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-rw-r--r--tools/testing/selftests/cgroup/cgroup_util.c578
1 files changed, 578 insertions, 0 deletions
diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c
new file mode 100644
index 000000000..5b16c7b0a
--- /dev/null
+++ b/tools/testing/selftests/cgroup/cgroup_util.c
@@ -0,0 +1,578 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/limits.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.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"
+
+static ssize_t read_text(const char *path, char *buf, size_t max_len)
+{
+ ssize_t len;
+ int fd;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return fd;
+
+ len = read(fd, buf, max_len - 1);
+ if (len < 0)
+ goto out;
+
+ buf[len] = 0;
+out:
+ close(fd);
+ return len;
+}
+
+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;
+
+ len = write(fd, buf, len);
+ if (len < 0) {
+ close(fd);
+ return len;
+ }
+
+ close(fd);
+
+ return len;
+}
+
+char *cg_name(const char *root, const char *name)
+{
+ size_t len = strlen(root) + strlen(name) + 2;
+ char *ret = malloc(len);
+
+ snprintf(ret, len, "%s/%s", root, name);
+
+ return ret;
+}
+
+char *cg_name_indexed(const char *root, const char *name, int index)
+{
+ size_t len = strlen(root) + strlen(name) + 10;
+ char *ret = malloc(len);
+
+ snprintf(ret, len, "%s/%s_%d", root, name, index);
+
+ return ret;
+}
+
+char *cg_control(const char *cgroup, const char *control)
+{
+ size_t len = strlen(cgroup) + strlen(control) + 2;
+ char *ret = malloc(len);
+
+ snprintf(ret, len, "%s/%s", cgroup, control);
+
+ return ret;
+}
+
+int cg_read(const char *cgroup, const char *control, char *buf, size_t len)
+{
+ char path[PATH_MAX];
+
+ snprintf(path, sizeof(path), "%s/%s", cgroup, control);
+
+ if (read_text(path, buf, len) >= 0)
+ return 0;
+
+ return -1;
+}
+
+int cg_read_strcmp(const char *cgroup, const char *control,
+ const char *expected)
+{
+ size_t size;
+ char *buf;
+ int ret;
+
+ /* Handle the case of comparing against empty string */
+ if (!expected)
+ return -1;
+ else
+ size = strlen(expected) + 1;
+
+ buf = malloc(size);
+ if (!buf)
+ return -1;
+
+ if (cg_read(cgroup, control, buf, size)) {
+ free(buf);
+ return -1;
+ }
+
+ ret = strcmp(expected, buf);
+ free(buf);
+ return ret;
+}
+
+int cg_read_strstr(const char *cgroup, const char *control, const char *needle)
+{
+ char buf[PAGE_SIZE];
+
+ if (cg_read(cgroup, control, buf, sizeof(buf)))
+ return -1;
+
+ return strstr(buf, needle) ? 0 : -1;
+}
+
+long cg_read_long(const char *cgroup, const char *control)
+{
+ char buf[128];
+
+ if (cg_read(cgroup, control, buf, sizeof(buf)))
+ return -1;
+
+ return atol(buf);
+}
+
+long cg_read_key_long(const char *cgroup, const char *control, const char *key)
+{
+ char buf[PAGE_SIZE];
+ char *ptr;
+
+ if (cg_read(cgroup, control, buf, sizeof(buf)))
+ return -1;
+
+ ptr = strstr(buf, key);
+ if (!ptr)
+ return -1;
+
+ return atol(ptr + strlen(key));
+}
+
+long cg_read_lc(const char *cgroup, const char *control)
+{
+ char buf[PAGE_SIZE];
+ const char delim[] = "\n";
+ char *line;
+ long cnt = 0;
+
+ if (cg_read(cgroup, control, buf, sizeof(buf)))
+ return -1;
+
+ for (line = strtok(buf, delim); line; line = strtok(NULL, delim))
+ cnt++;
+
+ return cnt;
+}
+
+int cg_write(const char *cgroup, const char *control, char *buf)
+{
+ char path[PATH_MAX];
+ ssize_t len = strlen(buf);
+
+ snprintf(path, sizeof(path), "%s/%s", cgroup, control);
+
+ if (write_text(path, buf, len) == len)
+ return 0;
+
+ return -1;
+}
+
+int cg_find_unified_root(char *root, size_t len)
+{
+ char buf[10 * PAGE_SIZE];
+ char *fs, *mount, *type;
+ const char delim[] = "\n\t ";
+
+ if (read_text("/proc/self/mounts", buf, sizeof(buf)) <= 0)
+ return -1;
+
+ /*
+ * Example:
+ * cgroup /sys/fs/cgroup cgroup2 rw,seclabel,noexec,relatime 0 0
+ */
+ for (fs = strtok(buf, delim); fs; fs = strtok(NULL, delim)) {
+ mount = strtok(NULL, delim);
+ type = strtok(NULL, delim);
+ strtok(NULL, delim);
+ strtok(NULL, delim);
+ strtok(NULL, delim);
+
+ if (strcmp(type, "cgroup2") == 0) {
