Merge "Implemented native functions and types for blastula management." (b4be5cdf) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/os/Zygote.java

+34 −13

Original line number	Diff line number	Diff line
		@@ -126,7 +126,7 @@ public final class Zygote {
		private Zygote() {}

		/** Called for some security initialization before any fork. */
		native static void nativeSecurityInit();
		static native void nativeSecurityInit();

		/**
		* Forks a new VM instance. The current VM must have been started
		@@ -184,15 +184,20 @@ public final class Zygote {
		return pid;
		}

		native private static int nativeForkAndSpecialize(int uid, int gid, int[] gids,int runtimeFlags,
		int[][] rlimits, int mountExternal, String seInfo, String niceName, int[] fdsToClose,
		int[] fdsToIgnore, boolean startChildZygote, String instructionSet, String appDataDir,
		String packageName, String[] packagesForUid, String[] visibleVolIds);
		private static native int nativeForkAndSpecialize(int uid, int gid, int[] gids,
		int runtimeFlags, int[][] rlimits, int mountExternal, String seInfo, String niceName,
		int[] fdsToClose, int[] fdsToIgnore, boolean startChildZygote, String instructionSet,
		String appDataDir, String packageName, String[] packagesForUid, String[] visibleVolIds);

		private static native void nativeSpecializeBlastula(int uid, int gid, int[] gids,
		int runtimeFlags, int[][] rlimits, int mountExternal, String seInfo, String niceName,
		boolean startChildZygote, String instructionSet, String appDataDir, String packageName,
		String[] packagesForUid, String[] visibleVolIds);

		/**
		* Called to do any initialization before starting an application.
		*/
		native static void nativePreApplicationInit();
		static native void nativePreApplicationInit();

		/**
		* Special method to start the system server process. In addition to the
		@@ -223,7 +228,8 @@ public final class Zygote {
		// Resets nice priority for zygote process.
		resetNicePriority();
		int pid = nativeForkSystemServer(
		uid, gid, gids, runtimeFlags, rlimits, permittedCapabilities, effectiveCapabilities);
		uid, gid, gids, runtimeFlags, rlimits,
		permittedCapabilities, effectiveCapabilities);
		// Enable tracing as soon as we enter the system_server.
		if (pid == 0) {
		Trace.setTracingEnabled(true, runtimeFlags);
		@@ -232,13 +238,13 @@ public final class Zygote {
		return pid;
		}

		native private static int nativeForkSystemServer(int uid, int gid, int[] gids, int runtimeFlags,
		private static native int nativeForkSystemServer(int uid, int gid, int[] gids, int runtimeFlags,
		int[][] rlimits, long permittedCapabilities, long effectiveCapabilities);

		/**
		* Lets children of the zygote inherit open file descriptors to this path.
		*/
		native protected static void nativeAllowFileAcrossFork(String path);
		protected static native void nativeAllowFileAcrossFork(String path);

		/**
		* Installs a seccomp filter that limits setresuid()/setresgid() to the passed-in range
		@@ -251,7 +257,22 @@ public final class Zygote {
		* Zygote unmount storage space on initializing.
		* This method is called once.
		*/
		native protected static void nativeUnmountStorageOnInit();
		protected static native void nativeUnmountStorageOnInit();

		protected static native void nativeGetSocketFDs(boolean isPrimary);

		private static native int nativeGetBlastulaPoolCount();

		private static native int nativeGetBlastulaPoolEventFD();

		private static native int nativeForkBlastula(int readPipeFD,
		int writePipeFD,
		int[] sessionSocketRawFDs);

		private static native int[] nativeGetBlastulaPipeFDs();

		private static native boolean nativeRemoveBlastulaTableEntry(int blastulaPID);


		private static void callPostForkSystemServerHooks() {
		// SystemServer specific post fork hooks run before child post fork hooks.

core/jni/com_android_internal_os_Zygote.cpp

+778 −324

File changed.

