[MIPS] Adding validator for MIPS architecture.

src/trusted/validator_mips/testdata/test_sp_updates.S

+# Copyright 2012 The Native Client Authors.  All rights reserved.
+# Use of this source code is governed by a BSD-style license that can
+# be found in the LICENSE file.
+# Copyright 2012 MIPS Technologies / RT-RK.
+
+#
+# Tests both legal and illegal variations on SP updates.
+#
+
+
+
+.globl _start
+_start:
+.align 4
+.set noreorder
+.set STORE_MASK,$t7
+
+bundle_sp_dest_reg:
+   addiu   $sp, $sp, 64             #error, b/c no mask after
+   and     $sp, $a0, $a1            #error, b/c no mask after
+   mfhi    $sp                      #error, b/c no mask after
+   clo     $sp, $a2                 #error, b/c no mask after
+   ins     $sp, $s3, 2, 10          #error, b/c no mask after
+   lui     $sp, 0x1f                #error, b/c no mask after
+   mfc1    $sp, $f12                #error, b/c no mask after
+   mfhc1   $sp, $f10                #error, b/c no mask after
+   mflo    $sp                      #error, b/c no mask after
+   movn    $sp, $v0, $v1            #error, b/c no mask after
+   movt    $sp, $s4, $fcc4          #error, b/c no mask after
+   mul     $sp, $s0, $s1            #error, b/c no mask after
+
+#modify sp w/ lw;
+bundle_load_into_sp:
+   lw      $sp, 16($a0)             #error, b/c no mask after
+   nop
+   lw      $sp, 16($a0)
+   and     $sp, $sp, STORE_MASK     #error
+
+bundle_mask_doesnt_need_mask:
+#ok
+   nop
+   and     $sp, $sp, STORE_MASK
+   nop
+   nop
+
+# a few instructions where sp is
+# 1st operand, but don't alter it
+
+bundle_sp_not_altered:
+   mthi    $sp                      #ok
+   mult    $sp, $t9                 #ok
+   nop
+   nop
+
+bundle_jalr_sp_t9:
+#this should be allowed, b/c $sp will still be in the untrusted area
+   nop
+   and     $t9, $t9, $t6
+   jalr    $sp, $t9                 #error
+    nop
+
+bundle_chk_delay_slot:
+   b       bundle_chk_cross_1
+    addiu   $sp, $sp, -32           #error
+   and     $sp, $sp, STORE_MASK
+   nop
+
+bundle_chk_cross_1:
+   nop
+   nop
+   nop
+   addiu   $sp, $sp, -32            #ok
+
+bundle_chk_cross_2:
+   and     $sp, $sp, STORE_MASK
+   nop
+   nop
+   nop
+
+bundle_ok:
+   add     $sp, $sp, 64             #ok
+   and     $sp, $sp, STORE_MASK
+   sub     $sp, $sp, 56             #ok
+   and     $sp, $sp, STORE_MASK
+
+end_of_code: