Re: [libvirt] [PATCH] qemu: fix use a nonexist address in qemuDomainAttachDeviceConfig
On 12/16/2014 08:00 PM, Peter Krempa wrote:
On 12/15/14 10:10, Luyao Huang wrote:
> We free them before, then use it. This make we always do
We clear the pointer, not free.
> virDomainDefAddImplicitControllers when attach a disk.
>
> Signed-off-by: Luyao Huang <lhuang(a)redhat.com>
> ---
> src/qemu/qemu_driver.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index df3ba6d..a9afa5d 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -7223,10 +7223,10 @@ qemuDomainAttachDeviceConfig(virQEMUCapsPtr qemuCaps,
> if (virDomainDiskInsert(vmdef, disk))
> return -1;
> /* vmdef has the pointer. Generic codes for vmdef will do all jobs */
> - dev->data.disk = NULL;
The comment even explains why the line is there. From that point on, the
pointer is owned by 'vmdef' and thus the original needs to be cleared so
that it isn't freed (and doulbe freed) later on.
Oh, i see. Thanks for your
review and i found seems i don't check if gdb
is real go to virDomainDefAddImplicitControllers, just check the
pointer's value is optimized out.
(gdb)
7204 dev->data.disk = NULL;
(gdb)
7205 if (disk->bus != VIR_DOMAIN_DISK_BUS_VIRTIO)
(gdb) p disk
$3 = <optimized out>
Thanks a lot for your help :)
> if (disk->bus != VIR_DOMAIN_DISK_BUS_VIRTIO)
Additionally, 'disk' contains still a valid copy of the pointer so the
code should run just fine.
> if (virDomainDefAddImplicitControllers(vmdef) < 0)
> return -1;
> + dev->data.disk = NULL;
So moving the line here doesn't make sense.
> if (qemuDomainAssignAddresses(vmdef, qemuCaps, NULL) < 0)
> return -1;
> break;
>
NACK,
Peter
Luyao