no_shm_selinux/Enrich.thy
author chunhan
Tue, 07 Jan 2014 22:04:06 +0800
changeset 90 003cac7b8bf5
parent 89 ded3f83f6cb9
child 93 dfde07c7cd6b
permissions -rw-r--r--
enrich_msgq

theory Enrich
imports Main Flask Static Init_prop Valid_prop Tainted_prop Delete_prop Co2sobj_prop S2ss_prop S2ss_prop2
 Temp
begin

(* enriched objects, closely related to static objects, so are only 3 kinds *)
datatype t_enrich_obj = 
  E_proc "t_process" "t_msgq" "t_msgq"
| E_file_link "t_file"
| E_file "t_file" "nat" 
 (*
| E_fd   "t_process" "t_fd" 
| E_inum "nat" *)
| E_msgq "t_msgq"
(*
| E_msg  "t_msgq"    "t_msg"
*)


(* objects that need dynamic indexing, all nature-numbers *)
datatype t_index_obj = 
  I_proc "t_process" 
| I_file "t_file"
| I_fd   "t_process" "t_fd"
| I_inum "nat"
| I_msgq "t_msgq"
| I_msg  "t_msgq"    "t_msg"

context tainting_s begin

fun no_del_event:: "t_event list \<Rightarrow> bool"
where
  "no_del_event [] = True"
| "no_del_event (Kill p p' # \<tau>)  = False"
| "no_del_event (Exit p # s) = False"
| "no_del_event (CloseFd p fd # \<tau>) = False"
| "no_del_event (UnLink p f # \<tau>) = False"
| "no_del_event (Rmdir p f # \<tau>)  = False"
(*
| "no_del_event (Rename p f f' # \<tau>)  = False"
*)
| "no_del_event (RemoveMsgq p q # \<tau>) = False"
(*
| "no_del_event (RecvMsg p q m # \<tau>)  = False"
*)
| "no_del_event (_ # \<tau>) = no_del_event \<tau>"

fun all_inums :: "t_state \<Rightarrow> t_inode_num set"
where
  "all_inums [] = current_inode_nums []"
| "all_inums (Open p f flags fd opt # s) = (
    case opt of
      None \<Rightarrow> all_inums s
    | Some i \<Rightarrow> all_inums s \<union> {i} )"
| "all_inums (Mkdir p f i # s) = (all_inums s \<union> {i})"
| "all_inums (CreateSock p af st fd i # s) = (all_inums s \<union> {i})"
| "all_inums (Accept p fd addr lport fd' i # s) = (all_inums s \<union> {i})"
| "all_inums (_ # s) = all_inums s"

fun all_fds :: "t_state \<Rightarrow> t_process \<Rightarrow> t_fd set"
where
  "all_fds [] = init_fds_of_proc"
| "all_fds (Open p f flags fd ipt # s) = (all_fds s) (p := all_fds s p \<union> {fd})"
| "all_fds (CreateSock p sf st fd i # s) = (all_fds s) (p := all_fds s p \<union> {fd})"
| "all_fds (Accept p fd' raddr port fd i # s) = (all_fds s) (p := all_fds s p \<union> {fd})"
| "all_fds (Clone p p' fds # s) = (all_fds s) (p' := fds)"
| "all_fds (_ # s) = all_fds s"

fun all_msgqs:: "t_state \<Rightarrow> t_msgq set"
where
  "all_msgqs [] = {}"
| "all_msgqs (CreateMsgq p q # s) = all_msgqs s \<union> {q}"
| "all_msgqs (e # s) = all_msgqs s"

fun all_msgs:: "t_state \<Rightarrow> t_msgq \<Rightarrow> t_msg set"
where
  "all_msgs [] q = {}"
| "all_msgs (CreateMsgq p q # s) q' = (if q' = q then {} else all_msgs s q')"
| "all_msgs (SendMsg p q m # s) q' = (if q' = q then all_msgs s q \<union> {m} else all_msgs s q')"
| "all_msgs (_ # s) q' = all_msgs s q'"

fun all_files:: "t_state \<Rightarrow> t_file set"
where
  "all_files [] = init_files "
| "all_files (Open p f flags fd opt # s) = (if opt = None then all_files s else (all_files s \<union> {f}))"
| "all_files (Mkdir p f inum # s) = all_files s \<union> {f}"
| "all_files (LinkHard p f f' # s) = all_files s \<union> {f'}"
| "all_files (e # s) = all_files s"

(*
fun notin_all:: "t_state \<Rightarrow> t_enrich_obj \<Rightarrow> bool"
where
  "notin_all s (E_proc p)  = (p \<notin> all_procs s)"
| "notin_all s (E_file f)  = (f \<notin> all_files s \<and> (\<exists> pf. parent f = Some pf \<and> is_dir s pf))"
| "notin_all s (E_fd p fd) = (fd \<notin> all_fds s p)"
| "notin_all s (E_inum i)  = (i \<notin> all_inums s)"
| "notin_all s (E_msgq q)  = (q \<notin> all_msgqs s)"
| "notin_all s (E_msg q m) = (m \<notin> all_msgs s q)"
*)

fun nums_of_recvmsg:: "t_state \<Rightarrow> t_process \<Rightarrow> nat"
where
  "nums_of_recvmsg [] p' = 0"
| "nums_of_recvmsg (RecvMsg p q m # s) p' = 
     (if p' = p then Suc (nums_of_recvmsg s p) else nums_of_recvmsg s p')"
| "nums_of_recvmsg (e # s) p' = nums_of_recvmsg s p'"

lemma nums_of_recv_0:
  "\<lbrakk>p \<notin> current_procs s; no_del_event s; valid s\<rbrakk> \<Longrightarrow> nums_of_recvmsg s p = 0"
apply (induct s, simp)
apply (frule vt_grant_os, frule vd_cons, case_tac a)
apply (auto)
done

lemma new_msgq_1:
  "\<lbrakk>new_msgq s \<le> q; q \<le> new_msgq s - Suc 0\<rbrakk> \<Longrightarrow> False"
apply (subgoal_tac "new_msgq s \<noteq> 0")
apply (simp, simp add:new_msgq_def next_nat_def)
done

fun notin_cur:: "t_state \<Rightarrow> t_enrich_obj \<Rightarrow> bool"
where
  "notin_cur s (E_proc p qmin qmax)  = 
    (p \<notin> current_procs s \<and> qmin = new_msgq s \<and> qmax = new_msgq s + (nums_of_recvmsg s p) - 1)"
| "notin_cur s (E_file f inum)  = 
    (f \<notin> current_files s \<and> (\<exists> pf. parent f = Some pf \<and> is_dir s pf) \<and> inum \<notin> current_inode_nums s)"
| "notin_cur s (E_file_link f)  = 
    (f \<notin> current_files s \<and> (\<exists> pf. parent f = Some pf \<and> is_dir s pf))"
| "notin_cur s (E_msgq q)  = (q \<notin> current_msgqs s)"

lemma not_all_procs_cons:
  "p \<notin> all_procs (e # s) \<Longrightarrow> p \<notin> all_procs s"
by (case_tac e, auto)

lemma not_all_procs_prop:
  "\<lbrakk>p' \<notin> all_procs s; p \<in> current_procs s; valid s\<rbrakk> \<Longrightarrow> p' \<noteq> p"
apply (induct s, rule notI, simp)
apply (frule vt_grant_os, frule vd_cons, frule not_all_procs_cons, simp, rule notI)
apply (case_tac a, auto)
done

lemma not_all_procs_prop2:
  "p' \<notin> all_procs s \<Longrightarrow> p' \<notin> init_procs"
apply (induct s, simp)
by (case_tac a, auto)

lemma not_all_procs_prop3:
  "p' \<notin> all_procs s \<Longrightarrow> p' \<notin> current_procs s"
apply (induct s, simp)
by (case_tac a, auto)

