1 files changed, 29 insertions, 20 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 5914c820a4f1..3f1fffa8e6d4 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -348,6 +348,7 @@ static bool wq_pod_enabled;		/* unbound CPU pod affinity enabled */
 
 /* buf for wq_update_unbound_pod_attrs(), protected by CPU hotplug exclusion */
 static struct workqueue_attrs *wq_update_pod_attrs_buf;
+static cpumask_var_t wq_update_pod_cpumask_buf;
 
 static DEFINE_MUTEX(wq_pool_mutex);	/* protects pools and workqueues list */
 static DEFINE_MUTEX(wq_pool_attach_mutex); /* protects worker attach/detach */
@@ -3699,6 +3700,20 @@ static bool wqattrs_equal(const struct workqueue_attrs *a,
 	return true;
 }
 
+/* Update @attrs with actually available CPUs */
+static void wqattrs_actualize_cpumask(struct workqueue_attrs *attrs,
+				      const cpumask_t *unbound_cpumask)
+{
+	/*
+	 * Calculate the effective CPU mask of @attrs given @unbound_cpumask. If
+	 * @attrs->cpumask doesn't overlap with @unbound_cpumask, we fallback to
+	 * @unbound_cpumask.
+	 */
+	cpumask_and(attrs->cpumask, attrs->cpumask, unbound_cpumask);
+	if (unlikely(cpumask_empty(attrs->cpumask)))
+		cpumask_copy(attrs->cpumask, unbound_cpumask);
+}
+
 /**
  * init_worker_pool - initialize a newly zalloc'd worker_pool
  * @pool: worker_pool to initialize
@@ -4222,32 +4237,22 @@ apply_wqattrs_prepare(struct workqueue_struct *wq,
 		goto out_free;
 
 	/*
-	 * Calculate the attrs of the default pwq with unbound_cpumask
-	 * which is wq_unbound_cpumask or to set to wq_unbound_cpumask.
-	 * If the user configured cpumask doesn't overlap with the
-	 * wq_unbound_cpumask, we fallback to the wq_unbound_cpumask.
-	 */
-	copy_workqueue_attrs(new_attrs, attrs);
-	cpumask_and(new_attrs->cpumask, new_attrs->cpumask, unbound_cpumask);
-	if (unlikely(cpumask_empty(new_attrs->cpumask)))
-		cpumask_copy(new_attrs->cpumask, unbound_cpumask);
-
-	/*
-	 * We may create multiple pwqs with differing cpumasks.  Make a
-	 * copy of @new_attrs which will be modified and used to obtain
-	 * pools.
-	 */
-	copy_workqueue_attrs(tmp_attrs, new_attrs);
-
-	/*
 	 * If something goes wrong during CPU up/down, we'll fall back to
 	 * the default pwq covering whole @attrs->cpumask.  Always create
 	 * it even if we don't use it immediately.
 	 */
+	copy_workqueue_attrs(new_attrs, attrs);
+	wqattrs_actualize_cpumask(new_attrs, unbound_cpumask);
 	ctx->dfl_pwq = alloc_unbound_pwq(wq, new_attrs);
 	if (!ctx->dfl_pwq)
 		goto out_free;
 
+	/*
+	 * We may create multiple pwqs with differing cpumasks. Make a copy of
+	 * @new_attrs which will be modified and used to obtain pools.
+	 */
+	copy_workqueue_attrs(tmp_attrs, new_attrs);
+
 	for_each_possible_cpu(cpu) {
 		if (new_attrs->ordered) {
 			ctx->dfl_pwq->refcnt++;
@@ -4414,18 +4419,20 @@ static void wq_update_pod(struct workqueue_struct *wq, int cpu,
 	 * CPU hotplug exclusion.
 	 */
 	target_attrs = wq_update_pod_attrs_buf;
-	cpumask = target_attrs->cpumask;
+	cpumask = wq_update_pod_cpumask_buf;
 
 	copy_workqueue_attrs(target_attrs, wq->unbound_attrs);
+	wqattrs_actualize_cpumask(target_attrs, wq_unbound_cpumask);
 
 	/* nothing to do if the target cpumask matches the current pwq */
-	wq_calc_pod_cpumask(wq->dfl_pwq->pool->attrs, pod, off_cpu, cpumask);
+	wq_calc_pod_cpumask(target_attrs, pod, off_cpu, cpumask);
 	pwq = rcu_dereference_protected(*per_cpu_ptr(wq->cpu_pwq, cpu),
 					lockdep_is_held(&wq_pool_mutex));
 	if (cpumask_equal(cpumask, pwq->pool->attrs->cpumask))
 		return;
 
 	/* create a new pwq */
+	cpumask_copy(target_attrs->cpumask, cpumask);
 	pwq = alloc_unbound_pwq(wq, target_attrs);
 	if (!pwq) {
 		pr_warn("workqueue: allocation failed while updating CPU pod affinity of \"%s\"\n",
@@ -6285,6 +6292,8 @@ void __init workqueue_init_early(void)
 	wq_update_pod_attrs_buf = alloc_workqueue_attrs();
 	BUG_ON(!wq_update_pod_attrs_buf);
 
+	BUG_ON(!alloc_cpumask_var(&wq_update_pod_cpumask_buf, GFP_KERNEL));
+
 	/* initialize CPU pools */
 	for_each_possible_cpu(cpu) {
 		struct worker_pool *pool;