[libvirt] [PATCH] virCgroupDetect: Print pid as long long

[Michal Privoznik]

On 06.10.2016 17:42, Daniel P. Berrange wrote:
> On Thu, Oct 06, 2016 at 05:18:11PM +0200, Pavel Hrdina wrote:
>> On Thu, Oct 06, 2016 at 04:58:40PM +0200, Michal Privoznik wrote:
>>> Pids are signed, report them as such.
>>>
>>> Before:
>>> Detected mount/mapping 2:cpuset at /sys/fs/cgroup/cpuset in /machine/qemu-4-fedora.libvirt-qemu/vcpu0 for pid 18446744073709551615
>>>
>>> After:
>>> Detected mount/mapping 2:cpuset at /sys/fs/cgroup/cpuset in /machine/qemu-4-fedora.libvirt-qemu/vcpu0 for pid -1
>>>
>>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>>> ---
>>>  src/util/vircgroup.c | 5 +++--
>>>  1 file changed, 3 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c
>>> index 8b52816..0a06a8a 100644
>>> --- a/src/util/vircgroup.c
>>> +++ b/src/util/vircgroup.c
>>> @@ -732,11 +732,12 @@ virCgroupDetect(virCgroupPtr group,
>>>              return -1;
>>>          }
>>>  
>>> -        VIR_DEBUG("Detected mount/mapping %zu:%s at %s in %s for pid %llu", i,
>>> +        VIR_DEBUG("Detected mount/mapping %zu:%s at %s in %s for pid %lld",
>>> +                  i,
>>>                    virCgroupControllerTypeToString(i),
>>>                    group->controllers[i].mountPoint,
>>>                    group->controllers[i].placement,
>>> -                  (unsigned long long)pid);
>>> +                  (long long) pid);
>>>      }
>>>  
>>>      return 0;
>>
>> Printing -1 instead of long number is better, but there are lot of
>> other places where we print pids as unsigned:
>>
>>   git grep "unsigned long long.*pid"
>>
>> it would be worth to change them too.
> 
> And add a syntax-check rule to detect such casts.

Well, I don't really like the idea turning every unsigned pid to signed.
There are places where a non-negative PID can be safely assumed (e.g.
virDomainQemuAttach, locking protocol). But okay, I will fix all the
occurrences that I think suffer the same problem and just exclude the
rest from syntax-check.

Michal