The reason for the crash was that there was not a write lock to
protect against file rotations in the server_audit plugin after an
audit plugin patch to changed audit mutexes to read & write locks.
The fixes are:
* Moving server_audit.c to use read & write locks (which improves
performance).
* Added functionality in file_logger.c to not do file rotations until
it is allowed by the caller (done without any interface changes for
the logging service).
* Move checking of file size limit to server_audit.c and if it is time to
do a rotation change the read lock to a write lock and tell file_logger
that it is now allowed to rotate the log files.
volatile != atomic.
volatile has no memory barrier schemantics, its for mmaped IO
so lets allow some optimizer gains and stop pretending it helps
with memory atomicity.
The MDEV lists a SEGV an assumption is made that an address was
partially read. As C packs structs strictly in order and on arm64 the
cache line size is 128 bits. A pointer (link - 64 bits), followed
by a hashnr (uint32 - 32 bits), leaves the following key (uchar *
64 bits), neither naturally aligned to any pointer and worse, split
across a cache line which is the processors view of an atomic
reservation of memory.
lf_dynarray_lvalue is assumed to return a 64 bit aligned address.
As a solution move the 32bit hashnr to the end so we don't get the
*key pointer split across two cache lines.
Tested by: Krunal Bauskar
Reviewer: Marko Mäkelä
This bug caused crashes of the server when processing queries with table
value constructors (TVC) that contained subqueries and were used itself as
subselects. For such TVCs the following transformation is applied at the
prepare stage:
VALUES (v1), ... (vn) => SELECT * FROM (VALUES (v1), ... (vn)) tvc_x.
This transformation allows to reduce the problem of evaluation of TVCs used
as subselects to the problem of evaluation of regular subselects.
The transformation is implemented in the wrap_tvc(). The code the function
to mimic the behaviour of the parser when processing the result of the
transformation. However this imitation was not free of some flaws. First
the function called the method exclude() that completely destroyed the
select tree structures below the transformed TVC. Second the function
used the procedure mysql_new_select to create st_select_lex nodes for
both wrapping select of the transformation and TVC. This also led to
constructing of invalid select tree structures.
The patch actually re-engineers the code of wrap_tvc().
Approved by Oleksandr Byelkin <sanja@mariadb.com>
Introduced by 85828b8f22
This is running 2 git processes in parallel, which, if unlucky can cause
either of them to fail with "File already exists" error.
- The commit 5fd3c7471e3e0673b50d309567c9747d36f09412(MDEV-24709)
resets the recv_no_ibuf_operations in
recv_recovery_from_checkpoint_start(), but InnoDB fails to reset
the variable recv_no_log_write() during that time and that leads
to the assert failure.
This was caused by two different bugs:
1) Information_schema tables where not locked by lock_tables, but
get_lock_data() was not filtering these out. This caused a crash when
mysql_unlock_some_tables() tried to unlock tables early, including
not locked information schema tables.
Fixed by not locking SYSTEM_TMP_TABLES
2) In some cases the optimizer will notice that we do not need to read
the information_schema tables at all. In this case
join_tab->read_record is not set, which caused a crash in
get_schema_tables_result()
Fixed by ignoring const tables in get_schema_tables_result()
1. wait for the binlog thread to reach the certain state, don't use
a debug_sync that's incorrectly placed to detect the state
2. no need to do a (non-deterministic) `show binlog events` to verify
what is guaranteed by the directly preceding line
add a new "debugger" to mtr, that runs the executable
under valgrind in gdb. valgrind pid is auto-detected,
but the delay (sleep) and vgdb path are hard-coded for now
"debugger" is anything that wraps execution of a target
binary (mysqld or mysqltest). Currently the list includes:
gdb, ddd, dbx, lldb, valgrind, strace, ktrace, rr,
devenv, windbg, vsjitdebugger.
for every debugger xxx, mtr will recognize four options:
--xxx, --boot-xxx, --manual-xxx, --client-xxx.
They all support an optional "=string" argument. String
being a semicolon-separated list of commands (e.g. for gdb)
or one (not semicolon-separated) command line of options
(e.g. for valgrind). Or both (e.g. --gdb='-quiet -nh;info files'
In embedded both --xxx and --client-xxx work.
Functionality changed/removed:
* --rr-args is gone
* --rr-dir is gone
* --manual-debug is gone
* --debugger={devenv|vc|windbg|vc_express|vsjitdebugger} is gone
* --strace-option is gone
* --stracer={strace|ktrace} is gone
* --valgrind only enables it for the server, not for everything
* --valgrind-all is gone
* --valgrind-mysqltest is gone
* --valgrind-mysqld is gone
* --valgrind-options is gone
* --valgrind-option is gone
* --valgrind-path is gone
* --callgrind is gone
* one cannot combine --valgrind --gdb anymore
* valgrind report doesn't add a fake test line to the output
* vc and vcexpress on windows are no longer supported
only collect persistent stats for columns explicitly listed
by the user in the ANALYZE TABLE PERSISTENT FOR COLUMNS (...)
clause. The engine can extend table->read_set as much as
it wants, it should not affect the collected statistics.
