KEYS: Fix some sparse warnings

Fix some sparse warnings in the keyrings code:

 (1) compat_keyctl_instantiate_key_iov() should be static.

 (2) There were a couple of places where a pointer was being compared against
     integer 0 rather than NULL.

 (3) keyctl_instantiate_key_common() should not take a __user-labelled iovec
     pointer as the caller must have copied the iovec to kernel space.

 (4) __key_link_begin() takes and __key_link_end() releases
     keyring_serialise_link_sem under some circumstances and so this should be
     declared.

     Note that adding __acquires() and __releases() for this doesn't help cure
     the warnings messages - something only commenting out both helps.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 7445875f6818..81e7852d281d 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -751,6 +751,7 @@ static void keyring_unlink_rcu_disposal(struct rcu_head *rcu)
 int __key_link_begin(struct key *keyring, const struct key_type *type,
 		     const char *description, unsigned long *_prealloc)
 	__acquires(&keyring->sem)
+	__acquires(&keyring_serialise_link_sem)
 {
 	struct keyring_list *klist, *nklist;
 	unsigned long prealloc;
@@ -960,6 +961,7 @@ void __key_link(struct key *keyring, struct key *key,
 void __key_link_end(struct key *keyring, struct key_type *type,
 		    unsigned long prealloc)
 	__releases(&keyring->sem)
+	__releases(&keyring_serialise_link_sem)
 {
 	BUG_ON(type == NULL);
 	BUG_ON(type->name == NULL);