diff options
| author | Zi Yan <ziy@nvidia.com> | 2026-02-24 22:12:31 -0500 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-03-04 09:44:22 -0800 |
| commit | f4355d6bb39fc8e53d772fa0654c8441b214e349 (patch) | |
| tree | 67c521c077a24e186fc4d6c330cad56aea01883b | |
| parent | d210fdcac9c0d1380eab448aebc93f602c1cd4e6 (diff) | |
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>
| -rw-r--r-- | mm/cma.c | 5 |
1 files changed, 4 insertions, 1 deletions
@@ -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); |