Re: [PATCH 1/2] tools/libs/evtchn: decouple more from mini-os

[Andrew Cooper <amc96@xxxxxxxx>]

On 10/01/2022 12:49, Juergen Gross wrote:
> On 10.01.22 13:25, Andrew Cooper wrote:
>> On 07/01/2022 10:35, Juergen Gross wrote:
>>> @@ -75,12 +86,25 @@ static void port_dealloc(struct evtchn_port_info
>>> *port_info)
>>>    */
>>>   int osdep_evtchn_open(xenevtchn_handle *xce, unsigned int flags)
>>>   {
>>> -    int fd = alloc_fd(FTYPE_EVTCHN);
>>> +    int fd;
>>> +    struct file *file;
>>> +    struct port_list *list;
>>> +
>>> +    list = malloc(sizeof(*list));
>>> +    if ( !list )
>>> +        return -1;
>>> +
>>> +    fd = alloc_fd(FTYPE_EVTCHN);
>>> +    file = get_file_from_fd(fd);
>>>   -    if ( fd == -1 )
>>> +    if ( !file )
>>> +    {
>>> +        free(list);
>>>           return -1;
>>> +    }
>>
>> This wants rearranging to keep alloc_fd() ahead of malloc().  With that,
>> there is no need for free(list) in this error path.
>
> Yeah, but the error path of malloc() having failed is quite nasty then.

Oh yeah.  This is ugly, but I guess it is better this way around.

~Andrew