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From: Andy Shevchenko <andriy.shevchenko@intel.com>
To: Rohit Sarkar <rohitsarkar5398@gmail.com>
Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
	jic23@kernel.org, dragos.bogdan@analog.com,
	Lars-Peter Clausen <lars@metafoo.de>,
	Michael Hennerich <Michael.Hennerich@analog.com>,
	Stefan Popa <stefan.popa@analog.com>,
	knaack.h@gmx.de, pmeerw@pmeerw.net
Subject: Re: [PATCH] iio: gyro: adis16136: use scnprintf instead of snprintf
Date: Sun, 22 Mar 2020 02:25:42 +0200	[thread overview]
Message-ID: <20200322002542.GA2826015@smile.fi.intel.com> (raw)
In-Reply-To: <5e723666.1c69fb81.3545b.79c3@mx.google.com>

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



  reply	other threads:[~2020-03-22  0:25 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-18 14:55 [PATCH] iio: gyro: adis16136: use scnprintf instead of snprintf Rohit Sarkar
2020-03-22  0:25 ` Andy Shevchenko [this message]
2020-03-22  6:11   ` Rohit Sarkar
2020-03-22 10:27     ` Andy Shevchenko
2020-03-23 15:04       ` David Laight
2020-03-23 16:05         ` 'Andy Shevchenko'

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