lh-l4v/proof/infoflow/PasUpdates.thy

297 lines
12 KiB
Plaintext

(*
* Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
*
* SPDX-License-Identifier: GPL-2.0-only
*)
text \<open>
Lemmas about updating the external flags of a PAS.
These flags are: pasSubject, pasMayEditReadyQueues and pasMayActivate.
\<close>
theory PasUpdates
imports
"ArchArch_IF"
"FinalCaps"
"AInvs.EmptyFail_AI"
begin
section \<open>Separation lemmas for the idle thread and domain fields\<close>
abbreviation (input) domain_fields where
"domain_fields P s \<equiv> P (domain_time s) (domain_index s) (domain_list s)"
lemma preemption_point_domain_fields[wp]:
"preemption_point \<lbrace>domain_fields P\<rbrace>"
by (simp add: preemption_point_def
| wp OR_choiceE_weak_wp modify_wp
| wpc
| simp add: reset_work_units_def update_work_units_def)+
locale PasUpdates_1 =
fixes aag :: "'a subject_label PAS"
assumes arch_post_cap_deletion_domain_fields[wp]:
"arch_post_cap_deletion acap \<lbrace>domain_fields P\<rbrace>"
and arch_finalise_cap_domain_fields[wp]:
"arch_finalise_cap acap b \<lbrace>domain_fields P\<rbrace>"
and prepare_thread_delete_domain_fields[wp]:
"prepare_thread_delete p \<lbrace>domain_fields P\<rbrace>"
begin
crunch domain_fields[wp]:
retype_region_ext, create_cap_ext, cap_insert_ext, ethread_set, cap_move_ext, empty_slot_ext,
cap_swap_ext, set_thread_state_ext, tcb_sched_action, reschedule_required, cap_swap_for_delete,
finalise_cap, cap_move, cap_swap, cap_delete, cancel_badged_sends, cap_insert
"domain_fields P"
( wp: syscall_valid crunch_wps rec_del_preservation cap_revoke_preservation modify_wp
simp: crunch_simps check_cap_at_def filterM_mapM unless_def
ignore: without_preemption filterM rec_del check_cap_at cap_revoke
ignore_del: retype_region_ext create_cap_ext cap_insert_ext ethread_set cap_move_ext
empty_slot_ext cap_swap_ext set_thread_state_ext tcb_sched_action reschedule_required)
lemma cap_revoke_domain_fields[wp]:
"cap_revoke a \<lbrace>domain_fields P\<rbrace>"
by (rule cap_revoke_preservation2; wp)
lemma invoke_cnode_domain_fields[wp]:
"invoke_cnode a \<lbrace>domain_fields P\<rbrace>"
unfolding invoke_cnode_def
by (wpsimp wp: get_cap_wp hoare_vcg_all_lift hoare_vcg_imp_lift | rule conjI)+
end
section \<open>PAS wellformedness property for non-interference\<close>
definition pas_wellformed_noninterference where
"pas_wellformed_noninterference aag \<equiv>
(\<forall>l \<in> range (pasObjectAbs aag) \<union> \<Union>(range (pasDomainAbs aag)) - {SilcLabel}.
pas_wellformed (aag\<lparr>pasSubject := l\<rparr>)) \<and>
(\<forall>d. SilcLabel \<notin> pasDomainAbs aag d) \<and> pas_domains_distinct aag"
lemma pas_wellformed_noninterference_domains_distinct:
"pas_wellformed_noninterference aag \<Longrightarrow> pas_domains_distinct aag"
by (simp add: pas_wellformed_noninterference_def)
lemma pas_wellformed_noninterference_silc[intro!]:
"pas_wellformed_noninterference aag \<Longrightarrow> SilcLabel \<notin> pasDomainAbs aag d"
by (fastforce simp: pas_wellformed_noninterference_def)
section \<open>PAS subject update\<close>
lemma pasObjectAbs_pasSubject_update:
"pasObjectAbs (aag\<lparr>pasSubject := x\<rparr>) = pasObjectAbs aag"
by simp
lemma pasASIDAbs_pasSubject_update:
"pasASIDAbs (aag\<lparr>pasSubject := x\<rparr>) = pasASIDAbs aag"
by simp
lemma pasIRQAbs_pasSubject_update:
"pasIRQAbs (aag\<lparr>pasSubject := x\<rparr>) = pasIRQAbs aag"
by simp
lemma state_irqs_to_policy_pasSubject_update:
"state_irqs_to_policy_aux (aag\<lparr>pasSubject := x\<rparr>) caps =
state_irqs_to_policy_aux aag caps"
apply (rule equalityI; clarify)
apply (erule state_irqs_to_policy_aux.cases, simp, blast intro: state_irqs_to_policy_aux.intros)
apply (erule state_irqs_to_policy_aux.cases)
apply simp
apply (subst pasObjectAbs_pasSubject_update[symmetric])
