Bug 1468084

Summary: undefined symbol my_progname in libnetsnmptrapd.so
Product: Red Hat Enterprise Linux 7 Reporter: k-endou
Component: net-snmpAssignee: Josef Ridky <jridky>
Status: CLOSED ERRATA QA Contact: David Jež <djez>
Severity: low Docs Contact:
Priority: unspecified    
Version: 7.3CC: awilliam, djez, ovasik, ppisar
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Fixed In Version: net-snmp-5.7.2-39.el7 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of:
: 1470004 (view as bug list) Environment:
Last Closed: 2019-08-06 13:08:42 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On:    
Bug Blocks: 1470004    
Description Flags
patch with solution
better patch none

Description k-endou 2017-07-06 01:39:15 UTC
Description of problem:
When I was trying to run a perl script which uses NetSNMP::TrapReceiver module,
I found the script aborts with an "undefined symbol" error.
The error message was:
Can't load '/usr/lib64/perl5/vendor_perl/auto/NetSNMP/TrapReceiver/TrapReceiver.so' for module NetSNMP::TrapReceiver: /lib64/libnetsnmptrapd.so.31: undefined symbol: my_progname at /usr/lib64/perl5/DynaLoader.pm line 190.

Version-Release number of selected component (if applicable):

How reproducible:
always when perl loads NetSNMP::TrapReceiver module

Steps to Reproduce:
1. execute "perl -MNetSNMP::TrapReceiver -e1"

Actual results:
aborts with the error message:
Can't load '/usr/lib64/perl5/vendor_perl/auto/NetSNMP/TrapReceiver/TrapReceiver.so' for module NetSNMP::TrapReceiver: /lib64/libnetsnmptrapd.so.31: undefined symbol: my_progname at /usr/lib64/perl5/DynaLoader.pm line 190.
 at -e line 0.
Compilation failed in require.
BEGIN failed--compilation aborted.

Expected results:
exits with no messages.

Additional info:
This seems caused by libnetsnmptrapd.so not linked dynamically to an appropriate mysql/mariadb library ( probably libmysqlclient.so ).
Because, no mysql/mariadb related library files appears in output of "ldd" command although libnetsnmptrapd.so contains some "my_*" or "mysql_*" symbols, which shown in "readelf -a".

Anyway, I also found a workaround to this problem.
Preloading libmysqlclient.so with "LD_PRELOAD" environment variable suppresses this error, and the script I tried runs normally now.
ex. $ LD_PRELOAD=/usr/lib64/mysql/libmysqlclient.so.18 perl -MNetSNMP::TrapReceiver -e1

Comment 2 Petr Pisar 2017-07-11 13:08:40 UTC
# ldd -r /usr/lib64/perl5/vendor_perl/auto/NetSNMP/TrapReceiver/TrapReceiver.so
undefined symbol: my_progname   (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_close   (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_stmt_error      (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_autocommit      (/lib64/libnetsnmptrapd.so.31)
undefined symbol: load_defaults (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_stmt_init       (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_stmt_prepare    (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_stmt_close      (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_real_connect    (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_commit  (/lib64/libnetsnmptrapd.so.31)
undefined symbol: my_init       (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_error   (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_stmt_bind_param (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_server_end      (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_stmt_sqlstate   (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_sqlstate        (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_errno   (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_init    (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_stmt_execute    (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_stmt_errno      (/lib64/libnetsnmptrapd.so.31)
undefined symbol: mysql_insert_id       (/lib64/libnetsnmptrapd.so.31)

From net-snmp build log:

libtool: link: gcc -shared  -fPIC -DPIC  .libs/snmptrapd_handlers.o .libs/snmptrapd_log.o .libs/snmptrapd_auth.o .libs/snmptrapd_sql.o   -L/builddir/build/BUILD/net-snmp-5.7.2/agent/.libs -L/builddir/build/BUILD/net-snmp-5.7.2/snmplib/.libs ../agent/.libs/libnetsnmpmibs.so -L/usr/lib64/perl5/CORE /builddir/build/BUILD/net-snmp-5.7.2/agent/.libs/libnetsnmpagent.so -lwrap /builddir/build/BUILD/net-snmp-5.7.2/snmplib/.libs/libnetsnmp.so -lsensors -lrpm -lrpmio ../snmplib/.libs/libnetsnmp.so -lssl -lcrypto -lperl -lresolv -lnsl -ldl -lm -lcrypt -lutil -lpthread -lc  -O2 -fstack-protector-strong -m64 -mtune=generic -fstack-protector -Wl,--enable-new-dtags -Wl,-rpath -Wl,/usr/lib64/perl5/CORE -fstack-protector -Wl,-z -Wl,relro -Wl,-z -Wl,now   -Wl,-soname -Wl,libnetsnmptrapd.so.31 -o .libs/libnetsnmptrapd.so.31.0.2

The symbols are indeed provided by libmysqlclient.so and the path is added into ld-linux.so configuration by file /etc/ld.so.conf.d/mariadb-x86_64.conf.

So the only missing piece is $(mysql_config --libs) option to the libnetsnmptrapd.so.31.0.2's linker command.

Obviously upstream thinks that plugins does not need explicit linkage <https://sourceforge.net/p/net-snmp/bugs/1563/>.

I think this is a bug in net-snmp build script.

Comment 3 Josef Ridky 2017-07-12 09:09:21 UTC
Created attachment 1296787 [details]
patch with solution

Comment 4 Adam Williamson 2017-07-20 17:17:27 UTC
That patch really doesn't seem like the right way to fix this. The only way I can think it might work is that it effectively results in that definition of LIBS getting 'leaked' out of the configure step, such that *everything* in the entire build process likely winds up getting linked against libmysqlclient / libmariadb .

Wouldn't a more appropriate fix be to change the rule for libnetsnmptrapd.$(LIB_EXTENSION)$(LIB_VERSION) in apps/Makefile.in ?

Comment 5 Adam Williamson 2017-07-20 18:06:01 UTC
Created attachment 1301954 [details]
better patch

I think this patch is more correct; it adds MYSQL_LIBS to the linking of libnetsnmptrapd. The other patch results in 21 occurrences of -lmariadb in the build process, including linking some libraries against libmariadb that do not *need* to be linked against it at all; this patch results in 8 occurrences of -lmariadb , but still fixes the bug (at least, the ldd command no longer reports any unresolved symbols).

Comment 6 Adam Williamson 2017-07-20 18:12:26 UTC
Filed upstream https://sourceforge.net/p/net-snmp/bugs/2792/ with my patch. I'm doing a Fedora Rawhide build with my patch, too.

Comment 11 errata-xmlrpc 2019-08-06 13:08:42 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.