On Thu, Jan 09, 2020 at 05:46:29PM -0800, Alexei Starovoitov wrote: > 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? Thanks Alexei, I'll squash patches 2, 3, 5 together and improve the new helper test, regarding bcc changes, I also need to work on that as the one I created a while ago now is not valid https://github.com/iovisor/bcc/pull/1901/commits/a81b4352173cb82922d4d4bb965a39f781fd7693 Bests
