[src/trunk]: src/sys/arch/x86/x86 There is no direct map on i386, and therefo...

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

details:   https://anonhg.NetBSD.org/src/rev/57cdd6496204
branches:  trunk
changeset: 816354:57cdd6496204
user:      maxv <maxv%NetBSD.org@localhost>
date:      Fri Jul 01 12:36:43 2016 +0000

description:
There is no direct map on i386, and therefore we always need to use
temporary VAs and PTEs when mapping an area. These temporary VAs don't
need to be executable. Put the NOX bit on them.

diffstat:

 sys/arch/x86/x86/pmap.c |  48 ++++++++++++++++++++++++++++++------------------
 1 files changed, 30 insertions(+), 18 deletions(-)

diffs (150 lines):

diff -r 6129218fea34 -r 57cdd6496204 sys/arch/x86/x86/pmap.c
--- a/sys/arch/x86/x86/pmap.c   Fri Jul 01 12:18:34 2016 +0000
+++ b/sys/arch/x86/x86/pmap.c   Fri Jul 01 12:36:43 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.205 2016/07/01 12:18:34 maxv Exp $  */
+/*     $NetBSD: pmap.c,v 1.206 2016/07/01 12:36:43 maxv Exp $  */
 
 /*-
  * Copyright (c) 2008, 2010, 2016 The NetBSD Foundation, Inc.
@@ -171,7 +171,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.205 2016/07/01 12:18:34 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.206 2016/07/01 12:36:43 maxv Exp $");
 
 #include "opt_user_ldt.h"
 #include "opt_lockdebug.h"
@@ -1642,7 +1642,8 @@
 #ifdef __HAVE_DIRECT_MAP
                memset((void *)PMAP_DIRECT_MAP(newp), 0, PAGE_SIZE);
 #else
-               pmap_pte_set(early_zero_pte, pmap_pa2pte(newp) | pteflags);
+               pmap_pte_set(early_zero_pte, pmap_pa2pte(newp) | pteflags |
+                   pmap_pg_nx);
                pmap_pte_flush();
                pmap_update_pg((vaddr_t)early_zerop);
                memset(early_zerop, 0, PAGE_SIZE);
@@ -1671,8 +1672,8 @@
                        pmap_pte_set(&kpm_pdir[pl_i(0, PTP_LEVELS)],
                            pmap_pa2pte(newp) | pteflags);
                }
-
 #endif /* XEN */
+
                pmap_pte_set(&pdes[pl_i(0, level)],
                    pmap_pa2pte(newp) | pteflags);
 
@@ -3081,6 +3082,9 @@
        void *zerova;
        int id;
 
+       const pd_entry_t pteflags = PG_V | PG_RW | pmap_pg_nx | PG_M | PG_U |
+           PG_k;
+
        kpreempt_disable();
        id = cpu_number();
        zpte = PTESLEW(zero_pte, id);
@@ -3091,7 +3095,7 @@
                panic("pmap_zero_page: lock botch");
 #endif
 
-       pmap_pte_set(zpte, pmap_pa2pte(pa) | PG_V | PG_RW | PG_M | PG_U | PG_k);
+       pmap_pte_set(zpte, pmap_pa2pte(pa) | pteflags);
        pmap_pte_flush();
        pmap_update_pg((vaddr_t)zerova);                /* flush TLB */
 
@@ -3101,6 +3105,7 @@
        pmap_pte_set(zpte, 0);                          /* zap ! */
        pmap_pte_flush();
 #endif
+
        kpreempt_enable();
 #endif /* defined(__HAVE_DIRECT_MAP) */
 }
@@ -3123,6 +3128,9 @@
        bool rv;
        int id;
 
+       const pd_entry_t pteflags = PG_V | PG_RW | pmap_pg_nx | PG_M | PG_U |
+           PG_k;
+
        id = cpu_number();
        zpte = PTESLEW(zero_pte, id);
        zerova = VASLEW(zerop, id);
@@ -3130,7 +3138,7 @@
        KASSERT(cpu_feature[0] & CPUID_SSE2);
        KASSERT(*zpte == 0);
 
-       pmap_pte_set(zpte, pmap_pa2pte(pa) | PG_V | PG_RW | PG_M | PG_U | PG_k);
+       pmap_pte_set(zpte, pmap_pa2pte(pa) | pteflags);
        pmap_pte_flush();
        pmap_update_pg((vaddr_t)zerova);                /* flush TLB */
 
@@ -3170,6 +3178,8 @@
        void *cdstva;
        int id;
 
+       const pd_entry_t pteflags = PG_V | PG_RW | pmap_pg_nx | PG_U | PG_k;
+
        kpreempt_disable();
        id = cpu_number();
        spte = PTESLEW(csrc_pte,id);
@@ -3179,9 +3189,8 @@
 
        KASSERT(*spte == 0 && *dpte == 0);
 
-       pmap_pte_set(spte, pmap_pa2pte(srcpa) | PG_V | PG_RW | PG_U | PG_k);
-       pmap_pte_set(dpte,
-           pmap_pa2pte(dstpa) | PG_V | PG_RW | PG_M | PG_U | PG_k);
+       pmap_pte_set(spte, pmap_pa2pte(srcpa) | pteflags);
+       pmap_pte_set(dpte, pmap_pa2pte(dstpa) | pteflags | PG_M);
        pmap_pte_flush();
        pmap_update_2pg((vaddr_t)csrcva, (vaddr_t)cdstva);
 
@@ -3192,6 +3201,7 @@
        pmap_pte_set(dpte, 0);
        pmap_pte_flush();
 #endif
+
        kpreempt_enable();
 #endif /* defined(__HAVE_DIRECT_MAP) */
 }
@@ -3208,16 +3218,18 @@
 
        KASSERT(kpreempt_disabled());
 
+#ifndef XEN
+       const pd_entry_t pteflags = PG_V | PG_RW | pmap_pg_nx | PG_U | PG_M |
+           PG_k;
+#else
+       const pd_entry_t pteflags = PG_V | pmap_pg_nx | PG_U | PG_M | PG_k;
+#endif
+
        id = cpu_number();
        ptppte = PTESLEW(ptp_pte, id);
        ptpva = VASLEW(ptpp, id);
-#if !defined(XEN)
-       pmap_pte_set(ptppte, pmap_pa2pte(VM_PAGE_TO_PHYS(ptp)) | PG_V | PG_M |
-           PG_RW | PG_U | PG_k);
-#else
-       pmap_pte_set(ptppte, pmap_pa2pte(VM_PAGE_TO_PHYS(ptp)) | PG_V | PG_M |
-           PG_U | PG_k);
-#endif
+       pmap_pte_set(ptppte, pmap_pa2pte(VM_PAGE_TO_PHYS(ptp)) | pteflags);
+
        pmap_pte_flush();
        pmap_update_pg((vaddr_t)ptpva);
 
@@ -4252,8 +4264,8 @@
                }
 #endif
                kpreempt_disable();
-               pmap_pte_set(early_zero_pte,
-                   pmap_pa2pte(*paddrp) | PG_V | PG_RW | PG_k);
+               pmap_pte_set(early_zero_pte, pmap_pa2pte(*paddrp) | PG_V |
+                   PG_RW | pmap_pg_nx | PG_k);
                pmap_pte_flush();
                pmap_update_pg((vaddr_t)early_zerop);
                memset(early_zerop, 0, PAGE_SIZE);