Backport from 6.0-codebase.

Bug #36098 Audit plugin (wl 3771) feature disabled in 6.0
avoid recusrive locking of LOCK_plugin

include/mysql/plugin_audit.h:
  fix incorrect version
sql/log.cc:
  move the common code to a shared header
sql/mysqld.cc:
  restore the deleted functionality
sql/set_var.cc:
  remove unused parameter
sql/sql_audit.h:
  two inline convenience functions
sql/sql_parse.cc:
  use a simplified convenience call
sql/sql_plugin.cc:
  unlock LOCK_plugin for plugin->init() call, add missing OOM check,
  issue "unknown variable" error in find_sys_var, not down the stack

6 files changed, 95 insertions, 62 deletions

diff --git a/sql/log.cc b/sql/log.cc
index ce309a0d1b2..267ca90db29 100644
--- a/sql/log.cc
+++ b/sql/log.cc
@@ -43,7 +43,6 @@
 
 /* max size of the log message */
 #define MAX_LOG_BUFFER_SIZE 1024
-#define MAX_USER_HOST_SIZE 512
 #define MAX_TIME_SIZE 32
 #define MY_OFF_T_UNDEF (~(my_off_t)0UL)
 
@@ -1069,7 +1068,6 @@ bool LOGGER::general_log_write(THD *thd, enum enum_server_command command,
   bool error= FALSE;
   Log_event_handler **current_handler= general_log_handler_list;
   char user_host_buff[MAX_USER_HOST_SIZE + 1];
-  Security_context *sctx= thd->security_ctx;
   uint user_host_len= 0;
   time_t current_time;
 
@@ -1081,21 +1079,15 @@ bool LOGGER::general_log_write(THD *thd, enum enum_server_command command,
     unlock();
     return 0;
   }
-  user_host_len= strxnmov(user_host_buff, MAX_USER_HOST_SIZE,
-                          sctx->priv_user ? sctx->priv_user : "", "[",
-                          sctx->user ? sctx->user : "", "] @ ",
-                          sctx->host ? sctx->host : "", " [",
-                          sctx->ip ? sctx->ip : "", "]", NullS) -
-                                                          user_host_buff;
+  user_host_len= make_user_name(thd, user_host_buff);
 
   current_time= my_time(0);
 
-  mysql_audit_general(thd, MYSQL_AUDIT_GENERAL_LOG, 0, current_time,
-                      user_host_buff, user_host_len,
-                      command_name[(uint) command].str,
-                      command_name[(uint) command].length,
-                      query, query_length,
-                      thd->variables.character_set_client,0);
+  mysql_audit_general_log(thd, current_time,
+                          user_host_buff, user_host_len,
+                          command_name[(uint) command].str,
+                          command_name[(uint) command].length,
+                          query, query_length);
                         
   while (*current_handler)
     error|= (*current_handler++)->
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 6803e0ef8a9..860dc0389d0 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -2923,15 +2923,10 @@ void my_message_sql(uint error, const char *str, myf MyFlags)
     error= ER_UNKNOWN_ERROR;
   }
 
+  mysql_audit_general(thd, MYSQL_AUDIT_GENERAL_ERROR, error, str);
+
   if (thd)
   {
-    mysql_audit_general(thd,MYSQL_AUDIT_GENERAL_ERROR,error,my_time(0),
-                        0,0,str,str ? strlen(str) : 0,
-                        thd->query(), thd->query_length(),
-                        thd->variables.character_set_client,
-                        thd->warning_info->current_row_for_warning());
-
-
     if (MyFlags & ME_FATALERROR)
       thd->is_fatal_error= 1;
     (void) thd->raise_condition(error,
diff --git a/sql/set_var.cc b/sql/set_var.cc
index 7a0325c3e68..86b1ef21032 100644
--- a/sql/set_var.cc
+++ b/sql/set_var.cc
@@ -3519,7 +3519,6 @@ void set_var_free()
   @param str	   Name of system variable to find
   @param length    Length of variable.  zero means that we should use strlen()
                    on the variable
-  @param no_error  Refuse to emit an error, even if one occurred.
 
   @retval
     pointer	pointer to variable definitions
@@ -3527,7 +3526,7 @@ void set_var_free()
     0		Unknown variable (error message is given)
 */
 
-sys_var *intern_find_sys_var(const char *str, uint length, bool no_error)
+sys_var *intern_find_sys_var(const char *str, uint length)
 {
   sys_var *var;
 
@@ -3537,9 +3536,6 @@ sys_var *intern_find_sys_var(const char *str, uint length, bool no_error)
   */
   var= (sys_var*) my_hash_search(&system_variable_hash,
 			      (uchar*) str, length ? length : strlen(str));
-  if (!(var || no_error))
-    my_error(ER_UNKNOWN_SYSTEM_VARIABLE, MYF(0), (char*) str);
-
   return var;
 }
 
diff --git a/sql/sql_audit.h b/sql/sql_audit.h
index 155211e7ba5..c25011d0d59 100644
--- a/sql/sql_audit.h
+++ b/sql/sql_audit.h
@@ -34,18 +34,21 @@ extern void mysql_audit_notify(THD *thd, uint event_class,
                                uint event_subtype, ...);
 extern void mysql_audit_release(THD *thd);
 
