Merge changes from topic 'exec-start-update-verifier'

* changes:
  init.rc: launch update_verifier with exec_start
  init: add exec_start command

init/README.md

@@ -311,6 +311,12 @@ Commands
   groups can be provided. No other commands will be run until this one
   finishes. _seclabel_ can be a - to denote default. Properties are expanded
   within _argument_.
+  Init halts executing commands until the forked process exits.
+
+`exec_start <service>`
+> Start service a given service and halt processing of additional init commands
+  until it returns.  It functions similarly to the `exec` command, but uses an
+  existing service definition instead of providing them as arguments.
 
 `export <name> <value>`
 > Set the environment variable _name_ equal to _value_ in the

init/builtins.cpp

@@ -167,19 +167,11 @@ static int do_enable(const std::vector<std::string>& args) {
 }
 
 static int do_exec(const std::vector<std::string>& args) {
-    Service* svc = ServiceManager::GetInstance().MakeExecOneshotService(args);
+    return ServiceManager::GetInstance().Exec(args) ? 0 : -1;
-    if (!svc) {
+}
-        return -1;
+
-    }
+static int do_exec_start(const std::vector<std::string>& args) {
-    if (!start_waiting_for_exec()) {
+    return ServiceManager::GetInstance().ExecStart(args[1]) ? 0 : -1;
-        return -1;
-    }
-    if (!svc->Start()) {
-        stop_waiting_for_exec();
-        ServiceManager::GetInstance().RemoveService(*svc);
-        return -1;
-    }
-    return 0;
 }
 
 static int do_export(const std::vector<std::string>& args) {
@@ -897,6 +889,7 @@ static int do_init_user0(const std::vector<std::string>& args) {
 
 BuiltinFunctionMap::Map& BuiltinFunctionMap::map() const {
     constexpr std::size_t kMax = std::numeric_limits<std::size_t>::max();
+    // clang-format off
     static const Map builtin_functions = {
         {"bootchart",               {1,     1,    do_bootchart}},
         {"chmod",                   {2,     2,    do_chmod}},
@@ -909,6 +902,7 @@ BuiltinFunctionMap::Map& BuiltinFunctionMap::map() const {
         {"domainname",              {1,     1,    do_domainname}},
         {"enable",                  {1,     1,    do_enable}},
         {"exec",                    {1,     kMax, do_exec}},
+        {"exec_start",              {1,     1,    do_exec_start}},
         {"export",                  {2,     2,    do_export}},
         {"hostname",                {1,     1,    do_hostname}},
         {"ifup",                    {1,     1,    do_ifup}},
@@ -942,5 +936,6 @@ BuiltinFunctionMap::Map& BuiltinFunctionMap::map() const {
         {"wait_for_prop",           {2,     2,    do_wait_for_prop}},
         {"write",                   {2,     2,    do_write}},
     };
+    // clang-format on
     return builtin_functions;
 }

init/init.cpp

@@ -84,8 +84,6 @@ static time_t process_needs_restart_at;
 
 const char *ENV[32];
 
-static std::unique_ptr<Timer> waiting_for_exec(nullptr);
-
 static int epoll_fd = -1;
 
 static std::unique_ptr<Timer> waiting_for_prop(nullptr);
@@ -133,23 +131,6 @@ int add_environment(const char *key, const char *val)
     return -1;
 }
 
-bool start_waiting_for_exec()
-{
-    if (waiting_for_exec) {
-        return false;
-    }
-    waiting_for_exec.reset(new Timer());
-    return true;
-}
-
-void stop_waiting_for_exec()
-{
-    if (waiting_for_exec) {
-        LOG(INFO) << "Wait for exec took " << *waiting_for_exec;
-        waiting_for_exec.reset();
-    }
-}
-
 bool start_waiting_for_property(const char *name, const char *value)
 {
     if (waiting_for_prop) {
@@ -1323,10 +1304,10 @@ int main(int argc, char** argv) {
         // By default, sleep until something happens.
         int epoll_timeout_ms = -1;
 
-        if (!(waiting_for_exec || waiting_for_prop)) {
+        if (!(waiting_for_prop || ServiceManager::GetInstance().IsWaitingForExec())) {
             am.ExecuteOneCommand();
         }
-        if (!(waiting_for_exec || waiting_for_prop)) {
+        if (!(waiting_for_prop || ServiceManager::GetInstance().IsWaitingForExec())) {
             restart_processes();
 
