From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Thu, 30 Jan 2014 11:49:43 +0000 (+0300)
Subject: hwrng: cleanup in hwrng_register()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d167b6e1fb8ad386b17485ca88804d14f1695805;p=linux-beck.git

hwrng: cleanup in hwrng_register()

My static checker complains that:

	drivers/char/hw_random/core.c:341 hwrng_register()
	warn: we tested 'old_rng' before and it was 'false'

The problem is that sometimes we test "if (!old_rng)" and sometimes we
test "if (must_register_misc)".  The static checker knows they are
equivalent but a human being reading the code could easily be confused.

I have simplified the code by removing the "must_register_misc" variable
and I have removed the redundant check on "if (!old_rng)".

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index a0f7724852eb..cf49f1c88f01 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -302,7 +302,6 @@ err_misc_dereg:
 
 int hwrng_register(struct hwrng *rng)
 {
-	int must_register_misc;
 	int err = -EINVAL;
 	struct hwrng *old_rng, *tmp;
 
@@ -327,7 +326,6 @@ int hwrng_register(struct hwrng *rng)
 			goto out_unlock;
 	}
 
-	must_register_misc = (current_rng == NULL);
 	old_rng = current_rng;
 	if (!old_rng) {
 		err = hwrng_init(rng);
@@ -336,13 +334,11 @@ int hwrng_register(struct hwrng *rng)
 		current_rng = rng;
 	}
 	err = 0;
-	if (must_register_misc) {
+	if (!old_rng) {
 		err = register_miscdev();
 		if (err) {
-			if (!old_rng) {
-				hwrng_cleanup(rng);
-				current_rng = NULL;
-			}
+			hwrng_cleanup(rng);
+			current_rng = NULL;
 			goto out_unlock;
 		}
 	}