[Xen-devel] [PATCH v2] xen/sched: fix error path in cpupool_unassign_cpu_start()

* [Xen-devel] [PATCH v2] xen/sched: fix error path in cpupool_unassign_cpu_start()
@ 2020-03-03  9:27 Juergen Gross
  2020-03-03 13:49 ` Dario Faggioli
  0 siblings, 1 reply; 2+ messages in thread
From: Juergen Gross @ 2020-03-03  9:27 UTC (permalink / raw)
  To: xen-devel; +Cc: Juergen Gross, George Dunlap, Dario Faggioli

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()).

While at it indent the present error label by one space.

Reported-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
V2:
- indent error labels (Jan Beulich)
---
 xen/common/sched/cpupool.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/xen/common/sched/cpupool.c b/xen/common/sched/cpupool.c
index b7721b5d02..9f70c7ec17 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);
@@ -474,8 +474,9 @@ 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:
+ out_rcu:
+    rcu_read_unlock(&sched_res_rculock);
+ out:
     spin_unlock(&cpupool_lock);
 
     return ret;
-- 
2.16.4


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