Original revid: alexey.kopytov@sun.com-20100723115254-jjwmhq97b9wl932l
> Bug #54476: crash when group_concat and 'with rollup' in
> prepared statements
>
> Using GROUP_CONCAT() together with the WITH ROLLUP modifier
> could crash the server.
>
> The reason was a combination of several facts:
>
> 1. The Item_func_group_concat class stores pointers to ORDER
> objects representing the columns in the ORDER BY clause of
> GROUP_CONCAT().
>
> 2. find_order_in_list() called from
> Item_func_group_concat::setup() modifies the ORDER objects so
> that their 'item' member points to the arguments list
> allocated in the Item_func_group_concat constructor.
>
> 3. In some cases (e.g. in JOIN::rollup_make_fields) a copy of
> the original Item_func_group_concat object could be created by
> using the Item_func_group_concat::Item_func_group_concat(THD
> *thd, Item_func_group_concat *item) copy constructor. The
> latter essentially creates a shallow copy of the source
> object. Memory for the arguments array is allocated on
> thd->mem_root, but the pointers for arguments and ORDER are
> copied verbatim.
>
> What happens in the test case is that when executing the query
> for the first time, after a copy of the original
> Item_func_group_concat object has been created by
> JOIN::rollup_make_fields(), find_order_in_list() is called for
> this new object. It then resolves ORDER BY by modifying the
> ORDER objects so that they point to elements of the arguments
> array which is local to the cloned object. When thd->mem_root
> is freed upon completing the execution, pointers in the ORDER
> objects become invalid. Those ORDER objects, however, are also
> shared with the original Item_func_group_concat object which is
> preserved between executions of a prepared statement. So the
> first call to find_order_in_list() for the original object on
> the second execution tries to dereference an invalid pointer.
>
> The solution is to create copies of the ORDER objects when
> copying Item_func_group_concat to not leave any stale pointers
> in other instances with different lifecycles.
mysql-test/r/func_gconcat.result:
Test case for bug #54476.
mysql-test/t/func_gconcat.test:
Test case for bug #54476.
sql/item_sum.cc:
Copy the ORDER objects pointed to by the elements of the
'order' array in the copy constructor of
Item_func_group_concat.
sql/table.h:
Removed the unused 'item_copy' member of the ORDER class.
Bug#57913 large negative number to string conversion functions crash
String object which is used as result container of the item
has uninitialized 'str_charset' field. This object
might be used later to preform some internal operations
and str_charset field is involved in these operations.
It leads to crash.
The fix is to intialize str_charset in my_decimal2string() func.
mysql-test/r/func_str.result:
test case
mysql-test/t/func_str.test:
test case
sql/my_decimal.cc:
intialize str_charset field for result string
in my_decimal2string() func.
--Bug#52157 various crashes and assertions with multi-table update, stored function
--Bug#54475 improper error handling causes cascading crashing failures in innodb/ndb
--Bug#57703 create view cause Assertion failed: 0, file .\item_subselect.cc, line 846
--Bug#57352 valgrind warnings when creating view
--Recently discovered problem when a nested materialized derived table is used
before being populated and it leads to incorrect result
We have several modes when we should disable subquery evaluation.
The reasons for disabling are different. It could be
uselessness of the evaluation as in case of 'CREATE VIEW'
or 'PREPARE stmt', or we should disable subquery evaluation
if tables are not locked yet as it happens in bug#54475, or
too early evaluation of subqueries can lead to wrong result
as it happened in Bug#19077.
Main problem is that if subquery items are treated as const
they are evaluated in ::fix_fields(), ::fix_length_and_dec()
of the parental items as a lot of these methods have
Item::val_...() calls inside.
We have to make subqueries non-const to prevent unnecessary
subquery evaluation. At the moment we have different methods
for this. Here is a list of these modes:
1. PREPARE stmt;
We use UNCACHEABLE_PREPARE flag.
It is set during parsing in sql_parse.cc, mysql_new_select() for
each SELECT_LEX object and cleared at the end of PREPARE in
sql_prepare.cc, init_stmt_after_parse(). If this flag is set
subquery becomes non-const and evaluation does not happen.
2. CREATE|ALTER VIEW, SHOW CREATE VIEW, I_S tables which
process FRM files
We use LEX::view_prepare_mode field. We set it before
view preparation and check this flag in
::fix_fields(), ::fix_length_and_dec().
