & ~UMUTEX_CONTESTED) != id)
return (EPERM);
newlock = umtx_unlock_val(flags, rb);
if ((owner & UMUTEX_CONTESTED) == 0) {
error = casueword32(&m->m_owner, owner, &old, newlock);
if (error == -1)
return (EFAULT);
if (error == 1) {
error = umtxq_check_susp(td, false);
if (error != 0)
return (error);
goto again;
}
MPASS(old == owner);
return (0);
}
/* 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.
*/
if (count > 1)
newlock |= UMUTEX_CONTESTED;
error = casueword32(&m->m_owner, owner, &old, newlock);
umtxq_lock(&key);
umtxq_signal(&key, 1);
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
if (error == -1)
return (EFAULT);
if (error == 1) {
if (old != owner)
return (EINVAL);
error = umtxq_check_susp(td, false);
if (error != 0)
return (error);
goto again;
}
return (0);
}
/*
* Check if the mutex is available and wake up a waiter,
* only for simple mutex.
*/
static int
do_wake_umutex(struct thread *td, struct umutex *m)
{
struct umtx_key key;
uint32_t owner;
uint32_t flags;
int error;
int count;
again:
error = fueword32(&m->m_owner, &owner);
if (error == -1)
return (EFAULT);
if ((owner & ~UMUTEX_CONTESTED) != 0 && owner != UMUTEX_RB_OWNERDEAD &&
owner != UMUTEX_RB_NOTRECOV)
return (0);
error = fueword32(&m->m_flags, &flags);
if (error == -1)
return (EFAULT);
/* 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);
if (count <= 1 && owner != UMUTEX_RB_OWNERDEAD &&
owner != UMUTEX_RB_NOTRECOV) {
error = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
UMUTEX_UNOWNED);
if (error == -1) {
error = EFAULT;
} else if (error == 1) {
umtxq_lock(&key);
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
error = umtxq_check_susp(td, false);
if (error != 0)
return (error);
goto again;
}
}
umtxq_lock(&key);
if (error == 0 && count != 0) {
MPASS((owner & ~UMUTEX_CONTESTED) == 0 ||
owner == UMUTEX_RB_OWNERDEAD ||
owner == UMUTEX_RB_NOTRECOV);
umtxq_signal(&key, 1);
}
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
return (error);
}
/*
* Check if the mutex has waiters and tries to fix contention bit.
*/
static int
do_wake2_umutex(struct thread *td, struct umutex *m, uint32_t flags)
{
struct umtx_key key;
uint32_t owner, old;
int type;
int error;
int count;
switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT |
UMUTEX_ROBUST)) {
case 0:
case UMUTEX_ROBUST:
type = TYPE_NORMAL_UMUTEX;
break;
case UMUTEX_PRIO_INHERIT:
type = TYPE_PI_UMUTEX;
break;
case (UMUTEX_PRIO_INHERIT | UMUTEX_ROBUST):
type = TYPE_PI_ROBUST_UMUTEX;
break;
case UMUTEX_PRIO_PROTECT:
type = TYPE_PP_UMUTEX;
break;
case (UMUTEX_PRIO_PROTECT | UMUTEX_ROBUST):
type = TYPE_PP_ROBUST_UMUTEX;
break;
default:
return (EINVAL);
}
if ((error = umtx_key_get(m, type, GET_SHARE(flags), &key)) != 0)
return (error);
owner = 0;
umtxq_lock(&key);
umtxq_busy(&key);
count = umtxq_count(&key);
umtxq_unlock(&key);
error = fueword32(&m->m_owner, &owner);
if (error == -1)
error = EFAULT;
/*
* Only repair contention bit if there is a waiter, this means
* the mutex is still being referenced by userland code,
* otherwise don't update any memory.
*/
while (error == 0 && (owner & UMUTEX_CONTESTED) == 0 &&
(count > 1 || (count == 1 && (owner & ~UMUTEX_CONTESTED) != 0))) {
error = casueword32(&m->m_owner, owner, &old,
owner | UMUTEX_CONTESTED);
if (error == -1) {
error = EFAULT;
break;
}
if (error == 0) {
MPASS(old == owner);
break;
}
owner = old;
error = umtxq_check_susp(td, false);
}
umtxq_lock(&key);
if (error == EFAULT) {
umtxq_signal(&key, INT_MAX);
} else if (count != 0 && ((owner & ~UMUTEX_CONTESTED) == 0 ||
owner == UMUTEX_RB_OWNERDEAD || owner == UMUTEX_RB_NOTRECOV))
umtxq_signal(&key, 1);
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
return (error);
}
static inline struct umtx_pi *
umtx_pi_alloc(int flags)
{
struct umtx_pi *pi;
pi = uma_zalloc(umtx_pi_zone, M_ZERO | flags);
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(&umtx_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);
}
static struct umtx_pi *
umtx_pi_next(struct umtx_pi *pi)
{
struct umtx_q *uq_owner;
if (pi->pi_owner == NULL)
return (NULL);
uq_owner = pi->pi_owner->td_umtxq;
if (uq_owner == NULL)
return (NULL);
return (uq_owner->uq_pi_blocked);
}
/*
* Floyd's Cycle-Finding Algorithm.
*/
static bool
umtx_pi_check_loop(struct umtx_pi *pi)
{
struct umtx_pi *pi1; /* fast iterator */
mtx_assert(&umtx_lock, MA_OWNED);
if (pi == NULL)
return (false);
pi1 = pi;
for (;;) {
pi = umtx_pi_next(pi);
if (pi == NULL)
break;
pi1 = umtx_pi_next(pi1);
if (pi1 == NULL)
break;
pi1 = umtx_pi_next(pi1);
if (pi1 == NULL)
break;
if (pi == pi1)
return (true);
}
return (false);
}
/*
* 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(&umtx_lock, MA_OWNED);
pri = UPRI(td);
uq = td->td_umtxq;
pi = uq->uq_pi_blocked;
if (pi == NULL)
return;
if (umtx_pi_check_loop(pi))
return;
for (;;) {
td = pi->pi_owner;
if (td == NULL || td == curthread)
return;
MPASS(td->td_proc != NULL);
MPASS(td->td_proc->p_magic == P_MAGIC);
thread_lock(td);
if (td->td_lend_user_pri > pri)
sched_lend_user_prio(td, pri);
else {
thread_unlock(td);
break;
}
thread_unlock(td);
/*
* Pick up the lock that td is blocked on.
*/
uq = td->td_umtxq;
pi = uq->uq_pi_blocked;
if (pi == NULL)
break;
/* Resort td on the list if needed. */
umtx_pi_adjust_thread(pi, td);
}
}
/*
* Unpropagate priority for a PI mutex when a thread blocked on
* it is interrupted by signal or resumed by others.
*/
static void
umtx_repropagate_priority(struct umtx_pi *pi)
{
struct umtx_q *uq, *uq_owner;
struct umtx_pi *pi2;
int pri;
mtx_assert(&umtx_lock, MA_OWNED);
if (umtx_pi_check_loop(pi))
return;
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;
thread_lock(pi->pi_owner);
sched_lend_user_prio(pi->pi_owner, pri);
thread_unlock(pi->pi_owner);
if ((pi = uq_owner->uq_pi_blocked) != NULL)
umtx_pi_adjust_thread(pi, uq_owner->uq_thread);
}
}
/*
* 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(&umtx_lock, MA_OWNED);
MPASS(pi->pi_owner == NULL);
pi->pi_owner = owner;
TAILQ_INSERT_TAIL(&uq_owner->uq_pi_contested, pi, pi_link);
}
/*
* Disown a PI mutex, and remove it from the owned list.
*/
static void
umtx_pi_disown(struct umtx_pi *pi)
{
mtx_assert(&umtx_lock, MA_OWNED);
TAILQ_REMOVE(&pi->pi_owner->td_umtxq->uq_pi_contested, pi, pi_link);
pi->pi_owner = NULL;
}
/*
* Claim ownership of a PI mutex.
*/
static int
umtx_pi_claim(struct umtx_pi *pi, struct thread *owner)
{
struct umtx_q *uq;
int pri;
mtx_lock(&umtx_lock);
if (pi->pi_owner == owner) {
mtx_unlock(&umtx_lock);
return (0);
}
if (pi->pi_owner != NULL) {
/*
* userland may have already messed the mutex, sigh.
*/
mtx_unlock(&umtx_lock);
return (EPERM);
}
umtx_pi_setowner(pi, owner);
uq = TAILQ_FIRST(&pi->pi_blocked);
if (uq != NULL) {
pri = UPRI(uq->uq_thread);
thread_lock(owner);
if (pri < UPRI(owner))
sched_lend_user_prio(owner, pri);
thread_unlock(owner);
}
mtx_unlock(&umtx_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_lock(&umtx_lock);
/*
* Pick up the lock that td is blocked on.
*/
pi = uq->uq_pi_blocked;
if (pi != NULL) {
umtx_pi_adjust_thread(pi, td);
umtx_repropagate_priority(pi);
}
mtx_unlock(&umtx_lock);
}
/*
* Sleep on a PI mutex.
*/
static int
umtxq_sleep_pi(struct umtx_q *uq, struct umtx_pi *pi, uint32_t owner,
const char *wmesg, struct abs_timeout *timo, bool shared)
{
struct thread *td, *td1;
struct umtx_q *uq1;
int error, pri;
#ifdef INVARIANTS
struct umtxq_chain *uc;
uc = umtxq_getchain(&pi->pi_key);
#endif
error = 0;
td = uq->uq_thread;
KASSERT(td == curthread, ("inconsistent uq_thread"));
UMTXQ_LOCKED_ASSERT(umtxq_getchain(&uq->uq_key));
KASSERT(uc->uc_busy != 0, ("umtx chain is not busy"));
umtxq_insert(uq);
mtx_lock(&umtx_lock);
if (pi->pi_owner == NULL) {
mtx_unlock(&umtx_lock);
td1 = tdfind(owner, shared ? -1 : td->td_proc->p_pid);
mtx_lock(&umtx_lock);
if (td1 != NULL) {
if (pi->pi_owner == NULL)
umtx_pi_setowner(pi, td1);
PROC_UNLOCK(td1->td_proc);
}
}
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;
thread_lock(td);
td->td_flags |= TDF_UPIBLOCKED;
thread_unlock(td);
umtx_propagate_priority(td);
mtx_unlock(&umtx_lock);
umtxq_unbusy(&uq->uq_key);
error = umtxq_sleep(uq, wmesg, timo);
umtxq_remove(uq);
mtx_lock(&umtx_lock);
uq->uq_pi_blocked = NULL;
thread_lock(td);
td->td_flags &= ~TDF_UPIBLOCKED;
thread_unlock(td);
TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq);
umtx_repropagate_priority(pi);
mtx_unlock(&umtx_lock);
umtxq_unlock(&uq->uq_key);
return (error);
}
/*
* Add reference count for a PI mutex.
