Bug#27430 "Crash in subquery code when in PS and table DDL changed after (6e4af99f) · Commits · Software / OSDI20 Artifacts / mariadb

sql/mysql_priv.h

+6 −6

Original line number	Diff line number	Diff line
		@@ -700,14 +700,14 @@ const char set_thd_proc_info(THD thd, const char *info,
		@sa Prepared_statement::reprepare()
		*/

		enum enum_metadata_type
		enum enum_table_ref_type
		{
		/** Initial value set by the parser */
		METADATA_NULL= 0,
		METADATA_VIEW,
		METADATA_BASE_TABLE,
		METADATA_I_S_TABLE,
		METADATA_TMP_TABLE
		TABLE_REF_NULL= 0,
		TABLE_REF_VIEW,
		TABLE_REF_BASE_TABLE,
		TABLE_REF_I_S_TABLE,
		TABLE_REF_TMP_TABLE
		};

		/*

sql/sp_head.cc

+3 −3

Original line number	Diff line number	Diff line
		@@ -1068,7 +1068,7 @@ sp_head::execute(THD *thd)
		LEX *old_lex;
		Item_change_list old_change_list;
		String old_packet;
		Metadata_version_observer *save_metadata_observer= thd->m_metadata_observer;
		Reprepare_observer *save_reprepare_observer= thd->m_reprepare_observer;

		Object_creation_ctx *saved_creation_ctx;

		@@ -1154,7 +1154,7 @@ sp_head::execute(THD *thd)
		of substatements (Bug#12257, Bug#27011, Bug#32868, Bug#33000),
		but it's not implemented yet.
		*/
		thd->m_metadata_observer= 0;
		thd->m_reprepare_observer= 0;

		/*
		It is also more efficient to save/restore current thd->lex once when
		@@ -1317,7 +1317,7 @@ sp_head::execute(THD *thd)
		thd->derived_tables= old_derived_tables;
		thd->variables.sql_mode= save_sql_mode;
		thd->abort_on_warning= save_abort_on_warning;
		thd->m_metadata_observer= save_metadata_observer;
		thd->m_reprepare_observer= save_reprepare_observer;

		thd->stmt_arena= old_arena;
		state= EXECUTED;

sql/sql_base.cc

+9 −9

Original line number	Diff line number	Diff line
		@@ -3737,8 +3737,8 @@ void assign_new_table_id(TABLE_SHARE *share)

		@sa Execute_observer
		@sa check_prepared_statement() to see cases when an observer is installed
		@sa TABLE_LIST::is_metadata_id_equal()
		@sa TABLE_SHARE::get_metadata_id()
		@sa TABLE_LIST::is_table_ref_id_equal()
		@sa TABLE_SHARE::get_table_ref_id()

		@param[in] thd used to report errors
		@param[in,out] tables TABLE_LIST instance created by the parser
		@@ -3754,10 +3754,10 @@ bool
		check_and_update_table_version(THD *thd,
		TABLE_LIST tables, TABLE_SHARE table_share)
		{
		if (! tables->is_metadata_id_equal(table_share))
		if (! tables->is_table_ref_id_equal(table_share))
		{
		if (thd->m_metadata_observer &&
		thd->m_metadata_observer->report_error(thd))
		if (thd->m_reprepare_observer &&
		thd->m_reprepare_observer->report_error(thd))
		{
		/*
		Version of the table share is different from the
		@@ -3768,14 +3768,14 @@ check_and_update_table_version(THD *thd,
		return TRUE;
		}
		/* Always maintain the latest version and type */
		tables->set_metadata_id(table_share);
		tables->set_table_ref_id(table_share);
		}
		#if 0
		#ifndef DBUG_OFF
		/* Spuriously reprepare each statement. */
		if (thd->m_metadata_observer && thd->stmt_arena->is_reprepared == FALSE)
		if (thd->m_reprepare_observer && thd->stmt_arena->is_reprepared == FALSE)
		{
		thd->m_metadata_observer->report_error(thd);
		thd->m_reprepare_observer->report_error(thd);
		return TRUE;
		}
		#endif
		@@ -3865,7 +3865,7 @@ static int open_unireg_entry(THD thd, TABLE entry, TABLE_LIST *table_list,
		Note, the assert below is known to fail inside stored
		procedures (Bug#27011).
		*/
		DBUG_ASSERT(thd->m_metadata_observer);
		DBUG_ASSERT(thd->m_reprepare_observer);
		check_and_update_table_version(thd, table_list, share);
		/* Always an error. */
		DBUG_ASSERT(thd->is_error());

sql/sql_class.cc

+14 −5

Original line number	Diff line number	Diff line
		@@ -198,6 +198,19 @@ bool foreign_key_prefix(Key a, Key b)
		** Thread specific functions
		****************************************************************************/

