[PATCH v3 2/2] mm/memory: return -ENOMEM for page-table allocation failure in insert_pages()

[Avi Weiss]

walk_to_pmd() returns NULL only when p4d_alloc(), pud_alloc(), or
pmd_alloc() fails. These are page-table allocation failures, but
insert_pages() currently reports them as -EFAULT.

Return -ENOMEM instead, consistent with the subsequent pte_alloc()
failure and with the single-page insert_page() path, which reports
failure of the same page-table allocation chain as -ENOMEM.

Address and range validation failures in vm_insert_pages() continue to
return -EFAULT. Keep the later -EFAULT return for
pte_offset_map_lock(), which is not an allocation failure.

Signed-off-by: Avi Weiss <thnkslprpt@xxxxxxxxx>
Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@xxxxxxxxxx>
---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index 2561dc6bdde6..27ffe1a99a08 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2569,7 +2569,7 @@ static int insert_pages(struct vm_area_struct *vma, unsigned long addr,
 more:
 	pmd = walk_to_pmd(mm, addr);
 	if (!pmd) {
-		err = -EFAULT;
+		err = -ENOMEM;
 		goto out;
 	}
 
-- 
2.43.0