padata: Use get_online_cpus/put_online_cpus

This patch puts get_online_cpus/put_online_cpus around the places
we modify the padata cpumask to ensure that no cpu goes offline
during this operation.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 13 insertions, 0 deletions

diff --git a/kernel/padata.c b/kernel/padata.c
index fc9f19a00ae4..82958e01564b 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -441,6 +441,8 @@ int padata_set_cpumask(struct padata_instance *pinst,
 
         mutex_lock(&pinst->lock);
 
+        get_online_cpus();
+
         pd = padata_alloc_pd(pinst, cpumask);
         if (!pd) {
                 err = -ENOMEM;
@@ -452,6 +454,8 @@ int padata_set_cpumask(struct padata_instance *pinst,
         padata_replace(pinst, pd);
 
 out:
+        put_online_cpus();
+
         mutex_unlock(&pinst->lock);
 
         return err;
@@ -485,8 +489,10 @@ int padata_add_cpu(struct padata_instance *pinst, int cpu)
 
         mutex_lock(&pinst->lock);
 
+        get_online_cpus();
         cpumask_set_cpu(cpu, pinst->cpumask);
         err = __padata_add_cpu(pinst, cpu);
+        put_online_cpus();
 
         mutex_unlock(&pinst->lock);
 
@@ -521,8 +527,10 @@ int padata_remove_cpu(struct padata_instance *pinst, int cpu)
 
         mutex_lock(&pinst->lock);
 
+        get_online_cpus();
         cpumask_clear_cpu(cpu, pinst->cpumask);
         err = __padata_remove_cpu(pinst, cpu);
+        put_online_cpus();
 
         mutex_unlock(&pinst->lock);
 
@@ -626,6 +634,8 @@ struct padata_instance *padata_alloc(const struct cpumask *cpumask,
         if (!pinst)
                 goto err;
 
+        get_online_cpus();
+
         pd = padata_alloc_pd(pinst, cpumask);
         if (!pd)
                 goto err_free_inst;
@@ -647,6 +657,8 @@ struct padata_instance *padata_alloc(const struct cpumask *cpumask,
         register_hotcpu_notifier(&pinst->cpu_notifier);
 #endif
 
+        put_online_cpus();
+
         mutex_init(&pinst->lock);
 
         return pinst;
@@ -655,6 +667,7 @@ err_free_pd:
         padata_free_pd(pd);
 err_free_inst:
         kfree(pinst);
+        put_online_cpus();
 err:
         return NULL;
 }