iio: addac: ad74xxx: Constify struct iio_chan_spec

[PATCH] iio: addac: ad74xxx: Constify struct iio_chan_spec

Posted by Christophe JAILLET 2 months, 3 weeks ago

'struct iio_chan_spec' are not modified in these drivers.

Constifying this structure moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  35749	   5879	    384	  42012	   a41c	drivers/iio/addac/ad74115.o
  32242	   3297	    384	  35923	   8c53	drivers/iio/addac/ad74413r.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  39109	   2519	    384	  42012	   a41c	drivers/iio/addac/ad74115.o
  33842	   1697	    384	  35923	   8c53	drivers/iio/addac/ad74413r.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested only
---
 drivers/iio/addac/ad74115.c  | 18 +++++++++---------
 drivers/iio/addac/ad74413r.c | 21 +++++++++++----------
 2 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/drivers/iio/addac/ad74115.c b/drivers/iio/addac/ad74115.c
index 12dc43d487b4..bdbdd67536ff 100644
--- a/drivers/iio/addac/ad74115.c
+++ b/drivers/iio/addac/ad74115.c
@@ -191,7 +191,7 @@ enum ad74115_gpio_mode {
 };
 
 struct ad74115_channels {
-	struct iio_chan_spec		*channels;
+	const struct iio_chan_spec	*channels;
 	unsigned int			num_channels;
 };
 
@@ -1295,46 +1295,46 @@ static const struct iio_info ad74115_info = {
 	_AD74115_ADC_CHANNEL(_type, index, BIT(IIO_CHAN_INFO_SCALE)	\
 					   | BIT(IIO_CHAN_INFO_OFFSET))
 
-static struct iio_chan_spec ad74115_voltage_input_channels[] = {
+static const struct iio_chan_spec ad74115_voltage_input_channels[] = {
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV1),
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
 };
 
-static struct iio_chan_spec ad74115_voltage_output_channels[] = {
+static const struct iio_chan_spec ad74115_voltage_output_channels[] = {
 	AD74115_DAC_CHANNEL(IIO_VOLTAGE, AD74115_DAC_CH_MAIN),
 	AD74115_ADC_CHANNEL(IIO_CURRENT, AD74115_ADC_CH_CONV1),
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
 };
 
-static struct iio_chan_spec ad74115_current_input_channels[] = {
+static const struct iio_chan_spec ad74115_current_input_channels[] = {
 	AD74115_ADC_CHANNEL(IIO_CURRENT, AD74115_ADC_CH_CONV1),
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
 };
 
-static struct iio_chan_spec ad74115_current_output_channels[] = {
+static const struct iio_chan_spec ad74115_current_output_channels[] = {
 	AD74115_DAC_CHANNEL(IIO_CURRENT, AD74115_DAC_CH_MAIN),
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV1),
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
 };
 
-static struct iio_chan_spec ad74115_2_wire_resistance_input_channels[] = {
+static const struct iio_chan_spec ad74115_2_wire_resistance_input_channels[] = {
 	_AD74115_ADC_CHANNEL(IIO_RESISTANCE, AD74115_ADC_CH_CONV1,
 			     BIT(IIO_CHAN_INFO_PROCESSED)),
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
 };
 
-static struct iio_chan_spec ad74115_3_4_wire_resistance_input_channels[] = {
+static const struct iio_chan_spec ad74115_3_4_wire_resistance_input_channels[] = {
 	AD74115_ADC_CHANNEL(IIO_RESISTANCE, AD74115_ADC_CH_CONV1),
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
 };
 
-static struct iio_chan_spec ad74115_digital_input_logic_channels[] = {
+static const struct iio_chan_spec ad74115_digital_input_logic_channels[] = {
 	AD74115_DAC_CHANNEL(IIO_VOLTAGE, AD74115_DAC_CH_COMPARATOR),
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV1),
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
 };
 
