x86/mm: Fix vmalloc_fault to use pXd_large

Gratian Crisan reported that vmalloc_fault() crashes when CONFIG_HUGETLBFS
is not set since the function inadvertently uses pXn_huge(), which always
return 0 in this case.  ioremap() does not depend on CONFIG_HUGETLBFS.

Fix vmalloc_fault() to call pXd_large() instead.

Fixes: f4eafd8b ("x86/mm: Fix vmalloc_fault() to handle large pages properly")
Reported-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20180313170347.3829-2-toshi.kani@hpe.com

arch/x86/mm/fault.c

@@ -330,7 +330,7 @@ static noinline int vmalloc_fault(unsigned long address)
 	if (!pmd_k)
 		return -1;
 
-	if (pmd_huge(*pmd_k))
+	if (pmd_large(*pmd_k))
 		return 0;
 
 	pte_k = pte_offset_kernel(pmd_k, address);
@@ -475,7 +475,7 @@ static noinline int vmalloc_fault(unsigned long address)
 	if (pud_none(*pud) || pud_pfn(*pud) != pud_pfn(*pud_ref))
 		BUG();
 
-	if (pud_huge(*pud))
+	if (pud_large(*pud))
 		return 0;
 
 	pmd = pmd_offset(pud, address);
@@ -486,7 +486,7 @@ static noinline int vmalloc_fault(unsigned long address)
 	if (pmd_none(*pmd) || pmd_pfn(*pmd) != pmd_pfn(*pmd_ref))
 		BUG();
 
-	if (pmd_huge(*pmd))
+	if (pmd_large(*pmd))
 		return 0;
 
 	pte_ref = pte_offset_kernel(pmd_ref, address);