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/file.c b/security/tomoyo/file.c
index 482f0e7..3c47286 100644
--- a/security/tomoyo/file.c
+++ b/security/tomoyo/file.c
@@ -213,6 +213,8 @@
* @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_globally_readable_entry(const char *filename,
const bool is_delete)
@@ -228,7 +230,7 @@
if (!saved_filename)
return -ENOMEM;
down_write(&tomoyo_globally_readable_list_lock);
- list_for_each_entry(ptr, &tomoyo_globally_readable_list, list) {
+ list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list, list) {
if (ptr->filename != saved_filename)
continue;
ptr->is_deleted = is_delete;
@@ -243,7 +245,7 @@
if (!new_entry)
goto out;
new_entry->filename = saved_filename;
- list_add_tail(&new_entry->list, &tomoyo_globally_readable_list);
+ list_add_tail_rcu(&new_entry->list, &tomoyo_globally_readable_list);
error = 0;
out:
up_write(&tomoyo_globally_readable_list_lock);
@@ -256,21 +258,22 @@
* @filename: The filename to check.
*
* Returns true if any domain can open @filename for reading, false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static bool tomoyo_is_globally_readable_file(const struct tomoyo_path_info *
filename)
{
struct tomoyo_globally_readable_file_entry *ptr;
bool found = false;
- down_read(&tomoyo_globally_readable_list_lock);
- list_for_each_entry(ptr, &tomoyo_globally_readable_list, list) {
+
+ list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list, list) {
if (!ptr->is_deleted &&
tomoyo_path_matches_pattern(filename, ptr->filename)) {
found = true;
break;
}
}
- up_read(&tomoyo_globally_readable_list_lock);
return found;
}
@@ -281,6 +284,8 @@
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
int tomoyo_write_globally_readable_policy(char *data, const bool is_delete)
{
@@ -293,13 +298,14 @@
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns true on success, false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head)
{
struct list_head *pos;
bool done = true;
- down_read(&tomoyo_globally_readable_list_lock);
list_for_each_cookie(pos, head->read_var2,
&tomoyo_globally_readable_list) {
struct tomoyo_globally_readable_file_entry *ptr;
@@ -313,7 +319,6 @@
if (!done)
break;
}
- up_read(&tomoyo_globally_readable_list_lock);
return done;
}
@@ -356,6 +361,8 @@
* @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_file_pattern_entry(const char *pattern,
const bool is_delete)
@@ -371,7 +378,7 @@
if (!saved_pattern)
return -ENOMEM;
down_write(&tomoyo_pattern_list_lock);
- list_for_each_entry(ptr, &tomoyo_pattern_list, list) {
+ list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) {
if (saved_pattern != ptr->pattern)
continue;
ptr->is_deleted = is_delete;
@@ -386,7 +393,7 @@
if (!new_entry)
goto out;
new_entry->pattern = saved_pattern;
- list_add_tail(&new_entry->list, &tomoyo_pattern_list);
+ list_add_tail_rcu(&new_entry->list, &tomoyo_pattern_list);
error = 0;
out:
up_write(&tomoyo_pattern_list_lock);
@@ -399,6 +406,8 @@
* @filename: The filename to find patterned pathname.
*
* Returns pointer to pathname pattern if matched, @filename otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static const struct tomoyo_path_info *
tomoyo_get_file_pattern(const struct tomoyo_path_info *filename)
@@ -406,8 +415,7 @@
struct tomoyo_pattern_entry *ptr;
const struct tomoyo_path_info *pattern = NULL;
- down_read(&tomoyo_pattern_list_lock);
- list_for_each_entry(ptr, &tomoyo_pattern_list, list) {
+ list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) {
if (ptr->is_deleted)
continue;
if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
@@ -420,7 +428,6 @@
break;
}
}
- up_read(&tomoyo_pattern_list_lock);
if (pattern)
filename = pattern;
return filename;
@@ -433,6 +440,8 @@
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
int tomoyo_write_pattern_policy(char *data, const bool is_delete)
