diff options
Diffstat (limited to 'samples/bpf/cgroup_helpers.c')
| -rw-r--r-- | samples/bpf/cgroup_helpers.c | 178 |
1 files changed, 0 insertions, 178 deletions
diff --git a/samples/bpf/cgroup_helpers.c b/samples/bpf/cgroup_helpers.c deleted file mode 100644 index f3bca3ade0f3..000000000000 --- a/samples/bpf/cgroup_helpers.c +++ /dev/null @@ -1,178 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -#define _GNU_SOURCE -#include <sched.h> -#include <sys/mount.h> -#include <sys/stat.h> -#include <sys/types.h> -#include <linux/limits.h> -#include <stdio.h> -#include <linux/sched.h> -#include <fcntl.h> -#include <unistd.h> -#include <ftw.h> - - -#include "cgroup_helpers.h" - -/* - * To avoid relying on the system setup, when setup_cgroup_env is called - * we create a new mount namespace, and cgroup namespace. The cgroup2 - * root is mounted at CGROUP_MOUNT_PATH - * - * Unfortunately, most people don't have cgroupv2 enabled at this point in time. - * It's easier to create our own mount namespace and manage it ourselves. - * - * We assume /mnt exists. - */ - -#define WALK_FD_LIMIT 16 -#define CGROUP_MOUNT_PATH "/mnt" -#define CGROUP_WORK_DIR "/cgroup-test-work-dir" -#define format_cgroup_path(buf, path) \ - snprintf(buf, sizeof(buf), "%s%s%s", CGROUP_MOUNT_PATH, \ - CGROUP_WORK_DIR, path) - -/** - * setup_cgroup_environment() - Setup the cgroup environment - * - * After calling this function, cleanup_cgroup_environment should be called - * once testing is complete. - * - * This function will print an error to stderr and return 1 if it is unable - * to setup the cgroup environment. If setup is successful, 0 is returned. - */ -int setup_cgroup_environment(void) -{ - char cgroup_workdir[PATH_MAX + 1]; - - format_cgroup_path(cgroup_workdir, ""); - - if (unshare(CLONE_NEWNS)) { - log_err("unshare"); - return 1; - } - - if (mount("none", "/", NULL, MS_REC | MS_PRIVATE, NULL)) { - log_err("mount fakeroot"); - return 1; - } - - if (mount("none", CGROUP_MOUNT_PATH, "cgroup2", 0, NULL) && errno != EBUSY) { - log_err("mount cgroup2"); - return 1; - } - - /* Cleanup existing failed runs, now that the environment is setup */ - cleanup_cgroup_environment(); - - if (mkdir(cgroup_workdir, 0777) && errno != EEXIST) { - log_err("mkdir cgroup work dir"); - return 1; - } - - return 0; -} - -static int nftwfunc(const char *filename, const struct stat *statptr, - int fileflags, struct FTW *pfwt) -{ - if ((fileflags & FTW_D) && rmdir(filename)) - log_err("Removing cgroup: %s", filename); - return 0; -} - - -static int join_cgroup_from_top(char *cgroup_path) -{ - char cgroup_procs_path[PATH_MAX + 1]; - pid_t pid = getpid(); - int fd, rc = 0; - - snprintf(cgroup_procs_path, sizeof(cgroup_procs_path), - "%s/cgroup.procs", cgroup_path); - - fd = open(cgroup_procs_path, O_WRONLY); - if (fd < 0) { - log_err("Opening Cgroup Procs: %s", cgroup_procs_path); - return 1; - } - - if (dprintf(fd, "%d\n", pid) < 0) { - log_err("Joining Cgroup"); - rc = 1; - } - - close(fd); - return rc; -} - -/** - * join_cgroup() - Join a cgroup - * @path: The cgroup path, relative to the workdir, to join - * - * This function expects a cgroup to already be created, relative to the cgroup - * work dir, and it joins it. For example, passing "/my-cgroup" as the path - * would actually put the calling process into the cgroup - * "/cgroup-test-work-dir/my-cgroup" - * - * On success, it returns 0, otherwise on failure it returns 1. - */ -int join_cgroup(char *path) -{ - char cgroup_path[PATH_MAX + 1]; - - format_cgroup_path(cgroup_path, path); - return join_cgroup_from_top(cgroup_path); -} - -/** - * cleanup_cgroup_environment() - Cleanup Cgroup Testing Environment - * - * This is an idempotent function to delete all temporary cgroups that - * have been created during the test, including the cgroup testing work - * directory. - * - * At call time, it moves the calling process to the root cgroup, and then - * runs the deletion process. It is idempotent, and should not fail, unless - * a process is lingering. - * - * On failure, it will print an error to stderr, and try to continue. - */ -void cleanup_cgroup_environment(void) -{ - char cgroup_workdir[PATH_MAX + 1]; - - format_cgroup_path(cgroup_workdir, ""); - join_cgroup_from_top(CGROUP_MOUNT_PATH); - nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT); -} - -/** - * create_and_get_cgroup() - Create a cgroup, relative to workdir, and get the FD - * @path: The cgroup path, relative to the workdir, to join - * - * This function creates a cgroup under the top level workdir and returns the - * file descriptor. It is idempotent. - * - * On success, it returns the file descriptor. On failure it returns 0. - * If there is a failure, it prints the error to stderr. - */ -int create_and_get_cgroup(char *path) -{ - char cgroup_path[PATH_MAX + 1]; - int fd; - - format_cgroup_path(cgroup_path, path); - if (mkdir(cgroup_path, 0777) && errno != EEXIST) { - log_err("mkdiring cgroup %s .. %s", path, cgroup_path); - return 0; - } - - fd = open(cgroup_path, O_RDONLY); - if (fd < 0) { - log_err("Opening Cgroup"); - return 0; - } - - return fd; -} |