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Swap userland code and kvm spaces so that userland lives from VM_MIN_ADDRESS

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to VM_MAXUSER_ADDRESS and KVM is above that.

Note that the userspace is surrounded by a configurable amount of
non-accessible barrier space to prevent accidental out-of-boundaries access
even when reading.
This commit is contained in:
reinoud 2011-08-24 12:54:46 +00:00
parent a14203e91d
commit 3136589636
2 changed files with 14 additions and 13 deletions
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6
sys/arch/usermode/include/vmparam.h
View File

@ -1,4 +1,4 @@
/* $NetBSD: vmparam.h,v 1.7 2011/08/24 11:26:43 reinoud Exp $ */
/* $NetBSD: vmparam.h,v 1.8 2011/08/24 12:54:47 reinoud Exp $ */
/*-
* Copyright (c) 2007 Jared D. McNeill <jmcneill@invisible.ca>
@ -38,9 +38,9 @@ extern paddr_t kmem_user_start, kmem_user_end;
#define VM_MIN_KERNEL_ADDRESS kmem_k_start
#define VM_MAX_KERNEL_ADDRESS kmem_k_end
#define VM_MIN_ADDRESS kmem_ext_start
#define VM_MAX_ADDRESS kmem_user_end
#define VM_MIN_ADDRESS kmem_user_start
#define VM_MAXUSER_ADDRESS kmem_user_end
#define VM_MAX_ADDRESS kmem_ext_end
#define VM_PHYSSEG_STRAT VM_PSTRAT_BIGFIRST
#define VM_PHYSSEG_MAX 1

21
sys/arch/usermode/usermode/pmap.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: pmap.c,v 1.29 2011/08/24 11:50:28 reinoud Exp $ */
/* $NetBSD: pmap.c,v 1.30 2011/08/24 12:54:46 reinoud Exp $ */
/*-
* Copyright (c) 2011 Reinoud Zandijk <reinoud@NetBSD.org>
@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.29 2011/08/24 11:50:28 reinoud Exp $");
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.30 2011/08/24 12:54:46 reinoud Exp $");
#include "opt_memsize.h"
#include "opt_kmempages.h"
@ -143,11 +143,6 @@ pmap_bootstrap(void)
/* make page aligned */
mpos = round_page((vaddr_t) mem_uvm) + PAGE_SIZE;
/* calculate KVM section (RW-) */
kmem_ext_start = mpos;
mpos += kmem_len;
kmem_ext_end = mpos;
/* low barrier (---) */
mpos += barrier_len;
@ -160,6 +155,11 @@ pmap_bootstrap(void)
/* upper barrier (---) */
mpos += barrier_len;
/* calculate KVM section (RW-) */
kmem_ext_start = mpos;
mpos += kmem_len;
kmem_ext_end = mpos;
#if 0
/* protect complete UVM area (---) */
addr = thunk_mmap((void*) mem_uvm,
@ -197,7 +197,7 @@ pmap_bootstrap(void)
if (wlen != 1)
panic("pmap_bootstrap: can't grow file\n");
/* (un)protect the current kernel and data sections */
/* protect the current kernel section */
/* XXX kernel stack? */
err = thunk_mprotect((void *) kmem_k_start, kmem_k_end - kmem_k_start,
PROT_READ | PROT_EXEC);
@ -210,6 +210,7 @@ pmap_bootstrap(void)
phys_npages = (free_end - free_start) / PAGE_SIZE;
pv_table_size = round_page(phys_npages * sizeof(struct pv_entry));
aprint_debug("claiming %"PRIu64" KB of pv_table for "
"%"PRIdPTR" pages of physical memory\n",
(uint64_t) pv_table_size/1024, (uintptr_t) phys_npages);
@ -233,7 +234,7 @@ pmap_bootstrap(void)
fpos += pv_table_size;
/* set up kernel pmap */
pm_nentries = (kmem_user_end - kmem_ext_start) / PAGE_SIZE;
pm_nentries = (VM_MAX_ADDRESS - VM_MIN_ADDRESS) / PAGE_SIZE;
pm_entries_size = round_page(pm_nentries * sizeof(struct pv_entry *));
aprint_debug("pmap va->pa lookup table is %"PRIu64" KB for %d logical pages\n",
pm_entries_size/1024, pm_nentries);
@ -473,7 +474,7 @@ pmap_do_enter(pmap_t pmap, vaddr_t va, paddr_t pa, vm_prot_t prot, uint flags, i
ppn = atop(pa);
lpn = atop(va - VM_MIN_ADDRESS); /* V->A */
#ifdef DIAGNOSTIC
if ((va < kmem_k_start) || (va > kmem_user_end))
if ((va < VM_MIN_ADDRESS) || (va > VM_MAX_ADDRESS))
panic("pmap_do_enter: invalid va isued\n");
#endif