[rt] random: Restore interrupt randomness dropped in 3.14.10-rt6

svn path=/dists/sid/linux/; revision=21527

debian/changelog

@@ -79,10 +79,10 @@ linux (3.14.12-1) UNRELEASED; urgency=medium
 
   [ Ben Hutchings ]
   * [rt] Update to 3.14.10-rt7:
-    - random: Do not add randomness from threaded interrupts
     - rtmutex: Resolve conflicts with changes in 3.14.10
     - sched: Do not clear PF_NO_SETAFFINITY flag in select_fallback_rq()
     - workqueue: Prevent deadlock/stall on RT
+  * [rt] random: Restore interrupt randomness dropped in 3.14.10-rt6
   * [s390,s390x] Ignore ABI change in lowcore structure (fixes FTBFS)
   * [m68k] block: Change IOSCHED_CFQ to built-in and make it the default
     I/O scheduler, consistent with other architectures

debian/patches/features/all/rt/random-make-it-work-on-rt.patch

@@ -10,7 +10,9 @@ entropy.
 
 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
 Cc: stable-rt@vger.kernel.org
-[bwh: Adjust context to apply on top of Debian ABI-maintaining patches]
+[bwh:
+ - Adjust context to apply on top of Debian ABI-maintaining patches
+ - Restore interrupt randomness dropped in 3.14.10-rt6]
 ---
  drivers/char/random.c   |   11 +++++++----
  include/linux/irqdesc.h |    1 +
@@ -102,3 +104,18 @@ Cc: stable-rt@vger.kernel.org
  
  	if (!noirqdebug)
  		note_interrupt(irq, desc, retval);
+--- a/kernel/irq/manage.c
++++ b/kernel/irq/manage.c
+@@ -942,6 +942,12 @@ static int irq_thread(void *data)
+ 		if (action_ret == IRQ_HANDLED)
+ 			atomic_inc(&desc->threads_handled);
+ 
++#ifdef CONFIG_PREEMPT_RT_FULL
++		migrate_disable();
++		add_interrupt_randomness(action->irq, 0,
++				desc->random_ip ^ (unsigned long) action);
++		migrate_enable();
++#endif
+ 		wake_threads_waitq(desc);
+ 	}
+