The leaks are all 40 bytes and happens in this call stack when running
mtr vcol.vcol_syntax:
alloc_root()
...
Virtual_column_info::fix_and_check_exp()
...
Delayed_insert::get_local_table()
The problem was that one copied a MEM_ROOT from THD to a TABLE without
taking into account that new blocks would be allocated through the
TABLE memroot (and would thus be leaked).
In general, one should NEVER copy MEM_ROOT from one object to another
without clearing the copied memroot!
Fixed by, at end of get_local_table(), copy all new allocated objects
to client_thd->mem_root.
Other things:
- Removed references to MEM_ROOT::total_alloc that was wrongly left
after a previous commit
This patch adds support for controlling of memory allocation
done by SP/PS that could happen on second and following executions.
As soon as SP or PS has been executed the first time its memory root
is marked as read only since no further memory allocation should
be performed on it. In case such allocation takes place it leads to
the assert hit for invariant that force no new memory allocations
takes place as soon as the SP/PS has been marked as read only.
The feature for control of memory allocation made on behalf SP/PS
is turned on when both debug build is on and the cmake option
-DWITH_PROTECT_STATEMENT_MEMROOT is set.
The reason for introduction of the new cmake option
-DWITH_PROTECT_STATEMENT_MEMROOT
to control memory allocation of second and following executions of
SP/PS is that for the current server implementation there are too many
places where such memory allocation takes place. As soon as all such
incorrect allocations be fixed the cmake option
-DWITH_PROTECT_STATEMENT_MEMROOT
can be removed and control of memory allocation made on second and
following executions can be turned on only for debug build. Before
every incorrect memory allocation be fixed it makes sense to guard
the checking of memory allocation on read only memory by extra cmake
option else we would get a lot of failing test on buildbot.
Moreover, fixing of all incorrect memory allocations could take pretty
long period of time, so for introducing the feature without necessary
to wait until all places throughout the source code be fixed it makes
sense to add the new cmake option.
This patch also fixes some bugs detected by valgrind after this
patch:
- Not enough copy_func elements was allocated by Create_tmp_table() which
causes an memory overwrite in Create_tmp_table::add_fields()
I added an ASSERT() to be able to detect this also without valgrind.
The bug was that TMP_TABLE_PARAM::copy_fields was not correctly set
when calling create_tmp_table().
- Aria::empty_bits is not allocated if there is no varchar/char/blob
fields in the table. Fixed code to take this into account.
This cannot cause any issues as this is just a memory access
into other Aria memory and the content of the memory would not be used.
- Aria::last_key_buff was not allocated big enough. This may have caused
issues with rtrees and ma_extra(HA_EXTRA_REMEMBER_POS) as they
would use the same memory area.
- Aria and MyISAM didn't take extended key parts into account, which
caused problems when copying rec_per_key from engine to sql level.
- Mark asan builds with 'asan' in version strihng to detect these in
not_valgrind_build.inc.
This is needed to not have main.sp-no-valgrind fail with asan.
Since 7c58e97 the PSI_memory_key was added to some routines in the
mysys/. This commit fixes synopses of functions that were updated with
the PSI_memory_key parameter.
The clang++ -stdlib=libc++ header file <fstream> depends on
<filesystem> that defines a member function path::root_name(),
which conflicts with the rather unused #define root_name()
that had been introduced in
commit 7c58e97bf6.
Because an instrumented -stdlib=libc++ (rather than the default
-stdlib=libstdc++) is easier to build for a working -fsanitize=memory
(cmake -DWITH_MSAN=ON), let us remove the conflicting #define for now.
This follows up commit
commit 94a520ddbe and
commit 7c5519c12d.
After these changes, the default test suites on a
cmake -DWITH_UBSAN=ON build no longer fail due to passing
null pointers as parameters that are declared to never be null,
but plenty of other runtime errors remain.