*/
static void
umtx_pi_ref(struct umtx_pi *pi)
{
UMTXQ_LOCKED_ASSERT(umtxq_getchain(&pi->pi_key));
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;
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(&umtx_lock);
if (pi->pi_owner != NULL)
umtx_pi_disown(pi);
KASSERT(TAILQ_EMPTY(&pi->pi_blocked),
("blocked queue not empty"));
mtx_unlock(&umtx_lock);
TAILQ_REMOVE(&uc->uc_pi_list, pi, pi_hashlink);
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,
struct _umtx_time *timeout, int try)
{
struct abs_timeout timo;
struct umtx_q *uq;
struct umtx_pi *pi, *new_pi;
uint32_t id, old_owner, owner, old;
int error, rv;
id = td->td_tid;
uq = td->td_umtxq;
if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
TYPE_PI_ROBUST_UMUTEX : TYPE_PI_UMUTEX, GET_SHARE(flags),
&uq->uq_key)) != 0)
return (error);
if (timeout != NULL)
abs_timeout_init2(&timo, timeout);
umtxq_lock(&uq->uq_key);
pi = umtx_pi_lookup(&uq->uq_key);
if (pi == NULL) {
new_pi = umtx_pi_alloc(M_NOWAIT);
if (new_pi == NULL) {
umtxq_unlock(&uq->uq_key);
new_pi = umtx_pi_alloc(M_WAITOK);
umtxq_lock(&uq->uq_key);
pi = umtx_pi_lookup(&uq->uq_key);
if (pi != NULL) {
umtx_pi_free(new_pi);
new_pi = NULL;
}
}
if (new_pi != NULL) {
new_pi->pi_key = uq->uq_key;
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.
*/
for (;;) {
/*
* Try the uncontested case. This should be done in userland.
*/
rv = casueword32(&m->m_owner, UMUTEX_UNOWNED, &owner, id);
/* The address was invalid. */
if (rv == -1) {
error = EFAULT;
break;
}
/* The acquire succeeded. */
if (rv == 0) {
MPASS(owner == UMUTEX_UNOWNED);
error = 0;
break;
}
if (owner == UMUTEX_RB_NOTRECOV) {
error = ENOTRECOVERABLE;
break;
}
/*
* Avoid overwriting a possible error from sleep due
* to the pending signal with suspension check result.
*/
if (error == 0) {
error = umtxq_check_susp(td, true);
if (error != 0)
break;
}
/* If no one owns it but it is contested try to acquire it. */
if (owner == UMUTEX_CONTESTED || owner == UMUTEX_RB_OWNERDEAD) {
old_owner = owner;
rv = casueword32(&m->m_owner, owner, &owner,
id | UMUTEX_CONTESTED);
/* The address was invalid. */
if (rv == -1) {
error = EFAULT;
break;
}
if (rv == 1) {
if (error == 0) {
error = umtxq_check_susp(td, true);
if (error != 0)
return (error);
}
/*
* If this failed the lock could
* changed, restart.
*/
continue;
}
MPASS(rv == 0);
MPASS(owner == old_owner);
umtxq_lock(&uq->uq_key);
umtxq_busy(&uq->uq_key);
error = umtx_pi_claim(pi, td);
umtxq_unbusy(&uq->uq_key);
umtxq_unlock(&uq->uq_key);
if (error != 0) {
/*
* Since we're going to return an
* error, restore the m_owner to its
* previous, unowned state to avoid
* compounding the problem.
*/
(void)casuword32(&m->m_owner,
id | UMUTEX_CONTESTED, old_owner);
}
if (error == 0 && old_owner == UMUTEX_RB_OWNERDEAD)
error = EOWNERDEAD;
break;
}
if ((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.
*/
rv = casueword32(&m->m_owner, owner, &old, owner |
UMUTEX_CONTESTED);
/* The address was invalid. */
if (rv == -1) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = EFAULT;
break;
}
if (rv == 1) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = umtxq_check_susp(td, true);
if (error != 0)
break;
/*
* The lock changed and we need to retry or we
* lost a race to the thread unlocking the
* umtx. Note that the UMUTEX_RB_OWNERDEAD
* value for owner is impossible there.
*/
continue;
}
umtxq_lock(&uq->uq_key);
/* We set the contested bit, sleep. */
MPASS(old == owner);
error = umtxq_sleep_pi(uq, pi, owner & ~UMUTEX_CONTESTED,
"umtxpi", timeout == NULL ? NULL : &timo,
(flags & USYNC_PROCESS_SHARED) != 0);
if (error != 0)
continue;
error = umtxq_check_susp(td, false);
if (error != 0)
break;
}
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, bool rb)
{
struct umtx_key key;
struct umtx_q *uq_first, *uq_first2, *uq_me;
struct umtx_pi *pi, *pi2;
uint32_t id, new_owner, old, owner;
int count, error, pri;
id = td->td_tid;
usrloop:
/*
* Make sure we own this mtx.
*/
error = fueword32(&m->m_owner, &owner);
if (error == -1)
return (EFAULT);
if ((owner & ~UMUTEX_CONTESTED) != id)
return (EPERM);
new_owner = umtx_unlock_val(flags, rb);
/* This should be done in userland */
if ((owner & UMUTEX_CONTESTED) == 0) {
error = casueword32(&m->m_owner, owner, &old, new_owner);
if (error == -1)
return (EFAULT);
if (error == 1) {
error = umtxq_check_susp(td, true);
if (error != 0)
return (error);
goto usrloop;
}
if (old == owner)
return (0);
owner = old;
}
/* We should only ever be in here for contested locks */
if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
TYPE_PI_ROBUST_UMUTEX : 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) {
mtx_lock(&umtx_lock);
pi = uq_first->uq_pi_blocked;
KASSERT(pi != NULL, ("pi == NULL?"));
if (pi->pi_owner != td && !(rb && pi->pi_owner == NULL)) {
mtx_unlock(&umtx_lock);
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
/* userland messed the mutex */
return (EPERM);
}
uq_me = td->td_umtxq;
if (pi->pi_owner == td)
umtx_pi_disown(pi);
/* get highest priority thread which is still sleeping. */
uq_first = TAILQ_FIRST(&pi->pi_blocked);
while (uq_first != NULL &&
(uq_first->uq_flags & UQF_UMTXQ) == 0) {
uq_first = TAILQ_NEXT(uq_first, uq_lockq);
}
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);
}
}
thread_lock(td);
sched_lend_user_prio(td, pri);
thread_unlock(td);
mtx_unlock(&umtx_lock);
if (uq_first)
umtxq_signal_thread(uq_first);
} else {
pi = umtx_pi_lookup(&key);
/*
* A umtx_pi can exist if a signal or timeout removed the
* last waiter from the umtxq, but there is still
* a thread in do_lock_pi() holding the umtx_pi.
*/
if (pi != NULL) {
/*
* The umtx_pi can be unowned, such as when a thread
* has just entered do_lock_pi(), allocated the
* umtx_pi, and unlocked the umtxq.
* If the current thread owns it, it must disown it.
*/
mtx_lock(&umtx_lock);
if (pi->pi_owner == td)
umtx_pi_disown(pi);
mtx_unlock(&umtx_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.
*/
if (count > 1)
new_owner |= UMUTEX_CONTESTED;
again:
error = casueword32(&m->m_owner, owner, &old, new_owner);
if (error == 1) {
error = umtxq_check_susp(td, false);
if (error == 0)
goto again;
}
umtxq_unbusy_unlocked(&key);
umtx_key_release(&key);
if (error == -1)
return (EFAULT);
if (error == 0 && old != owner)
return (EINVAL);
return (error);
}
/*
* Lock a PP mutex.
*/
static int
do_lock_pp(struct thread *td, struct umutex *m, uint32_t flags,
struct _umtx_time *timeout, int try)
{
struct abs_timeout timo;
struct umtx_q *uq, *uq2;
struct umtx_pi *pi;
uint32_t ceiling;
uint32_t owner, id;
int error, pri, old_inherited_pri, su, rv;
id = td->td_tid;
uq = td->td_umtxq;
if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags),
&uq->uq_key)) != 0)
return (error);
if (timeout != NULL)
abs_timeout_init2(&timo, timeout);
su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0);
for (;;) {
old_inherited_pri = uq->uq_inherited_pri;
umtxq_lock(&uq->uq_key);
umtxq_busy(&uq->uq_key);
umtxq_unlock(&uq->uq_key);
rv = fueword32(&m->m_ceilings[0], &ceiling);
if (rv == -1) {
error = EFAULT;
goto out;
}
ceiling = RTP_PRIO_MAX - ceiling;
if (ceiling > RTP_PRIO_MAX) {
error = EINVAL;
goto out;
}
mtx_lock(&umtx_lock);
if (UPRI(td) < PRI_MIN_REALTIME + ceiling) {
mtx_unlock(&umtx_lock);
error = EINVAL;
goto out;
}
if (su && PRI_MIN_REALTIME + ceiling < uq->uq_inherited_pri) {
uq->uq_inherited_pri = PRI_MIN_REALTIME + ceiling;
thread_lock(td);
if (uq->uq_inherited_pri < UPRI(td))
sched_lend_user_prio(td, uq->uq_inherited_pri);
thread_unlock(td);
}
mtx_unlock(&umtx_lock);
rv = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
id | UMUTEX_CONTESTED);
/* The address was invalid. */
if (rv == -1) {
error = EFAULT;
break;
}
if (rv == 0) {
MPASS(owner == UMUTEX_CONTESTED);
error = 0;
break;
}
/* rv == 1 */
if (owner == UMUTEX_RB_OWNERDEAD) {
rv = casueword32(&m->m_owner, UMUTEX_RB_OWNERDEAD,
&owner, id | UMUTEX_CONTESTED);
if (rv == -1) {
error = EFAULT;
break;
}
if (rv == 0) {
MPASS(owner == UMUTEX_RB_OWNERDEAD);
error = EOWNERDEAD; /* success */
break;
}
/*
* rv == 1, only check for suspension if we
* did not already catched a signal. If we
* get an error from the check, the same
* condition is checked by the umtxq_sleep()
* call below, so we should obliterate the
* error to not skip the last loop iteration.
