The things that usually go wrong:
- wp fall through: add +, e.g.
apply (wp select_wp) -> apply (wp select_wp)+
- precondition: you can remove most hoare_pre, but wpc still needs it, and
sometimes the wp instance relies on being able to fit a rule to the
current non-schematic precondition. In that case, use "including no_pre"
to switch off the automatic hoare_pre application.
- very rarely there is a schematic postcondition that interferes with the
new trivial cleanup rules, because the rest of the script assumes some
specific state afterwards (shouldn't happen in a reasonable proof, but
not all proofs are reasonable..). In that case, (wp_once ...)+ should
emulate the old behaviour precisely.
UserOp_IF had its own way of extracting the XN bit from page tables.
This is now unified with the existing functions in ADT_AI, which also
means that the proof for XN bit equality is basically the same as for
pt_rights and pt_lift.
Miki Tanaka
Gerwin Klein
Xin,Gao
Matthew Brecknell
Matthew Brecknell
Thomas Sewell