[PATCH 4.4 001/137] x86/mm: Fix types used in pgprot cacheability flags translations

Greg Kroah-Hartman
2016-02-24T04:04:56Z

From: Jan Beulich <JBeulich@suse.com>

commit 3625c2c234ef66acf21a72d47a5ffa94f6c5ebf2 upstream.

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 <jbeulich@suse.com>
Reviewed-by: Juergen Gross <JGross@suse.com>
Link: http://lkml.kernel.org/r/56A7635602000078000CAFF1@prv-mh.provo.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/include/asm/pgtable_types.h | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -363,20 +363,18 @@ static inline enum page_cache_mode pgpro
}
static inline pgprot_t pgprot_4k_2_large(pgprot_t pgprot)
{
+ pgprotval_t val = pgprot_val(pgprot);
pgprot_t new;
- unsigned long val;

- 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;
}
static inline pgprot_t pgprot_large_2_4k(pgprot_t pgprot)
{
+ pgprotval_t val = pgprot_val(pgprot);
pgprot_t new;
- unsigned long val;

- val = pgprot_val(pgprot);
pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
((val & _PAGE_PAT_LARGE) >>
(_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));