| Message ID | 20200722155103.979802-26-jic23@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | IIO: Fused set 1 and 2 of timestamp alignment fixes | expand |
On Wed, 22 Jul 2020 16:51:01 +0100 Jonathan Cameron <jic23@kernel.org> wrote: > From: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > One of a class of bugs pointed out by Lars in a recent review. > iio_push_to_buffers_with_timestamp assumes the buffer used is aligned > to the size of the timestamp (8 bytes). This is not guaranteed in > this driver which uses an array of smaller elements on the stack. > > We move to a suitable structure in the iio_priv() data with alignment > explicitly requested. This data is allocated with kzalloc so no > data can leak apart from previous readings. Note that previously > no leak at all could occur, but previous readings should never > be a problem. > > In this case the timestamp location depends on what other channels > are enabled. As such we can't use a structure without misleading > by suggesting only one possible timestamp location. > > Fixes: 50a6edb1b6e0 ("iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver") > Reported-by: Lars-Peter Clausen <lars@metafoo.de> > Cc: Akinobu Mita <akinobu.mita@gmail.com> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Applied with expand comment. Thanks, Jonathan > --- > drivers/iio/adc/ti-adc12138.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/iio/adc/ti-adc12138.c b/drivers/iio/adc/ti-adc12138.c > index e485719cd2c4..16f4fd7a04d9 100644 > --- a/drivers/iio/adc/ti-adc12138.c > +++ b/drivers/iio/adc/ti-adc12138.c > @@ -47,6 +47,8 @@ struct adc12138 { > struct completion complete; > /* The number of cclk periods for the S/H's acquisition time */ > unsigned int acquisition_time; > + /* 16x 2 bytes ADC data + 8 bytes timestamp */ > + __be16 data[20] __aligned(8); > > u8 tx_buf[2] ____cacheline_aligned; > u8 rx_buf[2]; > @@ -329,7 +331,6 @@ static irqreturn_t adc12138_trigger_handler(int irq, void *p) > struct iio_poll_func *pf = p; > struct iio_dev *indio_dev = pf->indio_dev; > struct adc12138 *adc = iio_priv(indio_dev); > - __be16 data[20] = { }; /* 16x 2 bytes ADC data + 8 bytes timestamp */ > __be16 trash; > int ret; > int scan_index; > @@ -345,7 +346,7 @@ static irqreturn_t adc12138_trigger_handler(int irq, void *p) > reinit_completion(&adc->complete); > > ret = adc12138_start_and_read_conv(adc, scan_chan, > - i ? &data[i - 1] : &trash); > + i ? &adc->data[i - 1] : &trash); > if (ret) { > dev_warn(&adc->spi->dev, > "failed to start conversion\n"); > @@ -362,7 +363,7 @@ static irqreturn_t adc12138_trigger_handler(int irq, void *p) > } > > if (i) { > - ret = adc12138_read_conv_data(adc, &data[i - 1]); > + ret = adc12138_read_conv_data(adc, &adc->data[i - 1]); > if (ret) { > dev_warn(&adc->spi->dev, > "failed to get conversion data\n"); > @@ -370,7 +371,7 @@ static irqreturn_t adc12138_trigger_handler(int irq, void *p) > } > } > > - iio_push_to_buffers_with_timestamp(indio_dev, data, > + iio_push_to_buffers_with_timestamp(indio_dev, adc->data, > iio_get_time_ns(indio_dev)); > out: > mutex_unlock(&adc->lock);
diff --git a/drivers/iio/adc/ti-adc12138.c b/drivers/iio/adc/ti-adc12138.c index e485719cd2c4..16f4fd7a04d9 100644 --- a/drivers/iio/adc/ti-adc12138.c +++ b/drivers/iio/adc/ti-adc12138.c @@ -47,6 +47,8 @@ struct adc12138 { struct completion complete; /* The number of cclk periods for the S/H's acquisition time */ unsigned int acquisition_time; + /* 16x 2 bytes ADC data + 8 bytes timestamp */ + __be16 data[20] __aligned(8); u8 tx_buf[2] ____cacheline_aligned; u8 rx_buf[2]; @@ -329,7 +331,6 @@ static irqreturn_t adc12138_trigger_handler(int irq, void *p) struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct adc12138 *adc = iio_priv(indio_dev); - __be16 data[20] = { }; /* 16x 2 bytes ADC data + 8 bytes timestamp */ __be16 trash; int ret; int scan_index; @@ -345,7 +346,7 @@ static irqreturn_t adc12138_trigger_handler(int irq, void *p) reinit_completion(&adc->complete); ret = adc12138_start_and_read_conv(adc, scan_chan, - i ? &data[i - 1] : &trash); + i ? &adc->data[i - 1] : &trash); if (ret) { dev_warn(&adc->spi->dev, "failed to start conversion\n"); @@ -362,7 +363,7 @@ static irqreturn_t adc12138_trigger_handler(int irq, void *p) } if (i) { - ret = adc12138_read_conv_data(adc, &data[i - 1]); + ret = adc12138_read_conv_data(adc, &adc->data[i - 1]); if (ret) { dev_warn(&adc->spi->dev, "failed to get conversion data\n"); @@ -370,7 +371,7 @@ static irqreturn_t adc12138_trigger_handler(int irq, void *p) } } - iio_push_to_buffers_with_timestamp(indio_dev, data, + iio_push_to_buffers_with_timestamp(indio_dev, adc->data, iio_get_time_ns(indio_dev)); out: mutex_unlock(&adc->lock);