-static struct iio_chan_spec ad74115_digital_input_loop_channels[] = {
+static const struct iio_chan_spec ad74115_digital_input_loop_channels[] = {
 	AD74115_DAC_CHANNEL(IIO_CURRENT, AD74115_DAC_CH_MAIN),
 	AD74115_DAC_CHANNEL(IIO_VOLTAGE, AD74115_DAC_CH_COMPARATOR),
 	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV1),
diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c
index 2410d72da49b..1e2f6d9804e3 100644
--- a/drivers/iio/addac/ad74413r.c
+++ b/drivers/iio/addac/ad74413r.c
@@ -45,8 +45,8 @@ struct ad74413r_channel_config {
 };
 
 struct ad74413r_channels {
-	struct iio_chan_spec	*channels;
-	unsigned int		num_channels;
+	const struct iio_chan_spec	*channels;
+	unsigned int			num_channels;
 };
 
 struct ad74413r_state {
@@ -1138,34 +1138,34 @@ static const struct iio_info ad74413r_info = {
 	AD74413R_ADC_CHANNEL(IIO_CURRENT,  BIT(IIO_CHAN_INFO_SCALE)	\
 			     | BIT(IIO_CHAN_INFO_OFFSET))
 
-static struct iio_chan_spec ad74413r_voltage_output_channels[] = {
+static const struct iio_chan_spec ad74413r_voltage_output_channels[] = {
 	AD74413R_DAC_CHANNEL(IIO_VOLTAGE, BIT(IIO_CHAN_INFO_SCALE)),
 	AD74413R_ADC_CURRENT_CHANNEL,
 };
 
-static struct iio_chan_spec ad74413r_current_output_channels[] = {
+static const struct iio_chan_spec ad74413r_current_output_channels[] = {
 	AD74413R_DAC_CHANNEL(IIO_CURRENT, BIT(IIO_CHAN_INFO_SCALE)),
 	AD74413R_ADC_VOLTAGE_CHANNEL,
 };
 
-static struct iio_chan_spec ad74413r_voltage_input_channels[] = {
+static const struct iio_chan_spec ad74413r_voltage_input_channels[] = {
 	AD74413R_ADC_VOLTAGE_CHANNEL,
 };
 
-static struct iio_chan_spec ad74413r_current_input_channels[] = {
+static const struct iio_chan_spec ad74413r_current_input_channels[] = {
 	AD74413R_ADC_CURRENT_CHANNEL,
 };
 
-static struct iio_chan_spec ad74413r_current_input_loop_channels[] = {
+static const struct iio_chan_spec ad74413r_current_input_loop_channels[] = {
 	AD74413R_DAC_CHANNEL(IIO_CURRENT, BIT(IIO_CHAN_INFO_SCALE)),
 	AD74413R_ADC_CURRENT_CHANNEL,
 };
 
-static struct iio_chan_spec ad74413r_resistance_input_channels[] = {
+static const struct iio_chan_spec ad74413r_resistance_input_channels[] = {
 	AD74413R_ADC_CHANNEL(IIO_RESISTANCE, BIT(IIO_CHAN_INFO_PROCESSED)),
 };
 
-static struct iio_chan_spec ad74413r_digital_input_channels[] = {
+static const struct iio_chan_spec ad74413r_digital_input_channels[] = {
 	AD74413R_ADC_VOLTAGE_CHANNEL,
 };
 
@@ -1270,7 +1270,8 @@ static int ad74413r_setup_channels(struct iio_dev *indio_dev)
 {
 	struct ad74413r_state *st = iio_priv(indio_dev);
 	struct ad74413r_channel_config *config;
-	struct iio_chan_spec *channels, *chans;
+	const struct iio_chan_spec *chans;
+	struct iio_chan_spec *channels;
 	unsigned int i, num_chans, chan_i;
 	int ret;
 
-- 
2.46.0

Re: [PATCH] iio: addac: ad74xxx: Constify struct iio_chan_spec

Posted by Jonathan Cameron 2 months, 3 weeks ago

On Sat,  7 Sep 2024 15:51:07 +0200
Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:

> 'struct iio_chan_spec' are not modified in these drivers.
> 
> Constifying this structure moves some data to a read-only section, so
> increase overall security.
> 
> On a x86_64, with allmodconfig:
> Before:
> ======
>    text	   data	    bss	    dec	    hex	filename
>   35749	   5879	    384	  42012	   a41c	drivers/iio/addac/ad74115.o
>   32242	   3297	    384	  35923	   8c53	drivers/iio/addac/ad74413r.o
> 
> After:
> =====
>    text	   data	    bss	    dec	    hex	filename
>   39109	   2519	    384	  42012	   a41c	drivers/iio/addac/ad74115.o
>   33842	   1697	    384	  35923	   8c53	drivers/iio/addac/ad74413r.o
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Looks obviously correct.  Hopefully looks are not being deceiving.

