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

src/trusted/service_runtime/sel_validate_image.c

 /*
  * 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 "native_client/src/include/concurrency_ops.h"
 #include "native_client/src/shared/platform/nacl_log.h"
 #include "native_client/src/shared/utils/types.h"
 #include "native_client/src/trusted/service_runtime/sel_ldr.h"
@@ skipping 55 matching lines @@
   }
   if (nap->validator_stub_out_mode) {
     /* Validation caching is currently incompatible with stubout. */
     metadata = NULL;
     cache = NULL;
     /* In stub out mode, we do two passes.  The second pass acts as a
        sanity check that bad instructions were indeed overwritten with
        allowable HLTs. */
     status = validator->Validate(guest_addr, data, size,
                                  TRUE, /* stub out */
+                                 nap->pnacl_mode,

[Petr Hosek, 2015/07/28 19:05:46]

This will become `nap->pnacl_mode ? DISABLE_UNSUPPORTED : 0`.

[ruiq, 2015/07/28 21:34:56]

Done.

                                  FALSE, /* text is not read-only */
                                  nap->cpu_features,
                                  metadata,
                                  cache);
   }
   if (status == NaClValidationSucceeded) {
     /* Fixed feature CPU mode implies read-only. */
     int readonly_text = nap->fixed_feature_cpu_mode;
     status = validator->Validate(guest_addr, data, size,
                                  FALSE, /* do not stub out */
+                                 nap->pnacl_mode,

[Petr Hosek, 2015/07/28 19:05:46]

ditto

[ruiq, 2015/07/28 21:34:56]

Done.

                                  readonly_text,
                                  nap->cpu_features,
                                  metadata,
                                  cache);
   }
   return NaClValidateStatus(status);
 }
 
 int NaClValidateCodeReplacement(struct NaClApp *nap, uintptr_t guest_addr,
                                 uint8_t *data_old, uint8_t *data_new,
@@ skipping 68 matching lines @@
         NaClLog(LOG_ERROR,
                 "Run sel_ldr in debug mode to ignore validation failure.\n");
         NaClLog(LOG_ERROR,
                 "Run ncval <module-name> for validation error details.\n");
         rcode = LOAD_VALIDATION_FAILED;
       }
     }
   }
   return rcode;
 }