*/
if (error == 0) {
error = umtxq_check_susp(td, false);
if (error == 0) {
if (try != 0)
error = EBUSY;
else
continue;
}
error = 0;
}
} else if (owner == UMUTEX_RB_NOTRECOV) {
error = ENOTRECOVERABLE;
}
if (try != 0)
error = EBUSY;
/*
* 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", timeout == NULL ?
NULL : &timo);
umtxq_remove(uq);
umtxq_unlock(&uq->uq_key);
mtx_lock(&umtx_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;
thread_lock(td);
sched_lend_user_prio(td, pri);
thread_unlock(td);
mtx_unlock(&umtx_lock);
}
if (error != 0 && error != EOWNERDEAD) {
mtx_lock(&umtx_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;
thread_lock(td);
sched_lend_user_prio(td, pri);
thread_unlock(td);
mtx_unlock(&umtx_lock);
}
out:
umtxq_unbusy_unlocked(&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, bool rb)
{
struct umtx_key key;
struct umtx_q *uq, *uq2;
struct umtx_pi *pi;
uint32_t id, owner, rceiling;
int error, pri, new_inherited_pri, su;
id = td->td_tid;
uq = td->td_umtxq;
su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0);
/*
* Make sure we own this mtx.
*/
error = fueword32(&m->m_owner, &owner);
if (error == -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, (flags & UMUTEX_ROBUST) != 0 ?
TYPE_PP_ROBUST_UMUTEX : 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, umtx_unlock_val(flags, rb) |
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(&umtx_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;
thread_lock(td);
sched_lend_user_prio(td, pri);
thread_unlock(td);
mtx_unlock(&umtx_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 flags, id, owner, save_ceiling;
int error, rv, rv1;
error = fueword32(&m->m_flags, &flags);
if (error == -1)
return (EFAULT);
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, (flags & UMUTEX_ROBUST) != 0 ?
TYPE_PP_ROBUST_UMUTEX : 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);
rv = fueword32(&m->m_ceilings[0], &save_ceiling);
if (rv == -1) {
error = EFAULT;
break;
}
rv = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
id | UMUTEX_CONTESTED);
if (rv == -1) {
error = EFAULT;
break;
}
if (owner == UMUTEX_CONTESTED) {
rv = suword32(&m->m_ceilings[0], ceiling);
rv1 = suword32(&m->m_owner, UMUTEX_CONTESTED);
error = (rv == 0 && rv1 == 0) ? 0: EFAULT;
break;
}
if ((owner & ~UMUTEX_CONTESTED) == id) {
rv = suword32(&m->m_ceilings[0], ceiling);
error = rv == 0 ? 0 : EFAULT;
break;
}
if (owner == UMUTEX_RB_OWNERDEAD) {
error = EOWNERDEAD;
break;
} else if (owner == UMUTEX_RB_NOTRECOV) {
error = ENOTRECOVERABLE;
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", NULL);
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) {
rv = suword32(old_ceiling, save_ceiling);
error = rv == 0 ? 0 : EFAULT;
}
return (error);
}
/*
* Lock a userland POSIX mutex.
*/
static int
do_lock_umutex(struct thread *td, struct umutex *m,
struct _umtx_time *timeout, int mode)
{
uint32_t flags;
int error;
error = fueword32(&m->m_flags, &flags);
if (error == -1)
return (EFAULT);
switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) {
case 0:
error = do_lock_normal(td, m, flags, timeout, mode);
break;
case UMUTEX_PRIO_INHERIT:
error = do_lock_pi(td, m, flags, timeout, mode);
break;
case UMUTEX_PRIO_PROTECT:
error = do_lock_pp(td, m, flags, timeout, mode);
break;
default:
return (EINVAL);
}
if (timeout == NULL) {
if (error == EINTR && mode != _UMUTEX_WAIT)
error = ERESTART;
} else {
/* 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, bool rb)
{
uint32_t flags;
int error;
error = fueword32(&m->m_flags, &flags);
if (error == -1)
return (EFAULT);
switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) {
case 0:
return (do_unlock_normal(td, m, flags, rb));
case UMUTEX_PRIO_INHERIT:
return (do_unlock_pi(td, m, flags, rb));
case UMUTEX_PRIO_PROTECT:
return (do_unlock_pp(td, m, flags, rb));
}
return (EINVAL);
}
static int
do_cv_wait(struct thread *td, struct ucond *cv, struct umutex *m,
struct timespec *timeout, u_long wflags)
{
struct abs_timeout timo;
struct umtx_q *uq;
uint32_t flags, clockid, hasw;
int error;
uq = td->td_umtxq;
error = fueword32(&cv->c_flags, &flags);
if (error == -1)
return (EFAULT);
error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &uq->uq_key);
if (error != 0)
return (error);
if ((wflags & CVWAIT_CLOCKID) != 0) {
error = fueword32(&cv->c_clockid, &clockid);
if (error == -1) {
umtx_key_release(&uq->uq_key);
return (EFAULT);
}
if (clockid < CLOCK_REALTIME ||
clockid >= CLOCK_THREAD_CPUTIME_ID) {
/* hmm, only HW clock id will work. */
umtx_key_release(&uq->uq_key);
return (EINVAL);
}
} else {
clockid = CLOCK_REALTIME;
}
umtxq_lock(&uq->uq_key);
umtxq_busy(&uq->uq_key);
umtxq_insert(uq);
umtxq_unlock(&uq->uq_key);
/*
* Set c_has_waiters to 1 before releasing user mutex, also
* don't modify cache line when unnecessary.
*/
error = fueword32(&cv->c_has_waiters, &hasw);
if (error == 0 && hasw == 0)
suword32(&cv->c_has_waiters, 1);
umtxq_unbusy_unlocked(&uq->uq_key);
error = do_unlock_umutex(td, m, false);
if (timeout != NULL)
abs_timeout_init(&timo, clockid, (wflags & CVWAIT_ABSTIME) != 0,
timeout);
umtxq_lock(&uq->uq_key);
if (error == 0) {
error = umtxq_sleep(uq, "ucond", timeout == NULL ?
NULL : &timo);
}
if ((uq->uq_flags & UQF_UMTXQ) == 0)
error = 0;
else {
/*
* This must be timeout,interrupted by signal or
* surprious wakeup, clear c_has_waiter flag when
* necessary.
*/
umtxq_busy(&uq->uq_key);
if ((uq->uq_flags & UQF_UMTXQ) != 0) {
int oldlen = uq->uq_cur_queue->length;
umtxq_remove(uq);
if (oldlen == 1) {
umtxq_unlock(&uq->uq_key);
suword32(&cv->c_has_waiters, 0);
umtxq_lock(&uq->uq_key);
}
}
umtxq_unbusy(&uq->uq_key);
if (error == ERESTART)
error = EINTR;
}
umtxq_unlock(&uq->uq_key);
umtx_key_release(&uq->uq_key);
return (error);
}
/*
* Signal a userland condition variable.
*/
static int
do_cv_signal(struct thread *td, struct ucond *cv)
{
struct umtx_key key;
int error, cnt, nwake;
uint32_t flags;
error = fueword32(&cv->c_flags, &flags);
if (error == -1)
return (EFAULT);
if ((error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &key)) != 0)
return (error);
umtxq_lock(&key);
umtxq_busy(&key);
cnt = umtxq_count(&key);
nwake = umtxq_signal(&key, 1);
if (cnt <= nwake) {
umtxq_unlock(&key);
error = suword32(&cv->c_has_waiters, 0);
if (error == -1)
error = EFAULT;
umtxq_lock(&key);
}
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
return (error);
}
static int
do_cv_broadcast(struct thread *td, struct ucond *cv)
{
struct umtx_key key;
int error;
uint32_t flags;
error = fueword32(&cv->c_flags, &flags);
if (error == -1)
return (EFAULT);
if ((error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &key)) != 0)
return (error);
umtxq_lock(&key);
umtxq_busy(&key);
umtxq_signal(&key, INT_MAX);
umtxq_unlock(&key);
error = suword32(&cv->c_has_waiters, 0);
if (error == -1)
error = EFAULT;
umtxq_unbusy_unlocked(&key);
umtx_key_release(&key);
return (error);
}
static int
do_rw_rdlock(struct thread *td, struct urwlock *rwlock, long fflag,
struct _umtx_time *timeout)
{
struct abs_timeout timo;
struct umtx_q *uq;
uint32_t flags, wrflags;
int32_t state, oldstate;
int32_t blocked_readers;
int error, error1, rv;
uq = td->td_umtxq;
error = fueword32(&rwlock->rw_flags, &flags);
if (error == -1)
return (EFAULT);
error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
if (error != 0)
return (error);
if (timeout != NULL)
abs_timeout_init2(&timo, timeout);
wrflags = URWLOCK_WRITE_OWNER;
if (!(fflag & URWLOCK_PREFER_READER) && !(flags & URWLOCK_PREFER_READER))
wrflags |= URWLOCK_WRITE_WAITERS;
for (;;) {
rv = fueword32(&rwlock->rw_state, &state);
if (rv == -1) {
umtx_key_release(&uq->uq_key);
return (EFAULT);
}
/* try to lock it */
while (!(state & wrflags)) {
if (__predict_false(URWLOCK_READER_COUNT(state) ==
URWLOCK_MAX_READERS)) {
umtx_key_release(&uq->uq_key);
return (EAGAIN);
}
rv = casueword32(&rwlock->rw_state, state,
&oldstate, state + 1);
if (rv == -1) {
umtx_key_release(&uq->uq_key);
return (EFAULT);
}
if (rv == 0) {
MPASS(oldstate == state);
umtx_key_release(&uq->uq_key);
return (0);
}
error = umtxq_check_susp(td, true);
if (error != 0)
break;
state = oldstate;
}
if (error)
break;
/* grab monitor lock */
umtxq_lock(&uq->uq_key);
umtxq_busy(&uq->uq_key);
umtxq_unlock(&uq->uq_key);
/*
* re-read the state, in case it changed between the try-lock above
* and the check below
*/
rv = fueword32(&rwlock->rw_state, &state);
if (rv == -1)
error = EFAULT;
/* set read contention bit */
while (error == 0 && (state & wrflags) &&
!(state & URWLOCK_READ_WAITERS)) {
rv = casueword32(&rwlock->rw_state, state,
&oldstate, state | URWLOCK_READ_WAITERS);
if (rv == -1) {
error = EFAULT;
break;
}
if (rv == 0) {
MPASS(oldstate == state);
goto sleep;
}
state = oldstate;
error = umtxq_check_susp(td, false);
if (error != 0)
break;
}
if (error != 0) {
umtxq_unbusy_unlocked(&uq->uq_key);
break;
}
/* state is changed while setting flags, restart */
if (!(state & wrflags)) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = umtxq_check_susp(td, true);
if (error != 0)
break;
continue;
}
sleep:
/*
* Contention bit is set, before sleeping, increase
* read waiter count.
