On Mon, Jun 19, 2023 at 08:18:20PM +0900, Vincent MAILHOL wrote: > On Fri. 16 juin 2023 at 16:34, Richard W.M. Jones <rjo...@redhat.com> wrote: > (...) > > > Last thing, the segfault on ldmtool [1] still seems a valid issue. > > > Even if I now do have a workaround for my problem, that segfault might > > > be worth a bit more investigation. > > > > Yes that does look like a real problem. Does it crash if you just run > > ldmtool as a normal command, nothing to do with libguestfs? Might be > > a good idea to try to get a stack trace of the crash. > > The fact is that it only crashes with the UUID 65534 in the qemu VM. I > am not sure what command line is passed to ldmtool for this crash to > occur. > > I can help to gather information, but my biggest issue is that I do > not know how to interact with the VM under /tmp/.guestfs-1001/
I think you've solved the problem now, but for future reference you can run: $ virt-rescue (there are various options, see the manual). This will create a virtual machine with the appliance and drop you into a shell. Rich. > [ 0.777352] ldmtool[164]: segfault at 0 ip 0000563a225cd6a5 sp > 00007ffe54965a60 error 4 in ldmtool[563a225cb000+3000] > ^^^^ ^^^^^^^^^^^^^^^^^^^ > This smells like a NULL pointer dereference. The instruction pointer > being 563a225cd6a5, I installed libguestfs-tools-dbgsym and tried a: > > addr2line -e /usr/bin/ldmtool 564a892506a5 > > Results: > > ??:0 > > Without conviction, I also tried in GDB: > > $ gdb /usr/bin/ldmtool > (...) > Reading symbols from /usr/bin/ldmtool... > Reading symbols from > /usr/lib/debug/.build-id/21/37b4a64903ebe427c242be08b8d496ba570583.debug... > (gdb) info line *0x564a892506a5 > No line number information available for address 0x564a892506a5 > > Debug symbols are correctly installed but impossible to convert that > instruction pointer into a line number. It is as if the ldmtool on my > host and the ldmtool in the qemu VM were from a different build. I > tried to mount /tmp/.guestfs-1001/appliance.d/root but that disk image > did not contain ldmtool. > > I am not sure how to generate a stack trace or a core dump within that > qemu VM. If you can tell me how to get an interactive prompt (or any > other guidance) I can try to collect more information. > > > Yours sincerely, > Vincent Mailhol -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://listman.redhat.com/mailman/listinfo/libguestfs
