Fully implement vfork. Vfork is now much much faster than even our

	fork. (On my machine, fork is about 240usecs, vfork is 78usecs.)

Implement rfork(!RFPROC !RFMEM), which allows a thread to divorce its memory
	from the other threads of a group.

Implement rfork(!RFPROC RFCFDG), which closes all file descriptors, eliminating
	possible existing shares with other threads/processes.

Implement rfork(!RFPROC RFFDG), which divorces the file descriptors for a
	thread from the rest of the group.

Fix the case where a thread does an exec.  It is almost nonsense for a thread
	to modify the other threads address space by an exec, so we
	now automatically divorce the address space before modifying it.

1 files changed, 7 insertions, 2 deletions

diff --git a/sys/kern/imgact_aout.c b/sys/kern/imgact_aout.c
index 4adbd05..a229720 100644
--- a/sys/kern/imgact_aout.c
+++ b/sys/kern/imgact_aout.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id$
+ *	$Id: imgact_aout.c,v 1.33 1997/02/22 09:38:55 peter Exp $
  */
 
 #include "opt_rlimit.h"
@@ -55,7 +55,7 @@ exec_aout_imgact(imgp)
 	struct image_params *imgp;
 {
 	const struct exec *a_out = (const struct exec *) imgp->image_header;
-	struct vmspace *vmspace = imgp->proc->p_vmspace;
+	struct vmspace *vmspace;
 	vm_offset_t vmaddr;
 	unsigned long virtual_offset;
 	unsigned long file_offset;
@@ -147,6 +147,11 @@ exec_aout_imgact(imgp)
 	exec_new_vmspace(imgp);
 
 	/*
+	 * The vm space can be changed by exec_new_vmspace
+	 */
+	vmspace = imgp->proc->p_vmspace;
+
+	/*
 	 * Map text/data read/execute
 	 */
 	vmaddr = virtual_offset;