Re: [RFC][PATCH 04/12] digest_lists: Objects
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2021-06-27 10:56:21
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linux-doc, linux-kselftest, linux-security-module, lkml
On Fri, Jun 25, 2021 at 06:56:06PM +0200, Roberto Sassu wrote:
quoted hunk ↗ jump to hunk
+++ b/security/integrity/digest_lists/digest_lists.h@@ -0,0 +1,117 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2005,2006,2007,2008 IBM Corporation + * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu <roberto.sassu@huawei.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2 of the + * License. + * + * File: digest_lists.h + * Unexported definitions for digest lists.
Unexported to whom?
+ */
+
+#ifndef __DIGEST_LISTS_INTERNAL_H
+#define __DIGEST_LISTS_INTERNAL_H
+
+#include <linux/types.h>
+#include <linux/crypto.h>
+#include <linux/fs.h>
+#include <linux/security.h>
+#include <linux/hash.h>
+#include <linux/tpm.h>
+#include <linux/audit.h>
+#include <crypto/hash_info.h>
+#include <linux/hash_info.h>
+#include <uapi/linux/digest_lists.h>
+
+#define MAX_DIGEST_SIZE 64
+#define HASH_BITS 10
+#define MEASURE_HTABLE_SIZE (1 << HASH_BITS)
+
+struct digest_list_item {
+ loff_t size;
+ u8 *buf;
+ u8 actions;
+ u8 digest[64];
+ enum hash_algo algo;
+ const char *label;
+};
+
+struct digest_list_item_ref {
+ struct digest_list_item *digest_list;
+ loff_t digest_offset;
+ loff_t hdr_offset;
+};
+
+struct digest_item {
+ /* hash table pointers */
+ struct hlist_node hnext;
+ /* digest list references (protected by RCU) */
+ struct digest_list_item_ref *refs;
+};
+
+struct h_table {
+ atomic_long_t len;Why is this atomic? Why would that matter?
+ struct hlist_head queue[MEASURE_HTABLE_SIZE];
+};
+
+static inline unsigned int hash_key(u8 *digest)
+{
+ return (digest[0] | digest[1] << 8) % MEASURE_HTABLE_SIZE;
+}Don't we have hashing functions in the kernel already?
+
+static inline struct compact_list_hdr *get_hdr(
+ struct digest_list_item *digest_list,
+ loff_t hdr_offset)
+{
+ return (struct compact_list_hdr *)(digest_list->buf + hdr_offset);
+}pointer math feels rough, are you shure you want to do this this way? thanks, greg k-h