#Fork with a Random PID - This current version DOESN'T work!!!
#Aaron Linville <aaron@linville.org>
#<http://www.linville.org/darwin.html>
#Index: bsd/kern/bsd_init.c
#===================================================================
#RCS file: /cvs/Darwin/xnu/bsd/kern/bsd_init.c,v
#retrieving revision 1.1.1.20.6.2
#diff -u -d -b -w -r1.1.1.20.6.2 bsd_init.c
--- bsd/kern/bsd_init.c 4 Mar 2002 18:51:31 -0000       1.1.1.20.6.2
+++ bsd/kern/bsd_init.c 17 Apr 2002 19:43:47 -0000
@@ -524,6 +524,8 @@
 
        bsd_utaskbootstrap();
 
+       randompid = 1;
+
        (void) thread_funnel_set(kernel_flock, FALSE);
 }

#Index: bsd/kern/kern_fork.c
#===================================================================
#RCS file: /cvs/Darwin/xnu/bsd/kern/kern_fork.c,v
#retrieving revision 1.1.1.13
#diff -u -d -b -w -r1.1.1.13 kern_fork.c
--- bsd/kern/kern_fork.c        7 Sep 2001 22:19:37 -0000       1.1.1.13
+++ bsd/kern/kern_fork.c        17 Apr 2002 19:43:47 -0000
@@ -86,6 +86,8 @@
 #define        DOVFORK 0x2     /* vfork() system call */
 static int fork1(struct proc *, long, register_t *);
 
+int randompid;          /* when set to 1, pid's go random */
+
 /*
  * fork system call.
  */
@@ -394,6 +396,8 @@
         * ready to use (from nextpid+1 through pidchecked-1).
         */
        nextpid++;
+       if(randompid)
+         nextpid = PID_MAX;
 retry:
        /*
         * If the process ID prototype has wrapped around,
@@ -401,7 +405,7 @@
         * tend to include daemons that don't exit.
         */
        if (nextpid >= PID_MAX) {
-               nextpid = 100;
+               nextpid = random() % PID_MAX;
                pidchecked = 0;
        }
        if (nextpid >= pidchecked) {
#===================================================================
#RCS file: /cvs/Darwin/xnu/bsd/sys/proc.h,v
#retrieving revision 1.1.1.13
#diff -u -d -b -w -r1.1.1.13 proc.h
--- bsd/sys/proc.h      7 Sep 2001 22:20:50 -0000       1.1.1.13
+++ bsd/sys/proc.h      17 Apr 2002 19:43:54 -0000
@@ -349,6 +349,7 @@
 extern u_long pgrphash;
 
 extern int nprocs, maxproc;            /* Current and max number of procs. */
+extern int randompid;                   /* fork() should create random pid's */
 
 LIST_HEAD(proclist, proc);
 extern struct proclist allproc;                /* List of all processes. */