Index: head/tests/sys/kern/kern_copyin.c
===================================================================
--- head/tests/sys/kern/kern_copyin.c	(revision 365326)
+++ head/tests/sys/kern/kern_copyin.c	(revision 365327)
@@ -1,96 +1,131 @@
 /*-
- * Copyright (c) 2015 The FreeBSD Foundation
+ * Copyright (c) 2015, 2020 The FreeBSD Foundation
  * All rights reserved.
  *
  * This software was developed by Konstantin Belousov <kib@FreeBSD.org>
  * under sponsorship from the FreeBSD Foundation.
  *
  * 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 AUTHOR 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 AUTHOR 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>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
+#include <sys/exec.h>
+#include <sys/sysctl.h>
 #include <errno.h>
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <atf-c.h>
 #include <vm/vm.h>
 #include <vm/pmap.h>
 #include <machine/vmparam.h>
 
 static int scratch_file;
 
 static int
 copyin_checker(uintptr_t uaddr, size_t len)
 {
 	ssize_t ret;
 
 	ret = write(scratch_file, (const void *)uaddr, len);
 	return (ret == -1 ? errno : 0);
 }
 
+#ifdef __amd64__
+static uintptr_t
+get_maxuser_address(void)
+{
+	size_t len;
+	uintptr_t psstrings;
+	int error, mib[4];
+
+	mib[0] = CTL_KERN;
+	mib[1] = KERN_PROC;
+	mib[2] = KERN_PROC_PS_STRINGS;
+	mib[3] = getpid();
+	error = sysctl(mib, nitems(mib), &psstrings, &len, NULL, 0);
+	if (error != 0)
+		return (0);
+
+	if (psstrings == PS_STRINGS_LA57)
+		return (VM_MAXUSER_ADDRESS_LA57);
+	if (psstrings == PS_STRINGS_LA48)
+		return (VM_MAXUSER_ADDRESS_LA48);
+	/* AMD LA48 with clipped UVA */
+	if (psstrings == PS_STRINGS_LA48 - PAGE_SIZE)
+		return (VM_MAXUSER_ADDRESS_LA48 - PAGE_SIZE);
+	return (0);
+}
+#endif
+
 #define	FMAX	ULONG_MAX
 
 ATF_TC_WITHOUT_HEAD(kern_copyin);
 ATF_TC_BODY(kern_copyin, tc)
 {
 	char template[] = "copyin.XXXXXX";
+	uintptr_t maxuser;
 
-#ifdef __mips__
+#if defined(__mips__)
 	/*
 	 * MIPS has different VM layout: the UVA map on mips ends the
 	 * highest mapped entry at the VM_MAXUSER_ADDRESS - PAGE_SIZE,
 	 * while all other arches map either stack or shared page up
 	 * to the VM_MAXUSER_ADDRESS.
 	 */
-	atf_tc_skip("Platform is not supported.");
+	maxuser = VM_MAXUSER_ADDRESS - PAGE_SIZE;
+#elif defined(__amd64__)
+	maxuser = get_maxuser_address();
+	ATF_REQUIRE(maxuser != 0);
+#else
+	maxuser = VM_MAXUSER_ADDRESS;
 #endif
 
 	scratch_file = mkstemp(template);
 	ATF_REQUIRE(scratch_file != -1);
 	unlink(template);
 
 	ATF_CHECK(copyin_checker(0, 0) == 0);
-	ATF_CHECK(copyin_checker(VM_MAXUSER_ADDRESS - 10, 9) == 0);
-	ATF_CHECK(copyin_checker(VM_MAXUSER_ADDRESS - 10, 10) == 0);
-	ATF_CHECK(copyin_checker(VM_MAXUSER_ADDRESS - 10, 11) == EFAULT);
-	ATF_CHECK(copyin_checker(VM_MAXUSER_ADDRESS - 1, 1) == 0);
-	ATF_CHECK(copyin_checker(VM_MAXUSER_ADDRESS, 0) == 0);
-	ATF_CHECK(copyin_checker(VM_MAXUSER_ADDRESS, 1) == EFAULT);
-	ATF_CHECK(copyin_checker(VM_MAXUSER_ADDRESS, 2) == EFAULT);
-	ATF_CHECK(copyin_checker(VM_MAXUSER_ADDRESS + 1, 0) == 0);
-	ATF_CHECK(copyin_checker(VM_MAXUSER_ADDRESS + 1, 2) == EFAULT);
+	ATF_CHECK(copyin_checker(maxuser - 10, 9) == 0);
+	ATF_CHECK(copyin_checker(maxuser - 10, 10) == 0);
+	ATF_CHECK(copyin_checker(maxuser - 10, 11) == EFAULT);
+	ATF_CHECK(copyin_checker(maxuser - 1, 1) == 0);
+	ATF_CHECK(copyin_checker(maxuser, 0) == 0);
+	ATF_CHECK(copyin_checker(maxuser, 1) == EFAULT);
+	ATF_CHECK(copyin_checker(maxuser, 2) == EFAULT);
+	ATF_CHECK(copyin_checker(maxuser + 1, 0) == 0);
+	ATF_CHECK(copyin_checker(maxuser + 1, 2) == EFAULT);
 	ATF_CHECK(copyin_checker(FMAX - 10, 9) == EFAULT);
 	ATF_CHECK(copyin_checker(FMAX - 10, 10) == EFAULT);
 	ATF_CHECK(copyin_checker(FMAX - 10, 11) == EFAULT);
 }
 
 ATF_TP_ADD_TCS(tp)
 {
 
 	ATF_TP_ADD_TC(tp, kern_copyin);
 	return (atf_no_error());
 }