Some bugs are fixed using this approach,
some are not(Bug#57352, Bug#57703). The problem here is
that we have a lot of ::fix_fields(), ::fix_length_and_dec()
where we use Item::val_...() calls for const items.
3. Derived tables with subquery = wrong result(Bug19077)
The reason of this bug is too early subquery evaluation.
It was fixed by adding Item::with_subselect field
The check of this field in appropriate places prevents
const item evaluation if the item have subquery.
The fix for Bug19077 fixes only the problem with
convert_constant_item() function and does not cover
other places(::fix_fields(), ::fix_length_and_dec() again)
where subqueries could be evaluated.
Example:
CREATE TABLE t1 (i INT, j BIGINT);
INSERT INTO t1 VALUES (1, 2), (2, 2), (3, 2);
SELECT * FROM (SELECT MIN(i) FROM t1
WHERE j = SUBSTRING('12', (SELECT * FROM (SELECT MIN(j) FROM t1) t2))) t3;
DROP TABLE t1;
4. Derived tables with subquery where subquery
is evaluated before table locking(Bug#54475, Bug#52157)
Suggested solution is following:
-Introduce new field LEX::context_analysis_only with the following
possible flags:
#define CONTEXT_ANALYSIS_ONLY_PREPARE 1
#define CONTEXT_ANALYSIS_ONLY_VIEW 2
#define CONTEXT_ANALYSIS_ONLY_DERIVED 4
-Set/clean these flags when we perform
context analysis operation
-Item_subselect::const_item() returns
result depending on LEX::context_analysis_only.
If context_analysis_only is set then we return
FALSE that means that subquery is non-const.
As all subquery types are wrapped by Item_subselect
it allow as to make subquery non-const when
it's necessary.
mysql-test/r/derived.result:
test case
mysql-test/r/multi_update.result:
test case
mysql-test/r/view.result:
test case
mysql-test/suite/innodb/r/innodb_multi_update.result:
test case
mysql-test/suite/innodb/t/innodb_multi_update.test:
test case
mysql-test/suite/innodb_plugin/r/innodb_multi_update.result:
test case
mysql-test/suite/innodb_plugin/t/innodb_multi_update.test:
test case
mysql-test/t/derived.test:
test case
mysql-test/t/multi_update.test:
test case
mysql-test/t/view.test:
test case
sql/item.cc:
--removed unnecessary code
sql/item_cmpfunc.cc:
--removed unnecessary checks
--THD::is_context_analysis_only() is replaced with LEX::is_ps_or_view_context_analysis()
sql/item_func.cc:
--refactored context analysis checks
sql/item_row.cc:
--removed unnecessary checks
sql/item_subselect.cc:
--removed unnecessary code
--added DBUG_ASSERT into Item_subselect::exec()
which asserts that subquery execution can not happen
if LEX::context_analysis_only is set, i.e. at context
analysis stage.
--Item_subselect::const_item()
Return FALSE if LEX::context_analysis_only is set.
It prevents subquery evaluation in ::fix_fields &
::fix_length_and_dec at context analysis stage.
sql/item_subselect.h:
--removed unnecessary code
sql/mysql_priv.h:
--Added new set of flags.
sql/sql_class.h:
--removed unnecessary code
sql/sql_derived.cc:
--added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_lex.cc:
--init LEX::context_analysis_only field
sql/sql_lex.h:
--New LEX::context_analysis_only field
sql/sql_parse.cc:
--removed unnecessary code
sql/sql_prepare.cc:
--removed unnecessary code
--added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_select.cc:
--refactored context analysis checks
sql/sql_show.cc:
--added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_view.cc:
--added LEX::context_analysis_only analysis intialization/cleanup
On this platform we seem to get lots of other signals
while waiting for SIGKILL to be delivered.
Solution: use sigsuspend(<all signals blocked>)
dbug/dbug.c:
New function _db_suicide_() which does kill(myself, -9) and then waits forever.
include/my_dbug.h:
Let DBUG_SUICE wait forever until the KILL signal is delivered, and process dies.
Auto increment value wraps when performing a bulk insert with
auto_increment_increment and auto_increment_offset greater than
one.