lemma not_all_msgqs_cons:
  "p \<notin> all_msgqs (e # s) \<Longrightarrow> p \<notin> all_msgqs s"
by (case_tac e, auto)

lemma not_all_msgqs_prop:
  "\<lbrakk>p' \<notin> all_msgqs s; p \<in> current_msgqs s; valid s\<rbrakk> \<Longrightarrow> p' \<noteq> p"
apply (induct s, rule notI, simp)
apply (frule vt_grant_os, frule vd_cons, frule not_all_msgqs_cons, simp, rule notI)
apply (case_tac a, auto)
done

lemma not_all_msgqs_prop3:
  "p' \<notin> all_msgqs s \<Longrightarrow> p' \<notin> current_msgqs s"
apply (induct s, simp)
by (case_tac a, auto)
  
fun enrich_not_alive :: "t_state \<Rightarrow> t_enrich_obj \<Rightarrow> t_index_obj \<Rightarrow> bool"
where
  "enrich_not_alive s obj (I_file f)  = 
  (f \<notin> current_files s \<and> (\<forall> inum. obj \<noteq> E_file f inum) \<and> obj \<noteq> E_file_link f)"
| "enrich_not_alive s obj (I_proc p)  = (p \<notin> current_procs s \<and> (\<forall> qmin qmax. obj \<noteq> E_proc p qmin qmax))"
| "enrich_not_alive s obj (I_fd p fd) = 
  ((p \<in> current_procs s \<longrightarrow> fd \<notin> current_proc_fds s p) \<and> (\<forall> qmin qmax. obj \<noteq> E_proc p qmin qmax))"
| "enrich_not_alive s obj (I_msgq q)  = (q \<notin> current_msgqs s \<and> obj \<noteq> E_msgq q \<and> 
     (case obj of
        E_proc p qmin qmax \<Rightarrow> \<not> (q \<ge> qmin \<and> q \<le> qmax)
      | _        \<Rightarrow> True) )"
| "enrich_not_alive s obj (I_inum i)  = (i \<notin> current_inode_nums s \<and> (\<forall> f. obj \<noteq> E_file f i))"
| "enrich_not_alive s obj (I_msg q m) = 
  ((q \<in> current_msgqs s \<longrightarrow> m \<notin> set (msgs_of_queue s q)) \<and> obj \<noteq> E_msgq q \<and>
     (case obj of
        E_proc p qmin qmax \<Rightarrow> \<not> (q \<ge> qmin \<and> q \<le> qmax)
      | _        \<Rightarrow> True) )"

lemma file_has_parent: "\<lbrakk>is_file s f; valid s\<rbrakk> \<Longrightarrow> \<exists> pf. is_dir s pf \<and> parent f = Some pf"
apply (case_tac f)
apply (simp, drule root_is_dir', simp+)
apply (simp add:parentf_is_dir_prop2)
done

lemma enrich_search_check:
  assumes grant: "search_check s (up, rp, tp) f"
  and cf2sf: "\<forall> f. f \<in> current_files s \<longrightarrow> cf2sfile s' f = cf2sfile s f"
  and vd: "valid s" and f_in: "is_file s f"  and f_in': "is_file s' f"
  and sec: "sectxt_of_obj s' (O_file f) = sectxt_of_obj s (O_file f)"
  shows "search_check s' (up, rp, tp) f"
proof (cases f)
  case Nil
  with f_in vd have "False" 
    by (auto dest:root_is_dir') 
  thus ?thesis by simp
next
  case (Cons n pf)
  from vd f_in obtain sf where sf: "cf2sfile s f = Some sf"
    apply (drule_tac is_file_in_current, drule_tac current_file_has_sfile, simp)
    apply (erule exE, simp)
    done
  then obtain psfs where psfs: "get_parentfs_ctxts s pf = Some psfs" using Cons
    by (auto simp:cf2sfile_def split:option.splits if_splits)
  from sf cf2sf f_in have sf': "cf2sfile s' f = Some sf" by (auto dest:is_file_in_current)
  then obtain psfs' where psfs': "get_parentfs_ctxts s' pf = Some psfs'"using Cons
    by (auto simp:cf2sfile_def split:option.splits if_splits)
  with sf sf' psfs have psfs_eq: "set psfs' = set psfs" using Cons f_in f_in'
    apply (simp add:cf2sfile_def split:option.splits)
    apply (case_tac sf, simp)
    done
  show ?thesis using grant f_in f_in' psfs psfs' psfs_eq sec
    apply (simp add:Cons split:option.splits)
    by (case_tac a, simp)
qed

lemma enrich_search_check':
  assumes grant: "search_check s (up, rp, tp) f"
  and cf2sf: "\<forall> f. f \<in> current_files s \<longrightarrow> cf2sfile s' f = cf2sfile s f"
  and vd: "valid s" and vd': "valid s'" and f_in: "is_dir s f"  and f_in': "is_dir s' f"
  and sec: "sectxt_of_obj s' (O_dir f) = sectxt_of_obj s (O_dir f)"
  shows "search_check s' (up, rp, tp) f"
proof (cases f)
  case Nil
  have "sectxt_of_obj s' (O_dir []) = sectxt_of_obj s (O_dir [])"
    using cf2sf 
    apply (erule_tac x = "[]" in allE)
    by (auto simp:cf2sfile_def root_sec_remains vd vd')
  thus ?thesis using grant Nil 
    by auto
next
  case (Cons n pf)
  from vd f_in obtain sf where sf: "cf2sfile s f = Some sf"
    apply (drule_tac is_dir_in_current, drule_tac current_file_has_sfile, simp)
    apply (erule exE, simp)
    done
  then obtain psfs where psfs: "get_parentfs_ctxts s pf = Some psfs" using Cons
    by (auto simp:cf2sfile_def split:option.splits if_splits)
  from sf cf2sf f_in have sf': "cf2sfile s' f = Some sf" by (auto dest:is_dir_in_current)
  then obtain psfs' where psfs': "get_parentfs_ctxts s' pf = Some psfs'"using Cons
    by (auto simp:cf2sfile_def split:option.splits if_splits)
  with sf sf' psfs have psfs_eq: "set psfs' = set psfs" using Cons f_in f_in'
    apply (drule_tac is_dir_not_file)
    apply (drule is_dir_not_file)    
    apply (simp add:cf2sfile_def split:option.splits)
    apply (case_tac sf, simp)
    done
  show ?thesis using grant f_in f_in' psfs psfs' psfs_eq sec
    apply (drule_tac is_dir_not_file)
    apply (drule_tac is_dir_not_file)
    apply (simp add:Cons split:option.splits)
    by (case_tac a, simp)
qed

lemma proc_filefd_has_sfd: "\<lbrakk>fd \<in> proc_file_fds s p; valid s\<rbrakk> \<Longrightarrow> \<exists> sfd. cfd2sfd s p fd = Some sfd"
apply (simp add:proc_file_fds_def)
apply (auto dest: current_filefd_has_sfd)
done

