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freebsd-skq/sys/kern/kern_umtx.c
Konstantin Belousov 6690381ef1 The dependency chain for priority-inheritance mutexes could be 
subverted by userspace into cycle.  Both umtx_propagate_priority() and
umtx_repropagate_priority() would then loop infinitely, owning the
spinlock.

Check for the cycle using standard Floyd' algorithm before doing the
pass in the affected functions.  Add simple check for condition of
tricking the thread into a wait for itself, which could be easily
simulated by usermode without race.

Found by:	Eric van Gyzen <eric@vangyzen.net>
In collaboration with:	Eric van Gyzen <eric@vangyzen.net>
Tested by:	pho
MFC after:	1 week
2015-01-31 12:27:40 +00:00

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/*-
* Copyright (c) 2004, David Xu <davidxu@freebsd.org>
* Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
* All rights reserved.
*
* 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_compat.h"
#include "opt_umtx_profiling.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.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/eventhandler.h>
#include <sys/umtx.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/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
#define UMTX_CHAINS 512
#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;
struct timespec cur;
struct timespec end;
};
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");
#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 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);
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_SPIN);
EVENTHANDLER_REGISTER(process_exec, umtx_exec_hook, NULL,
EVENTHANDLER_PRI_ANY);
}
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 = (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_chain *uc;
struct umtxq_queue *uh;
uc = umtxq_getchain(key);
UMTXQ_LOCKED_ASSERT(uc);
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_chain *uc;
struct umtxq_queue *uh;
*first = NULL;
uc = umtxq_getchain(key);
UMTXQ_LOCKED_ASSERT(uc);
uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
if (uh != NULL) {
*first = TAILQ_FIRST(&uh->head);
return (uh->length);
}
return (0);
}
static int
umtxq_check_susp(struct thread *td)
{
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 = 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_chain *uc;
struct umtxq_queue *uh;
struct umtx_q *uq;
int ret;
ret = 0;
uc = umtxq_getchain(key);
UMTXQ_LOCKED_ASSERT(uc);
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)
{
struct umtxq_chain *uc;
uc = umtxq_getchain(&uq->uq_key);
UMTXQ_LOCKED_ASSERT(uc);
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) {
kern_clock_gettime(curthread, clockid, &timo->end);
timo->cur = timo->end;
timespecadd(&timo->end, timeout);
} else {
timo->end = *timeout;
kern_clock_gettime(curthread, clockid, &timo->cur);
}
}
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);
tts = timo->end;
timespecsub(&tts, &timo->cur);
return (tstohz(&tts));
}
/*
* 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;
uc = umtxq_getchain(&uq->uq_key);
UMTXQ_LOCKED_ASSERT(uc);
for (;;) {
if (!(uq->uq_flags & UQF_UMTXQ))
return (0);
if (abstime != NULL) {
timo = abs_timeout_gethz(abstime);
if (timo < 0)
return (ETIMEDOUT);
} else
timo = 0;
error = msleep(uq, &uc->uc_lock, PCATCH | PDROP, wmesg, timo);
if (error != EWOULDBLOCK) {
umtxq_lock(&uq->uq_key);
break;
}
if (abstime != NULL)
abs_timeout_update(abstime);
umtxq_lock(&uq->uq_key);
}
return (error);
}
/*
* Convert userspace address into unique logical address.
*/
int
umtx_key_get(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 = entry->offset + entry->start -
(vm_offset_t)addr;
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);
ret = umtxq_signal(&key, n_wake);
umtxq_unlock(&key);
umtx_key_release(&key);
return (0);
}
/*
* Lock PTHREAD_PRIO_NONE protocol POSIX mutex.
*/
static int
do_lock_normal(struct thread *td, struct umutex *m, uint32_t flags,
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)
return (0);
} else {
/*
* 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 (owner == UMUTEX_UNOWNED)
return (0);
/* If no one owns it but it is contested try to acquire it. */
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 (owner == UMUTEX_CONTESTED)
return (0);
rv = umtxq_check_susp(td);
if (rv != 0)
return (rv);
/* If this failed the lock has changed, restart. */
continue;
}
}
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. */
if (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);
return (EFAULT);
}
/*
* We set the contested bit, sleep. Otherwise the lock changed
* and we need to retry or we lost a race to the thread
* unlocking the umtx.
