Re: [Qemu-devel] [PATCH V3] net/colo-compare.c: Fix memory leak and code style issue.

[Philippe Mathieu-Daudé]

On 7/18/19 12:37 PM, Peter Maydell wrote:
> On Thu, 18 Jul 2019 at 11:28, Philippe Mathieu-Daudé <address@hidden> wrote:
>>
>> On 7/18/19 11:22 AM, Zhang Chen wrote:
>>> From: Zhang Chen <address@hidden>
>>>
>>> This patch to fix the origin "char *data" menory leak, code style issue
>>
>> "memory"
>>
>>> and add necessary check here.
>>> Reported-by: Coverity (CID 1402785)
>>>
>>> Signed-off-by: Zhang Chen <address@hidden>
>>> ---
>>>  net/colo-compare.c | 28 +++++++++++++++++++++-------
>>>  1 file changed, 21 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/net/colo-compare.c b/net/colo-compare.c
>>> index 909dd6c6eb..fcccb4c6f6 100644
>>> --- a/net/colo-compare.c
>>> +++ b/net/colo-compare.c
>>> @@ -127,6 +127,17 @@ static int compare_chr_send(CompareState *s,
>>>                              uint32_t vnet_hdr_len,
>>>                              bool notify_remote_frame);
>>>
>>> +static bool packet_matches_str(const char *str,
>>> +                               uint8_t *buf,
>>
>> You can use 'uint8_t *buf'.
> 
> ?? that seems to be the same as what is written...

Oops sorry, I copy/pasted and  did not noticed I removed the 'const'
word. So I meant: You can use 'const uint8_t *buf'

>>
>>> +                               uint32_t packet_len)
>>> +{
>>> +    if (packet_len != strlen(str)) {
>>> +        return false;
>>> +    }
>>> +
>>> +    return !memcmp(str, buf, strlen(str));
>>
>> If you don't want to use a local variable to hold strlen(str), you can
>> reuse packet_len since it is the same value:
>>
>>        return !memcmp(str, buf, packet_len);
>>
>> However it makes the review harder, so I'd prefer using a str_len local var.
> 
> I'm pretty sure the compiler is going to optimise the
> strlen() away into a compile time constant anyway, so
> this is somewhat unnecessary micro-optimisation I think.

I was not sure, I'm glad to learn that :)

Thanks,

Phil.