lemma enrich_inherit_fds_check:
  assumes grant: "inherit_fds_check s (up, nr, nt) p fds"  and vd: "valid s"
  and cfd2sfd: "\<forall> p fd. fd \<in> proc_file_fds s p\<longrightarrow> cfd2sfd s' p fd = cfd2sfd s p fd"
  and fd_in: "fds \<subseteq> proc_file_fds s p" and fd_in': "fds \<subseteq> proc_file_fds s' p"
  shows "inherit_fds_check s' (up, nr, nt) p fds"
proof-
  have "\<And> fd. fd \<in> fds \<Longrightarrow> sectxt_of_obj s' (O_fd p fd) = sectxt_of_obj s (O_fd p fd)"
  proof-
    fix fd
    assume fd_in_fds: "fd \<in> fds"
    hence fd_in_cfds: "fd \<in> proc_file_fds s p" 
      and fd_in_cfds': "fd \<in> proc_file_fds s' p" 
      using fd_in fd_in' by auto
    with cfd2sfd
    have cfd_eq: "cfd2sfd s' p fd = cfd2sfd s p fd" by auto
    from fd_in_cfds obtain f where ffd: "file_of_proc_fd s p fd = Some f"
      by (auto simp:proc_file_fds_def)
    moreover have "flags_of_proc_fd s p fd \<noteq> None"
      using ffd vd by (auto dest:current_filefd_has_flags)
    moreover have "sectxt_of_obj s (O_fd p fd) \<noteq> None"
      using fd_in_cfds vd
      apply (rule_tac notI)
      by (auto dest!:current_has_sec' file_fds_subset_pfds[where p = p] intro:vd)
    moreover have "cf2sfile s f \<noteq> None"
      apply (rule notI)
      apply (drule current_file_has_sfile')
      using ffd
      by (auto simp:vd is_file_in_current dest:file_of_pfd_is_file)
    ultimately show "sectxt_of_obj s' (O_fd p fd) = sectxt_of_obj s (O_fd p fd)"
      using cfd_eq
      by (auto simp:cfd2sfd_def split:option.splits)
  qed
  hence "sectxts_of_fds s' p fds = sectxts_of_fds s p fds"
    by (simp add:sectxts_of_fds_def)
  thus ?thesis using grant
    by (simp add:inherit_fds_check_def)
qed


lemma enrich_inherit_fds_check_dup:
  assumes grant: "inherit_fds_check s (up, nr, nt) p fds"  and vd: "valid s"
  and cfd2sfd: "\<forall> fd. fd \<in> proc_file_fds s p \<longrightarrow> cfd2sfd s' p' fd = cfd2sfd s p fd"
  and fd_in: "fds' \<subseteq> fds \<inter> proc_file_fds s p" 
  shows "inherit_fds_check s' (up, nr, nt) p' fds'"
proof- 
  have "sectxts_of_fds s' p' fds' \<subseteq> sectxts_of_fds s p fds"
  proof-
    have "\<And> fd sfd. \<lbrakk>fd \<in> fds'; sectxt_of_obj s' (O_fd p' fd) = Some sfd\<rbrakk> 
                     \<Longrightarrow> \<exists> fd \<in> fds. sectxt_of_obj s (O_fd p fd) = Some sfd"
    proof-
      fix fd sfd
      assume fd_in_fds': "fd \<in> fds'"
        and sec: "sectxt_of_obj s' (O_fd p' fd) = Some sfd"
      from fd_in_fds' fd_in
      have fd_in_fds: "fd \<in> fds" and fd_in_cfds: "fd \<in> proc_file_fds s p" 
        by auto
      from fd_in_cfds obtain f where ffd: "file_of_proc_fd s p fd = Some f"
        by (auto simp:proc_file_fds_def)
      moreover have "flags_of_proc_fd s p fd \<noteq> None"
        using ffd vd by (auto dest:current_filefd_has_flags)
      moreover have "cf2sfile s f \<noteq> None"
        apply (rule notI)
        apply (drule current_file_has_sfile')
        using ffd
        by (auto simp:vd is_file_in_current dest:file_of_pfd_is_file)
      moreover have "sectxt_of_obj s (O_fd p fd) \<noteq> None"
        using fd_in_cfds vd
        apply (rule_tac notI)
        by (auto dest!:current_has_sec' file_fds_subset_pfds[where p = p] intro:vd)
      ultimately 
      have "sectxt_of_obj s (O_fd p fd) = Some sfd"
        using fd_in_cfds cfd2sfd sec
        apply (erule_tac x = fd in allE)
        apply (auto simp:cfd2sfd_def split:option.splits)
        done
      thus "\<exists> fd \<in> fds. sectxt_of_obj s (O_fd p fd) = Some sfd"
        using fd_in_fds
        by (rule_tac x = fd in bexI, auto)
    qed
    thus ?thesis by (auto simp:sectxts_of_fds_def)
  qed
  thus ?thesis using grant
    by (auto simp:inherit_fds_check_def inherit_fds_check_ctxt_def)
qed


