x86 validator: Rewrite non-temporal stores into cached memory accesses

src/trusted/validator/validation_cache_test.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 "gtest/gtest.h"
 
 #include <fcntl.h>
 
@@ skipping 31 matching lines @@
 const uint8_t ret[] = { 0xc3 };
 #endif
 
 // Example of an instruction which may get "stubbed out" (replaced with
 // HLTs) if the CPU does not support it.
 const uint8_t sse41[] =
     { 0x66, 0x0f, 0x3a, 0x0e, 0xd0, 0xc0 };  // pblendw $0xc0,%xmm0,%xmm2
 
 const uint8_t sse41_plus_nontemporal[] =
     { 0x66, 0x0f, 0x3a, 0x0e, 0xd0, 0xc0,  // pblendw $0xc0,%xmm0,%xmm2
-      0x0f, 0x18, 0x04, 0x24 };  // prefetchnta (%rsp)
+      // Example of a non-temporal instruction that is rewritten without
+      // being rejected entirely.
+#if NACL_BUILD_SUBARCH == 32
+      0x66, 0x0f, 0xe7, 0x04, 0x24  // movntdq %xmm0,(%esp)
+#else
+      0x66, 0x41, 0x0f, 0xe7, 0x07  // movntdq %xmm0,(%r15)
+#endif
+    };
 
 // Example of a valid JMP to outside the bundle, in a bundle containing an
 // instruction that gets stubbed out.
 const uint8_t sse41_plus_valid_jmp[] =
     { 0x66, 0x0f, 0x3a, 0x0e, 0xd0, 0xc0,  // pblendw $0xc0,%xmm0,%xmm2
       0xeb, 0x19 };  // jmp to a non-bundle-aligned nop in the next bundle
 
 // Example of an invalid JMP to outside the bundle, in a bundle containing
 // an instruction that gets stubbed out.
 const uint8_t sse41_plus_invalid_jmp[] =
@@ skipping 443 matching lines @@
   // One file we know must exist is this executable.
   AN_ARBITRARY_FILE_PATH = argv[0];
   // The IllegalInst test touches the log mutex deep inside the validator.
   // This causes an SEH exception to be thrown on Windows if the mutex is not
   // initialized.
   // http://code.google.com/p/nativeclient/issues/detail?id=1696
   NaClLogModuleInit();
   testing::InitGoogleTest(&argc, argv);
   return RUN_ALL_TESTS();
 }