6 files changed, 105 insertions, 118 deletions

diff --git a/Android.mk b/Android.mk
index 010a51630..55ec38799 100644
--- a/Android.mk
+++ b/Android.mk
@@ -215,4 +215,3 @@ include \
     $(LOCAL_PATH)/tests/Android.mk \
     $(LOCAL_PATH)/tools/Android.mk \
     $(LOCAL_PATH)/updater/Android.mk \
-    $(LOCAL_PATH)/update_verifier/Android.mk \
diff --git a/tests/Android.mk b/tests/Android.mk
index b29ff50f6..fd4497858 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -74,14 +74,6 @@ ifeq ($(AB_OTA_UPDATER),true)
 LOCAL_CFLAGS += -DAB_OTA_UPDATER=1
 endif
 
-ifeq ($(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY),true)
-LOCAL_CFLAGS += -DPRODUCT_SUPPORTS_VERITY=1
-endif
-
-ifeq ($(BOARD_AVB_ENABLE),true)
-LOCAL_CFLAGS += -DBOARD_AVB_ENABLE=1
-endif
-
 LOCAL_MODULE := recovery_component_test
 LOCAL_COMPATIBILITY_SUITE := device-tests
 LOCAL_C_INCLUDES := bootable/recovery
diff --git a/tests/component/update_verifier_test.cpp b/tests/component/update_verifier_test.cpp
index 1544bb2a4..f6ef6dcfd 100644
--- a/tests/component/update_verifier_test.cpp
+++ b/tests/component/update_verifier_test.cpp
@@ -17,6 +17,8 @@
 #include <string>
 
 #include <android-base/file.h>
+#include <android-base/properties.h>
+#include <android-base/strings.h>
 #include <android-base/test_utils.h>
 #include <gtest/gtest.h>
 #include <update_verifier/update_verifier.h>
@@ -24,11 +26,8 @@
 class UpdateVerifierTest : public ::testing::Test {
  protected:
   void SetUp() override {
-#if defined(PRODUCT_SUPPORTS_VERITY) || defined(BOARD_AVB_ENABLE)
-    verity_supported = true;
-#else
-    verity_supported = false;
-#endif
+    std::string verity_mode = android::base::GetProperty("ro.boot.veritymode", "");
+    verity_supported = android::base::EqualsIgnoreCase(verity_mode, "enforcing");
   }
 
   bool verity_supported;
diff --git a/update_verifier/Android.bp b/update_verifier/Android.bp
new file mode 100644
index 000000000..f6c7056d9
--- /dev/null
+++ b/update_verifier/Android.bp
@@ -0,0 +1,83 @@
+// Copyright (C) 2018 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+cc_defaults {
+    name: "update_verifier_defaults",
+
+    cflags: [
+        "-Wall",
+        "-Werror",
+    ],
+
+    local_include_dirs: [
+        "include",
+    ],
+}
+
+cc_library_static {
+    name: "libupdate_verifier",
+
+    defaults: [
+        "update_verifier_defaults",
+    ],
+
+    srcs: [
+        "update_verifier.cpp",
+    ],
+
+    export_include_dirs: [
+        "include",
+    ],
+
+    static_libs: [
+        "libotautil",
+    ],
+
+    shared_libs: [
+        "android.hardware.boot@1.0",
+        "libbase",
+        "libcutils",
+    ],
+}
+
+cc_binary {
+    name: "update_verifier",
+
+    defaults: [
+        "update_verifier_defaults",
+    ],
+
+    srcs: [
+        "update_verifier_main.cpp",
+    ],
+
+    static_libs: [
+        "libupdate_verifier",
+        "libotautil",
+    ],
+
+    shared_libs: [
+        "android.hardware.boot@1.0",
+        "libbase",
+        "libcutils",
+        "libhardware",
+        "libhidlbase",
+        "liblog",
+        "libutils",
+    ],
+
+    init_rc: [
+        "update_verifier.rc",
+    ],
+}
diff --git a/update_verifier/Android.mk b/update_verifier/Android.mk
deleted file mode 100644
index 0ff88546f..000000000
--- a/update_verifier/Android.mk
+++ /dev/null
@@ -1,77 +0,0 @@
-# Copyright (C) 2015 The Android Open Source Project
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-LOCAL_PATH := $(call my-dir)
-
-# libupdate_verifier (static library)
-# ===============================
-include $(CLEAR_VARS)
-
-LOCAL_SRC_FILES := \
-    update_verifier.cpp
-
-LOCAL_MODULE := libupdate_verifier
-
-LOCAL_STATIC_LIBRARIES := \
-    libotautil
-
-LOCAL_SHARED_LIBRARIES := \
-    libbase \
-    libcutils \
-    android.hardware.boot@1.0
-
-LOCAL_CFLAGS := -Wall -Werror
-
-LOCAL_EXPORT_C_INCLUDE_DIRS := \
-    $(LOCAL_PATH)/include
-
-LOCAL_C_INCLUDES := \
-    $(LOCAL_PATH)/include
-
-ifeq ($(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY),true)
-LOCAL_CFLAGS += -DPRODUCT_SUPPORTS_VERITY=1
-endif
-
-ifeq ($(BOARD_AVB_ENABLE),true)
-LOCAL_CFLAGS += -DBOARD_AVB_ENABLE=1
-endif
-
-include $(BUILD_STATIC_LIBRARY)
-
-# update_verifier (executable)
-# ===============================
-include $(CLEAR_VARS)
-
-LOCAL_SRC_FILES := \
-    update_verifier_main.cpp
-
-LOCAL_MODULE := update_verifier
-LOCAL_STATIC_LIBRARIES := \
-    libupdate_verifier \
-    libotautil
-
-LOCAL_SHARED_LIBRARIES := \
-    libbase \
-    libcutils \
-    libhardware \
-    liblog \
-    libutils \
-    libhidlbase \
-    android.hardware.boot@1.0
-
-LOCAL_CFLAGS := -Wall -Werror
-
-LOCAL_INIT_RC := update_verifier.rc
-
-include $(BUILD_EXECUTABLE)
diff --git a/update_verifier/update_verifier.cpp b/update_verifier/update_verifier.cpp
index 92d931371..dc7276326 100644
--- a/update_verifier/update_verifier.cpp
+++ b/update_verifier/update_verifier.cpp
@@ -15,24 +15,26 @@
  */
 
