TOMOYO: Use stack memory for pending entry.

Use stack memory for pending entry to reduce kmalloc() which will be kfree()d.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 48 insertions, 76 deletions

diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index a1723bbcde0..cd8ba444676 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -130,58 +130,47 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname,
 						  const bool is_not,
 						  const bool is_delete)
 {
-	struct tomoyo_domain_initializer_entry *entry = NULL;
 	struct tomoyo_domain_initializer_entry *ptr;
-	const struct tomoyo_path_info *saved_program = NULL;
-	const struct tomoyo_path_info *saved_domainname = NULL;
+	struct tomoyo_domain_initializer_entry e = { .is_not = is_not };
 	int error = is_delete ? -ENOENT : -ENOMEM;
-	bool is_last_name = false;
 
 	if (!tomoyo_is_correct_path(program, 1, -1, -1))
 		return -EINVAL; /* No patterns allowed. */
 	if (domainname) {
 		if (!tomoyo_is_domain_def(domainname) &&
 		    tomoyo_is_correct_path(domainname, 1, -1, -1))
-			is_last_name = true;
+			e.is_last_name = true;
 		else if (!tomoyo_is_correct_domain(domainname))
 			return -EINVAL;
-		saved_domainname = tomoyo_get_name(domainname);
-		if (!saved_domainname)
+		e.domainname = tomoyo_get_name(domainname);
+		if (!e.domainname)
 			goto out;
 	}
-	saved_program = tomoyo_get_name(program);
-	if (!saved_program)
+	e.program = tomoyo_get_name(program);
+	if (!e.program)
 		goto out;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &tomoyo_domain_initializer_list, list) {
-		if (ptr->is_not != is_not ||
-		    ptr->domainname != saved_domainname ||
-		    ptr->program != saved_program)
+		if (!tomoyo_is_same_domain_initializer_entry(ptr, &e))
 			continue;
 		ptr->is_deleted = is_delete;
 		error = 0;
 		break;
 	}
-	if (!is_delete && error && tomoyo_memory_ok(entry)) {
-		entry->domainname = saved_domainname;
-		saved_domainname = NULL;
-		entry->program = saved_program;
-		saved_program = NULL;
-		entry->is_not = is_not;
-		entry->is_last_name = is_last_name;
-		list_add_tail_rcu(&entry->list,
-				  &tomoyo_domain_initializer_list);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_domain_initializer_entry *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->list,
+					  &tomoyo_domain_initializer_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	tomoyo_put_name(saved_domainname);
-	tomoyo_put_name(saved_program);
-	kfree(entry);
+	tomoyo_put_name(e.domainname);
+	tomoyo_put_name(e.program);
 	return error;
 }
 
@@ -351,57 +340,47 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname,
 					     const bool is_not,
 					     const bool is_delete)
 {
-	struct tomoyo_domain_keeper_entry *entry = NULL;
 	struct tomoyo_domain_keeper_entry *ptr;
-	const struct tomoyo_path_info *saved_domainname = NULL;
-	const struct tomoyo_path_info *saved_program = NULL;
+	struct tomoyo_domain_keeper_entry e = { .is_not = is_not };
 	int error = is_delete ? -ENOENT : -ENOMEM;
-	bool is_last_name = false;
 
 	if (!tomoyo_is_domain_def(domainname) &&
 	    tomoyo_is_correct_path(domainname, 1, -1, -1))
-		is_last_name = true;
+		e.is_last_name = true;
 	else if (!tomoyo_is_correct_domain(domainname))
 		return -EINVAL;
 	if (program) {
 		if (!tomoyo_is_correct_path(program, 1, -1, -1))
 			return -EINVAL;
-		saved_program = tomoyo_get_name(program);
-		if (!saved_program)
+		e.program = tomoyo_get_name(program);
+		if (!e.program)
 			goto out;
 	}
-	saved_domainname = tomoyo_get_name(domainname);
-	if (!saved_domainname)
+	e.domainname = tomoyo_get_name(domainname);
+	if (!e.domainname)
 		goto out;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &tomoyo_domain_keeper_list, list) {
-		if (ptr->is_not != is_not ||
-		    ptr->domainname != saved_domainname ||
-		    ptr->program != saved_program)
+		if (!tomoyo_is_same_domain_keeper_entry(ptr, &e))
 			continue;
 		ptr->is_deleted = is_delete;
 		error = 0;
 		break;
 	}
-	if (!is_delete && error && tomoyo_memory_ok(entry)) {
-		entry->domainname = saved_domainname;
-		saved_domainname = NULL;
-		entry->program = saved_program;
-		saved_program = NULL;
-		entry->is_not = is_not;
-		entry->is_last_name = is_last_name;
-		list_add_tail_rcu(&entry->list, &tomoyo_domain_keeper_list);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_domain_keeper_entry *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->list,
+					  &tomoyo_domain_keeper_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	tomoyo_put_name(saved_domainname);
-	tomoyo_put_name(saved_program);
-	kfree(entry);
+	tomoyo_put_name(e.domainname);
+	tomoyo_put_name(e.program);
 	return error;
 }
 
@@ -553,45 +532,38 @@ static int tomoyo_update_alias_entry(const char *original_name,
 				     const char *aliased_name,
 				     const bool is_delete)
 {
-	struct tomoyo_alias_entry *entry = NULL;
 	struct tomoyo_alias_entry *ptr;
-	const struct tomoyo_path_info *saved_original_name;
-	const struct tomoyo_path_info *saved_aliased_name;
+	struct tomoyo_alias_entry e = { };
 	int error = is_delete ? -ENOENT : -ENOMEM;
 
 	if (!tomoyo_is_correct_path(original_name, 1, -1, -1) ||
 	    !tomoyo_is_correct_path(aliased_name, 1, -1, -1))
 		return -EINVAL; /* No patterns allowed. */
-	saved_original_name = tomoyo_get_name(original_name);
-	saved_aliased_name = tomoyo_get_name(aliased_name);
-	if (!saved_original_name || !saved_aliased_name)
+	e.original_name = tomoyo_get_name(original_name);
+	e.aliased_name = tomoyo_get_name(aliased_name);
+	if (!e.original_name || !e.aliased_name)
 		goto out;
-	if (!is_delete)
-		entry = kmalloc(sizeof(*entry), GFP_NOFS);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
 		goto out;
 	list_for_each_entry_rcu(ptr, &tomoyo_alias_list, list) {
-		if (ptr->original_name != saved_original_name ||
-		    ptr->aliased_name != saved_aliased_name)
+		if (!tomoyo_is_same_alias_entry(ptr, &e))
 			continue;
 		ptr->is_deleted = is_delete;
 		error = 0;
 		break;
 	}
-	if (!is_delete && error && tomoyo_memory_ok(entry)) {
-		entry->original_name = saved_original_name;
-		saved_original_name = NULL;
-		entry->aliased_name = saved_aliased_name;
-		saved_aliased_name = NULL;
-		list_add_tail_rcu(&entry->list, &tomoyo_alias_list);
-		entry = NULL;
-		error = 0;
+	if (!is_delete && error) {
+		struct tomoyo_alias_entry *entry =
+			tomoyo_commit_ok(&e, sizeof(e));
+		if (entry) {
+			list_add_tail_rcu(&entry->list, &tomoyo_alias_list);
+			error = 0;
+		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
  out:
-	tomoyo_put_name(saved_original_name);
-	tomoyo_put_name(saved_aliased_name);
-	kfree(entry);
+	tomoyo_put_name(e.original_name);
+	tomoyo_put_name(e.aliased_name);
 	return error;
 }