Add statmount08 test

Verify that statmount() raises EPERM when mount point is not accessible.

Signed-off-by: Andrea Cervesato <[email protected]>

runtest/syscalls

@@ -1581,6 +1581,7 @@ statmount04 statmount04
 statmount05 statmount05
 statmount06 statmount06
 statmount07 statmount07
+statmount08 statmount08
 
 statfs01 statfs01
 statfs01_64 statfs01_64

testcases/kernel/syscalls/statmount/.gitignore

@@ -5,3 +5,4 @@ statmount04
 statmount05
 statmount06
 statmount07
+statmount08

testcases/kernel/syscalls/statmount/statmount08.c

@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2024 SUSE LLC Andrea Cervesato <[email protected]>
+ */
+
+/*\
+ * [Description]
+ *
+ * Verify that statmount() raises EPERM when mount point is not accessible.
+ */
+
+#define _GNU_SOURCE
+
+#include <pwd.h>
+#include "statmount.h"
+#include "lapi/stat.h"
+
+#define MNTPOINT "mntpoint"
+
+static struct statmount *st_mount;
+static uint64_t root_id;
+
+static void run(void)
+{
+	if (SAFE_FORK())
+		return;
+
+	struct passwd *pw;
+
+	pw = SAFE_GETPWNAM("nobody");
+	SAFE_SETEGID(pw->pw_gid);
+	SAFE_SETEUID(pw->pw_uid);
+
+	memset(st_mount, 0, sizeof(struct statmount));
+
+	TST_EXP_FAIL(statmount(root_id,	STATMOUNT_SB_BASIC, st_mount,
+		sizeof(struct statmount), 0), EPERM);
+
+	exit(0);
+}
+
+
+static void setup(void)
+{
+	struct ltp_statx sx;
+
+	SAFE_UNSHARE(CLONE_NEWNS);
+
+	SAFE_STATX(AT_FDCWD, "/", 0, STATX_MNT_ID_UNIQUE, &sx);
+	root_id = sx.data.stx_mnt_id;
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	.setup = setup,
+	.needs_root = 1,
+	.forks_child = 1,
+	.min_kver = "6.8",
+	.bufs = (struct tst_buffers []) {
+		{&st_mount, .size = sizeof(struct statmount)},
+		{}
+	}
+};