apply (subst pasIRQAbs_pasSubject_update[symmetric])
apply (rule state_irqs_to_policy_aux.intros)
apply assumption+
done
lemma irq_map_wellformed_pasSubject_update:
"irq_map_wellformed_aux (aag\<lparr>pasSubject := x\<rparr>) irqn =
irq_map_wellformed_aux aag irqn"
by (clarsimp simp: irq_map_wellformed_aux_def)
lemma tcb_domain_map_wellformed_pasSubject_update:
"tcb_domain_map_wellformed_aux (aag\<lparr>pasSubject := x\<rparr>) irqn =
tcb_domain_map_wellformed_aux aag irqn"
by (clarsimp simp: tcb_domain_map_wellformed_aux_def)
locale PasUpdates_2 = PasUpdates_1 +
assumes arch_perform_invocation_domain_fields[wp]:
"arch_perform_invocation i \<lbrace>domain_fields P\<rbrace>"
and arch_invoke_irq_control_domain_fields[wp]:
"arch_invoke_irq_control ci \<lbrace>domain_fields P\<rbrace>"
and arch_invoke_irq_handler_domain_fields[wp]:
"arch_invoke_irq_handler hi \<lbrace>domain_fields P\<rbrace>"
and arch_post_modify_registers_domain_fields[wp]:
"arch_post_modify_registers cur t \<lbrace>domain_fields P\<rbrace>"
and handle_arch_fault_reply_domain_fields[wp]:
"handle_arch_fault_reply vmf thread x y \<lbrace>domain_fields P\<rbrace>"
and init_arch_objects_domain_fields[wp]:
"init_arch_objects typ ptr num sz refs \<lbrace>domain_fields P\<rbrace>"
and state_asids_to_policy_pasSubject_update:
"state_asids_to_policy (aag\<lparr>pasSubject := subject\<rparr>) s =
state_asids_to_policy aag s"
and state_asids_to_policy_pasMayActivate_update:
"state_asids_to_policy (aag\<lparr>pasMayActivate := b\<rparr>) s =
state_asids_to_policy aag s"
and state_asids_to_policy_pasMayEditReadyQueues_update:
"state_asids_to_policy (aag\<lparr>pasMayEditReadyQueues := b\<rparr>) s =
state_asids_to_policy aag s"
begin
crunch domain_fields[wp]:
set_domain,possible_switch_to,set_priority,set_extra_badge,handle_send,handle_recv,handle_reply
"domain_fields P"
(wp: syscall_valid crunch_wps mapME_x_inv_wp
simp: crunch_simps check_cap_at_def detype_def detype_ext_def mapM_x_defsym
ignore: check_cap_at syscall
ignore_del: set_domain set_priority possible_switch_to
rule: transfer_caps_loop_pres)
lemma pas_refined_pasSubject_update':
"\<lbrakk> pas_refined aag s; pas_wellformed (aag\<lparr>pasSubject := x\<rparr>) \<rbrakk>
\<Longrightarrow> pas_refined (aag\<lparr>pasSubject := x\<rparr>) s"
apply (subst pas_refined_def)
apply (safe del: subsetI)
apply (simp add: irq_map_wellformed_pasSubject_update pas_refined_def)
apply (simp add: tcb_domain_map_wellformed_pasSubject_update pas_refined_def)
apply (clarsimp simp: pas_refined_def)
apply (clarsimp simp: pas_refined_def state_asids_to_policy_pasSubject_update)
apply (fastforce simp: pas_refined_def state_irqs_to_policy_pasSubject_update)
done
lemma pas_wellformed_pasSubject_update:
"\<lbrakk> pas_wellformed_noninterference aag; l \<in> pasDomainAbs aag d \<rbrakk>
\<Longrightarrow> pas_wellformed (aag\<lparr>pasSubject := l\<rparr>)"
by (auto simp: pas_wellformed_noninterference_def)
lemmas pas_refined_pasSubject_update =
pas_refined_pasSubject_update'[OF _ pas_wellformed_pasSubject_update]
end
lemma guarded_pas_domain_pasSubject_update[simp]:
"guarded_pas_domain (aag\<lparr>pasSubject := x\<rparr>) s = guarded_pas_domain aag s"
by (simp add: guarded_pas_domain_def)
lemma silc_inv_pasSubject_update':
"\<lbrakk> silc_inv aag st s; x \<noteq> SilcLabel \<rbrakk>
\<Longrightarrow> silc_inv (aag\<lparr>pasSubject := x\<rparr>) st s"
by (auto simp: silc_inv_def silc_dom_equiv_def intra_label_cap_def cap_points_to_label_def)
lemma silc_inv_pasSubject_update:
"\<lbrakk> silc_inv aag st s; pas_wellformed_noninterference aag; l \<in> pasDomainAbs aag d \<rbrakk>
\<Longrightarrow> silc_inv (aag\<lparr>pasSubject := l\<rparr>) st s"
by (fastforce intro: silc_inv_pasSubject_update' dest: pas_wellformed_noninterference_silc)
section \<open>PAS MayActivate update\<close>
