Android6.0 PackageManagerService 安装lib

之前在PKMS预装三方应用时，放在system/third_app下面扫描出现了很多错，原因就是对安装lib和oat文件不熟悉。这篇博客就分析下这两项。

一、安装lib库

安装lib库代码，主要代码都在scanPackageDirtyLI函数中，先是调用了derivePackageAbi，这个函数中就把lib库的路径创建好了，也把lib库copy到这个目录下，然后后面会调用Installd的方法，在data/data/apk相关目录 下的lib 创建软链接到真正放lib的地方。

if ((scanFlags & SCAN_NEW_INSTALL) == 0) {
derivePackageAbi(pkg, scanFile, cpuAbiOverride, true /* extract libs */);

// Some system apps still use directory structure for native libraries
// in which case we might end up not detecting abi solely based on apk
// structure. Try to detect abi based on directory structure.
if (isSystemApp(pkg) && !pkg.isUpdatedSystemApp() &&
pkg.applicationInfo.primaryCpuAbi == null) {
setBundledAppAbisAndRoots(pkg, pkgSetting);
setNativeLibraryPaths(pkg);
}

} else {
if ((scanFlags & SCAN_MOVE) != 0) {
// We haven't run dex-opt for this move (since we've moved the compiled output too)
// but we already have this packages package info in the PackageSetting. We just
// use that and derive the native library path based on the new codepath.
pkg.applicationInfo.primaryCpuAbi = pkgSetting.primaryCpuAbiString;
pkg.applicationInfo.secondaryCpuAbi = pkgSetting.secondaryCpuAbiString;
}

// Set native library paths again. For moves, the path will be updated based on the
// ABIs we've determined above. For non-moves, the path will be updated based on the
// ABIs we determined during compilation, but the path will depend on the final
// package path (after the rename away from the stage path).
setNativeLibraryPaths(pkg);
}

if (true) Slog.i(TAG, "Linking native library dir for " + path);
final int[] userIds = sUserManager.getUserIds();
synchronized (mInstallLock) {
// Make sure all user data directories are ready to roll; we're okay
// if they already exist
if (!TextUtils.isEmpty(pkg.volumeUuid)) {
for (int userId : userIds) {
if (userId != 0) {
mInstaller.createUserData(pkg.volumeUuid, pkg.packageName,
UserHandle.getUid(userId, pkg.applicationInfo.uid), userId,
pkg.applicationInfo.seinfo);
}
}
}

// Create a native library symlink only if we have native libraries
// and if the native libraries are 32 bit libraries. We do not provide
// this symlink for 64 bit libraries.
if (pkg.applicationInfo.primaryCpuAbi != null &&
!VMRuntime.is64BitAbi(pkg.applicationInfo.primaryCpuAbi)) {
final String nativeLibPath = pkg.applicationInfo.nativeLibraryDir;
for (int userId : userIds) {
if (mInstaller.linkNativeLibraryDirectory(pkg.volumeUuid, pkg.packageName,
nativeLibPath, userId) < 0) {
throw new PackageManagerException(INSTALL_FAILED_INTERNAL_ERROR,
"Failed linking native library dir (user=" + userId + ")");
}
}
}
}

二、 确定lib目录

那我们先从最核心的derivePackageAbi函数开始分析，derivePackageAbi这个函数一开始就调用了setNativeLibraryPaths，因此我们还是先看下这个函数：

private void setNativeLibraryPaths(PackageParser.Package pkg) {
final ApplicationInfo info = pkg.applicationInfo;
final String codePath = pkg.codePath;
final File codeFile = new File(codePath);
final boolean bundledApp = info.isSystemApp() && !info.isUpdatedSystemApp();
final boolean asecApp = info.isForwardLocked() || info.isExternalAsec();

info.nativeLibraryRootDir = null;
info.nativeLibraryRootRequiresIsa = false;
info.nativeLibraryDir = null;
info.secondaryNativeLibraryDir = null;

if (isApkFile(codeFile)) {//是apk还是目录
// Monolithic install
if (bundledApp) {//系统应用相关
// If "/system/lib64/apkname" exists, assume that is the per-package
// native library directory to use; otherwise use "/system/lib/apkname".
final String apkRoot = calculateBundledApkRoot(info.sourceDir);
final boolean is64Bit = VMRuntime.is64BitInstructionSet(
getPrimaryInstructionSet(info));

