提交 f9732ea1 编写于 作者: T Tetsuo Handa 提交者: James Morris

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: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NJames Morris <jmorris@namei.org>
上级 778c4a4d
......@@ -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;
......
......@@ -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;
......
......@@ -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;
......
此差异已折叠。
......@@ -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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