Add a basic overview of the ordering of the backend of the compiler
and which stages specific dump info lines up with.
Signed-off-by: John Johansen <john.johansen@canonical.com>
The hfa stores next/check transitions in 16 bit fields to reduce memory
usage. However this means the state machine can on contain 2^16
states.
Allow the next/check tables to be 32 bit. This theoretically could allow
for 2^32 states however the base table uses the top 8 bits as flags
giving us only 2^24 bits to index into the next/check tables. With
most states having at least 1 transition this effectively caps the
number of states at 2^24.
To obtain 2^32 possible states a flags table needs to be added. Add
a skeleton around supporting a flags table, so we can note the remaining
work that needs to be done. This patch will only allow for 2^24 states.
Bug: https://gitlab.com/apparmor/apparmor/-/issues/419
Signed-off-by: John Johansen <john.johansen@canonical.com>
Update the state machine readme to better reflect how the chfa is
encoded and works. It still needs a lot more but fixes several errors
in the doc and adds some info about state differential encoding, oobs,
and comb compression.
Signed-off-by: John Johansen <john.johansen@canonical.com>
With the exception of the documentation fixes, these should all be
invisible to users.
Signed-off-by: Steve Beattie <steve.beattie@canonical.com>
Acked-by: Christian Boltz <apparmor@cboltz.de>
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/687