lemma enrich_valid_intro_cons:
  assumes vs': "valid s'" and vd': "valid (e # s)"
    and alive: "\<forall> obj. alive s obj \<longrightarrow> alive s' obj"
    and alive': "\<forall> obj. enrich_not_alive s obj' obj \<longrightarrow> enrich_not_alive s' obj' obj"
    and hungs: "files_hung_by_del s' = files_hung_by_del s"
    and cp2sp: "\<forall> p. p \<in> current_procs s \<longrightarrow> cp2sproc s' p = cp2sproc s p"
    and cf2sf: "\<forall> f. f \<in> current_files s \<longrightarrow> cf2sfile s' f = cf2sfile s f"
    and cq2sq: "\<forall> q. q \<in> current_msgqs s \<longrightarrow> cq2smsgq s' q = cq2smsgq s q"
    and ffd_remain: "\<forall> p fd f. file_of_proc_fd s p fd = Some f \<longrightarrow> file_of_proc_fd s' p fd = Some f"
    and fflags_remain: "\<forall> p fd flags. flags_of_proc_fd s p fd = Some flags \<longrightarrow> flags_of_proc_fd s' p fd = Some flags"
    and sms_remain: "\<forall> q. q \<in> current_msgqs s \<longrightarrow> msgs_of_queue s' q = msgs_of_queue s q"
   (* and empty_remain: "\<forall> f. dir_is_empty s f \<longrightarrow> dir_is_empty s' f" *)
    and cfd2sfd: "\<forall> p fd. fd \<in> proc_file_fds s p \<longrightarrow> cfd2sfd s' p fd = cfd2sfd s p fd"
    and nodel: "no_del_event (e # s)"
    and notin_cur: "notin_cur (e # s) obj'"
  shows "valid (e # s')"
proof-
  from vd' have os: "os_grant s e" and grant: "grant s e" and vd: "valid s"
    by (auto dest:vt_grant_os vt_grant vd_cons)
  show ?thesis
  proof (cases e)
    case (Execve p f fds)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:Execve)
    have f_in: "is_file s' f" using os alive
      apply (erule_tac x = "O_file f" in allE)
      by (auto simp:Execve)
    have fd_in: "fds \<subseteq> proc_file_fds s' p" using os alive ffd_remain
      by (auto simp:Execve proc_file_fds_def)
    have "os_grant s' e" using p_in f_in fd_in by (simp add:Execve)
    moreover have "grant s' e"
    proof-
      from grant obtain up rp tp uf rf tf 
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_file f) = Some (uf, rf, tf)" 
        by (simp add:Execve split:option.splits, blast)
      with grant obtain pu nr nt where p3: "npctxt_execve (up, rp, tp) (uf, rf, tf) = Some (pu, nr, nt)"
        by (simp add:Execve split:option.splits del:npctxt_execve.simps, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:Execve co2sobj.simps cp2sproc_def split:option.splits)
      from os have f_in': "is_file s f" by (simp add:Execve)
      from vd os have "\<exists> sf. cf2sfile s f = Some sf"
        by (auto dest!:is_file_in_current current_file_has_sfile simp:Execve)
      hence p2': "sectxt_of_obj s' (O_file f) = Some (uf, rf, tf)" using f_in f_in' p2 cf2sf
        apply (erule_tac x = f in allE)
        apply (auto dest:is_file_in_current simp:cf2sfile_def split:option.splits)
        apply (case_tac f, simp)
        apply (drule_tac s = s in root_is_dir', simp add:vd, simp+)
        done
      have "inherit_fds_check s' (pu, nr, nt) p fds"
      proof-
        have "fds \<subseteq> proc_file_fds s' p" using os ffd_remain Execve
          by (auto simp:proc_file_fds_def)
        thus ?thesis using Execve grant vd cfd2sfd p1 p2 p3 os
          apply (rule_tac s = s in enrich_inherit_fds_check)
          by (simp_all split:option.splits)
      qed
      moreover have "search_check s' (pu, rp, tp) f"
        using p1 p2 p2' vd cf2sf f_in' grant Execve p3 f_in
        apply (rule_tac s = s in enrich_search_check)
        by (simp_all split:option.splits)
      ultimately show ?thesis using p1' p2' p3
        apply (simp add:Execve split:option.splits) 
        using grant Execve p1 p2
        by (simp add:Execve grant p1 p2)
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (Clone p p' fds)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:Clone)
    have p'_not_in: "p' \<notin> current_procs s'" using  alive' notin_cur os Clone
      apply (erule_tac x = "I_proc p'" in allE)
      apply (auto dest:not_all_procs_prop3 simp del:nums_of_recvmsg.simps)
      done
    have fd_in: "fds \<subseteq> proc_file_fds s' p" using os alive ffd_remain
      by (auto simp:Clone proc_file_fds_def)
    have "os_grant s' e" using p_in p'_not_in fd_in by (simp add:Clone)
    moreover have "grant s' e" 
    proof-
      from grant obtain up rp tp 
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        apply (simp add:Clone split:option.splits)
        by (case_tac a, auto)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:Clone co2sobj.simps cp2sproc_def split:option.splits)
      have p2: "inherit_fds_check s' (up, rp, tp) p fds"
      proof-
        have "fds \<subseteq> proc_file_fds s' p" using os ffd_remain Clone
          by (auto simp:proc_file_fds_def)
        thus ?thesis using Clone grant vd cfd2sfd p1 os
          apply (rule_tac s = s in enrich_inherit_fds_check)
          by (simp_all split:option.splits)
      qed
      show ?thesis using p1 p2 p1' grant
        by (simp add:Clone)
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (Kill p p')
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:Kill)
    have p'_in: "p' \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p'" in allE)
      by (auto simp:Kill)
    have "os_grant s' e" using p_in p'_in by (simp add:Kill)
    moreover have "grant s' e" 
    proof-
      from grant obtain up rp tp up' rp' tp'
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p'1: "sectxt_of_obj s (O_proc p') = Some (up', rp', tp')"
        apply (simp add:Kill split:option.splits)
        by (case_tac a, case_tac aa, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:Kill co2sobj.simps cp2sproc_def split:option.splits)
      from p'1 have p'1': "sectxt_of_obj s' (O_proc p') = Some (up', rp', tp')"
        using os cp2sp
        apply (erule_tac x = p' in allE)
        by (auto simp:Kill co2sobj.simps cp2sproc_def split:option.splits)
      show ?thesis using p1 p'1 p1' p'1' grant
        by (simp add:Kill)
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (Ptrace p p')
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:Ptrace)
    have p'_in: "p' \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p'" in allE)
      by (auto simp:Ptrace)
    have "os_grant s' e" using p_in p'_in by (simp add:Ptrace)
    moreover have "grant s' e" 
    proof-
      from grant obtain up rp tp up' rp' tp'
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p'1: "sectxt_of_obj s (O_proc p') = Some (up', rp', tp')"
        apply (simp add:Ptrace split:option.splits)
        by (case_tac a, case_tac aa, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:Ptrace co2sobj.simps cp2sproc_def split:option.splits)
      from p'1 have p'1': "sectxt_of_obj s' (O_proc p') = Some (up', rp', tp')"
        using os cp2sp
        apply (erule_tac x = p' in allE)
        by (auto simp:Ptrace co2sobj.simps cp2sproc_def split:option.splits)
      show ?thesis using p1 p'1 p1' p'1' grant
        by (simp add:Ptrace)
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (Exit p)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:Exit)
    have "os_grant s' e" using p_in by (simp add:Exit)
    moreover have "grant s' e" 
      by (simp add:Exit)
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (Open p f flags fd opt)
    show ?thesis
    proof (cases opt)
      case None
      have p_in: "p \<in> current_procs s'" using os alive
        apply (erule_tac x = "O_proc p" in allE)
        by (auto simp:Open None)
      have f_in: "is_file s' f" using os alive
        apply (erule_tac x = "O_file f" in allE)
        by (auto simp:Open None)
      have fd_not_in: "fd \<notin> current_proc_fds s' p"
        using os alive' p_in notin_cur Open None
        apply (erule_tac x = "I_fd p fd" in allE)
        apply (case_tac obj')
        apply (auto dest:not_all_procs_prop3)
        done
      have "os_grant s' e" using p_in f_in fd_not_in os
        by (simp add:Open None)
      moreover have "grant s' e" 
      proof-
        from grant obtain up rp tp uf rf tf 
          where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
          and p2: "sectxt_of_obj s (O_file f) = Some (uf, rf, tf)" 
          apply (simp add:Open None split:option.splits)
          by (case_tac a, case_tac aa, blast)
        from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
          using os cp2sp
          apply (erule_tac x = p in allE)
          by (auto simp:Open None co2sobj.simps cp2sproc_def split:option.splits)
        from os have f_in': "is_file s f" by (simp add:Open None)
        from vd os have "\<exists> sf. cf2sfile s f = Some sf"
          by (auto dest!:is_file_in_current current_file_has_sfile simp:Open None)
        hence p2': "sectxt_of_obj s' (O_file f) = Some (uf, rf, tf)" using f_in f_in' p2 cf2sf
          apply (erule_tac x = f in allE)
          apply (auto dest:is_file_in_current simp:cf2sfile_def split:option.splits)
          apply (case_tac f, simp)
          apply (drule_tac s = s in root_is_dir', simp add:vd, simp+)
          done
        have "search_check s' (up, rp, tp) f"
          using p1 p2 p2' vd cf2sf f_in' grant Open None f_in
          apply (rule_tac s = s in enrich_search_check)
          by (simp_all split:option.splits)
        thus ?thesis using p1' p2' 
          apply (simp add:Open None split:option.splits) 
          using grant Open None p1 p2 
          by simp
      qed
      ultimately show ?thesis using vs'
        by (erule_tac valid.intros(2), simp+)
    next
      case (Some inum)
      from os obtain pf where pf_in_s: "is_dir s pf" and parent: "parent f = Some pf"
        by (auto simp:Open Some)
      have pf_in: "is_dir s' pf" using pf_in_s alive
        apply (erule_tac x = "O_dir pf" in allE)
        by simp
      have p_in: "p \<in> current_procs s'" using os alive
        apply (erule_tac x = "O_proc p" in allE)
        by (auto simp:Open Some)
      have f_not_in: "f \<notin> current_files s'" using os alive' Open Some notin_cur nodel
        apply (erule_tac x = "I_file f" in allE)
        by (case_tac obj', auto simp:current_files_simps)
      have fd_not_in: "fd \<notin> current_proc_fds s' p"
        using os alive' p_in Open Some notin_cur
        apply (erule_tac x = "I_fd p fd" in allE)
        apply (case_tac obj', auto dest:not_all_procs_prop3)
        done
      have inum_not_in: "inum \<notin> current_inode_nums s'"
        using os alive' Open Some notin_cur nodel
        apply (erule_tac x = "I_inum inum" in allE)
        apply (case_tac obj', auto)
        apply (auto simp add:current_inode_nums_def current_file_inums_def split:if_splits)
        done
      have "os_grant s' e" using p_in pf_in parent f_not_in fd_not_in inum_not_in os