*/
umtxq_lock(&uq->uq_key);
umtxq_unbusy(&uq->uq_key);
if (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);
}
return (0);
}
/*
* Unlock PTHREAD_PRIO_NONE protocol POSIX mutex.
*/
static int
do_unlock_normal(struct thread *td, struct umutex *m, uint32_t flags)
{
struct umtx_key key;
uint32_t owner, old, id;
int error;
int count;
id = td->td_tid;
/*
* Make sure we own this mtx.
*/
error = fueword32(&m->m_owner, &owner);
if (error == -1)
return (EFAULT);
if ((owner & ~UMUTEX_CONTESTED) != id)
return (EPERM);
if ((owner & UMUTEX_CONTESTED) == 0) {
error = casueword32(&m->m_owner, owner, &old, UMUTEX_UNOWNED);
if (error == -1)
return (EFAULT);
if (old == owner)
return (0);
owner = old;
}
/* We should only ever be in here for contested locks */
if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags),
&key)) != 0)
return (error);
umtxq_lock(&key);
umtxq_busy(&key);
count = umtxq_count(&key);
umtxq_unlock(&key);
/*
* When unlocking the umtx, it must be marked as unowned if
* there is zero or one thread only waiting for it.
* Otherwise, it must be marked as contested.
*/
error = casueword32(&m->m_owner, owner, &old,
count <= 1 ? UMUTEX_UNOWNED : UMUTEX_CONTESTED);
umtxq_lock(&key);
umtxq_signal(&key,1);
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
if (error == -1)
return (EFAULT);
if (old != owner)
return (EINVAL);
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;
error = fueword32(&m->m_owner, &owner);
if (error == -1)
return (EFAULT);
if ((owner & ~UMUTEX_CONTESTED) != 0)
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) {
error = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
UMUTEX_UNOWNED);
if (error == -1)
error = EFAULT;
}
umtxq_lock(&key);
if (error == 0 && count != 0 && (owner & ~UMUTEX_CONTESTED) == 0)
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)) {
case 0:
type = TYPE_NORMAL_UMUTEX;
break;
case UMUTEX_PRIO_INHERIT:
type = TYPE_PI_UMUTEX;
break;
case UMUTEX_PRIO_PROTECT:
type = TYPE_PP_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);
/*
* 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.
*/
if (count > 1) {
error = fueword32(&m->m_owner, &owner);
if (error == -1)
error = EFAULT;
while (error == 0 && (owner & UMUTEX_CONTESTED) == 0) {
error = casueword32(&m->m_owner, owner, &old,
owner | UMUTEX_CONTESTED);
if (error == -1) {
error = EFAULT;
break;
}
if (old == owner)
break;
owner = old;
error = umtxq_check_susp(td);
if (error != 0)
break;
}
} else if (count == 1) {
error = fueword32(&m->m_owner, &owner);
if (error == -1)
error = EFAULT;
while (error == 0 && (owner & ~UMUTEX_CONTESTED) != 0 &&
(owner & UMUTEX_CONTESTED) == 0) {
error = casueword32(&m->m_owner, owner, &old,
owner | UMUTEX_CONTESTED);
if (error == -1) {
error = EFAULT;
break;
}
if (old == owner)
break;
owner = old;
error = umtxq_check_susp(td);
if (error != 0)
break;
}
}
umtxq_lock(&key);
if (error == EFAULT) {
umtxq_signal(&key, INT_MAX);
} else if (count != 0 && (owner & ~UMUTEX_CONTESTED) == 0)
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);
if (pi->pi_owner != NULL)
panic("pi_ower != NULL");
pi->pi_owner = owner;
TAILQ_INSERT_TAIL(&uq_owner->uq_pi_contested, pi, pi_link);
}
/*
* Claim ownership of a PI mutex.
*/
static int
umtx_pi_claim(struct umtx_pi *pi, struct thread *owner)
{
struct umtx_q *uq, *uq_owner;
uq_owner = owner->td_umtxq;
mtx_lock_spin(&umtx_lock);
if (pi->pi_owner == owner) {
mtx_unlock_spin(&umtx_lock);
return (0);
}
if (pi->pi_owner != NULL) {
/*
* userland may have already messed the mutex, sigh.
