diff options
| author | Ted Unangst <tedu@cvs.openbsd.org> | 2004-05-30 22:35:44 +0000 |
|---|---|---|
| committer | Ted Unangst <tedu@cvs.openbsd.org> | 2004-05-30 22:35:44 +0000 |
| commit | 4cef0a0a624be440c173311156bd21f070b60d0b (patch) | |
| tree | 689526f15ca7262fb84c5c7227f01a290c5fba8c /sys | |
| parent | 853dc29baeebbd393803d2adfeb4a7485573fcd2 (diff) | |
only free pages if we have write permission and they are not COW.
prevents msync/madvise funniness
from art@ ok deraadt@
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/uvm/uvm_map.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c index cb292c7362d..90290b5a61e 100644 --- a/sys/uvm/uvm_map.c +++ b/sys/uvm/uvm_map.c @@ -1,4 +1,4 @@ -/* $OpenBSD: uvm_map.c,v 1.66 2004/05/03 07:14:53 tedu Exp $ */ +/* $OpenBSD: uvm_map.c,v 1.67 2004/05/30 22:35:43 tedu Exp $ */ /* $NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $ */ /* @@ -3039,11 +3039,18 @@ uvm_map_clean(map, start, end, flags) flush_object: /* * flush pages if we've got a valid backing object. + * + * Don't PGO_FREE if we don't have write permission + * and don't flush if this is a copy-on-write object + * since we can't know our permissions on it. */ offset = current->offset + (start - current->start); size = MIN(end, current->end) - start; - if (uobj != NULL) { + if (uobj != NULL && + ((flags & PGO_FREE) == 0 || + ((entry->max_protection & VM_PROT_WRITE) != 0 && + (entry->etype & UVM_ET_COPYONWRITE) == 0))) { simple_lock(&uobj->vmobjlock); rv = uobj->pgops->pgo_flush(uobj, offset, offset + size, flags); |