[PATCH 09/14] vdso/gettimeofday: Introduce vdso_get_timestamp()

From: Thomas Weißschuh
Date: Tue Jul 01 2025 - 05:02:11 EST


This code is duplicated and with the introduction of auxiliary clocks will
be duplicated even more.

Introduce a helper.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
---
lib/vdso/gettimeofday.c | 43 ++++++++++++++++++++++++-------------------
1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index 50611ba28abfcfc7841616e8787101ea1ffcb7d8..c383878bb5445a62d8fea6591e8550183852c2e6 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -87,6 +87,26 @@ static __always_inline void vdso_set_timespec(struct __kernel_timespec *ts, u64
ts->tv_nsec = ns;
}

+static __always_inline
+bool vdso_get_timestamp(const struct vdso_time_data *vd, const struct vdso_clock *vc,
+ unsigned int clkidx, u64 *sec, u64 *ns)
+{
+ const struct vdso_timestamp *vdso_ts = &vc->basetime[clkidx];
+ u64 cycles;
+
+ if (unlikely(!vdso_clocksource_ok(vc)))
+ return false;
+
+ cycles = __arch_get_hw_counter(vc->clock_mode, vd);
+ if (unlikely(!vdso_cycles_ok(cycles)))
+ return false;
+
+ *ns = vdso_calc_ns(vc, cycles, vdso_ts->nsec);
+ *sec = vdso_ts->sec;
+
+ return true;
+}
+
#ifdef CONFIG_TIME_NS

#ifdef CONFIG_GENERIC_VDSO_DATA_STORE
@@ -104,28 +124,20 @@ bool do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *
const struct vdso_time_data *vd = __arch_get_vdso_u_timens_data(vdns);
const struct timens_offset *offs = &vcns->offset[clk];
const struct vdso_clock *vc = vd->clock_data;
- const struct vdso_timestamp *vdso_ts;
- u64 cycles, ns;
u32 seq;
s64 sec;
+ u64 ns;

if (clk != CLOCK_MONOTONIC_RAW)
vc = &vc[CS_HRES_COARSE];
else
vc = &vc[CS_RAW];
- vdso_ts = &vc->basetime[clk];

do {
seq = vdso_read_begin(vc);

- if (unlikely(!vdso_clocksource_ok(vc)))
- return false;
-
- cycles = __arch_get_hw_counter(vc->clock_mode, vd);
- if (unlikely(!vdso_cycles_ok(cycles)))
+ if (!vdso_get_timestamp(vd, vc, clk, &sec, &ns))
return false;
- ns = vdso_calc_ns(vc, cycles, vdso_ts->nsec);
- sec = vdso_ts->sec;
} while (unlikely(vdso_read_retry(vc, seq)));

/* Add the namespace offset */
@@ -155,8 +167,7 @@ static __always_inline
bool do_hres(const struct vdso_time_data *vd, const struct vdso_clock *vc,
clockid_t clk, struct __kernel_timespec *ts)
{
- const struct vdso_timestamp *vdso_ts = &vc->basetime[clk];
- u64 cycles, sec, ns;
+ u64 sec, ns;
u32 seq;

/* Allows to compile the high resolution parts out */
@@ -183,14 +194,8 @@ bool do_hres(const struct vdso_time_data *vd, const struct vdso_clock *vc,
}
smp_rmb();

- if (unlikely(!vdso_clocksource_ok(vc)))
+ if (!vdso_get_timestamp(vd, vc, clk, &sec, &ns))
return false;
-
- cycles = __arch_get_hw_counter(vc->clock_mode, vd);
- if (unlikely(!vdso_cycles_ok(cycles)))
- return false;
- ns = vdso_calc_ns(vc, cycles, vdso_ts->nsec);
- sec = vdso_ts->sec;
} while (unlikely(vdso_read_retry(vc, seq)));

vdso_set_timespec(ts, sec, ns);

--
2.50.0