From: guenther <guenther@openbsd.org>
Date: Mon, 26 Jun 2023 19:03:03 +0000 (+0000)
Subject: On amd64, test whether PKU has been enabled and set our expectation
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=ff512342186fed5e9a2c01b55f00458c298093e0;p=openbsd

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@
---

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++;