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Rework uvm_map_protect():

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- Fix some locking bugs; a couple of places would return an error condition
  without unlocking the map.
- Deal with maps marked WIREFUTURE; if making an entry VM_PROT_NONE ->
  anything else, and it is not already marked as wired, wire it.
This commit is contained in:
thorpej 1999-07-18 00:41:56 +00:00
parent a382c0c34d
commit 5ee6f3960d
1 changed files with 44 additions and 11 deletions
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55
sys/uvm/uvm_map.c
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@ -1,4 +1,4 @@
/* $NetBSD: uvm_map.c,v 1.64 1999/07/17 21:35:49 thorpej Exp $ */
/* $NetBSD: uvm_map.c,v 1.65 1999/07/18 00:41:56 thorpej Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@ -1721,6 +1721,7 @@ uvm_map_protect(map, start, end, new_prot, set_max)
boolean_t set_max;
{
vm_map_entry_t current, entry;
int rv = KERN_SUCCESS;
UVMHIST_FUNC("uvm_map_protect"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_prot=0x%x)",
map, start, end, new_prot);
@ -1741,13 +1742,15 @@ uvm_map_protect(map, start, end, new_prot, set_max)
current = entry;
while ((current != &map->header) && (current->start < end)) {
if (UVM_ET_ISSUBMAP(current))
return (KERN_INVALID_ARGUMENT);
if ((new_prot & current->max_protection) != new_prot) {
vm_map_unlock(map);
return (KERN_PROTECTION_FAILURE);
if (UVM_ET_ISSUBMAP(current)) {
rv = KERN_INVALID_ARGUMENT;
goto out;
}
current = current->next;
if ((new_prot & current->max_protection) != new_prot) {
rv = KERN_PROTECTION_FAILURE;
goto out;
}
current = current->next;
}
/* go back and fix up protections (no need to clip this time). */
@ -1772,18 +1775,48 @@ uvm_map_protect(map, start, end, new_prot, set_max)
*/
if (current->protection != old_prot) {
/* update pmap! */
pmap_protect(map->pmap, current->start, current->end,
current->protection & MASK(entry));
}
/*
* If the map is configured to lock any future mappings,
* wire this entry now if the old protection was VM_PROT_NONE
* and the new protection is not VM_PROT_NONE.
*/
if ((map->flags & VM_MAP_WIREFUTURE) != 0 &&
VM_MAPENT_ISWIRED(entry) == 0 &&
old_prot == VM_PROT_NONE &&
new_prot != VM_PROT_NONE) {
if (uvm_map_pageable(map, entry->start,
entry->end, FALSE,
UVM_LK_ENTER|UVM_LK_EXIT) != KERN_SUCCESS) {
/*
* If locking the entry fails, remember the
* error if it's the first one. Note we
* still continue setting the protection in
* the map, but will return the resource
* shortage condition regardless.
*
* XXX Ignore what the actual error is,
* XXX just call it a resource shortage
* XXX so that it doesn't get confused
* XXX what uvm_map_protect() itself would
* XXX normally return.
*/
rv = KERN_RESOURCE_SHORTAGE;
}
}
current = current->next;
}
out:
vm_map_unlock(map);
UVMHIST_LOG(maphist, "<- done",0,0,0,0);
return(KERN_SUCCESS);
UVMHIST_LOG(maphist, "<- done, rv=%d",rv,0,0,0);
return (rv);
}
#undef max