*/
rv = fueword32(&rwlock->rw_blocked_readers,
&blocked_readers);
if (rv == -1) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = EFAULT;
break;
}
suword32(&rwlock->rw_blocked_readers, blocked_readers+1);
while (state & wrflags) {
umtxq_lock(&uq->uq_key);
umtxq_insert(uq);
umtxq_unbusy(&uq->uq_key);
error = umtxq_sleep(uq, "urdlck", timeout == NULL ?
NULL : &timo);
umtxq_busy(&uq->uq_key);
umtxq_remove(uq);
umtxq_unlock(&uq->uq_key);
if (error)
break;
rv = fueword32(&rwlock->rw_state, &state);
if (rv == -1) {
error = EFAULT;
break;
}
}
/* decrease read waiter count, and may clear read contention bit */
rv = fueword32(&rwlock->rw_blocked_readers,
&blocked_readers);
if (rv == -1) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = EFAULT;
break;
}
suword32(&rwlock->rw_blocked_readers, blocked_readers-1);
if (blocked_readers == 1) {
rv = fueword32(&rwlock->rw_state, &state);
if (rv == -1) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = EFAULT;
break;
}
for (;;) {
rv = casueword32(&rwlock->rw_state, state,
&oldstate, state & ~URWLOCK_READ_WAITERS);
if (rv == -1) {
error = EFAULT;
break;
}
if (rv == 0) {
MPASS(oldstate == state);
break;
}
state = oldstate;
error1 = umtxq_check_susp(td, false);
if (error1 != 0) {
if (error == 0)
error = error1;
break;
}
}
}
umtxq_unbusy_unlocked(&uq->uq_key);
if (error != 0)
break;
}
umtx_key_release(&uq->uq_key);
if (error == ERESTART)
error = EINTR;
return (error);
}
static int
do_rw_wrlock(struct thread *td, struct urwlock *rwlock, struct _umtx_time *timeout)
{
struct abs_timeout timo;
struct umtx_q *uq;
uint32_t flags;
int32_t state, oldstate;
int32_t blocked_writers;
int32_t blocked_readers;
int error, error1, rv;
uq = td->td_umtxq;
error = fueword32(&rwlock->rw_flags, &flags);
if (error == -1)
return (EFAULT);
error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
if (error != 0)
return (error);
if (timeout != NULL)
abs_timeout_init2(&timo, timeout);
blocked_readers = 0;
for (;;) {
rv = fueword32(&rwlock->rw_state, &state);
if (rv == -1) {
umtx_key_release(&uq->uq_key);
return (EFAULT);
}
while ((state & URWLOCK_WRITE_OWNER) == 0 &&
URWLOCK_READER_COUNT(state) == 0) {
rv = casueword32(&rwlock->rw_state, state,
&oldstate, state | URWLOCK_WRITE_OWNER);
if (rv == -1) {
umtx_key_release(&uq->uq_key);
return (EFAULT);
}
if (rv == 0) {
MPASS(oldstate == state);
umtx_key_release(&uq->uq_key);
return (0);
}
state = oldstate;
error = umtxq_check_susp(td, true);
if (error != 0)
break;
}
if (error) {
if ((state & (URWLOCK_WRITE_OWNER |
URWLOCK_WRITE_WAITERS)) == 0 &&
blocked_readers != 0) {
umtxq_lock(&uq->uq_key);
umtxq_busy(&uq->uq_key);
umtxq_signal_queue(&uq->uq_key, INT_MAX,
UMTX_SHARED_QUEUE);
umtxq_unbusy(&uq->uq_key);
umtxq_unlock(&uq->uq_key);
}
break;
}
/* grab monitor lock */
umtxq_lock(&uq->uq_key);
umtxq_busy(&uq->uq_key);
umtxq_unlock(&uq->uq_key);
/*
* Re-read the state, in case it changed between the
* try-lock above and the check below.
*/
rv = fueword32(&rwlock->rw_state, &state);
if (rv == -1)
error = EFAULT;
while (error == 0 && ((state & URWLOCK_WRITE_OWNER) ||
URWLOCK_READER_COUNT(state) != 0) &&
(state & URWLOCK_WRITE_WAITERS) == 0) {
rv = casueword32(&rwlock->rw_state, state,
&oldstate, state | URWLOCK_WRITE_WAITERS);
if (rv == -1) {
error = EFAULT;
break;
}
if (rv == 0) {
MPASS(oldstate == state);
goto sleep;
}
state = oldstate;
error = umtxq_check_susp(td, false);
if (error != 0)
break;
}
if (error != 0) {
umtxq_unbusy_unlocked(&uq->uq_key);
break;
}
if ((state & URWLOCK_WRITE_OWNER) == 0 &&
URWLOCK_READER_COUNT(state) == 0) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = umtxq_check_susp(td, false);
if (error != 0)
break;
continue;
}
sleep:
rv = fueword32(&rwlock->rw_blocked_writers,
&blocked_writers);
if (rv == -1) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = EFAULT;
break;
}
suword32(&rwlock->rw_blocked_writers, blocked_writers + 1);
while ((state & URWLOCK_WRITE_OWNER) ||
URWLOCK_READER_COUNT(state) != 0) {
umtxq_lock(&uq->uq_key);
umtxq_insert_queue(uq, UMTX_EXCLUSIVE_QUEUE);
umtxq_unbusy(&uq->uq_key);
error = umtxq_sleep(uq, "uwrlck", timeout == NULL ?
NULL : &timo);
umtxq_busy(&uq->uq_key);
umtxq_remove_queue(uq, UMTX_EXCLUSIVE_QUEUE);
umtxq_unlock(&uq->uq_key);
if (error)
break;
rv = fueword32(&rwlock->rw_state, &state);
if (rv == -1) {
error = EFAULT;
break;
}
}
rv = fueword32(&rwlock->rw_blocked_writers,
&blocked_writers);
if (rv == -1) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = EFAULT;
break;
}
suword32(&rwlock->rw_blocked_writers, blocked_writers-1);
if (blocked_writers == 1) {
rv = fueword32(&rwlock->rw_state, &state);
if (rv == -1) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = EFAULT;
break;
}
for (;;) {
rv = casueword32(&rwlock->rw_state, state,
&oldstate, state & ~URWLOCK_WRITE_WAITERS);
if (rv == -1) {
error = EFAULT;
break;
}
if (rv == 0) {
MPASS(oldstate == state);
break;
}
state = oldstate;
error1 = umtxq_check_susp(td, false);
/*
* We are leaving the URWLOCK_WRITE_WAITERS
* behind, but this should not harm the
* correctness.
*/
if (error1 != 0) {
if (error == 0)
error = error1;
break;
}
}
rv = fueword32(&rwlock->rw_blocked_readers,
&blocked_readers);
if (rv == -1) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = EFAULT;
break;
}
} else
blocked_readers = 0;
umtxq_unbusy_unlocked(&uq->uq_key);
}
umtx_key_release(&uq->uq_key);
if (error == ERESTART)
error = EINTR;
return (error);
}
static int
do_rw_unlock(struct thread *td, struct urwlock *rwlock)
{
struct umtx_q *uq;
uint32_t flags;
int32_t state, oldstate;
int error, rv, q, count;
uq = td->td_umtxq;
error = fueword32(&rwlock->rw_flags, &flags);
if (error == -1)
return (EFAULT);
error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
if (error != 0)
return (error);
error = fueword32(&rwlock->rw_state, &state);
if (error == -1) {
error = EFAULT;
goto out;
}
if (state & URWLOCK_WRITE_OWNER) {
for (;;) {
rv = casueword32(&rwlock->rw_state, state,
&oldstate, state & ~URWLOCK_WRITE_OWNER);
if (rv == -1) {
error = EFAULT;
goto out;
}
if (rv == 1) {
state = oldstate;
if (!(oldstate & URWLOCK_WRITE_OWNER)) {
error = EPERM;
goto out;
}
error = umtxq_check_susp(td, true);
if (error != 0)
goto out;
} else
break;
}
} else if (URWLOCK_READER_COUNT(state) != 0) {
for (;;) {
rv = casueword32(&rwlock->rw_state, state,
&oldstate, state - 1);
if (rv == -1) {
error = EFAULT;
goto out;
}
if (rv == 1) {
state = oldstate;
if (URWLOCK_READER_COUNT(oldstate) == 0) {
error = EPERM;
goto out;
}
error = umtxq_check_susp(td, true);
if (error != 0)
goto out;
} else
break;
}
} else {
error = EPERM;
goto out;
}
count = 0;
if (!(flags & URWLOCK_PREFER_READER)) {
if (state & URWLOCK_WRITE_WAITERS) {
count = 1;
q = UMTX_EXCLUSIVE_QUEUE;
} else if (state & URWLOCK_READ_WAITERS) {
count = INT_MAX;
q = UMTX_SHARED_QUEUE;
}
} else {
if (state & URWLOCK_READ_WAITERS) {
count = INT_MAX;
q = UMTX_SHARED_QUEUE;
} else if (state & URWLOCK_WRITE_WAITERS) {
count = 1;
q = UMTX_EXCLUSIVE_QUEUE;
}
}
if (count) {
umtxq_lock(&uq->uq_key);
umtxq_busy(&uq->uq_key);
umtxq_signal_queue(&uq->uq_key, count, q);
umtxq_unbusy(&uq->uq_key);
umtxq_unlock(&uq->uq_key);
}
out:
umtx_key_release(&uq->uq_key);
return (error);
}
#if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
static int
do_sem_wait(struct thread *td, struct _usem *sem, struct _umtx_time *timeout)
{
struct abs_timeout timo;
struct umtx_q *uq;
uint32_t flags, count, count1;
int error, rv, rv1;
uq = td->td_umtxq;
error = fueword32(&sem->_flags, &flags);
if (error == -1)
return (EFAULT);
error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &uq->uq_key);
if (error != 0)
return (error);
if (timeout != NULL)
abs_timeout_init2(&timo, timeout);
again:
umtxq_lock(&uq->uq_key);
umtxq_busy(&uq->uq_key);
umtxq_insert(uq);
umtxq_unlock(&uq->uq_key);
rv = casueword32(&sem->_has_waiters, 0, &count1, 1);
if (rv == 0)
rv1 = fueword32(&sem->_count, &count);
if (rv == -1 || (rv == 0 && (rv1 == -1 || count != 0)) || rv == 1) {
umtxq_lock(&uq->uq_key);
umtxq_unbusy(&uq->uq_key);
umtxq_remove(uq);
umtxq_unlock(&uq->uq_key);
if (rv == 1) {
rv = umtxq_check_susp(td, true);
if (rv == 0)
goto again;
error = rv;
goto out;
}
if (rv == 0)
rv = rv1;
error = rv == -1 ? EFAULT : 0;
goto out;
}
umtxq_lock(&uq->uq_key);
umtxq_unbusy(&uq->uq_key);
error = umtxq_sleep(uq, "usem", timeout == NULL ? NULL : &timo);
if ((uq->uq_flags & UQF_UMTXQ) == 0)
error = 0;
else {
umtxq_remove(uq);
/* A relative timeout cannot be restarted. */
if (error == ERESTART && timeout != NULL &&
(timeout->_flags & UMTX_ABSTIME) == 0)
error = EINTR;
}
umtxq_unlock(&uq->uq_key);
out:
umtx_key_release(&uq->uq_key);
return (error);
}
/*
* Signal a userland semaphore.
