[tip: timers/ptp] vdso/gettimeofday: Introduce vdso_clockid_valid()

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

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

Commit-ID:     b5df72706b044b30b17f5d623fe040b83e98be36
Gitweb:        https://git.kernel.org/tip/b5df72706b044b30b17f5d623fe040b83e98be36
Author:        Thomas Weißschuh <thomas.weissschuh@linutronix.de>
AuthorDate:    Tue, 01 Jul 2025 10:58:01 +02:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 07 Jul 2025 08:58:52 +02:00

vdso/gettimeofday: Introduce vdso_clockid_valid()

Move the clock ID validation check into a common helper.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250701-vdso-auxclock-v1-7-df7d9f87b9b8@linutronix.de

---
 lib/vdso/gettimeofday.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index c526653..215151b 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -71,6 +71,12 @@ static inline bool vdso_cycles_ok(u64 cycles)
 }
 #endif
 
+static __always_inline bool vdso_clockid_valid(clockid_t clock)
+{
+	/* Check for negative values or invalid clocks */
+	return likely((u32) clock < MAX_CLOCKS);
+}
+
 #ifdef CONFIG_TIME_NS
 
 #ifdef CONFIG_GENERIC_VDSO_DATA_STORE
@@ -268,8 +274,7 @@ __cvdso_clock_gettime_common(const struct vdso_time_data *vd, clockid_t clock,
 	const struct vdso_clock *vc = vd->clock_data;
 	u32 msk;
 
-	/* Check for negative values or invalid clocks */
-	if (unlikely((u32) clock >= MAX_CLOCKS))
+	if (!vdso_clockid_valid(clock))
 		return false;
 
 	/*
@@ -405,8 +410,7 @@ bool __cvdso_clock_getres_common(const struct vdso_time_data *vd, clockid_t cloc
 	u32 msk;
 	u64 ns;
 
-	/* Check for negative values or invalid clocks */
-	if (unlikely((u32) clock >= MAX_CLOCKS))
+	if (!vdso_clockid_valid(clock))
 		return false;
 
 	if (IS_ENABLED(CONFIG_TIME_NS) &&