{
@@ -445,13 +454,14 @@
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns true on success, false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head)
{
struct list_head *pos;
bool done = true;
- down_read(&tomoyo_pattern_list_lock);
list_for_each_cookie(pos, head->read_var2, &tomoyo_pattern_list) {
struct tomoyo_pattern_entry *ptr;
ptr = list_entry(pos, struct tomoyo_pattern_entry, list);
@@ -462,7 +472,6 @@
if (!done)
break;
}
- up_read(&tomoyo_pattern_list_lock);
return done;
}
@@ -505,6 +514,8 @@
* @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_no_rewrite_entry(const char *pattern,
const bool is_delete)
@@ -519,7 +530,7 @@
if (!saved_pattern)
return -ENOMEM;
down_write(&tomoyo_no_rewrite_list_lock);
- list_for_each_entry(ptr, &tomoyo_no_rewrite_list, list) {
+ list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) {
if (ptr->pattern != saved_pattern)
continue;
ptr->is_deleted = is_delete;
@@ -534,7 +545,7 @@
if (!new_entry)
goto out;
new_entry->pattern = saved_pattern;
- list_add_tail(&new_entry->list, &tomoyo_no_rewrite_list);
+ list_add_tail_rcu(&new_entry->list, &tomoyo_no_rewrite_list);
error = 0;
out:
up_write(&tomoyo_no_rewrite_list_lock);
@@ -548,14 +559,15 @@
*
* Returns true if @filename is specified by "deny_rewrite" directive,
* false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static bool tomoyo_is_no_rewrite_file(const struct tomoyo_path_info *filename)
{
struct tomoyo_no_rewrite_entry *ptr;
bool found = false;
- down_read(&tomoyo_no_rewrite_list_lock);
- list_for_each_entry(ptr, &tomoyo_no_rewrite_list, list) {
+ list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) {
if (ptr->is_deleted)
continue;
if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
@@ -563,7 +575,6 @@
found = true;
break;
}
- up_read(&tomoyo_no_rewrite_list_lock);
return found;
}
@@ -574,6 +585,8 @@
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
int tomoyo_write_no_rewrite_policy(char *data, const bool is_delete)
{
@@ -586,13 +599,14 @@
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns true on success, false otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
bool tomoyo_read_no_rewrite_policy(struct tomoyo_io_buffer *head)
{
struct list_head *pos;
bool done = true;
- down_read(&tomoyo_no_rewrite_list_lock);
list_for_each_cookie(pos, head->read_var2, &tomoyo_no_rewrite_list) {
struct tomoyo_no_rewrite_entry *ptr;
ptr = list_entry(pos, struct tomoyo_no_rewrite_entry, list);
@@ -603,7 +617,6 @@
if (!done)
break;
}
- up_read(&tomoyo_no_rewrite_list_lock);
return done;
}
@@ -621,6 +634,8 @@
* Current policy syntax uses "allow_read/write" instead of "6",
* "allow_read" instead of "4", "allow_write" instead of "2",
* "allow_execute" instead of "1".
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_update_file_acl(const char *filename, u8 perm,
struct tomoyo_domain_info * const domain,
@@ -658,6 +673,8 @@
* @may_use_pattern: True if patterned ACL is permitted.
*
* Returns 0 on success, -EPERM otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_check_single_path_acl2(const struct tomoyo_domain_info *
domain,
@@ -669,8 +686,7 @@
struct tomoyo_acl_info *ptr;
int error = -EPERM;
- 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) {
struct tomoyo_single_path_acl_record *acl;
if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_SINGLE_PATH_ACL)
continue;
@@ -693,7 +709,6 @@
error = 0;
break;
}
- up_read(&tomoyo_domain_acl_info_list_lock);
return error;
}
@@ -705,6 +720,8 @@
* @operation: Mode ("read" or "write" or "read/write" or "execute").
*
* Returns 0 on success, -EPERM otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_check_file_acl(const struct tomoyo_domain_info *domain,
const struct tomoyo_path_info *filename,
@@ -738,6 +755,8 @@
* @mode: Access control mode.
