On Wed, Dec 18, 2019 at 9:38 AM Carlos Neira <cneirabustos@xxxxxxxxx> wrote: > > Currently bpf_get_current_pid_tgid(), is used to do pid filtering in bcc's > scripts but this helper returns the pid as seen by the root namespace which is > fine when a bcc script is not executed inside a container. > When the process of interest is inside a container, pid filtering will not work > if bpf_get_current_pid_tgid() is used. > This helper addresses this limitation returning the pid as it's seen by the current > namespace where the script is executing. > > In the future different pid_ns files may belong to different devices, according to the > discussion between Eric Biederman and Yonghong in 2017 Linux plumbers conference. > To address that situation the helper requires inum and dev_t from /proc/self/ns/pid. > This helper has the same use cases as bpf_get_current_pid_tgid() as it can be > used to do pid filtering even inside a container. I think the set looks like fine. Please respin against bpf-next carrying over Yonghong's ack and I'll apply it. Please squash patch 2 and 3 together. Updates to tools/uapi/bpf.h don't need to be separated anymore. Patch 5 can be squashed into them as well. Could you also improve selftest from patch 4 to test new helper both inside and outside of some container? With unshare(CLONE_NEWPID) or something. Do you have corresponding bcc change to show how it's going to be used?
