3 files changed, 45 insertions, 2 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index f29221e95792..bb1d3619ca12 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -99,10 +99,13 @@ void proc_task_name(struct seq_file *m, struct task_struct *p, bool escape)
 {
         char *buf;
         size_t size;
-        char tcomm[sizeof(p->comm)];
+        char tcomm[64];
         int ret;
 
-        get_task_comm(tcomm, p);
+        if (p->flags & PF_WQ_WORKER)
+                wq_worker_comm(tcomm, sizeof(tcomm), p);
+        else
+                __get_task_comm(tcomm, sizeof(tcomm), p);
 
         size = seq_get_buf(m, &buf);
         if (escape) {
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 39a0e215022a..60d673e15632 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -494,6 +494,7 @@ extern unsigned int work_busy(struct work_struct *work);
 extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
 extern void print_worker_info(const char *log_lvl, struct task_struct *task);
 extern void show_workqueue_state(void);
+extern void wq_worker_comm(char *buf, size_t size, struct task_struct *task);
 
 /**
  * queue_work - queue work on a workqueue
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 3fbe0076492c..b4a39a15c931 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4577,6 +4577,45 @@ void show_workqueue_state(void)
         rcu_read_unlock_sched();
 }
 
+/* used to show worker information through /proc/PID/{comm,stat,status} */
+void wq_worker_comm(char *buf, size_t size, struct task_struct *task)
+{
+        struct worker *worker;
+        struct worker_pool *pool;
+        int off;
+
+        /* always show the actual comm */
+        off = strscpy(buf, task->comm, size);
+        if (off < 0)
+                return;
+
+        /* stabilize worker pool association */
+        mutex_lock(&wq_pool_attach_mutex);
+
+        worker = kthread_data(task);
+        pool = worker->pool;
+
+        if (pool) {
+                spin_lock_irq(&pool->lock);
+                /*
+                 * ->desc tracks information (wq name or set_worker_desc())
+                 * for the latest execution.  If current, prepend '+',
+                 * otherwise '-'.
+                 */
+                if (worker->desc[0] != '\0') {
+                        if (worker->current_work)
+                                scnprintf(buf + off, size - off, "+%s",
+                                          worker->desc);
+                        else
+                                scnprintf(buf + off, size - off, "-%s",
+                                          worker->desc);
+                }
+                spin_unlock_irq(&pool->lock);
+        }
+
+        mutex_unlock(&wq_pool_attach_mutex);
+}
+
 /*
  * CPU hotplug.
  *