Merge "init: always kill oneshot services' process groups." (8fa4d6c3) · Commits · e / os / android_system_core

init/service.cpp

+24 −4

Original line number	Diff line number	Diff line
		@@ -42,9 +42,11 @@

		#if defined(__ANDROID__)
		#include <ApexProperties.sysprop.h>
		#include <android/api-level.h>

		#include "mount_namespace.h"
		#include "property_service.h"
		#include "selinux.h"
		#else
		#include "host_init_stubs.h"
		#endif
		@@ -182,7 +184,7 @@ void Service::NotifyStateChange(const std::string& new_state) const {
		}
		}

		void Service::KillProcessGroup(int signal) {
		void Service::KillProcessGroup(int signal, bool report_oneshot) {
		// 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.
		@@ -190,11 +192,20 @@ void Service::KillProcessGroup(int signal) {
		if (!process_cgroup_empty_) {
		LOG(INFO) << "Sending signal " << signal << " to service '" << name_ << "' (pid " << pid_
		<< ") process group...";
		int max_processes = 0;
		int r;
		if (signal == SIGTERM) {
		r = killProcessGroupOnce(proc_attr_.uid, pid_, signal);
		r = killProcessGroupOnce(proc_attr_.uid, pid_, signal, &max_processes);
		} else {
		r = killProcessGroup(proc_attr_.uid, pid_, signal);
		r = killProcessGroup(proc_attr_.uid, pid_, signal, &max_processes);
		}

		if (report_oneshot && max_processes > 0) {
		LOG(WARNING)
		<< "Killed " << max_processes
		<< " additional processes from a oneshot process group for service '" << name_
		<< "'. This is new behavior, previously child processes would not be killed in "
		"this case.";
		}

		if (r == 0) process_cgroup_empty_ = true;
		@@ -244,7 +255,16 @@ void Service::SetProcessAttributesAndCaps() {

		void Service::Reap(const siginfo_t& siginfo) {
		if (!(flags_ & SVC_ONESHOT) \|\| (flags_ & SVC_RESTART)) {
		KillProcessGroup(SIGKILL);
		KillProcessGroup(SIGKILL, false);
		} else {
		// Legacy behavior from ~2007 until Android R: this else branch did not exist and we did not
		// kill the process group in this case.
		if (SelinuxGetVendorAndroidVersion() >= __ANDROID_API_R__) {
		// The new behavior in Android R is to kill these process groups in all cases. The
		// 'true' parameter instructions KillProcessGroup() to report a warning message where it
		// detects a difference in behavior has occurred.
		KillProcessGroup(SIGKILL, true);
		}
		}

		// Remove any socket resources we may have created.

init/service.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -132,7 +132,7 @@ class Service {
		private:
		void NotifyStateChange(const std::string& new_state) const;
		void StopOrReset(int how);
		void KillProcessGroup(int signal);
		void KillProcessGroup(int signal, bool report_oneshot = false);
		void SetProcessAttributesAndCaps();

		static unsigned long next_start_order_;

libprocessgroup/include/processgroup/processgroup.h

+5 −2

Original line number	Diff line number	Diff line
		@@ -47,11 +47,14 @@ void DropTaskProfilesResourceCaching();
		// Return 0 and removes the cgroup if there are no longer any processes in it.
		// Returns -1 in the case of an error occurring or if there are processes still running
		// even after retrying for up to 200ms.
		int killProcessGroup(uid_t uid, int initialPid, int signal);
		// If max_processes is not nullptr, it returns the maximum number of processes seen in the cgroup
		// during the killing process. Note that this can be 0 if all processes from the process group have
		// already been terminated.
		int killProcessGroup(uid_t uid, int initialPid, int signal, int* max_processes = nullptr);

		// Returns the same as killProcessGroup(), however it does not retry, which means
		// that it only returns 0 in the case that the cgroup exists and it contains no processes.
		int killProcessGroupOnce(uid_t uid, int initialPid, int signal);
		int killProcessGroupOnce(uid_t uid, int initialPid, int signal, int* max_processes = nullptr);

		int createProcessGroup(uid_t uid, int initialPid, bool memControl = false);

libprocessgroup/processgroup.cpp

+13 −5

Original line number	Diff line number	Diff line
		@@ -301,7 +301,8 @@ static int DoKillProcessGroupOnce(const char* cgroup, uid_t uid, int initialPid,
		return feof(fd.get()) ? processes : -1;
		}

		static int KillProcessGroup(uid_t uid, int initialPid, int signal, int retries) {
		static int KillProcessGroup(uid_t uid, int initialPid, int signal, int retries,
		int* max_processes) {
		std::string cpuacct_path;
		std::string memory_path;

		@@ -316,9 +317,16 @@ static int KillProcessGroup(uid_t uid, int initialPid, int signal, int retries)

		std::chrono::steady_clock::time_point start = std::chrono::steady_clock::now();

		if (max_processes != nullptr) {
		*max_processes = 0;
		}

		int retry = retries;
		int processes;
		while ((processes = DoKillProcessGroupOnce(cgroup, uid, initialPid, signal)) > 0) {
		if (max_processes != nullptr && processes > *max_processes) {
		*max_processes = processes;
		}
		LOG(VERBOSE) << "Killed " << processes << " processes for processgroup " << initialPid;
		if (retry > 0) {
		std::this_thread::sleep_for(5ms);
		@@ -359,12 +367,12 @@ static int KillProcessGroup(uid_t uid, int initialPid, int signal, int retries)
		}
		}

		int killProcessGroup(uid_t uid, int initialPid, int signal) {
		return KillProcessGroup(uid, initialPid, signal, 40 /retries/);
		int killProcessGroup(uid_t uid, int initialPid, int signal, int* max_processes) {
		return KillProcessGroup(uid, initialPid, signal, 40 /retries/, max_processes);
		}

		int killProcessGroupOnce(uid_t uid, int initialPid, int signal) {
		return KillProcessGroup(uid, initialPid, signal, 0 /retries/);
		int killProcessGroupOnce(uid_t uid, int initialPid, int signal, int* max_processes) {
		return KillProcessGroup(uid, initialPid, signal, 0 /retries/, max_processes);
		}

		int createProcessGroup(uid_t uid, int initialPid, bool memControl) {