TOMOYO: Replace rw_semaphore by mutex.

Since readers no longer use down_read(), writers no longer
need to use rw_semaphore. Replace individual rw_semaphore by
single mutex.

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>

1 files changed, 10 insertions, 16 deletions

diff --git a/security/tomoyo/file.c b/security/tomoyo/file.c
index 3c472867634f..5d1689d6e16c 100644
--- a/security/tomoyo/file.c
+++ b/security/tomoyo/file.c
@@ -167,9 +167,6 @@ static struct tomoyo_path_info *tomoyo_get_path(struct path *path)
         return NULL;
 }
 
-/* Lock for domain->acl_info_list. */
-DECLARE_RWSEM(tomoyo_domain_acl_info_list_lock);
-
 static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
                                          const char *filename2,
                                          struct tomoyo_domain_info *
@@ -204,7 +201,6 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
  * belongs to.
  */
 static LIST_HEAD(tomoyo_globally_readable_list);
-static DECLARE_RWSEM(tomoyo_globally_readable_list_lock);
 
 /**
  * tomoyo_update_globally_readable_entry - Update "struct tomoyo_globally_readable_file_entry" list.
@@ -229,7 +225,7 @@ static int tomoyo_update_globally_readable_entry(const char *filename,
         saved_filename = tomoyo_save_name(filename);
         if (!saved_filename)
                 return -ENOMEM;
-        down_write(&tomoyo_globally_readable_list_lock);
+        mutex_lock(&tomoyo_policy_lock);
         list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list, list) {
                 if (ptr->filename != saved_filename)
                         continue;
@@ -248,7 +244,7 @@ static int tomoyo_update_globally_readable_entry(const char *filename,
         list_add_tail_rcu(&new_entry->list, &tomoyo_globally_readable_list);
         error = 0;
  out:
-        up_write(&tomoyo_globally_readable_list_lock);
+        mutex_unlock(&tomoyo_policy_lock);
         return error;
 }
 
@@ -352,7 +348,6 @@ bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head)
  * current process from accessing other process's information.
  */
 static LIST_HEAD(tomoyo_pattern_list);
-static DECLARE_RWSEM(tomoyo_pattern_list_lock);
 
 /**
  * tomoyo_update_file_pattern_entry - Update "struct tomoyo_pattern_entry" list.
@@ -377,7 +372,7 @@ static int tomoyo_update_file_pattern_entry(const char *pattern,
         saved_pattern = tomoyo_save_name(pattern);
         if (!saved_pattern)
                 return -ENOMEM;
-        down_write(&tomoyo_pattern_list_lock);
+        mutex_lock(&tomoyo_policy_lock);
         list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) {
                 if (saved_pattern != ptr->pattern)
                         continue;
@@ -396,7 +391,7 @@ static int tomoyo_update_file_pattern_entry(const char *pattern,
         list_add_tail_rcu(&new_entry->list, &tomoyo_pattern_list);
         error = 0;
  out:
-        up_write(&tomoyo_pattern_list_lock);
+        mutex_unlock(&tomoyo_policy_lock);
         return error;
 }
 
@@ -505,7 +500,6 @@ bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head)
  * need to worry whether the file is already unlink()ed or not.
  */
 static LIST_HEAD(tomoyo_no_rewrite_list);
-static DECLARE_RWSEM(tomoyo_no_rewrite_list_lock);
 
 /**
  * tomoyo_update_no_rewrite_entry - Update "struct tomoyo_no_rewrite_entry" list.
@@ -529,7 +523,7 @@ static int tomoyo_update_no_rewrite_entry(const char *pattern,
         saved_pattern = tomoyo_save_name(pattern);
         if (!saved_pattern)
                 return -ENOMEM;
-        down_write(&tomoyo_no_rewrite_list_lock);
+        mutex_lock(&tomoyo_policy_lock);
         list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) {
                 if (ptr->pattern != saved_pattern)
                         continue;
@@ -548,7 +542,7 @@ static int tomoyo_update_no_rewrite_entry(const char *pattern,
         list_add_tail_rcu(&new_entry->list, &tomoyo_no_rewrite_list);
         error = 0;
  out:
-        up_write(&tomoyo_no_rewrite_list_lock);
+        mutex_unlock(&tomoyo_policy_lock);
         return error;
 }
 
@@ -881,7 +875,7 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
         saved_filename = tomoyo_save_name(filename);
         if (!saved_filename)
                 return -ENOMEM;
-        down_write(&tomoyo_domain_acl_info_list_lock);
+        mutex_lock(&tomoyo_policy_lock);
         if (is_delete)
                 goto delete;
         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
@@ -943,7 +937,7 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
                 break;
         }
  out:
-        up_write(&tomoyo_domain_acl_info_list_lock);
+        mutex_unlock(&tomoyo_policy_lock);
         return error;
 }
 
@@ -981,7 +975,7 @@ static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
         saved_filename2 = tomoyo_save_name(filename2);
         if (!saved_filename1 || !saved_filename2)
                 return -ENOMEM;
-        down_write(&tomoyo_domain_acl_info_list_lock);
+        mutex_lock(&tomoyo_policy_lock);
         if (is_delete)
                 goto delete;
         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
@@ -1027,7 +1021,7 @@ static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
                 break;
         }
  out:
-        up_write(&tomoyo_domain_acl_info_list_lock);
+        mutex_unlock(&tomoyo_policy_lock);
         return error;
 }