Messages in this thread Patch in this message | | | Date | Thu, 10 Dec 2009 00:53:26 -0000 | From | Thomas Gleixner <> | Subject | [patch 8/9] Documentation: Fix invalid rcu assumptions |
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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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