[PATCH V2] mm: vmalloc: don't remove inexistent guard hole in remove_vm_area()

From: Jerome Marchand
Date: Thu Nov 12 2015 - 11:37:26 EST

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@xxxxxxxxxx>
mm/vmalloc.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d045634..8e3c9c5 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);
- vm->size -= PAGE_SIZE;

return vm;
@@ -1468,8 +1467,8 @@ static void __vunmap(const void *addr, int deallocate_pages)

- 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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