		/** Push an error to the error stack and return TRUE for now. */

		bool
		Reprepare_observer::report_error(THD *thd)
		{
		my_error(ER_NEED_REPREPARE, MYF(ME_NO_WARNING_FOR_ERROR\|ME_NO_SP_HANDLER));

		m_invalidated= TRUE;

		return TRUE;
		}


		Open_tables_state::Open_tables_state(ulong version_arg)
		:version(version_arg), state_flags(0U)
		{
		@@ -360,10 +373,6 @@ char thd_security_context(THD thd, char *buffer, unsigned int length,
		return thd->strmake(str.ptr(), str.length());
		}

		Metadata_version_observer::~Metadata_version_observer()
		{
		}

		/**
		Clear this diagnostics area.

		@@ -2774,7 +2783,7 @@ void THD::restore_backup_open_tables_state(Open_tables_state *backup)
		handler_tables == 0 && derived_tables == 0 &&
		lock == 0 && locked_tables == 0 &&
		prelocked_mode == NON_PRELOCKED &&
		m_metadata_observer == NULL);
		m_reprepare_observer == NULL);
		set_open_tables_state(backup);
		DBUG_VOID_RETURN;
		}

sql/sql_class.h

+14 −15

Original line number	Diff line number	Diff line
		@@ -24,7 +24,7 @@
		#include "rpl_tblmap.h"

		/**
		An abstract interface that can be used to take an action when
		An interface that is used to take an action when
		the locking module notices that a table version has changed
		since the last execution. "Table" here may refer to any kind of
		table -- a base table, a temporary table, a view or an
		@@ -36,36 +36,35 @@
		parse tree may be no longer valid, e.g. in case it contains
		optimizations that depend on table metadata.

		This class provides an abstract interface (a method) that is
		This class provides an interface (a method) that is
		invoked when such a situation takes place.
		The implementation of the interface in most cases simply
		reports an error, but the exact details depend on the nature of
		the SQL statement.
		The implementation of the method simply reports an error, but
		the exact details depend on the nature of the SQL statement.

		At most 1 instance of this class is active at a time, in which
		case THD::m_metadata_observer is not NULL.
		case THD::m_reprepare_observer is not NULL.

		@sa check_and_update_table_version() for details of the
		version tracking algorithm

		@sa Execute_observer for details of how we detect that
		a metadata change is fatal and a re-prepare is necessary

		@sa Open_tables_state::m_metadata_observer for the life cycle
		@sa Open_tables_state::m_reprepare_observer for the life cycle
		of metadata observers.
		*/

		class Metadata_version_observer
		class Reprepare_observer
		{
		public:
		virtual ~Metadata_version_observer();
		/**
		Check if a change of metadata is OK. In future
		the signature of this method may be extended to accept the old
		and the new versions, but since currently the check is very
		simple, we only need the THD to report an error.
		*/
		virtual bool report_error(THD *thd)= 0;
		bool report_error(THD *thd);
		bool is_invalidated() const { return m_invalidated; }
		void reset_reprepare_observer() { m_invalidated= FALSE; }
		private:
		bool m_invalidated;
		};


		@@ -848,7 +847,7 @@ class Open_tables_state
		tracking.
		@sa check_and_update_table_version()
		*/
		Metadata_version_observer *m_metadata_observer;
		Reprepare_observer *m_reprepare_observer;

		/**
		List of regular tables in use by this thread. Contains temporary and
		@@ -953,7 +952,7 @@ class Open_tables_state
		extra_lock= lock= locked_tables= 0;
		prelocked_mode= NON_PRELOCKED;
		state_flags= 0U;
		m_metadata_observer= NULL;
		m_reprepare_observer= NULL;
		}
		};