iio: core: Constify struct configfs_item_operations and configfs_group_operations

[PATCH] iio: core: Constify struct configfs_item_operations and configfs_group_operations

Posted by Christophe JAILLET 1 month, 1 week ago

'struct configfs_item_operations' and 'configfs_group_operations' are not
modified in this driver.

Constifying these structures moves some data to a read-only section, so
increases overall security, especially when the structure holds some
function pointers.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
   5037	   1528	     64	   6629	   19e5	drivers/iio/industrialio-sw-device.o
   5509	   1528	     64	   7101	   1bbd	drivers/iio/industrialio-sw-trigger.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
   5133	   1432	     64	   6629	   19e5	drivers/iio/industrialio-sw-device.o
   5605	   1432	     64	   7101	   1bbd	drivers/iio/industrialio-sw-trigger.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested only.

This change is possible since commits f2f36500a63b and f7f78098690d.
---
 drivers/iio/industrialio-sw-device.c  | 2 +-
 drivers/iio/industrialio-sw-trigger.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/industrialio-sw-device.c b/drivers/iio/industrialio-sw-device.c
index cdaf30a3f233..3582524de0b8 100644
--- a/drivers/iio/industrialio-sw-device.c
+++ b/drivers/iio/industrialio-sw-device.c
@@ -148,7 +148,7 @@ static void device_drop_group(struct config_group *group,
 	config_item_put(item);
 }
 
-static struct configfs_group_operations device_ops = {
+static const struct configfs_group_operations device_ops = {
 	.make_group	= &device_make_group,
 	.drop_item	= &device_drop_group,
 };
diff --git a/drivers/iio/industrialio-sw-trigger.c b/drivers/iio/industrialio-sw-trigger.c
index d86a3305d9e8..334b6b10a784 100644
--- a/drivers/iio/industrialio-sw-trigger.c
+++ b/drivers/iio/industrialio-sw-trigger.c
@@ -152,7 +152,7 @@ static void trigger_drop_group(struct config_group *group,
 	config_item_put(item);
 }
 
-static struct configfs_group_operations trigger_ops = {
+static const struct configfs_group_operations trigger_ops = {
 	.make_group	= &trigger_make_group,
 	.drop_item	= &trigger_drop_group,
 };
-- 
2.52.0

Re: [PATCH] iio: core: Constify struct configfs_item_operations and configfs_group_operations

Posted by Jonathan Cameron 1 month, 1 week ago

On Mon, 29 Dec 2025 12:27:43 +0100
Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:

> 'struct configfs_item_operations' and 'configfs_group_operations' are not
> modified in this driver.
> 
> Constifying these structures moves some data to a read-only section, so
> increases overall security, especially when the structure holds some
> function pointers.
> 
> On a x86_64, with allmodconfig:
> Before:
> ======
>    text	   data	    bss	    dec	    hex	filename
>    5037	   1528	     64	   6629	   19e5	drivers/iio/industrialio-sw-device.o
>    5509	   1528	     64	   7101	   1bbd	drivers/iio/industrialio-sw-trigger.o
> 
> After:
> =====
>    text	   data	    bss	    dec	    hex	filename
>    5133	   1432	     64	   6629	   19e5	drivers/iio/industrialio-sw-device.o
>    5605	   1432	     64	   7101	   1bbd	drivers/iio/industrialio-sw-trigger.o
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Applied to the togreg branch of iio.git which I'll push out initially as testing
for 0-day to take a look at it.

Thanks,

Jonathan