X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=drivers%2Fchar%2Frandom.c;h=7ce1ac4baa6d81feccad163cb9c476edfb7278c9;hb=5a89770daad83df74d77a8d34a1ffaedae565ce9;hp=1838aa3d24feac6a09b9516acbb1ffd623e7f2db;hpb=f7edd5fbde8af44fa06218f56e0f648fc7a527c8;p=linux-2.6-omap-h63xx.git

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 1838aa3d24f..7ce1ac4baa6 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -407,7 +407,7 @@ struct entropy_store {
 	/* read-write data: */
 	spinlock_t lock;
 	unsigned add_ptr;
-	int entropy_count;
+	int entropy_count;	/* Must at no time exceed ->POOLBITS! */
 	int input_rotate;
 };
 
@@ -520,6 +520,7 @@ static void mix_pool_bytes(struct entropy_store *r, const void *in, int bytes)
 static void credit_entropy_bits(struct entropy_store *r, int nbits)
 {
 	unsigned long flags;
+	int entropy_count;
 
 	if (!nbits)
 		return;
@@ -527,20 +528,20 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits)
 	spin_lock_irqsave(&r->lock, flags);
 
 	DEBUG_ENT("added %d entropy credits to %s\n", nbits, r->name);
-	r->entropy_count += nbits;
-	if (r->entropy_count < 0) {
+	entropy_count = r->entropy_count;
+	entropy_count += nbits;
+	if (entropy_count < 0) {
 		DEBUG_ENT("negative entropy/overflow\n");
-		r->entropy_count = 0;
-	} else if (r->entropy_count > r->poolinfo->POOLBITS)
-		r->entropy_count = r->poolinfo->POOLBITS;
+		entropy_count = 0;
+	} else if (entropy_count > r->poolinfo->POOLBITS)
+		entropy_count = r->poolinfo->POOLBITS;
+	r->entropy_count = entropy_count;
 
 	/* should we wake readers? */
-	if (r == &input_pool &&
-	    r->entropy_count >= random_read_wakeup_thresh) {
+	if (r == &input_pool && entropy_count >= random_read_wakeup_thresh) {
 		wake_up_interruptible(&random_read_wait);
 		kill_fasync(&fasync, SIGIO, POLL_IN);
 	}
-
 	spin_unlock_irqrestore(&r->lock, flags);
 }