UBUNTU: Ubuntu-4.15.0-38.41

[mirror_ubuntu-bionic-kernel.git] / kernel / workqueue.c

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 43d18cb46308385865d14ce40906c4646d378063..f347f67cd4f6f9524f97bad0341371099f221ece 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -48,6 +48,7 @@
 #include <linux/moduleparam.h>
 #include <linux/uaccess.h>
 #include <linux/sched/isolation.h>
+#include <linux/nmi.h>
 
 #include "workqueue_internal.h"
 
@@ -4167,6 +4168,22 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active)
 }
 EXPORT_SYMBOL_GPL(workqueue_set_max_active);
 
+/**
+ * current_work - retrieve %current task's work struct
+ *
+ * Determine if %current task is a workqueue worker and what it's working on.
+ * Useful to find out the context that the %current task is running in.
+ *
+ * Return: work struct if %current task is a workqueue worker, %NULL otherwise.
+ */
+struct work_struct *current_work(void)
+{
+       struct worker *worker = current_wq_worker();
+
+       return worker ? worker->current_work : NULL;
+}
+EXPORT_SYMBOL(current_work);
+
 /**
  * current_is_workqueue_rescuer - is %current workqueue rescuer?
  *
@@ -4463,6 +4480,12 @@ void show_workqueue_state(void)
                        if (pwq->nr_active || !list_empty(&pwq->delayed_works))
                                show_pwq(pwq);
                        spin_unlock_irqrestore(&pwq->pool->lock, flags);
+                       /*
+                        * We could be printing a lot from atomic context, e.g.
+                        * sysrq-t -> show_workqueue_state(). Avoid triggering
+                        * hard lockup.
+                        */
+                       touch_nmi_watchdog();
                }
        }
 
@@ -4490,6 +4513,12 @@ void show_workqueue_state(void)
                pr_cont("\n");
        next_pool:
                spin_unlock_irqrestore(&pool->lock, flags);
+               /*
+                * We could be printing a lot from atomic context, e.g.
+                * sysrq-t -> show_workqueue_state(). Avoid triggering
+                * hard lockup.
+                */
+               touch_nmi_watchdog();
        }
 
        rcu_read_unlock_sched();
@@ -5297,7 +5326,7 @@ int workqueue_sysfs_register(struct workqueue_struct *wq)
 
        ret = device_register(&wq_dev->dev);
        if (ret) {
-               kfree(wq_dev);
+               put_device(&wq_dev->dev);
                wq->wq_dev = NULL;
                return ret;
        }