crypto: cavium/nitrox - remove check of list iterator against head past the loop...

When list_for_each_entry() completes the iteration over the whole list
without breaking the loop, the iterator value will be a bogus pointer
computed based on the head element.

While it is safe to use the pointer to determine if it was computed
based on the head element, either with list_entry_is_head() or
&pos->member == head, using the iterator variable after the loop should
be avoided.

In preparation to limit the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
index 6c61817996a3338b5a193557f7ffd5cb06fd3bb6..432a61aca0c5fae3994e9428e2916e659b738e36 100644 (file)
--- a/drivers/crypto/cavium/nitrox/nitrox_main.c
+++ b/drivers/crypto/cavium/nitrox/nitrox_main.c
@@ -269,15 +269,17 @@ static void nitrox_remove_from_devlist(struct nitrox_device *ndev)
 
 struct nitrox_device *nitrox_get_first_device(void)
 {
-       struct nitrox_device *ndev;
+       struct nitrox_device *ndev = NULL, *iter;
 
        mutex_lock(&devlist_lock);
-       list_for_each_entry(ndev, &ndevlist, list) {
-               if (nitrox_ready(ndev))
+       list_for_each_entry(iter, &ndevlist, list) {
+               if (nitrox_ready(iter)) {
+                       ndev = iter;
                        break;
+               }
        }
        mutex_unlock(&devlist_lock);
-       if (&ndev->list == &ndevlist)
+       if (!ndev)
                return NULL;
 
        refcount_inc(&ndev->refcnt);