[PATCH v1] ALSA: aoa: Constify struct configfs_item_operations and configfs_group_operations

[PATCH v1] ALSA: aoa: Constify struct configfs_item_operations and configfs_group_operations

[Christophe JAILLET]

'struct codec_connection' are not modified in this driver.

Constifying these structures moves some data to a read-only section, so
increases overall security.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  10034	   3392	     12	  13438	   347e	sound/aoa/fabrics/layout.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  10370	   3040	     12	  13422	   346e	sound/aoa/fabrics/layout.o

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

The fabric_data field in struct aoa_codecis is only used in
sound/aoa/fabrics/layout.c, so there should be no side effect for other
files that include sound/aoa/aoa.h
---
 sound/aoa/aoa.h            |  2 +-
 sound/aoa/fabrics/layout.c | 28 ++++++++++++++--------------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/sound/aoa/aoa.h b/sound/aoa/aoa.h
index badff9f7cd54..b92593f170ca 100644
--- a/sound/aoa/aoa.h
+++ b/sound/aoa/aoa.h
@@ -48,7 +48,7 @@ struct aoa_codec {
 	u32 connected;
 
 	/* data the fabric can associate with this structure */
-	void *fabric_data;
+	const void *fabric_data;
 
 	/* private! */
 	struct list_head list;
diff --git a/sound/aoa/fabrics/layout.c b/sound/aoa/fabrics/layout.c
index c18b55305294..c3ebb6de4789 100644
--- a/sound/aoa/fabrics/layout.c
+++ b/sound/aoa/fabrics/layout.c
@@ -55,7 +55,7 @@ struct codec_connection {
 
 struct codec_connect_info {
 	char *name;
-	struct codec_connection *connections;
+	const struct codec_connection *connections;
 };
 
 #define LAYOUT_FLAG_COMBO_LINEOUT_SPDIF	(1<<0)
@@ -116,7 +116,7 @@ MODULE_ALIAS("aoa-device-id-35");
 MODULE_ALIAS("aoa-device-id-44");
 
 /* onyx with all but microphone connected */
-static struct codec_connection onyx_connections_nomic[] = {
+static const struct codec_connection onyx_connections_nomic[] = {
 	{
 		.connected = CC_SPEAKERS | CC_HEADPHONE | CC_LINEOUT,
 		.codec_bit = 0,
@@ -133,7 +133,7 @@ static struct codec_connection onyx_connections_nomic[] = {
 };
 
 /* onyx on machines without headphone */
-static struct codec_connection onyx_connections_noheadphones[] = {
+static const struct codec_connection onyx_connections_noheadphones[] = {
 	{
 		.connected = CC_SPEAKERS | CC_LINEOUT |
 			     CC_LINEOUT_LABELLED_HEADPHONE,
@@ -157,7 +157,7 @@ static struct codec_connection onyx_connections_noheadphones[] = {
 };
 
 /* onyx on machines with real line-out */
-static struct codec_connection onyx_connections_reallineout[] = {
+static const struct codec_connection onyx_connections_reallineout[] = {
 	{
 		.connected = CC_SPEAKERS | CC_LINEOUT | CC_HEADPHONE,
 		.codec_bit = 0,
@@ -174,7 +174,7 @@ static struct codec_connection onyx_connections_reallineout[] = {
 };
 
 /* tas on machines without line out */
-static struct codec_connection tas_connections_nolineout[] = {
+static const struct codec_connection tas_connections_nolineout[] = {
 	{
 		.connected = CC_SPEAKERS | CC_HEADPHONE,
 		.codec_bit = 0,
@@ -191,7 +191,7 @@ static struct codec_connection tas_connections_nolineout[] = {
 };
 
 /* tas on machines with neither line out nor line in */
-static struct codec_connection tas_connections_noline[] = {
+static const struct codec_connection tas_connections_noline[] = {
 	{
 		.connected = CC_SPEAKERS | CC_HEADPHONE,
 		.codec_bit = 0,
@@ -204,7 +204,7 @@ static struct codec_connection tas_connections_noline[] = {
 };
 
