From: Sargun Dhillon <sar...@sargun.me> Date: Fri, 12 Aug 2016 08:54:35 -0700
> This patchset includes a helper and an example to determine whether the probe > is > currently executing in the context of a specific cgroup based on a cgroup bpf > map / array. The helper checks the cgroupsv2 hierarchy based on the handle in > the map and if the current cgroup is equal to it, or a descendant of it. The > helper was tested with the example program, and it was verified that the > correct > behaviour occurs in the interrupt context. > > In an earlier version of this patchset I had added an "opensnoop"-like tool, > and > I realized I was basically reimplementing a lot of the code that already > exists > in the bcc repo. So, instead I decided to write a test that creates a new > mount > namespace, mounts up the cgroupv2 hierarchy, and does some basic tests. I > used > the sync syscall as a canary for these tests because it's a simple, 0-arg > syscall. Once this patch is accepted, adding support to opensnoop will be > easy. > > I also added a task_under_cgroup_hierarchy function in cgroups.h, as this > pattern is used in a couple places. Converting those can be done in a later > patchset. > > Thanks to Alexei, Tejun, and Daniel for providing review. > > v1->v2: Clean up > v2->v3: Move around ifdefs out of *.c files, add an "integration" test > v3->v4: De-genercize arraymap fetching function; > rename helper from in_cgroup to under_cgroup (makes much more sense) > Split adding cgroups task_under_cgroup_hierarchy function > v4->v5: Fix formatting Series applied, thanks.
