[src-draft/trunk]: src/sys/net80211 Fix locking and destruction for task/time...

[Martin Husemann <martin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src-all/rev/0864718e5908
branches:  trunk
changeset: 947873:0864718e5908
user:      Martin Husemann <martin%NetBSD.org@localhost>
date:      Sat Dec 19 16:23:18 2020 +0100

description:
Fix locking and destruction for task/timer queues.

Add TIMEOUT_TASK_DESTROY() and TIMEOUT_TASK_DESTROY() macros to
clean up the corresponding task structures.

diffstat:

 sys/net80211/ieee80211_netbsd.c |  21 +++++++++++++++------
 sys/net80211/ieee80211_netbsd.h |  22 +++++++++++++++++-----
 2 files changed, 32 insertions(+), 11 deletions(-)

diffs (105 lines):

diff -r 16091167b277 -r 0864718e5908 sys/net80211/ieee80211_netbsd.c
--- a/sys/net80211/ieee80211_netbsd.c   Sat Dec 19 16:17:29 2020 +0100
+++ b/sys/net80211/ieee80211_netbsd.c   Sat Dec 19 16:23:18 2020 +0100
@@ -131,8 +131,8 @@
 void
 taskqueue_drain(struct workqueue *wq, struct task *task_item)
 {
+
        workqueue_wait(wq, &task_item->t_work);
-       mutex_destroy(&task_item->t_mutex);
 }
 
 static void
@@ -151,7 +151,12 @@
      struct timeout_task *timeout_task, int nticks)
 {
        mutex_enter(&timeout_task->to_task.t_mutex);
-       if (!timeout_task->to_scheduled) {
+       if (timeout_task->to_scheduled == -1) {
+               /* we are draining the task queue */
+               mutex_exit(&timeout_task->to_task.t_mutex);
+               return EIO;
+       }
+       if (timeout_task->to_scheduled == 0) {
                callout_reset(&timeout_task->to_callout, nticks, 
                    taskqueue_callout_enqueue, timeout_task);
                timeout_task->to_scheduled = 1;
@@ -170,16 +175,20 @@
        timeout_task->to_scheduled = 0;
        mutex_exit(&timeout_task->to_task.t_mutex);
 
-       // printf ("taskqueue_cancel_timeout called\n");
-
        return 0;
 }
 
 void
-taskqueue_drain_timeout(struct workqueue *queue, 
+taskqueue_drain_timeout(struct workqueue *wq, 
     struct timeout_task *timeout_task)
 {
-       // printf ("taskqueue_drain_timeout called\n");
+
+       mutex_enter(&timeout_task->to_task.t_mutex);
+       timeout_task->to_scheduled = -1;
+       callout_halt(&timeout_task->to_callout,
+           &timeout_task->to_task.t_mutex);
+       workqueue_wait(wq, &timeout_task->to_task.t_work);
+       mutex_exit(&timeout_task->to_task.t_mutex);
 }
 
 
diff -r 16091167b277 -r 0864718e5908 sys/net80211/ieee80211_netbsd.h
--- a/sys/net80211/ieee80211_netbsd.h   Sat Dec 19 16:17:29 2020 +0100
+++ b/sys/net80211/ieee80211_netbsd.h   Sat Dec 19 16:23:18 2020 +0100
@@ -107,10 +107,14 @@
 };
 
 struct timeout_task { 
-       struct task to_task;    /* Must be first so we can cast to a task. */
-       struct workqueue *to_wq;
-       callout_t   to_callout;
-       int         to_scheduled;
+       /* Must be first so we can cast to a task. */
+       struct task             to_task;
+       struct workqueue        *to_wq;
+       callout_t               to_callout;
+       int                     to_scheduled;   /* 0 inactive,
+                                                * 1 pending,
+                                                * -1 draining
+                                                */
 };
 
 
@@ -130,7 +134,6 @@
 int  ieee80211_clone_attach(void);
 void ieee80211_if_attach(struct ifnet *ifp, const uint8_t *lla);
 
-/* NNN ---- Need to add a way to mutex_destroy at the right time. */
 
 #define TASK_INIT(var, pri, func, arg) do { \
        (var)->t_func = func; \
@@ -140,6 +143,10 @@
        (var)->t_func_name = #func; \
 } while(0)
 
+#define TASK_DESTROY(var) do { \
+       mutex_destroy(&(var)->t_mutex);\
+} while(0)
+
 #define TIMEOUT_TASK_INIT(queue, task, pri, func, arg) do { \
        (task)->to_task.t_func = func; \
         (task)->to_task.t_arg = arg; \
@@ -151,6 +158,11 @@
        (task)->to_scheduled = 0;\
 } while (0)
 
+#define TIMEOUT_TASK_DESTROY(task) do { \
+       mutex_destroy(&(task)->to_task.t_mutex);\
+       callout_destroy(&(task)->to_callout);\
+} while (0)
+
 #define taskqueue workqueue
 #define taskqueue_free(queue)         workqueue_destroy(queue)