             // If there's a process that needs restarting, wake up in time for that.

init/init.h

@@ -32,10 +32,6 @@ void register_epoll_handler(int fd, void (*fn)());
 
 int add_environment(const char* key, const char* val);
 
-bool start_waiting_for_exec();
-
-void stop_waiting_for_exec();
-
 bool start_waiting_for_property(const char *name, const char *value);
 
 #endif  /* _INIT_INIT_H */

init/service.cpp

@@ -192,8 +192,8 @@ Service::Service(const std::string& name, unsigned flags, uid_t uid, gid_t gid,
 }
 
 void Service::NotifyStateChange(const std::string& new_state) const {
-    if ((flags_ & SVC_EXEC) != 0) {
+    if ((flags_ & SVC_TEMPORARY) != 0) {
-        // 'exec' commands don't have properties tracking their state.
+        // Services created by 'exec' are temporary and don't have properties tracking their state.
         return;
     }
 
@@ -260,7 +260,7 @@ void Service::SetProcessAttributes() {
     }
 }
 
-bool Service::Reap() {
+void Service::Reap() {
     if (!(flags_ & SVC_ONESHOT) || (flags_ & SVC_RESTART)) {
         KillProcessGroup(SIGKILL);
     }
@@ -271,7 +271,10 @@ bool Service::Reap() {
 
     if (flags_ & SVC_EXEC) {
         LOG(INFO) << "SVC_EXEC pid " << pid_ << " finished...";
-        return true;
+    }
+
+    if (flags_ & SVC_TEMPORARY) {
+        return;
     }
 
     pid_ = 0;
@@ -286,7 +289,7 @@ bool Service::Reap() {
     // Disabled and reset processes do not get restarted automatically.
     if (flags_ & (SVC_DISABLED | SVC_RESET))  {
         NotifyStateChange("stopped");
-        return false;
+        return;
     }
 
     // If we crash > 4 times in 4 minutes, reboot into recovery.
@@ -310,7 +313,7 @@ bool Service::Reap() {
     onrestart_.ExecuteAllCommands();
 
     NotifyStateChange("restarting");
-    return false;
+    return;
 }
 
 void Service::DumpState() const {
@@ -578,6 +581,18 @@ bool Service::ParseLine(const std::vector<std::string>& args, std::string* err)
     return (this->*parser)(args, err);
 }
 
+bool Service::ExecStart(std::unique_ptr<Timer>* exec_waiter) {
+    flags_ |= SVC_EXEC | SVC_ONESHOT;
+
+    exec_waiter->reset(new Timer);
+
+    if (!Start()) {
+        exec_waiter->reset();
+        return false;
+    }
+    return true;
+}
+
 bool Service::Start() {
     // Starting a service removes it from the disabled or reset state and
     // immediately takes it out of the restarting state if it was in there.
@@ -864,6 +879,35 @@ void ServiceManager::AddService(std::unique_ptr<Service> service) {
     services_.emplace_back(std::move(service));
 }
 
+bool ServiceManager::Exec(const std::vector<std::string>& args) {
+    Service* svc = MakeExecOneshotService(args);
+    if (!svc) {
+        LOG(ERROR) << "Could not create exec service";
+        return false;
+    }
+    if (!svc->ExecStart(&exec_waiter_)) {
+        LOG(ERROR) << "Could not start exec service";
+        ServiceManager::GetInstance().RemoveService(*svc);
+        return false;
+    }
+    return true;
+}
+
+bool ServiceManager::ExecStart(const std::string& name) {
+    Service* svc = FindServiceByName(name);
+    if (!svc) {
+        LOG(ERROR) << "ExecStart(" << name << "): Service not found";
+        return false;
+    }
+    if (!svc->ExecStart(&exec_waiter_)) {
+        LOG(ERROR) << "ExecStart(" << name << "): Could not start Service";
+        return false;
+    }
+    return true;
+}
+
+bool ServiceManager::IsWaitingForExec() const { return exec_waiter_ != nullptr; }
+
 Service* ServiceManager::MakeExecOneshotService(const std::vector<std::string>& args) {
     // Parse the arguments: exec [SECLABEL [UID [GID]*] --] COMMAND ARGS...
     // SECLABEL can be a - to denote default
@@ -887,7 +931,7 @@ Service* ServiceManager::MakeExecOneshotService(const std::vector<std::string>&
 
     exec_count_++;
     std::string name = StringPrintf("exec %d (%s)", exec_count_, str_args[0].c_str());
-    unsigned flags = SVC_EXEC | SVC_ONESHOT;
+    unsigned flags = SVC_EXEC | SVC_ONESHOT | SVC_TEMPORARY;
     CapSet no_capabilities;
     unsigned namespace_flags = 0;
 
