1 files changed, 47 insertions, 22 deletions

diff --git a/kernel/trace/trace_workqueue.c b/kernel/trace/trace_workqueue.c
index 97fcea4acce..209b379a472 100644
--- a/kernel/trace/trace_workqueue.c
+++ b/kernel/trace/trace_workqueue.c
@@ -9,6 +9,8 @@
 #include <trace/events/workqueue.h>
 #include <linux/list.h>
 #include <linux/percpu.h>
+#include <linux/slab.h>
+#include <linux/kref.h>
 #include "trace_stat.h"
 #include "trace.h"
 
@@ -16,6 +18,7 @@
 /* A cpu workqueue thread */
 struct cpu_workqueue_stats {
 	struct list_head            list;
+	struct kref                 kref;
 	int		            cpu;
 	pid_t			    pid;
 /* Can be inserted from interrupt or user context, need to be atomic */
@@ -39,9 +42,15 @@ struct workqueue_global_stats {
 static DEFINE_PER_CPU(struct workqueue_global_stats, all_workqueue_stat);
 #define workqueue_cpu_stat(cpu) (&per_cpu(all_workqueue_stat, cpu))
 
+static void cpu_workqueue_stat_free(struct kref *kref)
+{
+	kfree(container_of(kref, struct cpu_workqueue_stats, kref));
+}
+
 /* Insertion of a work */
 static void
-probe_workqueue_insertion(struct task_struct *wq_thread,
+probe_workqueue_insertion(void *ignore,
+			  struct task_struct *wq_thread,
 			  struct work_struct *work)
 {
 	int cpu = cpumask_first(&wq_thread->cpus_allowed);
@@ -62,7 +71,8 @@ found:
 
 /* Execution of a work */
 static void
-probe_workqueue_execution(struct task_struct *wq_thread,
+probe_workqueue_execution(void *ignore,
+			  struct task_struct *wq_thread,
 			  struct work_struct *work)
 {
 	int cpu = cpumask_first(&wq_thread->cpus_allowed);
@@ -82,7 +92,8 @@ found:
 }
 
 /* Creation of a cpu workqueue thread */
-static void probe_workqueue_creation(struct task_struct *wq_thread, int cpu)
+static void probe_workqueue_creation(void *ignore,
+				     struct task_struct *wq_thread, int cpu)
 {
 	struct cpu_workqueue_stats *cws;
 	unsigned long flags;
@@ -96,8 +107,8 @@ static void probe_workqueue_creation(struct task_struct *wq_thread, int cpu)
 		return;
 	}
 	INIT_LIST_HEAD(&cws->list);
+	kref_init(&cws->kref);
 	cws->cpu = cpu;
-
 	cws->pid = wq_thread->pid;
 
 	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
@@ -106,7 +117,8 @@ static void probe_workqueue_creation(struct task_struct *wq_thread, int cpu)
 }
 
 /* Destruction of a cpu workqueue thread */
-static void probe_workqueue_destruction(struct task_struct *wq_thread)
+static void
+probe_workqueue_destruction(void *ignore, struct task_struct *wq_thread)
 {
 	/* Workqueue only execute on one cpu */
 	int cpu = cpumask_first(&wq_thread->cpus_allowed);
@@ -118,7 +130,7 @@ static void probe_workqueue_destruction(struct task_struct *wq_thread)
 							list) {
 		if (node->pid == wq_thread->pid) {
 			list_del(&node->list);
-			kfree(node);
+			kref_put(&node->kref, cpu_workqueue_stat_free);
 			goto found;
 		}
 	}
@@ -137,9 +149,11 @@ static struct cpu_workqueue_stats *workqueue_stat_start_cpu(int cpu)
 
 	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
 
-	if (!list_empty(&workqueue_cpu_stat(cpu)->list))
+	if (!list_empty(&workqueue_cpu_stat(cpu)->list)) {
 		ret = list_entry(workqueue_cpu_stat(cpu)->list.next,
 				 struct cpu_workqueue_stats, list);
+		kref_get(&ret->kref);
+	}
 
