Merge tag 'for-linus-4.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git...
[muen/linux.git] / arch / x86 / xen / mmu_pv.c
index 6cf801ca11428fa5fd9c2d3c9931354f28575580..69145ea5532c306ab4cd52fb9bd428a0435eaa47 100644 (file)
@@ -1902,6 +1902,18 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
        /* Graft it onto L4[511][510] */
        copy_page(level2_kernel_pgt, l2);
 
+       /*
+        * Zap execute permission from the ident map. Due to the sharing of
+        * L1 entries we need to do this in the L2.
+        */
+       if (__supported_pte_mask & _PAGE_NX) {
+               for (i = 0; i < PTRS_PER_PMD; ++i) {
+                       if (pmd_none(level2_ident_pgt[i]))
+                               continue;
+                       level2_ident_pgt[i] = pmd_set_flags(level2_ident_pgt[i], _PAGE_NX);
+               }
+       }
+
        /* Copy the initial P->M table mappings if necessary. */
        i = pgd_index(xen_start_info->mfn_list);
        if (i && i < pgd_index(__START_KERNEL_map))