Test case from the 3b94309a6c applies - it used to crash,
because ha_partition extended table->read_set after the loop that
initialized some objects based on bits in the read_set but before the
loop that used these objects based on bits in the read_set.
This reverts the commit 3b94309a6c but keeps the test
Because the fix is a hack that isn't supposed to do anything,
and relies on a side-effect of rnd_init inside ha_partition.
A different fix is coming up.
on used subqueries
If a query was based on a table value constructor that contained subqueries
then EXPLAIN for such query did not contain any lines explaining the
execution plans of the subqueries.
This happened because
- no optimize() method was called for any subquery used by the table value
constructor when EXPLAIN command for the query was processed;
- EXPLAIN node created for the table value constructor itself did not
assume that some child nodes could be attached to it.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
- This is caused by commit ad6171b91c
(MDEV-22456). InnoDB reloads the evicted table again from dictionary.
In that case, AHI entries and current index object mismatches
happens. When index object mismatches then InnoDB should drop
the page hash AHI entries for the block. In
btr_search_drop_page_hash_index(), InnoDB should take exclusive
lock on the AHI latch if index is already freed to avoid the
freed memory access during buf_pool_resize()
This can cause crashes when accessing already released memory
The issue was the Item_default created a internal field, pointing to
share->default_values, to be used with the DEFAULT() function.
This does not work for BLOB fields as these are freed at end of query.
Fixed by storing BLOB field data inside and area allocated by
Item_default_value, like we do for nondeterministic default values.
Problem was that thd::awake assumes now that you hold THD::LOCK_thd_data
so we need to keep it when we call wsrep_thd_awake from
wsrep_abort_transaction.
Let us avoid the excessive allocation of explicit record locks
(a work-around of MDEV-24813) so that the test will execute
much faster under AddressSanitizer, MemorySanitizer, Valgrind.
The issue here was the read_set bitmap was not set for a field which
was used as a reference in an inner select.
We need to make sure that if we are in an inner select and we have
references from outer select then we update the table bitmaps for
such references.
Introduced a function in the class Item_subselect that would
update bitmaps of table for the references within a
subquery that are defined in outer selects.
Follow-up fix to commit 26f5033(MDEV-23449)
The GROUP BY clause inside IN/ALL/ANY subquery is removed
when there is no aggregate function or HAVING clause in the subquery.
When the GROUP BY clause is removed, a subquery can also be removed
if it part of the GROUP BY clause. This is done inside the function
remove_redundant_subquery_clauses. Here we walk over the GROUP BY list
and remove a subselect from its unit via the callback function
eliminate_subselect_processor.
The issue here was that when the query was being re-executed it was trying
to reinitialize the select that was removed as stated above.
This is not required, so the fix would be to remove select_lex
both from tree lex structure and the global list of nodes so that
we don't do the reinitialization again.
The issue here was histogram statistics were being used even when
the level of optimizer_use_condition_selectivity doesn't allow
usage of statistics from histogram.
The histogram statistics are read for a table only when
optimizer_use_condition_selectivity > 3. But the TABLE structure can be
stored in the internal table cache and be reused for the next query.
So in this case the histogram statistics will be available for the next query.
The fix would be to make sure to use the histogram statistics only when
optimizer_use_condition_selectivity > 3.
The test innodb.innodb_bug60049 used to check that the record
(ID,NAME)=(12,'SYS_FOREIGN_COLS') is the last record in the
secondary index of the system table SYS_TABLES.
But, ever since commit 2336558423
or mysql/mysql-server@082d59670f
that record no longer is the last one in the table!
The more recent test innodb.purge_secondary covers the purge
functionality much better.
innobase_rename_column_try(): When renaming SYS_FIELDS records
for secondary indexes, try to use both formats of SYS_FIELDS.POS
as keys, in case the PRIMARY KEY includes a column prefix.
Without this fix, an ALTER TABLE that renames a column followed
by a server restart (or LRU eviction of the table definition
from dict_sys) would make the table inaccessible.
The test requires adaptation for MariaDB, which is done
in this patch. In addition, this patch includes a fix for
the SST script startup code that adds escaping for special
characters on the command line (in case they are contained
in the arguments to mysqld). The fix does not require
separate tests, as the required tests are already part
of the mtr suite for Galera.
of two table value costructors
This bug affected queries with a [NOT] IN/ANY/ALL subquery whose top level
unit contained several table value constructors.
The problem appeared because the code of the function
Item_subselect::fix_fields() that was responsible for wrapping table
value constructors encountered at the top level unit of a [NOT] IN/ANY/ALL
subquery did not take into account that the chain of the select objects
comprising the unit were not immutable.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