        by (simp add:Open Some hungs)
      moreover have "grant s' e"  
      proof-
        from grant parent obtain up rp tp uf rf tf 
          where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
          and p2: "sectxt_of_obj s (O_dir pf) = Some (uf, rf, tf)" 
          apply (simp add:Open Some split:option.splits)
          by (case_tac a, case_tac aa, blast)
        from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
          using os cp2sp
          apply (erule_tac x = p in allE)
          by (auto simp:Open Some co2sobj.simps cp2sproc_def split:option.splits)
        from vd os pf_in_s have "\<exists> sf. cf2sfile s pf = Some sf"
          by (auto dest!:is_dir_in_current current_file_has_sfile simp:Open Some)
        hence p2': "sectxt_of_obj s' (O_dir pf) = Some (uf, rf, tf)" using p2 cf2sf pf_in pf_in_s
          apply (erule_tac x = pf in allE)
          apply (erule exE, frule_tac s = s in is_dir_in_current, simp)
          apply (drule is_dir_not_file, drule is_dir_not_file)
          apply (auto simp:cf2sfile_def split:option.splits)
          apply (case_tac pf, simp_all)
          by (simp add:sroot_def root_sec_remains vd vs')
        have "search_check s' (up, rp, tp) pf"
          using p1 p2 p2' vd cf2sf pf_in grant Open Some pf_in_s parent vs'
          apply (rule_tac s = s in enrich_search_check')
          by (simp_all split:option.splits)
        thus ?thesis using p1' p2' parent 
          apply (simp add:Open Some split:option.splits) 
          using grant Open Some p1 p2 
          by simp
      qed
      ultimately show ?thesis using vs'
        by (erule_tac valid.intros(2), simp+)
    qed
  next
    case (ReadFile p fd)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:ReadFile)
    have fd_in: "fd \<in> current_proc_fds s' p" using os alive
      apply (erule_tac x = "O_fd p fd" in allE)
      by (auto simp:ReadFile)
    obtain f where ffd: "file_of_proc_fd s p fd = Some f"
      using os ReadFile by auto
    hence f_in_s: "is_file s f" using vd
      by (auto intro:file_of_pfd_is_file)
    obtain flags where fflag: "flags_of_proc_fd s p fd = Some flags"
      using os ReadFile by auto
    have ffd_in: "file_of_proc_fd s' p fd = Some f"
      using ffd_remain ffd by auto
    hence f_in: "is_file s' f" using vs'
      by (auto intro:file_of_pfd_is_file)
    have flags_in: "flags_of_proc_fd s' p fd = Some flags"
      using fflags_remain fflag by auto
    have "os_grant s' e" using p_in fd_in ffd_in flags_in fflag os f_in 
      by (auto simp add:ReadFile is_file_in_current)
    moreover have "grant s' e" 
    proof-
      from grant ffd obtain up rp tp uf rf tf ufd rfd tfd
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_file f) = Some (uf, rf, tf)"
        and p3: "sectxt_of_obj s (O_fd p fd) = Some (ufd, rfd, tfd)"
        apply (simp add:ReadFile split:option.splits)
        by (case_tac a, case_tac aa, case_tac ab, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:ReadFile co2sobj.simps cp2sproc_def split:option.splits)
      from vd f_in_s have "\<exists> sf. cf2sfile s f = Some sf"
        by (auto dest!:is_file_in_current current_file_has_sfile)
      hence p2': "sectxt_of_obj s' (O_file f) = Some (uf, rf, tf)" using f_in f_in_s p2 cf2sf
        apply (erule_tac x = f in allE)
        apply (auto dest:is_file_in_current simp:cf2sfile_def split:option.splits)
        apply (case_tac f, simp)
        apply (drule_tac s = s in root_is_dir', simp add:vd, simp+)
        done
      have p3': "sectxt_of_obj s' (O_fd p fd) = Some (ufd, rfd, tfd)" 
        using cfd2sfd ffd_in ffd p3 f_in f_in_s vd
        apply (erule_tac x = p in allE)
        apply (erule_tac x = fd in allE)
        apply (simp add:proc_file_fds_def)
        apply (auto simp:cfd2sfd_def fflag flags_in p3 split:option.splits
          dest!:current_file_has_sfile' simp:is_file_in_current)
        done
      show ?thesis using p1' p2' p3' ffd_in ffd
        apply (simp add:ReadFile split:option.splits) 
        using grant p1 p2 p3 ReadFile
        by simp
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (WriteFile p fd)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:WriteFile)
    have fd_in: "fd \<in> current_proc_fds s' p" using os alive
      apply (erule_tac x = "O_fd p fd" in allE)
      by (auto simp:WriteFile)
    obtain f where ffd: "file_of_proc_fd s p fd = Some f"
      using os WriteFile by auto
    hence f_in_s: "is_file s f" using vd
      by (auto intro:file_of_pfd_is_file)
    obtain flags where fflag: "flags_of_proc_fd s p fd = Some flags"
      using os WriteFile by auto
    have ffd_in: "file_of_proc_fd s' p fd = Some f"
      using ffd_remain ffd by auto
    hence f_in: "is_file s' f" using vs'
      by (auto intro:file_of_pfd_is_file)
    have flags_in: "flags_of_proc_fd s' p fd = Some flags"
      using fflags_remain fflag by auto
    have "os_grant s' e" using p_in fd_in ffd_in flags_in fflag os f_in 
      by (auto simp add:WriteFile is_file_in_current)
    moreover have "grant s' e" 
    proof-
      from grant ffd obtain up rp tp uf rf tf ufd rfd tfd
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_file f) = Some (uf, rf, tf)"
        and p3: "sectxt_of_obj s (O_fd p fd) = Some (ufd, rfd, tfd)"
        apply (simp add:WriteFile split:option.splits)
        by (case_tac a, case_tac aa, case_tac ab, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:WriteFile co2sobj.simps cp2sproc_def split:option.splits)
      from vd f_in_s have "\<exists> sf. cf2sfile s f = Some sf"
        by (auto dest!:is_file_in_current current_file_has_sfile)
      hence p2': "sectxt_of_obj s' (O_file f) = Some (uf, rf, tf)" using f_in f_in_s p2 cf2sf
        apply (erule_tac x = f in allE)
        apply (auto dest:is_file_in_current simp:cf2sfile_def split:option.splits)
        apply (case_tac f, simp)
        apply (drule_tac s = s in root_is_dir', simp add:vd, simp+)
        done
      have p3': "sectxt_of_obj s' (O_fd p fd) = Some (ufd, rfd, tfd)" 
        using cfd2sfd ffd_in ffd p3 f_in f_in_s vd
        apply (erule_tac x = p in allE)
        apply (erule_tac x = fd in allE)
        apply (simp add:proc_file_fds_def)
        apply (auto simp:cfd2sfd_def fflag flags_in p3 split:option.splits
          dest!:current_file_has_sfile' simp:is_file_in_current)
        done
      show ?thesis using p1' p2' p3' ffd_in ffd
        apply (simp add:WriteFile split:option.splits) 
        using grant p1 p2 p3 WriteFile
        by simp
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (CloseFd p fd)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:CloseFd)
    have fd_in: "fd \<in> current_proc_fds s' p" using os alive
      apply (erule_tac x = "O_fd p fd" in allE)
      by (auto simp:CloseFd)
    have "os_grant s' e" using p_in fd_in 
      by (auto simp add:CloseFd)
    moreover have "grant s' e" 
      by(simp add:CloseFd)
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (UnLink p f)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:UnLink)
    have f_in: "is_file s' f" using os alive
      apply (erule_tac x = "O_file f" in allE)
      by (auto simp:UnLink)
    from os vd obtain pf where pf_in_s: "is_dir s pf"
      and parent: "parent f = Some pf"
      by (auto simp:UnLink dest!:file_has_parent)
    from pf_in_s alive have pf_in: "is_dir s' pf"
      apply (erule_tac x = "O_dir pf" in allE)
      by (auto simp:UnLink)
    have "os_grant s' e" using p_in f_in os
      by (simp add:UnLink hungs)
    moreover have "grant s' e" 
    proof-    
      from grant parent obtain up rp tp uf rf tf upf rpf tpf
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_file f) = Some (uf, rf, tf)" 
        and p3: "sectxt_of_obj s (O_dir pf) = Some (upf, rpf, tpf)" 
        apply (simp add:UnLink split:option.splits)
        by (case_tac a, case_tac aa, case_tac ab, blast) 
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:UnLink co2sobj.simps cp2sproc_def split:option.splits)
      from vd os pf_in_s have "\<exists> sf. cf2sfile s f = Some sf"
        by (auto dest!:is_file_in_current current_file_has_sfile simp:UnLink)
      hence p2': "sectxt_of_obj s' (O_file f) = Some (uf, rf, tf)" 
        using p2 cf2sf f_in os parent 
        apply (erule_tac x = f in allE)
        apply (erule exE, clarsimp simp:UnLink)
        apply (frule_tac s = s in is_file_in_current, simp)
        by (auto simp:cf2sfile_def split:option.splits)
      from vd os pf_in_s have "\<exists> sf. cf2sfile s pf = Some sf"
        by (auto dest!:is_dir_in_current current_file_has_sfile simp:UnLink)
      hence p3': "sectxt_of_obj s' (O_dir pf) = Some (upf, rpf, tpf)" using p3 cf2sf pf_in pf_in_s
        apply (erule_tac x = pf in allE)
        apply (erule exE, frule_tac s = s in is_dir_in_current, simp)
        apply (drule is_dir_not_file, drule is_dir_not_file)
        apply (auto simp:cf2sfile_def split:option.splits)
        apply (case_tac pf, simp_all)
        by (simp add:sroot_def root_sec_remains vd vs')
      have "search_check s' (up, rp, tp) f"
        using p1 p2 p2' vd cf2sf f_in grant UnLink os parent vs'
        apply (rule_tac s = s in enrich_search_check)
        by (simp_all split:option.splits)
      thus ?thesis using p1' p2' p3' parent 
        apply (simp add:UnLink split:option.splits) 
        using grant UnLink p1 p2 p3
        by simp
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (Rmdir p f)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:Rmdir)
    have f_in: "is_dir s' f" using os alive
      apply (erule_tac x = "O_dir f" in allE)
      by (auto simp:Rmdir dir_is_empty_def)
    have not_root: "f \<noteq> []" using os 
      by (auto simp:Rmdir)
    from os vd obtain pf where pf_in_s: "is_dir s pf"
      and parent: "parent f = Some pf"
      apply (auto simp:Rmdir dir_is_empty_def)
      apply (case_tac f, simp+)
      apply (drule parentf_is_dir_prop1, auto)
      done
    from pf_in_s alive have pf_in: "is_dir s' pf"
      apply (erule_tac x = "O_dir pf" in allE)
      by (auto simp:Rmdir)
    have empty_in: "dir_is_empty s' f" using os Rmdir notin_cur 
      apply (clarsimp simp add:dir_is_empty_def f_in)
      using alive'
      apply (erule_tac x = "I_file f'" in allE)
      apply simp
      apply (erule disjE)
      apply (erule_tac x = f' in allE, simp)
      apply (case_tac obj', simp_all)
      apply (clarsimp)
      apply (drule_tac f' = f in parent_ancen)
      apply (simp, rule notI, simp add:noJ_Anc)
      apply (case_tac "f = pf")
      using vd' Rmdir
      apply (simp_all add:is_dir_rmdir)
      apply (erule_tac x = pf in allE)
      apply (drule_tac f = pf in is_dir_in_current)
      apply (simp add:noJ_Anc)

