[PATCH v4 4/6] mm/huge_memory: convert VM_BUG* to VM_WARN* in __folio_split.

[Zi Yan]

These VM_BUG* can be handled gracefully without crashing kernel.

Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
---
 mm/huge_memory.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index d36f7bdaeb38..d6ff5e8c89d7 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3601,8 +3601,14 @@ 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);
+	if (!folio_test_locked(folio)) {
+		VM_WARN_ON_ONCE_FOLIO(1, folio);
+		return -EINVAL;
+	}
+	if (!folio_test_large(folio)) {
+		VM_WARN_ON_ONCE_FOLIO(1, folio);
+		return -EINVAL;
+	}
 
 	if (folio != page_folio(split_at) || folio != page_folio(lock_at))
 		return -EINVAL;
@@ -3766,7 +3772,11 @@ 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);
-- 
2.47.2