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systemd/src/basic/cgroup-util.c

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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <linux/fs.h>
#include <linux/magic.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/xattr.h>
#include <threads.h>
#include <unistd.h>
#include "alloc-util.h"
#include "capsule-util.h"
#include "cgroup-util.h"
#include "dirent-util.h"
#include "errno-util.h"
#include "extract-word.h"
#include "fd-util.h"
#include "fileio.h"
#include "format-util.h"
#include "fs-util.h"
#include "log.h"
#include "login-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "pidref.h"
#include "process-util.h"
#include "set.h"
#include "special.h"
#include "stat-util.h"
#include "string-table.h"
#include "string-util.h"
#include "strv.h"
#include "unit-name.h"
#include "user-util.h"
#include "xattr-util.h"
/* The structure to pass to name_to_handle_at() on cgroupfs2 */
typedef union {
struct file_handle file_handle;
uint8_t space[offsetof(struct file_handle, f_handle) + sizeof(uint64_t)];
} cg_file_handle;
#define CG_FILE_HANDLE_INIT \
(cg_file_handle) { \
.file_handle.handle_bytes = sizeof(uint64_t), \
.file_handle.handle_type = FILEID_KERNFS, \
}
#define CG_FILE_HANDLE_CGROUPID(fh) (*CAST_ALIGN_PTR(uint64_t, (fh).file_handle.f_handle))
int cg_path_open(const char *controller, const char *path) {
_cleanup_free_ char *fs = NULL;
int r;
r = cg_get_path(controller, path, /* suffix=*/ NULL, &fs);
if (r < 0)
return r;
return RET_NERRNO(open(fs, O_DIRECTORY|O_CLOEXEC));
}
int cg_cgroupid_open(int cgroupfs_fd, uint64_t id) {
_cleanup_close_ int fsfd = -EBADF;
if (cgroupfs_fd < 0) {
fsfd = open("/sys/fs/cgroup", O_CLOEXEC|O_DIRECTORY);
if (fsfd < 0)
return -errno;
cgroupfs_fd = fsfd;
}
cg_file_handle fh = CG_FILE_HANDLE_INIT;
CG_FILE_HANDLE_CGROUPID(fh) = id;
return RET_NERRNO(open_by_handle_at(cgroupfs_fd, &fh.file_handle, O_DIRECTORY|O_CLOEXEC));
}
int cg_path_from_cgroupid(int cgroupfs_fd, uint64_t id, char **ret) {
_cleanup_close_ int cgfd = -EBADF;
int r;
cgfd = cg_cgroupid_open(cgroupfs_fd, id);
if (cgfd < 0)
return cgfd;
_cleanup_free_ char *path = NULL;
r = fd_get_path(cgfd, &path);
if (r < 0)
return r;
if (!path_startswith(path, "/sys/fs/cgroup/"))
return -EXDEV; /* recognizable error */
if (ret)
*ret = TAKE_PTR(path);
return 0;
}
int cg_get_cgroupid_at(int dfd, const char *path, uint64_t *ret) {
cg_file_handle fh = CG_FILE_HANDLE_INIT;
int mnt_id;
assert(dfd >= 0 || (dfd == AT_FDCWD && path_is_absolute(path)));
assert(ret);
/* This is cgroupfs so we know the size of the handle, thus no need to loop around like
* name_to_handle_at_loop() does in mountpoint-util.c */
if (name_to_handle_at(dfd, strempty(path), &fh.file_handle, &mnt_id, isempty(path) ? AT_EMPTY_PATH : 0) < 0) {
assert(errno != EOVERFLOW);
return -errno;
}
*ret = CG_FILE_HANDLE_CGROUPID(fh);
return 0;
}
int cg_enumerate_processes(const char *controller, const char *path, FILE **ret) {
_cleanup_free_ char *fs = NULL;
FILE *f;
int r;
assert(ret);
r = cg_get_path(controller, path, "cgroup.procs", &fs);
if (r < 0)
return r;
f = fopen(fs, "re");
if (!f)
return -errno;
*ret = f;
return 0;
}
int cg_read_pid(FILE *f, pid_t *ret, CGroupFlags flags) {
unsigned long ul;
/* Note that the cgroup.procs might contain duplicates! See cgroups.txt for details. */
assert(f);
assert(ret);
/* NB: The kernel returns ENODEV if we tried to read from cgroup.procs of a cgroup that has been
* removed already. Callers should handle that! */
for (;;) {
errno = 0;
if (fscanf(f, "%lu", &ul) != 1) {
if (feof(f)) {
*ret = 0;
return 0;
}
return errno_or_else(EIO);
}
if (ul > PID_T_MAX)
return -EIO;
/* In some circumstances (e.g. WSL), cgroups might contain unmappable PIDs from other
* contexts. These show up as zeros, and depending on the caller, can either be plain
* skipped over, or returned as-is. */
if (ul == 0 && !FLAGS_SET(flags, CGROUP_DONT_SKIP_UNMAPPED))
