/*![:version:] Query Code */, where [:version:] is a sequence of 5
digits representing the mysql server version(e.g /*!50200 ... */),
is a special comment that the query in it can be executed on those
servers whose versions are larger than the version appearing in the
comment. It leads to a security issue when slave's version is larger
than master's. A malicious user can improve his privileges on slaves.
Because slave SQL thread is running with SUPER privileges, so it can
execute queries that he/she does not have privileges on master.
This bug is fixed with the logic below:
- To replace '!' with ' ' in the magic comments which are not applied on
master. So they become common comments and will not be applied on slave.
- Example:
'INSERT INTO t1 VALUES (1) /*!10000, (2)*/ /*!99999 ,(3)*/
will be binlogged as
'INSERT INTO t1 VALUES (1) /*!10000, (2)*/ /* 99999 ,(3)*/
SHOW DATABASES LIKE ... was not converting to lowercase on comparison as the
documentation is suggesting.
Fixed it to behave similarly to SHOW TABLES LIKE ... and updated the failing
on MacOSX lowercase_table2 test case.
Fix warnings flagged by the new warning option -Wunused-but-set-variable
that was added to GCC 4.6 and that is enabled by -Wunused and -Wall. The
option causes a warning whenever a local variable is assigned to but is
later unused. It also warns about meaningless pointer dereferences.
table with active trx
Essentially, the problem is that InnoDB does a implicit commit
when a cursor (table handler) is unlocked/closed, creating
a dissonance between the transaction state within the server
layer and the storage engine layer. Theoretically, a statement
transaction can encompass several table instances in a similar
manner to a multiple statement transaction, hence it does not
make sense to limit a statement transaction to the lifetime of
the table instances (cursors) used within it.
Since this particular instance of the problem is only triggerable
on 5.1 and is masked on 5.5 due 2PC being skipped (assertion is in
the prepare phase of a 2PC), the solution (which is less risky) is
to explicitly end the transaction before the cached table is unlock
on rename table.
The patch is to be null merged into trunk.
Problem: when SHOW BINLOG EVENTS was issued, it increased the value of
@@session.max_allowed_packet. This allowed a non-root user to increase
the amount of memory used by her thread arbitrarily. Thus, it removes
the bound on the amount of system resources used by a client, so it
presents a security risk (DoS attack).
Fix: it is correct to increase the value of @@session.max_allowed_packet
while executing SHOW BINLOG EVENTS (see BUG 30435). However, the
increase should only be temporary. Thus, the fix is to restore the value
when SHOW BINLOG EVENTS ends.
The value of @@session.max_allowed_packet is also increased in
mysql_binlog_send (i.e., the binlog dump thread). It is not clear if this
can cause any trouble, since normally the client that issues
COM_BINLOG_DUMP will not issue any other commands that would be affected
by the increased value of @@session.max_allowed_packet. However, we
restore the value just in case.
This assert checks that the server does not try to send OK to the
client if there has been some error during processing. This is done
to make sure that the error is in fact sent to the client.
The problem was that view errors during processing of WHERE conditions
in UPDATE statements where not detected by the update code. It therefore
tried to send OK to the client, triggering the assert.
The bug was only noticeable in debug builds.
This patch fixes the problem by making sure that the update code
checks for errors during condition processing and acts accordingly.
compiler problem
GCC-style inline assembly is not supported by the Sun Studio
compilers prior to version 12.
Added a check for the Sun Studio version to avoid using
_FPU_GETCW() / _FPU_SETCW() when inline assembly is
unsupported. This can lead to some differences in floating
point calculations on Solaris 8/x86 which, however, is not worth
bothering with Sun-style assembly .il templates.
Although the C standard mandates that sprintf return the number
of bytes written, some very ancient systems (i.e. SunOS 4)
returned a pointer to the buffer instead. Since these systems
are not supported anymore and are hopefully long dead by now,
simply remove the portability wrapper that dealt with this
discrepancy. The autoconf check was causing trouble with GCC.
In bug-28430 HA_PRIMARY_KEY_REQUIRED_FOR_POSITION
was disabled in the partitioning engine in the first patch,
That bug was later fixed a second time, but that flag
was not removed.