@@ -1027,8 +1071,13 @@ bool ServiceManager::ReapOneProcess() {
         return true;
     }
 
-    if (svc->Reap()) {
+    svc->Reap();
-        stop_waiting_for_exec();
+
+    if (svc->flags() & SVC_EXEC) {
+        LOG(INFO) << "Wait for exec took " << *exec_waiter_;
+        exec_waiter_.reset();
+    }
+    if (svc->flags() & SVC_TEMPORARY) {
         RemoveService(*svc);
     }
 

init/service.h

@@ -44,10 +44,13 @@
 #define SVC_RC_DISABLED 0x080     // Remember if the disabled flag was set in the rc script.
 #define SVC_RESTART 0x100         // Use to safely restart (stop, wait, start) a service.
 #define SVC_DISABLED_START 0x200  // A start was requested but it was disabled at the time.
-#define SVC_EXEC 0x400            // This synthetic service corresponds to an 'exec'.
+#define SVC_EXEC 0x400  // This service was started by either 'exec' or 'exec_start' and stops
+                        // init from processing more commands until it completes
 
 #define SVC_SHUTDOWN_CRITICAL 0x800  // This service is critical for shutdown and
                                      // should not be killed during shutdown
+#define SVC_TEMPORARY 0x1000  // This service was started by 'exec' and should be removed from the
+                              // service list once it is reaped.
 
 #define NR_SVC_SUPP_GIDS 12    // twelve supplementary groups
 
@@ -72,6 +75,7 @@ class Service {
 
     bool IsRunning() { return (flags_ & SVC_RUNNING) != 0; }
     bool ParseLine(const std::vector<std::string>& args, std::string* err);
+    bool ExecStart(std::unique_ptr<Timer>* exec_waiter);
     bool Start();
     bool StartIfNotDisabled();
     bool Enable();
@@ -80,7 +84,7 @@ class Service {
     void Terminate();
     void Restart();
     void RestartIfNeeded(time_t* process_needs_restart_at);
-    bool Reap();
+    void Reap();
     void DumpState() const;
     void SetShutdownCritical() { flags_ |= SVC_SHUTDOWN_CRITICAL; }
     bool IsShutdownCritical() const { return (flags_ & SVC_SHUTDOWN_CRITICAL) != 0; }
@@ -178,6 +182,9 @@ public:
 
     void AddService(std::unique_ptr<Service> service);
     Service* MakeExecOneshotService(const std::vector<std::string>& args);
+    bool Exec(const std::vector<std::string>& args);
+    bool ExecStart(const std::string& name);
+    bool IsWaitingForExec() const;
     Service* FindServiceByName(const std::string& name) const;
     Service* FindServiceByPid(pid_t pid) const;
     Service* FindServiceByKeychord(int keychord_id) const;
@@ -198,6 +205,8 @@ private:
     bool ReapOneProcess();
 
     static int exec_count_; // Every service needs a unique name.
+    std::unique_ptr<Timer> exec_waiter_;
+
     std::vector<std::unique_ptr<Service>> services_;
 };
 

rootdir/init.rc

@@ -598,7 +598,7 @@ on boot
 
 on nonencrypted
     # A/B update verifier that marks a successful boot.
-    exec - root cache -- /system/bin/update_verifier nonencrypted
+    exec_start update_verifier_nonencrypted
     class_start main
     class_start late_start
 
@@ -621,12 +621,12 @@ on property:vold.decrypt=trigger_post_fs_data
 
 on property:vold.decrypt=trigger_restart_min_framework
     # A/B update verifier that marks a successful boot.
-    exec - root cache -- /system/bin/update_verifier trigger_restart_min_framework
+    exec_start update_verifier
     class_start main
 
 on property:vold.decrypt=trigger_restart_framework
     # A/B update verifier that marks a successful boot.
-    exec - root cache -- /system/bin/update_verifier trigger_restart_framework
+    exec_start update_verifier
     class_start main
     class_start late_start