init: register signal blockers earlier

prevents potential race condition where a subsystem can terminate before
we fully block SIGCHLD, causing SIGCHLD to be sent to init and having
our entire process terminated ungracefully.

prevents bash and family from sending "Terminated" due to our process
receiving SIGTERM during a panic, since we already exit in there and
it'd be queued up if we do receive one

1 files changed, 12 insertions, 6 deletions

diff --git a/init/init.c b/init/init.c
index 5387043..3fe370f 100644
--- a/init/init.c
+++ b/init/init.c
@@ -62,6 +62,8 @@ static void do_initcalls(void)
     }
 }
 
+
+
 int main(void)
 {
     print("init: Hello world! Running " NAME " v" VERSION "!");
@@ -78,6 +80,15 @@ int main(void)
     }
     free(stack_rlimit);
 
+    /* configure signal handlers early to prevent race condition where subsystems
+       can terminate main process on accident, and disable Terminated output during
+       early-mode panic */
+    static sigset_t set;
+    sigaddset(&set, SIGCHLD);
+    sigaddset(&set, SIGINT);
+    sigaddset(&set, SIGTERM);
+    sigprocmask(SIG_BLOCK, &set, NULL);
+
     /* fetch token */
     char *token_base = getenv("TOKEN");
     if(!token_base)
@@ -99,13 +110,8 @@ int main(void)
     do_initcalls();
 
     /* Reaper. Much like init. */
-    siginfo_t siginfo;
-    static sigset_t set;
-    sigaddset(&set, SIGCHLD);
-    sigaddset(&set, SIGINT);
-    sigaddset(&set, SIGTERM);
-    sigprocmask(SIG_BLOCK, &set, NULL);
 
+    siginfo_t siginfo;
     while(subsystem_count > 0) {
         sigwaitinfo(&set, &siginfo);
         int sig = siginfo.si_signo;