The fix:
If overflow happened then return MAX_ULONGLONG value as an
indication of overflow and check this before storing the
value into the field in update_auto_increment().
mysql-test/r/auto_increment.result:
test case
mysql-test/suite/innodb/r/innodb-autoinc.result:
test case fix
mysql-test/suite/innodb/t/innodb-autoinc.test:
test case fix
mysql-test/suite/innodb_plugin/r/innodb-autoinc.result:
test case fix
mysql-test/suite/innodb_plugin/t/innodb-autoinc.test:
test case fix
mysql-test/t/auto_increment.test:
test case
sql/handler.cc:
If overflow happened then return MAX_ULONGLONG value as an
indication of overflow and check this before storing the
value into the field in update_auto_increment().
Explain fails at fix_fields stage and some items are left unfixed,
particulary Item_group_concat. Item_group_concat::orig_args field
is uninitialized in this case and Item_group_concat::print call
leads to crash.
The fix:
move the initialization of Item_group_concat::orig_args
into constructor.
mysql-test/r/func_gconcat.result:
test case
mysql-test/t/func_gconcat.test:
test case
sql/item_sum.cc:
move the initialization of Item_group_concat::orig_args
into constructor.
my_seek() and my_tell() functions now honour MY_WME flag.
include/mysys_err.h:
Fix for bug#48451: my_seek and my_tell ignore MY_WME flag
- EE_CANT_SEEK added, used in my_seek() and my_tell() functions.
mysys/errors.c:
Fix for bug#48451: my_seek and my_tell ignore MY_WME flag
- EE_CANT_SEEK added, used in my_seek() and my_tell() functions.
mysys/my_seek.c:
Fix for bug#48451: my_seek and my_tell ignore MY_WME flag
- my_seek() and my_tell() handle MY_WME flag.
mysys/my_symlink.c:
Fix for bug#48451: my_seek and my_tell ignore MY_WME flag
- __attribute__((unused)) removed, as myf MyFlags is
actually used in the my_realpath() function.
storage/myisam/ha_myisam.cc:
Fix for bug#48451: my_seek and my_tell ignore MY_WME flag
- check my_seek() result.
DROP/CREATE SCHEMA, CREATE TABLE, REPAIR.
The cause of assert was concurrent execution of
DROP DATABASE and REPAIR TABLE where first statement
deleted table's file .TMD at the same time as
REPAIR TABLE tried to read file details from the old file
that was just removed.
Additionally was fixed trouble when DROP TABLE try delete
all files belong to table being dropped at the same time
when REPAIR TABLE statement has just deleted .TMD file.
No regression test added because this would require adding a
sync point to mysys/my_redel.c. Since this bug is not present in
5.5+, adding test coverage was considered unnecessary.
The patch has been verified using RQG testing.
sql/sql_db.cc:
mysql_rm_known_files() modified: ignore possible ENOENT error
when trying delete all table's files. Such aggressive
algorithm permits skip already deleted (in another thread)
files.
Installation of Drop_table_error_handler as internal error handler
moved from mysql_rm_db() to mysql_rm_knowns_files() near to place
where source of possible errors (call to mysql_rm_table_part2) located.
storage/myisam/mi_check.c:
mi_repair() was modified: set param->retry_repair= 0
in order to don't call following failover procedure
in ha_myisam::repair().
mysqltest checks if the stmt is one that should be run in ps mode,
but regexp doesn't match if preceeded by /* */ comment.
Fix: match function will jump over /*..*/ if found at start
Backported use of setenv() from 5.5
This will remove the leak on systems that have setenv()
I have not fixed the string.c leak, it's a local variable
that the cleanup function cannot access.
When a query fails with a different error on the slave,
the sql thread outputs a message (M) containing:
1. the error message format for the master error code
2. the master error code
3. the error message for the slave's error code
4. the slave error code
Given that the slave has no information on the error message
itself that the master outputs, it can only print its own
version of the message format (but stripped from the
additional data if the message format requires). This may
confuse users.
To fix this we augment the slave's message (M) to explicitly
state that the master's message is actually an error message
format, the one associated with the given master error code
and that the slave server knows about.
When installing plugins, there is a missing check
for slash (/) in the path on Windows. Note that on
Windows, both / and \ can be used to separate
directories.
This patch fixes the issue by:
- Adding a FN_DIRSEP symbol for all platforms
consisting of a string of legal directory
separators.
- Adding a charset-aware version of strcspn().
- Adding a check_valid_path() function that uses
my_strcspn() to check if any FN_DIRSEP character
is in the supplied string.
- Using the check_valid_path() function in
sql_plugin.cc and sql_udf.cc (which means
replacing the existing test there).
include/config-netware.h:
Adding FN_DIRSEP
******
Adding FN_DIRSEP
include/config-win.h:
Adding FN_DIRSEP
******
Adding FN_DIRSEP
include/m_ctype.h:
Adding my_strspn() and my_strcspn().
