[PATCH -rfc 2/3] mm: kasan: shadow: move free_page() out of page table lock

[Kefeng Wang <wangkefeng.wang@huawei.com>]

free_page() is not needed to be protected by page table lock,
and it will take a little longer, so move it out of the spinlock.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/kasan/shadow.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index fd15e38ff80e..d7d6724da2e0 100644
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -423,12 +423,13 @@ static int kasan_depopulate_vmalloc_pte(pte_t *ptep, unsigned long addr,
 	page = (unsigned long)__va(pte_pfn(ptep_get(ptep)) << PAGE_SHIFT);
 
 	spin_lock(&init_mm.page_table_lock);
-
-	if (likely(!pte_none(ptep_get(ptep)))) {
+	if (likely(!pte_none(ptep_get(ptep))))
 		pte_clear(&init_mm, addr, ptep);
-		free_page(page);
-	}
+	else
+		page = 0;
 	spin_unlock(&init_mm.page_table_lock);
+	if (page)
+		free_page(page);
 
 	return 0;
 }
-- 
2.41.0