Re: [PATCH] [RFC] bpf: tracing: new helper bpf_get_current_cgroup_ino

[Y Song]

On Tue, May 22, 2018 at 8:35 PM, Alexei Starovoitov
<alexei.starovoitov@xxxxxxxxx> wrote:
> On Tue, May 22, 2018 at 08:33:24PM -0700, Y Song wrote:
>> +       struct cgroup *cgrp = task_dfl_cgroup(current);
>> +       if (!cgrp)
>> +               return -EINVAL;
>
> why this check is needed?

No reason :-) Originally I am concerned whether it is possible cgrp
could be NULL.
By looking at the code, it SEEMS to me that it could not be NULL, but I am not
100% sure (as I am not a cgroup expert). Since you are asking,
probably means it cannot be NULL, so will remove it in formal upstream patch.