Preview size limit exceeded, changes collapsed.

core/jni/fd_utils.cpp

+116 −157

Original line number	Diff line number	Diff line
		@@ -136,15 +136,14 @@ FileDescriptorWhitelist* FileDescriptorWhitelist::instance_ = nullptr;
		// open zygote file descriptor.
		class FileDescriptorInfo {
		public:
		// Create a FileDescriptorInfo for a given file descriptor. Returns
		// \|NULL\| if an error occurred.
		static FileDescriptorInfo* CreateFromFd(int fd, std::string* error_msg);
		// Create a FileDescriptorInfo for a given file descriptor.
		static FileDescriptorInfo* CreateFromFd(int fd, fail_fn_t fail_fn);

		// Checks whether the file descriptor associated with this object
		// refers to the same description.
		bool Restat() const;
		bool RefersToSameFile() const;

		bool ReopenOrDetach(std::string* error_msg) const;
		void ReopenOrDetach(fail_fn_t fail_fn) const;

		const int fd;
		const struct stat stat;
		@@ -170,19 +169,18 @@ class FileDescriptorInfo {
		// address).
		static bool GetSocketName(const int fd, std::string* result);

		bool DetachSocket(std::string* error_msg) const;
		void DetachSocket(fail_fn_t fail_fn) const;

		DISALLOW_COPY_AND_ASSIGN(FileDescriptorInfo);
		};

		// static
		FileDescriptorInfo* FileDescriptorInfo::CreateFromFd(int fd, std::string* error_msg) {
		FileDescriptorInfo* FileDescriptorInfo::CreateFromFd(int fd, fail_fn_t fail_fn) {
		struct stat f_stat;
		// This should never happen; the zygote should always have the right set
		// of permissions required to stat all its open files.
		if (TEMP_FAILURE_RETRY(fstat(fd, &f_stat)) == -1) {
		*error_msg = android::base::StringPrintf("Unable to stat %d", fd);
		return nullptr;
		fail_fn(android::base::StringPrintf("Unable to stat %d", fd));
		}

		const FileDescriptorWhitelist* whitelist = FileDescriptorWhitelist::Get();
		@@ -190,15 +188,13 @@ FileDescriptorInfo* FileDescriptorInfo::CreateFromFd(int fd, std::string* error_
		if (S_ISSOCK(f_stat.st_mode)) {
		std::string socket_name;
		if (!GetSocketName(fd, &socket_name)) {
		*error_msg = "Unable to get socket name";
		return nullptr;
		fail_fn("Unable to get socket name");
		}

		if (!whitelist->IsAllowed(socket_name)) {
		*error_msg = android::base::StringPrintf("Socket name not whitelisted : %s (fd=%d)",
		fail_fn(android::base::StringPrintf("Socket name not whitelisted : %s (fd=%d)",
		socket_name.c_str(),
		fd);
		return nullptr;
		fd));
		}

		return new FileDescriptorInfo(fd);
		@@ -211,26 +207,35 @@ FileDescriptorInfo* FileDescriptorInfo::CreateFromFd(int fd, std::string* error_
		// S_ISDIR : Not supported. (We could if we wanted to, but it's unused).
		// S_ISLINK : Not supported.
		// S_ISBLK : Not supported.
		// S_ISFIFO : Not supported. Note that the zygote uses pipes to communicate
		// with the child process across forks but those should have been closed
		// before we got to this point.
		// S_ISFIFO : Not supported. Note that the Zygote and blastulas use pipes to
		// communicate with the child processes across forks but those should have been
		// added to the redirection exemption list.
		if (!S_ISCHR(f_stat.st_mode) && !S_ISREG(f_stat.st_mode)) {
		*error_msg = android::base::StringPrintf("Unsupported st_mode %u", f_stat.st_mode);
		return nullptr;
		std::string mode = "Unknown";

		if (S_ISDIR(f_stat.st_mode)) {
		mode = "DIR";
		} else if (S_ISLNK(f_stat.st_mode)) {
		mode = "LINK";
		} else if (S_ISBLK(f_stat.st_mode)) {
		mode = "BLOCK";
		} else if (S_ISFIFO(f_stat.st_mode)) {
		mode = "FIFO";
		}

		fail_fn(android::base::StringPrintf("Unsupported st_mode for FD %d: %s", fd, mode.c_str()));
		}

		std::string file_path;
		const std::string fd_path = android::base::StringPrintf("/proc/self/fd/%d", fd);
		if (!android::base::Readlink(fd_path, &file_path)) {
		*error_msg = android::base::StringPrintf("Could not read fd link %s: %s",
		fail_fn(android::base::StringPrintf("Could not read fd link %s: %s",
		fd_path.c_str(),
		strerror(errno));
		return nullptr;
		strerror(errno)));
		}

		if (!whitelist->IsAllowed(file_path)) {
		*error_msg = std::string("Not whitelisted : ").append(file_path);
		return nullptr;
		fail_fn(std::string("Not whitelisted : ").append(file_path));
		}

