[src/trunk]: src/sys/arch Simplify the ASLR stuff, we don't care about resiza...

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

details:   https://anonhg.NetBSD.org/src/rev/39a54e5fffa4
branches:  trunk
changeset: 366485:39a54e5fffa4
user:      maxv <maxv%NetBSD.org@localhost>
date:      Wed Aug 29 06:17:26 2018 +0000

description:
Simplify the ASLR stuff, we don't care about resizable areas now, and it
makes the code more complicated for no good reason.

diffstat:

 sys/arch/amd64/amd64/machdep.c |  28 ++++------------------------
 sys/arch/x86/include/pmap.h    |   4 +---
 sys/arch/x86/x86/pmap.c        |   7 ++-----
 3 files changed, 7 insertions(+), 32 deletions(-)

diffs (143 lines):

diff -r 47bb166e4beb -r 39a54e5fffa4 sys/arch/amd64/amd64/machdep.c
--- a/sys/arch/amd64/amd64/machdep.c    Wed Aug 29 06:16:40 2018 +0000
+++ b/sys/arch/amd64/amd64/machdep.c    Wed Aug 29 06:17:26 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: machdep.c,v 1.316 2018/08/22 12:07:42 maxv Exp $       */
+/*     $NetBSD: machdep.c,v 1.317 2018/08/29 06:17:26 maxv Exp $       */
 
 /*
  * Copyright (c) 1996, 1997, 1998, 2000, 2006, 2007, 2008, 2011
@@ -110,7 +110,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.316 2018/08/22 12:07:42 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.317 2018/08/29 06:17:26 maxv Exp $");
 
 #include "opt_modular.h"
 #include "opt_user_ldt.h"
@@ -1617,75 +1617,55 @@
 
        /* User. [256, because we want to land in >= 256] */
        slotspace.area[SLAREA_USER].sslot = 0;
-       slotspace.area[SLAREA_USER].mslot = PDIR_SLOT_USERLIM+1;
        slotspace.area[SLAREA_USER].nslot = PDIR_SLOT_USERLIM+1;
        slotspace.area[SLAREA_USER].active = true;
-       slotspace.area[SLAREA_USER].dropmax = false;
 
 #ifdef XEN
        /* PTE. */
        slotspace.area[SLAREA_PTE].sslot = PDIR_SLOT_PTE;
-       slotspace.area[SLAREA_PTE].mslot = 1;
        slotspace.area[SLAREA_PTE].nslot = 1;
        slotspace.area[SLAREA_PTE].active = true;
-       slotspace.area[SLAREA_PTE].dropmax = false;
 #endif
 
 #ifdef __HAVE_PCPU_AREA
        /* Per-CPU. */
        slotspace.area[SLAREA_PCPU].sslot = PDIR_SLOT_PCPU;
-       slotspace.area[SLAREA_PCPU].mslot = 1;
        slotspace.area[SLAREA_PCPU].nslot = 1;
        slotspace.area[SLAREA_PCPU].active = true;
-       slotspace.area[SLAREA_PCPU].dropmax = false;
 #endif
 
 #ifdef __HAVE_DIRECT_MAP
-       /* Direct Map. */
-       slotspace.area[SLAREA_DMAP].sslot = PDIR_SLOT_DIRECT;
-       slotspace.area[SLAREA_DMAP].mslot = NL4_SLOT_DIRECT+1;
-       slotspace.area[SLAREA_DMAP].nslot = 0 /* variable */;
+       /* Direct Map. [Randomized later] */
        slotspace.area[SLAREA_DMAP].active = false;
-       slotspace.area[SLAREA_DMAP].dropmax = true;
 #endif
 
 #ifdef XEN
        /* Hypervisor. */
        slotspace.area[SLAREA_HYPV].sslot = 256;
-       slotspace.area[SLAREA_HYPV].mslot = 17;
        slotspace.area[SLAREA_HYPV].nslot = 17;
        slotspace.area[SLAREA_HYPV].active = true;
-       slotspace.area[SLAREA_HYPV].dropmax = false;
 #endif
 
