Module Name: src
Committed By: maxv
Date: Tue Aug 2 14:21:53 UTC 2016
Modified Files:
src/sys/arch/xen/x86: x86_xpmap.c
Log Message:
Map the kernel text, rodata and data+bss independently on Xen, with
respectively RX, R and RW.
To generate a diff of this commit:
cvs rdiff -u -r1.56 -r1.57 src/sys/arch/xen/x86/x86_xpmap.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/xen/x86/x86_xpmap.c
diff -u src/sys/arch/xen/x86/x86_xpmap.c:1.56 src/sys/arch/xen/x86/x86_xpmap.c:1.57
--- src/sys/arch/xen/x86/x86_xpmap.c:1.56 Tue Aug 2 13:29:35 2016
+++ src/sys/arch/xen/x86/x86_xpmap.c Tue Aug 2 14:21:53 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: x86_xpmap.c,v 1.56 2016/08/02 13:29:35 maxv Exp $ */
+/* $NetBSD: x86_xpmap.c,v 1.57 2016/08/02 14:21:53 maxv Exp $ */
/*
* Copyright (c) 2006 Mathieu Ropert <m...@adviseo.fr>
@@ -69,7 +69,7 @@
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.56 2016/08/02 13:29:35 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.57 2016/08/02 14:21:53 maxv Exp $");
#include "opt_xen.h"
#include "opt_ddb.h"
@@ -730,15 +730,24 @@ xen_bootstrap_tables(vaddr_t old_pgd, va
pd_entry_t *pdtpe, *pde, *pte;
pd_entry_t *bt_pgd;
paddr_t addr;
- vaddr_t page, avail, text_end, map_end;
+ vaddr_t page, avail, map_end;
int i;
+ extern char __rodata_start;
extern char __data_start;
+ extern char __kernel_end;
extern char *early_zerop; /* from pmap.c */
+ pt_entry_t pg_nx;
+ u_int descs[4];
__PRINTK(("xen_bootstrap_tables(%#" PRIxVADDR ", %#" PRIxVADDR ","
" %d, %d)\n",
old_pgd, new_pgd, old_count, new_count));
- text_end = ((vaddr_t)&__data_start) & ~PAGE_MASK;
+
+ /*
+ * Set the NX/XD bit, if available. descs[3] = %edx.
+ */
+ x86_cpuid(0x80000001, descs);
+ pg_nx = (descs[3] & CPUID_NOX) ? PG_NX : 0;
/*
* size of R/W area after kernel text:
@@ -776,8 +785,7 @@ xen_bootstrap_tables(vaddr_t old_pgd, va
}
#endif /* DOM0OPS */
- __PRINTK(("xen_bootstrap_tables text_end 0x%lx map_end 0x%lx\n",
- text_end, map_end));
+ __PRINTK(("xen_bootstrap_tables map_end 0x%lx\n", map_end));
__PRINTK(("console %#lx ", xen_start_info.console_mfn));
__PRINTK(("xenstore %#" PRIx32 "\n", xen_start_info.store_mfn));
@@ -907,10 +915,19 @@ xen_bootstrap_tables(vaddr_t old_pgd, va
IOM_BEGIN + (page - (vaddr_t)atdevbase);
}
#endif
+
pte[pl1_pi(page)] |= PG_k | PG_V;
- if (page < text_end) {
- /* map kernel text RO */
+ if (page < (vaddr_t)&__rodata_start) {
+ /* Map kernel text RX. */
pte[pl1_pi(page)] |= PG_RO;
+ } else if (page >= (vaddr_t)&__rodata_start &&
+ page < (vaddr_t)&__data_start) {
+ /* Map the kernel rodata R. */
+ pte[pl1_pi(page)] |= PG_RO | pg_nx;
+ } else if (page >= (vaddr_t)&__data_start &&
+ page < (vaddr_t)&__kernel_end) {
+ /* Map the kernel data+bss RW. */
+ pte[pl1_pi(page)] |= PG_RW | pg_nx;
} else if (page >= old_pgd &&
page < old_pgd + (old_count * PAGE_SIZE)) {
/* map old page tables RO */
