init: log control messages along with the process that sent them

It's currently not clear that init stops processes due to being sent a
control message nor who sent that message.

Bug: 73343913
Test: send control messages and see the logs
Change-Id: I9e9eff2001e649814107ea961b3b747a1f6da598

3 files changed, 21 insertions, 3 deletions

diff --git a/init/init.cpp b/init/init.cpp
index 7e4eaa8c2..efb9c1db3 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -35,6 +35,7 @@
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/properties.h>
+#include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <cutils/android_reboot.h>
 #include <keyutils.h>
@@ -63,7 +64,10 @@ using namespace std::string_literals;
 
 using android::base::boot_clock;
 using android::base::GetProperty;
+using android::base::ReadFileToString;
+using android::base::StringPrintf;
 using android::base::Timer;
+using android::base::Trim;
 
 namespace android {
 namespace init {
@@ -246,7 +250,7 @@ static const std::map<std::string, ControlMessageFunction>& get_control_message_
     return control_message_functions;
 }
 
-void handle_control_message(const std::string& msg, const std::string& name) {
+void HandleControlMessage(const std::string& msg, const std::string& name, pid_t pid) {
     const auto& map = get_control_message_map();
     const auto it = map.find(msg);
 
@@ -255,6 +259,18 @@ void handle_control_message(const std::string& msg, const std::string& name) {
         return;
     }
 
+    std::string cmdline_path = StringPrintf("proc/%d/cmdline", pid);
+    std::string process_cmdline;
+    if (ReadFileToString(cmdline_path, &process_cmdline)) {
+        std::replace(process_cmdline.begin(), process_cmdline.end(), '\0', ' ');
+        process_cmdline = Trim(process_cmdline);
+    } else {
+        process_cmdline = "unknown process";
+    }
+
+    LOG(INFO) << "Received control message '" << msg << "' for '" << name << "' from pid: " << pid
+              << " (" << process_cmdline << ")";
+
     const ControlMessageFunction& function = it->second;
 
     if (function.target == ControlTarget::SERVICE) {
diff --git a/init/init.h b/init/init.h
index ecce5d789..d4a0e963b 100644
--- a/init/init.h
+++ b/init/init.h
@@ -17,6 +17,8 @@
 #ifndef _INIT_INIT_H
 #define _INIT_INIT_H
 
+#include <sys/types.h>
+
 #include <string>
 #include <vector>
 
@@ -36,7 +38,7 @@ extern std::vector<std::string> late_import_paths;
 
 Parser CreateParser(ActionManager& action_manager, ServiceList& service_list);
 
-void handle_control_message(const std::string& msg, const std::string& arg);
+void HandleControlMessage(const std::string& msg, const std::string& arg, pid_t pid);
 
 void property_changed(const std::string& name, const std::string& value);
 
diff --git a/init/property_service.cpp b/init/property_service.cpp
index ecd5baa1d..0cf61840f 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -436,7 +436,7 @@ uint32_t HandlePropertySet(const std::string& name, const std::string& value,
             return PROP_ERROR_HANDLE_CONTROL_MESSAGE;
         }
 
-        handle_control_message(name.c_str() + 4, value.c_str());
+        HandleControlMessage(name.c_str() + 4, value, cr.pid);
         return PROP_SUCCESS;
     }