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Date: Thu, 20 Nov 2014 08:08:48 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 3/4] pcnet: fix Negative array index read
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To: Gonglei <arei.gonglei@huawei.com>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, "stefanha@redhat.com" <stefanha@redhat.com>, "Huangpeng (Peter)" <peter.huangpeng@huawei.com>



On 20/11/2014 07:44, Gonglei wrote:
> Maybe not, since two branch are "if and else if" not "if and else",
> so this change make the below code segment's wide ...
>> >     bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT);
>> >     s->phys_mem_read(s->dma_opaque, PHYSADDR(s, tmd.tbadr),
>> >                      s->buffer + s->xmit_pos, bcnt, CSR_BSWP(s));
>> >     s->xmit_pos += bcnt;
> ... more extensive.

After your patch that fixes the coverity report, they are

   if (a && b)
   else if (b)

so you can change it to

   if (!b) goto txdone;
   if (a) ...
   else ...

and then

   if (!b) goto txdone;
   <common part>
   if (!a) {
       <extra part from else>
   }

Paolo