1 files changed, 149 insertions, 0 deletions
diff --git a/tests/prctl-mdwe.c b/tests/prctl-mdwe.c
new file mode 100644
index 000000000..00c30e9a3
--- /dev/null
+++ b/tests/prctl-mdwe.c
@@ -0,0 +1,149 @@
+/*
+ * Check decoding of prctl PR_GET_MDWE/PR_SET_MDWE operations.
+ *
+ * Copyright (c) 2021-2023 The strace developers.
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "tests.h"
+#include "scno.h"
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <linux/prctl.h>
+
+static long injected_val;
+
+static long
+do_prctl(kernel_ulong_t cmd, kernel_ulong_t arg2, kernel_ulong_t arg3,
+	 kernel_ulong_t arg4, kernel_ulong_t arg5)
+{
+	long rc = syscall(__NR_prctl, cmd, arg2, arg3, arg4, arg5);
+
+	if (rc != injected_val) {
+		error_msg_and_fail("Return value (%ld) differs from expected "
+						   "injected value (%ld)",
+						   rc, injected_val);
+	}
+
+	return rc;
+}
+
+int
+main(int argc, char **argv)
+{
+	static const kernel_ulong_t bogus_arg2 =
+			(kernel_ulong_t) 0xdecafeedbeefda7eULL;
+	static const kernel_ulong_t bogus_arg3 =
+			(kernel_ulong_t) 0xbadc0dedfacef00dULL;
+	static const kernel_ulong_t bogus_arg4 =
+			(kernel_ulong_t) 0xcafeda7efeedbeefULL;
+	static const kernel_ulong_t bogus_arg5 =
+			(kernel_ulong_t) 0xfa57beeffacefeedULL;
+
+	static const struct {
+		long arg;
+		const char *str;
+	} get_strs[] = {
+			{-1,         ""},
+			{0,          ""},
+			{1,          " (PR_MDWE_REFUSE_EXEC_GAIN)"},
+			{2,          ""},
+			{3,          " (PR_MDWE_REFUSE_EXEC_GAIN|0x2)"},
+			{0x7ea1cafe, ""},
+	};
+	static const struct {
+		kernel_ulong_t arg;
+		const char *str;
+	} set_strs[] = {
+			{0,          "0"},
+			{1,          "PR_MDWE_REFUSE_EXEC_GAIN"},
+			{2,          "0x2 /* PR_MDWE_??? */"},
+			{3,          "PR_MDWE_REFUSE_EXEC_GAIN|0x2"},
+			{0x7ea1cafe, "0x7ea1cafe /* PR_MDWE_??? */"}
+	};
+
+	long rc;
+	unsigned long num_skip;
+	const char *str = NULL;
+	bool locked = false;
+
+	if (argc < 3)
+		error_msg_and_fail("Usage: %s NUM_SKIP INJECT_RETVAL", argv[0]);
+
+	num_skip = strtoul(argv[1], NULL, 0);
+	injected_val = strtol(argv[2], NULL, 0);
+
+	for (size_t i = 0; i < num_skip; i++) {
+		if ((prctl_marker() != injected_val) ||
+		    ((injected_val == -1) && (errno != ENOTTY)))
+			continue;
+
+		locked = true;
+		break;
+	}
+
+	if (!locked)
+		error_msg_and_fail("Have not locked on prctl(-1, -2, -3, -4"
+				   ", -5) returning %ld", injected_val);
+
+	/* PR_GET_MDWE */
+	for (unsigned int j = 0; j < 2; j++) {
+		if (j) {
+			rc = do_prctl(PR_GET_MDWE, bogus_arg2, bogus_arg3,
+						   bogus_arg4, bogus_arg5);
+		} else {
+			rc = do_prctl(PR_GET_MDWE, 0, 0, 0, 0);
+		}
+
+		const char *errstr = sprintrc(rc);
+
+		for (size_t i = 0; i < ARRAY_SIZE(get_strs); i++) {
+			if (get_strs[i].arg == rc) {
+				str = get_strs[i].str;
+				break;
+			}
+		}
+		if (!str)
+			error_msg_and_fail("Unknown return value: %ld", rc);
+
+		printf("prctl(PR_GET_MDWE, %s) = ", j ?
+#if SIZEOF_KERNEL_LONG_T > 4
+		       "0xdecafeedbeefda7e, 0xbadc0dedfacef00d"
+		       ", 0xcafeda7efeedbeef, 0xfa57beeffacefeed"
+#else
+		       "0xbeefda7e, 0xfacef00d, 0xfeedbeef, 0xfacefeed"
+#endif
+		       : "0, 0, 0, 0");
+		if (rc < 0)
+			printf("%s", errstr);
+		else
+			printf("%#lx", rc);
+		printf("%s (INJECTED)\n", str);
+	}
+
+	/* PR_SET_FP_MODE */
+	for (size_t i = 0; i < ARRAY_SIZE(set_strs); i++) {
+		rc = do_prctl(PR_SET_MDWE, set_strs[i].arg, 0, 0, 0);
+		printf("prctl(PR_SET_MDWE, %s, 0, 0, 0) = %s (INJECTED)\n",
+		       set_strs[i].str, sprintrc(rc));
+
+		rc = do_prctl(PR_SET_MDWE, set_strs[i].arg,
+			      bogus_arg3, bogus_arg4, bogus_arg5);
+		printf("prctl(PR_SET_MDWE, %s, %s) = %s (INJECTED)\n",
+		       set_strs[i].str,
+#if SIZEOF_KERNEL_LONG_T > 4
+		       "0xbadc0dedfacef00d, 0xcafeda7efeedbeef"
+		       ", 0xfa57beeffacefeed"
+#else
+		       "0xfacef00d, 0xfeedbeef, 0xfacefeed"
+#endif
+		       , sprintrc(rc));
+	}
+
+	puts("+++ exited with 0 +++");
+	return 0;
+}