[LTP] [PATCH v2 04/31] testcases: sysfs: Add sys_clocksource01

[Cyril Hrubis]

A test for /sys/devices/system/clocksource/* files.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
---
 runtest/sysfs                                 |  1 +
 testcases/kernel/sysfs/devices/Makefile       |  7 ++
 .../kernel/sysfs/devices/system/Makefile      |  7 ++
 .../devices/system/clocksource/.gitignore     |  1 +
 .../sysfs/devices/system/clocksource/Makefile |  7 ++
 .../system/clocksource/sys_clocksource01.c    | 67 +++++++++++++++++++
 6 files changed, 90 insertions(+)
 create mode 100644 testcases/kernel/sysfs/devices/Makefile
 create mode 100644 testcases/kernel/sysfs/devices/system/Makefile
 create mode 100644 testcases/kernel/sysfs/devices/system/clocksource/.gitignore
 create mode 100644 testcases/kernel/sysfs/devices/system/clocksource/Makefile
 create mode 100644 testcases/kernel/sysfs/devices/system/clocksource/sys_clocksource01.c

diff --git a/runtest/sysfs b/runtest/sysfs
index 142b4a290..7c014a57e 100644
--- a/runtest/sysfs
+++ b/runtest/sysfs
@@ -1,2 +1,3 @@
 sys_power01 sys_power01
 sys_kernel01 sys_kernel01
+sys_clocksource01 sys_clocksource01
diff --git a/testcases/kernel/sysfs/devices/Makefile b/testcases/kernel/sysfs/devices/Makefile
new file mode 100644
index 000000000..5c8e7a249
--- /dev/null
+++ b/testcases/kernel/sysfs/devices/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2026 Cyril Hrubis <chrubis@suse.cz>
+
+top_srcdir		?= ../../../..
+
+include $(top_srcdir)/include/mk/env_pre.mk
+include $(top_srcdir)/include/mk/generic_trunk_target.mk
diff --git a/testcases/kernel/sysfs/devices/system/Makefile b/testcases/kernel/sysfs/devices/system/Makefile
new file mode 100644
index 000000000..9bc26552c
--- /dev/null
+++ b/testcases/kernel/sysfs/devices/system/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2026 Cyril Hrubis <chrubis@suse.cz>
+
+top_srcdir		?= ../../../../..
+
+include $(top_srcdir)/include/mk/env_pre.mk
+include $(top_srcdir)/include/mk/generic_trunk_target.mk
diff --git a/testcases/kernel/sysfs/devices/system/clocksource/.gitignore b/testcases/kernel/sysfs/devices/system/clocksource/.gitignore
new file mode 100644
index 000000000..a04f05977
--- /dev/null
+++ b/testcases/kernel/sysfs/devices/system/clocksource/.gitignore
@@ -0,0 +1 @@
+/sys_clocksource01
diff --git a/testcases/kernel/sysfs/devices/system/clocksource/Makefile b/testcases/kernel/sysfs/devices/system/clocksource/Makefile
new file mode 100644
index 000000000..781865569
--- /dev/null
+++ b/testcases/kernel/sysfs/devices/system/clocksource/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2026 Cyril Hrubis <chrubis@suse.cz>
+
+top_srcdir		?= ../../../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/kernel/sysfs/devices/system/clocksource/sys_clocksource01.c b/testcases/kernel/sysfs/devices/system/clocksource/sys_clocksource01.c
new file mode 100644
index 000000000..534caddd8
--- /dev/null
+++ b/testcases/kernel/sysfs/devices/system/clocksource/sys_clocksource01.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 Cyril Hrubis <chrubis@suse.cz>
+ */
+
+/*\
+ * Sanity checks for the clocksource attributes exported under
+ * /sys/devices/system/clocksource/clocksourceN/.
+ *
+ * available_clocksource lists all clocksources the kernel can switch to,
+ * while current_clocksource names the one that is active. Unlike the
+ * bracketed-choice files elsewhere in sysfs, the currently selected
+ * clocksource is not marked inside available_clocksource, so the two files
+ * have to be cross-checked explicitly. For every clocksourceN directory the
+ * test verifies that:
+ *
+ * - current_clocksource is non-empty
+ * - current_clocksource is one of the tokens listed in available_clocksource
+ *
+ * The test skips with TCONF when no clocksource directory is present.
+ */
+
+#include <string.h>
+#include <dirent.h>
+#include "tst_test.h"
+#include "tst_sysfs_assert.h"
+
+#define CLOCKSOURCE "/sys/devices/system/clocksource"
+
+static void check_clocksource(const char *name)
+{
+	char current[64] = "";
+
+	tst_res(TINFO, "Checking %s", name);
+
+	TST_SYSFS_READ_STR(current, sizeof(current),
+			   CLOCKSOURCE "/%s/current_clocksource", name);
+
+	TST_SYSFS_ASSERT_TOKENS(NULL, current,
+				CLOCKSOURCE "/%s/available_clocksource", name);
+}
+
+static void do_test(void)
+{
+	DIR *d;
+	struct dirent *ent;
+	int found = 0;
+
+	d = SAFE_OPENDIR(CLOCKSOURCE);
+
+	while ((ent = SAFE_READDIR(d))) {
+		if (strncmp(ent->d_name, "clocksource", 11))
+			continue;
+
+		found = 1;
+		check_clocksource(ent->d_name);
+	}
+
+	SAFE_CLOSEDIR(d);
+
+	if (!found)
+		tst_res(TCONF, "No clocksource directory found");
+}
+
+static struct tst_test test = {
+	.test_all = do_test,
+};
-- 
2.54.0