diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/cgroup/cgroup_util.c | 254 |
1 files changed, 229 insertions, 25 deletions
diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c index 8f7131dcf1ff..4c52cc6f2f9c 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.c +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -5,17 +5,21 @@ #include <errno.h> #include <fcntl.h> #include <linux/limits.h> +#include <poll.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <string.h> +#include <sys/inotify.h> #include <sys/stat.h> #include <sys/types.h> #include <sys/wait.h> #include <unistd.h> #include "cgroup_util.h" +#include "../clone3/clone3_selftests.h" +/* Returns read len on success, or -errno on failure. */ static ssize_t read_text(const char *path, char *buf, size_t max_len) { ssize_t len; @@ -23,35 +27,29 @@ static ssize_t read_text(const char *path, char *buf, size_t max_len) fd = open(path, O_RDONLY); if (fd < 0) - return fd; + return -errno; len = read(fd, buf, max_len - 1); - if (len < 0) - goto out; - buf[len] = 0; -out: + if (len >= 0) + buf[len] = 0; + close(fd); - return len; + return len < 0 ? -errno : len; } +/* Returns written len on success, or -errno on failure. */ static ssize_t write_text(const char *path, char *buf, ssize_t len) { int fd; fd = open(path, O_WRONLY | O_APPEND); if (fd < 0) - return fd; + return -errno; len = write(fd, buf, len); - if (len < 0) { - close(fd); - return len; - } - close(fd); - - return len; + return len < 0 ? -errno : len; } char *cg_name(const char *root, const char *name) @@ -84,16 +82,16 @@ char *cg_control(const char *cgroup, const char *control) return ret; } +/* Returns 0 on success, or -errno on failure. */ int cg_read(const char *cgroup, const char *control, char *buf, size_t len) { char path[PATH_MAX]; + ssize_t ret; snprintf(path, sizeof(path), "%s/%s", cgroup, control); - if (read_text(path, buf, len) >= 0) - return 0; - - return -1; + ret = read_text(path, buf, len); + return ret >= 0 ? 0 : ret; } int cg_read_strcmp(const char *cgroup, const char *control, @@ -105,7 +103,7 @@ int cg_read_strcmp(const char *cgroup, const char *control, /* Handle the case of comparing against empty string */ if (!expected) - size = 32; + return -1; else size = strlen(expected) + 1; @@ -174,17 +172,27 @@ long cg_read_lc(const char *cgroup, const char *control) return cnt; } +/* Returns 0 on success, or -errno on failure. */ int cg_write(const char *cgroup, const char *control, char *buf) { char path[PATH_MAX]; - ssize_t len = strlen(buf); + ssize_t len = strlen(buf), ret; snprintf(path, sizeof(path), "%s/%s", cgroup, control); + ret = write_text(path, buf, len); + return ret == len ? 0 : ret; +} - if (write_text(path, buf, len) == len) - return 0; +int cg_write_numeric(const char *cgroup, const char *control, long value) +{ + char buf[64]; + int ret; - return -1; + ret = sprintf(buf, "%lu", value); + if (ret < 0) + return ret; + + return cg_write(cgroup, control, buf); } int cg_find_unified_root(char *root, size_t len) @@ -218,7 +226,7 @@ int cg_find_unified_root(char *root, size_t len) int cg_create(const char *cgroup) { - return mkdir(cgroup, 0644); + return mkdir(cgroup, 0755); } int cg_wait_for_proc_count(const char *cgroup, int count) @@ -251,6 +259,10 @@ int cg_killall(const char *cgroup) char buf[PAGE_SIZE]; char *ptr = buf; + /* If cgroup.kill exists use it. */ + if (!cg_write(cgroup, "cgroup.kill", "1")) + return 0; + if (cg_read(cgroup, "cgroup.procs", buf, sizeof(buf))) return -1; @@ -331,12 +343,112 @@ int cg_run(const char *cgroup, } } +pid_t clone_into_cgroup(int cgroup_fd) +{ +#ifdef CLONE_ARGS_SIZE_VER2 + pid_t pid; + + struct __clone_args args = { + .flags = CLONE_INTO_CGROUP, + .exit_signal = SIGCHLD, + .cgroup = cgroup_fd, + }; + + pid = sys_clone3(&args, sizeof(struct __clone_args)); + /* + * Verify that this is