		// File descriptor flags : currently on FD_CLOEXEC. We can set these
		@@ -238,11 +243,10 @@ FileDescriptorInfo* FileDescriptorInfo::CreateFromFd(int fd, std::string* error_
		// there won't be any races.
		const int fd_flags = TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD));
		if (fd_flags == -1) {
		*error_msg = android::base::StringPrintf("Failed fcntl(%d, F_GETFD) (%s): %s",
		fail_fn(android::base::StringPrintf("Failed fcntl(%d, F_GETFD) (%s): %s",
		fd,
		file_path.c_str(),
		strerror(errno));
		return nullptr;
		strerror(errno)));
		}

		// File status flags :
		@@ -259,11 +263,10 @@ FileDescriptorInfo* FileDescriptorInfo::CreateFromFd(int fd, std::string* error_
		// their presence and pass them in to open().
		int fs_flags = TEMP_FAILURE_RETRY(fcntl(fd, F_GETFL));
		if (fs_flags == -1) {
		*error_msg = android::base::StringPrintf("Failed fcntl(%d, F_GETFL) (%s): %s",
		fail_fn(android::base::StringPrintf("Failed fcntl(%d, F_GETFL) (%s): %s",
		fd,
		file_path.c_str(),
		strerror(errno));
		return nullptr;
		strerror(errno)));
		}

		// File offset : Ignore the offset for non seekable files.
		@@ -278,7 +281,7 @@ FileDescriptorInfo* FileDescriptorInfo::CreateFromFd(int fd, std::string* error_
		return new FileDescriptorInfo(f_stat, file_path, fd, open_flags, fd_flags, fs_flags, offset);
		}

		bool FileDescriptorInfo::Restat() const {
		bool FileDescriptorInfo::RefersToSameFile() const {
		struct stat f_stat;
		if (TEMP_FAILURE_RETRY(fstat(fd, &f_stat)) == -1) {
		PLOG(ERROR) << "Unable to restat fd " << fd;
		@@ -288,9 +291,9 @@ bool FileDescriptorInfo::Restat() const {
		return f_stat.st_ino == stat.st_ino && f_stat.st_dev == stat.st_dev;
		}

		bool FileDescriptorInfo::ReopenOrDetach(std::string* error_msg) const {
		void FileDescriptorInfo::ReopenOrDetach(fail_fn_t fail_fn) const {
		if (is_sock) {
		return DetachSocket(error_msg);
		return DetachSocket(fail_fn);
		}

		// NOTE: This might happen if the file was unlinked after being opened.
		@@ -299,57 +302,50 @@ bool FileDescriptorInfo::ReopenOrDetach(std::string* error_msg) const {
		const int new_fd = TEMP_FAILURE_RETRY(open(file_path.c_str(), open_flags));

		if (new_fd == -1) {
		*error_msg = android::base::StringPrintf("Failed open(%s, %i): %s",
		fail_fn(android::base::StringPrintf("Failed open(%s, %i): %s",
		file_path.c_str(),
		open_flags,
		strerror(errno));
		return false;
		strerror(errno)));
		}

		if (TEMP_FAILURE_RETRY(fcntl(new_fd, F_SETFD, fd_flags)) == -1) {
		close(new_fd);
		*error_msg = android::base::StringPrintf("Failed fcntl(%d, F_SETFD, %d) (%s): %s",
		fail_fn(android::base::StringPrintf("Failed fcntl(%d, F_SETFD, %d) (%s): %s",
		new_fd,
		fd_flags,
		file_path.c_str(),
		strerror(errno));
		return false;
		strerror(errno)));
		}

