PERFORCE change 169127 for review

[Robert Watson]

http://perforce.freebsd.org/chv.cgi?CH=169127

Change 169127 by rwatson at rwatson_freebsd_capabilities on 2009/10/02 12:32:03

	Close a race in which a process managed using a process descriptor is
	exiting simultaneously with the process descriptor being closed by
	extending coverage of the proctree lock during close.

Affected files ...

.. //depot/projects/trustedbsd/capabilities/src/sys/kern/sys_procdesc.c#13 edit

Differences ...

==== //depot/projects/trustedbsd/capabilities/src/sys/kern/sys_procdesc.c#13 (text+ko) ====

@@ -337,11 +337,11 @@
 	pd = fp->f_data;
 	fp->f_ops = &badfileops;
 	fp->f_data = NULL;
+
+	sx_xlock(&proctree_lock);
 	PROCDESC_LOCK(pd);
 	pd->pd_flags |= PD_CLOSED;
 	PROCDESC_UNLOCK(pd);
-
-	sx_xlock(&proctree_lock);
 	p = pd->pd_proc;
 	PROC_LOCK(p);
 	if (p->p_state == PRS_ZOMBIE) {