lh-l4v/proof/infoflow/ARM/ArchInfoFlow_IF.thy

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(*
* Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
*
* SPDX-License-Identifier: GPL-2.0-only
*)
theory ArchInfoFlow_IF
imports InfoFlow_IF
begin
context Arch begin global_naming ARM
named_theorems InfoFlow_IF_assms
lemma asid_pool_at_kheap:
"asid_pool_at ptr s = (\<exists>asid_pool. kheap s ptr = Some (ArchObj (ASIDPool asid_pool)))"
by (simp add: atyp_at_eq_kheap_obj)
lemma equiv_asid:
"equiv_asid asid s s' = equiv_asid' asid (arm_asid_table (arch_state s) (asid_high_bits_of asid))
(arm_asid_table (arch_state s') (asid_high_bits_of asid))
(kheap s) (kheap s')"
by (auto simp: equiv_asid_def equiv_asid'_def asid_pool_at_kheap split: option.splits )
lemma equiv_asids_refl[InfoFlow_IF_assms]:
"equiv_asids R s s"
by (auto simp: equiv_asids_def equiv_asid_def)
lemma equiv_asids_sym[InfoFlow_IF_assms]:
"equiv_asids R s t \<Longrightarrow> equiv_asids R t s"
by (auto simp: equiv_asids_def equiv_asid_def)
lemma equiv_asids_trans[InfoFlow_IF_assms]:
"\<lbrakk> equiv_asids R s t; equiv_asids R t u \<rbrakk> \<Longrightarrow> equiv_asids R s u"
by (fastforce simp: equiv_asids_def equiv_asid_def asid_pool_at_kheap)
lemma equiv_asids_non_asid_pool_kheap_update[InfoFlow_IF_assms]:
"\<lbrakk> equiv_asids R s s'; non_asid_pool_kheap_update s kh; non_asid_pool_kheap_update s' kh' \<rbrakk>
\<Longrightarrow> equiv_asids R (s\<lparr>kheap := kh\<rparr>) (s'\<lparr>kheap := kh'\<rparr>)"
apply (clarsimp simp: equiv_asids_def equiv_asid non_asid_pool_kheap_update_def)
apply (fastforce simp: equiv_asid'_def split: option.splits)
done
lemma equiv_asids_identical_kheap_updates[InfoFlow_IF_assms]:
"\<lbrakk> equiv_asids R s s'; identical_kheap_updates s s' kh kh' \<rbrakk>
\<Longrightarrow> equiv_asids R (s\<lparr>kheap := kh\<rparr>) (s'\<lparr>kheap := kh'\<rparr>)"
apply (clarsimp simp: equiv_asids_def equiv_asid_def identical_kheap_updates_def asid_pool_at_kheap)
apply (case_tac "kh pool_ptr = kh' pool_ptr"; fastforce)
done
lemma equiv_asids_trivial[InfoFlow_IF_assms]:
"(\<And>x. P x \<Longrightarrow> False) \<Longrightarrow> equiv_asids P x y"
by (auto simp: equiv_asids_def)
lemma equiv_asids_triv':
"\<lbrakk> equiv_asids R s s'; kheap t = kheap s; kheap t' = kheap s';
arm_asid_table (arch_state t) = arm_asid_table (arch_state s);
arm_asid_table (arch_state t') = arm_asid_table (arch_state s') \<rbrakk>
\<Longrightarrow> equiv_asids R t t'"
by (fastforce simp: equiv_asids_def equiv_asid equiv_asid'_def)
lemma equiv_asids_triv[InfoFlow_IF_assms]:
"\<lbrakk> equiv_asids R s s'; kheap t = kheap s; kheap t' = kheap s';
arch_state t = arch_state s; arch_state t' = arch_state s' \<rbrakk>
\<Longrightarrow> equiv_asids R t t'"
by (fastforce simp: equiv_asids_triv')
lemma globals_equiv_refl[InfoFlow_IF_assms]:
"globals_equiv s s"
by (simp add: globals_equiv_def idle_equiv_refl)
lemma globals_equiv_sym[InfoFlow_IF_assms]:
"globals_equiv s t \<Longrightarrow> globals_equiv t s"
by (auto simp: globals_equiv_def idle_equiv_def)
lemma globals_equiv_trans[InfoFlow_IF_assms]:
"\<lbrakk> globals_equiv s t; globals_equiv t u \<rbrakk> \<Longrightarrow> globals_equiv s u"
unfolding globals_equiv_def arch_globals_equiv_def
by clarsimp (metis idle_equiv_trans idle_equiv_def)
lemma equiv_asids_guard_imp[InfoFlow_IF_assms]:
"\<lbrakk> equiv_asids R s s'; \<And>x. Q x \<Longrightarrow> R x \<rbrakk> \<Longrightarrow> equiv_asids Q s s'"
by (auto simp: equiv_asids_def)
lemma dmo_loadWord_rev[InfoFlow_IF_assms]:
"reads_equiv_valid_inv A aag (K (for_each_byte_of_word (aag_can_read aag) p))
(do_machine_op (loadWord p))"
apply (rule gen_asm_ev)
apply (rule use_spec_ev)
apply (rule spec_equiv_valid_hoist_guard)
apply (rule do_machine_op_spec_rev)
apply (simp add: loadWord_def equiv_valid_def2 spec_equiv_valid_def)
apply (rule_tac R'="\<lambda>rv rv'. for_each_byte_of_word (\<lambda>y. rv y = rv' y) p" and Q="\<top>\<top>" and Q'="\<top>\<top>"
and P="\<top>" and P'="\<top>" in equiv_valid_2_bind_pre)
apply (rule_tac R'="(=)" and Q="\<lambda>r s. p && mask 2 = 0" and Q'="\<lambda>r s. p && mask 2 = 0"
and P="\<top>" and P'="\<top>" in equiv_valid_2_bind_pre)
apply (rule return_ev2)
apply (rule_tac f="word_rcat" in arg_cong)
apply (fastforce intro: is_aligned_no_wrap' word_plus_mono_right
simp: is_aligned_mask for_each_byte_of_word_def word_size_def) (* slow *)
apply (rule assert_ev2[OF refl])
apply (rule assert_wp)+
apply simp+
apply (clarsimp simp: equiv_valid_2_def in_monad for_each_byte_of_word_def)
apply (erule equiv_forD)
apply fastforce
apply (wp wp_post_taut loadWord_inv | simp)+
done
end
global_interpretation InfoFlow_IF_1?: InfoFlow_IF_1
proof goal_cases
interpret Arch .
case 1 show ?case
by (unfold_locales; (fact InfoFlow_IF_assms)?)
qed
end