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• Top-level-memory

Rme128

Read an unsigned 128-bit value from memory via an effective address.

Signature

(rme128 proc-mode eff-addr seg-reg r-x check-alignment? x86) 
  → 
(mv flg value x86-new)

Arguments

check-alignment? — Guard (booleanp check-alignment?).

Returns

value — Type (unsigned-byte-p 128 value), given (x86p x86).

x86-new — Type (x86p x86-new), given (x86p x86).

The effective address eff-addr is translated to a canonical linear address using ea-to-la. If this translation is successful and no other errors (like alignment errors) occur, then rml128 is called.

Prior to the effective address translation, we check whether read access is allowed. The only case in which it is not allowed is when a read access is attempted on an execute-only code segment, in 32-bit mode. In 64-bit mode, the R bit of the code segment descriptor is ignored (see Atmel manual, Dec'17, Volume 2, Section 4.8.1).

Definitions and Theorems

Function: rme128$inline

(defun rme128$inline (proc-mode eff-addr
                                seg-reg r-x check-alignment? x86)
 (declare (xargs :stobjs (x86)))
 (declare (type (integer 0 4) proc-mode)
          (type (signed-byte 64) eff-addr)
          (type (integer 0 5) seg-reg)
          (type (member :r :x) r-x))
 (declare (xargs :guard (booleanp check-alignment?)))
 (b*
  (((when
     (and (/= proc-mode 0)
          (= seg-reg 1)
          (eq r-x :r)
          (b* ((attr (loghead 16 (seg-hidden-attri seg-reg x86)))
               (r (code-segment-descriptor-attributesbits->r attr)))
            (= r 0))))
    (mv (list :execute-only-code-segment eff-addr)
        0 x86))
   ((mv flg lin-addr)
    (ea-to-la proc-mode eff-addr seg-reg 16 x86))
   ((when flg) (mv flg 0 x86))
   ((unless (or (not check-alignment?)
                (address-aligned-p lin-addr 16 nil)))
    (mv (list :unaligned-linear-address lin-addr)
        0 x86)))
  (rml128 lin-addr r-x x86)))

Theorem: return-type-of-rme128.value

(defthm return-type-of-rme128.value
  (implies (x86p x86)
           (b* (((mv ?flg acl2::?value ?x86-new)
                 (rme128$inline proc-mode eff-addr
                                seg-reg r-x check-alignment? x86)))
             (unsigned-byte-p 128 value)))
  :rule-classes :rewrite)

Theorem: x86p-of-rme128.x86-new

(defthm x86p-of-rme128.x86-new
  (implies (x86p x86)
           (b* (((mv ?flg acl2::?value ?x86-new)
                 (rme128$inline proc-mode eff-addr
                                seg-reg r-x check-alignment? x86)))
             (x86p x86-new)))
  :rule-classes :rewrite)

Theorem: n128p-of-mv-nth-1-rme128

(defthm n128p-of-mv-nth-1-rme128
 (unsigned-byte-p
      128
      (mv-nth 1
              (rme128 proc-mode eff-addr
                      seg-reg r-x check-alignment? x86)))
 :rule-classes
 (:rewrite
  (:type-prescription
      :corollary
      (natp (mv-nth 1
                    (rme128 proc-mode eff-addr
                            seg-reg r-x check-alignment? x86)))
      :hints
      (("Goal" :in-theory '(unsigned-byte-p integer-range-p natp))))
  (:linear
   :corollary
   (and (<= 0
            (mv-nth 1
                    (rme128 proc-mode eff-addr
                            seg-reg r-x check-alignment? x86)))
        (< (mv-nth 1
                   (rme128 proc-mode eff-addr
                           seg-reg r-x check-alignment? x86))
           340282366920938463463374607431768211456))
   :hints
   (("Goal"
        :in-theory '(unsigned-byte-p integer-range-p (:e expt)))))))

Theorem: rme128-value-when-error

(defthm rme128-value-when-error
  (implies (mv-nth 0
                   (rme128 proc-mode eff-addr
                           seg-reg r-x check-alignment? x86))
           (equal (mv-nth 1
                          (rme128 proc-mode eff-addr
                                  seg-reg r-x check-alignment? x86))
                  0)))

Theorem: rme128-does-not-affect-state-in-app-view

(defthm rme128-does-not-affect-state-in-app-view
  (implies (app-view x86)
           (equal (mv-nth 2
                          (rme128 proc-mode eff-addr
                                  seg-reg r-x check-alignment? x86))
                  x86)))

Theorem: xr-rme128-state-app-view

(defthm xr-rme128-state-app-view
 (implies
      (app-view x86)
      (equal (xr fld index
                 (mv-nth 2
                         (rme128 proc-mode eff-addr
                                 seg-reg r-x check-alignment? x86)))
             (xr fld index x86))))

Theorem: xr-rme128-state-sys-view

(defthm xr-rme128-state-sys-view
 (implies
      (and (not (equal fld :mem))
           (not (equal fld :fault))
           (not (equal fld :tlb)))
      (equal (xr fld index
                 (mv-nth 2
                         (rme128 proc-mode eff-addr
                                 seg-reg r-x check-alignment? x86)))
             (xr fld index x86))))

