TOMOYO: Use RCU primitives for list operation
Replace list operation with RCU primitives and replace
down_read()/up_read() with srcu_read_lock()/srcu_read_unlock().
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index 6c60616..f01b936 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -365,10 +365,9 @@
*
* @domainname: The domainname to find.
*
- * Caller must call down_read(&tomoyo_domain_list_lock); or
- * down_write(&tomoyo_domain_list_lock); .
- *
* Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
{
@@ -377,7 +376,7 @@
name.name = domainname;
tomoyo_fill_path_info(&name);
- list_for_each_entry(domain, &tomoyo_domain_list, list) {
+ list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
if (!domain->is_deleted &&
!tomoyo_pathcmp(&name, domain->domainname))
return domain;
@@ -829,6 +828,8 @@
* @domain: Pointer to "struct tomoyo_domain_info".
*
* Returns true if the domain is not exceeded quota, false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
{
@@ -837,8 +838,7 @@
if (!domain)
return true;
- down_read(&tomoyo_domain_acl_info_list_lock);
- list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
if (ptr->type & TOMOYO_ACL_DELETED)
continue;
switch (tomoyo_acl_type2(ptr)) {
@@ -866,7 +866,6 @@
break;
}
}
- up_read(&tomoyo_domain_acl_info_list_lock);
if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
return true;
if (!domain->quota_warned) {
@@ -1096,6 +1095,8 @@
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_update_manager_entry(const char *manager,
const bool is_delete)
@@ -1118,7 +1119,7 @@
if (!saved_manager)
return -ENOMEM;
down_write(&tomoyo_policy_manager_list_lock);
- list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
+ list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
if (ptr->manager != saved_manager)
continue;
ptr->is_deleted = is_delete;
@@ -1134,7 +1135,7 @@
goto out;
new_entry->manager = saved_manager;
new_entry->is_domain = is_domain;
- list_add_tail(&new_entry->list, &tomoyo_policy_manager_list);
+ list_add_tail_rcu(&new_entry->list, &tomoyo_policy_manager_list);
error = 0;
out:
up_write(&tomoyo_policy_manager_list_lock);
@@ -1147,6 +1148,8 @@
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
{
@@ -1166,6 +1169,8 @@
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns 0.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
{
@@ -1174,7 +1179,6 @@
if (head->read_eof)
return 0;
- down_read(&tomoyo_policy_manager_list_lock);
list_for_each_cookie(pos, head->read_var2,
&tomoyo_policy_manager_list) {
struct tomoyo_policy_manager_entry *ptr;
@@ -1186,7 +1190,6 @@
if (!done)
break;
}
- up_read(&tomoyo_policy_manager_list_lock);
head->read_eof = done;
return 0;
}
@@ -1196,6 +1199,8 @@
*
* Returns true if the current process is permitted to modify policy
* via /sys/kernel/security/tomoyo/ interface.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static bool tomoyo_is_policy_manager(void)
{
@@ -1209,29 +1214,25 @@
return true;
if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
return false;
- down_read(&tomoyo_policy_manager_list_lock);
- list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
+ list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
if (!ptr->is_deleted && ptr->is_domain
&& !tomoyo_pathcmp(domainname, ptr->manager)) {
found = true;
break;
}
}
- up_read(&tomoyo_policy_manager_list_lock);
if (found)
return true;
exe = tomoyo_get_exe();
if (!exe)
return false;
- down_read(&tomoyo_policy_manager_list_lock);
- list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
+ list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
if (!ptr->is_deleted && !ptr->is_domain
&& !strcmp(exe, ptr->manager->name)) {
found = true;
break;
}
}
- up_read(&tomoyo_policy_manager_list_lock);
if (!found) { /* Reduce error messages. */
static pid_t last_pid;
const pid_t pid = current->pid;
@@ -1252,6 +1253,8 @@
* @data: String to parse.
*
* Returns true on success, false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
const char *data)
@@ -1267,11 +1270,8 @@
domain = tomoyo_real_domain(p);
read_unlock(&tasklist_lock);
} else if (!strncmp(data, "domain=", 7)) {
- if (tomoyo_is_domain_def(data + 7)) {
- down_read(&tomoyo_domain_list_lock);
+ if (tomoyo_is_domain_def(data + 7))
domain = tomoyo_find_domain(data + 7);
- up_read(&tomoyo_domain_list_lock);
- }
} else
return false;
head->write_var1 = domain;
@@ -1285,13 +1285,11 @@
if (domain) {
struct tomoyo_domain_info *d;
head->read_var1 = NULL;
- down_read(&tomoyo_domain_list_lock);
- list_for_each_entry(d, &tomoyo_domain_list, list) {
+ list_for_each_entry_rcu(d, &tomoyo_domain_list, list) {
if (d == domain)
break;
head->read_var1 = &d->list;
}
- up_read(&tomoyo_domain_list_lock);
head->read_var2 = NULL;
head->read_bit = 0;
head->read_step = 0;
@@ -1307,6 +1305,8 @@
* @domainname: The name of domain.
