Merge "Newly create idmap only when it is stale" into oc-dev (4bf5dcce) · Commits · e / os / android_frameworks_native

cmds/installd/InstalldNativeService.cpp

+70 −8

Original line number	Diff line number	Diff line
		@@ -78,6 +78,7 @@ static constexpr const char* PKG_LIB_POSTFIX = "/lib";
		static constexpr const char* CACHE_DIR_POSTFIX = "/cache";
		static constexpr const char* CODE_CACHE_DIR_POSTFIX = "/code_cache";

		static constexpr const char *kIdMapPath = "/system/bin/idmap";
		static constexpr const char* IDMAP_PREFIX = "/data/resource-cache/";
		static constexpr const char* IDMAP_SUFFIX = "@idmap";

		@@ -1941,14 +1942,58 @@ out:

		static void run_idmap(const char target_apk, const char overlay_apk, int idmap_fd)
		{
		static const char *IDMAP_BIN = "/system/bin/idmap";
		static const size_t MAX_INT_LEN = 32;
		char idmap_str[MAX_INT_LEN];
		execl(kIdMapPath, kIdMapPath, "--fd", target_apk, overlay_apk,
		StringPrintf("%d", idmap_fd).c_str(), (char*)NULL);
		PLOG(ERROR) << "execl (" << kIdMapPath << ") failed";
		}

		static void run_verify_idmap(const char target_apk, const char overlay_apk, int idmap_fd)
		{
		execl(kIdMapPath, kIdMapPath, "--verify", target_apk, overlay_apk,
		StringPrintf("%d", idmap_fd).c_str(), (char*)NULL);
		PLOG(ERROR) << "execl (" << kIdMapPath << ") failed";
		}

		static bool delete_stale_idmap(const char* target_apk, const char* overlay_apk,
		const char* idmap_path, int32_t uid) {
		int idmap_fd = open(idmap_path, O_RDWR);
		if (idmap_fd < 0) {
		PLOG(ERROR) << "idmap open failed: " << idmap_path;
		unlink(idmap_path);
		return true;
		}

		pid_t pid;
		pid = fork();
		if (pid == 0) {
		/* child -- drop privileges before continuing */
		if (setgid(uid) != 0) {
		LOG(ERROR) << "setgid(" << uid << ") failed during idmap";
		exit(1);
		}
		if (setuid(uid) != 0) {
		LOG(ERROR) << "setuid(" << uid << ") failed during idmap";
		exit(1);
		}
		if (flock(idmap_fd, LOCK_EX \| LOCK_NB) != 0) {
		PLOG(ERROR) << "flock(" << idmap_path << ") failed during idmap";
		exit(1);
		}

		snprintf(idmap_str, sizeof(idmap_str), "%d", idmap_fd);
		run_verify_idmap(target_apk, overlay_apk, idmap_fd);
		exit(1); /* only if exec call to deleting stale idmap failed */
		} else {
		int status = wait_child(pid);
		close(idmap_fd);

		execl(IDMAP_BIN, IDMAP_BIN, "--fd", target_apk, overlay_apk, idmap_str, (char*)NULL);
		ALOGE("execl(%s) failed: %s\n", IDMAP_BIN, strerror(errno));
		if (status != 0) {
		// Failed on verifying if idmap is made from target_apk and overlay_apk.
		LOG(DEBUG) << "delete stale idmap: " << idmap_path;
		unlink(idmap_path);
		return true;
		}
		}
		return false;
		}

		// Transform string /a/b/c.apk to (prefix)/a@b@c.apk@(suffix)
		@@ -1997,6 +2042,8 @@ binder::Status InstalldNativeService::idmap(const std::string& targetApkPath,

		int idmap_fd = -1;
		char idmap_path[PATH_MAX];
		struct stat idmap_stat;
		bool outdated = false;

		if (flatten_path(IDMAP_PREFIX, IDMAP_SUFFIX, overlay_apk,
		idmap_path, sizeof(idmap_path)) == -1) {
		@@ -2004,8 +2051,18 @@ binder::Status InstalldNativeService::idmap(const std::string& targetApkPath,
		goto fail;
		}

		unlink(idmap_path);
		if (stat(idmap_path, &idmap_stat) < 0) {
		outdated = true;
		} else {
		outdated = delete_stale_idmap(target_apk, overlay_apk, idmap_path, uid);
		}

		if (outdated) {
		idmap_fd = open(idmap_path, O_RDWR \| O_CREAT \| O_EXCL, 0644);
		} else {
		idmap_fd = open(idmap_path, O_RDWR);
		}

		if (idmap_fd < 0) {
		ALOGE("idmap cannot open '%s' for output: %s\n", idmap_path, strerror(errno));
		goto fail;
		@@ -2019,6 +2076,11 @@ binder::Status InstalldNativeService::idmap(const std::string& targetApkPath,
		goto fail;
		}

		if (!outdated) {
		close(idmap_fd);
		return ok();
		}

		pid_t pid;
		pid = fork();
		if (pid == 0) {