On Tuesday 15 February 2022 20:11:09 Armin Wolf wrote:
> Right now, we only use bits 0 to 7 of the fan/temp sensor number
> by doing number & 0xff. Passing the value as a u8 makes this
> step unnecessary. Also add checks to the ioctl handler since
> users might get confused when passing 0x00000101 does the same
> as passing 0x00000001.
>
> Tested on a Dell Inspiron 3505.
>
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
Reviewed-by: Pali Rohár <pali@xxxxxxxxxx>
> ---
> drivers/hwmon/dell-smm-hwmon.c | 68 ++++++++++++++++++++++------------
> 1 file changed, 45 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
> index 3b49e55d060f..a102034a1d38 100644
> --- a/drivers/hwmon/dell-smm-hwmon.c
> +++ b/drivers/hwmon/dell-smm-hwmon.c
> @@ -21,6 +21,7 @@
> #include <linux/errno.h>
> #include <linux/hwmon.h>
> #include <linux/init.h>
> +#include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/mutex.h>
> #include <linux/platform_device.h>
> @@ -254,46 +255,52 @@ static int i8k_smm(struct smm_regs *regs)
> /*
> * Read the fan status.
> */
> -static int i8k_get_fan_status(const struct dell_smm_data *data, int fan)
> +static int i8k_get_fan_status(const struct dell_smm_data *data, u8 fan)
> {
> - struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
> + struct smm_regs regs = {
> + .eax = I8K_SMM_GET_FAN,
> + .ebx = fan,
> + };
>
> if (data->disallow_fan_support)
> return -EINVAL;
>
> - regs.ebx = fan & 0xff;
> return i8k_smm(®s) ? : regs.eax & 0xff;
> }
>
> /*
> * Read the fan speed in RPM.
> */
> -static int i8k_get_fan_speed(const struct dell_smm_data *data, int fan)
> +static int i8k_get_fan_speed(const struct dell_smm_data *data, u8 fan)
> {
> - struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
> + struct smm_regs regs = {
> + .eax = I8K_SMM_GET_SPEED,
> + .ebx = fan,
> + };
>
> if (data->disallow_fan_support)
> return -EINVAL;
>
> - regs.ebx = fan & 0xff;
> return i8k_smm(®s) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
> }
>
> /*
> * Read the fan type.
> */
> -static int _i8k_get_fan_type(const struct dell_smm_data *data, int fan)
> +static int _i8k_get_fan_type(const struct dell_smm_data *data, u8 fan)
> {
> - struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
> + struct smm_regs regs = {
> + .eax = I8K_SMM_GET_FAN_TYPE,
> + .ebx = fan,
> + };
>
> if (data->disallow_fan_support || data->disallow_fan_type_call)
> return -EINVAL;
>
> - regs.ebx = fan & 0xff;
> return i8k_smm(®s) ? : regs.eax & 0xff;
> }
>
> -static int i8k_get_fan_type(struct dell_smm_data *data, int fan)
> +static int i8k_get_fan_type(struct dell_smm_data *data, u8 fan)
> {
> /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
> if (data->fan_type[fan] == INT_MIN)
> @@ -305,14 +312,16 @@ static int i8k_get_fan_type(struct dell_smm_data *data, int fan)
> /*
> * Read the fan nominal rpm for specific fan speed.
> */
> -static int __init i8k_get_fan_nominal_speed(const struct dell_smm_data *data, int fan, int speed)
> +static int __init i8k_get_fan_nominal_speed(const struct dell_smm_data *data, u8 fan, int speed)
> {
> - struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
> + struct smm_regs regs = {
> + .eax = I8K_SMM_GET_NOM_SPEED,
> + .ebx = fan | (speed << 8),
> + };
>
> if (data->disallow_fan_support)
> return -EINVAL;
>
> - regs.ebx = (fan & 0xff) | (speed << 8);
> return i8k_smm(®s) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
> }
>
> @@ -333,7 +342,7 @@ static int i8k_enable_fan_auto_mode(const struct dell_smm_data *data, bool enabl
> /*
> * Set the fan speed (off, low, high, ...).
> */
> -static int i8k_set_fan(const struct dell_smm_data *data, int fan, int speed)
> +static int i8k_set_fan(const struct dell_smm_data *data, u8 fan, int speed)
> {
> struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
>
> @@ -341,33 +350,35 @@ static int i8k_set_fan(const struct dell_smm_data *data, int fan, int speed)
> return -EINVAL;
>
> speed = (speed < 0) ? 0 : ((speed > data->i8k_fan_max) ? data->i8k_fan_max : speed);
> - regs.ebx = (fan & 0xff) | (speed << 8);
> + regs.ebx = fan | (speed << 8);
>
> return i8k_smm(®s);
> }
>
> -static int __init i8k_get_temp_type(int sensor)
> +static int __init i8k_get_temp_type(u8 sensor)
> {
> - struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
> + struct smm_regs regs = {
> + .eax = I8K_SMM_GET_TEMP_TYPE,
> + .ebx = sensor,
> + };
>
> - regs.ebx = sensor & 0xff;
> return i8k_smm(®s) ? : regs.eax & 0xff;
> }
>
> /*
> * Read the cpu temperature.
> */
> -static int _i8k_get_temp(int sensor)
> +static int _i8k_get_temp(u8 sensor)
> {
> struct smm_regs regs = {
> .eax = I8K_SMM_GET_TEMP,
> - .ebx = sensor & 0xff,
> + .ebx = sensor,
> };
>
> return i8k_smm(®s) ? : regs.eax & 0xff;
> }
>
> -static int i8k_get_temp(int sensor)
> +static int i8k_get_temp(u8 sensor)
> {
> int temp = _i8k_get_temp(sensor);
>
> @@ -500,6 +511,9 @@ static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> if (copy_from_user(&val, argp, sizeof(int)))
> return -EFAULT;
>
> + if (val > U8_MAX || val < 0)
> + return -EINVAL;
> +
> val = i8k_get_fan_speed(data, val);
> break;
>
> @@ -507,6 +521,9 @@ static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> if (copy_from_user(&val, argp, sizeof(int)))
> return -EFAULT;
>
> + if (val > U8_MAX || val < 0)
> + return -EINVAL;
> +
> val = i8k_get_fan_status(data, val);
> break;
>
> @@ -517,6 +534,9 @@ static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> if (copy_from_user(&val, argp, sizeof(int)))
> return -EFAULT;
>
> + if (val > U8_MAX || val < 0)
> + return -EINVAL;
> +
> if (copy_from_user(&speed, argp + 1, sizeof(int)))
> return -EFAULT;
>
> @@ -924,7 +944,8 @@ static int __init dell_smm_init_hwmon(struct device *dev)
> {
> struct dell_smm_data *data = dev_get_drvdata(dev);
> struct device *dell_smm_hwmon_dev;
> - int i, state, err;
> + int state, err;
> + u8 i;
>
> for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
> data->temp_type[i] = i8k_get_temp_type(i);
> @@ -1245,7 +1266,8 @@ static int __init dell_smm_probe(struct platform_device *pdev)
> {
> struct dell_smm_data *data;
> const struct dmi_system_id *id, *fan_control;
> - int fan, ret;
> + int ret;
> + u8 fan;
>
> data = devm_kzalloc(&pdev->dev, sizeof(struct dell_smm_data), GFP_KERNEL);
> if (!data)
> --
> 2.30.2
>
