BUG: Bad page map in process Xorg  pte:3c7fc067 pmd:5ea91067
page:c17c3f80 flags:80000014 count:0 mapcount:-1 mapping:(null) index:b458e
addr:b67a3000 vm_flags:00100073 anon_vma:f0917600 mapping:(null) index:b67a3
Pid: 1528, comm: Xorg Tainted: P           2.6.31-14-generic #48-Ubuntu
Call Trace:
 [<c056e41c>] ? printk+0x18/0x1c
 [<c01c8a89>] print_bad_pte+0x139/0x1f0
 [<c01ca5e7>] zap_pte_range+0x3d7/0x3e0
 [<c01ca866>] unmap_vmas+0x186/0x350
 [<c01cf8d0>] unmap_region+0x90/0x120
 [<c01cfb3e>] do_munmap+0x1de/0x280
 [<c01cfc1d>] sys_munmap+0x3d/0x60
 [<c010336c>] syscall_call+0x7/0xb