validator_ragel: Link into TCB, use under env var

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/shared/platform/nacl_log.h"
 #include "native_client/src/trusted/service_runtime/sel_ldr.h"
 #include "native_client/src/trusted/validator/ncvalidate.h"
 
 const size_t kMinimumCachedCodeSize = 40000;
 
 /* Translate validation status to values wanted by sel_ldr. */
 static int NaClValidateStatus(NaClValidationStatus status) {
   switch (status) {
     case NaClValidationSucceeded:
       return LOAD_OK;
     case NaClValidationFailedOutOfMemory:
       /* Note: this is confusing, but is what sel_ldr is expecting. */
       return LOAD_BAD_FILE;
     case NaClValidationFailed:
     case NaClValidationFailedNotImplemented:
     case NaClValidationFailedCpuNotSupported:
     case NaClValidationFailedSegmentationIssue:
     default:
       return LOAD_VALIDATION_FAILED;
   }
 }
 
+typedef NaClValidationStatus (*ValidateFunc) (
+    uintptr_t, uint8_t*, size_t, int, int,
+    const NaClCPUFeatures*, struct NaClValidationCache*);
+
+static ValidateFunc NaClSelectValidator(struct NaClApp *nap) {
+  ValidateFunc ret = NACL_SUBARCH_NAME(ApplyValidator,
+                                       NACL_TARGET_ARCH, NACL_TARGET_SUBARCH);
+#ifdef __arm__
+  UNREFERENCED_PARAMETER(nap);
+#else
+  if (nap->enable_dfa_validator) {
+    ret = NACL_SUBARCH_NAME(ApplyDfaValidator,
+                            NACL_TARGET_ARCH, NACL_TARGET_SUBARCH);
+  }
+#endif
+  return ret;
+}
+
 int NaClValidateCode(struct NaClApp *nap, uintptr_t guest_addr,
                      uint8_t *data, size_t size) {
   NaClValidationStatus status = NaClValidationSucceeded;
-
   struct NaClValidationCache *cache = nap->validation_cache;
+  ValidateFunc validate_func = NaClSelectValidator(nap);
 
   if (size < kMinimumCachedCodeSize) {
     /*
      * Don't cache the validation of small code chunks for three reasons:
      * 1) The size of the validation cache will be bounded.  Cache entries are
      *    better used for bigger code.
      * 2) The per-transaction overhead of validation caching is more noticeable
      *    for small code.
      * 3) JITs tend to generate a lot of small code chunks, and JITed code may
      *    never be seen again.  Currently code size is the best mechanism we
@@ skipping 14 matching lines @@
     NaClLog(LOG_FATAL,
             "stub_out_mode and fixed_feature_cpu_mode are incompatible\n");
     return LOAD_VALIDATION_FAILED;
   }
   if (nap->validator_stub_out_mode) {
     /* Validation caching is currently incompatible with stubout. */
     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 = NACL_SUBARCH_NAME(ApplyValidator,
-                               NACL_TARGET_ARCH,
-                               NACL_TARGET_SUBARCH)(
-                                   guest_addr, data, size,
-                                   TRUE, /* stub out */
-                                   FALSE, /* text is not read-only */
-                                   &nap->cpu_features,
-                                   cache);
+    status = validate_func(guest_addr, data, size,
+                           TRUE, /* stub out */
+                           FALSE, /* text is not read-only */
+                           &nap->cpu_features,
+                           cache);
   }
   if (status == NaClValidationSucceeded) {
-    /* Fixed feature CPU mode implies read-only */
+    /* Fixed feature CPU mode implies read-only. */
     int readonly_text = nap->fixed_feature_cpu_mode;
-    status = NACL_SUBARCH_NAME(ApplyValidator,
-                               NACL_TARGET_ARCH,
-                               NACL_TARGET_SUBARCH)(
-                                   guest_addr, data, size,
-                                   FALSE, /* do not stub out */
-                                   readonly_text,
-                                   &nap->cpu_features,
-                                   cache);
+    status = validate_func(guest_addr, data, size,
+                           FALSE, /* do not stub out */
+                           readonly_text,
+                           &nap->cpu_features,
+                           cache);
   }
   return NaClValidateStatus(status);
 }
 
 int NaClValidateCodeReplacement(struct NaClApp *nap, uintptr_t guest_addr,
                                 uint8_t *data_old, uint8_t *data_new,
                                 size_t size) {
   if (nap->validator_stub_out_mode) return LOAD_BAD_FILE;
   if (nap->fixed_feature_cpu_mode) return LOAD_BAD_FILE;
 
@@ skipping 53 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;
 }