continue;
*ret = (pid_t) ul;
return 1;
}
}
int cg_read_pidref(FILE *f, PidRef *ret, CGroupFlags flags) {
int r;
assert(f);
assert(ret);
for (;;) {
pid_t pid;
r = cg_read_pid(f, &pid, flags);
if (r < 0)
return log_debug_errno(r, "Failed to read pid from cgroup item: %m");
if (r == 0) {
*ret = PIDREF_NULL;
return 0;
}
if (pid == 0)
return -EREMOTE;
r = pidref_set_pid(ret, pid);
if (r >= 0)
return 1;
if (r != -ESRCH)
return r;
/* ESRCH → gone by now? just skip over it, read the next */
}
}
bool cg_kill_supported(void) {
static thread_local int supported = -1;
if (supported >= 0)
return supported;
if (cg_all_unified() <= 0)
return (supported = false);
if (access("/sys/fs/cgroup/init.scope/cgroup.kill", F_OK) >= 0)
return (supported = true);
if (errno != ENOENT)
log_debug_errno(errno, "Failed to check whether cgroup.kill is available, assuming not: %m");
return (supported = false);
}
int cg_enumerate_subgroups(const char *controller, const char *path, DIR **ret) {
_cleanup_free_ char *fs = NULL;
DIR *d;
int r;
assert(ret);
/* This is not recursive! */
r = cg_get_path(controller, path, NULL, &fs);
if (r < 0)
return r;
d = opendir(fs);
if (!d)
return -errno;
*ret = d;
return 0;
}
int cg_read_subgroup(DIR *d, char **ret) {
assert(d);
assert(ret);
FOREACH_DIRENT_ALL(de, d, return -errno) {
if (de->d_type != DT_DIR)
continue;
if (dot_or_dot_dot(de->d_name))
continue;
return strdup_to_full(ret, de->d_name);
}
*ret = NULL;
return 0;
}
int cg_kill(
const char *path,
int sig,
CGroupFlags flags,
Set *killed_pids,
cg_kill_log_func_t log_kill,
void *userdata) {
_cleanup_set_free_ Set *allocated_set = NULL;
int r, ret = 0;
assert(path);
assert(sig >= 0);
/* Don't send SIGCONT twice. Also, SIGKILL always works even when process is suspended, hence
* don't send SIGCONT on SIGKILL. */
if (IN_SET(sig, SIGCONT, SIGKILL))
flags &= ~CGROUP_SIGCONT;
/* This goes through the tasks list and kills them all. This is repeated until no further processes
* are added to the tasks list, to properly handle forking processes.
*
* When sending SIGKILL, prefer cg_kill_kernel_sigkill(), which is fully atomic. */
if (!killed_pids) {
killed_pids = allocated_set = set_new(NULL);
if (!killed_pids)
return -ENOMEM;
}
bool done;
do {
_cleanup_fclose_ FILE *f = NULL;
int ret_log_kill;
done = true;
r = cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, path, &f);
if (r == -ENOENT)
break;
if (r < 0)
return RET_GATHER(ret, log_debug_errno(r, "Failed to enumerate cgroup items: %m"));
for (;;) {
_cleanup_(pidref_done) PidRef pidref = PIDREF_NULL;
r = cg_read_pidref(f, &pidref, flags);
if (r == -ENODEV) {
/* reading from cgroup.pids will result in ENODEV if the cgroup is
* concurrently removed. Just leave in that case, because a removed cgroup
* contains no processes anymore. */
done = true;
break;
}
if (r < 0)
return RET_GATHER(ret, log_debug_errno(r, "Failed to read pidref from cgroup '%s': %m", path));
if (r == 0)
break;
if ((flags & CGROUP_IGNORE_SELF) && pidref_is_self(&pidref))
continue;
if (set_contains(killed_pids, PID_TO_PTR(pidref.pid)))
continue;
/* Ignore kernel threads to mimic the behavior of cgroup.kill. */
if (pidref_is_kernel_thread(&pidref) > 0) {
log_debug("Ignoring kernel thread with pid " PID_FMT " in cgroup '%s'", pidref.pid, path);
continue;
}
if (log_kill)
ret_log_kill = log_kill(&pidref, sig, userdata);
/* If we haven't killed this process yet, kill it */
r = pidref_kill(&pidref, sig);
if (r < 0 && r != -ESRCH)
RET_GATHER(ret, log_debug_errno(r, "Failed to kill process with pid " PID_FMT " from cgroup '%s': %m", pidref.pid, path));
if (r >= 0) {
if (flags & CGROUP_SIGCONT)
(void) pidref_kill(&pidref, SIGCONT);
if (ret == 0) {
if (log_kill)
ret = ret_log_kill;
else
ret = 1;
}
}
done = false;
r = set_put(killed_pids, PID_TO_PTR(pidref.pid));
if (r < 0)
return RET_GATHER(ret, r);
}
/* To avoid racing against processes which fork quicker than we can kill them, we repeat this