*/
static int
do_sem_wake(struct thread *td, struct _usem *sem)
{
struct umtx_key key;
int error, cnt;
uint32_t flags;
error = fueword32(&sem->_flags, &flags);
if (error == -1)
return (EFAULT);
if ((error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &key)) != 0)
return (error);
umtxq_lock(&key);
umtxq_busy(&key);
cnt = umtxq_count(&key);
if (cnt > 0) {
/*
* Check if count is greater than 0, this means the memory is
* still being referenced by user code, so we can safely
* update _has_waiters flag.
*/
if (cnt == 1) {
umtxq_unlock(&key);
error = suword32(&sem->_has_waiters, 0);
umtxq_lock(&key);
if (error == -1)
error = EFAULT;
}
umtxq_signal(&key, 1);
}
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
return (error);
}
#endif
static int
do_sem2_wait(struct thread *td, struct _usem2 *sem, struct _umtx_time *timeout)
{
struct abs_timeout timo;
struct umtx_q *uq;
uint32_t count, flags;
int error, rv;
uq = td->td_umtxq;
flags = fuword32(&sem->_flags);
error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &uq->uq_key);
if (error != 0)
return (error);
if (timeout != NULL)
abs_timeout_init2(&timo, timeout);
again:
umtxq_lock(&uq->uq_key);
umtxq_busy(&uq->uq_key);
umtxq_insert(uq);
umtxq_unlock(&uq->uq_key);
rv = fueword32(&sem->_count, &count);
if (rv == -1) {
umtxq_lock(&uq->uq_key);
umtxq_unbusy(&uq->uq_key);
umtxq_remove(uq);
umtxq_unlock(&uq->uq_key);
umtx_key_release(&uq->uq_key);
return (EFAULT);
}
for (;;) {
if (USEM_COUNT(count) != 0) {
umtxq_lock(&uq->uq_key);
umtxq_unbusy(&uq->uq_key);
umtxq_remove(uq);
umtxq_unlock(&uq->uq_key);
umtx_key_release(&uq->uq_key);
return (0);
}
if (count == USEM_HAS_WAITERS)
break;
rv = casueword32(&sem->_count, 0, &count, USEM_HAS_WAITERS);
if (rv == 0)
break;
umtxq_lock(&uq->uq_key);
umtxq_unbusy(&uq->uq_key);
umtxq_remove(uq);
umtxq_unlock(&uq->uq_key);
umtx_key_release(&uq->uq_key);
if (rv == -1)
return (EFAULT);
rv = umtxq_check_susp(td, true);
if (rv != 0)
return (rv);
goto again;
}
umtxq_lock(&uq->uq_key);
umtxq_unbusy(&uq->uq_key);
error = umtxq_sleep(uq, "usem", timeout == NULL ? NULL : &timo);
if ((uq->uq_flags & UQF_UMTXQ) == 0)
error = 0;
else {
umtxq_remove(uq);
if (timeout != NULL && (timeout->_flags & UMTX_ABSTIME) == 0) {
/* A relative timeout cannot be restarted. */
if (error == ERESTART)
error = EINTR;
if (error == EINTR) {
abs_timeout_update(&timo);
timespecsub(&timo.end, &timo.cur,
&timeout->_timeout);
}
}
}
umtxq_unlock(&uq->uq_key);
umtx_key_release(&uq->uq_key);
return (error);
}
/*
* Signal a userland semaphore.
*/
static int
do_sem2_wake(struct thread *td, struct _usem2 *sem)
{
struct umtx_key key;
int error, cnt, rv;
uint32_t count, flags;
rv = fueword32(&sem->_flags, &flags);
if (rv == -1)
return (EFAULT);
if ((error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &key)) != 0)
return (error);
umtxq_lock(&key);
umtxq_busy(&key);
cnt = umtxq_count(&key);
if (cnt > 0) {
/*
* If this was the last sleeping thread, clear the waiters
* flag in _count.
*/
if (cnt == 1) {
umtxq_unlock(&key);
rv = fueword32(&sem->_count, &count);
while (rv != -1 && count & USEM_HAS_WAITERS) {
rv = casueword32(&sem->_count, count, &count,
count & ~USEM_HAS_WAITERS);
if (rv == 1) {
rv = umtxq_check_susp(td, true);
if (rv != 0)
break;
}
}
if (rv == -1)
error = EFAULT;
else if (rv > 0) {
error = rv;
}
umtxq_lock(&key);
}
umtxq_signal(&key, 1);
}
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
return (error);
}
inline int
umtx_copyin_timeout(const void *addr, struct timespec *tsp)
{
int error;
error = copyin(addr, tsp, sizeof(struct timespec));
if (error == 0) {
if (tsp->tv_sec < 0 ||
tsp->tv_nsec >= 1000000000 ||
tsp->tv_nsec < 0)
error = EINVAL;
}
return (error);
}
static inline int
umtx_copyin_umtx_time(const void *addr, size_t size, struct _umtx_time *tp)
{
int error;
if (size <= sizeof(struct timespec)) {
tp->_clockid = CLOCK_REALTIME;
tp->_flags = 0;
error = copyin(addr, &tp->_timeout, sizeof(struct timespec));
} else
error = copyin(addr, tp, sizeof(struct _umtx_time));
if (error != 0)
return (error);
if (tp->_timeout.tv_sec < 0 ||
tp->_timeout.tv_nsec >= 1000000000 || tp->_timeout.tv_nsec < 0)
return (EINVAL);
return (0);
}
static int
__umtx_op_unimpl(struct thread *td, struct _umtx_op_args *uap)
{
return (EOPNOTSUPP);
}
static int
__umtx_op_wait(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time timeout, *tm_p;
int error;
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time(
uap->uaddr2, (size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_wait(td, uap->obj, uap->val, tm_p, 0, 0));
}
static int
__umtx_op_wait_uint(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time timeout, *tm_p;
int error;
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time(
uap->uaddr2, (size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_wait(td, uap->obj, uap->val, tm_p, 1, 0));
}
static int
__umtx_op_wait_uint_private(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
int error;
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time(
uap->uaddr2, (size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_wait(td, uap->obj, uap->val, tm_p, 1, 1));
}
static int
__umtx_op_wake(struct thread *td, struct _umtx_op_args *uap)
{
return (kern_umtx_wake(td, uap->obj, uap->val, 0));
}
#define BATCH_SIZE 128
static int
__umtx_op_nwake_private(struct thread *td, struct _umtx_op_args *uap)
{
char *uaddrs[BATCH_SIZE], **upp;
int count, error, i, pos, tocopy;
upp = (char **)uap->obj;
error = 0;
for (count = uap->val, pos = 0; count > 0; count -= tocopy,
pos += tocopy) {
tocopy = MIN(count, BATCH_SIZE);
error = copyin(upp + pos, uaddrs, tocopy * sizeof(char *));
if (error != 0)
break;
for (i = 0; i < tocopy; ++i)
kern_umtx_wake(td, uaddrs[i], INT_MAX, 1);
maybe_yield();
}
return (error);
}
static int
__umtx_op_wake_private(struct thread *td, struct _umtx_op_args *uap)
{
return (kern_umtx_wake(td, uap->obj, uap->val, 1));
}
static int
__umtx_op_lock_umutex(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time(
uap->uaddr2, (size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_lock_umutex(td, uap->obj, tm_p, 0));
}
static int
__umtx_op_trylock_umutex(struct thread *td, struct _umtx_op_args *uap)
{
return (do_lock_umutex(td, uap->obj, NULL, _UMUTEX_TRY));
}
static int
__umtx_op_wait_umutex(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time(
uap->uaddr2, (size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_lock_umutex(td, uap->obj, tm_p, _UMUTEX_WAIT));
}
static int
__umtx_op_wake_umutex(struct thread *td, struct _umtx_op_args *uap)
{
return (do_wake_umutex(td, uap->obj));
}
static int
__umtx_op_unlock_umutex(struct thread *td, struct _umtx_op_args *uap)
{
return (do_unlock_umutex(td, uap->obj, false));
}
static int
__umtx_op_set_ceiling(struct thread *td, struct _umtx_op_args *uap)
{
return (do_set_ceiling(td, uap->obj, uap->val, uap->uaddr1));
}
static int
__umtx_op_cv_wait(struct thread *td, struct _umtx_op_args *uap)
{
struct timespec *ts, timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL)
ts = NULL;
else {
error = umtx_copyin_timeout(uap->uaddr2, &timeout);
if (error != 0)
return (error);
ts = &timeout;
}
return (do_cv_wait(td, uap->obj, uap->uaddr1, ts, uap->val));
}
static int
__umtx_op_cv_signal(struct thread *td, struct _umtx_op_args *uap)
{
return (do_cv_signal(td, uap->obj));
}
static int
__umtx_op_cv_broadcast(struct thread *td, struct _umtx_op_args *uap)
{
return (do_cv_broadcast(td, uap->obj));
}
static int
__umtx_op_rw_rdlock(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL) {
error = do_rw_rdlock(td, uap->obj, uap->val, 0);
