[PATCH 2/2] mm: vmalloc: Pass proper vm_start into debugobjects

From: Chintan Pandya
Date: Fri Apr 13 2018 - 07:34:27 EST


Client can call vunmap with some intermediate 'addr'
which may not be the start of the VM area. Entire
unmap code works with vm->vm_start which is proper
but debug object API is called with 'addr'. This
could be a problem within debug objects.

Pass proper start address into debug object API.

Signed-off-by: Chintan Pandya <cpandya@xxxxxxxxxxxxxx>
---
mm/vmalloc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 9ff21a1..28034c55 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1526,8 +1526,8 @@ static void __vunmap(const void *addr, int deallocate_pages)
return;
}

- debug_check_no_locks_freed(addr, get_vm_area_size(area));
- debug_check_no_obj_freed(addr, get_vm_area_size(area));
+ debug_check_no_locks_freed(area->addr, get_vm_area_size(area));
+ debug_check_no_obj_freed(area->addr, get_vm_area_size(area));

remove_vm_area(addr);
if (deallocate_pages) {
--
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