svn commit: r353463 - head/sys/vm
Konstantin Belousov
kib at FreeBSD.org
Sun Oct 13 06:56:46 UTC 2019
Author: kib
Date: Sun Oct 13 06:56:45 2019
New Revision: 353463
URL: https://svnweb.freebsd.org/changeset/base/353463
Log:
Restore nofaulting operations after r352807
The TDP_NOFAULTING flag should be checked in vm_fault(), not in
vm_fault_trap(). Otherwise kernel accesses to userspace, like
vn_io_fault(), enter vm locking when it should not.
Reported and tested by: pho
Reviewed by: alc, markj
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Differential revision: https://reviews.freebsd.org/D21992
Modified:
head/sys/vm/vm_fault.c
Modified: head/sys/vm/vm_fault.c
==============================================================================
--- head/sys/vm/vm_fault.c Sun Oct 13 05:11:53 2019 (r353462)
+++ head/sys/vm/vm_fault.c Sun Oct 13 06:56:45 2019 (r353463)
@@ -554,15 +554,11 @@ int
vm_fault_trap(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
int fault_flags, int *signo, int *ucode)
{
- struct thread *td;
int result;
MPASS(signo == NULL || ucode != NULL);
- td = curthread;
- if ((td->td_pflags & TDP_NOFAULTING) != 0)
- return (KERN_PROTECTION_FAILURE);
#ifdef KTRACE
- if (map != kernel_map && KTRPOINT(td, KTR_FAULT))
+ if (map != kernel_map && KTRPOINT(curthread, KTR_FAULT))
ktrfault(vaddr, fault_type);
#endif
result = vm_fault(map, trunc_page(vaddr), fault_type, fault_flags,
@@ -574,7 +570,7 @@ vm_fault_trap(vm_map_t map, vm_offset_t vaddr, vm_prot
result == KERN_OUT_OF_BOUNDS,
("Unexpected Mach error %d from vm_fault()", result));
#ifdef KTRACE
- if (map != kernel_map && KTRPOINT(td, KTR_FAULTEND))
+ if (map != kernel_map && KTRPOINT(curthread, KTR_FAULTEND))
ktrfaultend(result);
#endif
if (result != KERN_SUCCESS && signo != NULL) {
@@ -644,6 +640,10 @@ vm_fault(vm_map_t map, vm_offset_t vaddr, vm_prot_t fa
bool dead, hardfault, is_first_object_locked;
VM_CNT_INC(v_vm_faults);
+
+ if ((curthread->td_pflags & TDP_NOFAULTING) != 0)
+ return (KERN_PROTECTION_FAILURE);
+
fs.vp = NULL;
faultcount = 0;
nera = -1;
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