On Wed, 30 Mar 2022 17:52:13 +0300
Andy Shevchenko <andriy.shevchenko@xxxxxxxxx> wrote:
> On Mon, Mar 28, 2022 at 09:53:07PM +0200, Marek Vasut wrote:
> > Add runtime check to verify whether storagebits are at least as big
> > as shifted realbits. This should help spot broken drivers which may
> > set realbits + shift above storagebits.
>
> Let's go with it.
> Reviewed-by: Andy Shevchenko <andy@xxxxxxxxxx>
Agreed. Applied with a slight change to the title to make it clear
we don't just print the error, we also fail the iio_device_register() call
Applied to the togreg branch of iio.git and pushed out as testing both to let
0-day poke at it and because I will rebase on rc1 once available.
Thanks,
Jonathan
>
> > Signed-off-by: Marek Vasut <marex@xxxxxxx>
> > Cc: Andy Shevchenko <andy@xxxxxxxxxx>
> > Cc: Daniel Baluta <daniel.baluta@xxxxxxx>
> > Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> > ---
> > V2: Use dev_err() instead as WARN_ON() may panic() the kernel on existing machines
> > V3: Abort probe and return -EINVAL in case this condition is triggered
> > ---
> > drivers/iio/industrialio-buffer.c | 13 +++++++++++++
> > 1 file changed, 13 insertions(+)
> >
> > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
> > index b078eb2f3c9de..75a1c57b49102 100644
> > --- a/drivers/iio/industrialio-buffer.c
> > +++ b/drivers/iio/industrialio-buffer.c
> > @@ -1629,6 +1629,19 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
> > if (channels[i].scan_index < 0)
> > continue;
> >
> > + /* Verify that sample bits fit into storage */
> > + if (channels[i].scan_type.storagebits <
> > + channels[i].scan_type.realbits +
> > + channels[i].scan_type.shift) {
> > + dev_err(&indio_dev->dev,
> > + "Channel %d storagebits (%d) < shifted realbits (%d + %d)\n",
> > + i, channels[i].scan_type.storagebits,
> > + channels[i].scan_type.realbits,
> > + channels[i].scan_type.shift);
> > + ret = -EINVAL;
> > + goto error_cleanup_dynamic;
> > + }
> > +
> > ret = iio_buffer_add_channel_sysfs(indio_dev, buffer,
> > &channels[i]);
> > if (ret < 0)
> > --
> > 2.35.1
> >
>
