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When vm_map_wire(9) is allowed to skip holes in the wired region, skip

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the mappings without any of read and execution rights, in particular,
the PROT_NONE entries. This makes mlockall(2) work for the process
address space that has such mappings.

Since protection mode of the entry may change between setting
MAP_ENTRY_IN_TRANSITION and final pass over the region that records
the wire status of the entries, allocate new map entry flag
MAP_ENTRY_WIRE_SKIPPED to mark the skipped PROT_NONE entries.

Reported and tested by:	Hans Ottevanger <fbsdhackers beasties demon nl>
Reviewed by:	alc
MFC after:	3 weeks
This commit is contained in:
Konstantin Belousov 2009-04-10 10:16:03 +00:00
parent a3c8e04ef7
commit 6d7e809123
2 changed files with 17 additions and 1 deletions
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16
sys/vm/vm_map.c
View File

@ -2217,6 +2217,16 @@ vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end,
*
*/
if (entry->wired_count == 0) {
if ((entry->protection & (VM_PROT_READ|VM_PROT_EXECUTE))
== 0) {
if ((flags & VM_MAP_WIRE_HOLESOK) == 0) {
end = entry->end;
rv = KERN_INVALID_ADDRESS;
goto done;
}
entry->eflags |= MAP_ENTRY_WIRE_SKIPPED;
goto next_entry;
}
entry->wired_count++;
saved_start = entry->start;
saved_end = entry->end;
@ -2274,6 +2284,7 @@ vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end,
* Check the map for holes in the specified region.
* If VM_MAP_WIRE_HOLESOK was specified, skip this check.
*/
next_entry:
if (((flags & VM_MAP_WIRE_HOLESOK) == 0) &&
(entry->end < end && (entry->next == &map->header ||
entry->next->start > entry->end))) {
@ -2295,6 +2306,8 @@ done:
}
entry = first_entry;
while (entry != &map->header && entry->start < end) {
if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0)
goto next_entry_done;
if (rv == KERN_SUCCESS) {
if (user_wire)
entry->eflags |= MAP_ENTRY_USER_WIRED;
@ -2317,9 +2330,10 @@ done:
entry->object.vm_object->type == OBJT_DEVICE);
}
}
next_entry_done:
KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION,
("vm_map_wire: in-transition flag missing"));
entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION|MAP_ENTRY_WIRE_SKIPPED);
if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
need_wakeup = TRUE;

2
sys/vm/vm_map.h
View File

@ -137,6 +137,8 @@ struct vm_map_entry {
#define MAP_ENTRY_GROWS_DOWN 0x1000 /* Top-down stacks */
#define MAP_ENTRY_GROWS_UP 0x2000 /* Bottom-up stacks */
#define MAP_ENTRY_WIRE_SKIPPED 0x4000
#ifdef _KERNEL
static __inline u_char
vm_map_entry_behavior(vm_map_entry_t entry)