Commit 0fd64c23 authored by Borislav Petkov's avatar Borislav Petkov Committed by Matt Fleming
Browse files

x86/mm/pageattr: Lookup address in an arbitrary PGD 



This is preparatory work in order to be able to map pages into a
specified PGD and not implicitly and only into init_mm.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
parent f4fccac0

arch/x86/mm/pageattr.c

+26 −10
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
 */

struct cpa_data {

	unsigned long	*vaddr;

	pgd_t		*pgd;

	pgprot_t	mask_set;

	pgprot_t	mask_clr;

	int		numpages;
@@ -322,17 +323,9 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address, 
	return prot;

}



/*

 * Lookup the page table entry for a virtual address. Return a pointer

 * to the entry and the level of the mapping.

 *

 * Note: We return pud and pmd either when the entry is marked large

 * or when the present bit is not set. Otherwise we would return a

 * pointer to a nonexisting mapping.

 */

pte_t *lookup_address(unsigned long address, unsigned int *level)

static pte_t *__lookup_address_in_pgd(pgd_t *pgd, unsigned long address,

				      unsigned int *level)

{

	pgd_t *pgd = pgd_offset_k(address);

	pud_t *pud;

	pmd_t *pmd;
@@ -361,8 +354,31 @@ pte_t *lookup_address(unsigned long address, unsigned int *level) 


	return pte_offset_kernel(pmd, address);

}



/*

 * Lookup the page table entry for a virtual address. Return a pointer

 * to the entry and the level of the mapping.

 *

 * Note: We return pud and pmd either when the entry is marked large

 * or when the present bit is not set. Otherwise we would return a

 * pointer to a nonexisting mapping.

 */

pte_t *lookup_address(unsigned long address, unsigned int *level)

{

        return __lookup_address_in_pgd(pgd_offset_k(address), address, level);

}

EXPORT_SYMBOL_GPL(lookup_address);



static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address,

				  unsigned int *level)

{

        if (cpa->pgd)

		return __lookup_address_in_pgd(cpa->pgd + pgd_index(address),

					       address, level);



        return lookup_address(address, level);

}



/*

 * This is necessary because __pa() does not work on some

 * kinds of memory, like vmalloc() or the alloc_remap()