releases/4.4.3/x86-mm-fix-types-used-in-pgprot-cacheability-flags-translations.patch

   1 From 3625c2c234ef66acf21a72d47a5ffa94f6c5ebf2 Mon Sep 17 00:00:00 2001
   2 From: Jan Beulich <JBeulich@suse.com>
   3 Date: Tue, 26 Jan 2016 04:15:18 -0700
   4 Subject: x86/mm: Fix types used in pgprot cacheability flags translations
   5
   6 From: Jan Beulich <JBeulich@suse.com>
   7
   8 commit 3625c2c234ef66acf21a72d47a5ffa94f6c5ebf2 upstream.
   9
  10 For PAE kernels "unsigned long" is not suitable to hold page protection
  11 flags, since _PAGE_NX doesn't fit there. This is the reason for quite a
  12 few W+X pages getting reported as insecure during boot (observed namely
  13 for the entire initrd range).
  14
  15 Fixes: 281d4078be ("x86: Make page cache mode a real type")
  16 Signed-off-by: Jan Beulich <jbeulich@suse.com>
  17 Reviewed-by: Juergen Gross <JGross@suse.com>
  18 Link: http://lkml.kernel.org/r/56A7635602000078000CAFF1@prv-mh.provo.novell.com
  19 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  20 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  21
  22 ---
  23  arch/x86/include/asm/pgtable_types.h |    6 ++----
  24  1 file changed, 2 insertions(+), 4 deletions(-)
  25
  26 --- a/arch/x86/include/asm/pgtable_types.h
  27 +++ b/arch/x86/include/asm/pgtable_types.h
  28 @@ -363,20 +363,18 @@ static inline enum page_cache_mode pgpro
  29  }
  30  static inline pgprot_t pgprot_4k_2_large(pgprot_t pgprot)
  31  {
  32 +       pgprotval_t val = pgprot_val(pgprot);
  33         pgprot_t new;
  34 -       unsigned long val;
  35
  36 -       val = pgprot_val(pgprot);
  37         pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
  38                 ((val & _PAGE_PAT) << (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));
  39         return new;
  40  }
  41  static inline pgprot_t pgprot_large_2_4k(pgprot_t pgprot)
  42  {
  43 +       pgprotval_t val = pgprot_val(pgprot);
  44         pgprot_t new;
  45 -       unsigned long val;
  46
  47 -       val = pgprot_val(pgprot);
  48         pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
  49                           ((val & _PAGE_PAT_LARGE) >>
  50                            (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));