-
+#define MAX_USER_HOST_SIZE 512
+static inline uint make_user_name(THD *thd, char *buf)
+{
+  Security_context *sctx= thd->security_ctx;
+  return strxnmov(buf, MAX_USER_HOST_SIZE,
+                  sctx->priv_user ? sctx->priv_user : "", "[",
+                  sctx->user ? sctx->user : "", "] @ ",
+                  sctx->host ? sctx->host : "", " [",
+                  sctx->ip ? sctx->ip : "", "]", NullS) - buf;
+}
 
 /**
-  Call audit plugins of GENERAL audit class.
-  event_subtype should be set to one of:
-    MYSQL_AUDIT_GENERAL_LOG
-    MYSQL_AUDIT_GENERAL_ERROR
-    MYSQL_AUDIT_GENERAL_RESULT
+  Call audit plugins of GENERAL audit class, MYSQL_AUDIT_GENERAL_LOG subtype.
   
   @param[in] thd
-  @param[in] event_subtype    Type of general audit event.
-  @param[in] error_code       Error code
   @param[in] time             time that event occurred
   @param[in] user             User name
   @param[in] userlen          User name length
@@ -53,24 +56,74 @@ extern void mysql_audit_release(THD *thd);
   @param[in] cmdlen           Command name length
   @param[in] query            Query string
   @param[in] querylen         Query string length
-  @param[in] clientcs         Charset of query string
-  @param[in] rows             Number of affected rows
 */
  
 static inline
+void mysql_audit_general_log(THD *thd, time_t time,
+                             const char *user, uint userlen,
+                             const char *cmd, uint cmdlen,
+                             const char *query, uint querylen)
+{
+#ifndef EMBEDDED_LIBRARY
+  if (mysql_global_audit_mask[0] & MYSQL_AUDIT_GENERAL_CLASSMASK)
+  {
+    CHARSET_INFO *clientcs= thd ? thd->variables.character_set_client
+                                : global_system_variables.character_set_client;
+
+    mysql_audit_notify(thd, MYSQL_AUDIT_GENERAL_CLASS, MYSQL_AUDIT_GENERAL_LOG,
+                       0, time, user, userlen, cmd, cmdlen,
+                       query, querylen, clientcs, 0);
+  }
+#endif
+}
+
+/**
+  Call audit plugins of GENERAL audit class.
+  event_subtype should be set to one of:
+    MYSQL_AUDIT_GENERAL_ERROR
+    MYSQL_AUDIT_GENERAL_RESULT
+  
+  @param[in] thd
+  @param[in] event_subtype    Type of general audit event.
+  @param[in] error_code       Error code
+  @param[in] msg              Message
+*/
+static inline
 void mysql_audit_general(THD *thd, uint event_subtype,
-                         int error_code, time_t time,
-                         const char *user, uint userlen,
-                         const char *cmd, uint cmdlen,
-                         const char *query, uint querylen,
-                         CHARSET_INFO *clientcs,
-                         ha_rows rows)
+                         int error_code, const char *msg)
 {
 #ifndef EMBEDDED_LIBRARY
   if (mysql_global_audit_mask[0] & MYSQL_AUDIT_GENERAL_CLASSMASK)
+  {
+    time_t time= my_time(0);
+    uint msglen= msg ? strlen(msg) : 0;
+    const char *query, *user;
+    uint querylen, userlen;
+    char user_buff[MAX_USER_HOST_SIZE];
+    CHARSET_INFO *clientcs;
+    ha_rows rows;
+
+    if (thd)
+    {
+      query= thd->query();
+      querylen= thd->query_length();
+      user= user_buff;
+      userlen= make_user_name(thd, user_buff);
+      clientcs= thd->variables.character_set_client;
+      rows= thd->warning_info->current_row_for_warning();
+    }
+    else
+    {
+      query= user= 0;
+      querylen= userlen= 0;
+      clientcs= global_system_variables.character_set_client;
+      rows= 0;
+    }
+
     mysql_audit_notify(thd, MYSQL_AUDIT_GENERAL_CLASS, event_subtype,
-                       error_code, time, user, userlen, cmd, cmdlen,
+                       error_code, time, user, userlen, msg, msglen,
                        query, querylen, clientcs, rows);
+  }
 #endif
 }
 
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 9328b29f182..eeaefde6588 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -1485,13 +1485,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
   close_thread_tables(thd);
 
   if (!thd->is_error() && !thd->killed_errno())
-  {
-    mysql_audit_general(thd,MYSQL_AUDIT_GENERAL_RESULT,0,my_time(0),
-                        0,0,0,0,
-                        thd->query(), thd->query_length(),
-                        thd->variables.character_set_client,
-                        thd->warning_info->current_row_for_warning());
-  }
+    mysql_audit_general(thd, MYSQL_AUDIT_GENERAL_RESULT, 0, 0);
 
   log_slow_statement(thd);
 
diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
index bcaeb452894..9e8b8785d5a 100644
--- a/sql/sql_plugin.cc
+++ b/sql/sql_plugin.cc
@@ -229,7 +229,7 @@ static void reap_plugins(void);
 
