mm/huge_memory: convert VM_BUG* to VM_WARN* in __folio_split

These VM_BUG* can be handled gracefully without crashing kernel.

Link: https://lkml.kernel.org/r/20250718023000.4044406-5-ziy@nvidia.com
Link: https://lkml.kernel.org/r/20250718183720.4054515-5-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Antonio Quartulli <antonio@mandelbit.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <k.shutemov@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index d36f7bdaeb38383781713f37eeb9c4b33c309969..d98283164edabd9156eeaa46f072a425d98bc3e9 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3601,8 +3601,8 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
        pgoff_t end;
        bool is_hzp;
 
-       VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
-       VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
+       VM_WARN_ON_ONCE_FOLIO(!folio_test_locked(folio), folio);
+       VM_WARN_ON_ONCE_FOLIO(!folio_test_large(folio), folio);
 
        if (folio != page_folio(split_at) || folio != page_folio(lock_at))
                return -EINVAL;
@@ -3766,7 +3766,11 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
                }
 
                if (folio_test_swapcache(folio)) {
-                       VM_BUG_ON(mapping);
+                       if (mapping) {
+                               VM_WARN_ON_ONCE_FOLIO(mapping, folio);
+                               ret = -EINVAL;
+                               goto fail;
+                       }
 
                        swap_cache = swap_address_space(folio->swap);
                        xa_lock(&swap_cache->i_pages);