// This is a bundled system app so choose the path based on the ABI.
// if it's a 64 bit abi, use lib64 otherwise use lib32. Note that this
// is just the default path.
final String apkName = deriveCodePathName(codePath);
final String libDir = is64Bit ? LIB64_DIR_NAME : LIB_DIR_NAME;
info.nativeLibraryRootDir = Environment.buildPath(new File(apkRoot), libDir,
apkName).getAbsolutePath();

if (info.secondaryCpuAbi != null) {
final String secondaryLibDir = is64Bit ? LIB_DIR_NAME : LIB64_DIR_NAME;
info.secondaryNativeLibraryDir = Environment.buildPath(new File(apkRoot),
secondaryLibDir, apkName).getAbsolutePath();
}
} else if (asecApp) {
info.nativeLibraryRootDir = new File(codeFile.getParentFile(), LIB_DIR_NAME)
.getAbsolutePath();
} else {
final String apkName = deriveCodePathName(codePath);
info.nativeLibraryRootDir = new File(mAppLib32InstallDir, apkName)//在data/app-lib下建一个apk的目录
.getAbsolutePath();
}

info.nativeLibraryRootRequiresIsa = false;
info.nativeLibraryDir = info.nativeLibraryRootDir;
} else {//如果是目录
// Cluster install
info.nativeLibraryRootDir = new File(codeFile, LIB_DIR_NAME).getAbsolutePath();//目录下直接建一个lib目录
info.nativeLibraryRootRequiresIsa = true;

info.nativeLibraryDir = new File(info.nativeLibraryRootDir,
getPrimaryInstructionSet(info)).getAbsolutePath();

if (info.secondaryCpuAbi != null) {
info.secondaryNativeLibraryDir = new File(info.nativeLibraryRootDir,
VMRuntime.getInstructionSet(info.secondaryCpuAbi)).getAbsolutePath();
}
}
}

上面这个函数就是看lib库最终的目录，我们先看逻辑，先来看文件是否是apk，如果不是apk是目录的话，直接在当前目录建一个lib目录。如果是普通应用就在data/app-lib下建一个apk目录。如果是系统应用会调用calculateBundledApkRoot函数来确定目录,最终会在system/lib vendor/lib oem/lib下建立相关目录。

calculateBundledApkRoot函数就是看apk是在system目录最终返回system目录，oem或者vendor目录最后返回oem或者vendor目录。

private static String calculateBundledApkRoot(final String codePathString) {
final File codePath = new File(codePathString);
final File codeRoot;
if (FileUtils.contains(Environment.getRootDirectory(), codePath)) {
codeRoot = Environment.getRootDirectory();
} else if (FileUtils.contains(Environment.getOemDirectory(), codePath)) {
codeRoot = Environment.getOemDirectory();
} else if (FileUtils.contains(Environment.getVendorDirectory(), codePath)) {
codeRoot = Environment.getVendorDirectory();
} else {
// Unrecognized code path; take its top real segment as the apk root:
// e.g. /something/app/blah.apk => /something
try {
File f = codePath.getCanonicalFile();
File parent = f.getParentFile();    // non-null because codePath is a file
File tmp;
while ((tmp = parent.getParentFile()) != null) {
f = parent;
parent = tmp;
}
codeRoot = f;
Slog.w(TAG, "Unrecognized code path "
+ codePath + " - using " + codeRoot);
} catch (IOException e) {
// Can't canonicalize the code path -- shenanigans?
Slog.w(TAG, "Can't canonicalize code path " + codePath);
return Environment.getRootDirectory().getPath();
}
}
return codeRoot.getPath();
}

三、从apk中copy lib库

然后我们来看derivePackageAbi函数，我们先调用了setNativeLibraryPaths来确定了lib库的目录，然后NativeLibraryHelper.Handle.create来打开lapk中文件，接着又调用NativeLibraryHelper.copyNativeBinariesForSupportedAbi把apk的lib库文件copy到创建的lib目录。

public void derivePackageAbi(PackageParser.Package pkg, File scanFile,
String cpuAbiOverride, boolean extractLibs)
throws PackageManagerException {
setNativeLibraryPaths(pkg);

if (pkg.isForwardLocked() || pkg.applicationInfo.isExternalAsec() ||
(isSystemApp(pkg) && !pkg.isUpdatedSystemApp())) {
extractLibs = false;
}

final String nativeLibraryRootStr = pkg.applicationInfo.nativeLibraryRootDir;
final boolean useIsaSpecificSubdirs = pkg.applicationInfo.nativeLibraryRootRequiresIsa;

NativeLibraryHelper.Handle handle = null;
try {
handle = NativeLibraryHelper.Handle.create(scanFile);
final File nativeLibraryRoot = new File(nativeLibraryRootStr);

