From bcc2b02f4c1b36bc67272df7119b75bac78525ab Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Thu, 20 Dec 2012 15:05:18 -0800 Subject: [PATCH] mm: cma: WARN if freed memory is still in use Memory returned to free_contig_range() must have no other references. Let kernel to complain loudly if page reference count is not equal to 1. [rientjes@google.com: support sparsemem] Signed-off-by: Marek Szyprowski Reviewed-by: Kyungmin Park Acked-by: Michal Nazarewicz Signed-off-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2ad2ad168efe..4ba5e37127fc 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5978,8 +5978,15 @@ done: void free_contig_range(unsigned long pfn, unsigned nr_pages) { - for (; nr_pages--; ++pfn) - __free_page(pfn_to_page(pfn)); + unsigned int count = 0; + + for (; nr_pages--; pfn++) { + struct page *page = pfn_to_page(pfn); + + count += page_count(page) != 1; + __free_page(page); + } + WARN(count != 0, "%d pages are still in use!\n", count); } #endif -- 2.34.1