Merge "init: reap zombies only after kill(-pid, ...)" (a51c40ce) · Commits · e / os / android_system_core

init/service.cpp

+20 −11

Original line number	Diff line number	Diff line
		@@ -34,6 +34,7 @@
		#include <android-base/logging.h>
		#include <android-base/parseint.h>
		#include <android-base/properties.h>
		#include <android-base/scopeguard.h>
		#include <android-base/stringprintf.h>
		#include <android-base/strings.h>
		#include <processgroup/processgroup.h>
		@@ -47,6 +48,7 @@
		using android::base::boot_clock;
		using android::base::GetProperty;
		using android::base::Join;
		using android::base::make_scope_guard;
		using android::base::ParseInt;
		using android::base::StartsWith;
		using android::base::StringPrintf;
		@@ -1088,14 +1090,24 @@ void ServiceManager::DumpState() const {
		}

		bool ServiceManager::ReapOneProcess() {
		int status;
		pid_t pid = TEMP_FAILURE_RETRY(waitpid(-1, &status, WNOHANG));
		if (pid == 0) {
		siginfo_t siginfo = {};
		// This returns a zombie pid or informs us that there are no zombies left to be reaped.
		// It does NOT reap the pid; that is done below.
		if (TEMP_FAILURE_RETRY(waitid(P_ALL, 0, &siginfo, WEXITED \| WNOHANG \| WNOWAIT)) != 0) {
		PLOG(ERROR) << "waitid failed";
		return false;
		} else if (pid == -1) {
		PLOG(ERROR) << "waitpid failed";
		return false;
		} else if (PropertyChildReap(pid)) {
		}

		auto pid = siginfo.si_pid;
		if (pid == 0) return false;

		// At this point we know we have a zombie pid, so we use this scopeguard to reap the pid
		// whenever the function returns from this point forward.
		// We do NOT want to reap the zombie earlier as in Service::Reap(), we kill(-pid, ...) and we
		// want the pid to remain valid throughout that (and potentially future) usages.
		auto reaper = make_scope_guard([pid] { TEMP_FAILURE_RETRY(waitpid(pid, nullptr, WNOHANG)); });

		if (PropertyChildReap(pid)) {
		return true;
		}

		@@ -1112,14 +1124,11 @@ bool ServiceManager::ReapOneProcess() {
		name = StringPrintf("Untracked pid %d", pid);
		}

		auto status = siginfo.si_status;
		if (WIFEXITED(status)) {
		LOG(INFO) << name << " exited with status " << WEXITSTATUS(status) << wait_string;
		} else if (WIFSIGNALED(status)) {
		LOG(INFO) << name << " killed by signal " << WTERMSIG(status) << wait_string;
		} else if (WIFSTOPPED(status)) {
		LOG(INFO) << name << " stopped by signal " << WSTOPSIG(status) << wait_string;
		} else {
		LOG(INFO) << name << " state changed" << wait_string;
		}

		if (!svc) {