From 34437e67a6727885bdf6cbfd8441b1ac43a1ee65 Mon Sep 17 00:00:00 2001
From: Toshi Kani <toshi.kani@hpe.com>
Date: Thu, 17 Sep 2015 12:24:20 -0600
Subject: [PATCH] x86/mm: Fix slow_virt_to_phys() to handle large PAT bit
slow_virt_to_phys() calls lookup_address() to obtain *pte and
its level. It then calls pte_pfn() to obtain a physical address
for any level. However, this physical address is not correct
when the large PAT bit is set because pte_pfn() does not mask
the large PAT bit properly for PUD/PMD.
Fix slow_virt_to_phys() to use pud_pfn() and pmd_pfn() for 1GB
and 2MB mapping levels.
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Konrad Wilk <konrad.wilk@oracle.com>
Cc: Robert Elliot <elliott@hpe.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1442514264-12475-8-git-send-email-toshi.kani@hpe.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/mm/pageattr.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 2c44c07923012..1441368a79319 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -414,18 +414,28 @@ pmd_t *lookup_pmd_address(unsigned long address)
phys_addr_t slow_virt_to_phys(void *__virt_addr)
{
unsigned long virt_addr = (unsigned long)__virt_addr;
- phys_addr_t phys_addr;
- unsigned long offset;
+ unsigned long phys_addr, offset;
enum pg_level level;
- unsigned long pmask;
pte_t *pte;
pte = lookup_address(virt_addr, &level);
BUG_ON(!pte);
- pmask = page_level_mask(level);
- offset = virt_addr & ~pmask;
- phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT;
- return (phys_addr | offset);
+
+ switch (level) {
+ case PG_LEVEL_1G:
+ phys_addr = pud_pfn(*(pud_t *)pte) << PAGE_SHIFT;
+ offset = virt_addr & ~PUD_PAGE_MASK;
+ break;
+ case PG_LEVEL_2M:
+ phys_addr = pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT;
+ offset = virt_addr & ~PMD_PAGE_MASK;
+ break;
+ default:
+ phys_addr = pte_pfn(*pte) << PAGE_SHIFT;
+ offset = virt_addr & ~PAGE_MASK;
+ }
+
+ return (phys_addr_t)(phys_addr | offset);
}
EXPORT_SYMBOL_GPL(slow_virt_to_phys);
--
2.49.0