From ff512342186fed5e9a2c01b55f00458c298093e0 Mon Sep 17 00:00:00 2001
From: guenther <guenther@openbsd.org>
Date: Mon, 26 Jun 2023 19:03:03 +0000
Subject: [PATCH] On amd64, test whether PKU has been enabled and set our
 expectation of the results based on that.  Also, the system now enforces
 unreadability in copyin() of ld.so, libc, and application text, even when PKU
 isn't enabled, so adjust those results to match.

ok deraadt@ anton@
---
 regress/sys/kern/xonly/xonly.c | 36 +++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/regress/sys/kern/xonly/xonly.c b/regress/sys/kern/xonly/xonly.c
index 89268d947c9..c54b97c918d 100644
--- a/regress/sys/kern/xonly/xonly.c
+++ b/regress/sys/kern/xonly/xonly.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: xonly.c,v 1.1 2023/01/18 19:18:49 anton Exp $	*/
+/*	$OpenBSD: xonly.c,v 1.2 2023/06/26 19:03:03 guenther Exp $	*/
 
 #include <sys/types.h>
 #include <sys/mman.h>
@@ -26,6 +26,8 @@ void *setup_mmap_nrx(void);
 void *setup_mmap_nwx(void);
 void *setup_mmap_xnwx(void);
 
+char	***_csu_finish(char **_argv, char **_envp, void (*_cleanup)(void));
+
 struct outcome {
 	int uu;
 	int ku;
@@ -46,11 +48,11 @@ struct readable {
 	{ "mmap nwx",	setup_mmap_nwx, 0,	NULL,	0, {} },
 	{ "mmap xnwx",	setup_mmap_xnwx, 0,	NULL,	0, {} },
 	{ "main",	NULL, 1,		&main,	0, {} },
-	{ "libc",	NULL, 1,		&open,	0, {} },
+	{ "libc",	NULL, 1,		&_csu_finish, 0, {} },
 };
 
 static struct outcome expectations[2][8] = {
-#if defined(__aarch64__)
+#if defined(__aarch64__) || defined(__amd64__)
 	[0] = {
 		/* ld.so */	{ UNREADABLE,	UNREADABLE },
 		/* mmap xz */	{ UNREADABLE,	UNREADABLE },
@@ -61,20 +63,21 @@ static struct outcome expectations[2][8] = {
 		/* main */	{ UNREADABLE,	UNREADABLE },
 		/* libc */	{ UNREADABLE,	UNREADABLE },
 	},
-#elif defined(__amd64__)
+#else
+#error "unknown architecture"
+#endif
+#if defined(__amd64__)
 	/* PKU not available. */
-	[0] = {
-		/* ld.so */	{ READABLE,	READABLE },
+	[1] = {
+		/* ld.so */	{ READABLE,	UNREADABLE },
 		/* mmap xz */	{ UNREADABLE,	UNREADABLE },
 		/* mmap x */	{ READABLE,	READABLE },
 		/* mmap nrx */	{ READABLE,	READABLE },
 		/* mmap nwx */	{ READABLE,	READABLE },
 		/* mmap xnwx */	{ READABLE,	READABLE },
-		/* main */	{ READABLE,	READABLE },
-		/* libc */	{ READABLE,	READABLE },
+		/* main */	{ READABLE,	UNREADABLE },
+		/* libc */	{ READABLE,	UNREADABLE },
 	},
-#else
-#error "unknown architecture"
 #endif
 };
 
@@ -186,6 +189,17 @@ main(void)
 	size_t i;
 	int p[2];
 	int error = 0;
+	const struct outcome *desires = expectations[0];
+
+#if defined(__amd64__)
+	{
+		uint32_t ebx, ecx, edx;
+		asm("cpuid" : "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (7), "c" (0));
+		if ((ecx & 8) == 0) /* SEFF0ECX_PKU */
+			desires = expectations[1];
+	}
+#endif
+
 
 	signal(SIGSEGV, sigsegv);
 	signal(SIGBUS, sigsegv);
@@ -222,7 +236,7 @@ main(void)
 			printf("%-16s  %18p  %-12s %-12s\n", r->name, r->addr,
 			    "skipped", "skipped");
 		} else {
-			const struct outcome *want = &expectations[0][i];
+			const struct outcome *want = &desires[i];
 
 			if (r->got.uu != want->uu || r->got.ku != want->ku)
 				error++;
-- 
2.20.1