Merge "Kill services even when cgroups is disabled" (5c3e2481) · Commits · e / os / android_system_core

init/service.cpp

+0 −2

Original line number	Diff line number	Diff line
		@@ -712,8 +712,6 @@ Result<void> Service::Start() {
		if (use_memcg) {
		ConfigureMemcg();
		}
		} else {
		process_cgroup_empty_ = true;
		}

		if (oom_score_adjust_ != DEFAULT_OOM_SCORE_ADJUST) {

libprocessgroup/processgroup.cpp

+59 −39

Original line number	Diff line number	Diff line
		@@ -367,8 +367,17 @@ err:
		// Returns 0 if there are no processes in the process cgroup left to kill
		// Returns -1 on error
		static int DoKillProcessGroupOnce(const char* cgroup, uid_t uid, int initialPid, int signal) {
		// We separate all of the pids in the cgroup into those pids that are also the leaders of
		// process groups (stored in the pgids set) and those that are not (stored in the pids set).
		std::set<pid_t> pgids;
		pgids.emplace(initialPid);
		std::set<pid_t> pids;

		std::unique_ptr<FILE, decltype(&fclose)> fd(nullptr, fclose);

		if (CgroupsAvailable()) {
		auto path = ConvertUidPidToPath(cgroup, uid, initialPid) + PROCESSGROUP_CGROUP_PROCS_FILE;
		std::unique_ptr<FILE, decltype(&fclose)> fd(fopen(path.c_str(), "re"), fclose);
		fd.reset(fopen(path.c_str(), "re"));
		if (!fd) {
		if (errno == ENOENT) {
		// This happens when process is already dead
		@@ -378,21 +387,15 @@ static int DoKillProcessGroupOnce(const char* cgroup, uid_t uid, int initialPid,
		<< initialPid;
		return -1;
		}

		// We separate all of the pids in the cgroup into those pids that are also the leaders of
		// process groups (stored in the pgids set) and those that are not (stored in the pids set).
		std::set<pid_t> pgids;
		pgids.emplace(initialPid);
		std::set<pid_t> pids;

		pid_t pid;
		int processes = 0;
		bool file_is_empty = true;
		while (fscanf(fd.get(), "%d\n", &pid) == 1 && pid >= 0) {
		processes++;
		file_is_empty = false;
		if (pid == 0) {
		// Should never happen... but if it does, trying to kill this
		// will boomerang right back and kill us! Let's not let that happen.
		LOG(WARNING) << "Yikes, we've been told to kill pid 0! How about we don't do that?";
		LOG(WARNING)
		<< "Yikes, we've been told to kill pid 0! How about we don't do that?";
		continue;
		}
		pid_t pgid = getpgid(pid);
		@@ -403,6 +406,10 @@ static int DoKillProcessGroupOnce(const char* cgroup, uid_t uid, int initialPid,
		pids.emplace(pid);
		}
		}
		if (file_is_empty) {
		// This happens when process is already dead
		return 0;
		}

		// Erase all pids that will be killed when we kill the process groups.
		for (auto it = pids.begin(); it != pids.end();) {
		@@ -413,13 +420,17 @@ static int DoKillProcessGroupOnce(const char* cgroup, uid_t uid, int initialPid,
		++it;
		}
		}
		}

		int processes = 0;
		// Kill all process groups.
		for (const auto pgid : pgids) {
		LOG(VERBOSE) << "Killing process group " << -pgid << " in uid " << uid
		<< " as part of process cgroup " << initialPid;

		if (kill(-pgid, signal) == -1 && errno != ESRCH) {
		if (kill(-pgid, signal) == 0) {
		processes++;
		} else if (errno != ESRCH) {
		PLOG(WARNING) << "kill(" << -pgid << ", " << signal << ") failed";
		}
		}
		@@ -429,18 +440,22 @@ static int DoKillProcessGroupOnce(const char* cgroup, uid_t uid, int initialPid,
		LOG(VERBOSE) << "Killing pid " << pid << " in uid " << uid << " as part of process cgroup "
		<< initialPid;

		if (kill(pid, signal) == -1 && errno != ESRCH) {
		if (kill(pid, signal) == 0) {
		processes++;
		} else if (errno != ESRCH) {
		PLOG(WARNING) << "kill(" << pid << ", " << signal << ") failed";
		}
		}

		return feof(fd.get()) ? processes : -1;
		return (!fd \|\| feof(fd.get())) ? processes : -1;
		}

		static int KillProcessGroup(uid_t uid, int initialPid, int signal, int retries,
		int* max_processes) {
		std::string hierarchy_root_path;
		if (CgroupsAvailable()) {
		CgroupGetControllerPath(CGROUPV2_CONTROLLER_NAME, &hierarchy_root_path);
		}
		const char* cgroup = hierarchy_root_path.c_str();

		std::chrono::steady_clock::time_point start = std::chrono::steady_clock::now();
		@@ -485,6 +500,11 @@ static int KillProcessGroup(uid_t uid, int initialPid, int signal, int retries,
		<< " in " << static_cast<int>(ms) << "ms";
		}

		if (!CgroupsAvailable()) {
		// nothing to do here, if cgroups isn't available
		return 0;
		}

		// 400 retries correspond to 2 secs max timeout
		int err = RemoveProcessGroup(cgroup, uid, initialPid, 400);