 /*
- * This program verifies the integrity of the partitions after an A/B OTA
- * update. It gets invoked by init, and will only perform the verification if
- * it's the first boot post an A/B OTA update.
+ * update_verifier verifies the integrity of the partitions after an A/B OTA update. It gets invoked
+ * by init, and will only perform the verification if it's the first boot post an A/B OTA update
+ * (https://source.android.com/devices/tech/ota/ab/#after_reboot).
  *
- * Update_verifier relies on dm-verity to capture any corruption on the partitions
- * being verified. And its behavior varies depending on the dm-verity mode.
- * Upon detection of failures:
+ * update_verifier relies on device-mapper-verity (dm-verity) to capture any corruption on the
+ * partitions being verified (https://source.android.com/security/verifiedboot). The verification
+ * will be skipped, if dm-verity is not enabled on the device.
+ *
+ * Upon detecting verification failures, the device will be rebooted, although the trigger of the
+ * reboot depends on the dm-verity mode.
  *   enforcing mode: dm-verity reboots the device
  *   eio mode: dm-verity fails the read and update_verifier reboots the device
  *   other mode: not supported and update_verifier reboots the device
  *
- * After a predefined number of failing boot attempts, the bootloader should
- * mark the slot as unbootable and stops trying. Other dm-verity modes (
- * for example, veritymode=EIO) are not accepted and simply lead to a
- * verification failure.
+ * All these reboots prevent the device from booting into a known corrupt state. If the device
+ * continuously fails to boot into the new slot, the bootloader should mark the slot as unbootable
+ * and trigger a fallback to the old slot.
  *
- * The current slot will be marked as having booted successfully if the
- * verifier reaches the end after the verification.
+ * The current slot will be marked as having booted successfully if the verifier reaches the end
+ * after the verification.
  */
 
 #include "update_verifier/update_verifier.h"
@@ -103,12 +105,10 @@ static bool read_blocks(const std::string& partition, const std::string& range_s
       PLOG(WARNING) << "Failed to read " << path;
     } else {
       std::string dm_block_name = android::base::Trim(content);
-#ifdef BOARD_AVB_ENABLE
       // AVB is using 'vroot' for the root block device but we're expecting 'system'.
       if (dm_block_name == "vroot") {
         dm_block_name = "system";
       }
-#endif
       if (dm_block_name == partition) {
         dm_block_device = DEV_PATH + std::string(namelist[n]->d_name);
         while (n--) {
@@ -264,19 +264,13 @@ int update_verifier(int argc, char** argv) {
   if (is_successful == BoolResult::FALSE) {
     // The current slot has not booted successfully.
 
-#if defined(PRODUCT_SUPPORTS_VERITY) || defined(BOARD_AVB_ENABLE)
     bool skip_verification = false;
     std::string verity_mode = android::base::GetProperty("ro.boot.veritymode", "");
     if (verity_mode.empty()) {
-      // With AVB it's possible to disable verification entirely and
-      // in this case ro.boot.veritymode is empty.
-#if defined(BOARD_AVB_ENABLE)
-      LOG(WARNING) << "verification has been disabled; marking without verification.";
+      // Skip the verification if ro.boot.veritymode property is not set. This could be a result
+      // that device doesn't support dm-verity, or has disabled that.
+      LOG(WARNING) << "dm-verity not enabled; marking without verification.";
       skip_verification = true;
-#else
-      LOG(ERROR) << "Failed to get dm-verity mode.";
-      return reboot_device();
-#endif
     } else if (android::base::EqualsIgnoreCase(verity_mode, "eio")) {
       // We shouldn't see verity in EIO mode if the current slot hasn't booted successfully before.
       // Continue the verification until we fail to read some blocks.
@@ -285,7 +279,7 @@ int update_verifier(int argc, char** argv) {
       LOG(WARNING) << "dm-verity in disabled mode; marking without verification.";
       skip_verification = true;
     } else if (verity_mode != "enforcing") {
-      LOG(ERROR) << "Unexpected dm-verity mode : " << verity_mode << ", expecting enforcing.";
+      LOG(ERROR) << "Unexpected dm-verity mode: " << verity_mode << ", expecting enforcing.";
       return reboot_device();
     }
 
@@ -296,9 +290,6 @@ int update_verifier(int argc, char** argv) {
         return reboot_device();
       }
     }
-#else
-    LOG(WARNING) << "dm-verity not enabled; marking without verification.";
-#endif
 
     CommandResult cr;
     module->markBootSuccessful([&cr](CommandResult result) { cr = result; });