On Wed, May 22, 2019 at 03:18:43PM -0700, Stanislav Fomichev wrote: > On 05/22, Roman Gushchin wrote: > > Enable all available cgroup v2 controllers when setting up > > the environment for the bpf kselftests. It's required to properly test > > the bpf prog auto-detach feature. Also it will generally increase > > the code coverage. > > > > Signed-off-by: Roman Gushchin <guro@xxxxxx> > > --- > > tools/testing/selftests/bpf/cgroup_helpers.c | 58 ++++++++++++++++++++ > > 1 file changed, 58 insertions(+) > > > > diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c > > index 6692a40a6979..4533839c0ce0 100644 > > --- a/tools/testing/selftests/bpf/cgroup_helpers.c > > +++ b/tools/testing/selftests/bpf/cgroup_helpers.c > > @@ -33,6 +33,61 @@ > > snprintf(buf, sizeof(buf), "%s%s%s", CGROUP_MOUNT_PATH, \ > > CGROUP_WORK_DIR, path) > > > > +/** > > + * enable_all_controllers() - Enable all available cgroup v2 controllers > > + * > > + * Enable all available cgroup v2 controllers in order to increase > > + * the code coverage. > > + * > > + * If successful, 0 is returned. > > + */ > > +int enable_all_controllers(char *cgroup_path) > > +{ > > + char path[PATH_MAX + 1]; > > + char buf[PATH_MAX]; > > + char *c, *c2; > > + int fd, cfd; > > + size_t len; > > + > > + snprintf(path, sizeof(path), "%s/cgroup.controllers", cgroup_path); > > + fd = open(path, O_RDONLY); > > + if (fd < 0) { > > + log_err("Opening cgroup.controllers: %s", path); > > + return -1; > > + } > > + > > + len = read(fd, buf, sizeof(buf) - 1); > > + if (len < 0) { > > + close(fd); > > + log_err("Reading cgroup.controllers: %s", path); > > + return -1; > > + } > > + > > + close(fd); > > + > > + /* No controllers available? We're probably on cgroup v1. */ > > + if (len == 0) > > + return 0; > > + > > + snprintf(path, sizeof(path), "%s/cgroup.subtree_control", cgroup_path); > > + cfd = open(path, O_RDWR); > > + if (cfd < 0) { > > + log_err("Opening cgroup.subtree_control: %s", path); > > + return -1; > > + } > > + > > [..] > > + buf[len] = 0; > nit: move this up a bit? Right after: Ok, np. Thanks!