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authorNeilBrown <neilb@suse.com>2018-12-03 11:30:30 +1100
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2018-12-19 13:52:44 -0500
commitf06bc03339ad4c1baa964a5f0606247ac1c3c50b (patch)
treeb31f33d2bd3099e6366d8cdf73cb1bcb3458fdce /include/linux/cred.h
parenta6d8e7637faac93f362b694311bff64d5a8c701e (diff)
cred: allow get_cred() and put_cred() to be given NULL.
It is common practice for helpers like this to silently, accept a NULL pointer. get_rpccred() and put_rpccred() used by NFS act this way and using the same interface will ease the conversion for NFS, and simplify the resulting code. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'include/linux/cred.h')
-rw-r--r--include/linux/cred.h14
1 files changed, 9 insertions, 5 deletions
diff --git a/include/linux/cred.h b/include/linux/cred.h
index 48979fcb95cf..4907c9df86b3 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -237,7 +237,7 @@ static inline struct cred *get_new_cred(struct cred *cred)
* @cred: The credentials to reference
*
* Get a reference on the specified set of credentials. The caller must
- * release the reference.
+ * release the reference. If %NULL is passed, it is returned with no action.
*
* This is used to deal with a committed set of credentials. Although the
* pointer is const, this will temporarily discard the const and increment the
@@ -248,6 +248,8 @@ static inline struct cred *get_new_cred(struct cred *cred)
static inline const struct cred *get_cred(const struct cred *cred)
{
struct cred *nonconst_cred = (struct cred *) cred;
+ if (!cred)
+ return cred;
validate_creds(cred);
return get_new_cred(nonconst_cred);
}
@@ -268,7 +270,7 @@ static inline const struct cred *get_cred_rcu(const struct cred *cred)
* @cred: The credentials to release
*
* Release a reference to a set of credentials, deleting them when the last ref
- * is released.
+ * is released. If %NULL is passed, nothing is done.
*
* This takes a const pointer to a set of credentials because the credentials
* on task_struct are attached by const pointers to prevent accidental
@@ -278,9 +280,11 @@ static inline void put_cred(const struct cred *_cred)
{
struct cred *cred = (struct cred *) _cred;
- validate_creds(cred);
- if (atomic_dec_and_test(&(cred)->usage))
- __put_cred(cred);
+ if (cred) {
+ validate_creds(cred);
+ if (atomic_dec_and_test(&(cred)->usage))
+ __put_cred(cred);
+ }
}
/**