From 7511c3ede752e6dd67df20779b4e11effe102637 Mon Sep 17 00:00:00 2001
From: Jerome Marchand <jmarchan@redhat.com>
Date: Fri, 20 Nov 2015 15:57:02 -0800
Subject: [PATCH] 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>
---
mm/vmalloc.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d04563480c94f..8e3c9c5a3042b 100644
--- 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;
--
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