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Date:   Mon, 6 Apr 2020 13:00:16 -0700
From:   Matthew Wilcox <willy@infradead.org>
To:     Waiman Long <longman@redhat.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        David Howells <dhowells@redhat.com>,
        Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>, linux-mm@kvack.org,
        keyrings@vger.kernel.org, linux-kernel@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Joe Perches <joe@perches.com>,
        David Rientjes <rientjes@google.com>
Subject: Re: [PATCH v2] mm: Add kvfree_sensitive() for freeing sensitive data
 objects
Message-ID: <20200406200016.GJ21484@bombadil.infradead.org>
References: <20200406185827.22249-1-longman@redhat.com>
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On Mon, Apr 06, 2020 at 02:58:27PM -0400, Waiman Long wrote:
> +/**
> + * kvfree_sensitive - free a data object containing sensitive information
> + * @addr - address of the data object to be freed
> + * @len  - length of the data object

Did you try building this with W=1?  I believe this is incorrect kerneldoc.
It should be @addr: and @len:

Also, it reads better in the htmldocs if you capitalise the first letter
of each sentence and finish with a full stop.

> @@ -914,7 +911,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
>  		 */
>  		if (ret > key_data_len) {
>  			if (unlikely(key_data))
> -				__kvzfree(key_data, key_data_len);
> +				kvfree_sensitive(key_data, key_data_len);

I'd drop the test of key_data here.