No need to disable this flag, as it leads to bad
choise in row replication.
The problem there is that HAVING condition evaluates const
parts of condition despite the condition has references
on aggregate functions. Table t1 became const tables
after make_join_statistics and table1.pk = 1, HAVING is
transformed into MAX(1) < 7 and taken away from HAVING.
The fix is to skip evaluation of HAVING conts parts if
HAVING condition has references on aggregate functions.
The handler function for reading one row from a specific index
was not optimized in the partitioning handler since it
used the default implementation.
No test case since it is performance only, verified by hand.
Since the original fix for this bug lowercases the search pattern it's not a
good idea to copy the search pattern to the output instead of the real table
name found (since, depending on the case mode these two names may differ in
case).
Fixed the infrmation_schema.test failure by making sure the actual table
name of an inoformation schema table is passed instead of the lookup pattern
even when the pattern doesn't contain wildcards.
The default value of the myisam_max_extra_sort_file_size could be
higher than the maximum accepted value, leading to warnings upon
the server start.
The solution is to simply set the value to the maximum value in a
32-bit built (2147483647, one less than the current). This should
be harmless as the option is currently unused in 5.1.
The problem was that a user could supply supply data in chunks
via the COM_STMT_SEND_LONG_DATA command to prepared statement
parameter other than of type TEXT or BLOB. This posed a problem
since other parameter types aren't setup to handle long data,
which would lead to a crash when attempting to use the supplied
data.
Given that long data can be supplied at any stage of a prepared
statement, coupled with the fact that the type of a parameter
marker might change between consecutive executions, the solution
is to validate at execution time each parameter marker for which
a data stream was provided. If the parameter type is not TEXT or
BLOB (that is, if the type is not able to handle a data stream),
a error is returned.
DROP USER
RENAME USER CURRENT_USER() ...
GRANT ... TO CURRENT_USER()
REVOKE ... FROM CURRENT_USER()
ALTER DEFINER = CURRENT_USER() EVENTbut, When these statements are binlogged, CURRENT_USER() just is binlogged
as 'CURRENT_USER()', it is not expanded to the real user name. When slave
executes the log event, 'CURRENT_USER()' is expand to the user of slave
SQL thread, but SQL thread's user name always NULL. This breaks the replication.
After this patch, session's user will be written into query log events
if these statements call CURREN_USER() or 'ALTER EVENT' does not assign a definer.
This deadlock happened if DROP DATABASE was blocked due to an open
HANDLER table from a different connection. While DROP DATABASE
is blocked, it holds the LOCK_mysql_create_db mutex. This results
in a deadlock if the connection with the open HANDLER table tries
to execute a CREATE/ALTER/DROP DATABASE statement as they all
try to acquire LOCK_mysql_create_db.
This patch makes this deadlock scenario very unlikely by closing and
marking for re-open all HANDLER tables for which there are pending
conflicing locks, before LOCK_mysql_create_db is acquired.
However, there is still a very slight possibility that a connection
could access one of these HANDLER tables between closing/marking for
re-open and the acquisition of LOCK_mysql_create_db.
This patch is for 5.1 only, a separate and complete fix will be
made for 5.5+.
Test case added to schema.test.
returns nothing
When looking for table or database names inside INFORMATION_SCHEMA
we must convert the table and database names to lowercase (just as it's
done in the rest of the server) when lowercase_table_names is non-zero.
This will allow us to find the same tables that we would find if there
is no condition.
Fixed by converting to lower case when extracting the database and
table name conditions.
Test case added.
DROP USER
RENAME USER CURRENT_USER() ...
GRANT ... TO CURRENT_USER()
REVOKE ... FROM CURRENT_USER()
ALTER DEFINER = CURRENT_USER() EVENTbut, When these statements are binlogged, CURRENT_USER() just is binlogged
as 'CURRENT_USER()', it is not expanded to the real user name. When slave
executes the log event, 'CURRENT_USER()' is expand to the user of slave
SQL thread, but SQL thread's user name always NULL. This breaks the replication.
