Update apparmor_kernel_development_guide

apparmor_kernel_development_guide.md

@@ -419,83 +419,6 @@ policydb
 
 # stacking
 
-# Notifications
-
-Notifications are based on apparmor audit messages. However instead of being converted to a text format they are passed in machine native binary structure.
-
-AppArmor can not sleep in the majority of the LSM hooks due to locking. Even if the LSM hook allows the task to sleep, apparmor's internal locking (even just rcu_read_lock) prevents sleeping within code. To avoid having to deal with the locking issues, notifications are delayed until hook exit.
-
-Each hook that allows notifications gets a aa_notify struct
-
-  DEFINE_NOTIFY(name, ...)
-
-And at hook exit
-
-  DO_NOTIFY(name, ...)
-
-If a notification is determined to be needed the audit message is queued up on the aa_notify struct. And it is handled in DO_NOTIFY at the end of the hook. This allows us to avoid apparmor internal locking and also to group multiple notifications into a single message.
-
-## Audit messages and allocations
-
-The queue of audit messages requires that they be allocated via heap memory, but we also don't want the regular audit path to fail. ???
-
-It does however require that audit messages are NOT allocated from the stac
-
-
-
-
-profile flags
-rule flags
-
-multiple notification
-- profile loads
-- per profile in stack
-
-apparmor audit msg -> audit msg cache -> dedup -> copy msg -> insert in msg cache -> send to audit subsystem
-                   |                          |            |
-                   |                           -> drop msg |
-                   |                                        -> send to audit subsystem
-                   -> notify queue -> insert queue on waiting
-
-multicast
-- policy changes
-- complain messages
-prompting
-- synchronous
-- asynch + ptrace and restart
-
-prompt failing
-- interrupts
-- time outs
-
-how to keep alive
-restarting request
-
-down grading prompt
-
-## ???
-audit structs
-
-
-## user space api
-
-### include file
-
-### setting up notifications
-
-open file
-use ioctl to set notification
-wait for notifications
-read file
-- reply
-
-link to userspace api provided by library.
-
-## ???
-
-
-
-
 
 # Delegation
 - TODO: this is not implemented yet.