[libvirt] [PATCH 2/2] virDomainFormatSchedDef: Check @schedMap bounds
In the function, @schedMap is a bitmap used to track pinning of
scheduling units (e.g. vcpu, iothreads). However, as a corner
case it may happen that it's empty but the scheduler is set to
either RR or FIFO. If that's the case we may get -1 when asking
for the next bit set in @schedMap and proceed with that. The code
is able to deal with that because we are ignoring some errors
afterwards, but it's safer to check upfront.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/conf/domain_conf.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 67415fa..a842ee4 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -21485,20 +21485,21 @@ virDomainFormatSchedDef(virDomainDefPtr def,
case VIR_PROC_POLICY_FIFO:
case VIR_PROC_POLICY_RR:
virBitmapClearAll(prioMap);
- hasPriority = true;
/* we need to find a subset of vCPUs with the given scheduler
* that share the priority */
- nextprio = virBitmapNextSetBit(schedMap, -1);
- sched = func(def, nextprio);
- priority = sched->priority;
-
- ignore_value(virBitmapSetBit(prioMap, nextprio));
-
- while ((nextprio = virBitmapNextSetBit(schedMap, nextprio)) > -1) {
+ if ((nextprio = virBitmapNextSetBit(schedMap, -1)) > -1) {
sched = func(def, nextprio);
- if (sched->priority == priority)
- ignore_value(virBitmapSetBit(prioMap, nextprio));
+ priority = sched->priority;
+ hasPriority = true;
+
+ ignore_value(virBitmapSetBit(prioMap, nextprio));
+
+ while ((nextprio = virBitmapNextSetBit(schedMap, nextprio)) > -1)
{
+ sched = func(def, nextprio);
+ if (sched->priority == priority)
+ ignore_value(virBitmapSetBit(prioMap, nextprio));
+ }
}
currentMap = prioMap;
--
2.4.10