diff options
Diffstat (limited to 'tools/testing/selftests/cgroup/cgroup_util.c')
-rw-r--r-- | tools/testing/selftests/cgroup/cgroup_util.c | 331 |
1 files changed, 331 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 000000000000..b69bdeb4b9fe --- /dev/null +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -0,0 +1,331 @@ +/* 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" + +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, size_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; +} + +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 = strlen(expected) + 1; + char *buf; + + buf = malloc(size); + if (!buf) + return -1; + + if (cg_read(cgroup, control, buf, size)) + return -1; + + return strcmp(expected, buf); +} + +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)); +} + +int cg_write(const char *cgroup, const char *control, char *buf) +{ + char path[PATH_MAX]; + size_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(fs, "cgroup") == 0 && + strcmp(type, "cgroup2") == 0) { + strncpy(root, mount, len); + return 0; + } + } + + return -1; +} + +int cg_create(const char *cgroup) +{ + return mkdir(cgroup, 0644); +} + +static 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) { + ret = cg_killall(cgroup); + if (ret) + return ret; + usleep(100); + goto retry; + } + + if (ret && errno == ENOENT) + ret = 0; + + return ret; +} + +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; + } +} + +int cg_run_nowait(const char *cgroup, + int (*fn)(const char *cgroup, void *arg), + void *arg) +{ + int pid; + + 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; +} |