[PATCH net-next 1/2] net: dsa: mv88e6xxx: Constify struct devlink_region_ops and struct mv88e6xxx_region

[PATCH net-next 1/2] net: dsa: mv88e6xxx: Constify struct devlink_region_ops and struct mv88e6xxx_region

[Christophe JAILLET]

'struct devlink_region_ops' and 'struct mv88e6xxx_region' 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, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  18076	   6496	     64	  24636	   603c	drivers/net/dsa/mv88e6xxx/devlink.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  18652	   5920	     64	  24636	   603c	drivers/net/dsa/mv88e6xxx/devlink.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested only
---
 drivers/net/dsa/mv88e6xxx/devlink.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx/devlink.c b/drivers/net/dsa/mv88e6xxx/devlink.c
index 195460a0a0d4..aec652e33fc1 100644
--- a/drivers/net/dsa/mv88e6xxx/devlink.c
+++ b/drivers/net/dsa/mv88e6xxx/devlink.c
@@ -647,7 +647,7 @@ static struct mv88e6xxx_region_priv mv88e6xxx_region_global1_priv = {
 	.id = MV88E6XXX_REGION_GLOBAL1,
 };
 
-static struct devlink_region_ops mv88e6xxx_region_global1_ops = {
+static const struct devlink_region_ops mv88e6xxx_region_global1_ops = {
 	.name = "global1",
 	.snapshot = mv88e6xxx_region_global_snapshot,
 	.destructor = kfree,
@@ -658,32 +658,32 @@ static struct mv88e6xxx_region_priv mv88e6xxx_region_global2_priv = {
 	.id = MV88E6XXX_REGION_GLOBAL2,
 };
 
-static struct devlink_region_ops mv88e6xxx_region_global2_ops = {
+static const struct devlink_region_ops mv88e6xxx_region_global2_ops = {
 	.name = "global2",
 	.snapshot = mv88e6xxx_region_global_snapshot,
 	.destructor = kfree,
 	.priv = &mv88e6xxx_region_global2_priv,
 };
 
-static struct devlink_region_ops mv88e6xxx_region_atu_ops = {
+static const struct devlink_region_ops mv88e6xxx_region_atu_ops = {
 	.name = "atu",
 	.snapshot = mv88e6xxx_region_atu_snapshot,
 	.destructor = kfree,
 };
 
-static struct devlink_region_ops mv88e6xxx_region_vtu_ops = {
+static const struct devlink_region_ops mv88e6xxx_region_vtu_ops = {
 	.name = "vtu",
 	.snapshot = mv88e6xxx_region_vtu_snapshot,
 	.destructor = kfree,
 };
 
-static struct devlink_region_ops mv88e6xxx_region_stu_ops = {
+static const struct devlink_region_ops mv88e6xxx_region_stu_ops = {
 	.name = "stu",
 	.snapshot = mv88e6xxx_region_stu_snapshot,
 	.destructor = kfree,
 };
 
-static struct devlink_region_ops mv88e6xxx_region_pvt_ops = {
+static const struct devlink_region_ops mv88e6xxx_region_pvt_ops = {
 	.name = "pvt",
 	.snapshot = mv88e6xxx_region_pvt_snapshot,
 	.destructor = kfree,
@@ -696,13 +696,13 @@ static const struct devlink_port_region_ops mv88e6xxx_region_port_ops = {
 };
 
 struct mv88e6xxx_region {
-	struct devlink_region_ops *ops;
+	const struct devlink_region_ops *ops;
 	u64 size;
 
 	bool (*cond)(struct mv88e6xxx_chip *chip);
 };
 
-static struct mv88e6xxx_region mv88e6xxx_regions[] = {
+static const struct mv88e6xxx_region mv88e6xxx_regions[] = {
 	[MV88E6XXX_REGION_GLOBAL1] = {
 		.ops = &mv88e6xxx_region_global1_ops,
 		.size = 32 * sizeof(u16)
@@ -768,7 +768,7 @@ int mv88e6xxx_setup_devlink_regions_global(struct dsa_switch *ds)
 {
 	bool (*cond)(struct mv88e6xxx_chip *chip);
 	struct mv88e6xxx_chip *chip = ds->priv;
-	struct devlink_region_ops *ops;
+	const struct devlink_region_ops *ops;
 	struct devlink_region *region;
 	u64 size;
 	int i, j;
-- 
2.50.0

[PATCH net-next 2/2] net: dsa: mv88e6xxx: Use kcalloc()

[Christophe JAILLET]

Use kcalloc() instead of hand writing it. This is less verbose.

