Materialized_cursor included MEM_ROOT where it itself (Materialized_cursor)
was allocated. Materialized_cursor inherits from Server_side_cursor,
and Server_side_cursor::operator delete frees this mem_root.
This offends MSAN with poison_in_dtor, because when Materialized_cursor
is destroyed, MEM_ROOT is poisoned and Server_side_cursor::operator delete
accesses memory it really shouldn't.
Fix:
* MEM_ROOT is moved into Server_side_cursor. Materialized_cursor is
the only class inheriting from it, so nobody is affected.
* operator delete is replaced with a function cdestroy() which
saves the MEM_ROOT, deletes the object, then frees the root.
* cannot close() from ~Materialized_cursor anymore, main_mem_root
should be copied before the destruction
* remove redundant checks for `len` in `get_param_length()`
* validate return value `length` in `get_param_length()`
* fix all `Item_param::set_param_XXX()` methods to never read past `len`
note that all `Item_param::set_param_XXX()` methods correctly handle
zero-length values.
Remove the unscoped #pragma GCC diagnostic ignored
"-Wdeprecated-declarations" from include/violite.h and replace all
sprintf/vsprintf calls with snprintf/vsnprintf across the codebase.
Where possible, pass actual buffer sizes as function parameters
instead of using hardcoded constants or recomputing strlen().
Notable API changes:
- get_date(): added to_len parameter for buffer size
- nice_time(), end_timer() in client/mysql.cc: added buff_size
- generate_new_name(): added name_size parameter
- calc_md5(): added buffer_size parameter (fixes off-by-one)
- MD5_HASH_TO_STRING macro: added _size parameter
- Added MYSQL_UDF_MAX_RESULT_LENGTH constant in mysql_com.h
Also fixed a pre-existing bug in sql/rpl_mi.cc where the ellipsis
"..." was written to the wrong buffer (dbuff instead of buff).
Vendored code is excluded: extra/readline, extra/wolfssl,
wsrep-lib, libmariadb, storage/mroonga/vendor, zlib.
With_element::prepare_unreferenced() contains query from recursive CTE
which is upper owner of unreferenced CTE itself. Such recursive
derived table is resolved into its expression and it tries to resolve
fields or any other data from subqueries which are not yet
prepared. These subqueries are preparing in upper frames of the same
stack after prepare_unreferenced() finishes.
That does not happen when recursion happens in referenced CTE because
in that case there are links between the derived tables defined by the
parser and descending into such recursion descends further into all
the dependency queries. No such link exists in unreferenced query
therefore it misses its upper dependencies.
The fix moves prepare_unreferenced() later after JOIN::prepare() so it
has the chance to access all the prepared data.
There may be another fix of failing unreferenced queries with error as
such kind of queries seem to be not usable.
Lots of different cases, SELECT, SELECT DEFAULT(),
UPDATE t SET x=DEFAULT, prepares statements,
opening of a table for the I_S, prelocking (so TL_WRITE),
insert with subquery (so SQLCOM_SELECT), etc.
Don't check NEXTVAL privileges in fix_fields() anymore, it cannot
possibly handle all the cases correctly. Make a special method
Item_func_nextval::check_access() for that and invoke it from
* fix_fields on explicit SELECT NEXTVAL()
(but not if NEXTVAL() is used in a DEFAULT clause)
* when DEFAULT bareword in used in, say, UPDATE t SET x=DEFAULT
(but not if DEFAULT() itself is used in a DEFAULT clause)
* in CREATE TABLE
* in ALTER TABLE ALGORITHM=INPLACE (that doesn't go CREATE TABLE path)
* on INSERT
helpers
* Virtual_column_info::check_access() to walk the item tree and invoke
Item::check_access()
* TABLE::check_sequence_privileges() to iterate default expressions
and invoke Virtual_column_info::check_access()
also, single-table UPDATE in prepared statements now associates
value items with fields just as multi-update already did, fixes the
case of PREPARE s "UPDATE t SET x=?"; EXECUTE s USING DEFAULT.
Problem:
Empty queries are incremented if no rows are sent to the client in the
EXECUTE phase of select query. With cursor protocol, rows are not sent
during EXECUTE phase; they are sent later in FETCH phase. Hence,
queries executed with cursor protocol are always falsely treated as
empty in EXECUTE phase.
