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Acquire sched_lock around use of FOREACH_KSEGRP_IN_PROC, accesses

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to kg_nice and calls to sched_nice() in getpriority() and setpriority()
(really donice()).
This commit is contained in:
tjr 2003-03-12 11:24:41 +00:00
parent 59d5730195
commit 679efe569a
1 changed files with 15 additions and 3 deletions
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18
sys/kern/kern_resource.c
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@ -98,17 +98,21 @@ getpriority(td, uap)
switch (uap->which) {
case PRIO_PROCESS:
if (uap->who == 0)
if (uap->who == 0) {
mtx_lock_spin(&sched_lock);
low = td->td_ksegrp->kg_nice;
else {
mtx_unlock_spin(&sched_lock);
} else {
p = pfind(uap->who);
if (p == NULL)
break;
if (p_cansee(td, p) == 0) {
mtx_lock_spin(&sched_lock);
FOREACH_KSEGRP_IN_PROC(p, kg) {
if (kg->kg_nice < low)
low = kg->kg_nice;
}
mtx_unlock_spin(&sched_lock);
}
PROC_UNLOCK(p);
}
@ -132,10 +136,12 @@ getpriority(td, uap)
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
PROC_LOCK(p);
if (!p_cansee(td, p)) {
mtx_lock_spin(&sched_lock);
FOREACH_KSEGRP_IN_PROC(p, kg) {
if (kg->kg_nice < low)
low = kg->kg_nice;
}
mtx_unlock_spin(&sched_lock);
}
PROC_UNLOCK(p);
}
@ -151,10 +157,12 @@ getpriority(td, uap)
PROC_LOCK(p);
if (!p_cansee(td, p) &&
p->p_ucred->cr_uid == uap->who) {
mtx_lock_spin(&sched_lock);
FOREACH_KSEGRP_IN_PROC(p, kg) {
if (kg->kg_nice < low)
low = kg->kg_nice;
}
mtx_unlock_spin(&sched_lock);
}
PROC_UNLOCK(p);
}
@ -289,15 +297,19 @@ donice(struct thread *td, struct proc *p, int n)
* Only allow nicing if to more than the lowest nice.
* e.g. nices of 4,3,2 allow nice to 3 but not 1
*/
mtx_lock_spin(&sched_lock);
FOREACH_KSEGRP_IN_PROC(p, kg) {
if (kg->kg_nice < low)
low = kg->kg_nice;
}
if (n < low && suser(td))
if (n < low && suser(td)) {
mtx_unlock_spin(&sched_lock);
return (EACCES);
}
FOREACH_KSEGRP_IN_PROC(p, kg) {
sched_nice(kg, n);
}
mtx_unlock_spin(&sched_lock);
return (0);
}