Merge changes from topic "move_bionic_to_apex3" am: a15f385821 (7ce93d2d) · Commits · e / os / android_system_core

adb/daemon/file_sync_service.cpp

+86 −0

Original line number	Diff line number	Diff line
		@@ -25,6 +25,7 @@
		#include <stdio.h>
		#include <stdlib.h>
		#include <string.h>
		#include <sys/mount.h>
		#include <sys/stat.h>
		#include <sys/types.h>
		#include <unistd.h>
		@@ -209,6 +210,22 @@ done:
		return WriteFdExactly(s, &msg.dent, sizeof(msg.dent));
		}

		static bool is_mountpoint(const std::string& path, pid_t tid) {
		const std::string mountinfo_path = "/proc/" + std::to_string(tid) + "/mountinfo";
		std::string mountinfo;
		if (!android::base::ReadFileToString(mountinfo_path, &mountinfo)) {
		PLOG(ERROR) << "Failed to open " << mountinfo_path;
		return false;
		}
		std::vector<std::string> lines = android::base::Split(mountinfo, "\n");
		return std::find_if(lines.begin(), lines.end(), [&path](const auto& line) {
		auto tokens = android::base::Split(line, " ");
		// line format is ...
		// mountid parentmountid major:minor sourcepath targetpath option ...
		return tokens.size() >= 4 && tokens[4] == path;
		}) != lines.end();
		}

		// Make sure that SendFail from adb_io.cpp isn't accidentally used in this file.
		#pragma GCC poison SendFail

		@@ -415,6 +432,18 @@ static bool do_send(int s, const std::string& spec, std::vector<char>& buffer) {
		struct stat st;
		bool do_unlink = (lstat(path.c_str(), &st) == -1) \|\| S_ISREG(st.st_mode) \|\|
		(S_ISLNK(st.st_mode) && !S_ISLNK(mode));

		// If the path is a file that is a mount point, don't unlink it, but instead
		// truncate to zero. If unlinked, existing mounts on the path is all
		// unmounted
		if (S_ISREG(st.st_mode) && is_mountpoint(path, getpid())) {
		do_unlink = false;
		if (truncate(path.c_str(), 0) == -1) {
		SendSyncFail(s, "truncate to zero failed");
		return false;
		}
		}

		if (do_unlink) {
		adb_unlink(path.c_str());
		}
		@@ -546,7 +575,64 @@ static bool handle_sync_command(int fd, std::vector<char>& buffer) {
		return true;
		}

		#if defined(__ANDROID__)
		class FileSyncPreparer {
		public:
		FileSyncPreparer() : saved_ns_fd_(-1), rooted_(getuid() == 0) {
		const std::string namespace_path = "/proc/" + std::to_string(gettid()) + "/ns/mnt";
		const int ns_fd = adb_open(namespace_path.c_str(), O_RDONLY \| O_CLOEXEC);
		if (ns_fd == -1) {
		if (rooted_) PLOG(ERROR) << "Failed to save mount namespace";
		return;
		}
		saved_ns_fd_.reset(ns_fd);

		// Note: this is for the current thread only
		if (unshare(CLONE_NEWNS) != 0) {
		if (rooted_) PLOG(ERROR) << "Failed to clone mount namespace";
		return;
		}

		// Set the propagation type of / to private so that unmount below is
		// not propagated to other mount namespaces.
		if (mount(nullptr, "/", nullptr, MS_PRIVATE \| MS_REC, nullptr) == -1) {
		if (rooted_) PLOG(ERROR) << "Could not change propagation type of / to MS_PRIVATE";
		return;
		}

		// unmount /bionic which is bind-mount to itself by init. Under /bionic,
		// there are other bind mounts for the bionic files. By unmounting this,
		// we unmount them all thus revealing the raw file system that is the
		// same as the local file system seen by the adb client.
		if (umount2("/bionic", MNT_DETACH) == -1 && errno != ENOENT) {
		if (rooted_) PLOG(ERROR) << "Could not unmount /bionic to reveal raw filesystem";
		return;
		}
		}

