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Commit 34437e67 authored by Toshi Kani's avatar Toshi Kani Committed by Thomas Gleixner
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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: default avatarToshi 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: default avatarThomas Gleixner <tglx@linutronix.de>
parent da25e628

arch/x86/mm/pageattr.c

+17 −7
Original line number Diff line number Diff line
@@ -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);