diff mbox series

[v2,1/2] power: supply: samsung-sdi-battery: Constify struct power_supply_vbat_ri_table

Message ID d01818abd880bf435d1106a9a6cc11a7a8a3e661.1719125040.git.christophe.jaillet@wanadoo.fr (mailing list archive)
State Handled Elsewhere, archived
Headers show
Series [v2,1/2] power: supply: samsung-sdi-battery: Constify struct power_supply_vbat_ri_table | expand

Commit Message

Christophe JAILLET June 23, 2024, 6:45 a.m. UTC 
'struct power_supply_vbat_ri_table' are not modified in this driver.

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

In order to do it, some code also needs to be adjusted to this new const
qualifier.

On a x86_64, with allmodconfig:
Before:
======
$ size drivers/power/supply/samsung-sdi-battery.o
   text	   data	    bss	    dec	    hex	filename
    955	   7664	      0	   8619	   21ab	drivers/power/supply/samsung-sdi-battery.o

After:
=====
$ size drivers/power/supply/samsung-sdi-battery.o
   text	   data	    bss	    dec	    hex	filename
   4055	   4584	      0	   8639	   21bf	drivers/power/supply/samsung-sdi-battery.o

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

Changes in v2
  - Add Linus Walleij <linus.walleij@linaro.org> in Cc  [Sebastian Reichel]

v1: https://lore.kernel.org/all/bab3f44b62275c91d039b82dac1c32167c0c3bad.1717253900.git.christophe.jaillet@wanadoo.fr/
---
 drivers/power/supply/power_supply_core.c   |  2 +-
 drivers/power/supply/samsung-sdi-battery.c | 24 +++++++++++-----------
 include/linux/power_supply.h               |  4 ++--
 3 files changed, 15 insertions(+), 15 deletions(-)

Comments

Linus Walleij June 26, 2024, 10:37 a.m. UTC | #1 
On Sun, Jun 23, 2024 at 8:45 AM Christophe JAILLET
<christophe.jaillet@wanadoo.fr> wrote:

> 'struct power_supply_vbat_ri_table' are not modified in this driver.
>
> Constifying these structures moves some data to a read-only section, so
> increase overall security.
>
> In order to do it, some code also needs to be adjusted to this new const
> qualifier.
>
> On a x86_64, with allmodconfig:
> Before:
> ======
> $ size drivers/power/supply/samsung-sdi-battery.o
>    text    data     bss     dec     hex filename
>     955    7664       0    8619    21ab drivers/power/supply/samsung-sdi-battery.o
>
> After:
> =====
> $ size drivers/power/supply/samsung-sdi-battery.o
>    text    data     bss     dec     hex filename
>    4055    4584       0    8639    21bf drivers/power/supply/samsung-sdi-battery.o
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Really neat!
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij
diff mbox series

Patch

diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index fefe938c9342..022d0e4bf621 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -1024,7 +1024,7 @@  EXPORT_SYMBOL_GPL(power_supply_temp2resist_simple);
 int power_supply_vbat2ri(struct power_supply_battery_info *info,
 			 int vbat_uv, bool charging)
 {
-	struct power_supply_vbat_ri_table *vbat2ri;
+	const struct power_supply_vbat_ri_table *vbat2ri;
 	int table_len;
 	int i, high, low;
 