      apply (clarsimp)
      apply (drule_tac f' = f in parent_ancen)
      apply (simp, rule notI, simp add:noJ_Anc)
      apply (case_tac "f = pf")
      using vd' Rmdir
      apply (simp_all add:is_dir_rmdir)
      apply (erule_tac x = pf in allE)
      apply (drule_tac f = pf in is_dir_in_current)
      apply (simp add:noJ_Anc)
      done
    have "os_grant s' e" using p_in f_in os empty_in
      by (simp add:Rmdir hungs)
    moreover have "grant s' e" 
    proof-
      from grant parent obtain up rp tp uf rf tf upf rpf tpf
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_dir f) = Some (uf, rf, tf)" 
        and p3: "sectxt_of_obj s (O_dir pf) = Some (upf, rpf, tpf)" 
        apply (simp add:Rmdir split:option.splits)
        by (case_tac a, case_tac aa, case_tac ab, blast) 
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:Rmdir co2sobj.simps cp2sproc_def split:option.splits)
      from vd os pf_in_s have "\<exists> sf. cf2sfile s f = Some sf"
        by (auto dest!:is_dir_in_current current_file_has_sfile simp:dir_is_empty_def Rmdir)
      hence p2': "sectxt_of_obj s' (O_dir f) = Some (uf, rf, tf)" 
        using p2 cf2sf f_in os parent 
        apply (erule_tac x = f in allE)
        apply (erule exE, clarsimp simp:Rmdir dir_is_empty_def)
        apply (frule_tac s = s in is_dir_in_current, simp)
        apply (drule is_dir_not_file, drule is_dir_not_file)
        by (auto simp:cf2sfile_def split:option.splits)
      from vd os pf_in_s have "\<exists> sf. cf2sfile s pf = Some sf"
        by (auto dest!:is_dir_in_current current_file_has_sfile simp:Rmdir)
      hence p3': "sectxt_of_obj s' (O_dir pf) = Some (upf, rpf, tpf)" using p3 cf2sf pf_in pf_in_s
        apply (erule_tac x = pf in allE)
        apply (erule exE, frule_tac s = s in is_dir_in_current, simp)
        apply (drule is_dir_not_file, drule is_dir_not_file)
        apply (auto simp:cf2sfile_def split:option.splits)
        apply (case_tac pf, simp_all)
        by (simp add:sroot_def root_sec_remains vd vs')
      have "search_check s' (up, rp, tp) f"
        using p1 p2 p2' vd cf2sf f_in grant Rmdir os parent vs'
        apply (rule_tac s = s in enrich_search_check')
        by (simp_all add:dir_is_empty_def split:option.splits)
      thus ?thesis using p1' p2' p3' parent 
        apply (simp add:Rmdir split:option.splits) 
        using grant Rmdir p1 p2 p3
        by simp
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (Mkdir p f inum)
    from os obtain pf where pf_in_s: "is_dir s pf" and parent: "parent f = Some pf"
      by (auto simp:Mkdir)
    have pf_in: "is_dir s' pf" using pf_in_s alive
      apply (erule_tac x = "O_dir pf" in allE)
      by simp
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:Mkdir)
    have f_not_in: "f \<notin> current_files s'"
      using os alive' Mkdir notin_cur
      apply (erule_tac x = "I_file f" in allE)
      by (auto simp:current_files_simps)
    have inum_not_in: "inum \<notin> current_inode_nums s'"
      using os alive' Mkdir notin_cur
      apply (erule_tac x = "I_inum inum" in allE)
      apply (auto simp:current_inode_nums_def current_file_inums_def split:if_splits)
      done
    have "os_grant s' e" using p_in pf_in parent f_not_in os inum_not_in
      by (simp add:Mkdir hungs)
    moreover have "grant s' e"  
    proof-
      from grant parent obtain up rp tp uf rf tf 
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_dir pf) = Some (uf, rf, tf)" 
        apply (simp add:Mkdir split:option.splits)
        by (case_tac a, case_tac aa, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:Mkdir co2sobj.simps cp2sproc_def split:option.splits)
      from vd os pf_in_s have "\<exists> sf. cf2sfile s pf = Some sf"
        by (auto dest!:is_dir_in_current current_file_has_sfile simp:Mkdir)
      hence p2': "sectxt_of_obj s' (O_dir pf) = Some (uf, rf, tf)" using p2 cf2sf pf_in pf_in_s
        apply (erule_tac x = pf in allE)
        apply (erule exE, frule_tac s = s in is_dir_in_current, simp)
        apply (drule is_dir_not_file, drule is_dir_not_file)
        apply (auto simp:cf2sfile_def split:option.splits)
        apply (case_tac pf, simp_all)
        by (simp add:sroot_def root_sec_remains vd vs')
      have "search_check s' (up, rp, tp) pf"
        using p1 p2 p2' vd cf2sf pf_in grant Mkdir pf_in_s parent vs'
        apply (rule_tac s = s in enrich_search_check')
        apply (simp_all split:option.splits)
        done
      thus ?thesis using p1' p2' parent 
        apply (simp add:Mkdir split:option.splits) 
        using grant Mkdir p1 p2 
        apply simp 
        done
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (LinkHard p f f')
    from os obtain pf where pf_in_s: "is_dir s pf" and parent: "parent f' = Some pf"
      by (auto simp:LinkHard)
    have pf_in: "is_dir s' pf" using pf_in_s alive
      apply (erule_tac x = "O_dir pf" in allE)
      by simp
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:LinkHard)
    have f'_not_in: "f' \<notin> current_files s'" 
      using os alive' LinkHard notin_cur vd'
      apply (erule_tac x = "I_file f'" in allE)
      apply (auto simp:LinkHard current_files_simps)
      done
    have f_in: "is_file s' f" using os alive
      apply (erule_tac x = "O_file f" in allE)
      by (auto simp:LinkHard)
    have "os_grant s' e" using p_in pf_in parent os f_in f'_not_in
      by (simp add:LinkHard hungs)
    moreover have "grant s' e"
    proof-
      from grant parent obtain up rp tp uf rf tf upf rpf tpf
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_file f) = Some (uf, rf, tf)" 
        and p3: "sectxt_of_obj s (O_dir pf) = Some (upf, rpf, tpf)" 
        apply (simp add:LinkHard split:option.splits)
        by (case_tac a, case_tac aa, case_tac ab, blast) 
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:LinkHard co2sobj.simps cp2sproc_def split:option.splits)
      from vd os pf_in_s have "\<exists> sf. cf2sfile s f = Some sf"
        by (auto dest!:is_file_in_current current_file_has_sfile simp:LinkHard)
      hence p2': "sectxt_of_obj s' (O_file f) = Some (uf, rf, tf)" 
        using p2 cf2sf f_in os parent 
        apply (erule_tac x = f in allE)
        apply (erule exE, clarsimp simp:LinkHard)
        apply (frule_tac s = s in is_file_in_current, simp)
        apply (auto simp:cf2sfile_def split:option.splits)
        apply (case_tac f, simp)
        by (drule_tac s = s in root_is_dir', simp add:vd, simp+)
      from vd os pf_in_s have "\<exists> sf. cf2sfile s pf = Some sf"
        by (auto dest!:is_dir_in_current current_file_has_sfile simp:LinkHard)
      hence p3': "sectxt_of_obj s' (O_dir pf) = Some (upf, rpf, tpf)" using p3 cf2sf pf_in pf_in_s
        apply (erule_tac x = pf in allE)
        apply (erule exE, frule_tac s = s in is_dir_in_current, simp)
        apply (drule is_dir_not_file, drule is_dir_not_file)
        apply (auto simp:cf2sfile_def split:option.splits)
        apply (case_tac pf, simp_all)
        by (simp add:sroot_def root_sec_remains vd vs')
      have "search_check s' (up, rp, tp) f"
        using p1 p2 p2' vd cf2sf f_in grant LinkHard os parent vs'
        apply (rule_tac s = s in enrich_search_check)
        by (simp_all split:option.splits)
      moreover have "search_check s' (up, rp, tp) pf"
        using p1 p3 p3' vd cf2sf pf_in grant LinkHard os parent vs'
        apply (rule_tac s = s in enrich_search_check')
        apply (simp_all split:option.splits)
        done
      ultimately show ?thesis using p1' p2' p3' parent 
        apply (simp add:LinkHard split:option.splits) 
        using grant LinkHard p1 p2 p3
        apply simp 
        done
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (Truncate p f len)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:Truncate)
