d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Do not map the shared page COW. If the process wired its address

Browse Source 
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:	<huanghwh@yahoo.com>
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
This commit is contained in:
kib 2013-06-03 04:32:53 +00:00
parent f82ed4d643
commit fd6876af27
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
sys/kern/kern_exec.c
View File

@ -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);