A mechanism to identify/forbid/"rewrite" non-temporal instructions (and other)

src/trusted/validator/ncvalidate.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_X86_NCVALIDATE_H__
 #define NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_X86_NCVALIDATE_H__
 
 /* Defines the API exposed by the Native Client validators. */
 
 #include "native_client/src/include/build_config.h"
 #include "native_client/src/include/nacl_base.h"
 #include "native_client/src/include/portability.h"
 #include "native_client/src/trusted/cpu_features/cpu_features.h"
 
 
 EXTERN_C_BEGIN
 
 struct NaClValidationCache;
 struct NaClValidationMetadata;
 
+/* Defines possible validation flags. */
+typedef enum NaClValidationFlags {
+  DISABLE_NONTEMPORALS = 0x1,
+  X86_VALIDATION_FLAGS_MASK = 0x1,

[Mark Seaborn, 2015/07/29 16:09:23]

Nit: these should really have a "NACL_" prefix to namespace them

You might also consider reversing the order, i.e.
NACL_VALIDATION_FLAGS_MASK_X86.

+  ARM_VALIDATION_FLAGS_MASK = 0x0,
+  MIPS_VALIDATION_FLAGS_MASK = 0x0
+} NaClValidationFlags;
+
 /* Defines possible validation status values. */
 typedef enum NaClValidationStatus {
   /* The call to the validator succeeded. */
   NaClValidationSucceeded,
   /* The call to the validator failed (Reason unspecified) */
   NaClValidationFailed,
   /* The call to the validator failed, due to not enough memory. */
   NaClValidationFailedOutOfMemory,
   /* The call to the validator failed, due to it not being implemented yet. */
   NaClValidationFailedNotImplemented,
@@ skipping 23 matching lines @@
  *           in sel_ldr or command-line tool).
  *    readonly_text - If code should be considered read-only.
  *    cpu_features - The CPU features to support while validating.
  *    cache - Pointer to NaCl validation cache.
  */
 typedef NaClValidationStatus (*NaClValidateFunc)(
     uintptr_t guest_addr,
     uint8_t *data,
     size_t size,
     int stubout_mode,
+    uint32_t flags,
     int readonly_text,
     const NaClCPUFeatures *cpu_features,
     const struct NaClValidationMetadata *metadata,
     struct NaClValidationCache *cache);
 
 /* Function type to copy an instruction safely. Returns non-zero on success.
  * Implemented by the Service Runtime.
  */
 typedef int (*NaClCopyInstructionFunc)(
     uint8_t *dst,
@@ skipping 127 matching lines @@
                                        NACL_BUILD_ARCH,
                                        NACL_BUILD_SUBARCH)(
     uintptr_t guest_addr,
     uint8_t *data,
     size_t size,
     const NaClCPUFeatures *cpu_features);
 
 EXTERN_C_END
 
 #endif  /*  NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_X86_NCVALIDATE_H__ */