mm: vmalloc: don't remove inexistent guard hole in remove_vm_area()

Commit 71394fe50146 ("mm: vmalloc: add flag preventing guard hole
allocation") missed a spot.  Currently remove_vm_area() decreases vm->size
to "remove" the guard hole page, even when it isn't present.  All but one
users just free the vm_struct rigth away and never access vm->size anyway.

Don't touch the size in remove_vm_area() and have __vunmap() use the
proper get_vm_area_size() helper.

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d04563480c94f4137efb6102e8d8beaef3a9dda7..8e3c9c5a3042b6149ff783bb1dfc0c0e08dc4046 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1443,7 +1443,6 @@ struct vm_struct *remove_vm_area(const void *addr)
                vmap_debug_free_range(va->va_start, va->va_end);
                kasan_free_shadow(vm);
                free_unmap_vmap_area(va);
-               vm->size -= PAGE_SIZE;
 
                return vm;
        }
@@ -1468,8 +1467,8 @@ static void __vunmap(const void *addr, int deallocate_pages)
                return;
        }
 
-       debug_check_no_locks_freed(addr, area->size);
-       debug_check_no_obj_freed(addr, area->size);
+       debug_check_no_locks_freed(addr, get_vm_area_size(area));
+       debug_check_no_obj_freed(addr, get_vm_area_size(area));
 
        if (deallocate_pages) {
                int i;