x86/speculation/l1tf: Protect NUMA-balance entries against L1TF

NUMA balancing has its own functions that manipulated the PRESENT flag
in PTEs and PMDs.  These were not affected by the changes in commit
6b28baca9b1f "x86/speculation/l1tf: Protect PROT_NONE PTEs against
speculation".

This is not a problem upstream because NUMA balancing was changed to
use {pte,pmd}_modify() in Linux 4.0.

Override the generic implementations for x86 with implementations
that do the same inversion as {pte,pmd}_modify().

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: x86@kernel.org
Cc: Mel Gorman <mgorman@suse.de>

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index b152e967a7f8cee76739a6e083f91c1321a684f1..cf23aa1915ce1993e2cf374832ed505afc125202 100644 (file)
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -419,6 +419,54 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
        return __pmd(val);
 }
 
+#ifdef CONFIG_NUMA_BALANCING
+
+static inline pte_t pte_mknonnuma(pte_t pte)
+{
+       pteval_t val = pte_val(pte), oldval = val;
+
+       val &= ~_PAGE_NUMA;
+       val |= (_PAGE_PRESENT|_PAGE_ACCESSED);
+       val = flip_protnone_guard(oldval, val, PTE_PFN_MASK);
+       return __pte(val);
+}
+#define pte_mknonnuma pte_mknonnuma
+
+static inline pte_t pte_mknuma(pte_t pte)
+{
+       pteval_t val = pte_val(pte), oldval = val;
+
+       val &= ~_PAGE_PRESENT;
+       val |= _PAGE_NUMA;
+       val = flip_protnone_guard(oldval, val, PTE_PFN_MASK);
+       return __pte(val);
+}
+#define pte_mknuma pte_mknuma
+
+static inline pmd_t pmd_mknonnuma(pmd_t pmd)
+{
+       pmdval_t val = pmd_val(pmd), oldval = val;
+
+       val &= ~_PAGE_NUMA;
+       val |= (_PAGE_PRESENT|_PAGE_ACCESSED);
+       val = flip_protnone_guard(oldval, val, PTE_PFN_MASK);
+       return __pmd(val);
+}
+#define pmd_mknonnuma pmd_mknonnuma
+
+static inline pmd_t pmd_mknuma(pmd_t pmd)
+{
+       pmdval_t val = pmd_val(pmd), oldval = val;
+
+       val &= ~_PAGE_PRESENT;
+       val |= _PAGE_NUMA;
+       val = flip_protnone_guard(oldval, val, PTE_PFN_MASK);
+       return __pmd(val);
+}
+#define pmd_mknuma pmd_mknuma
+
+#endif /* CONFIG_NUMA_BALANCING */
+
 /* mprotect needs to preserve PAT bits when updating vm_page_prot */
 #define pgprot_modify pgprot_modify
 static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)