1    :  // Copyright 2012 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  
  15    :  #include "syzygy/agent/asan/asan_shadow.h"
  16    :  
  17    :  #include "base/rand_util.h"
  18    :  #include "gtest/gtest.h"
  19    :  #include "syzygy/common/align.h"
  20    :  
  21    :  namespace agent {
  22    :  namespace asan {
  23    :  
  24    :  namespace {
  25    :  
  26    :  // A derived class to expose protected members for unit-testing.
  27    :  class TestShadow : public Shadow {
  28    :   public:
  29    :    using Shadow::Reset;
  30    :  };
  31    :  
  32    :  }  // namespace
  33    :  
  34  E :  TEST(ShadowTest, PoisonUnpoisonAccess) {
  35    :    // Reset the shadow memory.
  36  E :    TestShadow::Reset();
  37  E :    for (size_t i = 0; i < 100; ++i) {
  38    :      // Use a random 8-byte aligned end address.
  39  E :      const size_t size = base::RandInt(1, 16384);
  40    :      const uint8* end_addr =
  41  E :          reinterpret_cast<const uint8*>(base::RandInt(65536, 10*1024*1024) * 8);
  42  E :      const uint8* start_addr = end_addr - size;
  43    :  
  44  E :      for (size_t i = 0; i < size; ++i) {
  45  E :        EXPECT_TRUE(Shadow::IsAccessible(start_addr + i));
  46  E :      }
  47    :  
  48  E :      Shadow::Poison(start_addr, size, Shadow::kHeapNonAccessibleByteMask);
  49  E :      for (size_t i = 0; i < size; ++i) {
  50  E :        EXPECT_FALSE(Shadow::IsAccessible(start_addr + i));
  51  E :      }
  52  E :      EXPECT_TRUE(Shadow::IsAccessible(start_addr - 1));
  53  E :      EXPECT_TRUE(Shadow::IsAccessible(start_addr + size));
  54    :  
  55  E :      const size_t aligned_size = common::AlignUp(size, 8);
  56  E :      const uint8* aligned_start_addr = end_addr - aligned_size;
  57  E :      Shadow::Unpoison(aligned_start_addr, aligned_size);
  58  E :      for (size_t i = 0; i < size; ++i) {
  59  E :        EXPECT_TRUE(Shadow::IsAccessible(start_addr + i));
  60  E :      }
  61  E :    }
  62  E :  }
  63    :  
  64    :  }  // namespace asan
  65    :  }  // namespace agent