Messages in this thread Patch in this message | | | From | Yu Zhao <> | Subject | [PATCH v2 2/2] mm: verify compound order when freeing a page | Date | Wed, 15 Oct 2014 12:20:05 -0700 |
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This allows us to catch the bug fixed in the previous patch (mm: free compound page with correct order).
Here we also verify whether a page is tail page or not -- tail pages are supposed to be freed along with their head, not by themselves.
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Yu Zhao <yuzhao@google.com> --- mm/page_alloc.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 736d8e1..5bf44e4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -750,6 +750,9 @@ static bool free_pages_prepare(struct page *page, unsigned int order) int i; int bad = 0; + VM_BUG_ON_PAGE(PageTail(page), page); + VM_BUG_ON_PAGE(PageHead(page) && compound_order(page) != order, page); + trace_mm_page_free(page, order); kmemcheck_free_shadow(page, order); -- 2.1.0.rc2.206.gedb03e5
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