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-rw-r--r--contrib/netbsd-tests/lib/libc/arch/i386/exec_prot_support.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/contrib/netbsd-tests/lib/libc/arch/i386/exec_prot_support.c b/contrib/netbsd-tests/lib/libc/arch/i386/exec_prot_support.c
new file mode 100644
index 0000000..11a20f5
--- /dev/null
+++ b/contrib/netbsd-tests/lib/libc/arch/i386/exec_prot_support.c
@@ -0,0 +1,65 @@
+/* $NetBSD: exec_prot_support.c,v 1.1 2011/07/18 23:16:09 jym Exp $ */
+
+/*-
+ * Copyright (c) 2011 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jean-Yves Migeon.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__RCSID("$NetBSD: exec_prot_support.c,v 1.1 2011/07/18 23:16:09 jym Exp $");
+
+#include <stdlib.h>
+#include <sys/sysctl.h>
+
+#include "../../common/exec_prot.h"
+
+/*
+ * Support for executable space protection has always been erratic under i386.
+ * Originally IA-32 can't do per-page execute permission, so it is
+ * implemented using different executable segments for %cs (code segment).
+ * This only allows coarse grained protection, especially when memory starts
+ * being fragmented.
+ * Later, PAE was introduced together with a NX/XD bit in the page table
+ * entry to offer per-page permission.
+ */
+int
+exec_prot_support(void)
+{
+ int pae;
+ size_t pae_len = sizeof(pae);
+
+ if (sysctlbyname("machdep.pae", &pae, &pae_len, NULL, 0) == -1)
+ return PARTIAL_XP;
+
+ if (pae == 1) {
+ if (system("cpuctl identify 0 | grep -q NOX") == 0 ||
+ system("cpuctl identify 0 | grep -q XD") == 0)
+ return PERPAGE_XP;
+ }
+
+ return PARTIAL_XP;
+}
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