Red Hat Bugzilla – Bug 314131
GDB issues error when debugging multiple threads
Last modified: 2008-01-15 17:56:45 EST
Description of problem: I'm trying to debug simple multithreaded app and get the following error: [Thread debugging using libthread_db enabled] Cannot find new threads: generic error Can set break points and trace as shown below. (gdb) Here is the info.. GNU gdb Red Hat Linux (6.6-15.fc7rh) Copyright (C) 2006 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-redhat-linux-gnu"... Using host libthread_db library "/lib/libthread_db.so.1". (gdb) list 9 #include <iostream> 10 11 void helloworld(const char* who) 12 { 13 std::cout << who << "says, \"Hello World.\"" << std::endl; 14 } 15 16 int main() 17 { 18 boost::thread thrd(boost::bind(&helloworld, "Bob")); (gdb) list 19 thrd.join(); 20 } 21 (gdb) b main Breakpoint 1 at 0x8048320: file ../helloworld.cpp, line 18. (gdb) run Starting program: /home/tcmichals/workspace/example/Debug/example [Thread debugging using libthread_db enabled] Cannot find new threads: generic error (gdb) n Single stepping until exit from function _start, which has no line number information. Cannot find user-level thread for LWP 3719: generic error (gdb) n Single stepping until exit from function _start, which has no line number information. Cannot find user-level thread for LWP 3719: generic error The kernel version is: Linux version 2.6.22.4-65.fc7 (kojibuilder@xenbuilder2.fedora.redhat.com) (gcc v ersion 4.1.2 20070502 (Red Hat 4.1.2-12)) #1 SMP Tue Aug 21 22:36:56 EDT 2007 Several posting on this issue i.e. http://sourceware.org/ml/gdb/2007-08/msg00128.html Version-Release number of selected component (if applicable): 2.6.22.4-65.fc7 How reproducible: Very Steps to Reproduce: 1. Using boost example, I can send it, but it is a simple program 9 #include <iostream> 10 11 void helloworld(const char* who) 12 { 13 std::cout << who << "says, \"Hello World.\"" << std::endl; 14 } 15 16 int main() 17 { 18 boost::thread thrd(boost::bind(&helloworld, "Bob")); (gdb) list 19 thrd.join(); 20 } Actual results: gdb displays this error, Cannot find new threads: generic error Expected results: It should not display this error, gdb works, but I'm trying to understand this error Additional info: Posted report on GDB website http://sourceware.org/ml/gdb/2007-09/msg00274.html and they said it is a kernel/gdb issue...
The bug reported at: http://sourceware.org/ml/gdb/2007-08/msg00128.html is a different one - it is about x86_64 kernel vs. i386 debugger. That would be a fixed Bug 247561 but I expect you have no 64-bit kernel. (going to check the i586 kernel)
(In reply to comment #1) > The bug reported at: > http://sourceware.org/ml/gdb/2007-08/msg00128.html > is a different one - it is about x86_64 kernel vs. i386 debugger. > That would be a fixed Bug 247561 but I expect you have no 64-bit kernel. > > (going to check the i586 kernel) > That is correct, just downloaded FC7, the did a CVS get on boost and created a simple app and got this issue. If you want I can attach the binary and source etc later in the day.
Created attachment 212811 [details] Unsuccessful reproducibility logs .tar.gz. Sorry but not reproducible. Linux version 2.6.22.4-65.fc7 (kojibuilder@xenbuilder4.fedora.phx.redhat.com) (gcc version 4.1.2 20070502 (Red Hat 4.1.2-12)) #1 SMP Tue Aug 21 21:32:04 EDT 2007 kernel-2.6.22.4-65.fc7.i586 gdb-6.6-15.fc7.i386 glibc-2.6-4.i686 Compiled by: g++ -o helloworld helloworld.cpp -Wall -ggdb2 -pthread -lboost_thread Source from: boost_1_34_1.tar.gz boost_1_34_1/libs/thread/tutorial/helloworld.cpp GNU gdb Red Hat Linux (6.6-15.fc7rh) Copyright (C) 2006 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-redhat-linux-gnu"... Using host libthread_db library "/lib/libthread_db.so.1". (gdb) start Breakpoint 1 at 0x8048998: file helloworld.cpp, line 17. Starting program: /root/jkratoch/redhat/state1/helloworld [Thread debugging using libthread_db enabled] [New Thread -1208108832 (LWP 2764)] [Switching to Thread -1208108832 (LWP 2764)] main () at helloworld.cpp:17 17 boost::thread thrd(&helloworld); (gdb) c Continuing. Hello World! [New Thread -1208112240 (LWP 2767)] [Thread -1208112240 (LWP 2767) exited] Program exited normally. (gdb) q
(In reply to comment #0) > The kernel version is: > Linux version 2.6.22.4-65.fc7 (kojibuilder@xenbuilder2.fedora.redhat.com) (gcc version 4.1.2 20070502 (Red Hat 4.1.2-12)) #1 SMP Tue Aug 21 22:36:56 EDT 2007 BTW you run i686 kernel according to the timestamp, still it is unreproducible for me. I would be interested if there is some incompatibility.