Applied.  Note this is probably next cycle material now given timing.
Jonathan

> ---
> Compile tested only
> ---
>  drivers/iio/addac/ad74115.c  | 18 +++++++++---------
>  drivers/iio/addac/ad74413r.c | 21 +++++++++++----------
>  2 files changed, 20 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/iio/addac/ad74115.c b/drivers/iio/addac/ad74115.c
> index 12dc43d487b4..bdbdd67536ff 100644
> --- a/drivers/iio/addac/ad74115.c
> +++ b/drivers/iio/addac/ad74115.c
> @@ -191,7 +191,7 @@ enum ad74115_gpio_mode {
>  };
>  
>  struct ad74115_channels {
> -	struct iio_chan_spec		*channels;
> +	const struct iio_chan_spec	*channels;
>  	unsigned int			num_channels;
>  };
>  
> @@ -1295,46 +1295,46 @@ static const struct iio_info ad74115_info = {
>  	_AD74115_ADC_CHANNEL(_type, index, BIT(IIO_CHAN_INFO_SCALE)	\
>  					   | BIT(IIO_CHAN_INFO_OFFSET))
>  
> -static struct iio_chan_spec ad74115_voltage_input_channels[] = {
> +static const struct iio_chan_spec ad74115_voltage_input_channels[] = {
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV1),
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
>  };
>  
> -static struct iio_chan_spec ad74115_voltage_output_channels[] = {
> +static const struct iio_chan_spec ad74115_voltage_output_channels[] = {
>  	AD74115_DAC_CHANNEL(IIO_VOLTAGE, AD74115_DAC_CH_MAIN),
>  	AD74115_ADC_CHANNEL(IIO_CURRENT, AD74115_ADC_CH_CONV1),
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
>  };
>  
> -static struct iio_chan_spec ad74115_current_input_channels[] = {
> +static const struct iio_chan_spec ad74115_current_input_channels[] = {
>  	AD74115_ADC_CHANNEL(IIO_CURRENT, AD74115_ADC_CH_CONV1),
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
>  };
>  
> -static struct iio_chan_spec ad74115_current_output_channels[] = {
> +static const struct iio_chan_spec ad74115_current_output_channels[] = {
>  	AD74115_DAC_CHANNEL(IIO_CURRENT, AD74115_DAC_CH_MAIN),
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV1),
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
>  };
>  
> -static struct iio_chan_spec ad74115_2_wire_resistance_input_channels[] = {
> +static const struct iio_chan_spec ad74115_2_wire_resistance_input_channels[] = {
>  	_AD74115_ADC_CHANNEL(IIO_RESISTANCE, AD74115_ADC_CH_CONV1,
>  			     BIT(IIO_CHAN_INFO_PROCESSED)),
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
>  };
>  
> -static struct iio_chan_spec ad74115_3_4_wire_resistance_input_channels[] = {
> +static const struct iio_chan_spec ad74115_3_4_wire_resistance_input_channels[] = {
>  	AD74115_ADC_CHANNEL(IIO_RESISTANCE, AD74115_ADC_CH_CONV1),
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
>  };
>  
> -static struct iio_chan_spec ad74115_digital_input_logic_channels[] = {
> +static const struct iio_chan_spec ad74115_digital_input_logic_channels[] = {
>  	AD74115_DAC_CHANNEL(IIO_VOLTAGE, AD74115_DAC_CH_COMPARATOR),
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV1),
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV2),
>  };
>  
