Merge tag 'v5.0-rc1' into next-general

Linux 5.0-rc1

Sync to pick up LSM stacking work (which is based on -rc1).

1 files changed, 21 insertions, 5 deletions

diff --git a/include/linux/cred.h b/include/linux/cred.h
index 7eed6101c791..4907c9df86b3 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -169,6 +169,7 @@ extern int change_create_files_as(struct cred *, struct inode *);
 extern int set_security_override(struct cred *, u32);
 extern int set_security_override_from_ctx(struct cred *, const char *);
 extern int set_create_files_as(struct cred *, struct inode *);
+extern int cred_fscmp(const struct cred *, const struct cred *);
 extern void __init cred_init(void);
 
 /*
@@ -236,7 +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
@@ -247,16 +248,29 @@ 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);
 }
 
+static inline const struct cred *get_cred_rcu(const struct cred *cred)
+{
+	struct cred *nonconst_cred = (struct cred *) cred;
+	if (!cred)
+		return NULL;
+	if (!atomic_inc_not_zero(&nonconst_cred->usage))
+		return NULL;
+	validate_creds(cred);
+	return 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.
+ * 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 +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);
+	}
 }
 
 /**