Marc-André Lureau <marcandre.lur...@gmail.com> writes:
> On Wed, Mar 2, 2016 at 4:53 PM, Markus Armbruster <arm...@redhat.com> wrote:
>>>> + if (msg == -1) {
>>>> + process_msg_shmem(s, fd);
>>>
>>> the previous code used to close fd if any, it's worth to keep that imho
>>
>> I'm blind. Where?
>
> Sorry, wrong place I looked at, seems you got them all.
>
> if (msg < -1 || msg > IVSHMEM_MAX_PEERS) {
> error_report("server sent invalid message %" PRId64, msg);
> close(fd);
> return;
> }
>
>
> However, why not keep the if fd != -1 here (not a great idea to call
> close otherwise)
We refuse to make the code more verbose to avoid free(NULL), and I very
much agree with that.
close(-1) is like free(NULL) in that it is perfectly safe. Where they
differ is performance: free() checks for null right away, but close()
checks only after switching to supervisor mode. Doesn't matter on an
error path.
