[PATCH v2 1/3] mm/memory: move page_count() check into validate_page_before_insert()

From: David Hildenbrand
Date: Wed May 22 2024 - 08:57:45 EST


We'll now also cover the case where insert_page() is called from
__vm_insert_mixed(), which sounds like the right thing to do.

Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
mm/memory.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index b5453b86ec4b..a3aad7e58914 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1987,6 +1987,8 @@ static int validate_page_before_insert(struct page *page)
{
struct folio *folio = page_folio(page);

+ if (!folio_ref_count(folio))
+ return -EINVAL;
if (folio_test_anon(folio) || folio_test_slab(folio) ||
page_has_type(page))
return -EINVAL;
@@ -2041,8 +2043,6 @@ static int insert_page_in_batch_locked(struct vm_area_struct *vma, pte_t *pte,
{
int err;

- if (!page_count(page))
- return -EINVAL;
err = validate_page_before_insert(page);
if (err)
return err;
@@ -2176,8 +2176,6 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr,
{
if (addr < vma->vm_start || addr >= vma->vm_end)
return -EFAULT;
- if (!page_count(page))
- return -EINVAL;
if (!(vma->vm_flags & VM_MIXEDMAP)) {
BUG_ON(mmap_read_trylock(vma->vm_mm));
BUG_ON(vma->vm_flags & VM_PFNMAP);
--
2.45.0