    have f_in: "is_file s' f" using os alive
      apply (erule_tac x = "O_file f" in allE)
      by (auto simp:Truncate)
    have "os_grant s' e" using p_in f_in by (simp add:Truncate)
    moreover have "grant s' e"
    proof-
      from grant obtain up rp tp uf rf tf 
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_file f) = Some (uf, rf, tf)" 
        apply (simp add:Truncate split:option.splits)
        by (case_tac a, case_tac aa, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:Truncate co2sobj.simps cp2sproc_def split:option.splits)
      from os have f_in': "is_file s f" by (simp add:Truncate)
      from vd os have "\<exists> sf. cf2sfile s f = Some sf"
        by (auto dest!:is_file_in_current current_file_has_sfile simp:Truncate)
      hence p2': "sectxt_of_obj s' (O_file f) = Some (uf, rf, tf)" using f_in f_in' p2 cf2sf
        apply (erule_tac x = f in allE)
        apply (auto dest:is_file_in_current simp:cf2sfile_def split:option.splits)
        apply (case_tac f, simp)
        apply (drule_tac s = s in root_is_dir', simp add:vd, simp+)
        done
      have "search_check s' (up, rp, tp) f"
        using p1 p2 p2' vd cf2sf f_in' grant Truncate f_in
        apply (rule_tac s = s in enrich_search_check)
        by (simp_all split:option.splits)
      thus ?thesis using p1' p2' 
        apply (simp add:Truncate split:option.splits) 
        using grant Truncate p1 p2
        by (simp add:Truncate grant p1 p2)
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (CreateMsgq p q)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:CreateMsgq)
    have q_not_in: "q \<notin> current_msgqs s'" 
      using os alive' CreateMsgq notin_cur nodel vd
      apply (erule_tac x = "I_msgq q" in allE)
      apply (auto split:t_enrich_obj.splits)
      apply (drule nums_of_recv_0, simp+)
      apply (drule new_msgq_1, simp+)
      done      
    have "os_grant s' e" using p_in q_not_in by (simp add:CreateMsgq)
    moreover have "grant s' e" 
    proof-
      from grant obtain up rp tp 
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        apply (simp add:CreateMsgq split:option.splits)
        by (case_tac a, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:CreateMsgq co2sobj.simps cp2sproc_def split:option.splits)
      show ?thesis using p1' 
        apply (simp add:CreateMsgq split:option.splits) 
        using grant CreateMsgq p1
        by simp
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)
  next
    case (RemoveMsgq p q)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:RemoveMsgq)
    have q_in: "q \<in> current_msgqs s'" using os alive
      apply (erule_tac x = "O_msgq q" in allE)
      by (simp add:RemoveMsgq)
    have "os_grant s' e" using p_in q_in by (simp add:RemoveMsgq)
    moreover have "grant s' e" 
    proof-
      from grant obtain up rp tp uq rq tq
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_msgq q) = Some (uq, rq, tq)"
        apply (simp add:RemoveMsgq split:option.splits)
        by (case_tac a, case_tac aa, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:RemoveMsgq co2sobj.simps cp2sproc_def split:option.splits)
      from p2 have p2': "sectxt_of_obj s' (O_msgq q) = Some (uq, rq, tq)"
        using os cq2sq vd
        apply (erule_tac x = q in allE)
        by (auto simp:RemoveMsgq co2sobj.simps cq2smsgq_def dest!:current_has_sms' split:option.splits)
      show ?thesis using p1' p2' grant p1 p2
        by (simp add:RemoveMsgq)
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)  
  next
    case (SendMsg p q m)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:SendMsg)
    have q_in: "q \<in> current_msgqs s'" using os alive
      apply (erule_tac x = "O_msgq q" in allE)
      by (simp add:SendMsg)
    have m_not_in: "m \<notin> set (msgs_of_queue s' q)" 
      using os alive' notin_cur SendMsg q_in nodel vd
      apply (erule_tac x = "I_msg q m" in allE)
      apply (case_tac obj', auto dest:not_all_msgqs_prop3)
      apply (drule nums_of_recv_0, simp+)
      apply (drule new_msgq_1, simp+)
      done
    have "os_grant s' e" using p_in q_in m_not_in sms_remain os
      by (simp add:SendMsg)
    moreover have "grant s' e" 
    proof-
      from grant obtain up rp tp uq rq tq
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_msgq q) = Some (uq, rq, tq)"
        apply (simp add:SendMsg split:option.splits)
        by (case_tac a, case_tac aa, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:SendMsg co2sobj.simps cp2sproc_def split:option.splits)
      from p2 have p2': "sectxt_of_obj s' (O_msgq q) = Some (uq, rq, tq)"
        using os cq2sq vd
        apply (erule_tac x = q in allE)
        by (auto simp:SendMsg co2sobj.simps cq2smsgq_def dest!:current_has_sms' split:option.splits)
      show ?thesis using p1' p2' grant p1 p2
        by (simp add:SendMsg)
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)  
  next
    case (RecvMsg p q m)
    have p_in: "p \<in> current_procs s'" using os alive
      apply (erule_tac x = "O_proc p" in allE)
      by (auto simp:RecvMsg)
    have q_in: "q \<in> current_msgqs s'" using os alive
      apply (erule_tac x = "O_msgq q" in allE)
      by (simp add:RecvMsg) 
    have m_in: "m = hd (msgs_of_queue s' q)" 
      and sms_not_empty: "msgs_of_queue s' q \<noteq> []"
      using os sms_remain
      by (auto simp:RecvMsg)
    have "os_grant s' e" using p_in q_in m_in sms_not_empty os
      by (simp add:RecvMsg)
    moreover have "grant s' e" 
    proof-
      from grant obtain up rp tp uq rq tq um rm tm
        where p1: "sectxt_of_obj s (O_proc p) = Some (up, rp, tp)"
        and p2: "sectxt_of_obj s (O_msgq q) = Some (uq, rq, tq)"
        and p3: "sectxt_of_obj s (O_msg q m) = Some (um, rm, tm)"
        apply (simp add:RecvMsg split:option.splits)
        by (case_tac a, case_tac aa, case_tac ab, blast)
      from p1 have p1': "sectxt_of_obj s' (O_proc p) = Some (up, rp, tp)"
        using os cp2sp
        apply (erule_tac x = p in allE)
        by (auto simp:RecvMsg co2sobj.simps cp2sproc_def split:option.splits)
      from p2 have p2': "sectxt_of_obj s' (O_msgq q) = Some (uq, rq, tq)"
        using os cq2sq vd
        apply (erule_tac x = q in allE)
        by (auto simp:RecvMsg co2sobj.simps cq2smsgq_def dest!:current_has_sms' split:option.splits)
      from p3 have p3': "sectxt_of_obj s' (O_msg q m) = Some (um, rm, tm)"
        using sms_remain cq2sq vd os p2 p2' p3 
        apply (erule_tac x = q in allE)
        apply (erule_tac x = q in allE)
        apply (clarsimp simp:RecvMsg)
        apply (simp add:cq2smsgq_def split:option.splits if_splits)
        apply (drule current_has_sms', simp, simp)
        apply (case_tac "msgs_of_queue s q", simp)
        apply (simp add:cqm2sms.simps split:option.splits)
        apply (auto simp add:cm2smsg_def split:option.splits if_splits)[1]
        done
      show ?thesis using p1' p2' p3' grant p1 p2 p3
        by (simp add:RecvMsg)
    qed
    ultimately show ?thesis using vs'
      by (erule_tac valid.intros(2), simp+)  
  next
    case (CreateSock p af st fd inum)
    show ?thesis using grant
      by (simp add:CreateSock)
  next
    case (Bind p fd addr)
    show ?thesis using grant
      by (simp add:Bind)
  next
    case (Connect p fd addr)
    show ?thesis using grant
      by (simp add:Connect)
  next
    case (Listen p fd)
    show ?thesis using grant
      by (simp add:Listen)
  next
    case (Accept p fd addr port fd' inum)
    show ?thesis using grant
      by (simp add:Accept)
  next
    case (SendSock p fd)
    show ?thesis using grant
      by (simp add:SendSock)
  next
    case (RecvSock p fd)
    show ?thesis using grant
      by (simp add:RecvSock)
  next
    case (Shutdown p fd how)
    show ?thesis using grant
      by (simp add:Shutdown)
  qed 
qed

