1 files changed, 26 insertions, 18 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 9657315405de..bc2e09a8ea61 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kernel/workqueue.c - generic async execution with shared worker pool
  *
@@ -3338,21 +3339,20 @@ void free_workqueue_attrs(struct workqueue_attrs *attrs)
 
 /**
  * alloc_workqueue_attrs - allocate a workqueue_attrs
- * @gfp_mask: allocation mask to use
  *
  * Allocate a new workqueue_attrs, initialize with default settings and
  * return it.
  *
  * Return: The allocated new workqueue_attr on success. %NULL on failure.
  */
-struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask)
+struct workqueue_attrs *alloc_workqueue_attrs(void)
 {
 	struct workqueue_attrs *attrs;
 
-	attrs = kzalloc(sizeof(*attrs), gfp_mask);
+	attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
 	if (!attrs)
 		goto fail;
-	if (!alloc_cpumask_var(&attrs->cpumask, gfp_mask))
+	if (!alloc_cpumask_var(&attrs->cpumask, GFP_KERNEL))
 		goto fail;
 
 	cpumask_copy(attrs->cpumask, cpu_possible_mask);
@@ -3430,7 +3430,7 @@ static int init_worker_pool(struct worker_pool *pool)
 	pool->refcnt = 1;
 
 	/* shouldn't fail above this point */
-	pool->attrs = alloc_workqueue_attrs(GFP_KERNEL);
+	pool->attrs = alloc_workqueue_attrs();
 	if (!pool->attrs)
 		return -ENOMEM;
 	return 0;
@@ -3895,8 +3895,8 @@ apply_wqattrs_prepare(struct workqueue_struct *wq,
 
 	ctx = kzalloc(struct_size(ctx, pwq_tbl, nr_node_ids), GFP_KERNEL);
 
-	new_attrs = alloc_workqueue_attrs(GFP_KERNEL);
-	tmp_attrs = alloc_workqueue_attrs(GFP_KERNEL);
+	new_attrs = alloc_workqueue_attrs();
+	tmp_attrs = alloc_workqueue_attrs();
 	if (!ctx || !new_attrs || !tmp_attrs)
 		goto out_free;
 
@@ -4030,6 +4030,8 @@ static int apply_workqueue_attrs_locked(struct workqueue_struct *wq,
  *
  * Performs GFP_KERNEL allocations.
  *
+ * Assumes caller has CPU hotplug read exclusion, i.e. get_online_cpus().
+ *
  * Return: 0 on success and -errno on failure.
  */
 int apply_workqueue_attrs(struct workqueue_struct *wq,
@@ -4037,13 +4039,14 @@ int apply_workqueue_attrs(struct workqueue_struct *wq,
 {
 	int ret;
 
-	apply_wqattrs_lock();
+	lockdep_assert_cpus_held();
+
+	mutex_lock(&wq_pool_mutex);
 	ret = apply_workqueue_attrs_locked(wq, attrs);
-	apply_wqattrs_unlock();
+	mutex_unlock(&wq_pool_mutex);
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(apply_workqueue_attrs);
 
 /**
  * wq_update_unbound_numa - update NUMA affinity of a wq for CPU hot[un]plug
@@ -4153,16 +4156,21 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq)
 			mutex_unlock(&wq->mutex);
 		}
 		return 0;
-	} else if (wq->flags & __WQ_ORDERED) {
+	}
+
+	get_online_cpus();
+	if (wq->flags & __WQ_ORDERED) {
 		ret = apply_workqueue_attrs(wq, ordered_wq_attrs[highpri]);
 		/* there should only be single pwq for ordering guarantee */
 		WARN(!ret && (wq->pwqs.next != &wq->dfl_pwq->pwqs_node ||
 			      wq->pwqs.prev != &wq->dfl_pwq->pwqs_node),
 		     "ordering guarantee broken for workqueue %s\n", wq->name);
-		return ret;
 	} else {
-		return apply_workqueue_attrs(wq, unbound_std_wq_attrs[highpri]);
+		ret = apply_workqueue_attrs(wq, unbound_std_wq_attrs[highpri]);
 	}
+	put_online_cpus();
+
+	return ret;
 }
 
 static int wq_clamp_max_active(int max_active, unsigned int flags,
@@ -4241,7 +4249,7 @@ struct workqueue_struct *alloc_workqueue(const char *fmt,
 		return NULL;
 
 	if (flags & WQ_UNBOUND) {
-		wq->unbound_attrs = alloc_workqueue_attrs(GFP_KERNEL);
+		wq->unbound_attrs = alloc_workqueue_attrs();
 		if (!wq->unbound_attrs)
 			goto err_free_wq;
 	}
@@ -5394,7 +5402,7 @@ static struct workqueue_attrs *wq_sysfs_prep_attrs(struct workqueue_struct *wq)
 
 	lockdep_assert_held(&wq_pool_mutex);
 
-	attrs = alloc_workqueue_attrs(GFP_KERNEL);
+	attrs = alloc_workqueue_attrs();
 	if (!attrs)
 		return NULL;
 
@@ -5816,7 +5824,7 @@ static void __init wq_numa_init(void)
 		return;
 	}
 
-	wq_update_unbound_numa_attrs_buf = alloc_workqueue_attrs(GFP_KERNEL);
+	wq_update_unbound_numa_attrs_buf = alloc_workqueue_attrs();
 	BUG_ON(!wq_update_unbound_numa_attrs_buf);
 
 	/*
@@ -5891,7 +5899,7 @@ int __init workqueue_init_early(void)
 	for (i = 0; i < NR_STD_WORKER_POOLS; i++) {
 		struct workqueue_attrs *attrs;
 
-		BUG_ON(!(attrs = alloc_workqueue_attrs(GFP_KERNEL)));
+		BUG_ON(!(attrs = alloc_workqueue_attrs()));
 		attrs->nice = std_nice[i];
 		unbound_std_wq_attrs[i] = attrs;
 
@@ -5900,7 +5908,7 @@ int __init workqueue_init_early(void)
 		 * guaranteed by max_active which is enforced by pwqs.
 		 * Turn off NUMA so that dfl_pwq is used for all nodes.
 		 */
-		BUG_ON(!(attrs = alloc_workqueue_attrs(GFP_KERNEL)));
+		BUG_ON(!(attrs = alloc_workqueue_attrs()));
 		attrs->nice = std_nice[i];
 		attrs->no_numa = true;
 		ordered_wq_attrs[i] = attrs;