Also move the initialization of 'count' to save some LoC.

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  18652	   5920	     64	  24636	   603c	drivers/net/dsa/mv88e6xxx/devlink.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  18498	   5920	     64	  24482	   5fa2	drivers/net/dsa/mv88e6xxx/devlink.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested only
---
 drivers/net/dsa/mv88e6xxx/devlink.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx/devlink.c b/drivers/net/dsa/mv88e6xxx/devlink.c
index aec652e33fc1..da69e0b85879 100644
--- a/drivers/net/dsa/mv88e6xxx/devlink.c
+++ b/drivers/net/dsa/mv88e6xxx/devlink.c
@@ -376,19 +376,14 @@ static int mv88e6xxx_region_atu_snapshot(struct devlink *dl,
 	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
 	struct mv88e6xxx_devlink_atu_entry *table;
 	struct mv88e6xxx_chip *chip = ds->priv;
-	int fid = -1, err = 0, count;
+	int fid = -1, err = 0, count = 0;
 
-	table = kmalloc_array(mv88e6xxx_num_databases(chip),
-			      sizeof(struct mv88e6xxx_devlink_atu_entry),
-			      GFP_KERNEL);
+	table = kcalloc(mv88e6xxx_num_databases(chip),
+			sizeof(struct mv88e6xxx_devlink_atu_entry),
+			GFP_KERNEL);
 	if (!table)
 		return -ENOMEM;
 
-	memset(table, 0, mv88e6xxx_num_databases(chip) *
-	       sizeof(struct mv88e6xxx_devlink_atu_entry));
-
-	count = 0;
-
 	mv88e6xxx_reg_lock(chip);
 
 	while (1) {
-- 
2.50.0

Re: [PATCH net-next 1/2] net: dsa: mv88e6xxx: Constify struct devlink_region_ops and struct mv88e6xxx_region

[Andrew Lunn]

On Sun, Jun 29, 2025 at 02:35:49PM +0200, Christophe JAILLET wrote:
> 'struct devlink_region_ops' and 'struct mv88e6xxx_region' 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, as an example:
> Before:
> ======
>    text	   data	    bss	    dec	    hex	filename
>   18076	   6496	     64	  24636	   603c	drivers/net/dsa/mv88e6xxx/devlink.o
> 
> After:
> =====
>    text	   data	    bss	    dec	    hex	filename
>   18652	   5920	     64	  24636	   603c	drivers/net/dsa/mv88e6xxx/devlink.o
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH net-next 2/2] net: dsa: mv88e6xxx: Use kcalloc()

[Andrew Lunn]

On Sun, Jun 29, 2025 at 02:35:50PM +0200, Christophe JAILLET wrote:
> Use kcalloc() instead of hand writing it. This is less verbose.
> 
> Also move the initialization of 'count' to save some LoC.
> 
> On a x86_64, with allmodconfig, as an example:
> Before:
> ======
>    text	   data	    bss	    dec	    hex	filename
>   18652	   5920	     64	  24636	   603c	drivers/net/dsa/mv88e6xxx/devlink.o
> 
> After:
> =====
>    text	   data	    bss	    dec	    hex	filename
>   18498	   5920	     64	  24482	   5fa2	drivers/net/dsa/mv88e6xxx/devlink.o
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH net-next 1/2] net: dsa: mv88e6xxx: Constify struct devlink_region_ops and struct mv88e6xxx_region

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Sun, 29 Jun 2025 14:35:49 +0200 you wrote:
> 'struct devlink_region_ops' and 'struct mv88e6xxx_region' 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.
> 
> [...]

Here is the summary with links:
  - [net-next,1/2] net: dsa: mv88e6xxx: Constify struct devlink_region_ops and struct mv88e6xxx_region
    https://git.kernel.org/netdev/net-next/c/ff2d4cfdaf91
  - [net-next,2/2] net: dsa: mv88e6xxx: Use kcalloc()
    https://git.kernel.org/netdev/net-next/c/a63b5a0bb740

You are awesome, thank you!
-- 
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