Passing a null pointer to a nonnull argument is not only undefined
behaviour, but it also grants the compiler the permission to optimize
away further checks whether the pointer is null. GCC -O2 at least
starting with version 8 may do that, potentially causing SIGSEGV.
These problems were caught in a WITH_UBSAN=ON build with the
Bug#7024 test in main.view.
In AddressSanitizer, we only want memory poisoning to happen
in connection with custom memory allocation or freeing.
The primary use of MEM_UNDEFINED is for declaring memory uninitialized
in Valgrind or MemorySanitizer. We do not want MEM_UNDEFINED to
have the unwanted side effect that AddressSanitizer would no longer
be able to complain about accessing unallocated memory.
MEM_UNDEFINED(): Define as no-op for AddressSanitizer.
MEM_MAKE_ADDRESSABLE(): Define as MEM_UNDEFINED() or
ASAN_UNPOISON_MEMORY_REGION().
MEM_CHECK_ADDRESSABLE(): Wrap also __asan_region_is_poisoned().
This patch is for MEM_ROOT only.
In debug mode add 8 byte of poisoned memory before every allocated chunk.
On the right of every chunk there will be either 1-7 trailing poisoned bytes, or
next chunk's redzone, or poisoned non allocated memory or redzone of a
malloc()ed buffer.
This will make it easier to how memory allocation is done when debugging
with either DBUG or gdb.
Will especially help when debugging stored procedures
Main change is a name argument as second argument to init_alloc_root()
init_sql_alloc()
Other things:
- Added DBUG_ENTER/EXIT to some Virtual_tmp_table functions
TRASH was mapped to TRASH_FREE and was supposed to be used for memory
that should not be accessed anymore, while TRASH_ALLOC() is to be
used for uninitialized but to-be-used memory.
But sometimes TRASH() was used in the latter sense.
Remove TRASH() macro, always use explicit TRASH_ALLOC() or TRASH_FREE().
The background is that one user had a lot of views and using some complex
queries on information schema temporary memory of more than 2G was used.
- Added new element 'total_alloc' to MEM_ROOT for easier debugging.
- Added MAX_MEMORY_USED to information_schema.processlist.
- Added new status variable "Memory_used_initial" that shows how much MariaDB
uses at startup. This gives the base value for "Memory_used".
- Reuse memory continuously for information schema queries instead of
only freeing memory at query end.
Other things
- Removed some not needed set_notnull() calls for not null columns.
Addendum:
* Before calling THD::init_for_queries(), flip the current_thd to wsrep
thread so that memory gets allocated for the right THD.
* Use wsrep_creating_startup_threads instead of plugins_are_initialized
as the condition for the execution of THD::init_for_queries() within
start_wsrep_THD(), as use of latter could still leave some room for
race.
commit 85fd3d901311688e18ffce92ffc78129e5625791
Author: Monty <monty@mariadb.org>
Date: Fri Aug 29 14:07:43 2014 +0300
my_alloc.c
- Changed 0x%lx -> %p
array.c:
- Static (preallocated) buffer can now be anywhere
my_sys.h
- Define MY_INIT_BUFFER_USED
sql_delete.cc & sql_lex.cc
- Use memroot when allocating classes (avoids call to current_thd)
sql_explain.h:
- Use preallocated buffers
sql_explain.cc:
- Use preallocated buffers and memroot
sql_select.cc:
- Use multi_alloc_root() instead of many alloc_root()
- Update calls to Explain
This is port of fix for MySQL BUG#17647863.
revno: 5572
revision-id: jon.hauglid@oracle.com-20131030232243-b0pw98oy72uka2sj
committer: Jon Olav Hauglid <jon.hauglid@oracle.com>
timestamp: Thu 2013-10-31 00:22:43 +0100
message:
Bug#17647863: MYSQL DOES NOT COMPILE ON OSX 10.9 GM
Rename test() macro to MY_TEST() to avoid conflict with libc++.
