[PATCH 4.14 15/69] x86/mm: Check for pfn instead of page in vmalloc_sync_one()

[Greg Kroah-Hartman]

From: Joerg Roedel <jroedel@xxxxxxx>

commit 51b75b5b563a2637f9d8dc5bd02a31b2ff9e5ea0 upstream.

Do not require a struct page for the mapped memory location because it
might not exist. This can happen when an ioremapped region is mapped with
2MB pages.

Fixes: 5d72b4fba40ef ('x86, mm: support huge I/O mapping capability I/F')
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190719184652.11391-2-joro@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/mm/fault.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -266,7 +266,7 @@ static inline pmd_t *vmalloc_sync_one(pg
 	if (!pmd_present(*pmd))
 		set_pmd(pmd, *pmd_k);
 	else
-		BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k));
+		BUG_ON(pmd_pfn(*pmd) != pmd_pfn(*pmd_k));
 
 	return pmd_k;
 }