*/
mtx_unlock_spin(&umtx_lock);
return (EPERM);
}
umtx_pi_setowner(pi, owner);
uq = TAILQ_FIRST(&pi->pi_blocked);
if (uq != NULL) {
int pri;
pri = UPRI(uq->uq_thread);
thread_lock(owner);
if (pri < UPRI(owner))
sched_lend_user_prio(owner, pri);
thread_unlock(owner);
}
mtx_unlock_spin(&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_spin(&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_spin(&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)
{
struct umtxq_chain *uc;
struct thread *td, *td1;
struct umtx_q *uq1;
int pri;
int error = 0;
td = uq->uq_thread;
KASSERT(td == curthread, ("inconsistent uq_thread"));
uc = umtxq_getchain(&uq->uq_key);
UMTXQ_LOCKED_ASSERT(uc);
KASSERT(uc->uc_busy != 0, ("umtx chain is not busy"));
umtxq_insert(uq);
mtx_lock_spin(&umtx_lock);
if (pi->pi_owner == NULL) {
mtx_unlock_spin(&umtx_lock);
/* XXX Only look up thread in current process. */
td1 = tdfind(owner, curproc->p_pid);
mtx_lock_spin(&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_spin(&umtx_lock);
umtxq_unbusy(&uq->uq_key);
error = umtxq_sleep(uq, wmesg, timo);
umtxq_remove(uq);
mtx_lock_spin(&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_spin(&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)
{
struct umtxq_chain *uc;
uc = umtxq_getchain(&pi->pi_key);
UMTXQ_LOCKED_ASSERT(uc);
pi->pi_refcount++;
}
/*
* Decrease reference count for a PI mutex, if the counter
* is decreased to zero, its memory space is freed.
*/
static void
umtx_pi_unref(struct umtx_pi *pi)
{
struct umtxq_chain *uc;
uc = umtxq_getchain(&pi->pi_key);
UMTXQ_LOCKED_ASSERT(uc);
KASSERT(pi->pi_refcount > 0, ("invalid reference count"));
if (--pi->pi_refcount == 0) {
mtx_lock_spin(&umtx_lock);
if (pi->pi_owner != NULL) {
TAILQ_REMOVE(&pi->pi_owner->td_umtxq->uq_pi_contested,
pi, pi_link);
pi->pi_owner = NULL;
}
KASSERT(TAILQ_EMPTY(&pi->pi_blocked),
("blocked queue not empty"));
mtx_unlock_spin(&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, owner, old;
int error, rv;
id = td->td_tid;
uq = td->td_umtxq;
if ((error = umtx_key_get(m, TYPE_PI_UMUTEX, GET_SHARE(flags),
&uq->uq_key)) != 0)
return (error);
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 (owner == UMUTEX_UNOWNED) {
error = 0;
break;
}
/* If no one owns it but it is contested try to acquire it. */
if (owner == UMUTEX_CONTESTED) {
rv = casueword32(&m->m_owner,
UMUTEX_CONTESTED, &owner, id | UMUTEX_CONTESTED);
/* The address was invalid. */
if (rv == -1) {
error = EFAULT;
break;
}
if (owner == UMUTEX_CONTESTED) {
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);
break;
}
error = umtxq_check_susp(td);
if (error != 0)
break;
/* If this failed the lock has changed, restart. */
continue;
}
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;
}
umtxq_lock(&uq->uq_key);
/*
* We set the contested bit, sleep. Otherwise the lock changed
* and we need to retry or we lost a race to the thread
* unlocking the umtx.
*/
if (old == owner) {
error = umtxq_sleep_pi(uq, pi, owner & ~UMUTEX_CONTESTED,
"umtxpi", timeout == NULL ? NULL : &timo);
if (error != 0)
continue;
} else {
umtxq_unbusy(&uq->uq_key);
umtxq_unlock(&uq->uq_key);
}
error = umtxq_check_susp(td);
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)
{
struct umtx_key key;
struct umtx_q *uq_first, *uq_first2, *uq_me;
struct umtx_pi *pi, *pi2;
uint32_t owner, old, id;
int error;
int count;
int pri;
id = td->td_tid;
/*
* Make sure we own this mtx.
