Re: [RFC][PATCH v2 10/12] diglim: Interfaces - digests_count

Mauro Carvalho Chehab
2021-07-28T12:45:39Z

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;