After this patch, session's user will be written into query log events
if these statements call CURREN_USER() or 'ALTER EVENT' does not assign a definer.
Apart strict-aliasing warnings, fix the remaining warnings
generated by GCC 4.4.4 -Wall and -Wextra flags.
One major source of warnings was the in-house function my_bcmp
which (unconventionally) took pointers to unsigned characters
as the byte sequences to be compared. Since my_bcmp and bcmp
are deprecated functions whose only difference with memcmp is
the return value, every use of the function is replaced with
memcmp as the special return value wasn't actually being used
by any caller.
There were also various other warnings, mostly due to type
mismatches, missing return values, missing prototypes, dead
code (unreachable) and ignored return values.
POSIX requires that a signal handler defined with sigaction()
is not reset on delivering a signal unless SA_NODEFER or
SA_RESETHAND is set. It is therefore unnecessary to redefine
the handler on signal delivery on platforms where sigaction()
is used without those flags.
The problem is that QUICK_SELECT_DESC behaviour depends
on used_key_parts value which can be bigger than selected
best_key_parts value if an engine supports clustered key.
But used_key_parts is overwritten with best_key_parts
value that prevents from correct selection of index
access method. The fix is to preserve used_key_parts
value for further use in QUICK_SELECT_DESC.
During creation of the table list of
processed tables hidden I_S table 'VARIABLES'
is erroneously added into the table list.
it leads to ER_UNKNOWN_TABLE error in
TABLE_LIST::add_table_to_list() function.
The fix is to skip addition of hidden I_S
tables into the table list.
require O(#scans) memory
When an index merge operation was restarted, it would
re-allocate the Unique object controlling the duplicate row
ID elimination. Fixed by making the Unique object a member
of QUICK_INDEX_MERGE_SELECT and thus reusing it throughout
the lifetime of this object.
file .\filesort.cc, line 149 (part II)
Problem: the server didn't disregard sort order
for some zero length tuples.
Fix: skip sort order in such a case
(zero length NOT NULL string functions).
Calculating the estimated number of records for a range scan
may take a significant time, and it was impossible for a user
to interrupt that process by killing the connection or the
query.
Fixed by checking the thread's 'killed' status in
check_quick_keys() and interrupting the calculation process if
it is set to a non-zero value.
strict aliasing violations.
Post-merge fix: include my_compiler.h before my_attribute.h
as the latter will undef __attribute__ if the compiler is not
GCC. Based on the compiler version, in my_compiler.h we know
for sure whether the aligned attribute is supported. Furthermore,
undefining attribute might cause bugs if some system header
uses it.
strict aliasing violations.
Another rather noisy violation of strict aliasing rules
is the spatial code which makes use of stack-based memory
(of type Geometry_buffer) to provide placement for Geometry
objects. Although a placement new is allowed to dynamically
change the type of a object, the object returned by the
new placement was being ignored and the original stack-based
object was being casted to the new type, thus violating strict
aliasing rules.
The solution is to reorganize the code so that the object
returned by the new placement is used instead of casting the
original object. Also, to ensure that the stack-based object
is properly aligned with respect to the objects it provides
placement for, a set of compiler-dependent macros and types
are introduced so that the alignment of objects can be inquired
and specified.
and reverse() function
3 problems fixed :
1. The reported problem : caused by incorrect parsing of
the file as ucs data resulting in wrong length of the parsed
string. Fixed by truncating the invalid trailing bytes
(non-complete multibyte characters) when reading from the file
2. LOAD DATA when reading from a proper UCS2 file wasn't
recognizing the new line characters. Fixed by first looking
if a byte is a new line (or any other special) character before
reading it as a part of a multibyte character.
3. When using user variables to hold the column data in LOAD
DATA the character set of the user variable was set incorrectly
to the database charset. Fixed by setting it to the charset
specified by LOAD DATA (if any).
bytes_received/bytes_sent are ulonglong so they cannot be handled by the
ulong handling code in add_to_status/add_diff_to_status().
Fixed by adding code to handle these two variables in
add_to_status()/add_diff_to_status() and making sure they are not a subject
to the ulong handling code.