*/
error = fueword32(&m->m_owner, &owner);
if (error == -1)
return (EFAULT);
if ((owner & ~UMUTEX_CONTESTED) != id)
return (EPERM);
/* This should be done in userland */
if ((owner & UMUTEX_CONTESTED) == 0) {
error = casueword32(&m->m_owner, owner, &old, UMUTEX_UNOWNED);
if (error == -1)
return (EFAULT);
if (old == owner)
return (0);
owner = old;
}
/* We should only ever be in here for contested locks */
if ((error = umtx_key_get(m, TYPE_PI_UMUTEX, GET_SHARE(flags),
&key)) != 0)
return (error);
umtxq_lock(&key);
umtxq_busy(&key);
count = umtxq_count_pi(&key, &uq_first);
if (uq_first != NULL) {
mtx_lock_spin(&umtx_lock);
pi = uq_first->uq_pi_blocked;
KASSERT(pi != NULL, ("pi == NULL?"));
if (pi->pi_owner != curthread) {
mtx_unlock_spin(&umtx_lock);
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
/* userland messed the mutex */
return (EPERM);
}
uq_me = curthread->td_umtxq;
pi->pi_owner = NULL;
TAILQ_REMOVE(&uq_me->uq_pi_contested, pi, pi_link);
/* 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(curthread);
sched_lend_user_prio(curthread, pri);
thread_unlock(curthread);
mtx_unlock_spin(&umtx_lock);
if (uq_first)
umtxq_signal_thread(uq_first);
}
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.
*/
error = casueword32(&m->m_owner, owner, &old,
count <= 1 ? UMUTEX_UNOWNED : UMUTEX_CONTESTED);
umtxq_unbusy_unlocked(&key);
umtx_key_release(&key);
if (error == -1)
return (EFAULT);
if (old != owner)
return (EINVAL);
return (0);
}
/*
* Lock a PP mutex.
*/
static int
do_lock_pp(struct thread *td, struct umutex *m, uint32_t flags,
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, 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_spin(&umtx_lock);
if (UPRI(td) < PRI_MIN_REALTIME + ceiling) {
mtx_unlock_spin(&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_spin(&umtx_lock);
rv = casueword32(&m->m_owner,
UMUTEX_CONTESTED, &owner, id | UMUTEX_CONTESTED);
/* The address was invalid. */
if (rv == -1) {
error = EFAULT;
break;
}
if (owner == UMUTEX_CONTESTED) {
error = 0;
break;
}
if (try != 0) {
error = EBUSY;
break;
}
/*
* If we caught a signal, we have retried and now
* exit immediately.
*/
if (error != 0)
break;
umtxq_lock(&uq->uq_key);
umtxq_insert(uq);
umtxq_unbusy(&uq->uq_key);
error = umtxq_sleep(uq, "umtxpp", timeout == NULL ?
NULL : &timo);
umtxq_remove(uq);
umtxq_unlock(&uq->uq_key);
mtx_lock_spin(&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_spin(&umtx_lock);
}
if (error != 0) {
mtx_lock_spin(&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_spin(&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)
{
struct umtx_key key;
struct umtx_q *uq, *uq2;
struct umtx_pi *pi;
uint32_t owner, id;
uint32_t rceiling;
int error, pri, new_inherited_pri, su;
id = td->td_tid;
uq = td->td_umtxq;
su = (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, TYPE_PP_UMUTEX, GET_SHARE(flags),
&key)) != 0)
return (error);
umtxq_lock(&key);
umtxq_busy(&key);
umtxq_unlock(&key);
/*
* For priority protected mutex, always set unlocked state
* to UMUTEX_CONTESTED, so that userland always enters kernel
* to lock the mutex, it is necessary because thread priority
* has to be adjusted for such mutex.
*/
error = suword32(&m->m_owner, UMUTEX_CONTESTED);
umtxq_lock(&key);
if (error == 0)
umtxq_signal(&key, 1);
umtxq_unbusy(&key);
umtxq_unlock(&key);
if (error == -1)
error = EFAULT;
else {
mtx_lock_spin(&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_spin(&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 save_ceiling;
uint32_t owner, id;
uint32_t flags;
int error, rv;
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, 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) {
suword32(&m->m_ceilings[0], ceiling);
suword32(&m->m_owner, UMUTEX_CONTESTED);
error = 0;
break;
}
if ((owner & ~UMUTEX_CONTESTED) == id) {
suword32(&m->m_ceilings[0], ceiling);
error = 0;
break;
}
/*
* If we caught a signal, we have retried and now
* exit immediately.
*/
if (error != 0)
break;
/*
* We set the contested bit, sleep. Otherwise the lock changed
* and we need to retry or we lost a race to the thread
* unlocking the umtx.