 #ifdef KASAN
        /* ASAN. */
        slotspace.area[SLAREA_ASAN].sslot = L4_SLOT_KASAN;
-       slotspace.area[SLAREA_ASAN].mslot = NL4_SLOT_KASAN;
        slotspace.area[SLAREA_ASAN].nslot = NL4_SLOT_KASAN;
        slotspace.area[SLAREA_ASAN].active = true;
-       slotspace.area[SLAREA_ASAN].dropmax = false;
 #endif
 
        /* Kernel. */
        slotspace.area[SLAREA_KERN].sslot = L4_SLOT_KERNBASE;
-       slotspace.area[SLAREA_KERN].mslot = 1;
        slotspace.area[SLAREA_KERN].nslot = 1;
        slotspace.area[SLAREA_KERN].active = true;
-       slotspace.area[SLAREA_KERN].dropmax = false;
 
        /* Main. */
-       slotspace.area[SLAREA_MAIN].mslot = NKL4_MAX_ENTRIES+1;
-       slotspace.area[SLAREA_MAIN].dropmax = false;
        va = slotspace_rand(SLAREA_MAIN, NKL4_MAX_ENTRIES * NBPD_L4,
-           NBPD_L4);
+           NBPD_L4); /* TODO: NBPD_L1 */
        vm_min_kernel_address = va;
        vm_max_kernel_address = va + NKL4_MAX_ENTRIES * NBPD_L4;
 
 #ifndef XEN
        /* PTE. */
-       slotspace.area[SLAREA_PTE].mslot = 1;
-       slotspace.area[SLAREA_PTE].dropmax = false;
        va = slotspace_rand(SLAREA_PTE, NBPD_L4, NBPD_L4);
        pte_base = (pd_entry_t *)va;
 #endif
diff -r 47bb166e4beb -r 39a54e5fffa4 sys/arch/x86/include/pmap.h
--- a/sys/arch/x86/include/pmap.h       Wed Aug 29 06:16:40 2018 +0000
+++ b/sys/arch/x86/include/pmap.h       Wed Aug 29 06:17:26 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.h,v 1.85 2018/08/20 15:04:52 maxv Exp $   */
+/*     $NetBSD: pmap.h,v 1.86 2018/08/29 06:17:26 maxv Exp $   */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -169,9 +169,7 @@
        struct {
                size_t sslot; /* start slot */
                size_t nslot; /* # of slots */
-               size_t mslot; /* max # of slots */
                bool active;  /* area is active */
-               bool dropmax; /* !resizable */
        } area[SLSPACE_NAREAS];
 };
 
diff -r 47bb166e4beb -r 39a54e5fffa4 sys/arch/x86/x86/pmap.c
--- a/sys/arch/x86/x86/pmap.c   Wed Aug 29 06:16:40 2018 +0000
+++ b/sys/arch/x86/x86/pmap.c   Wed Aug 29 06:17:26 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.305 2018/08/22 12:07:43 maxv Exp $  */
+/*     $NetBSD: pmap.c,v 1.306 2018/08/29 06:17:26 maxv Exp $  */
 
 /*
  * Copyright (c) 2008, 2010, 2016, 2017 The NetBSD Foundation, Inc.
@@ -157,7 +157,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.305 2018/08/22 12:07:43 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.306 2018/08/29 06:17:26 maxv Exp $");
 
 #include "opt_user_ldt.h"
 #include "opt_lockdebug.h"
@@ -1473,9 +1473,6 @@
        slotspace.area[type].sslot = pl4_i(va);
        slotspace.area[type].nslot =
            pmap_pagetree_nentries_range(va, va+sz, NBPD_L4);
-       if (slotspace.area[type].dropmax) {
-               slotspace.area[type].mslot = slotspace.area[type].nslot;
-       }
        slotspace.area[type].active = true;
 
        return va;