Theorem: rme128-xw-app-view

(defthm rme128-xw-app-view
 (implies
  (and (app-view x86)
       (not (equal fld :mem))
       (not (equal fld :app-view))
       (not (equal fld :seg-hidden-base))
       (not (equal fld :seg-hidden-limit))
       (not (equal fld :seg-hidden-attr))
       (not (equal fld :seg-visible))
       (not (equal fld :msr)))
  (and (equal (mv-nth 0
                      (rme128 proc-mode
                              eff-addr seg-reg r-x check-alignment?
                              (xw fld index value x86)))
              (mv-nth 0
                      (rme128 proc-mode eff-addr
                              seg-reg r-x check-alignment? x86)))
       (equal (mv-nth 1
                      (rme128 proc-mode
                              eff-addr seg-reg r-x check-alignment?
                              (xw fld index value x86)))
              (mv-nth 1
                      (rme128 proc-mode eff-addr
                              seg-reg r-x check-alignment? x86))))))

Theorem: rme128-xw-sys-view

(defthm rme128-xw-sys-view
 (implies
  (and (not (app-view x86))
       (not (equal fld :fault))
       (not (equal fld :seg-visible))
       (not (equal fld :seg-hidden-base))
       (not (equal fld :seg-hidden-limit))
       (not (equal fld :seg-hidden-attr))
       (not (equal fld :mem))
       (not (equal fld :ctr))
       (not (equal fld :msr))
       (not (equal fld :rflags))
       (not (equal fld :app-view))
       (not (equal fld :tlb))
       (not (equal fld :marking-view))
       (not (equal fld :implicit-supervisor-access))
       (member-equal fld *x86-field-names-as-keywords*))
  (and
    (equal (mv-nth 0
                   (rme128 proc-mode
                           eff-addr seg-reg r-x check-alignment?
                           (xw fld index value x86)))
           (mv-nth 0
                   (rme128 proc-mode eff-addr
                           seg-reg r-x check-alignment? x86)))
    (equal (mv-nth 1
                   (rme128 proc-mode
                           eff-addr seg-reg r-x check-alignment?
                           (xw fld index value x86)))
           (mv-nth 1
                   (rme128 proc-mode eff-addr
                           seg-reg r-x check-alignment? x86)))
    (equal
         (mv-nth 2
                 (rme128 proc-mode
                         eff-addr seg-reg r-x check-alignment?
                         (xw fld index value x86)))
         (xw fld index value
             (mv-nth 2
                     (rme128 proc-mode eff-addr
                             seg-reg r-x check-alignment? x86)))))))

Theorem: rme128-xw-sys-view-rflags-not-ac

(defthm rme128-xw-sys-view-rflags-not-ac
 (implies
  (and (not (app-view x86))
       (equal (rflagsbits->ac value)
              (rflagsbits->ac (rflags x86))))
  (and
    (equal (mv-nth 0
                   (rme128 proc-mode
                           eff-addr seg-reg r-x check-alignment?
                           (xw :rflags nil value x86)))
           (mv-nth 0
                   (rme128 proc-mode eff-addr
                           seg-reg r-x check-alignment? x86)))
    (equal (mv-nth 1
                   (rme128 proc-mode
                           eff-addr seg-reg r-x check-alignment?
                           (xw :rflags nil value x86)))
           (mv-nth 1
                   (rme128 proc-mode eff-addr
                           seg-reg r-x check-alignment? x86)))
    (equal
         (mv-nth 2
                 (rme128 proc-mode
                         eff-addr seg-reg r-x check-alignment?
                         (xw :rflags nil value x86)))
         (xw :rflags nil value
             (mv-nth 2
                     (rme128 proc-mode eff-addr
                             seg-reg r-x check-alignment? x86)))))))

Theorem: rme128-when-64-bit-modep-and-not-fs/gs

(defthm rme128-when-64-bit-modep-and-not-fs/gs
  (implies (and (not (equal seg-reg 4))
                (not (equal seg-reg 5))
                (canonical-address-p eff-addr)
                (or (not check-alignment?)
                    (address-aligned-p eff-addr 16 nil)))
           (equal (rme128 0 eff-addr
                          seg-reg r-x check-alignment? x86)
                  (rml128 eff-addr r-x x86))))

Theorem: rme128-unaligned-when-64-bit-modep-and-not-fs/gs

(defthm rme128-unaligned-when-64-bit-modep-and-not-fs/gs
  (implies (and (not (equal seg-reg 4))
                (not (equal seg-reg 5))
                (not (or (not check-alignment?)
                         (address-aligned-p eff-addr 16 nil)))
                (canonical-address-p eff-addr))
           (equal (rme128 0 eff-addr
                          seg-reg r-x check-alignment? x86)
                  (list (list :unaligned-linear-address eff-addr)
                        0 x86))))

Theorem: rme128-when-64-bit-modep-and-fs/gs

(defthm rme128-when-64-bit-modep-and-fs/gs
 (implies
      (or (equal seg-reg 4) (equal seg-reg 5))
      (equal (rme128 0 eff-addr
                     seg-reg r-x check-alignment? x86)
             (b* (((mv flg lin-addr)
                   (b* (((mv base & &)
                         (segment-base-and-bounds 0 seg-reg x86))
                        (lin-addr (i64 (+ base (n64 eff-addr)))))
                     (if (canonical-address-p lin-addr)
                         (mv nil lin-addr)
                       (mv (list :non-canonical-address lin-addr)
                           0))))
                  ((when flg) (mv flg 0 x86))
                  ((unless (or (not check-alignment?)
                               (address-aligned-p lin-addr 16 nil)))
                   (mv (list :unaligned-linear-address lin-addr)
                       0 x86)))
               (rml128 lin-addr r-x x86)))))