Essentially, the problem is that safemalloc is excruciatingly
slow as it checks all allocated blocks for overrun at each
memory management primitive, yielding a almost exponential
slowdown for the memory management functions (malloc, realloc,
free). The overrun check basically consists of verifying some
bytes of a block for certain magic keys, which catches some
simple forms of overrun. Another minor problem is violation
of aliasing rules and that its own internal list of blocks
is prone to corruption.
Another issue with safemalloc is rather the maintenance cost
as the tool has a significant impact on the server code.
Given the magnitude of memory debuggers available nowadays,
especially those that are provided with the platform malloc
implementation, maintenance of a in-house and largely obsolete
memory debugger becomes a burden that is not worth the effort
due to its slowness and lack of support for detecting more
common forms of heap corruption.
Since there are third-party tools that can provide the same
functionality at a lower or comparable performance cost, the
solution is to simply remove safemalloc. Third-party tools
can provide the same functionality at a lower or comparable
performance cost.
The removal of safemalloc also allows a simplification of the
malloc wrappers, removing quite a bit of kludge: redefinition
of my_malloc, my_free and the removal of the unused second
argument of my_free. Since free() always check whether the
supplied pointer is null, redudant checks are also removed.
Also, this patch adds unit testing for my_malloc and moves
my_realloc implementation into the same file as the other
memory allocation primitives.
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.
mysqld-debug.exe in 5.5.3 on windows
Fix:
- Do not rename PDB, install mysqld.pdb matching
mysqld-debug.exe into bin\debug subdirectory
- Stack tracing code will now additionally look in
debug subdirectory of the application directory
for debug symbols.
- Small cleanup in stacktracing code: link with
dbghelp rather than load functions dynamically
at runtime, since dbghelp.dll is always present.
- Install debug binaries with WiX
Bug#47633 - assert in ha_myisammrg::info during OPTIMIZE
The server crashed on an attempt to optimize a MERGE table with
non-existent child table.
mysql_admin_table() relied on the table to be successfully open
if a table object had been allocated.
Changed code to check return value of the open function before
calling a handler:: function on it.
strict aliasing violations.
Essentially, the problem is that large parts of the server were
developed in simpler times (last decades, pre C99 standard) when
strict aliasing and compilers supporting such optimizations were
rare to non-existent. Thus, when compiling the server with a modern
compiler that uses strict aliasing rules to perform optimizations,
there are several places in the code that might trigger undefined
behavior.
As evinced by some recent bugs, GCC does a somewhat good of job
misoptimizing such code, but on the other hand also gives warnings
about suspicious code. One problem is that the warnings aren't
always accurate, yet we can't afford to just shut them off as we
might miss real cases. False-positive cases are aggravated mostly
by casts that are likely to trigger undefined behavior.
The solution is to start a cleanup process focused on fixing and
reducing the amount of strict-aliasing related warnings produced
by GCC and others compilers. A good deal of noise reduction can
be achieved by just removing useless casts that are product of
historical cruft and are likely to trigger undefined behavior if
dereferenced.
Prior to this fix, mysys mutexes such as THR_LOCK_lock could be initialized
twice by a call to my_init().
The root cause was out of place initialization in my_basic_init(),
calling my_thread_global_init().
With this fix,
- my_basic_init() properly initializes the mutex implementation itself,
for SAFE or FAST mutexes, and for platform dependent initializations,
before initialiazing a mutex.
- my_init() properly initializes mysys mutexes once,
when making the first call to my_thread_global_init().
Conflicts:
Text conflict in mysql-test/r/archive.result
Contents conflict in mysql-test/r/innodb_bug38231.result
Text conflict in mysql-test/r/mdl_sync.result
Text conflict in mysql-test/suite/binlog/t/disabled.def
Text conflict in mysql-test/suite/rpl_ndb/r/rpl_ndb_binlog_format_errors.result
Text conflict in mysql-test/t/archive.test
Contents conflict in mysql-test/t/innodb_bug38231.test
Text conflict in mysql-test/t/mdl_sync.test
Text conflict in sql/sp_head.cc
Text conflict in sql/sql_show.cc
Text conflict in sql/table.cc
Text conflict in sql/table.h
Fix various mismatches between function's language linkage. Any
particular function that is declared in C++ but should be callable
from C must have C linkage. Note that function types with different
linkages are also distinct. Thus, if a function type is declared in
C code, it will have C linkage (same if declared in a extern "C"
block).
Due to a BZR bug, that merge was done by the following command:
bzr merge -r 'revid:tor.didriksen@sun.com-20100527074248-6qtv0p1ugy6o1hjo..' <mysql-trunk-bugfixing path>
Item_hex_string::Item_hex_string
The status of memory allocation in the Lex_input_stream (called
from the Parser_state constructor) was not checked which led to
a parser crash in case of the out-of-memory error.
The solution is to introduce new init() member function in
Parser_state and Lex_input_stream so that status of memory
allocation can be returned to the caller.
TO DO: Enable this in CMake-based builds.
------------------------------------------------------------
revno: 3474
revision-id: marko.makela@oracle.com-20100520104042-ma2nsscqdvwoph8k
parent: marko.makela@oracle.com-20100519081618-h38q02qxuvcowbtk
committer: Marko Mäkelä <marko.makela@oracle.com>
branch nick: 5.1-innodb
timestamp: Thu 2010-05-20 13:40:42 +0300
message:
Bug#53593: Add some instrumentation to improve Valgrind sensitivity
BUILD/*: Add valgrind_configs=--with-valgrind.
