From 596092ef8beaa73891da4f406446b283cc566cdb Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Sat, 25 May 2019 09:37:41 -0700 Subject: [PATCH] selftests/bpf: enable all available cgroup v2 controllers 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 Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/cgroup_helpers.c | 57 ++++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index 6692a40a6979..0d89f0396be4 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -33,6 +33,60 @@ 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; + } + buf[len] = 0; + 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; + } + + for (c = strtok_r(buf, " ", &c2); c; c = strtok_r(NULL, " ", &c2)) { + if (dprintf(cfd, "+%s\n", c) <= 0) { + log_err("Enabling controller %s: %s", c, path); + close(cfd); + return 1; + } + } + close(cfd); + return 0; +} + /** * setup_cgroup_environment() - Setup the cgroup environment * @@ -71,6 +125,9 @@ int setup_cgroup_environment(void) return 1; } + if (enable_all_controllers(cgroup_workdir)) + return 1; + return 0; } -- 2.45.2