On Wed, Aug 23, 2023 at 05:58:06PM +0200, Angel Iglesias wrote:
> Improve device detection in certain chip families known to have various
> chip ids.
IDs
...
> #include <linux/completion.h>
> #include <linux/pm_runtime.h>
> #include <linux/random.h>
> +#include <linux/overflow.h>
Please, preserve ordering.
...
> struct bmp280_data *data;
> struct gpio_desc *gpiod;
> unsigned int chip_id;
> - int ret;
> + int ret, i;
unsigned int i;
...
> + if (i == data->chip_info->num_chip_id) {
> + size_t nbuf;
> + char *buf;
> +
> + // 0x<id>, so four chars per number plus one space + ENDL
> + if (check_mul_overflow(5, data->chip_info->num_chip_id, &nbuf))
> + return ret;
> +
> + buf = kmalloc_array(nbuf, sizeof(char), GFP_KERNEL);
We almost never do a array allocation for byte sizes. Instead of the above you
need to use
buf = kmalloc_array(data->chip_info->num_chip_id, 5, GFP_KERNEL);
> + if (!buf)
This check assumes that num_chip_id is never 0, so...
> + return ret;
> +
> + for (i = 0; i < data->chip_info->num_chip_id; i++)
> + snprintf(&buf[i*5], nbuf, "0x%x ", data->chip_info->chip_id[i]);
> + buf[nbuf-1] = '\0';
...this is redundant assignment. sprintf() guarantees the NUL termination.
> +
> + dev_err(dev, "bad chip id: expected [ %s ] got 0x%x\n", buf, chip_id);
"...expected one of..."
> + kfree(buf);
> + return ret;
Oh, I didn't get that you allocated memory only to print a message...
> }
--
With Best Regards,
Andy Shevchenko
