Re: [Qemu-devel] [PATCH] virtio-blk: Do not segfault fault if failed to initialize dataplane

[Kevin Wolf]

Am 19.03.2013 um 09:37 hat KONRAD Frédéric geschrieben:
> On 19/03/2013 09:27, Dunrong Huang wrote:
> >$ ~/usr/bin/qemu-system-x86_64 -enable-kvm -m 1024 -drive 
> >if=none,id=drive0,cache=none,aio=native,format=raw,file=/root/Image/centos-6.4.raw
> > -device virtio-blk-pci,drive=drive0,scsi=off,x-data-plane=on,config-wce=on 
> ># make dataplane fail to initialize
> >qemu-system-x86_64: -device 
> >virtio-blk-pci,drive=drive0,scsi=off,x-data-plane=on,config-wce=on: device 
> >is incompatible with x-data-plane, use config-wce=off
> >*** glibc detected *** /root/usr/bin/qemu-system-x86_64: free(): invalid 
> >pointer: 0x00007f001fef12f8 ***
> >======= Backtrace: =========
> >/lib64/libc.so.6(+0x7d776)[0x7f00153a5776]
> >/root/usr/bin/qemu-system-x86_64(+0x2c34ec)[0x7f001cf5b4ec]
> >/root/usr/bin/qemu-system-x86_64(+0x342f9a)[0x7f001cfdaf9a]
> >/root/usr/bin/qemu-system-x86_64(+0x33694e)[0x7f001cfce94e]
> >....................
> >
> >  (gdb) bt
> >  #0  0x00007f3bf3a12015 in raise () from /lib64/libc.so.6
> >  #1  0x00007f3bf3a1348b in abort () from /lib64/libc.so.6
> >  #2  0x00007f3bf3a51a4e in __libc_message () from /lib64/libc.so.6
> >  #3  0x00007f3bf3a57776 in malloc_printerr () from /lib64/libc.so.6
> >  #4  0x00007f3bfb60d4ec in free_and_trace (mem=0x7f3bfe0129f8) at vl.c:2786
> >  #5  0x00007f3bfb68cf9a in virtio_cleanup (vdev=0x7f3bfe0129f8) at 
> > /root/Develop/QEMU/qemu/hw/virtio.c:900
> >  #6  0x00007f3bfb68094e in virtio_blk_device_init (vdev=0x7f3bfe0129f8) at 
> > /root/Develop/QEMU/qemu/hw/virtio-blk.c:666
> >  #7  0x00007f3bfb68dadf in virtio_device_init (qdev=0x7f3bfe0129f8) at 
> > /root/Develop/QEMU/qemu/hw/virtio.c:1092
> >  #8  0x00007f3bfb50da46 in device_realize (dev=0x7f3bfe0129f8, 
> > err=0x7fff479c9258) at hw/qdev.c:176
> >.............................
> >
> >In virtio_blk_device_init(), the memory which vdev point to is a static
> >member of "struct VirtIOBlkPCI", not heap memory, and it does not
> >get freed. So we shoule use virtio_common_cleanup() to clean this 
> >VirtIODevice
> >rather than virtio_cleanup(), which attempts to free the vdev.
> >
> >This error was introduced by commit 05ff686536f408ba6e8426b1b54d25bd3379fda2
> >recently.
> >
> >Signed-off-by: Dunrong Huang <address@hidden>
> Reviewed-by: KONRAD Frederic <address@hidden>
> 
> Oops sorry for that :/

So virtio_init() has to be paired with virtio_common_cleanup(), and
virtio_common_init() with virtio_cleanup()? Confusing...

Anyway, the patch looks correct. Thanks, applied to the block branch.

Kevin