diff --git a/drivers/power/supply/samsung-sdi-battery.c b/drivers/power/supply/samsung-sdi-battery.c
index b33daab798b9..725fbe09379e 100644
--- a/drivers/power/supply/samsung-sdi-battery.c
+++ b/drivers/power/supply/samsung-sdi-battery.c
@@ -25,7 +25,7 @@  struct samsung_sdi_battery {
  * tables apply depending on whether we are charging or not.
  */
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb_l1m7flu[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb_l1m7flu[] = {
 	{ .vbat_uv = 4240000, .ri_uohm = 160000 },
 	{ .vbat_uv = 4210000, .ri_uohm = 179000 },
 	{ .vbat_uv = 4180000, .ri_uohm = 183000 },
@@ -53,7 +53,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb_l1m7flu
 	{ .vbat_uv = 3300000, .ri_uohm = 339000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb_l1m7flu[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb_l1m7flu[] = {
 	{ .vbat_uv = 4302000, .ri_uohm = 230000 },
 	{ .vbat_uv = 4276000, .ri_uohm = 345000 },
 	{ .vbat_uv = 4227000, .ri_uohm = 345000 },
@@ -73,7 +73,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb_l1m7flu[]
 	{ .vbat_uv = 3590000, .ri_uohm = 164000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb425161la[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb425161la[] = {
 	{ .vbat_uv = 4240000, .ri_uohm = 160000 },
 	{ .vbat_uv = 4210000, .ri_uohm = 179000 },
 	{ .vbat_uv = 4180000, .ri_uohm = 183000 },
@@ -105,7 +105,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb425161la
 	{ .vbat_uv = 3300000, .ri_uohm = 339000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb425161la[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb425161la[] = {
 	{ .vbat_uv = 4345000, .ri_uohm = 230000 },
 	{ .vbat_uv = 4329000, .ri_uohm = 238000 },
 	{ .vbat_uv = 4314000, .ri_uohm = 225000 },
@@ -182,7 +182,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb425161la[]
 	{ .vbat_uv = 3590000, .ri_uohm = 164000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb425161lu[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb425161lu[] = {
 	{ .vbat_uv = 4240000, .ri_uohm = 160000 },
 	{ .vbat_uv = 4210000, .ri_uohm = 179000 },
 	{ .vbat_uv = 4180000, .ri_uohm = 183000 },
@@ -214,7 +214,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb425161lu
 	{ .vbat_uv = 3300000, .ri_uohm = 339000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb425161lu[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb425161lu[] = {
 	{ .vbat_uv = 4346000, .ri_uohm = 293000 },
 	{ .vbat_uv = 4336000, .ri_uohm = 290000 },
 	{ .vbat_uv = 4315000, .ri_uohm = 274000 },
@@ -244,7 +244,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb425161lu[]
 	{ .vbat_uv = 3590000, .ri_uohm = 164000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb485159lu[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb485159lu[] = {
 	{ .vbat_uv = 4240000, .ri_uohm = 160000 },
 	{ .vbat_uv = 4210000, .ri_uohm = 179000 },
 	{ .vbat_uv = 4180000, .ri_uohm = 183000 },
@@ -271,7 +271,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb485159lu
 	{ .vbat_uv = 3300000, .ri_uohm = 339000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb485159lu[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb485159lu[] = {
 	{ .vbat_uv = 4302000, .ri_uohm = 200000 },
 	{ .vbat_uv = 4258000, .ri_uohm = 206000 },
 	{ .vbat_uv = 4200000, .ri_uohm = 231000 },
@@ -291,7 +291,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb485159lu[]
 	{ .vbat_uv = 3590000, .ri_uohm = 164000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb535151vu[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb535151vu[] = {
 	{ .vbat_uv = 4071000, .ri_uohm = 158000 },
 	{ .vbat_uv = 4019000, .ri_uohm = 187000 },
 	{ .vbat_uv = 3951000, .ri_uohm = 191000 },
@@ -311,7 +311,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb535151vu
 	{ .vbat_uv = 3280000, .ri_uohm = 250000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb535151vu[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb535151vu[] = {
 	{ .vbat_uv = 4190000, .ri_uohm = 214000 },
 	{ .vbat_uv = 4159000, .ri_uohm = 252000 },
 	{ .vbat_uv = 4121000, .ri_uohm = 245000 },
@@ -331,7 +331,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb535151vu[]
 	{ .vbat_uv = 3510000, .ri_uohm = 228000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb585157lu[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb585157lu[] = {
 	{ .vbat_uv = 4194000, .ri_uohm = 121000 },
 	{ .vbat_uv = 4169000, .ri_uohm = 188000 },
 	{ .vbat_uv = 4136000, .ri_uohm = 173000 },
@@ -401,7 +401,7 @@  static struct power_supply_vbat_ri_table samsung_vbat2res_discharging_eb585157lu
 	{ .vbat_uv = 3161000, .ri_uohm = 452000 },
 };
 
-static struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb585157lu[] = {
+static const struct power_supply_vbat_ri_table samsung_vbat2res_charging_eb585157lu[] = {
 	{ .vbat_uv = 4360000, .ri_uohm = 128000 },
 	{ .vbat_uv = 4325000, .ri_uohm = 130000 },
 	{ .vbat_uv = 4316000, .ri_uohm = 148000 },
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 65082ef75692..5061eeecf62e 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -755,9 +755,9 @@  struct power_supply_battery_info {
 	int ocv_table_size[POWER_SUPPLY_OCV_TEMP_MAX];
 	struct power_supply_resistance_temp_table *resist_table;
 	int resist_table_size;
-	struct power_supply_vbat_ri_table *vbat2ri_discharging;
+	const struct power_supply_vbat_ri_table *vbat2ri_discharging;
 	int vbat2ri_discharging_size;
-	struct power_supply_vbat_ri_table *vbat2ri_charging;
+	const struct power_supply_vbat_ri_table *vbat2ri_charging;
 	int vbat2ri_charging_size;
 	int bti_resistance_ohm;
 	int bti_resistance_tolerance;