* until no new pids need to be killed. */
} while (!done);
return ret;
}
int cg_kill_recursive(
const char *path,
int sig,
CGroupFlags flags,
Set *killed_pids,
cg_kill_log_func_t log_kill,
void *userdata) {
_cleanup_set_free_ Set *allocated_set = NULL;
_cleanup_closedir_ DIR *d = NULL;
int r, ret;
assert(path);
assert(sig >= 0);
if (!killed_pids) {
killed_pids = allocated_set = set_new(NULL);
if (!killed_pids)
return -ENOMEM;
}
ret = cg_kill(path, sig, flags, killed_pids, log_kill, userdata);
r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, path, &d);
if (r < 0) {
if (r != -ENOENT)
RET_GATHER(ret, log_debug_errno(r, "Failed to enumerate cgroup '%s' subgroups: %m", path));
return ret;
}
for (;;) {
_cleanup_free_ char *fn = NULL, *p = NULL;
r = cg_read_subgroup(d, &fn);
if (r < 0) {
RET_GATHER(ret, log_debug_errno(r, "Failed to read subgroup from cgroup '%s': %m", path));
break;
}
if (r == 0)
break;
p = path_join(empty_to_root(path), fn);
if (!p)
return -ENOMEM;
r = cg_kill_recursive(p, sig, flags, killed_pids, log_kill, userdata);
if (r < 0)
log_debug_errno(r, "Failed to recursively kill processes in cgroup '%s': %m", p);
if (r != 0 && ret >= 0)
ret = r;
}
return ret;
}
int cg_kill_kernel_sigkill(const char *path) {
_cleanup_free_ char *killfile = NULL;
int r;
/* Kills the cgroup at `path` directly by writing to its cgroup.kill file. This sends SIGKILL to all
* processes in the cgroup and has the advantage of being completely atomic, unlike cg_kill_items(). */
assert(path);
if (!cg_kill_supported())
return -EOPNOTSUPP;
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, "cgroup.kill", &killfile);
if (r < 0)
return r;
r = write_string_file(killfile, "1", WRITE_STRING_FILE_DISABLE_BUFFER);
if (r < 0)
return log_debug_errno(r, "Failed to write to cgroup.kill for cgroup '%s': %m", path);
return 0;
}
static const char *controller_to_dirname(const char *controller) {
assert(controller);
/* Converts a controller name to the directory name below /sys/fs/cgroup/ we want to mount it
* to. Effectively, this just cuts off the name= prefixed used for named hierarchies, if it is
* specified. */
if (streq(controller, SYSTEMD_CGROUP_CONTROLLER)) {
if (cg_hybrid_unified() > 0)
controller = SYSTEMD_CGROUP_CONTROLLER_HYBRID;
else
controller = SYSTEMD_CGROUP_CONTROLLER_LEGACY;
}
return startswith(controller, "name=") ?: controller;
}
static int join_path_legacy(const char *controller, const char *path, const char *suffix, char **ret) {
const char *dn;
char *t = NULL;
assert(ret);
assert(controller);
dn = controller_to_dirname(controller);
if (isempty(path) && isempty(suffix))
t = path_join("/sys/fs/cgroup", dn);
else if (isempty(path))
t = path_join("/sys/fs/cgroup", dn, suffix);
else if (isempty(suffix))
t = path_join("/sys/fs/cgroup", dn, path);
else
t = path_join("/sys/fs/cgroup", dn, path, suffix);
if (!t)
return -ENOMEM;
*ret = t;
return 0;
}
static int join_path_unified(const char *path, const char *suffix, char **ret) {
char *t;
assert(ret);
if (isempty(path) && isempty(suffix))
t = strdup("/sys/fs/cgroup");
else if (isempty(path))
t = path_join("/sys/fs/cgroup", suffix);
else if (isempty(suffix))
t = path_join("/sys/fs/cgroup", path);
else
t = path_join("/sys/fs/cgroup", path, suffix);
if (!t)
return -ENOMEM;
*ret = t;
return 0;
}
int cg_get_path(const char *controller, const char *path, const char *suffix, char **ret) {
int r;
assert(ret);
if (!controller) {
char *t;
/* If no controller is specified, we return the path *below* the controllers, without any
* prefix. */
if (isempty(path) && isempty(suffix))
return -EINVAL;
if (isempty(suffix))
t = strdup(path);
else if (isempty(path))
t = strdup(suffix);
else
t = path_join(path, suffix);
if (!t)
return -ENOMEM;
*ret = path_simplify(t);
return 0;
}
if (!cg_controller_is_valid(controller))
return -EINVAL;
r = cg_all_unified();
if (r < 0)
return r;
if (r > 0)
r = join_path_unified(path, suffix, ret);