 	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
 
@@ -162,9 +176,9 @@ static void *workqueue_stat_start(struct tracer_stat *trace)
 static void *workqueue_stat_next(void *prev, int idx)
 {
 	struct cpu_workqueue_stats *prev_cws = prev;
+	struct cpu_workqueue_stats *ret;
 	int cpu = prev_cws->cpu;
 	unsigned long flags;
-	void *ret = NULL;
 
 	spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
 	if (list_is_last(&prev_cws->list, &workqueue_cpu_stat(cpu)->list)) {
@@ -175,11 +189,14 @@ static void *workqueue_stat_next(void *prev, int idx)
 				return NULL;
 		} while (!(ret = workqueue_stat_start_cpu(cpu)));
 		return ret;
+	} else {
+		ret = list_entry(prev_cws->list.next,
+				 struct cpu_workqueue_stats, list);
+		kref_get(&ret->kref);
 	}
 	spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
 
-	return list_entry(prev_cws->list.next, struct cpu_workqueue_stats,
-			  list);
+	return ret;
 }
 
 static int workqueue_stat_show(struct seq_file *s, void *p)
@@ -203,6 +220,13 @@ static int workqueue_stat_show(struct seq_file *s, void *p)
 	return 0;
 }
 
+static void workqueue_stat_release(void *stat)
+{
+	struct cpu_workqueue_stats *node = stat;
+
+	kref_put(&node->kref, cpu_workqueue_stat_free);
+}
+
 static int workqueue_stat_headers(struct seq_file *s)
 {
 	seq_printf(s, "# CPU  INSERTED  EXECUTED   NAME\n");
@@ -215,6 +239,7 @@ struct tracer_stat workqueue_stats __read_mostly = {
 	.stat_start = workqueue_stat_start,
 	.stat_next = workqueue_stat_next,
 	.stat_show = workqueue_stat_show,
+	.stat_release = workqueue_stat_release,
 	.stat_headers = workqueue_stat_headers
 };
 
@@ -238,35 +263,35 @@ int __init trace_workqueue_early_init(void)
 {
 	int ret, cpu;
 
-	ret = register_trace_workqueue_insertion(probe_workqueue_insertion);
+	for_each_possible_cpu(cpu) {
+		spin_lock_init(&workqueue_cpu_stat(cpu)->lock);
+		INIT_LIST_HEAD(&workqueue_cpu_stat(cpu)->list);
+	}
+
+	ret = register_trace_workqueue_insertion(probe_workqueue_insertion, NULL);
 	if (ret)
 		goto out;
 
-	ret = register_trace_workqueue_execution(probe_workqueue_execution);
+	ret = register_trace_workqueue_execution(probe_workqueue_execution, NULL);
 	if (ret)
 		goto no_insertion;
 
-	ret = register_trace_workqueue_creation(probe_workqueue_creation);
+	ret = register_trace_workqueue_creation(probe_workqueue_creation, NULL);
 	if (ret)
 		goto no_execution;
 
-	ret = register_trace_workqueue_destruction(probe_workqueue_destruction);
+	ret = register_trace_workqueue_destruction(probe_workqueue_destruction, NULL);
 	if (ret)
 		goto no_creation;
 
-	for_each_possible_cpu(cpu) {
-		spin_lock_init(&workqueue_cpu_stat(cpu)->lock);
-		INIT_LIST_HEAD(&workqueue_cpu_stat(cpu)->list);
-	}
-
 	return 0;
 
 no_creation:
-	unregister_trace_workqueue_creation(probe_workqueue_creation);
+	unregister_trace_workqueue_creation(probe_workqueue_creation, NULL);
 no_execution:
-	unregister_trace_workqueue_execution(probe_workqueue_execution);
+	unregister_trace_workqueue_execution(probe_workqueue_execution, NULL);
 no_insertion:
-	unregister_trace_workqueue_insertion(probe_workqueue_insertion);
+	unregister_trace_workqueue_insertion(probe_workqueue_insertion, NULL);
 out:
 	pr_warning("trace_workqueue: unable to trace workqueues\n");