[PATCH 2/2] thermal/drivers/mediatek/lvts_thermal: Fix wrong lvts_ctrl index
Nicolas Pitre
npitre at baylibre.com
Fri May 3 08:45:48 PDT 2024
On Fri, 3 May 2024, Julien Panis wrote:
> In 'lvts_should_update_thresh()' and 'lvts_ctrl_start()' functions,
> the parameter passed to 'lvts_for_each_valid_sensor()' macro is always
> 'lvts_ctrl->lvts_data->lvts_ctrl'. In other words, the array index 0
> is systematically passed as 'struct lvts_ctrl_data' type item, even
> when another item should be consumed instead.
>
> Hence, the 'valid_sensor_mask' value which is selected can be wrong
> because unrelated to the 'struct lvts_ctrl_data' type item that should
> be used. Hence, some thermal zone can be registered for a sensor 'i'
> that does not actually exist. Because of the invalid address used
> as 'lvts_sensor[i].msr', this situation ends up with a crash in
> 'lvts_get_temp()' function, where this 'msr' pointer is passed to
> 'readl_poll_timeout()' function. The following message is output:
> "Unable to handle kernel NULL pointer dereference at virtual
> address <msr>", with <msr> = 0.
>
> This patch fixes the issue.
>
> Fixes: 11e6f4c31447 ("thermal/drivers/mediatek/lvts_thermal: Allow early empty sensor slots")
> Signed-off-by: Julien Panis <jpanis at baylibre.com>
Reviewed-by: Nicolas Pitre <npitre at baylibre.com>
> ---
> drivers/thermal/mediatek/lvts_thermal.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c
> index 18a796386cd0..d7df6f09938b 100644
> --- a/drivers/thermal/mediatek/lvts_thermal.c
> +++ b/drivers/thermal/mediatek/lvts_thermal.c
> @@ -116,9 +116,9 @@ struct lvts_ctrl_data {
> ((s2) ? BIT(2) : 0) | \
> ((s3) ? BIT(3) : 0))
>
> -#define lvts_for_each_valid_sensor(i, lvts_ctrl_data) \
> +#define lvts_for_each_valid_sensor(i, lvts_ctrl) \
> for ((i) = 0; (i) < LVTS_SENSOR_MAX; (i)++) \
> - if (!((lvts_ctrl_data)->valid_sensor_mask & BIT(i))) \
> + if (!((lvts_ctrl)->valid_sensor_mask & BIT(i))) \
> continue; \
> else
>
> @@ -145,6 +145,7 @@ struct lvts_ctrl {
> const struct lvts_data *lvts_data;
> u32 calibration[LVTS_SENSOR_MAX];
> u32 hw_tshut_raw_temp;
> + u8 valid_sensor_mask;
> int mode;
> void __iomem *base;
> int low_thresh;
> @@ -356,7 +357,7 @@ static bool lvts_should_update_thresh(struct lvts_ctrl *lvts_ctrl, int high)
> if (high > lvts_ctrl->high_thresh)
> return true;
>
> - lvts_for_each_valid_sensor(i, lvts_ctrl->lvts_data->lvts_ctrl)
> + lvts_for_each_valid_sensor(i, lvts_ctrl)
> if (lvts_ctrl->sensors[i].high_thresh == lvts_ctrl->high_thresh
> && lvts_ctrl->sensors[i].low_thresh == lvts_ctrl->low_thresh)
> return false;
> @@ -617,6 +618,8 @@ static int lvts_sensor_init(struct device *dev, struct lvts_ctrl *lvts_ctrl,
> lvts_sensor[i].high_thresh = INT_MIN;
> };
>
> + lvts_ctrl->valid_sensor_mask = lvts_ctrl_data->valid_sensor_mask;
> +
> return 0;
> }
>
> @@ -1112,7 +1115,7 @@ static int lvts_ctrl_start(struct device *dev, struct lvts_ctrl *lvts_ctrl)
> u32 *sensor_bitmap = lvts_ctrl->mode == LVTS_MSR_IMMEDIATE_MODE ?
> sensor_imm_bitmap : sensor_filt_bitmap;
>
> - lvts_for_each_valid_sensor(i, lvts_ctrl->lvts_data->lvts_ctrl) {
> + lvts_for_each_valid_sensor(i, lvts_ctrl) {
>
> int dt_id = lvts_sensors[i].dt_id;
>
>
> --
> 2.37.3
>
>
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