Utilities/logout: Refactor to use Core::SessionManagement::logout

Userland/Utilities/logout.cpp

@@ -4,20 +4,11 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <LibCore/ProcessStatisticsReader.h>
+#include <LibCore/SessionManagement.h>
 #include <LibCore/System.h>
 #include <LibMain/Main.h>
 #include <signal.h>
 
-static Core::ProcessStatistics const& get_proc(Core::AllProcessesStatistics const& stats, pid_t pid)
-{
-    for (auto& proc : stats.processes) {
-        if (proc.pid == pid)
-            return proc;
-    }
-    VERIFY_NOT_REACHED();
-}
-
 ErrorOr<int> serenity_main(Main::Arguments)
 {
     TRY(Core::System::pledge("stdio proc rpath"));
@@ -25,25 +16,7 @@ ErrorOr<int> serenity_main(Main::Arguments)
     TRY(Core::System::unveil("/etc/passwd", "r"));
     TRY(Core::System::unveil(nullptr, nullptr));
 
-    // logout finds the highest session up all nested sessions, and kills it.
-    auto stats = Core::ProcessStatisticsReader::get_all();
-    if (!stats.has_value()) {
-        warnln("couldn't get process statistics");
-        return 1;
-    }
-
-    pid_t sid = getsid(0);
-    while (true) {
-        pid_t parent = get_proc(stats.value(), sid).ppid;
-        pid_t parent_sid = get_proc(stats.value(), parent).sid;
-
-        if (parent_sid == 0)
-            break;
-
-        sid = parent_sid;
-    }
-
-    TRY(Core::System::kill(-sid, SIGTERM));
+    TRY(Core::SessionManagement::logout());
 
     return 0;
 }