From f4355d6bb39fc8e53d772fa0654c8441b214e349 Mon Sep 17 00:00:00 2001 From: Zi Yan Date: Tue, 24 Feb 2026 22:12:31 -0500 Subject: mm/cma: move put_page_testzero() out of VM_WARN_ON in cma_release() When CONFIG_DEBUG_VM is not set, VM_WARN_ON is a NOP. Putting any statement with side effect inside it is incorrect. Collect all !put_page_testzero() results and check the sum using WARN instead after the loop. It restores the same check in free_contig_range() before commit e0c1326779cc ("mm: page_alloc: add alloc_contig_frozen_{range,pages}()"), the commit prior to the Fixes one. Link: https://lkml.kernel.org/r/20260225031231.2352011-1-ziy@nvidia.com Fixes: 9bda131c6093 ("mm: cma: add cma_alloc_frozen{_compound}()") Signed-off-by: Zi Yan Reported-by: Ron Economos Closes: https://lore.kernel.org/all/1b17c38f-30d3-4bb4-a7e1-e74b19ada885@w6rz.net/ Suggested-by: Kefeng Wang Reviewed-by: Vishal Moola (Oracle) Debugged-by: David Hildenbrand (Arm) Acked-by: David Hildenbrand (Arm) Tested-by: Ron Economos Reviewed-by: Kefeng Wang Reviewed-by: Anshuman Khandual Reviewed-by: SeongJae Park Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/cma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/cma.c b/mm/cma.c index 94b5da468a7d..15cc0ae76c8e 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -1013,6 +1013,7 @@ bool cma_release(struct cma *cma, const struct page *pages, unsigned long count) { struct cma_memrange *cmr; + unsigned long ret = 0; unsigned long i, pfn; cmr = find_cma_memrange(cma, pages, count); @@ -1021,7 +1022,9 @@ bool cma_release(struct cma *cma, const struct page *pages, pfn = page_to_pfn(pages); for (i = 0; i < count; i++, pfn++) - VM_WARN_ON(!put_page_testzero(pfn_to_page(pfn))); + ret += !put_page_testzero(pfn_to_page(pfn)); + + WARN(ret, "%lu pages are still in use!\n", ret); __cma_release_frozen(cma, cmr, pages, count); -- cgit v1.2.3