Add validation caching interface.

src/trusted/validator/x86/32/ncvalidate.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.
  */
 
 /* Implement the ApplyValidator API for the x86-32 architecture. */
 
 #include "native_client/src/trusted/validator/ncvalidate.h"
 #include "native_client/src/trusted/validator/x86/ncval_seg_sfi/ncvalidate.h"
 #include "native_client/src/trusted/validator/x86/ncval_seg_sfi/ncvalidate_detailed.h"
+/* TODO(ncbray) is there a better way to access validation stats? */

[Mark Seaborn, 2012/03/01 00:26:20]

You could add a getter function

[Nick Bray (chromium), 2012/03/01 01:25:16]

Done.

+#include "native_client/src/trusted/validator/x86/ncval_seg_sfi/ncvalidate_internaltypes.h"
 #include <assert.h>
 
 /* Be sure the correct compile flags are defined for this. */
 #if NACL_ARCH(NACL_TARGET_ARCH) != NACL_x86
 # error("Can't compile, target is for x86-32")
 #else
 # if NACL_TARGET_SUBARCH != 32
 #  error("Can't compile, target is for x86-32")
 # endif
 #endif
 
 static NaClValidationStatus NCApplyValidatorSilently_x86_32(
     uintptr_t guest_addr,
     uint8_t *data,
     size_t size,
     int bundle_size,
-    NaClCPUFeaturesX86 *cpu_features) {
+    NaClCPUFeaturesX86 *cpu_features,
+    NaClValidationCache *cache) {
   struct NCValidatorState *vstate;
   int validator_result = 0;
 

[Mark Seaborn, 2012/03/01 00:26:20]

remove empty line, keep variables block together?

[Nick Bray (chromium), 2012/03/01 01:25:16]

Done.

+  void *query = NULL;
+
+  if (cache != NULL)
+    query = cache->CreateQuery(cache->context);
+
+  if (query != NULL) {
+    const char validator_id[] = "x86-32";
+    cache->AddData(query, (uint8_t *) validator_id, sizeof(validator_id));
+    cache->AddData(query, (uint8_t *) cpu_features, sizeof(NaClCPUFeaturesX86));

[Mark Seaborn, 2012/03/01 00:26:20]

sizeof(*cpu_features) reduces the risk of skew

[Nick Bray (chromium), 2012/03/01 01:25:16]

Done.

+    cache->AddData(query, data, size);
+    if (cache->DoQuery(query)) {
+      cache->DestroyQuery(query);
+      return NaClValidationSucceeded;
+    }
+  }
+
   vstate = NCValidateInit(guest_addr, size, bundle_size, cpu_features);
-  if (vstate == NULL) return NaClValidationFailedOutOfMemory;
+  if (vstate == NULL) {
+    if (query != NULL)
+      cache->DestroyQuery(query);
+    return NaClValidationFailedOutOfMemory;
+  }
   NCValidateSegment(data, guest_addr, size, vstate);
   validator_result = NCValidateFinish(vstate);
+
+  if (query != NULL) {
+    /* Don't cache the result if the code is modified. */
+    if (validator_result == 0 && vstate->stats.didstubout == 0)
+      cache->SetValidates(query);
+    cache->DestroyQuery(query);
+  }
+
   NCValidateFreeState(&vstate);
   return (validator_result == 0)
       ? NaClValidationSucceeded : NaClValidationFailed;
 }
 
 NaClValidationStatus NCApplyValidatorStubout_x86_32(
     uintptr_t guest_addr,
     uint8_t *data,
     size_t size,
     int bundle_size,
     NaClCPUFeaturesX86 *cpu_features) {
   struct NCValidatorState *vstate;
 
   vstate = NCValidateInitDetailed(guest_addr, size, bundle_size, cpu_features);
   if (vstate == NULL) return NaClValidationFailedOutOfMemory;
   NCValidateSetStubOutMode(vstate, 1);
   NCValidateSegment(data, guest_addr, size, vstate);
   NCValidateFinish(vstate);
   NCValidateFreeState(&vstate);
   return NaClValidationSucceeded;
 }
 
 NaClValidationStatus NACL_SUBARCH_NAME(ApplyValidator, NACL_TARGET_ARCH, 32) (
     enum NaClSBKind sb_kind,
     NaClApplyValidationKind kind,
     uintptr_t guest_addr,
     uint8_t *data,
     size_t size,
     int bundle_size,
-    NaClCPUFeaturesX86 *cpu_features) {
+    NaClCPUFeaturesX86 *cpu_features,
+    NaClValidationCache *cache) {
   NaClValidationStatus status = NaClValidationFailedNotImplemented;
   assert(NACL_SB_DEFAULT == sb_kind);
   if (bundle_size == 16 || bundle_size == 32) {
     if (!NaClArchSupported(cpu_features))
       return NaClValidationFailedCpuNotSupported;
     switch (kind) {
       case NaClApplyCodeValidation:
         status = NCApplyValidatorSilently_x86_32(
-            guest_addr, data, size, bundle_size, cpu_features);
+            guest_addr, data, size, bundle_size, cpu_features, cache);
         break;
       case NaClApplyValidationDoStubout:
         status = NCApplyValidatorStubout_x86_32(
             guest_addr, data, size, bundle_size, cpu_features);
         break;
       default:
         /* If reached, it isn't implemented (yet). */
         break;
     }
   }
@@ skipping 14 matching lines @@
     if (!NaClArchSupported(cpu_features)) {
       status = NaClValidationFailedCpuNotSupported;
     } else {
       status = NCValidateSegmentPair(data_old, data_new, guest_addr,
                                      size, bundle_size, cpu_features)
         ? NaClValidationSucceeded : NaClValidationFailed;
     }
   }
   return status;
 }