[v1] vdso/gettimeofday: Add a helper to test if a clock is namespaced

[tip: timers/vdso] vdso/gettimeofday: Add a helper to test if a clock is namespaced

Posted by tip-bot2 for Thomas Weißschuh 4 weeks ago

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

Commit-ID:     daa2b92d33a4038123598aff55240ae3c54f870c
Gitweb:        https://git.kernel.org/tip/daa2b92d33a4038123598aff55240ae3c54f870c
Author:        Thomas Weißschuh <thomas.weissschuh@linutronix.de>
AuthorDate:    Fri, 27 Feb 2026 07:43:22 +01:00
Committer:     Thomas Gleixner <tglx@kernel.org>
CommitterDate: Wed, 11 Mar 2026 10:27:35 +01:00

vdso/gettimeofday: Add a helper to test if a clock is namespaced

Currently this logic is duplicate multiple times.

Add a helper for it to make the code more readable.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260227-vdso-cleanups-v1-3-c848b4bc4850@linutronix.de
---
 include/vdso/helpers.h  |  7 ++++++-
 lib/vdso/gettimeofday.c |  9 +++------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/include/vdso/helpers.h b/include/vdso/helpers.h
index 9ccf6b5..a776554 100644
--- a/include/vdso/helpers.h
+++ b/include/vdso/helpers.h
@@ -7,6 +7,11 @@
 #include <asm/barrier.h>
 #include <vdso/datapage.h>
 
+static __always_inline bool vdso_is_timens_clock(const struct vdso_clock *vc)
+{
+	return IS_ENABLED(CONFIG_TIME_NS) && vc->clock_mode == VDSO_CLOCKMODE_TIMENS;
+}
+
 static __always_inline u32 vdso_read_begin(const struct vdso_clock *vc)
 {
 	u32 seq;
@@ -31,7 +36,7 @@ static __always_inline u32 vdso_read_begin(const struct vdso_clock *vc)
 static __always_inline bool vdso_read_begin_timens(const struct vdso_clock *vc, u32 *seq)
 {
 	while (unlikely((*seq = READ_ONCE(vc->seq)) & 1)) {
-		if (IS_ENABLED(CONFIG_TIME_NS) && vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
+		if (vdso_is_timens_clock(vc))
 			return true;
 		cpu_relax();
 	}
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index e493696..2faed78 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -343,8 +343,7 @@ __cvdso_gettimeofday_data(const struct vdso_time_data *vd,
 	}
 
 	if (unlikely(tz != NULL)) {
-		if (IS_ENABLED(CONFIG_TIME_NS) &&
-		    vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
+		if (vdso_is_timens_clock(vc))
 			vd = __arch_get_vdso_u_timens_data(vd);
 
 		tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
@@ -367,8 +366,7 @@ __cvdso_time_data(const struct vdso_time_data *vd, __kernel_old_time_t *time)
 	const struct vdso_clock *vc = vd->clock_data;
 	__kernel_old_time_t t;
 
-	if (IS_ENABLED(CONFIG_TIME_NS) &&
-	    vc->clock_mode == VDSO_CLOCKMODE_TIMENS) {
+	if (vdso_is_timens_clock(vc)) {
 		vd = __arch_get_vdso_u_timens_data(vd);
 		vc = vd->clock_data;
 	}
@@ -399,8 +397,7 @@ bool __cvdso_clock_getres_common(const struct vdso_time_data *vd, clockid_t cloc
 	if (!vdso_clockid_valid(clock))
 		return false;
 
-	if (IS_ENABLED(CONFIG_TIME_NS) &&
-	    vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
+	if (vdso_is_timens_clock(vc))
 		vd = __arch_get_vdso_u_timens_data(vd);
 
 	/*

Re: [tip: timers/vdso] vdso/gettimeofday: Add a helper to test if a clock is namespaced