// Null out the abis so that they can be recalculated.
pkg.applicationInfo.primaryCpuAbi = null;
pkg.applicationInfo.secondaryCpuAbi = null;
if (isMultiArch(pkg.applicationInfo)) {
// Warn if we've set an abiOverride for multi-lib packages..
// By definition, we need to copy both 32 and 64 bit libraries for
// such packages.
if (pkg.cpuAbiOverride != null
&& !NativeLibraryHelper.CLEAR_ABI_OVERRIDE.equals(pkg.cpuAbiOverride)) {
Slog.w(TAG, "Ignoring abiOverride for multi arch application.");
}

int abi32 = PackageManager.NO_NATIVE_LIBRARIES;
int abi64 = PackageManager.NO_NATIVE_LIBRARIES;
if (Build.SUPPORTED_32_BIT_ABIS.length > 0) {
if (extractLibs) {
abi32 = NativeLibraryHelper.copyNativeBinariesForSupportedAbi(handle,
nativeLibraryRoot, Build.SUPPORTED_32_BIT_ABIS,
useIsaSpecificSubdirs);
} else {
abi32 = NativeLibraryHelper.findSupportedAbi(handle, Build.SUPPORTED_32_BIT_ABIS);
}
}

maybeThrowExceptionForMultiArchCopy(
"Error unpackaging 32 bit native libs for multiarch app.", abi32);

if (Build.SUPPORTED_64_BIT_ABIS.length > 0) {
if (extractLibs) {
abi64 = NativeLibraryHelper.copyNativeBinariesForSupportedAbi(handle,
nativeLibraryRoot, Build.SUPPORTED_64_BIT_ABIS,
useIsaSpecificSubdirs);
} else {
abi64 = NativeLibraryHelper.findSupportedAbi(handle, Build.SUPPORTED_64_BIT_ABIS);
}
}

maybeThrowExceptionForMultiArchCopy(
"Error unpackaging 64 bit native libs for multiarch app.", abi64);

if (abi64 >= 0) {
pkg.applicationInfo.primaryCpuAbi = Build.SUPPORTED_64_BIT_ABIS[abi64];
}

if (abi32 >= 0) {
final String abi = Build.SUPPORTED_32_BIT_ABIS[abi32];
if (abi64 >= 0) {
pkg.applicationInfo.secondaryCpuAbi = abi;
} else {
pkg.applicationInfo.primaryCpuAbi = abi;
}
}
} else {
String[] abiList = (cpuAbiOverride != null) ?
new String[] { cpuAbiOverride } : Build.SUPPORTED_ABIS;

// Enable gross and lame hacks for apps that are built with old
// SDK tools. We must scan their APKs for renderscript bitcode and
// not launch them if it's present. Don't bother checking on devices
// that don't have 64 bit support.
boolean needsRenderScriptOverride = false;
if (Build.SUPPORTED_64_BIT_ABIS.length > 0 && cpuAbiOverride == null &&
NativeLibraryHelper.hasRenderscriptBitcode(handle)) {
abiList = Build.SUPPORTED_32_BIT_ABIS;
needsRenderScriptOverride = true;
}
final int copyRet;
if (extractLibs) {
copyRet = NativeLibraryHelper.copyNativeBinariesForSupportedAbi(handle,
nativeLibraryRoot, abiList, useIsaSpecificSubdirs);
} else {
copyRet = NativeLibraryHelper.findSupportedAbi(handle, abiList);
}

if (copyRet < 0 && copyRet != PackageManager.NO_NATIVE_LIBRARIES) {
throw new PackageManagerException(INSTALL_FAILED_INTERNAL_ERROR,
"Error unpackaging native libs for app, errorCode=" + copyRet);
}

if (copyRet >= 0) {
pkg.applicationInfo.primaryCpuAbi = abiList[copyRet];
} else if (copyRet == PackageManager.NO_NATIVE_LIBRARIES && cpuAbiOverride != null) {
pkg.applicationInfo.primaryCpuAbi = cpuAbiOverride;
} else if (needsRenderScriptOverride) {
pkg.applicationInfo.primaryCpuAbi = abiList[0];
}
}
} catch (IOException ioe) {
Slog.e(TAG, "Unable to get canonical file " + ioe.toString());
} finally {
IoUtils.closeQuietly(handle);
}

// Now that we've calculated the ABIs and determined if it's an internal app,
// we will go ahead and populate the nativeLibraryPath.
setNativeLibraryPaths(pkg);
}

然后我们再回到scanPackageDirtyLI函数，下面会调用Installd的linkNativeLibraryDirectory函数来创建lib库的软链接

if (pkg.applicationInfo.primaryCpuAbi != null &&
!VMRuntime.is64BitAbi(pkg.applicationInfo.primaryCpuAbi)) {
final String nativeLibPath = pkg.applicationInfo.nativeLibraryDir;
for (int userId : userIds) {
if (mInstaller.linkNativeLibraryDirectory(pkg.volumeUuid, pkg.packageName,
nativeLibPath, userId) < 0) {
throw new PackageManagerException(INSTALL_FAILED_INTERNAL_ERROR,
"Failed linking native library dir (user=" + userId + ")");
}
}
}

