From 89876c9580bb85e1e9ad05a2d3e742e71b7fbff3 Mon Sep 17 00:00:00 2001
From: Davin McCall <davmac@davmac.org>
Date: Tue, 4 Jul 2017 19:07:37 +0100
Subject: [PATCH] Consolidate linux-specific code.

---
 src/dinit.cc | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/src/dinit.cc b/src/dinit.cc
index fa804eb..ae859e0 100644
--- a/src/dinit.cc
+++ b/src/dinit.cc
@@ -14,6 +14,8 @@
 #include <pwd.h>
 #ifdef __linux__
 #include <sys/prctl.h>
+#include <sys/klog.h>
+#include <sys/reboot.h>
 #endif
 
 #include "dasynq.h"
@@ -22,11 +24,6 @@
 #include "dinit-log.h"
 #include "dinit-socket.h"
 
-#ifdef __linux__
-#include <sys/klog.h>
-#include <sys/reboot.h>
-#endif
-
 /*
  * When running as the system init process, Dinit processes the following signals:
  *
@@ -40,7 +37,6 @@
  * services even if the halt/reboot commands are unavailable for some reason.
  */
 
-
 using namespace dasynq;
 using eventloop_t = event_loop<null_mutex>;
 
@@ -223,10 +219,6 @@ int dinit_main(int argc, char **argv)
         if (twofd > 2) close(twofd);
     }
 
-#ifdef __linux__
-    prctl(PR_SET_CHILD_SUBREAPER, 1);
-#endif
-
     /* Set up signal handlers etc */
     /* SIG_CHILD is ignored by default: good */
     sigset_t sigwait_set;
@@ -305,6 +297,10 @@ int dinit_main(int argc, char **argv)
         // Make ctrl+alt+del combination send SIGINT to PID 1 (this process)
         reboot(RB_DISABLE_CAD);
     }
+
+    // Mark ourselves as a subreaper. This means that if a process we start double-forks, the
+    // orphaned child will re-parent to us rather than to PID 1 (although that could be us too).
+    prctl(PR_SET_CHILD_SUBREAPER, 1);
 #endif
     
     /* start requested services */
-- 
2.25.1