 
 /* declared in set_var.cc */
-extern sys_var *intern_find_sys_var(const char *str, uint length, bool no_error);
+extern sys_var *intern_find_sys_var(const char *str, uint length);
 extern bool throw_bounds_warning(THD *thd, bool fixed, bool unsignd,
                                  const char *name, longlong val);
 
@@ -1014,6 +1014,9 @@ static int plugin_initialize(struct st_plugin_int *plugin)
   DBUG_ENTER("plugin_initialize");
 
   safe_mutex_assert_owner(&LOCK_plugin);
+  DBUG_ASSERT(plugin->state == PLUGIN_IS_UNINITIALIZED);
+
+  pthread_mutex_unlock(&LOCK_plugin);
   if (plugin_type_initialize[plugin->plugin->type])
   {
     if ((*plugin_type_initialize[plugin->plugin->type])(plugin))
@@ -1033,6 +1036,8 @@ static int plugin_initialize(struct st_plugin_int *plugin)
     }
   }
 
+  pthread_mutex_lock(&LOCK_plugin);
+
   plugin->state= PLUGIN_IS_READY;
 
   if (plugin->plugin->status_vars)
@@ -1050,9 +1055,10 @@ static int plugin_initialize(struct st_plugin_int *plugin)
       {0, 0, SHOW_UNDEF}
     };
     if (add_status_vars(array)) // add_status_vars makes a copy
-      goto err;
+      goto err1;
 #else
-    add_status_vars(plugin->plugin->status_vars); // add_status_vars makes a copy
+    if (add_status_vars(plugin->plugin->status_vars))
+      goto err1;
 #endif /* FIX_LATER */
   }
 
@@ -1074,6 +1080,8 @@ static int plugin_initialize(struct st_plugin_int *plugin)
 
   DBUG_RETURN(0);
 err:
+  pthread_mutex_lock(&LOCK_plugin);
+err1:
   DBUG_RETURN(1);
 }
 
@@ -1686,7 +1694,6 @@ bool mysql_install_plugin(THD *thd, const LEX_STRING *name, const LEX_STRING *dl
   }
   else
   {
-    DBUG_ASSERT(tmp->state == PLUGIN_IS_UNINITIALIZED);
     if (plugin_initialize(tmp))
     {
       my_error(ER_CANT_INITIALIZE_UDF, MYF(0), name->str,
@@ -2164,7 +2171,7 @@ sys_var *find_sys_var(THD *thd, const char *str, uint length)
 
   pthread_mutex_lock(&LOCK_plugin);
   rw_rdlock(&LOCK_system_variables_hash);
-  if ((var= intern_find_sys_var(str, length, false)) &&
+  if ((var= intern_find_sys_var(str, length)) &&
       (pi= var->cast_pluginvar()))
   {
     rw_unlock(&LOCK_system_variables_hash);
@@ -2183,11 +2190,7 @@ sys_var *find_sys_var(THD *thd, const char *str, uint length)
     rw_unlock(&LOCK_system_variables_hash);
   pthread_mutex_unlock(&LOCK_plugin);
 
-  /*
-    If the variable exists but the plugin it is associated with is not ready
-    then the intern_plugin_lock did not raise an error, so we do it here.
-  */
-  if (pi && !var)
+  if (!var)
     my_error(ER_UNKNOWN_SYSTEM_VARIABLE, MYF(0), (char*) str);
   DBUG_RETURN(var);
 }
@@ -2390,7 +2393,7 @@ static uchar *intern_sys_var_ptr(THD* thd, int offset, bool global_lock)
       st_bookmark *v= (st_bookmark*) my_hash_element(&bookmark_hash,idx);
 
       if (v->version <= thd->variables.dynamic_variables_version ||
-          !(var= intern_find_sys_var(v->key + 1, v->name_len, true)) ||
+          !(var= intern_find_sys_var(v->key + 1, v->name_len)) ||
           !(pi= var->cast_pluginvar()) ||
           v->key[0] != (pi->plugin_var->flags & PLUGIN_VAR_TYPEMASK))
         continue;
@@ -2483,7 +2486,7 @@ static void cleanup_variables(THD *thd, struct system_variables *vars)
   {
     v= (st_bookmark*) my_hash_element(&bookmark_hash, idx);
     if (v->version > vars->dynamic_variables_version ||
-        !(var= intern_find_sys_var(v->key + 1, v->name_len, true)) ||
+        !(var= intern_find_sys_var(v->key + 1, v->name_len)) ||
         !(pivar= var->cast_pluginvar()) ||
         v->key[0] != (pivar->plugin_var->flags & PLUGIN_VAR_TYPEMASK))
       continue;