四、创建lib软链接

最后在installd中调用如下代码，最后调用symlink来创建软链接。

int linklib(const char* uuid, const char* pkgname, const char* asecLibDir, int userId)
{
struct stat s, libStat;
int rc = 0;

std::string _pkgdir(create_data_user_package_path(uuid, userId, pkgname));
std::string _libsymlink(_pkgdir + PKG_LIB_POSTFIX);

const char* pkgdir = _pkgdir.c_str();
const char* libsymlink = _libsymlink.c_str();

if (stat(pkgdir, &s) < 0) return -1;

if (chown(pkgdir, AID_INSTALL, AID_INSTALL) < 0) {
ALOGE("failed to chown '%s': %s\n", pkgdir, strerror(errno));
return -1;
}

if (chmod(pkgdir, 0700) < 0) {
ALOGE("linklib() 1: failed to chmod '%s': %s\n", pkgdir, strerror(errno));
rc = -1;
goto out;
}

if (lstat(libsymlink, &libStat) < 0) {
if (errno != ENOENT) {
ALOGE("couldn't stat lib dir: %s\n", strerror(errno));
rc = -1;
goto out;
}
} else {
if (S_ISDIR(libStat.st_mode)) {
if (delete_dir_contents(libsymlink, 1, NULL) < 0) {
rc = -1;
goto out;
}
} else if (S_ISLNK(libStat.st_mode)) {
if (unlink(libsymlink) < 0) {
ALOGE("couldn't unlink lib dir: %s\n", strerror(errno));
rc = -1;
goto out;
}
}
}

if (symlink(asecLibDir, libsymlink) < 0) {
ALOGE("couldn't symlink directory '%s' -> '%s': %s\n", libsymlink, asecLibDir,
strerror(errno));
rc = -errno;
goto out;
}

out:
if (chmod(pkgdir, s.st_mode) < 0) {
ALOGE("linklib() 2: failed to chmod '%s': %s\n", pkgdir, strerror(errno));
rc = -errno;
}

if (chown(pkgdir, s.st_uid, s.st_gid) < 0) {
ALOGE("failed to chown '%s' : %s\n", pkgdir, strerror(errno));
return -errno;
}

return rc;
}

五、实例

这节主要看下具体apk的安装目录

5.1 普通应用

5.1.1 没有目录

没有目录的且是普通apk的lib安装位置

root@lc1861evb_arm64:/data/app-lib # ls
IflytekInput
MOffice
NotePadPlus

再来看data/data下面的讯飞目录，lib目录直接是软链接到/data/app_lib/IflytekInput

drwxrwx--x u0_a61 u0_a61 2016-09-21 22:16 cache
drwxrwx--x u0_a61 u0_a61 2016-09-21 22:16 code_cache
drwxrwx--x u0_a61 u0_a61 2016-09-21 22:16 databases
drwxrwx--x u0_a61 u0_a61 2016-09-21 22:16 files
lrwxrwxrwx root root 2016-09-21 22:47 lib -> /data/app-lib/IflytekInput
drwx------ u0_a61 u0_a61 2016-09-21 22:47 shared_prefs

5.1.2 有目录

而如果我们把讯飞输入法放在data/app/IflytekInput目录下，就会把lib文件放在该目录下

root@lte26007:/data/app/IflytekInput # ls
IflytekInput.apk
lib

当然软链接也会到/data/app/IflytekInput/lib/arm目录

root@lte26007:/data/data/com.iflytek.inputmethod # ls -l
drwxrwx--x u0_a62 u0_a62 1980-01-08 07:12 cache
drwxrwx--x u0_a62 u0_a62 1980-01-08 07:12 code_cache
drwxrwx--x u0_a62 u0_a62 1980-01-08 07:12 databases
drwxrwx--x u0_a62 u0_a62 1980-01-08 07:12 files
lrwxrwxrwx root root 1980-01-08 07:11 lib -> /data/app/IflytekInput/lib/arm
drwx------ u0_a62 u0_a62 1980-01-08 07:12 shared_prefs

5.2 系统应用

系统应用很奇怪，在扫描时无论是有目录还是没有目录，最后都没有生成lib目录，也没有copylib库（在手机上面busybox find相关库也没有找到），但是data/data相关app下面有lib的软链接，但是打开错误。

这个后续还要继续研究下。