Ah ha!  I just learned about "gdb bt full".  The existing core dump might have what you need: Line #442.  However, the line numbers for the source code in the source tree that my Gentoo system is building from does not match exactly what you listed.

Line #442 for me is the one containing the "STREQ" macro:

    virObjectLock(mgr);
    for (i = 0; i < vm->nseclabels; i++) {
        for (j = 0; sec_managers[j]; j++)
            if (STREQ(vm->seclabels[i]->model, sec_managers[j]->drv->name))
                break;


I can rebuild with "-O0" and try again.  If I can still trigger the crash, the backtrace might have useful values for the optimized variables.  I'll post again in a few minutes.



(gdb) bt full
#0  0x00007fe4750c5d76 in __strcmp_sse42 () from /lib64/libc.so.6
No symbol table info available.
#1  0x00007fe47578ad31 in virSecurityManagerGenLabel (mgr=0x7fe4640acfa0, vm=0x7fe4640c5e40) at security/security_manager.c:442
        ret = -1
        i = <optimized out>
        j = <optimized out>
        sec_managers = 0x7fe458001880
        seclabel = <optimized out>
        generated = false
        __FUNCTION__ = "virSecurityManagerGenLabel"
        __func__ = "virSecurityManagerGenLabel"
#2  0x00007fe46aa92979 in virLXCProcessStart (conn=0x7fe460000a80, driver=0x7fe4640bd340, vm=0x7fe4640c1610, autoDestroy=false,
    reason=VIR_DOMAIN_RUNNING_BOOTED) at lxc/lxc_process.c:1144
        rc = -1
        r = <optimized out>
        nttyFDs = 1
        ttyFDs = 0x7fe458001790
        i = <optimized out>
        logfile = 0x7fe458000ad0 "/var/log/libvirt/lxc/dwj-hfax-dev.log"
        logfd = -1
        nveths = 0
        veths = 0x0
        handshakefds = {-1, -1}
        pos = -1
        ebuf = "\000\000\000\000\344\177\000\000\020\000\000\000\000\000\000\000\376\377\377\377\377\377\377\377\000\000\000\000\000\000\000\000\377\377\377\377", '\000' <repeats 12 times>"\364, \377\377\377\377\377\377\377\220Y|u\344\177\000\000\034\313\376t\344\177\000\000\000\000\000\000\020\000\000\000\217\b~u\344\177\000\000\000\000\000\000\000\000\000\000\250\246\327o\344\177\000\000t\b~u\344\177\000\000\000\000\000\000\000\000\000\000\020", '\000' <repeats 15 times>, "P\251\327o", '\000' <repeats 12 times>, "\006\247\327o\344\177\000\000\034\313\376t\344\177\000\000\000\000\000\000\344\177\000\000C\342{u\344\177\000\000x\247\327o\344\177\000\000\b\247\327o2739\000\342{u\344\177\000\000\000\000\000\000\000\000\000\000x", '\000' <repeats 15 times>"\247, Z\016v\000\000\000\000(\000\000\000\060\000\000\000\200\246\327o\344\177\000\000\300\245\327o\344\177\000\000\n", '\000' <repeats 31 times>"\227"...
        timestamp = <optimized out>
        cmd = 0x0
        priv = 0x7fe464022500
        err = 0x0
        __FUNCTION__ = "virLXCProcessStart"
        __func__ = "virLXCProcessStart"
---Type <return> to continue, or q <return> to quit---
#3  0x00007fe46aa9736e in lxcDomainCreateWithFlags (dom=0x7fe4580008c0, flags=<optimized out>) at lxc/lxc_driver.c:1054
        driver = 0x7fe4640bd340
        vm = 0x7fe4640c1610
        event = 0x0
        ret = -1
        __FUNCTION__ = "lxcDomainCreateWithFlags"



On Mon, Jul 15, 2013 at 7:06 AM, Dennis Jenkins <dennis.jenkins.75@gmail.com> wrote:

On Mon, Jul 15, 2013 at 3:18 AM, Michal Privoznik <mprivozn@redhat.com> wrote:

Interesting. If you are still able to reproduce the crash, can you try to get the line number within virSecurityManagerGenLabel where the crash happened? I think it's the STREQ line (440 linenr). Question is whether model or name is NULL.



I'll try.

I'm not sure why GDB failed to list line numbers in the backtrace.  I will recompile libvirt with "-O0 -g3" and try again.

I'm running libvirt on my Gentoo development server, built from portage.  Instead of tinkering with portage and rebuilding libvirt, I thought that I would just try the latest pull from git.  "./configure" fails, unable to find an input file.  I'll try again, using the same source tarball as listed in Gentoo's ebuild.

ostara libvirt # CFLAGS="-O0 -g3" ./configure --with-lxc

config.status: creating libvirt.pc
config.status: creating libvirt.spec
config.status: error: cannot find input file: `mingw32-libvirt.spec.in'