diff options
| author | NeilBrown <neilb@suse.com> | 2018-12-03 11:30:30 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-10-06 15:05:11 +0200 |
| commit | babe2c4a00da1c28c006f6c0e0b22f3c82581fe5 (patch) | |
| tree | e7ac2638a53a4974fb458a7583e7a096e60f3e0b | |
| parent | c3156fea4d8a0e643625dff69a0421e872d1fdae (diff) | |
cred: allow get_cred() and put_cred() to be given NULL.
commit f06bc03339ad4c1baa964a5f0606247ac1c3c50b upstream.
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>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/linux/cred.h | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/include/linux/cred.h b/include/linux/cred.h index 2a0d4674294e..493516e97e45 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -235,7 +235,7 @@ 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 @@ -246,6 +246,8 @@ 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); nonconst_cred->non_rcu = 0; return get_new_cred(nonconst_cred); @@ -256,7 +258,7 @@ static inline const struct cred *get_cred(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 @@ -266,9 +268,11 @@ 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); + } } /** |