BUILD/*: Remove -USAFEMALLOC from valgrind_flags.
configure.in: Add AC_ARG_WITH(valgrind) and HAVE_VALGRIND.
include/my_sys.h: Define a number of MEM_ wrappers for VALGRIND_ functions.
include/my_sys.h: Make TRASH do MEM_UNDEFINED().
include/m_string.h: Remove unused macro bzero_if_purify(A,B).
_mymalloc(): Declare MEM_UNDEFINED() on the allocated memory.
_myfree(): Declare MEM_NOACCESS() on the freed memory.
storage/innobase/include/univ.i: Enable UNIV_DEBUG_VALGRIND based on
HAVE_VALGRIND rather than HAVE_purify.
Possible things to do:
* In my_global.h, remove the defined(HAVE_purify) condition
from the _WIN32 uint3korr().
* In my_global.h *int*korr(), use | instead of +
in order to keep the Valgrind V bits accurate
* Consider replacing HAVE_purify with HAVE_VALGRIND
* Use VALGRIND_CREATE_BLOCK, VALGRIND_DISCARD in mem_root and similar places
BUILD/*: Add valgrind_configs=--with-valgrind.
BUILD/*: Remove -USAFEMALLOC from valgrind_flags.
configure.in: Add AC_ARG_WITH(valgrind) and HAVE_VALGRIND.
include/my_sys.h: Define a number of MEM_ wrappers for VALGRIND_ functions.
include/my_sys.h: Make TRASH do MEM_UNDEFINED().
include/m_string.h: Remove unused macro bzero_if_purify(A,B).
_mymalloc(): Declare MEM_UNDEFINED() on the allocated memory.
_myfree(): Declare MEM_NOACCESS() on the freed memory.
storage/innobase/include/univ.i: Enable UNIV_DEBUG_VALGRIND based on
HAVE_VALGRIND rather than HAVE_purify.
Possible things to do:
* In my_global.h, remove the defined(HAVE_purify) condition
from the _WIN32 uint3korr().
* In my_global.h *int*korr(), use | instead of +
in order to keep the Valgrind V bits accurate
* Consider replacing HAVE_purify with HAVE_VALGRIND
* Use VALGRIND_CREATE_BLOCK, VALGRIND_DISCARD in mem_root and similar places
(make relies GNU extentions). The patch was partially
backport from 6.0.
Original comment:
bug#30708: make relies GNU extensions. Now that we no longer use
BitKeeper we can safely remove the SCCS handling with no loss of
functionality.
Conflicts:
Text conflict in mysql-test/r/grant.result
Text conflict in mysql-test/t/grant.test
Text conflict in mysys/mf_loadpath.c
Text conflict in sql/slave.cc
Text conflict in sql/sql_priv.h
Bug#53417 my_getwd() makes assumptions on the buffer sizes which not always hold true
The mysys library contains many functions for rewriting file paths. Most of these
functions makes implicit assumptions on the buffer sizes they write to. If a path is put
in my_realpath() it will propagate to my_getwd() which assumes that the buffer holding
the path name is greater than 2. This is not true in cases.
In the special case where a VARBIN_ITEM is passed as argument to the LOAD_FILE function
this can lead to a crash.
This patch fixes the issue by introduce more safe guards agaist buffer overruns.
Several problems addressed:
1. The maximum value for --open_files_limit on non-windows boxes
is now raised to UINT_MAX (the maximum possible without significant
changes in the code). The maximum value on windows is kept to be
2048 due to a known limitation (bug 24509).
2. mysqld_safe now supports --open_files_limit=xx in addition to
--open-files-limit=xx
3. mysqld_safe always passes through --open[_-]files[_-]limit
to the underlying mysqld. It used to pass it through only if it
the user running the script has access to the root directory or
there was an --user argument specified.
4. Fixed a prototype in my_file.c to match its counterpart in
the other #ifdef branch.
Conflicts:
Text conflict in mysql-test/suite/binlog/r/binlog_row_mix_innodb_myisam.result
Text conflict in sql/log.cc
Text conflict in sql/set_var.cc
Text conflict in sql/sql_class.cc
Conflicts:
Text conflict in client/mysqlbinlog.cc
Text conflict in mysql-test/Makefile.am
Text conflict in mysql-test/collections/default.daily
Text conflict in mysql-test/r/mysqlbinlog_row_innodb.result
Text conflict in mysql-test/suite/rpl/r/rpl_typeconv_innodb.result
Text conflict in mysql-test/suite/rpl/t/rpl_get_master_version_and_clock.test
Text conflict in mysql-test/suite/rpl/t/rpl_row_create_table.test
Text conflict in mysql-test/suite/rpl/t/rpl_slave_skip.test
Text conflict in mysql-test/suite/rpl/t/rpl_typeconv_innodb.test
Text conflict in mysys/charset.c
Text conflict in sql/field.cc
Text conflict in sql/field.h
Text conflict in sql/item.h
Text conflict in sql/item_func.cc
Text conflict in sql/log.cc
Text conflict in sql/log_event.cc
Text conflict in sql/log_event_old.cc
Text conflict in sql/mysqld.cc
Text conflict in sql/rpl_utility.cc
Text conflict in sql/rpl_utility.h
Text conflict in sql/set_var.cc
Text conflict in sql/share/Makefile.am
Text conflict in sql/sql_delete.cc
Text conflict in sql/sql_plugin.cc
Text conflict in sql/sql_select.cc
Text conflict in sql/sql_table.cc
Text conflict in storage/example/ha_example.h
Text conflict in storage/federated/ha_federated.cc
Text conflict in storage/myisammrg/ha_myisammrg.cc
Text conflict in storage/myisammrg/myrg_open.c
function on windows
When making sure that the directory path ends up with a
slash/backslash we need to check for the correct length of
the buffer and trim at the appropriate location so we don't
write past the end of the buffer.
