1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/stringify.h>
11 int cgroupfs_find_mountpoint(char *buf, size_t maxlen, const char *subsys)
14 char mountpoint[PATH_MAX + 1], tokens[PATH_MAX + 1], type[PATH_MAX + 1];
15 char path_v1[PATH_MAX + 1], path_v2[PATH_MAX + 2], *path;
16 char *token, *saved_ptr = NULL;
18 fp = fopen("/proc/mounts", "r");
23 * in order to handle split hierarchy, we need to scan /proc/mounts
24 * and inspect every cgroupfs mount point to find one that has
25 * perf_event subsystem
30 while (fscanf(fp, "%*s %"__stringify(PATH_MAX)"s %"__stringify(PATH_MAX)"s %"
31 __stringify(PATH_MAX)"s %*d %*d\n",
32 mountpoint, type, tokens) == 3) {
34 if (!path_v1[0] && !strcmp(type, "cgroup")) {
36 token = strtok_r(tokens, ",", &saved_ptr);
38 while (token != NULL) {
39 if (subsys && !strcmp(token, subsys)) {
40 strcpy(path_v1, mountpoint);
43 token = strtok_r(NULL, ",", &saved_ptr);
47 if (!path_v2[0] && !strcmp(type, "cgroup2"))
48 strcpy(path_v2, mountpoint);
50 if (path_v1[0] && path_v2[0])
62 if (strlen(path) < maxlen) {