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Fix the lock order reversal between the sigio lock and a process/pgrp lock in

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funsetownlst() by locking the sigio lock across funsetownlst().
This commit is contained in:
Seigo Tanimura 2002-05-03 05:32:25 +00:00
parent cb5e1f4f73
commit c8d8a686e4
3 changed files with 10 additions and 2 deletions
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8
sys/kern/kern_descrip.c
View File

@ -571,6 +571,8 @@ funsetownlst(sigiolst)
struct proc *p;
struct pgrp *pg;
SIGIO_ASSERT(MA_OWNED);
sigio = SLIST_FIRST(sigiolst);
if (sigio == NULL)
return;
@ -591,28 +593,30 @@ funsetownlst(sigiolst)
}
while ((sigio = SLIST_FIRST(sigiolst)) != NULL) {
SIGIO_LOCK();
*(sigio->sio_myref) = NULL;
SIGIO_UNLOCK();
if (pg != NULL) {
KASSERT(sigio->sio_pgid < 0, ("Proc sigio in pgrp sigio list"));
KASSERT(sigio->sio_pgrp == pg, ("Bogus pgrp in sigio list"));
SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio);
PGRP_UNLOCK(pg);
SIGIO_UNLOCK();
crfree(sigio->sio_ucred);
mtx_lock(&Giant);
FREE(sigio, M_SIGIO);
mtx_unlock(&Giant);
SIGIO_LOCK();
PGRP_LOCK(pg);
} else /* if (p != NULL) */ {
KASSERT(sigio->sio_pgid > 0, ("Pgrp sigio in proc sigio list"));
KASSERT(sigio->sio_proc == p, ("Bogus proc in sigio list"));
SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio);
PROC_UNLOCK(p);
SIGIO_UNLOCK();
crfree(sigio->sio_ucred);
mtx_lock(&Giant);
FREE(sigio, M_SIGIO);
mtx_unlock(&Giant);
SIGIO_LOCK();
PROC_LOCK(p);
}
}

2
sys/kern/kern_exit.c
View File

@ -191,9 +191,11 @@ exit1(td, rv)
* Reset any sigio structures pointing to us as a result of
* F_SETOWN with our pid.
*/
SIGIO_LOCK();
PROC_LOCK(p);
funsetownlst(&p->p_sigiolst);
PROC_UNLOCK(p);
SIGIO_UNLOCK();
/*
* Close open files and release open-file table.

2
sys/kern/kern_proc.c
View File

@ -474,6 +474,7 @@ pgdelete(pgrp)
PGRP_LOCK_ASSERT(pgrp, MA_NOTOWNED);
SESS_LOCK_ASSERT(pgrp->pg_session, MA_NOTOWNED);
SIGIO_LOCK();
PGRP_LOCK(pgrp);
/*
@ -481,6 +482,7 @@ pgdelete(pgrp)
* F_SETOWN with our pgid.
*/
funsetownlst(&pgrp->pg_sigiolst);
SIGIO_UNLOCK();
if (pgrp->pg_session->s_ttyp != NULL &&
pgrp->pg_session->s_ttyp->t_pgrp == pgrp)