[patch 8/9] Documentation: Fix invalid rcu assumptions

[Thomas Gleixner]

1) spinlock held is not equivalent to rcu_read_lock()

2) remove the stale signal code snippet

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxx>
Cc: Vegard Nossum <vegardno@xxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
---
 Documentation/credentials.txt |    3 ---
 Documentation/kmemcheck.txt   |    3 +--
 2 files changed, 1 insertion(+), 5 deletions(-)

Index: linux-2.6-tip/Documentation/credentials.txt
===================================================================
--- linux-2.6-tip.orig/Documentation/credentials.txt
+++ linux-2.6-tip/Documentation/credentials.txt
@@ -408,9 +408,6 @@ This should be used inside the RCU read 
 		...
 	}
 
-A function need not get RCU read lock to use __task_cred() if it is holding a
-spinlock at the time as this implicitly holds the RCU read lock.
-
 Should it be necessary to hold another task's credentials for a long period of
 time, and possibly to sleep whilst doing so, then the caller should get a
 reference on them using:
Index: linux-2.6-tip/Documentation/kmemcheck.txt
===================================================================
--- linux-2.6-tip.orig/Documentation/kmemcheck.txt
+++ linux-2.6-tip/Documentation/kmemcheck.txt
@@ -429,8 +429,7 @@ Let's take a look at it:
 193         /*
 194          * We won't get problems with the target's UID changing under us
 195          * because changing it requires RCU be used, and if t != current, the
-196          * caller must be holding the RCU readlock (by way of a spinlock) and
-197          * we use RCU protection here
+196          * caller must be holding the RCU readlocke
 198          */
 199         user = get_uid(__task_cred(t)->user);
 200         atomic_inc(&user->sigpending);


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