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Date: Wed, 22 Jan 2014 07:51:49 +0200
From: Orit Wasserman <owasserm@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v2] migration:fix free XBZRLE decoded_buf
 wrong
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To: "Gonglei (Arei)" <arei.gonglei@huawei.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, "qemu-stable@nongnu.org" <qemu-stable@nongnu.org>, Peter Maydell <peter.maydell@linaro.org>, "anthony@codemonkey.ws" <anthony@codemonkey.ws>, "pbonzini@redhat.com" <pbonzini@redhat.com>
Cc: "chenliang (T)" <chenliang88@huawei.com>, Luonengjun <luonengjun@huawei.com>, "Huangweidong (Hardware)" <huangweidong@huawei.com>

On 01/21/2014 02:58 PM, Gonglei (Arei) wrote:
>
>> -----Original Message-----
>> From: Orit Wasserman [mailto:owasserm@redhat.com]
>> Sent: Tuesday, January 21, 2014 8:24 PM
>> To: Gonglei (Arei); qemu-devel@nongnu.org; qemu-stable@nongnu.org; Peter
>> Maydell; anthony@codemonkey.ws; pbonzini@redhat.com
>> Cc: chenliang (T); Luonengjun; Huangweidong (Hardware)
>> Subject: Re: [Qemu-devel] [PATCH v2] migration:fix free XBZRLE decoded_buf
>> wrong
>>
>> On 01/21/2014 02:11 PM, Gonglei (Arei) wrote:
>>> Hi,
>>>
>>> This is an update of my patch.
>>> Modifications in v2:
>>> * Removing excess check for g_free
>>> * The structure of XBZRLE is divided into two halves.One is for
>>> * src side, another is for dest side.
>>>
>>
>> What is the benefit of splitting the structure?
>> decode_buf is only allocated (and freed) in the destination any way.
>
> Yeah, you are right. Splitting the structure is not necessary.
> The key to do that is just for clear logic. As Peter said:
> the current arrangement looks extremely prone to bugs like
> this one where somebody forgets that some of the fields are
> not relevant to whichever of src/dst the code path they're
> writing is used on.
>
> Best regards,
> -Gonglei
>

Sounds reasonable.
Thanks for finding the leak and fixing it.

Orit

Orit