Re: [Qemu-trivial] [PATCH] pcie: remove duplicate assertion

[Cao jin <caoj.fnst@cn.fujitsu.com>]

On 01/10/2017 06:37 AM, Michael S. Tsirkin wrote:
> On Fri, Dec 23, 2016 at 10:16:30AM +0800, Cao jin wrote:
>> "size >= 8" connote "size > 0"
>>
>> Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
> 
> Isn't the point to check for overflows?
> 

Make sense. If it is intended to check overflows, the following sequence
would make more sense:

    assert(offset >= PCI_CONFIG_SPACE_SIZE);
    assert(size >= 8);
    assert(offset < offset + size);
    assert(offset + size <= PCIE_CONFIG_SPACE_SIZE);

or else, size 0 will pass the assert(offset < offset + size) first and
hit assert(size >= 8)
-- 
Sincerely,
Cao jin

>> ---
>>  hw/pci/pcie.c | 1 -
>>  1 file changed, 1 deletion(-)
>>
>> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
>> index 39b10b852d91..f864c5cd5458 100644
>> --- a/hw/pci/pcie.c
>> +++ b/hw/pci/pcie.c
>> @@ -668,7 +668,6 @@ void pcie_add_capability(PCIDevice *dev,
>>      uint16_t next;
>>  
>>      assert(offset >= PCI_CONFIG_SPACE_SIZE);
>> -    assert(offset < offset + size);
>>      assert(offset + size <= PCIE_CONFIG_SPACE_SIZE);
>>      assert(size >= 8);
>>      assert(pci_is_express(dev));
>> -- 
>> 2.1.0
>>
>>
> 
> 
>