[PATCH v5 01/13] ima: Remove ima_h_table structure

[Roberto Sassu <roberto.sassu@huaweicloud.com>]

From: Roberto Sassu <roberto.sassu@huawei.com>

With the upcoming change of dynamically allocating and replacing the hash
table, the ima_h_table structure would have been replaced with a new one.

However, since the ima_h_table structure contains also the counters for
number of measurements entries and violations, we would have needed to
preserve their values in the new ima_h_table structure.

Instead, separate those counters from the hash table, remove the
ima_h_table structure, and just replace the hash table pointer.

Finally, rename ima_show_htable_value(), ima_show_htable_violations()
and ima_htable_violations_ops respectively to ima_show_counter(),
ima_show_num_violations() and ima_num_violations_ops.

Link: https://github.com/linux-integrity/linux/issues/1
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 security/integrity/ima/ima.h       |  9 +++------
 security/integrity/ima/ima_api.c   |  2 +-
 security/integrity/ima/ima_fs.c    | 19 +++++++++----------
 security/integrity/ima/ima_kexec.c |  2 +-
 security/integrity/ima/ima_queue.c | 17 ++++++++++-------
 5 files changed, 24 insertions(+), 25 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 69e9bf0b82c6..51a8a582df56 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -324,12 +324,9 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
  */
 extern spinlock_t ima_queue_lock;
 
-struct ima_h_table {
-	atomic_long_t len;	/* number of stored measurements in the list */
-	atomic_long_t violations;
-	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
-};
-extern struct ima_h_table ima_htable;
+extern atomic_long_t ima_num_entries;
+extern atomic_long_t ima_num_violations;
+extern struct hlist_head ima_htable[IMA_MEASURE_HTABLE_SIZE];
 
 static inline unsigned int ima_hash_key(u8 *digest)
 {
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 0916f24f005f..122d127e108d 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -146,7 +146,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
 	int result;
 
 	/* can overflow, only indicator */
-	atomic_long_inc(&ima_htable.violations);
+	atomic_long_inc(&ima_num_violations);
 
 	result = ima_alloc_init_template(&event_data, &entry, NULL);
 	if (result < 0) {
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index ca4931a95098..aaa460d70ff7 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -38,8 +38,8 @@ __setup("ima_canonical_fmt", default_canonical_fmt_setup);
 
 static int valid_policy = 1;
 
-static ssize_t ima_show_htable_value(char __user *buf, size_t count,
-				     loff_t *ppos, atomic_long_t *val)
+static ssize_t ima_show_counter(char __user *buf, size_t count, loff_t *ppos,
+				atomic_long_t *val)
 {
 	char tmpbuf[32];	/* greater than largest 'long' string value */
 	ssize_t len;
@@ -48,15 +48,14 @@ static ssize_t ima_show_htable_value(char __user *buf, size_t count,
 	return simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
 }
 
-static ssize_t ima_show_htable_violations(struct file *filp,
-					  char __user *buf,
-					  size_t count, loff_t *ppos)
+static ssize_t ima_show_num_violations(struct file *filp, char __user *buf,
+				       size_t count, loff_t *ppos)
 {
-	return ima_show_htable_value(buf, count, ppos, &ima_htable.violations);
+	return ima_show_counter(buf, count, ppos, &ima_num_violations);
 }
 
-static const struct file_operations ima_htable_violations_ops = {
-	.read = ima_show_htable_violations,
+static const struct file_operations ima_num_violations_ops = {
+	.read = ima_show_num_violations,
 	.llseek = generic_file_llseek,
 };
 
@@ -64,7 +63,7 @@ static ssize_t ima_show_measurements_count(struct file *filp,
 					   char __user *buf,
 					   size_t count, loff_t *ppos)
 {
-	return ima_show_htable_value(buf, count, ppos, &ima_htable.len);
+	return ima_show_counter(buf, count, ppos, &ima_num_entries);
 
 }
 
@@ -545,7 +544,7 @@ int __init ima_fs_init(void)
 	}
 
 	dentry = securityfs_create_file("violations", S_IRUSR | S_IRGRP,
-				   ima_dir, NULL, &ima_htable_violations_ops);
+				   ima_dir, NULL, &ima_num_violations_ops);
 	if (IS_ERR(dentry)) {
 		ret = PTR_ERR(dentry);
 		goto out;
diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
index 36a34c54de58..5801649fbbef 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -43,7 +43,7 @@ void ima_measure_kexec_event(const char *event_name)
 	int n;
 
 	buf_size = ima_get_binary_runtime_size();
-	len = atomic_long_read(&ima_htable.len);
+	len = atomic_long_read(&ima_num_entries);
 
 	n = scnprintf(ima_kexec_event, IMA_KEXEC_EVENT_LEN,
 		      "kexec_segment_size=%lu;ima_binary_runtime_size=%lu;"
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index 319522450854..1f6515f7d015 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -32,11 +32,14 @@ static unsigned long binary_runtime_size;
 static unsigned long binary_runtime_size = ULONG_MAX;
 #endif
 
+/* num of stored measurements in the list */
+atomic_long_t ima_num_entries = ATOMIC_LONG_INIT(0);
+/* num of violations in the list */
+atomic_long_t ima_num_violations = ATOMIC_LONG_INIT(0);
+
 /* key: inode (before secure-hashing a file) */
-struct ima_h_table ima_htable = {
-	.len = ATOMIC_LONG_INIT(0),
-	.violations = ATOMIC_LONG_INIT(0),
-	.queue[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT
+struct hlist_head ima_htable[IMA_MEASURE_HTABLE_SIZE] = {
+	[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT
 };
 
 /* mutex protects atomicity of extending measurement list
@@ -61,7 +64,7 @@ static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value,
 
 	key = ima_hash_key(digest_value);
 	rcu_read_lock();
-	hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) {
+	hlist_for_each_entry_rcu(qe, &ima_htable[key], hnext) {
 		rc = memcmp(qe->entry->digests[ima_hash_algo_idx].digest,
 			    digest_value, hash_digest_size[ima_hash_algo]);
 		if ((rc == 0) && (qe->entry->pcr == pcr)) {
@@ -113,10 +116,10 @@ static int ima_add_digest_entry(struct ima_template_entry *entry,
 	INIT_LIST_HEAD(&qe->later);
 	list_add_tail_rcu(&qe->later, &ima_measurements);
 
-	atomic_long_inc(&ima_htable.len);
+	atomic_long_inc(&ima_num_entries);
 	if (update_htable) {
 		key = ima_hash_key(entry->digests[ima_hash_algo_idx].digest);
-		hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
+		hlist_add_head_rcu(&qe->hnext, &ima_htable[key]);
 	}
 
 	if (binary_runtime_size != ULONG_MAX) {
-- 
2.43.0