Skip to content

Commit

Permalink
x86/pgtable: Move pgdp kernel/user conversion functions to pgtable.h
Browse files Browse the repository at this point in the history
Make them available on 32 bit and clone_pgd_range() happy.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Pavel 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/1531906876-13451-19-git-send-email-joro@8bytes.org
  • Loading branch information
Joerg Roedel authored and Thomas Gleixner committed Jul 19, 2018
1 parent e3238fa commit 8372d66
Show file tree
Hide file tree
Showing 2 changed files with 49 additions and 49 deletions.
49 changes: 49 additions & 0 deletions arch/x86/include/asm/pgtable.h
Original file line number Diff line number Diff line change
Expand Up @@ -1155,6 +1155,55 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
}
#endif

#ifdef CONFIG_PAGE_TABLE_ISOLATION
/*
* All top-level PAGE_TABLE_ISOLATION page tables are order-1 pages
* (8k-aligned and 8k in size). The kernel one is at the beginning 4k and
* the user one is in the last 4k. To switch between them, you
* just need to flip the 12th bit in their addresses.
*/
#define PTI_PGTABLE_SWITCH_BIT PAGE_SHIFT

/*
* This generates better code than the inline assembly in
* __set_bit().
*/
static inline void *ptr_set_bit(void *ptr, int bit)
{
unsigned long __ptr = (unsigned long)ptr;

__ptr |= BIT(bit);
return (void *)__ptr;
}
static inline void *ptr_clear_bit(void *ptr, int bit)
{
unsigned long __ptr = (unsigned long)ptr;

__ptr &= ~BIT(bit);
return (void *)__ptr;
}

static inline pgd_t *kernel_to_user_pgdp(pgd_t *pgdp)
{
return ptr_set_bit(pgdp, PTI_PGTABLE_SWITCH_BIT);
}

static inline pgd_t *user_to_kernel_pgdp(pgd_t *pgdp)
{
return ptr_clear_bit(pgdp, PTI_PGTABLE_SWITCH_BIT);
}

static inline p4d_t *kernel_to_user_p4dp(p4d_t *p4dp)
{
return ptr_set_bit(p4dp, PTI_PGTABLE_SWITCH_BIT);
}

static inline p4d_t *user_to_kernel_p4dp(p4d_t *p4dp)
{
return ptr_clear_bit(p4dp, PTI_PGTABLE_SWITCH_BIT);
}
#endif /* CONFIG_PAGE_TABLE_ISOLATION */

/*
* clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
*
Expand Down
49 changes: 0 additions & 49 deletions arch/x86/include/asm/pgtable_64.h
Original file line number Diff line number Diff line change
Expand Up @@ -132,55 +132,6 @@ static inline pud_t native_pudp_get_and_clear(pud_t *xp)
#endif
}

#ifdef CONFIG_PAGE_TABLE_ISOLATION
/*
* All top-level PAGE_TABLE_ISOLATION page tables are order-1 pages
* (8k-aligned and 8k in size). The kernel one is at the beginning 4k and
* the user one is in the last 4k. To switch between them, you
* just need to flip the 12th bit in their addresses.
*/
#define PTI_PGTABLE_SWITCH_BIT PAGE_SHIFT

/*
* This generates better code than the inline assembly in
* __set_bit().
*/
static inline void *ptr_set_bit(void *ptr, int bit)
{
unsigned long __ptr = (unsigned long)ptr;

__ptr |= BIT(bit);
return (void *)__ptr;
}
static inline void *ptr_clear_bit(void *ptr, int bit)
{
unsigned long __ptr = (unsigned long)ptr;

__ptr &= ~BIT(bit);
return (void *)__ptr;
}

static inline pgd_t *kernel_to_user_pgdp(pgd_t *pgdp)
{
return ptr_set_bit(pgdp, PTI_PGTABLE_SWITCH_BIT);
}

static inline pgd_t *user_to_kernel_pgdp(pgd_t *pgdp)
{
return ptr_clear_bit(pgdp, PTI_PGTABLE_SWITCH_BIT);
}

static inline p4d_t *kernel_to_user_p4dp(p4d_t *p4dp)
{
return ptr_set_bit(p4dp, PTI_PGTABLE_SWITCH_BIT);
}

static inline p4d_t *user_to_kernel_p4dp(p4d_t *p4dp)
{
return ptr_clear_bit(p4dp, PTI_PGTABLE_SWITCH_BIT);
}
#endif /* CONFIG_PAGE_TABLE_ISOLATION */

/*
* Page table pages are page-aligned. The lower half of the top
* level is used for userspace and the top half for the kernel.
Expand Down

0 comments on commit 8372d66

Please sign in to comment.