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Date:   Wed, 28 Jul 2021 14:45:29 +0200
From:   Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
To:     Roberto Sassu <roberto.sassu@huawei.com>
Cc:     <zohar@linux.ibm.com>, <gregkh@linuxfoundation.org>,
        <linux-integrity@vger.kernel.org>,
        <linux-security-module@vger.kernel.org>,
        <linux-doc@vger.kernel.org>, <linux-kselftest@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, kernel test robot <lkp@intel.com>
Subject: Re: [RFC][PATCH v2 10/12] diglim: Interfaces - digests_count
Message-ID: <20210728144529.756dfc94@sal.lan>
In-Reply-To: <20210726163700.2092768-11-roberto.sassu@huawei.com>
References: <20210726163700.2092768-1-roberto.sassu@huawei.com>
        <20210726163700.2092768-11-roberto.sassu@huawei.com>
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Em Mon, 26 Jul 2021 18:36:58 +0200
Roberto Sassu <roberto.sassu@huawei.com> escreveu:

> Introduce the digests_count interface, which shows the current number of
> digests stored in the hash table by type.
> 
> Reported-by: kernel test robot <lkp@intel.com> (frame size warning)
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>

Patches 7 to 10 also LGTM.

> ---
>  security/integrity/diglim/fs.c | 48 ++++++++++++++++++++++++++++++++++
>  1 file changed, 48 insertions(+)
> 
> diff --git a/security/integrity/diglim/fs.c b/security/integrity/diglim/fs.c
> index f1c1fc56448a..3b1d9616cb62 100644
> --- a/security/integrity/diglim/fs.c
> +++ b/security/integrity/diglim/fs.c
> @@ -23,6 +23,7 @@
>  #include "diglim.h"
>  
>  #define MAX_DIGEST_LIST_SIZE (64 * 1024 * 1024 - 1)
> +#define TMPBUF_SIZE 512
>  
>  static struct dentry *diglim_dir;
>  /**
> @@ -36,6 +37,13 @@ static struct dentry *diglim_dir;
>   * removed.
>   */
>  static struct dentry *digest_lists_loaded_dir;
> +/**
> + * DOC: digests_count
> + *
> + * digests_count shows the current number of digests stored in the hash
> + * table by type.
> + */
> +static struct dentry *digests_count;
>  /**
>   * DOC: digest_label
>   *
> @@ -73,6 +81,39 @@ static struct dentry *digest_list_del_dentry;
>  char digest_query[CRYPTO_MAX_ALG_NAME + 1 + IMA_MAX_DIGEST_SIZE * 2 + 1];
>  char digest_label[NAME_MAX + 1];
>  
> +static char *types_str[COMPACT__LAST] = {
> +	[COMPACT_PARSER] = "Parser",
> +	[COMPACT_FILE] = "File",
> +	[COMPACT_METADATA] = "Metadata",
> +	[COMPACT_DIGEST_LIST] = "Digest list",
> +};
> +
> +static ssize_t diglim_show_htable_len(struct file *filp, char __user *buf,
> +				      size_t count, loff_t *ppos)
> +{
> +	char *tmpbuf;
> +	ssize_t ret, len = 0;
> +	int i;
> +
> +	tmpbuf = kmalloc(TMPBUF_SIZE, GFP_KERNEL);
> +	if (!tmpbuf)
> +		return -ENOMEM;
> +
> +	for (i = COMPACT_PARSER; i < COMPACT__LAST; i++)
> +		len += scnprintf(tmpbuf + len, TMPBUF_SIZE - len,
> +				 "%s digests: %lu\n", types_str[i],
> +				 htable[i].len);
> +
> +	ret = simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
> +	kfree(tmpbuf);
> +	return ret;
> +}
> +
> +static const struct file_operations htable_len_ops = {
> +	.read = diglim_show_htable_len,
> +	.llseek = generic_file_llseek,
> +};
> +
>  static int parse_digest_list_filename(const char *digest_list_filename,
>  				      u8 *digest, enum hash_algo *algo)
>  {
> @@ -696,6 +737,12 @@ static int __init diglim_fs_init(void)
>  	if (IS_ERR(digest_lists_loaded_dir))
>  		goto out;
>  
> +	digests_count = securityfs_create_file("digests_count", 0440,
> +					       diglim_dir, NULL,
> +					       &htable_len_ops);
> +	if (IS_ERR(digests_count))
> +		goto out;
> +
>  	digest_list_add_dentry = securityfs_create_file("digest_list_add", 0200,
>  						diglim_dir, NULL,
>  						&digest_list_upload_ops);
> @@ -726,6 +773,7 @@ static int __init diglim_fs_init(void)
>  	securityfs_remove(digest_label_dentry);
>  	securityfs_remove(digest_list_del_dentry);
>  	securityfs_remove(digest_list_add_dentry);
> +	securityfs_remove(digests_count);
>  	securityfs_remove(digest_lists_loaded_dir);
>  	securityfs_remove(diglim_dir);
>  	return -1;