svn commit: r199869 - head/sys/vm

[Alan Cox]

Author: alc
Date: Fri Nov 27 22:08:29 2009
New Revision: 199869
URL: http://svn.freebsd.org/changeset/base/199869

Log:
  Support the new VM_PROT_COPY option on wired pages.  The effect of which
  is that a debugger can now set a breakpoint in a program that uses mlock(2)
  on its text segment or mlockall(2) on its entire address space.

Modified:
  head/sys/vm/vm_fault.c

Modified: head/sys/vm/vm_fault.c
==============================================================================
--- head/sys/vm/vm_fault.c	Fri Nov 27 20:24:11 2009	(r199868)
+++ head/sys/vm/vm_fault.c	Fri Nov 27 22:08:29 2009	(r199869)
@@ -273,7 +273,7 @@ RetryFault:;
 	fs.lookup_still_valid = TRUE;
 
 	if (wired)
-		fault_type = prot;
+		fault_type = prot | (fault_type & VM_PROT_COPY);
 
 	fs.first_m = NULL;
 
@@ -759,8 +759,11 @@ vnode_locked:
 				 */
 				pmap_copy_page(fs.m, fs.first_m);
 				fs.first_m->valid = VM_PAGE_BITS_ALL;
-			}
-			if (fs.m) {
+				if (wired && (fault_flags &
+				    VM_FAULT_CHANGE_WIRING) == 0) {
+					vm_page_wire(fs.first_m);
+					vm_page_unwire(fs.m, FALSE);
+				}
 				/*
 				 * We no longer need the old page or object.
 				 */