+ strncpy(root, mount, len);
+ return 0;
+ }
+ }
+
+ return -1;
+}
+
+int cg_create(const char *cgroup)
+{
+ return mkdir(cgroup, 0755);
+}
+
+int cg_wait_for_proc_count(const char *cgroup, int count)
+{
+ char buf[10 * PAGE_SIZE] = {0};
+ int attempts;
+ char *ptr;
+
+ for (attempts = 10; attempts >= 0; attempts--) {
+ int nr = 0;
+
+ if (cg_read(cgroup, "cgroup.procs", buf, sizeof(buf)))
+ break;
+
+ for (ptr = buf; *ptr; ptr++)
+ if (*ptr == '\n')
+ nr++;
+
+ if (nr >= count)
+ return 0;
+
+ usleep(100000);
+ }
+
+ return -1;
+}
+
+int cg_killall(const char *cgroup)
+{
+ char buf[PAGE_SIZE];
+ char *ptr = buf;
+
+ if (cg_read(cgroup, "cgroup.procs", buf, sizeof(buf)))
+ return -1;
+
+ while (ptr < buf + sizeof(buf)) {
+ int pid = strtol(ptr, &ptr, 10);
+
+ if (pid == 0)
+ break;
+ if (*ptr)
+ ptr++;
+ else
+ break;
+ if (kill(pid, SIGKILL))
+ return -1;
+ }
+
+ return 0;
+}
+
+int cg_destroy(const char *cgroup)
+{
+ int ret;
+
+retry:
+ ret = rmdir(cgroup);
+ if (ret && errno == EBUSY) {
+ cg_killall(cgroup);
+ usleep(100);
+ goto retry;
+ }
+
+ if (ret && errno == ENOENT)
+ ret = 0;
+
+ return ret;
+}
+
+int cg_enter(const char *cgroup, int pid)
+{
+ char pidbuf[64];
+
+ snprintf(pidbuf, sizeof(pidbuf), "%d", pid);
+ return cg_write(cgroup, "cgroup.procs", pidbuf);
+}
+
+int cg_enter_current(const char *cgroup)
+{
+ return cg_write(cgroup, "cgroup.procs", "0");
+}
+
+int cg_enter_current_thread(const char *cgroup)
+{
+ return cg_write(cgroup, "cgroup.threads", "0");
+}
+
+int cg_run(const char *cgroup,
+ int (*fn)(const char *cgroup, void *arg),
+ void *arg)
+{
+ int pid, retcode;
+
+ pid = fork();
+ if (pid < 0) {
+ return pid;
+ } else if (pid == 0) {
+ char buf[64];
+
+ snprintf(buf, sizeof(buf), "%d", getpid());
+ if (cg_write(cgroup, "cgroup.procs", buf))
+ exit(EXIT_FAILURE);
+ exit(fn(cgroup, arg));
+ } else {
+ waitpid(pid, &retcode, 0);
+ if (WIFEXITED(retcode))
+ return WEXITSTATUS(retcode);
+ else
+ return -1;
+ }
+}
+
+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];
+
+ snprintf(buf, sizeof(buf), "%d", getpid());
+ if (cg_write(cgroup, "cgroup.procs", buf))
+ exit(EXIT_FAILURE);
+ exit(fn(cgroup, arg));
+ }
+
+ return pid;
+}
+
+int get_temp_fd(void)
+{
+ return open(".", O_TMPFILE | O_RDWR | O_EXCL);
+}
+
+int alloc_pagecache(int fd, size_t size)
+{
+ char buf[PAGE_SIZE];
+ struct stat st;
+ int i;
+
+ if (fstat(fd, &st))
+ goto cleanup;
+
+ size += st.st_size;
+
+ if (ftruncate(fd, size))
+ goto cleanup;
+
+ for (i = 0; i < size; i += sizeof(buf))
+ read(fd, buf, sizeof(buf));
+
+ return 0;
+
+cleanup:
+ return -1;
+}
+
+int alloc_anon(const char *cgroup, void *arg)
+{
+ size_t size = (unsigned long)arg;
+ char *buf, *ptr;
+
+ buf = malloc(size);
+ for (ptr = buf; ptr < buf + size; ptr += PAGE_SIZE)
+ *ptr = 0;
+
+ free(buf);
+ return 0;
+}
+
+int is_swap_enabled(void)
+{
+ char buf[PAGE_SIZE];
+ const char delim[] = "\n";
+ int cnt = 0;
+ char *line;
+
+ if (read_text("/proc/swaps", buf, sizeof(buf)) <= 0)
+ return -1;
+
+ for (line = strtok(buf, delim); line; line = strtok(NULL, delim))
+ cnt++;
+
+ return cnt > 1;
+}
+
+int set_oom_adj_score(int pid, int score)
+{
+ char path[PATH_MAX];
+ int fd, len;
+
+ sprintf(path, "/proc/%d/oom_score_adj", pid);
+
+ fd = open(path, O_WRONLY | O_APPEND);
+ if (fd < 0)
+ return fd;
+
+ len = dprintf(fd, "%d", score);
+ if (len < 0) {
+ close(fd);
+ return len;
+ }
+
+ close(fd);
+ return 0;
+}
+
+ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t size)
+{
+ char path[PATH_MAX];
+
+ if (!pid)
+ snprintf(path, sizeof(path), "/proc/%s/%s",
+ thread ? "thread-self" : "self", item);
+ else
+ snprintf(path, sizeof(path), "/proc/%d/%s", pid, item);
+
+ return read_text(path, buf, size);
+}
+
+int proc_read_strstr(int pid, bool thread, const char *item, const char *needle)
+{
+ char buf[PAGE_SIZE];
+
+ if (proc_read_text(pid, thread, item, buf, sizeof(buf)) < 0)
+ return -1;
+
+ 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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-17 01:26:18 +0000