From 92c49bcb3098050d41dd32a782a97cbd7a88675a Mon Sep 17 00:00:00 2001
From: Luis Hector Chavez <lhchavez@google.com>
Date: Fri, 27 Jul 2018 11:19:25 -0700
Subject: [PATCH] init: Cleanly shut down subcontext processes

This change adds an explicit cleanup for the subcontext processes and
avoids them from respawning, which causes a bunch of LOG(FATAL)s when
the system is going down.

Bug: 80425914
Test: kill -TERM $INIT_PID, no crashes for subcontext inits

Change-Id: I135191d959c1dd921b102af316b24d2bc161d6c9
---
 init/reboot.cpp     |  1 +
 init/subcontext.cpp | 12 +++++++++++-
 init/subcontext.h   |  1 +
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/init/reboot.cpp b/init/reboot.cpp
index 6f6e39f25..11507f489 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -443,6 +443,7 @@ void DoReboot(unsigned int cmd, const std::string& reason, const std::string& re
     for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) {
         if (!s->IsShutdownCritical()) s->Stop();
     }
+    SubcontextTerminate();
     ReapAnyOutstandingChildren();
 
     // 3. send volume shutdown to vold
diff --git a/init/subcontext.cpp b/init/subcontext.cpp
index 267d530f0..ee7251328 100644
--- a/init/subcontext.cpp
+++ b/init/subcontext.cpp
@@ -352,6 +352,7 @@ Result<std::vector<std::string>> Subcontext::ExpandArgs(const std::vector<std::s
 }
 
 static std::vector<Subcontext> subcontexts;
+static bool shutting_down;
 
 std::vector<Subcontext>* InitializeSubcontexts() {
     if (SelinuxHasVendorInit()) {
@@ -365,12 +366,21 @@ std::vector<Subcontext>* InitializeSubcontexts() {
 bool SubcontextChildReap(pid_t pid) {
     for (auto& subcontext : subcontexts) {
         if (subcontext.pid() == pid) {
-            subcontext.Restart();
+            if (!shutting_down) {
+                subcontext.Restart();
+            }
             return true;
         }
     }
     return false;
 }
 
+void SubcontextTerminate() {
+    shutting_down = true;
+    for (auto& subcontext : subcontexts) {
+        kill(subcontext.pid(), SIGTERM);
+    }
+}
+
 }  // namespace init
 }  // namespace android
diff --git a/init/subcontext.h b/init/subcontext.h
index 22d7d43bd..628fd50e7 100644
--- a/init/subcontext.h
+++ b/init/subcontext.h
@@ -63,6 +63,7 @@ class Subcontext {
 int SubcontextMain(int argc, char** argv, const KeywordFunctionMap* function_map);
 std::vector<Subcontext>* InitializeSubcontexts();
 bool SubcontextChildReap(pid_t pid);
+void SubcontextTerminate();
 
 }  // namespace init
 }  // namespace android