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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 <ziy@nvidia.com>
Reported-by: Ron Economos <re@w6rz.net>
Closes: https://lore.kernel.org/all/1b17c38f-30d3-4bb4-a7e1-e74b19ada885@w6rz.net/
Suggested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Debugged-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Tested-by: Ron Economos <re@w6rz.net>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

authored by

Zi Yan and committed by
Andrew Morton
f4355d6b d210fdca

+4 -1
+4 -1
mm/cma.c
··· 1013 1013 unsigned long count) 1014 1014 { 1015 1015 struct cma_memrange *cmr; 1016 + unsigned long ret = 0; 1016 1017 unsigned long i, pfn; 1017 1018 1018 1019 cmr = find_cma_memrange(cma, pages, count); ··· 1022 1021 1023 1022 pfn = page_to_pfn(pages); 1024 1023 for (i = 0; i < count; i++, pfn++) 1025 - VM_WARN_ON(!put_page_testzero(pfn_to_page(pfn))); 1024 + ret += !put_page_testzero(pfn_to_page(pfn)); 1025 + 1026 + WARN(ret, "%lu pages are still in use!\n", ret); 1026 1027 1027 1028 __cma_release_frozen(cma, cmr, pages, count); 1028 1029