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Index: vm_map.c
===================================================================
--- vm_map.c
+++ vm_map.c
@@ -2453,6 +2453,7 @@
vm_map_entry_t current, entry, in_tran;
vm_object_t obj;
struct ucred *cred;
+ vm_ooffset_t to_reserve;
vm_prot_t old_prot;
if (start == end)
@@ -2460,6 +2461,7 @@
again:
in_tran = NULL;
+ to_reserve = 0;
vm_map_lock(map);
/*
@@ -2472,14 +2474,12 @@
VM_MAP_RANGE_CHECK(map, start, end);
- if (vm_map_lookup_entry(map, start, &entry)) {
- vm_map_clip_start(map, entry, start);
- } else {
+ if (!vm_map_lookup_entry(map, start, &entry))
entry = entry->next;
- }
/*
- * Make a first pass to check for protection violations.
+ * Make a first pass to check for protection violations and calculate
+ * needed swap space.
*/
for (current = entry; current->start < end; current = current->next) {
if ((current->eflags & MAP_ENTRY_GUARD) != 0)
@@ -2492,8 +2492,27 @@
vm_map_unlock(map);
return (KERN_PROTECTION_FAILURE);
}
- if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0)
+ if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0) {
in_tran = entry;
+ continue;
+ }
+ if (set_max || ENTRY_CHARGED(current) || in_tran == NULL ||
+ ((new_prot & ~current->protection) & VM_PROT_WRITE) == 0) {
+ continue;
+ }
+ obj = current->object.vm_object;
+ if (obj == NULL &&
+ (current->eflags & MAP_ENTRY_NEEDS_COPY) != 0 &&
+ !map->system_map)
+ to_reserve += current->end - current->start;
+ else if (obj == NULL &&
+ ((current->eflags & MAP_ENTRY_NEEDS_COPY) != 0))
+ to_reserve += ulmin(end, current->end) -
+ ulmax(start, current->start);
+ else if (obj != NULL &&
+ (obj->type == OBJT_DEFAULT ||
+ obj->type == OBJT_SWAP))
+ to_reserve += ptoa(obj->size);
}
/*
@@ -2509,72 +2528,60 @@
vm_map_unlock_and_wait(map, 0);
goto again;
}
+ if (!swap_reserve(to_reserve)) {
+ vm_map_unlock(map);
+ return (KERN_RESOURCE_SHORTAGE);
+ }
/*
- * Do an accounting pass for private read-only mappings that
+ * Look for private read-only mappings that
* now will do cow due to allowed write (e.g. debugger sets
- * breakpoint on text segment)
+ * breakpoint on text segment). Fix up protections.
*/
+ if (entry->start < start)
+ vm_map_clip_start(map, entry, start);
for (current = entry; current->start < end; current = current->next) {
-
vm_map_clip_end(map, current, end);
-
- if (set_max ||
- ((new_prot & ~(current->protection)) & VM_PROT_WRITE) == 0 ||
- ENTRY_CHARGED(current) ||
- (current->eflags & MAP_ENTRY_GUARD) != 0) {
+ if ((current->eflags & MAP_ENTRY_GUARD) != 0)
continue;
- }
+ old_prot = current->protection;
+ do {
+ if (set_max ||
+ ((new_prot & ~old_prot) & VM_PROT_WRITE) == 0 ||
+ ENTRY_CHARGED(current))
+ break;
+ cred = curthread->td_ucred;
+ obj = current->object.vm_object;
- cred = curthread->td_ucred;
- obj = current->object.vm_object;
+ if (obj == NULL ||
+ (current->eflags & MAP_ENTRY_NEEDS_COPY) != 0) {
+ to_reserve -= current->end - current->start;
+ crhold(cred);
+ current->cred = cred;
+ break;
+ }
+ VM_OBJECT_WLOCK(obj);
+ if (obj->type != OBJT_DEFAULT &&
+ obj->type != OBJT_SWAP) {
+ VM_OBJECT_WUNLOCK(obj);
+ break;
+ }
- if (obj == NULL || (current->eflags & MAP_ENTRY_NEEDS_COPY)) {
- if (!swap_reserve(current->end - current->start)) {
- vm_map_unlock(map);
- return (KERN_RESOURCE_SHORTAGE);
- }
+ /*
+ * Charge for the whole object allocation now, since
+ * we cannot distinguish between non-charged and
+ * charged clipped mapping of the same object later.
+ */
+ KASSERT(obj->charge == 0,
+ ("vm_map_protect: object %p overcharged (entry %p)",
+ obj, current));
+ to_reserve -= ptoa(obj->size);
crhold(cred);
- current->cred = cred;
- continue;
- }
-
- VM_OBJECT_WLOCK(obj);
- if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) {
+ obj->cred = cred;
+ obj->charge = ptoa(obj->size);
VM_OBJECT_WUNLOCK(obj);
- continue;
- }
+ } while (false);
- /*
- * Charge for the whole object allocation now, since
- * we cannot distinguish between non-charged and
- * charged clipped mapping of the same object later.
- */
- KASSERT(obj->charge == 0,
- ("vm_map_protect: object %p overcharged (entry %p)",
- obj, current));
- if (!swap_reserve(ptoa(obj->size))) {
- VM_OBJECT_WUNLOCK(obj);
- vm_map_unlock(map);
- return (KERN_RESOURCE_SHORTAGE);
- }
-
- crhold(cred);
- obj->cred = cred;
- obj->charge = ptoa(obj->size);
- VM_OBJECT_WUNLOCK(obj);
- }
-
- /*
- * Go back and fix up protections. [Note that clipping is not
- * necessary the second time.]
- */
- for (current = entry; current->start < end; current = current->next) {
- if ((current->eflags & MAP_ENTRY_GUARD) != 0)
- continue;
-
- old_prot = current->protection;
-
if (set_max)
current->protection =
(current->max_protection = new_prot) &
@@ -2607,6 +2614,8 @@
}
vm_map_simplify_entry(map, current);
}
+ KASSERT(to_reserve == 0,
+ ("vm_map_protect: wrong amount reserved"));
vm_map_unlock(map);
return (KERN_SUCCESS);
}

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