As suggested by Andrew, add a generic initial locking scheme used throughout all sysv ipc mechanisms. Documenting the ids rwsem, how rcu can be enough to do the initial checks and when to actually acquire the kern_ipc_perm.lock spinlock.
I found that adding it to util.c was generic enough. Signed-off-by: Davidlohr Bueso <[email protected]> --- ipc/util.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/ipc/util.c b/ipc/util.c index 8f12fe3..639bf38 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -15,6 +15,14 @@ * Jun 2006 - namespaces ssupport * OpenVZ, SWsoft Inc. * Pavel Emelianov <[email protected]> + * + * General sysv ipc locking scheme: + * when doing ipc id lookups, take the ids->rwsem + * rcu_read_lock() + * obtain the ipc object (kern_ipc_perm) + * perform security, capabilities, auditing and permission checks, etc. + * acquire the ipc lock (kern_ipc_perm.lock) throught ipc_lock_object() + * perform data updates (ie: SET, RMID, LOCK/UNLOCK commands) */ #include <linux/mm.h> -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