******
Adding my_strspn() and my_strcspn().
include/my_global.h:
Adding FN_DIRSEP
******
Adding FN_DIRSEP
mysql-test/t/plugin_not_embedded.test:
Adding test that file names containing / is
disallowed on *all* platforms.
******
Adding test that file names containing / is
disallowed on *all* platforms.
sql/sql_plugin.cc:
Introducing check_if_path() function for
checking if filename is a path to include
/ on Windows.
******
Introducing check_if_path() function for
checking if filename is a path to include
/ on Windows.
sql/sql_udf.cc:
Switching to use check_if_path() function.
******
Switching to use check_if_path() function.
strings/my_strchr.c:
Adding my_strspn() and my_strcspn().
******
Adding my_strspn() and my_strcspn().
Fixing the testcase to use the database name
as connected_db instead of 'test' database.
mysql-test/r/mysql.result:
Additional fix in the test for bug#54899.
mysql-test/t/mysql.test:
Additional fix in the test for bug#54899.
when generating new name.
If find_uniq_filename returns an error, then this error is not
being propagated upwards, and execution does not report error to
the user (although a entry in the error log is generated).
Additionally, some more errors were ignored in new_file_impl:
- when writing the rotate event
- when reopening the index and binary log file
This patch addresses this by propagating the error up in the
execution stack. Furthermore, when rotation of the binary log
fails, an incident event is written, because there may be a
chance that some changes for a given statement, were not properly
logged. For example, in SBR, LOAD DATA INFILE statement requires
more than one event to be logged, should rotation fail while
logging part of the LOAD DATA events, then the logged data would
become inconsistent with the data in the storage engine.
mysql-test/include/restart_mysqld.inc:
Refactored restart_mysqld so that it is not hardcoded for
mysqld.1, but rather for the current server.
mysql-test/suite/binlog/t/binlog_index.test:
The error on open of index and binary log on new_file_impl
is now caught. Thence the user will get an error message.
We need to accomodate this change in the test case for the
failing FLUSH LOGS.
mysql-test/suite/rpl/t/rpl_binlog_errors-master.opt:
Sets max_binlog_size to 4096.
mysql-test/suite/rpl/t/rpl_binlog_errors.test:
Added some test cases for asserting that the error is found
and reported.
sql/handler.cc:
Catching error now returned by unlog (in ha_commit_trans) and
returning it.
sql/log.cc:
Propagating errors from new_file_impl upwards. The errors that
new_file_impl catches now are:
- error on generate_new_name
- error on writing the rotate event
- error when opening the index or the binary log file.
sql/log.h:
Changing declaration of:
- rotate_and_purge
- new_file
- new_file_without_locking
- new_file_impl
- unlog
They now return int instead of void.
sql/mysql_priv.h:
Change signature of reload_acl_and_cache so that write_to_binlog
is an int instead of bool.
sql/mysqld.cc:
Redeclaring not_used var as int instead of bool.
sql/rpl_injector.cc:
Changes to catch the return from rotate_and_purge.
sql/slave.cc:
Changes to catch the return values for new_file and rotate_relay_log.
sql/slave.h:
Changes to rotate_relay_log declaration (now returns int
instead of void).
sql/sql_load.cc:
In SBR, some logging of LOAD DATA events goes through
IO_CACHE_CALLBACK invocation at mf_iocache.c:_my_b_get. The
IO_CACHE implementation is ignoring the return value for from
these callbacks (pre_read and post_read), so we need to find out
at the end of the execution if the error is set or not in THD.
sql/sql_parse.cc:
Catching the rotate_relay_log and rotate_and_purge return values.
Semantic change in reload_acl_and_cache so that we report errors
in binlog interactions through the write_to_binlog output parameter.
If there was any failure while rotating the binary log, we should
then report the error to the client when handling SQLCOMM_FLUSH.
integral type. Use intptr which is designed to hold pointer values
and pass it to off_t.
mysys/stacktrace.c:
Add a compile time assert to ensure that off_t is large enough
to hold the pointer value.
