Re: [Qemu-devel] failed kpartx on qemu-aarch64-static

[Peter Maydell]

On 2 July 2016 at 17:25, Chanho Park <address@hidden> wrote:
> I've got a kpartx crash frin qemu-aarch64 user emulation.
> The version of qemu-aarch64-static is 2.5.0 and it was also occurred
> on 2.5.1 version.
>
> /usr/bin/qemu-aarch64-static --version
> qemu-aarch64 version 2.5.0 (Debian 1:2.5+dfsg-5ubuntu10.1), Copyright
> (c) 2003-2008 Fabrice Bellard
>
> == Bug report ==
> kpartx -a -v test.img
> Unsupported ioctl: cmd=0x4c82

That's QEMU saying we don't support the ioctl, which is
LOOP_CTL_GET_FREE.

> *** stack smashing detected ***: /usr/sbin/kpartx terminated
> ======= Backtrace: =========
> /lib64/libc.so.6(+0x6e334)[0x400091d334]
> /lib64/libc.so.6(__fortify_fail+0x48)[0x400099dd60]
> /lib64/libc.so.6(+0xeed14)[0x400099dd14]
> /usr/sbin/kpartx[0x40385c]
> /usr/sbin/kpartx(read_gpt_pt+0x40)[0x404710]
> /usr/sbin/kpartx[0x402794]
> /lib64/libc.so.6(__libc_start_main+0xe8)[0x40008ce810]
> /usr/sbin/kpartx[0x403100]

This might be the result of kpartx's error handling
code not reacting well to the ioctl failing, or it might
be a different problem.

Can you retest with current QEMU git master, please?
(It will still have the missing ioctl but if the crash
is a threading or signal related problem there's a good
chance we'll do better in those areas than 2.5 was.)

I'll sort out a patch for adding the missing ioctls next
week; they should be straightforward.

thanks
-- PMM