		if (TEMP_FAILURE_RETRY(fcntl(new_fd, F_SETFL, fs_flags)) == -1) {
		close(new_fd);
		*error_msg = android::base::StringPrintf("Failed fcntl(%d, F_SETFL, %d) (%s): %s",
		fail_fn(android::base::StringPrintf("Failed fcntl(%d, F_SETFL, %d) (%s): %s",
		new_fd,
		fs_flags,
		file_path.c_str(),
		strerror(errno));
		return false;
		strerror(errno)));
		}

		if (offset != -1 && TEMP_FAILURE_RETRY(lseek64(new_fd, offset, SEEK_SET)) == -1) {
		close(new_fd);
		*error_msg = android::base::StringPrintf("Failed lseek64(%d, SEEK_SET) (%s): %s",
		fail_fn(android::base::StringPrintf("Failed lseek64(%d, SEEK_SET) (%s): %s",
		new_fd,
		file_path.c_str(),
		strerror(errno));
		return false;
		strerror(errno)));
		}

		int dupFlags = (fd_flags & FD_CLOEXEC) ? O_CLOEXEC : 0;
		if (TEMP_FAILURE_RETRY(dup3(new_fd, fd, dupFlags)) == -1) {
		int dup_flags = (fd_flags & FD_CLOEXEC) ? O_CLOEXEC : 0;
		if (TEMP_FAILURE_RETRY(dup3(new_fd, fd, dup_flags)) == -1) {
		close(new_fd);
		*error_msg = android::base::StringPrintf("Failed dup3(%d, %d, %d) (%s): %s",
		fail_fn(android::base::StringPrintf("Failed dup3(%d, %d, %d) (%s): %s",
		fd,
		new_fd,
		dupFlags,
		dup_flags,
		file_path.c_str(),
		strerror(errno));
		return false;
		strerror(errno)));
		}

		close(new_fd);

		return true;
		}

		FileDescriptorInfo::FileDescriptorInfo(int fd) :
		@@ -375,7 +371,6 @@ FileDescriptorInfo::FileDescriptorInfo(struct stat stat, const std::string& file
		is_sock(false) {
		}

		// static
		bool FileDescriptorInfo::GetSocketName(const int fd, std::string* result) {
		sockaddr_storage ss;
		sockaddr* addr = reinterpret_cast<sockaddr*>(&ss);
		@@ -419,86 +414,75 @@ bool FileDescriptorInfo::GetSocketName(const int fd, std::string* result) {
		return true;
		}

		bool FileDescriptorInfo::DetachSocket(std::string* error_msg) const {
		void FileDescriptorInfo::DetachSocket(fail_fn_t fail_fn) const {
		const int dev_null_fd = open("/dev/null", O_RDWR);
		if (dev_null_fd < 0) {
		*error_msg = std::string("Failed to open /dev/null: ").append(strerror(errno));
		return false;
		fail_fn(std::string("Failed to open /dev/null: ").append(strerror(errno)));
		}

		if (dup2(dev_null_fd, fd) == -1) {
		*error_msg = android::base::StringPrintf("Failed dup2 on socket descriptor %d: %s",
		fail_fn(android::base::StringPrintf("Failed dup2 on socket descriptor %d: %s",
		fd,
		strerror(errno));
		return false;
		strerror(errno)));
		}

		if (close(dev_null_fd) == -1) {
		*error_msg = android::base::StringPrintf("Failed close(%d): %s", dev_null_fd, strerror(errno));
		return false;
		fail_fn(android::base::StringPrintf("Failed close(%d): %s", dev_null_fd, strerror(errno)));
		}

		return true;
		}

		// static
		FileDescriptorTable* FileDescriptorTable::Create(const std::vector<int>& fds_to_ignore,
		std::string* error_msg) {
		DIR* d = opendir(kFdPath);
		if (d == nullptr) {
		*error_msg = std::string("Unable to open directory ").append(kFdPath);
		return nullptr;
		fail_fn_t fail_fn) {
		DIR* proc_fd_dir = opendir(kFdPath);
		if (proc_fd_dir == nullptr) {
		fail_fn(std::string("Unable to open directory ").append(kFdPath));
		}
		int dir_fd = dirfd(d);
		dirent* e;

		int dir_fd = dirfd(proc_fd_dir);
		dirent* dir_entry;

		std::unordered_map<int, FileDescriptorInfo*> open_fd_map;
		while ((e = readdir(d)) != NULL) {
		const int fd = ParseFd(e, dir_fd);
		while ((dir_entry = readdir(proc_fd_dir)) != nullptr) {
		const int fd = ParseFd(dir_entry, dir_fd);
		if (fd == -1) {
		continue;
		}

		if (std::find(fds_to_ignore.begin(), fds_to_ignore.end(), fd) != fds_to_ignore.end()) {
		LOG(INFO) << "Ignoring open file descriptor " << fd;
		continue;
		}

