Provide metadata to validator to allow faster caching.

src/trusted/validator_arm/ncvalidate.cc

 /*
  * 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.
  */
 
 #include <climits>
 #include <limits>
 #include <vector>
 
@@ skipping 126 matching lines @@
   return 0;
 }
 
 static NaClValidationStatus ApplyValidatorArm(
     uintptr_t guest_addr,
     uint8_t *data,
     size_t size,
     int stubout_mode,
     int readonly_text,
     const NaClCPUFeatures *cpu_features,
+    const struct NaClValidationMetadata *metadata,
     struct NaClValidationCache *cache) {
   /* The ARM validator is currently unsafe w.r.t. caching. */
+  UNREFERENCED_PARAMETER(metadata);
   UNREFERENCED_PARAMETER(cache);
   CheckAddressAlignAndOverflow((uint8_t *) guest_addr, size);
   CheckAddressOverflow(data, size);
   CheckAddressOverflow(data, size);
 
   if (stubout_mode)
     return NaClValidationFailedNotImplemented;
   if (readonly_text)
     return NaClValidationFailedNotImplemented;
 
@@ skipping 32 matching lines @@
   // so is their mix (single instruction update is atomic).
   // We just have to make sure that unintended fallthrough doesn't
   // happen, and we don't change position of guard instructions.
   // Problem is that code is mapped for execution at different address
   // that one we use here, and ARM usually use virtually indexed caches,
   // so we couldn't invalidate correctly anyway.
   return 0;
 }
 
 EXTERN_C_END