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_check_file_perm2(struct tomoyo_domain_info * const domain,
const struct tomoyo_path_info *filename,
@@ -791,6 +810,8 @@
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
int tomoyo_write_file_policy(char *data, struct tomoyo_domain_info *domain,
const bool is_delete)
@@ -838,6 +859,8 @@
* @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_single_path_acl(const u8 type, const char *filename,
struct tomoyo_domain_info *
@@ -861,7 +884,7 @@
down_write(&tomoyo_domain_acl_info_list_lock);
if (is_delete)
goto delete;
- list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
if (tomoyo_acl_type1(ptr) != TOMOYO_TYPE_SINGLE_PATH_ACL)
continue;
acl = container_of(ptr, struct tomoyo_single_path_acl_record,
@@ -894,12 +917,12 @@
if (perm == (1 << TOMOYO_TYPE_READ_WRITE_ACL))
acl->perm |= rw_mask;
acl->filename = saved_filename;
- list_add_tail(&acl->head.list, &domain->acl_info_list);
+ list_add_tail_rcu(&acl->head.list, &domain->acl_info_list);
error = 0;
goto out;
delete:
error = -ENOENT;
- list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_SINGLE_PATH_ACL)
continue;
acl = container_of(ptr, struct tomoyo_single_path_acl_record,
@@ -934,6 +957,8 @@
* @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_double_path_acl(const u8 type, const char *filename1,
const char *filename2,
@@ -959,7 +984,7 @@
down_write(&tomoyo_domain_acl_info_list_lock);
if (is_delete)
goto delete;
- list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
if (tomoyo_acl_type1(ptr) != TOMOYO_TYPE_DOUBLE_PATH_ACL)
continue;
acl = container_of(ptr, struct tomoyo_double_path_acl_record,
@@ -982,12 +1007,12 @@
acl->perm = perm;
acl->filename1 = saved_filename1;
acl->filename2 = saved_filename2;
- list_add_tail(&acl->head.list, &domain->acl_info_list);
+ list_add_tail_rcu(&acl->head.list, &domain->acl_info_list);
error = 0;
goto out;
delete:
error = -ENOENT;
- list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_DOUBLE_PATH_ACL)
continue;
acl = container_of(ptr, struct tomoyo_double_path_acl_record,
@@ -1014,6 +1039,8 @@
* @filename: Filename to check.
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_check_single_path_acl(struct tomoyo_domain_info *domain,
const u8 type,
@@ -1033,6 +1060,8 @@
* @filename2: Second filename to check.
*
* Returns 0 on success, -EPERM otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_check_double_path_acl(const struct tomoyo_domain_info *domain,
const u8 type,
@@ -1047,8 +1076,7 @@
if (!tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE))
return 0;
- 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) {
struct tomoyo_double_path_acl_record *acl;
if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_DOUBLE_PATH_ACL)
continue;
@@ -1063,7 +1091,6 @@
error = 0;
break;
}
- up_read(&tomoyo_domain_acl_info_list_lock);
return error;
}
@@ -1076,6 +1103,8 @@
* @mode: Access control mode.
*
* Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
static int tomoyo_check_single_path_permission2(struct tomoyo_domain_info *
const domain, u8 operation,
@@ -1124,6 +1153,8 @@
* @filename: Check permission for "execute".
*
* Returns 0 on success, negativevalue otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
*/
int tomoyo_check_exec_perm(struct tomoyo_domain_info *domain,
const struct tomoyo_path_info *filename)
@@ -1152,6 +1183,7 @@
struct tomoyo_path_info *buf;
const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
const bool is_enforce = (mode == 3);
+ int idx;
if (!mode || !path->mnt)
return 0;
@@ -1163,6 +1195,7 @@
* don't call me.
*/
return 0;
+ idx = tomoyo_read_lock();
buf = tomoyo_get_path(path);
if (!buf)
goto out;
@@ -1188,6 +1221,7 @@
buf, mode);
out:
tomoyo_free(buf);
+ tomoyo_read_unlock(idx);
if (!is_enforce)
error = 0;
return error;
@@ -1209,9 +1243,11 @@
struct tomoyo_path_info *buf;
const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
const bool is_enforce = (mode == 3);
+ int idx;
if (!mode || !path->mnt)
return 0;
+ idx = tomoyo_read_lock();
buf = tomoyo_get_path(path);
if (!buf)
goto out;
@@ -1231,6 +1267,7 @@
mode);
out:
tomoyo_free(buf);
+ tomoyo_read_unlock(idx);
if (!is_enforce)
error = 0;
return error;
@@ -1251,9 +1288,12 @@
const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
const bool is_enforce = (mode == 3);
struct tomoyo_path_info *buf;
+ int idx;
if (!mode || !filp->f_path.mnt)
return 0;
+
+ idx = tomoyo_read_lock();
buf = tomoyo_get_path(&filp->f_path);
if (!buf)
goto out;
@@ -1266,6 +1306,7 @@
buf, mode);
out:
tomoyo_free(buf);
+ tomoyo_read_unlock(idx);
if (!is_enforce)
error = 0;
return error;
@@ -1290,9 +1331,11 @@
const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
const bool is_enforce = (mode == 3);
const char *msg;
+ int idx;
if (!mode || !path1->mnt || !path2->mnt)
return 0;
+ idx = tomoyo_read_lock();
buf1 = tomoyo_get_path(path1);
buf2 = tomoyo_get_path(path2);
if (!buf1 || !buf2)
@@ -1331,6 +1374,7 @@
out:
tomoyo_free(buf1);
tomoyo_free(buf2);
+ tomoyo_read_unlock(idx);
if (!is_enforce)
error = 0;
return error;