net: net_enable_timestamp() can be called from irq contexts

am: a70c328597

Change-Id: I79a15d07b95126c554366c5b9c266cdb73e8f823

diff --git a/net/core/dev.c b/net/core/dev.c
index 08215a85c742a9999bf4cb2cd2b6b11e4a6fade0..48399d8ce614695607348c1c3b667931465b4576 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1677,27 +1677,54 @@ EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
 static struct static_key netstamp_needed __read_mostly;
 #ifdef HAVE_JUMP_LABEL
 static atomic_t netstamp_needed_deferred;
+static atomic_t netstamp_wanted;
 static void netstamp_clear(struct work_struct *work)
 {
        int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
+       int wanted;
 
-       while (deferred--)
-               static_key_slow_dec(&netstamp_needed);
+       wanted = atomic_add_return(deferred, &netstamp_wanted);
+       if (wanted > 0)
+               static_key_enable(&netstamp_needed);
+       else
+               static_key_disable(&netstamp_needed);
 }
 static DECLARE_WORK(netstamp_work, netstamp_clear);
 #endif
 
 void net_enable_timestamp(void)
 {
+#ifdef HAVE_JUMP_LABEL
+       int wanted;
+
+       while (1) {
+               wanted = atomic_read(&netstamp_wanted);
+               if (wanted <= 0)
+                       break;
+               if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted + 1) == wanted)
+                       return;
+       }
+       atomic_inc(&netstamp_needed_deferred);
+       schedule_work(&netstamp_work);
+#else
        static_key_slow_inc(&netstamp_needed);
+#endif
 }
 EXPORT_SYMBOL(net_enable_timestamp);
 
 void net_disable_timestamp(void)
 {
 #ifdef HAVE_JUMP_LABEL
-       /* net_disable_timestamp() can be called from non process context */
-       atomic_inc(&netstamp_needed_deferred);
+       int wanted;
+
+       while (1) {
+               wanted = atomic_read(&netstamp_wanted);
+               if (wanted <= 1)
+                       break;
+               if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted - 1) == wanted)
+                       return;
+       }
+       atomic_dec(&netstamp_needed_deferred);
        schedule_work(&netstamp_work);
 #else
        static_key_slow_dec(&netstamp_needed);