From: Marek Szyprowski <m.szyprowski@samsung.com> Date: Thu, 20 Dec 2012 23:05:18 +0000 (-0800) Subject: mm: cma: WARN if freed memory is still in use X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=bcc2b02f4c1b36bc67272df7119b75bac78525ab;p=openwrt%2Fstaging%2Fblogic.git 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 <m.szyprowski@samsung.com> Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- 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