[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/e09491fed6b2
branches:  trunk
changeset: 346212:e09491fed6b2
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 566bba03f261 -r e09491fed6b2 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);