lemma current_proc_fds_in_curp:
  "\<lbrakk>fd \<in> current_proc_fds s p; valid s\<rbrakk> \<Longrightarrow> p \<in> current_procs s"
apply (induct s)
apply (simp add:init_fds_of_proc_prop1)
apply (frule vt_grant_os, frule vd_cons)
apply (case_tac a, auto split:if_splits option.splits)
done

lemma get_parentfs_ctxts_prop:
  "\<lbrakk>get_parentfs_ctxts s (a # f) = Some ctxts; sectxt_of_obj s (O_dir f) = Some ctxt; valid s\<rbrakk>
   \<Longrightarrow> ctxt \<in> set (ctxts)"
apply (induct f)
apply (auto split:option.splits)
done

lemma search_check_allp_intro:
  "\<lbrakk>search_check s sp pf; get_parentfs_ctxts s pf = Some ctxts; valid s; is_dir s pf\<rbrakk>
   \<Longrightarrow> search_check_allp sp (set ctxts)"
apply (case_tac pf)
apply (simp split:option.splits if_splits add:search_check_allp_def)
apply (rule ballI)
apply (auto simp:search_check_ctxt_def search_check_dir_def split:if_splits option.splits)
apply (auto simp:search_check_allp_def search_check_file_def)
apply (frule is_dir_not_file, simp)
done

lemma search_check_leveling_f:
  "\<lbrakk>search_check s sp pf; parent f = Some pf; is_file s f; valid s;
    sectxt_of_obj s (O_file f) = Some fctxt; search_check_file sp fctxt\<rbrakk>
   \<Longrightarrow> search_check s sp f"
apply (case_tac f, simp+)
apply (auto split:option.splits simp:search_check_ctxt_def)
apply (frule parentf_is_dir_prop2, simp)
apply (erule get_pfs_secs_prop, simp)
apply (erule_tac search_check_allp_intro, simp_all)
apply (simp add:parentf_is_dir_prop2)
done


lemma current_fflag_in_fds:
  "\<lbrakk>flags_of_proc_fd s p fd = Some flag; valid s\<rbrakk> \<Longrightarrow> fd \<in> current_proc_fds s p"
apply (induct s arbitrary:p)
apply (simp add:flags_of_proc_fd.simps file_of_proc_fd.simps init_oflags_prop2) 
apply (frule vd_cons, frule vt_grant_os, case_tac a)
apply (auto split:if_splits option.splits dest:proc_fd_in_fds)
done

lemma current_fflag_has_ffd:
  "\<lbrakk>flags_of_proc_fd s p fd = Some flag; valid s\<rbrakk> \<Longrightarrow> \<exists> f. file_of_proc_fd s p fd = Some f"
apply (induct s arbitrary:p)
apply (simp add: file_of_proc_fd.simps init_fileflag_valid) 
apply (frule vd_cons, frule vt_grant_os, case_tac a)
apply (auto split:if_splits option.splits dest:proc_fd_in_fds)
done

lemma oflags_check_remove_create: 
  "oflags_check flags sp sf \<Longrightarrow> oflags_check (remove_create_flag flags) sp sf"
apply (case_tac flags)
apply (auto simp:oflags_check_def perms_of_flags_def perm_of_oflag_def split:bool.splits)
done

end

end