Messages in this thread | | | Date | Mon, 16 Oct 2023 10:53:38 +0300 | From | Andy Shevchenko <> | Subject | Re: [PATCH 4/5] iio: pressure: bmp280: Allow multiple chips id per family of devices |
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On Sun, Oct 15, 2023 at 05:16:26PM +0200, Angel Iglesias wrote: > Improve device detection in certain chip families known to have various > chip ids.
...
> +#include <linux/overflow.h>
Probably you don't need this, see below.
...
> ret = regmap_read(regmap, data->chip_info->id_reg, &chip_id); > if (ret < 0) > return ret;
> + 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(data->chip_info->num_chip_id, 5, &nbuf)) > + return ret;
First of all, it _implicitly_ returns 0 here...
> + buf = kmalloc_array(data->chip_info->num_chip_id, 5, GFP_KERNEL); > + if (!buf) > + return ret;
...and here.
Second, kmalloc_array() has that check inside.
Third, define this magic 5 either as strlen(), or a constant (in latter case with the comment of its meaning).
> + for (i = 0; i < data->chip_info->num_chip_id; i++) > + snprintf(&buf[i*5], nbuf - i*5, "0x%x ", data->chip_info->chip_id[i]);
Fourth, use incremental position, i.e. use retuned value from snprintf().
> + dev_err(dev, "bad chip id: expected one of [ %s ] got 0x%x\n", buf, chip_id); > + kfree(buf);
> + return ret;
As per "first" and "second" above.
> }
-- With Best Regards, Andy Shevchenko
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