On 05/23/2018 06:31 AM, Y Song wrote: > 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. Aside from this the cgrp->kn->id.id is also u64, so overlapping this with error codes we'll get into a similar issue as with bpf_perf_event_read(). -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
