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Commit 76e258ad authored by Joerg Roedel's avatar Joerg Roedel Committed by Thomas Gleixner
Browse files

x86/pgtable: Move two more functions from pgtable_64.h to pgtable.h 



These two functions are required for PTI on 32 bit:

	* pgdp_maps_userspace()
	* pgd_large()

Also re-implement pgdp_maps_userspace() so that it will work on 64 and 32
bit kernels.

Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarPavel Machek <pavel@ucw.cz>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Waiman Long <llong@redhat.com>
Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
Cc: joro@8bytes.org
Link: https://lkml.kernel.org/r/1531906876-13451-21-git-send-email-joro@8bytes.org
parent fcbbd977

arch/x86/include/asm/pgtable-2level_types.h

+3 −0
Original line number Diff line number Diff line
@@ -35,4 +35,7 @@ typedef union { 


#define PTRS_PER_PTE	1024



/* This covers all VMSPLIT_* and VMSPLIT_*_OPT variants */

#define PGD_KERNEL_START	(CONFIG_PAGE_OFFSET >> PGDIR_SHIFT)



#endif /* _ASM_X86_PGTABLE_2LEVEL_DEFS_H */

arch/x86/include/asm/pgtable-3level_types.h

+1 −0
Original line number Diff line number Diff line
@@ -46,5 +46,6 @@ typedef union { 
#define PTRS_PER_PTE	512



#define MAX_POSSIBLE_PHYSMEM_BITS	36

#define PGD_KERNEL_START	(CONFIG_PAGE_OFFSET >> PGDIR_SHIFT)



#endif /* _ASM_X86_PGTABLE_3LEVEL_DEFS_H */

arch/x86/include/asm/pgtable.h

+15 −0
Original line number Diff line number Diff line
@@ -1177,6 +1177,21 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, 
	}

}

#endif

/*

 * Page table pages are page-aligned.  The lower half of the top

 * level is used for userspace and the top half for the kernel.

 *

 * Returns true for parts of the PGD that map userspace and

 * false for the parts that map the kernel.

 */

static inline bool pgdp_maps_userspace(void *__ptr)

{

	unsigned long ptr = (unsigned long)__ptr;



	return (((ptr & ~PAGE_MASK) / sizeof(pgd_t)) < PGD_KERNEL_START);

}



static inline int pgd_large(pgd_t pgd) { return 0; }



#ifdef CONFIG_PAGE_TABLE_ISOLATION

/*

arch/x86/include/asm/pgtable_32.h

+0 −2
Original line number Diff line number Diff line
@@ -34,8 +34,6 @@ static inline void check_pgt_cache(void) { } 
void paging_init(void);

void sync_initial_page_table(void);



static inline int pgd_large(pgd_t pgd) { return 0; }



/*

 * Define this if things work differently on an i386 and an i486:

 * it will (on an i486) warn about kernel memory accesses that are

arch/x86/include/asm/pgtable_64.h

+0 −36
Original line number Diff line number Diff line
@@ -132,41 +132,6 @@ static inline pud_t native_pudp_get_and_clear(pud_t *xp) 
#endif

}



/*

 * Page table pages are page-aligned.  The lower half of the top

 * level is used for userspace and the top half for the kernel.

 *

 * Returns true for parts of the PGD that map userspace and

 * false for the parts that map the kernel.

 */

static inline bool pgdp_maps_userspace(void *__ptr)

{

	unsigned long ptr = (unsigned long)__ptr;



	return (ptr & ~PAGE_MASK) < (PAGE_SIZE / 2);

}



#ifdef CONFIG_PAGE_TABLE_ISOLATION

pgd_t __pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd);



/*

 * Take a PGD location (pgdp) and a pgd value that needs to be set there.

 * Populates the user and returns the resulting PGD that must be set in

 * the kernel copy of the page tables.

 */

static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd)

{

	if (!static_cpu_has(X86_FEATURE_PTI))

		return pgd;

	return __pti_set_user_pgtbl(pgdp, pgd);

}

#else

static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd)

{

	return pgd;

}

#endif



static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d)

{

	pgd_t pgd;
@@ -206,7 +171,6 @@ extern void sync_global_pgds(unsigned long start, unsigned long end); 
/*

 * Level 4 access.

 */

static inline int pgd_large(pgd_t pgd) { return 0; }

#define mk_kernel_pgd(address) __pgd((address) | _KERNPG_TABLE)



/* PUD - Level3 access */