Commit f9732ea1 authored by Tetsuo Handa's avatar Tetsuo Handa Committed by James Morris
Browse files

TOMOYO: Simplify garbage collector. 



When TOMOYO started using garbage collector at commit 847b173e "TOMOYO: Add
garbage collector.", we waited for close() before kfree(). Thus, elements to be
kfree()d were queued up using tomoyo_gc_list list.

But it turned out that tomoyo_element_linked_by_gc() tends to choke garbage
collector when certain pattern of entries are queued.

Since garbage collector is no longer waiting for close() since commit 2e503bbb
"TOMOYO: Fix lockdep warning.", we can remove tomoyo_gc_list list and
tomoyo_element_linked_by_gc() by doing sequential processing.

Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
parent 778c4a4d

security/tomoyo/common.h

+5 −2
Original line number Diff line number Diff line
@@ -52,6 +52,9 @@ 


#define TOMOYO_EXEC_TMPSIZE     4096



/* Garbage collector is trying to kfree() this element. */

#define TOMOYO_GC_IN_PROGRESS -1



/* Profile number is an integer between 0 and 255. */

#define TOMOYO_MAX_PROFILES 256
@@ -398,7 +401,7 @@ enum tomoyo_pref_index { 
/* Common header for holding ACL entries. */

struct tomoyo_acl_head {

	struct list_head list;

	bool is_deleted;

	s8 is_deleted; /* true or false or TOMOYO_GC_IN_PROGRESS */

} __packed;



/* Common header for shared entries. */
@@ -665,7 +668,7 @@ struct tomoyo_condition { 
struct tomoyo_acl_info {

	struct list_head list;

	struct tomoyo_condition *cond; /* Maybe NULL. */

	bool is_deleted;

	s8 is_deleted; /* true or false or TOMOYO_GC_IN_PROGRESS */

	u8 type; /* One of values in "enum tomoyo_acl_entry_type_index". */

} __packed;

security/tomoyo/condition.c

+4 −4
Original line number Diff line number Diff line
@@ -400,8 +400,9 @@ static struct tomoyo_condition *tomoyo_commit_condition 
		found = true;

		goto out;

	}

	list_for_each_entry_rcu(ptr, &tomoyo_condition_list, head.list) {

		if (!tomoyo_same_condition(ptr, entry))

	list_for_each_entry(ptr, &tomoyo_condition_list, head.list) {

		if (!tomoyo_same_condition(ptr, entry) ||

		    atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS)

			continue;

		/* Same entry found. Share this entry. */

		atomic_inc(&ptr->head.users);
@@ -411,8 +412,7 @@ static struct tomoyo_condition *tomoyo_commit_condition 
	if (!found) {

		if (tomoyo_memory_ok(entry)) {

			atomic_set(&entry->head.users, 1);

			list_add_rcu(&entry->head.list,

				     &tomoyo_condition_list);

			list_add(&entry->head.list, &tomoyo_condition_list);

		} else {

			found = true;

			ptr = NULL;

security/tomoyo/domain.c

+4 −0
Original line number Diff line number Diff line
@@ -39,6 +39,8 @@ int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size, 
	if (mutex_lock_interruptible(&tomoyo_policy_lock))

		return -ENOMEM;

	list_for_each_entry_rcu(entry, list, list) {

		if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)

			continue;

		if (!check_duplicate(entry, new_entry))

			continue;

		entry->is_deleted = param->is_delete;
@@ -115,6 +117,8 @@ int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size, 
	if (mutex_lock_interruptible(&tomoyo_policy_lock))

		goto out;

	list_for_each_entry_rcu(entry, list, list) {

		if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)

			continue;

		if (!tomoyo_same_acl_head(entry, new_entry) ||

		    !check_duplicate(entry, new_entry))

			continue;

security/tomoyo/gc.c

+169 −311

File changed.

Preview size limit exceeded, changes collapsed.

security/tomoyo/memory.c

+4 −2
Original line number Diff line number Diff line
@@ -123,7 +123,8 @@ struct tomoyo_group *tomoyo_get_group(struct tomoyo_acl_param *param, 
		goto out;

	list = &param->ns->group_list[idx];

	list_for_each_entry(group, list, head.list) {

		if (e.group_name != group->group_name)

		if (e.group_name != group->group_name ||

		    atomic_read(&group->head.users) == TOMOYO_GC_IN_PROGRESS)

			continue;

		atomic_inc(&group->head.users);

		found = true;
@@ -175,7 +176,8 @@ const struct tomoyo_path_info *tomoyo_get_name(const char *name) 
	if (mutex_lock_interruptible(&tomoyo_policy_lock))

		return NULL;

	list_for_each_entry(ptr, head, head.list) {

		if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name))

		if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name) ||

		    atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS)

			continue;

		atomic_inc(&ptr->head.users);

		goto out;

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