Re: [Xen-devel] [RFC Patch v4 7/9] correct xc_domain_save()'s return value

[Wen Congyang <wency@xxxxxxxxxxxxxx>]

On 09/22/2014 03:46 PM, Olaf Hering wrote:
> On Mon, Sep 22, Wen Congyang wrote:
> 
>> On 09/22/2014 03:30 PM, Olaf Hering wrote:
>>> On Mon, Sep 22, Wen Congyang wrote:
>>>
>>>>      if ( !(*suspend)(data) )
>>>>      {
>>>>          ERROR("Suspend request failed");
>>>> +        errno = errno ? : -1;
>>>
>>> -1 is not a valid value for errno, it should be ESOMETHING.
>>
>> But, we don't know what's wrong, so I don't know which ESOMETHING is
>> OK here...
> 
> The called function has to set errno. If it doesnt do that today, fix
> the callbacks.

The callbacks may be implemented in libxl, which is another process.
xc_domain_save() is a public API, and the caller may forget to set
the errno...

So we cannot assume that the callbacks has set the errno

Thanks
Wen Congyang

> 
> Olaf
> .
> 


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