Ok, this might be a user error, but... I did exactly what you did and yes it worked. I'm using the latest and greatest from boost cvs. So mine is in /usr/local/lib... So using that library and changing the path ... [tcmichals@localhost examples]$ g++ -o helloworld helloworld.cpp -Wall -ggdb2 - pthread -L/usr/local/lib -lboost_thread-gcc41-mt-d [tcmichals@localhost examples]$ gdb helloworld GNU gdb Red Hat Linux (6.6-15.fc7rh) Copyright (C) 2006 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-redhat-linux-gnu"... Using host libthread_db library "/lib/libthread_db.so.1". (gdb) b main Breakpoint 1 at 0x8048a78: file helloworld.cpp, line 17. (gdb) start Breakpoint 2 at 0x8048a78: file helloworld.cpp, line 17. Starting program: /home/tcmichals/examples/helloworld /home/tcmichals/examples/helloworld: error while loading shared libraries: libb ost_thread-gcc41-mt-d-1_35.so.1.35.0: cannot open shared object file: No such f le or directory Program exited with code 0177. (gdb) exit Undefined command: "exit". Try "help". (gdb) quit [tcmichals@localhost examples]$ export LD_LIBRARY_PATH=/usr/local/lib [tcmichals@localhost examples]$ gdb helloworld GNU gdb Red Hat Linux (6.6-15.fc7rh) Copyright (C) 2006 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-redhat-linux-gnu"... Using host libthread_db library "/lib/libthread_db.so.1". (gdb) b main Breakpoint 1 at 0x8048a78: file helloworld.cpp, line 17. (gdb) start Breakpoint 2 at 0x8048a78: file helloworld.cpp, line 17. Starting program: /home/tcmichals/examples/helloworld [Thread debugging using libthread_db enabled] [New Thread -1209014576 (LWP 2826)] [Switching to Thread -1209014576 (LWP 2826)] Breakpoint 1, main () at helloworld.cpp:17 17 boost::thread thrd(&helloworld); (gdb) It worked!!! ok if I do the following: The program is running. Exit anyway? (y or n) y [tcmichals@localhost examples]$ g++ -static -o helloworld helloworld.cpp -Wall -ggdb2 -pthread -L/usr/local/lib -lboost_thread-gcc41-mt-d [tcmichals@localhost examples]$ [tcmichals@localhost examples]$ ls /usr/local/lib/libboost_thread* /usr/local/lib/libboost_thread-gcc41-mt-1_35.a /usr/local/lib/libboost_thread-gcc41-mt-1_35.so /usr/local/lib/libboost_thread-gcc41-mt-1_35.so.1.35.0 /usr/local/lib/libboost_thread-gcc41-mt.a /usr/local/lib/libboost_thread-gcc41-mt-d-1_35.a /usr/local/lib/libboost_thread-gcc41-mt-d-1_35.so /usr/local/lib/libboost_thread-gcc41-mt-d-1_35.so.1.35.0 /usr/local/lib/libboost_thread-gcc41-mt-d.a /usr/local/lib/libboost_thread-gcc41-mt-d.so /usr/local/lib/libboost_thread-gcc41-mt.so [tcmichals@localhost examples]$ [tcmichals@localhost examples]$ gdb helloworld GNU gdb Red Hat Linux (6.6-15.fc7rh) Copyright (C) 2006 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-redhat-linux-gnu"... Using host libthread_db library "/lib/libthread_db.so.1". (gdb) b main Breakpoint 1 at 0x80482ac: file helloworld.cpp, line 17. (gdb) start Breakpoint 2 at 0x80482ac: file helloworld.cpp, line 17. Starting program: /home/tcmichals/examples/helloworld [Thread debugging using libthread_db enabled] Cannot find new threads: generic error (gdb) Then I try to exit gdb and it locks up... But I thought -static links the static library? well, now atleast I know what the difference is and the issue, but don't know why.
http://sourceware.org/ml/gdb/2007-10/msg00009.html You need a current CVS snapshot of both gdb and glibc to debug static applications using NPTL. It won't be fixed until GDB 6.7 and GLIBC 2.7. So, have to wait.. but understand the issue now...
Yes, static binaries with threads is a known problem, you should have written the compilation commandline. http://people.redhat.com/drepper/no_static_linking.html
glibc is already fixed in Fedora 8; it is still broken in Fedora 7. GDB got a fix now * Thu Jan 10 2008 Jan Kratochvil <jan.kratochvil@redhat.com> - 6.6-40 - Fix+test (backport) threading of statically linked inferiors (BZ 314131). - It requires recent glibc to work in this case properly. being now built as: http://koji.fedoraproject.org/koji/taskinfo?taskID=342641 and it should be pushed by Bodhi / Fedora Updates soon. Fedora 7 would primarily need the glibc fix; I would suggest Fedora 8 upgrade as a better choice.
gdb-6.6-40.fc8 has been pushed to the Fedora 8 stable repository. If problems still persist, please make note of it in this bug report.