Re: commit 0fc9d10 : chroot under kernel 3.4.x core dumps

[Konstantin Khlebnikov <khlebnikov@openvz.org>]

Toralf Förster wrote:
>
> When I try under kernel versions 3.4.[01] to chroot into a user mode
> linux image, I often get this :
>
> + mount -o loop /home/tfoerste/virtual/uml/gentoo_unstable /mnt/loop
> + mount -t proc none /mnt/loop/proc
> + mount -o bind /dev /mnt/loop/dev
> + mount -o bind /dev/pts /mnt/loop/dev/pts
> + mount -o bind /usr/portage /mnt/loop/usr/portage
> + mount -o bind /usr/local/portage /mnt/loop/usr/local/portage
> + mount -o bind /tmp/uml_portage /mnt/loop/var/tmp/portage
> + chroot /mnt/loop /bin/bash
> /home/tfoerste/workspace/bin/chr_uml.sh: line 55:  4143 Segmentation
> fault      (core dumped) chroot /mnt/loop /bin/bash
>
>
> The core file itself is only 400 KB in size and the back trace with gbd
> is meaningless :
>
> Core was generated by `/bin/bash'.
> Program terminated with signal 11, Segmentation fault.
> #0  0xb75cac00 in ?? ()
> (gdb) bt
> #0  0xb75cac00 in ?? ()
> #1  0xb76f4ff4 in ?? ()
> Cannot access memory at address 0xffffffdc
>
> In the rare cases, where the chroot doesn't crash, all subsequent
> commands cores instead. Furthermore it seems, that the boinc grid
> software has problems too under kernel 3.4.1.
> All kernel 3.3.x works fine.
>
> I bisected it to :
>
> commit 0fc9d1040313047edf6a39fd4d7c7defdca97c62
> Author: Konstantin Khlebnikov<khlebnikov@openvz.org>
> Date:   Wed Mar 28 14:42:54 2012 -0700
>
>      radix-tree: use iterators in find_get_pages* functions
>
>

I have two reports about this, and NFS is mentioned in both. Did you use it?