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    Subject[patch 8/9] Documentation: Fix invalid rcu assumptions
    1) spinlock held is not equivalent to rcu_read_lock()

    2) remove the stale signal code snippet

    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Cc: Randy Dunlap <rdunlap@xenotime.net>
    Cc: Vegard Nossum <vegardno@ifi.uio.no>
    Cc: James Morris <jmorris@namei.org>
    ---
    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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