Posted by Thomas Weißschuh 4 weeks ago

On Wed, Mar 11, 2026 at 09:31:30AM +0000, tip-bot2 for Thomas Weißschuh wrote:
> The following commit has been merged into the timers/vdso branch of tip:
> 
> Commit-ID:     daa2b92d33a4038123598aff55240ae3c54f870c
> Gitweb:        https://git.kernel.org/tip/daa2b92d33a4038123598aff55240ae3c54f870c
> Author:        Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> AuthorDate:    Fri, 27 Feb 2026 07:43:22 +01:00
> Committer:     Thomas Gleixner <tglx@kernel.org>
> CommitterDate: Wed, 11 Mar 2026 10:27:35 +01:00
> 
> vdso/gettimeofday: Add a helper to test if a clock is namespaced
> 
> Currently this logic is duplicate multiple times.
> 
> Add a helper for it to make the code more readable.
> 
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Link: https://patch.msgid.link/20260227-vdso-cleanups-v1-3-c848b4bc4850@linutronix.de
> ---
>  include/vdso/helpers.h  |  7 ++++++-
>  lib/vdso/gettimeofday.c |  9 +++------
>  2 files changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/include/vdso/helpers.h b/include/vdso/helpers.h
> index 9ccf6b5..a776554 100644
> --- a/include/vdso/helpers.h
> +++ b/include/vdso/helpers.h
> @@ -7,6 +7,11 @@
>  #include <asm/barrier.h>
>  #include <vdso/datapage.h>
>  
> +static __always_inline bool vdso_is_timens_clock(const struct vdso_clock *vc)
> +{
> +	return IS_ENABLED(CONFIG_TIME_NS) && vc->clock_mode == VDSO_CLOCKMODE_TIMENS;
> +}

Welp, I never seem to have tested this together with my own vDSO header cleanup
series. This fails to build because VDSO_CLOCKMODE_TIMENS is not visible.
There should be an include of <vdso/clocksource.h> above.

Could you fix this up, or drop the series so I can resubmit it?

> +
>  static __always_inline u32 vdso_read_begin(const struct vdso_clock *vc)
>  {
>  	u32 seq;

(...)

Re: [tip: timers/vdso] vdso/gettimeofday: Add a helper to test if a clock is namespaced

Posted by Borislav Petkov 4 weeks ago

On Wed, Mar 11, 2026 at 11:47:26AM +0100, Thomas Weißschuh wrote:
> > +static __always_inline bool vdso_is_timens_clock(const struct vdso_clock *vc)
> > +{
> > +	return IS_ENABLED(CONFIG_TIME_NS) && vc->clock_mode == VDSO_CLOCKMODE_TIMENS;
> > +}
> 
> Welp, I never seem to have tested this together with my own vDSO header cleanup
> series. This fails to build because VDSO_CLOCKMODE_TIMENS is not visible.
> There should be an include of <vdso/clocksource.h> above.
> 
> Could you fix this up, or drop the series so I can resubmit it?

Lemme fix that up. I just saw it here too.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

Re: [tip: timers/vdso] vdso/gettimeofday: Add a helper to test if a clock is namespaced

Posted by Thomas Weißschuh 4 weeks ago

On Wed, Mar 11, 2026 at 02:51:26PM +0100, Borislav Petkov wrote:
> On Wed, Mar 11, 2026 at 11:47:26AM +0100, Thomas Weißschuh wrote:
> > > +static __always_inline bool vdso_is_timens_clock(const struct vdso_clock *vc)
> > > +{
> > > +	return IS_ENABLED(CONFIG_TIME_NS) && vc->clock_mode == VDSO_CLOCKMODE_TIMENS;
> > > +}
> > 
> > Welp, I never seem to have tested this together with my own vDSO header cleanup
> > series. This fails to build because VDSO_CLOCKMODE_TIMENS is not visible.
> > There should be an include of <vdso/clocksource.h> above.
> > 
> > Could you fix this up, or drop the series so I can resubmit it?
> 
> Lemme fix that up. I just saw it here too.

Thanks! And sorry for the extra work.


Thomas

Re: [tip: timers/vdso] vdso/gettimeofday: Add a helper to test if a clock is namespaced

Posted by Borislav Petkov 4 weeks ago

On Wed, Mar 11, 2026 at 03:01:05PM +0100, Thomas Weißschuh wrote:
> On Wed, Mar 11, 2026 at 02:51:26PM +0100, Borislav Petkov wrote:
> > On Wed, Mar 11, 2026 at 11:47:26AM +0100, Thomas Weißschuh wrote:
> > > > +static __always_inline bool vdso_is_timens_clock(const struct vdso_clock *vc)
> > > > +{
> > > > +	return IS_ENABLED(CONFIG_TIME_NS) && vc->clock_mode == VDSO_CLOCKMODE_TIMENS;
> > > > +}
> > > 
> > > Welp, I never seem to have tested this together with my own vDSO header cleanup
> > > series. This fails to build because VDSO_CLOCKMODE_TIMENS is not visible.
> > > There should be an include of <vdso/clocksource.h> above.
> > > 
> > > Could you fix this up, or drop the series so I can resubmit it?
> > 
> > Lemme fix that up. I just saw it here too.
> 
> Thanks! And sorry for the extra work.

No worries. 

Btw, this patch itself builds still, I guess the breakage is caused by one of
the following ones.

I won't chase that though because this one is using VDSO_CLOCKMODE_TIMENS and
I will simply add the clocksource.h include here.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette