On Wed, Jul 31, 2024 at 02:14:01PM GMT, Rob Herring (Arm) wrote:
> There's no need to get the length of an DT array property before
> parsing the array. of_property_read_variable_u32_array() takes a
> minimum and maximum length and returns the actual length (or error
> code).
>
> This is part of a larger effort to remove callers of of_get_property()
> and similar functions. of_get_property() leaks the DT property data
> pointer which is a problem for dynamically allocated nodes which may
> be freed.
> ---
> drivers/input/keyboard/tegra-kbc.c | 72 +++++++++++-------------------
> 1 file changed, 27 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/input/keyboard/tegra-kbc.c b/drivers/input/keyboard/tegra-kbc.c
> index a1765ed8c825..53f39fc155ea 100644
> --- a/drivers/input/keyboard/tegra-kbc.c
> +++ b/drivers/input/keyboard/tegra-kbc.c
> @@ -491,12 +491,10 @@ static int tegra_kbc_parse_dt(struct tegra_kbc *kbc)
> struct device_node *np = kbc->dev->of_node;
> u32 prop;
> int i;
> - u32 num_rows = 0;
> - u32 num_cols = 0;
> + int num_rows;
> + int num_cols;
> u32 cols_cfg[KBC_MAX_GPIO];
> u32 rows_cfg[KBC_MAX_GPIO];
> - int proplen;
> - int ret;
>
> if (!of_property_read_u32(np, "nvidia,debounce-delay-ms", &prop))
> kbc->debounce_cnt = prop;
> @@ -510,56 +508,23 @@ static int tegra_kbc_parse_dt(struct tegra_kbc *kbc)
> of_property_read_bool(np, "nvidia,wakeup-source")) /* legacy */
> kbc->wakeup = true;
>
> - if (!of_get_property(np, "nvidia,kbc-row-pins", &proplen)) {
> - dev_err(kbc->dev, "property nvidia,kbc-row-pins not found\n");
> - return -ENOENT;
> - }
> - num_rows = proplen / sizeof(u32);
> -
> - if (!of_get_property(np, "nvidia,kbc-col-pins", &proplen)) {
> - dev_err(kbc->dev, "property nvidia,kbc-col-pins not found\n");
> - return -ENOENT;
> - }
> - num_cols = proplen / sizeof(u32);
> -
> - if (num_rows > kbc->hw_support->max_rows) {
> - dev_err(kbc->dev,
> - "Number of rows is more than supported by hardware\n");
> - return -EINVAL;
> - }
> -
> - if (num_cols > kbc->hw_support->max_columns) {
> - dev_err(kbc->dev,
> - "Number of cols is more than supported by hardware\n");
> - return -EINVAL;
> - }
> -
> - if (!of_get_property(np, "linux,keymap", &proplen)) {
> + if (!of_property_present(np, "linux,keymap")) {
> dev_err(kbc->dev, "property linux,keymap not found\n");
> return -ENOENT;
> }
>
> - if (!num_rows || !num_cols || ((num_rows + num_cols) > KBC_MAX_GPIO)) {
> - dev_err(kbc->dev,
> - "keypad rows/columns not properly specified\n");
> - return -EINVAL;
> - }
> -
> /* Set all pins as non-configured */
> for (i = 0; i < kbc->num_rows_and_columns; i++)
> kbc->pin_cfg[i].type = PIN_CFG_IGNORE;
>
> - ret = of_property_read_u32_array(np, "nvidia,kbc-row-pins",
> - rows_cfg, num_rows);
> - if (ret < 0) {
> + num_rows = of_property_read_variable_u32_array(np, "nvidia,kbc-row-pins",
> + rows_cfg, 1, KBC_MAX_GPIO);
> + if (num_rows < 0) {
> dev_err(kbc->dev, "Rows configurations are not proper\n");
> - return -EINVAL;
> - }
> -
> - ret = of_property_read_u32_array(np, "nvidia,kbc-col-pins",
> - cols_cfg, num_cols);
> - if (ret < 0) {
> - dev_err(kbc->dev, "Cols configurations are not proper\n");
> + return num_rows;
> + } else if (num_rows > kbc->hw_support->max_rows) {
> + dev_err(kbc->dev,
> + "Number of rows is more than supported by hardware\n");
> return -EINVAL;
> }
>
> @@ -568,11 +533,28 @@ static int tegra_kbc_parse_dt(struct tegra_kbc *kbc)
> kbc->pin_cfg[rows_cfg[i]].num = i;
> }
>
> + num_cols = of_property_read_variable_u32_array(np, "nvidia,kbc-col-pins",
> + cols_cfg, 1, KBC_MAX_GPIO);
> + if (num_cols < 0) {
> + dev_err(kbc->dev, "Cols configurations are not proper\n");
> + return num_cols;
> + } else if (num_cols > kbc->hw_support->max_columns) {
> + dev_err(kbc->dev,
> + "Number of cols is more than supported by hardware\n");
> + return -EINVAL;
> + }
> +
> for (i = 0; i < num_cols; i++) {
> kbc->pin_cfg[cols_cfg[i]].type = PIN_CFG_COL;
> kbc->pin_cfg[cols_cfg[i]].num = i;
> }
>
> + if (!num_rows || !num_cols || ((num_rows + num_cols) > KBC_MAX_GPIO)) {
> + dev_err(kbc->dev,
> + "keypad rows/columns not properly specified\n");
> + return -EINVAL;
> + }
Previously we wouldn't try to initialize the columns when the
rows/columns were invalid, so this block could move before the last for
loop above.
But it doesn't really matter given that these are exceptions and really
shouldn't happen, so:
Acked-by: Thierry Reding <treding@xxxxxxxxxx>
Attachment:
signature.asc
Description: PGP signature