Improved error handling such that queries against Information_Schema.Tables won't
fail if a Federated table is unable to connect to remote host.
sql/sql_show.cc:
If Handler::Info() fails, save error text in TABLE COMMENTS column, clear error.
win x86 debug_max
The windows MTR run exhibited a different test execution
ordering (due to the fact that in these platforms MTR is invoked
with --parallel > 1). This uncovered a bug in the aforementioned
test case, which is triggered by the following conditions:
1. server is not restarted between two different tests;
2. the test before binlog.binlog_row_failure_mixing_engines
issues flush logs;
3. binlog.binlog_row_failure_mixing_engines uses binlog
positions to limit the output of show_binlog_events;
4. binlog.binlog_row_failure_mixing_engines does not state which
binlog file to use, thence it uses a wrong binlog file with
the correct position.
There are two possible fixes: 1. make sure that the test start
from a clean slate - binlog wise; 2. in addition to the position,
also state the binary log file before sourcing
show_binlog_events.inc .
We go for fix#1, ie, deploy a RESET MASTER before the test is
actually started.
The problem is that the logic which checks if a pointer is
valid relies on a poor heuristic based on the start and end
addresses of the data segment and heap.
Apart from miscalculating the heap bounds, this approach also
suffers from the fact that memory can come from places other
than the heap. See Bug#58528 for a more detailed explanation.
On Linux, the solution is to access the process's memory
through /proc/self/task/<tid>/mem, which allows for retrieving
the contents of pages within the virtual address space of
the calling process. If a address range is not mapped, a
input/output error is returned.
client/mysqltest.cc:
Use new interface to my_safe_print_str.
include/my_stacktrace.h:
Drop name from my_safe_print_str.
mysys/stacktrace.c:
Access the process's memory through a file descriptor and
dump the contents of the memory range. The file descriptor
offset is equivalent to a offset into the address space.
Do not print the name of the variable associated with the
address. It can be better accomplished at a higher level.
sql/mysqld.cc:
Put the variable dumping information within its own newline block.
Use symbolic names which better convey information to the user.
the DROP statement ..."
Problem: When using temporary tables and closing a session, an
implicit DROP TEMPORARY TABLE IF EXISTS is written to the binary
log (while cleaning up the context of the session THD - see:
sql_class.cc:THD::cleanup which calls close_temporary_tables).
close_temporary_tables, first checks if the binary log is opened
and then proceeds to creating the DROP statements. Then, such
statements, are written to the binary log through
MYSQL_BIN_LOG::write(Log_event *). Inside, there is another check
if the binary log is opened and if not an error is returned. This
is where the faulty behavior is triggered. Given that the test
case replays a binary log, with temp tables statements, and right
after it issues RESET MASTER, there is a chance that is_open will
report false (when the mysql session is closed and the temporary
tables are written).
is_open may return false, because MYSQL_BIN_LOG::reset_logs is
not setting the correct flag (LOG_CLOSE_TO_BE_OPENED), on the
MYSQL_LOG_BIN::log_state (instead it sets just the
LOG_CLOSE_INDEX flag, leaving the log_state to
LOG_CLOSED). Thence, when writing the DROP statement as part of
the THD::cleanup, the thread could get a return value of false
for is_open - inside MYSQL_BIN_LOG::write, ultimately reporting
that it can't write the event to the binary log.
Fix: We fix this by adding the correct flag, missing in the
second close.
metadata"
Improved error handling such that queries against Information_Schema.Tables won't
fail if a federated table can't make a remote connection.
mysql-test/r/merge.result:
Updated with warnings that were previously masked.
mysql-test/r/show_check.result:
Updated with warnings that were previously masked.
mysql-test/r/view.result:
Updated with warnings that were previously masked.
sql/sql_show.cc:
If get_schema_tables_record() encounters an error, push a warning,
set the TABLE COMMENT column with the error text, and clear the
error so that the operation can continue.
When using BINLOG statement to execute rows log events, session variables
foreign_key_checks and unique_checks are changed temporarily. As each rows
log event has their own special session environment and its own
foreign_key_checks and unique_checks can be different from current session
which executing the BINLOG statement. But these variables are not restored
correctly after BINLOG statement. This problem will cause that the following
statements fail or generate unexpected data.
In this patch, code is added to backup and restore these two variables.
So BINLOG statement will not affect current session's variables again.
mysql-test/extra/binlog_tests/binlog.test:
Add test to verify this patch.
mysql-test/suite/binlog/r/binlog_row_binlog.result:
Add test to verify this patch.
mysql-test/suite/binlog/r/binlog_stm_binlog.result:
Add test to verify this patch.
sql/sql_binlog.cc:
Add code to backup and restore thd->options.
