Author: kib
Date: Mon Jun 3 04:32:53 2013
New Revision: 251285
URL: http://svnweb.freebsd.org/changeset/base/251285
Log:
Do not map the shared page COW. If the process wired its address
space, fork(2) would cause shadowing of the physical object and
copying of the shared page into private copy, effectively preventing
updates for the exported timehands structure and stopping the clock.
Specify the maximum allowed permissions for the page to be read and
execute, preventing write from the user mode.
Reported and tested by: <huang...@yahoo.com>
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Modified:
head/sys/kern/kern_exec.c
Modified: head/sys/kern/kern_exec.c
==============================================================================
--- head/sys/kern/kern_exec.c Mon Jun 3 04:22:42 2013 (r251284)
+++ head/sys/kern/kern_exec.c Mon Jun 3 04:32:53 2013 (r251285)
@@ -1050,8 +1050,9 @@ exec_new_vmspace(imgp, sv)
vm_object_reference(obj);
error = vm_map_fixed(map, obj, 0,
sv->sv_shared_page_base, sv->sv_shared_page_len,
- VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
- MAP_COPY_ON_WRITE | MAP_ACC_NO_CHARGE);
+ VM_PROT_READ | VM_PROT_EXECUTE,
+ VM_PROT_READ | VM_PROT_EXECUTE,
+ MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE);
if (error) {
vm_object_deallocate(obj);
return (error);
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