} else {
error = umtx_copyin_umtx_time(uap->uaddr2,
(size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
error = do_rw_rdlock(td, uap->obj, uap->val, &timeout);
}
return (error);
}
static int
__umtx_op_rw_wrlock(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL) {
error = do_rw_wrlock(td, uap->obj, 0);
} else {
error = umtx_copyin_umtx_time(uap->uaddr2,
(size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
error = do_rw_wrlock(td, uap->obj, &timeout);
}
return (error);
}
static int
__umtx_op_rw_unlock(struct thread *td, struct _umtx_op_args *uap)
{
return (do_rw_unlock(td, uap->obj));
}
#if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
static int
__umtx_op_sem_wait(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time(
uap->uaddr2, (size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_sem_wait(td, uap->obj, tm_p));
}
static int
__umtx_op_sem_wake(struct thread *td, struct _umtx_op_args *uap)
{
return (do_sem_wake(td, uap->obj));
}
#endif
static int
__umtx_op_wake2_umutex(struct thread *td, struct _umtx_op_args *uap)
{
return (do_wake2_umutex(td, uap->obj, uap->val));
}
static int
__umtx_op_sem2_wait(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
size_t uasize;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL) {
uasize = 0;
tm_p = NULL;
} else {
uasize = (size_t)uap->uaddr1;
error = umtx_copyin_umtx_time(uap->uaddr2, uasize, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
error = do_sem2_wait(td, uap->obj, tm_p);
if (error == EINTR && uap->uaddr2 != NULL &&
(timeout._flags & UMTX_ABSTIME) == 0 &&
uasize >= sizeof(struct _umtx_time) + sizeof(struct timespec)) {
error = copyout(&timeout._timeout,
(struct _umtx_time *)uap->uaddr2 + 1,
sizeof(struct timespec));
if (error == 0) {
error = EINTR;
}
}
return (error);
}
static int
__umtx_op_sem2_wake(struct thread *td, struct _umtx_op_args *uap)
{
return (do_sem2_wake(td, uap->obj));
}
#define USHM_OBJ_UMTX(o) \
((struct umtx_shm_obj_list *)(&(o)->umtx_data))
#define USHMF_REG_LINKED 0x0001
#define USHMF_OBJ_LINKED 0x0002
struct umtx_shm_reg {
TAILQ_ENTRY(umtx_shm_reg) ushm_reg_link;
LIST_ENTRY(umtx_shm_reg) ushm_obj_link;
struct umtx_key ushm_key;
struct ucred *ushm_cred;
struct shmfd *ushm_obj;
u_int ushm_refcnt;
u_int ushm_flags;
};
LIST_HEAD(umtx_shm_obj_list, umtx_shm_reg);
TAILQ_HEAD(umtx_shm_reg_head, umtx_shm_reg);
static uma_zone_t umtx_shm_reg_zone;
static struct umtx_shm_reg_head umtx_shm_registry[UMTX_CHAINS];
static struct mtx umtx_shm_lock;
static struct umtx_shm_reg_head umtx_shm_reg_delfree =
TAILQ_HEAD_INITIALIZER(umtx_shm_reg_delfree);
static void umtx_shm_free_reg(struct umtx_shm_reg *reg);
static void
umtx_shm_reg_delfree_tq(void *context __unused, int pending __unused)
{
struct umtx_shm_reg_head d;
struct umtx_shm_reg *reg, *reg1;
TAILQ_INIT(&d);
mtx_lock(&umtx_shm_lock);
TAILQ_CONCAT(&d, &umtx_shm_reg_delfree, ushm_reg_link);
mtx_unlock(&umtx_shm_lock);
TAILQ_FOREACH_SAFE(reg, &d, ushm_reg_link, reg1) {
TAILQ_REMOVE(&d, reg, ushm_reg_link);
umtx_shm_free_reg(reg);
}
}
static struct task umtx_shm_reg_delfree_task =
TASK_INITIALIZER(0, umtx_shm_reg_delfree_tq, NULL);
static struct umtx_shm_reg *
umtx_shm_find_reg_locked(const struct umtx_key *key)
{
struct umtx_shm_reg *reg;
struct umtx_shm_reg_head *reg_head;
KASSERT(key->shared, ("umtx_p_find_rg: private key"));
mtx_assert(&umtx_shm_lock, MA_OWNED);
reg_head = &umtx_shm_registry[key->hash];
TAILQ_FOREACH(reg, reg_head, ushm_reg_link) {
KASSERT(reg->ushm_key.shared,
("non-shared key on reg %p %d", reg, reg->ushm_key.shared));
if (reg->ushm_key.info.shared.object ==
key->info.shared.object &&
reg->ushm_key.info.shared.offset ==
key->info.shared.offset) {
KASSERT(reg->ushm_key.type == TYPE_SHM, ("TYPE_USHM"));
KASSERT(reg->ushm_refcnt > 0,
("reg %p refcnt 0 onlist", reg));
KASSERT((reg->ushm_flags & USHMF_REG_LINKED) != 0,
("reg %p not linked", reg));
reg->ushm_refcnt++;
return (reg);
}
}
return (NULL);
}
static struct umtx_shm_reg *
umtx_shm_find_reg(const struct umtx_key *key)
{
struct umtx_shm_reg *reg;
mtx_lock(&umtx_shm_lock);
reg = umtx_shm_find_reg_locked(key);
mtx_unlock(&umtx_shm_lock);
return (reg);
}
static void
umtx_shm_free_reg(struct umtx_shm_reg *reg)
{
chgumtxcnt(reg->ushm_cred->cr_ruidinfo, -1, 0);
crfree(reg->ushm_cred);
shm_drop(reg->ushm_obj);
uma_zfree(umtx_shm_reg_zone, reg);
}
static bool
umtx_shm_unref_reg_locked(struct umtx_shm_reg *reg, bool force)
{
bool res;
mtx_assert(&umtx_shm_lock, MA_OWNED);
KASSERT(reg->ushm_refcnt > 0, ("ushm_reg %p refcnt 0", reg));
reg->ushm_refcnt--;
res = reg->ushm_refcnt == 0;
if (res || force) {
if ((reg->ushm_flags & USHMF_REG_LINKED) != 0) {
TAILQ_REMOVE(&umtx_shm_registry[reg->ushm_key.hash],
reg, ushm_reg_link);
reg->ushm_flags &= ~USHMF_REG_LINKED;
}
if ((reg->ushm_flags & USHMF_OBJ_LINKED) != 0) {
LIST_REMOVE(reg, ushm_obj_link);
reg->ushm_flags &= ~USHMF_OBJ_LINKED;
}
}
return (res);
}
static void
umtx_shm_unref_reg(struct umtx_shm_reg *reg, bool force)
{
vm_object_t object;
bool dofree;
if (force) {
object = reg->ushm_obj->shm_object;
VM_OBJECT_WLOCK(object);
object->flags |= OBJ_UMTXDEAD;
VM_OBJECT_WUNLOCK(object);
}
mtx_lock(&umtx_shm_lock);
dofree = umtx_shm_unref_reg_locked(reg, force);
mtx_unlock(&umtx_shm_lock);
if (dofree)
umtx_shm_free_reg(reg);
}
void
umtx_shm_object_init(vm_object_t object)
{
LIST_INIT(USHM_OBJ_UMTX(object));
}
void
umtx_shm_object_terminated(vm_object_t object)
{
struct umtx_shm_reg *reg, *reg1;
bool dofree;
if (LIST_EMPTY(USHM_OBJ_UMTX(object)))
return;
dofree = false;
mtx_lock(&umtx_shm_lock);
LIST_FOREACH_SAFE(reg, USHM_OBJ_UMTX(object), ushm_obj_link, reg1) {
if (umtx_shm_unref_reg_locked(reg, true)) {
TAILQ_INSERT_TAIL(&umtx_shm_reg_delfree, reg,
ushm_reg_link);
dofree = true;
}
}
mtx_unlock(&umtx_shm_lock);
if (dofree)
taskqueue_enqueue(taskqueue_thread, &umtx_shm_reg_delfree_task);
}
static int
umtx_shm_create_reg(struct thread *td, const struct umtx_key *key,
struct umtx_shm_reg **res)
{
struct umtx_shm_reg *reg, *reg1;
struct ucred *cred;
int error;
reg = umtx_shm_find_reg(key);
if (reg != NULL) {
*res = reg;
return (0);
}
cred = td->td_ucred;
if (!chgumtxcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_UMTXP)))
return (ENOMEM);
reg = uma_zalloc(umtx_shm_reg_zone, M_WAITOK | M_ZERO);
reg->ushm_refcnt = 1;
bcopy(key, &reg->ushm_key, sizeof(*key));
reg->ushm_obj = shm_alloc(td->td_ucred, O_RDWR);
reg->ushm_cred = crhold(cred);
error = shm_dotruncate(reg->ushm_obj, PAGE_SIZE);
if (error != 0) {
umtx_shm_free_reg(reg);
return (error);
}
mtx_lock(&umtx_shm_lock);
reg1 = umtx_shm_find_reg_locked(key);
if (reg1 != NULL) {
mtx_unlock(&umtx_shm_lock);
umtx_shm_free_reg(reg);
*res = reg1;
return (0);
}
reg->ushm_refcnt++;
TAILQ_INSERT_TAIL(&umtx_shm_registry[key->hash], reg, ushm_reg_link);
LIST_INSERT_HEAD(USHM_OBJ_UMTX(key->info.shared.object), reg,
ushm_obj_link);
reg->ushm_flags = USHMF_REG_LINKED | USHMF_OBJ_LINKED;
mtx_unlock(&umtx_shm_lock);
*res = reg;
return (0);
}
static int
umtx_shm_alive(struct thread *td, void *addr)
{
vm_map_t map;
vm_map_entry_t entry;
vm_object_t object;
vm_pindex_t pindex;
vm_prot_t prot;
int res, ret;
boolean_t wired;
map = &td->td_proc->p_vmspace->vm_map;
res = vm_map_lookup(&map, (uintptr_t)addr, VM_PROT_READ, &entry,
&object, &pindex, &prot, &wired);
if (res != KERN_SUCCESS)
return (EFAULT);
if (object == NULL)
ret = EINVAL;
else
ret = (object->flags & OBJ_UMTXDEAD) != 0 ? ENOTTY : 0;
vm_map_lookup_done(map, entry);
return (ret);