		FileDescriptorInfo* info = FileDescriptorInfo::CreateFromFd(fd, error_msg);
		if (info == NULL) {
		if (closedir(d) == -1) {
		PLOG(ERROR) << "Unable to close directory";
		}
		return NULL;
		}
		open_fd_map[fd] = info;
		open_fd_map[fd] = FileDescriptorInfo::CreateFromFd(fd, fail_fn);
		}

		if (closedir(d) == -1) {
		*error_msg = "Unable to close directory";
		return nullptr;
		if (closedir(proc_fd_dir) == -1) {
		fail_fn("Unable to close directory");
		}

		return new FileDescriptorTable(open_fd_map);
		}

		bool FileDescriptorTable::Restat(const std::vector<int>& fds_to_ignore, std::string* error_msg) {
		void FileDescriptorTable::Restat(const std::vector<int>& fds_to_ignore, fail_fn_t fail_fn) {
		std::set<int> open_fds;

		// First get the list of open descriptors.
		DIR* d = opendir(kFdPath);
		if (d == NULL) {
		*error_msg = android::base::StringPrintf("Unable to open directory %s: %s",
		DIR* proc_fd_dir = opendir(kFdPath);
		if (proc_fd_dir == nullptr) {
		fail_fn(android::base::StringPrintf("Unable to open directory %s: %s",
		kFdPath,
		strerror(errno));
		return false;
		strerror(errno)));
		}

		int dir_fd = dirfd(d);
		dirent* e;
		while ((e = readdir(d)) != NULL) {
		const int fd = ParseFd(e, dir_fd);
		int dir_fd = dirfd(proc_fd_dir);
		dirent* dir_entry;
		while ((dir_entry = readdir(proc_fd_dir)) != nullptr) {
		const int fd = ParseFd(dir_entry, dir_fd);
		if (fd == -1) {
		continue;
		}

		if (std::find(fds_to_ignore.begin(), fds_to_ignore.end(), fd) != fds_to_ignore.end()) {
		LOG(INFO) << "Ignoring open file descriptor " << fd;
		continue;
		@@ -507,27 +491,24 @@ bool FileDescriptorTable::Restat(const std::vector<int>& fds_to_ignore, std::str
		open_fds.insert(fd);
		}

		if (closedir(d) == -1) {
		*error_msg = android::base::StringPrintf("Unable to close directory: %s", strerror(errno));
		return false;
		if (closedir(proc_fd_dir) == -1) {
		fail_fn(android::base::StringPrintf("Unable to close directory: %s", strerror(errno)));
		}

		return RestatInternal(open_fds, error_msg);
		RestatInternal(open_fds, fail_fn);
		}

		// Reopens all file descriptors that are contained in the table. Returns true
		// if all descriptors were successfully re-opened or detached, and false if an
		// error occurred.
		bool FileDescriptorTable::ReopenOrDetach(std::string* error_msg) {
		// Reopens all file descriptors that are contained in the table.
		void FileDescriptorTable::ReopenOrDetach(fail_fn_t fail_fn) {
		std::unordered_map<int, FileDescriptorInfo*>::const_iterator it;
		for (it = open_fd_map_.begin(); it != open_fd_map_.end(); ++it) {
		const FileDescriptorInfo* info = it->second;
		if (info == NULL \|\| !info->ReopenOrDetach(error_msg)) {
		return false;
		if (info == nullptr) {
		return;
		} else {
		info->ReopenOrDetach(fail_fn);
		}
		}

		return true;
		}

		FileDescriptorTable::FileDescriptorTable(
		@@ -535,9 +516,7 @@ FileDescriptorTable::FileDescriptorTable(
		: open_fd_map_(map) {
		}

