commit 3295514841c2112d94451ba5deaf54f5afb78ea9
author Al Viro <viro@ZenIV.linux.org.uk> Sun Aug 07 18:55:11 2011 +0100
committer Linus Torvalds <torvalds@linux-foundation.org> Sun Aug 07 13:42:35 2011 -0700
tree 6df351cb1febbcd011d24fcf99d1b08167c68d5e
parent 7813b94a54987571082ff19e9d87eabbfec23b4e

fix rcu annotations noise in cred.h

task->cred is declared as __rcu, and access to other tasks' ->cred is,
indeed, protected.  Access to current->cred does not need rcu_dereference()
at all, since only the task itself can change its ->cred.  sparse, of
course, has no way of knowing that...

Add force-cast in current_cred(), make current_fsuid() et.al. use it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/cred.h

diff --git a/include/linux/cred.h b/include/linux/cred.h
index 48e82af..98f46ef 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -265,10 +265,11 @@
 /**
  * current_cred - Access the current task's subjective credentials
  *
- * Access the subjective credentials of the current task.
+ * Access the subjective credentials of the current task.  RCU-safe,
+ * since nobody else can modify it.
  */
 #define current_cred() \
-	(current->cred)
+	(*(__force struct cred **)&current->cred)
 
 /**
  * __task_cred - Access a task's objective credentials
@@ -307,7 +308,7 @@
 ({							\
 	struct user_struct *__u;			\
 	struct cred *__cred;				\
-	__cred = (struct cred *) current_cred();	\
+	__cred = current_cred();			\
 	__u = get_uid(__cred->user);			\
 	__u;						\
 })
@@ -322,7 +323,7 @@
 ({							\
 	struct group_info *__groups;			\
 	struct cred *__cred;				\
-	__cred = (struct cred *) current_cred();	\
+	__cred = current_cred();			\
 	__groups = get_group_info(__cred->group_info);	\
 	__groups;					\
 })
@@ -341,7 +342,7 @@
 
 #define current_cred_xxx(xxx)			\
 ({						\
-	current->cred->xxx;			\
+	current_cred()->xxx;			\
 })
 
 #define current_uid()		(current_cred_xxx(uid))