> -static struct iio_chan_spec ad74115_digital_input_loop_channels[] = {
> +static const struct iio_chan_spec ad74115_digital_input_loop_channels[] = {
>  	AD74115_DAC_CHANNEL(IIO_CURRENT, AD74115_DAC_CH_MAIN),
>  	AD74115_DAC_CHANNEL(IIO_VOLTAGE, AD74115_DAC_CH_COMPARATOR),
>  	AD74115_ADC_CHANNEL(IIO_VOLTAGE, AD74115_ADC_CH_CONV1),
> diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c
> index 2410d72da49b..1e2f6d9804e3 100644
> --- a/drivers/iio/addac/ad74413r.c
> +++ b/drivers/iio/addac/ad74413r.c
> @@ -45,8 +45,8 @@ struct ad74413r_channel_config {
>  };
>  
>  struct ad74413r_channels {
> -	struct iio_chan_spec	*channels;
> -	unsigned int		num_channels;
> +	const struct iio_chan_spec	*channels;
> +	unsigned int			num_channels;
>  };
>  
>  struct ad74413r_state {
> @@ -1138,34 +1138,34 @@ static const struct iio_info ad74413r_info = {
>  	AD74413R_ADC_CHANNEL(IIO_CURRENT,  BIT(IIO_CHAN_INFO_SCALE)	\
>  			     | BIT(IIO_CHAN_INFO_OFFSET))
>  
> -static struct iio_chan_spec ad74413r_voltage_output_channels[] = {
> +static const struct iio_chan_spec ad74413r_voltage_output_channels[] = {
>  	AD74413R_DAC_CHANNEL(IIO_VOLTAGE, BIT(IIO_CHAN_INFO_SCALE)),
>  	AD74413R_ADC_CURRENT_CHANNEL,
>  };
>  
> -static struct iio_chan_spec ad74413r_current_output_channels[] = {
> +static const struct iio_chan_spec ad74413r_current_output_channels[] = {
>  	AD74413R_DAC_CHANNEL(IIO_CURRENT, BIT(IIO_CHAN_INFO_SCALE)),
>  	AD74413R_ADC_VOLTAGE_CHANNEL,
>  };
>  
> -static struct iio_chan_spec ad74413r_voltage_input_channels[] = {
> +static const struct iio_chan_spec ad74413r_voltage_input_channels[] = {
>  	AD74413R_ADC_VOLTAGE_CHANNEL,
>  };
>  
> -static struct iio_chan_spec ad74413r_current_input_channels[] = {
> +static const struct iio_chan_spec ad74413r_current_input_channels[] = {
>  	AD74413R_ADC_CURRENT_CHANNEL,
>  };
>  
> -static struct iio_chan_spec ad74413r_current_input_loop_channels[] = {
> +static const struct iio_chan_spec ad74413r_current_input_loop_channels[] = {
>  	AD74413R_DAC_CHANNEL(IIO_CURRENT, BIT(IIO_CHAN_INFO_SCALE)),
>  	AD74413R_ADC_CURRENT_CHANNEL,
>  };
>  
> -static struct iio_chan_spec ad74413r_resistance_input_channels[] = {
> +static const struct iio_chan_spec ad74413r_resistance_input_channels[] = {
>  	AD74413R_ADC_CHANNEL(IIO_RESISTANCE, BIT(IIO_CHAN_INFO_PROCESSED)),
>  };
>  
> -static struct iio_chan_spec ad74413r_digital_input_channels[] = {
> +static const struct iio_chan_spec ad74413r_digital_input_channels[] = {
>  	AD74413R_ADC_VOLTAGE_CHANNEL,
>  };
>  
> @@ -1270,7 +1270,8 @@ static int ad74413r_setup_channels(struct iio_dev *indio_dev)
>  {
>  	struct ad74413r_state *st = iio_priv(indio_dev);
>  	struct ad74413r_channel_config *config;
> -	struct iio_chan_spec *channels, *chans;
> +	const struct iio_chan_spec *chans;
> +	struct iio_chan_spec *channels;
>  	unsigned int i, num_chans, chan_i;
>  	int ret;
>

[PATCH] iio: addac: ad74xxx: Constify struct iio_chan_spec​

[PATCH] iio: addac: ad74xxx: Constify struct iio_chan_spec