[src/trunk]: src/sys/arch/xen/x86 Map the recursive slot and page table pages...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/521f849cb3fa
branches:  trunk
changeset: 816931:521f849cb3fa
user:      maxv <maxv%NetBSD.org@localhost>
date:      Wed Aug 03 11:51:18 2016 +0000

description:
Map the recursive slot and page table pages as non-executable on Xen. Same
as normal x86.

diffstat:

 sys/arch/xen/x86/x86_xpmap.c |  29 +++++++++++++++++------------
 1 files changed, 17 insertions(+), 12 deletions(-)

diffs (77 lines):

diff -r 0aa9feb49a8e -r 521f849cb3fa sys/arch/xen/x86/x86_xpmap.c
--- a/sys/arch/xen/x86/x86_xpmap.c      Wed Aug 03 09:11:18 2016 +0000
+++ b/sys/arch/xen/x86/x86_xpmap.c      Wed Aug 03 11:51:18 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: x86_xpmap.c,v 1.57 2016/08/02 14:21:53 maxv Exp $      */
+/*     $NetBSD: x86_xpmap.c,v 1.58 2016/08/03 11:51:18 maxv Exp $      */
 
 /*
  * Copyright (c) 2006 Mathieu Ropert <mro%adviseo.fr@localhost>
@@ -69,7 +69,7 @@
 
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.57 2016/08/02 14:21:53 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.58 2016/08/03 11:51:18 maxv Exp $");
 
 #include "opt_xen.h"
 #include "opt_ddb.h"
@@ -918,7 +918,7 @@
 
                        pte[pl1_pi(page)] |= PG_k | PG_V;
                        if (page < (vaddr_t)&__rodata_start) {
-                               /* Map kernel text RX. */
+                               /* Map the kernel text RX. */
                                pte[pl1_pi(page)] |= PG_RO;
                        } else if (page >= (vaddr_t)&__rodata_start &&
                            page < (vaddr_t)&__data_start) {
@@ -930,12 +930,12 @@
                                pte[pl1_pi(page)] |= PG_RW | pg_nx;
                        } else if (page >= old_pgd &&
                            page < old_pgd + (old_count * PAGE_SIZE)) {
-                               /* map old page tables RO */
-                               pte[pl1_pi(page)] |= PG_RO;
+                               /* Map the old page tables R. */
+                               pte[pl1_pi(page)] |= PG_RO | pg_nx;
                        } else if (page >= new_pgd &&
                            page < new_pgd + ((new_count + l2_4_count) * PAGE_SIZE)) {
-                               /* map new page tables RO */
-                               pte[pl1_pi(page)] |= PG_RO;
+                               /* Map the new page tables R. */
+                               pte[pl1_pi(page)] |= PG_RO | pg_nx;
 #ifdef i386
                        } else if (page == (vaddr_t)tmpgdt) {
                                /*
@@ -1028,15 +1028,19 @@
        xpq_queue_pin_l2_table(xpmap_ptom_masked(addr));
 #endif
 #else /* PAE */
-       /* recursive entry in higher-level per-cpu PD and pmap_kernel() */
-       bt_pgd[PDIR_SLOT_PTE] = xpmap_ptom_masked((paddr_t)bt_pgd - KERNBASE) | PG_k | PG_V;
+
+       /* Recursive entry in pmap_kernel(). */
+       bt_pgd[PDIR_SLOT_PTE] = xpmap_ptom_masked((paddr_t)bt_pgd - KERNBASE)
+           | PG_k | PG_RO | PG_V | pg_nx;
 #ifdef __x86_64__
-          bt_cpu_pgd[PDIR_SLOT_PTE] =
-                  xpmap_ptom_masked((paddr_t)bt_cpu_pgd - KERNBASE) | PG_k | PG_V;
-#endif /* __x86_64__ */
+       /* Recursive entry in higher-level per-cpu PD. */
+       bt_cpu_pgd[PDIR_SLOT_PTE] = xpmap_ptom_masked((paddr_t)bt_cpu_pgd - KERNBASE)
+           | PG_k | PG_RO | PG_V | pg_nx;
+#endif
        __PRINTK(("bt_pgd[PDIR_SLOT_PTE] va %#" PRIxVADDR " pa %#" PRIxPADDR
            " entry %#" PRIxPADDR "\n", new_pgd, (paddr_t)new_pgd - KERNBASE,
            bt_pgd[PDIR_SLOT_PTE]));
+
        /* Mark tables RO */
        xen_bt_set_readonly((vaddr_t) pde);
 #endif
@@ -1046,6 +1050,7 @@
 #if PTP_LEVELS > 3
        xen_bt_set_readonly(new_pgd);
 #endif
+
        /* Pin the PGD */
        __PRINTK(("pin PGD: %"PRIxVADDR"\n", new_pgd - KERNBASE));
 #ifdef __x86_64__