*
* Returns 0.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_delete_domain(char *domainname)
{
@@ -1317,7 +1317,7 @@
tomoyo_fill_path_info(&name);
down_write(&tomoyo_domain_list_lock);
/* Is there an active domain? */
- list_for_each_entry(domain, &tomoyo_domain_list, list) {
+ list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
/* Never delete tomoyo_kernel_domain */
if (domain == &tomoyo_kernel_domain)
continue;
@@ -1337,6 +1337,8 @@
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
{
@@ -1359,11 +1361,9 @@
domain = NULL;
if (is_delete)
tomoyo_delete_domain(data);
- else if (is_select) {
- down_read(&tomoyo_domain_list_lock);
+ else if (is_select)
domain = tomoyo_find_domain(data);
- up_read(&tomoyo_domain_list_lock);
- } else
+ else
domain = tomoyo_find_or_assign_new_domain(data, 0);
head->write_var1 = domain;
return 0;
@@ -1508,6 +1508,8 @@
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns 0.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
{
@@ -1519,7 +1521,6 @@
return 0;
if (head->read_step == 0)
head->read_step = 1;
- down_read(&tomoyo_domain_list_lock);
list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
struct tomoyo_domain_info *domain;
const char *quota_exceeded = "";
@@ -1552,7 +1553,6 @@
if (head->read_step == 3)
goto tail_mark;
/* Print ACL entries in the domain. */
- down_read(&tomoyo_domain_acl_info_list_lock);
list_for_each_cookie(apos, head->read_var2,
&domain->acl_info_list) {
struct tomoyo_acl_info *ptr
@@ -1562,7 +1562,6 @@
if (!done)
break;
}
- up_read(&tomoyo_domain_acl_info_list_lock);
if (!done)
break;
head->read_step = 3;
@@ -1574,7 +1573,6 @@
if (head->read_single_domain)
break;
}
- up_read(&tomoyo_domain_list_lock);
head->read_eof = done;
return 0;
}
@@ -1590,6 +1588,8 @@
*
* ( echo "select " $domainname; echo "use_profile " $profile ) |
* /usr/lib/ccs/loadpolicy -d
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
{
@@ -1601,9 +1601,7 @@
if (!cp)
return -EINVAL;
*cp = '\0';
- down_read(&tomoyo_domain_list_lock);
domain = tomoyo_find_domain(cp + 1);
- up_read(&tomoyo_domain_list_lock);
if (strict_strtoul(data, 10, &profile))
return -EINVAL;
if (domain && profile < TOMOYO_MAX_PROFILES
@@ -1625,6 +1623,8 @@
* awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
* domainname = $0; } else if ( $1 == "use_profile" ) {
* print $2 " " domainname; domainname = ""; } } ; '
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
{
@@ -1633,7 +1633,6 @@
if (head->read_eof)
return 0;
- down_read(&tomoyo_domain_list_lock);
list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
struct tomoyo_domain_info *domain;
domain = list_entry(pos, struct tomoyo_domain_info, list);
@@ -1644,7 +1643,6 @@
if (!done)
break;
}
- up_read(&tomoyo_domain_list_lock);
head->read_eof = done;
return 0;
}
@@ -1701,6 +1699,8 @@
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
{
@@ -1735,6 +1735,8 @@
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns 0 on success, -EINVAL otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
{
@@ -1864,15 +1866,13 @@
tomoyo_policy_loaded = true;
{ /* Check all profiles currently assigned to domains are defined. */
struct tomoyo_domain_info *domain;
- down_read(&tomoyo_domain_list_lock);
- list_for_each_entry(domain, &tomoyo_domain_list, list) {
+ list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
const u8 profile = domain->profile;
if (tomoyo_profile_ptr[profile])
continue;
panic("Profile %u (used by '%s') not defined.\n",
profile, domain->domainname->name);
}
- up_read(&tomoyo_domain_list_lock);
}
}
@@ -1920,6 +1920,8 @@
* @file: Pointer to "struct file".
*
* Associates policy handler and returns 0 on success, -ENOMEM otherwise.
+ *
+ * Caller acquires tomoyo_read_lock().
*/
static int tomoyo_open_control(const u8 type, struct file *file)
{
@@ -2005,6 +2007,7 @@
return -ENOMEM;
}
}
+ head->reader_idx = tomoyo_read_lock();
file->private_data = head;
/*
* Call the handler now if the file is
@@ -2026,6 +2029,8 @@
* @buffer_len: Size of @buffer.
*
* Returns bytes read on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_read_control(struct file *file, char __user *buffer,
const int buffer_len)
@@ -2069,6 +2074,8 @@
* @buffer_len: Size of @buffer.
*
* Returns @buffer_len on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_write_control(struct file *file, const char __user *buffer,
const int buffer_len)
@@ -2119,11 +2126,14 @@
* @file: Pointer to "struct file".
*
* Releases memory and returns 0.
+ *
+ * Caller looses tomoyo_read_lock().
*/
static int tomoyo_close_control(struct file *file)
{
struct tomoyo_io_buffer *head = file->private_data;
+ tomoyo_read_unlock(head->reader_idx);
/* Release memory used for policy I/O. */
tomoyo_free(head->read_buf);
head->read_buf = NULL;