[MIPS] Make validator allow only two load patterns via $t8

src/trusted/validator_mips/validator.h

 /*
  * Copyright (c) 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.
  */
 
 #ifndef NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_MIPS_VALIDATOR_H
 #define NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_MIPS_VALIDATOR_H
 
 /*
@@ skipping 256 matching lines @@
   }
 
   bool IsJmpReg() const {
     return decoder_->IsJmpReg();
   }
 
   bool IsLoadStore() const {
     return decoder_->IsLoadStore();
   }
 
+  bool IsLoadWord() const {
+    return decoder_->IsLoadWord();
+  }
+
+  uint32_t GetImm() const {
+    return decoder_->GetImm(inst_);
+  }
+
   bool IsDirectJump() const {
     return decoder_->IsDirectJump();
   }
 
   bool IsDestGprReg(nacl_mips_dec::RegisterList rl) const {
     return rl.ContainsAny(nacl_mips_dec::RegisterList(DestGprReg()));
   }
 
   bool IsDataRegMask() const {
     return IsMask(DestGprReg(), nacl_mips_dec::Register::LoadStoreMask());
@@ skipping 91 matching lines @@
  */
 
 // An instruction is unsafe -- more information in the SafetyLevel.
 const char * const kProblemUnsafe = "kProblemUnsafe";
 // A branch would break a pseudo-operation pattern.
 const char * const kProblemBranchSplitsPattern = "kProblemBranchSplitsPattern";
 // A branch targets an invalid code address (out of segment).
 const char * const kProblemBranchInvalidDest = "kProblemBranchInvalidDest";
 // A load/store uses an unsafe (non-masked) base address.
 const char * const kProblemUnsafeLoadStore = "kProblemUnsafeLoadStore";
+// A thread pointer load/store is unsafe.
+const char * const kProblemUnsafeLoadStoreThreadPointer =
+    "kProblemUnsafeLoadStoreThreadPointer";
 // An instruction updates a data-address register (e.g. SP) without masking.
 const char * const kProblemUnsafeDataWrite = "kProblemUnsafeDataWrite";
 // An instruction updates a read-only register (e.g. t6, t7, t8).
 const char * const kProblemReadOnlyRegister = "kProblemReadOnlyRegister";
 // A pseudo-op pattern crosses a bundle boundary.
 const char * const kProblemPatternCrossesBundle =
     "kProblemPatternCrossesBundle";
 // A linking branch instruction is not in the last bundle slot.
 const char * const kProblemMisalignedCall = "kProblemMisalignedCall";
 // A data register is found in a branch delay slot.
 const char * const kProblemDataRegInDelaySlot = "kProblemDataRegInDelaySlot";
 // A jump to trampoline instruction which is not a start of a bundle.
 const char * const kProblemUnalignedJumpToTrampoline =
     "kProblemUnalignedJumpToTrampoline";
 // A jump register instruction is not guarded.
 const char * const kProblemUnsafeJumpRegister = "kProblemUnsafeJumpRegister";
 // Two consecutive branches/jumps. Branch/jump in the delay slot.
 const char * const kProblemBranchInDelaySlot = "kProblemBranchInDelaySlot";
 }  // namespace nacl_mips_val
 
 #endif  // NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_MIPS_VALIDATOR_H