Starting with commit 210855ce5d6803f41d672d75be3334726f52a9df
Valgrind became aware that the unused tail of the buffer that
is returned by thd_get_xid() is actually uninitialized.
The problem should exist already in MySQL 5.0. I was able to
repeat it on MariaDB Server 5.5 with some additional instrumentation.
InnoDB is allocating 128+4+4 bytes for the XID and the lengths of
its components, even when the XID is shorter than 64+64 bytes.
In MariaDB Server 10.3, while running the test main.xa_binlog,
in the xid_t::set() that is called by sql_yacc.yy, the 128-byte data
buffer was uninitialized according to Valgrind, and only the first bytes
were initialized. When the xid_t::data was copied to
thd.transaction.xid_state.xid.data, it happened so that the entire
target buffer was considered initialized. With MariaDB Server 10.4 since
the said commit, Valgrind will correctly be detect the tail of the buffer
as uninitialized.
The impact of this bug is as follows:
(1) InnoDB will write unnecessarily much redo log for XA PREPARE.
(2) InnoDB will write garbage bytes to the redo log and undo log pages.
(3) The garbage should be 'harmless', because on recovery, only the
actual payload of the XID will be used, based on the written length.
trx_rseg_write_wsrep_checkpoint(), trx_undo_write_xid(): Write only
the actually used length of xid->data to the data page, and
zero out the rest of the buffer by mlog_memset().
This fixes the following test failures related to index cardinality:
main.join main.stat_tables main.partition main.stat_tables_innodb
innodb.innodb_bug57252
- Initialize variables that could be used uninitialized
- Added extra end space to DbugStringItemTypeValue to get rid of warnings
from c_ptr()
- Session_sysvars_tracker::update() accessed unitialized memory if called
with NULL value.
- get_schema_stat_record() accessed unitialized memory if HA_KEY_LONG_HASH
was used
- parse_vcol_defs() accessed random memory for tables without keys.
* Made make_versioned_*() proxies inline;
* Renamed truncate_history to delete_history
Part of:
MDEV-19814 Server crash in row_upd_del_mark_clust_rec or Assertion
`update->n_fields < ulint(table->n_cols + table->n_v_cols)' failed in
upd_node_t::make_versioned_helper
This removes the test combination
rocksdb_rpl.mdev12179 'innodb,row,row-write-committed-slave-gtid-optimized'
for which the server failed to start due to the invalid parameter
slave_gtid_info=optimized.
This was broken in 5173e396ffce706954f7302e9854126aadab4c54
fts_sync(): Remove the constant parameter has_dict=false.
fts_sync_table(): Remove the constant parameter has_dict=false,
and the redundant parameter unlock_cache = !wait.
Make wait=true the default parameter.