		bool FileDescriptorTable::RestatInternal(std::set<int>& open_fds, std::string* error_msg) {
		bool error = false;

		void FileDescriptorTable::RestatInternal(std::set<int>& open_fds, fail_fn_t fail_fn) {
		// Iterate through the list of file descriptors we've already recorded
		// and check whether :
		//
		@@ -560,28 +539,18 @@ bool FileDescriptorTable::RestatInternal(std::set<int>& open_fds, std::string* e
		} else {
		// The entry from the file descriptor table is still open. Restat
		// it and check whether it refers to the same file.
		const bool same_file = it->second->Restat();
		if (!same_file) {
		if (!it->second->RefersToSameFile()) {
		// The file descriptor refers to a different description. We must
		// update our entry in the table.
		delete it->second;
		it->second = FileDescriptorInfo::CreateFromFd(*element, error_msg);
		if (it->second == NULL) {
		// The descriptor no longer no longer refers to a whitelisted file.
		// We flag an error and remove it from the list of files we're
		// tracking.
		error = true;
		it = open_fd_map_.erase(it);
		} else {
		// Successfully restatted the file, move on to the next open FD.
		++it;
		}
		it->second = FileDescriptorInfo::CreateFromFd(*element, fail_fn);
		} else {
		// It's the same file. Nothing to do here. Move on to the next open
		// FD.
		++it;
		}

		++it;

		// Finally, remove the FD from the set of open_fds. We do this last because
		// \|element\| will not remain valid after a call to erase.
		open_fds.erase(element);
		@@ -600,25 +569,15 @@ bool FileDescriptorTable::RestatInternal(std::set<int>& open_fds, std::string* e
		std::set<int>::const_iterator it;
		for (it = open_fds.begin(); it != open_fds.end(); ++it) {
		const int fd = (*it);
		FileDescriptorInfo* info = FileDescriptorInfo::CreateFromFd(fd, error_msg);
		if (info == NULL) {
		// A newly opened file is not on the whitelist. Flag an error and
		// continue.
		error = true;
		} else {
		// Track the newly opened file.
		open_fd_map_[fd] = info;
		open_fd_map_[fd] = FileDescriptorInfo::CreateFromFd(fd, fail_fn);
		}
		}
		}

		return !error;
		}

		// static
		int FileDescriptorTable::ParseFd(dirent* e, int dir_fd) {
		int FileDescriptorTable::ParseFd(dirent* dir_entry, int dir_fd) {
		char* end;
		const int fd = strtol(e->d_name, &end, 10);
		const int fd = strtol(dir_entry->d_name, &end, 10);
		if ((*end) != '\0') {
		return -1;
		}

core/jni/fd_utils.h

+7 −4

Original line number	Diff line number	Diff line
		@@ -30,6 +30,9 @@

		class FileDescriptorInfo;

		// This type is duplicated in com_android_internal_os_Zygote.cpp
		typedef const std::function<void(std::string)>& fail_fn_t;

		// Whitelist of open paths that the zygote is allowed to keep open.
		//
		// In addition to the paths listed in kPathWhitelist in file_utils.cpp, and
		@@ -76,19 +79,19 @@ class FileDescriptorTable {
		// /proc/self/fd for the list of open file descriptors and collects
		// information about them. Returns NULL if an error occurs.
		static FileDescriptorTable* Create(const std::vector<int>& fds_to_ignore,
		std::string* error_msg);
		fail_fn_t fail_fn);

		bool Restat(const std::vector<int>& fds_to_ignore, std::string* error_msg);
		void Restat(const std::vector<int>& fds_to_ignore, fail_fn_t fail_fn);

		// Reopens all file descriptors that are contained in the table. Returns true
		// if all descriptors were successfully re-opened or detached, and false if an
		// error occurred.
		bool ReopenOrDetach(std::string* error_msg);
		void ReopenOrDetach(fail_fn_t fail_fn);

		private:
		explicit FileDescriptorTable(const std::unordered_map<int, FileDescriptorInfo*>& map);

		bool RestatInternal(std::set<int>& open_fds, std::string* error_msg);
		void RestatInternal(std::set<int>& open_fds, fail_fn_t fail_fn);

		static int ParseFd(dirent* e, int dir_fd);