[PATCH 4/9] mm/page_alloc: add a VM_BUG in __free_one_page() if the zone is uninitialized.

From: Cody P Schafer
Date: Thu Jan 17 2013 - 17:55:54 EST


From: Cody P Schafer <jmesmon@xxxxxxxxx>

Freeing pages to uninitialized zones is not handled by
__free_one_page(), and should never happen when the code is correct.

Ran into this while writing some code that dynamically onlines extra
zones.

Signed-off-by: Cody P Schafer <cody@xxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e2574ea..f8ed277 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -530,6 +530,8 @@ static inline void __free_one_page(struct page *page,
unsigned long uninitialized_var(buddy_idx);
struct page *buddy;

+ VM_BUG_ON(!zone_is_initialized(zone));
+
if (unlikely(PageCompound(page)))
if (unlikely(destroy_compound_page(page, order)))
return;
--
1.8.0.3

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