Errors When using "INSTALL PLUGIN"

[RingsC]

Hi,
There is maybe a error. The problem describe as following:
Going into the mysqld directory and starts mysql serverice by running"./mysqld". after service startup completely.
I use sql command to install the plugin, such as "INSTALL PLUGIN AUDIT SONAME "libaudit_plugin.so" ", the plugin will be installed successfully, but we also get the errors "ERROR 29 (HY000): File './mysqld' not found (Errcode: 2 - No such file or directory)". Although, an error message comes out, but the plugin are installed truly. "show variables likes "%audit%"" does work.

I try figure out what's going on. and i found that in function,"". calc_file_md5, it can not open the file "./mysqld"
because that the current directory has been changed to data directory but the place where the mysqld placed in. So in calc_file_md5 function, can not open "./mysqld" and error comes out.
When we use my.cnf to startup the service, the input params of calc_file_md5 is a full path, such as "/xxx/xx/xxx/mysqld", so that open function can find mysqld.

the call stack as following:
#0 Diagnostics_area::set_error_status (this=0x7f9398003b58, mysql_errno=29,
message_text=0x7f93a5520d60 "File './mysqld' not found (Errcode: 2 - No such file or directory)", returned_sqlstate=0x2058909 "HY000")
at /home/homli/work/MySQL-Audit/sql/sql_error.cc:438
#1 0x000000000150a4b0 in THD::raise_condition (this=0x7f9398000df0, sql_errno=29, sqlstate=0x2058909 "HY000", level=Sql_condition::SL_ERROR,
msg=0x7f93a5520d60 "File './mysqld' not found (Errcode: 2 - No such file or directory)", use_condition_handler=false)
at /home/homli/work/MySQL-Audit/sql/sql_class.cc:1444
#2 0x0000000000ea8776 in my_message_sql (error=29, str=0x7f93a5520d60 "File './mysqld' not found (Errcode: 2 - No such file or directory)", MyFlags=0)
at /home/homli/work/MySQL-Audit/sql/mysqld.cc:2255
#3 0x00000000018b13f1 in my_error (nr=29, MyFlags=0) at /home/homli/work/MySQL-Audit/mysys/my_error.c:210
#4 0x00000000018b5e58 in my_register_filename (fd=-1, FileName=0x7ffcdd97851c "./mysqld", type_of_file=FILE_BY_OPEN, error_message_number=29, MyFlags=16)
at /home/homli/work/MySQL-Audit/mysys/my_open.c:167
#5 0x00000000018b5898 in my_open (FileName=0x7ffcdd97851c "./mysqld", Flags=0, MyFlags=16) at /home/homli/work/MySQL-Audit/mysys/my_open.c:52
#6 0x00007f939c0166d4 in calc_file_md5 (file_name=0x7ffcdd97851c "./mysqld", digest_str=0x7f93a55254f0 "") at audit_plugin.cc:1280
#7 0x00007f939c0168e1 in setup_offsets () at audit_plugin.cc:1341
#8 0x00007f939c01a95b in audit_plugin_init (p=0x7f93980b9a30) at audit_plugin.cc:2019
#9 0x0000000000ebf2d3 in initialize_audit_plugin (plugin=0x7f93980b9a30) at /home/homli/work/MySQL-Audit/sql/sql_audit.cc:1270
#10 0x000000000159e84c in plugin_initialize (plugin=0x7f93980b9a30) at /home/homli/work/MySQL-Audit/sql/sql_plugin.cc:1197
#11 0x00000000015a0b65 in mysql_install_plugin (thd=0x7f9398000df0, name=0x7f9398006220, dl=0x7f9398006230) at /home/homli/work/MySQL-Audit/sql/sql_plugin.cc:2044
#12 0x00000000015a674d in Sql_cmd_install_plugin::execute (this=0x7f9398006218, thd=0x7f9398000df0) at /home/homli/work/MySQL-Audit/sql/sql_plugin.cc:4254
#13 0x0000000001576178 in mysql_execute_command (thd=0x7f9398000df0, first_level=true) at /home/homli/work/MySQL-Audit/sql/sql_parse.cc:4894
#14 0x0000000001578101 in mysql_parse (thd=0x7f9398000df0, parser_state=0x7f93a5527610) at /home/homli/work/MySQL-Audit/sql/sql_parse.cc:5612

[RingsC]

BTW: mysql version: 5.7.18-debug, and my.cnf as following:
[mysqld]
basedir=/home/homli/work/MySQL-Audit/bin
datadir=/home/homli/work/MySQL-Audit/bin/data
plugin-dir=/home/homli/work/MySQL-Audit/bin/lib/plugin/
user=root
port=3306
max_connections=4000
log-error=/home/homli/work/MySQL-Audit/bin/data/homli.qiyi.com.err
pid-file=/home/homli/work/MySQL-Audit/bin/data/homli.qiyi.com.pid

[aharonrobbins]

Thanks for the note. We will investigate possible solutions for this.

[aharonrobbins]

Hi. If I upload a patch here, can you apply it, build the plugin, and test that it works for you? I have a thought as to how to address the issue. Thanks.

[RingsC]

Yes, I will do that.

[aharonrobbins]

Here is the diff. Please let me know how it goes. I'll be unavailable tomorrow but will check the following day.

Thanks!

proc-open-diff.txt

[RingsC]

I have verified this path and it works on *nix platform, but how about the windows platform? and it seems that the input para of calc_file_md5 is unnecessary.

The debug info as following:
Breakpoint 1, calc_file_md5 (file_name=0x7ffdf4e78515 "./mysqld", digest_str=0x7fcf413084f0 "") at audit_plugin.cc:1277
1277 unsigned char digest[16] = {0};
(gdb) n
1278 bool ret = false;
(gdb)
1281 sprintf(pidFilename, "/proc/%d/exe", getpid());
(gdb)
1282 if ((fd = my_open(pidFilename, O_RDONLY, MYF(MY_WME))) < 0)
(gdb) p pidFilename
$1 = "/proc/24873/exe\000@\314\311\002\000\000\000\000fa\000\000\000\000\000\000\325\031\033\060\317\177\000\000\200\363\321\002\000\000\000\000\060\200\060A\317\177\000\000X\255\337\001\000\000\000\000\000\t\000L\317\177\000\000\000\t\000L\317\177\000\000\200\200\060A\317\177\000\000\263\325\337\001\000\000\000\000p\205\060A".

[aharonrobbins]

Thanks for checking. I will consider just using the file in /proc instead of the input parameter. Checking it first allows us to print a message.

You ask about Windows. The plugin isn't supported on Windows; we only support Linux.

Thanks.

[RingsC]

Okay, Thanks.

[aharonrobbins]

The fix for this issue is now pushed to Github and binaries (dev-snapshot) have been uploaded to bintray.com. Thanks.