[PATCH 1/4][SRU][B-HWE][D][V3] x86/mm: Check for pfn instead of page in vmalloc_sync_one()

[Colin King]

From: Joerg Roedel <jroedel at suse.de>

BugLink: https://bugs.launchpad.net/bugs/1838115

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 at suse.de>
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen at linux.intel.com>
Link: https://lkml.kernel.org/r/20190719184652.11391-2-joro@8bytes.org
(cherry picked from commit 51b75b5b563a2637f9d8dc5bd02a31b2ff9e5ea0)
Signed-off-by: Colin Ian King <colin.king at canonical.com>
---
 arch/x86/mm/fault.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 9d5c75f..2d61c7b 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -199,7 +199,7 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
 	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;
 }
-- 
2.7.4