Merge "init: move killing of process groups to libprocessgroup" into oc-dr1-dev (9cf4000f) · Commits · e / os / android_system_core

init/service.cpp

+0 −11

Original line number	Diff line number	Diff line
		@@ -209,17 +209,6 @@ void Service::NotifyStateChange(const std::string& new_state) const {
		}

		void Service::KillProcessGroup(int signal) {
		// We ignore reporting errors of ESRCH as this commonly happens in the below case,
		// 1) Terminate() is called, which sends SIGTERM to the process
		// 2) The process successfully exits
		// 3) ReapOneProcess() is called, which calls waitpid(-1, ...) which removes the pid entry.
		// 4) Reap() is called, which sends SIGKILL, but the pid no longer exists.
		// TODO: sigaction for SIGCHLD reports the pid of the exiting process,
		// we should do this kill with that pid first before calling waitpid().
		if (kill(-pid_, signal) == -1 && errno != ESRCH) {
		PLOG(ERROR) << "kill(" << pid_ << ", " << signal << ") failed";
		}

		// If we've already seen a successful result from killProcessGroup*(), then we have removed
		// the cgroup already and calling these functions a second time will simply result in an error.
		// This is true regardless of which signal was sent.

libprocessgroup/processgroup.cpp

+40 −0

Original line number	Diff line number	Diff line
		@@ -27,10 +27,12 @@
		#include <string.h>
		#include <sys/stat.h>
		#include <sys/types.h>
		#include <unistd.h>

		#include <chrono>
		#include <memory>
		#include <mutex>
		#include <set>
		#include <thread>

		#include <android-base/logging.h>
		@@ -258,6 +260,12 @@ static int doKillProcessGroupOnce(uid_t uid, int initialPid, int signal) {
		return -errno;
		}

		// 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;

		int ret;
		pid_t pid;
		int processes = 0;
		@@ -269,8 +277,40 @@ static int doKillProcessGroupOnce(uid_t uid, int initialPid, int signal) {
		LOG(WARNING) << "Yikes, we've been told to kill pid 0! How about we don't do that?";
		continue;
		}
		pid_t pgid = getpgid(pid);
		if (pgid == -1) PLOG(ERROR) << "getpgid(" << pid << ") failed";
		if (pgid == pid) {
		pgids.emplace(pid);
		} else {
		pids.emplace(pid);
		}
		}

		// Erase all pids that will be killed when we kill the process groups.
		for (auto it = pids.begin(); it != pids.end();) {
		pid_t pgid = getpgid(pid);
		if (pgids.count(pgid) == 1) {
		it = pids.erase(it);
		} else {
		++it;
		}
		}

		// 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) {
		PLOG(WARNING) << "kill(" << -pgid << ", " << signal << ") failed";
		}
		}

		// Kill remaining pids.
		for (const auto pid : pids) {
		LOG(VERBOSE) << "Killing pid " << pid << " in uid " << uid << " as part of process cgroup "
		<< initialPid;

		if (kill(pid, signal) == -1) {
		PLOG(WARNING) << "kill(" << pid << ", " << signal << ") failed";
		}