lemma prop_of_pasMayActivate_update_idemp:
"\<lbrakk> P aag; pasMayActivate aag = v \<rbrakk> \<Longrightarrow> P (aag\<lparr>pasMayActivate := v\<rparr>)"
by (hypsubst, auto)
lemma pasObjectAbs_pasMayActivate_update:
"pasObjectAbs (aag\<lparr>pasMayActivate := x\<rparr>) = pasObjectAbs aag"
by simp
lemma pasASIDAbs_pasMayActivate_update:
"pasASIDAbs (aag\<lparr>pasMayActivate := x\<rparr>) = pasASIDAbs aag"
by simp
lemma pasIRQAbs_pasMayActivate_update:
"pasIRQAbs (aag\<lparr>pasMayActivate := x\<rparr>) = pasIRQAbs aag"
by simp
lemma state_irqs_to_policy_pasMayActivate_update:
"state_irqs_to_policy (aag\<lparr>pasMayActivate := x\<rparr>) s =
state_irqs_to_policy aag s"
apply (rule equalityI)
apply (clarify)
apply (erule state_irqs_to_policy_aux.cases
| simp
| fastforce intro: state_irqs_to_policy_aux.intros)+
apply (clarify)
apply (erule state_irqs_to_policy_aux.cases)
apply (simp, subst pasObjectAbs_pasMayActivate_update[symmetric]
, subst pasIRQAbs_pasMayActivate_update[symmetric]
, rule state_irqs_to_policy_aux.intros, assumption+)
done
lemma guarded_pas_domainMayActivate_update[simp]:
"guarded_pas_domain (aag\<lparr>pasMayActivate := False\<rparr>) = guarded_pas_domain aag"
by (simp add: guarded_pas_domain_def)
lemma cdt_change_allowedMayActivate_update[simp]:
"cdt_change_allowed (aag\<lparr>pasMayActivate := x\<rparr>) = cdt_change_allowed aag "
by (simp add: cdt_change_allowed_def[abs_def] cdt_direct_change_allowed.simps direct_call_def)
section \<open>PAS MayEditReadyQueue update\<close>
lemma prop_of_pasMayEditReadyQueues_update_idemp:
"\<lbrakk> P aag; pasMayEditReadyQueues aag = v \<rbrakk> \<Longrightarrow> P (aag\<lparr>pasMayEditReadyQueues := v\<rparr>)"
by clarsimp
lemma pasObjectAbs_pasMayEditReadyQueues_update:
"pasObjectAbs (aag\<lparr>pasMayEditReadyQueues := x\<rparr>) = pasObjectAbs aag"
by simp
lemma pasASIDAbs_pasMayEditReadyQueues_update:
"pasASIDAbs (aag\<lparr>pasMayEditReadyQueues := x\<rparr>) = pasASIDAbs aag"
by simp
lemma pasIRQAbs_pasMayEditReadyQueues_update:
"pasIRQAbs (aag\<lparr>pasMayEditReadyQueues := x\<rparr>) = pasIRQAbs aag"
by simp
lemma state_irqs_to_policy_pasMayEditReadyQueues_update:
"state_irqs_to_policy (aag\<lparr>pasMayEditReadyQueues := x\<rparr>) s =
state_irqs_to_policy aag s"
apply (rule equalityI)
apply (clarify)
apply (erule state_irqs_to_policy_aux.cases
| simp
| fastforce intro: state_irqs_to_policy_aux.intros)+
apply (clarify)
apply (erule state_irqs_to_policy_aux.cases)
apply (simp, subst pasObjectAbs_pasMayEditReadyQueues_update[symmetric]
, subst pasIRQAbs_pasMayEditReadyQueues_update[symmetric]
, rule state_irqs_to_policy_aux.intros, assumption+)
done
context PasUpdates_2 begin
lemma pas_refined_pasMayActivate_update:
"pas_refined aag s
\<Longrightarrow> pas_refined (aag\<lparr>pasMayActivate := x\<rparr>) s"
by (simp add: pas_refined_def irq_map_wellformed_aux_def
state_asids_to_policy_pasMayActivate_update[simplified]
state_irqs_to_policy_pasMayActivate_update tcb_domain_map_wellformed_aux_def)
lemma pas_refined_pasMayEditReadyQueues_update:
"pas_refined aag s
\<Longrightarrow> pas_refined (aag\<lparr>pasMayEditReadyQueues := x\<rparr>) s"
by (clarsimp simp: pas_refined_def irq_map_wellformed_aux_def tcb_domain_map_wellformed_aux_def
state_asids_to_policy_pasMayEditReadyQueues_update[simplified]
state_irqs_to_policy_pasMayEditReadyQueues_update)
end
lemma guarded_pas_domainMayEditReadyQueues_update[simp]:
"guarded_pas_domain (aag\<lparr>pasMayEditReadyQueues := False\<rparr>) = guarded_pas_domain aag"
by (simp add: guarded_pas_domain_def)
lemma cdt_change_allowedMayEditReadyQueues_update[simp]:
"cdt_change_allowed (aag\<lparr>pasMayEditReadyQueues := x\<rparr>) =
cdt_change_allowed aag"
by (simp add: cdt_change_allowed_def[abs_def] cdt_direct_change_allowed.simps direct_call_def)
end