		~FileSyncPreparer() {
		if (saved_ns_fd_.get() != -1) {
		// In fact, this is not strictly required because this thread for file
		// sync service will be destroyed after the current transfer is all
		// done. However, let's restore the ns in case the same thread is
		// reused by multiple transfers in the future refactoring.
		if (setns(saved_ns_fd_, CLONE_NEWNS) == -1) {
		PLOG(ERROR) << "Failed to restore saved mount namespace";
		}
		}
		}

		private:
		unique_fd saved_ns_fd_;
		bool rooted_;
		};
		#endif

		void file_sync_service(unique_fd fd) {
		#if defined(__ANDROID__)
		FileSyncPreparer preparer;
		#endif

		std::vector<char> buffer(SYNC_DATA_MAX);

		while (handle_sync_command(fd.get(), buffer)) {

adb/daemon/remount_service.cpp

+19 −0

Original line number	Diff line number	Diff line
		@@ -230,6 +230,23 @@ static void reboot_for_remount(int fd, bool need_fsck) {
		android::base::SetProperty(ANDROID_RB_PROPERTY, reboot_cmd.c_str());
		}

		static void try_unmount_bionic(int fd) {
		static constexpr const char* kBionic = "/bionic";
		struct statfs buf;
		if (statfs(kBionic, &buf) == -1) {
		WriteFdFmt(fd, "statfs of the %s mount failed: %s.\n", kBionic, strerror(errno));
		return;
		}
		if (buf.f_flags & ST_RDONLY) {
		// /bionic is on a read-only partition; can happen for
		// non-system-as-root-devices. Don' try to unmount.
		return;
		}
		// Success/Fail of the actual remount will be reported by the function.
		remount_partition(fd, kBionic);
		return;
		}

		void remount_service(unique_fd fd, const std::string& cmd) {
		bool user_requested_reboot = cmd == "-R";

		@@ -323,6 +340,8 @@ void remount_service(unique_fd fd, const std::string& cmd) {
		return;
		}

		try_unmount_bionic(fd.get());

		if (!success) {
		WriteFdExactly(fd.get(), "remount failed\n");
		} else {

fs_mgr/tests/adb-remount-test.sh

+20 −0

Original line number	Diff line number	Diff line
		@@ -569,6 +569,18 @@ B="`adb_cat /vendor/hello`" \|\|
		die "vendor hello"
		check_eq "${A}" "${B}" /vendor before reboot

		# download libc.so, append some gargage, push back, and check if the file is updated.
		tempdir="`mktemp -d`"
		cleanup() {
		rm -rf ${tempdir}
		}
		adb pull /system/lib/bootstrap/libc.so ${tempdir} \|\| die "pull libc.so from device"
		garbage="`hexdump -n 16 -e '4/4 "%08X" 1 "\n"' /dev/random`"
		echo ${garbage} >> ${tempdir}/libc.so
		adb push ${tempdir}/libc.so /system/lib/bootstrap/libc.so \|\| die "push libc.so to device"
		adb pull /system/lib/bootstrap/libc.so ${tempdir}/libc.so.fromdevice \|\| die "pull libc.so from device"
		diff ${tempdir}/libc.so ${tempdir}/libc.so.fromdevice > /dev/null \|\| die "libc.so differ"

		echo "${GREEN}[ RUN ]${NORMAL} reboot to confirm content persistent" >&2

		adb_reboot &&
		@@ -607,6 +619,14 @@ adb_root &&
		check_eq "${A}" "${B}" vendor after reboot
		echo "${GREEN}[ OK ]${NORMAL} /vendor content remains after reboot" >&2

		# check if the updated libc.so is persistent after reboot
		adb_root &&
		adb pull /system/lib/bootstrap/libc.so ${tempdir}/libc.so.fromdevice \|\|
		die "pull libc.so from device"
		diff ${tempdir}/libc.so ${tempdir}/libc.so.fromdevice > /dev/null \|\| die "libc.so differ"
		rm -r ${tempdir}
		echo "${GREEN}[ OK ]${NORMAL} /system/lib/bootstrap/libc.so content remains after reboot" >&2

		echo "${GREEN}[ RUN ]${NORMAL} flash vendor, confirm its content disappears" >&2

		H=`adb_sh echo '${HOSTNAME}' </dev/null 2>/dev/null`