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.
Problem:
=======
rpl.rpl_slave_load_tmpdir_not_exist 'stmt' w3 [ fail ] Found warnings/errors
in server log file!
Test ended at 2017-09-27 20:34:55
[Warning] Master is configured to log replication events with checksum, but
will not send such events to slaves that cannot process them
^ Found warnings in /mnt/buildbot/build/mariadb-10.2.10/mysql-test/var/3/log/mysqld.1.err
ok
Analysis:
========
When slave tries to connect to master 'get_master_version_and_clock' function
is invoked to perform elaborated slave-master handshake. During this process
slave server queries master server, to know if it is checksum aware and at the
same time master is notified about its CRC-awareness. The master's side
instant value of @@global.binlog_checksum is stored in the dump thread's
uservar area as well as cached locally to become known in consensus by master
and slave.
Post hand-shake slave requests master for binlog dump. It sends
'COM_BINLOG_DUMP'. This command is sent to master by 'cli_advanced_command'
call. If there is some temporary network failure during this request_dump
call, 'end_server' is invoked to close the current connection between master
and slave. Upon connection close the dump thread on the master gets terminated
and it clears the 'uservar' data it got through master-slave handshake.
The 'COM_BINLOG_DUMP' command is sent once again without master-slave
handshake. Since the checksum data is not available with new dump thread a
warning gets reported.
Fix:
===
Upon network write error donot attempt reconnect, proceed to master-slave
handshake. This ensures that master is aware of slave's capability to use
checksums.
Some .c and .cc files are compiled as part of Mariabackup.
Enabling -Wconversion for InnoDB would also enable it for
Mariabackup. The .h files are being included during
InnoDB or Mariabackup compilation.
Notably, GCC 5 (but not GCC 4 or 6 or later versions)
would report -Wconversion for x|=y when the type is
unsigned char. So, we will either write x=(uchar)(x|y)
or disable the -Wconversion warning for GCC 5.
bitmap_set_bit(), bitmap_flip_bit(), bitmap_clear_bit(), bitmap_is_set():
Always implement as inline functions.
cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Debug
Maintainer mode makes all warnings errors. This patch fix warnings. Mostly about
deprecated `register` keyword.
Too much warnings came from Mroonga and I gave up on it.
Returned accidentally removed undefinition of MYSQL_SERVER in net_serv.cc inside embedded server
(embedded server uses real_net_read/write only as a client)
Prevented attempt to clean up embedded server if it was not initialized
Handle string length as size_t, consistently (almost always:))
Change function prototypes to accept size_t, where in the past
ulong or uint were used. change local/member variables to size_t
when appropriate.
This fix excludes rocksdb, spider,spider, sphinx and connect for now.
Fixed thd_set_peer_addr() to propagate host error count from
ip_to_hostname() to check_connection(), which tests this count to clear
errors affter successful authentication.
- Added sql/mariadb.h file that should be included first by files in sql
directory, if sql_plugin.h is not used (sql_plugin.h adds SHOW variables
that must be done before my_global.h is included)
- Removed a lot of include my_global.h from include files
- Removed include's of some files that my_global.h automatically includes
- Removed duplicated include's of my_sys.h
- Replaced include my_config.h with my_global.h
Don't use the server's version, that expects a valid THD.
Modify net_serv.cc not not use any THD if MYSQL_SERVER isn't defined.
This reverts commit aaddac5cd7.
accept proxy protocol header from client connections.
The new server variable 'proxy_protocol_networks' contains list
of networks from which proxy header is accepted.
THREE BYTES ON X86
Analysis:
=========
The macro uint3korr reads 4 bytes of data instead of 3 on
on x86 machines.
Multiple definitions were created for this macro for
optimization in WIN32. The idea was to optimize reading of
3 byte ints by reading an ordinary int and masking away the
unused byte. However this is an undefined behavior. It will
be an issue unless users are aware of allocating an extra
byte for using this macro.
Fix:
====
Removing the definition which reads 4 bytes of data. The
only definition of this macro would now read just 3 bytes
of data thus prohibiting the usage of an extra byte.
Note:
=====
This is a backport of Patches #5 and #6 for Bug#17922198.
compiled for debugging, when the server goes down
This happens in the following scenario:
- Server gets a shutdown message
- Servers sends error ER_CONNECTION_KILLED to the clients connection
- The client sends a query to the server, before the server has time to
close the connection to the client
- Client reads the ER_CONNECTION_KILLED error message
In the above case, the packet number for the reply is one less than
what the client expected and the client prints "Packets out of order".
Fixed the following way:
- The client accepts now error packages with a packet number
one less than expected.
- To ensure that this issue can be detected early in my_real_read(), error
messages sent to the client are not compressed, even when compressed protocol is used.
Commit#ebd24626ca38e7fa1e3da2acdcf88540be70fabe obsoleted the THREAD and
THREAD_SAFE_CLIENT preprocessor symbols. This is not removed in the
sql/net_serv.cc thereby the code that retries on EINTR became dead code.
Remove the THREAD_SAFE_CLIENT preprocessor directive form sql/net_serv.cc.
Also check errno for EINTR only if there is an error in preceding read call.
