[patch] hw_random: cleanup in hwrng_register()

From: Dan Carpenter
Date: Thu Jan 30 2014 - 06:50:17 EST


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@xxxxxxxxxx>

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index b9495a8c05c6..463382036a01 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -301,7 +301,6 @@ err_misc_dereg:

int hwrng_register(struct hwrng *rng)
{
- int must_register_misc;
int err = -EINVAL;
struct hwrng *old_rng, *tmp;

@@ -326,7 +325,6 @@ 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);
@@ -335,13 +333,11 @@ 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;
}
}
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