Module Name: src
Committed By: reinoud
Date: Sun Aug 5 16:51:59 UTC 2018
Modified Files:
src/sys/arch/usermode/usermode: pmap.c
Log Message:
To avoid possible collisions between the NetBSD/userland kernel and possible
host kernel memory allocation schemes, allocate two dedicated pages for page
copying and page zeroing.
To generate a diff of this commit:
cvs rdiff -u -r1.112 -r1.113 src/sys/arch/usermode/usermode/pmap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/usermode/usermode/pmap.c
diff -u src/sys/arch/usermode/usermode/pmap.c:1.112 src/sys/arch/usermode/usermode/pmap.c:1.113
--- src/sys/arch/usermode/usermode/pmap.c:1.112 Fri Aug 3 11:18:22 2018
+++ src/sys/arch/usermode/usermode/pmap.c Sun Aug 5 16:51:59 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.112 2018/08/03 11:18:22 reinoud Exp $ */
+/* $NetBSD: pmap.c,v 1.113 2018/08/05 16:51:59 reinoud Exp $ */
/*-
* Copyright (c) 2011 Reinoud Zandijk <[email protected]>
@@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.112 2018/08/03 11:18:22 reinoud Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.113 2018/08/05 16:51:59 reinoud Exp $");
#include "opt_memsize.h"
#include "opt_kmempages.h"
@@ -101,6 +101,8 @@ static int pm_nentries = 0;
static int pm_nl1 = 0;
static int pm_l1_size = 0;
static uint64_t pm_entries_size = 0;
+static void *pm_tmp_p0;
+static void *pm_tmp_p1;
static struct pool pmap_pool;
static struct pool pmap_pventry_pool;
@@ -183,6 +185,11 @@ pmap_bootstrap(void)
kmem_kvm_end = kmem_k_start - barrier_len;
kmem_kvm_start = kmem_kvm_end - KVMSIZE;
+ /* allow some pmap scratch space */
+ pm_tmp_p0 = (void *) (kmem_kvm_start);
+ pm_tmp_p1 = (void *) (kmem_kvm_start + PAGE_SIZE);
+ kmem_kvm_start += 2*PAGE_SIZE;
+
/* claim an area for userland (---/R--/RW-/RWX) */
kmem_user_start = vm_min_addr;
kmem_user_end = kmem_kvm_start - barrier_len;
@@ -1227,14 +1234,12 @@ pmap_zero_page(paddr_t pa)
if (pa & (PAGE_SIZE-1))
panic("%s: unaligned address passed : %p\n", __func__, (void *) pa);
- blob = thunk_mmap(NULL, PAGE_SIZE,
+ blob = thunk_mmap(pm_tmp_p0, PAGE_SIZE,
THUNK_PROT_READ | THUNK_PROT_WRITE,
- THUNK_MAP_FILE | THUNK_MAP_SHARED,
+ THUNK_MAP_FILE | THUNK_MAP_FIXED | THUNK_MAP_SHARED,
mem_fh, pa);
- if (!blob)
+ if (blob != pm_tmp_p0)
panic("%s: couldn't get mapping", __func__);
- if (blob < (char *) kmem_k_end)
- panic("%s: mmap in illegal memory range", __func__);
memset(blob, 0, PAGE_SIZE);
@@ -1254,25 +1259,21 @@ pmap_copy_page(paddr_t src_pa, paddr_t d
thunk_printf_debug("pmap_copy_page: pa src %p, pa dst %p\n",
(void *) src_pa, (void *) dst_pa);
- /* XXX bug alart: can we allow the kernel to make a decision on this? */
- sblob = thunk_mmap(NULL, PAGE_SIZE,
+ /* source */
+ sblob = thunk_mmap(pm_tmp_p0, PAGE_SIZE,
THUNK_PROT_READ,
- THUNK_MAP_FILE | THUNK_MAP_SHARED,
+ THUNK_MAP_FILE | THUNK_MAP_FIXED | THUNK_MAP_SHARED,
mem_fh, src_pa);
- if (!sblob)
+ if (sblob != pm_tmp_p0)
panic("%s: couldn't get src mapping", __func__);
- if (sblob < (char *) kmem_k_end)
- panic("%s: mmap in illegal memory range", __func__);
- /* XXX bug alart: can we allow the kernel to make a decision on this? */
- dblob = thunk_mmap(NULL, PAGE_SIZE,
+ /* destination */
+ dblob = thunk_mmap(pm_tmp_p1, PAGE_SIZE,
THUNK_PROT_READ | THUNK_PROT_WRITE,
- THUNK_MAP_FILE | THUNK_MAP_SHARED,
+ THUNK_MAP_FILE | THUNK_MAP_FIXED | THUNK_MAP_SHARED,
mem_fh, dst_pa);
- if (!dblob)
+ if (dblob != pm_tmp_p1)
panic("%s: couldn't get dst mapping", __func__);
- if (dblob < (char *) kmem_k_end)
- panic("%s: mmap in illegal memory range", __func__);
memcpy(dblob, sblob, PAGE_SIZE);
