Re: [PATCH] iio: gyro: adis16136: use scnprintf instead of snprintf

[Andy Shevchenko]

On Wed, Mar 18, 2020 at 08:25:22PM +0530, Rohit Sarkar wrote:
> scnprintf returns the actual number of bytes written into the buffer as
> opposed to snprintf which returns the number of bytes that would have
> been written if the buffer was big enough. Using the output of snprintf
> may lead to difficult to detect bugs.

Nice. Have you investigate the code?

> @@ -96,7 +96,7 @@ static ssize_t adis16136_show_serial(struct file *file,
>  	if (ret)
>  		return ret;
>  
> -	len = snprintf(buf, sizeof(buf), "%.4x%.4x%.4x-%.4x\n", lot1, lot2,
> +	len = scnprintf(buf, sizeof(buf), "%.4x%.4x%.4x-%.4x\n", lot1, lot2,
>  		lot3, serial);
>  
>  	return simple_read_from_buffer(userbuf, count, ppos, buf, len);

The buffer size is 20, the pattern size I count to 19. Do you think snprintf()
can fail?

-- 
With Best Regards,
Andy Shevchenko