a genuine test failure: + * ENOSYS -> clone3() not available + * E2BIG -> CLONE_INTO_CGROUP not available + */ + if (pid < 0 && (errno == ENOSYS || errno == E2BIG)) + goto pretend_enosys; + + return pid; + +pretend_enosys: +#endif + errno = ENOSYS; + return -ENOSYS; +} + +int clone_reap(pid_t pid, int options) +{ + int ret; + siginfo_t info = { + .si_signo = 0, + }; + +again: + ret = waitid(P_PID, pid, &info, options | __WALL | __WNOTHREAD); + if (ret < 0) { + if (errno == EINTR) + goto again; + return -1; + } + + if (options & WEXITED) { + if (WIFEXITED(info.si_status)) + return WEXITSTATUS(info.si_status); + } + + if (options & WSTOPPED) { + if (WIFSTOPPED(info.si_status)) + return WSTOPSIG(info.si_status); + } + + if (options & WCONTINUED) { + if (WIFCONTINUED(info.si_status)) + return 0; + } + + return -1; +} + +int dirfd_open_opath(const char *dir) +{ + return open(dir, O_DIRECTORY | O_CLOEXEC | O_NOFOLLOW | O_PATH); +} + +#define close_prot_errno(fd) \ + if (fd >= 0) { \ + int _e_ = errno; \ + close(fd); \ + errno = _e_; \ + } + +static int clone_into_cgroup_run_nowait(const char *cgroup, + int (*fn)(const char *cgroup, void *arg), + void *arg) +{ + int cgroup_fd; + pid_t pid; + + cgroup_fd = dirfd_open_opath(cgroup); + if (cgroup_fd < 0) + return -1; + + pid = clone_into_cgroup(cgroup_fd); + close_prot_errno(cgroup_fd); + if (pid == 0) + exit(fn(cgroup, arg)); + + return pid; +} + int cg_run_nowait(const char *cgroup, int (*fn)(const char *cgroup, void *arg), void *arg) { int pid; + pid = clone_into_cgroup_run_nowait(cgroup, fn, arg); + if (pid > 0) + return pid; + + /* Genuine test failure. */ + if (pid < 0 && errno != ENOSYS) + return -1; + pid = fork(); if (pid == 0) { char buf[64]; @@ -428,6 +540,18 @@ int set_oom_adj_score(int pid, int score) return 0; } +int proc_mount_contains(const char *option) +{ + char buf[4 * PAGE_SIZE]; + ssize_t read; + + read = read_text("/proc/mounts", buf, sizeof(buf)); + if (read < 0) + return read; + + return strstr(buf, option) != NULL; +} + ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t size) { char path[PATH_MAX]; @@ -438,7 +562,8 @@ ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t else snprintf(path, sizeof(path), "/proc/%d/%s", pid, item); - return read_text(path, buf, size); + size = read_text(path, buf, size); + return size < 0 ? -1 : size; } int proc_read_strstr(int pid, bool thread, const char *item, const char *needle) @@ -450,3 +575,82 @@ int proc_read_strstr(int pid, bool thread, const char *item, const char *needle) return strstr(buf, needle) ? 0 : -1; } + +int clone_into_cgroup_run_wait(const char *cgroup) +{ + int cgroup_fd; + pid_t pid; + + cgroup_fd = dirfd_open_opath(cgroup); + if (cgroup_fd < 0) + return -1; + + pid = clone_into_cgroup(cgroup_fd); + close_prot_errno(cgroup_fd); + if (pid < 0) + return -1; + + if (pid == 0) + exit(EXIT_SUCCESS); + + /* + * We don't care whether this fails. We only care whether the initial + * clone succeeded. + */ + (void)clone_reap(pid, WEXITED); + return 0; +} + +static int __prepare_for_wait(const char *cgroup, const char *filename) +{ + int fd, ret = -1; + + fd = inotify_init1(0); + if (fd == -1) + return fd; + + ret = inotify_add_watch(fd, cg_control(cgroup, filename), IN_MODIFY); + if (ret == -1) { + close(fd); + fd = -1; + } + + return fd; +} + +int cg_prepare_for_wait(const char *cgroup) +{ + return __prepare_for_wait(cgroup, "cgroup.events"); +} + +int memcg_prepare_for_wait(const char *cgroup) +{ + return __prepare_for_wait(cgroup, "memory.events"); +} + +int cg_wait_for(int fd) +{ + int ret = -1; + struct pollfd fds = { + .fd = fd, + .events = POLLIN, + }; + + while (true) { + ret = poll(&fds, 1, 10000); + + if (ret == -1) { + if (errno == EINTR) + continue; + + break; + } + + if (ret > 0 && fds.revents & POLLIN) { + ret = 0; + break; + } + } + + return ret; +} |