}
static void
umtx_shm_init(void)
{
int i;
umtx_shm_reg_zone = uma_zcreate("umtx_shm", sizeof(struct umtx_shm_reg),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
mtx_init(&umtx_shm_lock, "umtxshm", NULL, MTX_DEF);
for (i = 0; i < nitems(umtx_shm_registry); i++)
TAILQ_INIT(&umtx_shm_registry[i]);
}
static int
umtx_shm(struct thread *td, void *addr, u_int flags)
{
struct umtx_key key;
struct umtx_shm_reg *reg;
struct file *fp;
int error, fd;
if (__bitcount(flags & (UMTX_SHM_CREAT | UMTX_SHM_LOOKUP |
UMTX_SHM_DESTROY| UMTX_SHM_ALIVE)) != 1)
return (EINVAL);
if ((flags & UMTX_SHM_ALIVE) != 0)
return (umtx_shm_alive(td, addr));
error = umtx_key_get(addr, TYPE_SHM, PROCESS_SHARE, &key);
if (error != 0)
return (error);
KASSERT(key.shared == 1, ("non-shared key"));
if ((flags & UMTX_SHM_CREAT) != 0) {
error = umtx_shm_create_reg(td, &key, &reg);
} else {
reg = umtx_shm_find_reg(&key);
if (reg == NULL)
error = ESRCH;
}
umtx_key_release(&key);
if (error != 0)
return (error);
KASSERT(reg != NULL, ("no reg"));
if ((flags & UMTX_SHM_DESTROY) != 0) {
umtx_shm_unref_reg(reg, true);
} else {
#if 0
#ifdef MAC
error = mac_posixshm_check_open(td->td_ucred,
reg->ushm_obj, FFLAGS(O_RDWR));
if (error == 0)
#endif
error = shm_access(reg->ushm_obj, td->td_ucred,
FFLAGS(O_RDWR));
if (error == 0)
#endif
error = falloc_caps(td, &fp, &fd, O_CLOEXEC, NULL);
if (error == 0) {
shm_hold(reg->ushm_obj);
finit(fp, FFLAGS(O_RDWR), DTYPE_SHM, reg->ushm_obj,
&shm_ops);
td->td_retval[0] = fd;
fdrop(fp, td);
}
}
umtx_shm_unref_reg(reg, false);
return (error);
}
static int
__umtx_op_shm(struct thread *td, struct _umtx_op_args *uap)
{
return (umtx_shm(td, uap->uaddr1, uap->val));
}
static int
umtx_robust_lists(struct thread *td, struct umtx_robust_lists_params *rbp)
{
td->td_rb_list = rbp->robust_list_offset;
td->td_rbp_list = rbp->robust_priv_list_offset;
td->td_rb_inact = rbp->robust_inact_offset;
return (0);
}
static int
__umtx_op_robust_lists(struct thread *td, struct _umtx_op_args *uap)
{
struct umtx_robust_lists_params rb;
int error;
if (uap->val > sizeof(rb))
return (EINVAL);
bzero(&rb, sizeof(rb));
error = copyin(uap->uaddr1, &rb, uap->val);
if (error != 0)
return (error);
return (umtx_robust_lists(td, &rb));
}
typedef int (*_umtx_op_func)(struct thread *td, struct _umtx_op_args *uap);
static const _umtx_op_func op_table[] = {
[UMTX_OP_RESERVED0] = __umtx_op_unimpl,
[UMTX_OP_RESERVED1] = __umtx_op_unimpl,
[UMTX_OP_WAIT] = __umtx_op_wait,
[UMTX_OP_WAKE] = __umtx_op_wake,
[UMTX_OP_MUTEX_TRYLOCK] = __umtx_op_trylock_umutex,
[UMTX_OP_MUTEX_LOCK] = __umtx_op_lock_umutex,
[UMTX_OP_MUTEX_UNLOCK] = __umtx_op_unlock_umutex,
[UMTX_OP_SET_CEILING] = __umtx_op_set_ceiling,
[UMTX_OP_CV_WAIT] = __umtx_op_cv_wait,
[UMTX_OP_CV_SIGNAL] = __umtx_op_cv_signal,
[UMTX_OP_CV_BROADCAST] = __umtx_op_cv_broadcast,
[UMTX_OP_WAIT_UINT] = __umtx_op_wait_uint,
[UMTX_OP_RW_RDLOCK] = __umtx_op_rw_rdlock,
[UMTX_OP_RW_WRLOCK] = __umtx_op_rw_wrlock,
[UMTX_OP_RW_UNLOCK] = __umtx_op_rw_unlock,
[UMTX_OP_WAIT_UINT_PRIVATE] = __umtx_op_wait_uint_private,
[UMTX_OP_WAKE_PRIVATE] = __umtx_op_wake_private,
[UMTX_OP_MUTEX_WAIT] = __umtx_op_wait_umutex,
[UMTX_OP_MUTEX_WAKE] = __umtx_op_wake_umutex,
#if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
[UMTX_OP_SEM_WAIT] = __umtx_op_sem_wait,
[UMTX_OP_SEM_WAKE] = __umtx_op_sem_wake,
#else
[UMTX_OP_SEM_WAIT] = __umtx_op_unimpl,
[UMTX_OP_SEM_WAKE] = __umtx_op_unimpl,
#endif
[UMTX_OP_NWAKE_PRIVATE] = __umtx_op_nwake_private,
[UMTX_OP_MUTEX_WAKE2] = __umtx_op_wake2_umutex,
[UMTX_OP_SEM2_WAIT] = __umtx_op_sem2_wait,
[UMTX_OP_SEM2_WAKE] = __umtx_op_sem2_wake,
[UMTX_OP_SHM] = __umtx_op_shm,
[UMTX_OP_ROBUST_LISTS] = __umtx_op_robust_lists,
};
int
sys__umtx_op(struct thread *td, struct _umtx_op_args *uap)
{
if ((unsigned)uap->op < nitems(op_table))
return (*op_table[uap->op])(td, uap);
return (EINVAL);
}
#ifdef COMPAT_FREEBSD32
struct timespec32 {
int32_t tv_sec;
int32_t tv_nsec;
};
struct umtx_time32 {
struct timespec32 timeout;
uint32_t flags;
uint32_t clockid;
};
static inline int
umtx_copyin_timeout32(void *addr, struct timespec *tsp)
{
struct timespec32 ts32;
int error;
error = copyin(addr, &ts32, sizeof(struct timespec32));
if (error == 0) {
if (ts32.tv_sec < 0 ||
ts32.tv_nsec >= 1000000000 ||
ts32.tv_nsec < 0)
error = EINVAL;
else {
tsp->tv_sec = ts32.tv_sec;
tsp->tv_nsec = ts32.tv_nsec;
}
}
return (error);
}
static inline int
umtx_copyin_umtx_time32(const void *addr, size_t size, struct _umtx_time *tp)
{
struct umtx_time32 t32;
int error;
t32.clockid = CLOCK_REALTIME;
t32.flags = 0;
if (size <= sizeof(struct timespec32))
error = copyin(addr, &t32.timeout, sizeof(struct timespec32));
else
error = copyin(addr, &t32, sizeof(struct umtx_time32));
if (error != 0)
return (error);
if (t32.timeout.tv_sec < 0 ||
t32.timeout.tv_nsec >= 1000000000 || t32.timeout.tv_nsec < 0)
return (EINVAL);
tp->_timeout.tv_sec = t32.timeout.tv_sec;
tp->_timeout.tv_nsec = t32.timeout.tv_nsec;
tp->_flags = t32.flags;
tp->_clockid = t32.clockid;
return (0);
}
static int
__umtx_op_wait_compat32(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
int error;
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time32(uap->uaddr2,
(size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_wait(td, uap->obj, uap->val, tm_p, 1, 0));
}
static int
__umtx_op_lock_umutex_compat32(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time32(uap->uaddr2,
(size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_lock_umutex(td, uap->obj, tm_p, 0));
}
static int
__umtx_op_wait_umutex_compat32(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time32(uap->uaddr2,
(size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_lock_umutex(td, uap->obj, tm_p, _UMUTEX_WAIT));
}
static int
__umtx_op_cv_wait_compat32(struct thread *td, struct _umtx_op_args *uap)
{
struct timespec *ts, timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL)
ts = NULL;
else {
error = umtx_copyin_timeout32(uap->uaddr2, &timeout);
if (error != 0)
return (error);
ts = &timeout;
}
return (do_cv_wait(td, uap->obj, uap->uaddr1, ts, uap->val));
}
static int
__umtx_op_rw_rdlock_compat32(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL) {
error = do_rw_rdlock(td, uap->obj, uap->val, 0);
} else {
error = umtx_copyin_umtx_time32(uap->uaddr2,
(size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
error = do_rw_rdlock(td, uap->obj, uap->val, &timeout);
}
return (error);
}
static int
__umtx_op_rw_wrlock_compat32(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL) {
error = do_rw_wrlock(td, uap->obj, 0);
} else {
error = umtx_copyin_umtx_time32(uap->uaddr2,
(size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
error = do_rw_wrlock(td, uap->obj, &timeout);
}
return (error);
}
static int
__umtx_op_wait_uint_private_compat32(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
int error;
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time32(
uap->uaddr2, (size_t)uap->uaddr1,&timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_wait(td, uap->obj, uap->val, tm_p, 1, 1));
}
#if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
static int
__umtx_op_sem_wait_compat32(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL)
tm_p = NULL;
else {
error = umtx_copyin_umtx_time32(uap->uaddr2,
(size_t)uap->uaddr1, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
return (do_sem_wait(td, uap->obj, tm_p));
}
#endif
static int
__umtx_op_sem2_wait_compat32(struct thread *td, struct _umtx_op_args *uap)
{
struct _umtx_time *tm_p, timeout;
size_t uasize;
