On 26/01/16 12:15, Jan Beulich wrote:
> For PAE kernels "unsigned long" is not suitable to hold page protection
> flags, since _PAGE_NX doesn't fit there. This is the reason for quite a
> few W+X pages getting reported as insecure during boot (observed namely
> for the entire initrd range).
>
> Fixes: 281d4078be ("x86: Make page cache mode a real type")
> Signed-off-by: Jan Beulich <jbeul...@suse.com>
> Cc: Juergen Gross <jgr...@suse.com>
Reviewed-by: Juergen Gross <jgr...@suse.com>
> ---
> v2: Remove code enhancement part, as requested by tglx.
> ---
> arch/x86/include/asm/pgtable_types.h | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> --- 4.5-rc1/arch/x86/include/asm/pgtable_types.h
> +++ 4.5-rc1-ix86-PAE-pgprot-xlat/arch/x86/include/asm/pgtable_types.h
> @@ -367,9 +367,8 @@ static inline enum page_cache_mode pgpro
> static inline pgprot_t pgprot_4k_2_large(pgprot_t pgprot)
> {
> pgprot_t new;
> - unsigned long val;
> + pgprotval_t val = pgprot_val(pgprot);
>
> - val = pgprot_val(pgprot);
> pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
> ((val & _PAGE_PAT) << (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));
> return new;
> @@ -377,9 +376,8 @@ static inline pgprot_t pgprot_4k_2_large
> static inline pgprot_t pgprot_large_2_4k(pgprot_t pgprot)
> {
> pgprot_t new;
> - unsigned long val;
> + pgprotval_t val = pgprot_val(pgprot);
>
> - val = pgprot_val(pgprot);
> pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
> ((val & _PAGE_PAT_LARGE) >>
> (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));
>
>
>
>
