Merge "adb: report subprocess creation errors to the client." (046bf3b2) · Commits · e / os / android_system_core

adb/shell_service.cpp

+60 −13

Original line number	Diff line number	Diff line
		@@ -192,7 +192,7 @@ class Subprocess {

		// Sets up FDs, forks a subprocess, starts the subprocess manager thread,
		// and exec's the child. Returns false on failure.
		bool ForkAndExec();
		bool ForkAndExec(std::string* _Nonnull error);

		private:
		// Opens the file at \|pts_name\|.
		@@ -250,7 +250,7 @@ Subprocess::~Subprocess() {
		WaitForExit();
		}

		bool Subprocess::ForkAndExec() {
		bool Subprocess::ForkAndExec(std::string* error) {
		ScopedFd child_stdinout_sfd, child_stderr_sfd;
		ScopedFd parent_error_sfd, child_error_sfd;
		char pts_name[PATH_MAX];
		@@ -265,7 +265,9 @@ bool Subprocess::ForkAndExec() {
		// use threads, logging directly from the child might deadlock due to locks held in another
		// thread during the fork.
		if (!CreateSocketpair(&parent_error_sfd, &child_error_sfd)) {
		LOG(ERROR) << "failed to create pipe for subprocess error reporting";
		*error = android::base::StringPrintf(
		"failed to create pipe for subprocess error reporting: %s", strerror(errno));
		return false;
		}

		// Construct the environment for the child before we fork.
		@@ -316,18 +318,22 @@ bool Subprocess::ForkAndExec() {
		stdinout_sfd_.Reset(fd);
		} else {
		if (!CreateSocketpair(&stdinout_sfd_, &child_stdinout_sfd)) {
		*error = android::base::StringPrintf("failed to create socketpair for stdin/out: %s",
		strerror(errno));
		return false;
		}
		// Raw subprocess + shell protocol allows for splitting stderr.
		if (protocol_ == SubprocessProtocol::kShell &&
		!CreateSocketpair(&stderr_sfd_, &child_stderr_sfd)) {
		*error = android::base::StringPrintf("failed to create socketpair for stderr: %s",
		strerror(errno));
		return false;
		}
		pid_ = fork();
		}

		if (pid_ == -1) {
		PLOG(ERROR) << "fork failed";
		*error = android::base::StringPrintf("fork failed: %s", strerror(errno));
		return false;
		}

		@@ -357,7 +363,8 @@ bool Subprocess::ForkAndExec() {
		} else {
		execle(_PATH_BSHELL, _PATH_BSHELL, "-c", command_.c_str(), nullptr, cenv.data());
		}
		WriteFdExactly(child_error_sfd.fd(), "exec '" _PATH_BSHELL "' failed");
		WriteFdExactly(child_error_sfd.fd(), "exec '" _PATH_BSHELL "' failed: ");
		WriteFdExactly(child_error_sfd.fd(), strerror(errno));
		child_error_sfd.Reset();
		_Exit(1);
		}
		@@ -370,7 +377,7 @@ bool Subprocess::ForkAndExec() {
		child_error_sfd.Reset();
		std::string error_message = ReadAll(parent_error_sfd.fd());
		if (!error_message.empty()) {
		LOG(ERROR) << error_message;
		*error = error_message;
		return false;
		}

		@@ -382,6 +389,9 @@ bool Subprocess::ForkAndExec() {
		} else {
		// Shell protocol: create another socketpair to intercept data.
		if (!CreateSocketpair(&protocol_sfd_, &local_socket_sfd_)) {
		*error = android::base::StringPrintf(
		"failed to create socketpair to intercept data: %s", strerror(errno));
		kill(pid_, SIGKILL);
		return false;
		}
		D("protocol FD = %d", protocol_sfd_.fd());
		@@ -389,7 +399,8 @@ bool Subprocess::ForkAndExec() {
		input_.reset(new ShellProtocol(protocol_sfd_.fd()));
		output_.reset(new ShellProtocol(protocol_sfd_.fd()));
		if (!input_ \|\| !output_) {
		LOG(ERROR) << "failed to allocate shell protocol objects";
		*error = "failed to allocate shell protocol objects";
		kill(pid_, SIGKILL);
		return false;
		}

		@@ -400,7 +411,9 @@ bool Subprocess::ForkAndExec() {
		for (int fd : {stdinout_sfd_.fd(), stderr_sfd_.fd()}) {
		if (fd >= 0) {
		if (!set_file_block_mode(fd, false)) {
		LOG(ERROR) << "failed to set non-blocking mode for fd " << fd;
		*error = android::base::StringPrintf(
		"failed to set non-blocking mode for fd %d", fd);
		kill(pid_, SIGKILL);
		return false;
		}
		}
		@@ -408,7 +421,9 @@ bool Subprocess::ForkAndExec() {
		}

		if (!adb_thread_create(ThreadHandler, this)) {
		PLOG(ERROR) << "failed to create subprocess thread";
		*error =
		android::base::StringPrintf("failed to create subprocess thread: %s", strerror(errno));
		kill(pid_, SIGKILL);
		return false;
		}

		@@ -710,6 +725,37 @@ void Subprocess::WaitForExit() {

		} // namespace

		// Create a pipe containing the error.
		static int ReportError(SubprocessProtocol protocol, const std::string& message) {
		int pipefd[2];
		if (pipe(pipefd) != 0) {
		LOG(ERROR) << "failed to create pipe to report error";
		return -1;
		}

		std::string buf = android::base::StringPrintf("error: %s\n", message.c_str());
		if (protocol == SubprocessProtocol::kShell) {
		ShellProtocol::Id id = ShellProtocol::kIdStderr;
		uint32_t length = buf.length();
		WriteFdExactly(pipefd[1], &id, sizeof(id));
		WriteFdExactly(pipefd[1], &length, sizeof(length));
		}

		WriteFdExactly(pipefd[1], buf.data(), buf.length());

		if (protocol == SubprocessProtocol::kShell) {
		ShellProtocol::Id id = ShellProtocol::kIdExit;
		uint32_t length = 1;
		char exit_code = 126;
		WriteFdExactly(pipefd[1], &id, sizeof(id));
		WriteFdExactly(pipefd[1], &length, sizeof(length));
		WriteFdExactly(pipefd[1], &exit_code, sizeof(exit_code));
		}

		adb_close(pipefd[1]);
		return pipefd[0];
		}

		int StartSubprocess(const char* name, const char* terminal_type,
		SubprocessType type, SubprocessProtocol protocol) {
		D("starting %s subprocess (protocol=%s, TERM=%s): '%s'",
		@@ -720,13 +766,14 @@ int StartSubprocess(const char* name, const char* terminal_type,
		Subprocess* subprocess = new Subprocess(name, terminal_type, type, protocol);
		if (!subprocess) {
		LOG(ERROR) << "failed to allocate new subprocess";
		return -1;
		return ReportError(protocol, "failed to allocate new subprocess");
		}

		if (!subprocess->ForkAndExec()) {
		LOG(ERROR) << "failed to start subprocess";
		std::string error;
		if (!subprocess->ForkAndExec(&error)) {
		LOG(ERROR) << "failed to start subprocess: " << error;
		delete subprocess;
		return -1;
		return ReportError(protocol, error);
		}

		D("subprocess creation successful: local_socket_fd=%d, pid=%d",