Re: [PATCH v3 3/3] iio: imu: st_lsm6dsx: add support for rotation sensor

From: Francesco Lavra

Date: Tue Jan 20 2026 - 05:03:34 EST


On Tue, 2026-01-20 at 11:36 +0200, Andy Shevchenko wrote:
> On Tue, Jan 20, 2026 at 10:28:15AM +0100, Francesco Lavra wrote:
> > On Mon, 2026-01-19 at 12:33 +0200, Andy Shevchenko wrote:
> > > On Mon, Jan 19, 2026 at 11:04:49AM +0100, Francesco Lavra wrote:
>
> ...
>
> > > > +       snprintf(sensor->name, sizeof(sensor->name), "%s_sf",
> > > > name);
> > >
> > > Does GCC complain on this (`make W=1` build)?
> > > Since this can cut the string and we don't check the return value,
> > > the Q
> > > is:
> > > is this okay to have a reduced string?
> >
> > gcc does not complain with W=1. sensor->name is appropriately sized to
> > accommodate the longest possible name; if it wasn't, the string would
> > be
> > cut in the accel and gyro IIO devices too (which use a longer suffix
> > than
> > "_sf").
>
> Right, the question is if compiler can prove that or not.
>
> We have several patches in input subsystem to hide the warning by
> switching
> to scnprintf(), which I consider not the best approach, but still it
> depends
> if we care about cut or not. If we do, we should check for overflow.

A truncated string would result in a corrupted value in
/sys/bus/iio/devices/iio:deviceX/name, so I would say we do care if it's
truncated. But I think the most appropriate check we could add in the code
is a BUG_ON(); would that be acceptable?

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