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fix race in sleep

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This commit is contained in:
Oscar Zhao 2019-04-05 15:23:07 -04:00
parent b2e5289a2d
commit cb22931bab
1 changed files with 31 additions and 14 deletions
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45
sys/kern/kern_event.c
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@ -1738,8 +1738,8 @@ findkn:
filedesc_unlock = 0; filedesc_unlock = 0;
} }
kn->kn_fluxwait = 1; kn->kn_fluxwait = 1;
KN_FLUX_UNLOCK(kn); KQ_UNLOCK(kq);
msleep(kn, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0); msleep(kn, &kn->kn_fluxlock, PSOCK | PDROP, "kqflxwt", 0);
if (fp != NULL) { if (fp != NULL) {
fdrop(fp, td); fdrop(fp, td);
@ -2558,11 +2558,13 @@ retry:
knote_flux_wakeup(kn); knote_flux_wakeup(kn);
} }
kn->kn_fluxwait = 1; kn->kn_fluxwait = 1;
KN_FLUX_UNLOCK(kn); KEVQ_UNLOCK(kevq);
CTR3(KTR_KQ, "kqueue_scan: td %d fluxwait on kn %p marker %p", td->td_tid, kn, marker); CTR3(KTR_KQ, "kqueue_scan: td %d fluxwait on kn %p marker %p", td->td_tid, kn, marker);
error = msleep(kn, &kevq->lock, PSOCK, error = msleep(kn, &kn->kn_fluxlock, PSOCK | PDROP,
"kevqflxwt3", 0); "kevqflxwt3", 0);
KEVQ_LOCK(kevq);
CTR3(KTR_KQ, "kqueue_scan: td %d fluxwait WAKEUP kn %p marker %p", td->td_tid, kn, marker); CTR3(KTR_KQ, "kqueue_scan: td %d fluxwait WAKEUP kn %p marker %p", td->td_tid, kn, marker);
continue; continue;
} }
@ -2886,8 +2888,11 @@ kevq_drain(struct kevq *kevq)
if (kn_in_flux(kn)) { if (kn_in_flux(kn)) {
kn->kn_fluxwait = 1; kn->kn_fluxwait = 1;
CTR2(KTR_KQ, "kevq_drain %p fluxwait knote %p", kevq, kn); CTR2(KTR_KQ, "kevq_drain %p fluxwait knote %p", kevq, kn);
KN_FLUX_UNLOCK(kn);
msleep(kn, &kevq->lock, PSOCK, "kevqclose2", 0); KEVQ_UNLOCK(kevq);
msleep(kn, &kn->kn_fluxlock, PSOCK | PDROP, "kevqclose2", 0);
KEVQ_LOCK(kevq);
continue; continue;
} }
@ -2991,11 +2996,15 @@ kqueue_drain(struct kqueue *kq, struct kevq *kevq, struct thread *td)
// destroy knotes first // destroy knotes first
for (i = 0; i < kq->kq_knlistsize; i++) { for (i = 0; i < kq->kq_knlistsize; i++) {
while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) { while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) {
KQ_OWNED(kq);
KN_FLUX_LOCK(kn); KN_FLUX_LOCK(kn);
if (kn_in_flux(kn)) { if (kn_in_flux(kn)) {
kn->kn_fluxwait = 1; kn->kn_fluxwait = 1;
KN_FLUX_UNLOCK(kn);
msleep(kn, &kq->kq_lock, PSOCK, "kqclo1", 0); KQ_UNLOCK(kq);
msleep(kn, &kn->kn_fluxlock, PSOCK | PDROP, "kqclo1", 0);
KQ_LOCK(kq);
continue; continue;
} }
knote_enter_flux(kn); knote_enter_flux(kn);
@ -3008,11 +3017,15 @@ kqueue_drain(struct kqueue *kq, struct kevq *kevq, struct thread *td)
if (kq->kq_knhashmask != 0) { if (kq->kq_knhashmask != 0) {
for (i = 0; i <= kq->kq_knhashmask; i++) { for (i = 0; i <= kq->kq_knhashmask; i++) {
while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) { while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) {
KQ_OWNED(kq);
KN_FLUX_LOCK(kn); KN_FLUX_LOCK(kn);
if (kn_in_flux(kn)) { if (kn_in_flux(kn)) {
kn->kn_fluxwait = 1; kn->kn_fluxwait = 1;
KN_FLUX_UNLOCK(kn);
msleep(kn, &kq->kq_lock, PSOCK, "kqclo2", 0); KQ_UNLOCK(kq);
msleep(kn, &kn->kn_fluxlock, PSOCK | PDROP, "kqclo2", 0);
KQ_LOCK(kq);
continue; continue;
} }
knote_enter_flux(kn); knote_enter_flux(kn);
@ -3535,8 +3548,9 @@ again: /* need to reacquire lock since we have dropped it */
KASSERT(kn_in_flux(kn), ("knote removed w/o list lock")); KASSERT(kn_in_flux(kn), ("knote removed w/o list lock"));
knl->kl_unlock(knl->kl_lockarg); knl->kl_unlock(knl->kl_lockarg);
kn->kn_fluxwait = 1; kn->kn_fluxwait = 1;
KN_FLUX_UNLOCK(kn); KQ_UNLOCK(kq);
msleep(kn, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); msleep(kn, &kn->kn_fluxlock, PSOCK | PDROP, "kqkclr", 0);
kq = NULL; kq = NULL;
goto again; goto again;
} }
@ -3582,8 +3596,11 @@ again:
if (influx) if (influx)
knote_flux_wakeup(kn); knote_flux_wakeup(kn);
kn->kn_fluxwait = 1; kn->kn_fluxwait = 1;
KN_FLUX_UNLOCK(kn);
msleep(kn, &kq->kq_lock, PSOCK, "kqflxwt4", 0); KQ_UNLOCK(kq);
msleep(kn, &kn->kn_fluxlock, PSOCK | PDROP, "kqflxwt4", 0);
KQ_LOCK(kq);
goto again; goto again;
} }
knote_enter_flux(kn); knote_enter_flux(kn);