int error;
/* Allow a null timespec (wait forever). */
if (uap->uaddr2 == NULL) {
uasize = 0;
tm_p = NULL;
} else {
uasize = (size_t)uap->uaddr1;
error = umtx_copyin_umtx_time32(uap->uaddr2, uasize, &timeout);
if (error != 0)
return (error);
tm_p = &timeout;
}
error = do_sem2_wait(td, uap->obj, tm_p);
if (error == EINTR && uap->uaddr2 != NULL &&
(timeout._flags & UMTX_ABSTIME) == 0 &&
uasize >= sizeof(struct umtx_time32) + sizeof(struct timespec32)) {
struct timespec32 remain32 = {
.tv_sec = timeout._timeout.tv_sec,
.tv_nsec = timeout._timeout.tv_nsec
};
error = copyout(&remain32,
(struct umtx_time32 *)uap->uaddr2 + 1,
sizeof(struct timespec32));
if (error == 0) {
error = EINTR;
}
}
return (error);
}
static int
__umtx_op_nwake_private32(struct thread *td, struct _umtx_op_args *uap)
{
uint32_t uaddrs[BATCH_SIZE], **upp;
int count, error, i, pos, tocopy;
upp = (uint32_t **)uap->obj;
error = 0;
for (count = uap->val, pos = 0; count > 0; count -= tocopy,
pos += tocopy) {
tocopy = MIN(count, BATCH_SIZE);
error = copyin(upp + pos, uaddrs, tocopy * sizeof(uint32_t));
if (error != 0)
break;
for (i = 0; i < tocopy; ++i)
kern_umtx_wake(td, (void *)(intptr_t)uaddrs[i],
INT_MAX, 1);
maybe_yield();
}
return (error);
}
struct umtx_robust_lists_params_compat32 {
uint32_t robust_list_offset;
uint32_t robust_priv_list_offset;
uint32_t robust_inact_offset;
};
static int
__umtx_op_robust_lists_compat32(struct thread *td, struct _umtx_op_args *uap)
{
struct umtx_robust_lists_params rb;
struct umtx_robust_lists_params_compat32 rb32;
int error;
if (uap->val > sizeof(rb32))
return (EINVAL);
bzero(&rb, sizeof(rb));
bzero(&rb32, sizeof(rb32));
error = copyin(uap->uaddr1, &rb32, uap->val);
if (error != 0)
return (error);
rb.robust_list_offset = rb32.robust_list_offset;
rb.robust_priv_list_offset = rb32.robust_priv_list_offset;
rb.robust_inact_offset = rb32.robust_inact_offset;
return (umtx_robust_lists(td, &rb));
}
static const _umtx_op_func op_table_compat32[] = {
[UMTX_OP_RESERVED0] = __umtx_op_unimpl,
[UMTX_OP_RESERVED1] = __umtx_op_unimpl,
[UMTX_OP_WAIT] = __umtx_op_wait_compat32,
[UMTX_OP_WAKE] = __umtx_op_wake,
[UMTX_OP_MUTEX_TRYLOCK] = __umtx_op_trylock_umutex,
[UMTX_OP_MUTEX_LOCK] = __umtx_op_lock_umutex_compat32,
[UMTX_OP_MUTEX_UNLOCK] = __umtx_op_unlock_umutex,
[UMTX_OP_SET_CEILING] = __umtx_op_set_ceiling,
[UMTX_OP_CV_WAIT] = __umtx_op_cv_wait_compat32,
[UMTX_OP_CV_SIGNAL] = __umtx_op_cv_signal,
[UMTX_OP_CV_BROADCAST] = __umtx_op_cv_broadcast,
[UMTX_OP_WAIT_UINT] = __umtx_op_wait_compat32,
[UMTX_OP_RW_RDLOCK] = __umtx_op_rw_rdlock_compat32,
[UMTX_OP_RW_WRLOCK] = __umtx_op_rw_wrlock_compat32,
[UMTX_OP_RW_UNLOCK] = __umtx_op_rw_unlock,
[UMTX_OP_WAIT_UINT_PRIVATE] = __umtx_op_wait_uint_private_compat32,
[UMTX_OP_WAKE_PRIVATE] = __umtx_op_wake_private,
[UMTX_OP_MUTEX_WAIT] = __umtx_op_wait_umutex_compat32,
[UMTX_OP_MUTEX_WAKE] = __umtx_op_wake_umutex,
#if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
[UMTX_OP_SEM_WAIT] = __umtx_op_sem_wait_compat32,
[UMTX_OP_SEM_WAKE] = __umtx_op_sem_wake,
#else
[UMTX_OP_SEM_WAIT] = __umtx_op_unimpl,
[UMTX_OP_SEM_WAKE] = __umtx_op_unimpl,
#endif
[UMTX_OP_NWAKE_PRIVATE] = __umtx_op_nwake_private32,
[UMTX_OP_MUTEX_WAKE2] = __umtx_op_wake2_umutex,
[UMTX_OP_SEM2_WAIT] = __umtx_op_sem2_wait_compat32,
[UMTX_OP_SEM2_WAKE] = __umtx_op_sem2_wake,
[UMTX_OP_SHM] = __umtx_op_shm,
[UMTX_OP_ROBUST_LISTS] = __umtx_op_robust_lists_compat32,
};
int
freebsd32__umtx_op(struct thread *td, struct freebsd32__umtx_op_args *uap)
{
if ((unsigned)uap->op < nitems(op_table_compat32)) {
return (*op_table_compat32[uap->op])(td,
(struct _umtx_op_args *)uap);
}
return (EINVAL);
}
#endif
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.
*
* Clear robust lists for all process' threads, not delaying the
* cleanup to thread_exit hook, since the relevant address space is
* destroyed right now.
*/
static void
umtx_exec_hook(void *arg __unused, struct proc *p,
struct image_params *imgp __unused)
{
struct thread *td;
KASSERT(p == curproc, ("need curproc"));
KASSERT((p->p_flag & P_HADTHREADS) == 0 ||
(p->p_flag & P_STOPPED_SINGLE) != 0,
("curproc must be single-threaded"));
/*
* There is no need to lock the list as only this thread can be
* running.
*/
FOREACH_THREAD_IN_PROC(p, td) {
KASSERT(td == curthread ||
((td->td_flags & TDF_BOUNDARY) != 0 && TD_IS_SUSPENDED(td)),
("running thread %p %p", p, td));
umtx_thread_cleanup(td);
td->td_rb_list = td->td_rbp_list = td->td_rb_inact = 0;
}
}
/*
* thread_exit() hook.
*/
void
umtx_thread_exit(struct thread *td)
{
umtx_thread_cleanup(td);
}
static int
umtx_read_uptr(struct thread *td, uintptr_t ptr, uintptr_t *res)
{
u_long res1;
#ifdef COMPAT_FREEBSD32
uint32_t res32;
#endif
int error;
#ifdef COMPAT_FREEBSD32
if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
error = fueword32((void *)ptr, &res32);
if (error == 0)
res1 = res32;
} else
#endif
{
error = fueword((void *)ptr, &res1);
}
if (error == 0)
*res = res1;
else
error = EFAULT;
return (error);
}
static void
umtx_read_rb_list(struct thread *td, struct umutex *m, uintptr_t *rb_list)
{
#ifdef COMPAT_FREEBSD32
struct umutex32 m32;
if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
memcpy(&m32, m, sizeof(m32));
*rb_list = m32.m_rb_lnk;
} else
#endif
*rb_list = m->m_rb_lnk;
}
static int
umtx_handle_rb(struct thread *td, uintptr_t rbp, uintptr_t *rb_list, bool inact)
{
struct umutex m;
int error;
KASSERT(td->td_proc == curproc, ("need current vmspace"));
error = copyin((void *)rbp, &m, sizeof(m));
if (error != 0)
return (error);
if (rb_list != NULL)
umtx_read_rb_list(td, &m, rb_list);
if ((m.m_flags & UMUTEX_ROBUST) == 0)
return (EINVAL);
if ((m.m_owner & ~UMUTEX_CONTESTED) != td->td_tid)
/* inact is cleared after unlock, allow the inconsistency */
return (inact ? 0 : EINVAL);
return (do_unlock_umutex(td, (struct umutex *)rbp, true));
}
static void
umtx_cleanup_rb_list(struct thread *td, uintptr_t rb_list, uintptr_t *rb_inact,
const char *name)
{
int error, i;
uintptr_t rbp;
bool inact;
if (rb_list == 0)
return;
error = umtx_read_uptr(td, rb_list, &rbp);
for (i = 0; error == 0 && rbp != 0 && i < umtx_max_rb; i++) {
if (rbp == *rb_inact) {
inact = true;
*rb_inact = 0;
} else
inact = false;
error = umtx_handle_rb(td, rbp, &rbp, inact);
}
if (i == umtx_max_rb && umtx_verbose_rb) {
uprintf("comm %s pid %d: reached umtx %smax rb %d\n",
td->td_proc->p_comm, td->td_proc->p_pid, name, umtx_max_rb);
}
if (error != 0 && umtx_verbose_rb) {
uprintf("comm %s pid %d: handling %srb error %d\n",
td->td_proc->p_comm, td->td_proc->p_pid, name, error);
}
}
/*
* Clean up umtx data.
*/
static void
umtx_thread_cleanup(struct thread *td)
{
struct umtx_q *uq;
struct umtx_pi *pi;
uintptr_t rb_inact;
/*
* Disown pi mutexes.
*/
uq = td->td_umtxq;
if (uq != NULL) {
if (uq->uq_inherited_pri != PRI_MAX ||
!TAILQ_EMPTY(&uq->uq_pi_contested)) {
mtx_lock(&umtx_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);
}
mtx_unlock(&umtx_lock);
}
sched_lend_user_prio_cond(td, PRI_MAX);
}
if (td->td_rb_inact == 0 && td->td_rb_list == 0 && td->td_rbp_list == 0)
return;
/*
* Handle terminated robust mutexes. Must be done after
* robust pi disown, otherwise unlock could see unowned
* entries.
*/
rb_inact = td->td_rb_inact;
if (rb_inact != 0)
(void)umtx_read_uptr(td, rb_inact, &rb_inact);
umtx_cleanup_rb_list(td, td->td_rb_list, &rb_inact, "");
umtx_cleanup_rb_list(td, td->td_rbp_list, &rb_inact, "priv ");
if (rb_inact != 0)
(void)umtx_handle_rb(td, rb_inact, NULL, true);
}
Reference in New Issue View Git Blame Copy Permalink