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

[KONRAD Frédéric]

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 :/
> ---
>   hw/virtio-blk.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
> index e6f8875..f2143fd 100644
> --- a/hw/virtio-blk.c
> +++ b/hw/virtio-blk.c
> @@ -663,7 +663,7 @@ static int virtio_blk_device_init(VirtIODevice *vdev)
>       s->vq = virtio_add_queue(vdev, 128, virtio_blk_handle_output);
>   #ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
>       if (!virtio_blk_data_plane_create(vdev, blk, &s->dataplane)) {
> -        virtio_cleanup(vdev);
> +        virtio_common_cleanup(vdev);
>           return -1;
>       }
>   #endif