| Message ID | 20200303080300.12467-1-jgross@suse.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xen/sched: fix error path in cpupool_unassign_cpu_start() | expand |
On 03.03.2020 09:03, Juergen Gross wrote: > In case moving away all domains from the cpu to be removed is failing > in cpupool_unassign_cpu_start() the error path is missing to release > sched_res_rculock. > > The normal exit path is releasing domlist_read_lock instead (this is > currently no problem as the reference to the specific rcu lock is not > used by rcu_read_unlock()). > > Reported-by: Igor Druzhinin <igor.druzhinin@citrix.com> > Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> albeit preferably with ... > --- a/xen/common/sched/cpupool.c > +++ b/xen/common/sched/cpupool.c > @@ -466,7 +466,7 @@ static int cpupool_unassign_cpu_start(struct cpupool *c, unsigned int cpu) > } > rcu_read_unlock(&domlist_read_lock); > if ( ret ) > - goto out; > + goto out_rcu; > } > cpupool_moving_cpu = cpu; > atomic_inc(&c->refcnt); > @@ -474,7 +474,8 @@ static int cpupool_unassign_cpu_start(struct cpupool *c, unsigned int cpu) > cpumask_andnot(c->cpu_valid, c->cpu_valid, cpus); > cpumask_and(c->res_valid, c->cpu_valid, &sched_res_mask); > > - rcu_read_unlock(&domlist_read_lock); > +out_rcu: ... the label indented by at least one blank, at which point it may make sense to also ... > + rcu_read_unlock(&sched_res_rculock); > out: ... correct this one. Jan
diff --git a/xen/common/sched/cpupool.c b/xen/common/sched/cpupool.c index b7721b5d02..4bf3d8434d 100644 --- a/xen/common/sched/cpupool.c +++ b/xen/common/sched/cpupool.c @@ -466,7 +466,7 @@ static int cpupool_unassign_cpu_start(struct cpupool *c, unsigned int cpu) } rcu_read_unlock(&domlist_read_lock); if ( ret ) - goto out; + goto out_rcu; } cpupool_moving_cpu = cpu; atomic_inc(&c->refcnt); @@ -474,7 +474,8 @@ static int cpupool_unassign_cpu_start(struct cpupool *c, unsigned int cpu) cpumask_andnot(c->cpu_valid, c->cpu_valid, cpus); cpumask_and(c->res_valid, c->cpu_valid, &sched_res_mask); - rcu_read_unlock(&domlist_read_lock); +out_rcu: + rcu_read_unlock(&sched_res_rculock); out: spin_unlock(&cpupool_lock);
In case moving away all domains from the cpu to be removed is failing in cpupool_unassign_cpu_start() the error path is missing to release sched_res_rculock. The normal exit path is releasing domlist_read_lock instead (this is currently no problem as the reference to the specific rcu lock is not used by rcu_read_unlock()). Reported-by: Igor Druzhinin <igor.druzhinin@citrix.com> Signed-off-by: Juergen Gross <jgross@suse.com> --- xen/common/sched/cpupool.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)