*/
umtxq_lock(&uq->uq_key);
umtxq_insert(uq);
umtxq_unbusy(&uq->uq_key);
error = umtxq_sleep(uq, "umtxpp", 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)
suword32(old_ceiling, save_ceiling);
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)
{
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));
case UMUTEX_PRIO_INHERIT:
return (do_unlock_pi(td, m, flags));
case UMUTEX_PRIO_PROTECT:
return (do_unlock_pp(td, m, flags));
}
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);
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, 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 (oldstate == state) {
umtx_key_release(&uq->uq_key);
return (0);
}
error = umtxq_check_susp(td);
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 (oldstate == state)
goto sleep;
state = oldstate;
error = umtxq_check_susp(td);
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);
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)
error = EFAULT;
while (error == 0) {
rv = casueword32(&rwlock->rw_state, state,
&oldstate, state & ~URWLOCK_READ_WAITERS);
if (rv == -1) {
error = EFAULT;
break;
}
if (oldstate == state)
break;
state = oldstate;
error = umtxq_check_susp(td);
}
}
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, 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) && 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 (oldstate == state) {
umtx_key_release(&uq->uq_key);
return (0);
}
state = oldstate;
error = umtxq_check_susp(td);
if (error != 0)
break;
}
if (error) {
if (!(state & (URWLOCK_WRITE_OWNER|URWLOCK_WRITE_WAITERS)) &&
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 (oldstate == state)
goto sleep;
state = oldstate;
error = umtxq_check_susp(td);
if (error != 0)
break;
}
if (error != 0) {
umtxq_unbusy_unlocked(&uq->uq_key);
break;
}
if (!(state & URWLOCK_WRITE_OWNER) && URWLOCK_READER_COUNT(state) == 0) {
umtxq_unbusy_unlocked(&uq->uq_key);
error = umtxq_check_susp(td);
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 (oldstate == state)
break;
state = oldstate;
error = umtxq_check_susp(td);
/*
* We are leaving the URWLOCK_WRITE_WAITERS
* behind, but this should not harm the
* correctness.
*/
if (error != 0)
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 (oldstate != state) {
state = oldstate;
if (!(oldstate & URWLOCK_WRITE_OWNER)) {
error = EPERM;
goto out;
}
error = umtxq_check_susp(td);
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 (oldstate != state) {
state = oldstate;
if (URWLOCK_READER_COUNT(oldstate) == 0) {
error = EPERM;
goto out;
}
error = umtxq_check_susp(td);
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;
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);
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)
rv = fueword32(&sem->_count, &count);
if (rv == -1 || 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 (rv == -1 ? EFAULT : 0);
}
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);
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) {
umtxq_signal(&key, 1);
/*
* 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_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);
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 == -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);
}
if (count == 0)
break;
}
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);
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) {
umtxq_signal(&key, 1);
/*
* 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)
error = EFAULT;
umtxq_lock(&key);
}
}
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)
{
int count = uap->val;
void *uaddrs[BATCH_SIZE];
char **upp = (char **)uap->obj;
int tocopy;
int error = 0;
int i, pos = 0;
while (count > 0) {
tocopy = count;
if (tocopy > BATCH_SIZE)
tocopy = 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);
count -= tocopy;
pos += tocopy;
}
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);
}
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;
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_sem2_wait(td, uap->obj, tm_p));
