[PATCH 4.9 220/241] x86/mm: Fix vmalloc_fault to use pXd_large

From: Greg Kroah-Hartman
Date: Mon Mar 19 2018 - 15:00:55 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Toshi Kani <toshi.kani@xxxxxxx>

commit 18a955219bf7d9008ce480d4451b6b8bf4483a22 upstream.

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: f4eafd8bcd52 ("x86/mm: Fix vmalloc_fault() to handle large pages properly")
Reported-by: Gratian Crisan <gratian.crisan@xxxxxx>
Signed-off-by: Toshi Kani <toshi.kani@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20180313170347.3829-2-toshi.kani@xxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/mm/fault.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -343,7 +343,7 @@ static noinline int vmalloc_fault(unsign
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);
@@ -463,7 +463,7 @@ static noinline int vmalloc_fault(unsign
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);
@@ -474,7 +474,7 @@ static noinline int vmalloc_fault(unsign
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);