GCC Bugzilla Bug 36568

test w/o threads:

$ ./u
0x400a74 handler+0x1a
0x400a95 crash+0x10
0x400afd main+0x60
0x7fa92f9e74a4 __libc_start_main+0xf4

test w/ threads:

$ ./u threaded
0x400a74 handler+0x1a
0x400a95 crash+0x10
0x7fcea7803a3d clone+0x6d
0x7fcea7803a3d clone+0x6d
0x7fcea7803a3d clone+0x6d
0x7fcea7803a3d clone+0x6d
0x7fcea7803a3d clone+0x6d
0x7fcea7803a3d clone+0x6d
0x7fcea7803a3d clone+0x6d
0x7fcea7803a3d clone+0x6d
0x7fcea7803a3d clone+0x6d
(...)

gdb stops unwinding at clone():

$ gdb ./u
(gdb) set args threaded
(gdb) r
(...)
[New Thread 0x7fdd9636b6f0 (LWP 7318)]
[New Thread 0x42501950 (LWP 7322)]
(...)
Breakpoint 2, handler (signalNumber=11) at u.c:25
25              _Unwind_Backtrace( helper, 0 );
(gdb) bt
#0  handler (signalNumber=11) at u.c:25
#1  <signal handler called>
#2  0x0000000000400a95 in crash () at u.c:32
#3  0x00007fa0eef04070 in start_thread () from /lib64/libpthread.so.0
#4  0x00007fa0eea6da3d in clone () from /lib64/libc.so.6

gcc-4.2.4-1.x86_64
glibc-2.8-3.x86_64
gdb-6.8-1.x86_64

Created an attachment (id=15781) [edit]
testcase.

Created an attachment (id=15782) [edit]
testcase makefile.

Created an attachment (id=15812) [edit]
A patch which comes with debian and ubuntu which solves this problem

A patch which is provided with ubuntu and debian which solves the 
problem of the infinite _Unwind_Backtrace automagically. I chanced upon this
luckily. In ubuntu do apt-get install glibc-source and in patches/amd64/ 
you will find it.

*** Bug 36621 has been marked as a duplicate of this bug. ***

This is a glibc bug then.

forwarded to libc bugzilla:
http://sources.redhat.com/bugzilla/show_bug.cgi?id=6693

(In reply to comment #5)
> This is a glibc bug then.
> 

hmm, Ulrich Drepper rejects this bug report.
http://sources.redhat.com/bugzilla/show_bug.cgi?id=6693#c1