[tip: timers/vdso] selftests: vDSO: vdso_test_correctness: Add a test for time()

["tip-bot2 for Thomas Weißschuh" <tip-bot2@linutronix.de>]

The following commit has been merged into the timers/vdso branch of tip:

Commit-ID:     f7178f159b2a36d070fd43b0d751e4e4415ec39e
Gitweb:        https://git.kernel.org/tip/f7178f159b2a36d070fd43b0d751e4e4415ec39e
Author:        Thomas Weißschuh <thomas.weissschuh@linutronix.de>
AuthorDate:    Fri, 27 Feb 2026 07:46:01 +01:00
Committer:     Thomas Gleixner <tglx@kernel.org>
CommitterDate: Wed, 11 Mar 2026 10:27:40 +01:00

selftests: vDSO: vdso_test_correctness: Add a test for time()

Extend the test to also cover the time() function.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260227-vdso-selftest-cleanups-v2-6-d84830fa8beb@linutronix.de
---
 tools/testing/selftests/vDSO/vdso_test_correctness.c | 66 +++++++++++-
 1 file changed, 66 insertions(+)

diff --git a/tools/testing/selftests/vDSO/vdso_test_correctness.c b/tools/testing/selftests/vDSO/vdso_test_correctness.c
index a94ab4d..5c5a07d 100644
--- a/tools/testing/selftests/vDSO/vdso_test_correctness.c
+++ b/tools/testing/selftests/vDSO/vdso_test_correctness.c
@@ -55,6 +55,10 @@ typedef long (*vgtod_t)(struct timeval *tv, struct timezone *tz);
 
 vgtod_t vdso_gettimeofday;
 
+typedef time_t (*vtime_t)(__kernel_time_t *tloc);
+
+vtime_t vdso_time;
+
 typedef long (*getcpu_t)(unsigned *, unsigned *, void *);
 
 getcpu_t vgetcpu;
@@ -133,6 +137,10 @@ static void fill_function_pointers(void)
 	if (!vdso_gettimeofday)
 		printf("Warning: failed to find gettimeofday in vDSO\n");
 
+	vdso_time = (vtime_t)vdso_sym(version, name[2]);
+	if (!vdso_time)
+		printf("Warning: failed to find time in vDSO\n");
+
 }
 
 static long sys_getcpu(unsigned * cpu, unsigned * node,
@@ -156,6 +164,16 @@ static inline int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
 	return syscall(__NR_gettimeofday, tv, tz);
 }
 
+static inline __kernel_old_time_t sys_time(__kernel_old_time_t *tloc)
+{
+#ifdef __NR_time
+	return syscall(__NR_time, tloc);
+#else
+	errno = ENOSYS;
+	return -1;
+#endif
+}
+
 static void test_getcpu(void)
 {
 	printf("[RUN]\tTesting getcpu...\n");
@@ -422,6 +440,53 @@ static void test_gettimeofday(void)
 	VDSO_CALL(vdso_gettimeofday, 2, &vdso, NULL);
 }
 
+static void test_time(void)
+{
+	__kernel_old_time_t start, end, vdso_ret, vdso_param;
+
+	if (!vdso_time)
+		return;
+
+	printf("[RUN]\tTesting time...\n");
+
+	if (sys_time(&start) < 0) {
+		if (errno == -ENOSYS) {
+			printf("[SKIP]\tNo time() support\n");
+		} else {
+			printf("[FAIL]\tsys_time failed (%d)\n", errno);
+			nerrs++;
+		}
+		return;
+	}
+
+	vdso_ret = VDSO_CALL(vdso_time, 1, &vdso_param);
+	end = sys_time(NULL);
+
+	if (vdso_ret < 0 || end < 0) {
+		printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n",
+		       (int)vdso_ret, errno);
+		nerrs++;
+		return;
+	}
+
+	printf("\t%lld %lld %lld\n",
+	       (long long)start,
+	       (long long)vdso_ret,
+	       (long long)end);
+
+	if (vdso_ret != vdso_param) {
+		printf("[FAIL]\tinconsistent return values: %lld %lld\n",
+		       (long long)vdso_ret, (long long)vdso_param);
+		nerrs++;
+		return;
+	}
+
+	if (!(start <= vdso_ret) || !(vdso_ret <= end)) {
+		printf("[FAIL]\tTimes are out of sequence\n");
+		nerrs++;
+	}
+}
+
 int main(int argc, char **argv)
 {
 	version = versions[VDSO_VERSION];
@@ -432,6 +497,7 @@ int main(int argc, char **argv)
 	test_clock_gettime();
 	test_clock_gettime64();
 	test_gettimeofday();
+	test_time();
 
 	/*
 	 * Test getcpu() last so that, if something goes wrong setting affinity,