diff options
| -rw-r--r-- | sql/sql_audit.cc | 44 | ||||
| -rw-r--r-- | sql/sql_audit.h | 1 | ||||
| -rw-r--r-- | sql/sql_plugin.cc | 44 |
3 files changed, 74 insertions, 15 deletions
diff --git a/sql/sql_audit.cc b/sql/sql_audit.cc index 7d269d455a9..b7d363dc09a 100644 --- a/sql/sql_audit.cc +++ b/sql/sql_audit.cc @@ -138,6 +138,30 @@ static my_bool acquire_plugins(THD *thd, plugin_ref plugin, void *arg) /** + @brief Acquire audit plugins + + @param[in] thd MySQL thread handle + @param[in] event_class Audit event class + + @details Ensure that audit plugins interested in given event + class are locked by current thread. +*/ +void mysql_audit_acquire_plugins(THD *thd, uint event_class) +{ + unsigned long event_class_mask[MYSQL_AUDIT_CLASS_MASK_SIZE]; + DBUG_ENTER("mysql_audit_acquire_plugins"); + set_audit_mask(event_class_mask, event_class); + if (thd && !check_audit_mask(mysql_global_audit_mask, event_class_mask) && + check_audit_mask(thd->audit_class_mask, event_class_mask)) + { + plugin_foreach(thd, acquire_plugins, MYSQL_AUDIT_PLUGIN, &event_class); + add_audit_mask(thd->audit_class_mask, event_class_mask); + } + DBUG_VOID_RETURN; +} + + +/** Notify the audit system of an event @param[in] thd @@ -151,21 +175,8 @@ void mysql_audit_notify(THD *thd, uint event_class, uint event_subtype, ...) { va_list ap; audit_handler_t *handlers= audit_handlers + event_class; - unsigned long event_class_mask[MYSQL_AUDIT_CLASS_MASK_SIZE]; - DBUG_ASSERT(event_class < audit_handlers_count); - - set_audit_mask(event_class_mask, event_class); - /* - Check to see if we have acquired the audit plugins for the - required audit event classes. - */ - if (thd && check_audit_mask(thd->audit_class_mask, event_class_mask)) - { - plugin_foreach(thd, acquire_plugins, MYSQL_AUDIT_PLUGIN, &event_class); - add_audit_mask(thd->audit_class_mask, event_class_mask); - } - + mysql_audit_acquire_plugins(thd, event_class); va_start(ap, event_subtype); (*handlers)(thd, event_subtype, ap); va_end(ap); @@ -448,6 +459,11 @@ static void event_class_dispatch(THD *thd, const struct mysql_event *event) #else /* EMBEDDED_LIBRARY */ +void mysql_audit_acquire_plugins(THD *thd, uint event_class) +{ +} + + void mysql_audit_initialize() { } diff --git a/sql/sql_audit.h b/sql/sql_audit.h index 5b6962b9ecb..953e41f1f06 100644 --- a/sql/sql_audit.h +++ b/sql/sql_audit.h @@ -29,6 +29,7 @@ extern void mysql_audit_finalize(); extern void mysql_audit_init_thd(THD *thd); extern void mysql_audit_free_thd(THD *thd); +extern void mysql_audit_acquire_plugins(THD *thd, uint event_class); extern void mysql_audit_notify(THD *thd, uint event_class, diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc index e3323260373..2d317eb56ef 100644 --- a/sql/sql_plugin.cc +++ b/sql/sql_plugin.cc @@ -29,7 +29,7 @@ #include "records.h" // init_read_record, end_read_record #include <my_pthread.h> #include <my_getopt.h> -#include <mysql/plugin_audit.h> +#include "sql_audit.h" #include "lock.h" // MYSQL_LOCK_IGNORE_TIMEOUT #define REPORT_TO_LOG 1 #define REPORT_TO_USER 2 @@ -1703,6 +1703,27 @@ bool mysql_install_plugin(THD *thd, const LEX_STRING *name, const LEX_STRING *dl MYSQL_LOCK_IGNORE_TIMEOUT))) DBUG_RETURN(TRUE); + /* + Pre-acquire audit plugins for events that may potentially occur + during [UN]INSTALL PLUGIN. + + When audit event is triggered, audit subsystem acquires interested + plugins by walking through plugin list. Evidently plugin list + iterator protects plugin list by acquiring LOCK_plugin, see + plugin_foreach_with_mask(). + + On the other hand [UN]INSTALL PLUGIN is acquiring LOCK_plugin + rather for a long time. + + When audit event is triggered during [UN]INSTALL PLUGIN, plugin + list iterator acquires the same lock (within the same thread) + second time. + + This hack should be removed when LOCK_plugin is fixed so it + protects only what it supposed to protect. + */ + mysql_audit_acquire_plugins(thd, MYSQL_AUDIT_GENERAL_CLASS); + mysql_mutex_lock(&LOCK_plugin); mysql_rwlock_wrlock(&LOCK_system_variables_hash); @@ -1783,6 +1804,27 @@ bool mysql_uninstall_plugin(THD *thd, const LEX_STRING *name) if (! (table= open_ltable(thd, &tables, TL_WRITE, MYSQL_LOCK_IGNORE_TIMEOUT))) DBUG_RETURN(TRUE); + /* + Pre-acquire audit plugins for events that may potentially occur + during [UN]INSTALL PLUGIN. + + When audit event is triggered, audit subsystem acquires interested + plugins by walking through plugin list. Evidently plugin list + iterator protects plugin list by acquiring LOCK_plugin, see + plugin_foreach_with_mask(). + + On the other hand [UN]INSTALL PLUGIN is acquiring LOCK_plugin + rather for a long time. + + When audit event is triggered during [UN]INSTALL PLUGIN, plugin + list iterator acquires the same lock (within the same thread) + second time. + + This hack should be removed when LOCK_plugin is fixed so it + protects only what it supposed to protect. + */ + mysql_audit_acquire_plugins(thd, MYSQL_AUDIT_GENERAL_CLASS); + mysql_mutex_lock(&LOCK_plugin); if (!(plugin= plugin_find_internal(name, MYSQL_ANY_PLUGIN))) { |