Merge "Adding a build id check to blob cache." into mnc-dev (338142aa) · Commits · e / os / android_system_core

include/utils/BlobCache.h

+6 −0

Original line number	Original line	Diff line number	Diff line
	@@ -185,6 +185,12 @@ private:
	// mNumEntries is number of cache entries following the header in the		// mNumEntries is number of cache entries following the header in the
	// data.		// data.
	size_t mNumEntries;		size_t mNumEntries;

			// mBuildId is the build id of the device when the cache was created.
			// When an update to the build happens (via an OTA or other update) this
			// is used to invalidate the cache.
			int mBuildIdLength;
			char mBuildId[];
	};		};

	// An EntryHeader is the header for a serialized cache entry. No need to		// An EntryHeader is the header for a serialized cache entry. No need to

libutils/Android.mk

+3 −2

Original line number	Original line	Diff line number	Diff line
	@@ -16,7 +16,6 @@ LOCAL_PATH:= $(call my-dir)

	commonSources:= \		commonSources:= \
	BasicHashtable.cpp \		BasicHashtable.cpp \
	BlobCache.cpp \
	CallStack.cpp \		CallStack.cpp \
	FileMap.cpp \		FileMap.cpp \
	JenkinsHash.cpp \		JenkinsHash.cpp \
	@@ -74,6 +73,7 @@ include $(CLEAR_VARS)
	# we have the common sources, plus some device-specific stuff		# we have the common sources, plus some device-specific stuff
	LOCAL_SRC_FILES:= \		LOCAL_SRC_FILES:= \
	$(commonSources) \		$(commonSources) \
			BlobCache.cpp \
	Looper.cpp \		Looper.cpp \
	Trace.cpp		Trace.cpp

	@@ -83,7 +83,8 @@ endif
	LOCAL_CFLAGS += -Werror		LOCAL_CFLAGS += -Werror

	LOCAL_STATIC_LIBRARIES := \		LOCAL_STATIC_LIBRARIES := \
	libcutils		libcutils \
			libc

	LOCAL_SHARED_LIBRARIES := \		LOCAL_SHARED_LIBRARIES := \
	libbacktrace \		libbacktrace \

libutils/BlobCache.cpp

+14 −5

Original line number	Original line	Diff line number	Diff line
	@@ -25,13 +25,15 @@
	#include <utils/Errors.h>		#include <utils/Errors.h>
	#include <utils/Log.h>		#include <utils/Log.h>

			#include <cutils/properties.h>

	namespace android {		namespace android {

	// BlobCache::Header::mMagicNumber value		// BlobCache::Header::mMagicNumber value
	static const uint32_t blobCacheMagic = ('_' << 24) + ('B' << 16) + ('b' << 8) + '$';		static const uint32_t blobCacheMagic = ('_' << 24) + ('B' << 16) + ('b' << 8) + '$';

	// BlobCache::Header::mBlobCacheVersion value		// BlobCache::Header::mBlobCacheVersion value
	static const uint32_t blobCacheVersion = 2;		static const uint32_t blobCacheVersion = 3;

	// BlobCache::Header::mDeviceVersion value		// BlobCache::Header::mDeviceVersion value
	static const uint32_t blobCacheDeviceVersion = 1;		static const uint32_t blobCacheDeviceVersion = 1;
	@@ -165,7 +167,7 @@ static inline size_t align4(size_t size) {
	}		}

	size_t BlobCache::getFlattenedSize() const {		size_t BlobCache::getFlattenedSize() const {
	size_t size = align4(sizeof(Header));		size_t size = align4(sizeof(Header) + PROPERTY_VALUE_MAX);
	for (size_t i = 0; i < mCacheEntries.size(); i++) {		for (size_t i = 0; i < mCacheEntries.size(); i++) {
	const CacheEntry& e(mCacheEntries[i]);		const CacheEntry& e(mCacheEntries[i]);
	sp<Blob> keyBlob = e.getKey();		sp<Blob> keyBlob = e.getKey();
	@@ -187,10 +189,13 @@ status_t BlobCache::flatten(void* buffer, size_t size) const {
	header->mBlobCacheVersion = blobCacheVersion;		header->mBlobCacheVersion = blobCacheVersion;
	header->mDeviceVersion = blobCacheDeviceVersion;		header->mDeviceVersion = blobCacheDeviceVersion;
	header->mNumEntries = mCacheEntries.size();		header->mNumEntries = mCacheEntries.size();
			char buildId[PROPERTY_VALUE_MAX];
			header->mBuildIdLength = property_get("ro.build.id", buildId, "");
			memcpy(header->mBuildId, buildId, header->mBuildIdLength);

	// Write cache entries		// Write cache entries
	uint8_t* byteBuffer = reinterpret_cast<uint8_t*>(buffer);		uint8_t* byteBuffer = reinterpret_cast<uint8_t*>(buffer);
	off_t byteOffset = align4(sizeof(Header));		off_t byteOffset = align4(sizeof(Header) + header->mBuildIdLength);
	for (size_t i = 0; i < mCacheEntries.size(); i++) {		for (size_t i = 0; i < mCacheEntries.size(); i++) {
	const CacheEntry& e(mCacheEntries[i]);		const CacheEntry& e(mCacheEntries[i]);
	sp<Blob> keyBlob = e.getKey();		sp<Blob> keyBlob = e.getKey();
	@@ -239,15 +244,19 @@ status_t BlobCache::unflatten(void const* buffer, size_t size) {
	ALOGE("unflatten: bad magic number: %" PRIu32, header->mMagicNumber);		ALOGE("unflatten: bad magic number: %" PRIu32, header->mMagicNumber);
	return BAD_VALUE;		return BAD_VALUE;
	}		}
			char buildId[PROPERTY_VALUE_MAX];
			int len = property_get("ro.build.id", buildId, "");
	if (header->mBlobCacheVersion != blobCacheVersion \|\|		if (header->mBlobCacheVersion != blobCacheVersion \|\|
	header->mDeviceVersion != blobCacheDeviceVersion) {		header->mDeviceVersion != blobCacheDeviceVersion \|\|
			len != header->mBuildIdLength \|\|
			strncmp(buildId, header->mBuildId, len)) {
	// We treat version mismatches as an empty cache.		// We treat version mismatches as an empty cache.
	return OK;		return OK;
	}		}

	// Read cache entries		// Read cache entries
	const uint8_t* byteBuffer = reinterpret_cast<const uint8_t*>(buffer);		const uint8_t* byteBuffer = reinterpret_cast<const uint8_t*>(buffer);
	off_t byteOffset = align4(sizeof(Header));		off_t byteOffset = align4(sizeof(Header) + header->mBuildIdLength);
	size_t numEntries = header->mNumEntries;		size_t numEntries = header->mNumEntries;
	for (size_t i = 0; i < numEntries; i++) {		for (size_t i = 0; i < numEntries; i++) {
	if (byteOffset + sizeof(EntryHeader) > size) {		if (byteOffset + sizeof(EntryHeader) > size) {