[PATCH 01/12] cred: add prepare credential guard

[Christian Brauner]

A lot of code uses the following pattern:

* prepare new credentials
* modify them for their use-case
* drop them

Support that easier with the new guard infrastructure.

Signed-off-by: Christian Brauner <brauner at kernel.org>
---
 include/linux/cred.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/cred.h b/include/linux/cred.h
index 1778c0535b90..a1e33227e0c2 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -285,6 +285,11 @@ static inline void put_cred(const struct cred *cred)
 	put_cred_many(cred, 1);
 }
 
+DEFINE_CLASS(prepare_creds,
+	      struct cred *,
+	      if (_T) put_cred(_T),
+	      prepare_creds(), void)
+
 DEFINE_FREE(put_cred, struct cred *, if (!IS_ERR_OR_NULL(_T)) put_cred(_T))
 
 /**

-- 
2.47.3