summaryrefslogtreecommitdiff
path: root/include/linux/cred.h
diff options
context:
space:
mode:
authorMateusz Guzik <mjguzik@gmail.com>2023-09-09 22:19:32 +0300
committerPaul Moore <paul@paul-moore.com>2023-09-22 02:29:30 +0300
commit41e845628511878d6e89e2a9249c095e72aab7eb (patch)
tree4c23b005302b82e9987a21af0391c7ab3a32f623 /include/linux/cred.h
parent20a2aa47097aae7016209c4dbe392b3b25e0d883 (diff)
downloadlinux-41e845628511878d6e89e2a9249c095e72aab7eb.tar.xz
cred: add get_cred_many and put_cred_many
Some of the frequent consumers of get_cred and put_cred operate on 2 references on the same creds back-to-back. Switch them to doing the work in one go instead. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> [PM: removed changelog from commit description] Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'include/linux/cred.h')
-rw-r--r--include/linux/cred.h59
1 files changed, 50 insertions, 9 deletions
diff --git a/include/linux/cred.h b/include/linux/cred.h
index f923528d5cc4..56bc432fe49b 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -219,6 +219,20 @@ static inline bool cap_ambient_invariant_ok(const struct cred *cred)
}
/**
+ * get_new_cred_many - Get references on a new set of credentials
+ * @cred: The new credentials to reference
+ * @nr: Number of references to acquire
+ *
+ * Get references on the specified set of new credentials. The caller must
+ * release all acquired references.
+ */
+static inline struct cred *get_new_cred_many(struct cred *cred, int nr)
+{
+ atomic_add(nr, &cred->usage);
+ return cred;
+}
+
+/**
* get_new_cred - Get a reference on a new set of credentials
* @cred: The new credentials to reference
*
@@ -227,16 +241,16 @@ static inline bool cap_ambient_invariant_ok(const struct cred *cred)
*/
static inline struct cred *get_new_cred(struct cred *cred)
{
- atomic_inc(&cred->usage);
- return cred;
+ return get_new_cred_many(cred, 1);
}
/**
- * get_cred - Get a reference on a set of credentials
+ * get_cred_many - Get references on a set of credentials
* @cred: The credentials to reference
+ * @nr: Number of references to acquire
*
- * Get a reference on the specified set of credentials. The caller must
- * release the reference. If %NULL is passed, it is returned with no action.
+ * Get references on the specified set of credentials. The caller must release
+ * all acquired 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
@@ -244,14 +258,28 @@ static inline struct cred *get_new_cred(struct cred *cred)
* accidental alteration of a set of credentials that should be considered
* immutable.
*/
-static inline const struct cred *get_cred(const struct cred *cred)
+static inline const struct cred *get_cred_many(const struct cred *cred, int nr)
{
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);
+ return get_new_cred_many(nonconst_cred, nr);
+}
+
+/*
+ * get_cred - Get a reference on a set of credentials
+ * @cred: The credentials to reference
+ *
+ * Get a reference on the specified set of credentials. The caller must
+ * release the reference. If %NULL is passed, it is returned with no action.
+ *
+ * This is used to deal with a committed set of credentials.
+ */
+static inline const struct cred *get_cred(const struct cred *cred)
+{
+ return get_cred_many(cred, 1);
}
static inline const struct cred *get_cred_rcu(const struct cred *cred)
@@ -269,6 +297,7 @@ static inline const struct cred *get_cred_rcu(const struct cred *cred)
/**
* put_cred - Release a reference to a set of credentials
* @cred: The credentials to release
+ * @nr: Number of references to release
*
* Release a reference to a set of credentials, deleting them when the last ref
* is released. If %NULL is passed, nothing is done.
@@ -277,17 +306,29 @@ static inline const struct cred *get_cred_rcu(const struct cred *cred)
* on task_struct are attached by const pointers to prevent accidental
* alteration of otherwise immutable credential sets.
*/
-static inline void put_cred(const struct cred *_cred)
+static inline void put_cred_many(const struct cred *_cred, int nr)
{
struct cred *cred = (struct cred *) _cred;
if (cred) {
validate_creds(cred);
- if (atomic_dec_and_test(&(cred)->usage))
+ if (atomic_sub_and_test(nr, &cred->usage))
__put_cred(cred);
}
}
+/*
+ * put_cred - Release a reference to a set of credentials
+ * @cred: The credentials to release
+ *
+ * Release a reference to a set of credentials, deleting them when the last ref
+ * is released. If %NULL is passed, nothing is done.
+ */
+static inline void put_cred(const struct cred *cred)
+{
+ put_cred_many(cred, 1);
+}
+
/**
* current_cred - Access the current task's subjective credentials
*