1 files changed, 31 insertions, 5 deletions

diff --git a/drivers/char/random.c b/drivers/char/random.c
index c8752eaad483..705a839f1796 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -558,9 +558,26 @@ struct timer_rand_state {
         unsigned dont_count_entropy:1;
 };
 
-static struct timer_rand_state input_timer_state;
 static struct timer_rand_state *irq_timer_state[NR_IRQS];
 
+static struct timer_rand_state *get_timer_rand_state(unsigned int irq)
+{
+        if (irq >= nr_irqs)
+                return NULL;
+
+        return irq_timer_state[irq];
+}
+
+static void set_timer_rand_state(unsigned int irq, struct timer_rand_state *state)
+{
+        if (irq >= nr_irqs)
+                return;
+
+        irq_timer_state[irq] = state;
+}
+
+static struct timer_rand_state input_timer_state;
+
 /*
  * This function adds entropy to the entropy "pool" by using timing
  * delays.  It uses the timer_rand_state structure to make an estimate
@@ -648,11 +665,15 @@ EXPORT_SYMBOL_GPL(add_input_randomness);
 
 void add_interrupt_randomness(int irq)
 {
-        if (irq >= NR_IRQS || irq_timer_state[irq] == NULL)
+        struct timer_rand_state *state;
+
+        state = get_timer_rand_state(irq);
+
+        if (state == NULL)
                 return;
 
         DEBUG_ENT("irq event %d\n", irq);
-        add_timer_randomness(irq_timer_state[irq], 0x100 + irq);
+        add_timer_randomness(state, 0x100 + irq);
 }
 
 #ifdef CONFIG_BLOCK
@@ -912,7 +933,12 @@ void rand_initialize_irq(int irq)
 {
         struct timer_rand_state *state;
 
-        if (irq >= NR_IRQS || irq_timer_state[irq])
+        if (irq >= nr_irqs)
+                return;
+
+        state = get_timer_rand_state(irq);
+
+        if (state)
                 return;
 
         /*
@@ -921,7 +947,7 @@ void rand_initialize_irq(int irq)
          */
         state = kzalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
         if (state)
-                irq_timer_state[irq] = state;
+                set_timer_rand_state(irq, state);
 }
 
 #ifdef CONFIG_BLOCK