 /* tas on machines without microphone */
-static struct codec_connection tas_connections_nomic[] = {
+static const struct codec_connection tas_connections_nomic[] = {
 	{
 		.connected = CC_SPEAKERS | CC_HEADPHONE | CC_LINEOUT,
 		.codec_bit = 0,
@@ -217,7 +217,7 @@ static struct codec_connection tas_connections_nomic[] = {
 };
 
 /* tas on machines with everything connected */
-static struct codec_connection tas_connections_all[] = {
+static const struct codec_connection tas_connections_all[] = {
 	{
 		.connected = CC_SPEAKERS | CC_HEADPHONE | CC_LINEOUT,
 		.codec_bit = 0,
@@ -233,7 +233,7 @@ static struct codec_connection tas_connections_all[] = {
 	{} /* terminate array by .connected == 0 */
 };
 
-static struct codec_connection toonie_connections[] = {
+static const struct codec_connection toonie_connections[] = {
 	{
 		.connected = CC_SPEAKERS | CC_HEADPHONE,
 		.codec_bit = 0,
@@ -241,7 +241,7 @@ static struct codec_connection toonie_connections[] = {
 	{} /* terminate array by .connected == 0 */
 };
 
-static struct codec_connection topaz_input[] = {
+static const struct codec_connection topaz_input[] = {
 	{
 		.connected = CC_DIGITALIN,
 		.codec_bit = 0,
@@ -249,7 +249,7 @@ static struct codec_connection topaz_input[] = {
 	{} /* terminate array by .connected == 0 */
 };
 
-static struct codec_connection topaz_output[] = {
+static const struct codec_connection topaz_output[] = {
 	{
 		.connected = CC_DIGITALOUT,
 		.codec_bit = 1,
@@ -257,7 +257,7 @@ static struct codec_connection topaz_output[] = {
 	{} /* terminate array by .connected == 0 */
 };
 
-static struct codec_connection topaz_inout[] = {
+static const struct codec_connection topaz_inout[] = {
 	{
 		.connected = CC_DIGITALIN,
 		.codec_bit = 0,
@@ -772,7 +772,7 @@ static int check_codec(struct aoa_codec *codec,
 {
 	const u32 *ref;
 	char propname[32];
-	struct codec_connection *cc;
+	const struct codec_connection *cc;
 
 	/* if the codec has a 'codec' node, we require a reference */
 	if (of_node_name_eq(codec->node, "codec")) {
@@ -895,7 +895,7 @@ static void layout_notify(void *data)
 
 static void layout_attached_codec(struct aoa_codec *codec)
 {
-	struct codec_connection *cc;
+	const struct codec_connection *cc;
 	struct snd_kcontrol *ctl;
 	int headphones, lineout;
 	struct layout_dev *ldev = layout_device;
-- 
2.53.0

Re: [PATCH v1] ALSA: aoa: Constify struct configfs_item_operations and configfs_group_operations

[Johannes Berg]

On Thu, 2026-02-26 at 21:43 +0100, Christophe JAILLET wrote:
> 'struct codec_connection' are not modified in this driver.
> 
> Constifying these structures moves some data to a read-only section, so
> increases overall security.
> 

The security claim seems like a stretch for this data, but I guess since
it's never modified making it const makes some sense.

johannes

Re: [PATCH v1] ALSA: aoa: Constify struct configfs_item_operations and configfs_group_operations

[Christophe JAILLET]

Le 26/02/2026 à 21:47, Johannes Berg a écrit :
> On Thu, 2026-02-26 at 21:43 +0100, Christophe JAILLET wrote:
>> 'struct codec_connection' are not modified in this driver.
>>
>> Constifying these structures moves some data to a read-only section, so
>> increases overall security.
>>
> 
> The security claim seems like a stretch for this data, but I guess since
> it's never modified making it const makes some sense.

You are right, in this case the security claim is a bit too much.
I use the same template for all such patches, and some times, it is less 
relevant.

The claim makes much more sense when the struct has some function pointers.


Please not the the subject is broken (configfs_item_operations...)
I've sent the same patch with the correct subject.
Sorry for the noise.

CJ


> 
> johannes
> 
>