vdso/gettimeofday: Clean up read of tz_minuteswest and tz_dsttime

[PATCH] vdso/gettimeofday: Clean up read of tz_minuteswest and tz_dsttime

Posted by Thomas Weißschuh 3 weeks, 2 days ago

When these fields got moved from 'struct vdso_time_data' to the new
'struct vdso_clock', this access was forgotten.

'vd' is not an array, but a pointer to a single structure. The code
works by accident in its current form as CS_HRES_COARSE is 0.

Replace the incorrect array access with a regular pointer dereference.

Fixes: 886653e36639 ("vdso: Rework struct vdso_time_data and introduce struct vdso_clock")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 lib/vdso/gettimeofday.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index f7a591aba59f..6e9b03051bee 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -374,8 +374,8 @@ __cvdso_gettimeofday_data(const struct vdso_time_data *vd,
 		if (vdso_is_timens_clock(vc))
 			vd = vdso_timens_data(vd);
 
-		tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
-		tz->tz_dsttime = vd[CS_HRES_COARSE].tz_dsttime;
+		tz->tz_minuteswest = vd->tz_minuteswest;
+		tz->tz_dsttime = vd->tz_dsttime;
 	}
 
 	return 0;

---
base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
change-id: 20260902-vdso-tz-b999f43c24bb

Best regards,
--  
Thomas Weißschuh <thomas.weissschuh@linutronix.de>

Re: [PATCH] vdso/gettimeofday: Clean up read of tz_minuteswest and tz_dsttime

Posted by Vincenzo Frascino 3 weeks, 2 days ago


On 02/09/2026 13:06, Thomas Weißschuh wrote:
> When these fields got moved from 'struct vdso_time_data' to the new
> 'struct vdso_clock', this access was forgotten.
> 
> 'vd' is not an array, but a pointer to a single structure. The code
> works by accident in its current form as CS_HRES_COARSE is 0.
> 
> Replace the incorrect array access with a regular pointer dereference.
> 
> Fixes: 886653e36639 ("vdso: Rework struct vdso_time_data and introduce struct vdso_clock")
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
>  lib/vdso/gettimeofday.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
> index f7a591aba59f..6e9b03051bee 100644
> --- a/lib/vdso/gettimeofday.c
> +++ b/lib/vdso/gettimeofday.c
> @@ -374,8 +374,8 @@ __cvdso_gettimeofday_data(const struct vdso_time_data *vd,
>  		if (vdso_is_timens_clock(vc))
>  			vd = vdso_timens_data(vd);
>  
> -		tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
> -		tz->tz_dsttime = vd[CS_HRES_COARSE].tz_dsttime;
> +		tz->tz_minuteswest = vd->tz_minuteswest;
> +		tz->tz_dsttime = vd->tz_dsttime;
>  	}
>  
>  	return 0;
> 
> ---
> base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
> change-id: 20260902-vdso-tz-b999f43c24bb
> 
> Best regards,
> --  
> Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> 

-- 
Regards,
Vincenzo

Re: [PATCH] vdso/gettimeofday: Clean up read of tz_minuteswest and tz_dsttime

Posted by Nam Cao 3 weeks, 2 days ago

Thomas Weißschuh <thomas.weissschuh@linutronix.de> writes:
> When these fields got moved from 'struct vdso_time_data' to the new
> 'struct vdso_clock', this access was forgotten.
>
> 'vd' is not an array, but a pointer to a single structure. The code
> works by accident in its current form as CS_HRES_COARSE is 0.
>
> Replace the incorrect array access with a regular pointer dereference.
>
> Fixes: 886653e36639 ("vdso: Rework struct vdso_time_data and introduce struct vdso_clock")
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

Reviewed-by: Nam Cao <namcao@linutronix.de>