2024-05-04 22:44:43

by Christophe JAILLET

Subject: [PATCH] rtc: rx6110: Constify struct regmap_config

'regmap_spi_config' and 'regmap_i2c_config' are not modified in this diver
and are only used as a const struct regmap_config.

Constifying these structures 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
8896 1554 32 10482 28f2 drivers/rtc/rtc-rx6110.o

After:
text data bss dec hex filename
9536 914 32 10482 28f2 drivers/rtc/rtc-rx6110.o

Signed-off-by: Christophe JAILLET <[email protected]>
---
drivers/rtc/rtc-rx6110.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-rx6110.c b/drivers/rtc/rtc-rx6110.c
index 834274db8c3f..af6dd6ccbe3b 100644
--- a/drivers/rtc/rtc-rx6110.c
+++ b/drivers/rtc/rtc-rx6110.c
@@ -330,7 +330,7 @@ static int rx6110_probe(struct rx6110_data *rx6110, struct device *dev)
}

#if IS_ENABLED(CONFIG_SPI_MASTER)
-static struct regmap_config regmap_spi_config = {
+static const struct regmap_config regmap_spi_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = RX6110_REG_IRQ,
@@ -410,7 +410,7 @@ static void rx6110_spi_unregister(void)
#endif /* CONFIG_SPI_MASTER */

#if IS_ENABLED(CONFIG_I2C)
-static struct regmap_config regmap_i2c_config = {
+static const struct regmap_config regmap_i2c_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = RX6110_REG_IRQ,
--
2.45.0

2024-05-07 21:43:58

by Alexandre Belloni

Subject: Re: [PATCH] rtc: rx6110: Constify struct regmap_config

On Sun, 05 May 2024 00:43:07 +0200, Christophe JAILLET wrote:
> 'regmap_spi_config' and 'regmap_i2c_config' are not modified in this diver
> and are only used as a const struct regmap_config.
>
> Constifying these structures 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
> 8896 1554 32 10482 28f2 drivers/rtc/rtc-rx6110.o
>
> [...]

Applied, thanks!

[1/1] rtc: rx6110: Constify struct regmap_config
https://git.kernel.org/abelloni/c/6a216cbadbe0

Best regards,

--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com