}
static int
__umtx_op_sem2_wake(struct thread *td, struct _umtx_op_args *uap)
{
return do_sem2_wake(td, uap->obj);
}
typedef int (*_umtx_op_func)(struct thread *td, struct _umtx_op_args *uap);
static _umtx_op_func op_table[] = {
__umtx_op_unimpl, /* UMTX_OP_RESERVED0 */
__umtx_op_unimpl, /* UMTX_OP_RESERVED1 */
__umtx_op_wait, /* UMTX_OP_WAIT */
__umtx_op_wake, /* UMTX_OP_WAKE */
__umtx_op_trylock_umutex, /* UMTX_OP_MUTEX_TRYLOCK */
__umtx_op_lock_umutex, /* UMTX_OP_MUTEX_LOCK */
__umtx_op_unlock_umutex, /* UMTX_OP_MUTEX_UNLOCK */
__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_wait_umutex, /* UMTX_OP_MUTEX_WAIT */
__umtx_op_wake_umutex, /* UMTX_OP_MUTEX_WAKE */
#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_unimpl, /* UMTX_OP_SEM_WAIT */
__umtx_op_unimpl, /* UMTX_OP_SEM_WAKE */
#endif
__umtx_op_nwake_private, /* UMTX_OP_NWAKE_PRIVATE */
__umtx_op_wake2_umutex, /* UMTX_OP_MUTEX_WAKE2 */
__umtx_op_sem2_wait, /* UMTX_OP_SEM2_WAIT */
__umtx_op_sem2_wake, /* UMTX_OP_SEM2_WAKE */
};
int
sys__umtx_op(struct thread *td, struct _umtx_op_args *uap)
{
if ((unsigned)uap->op < UMTX_OP_MAX)
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_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_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;
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_sem2_wait(td, uap->obj, tm_p));
}
static int
__umtx_op_nwake_private32(struct thread *td, struct _umtx_op_args *uap)
{
int count = uap->val;
uint32_t uaddrs[BATCH_SIZE];
uint32_t **upp = (uint32_t **)uap->obj;
int tocopy;
int error = 0;
int i, pos = 0;
while (count > 0) {
tocopy = count;
if (tocopy > BATCH_SIZE)
tocopy = 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);
count -= tocopy;
pos += tocopy;
}
return (error);
}
static _umtx_op_func op_table_compat32[] = {
__umtx_op_unimpl, /* UMTX_OP_RESERVED0 */
__umtx_op_unimpl, /* UMTX_OP_RESERVED1 */
__umtx_op_wait_compat32, /* UMTX_OP_WAIT */
__umtx_op_wake, /* UMTX_OP_WAKE */
__umtx_op_trylock_umutex, /* UMTX_OP_MUTEX_LOCK */
__umtx_op_lock_umutex_compat32, /* UMTX_OP_MUTEX_TRYLOCK */
__umtx_op_unlock_umutex, /* UMTX_OP_MUTEX_UNLOCK */
__umtx_op_set_ceiling, /* UMTX_OP_SET_CEILING */
__umtx_op_cv_wait_compat32, /* UMTX_OP_CV_WAIT*/
__umtx_op_cv_signal, /* UMTX_OP_CV_SIGNAL */
__umtx_op_cv_broadcast, /* UMTX_OP_CV_BROADCAST */
__umtx_op_wait_compat32, /* UMTX_OP_WAIT_UINT */
__umtx_op_rw_rdlock_compat32, /* UMTX_OP_RW_RDLOCK */
__umtx_op_rw_wrlock_compat32, /* UMTX_OP_RW_WRLOCK */
__umtx_op_rw_unlock, /* UMTX_OP_RW_UNLOCK */
__umtx_op_wait_uint_private_compat32, /* UMTX_OP_WAIT_UINT_PRIVATE */
__umtx_op_wake_private, /* UMTX_OP_WAKE_PRIVATE */
__umtx_op_wait_umutex_compat32, /* UMTX_OP_MUTEX_WAIT */
__umtx_op_wake_umutex, /* UMTX_OP_MUTEX_WAKE */
#if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
__umtx_op_sem_wait_compat32, /* UMTX_OP_SEM_WAIT */
__umtx_op_sem_wake, /* UMTX_OP_SEM_WAKE */
#else
__umtx_op_unimpl, /* UMTX_OP_SEM_WAIT */
__umtx_op_unimpl, /* UMTX_OP_SEM_WAKE */
#endif
__umtx_op_nwake_private32, /* UMTX_OP_NWAKE_PRIVATE */
__umtx_op_wake2_umutex, /* UMTX_OP_MUTEX_WAKE2 */
__umtx_op_sem2_wait_compat32, /* UMTX_OP_SEM2_WAIT */
__umtx_op_sem2_wake, /* UMTX_OP_SEM2_WAKE */
};
int
freebsd32_umtx_op(struct thread *td, struct freebsd32_umtx_op_args *uap)
{
if ((unsigned)uap->op < UMTX_OP_MAX)
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.
*/
static void
umtx_exec_hook(void *arg __unused, struct proc *p __unused,
struct image_params *imgp __unused)
{
umtx_thread_cleanup(curthread);
}
/*
* thread_exit() hook.
*/
void
umtx_thread_exit(struct thread *td)
{
umtx_thread_cleanup(td);
}
/*
* clean up umtx data.
*/
static void
umtx_thread_cleanup(struct thread *td)
{
struct umtx_q *uq;
struct umtx_pi *pi;
if ((uq = td->td_umtxq) == NULL)
return;
mtx_lock_spin(&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_spin(&umtx_lock);
thread_lock(td);
sched_lend_user_prio(td, PRI_MAX);
thread_unlock(td);
}
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