Revert "made parent kill childeren"

This reverts commit 8f176fdac8.

fork_bomb/fork_bomb.c

@@ -7,6 +7,7 @@
 #include <ctype.h>
 #include <time.h>
 #include <signal.h>
+#include <sys/prctl.h>
 
 
 #define DEFAULT_NUM_LEN 512
@@ -201,36 +202,6 @@ static long read_self_ticks(void) {
   return utime + stime;
 }
 
-static void kill_children_of(pid_t ppid) {
-  DIR *dir = opendir("/proc");
-  if (!dir) {
-    return;
-  }
-  struct dirent *ent;
-  while ((ent = readdir(dir)) != NULL) {
-    if (ent->d_type != DT_DIR || !is_numeric_dir(ent->d_name)) {
-      continue;
-    }
-    char path[256];
-    snprintf(path, sizeof(path), "/proc/%s/stat", ent->d_name);
-    FILE *f = fopen(path, "r");
-    if (!f) {
-      continue;
-    }
-    long pid = 0;
-    long parent = 0;
-    char comm[256];
-    char state = 0;
-    if (fscanf(f, "%ld (%255[^)]) %c %ld", &pid, comm, &state, &parent) == 4) {
-      if (parent == (long)ppid) {
-        kill((pid_t)pid, SIGKILL);
-      }
-    }
-    fclose(f);
-  }
-  closedir(dir);
-}
-
 static void read_cpu_total(long *total, long *idle) {
   FILE *f = fopen("/proc/stat", "r");
   if (!f) {
@@ -318,6 +289,12 @@ int main(void)
     }
 
     if (pid == 0) {
+      if (prctl(PR_SET_PDEATHSIG, SIGKILL) != 0) {
+        _exit(1);
+      }
+      if (getppid() == 1) {
+        _exit(0);
+      }
       pause();
       return 0;
     }
@@ -382,8 +359,6 @@ int main(void)
     }
   }
 
-  kill_children_of(getpid());
-
   fclose(csv);
 
   return 0;