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| author | NeilBrown <neilb@suse.com> | 2018-12-03 11:30:30 +1100 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2018-12-19 13:52:44 -0500 |
| commit | f06bc03339ad4c1baa964a5f0606247ac1c3c50b (patch) | |
| tree | b31f33d2bd3099e6366d8cdf73cb1bcb3458fdce /include/linux/cred.h | |
| parent | a6d8e7637faac93f362b694311bff64d5a8c701e (diff) | |
| download | linux-f06bc03339ad4c1baa964a5f0606247ac1c3c50b.tar.gz linux-f06bc03339ad4c1baa964a5f0606247ac1c3c50b.tar.bz2 linux-f06bc03339ad4c1baa964a5f0606247ac1c3c50b.zip | |
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.h | 14 |
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); + } } /** |