[Bug libc/2377] New: Deadlock between dlclose and c++ exception/unwind

[Bug libc/2377] New: Deadlock between dlclose and c++ exception/unwind

[sjmunroe at us dot ibm dot com]

In this case an application is calling a library via dlopen/dlsym/dlclose. This
library created a service thread that it needs to terminate when dlclose is
called. But if the service thread takes an exception after the call to dlclose
and the libraries call to pthread_join then the service thread will hang in the
unwind code and the join will never complete.

-- 
           Summary: Deadlock between dlclose and c++ exception/unwind
           Product: glibc
           Version: unspecified
            Status: NEW
          Severity: critical
          Priority: P1
         Component: libc
        AssignedTo: drepper at redhat dot com
        ReportedBy: sjmunroe at us dot ibm dot com
                CC: glibc-bugs at sources dot redhat dot com
 GCC build triplet: powerpc-linux
  GCC host triplet: powerpc64-linux
GCC target triplet: powerpc-linux


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[Bug libc/2377] Deadlock between dlclose and c++ exception/unwind

[sjmunroe at us dot ibm dot com]

------- Additional Comments From sjmunroe at us dot ibm dot com  2006-02-21 16:55 -------
Created an attachment (id=879)
 --> (http://sourceware.org/bugzilla/attachment.cgi?id=879&action=view)
dlclose/exception testcase

Untar this file and cd in the dllock_bug directory. Then run "make". This will
build and run the testcase. 

-- 


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[Bug libc/2377] Deadlock between dlclose and c++ exception/unwind

[sjmunroe at us dot ibm dot com]

------- Additional Comments From sjmunroe at us dot ibm dot com  2006-02-21 17:00 -------
Created an attachment (id=880)
 --> (http://sourceware.org/bugzilla/attachment.cgi?id=880&action=view)
Hand built back trace of the two threads after the hang.

gdb does not give a useful back trace on powerpc fo this condition. So the
attached text file contains a handbuilt backtrace for the both threads.

-- 


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[Bug libc/2377] Deadlock between dlclose and c++ exception/unwind

[sjmunroe at us dot ibm dot com]

------- Additional Comments From sjmunroe at us dot ibm dot com  2006-02-21 17:02 -------
Example test case log:

parent   main:        called dlopen
parent   main:        calling dlsym for lib_func
parent   main:        calling lib_func
parent   lib_func:    arg1=test string
parent   lib_func:    thread created, rc=0
parent   main:        back, sleep(2)...
child    run_it:      new thread
child    run_it:      sleep(3)...
parent   main:        calling dlclose
parent   fini_Lib:    calling pthread_join
child    run_it:      awake again
child    run_it:      throw (this might hang)

-- 


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[Bug libc/2377] Deadlock between dlclose and c++ exception/unwind

[sjmunroe at us dot ibm dot com]

------- Additional Comments From sjmunroe at us dot ibm dot com  2006-02-21 17:11 -------
This testcase hangs on all the systems I have tested so far. Including;
powerpc and powerpc64, gcc-3.3.3/glibc-2.3.3, gcc-3.4.4/glibc-2.3.4, and
gcc-4.1.0/glibc-trunk.

I have try this on i686 gcc-3.3.3/glibc-2.3.3 and see the same failure there.

I suspect this general problem involving dl-close and g++ exception/unwind
processing.

-- 


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[Bug libc/2377] Deadlock between dlclose and c++ exception/unwind

[rsa at us dot ibm dot com]

------- Additional Comments From rsa at us dot ibm dot com  2006-03-20 22:30 -------
I experienced the same problems on x86:

Target: i486-linux-gnu
gcc-4.0.3/glibc-2.3.5

I'll test on x86-64 if I can find some hardware lying around.

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           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rsa at us dot ibm dot com


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[Bug libc/2377] Deadlock between dlclose and c++ exception/unwind

[rsa at us dot ibm dot com]

------- Additional Comments From rsa at us dot ibm dot com  2006-03-21 20:36 -------
I tested this on x86-64 and it fails there as well.

Target: x86-64
gcc-4.0.1/glibc-2.3.5

-- 


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[Bug libc/2377] Deadlock between dlclose and c++ exception/unwind

[drepper at redhat dot com]

------- Additional Comments From drepper at redhat dot com  2006-05-02 22:02 -------
Nothing related to C++, exceptions, and dlopen can be critical.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal


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[Bug libc/2377] Deadlock between dlclose and c++ exception/unwind

[schwab at linux-m68k dot org]

------- Additional Comments From schwab at linux-m68k dot org  2010-09-02 15:52 -------
Appears to work fine in 2.12.

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           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


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