Fix:
For cursor protocol, empty queries are now counted during the FETCH
phase. This ensures counter correctly reflects whether any rows were
actually sent to the client.
Tests included in `mysql-test/main/show.test`.
Issue:
Mariadb acquires additional MDL locks on UPDATE/INSERT/DELETE statements
on table with foreign keys. For example, table t1 references t2, an
UPDATE to t1 will MDL lock t2 in addition to t1.
A replica may deliver an ALTER t1 and UPDATE t2 concurrently for
applying. Then the UPDATE may acquire MDL lock for t1, followed by a
conflict when the ALTER attempts to MDL lock on t1. Causing a BF-BF
conflict.
Solution:
Additional keys for the referenced/foreign table needs to be added
to avoid potential MDL conflicts with concurrent update and DDLs.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
The SQL service leaves the affected rows uninitialized.
The initialization of the spider plugin that uses
this service will fail under MSAN because there isn't
an initialized value to return at the end of the query.
Get rid of need of matherialization for usual INSERT (cache results in
Item_cache* if needed)
- subqueries in VALUE do not see new records in the table we are
inserting to
- subqueries in RETIRNING prohibited to use the table we are inserting to
Protocol_text constructor allocated memory on an optional prealloc argument.
This was along with its subclass Protocol_local.
Remove this functionality to an independent member function "allocate".
Replace two use with existing error handling on insufficient
resources at the err label.
Protocol_local, that inherits from Protocol_text had one use that
requested an allocation of 0. So it wasn't needed.
The fix for MDEV-35318 has introduced LEX::needs_reprepare and logic in
Prepared_statement::execute_loop() and sp_lex_keeper::
validate_lex_and_exec_core() to re-prepare the statement if it has hit
an error when doing once-per-statement-life optimizations.
But there is also third code path: PS with Array Binding is handled in
Prepared_statement::execute_bulk_loop(). Add handling there as well.
Followup to fix for MDEV-35318: In Prepared_statement::execute_loop(),
if we enter this function with lex->needs_reprepare=true, we need to
re-prepare the statement.
We also need to call set_parameters() to get PS parameter values. We
failed to do this and that's the bug.
Note that we need to also handle the other reprepare scenario: when
we get into Prepared_statement::execute_loop(), call set_parameters()
and then hit a "DDL was changed" error with reprepare_observer,
we should NOT call set_parameters() again.
The parameters have already been transferred to the reprepared statement
in Prepared_statement::reprepare()|swap_parameter_array().
* rpl.rpl_system_versioning_partitions updated for MDEV-32188
* innodb.row_size_error_log_warnings_3 changed error for MDEV-33658
(checks are done in a different order)
Alternative, more general fix, Variant 2.
The problem was as follows: Suppose we are running a PS/SP statement and
we get an error while doing optimization that is done once per statement
life. This may leave the statement data structures in an undefined state,
where it is not safe to execute it again.
The fix: introduce LEX::needs_reprepare and set it in such cases.
Make PS and SP runtime check it and re-prepare the statement before
executing it again.
We do not use Reprepare_observer, because it turns out it is tightly tied
to watching versions of statement's objects. For example, it must not be
used when running the statement for the first time, exactly when the
once-per-statement-lifetime optimizations are done.
- Needless engaged_ removed;
- SCOPE_VALUE, SCOPE_SET, SCOPE_CLEAR macros for neater declaration;
- IF_CLASS / IF_NOT_CLASS SFINAE checkers to pass arg by value or
reference;
- inline keyword;
- couple of refactorings of temporary free_list.
The problems were that:
1) resources was freed "asimetric" normal execution in send_eof,
in case of error in destructor.
2) destructor was not called in case of SP for result objects.
(so if the last SP execution ended with error resorces was not
freeded on reinit before execution (cleanup() called before next
execution) and destructor also was not called due to lack of
delete call for the object)
Result cleanup() renamed to reset_for_next_ps_execution() to better
reflect function().
All result method revised and freeing resources made "symetric".
Destructor of result object called for SP.
Added skipped invalidation in case of error in insert.
Removed misleading naming of reset(thd) (could be mixed with
with reset()).