else
r = join_path_legacy(controller, path, suffix, ret);
if (r < 0)
return r;
path_simplify(*ret);
return 0;
}
static int controller_is_v1_accessible(const char *root, const char *controller) {
const char *cpath, *dn;
assert(controller);
dn = controller_to_dirname(controller);
/* If root if specified, we check that:
* - possible subcgroup is created at root,
* - we can modify the hierarchy. */
cpath = strjoina("/sys/fs/cgroup/", dn, root, root ? "/cgroup.procs" : NULL);
return access_nofollow(cpath, root ? W_OK : F_OK);
}
int cg_get_path_and_check(const char *controller, const char *path, const char *suffix, char **ret) {
int r;
assert(controller);
assert(ret);
if (!cg_controller_is_valid(controller))
return -EINVAL;
r = cg_all_unified();
if (r < 0)
return r;
if (r > 0) {
/* In the unified hierarchy all controllers are considered accessible,
* except for the named hierarchies */
if (startswith(controller, "name="))
return -EOPNOTSUPP;
} else {
/* Check if the specified controller is actually accessible */
r = controller_is_v1_accessible(NULL, controller);
if (r < 0)
return r;
}
return cg_get_path(controller, path, suffix, ret);
}
int cg_set_xattr(const char *path, const char *name, const void *value, size_t size, int flags) {
_cleanup_free_ char *fs = NULL;
int r;
assert(path);
assert(name);
assert(value || size <= 0);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
if (r < 0)
return r;
return RET_NERRNO(setxattr(fs, name, value, size, flags));
}
int cg_get_xattr(const char *path, const char *name, char **ret, size_t *ret_size) {
_cleanup_free_ char *fs = NULL;
int r;
assert(path);
assert(name);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
if (r < 0)
return r;
return lgetxattr_malloc(fs, name, ret, ret_size);
}
int cg_get_xattr_bool(const char *path, const char *name) {
_cleanup_free_ char *fs = NULL;
int r;
assert(path);
assert(name);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
if (r < 0)
return r;
return getxattr_at_bool(AT_FDCWD, fs, name, /* at_flags= */ 0);
}
int cg_remove_xattr(const char *path, const char *name) {
_cleanup_free_ char *fs = NULL;
int r;
assert(path);
assert(name);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
if (r < 0)
return r;
return RET_NERRNO(removexattr(fs, name));
}
int cg_pid_get_path(const char *controller, pid_t pid, char **ret_path) {
_cleanup_fclose_ FILE *f = NULL;
const char *fs, *controller_str = NULL; /* avoid false maybe-uninitialized warning */
int unified, r;
assert(pid >= 0);
assert(ret_path);
if (controller) {
if (!cg_controller_is_valid(controller))
return -EINVAL;
} else
controller = SYSTEMD_CGROUP_CONTROLLER;
unified = cg_unified_controller(controller);
if (unified < 0)
return unified;
if (unified == 0) {
if (streq(controller, SYSTEMD_CGROUP_CONTROLLER))
controller_str = SYSTEMD_CGROUP_CONTROLLER_LEGACY;
else
controller_str = controller;
}
fs = procfs_file_alloca(pid, "cgroup");
r = fopen_unlocked(fs, "re", &f);
if (r == -ENOENT)
return -ESRCH;
if (r < 0)
return r;
for (;;) {
_cleanup_free_ char *line = NULL;
char *e;
r = read_line(f, LONG_LINE_MAX, &line);
if (r < 0)
return r;
if (r == 0)
return -ENODATA;
if (unified) {
e = startswith(line, "0:");
if (!e)
continue;
e = strchr(e, ':');
if (!e)
continue;
} else {
char *l;
l = strchr(line, ':');
if (!l)
continue;
l++;
e = strchr(l, ':');
if (!e)
continue;
*e = 0;
assert(controller_str);
r = string_contains_word(l, ",", controller_str);
if (r < 0)
return r;
if (r == 0)
continue;
}
_cleanup_free_ char *path = strdup(e + 1);
if (!path)
return -ENOMEM;
/* Refuse cgroup paths from outside our cgroup namespace */
if (startswith(path, "/../"))
return -EUNATCH;
/* Truncate suffix indicating the process is a zombie */
e = endswith(path, " (deleted)");
if (e)
*e = 0;
*ret_path = TAKE_PTR(path);
return 0;
}
}
int cg_pidref_get_path(const char *controller, const PidRef *pidref, char **ret_path) {
_cleanup_free_ char *path = NULL;
int r;
assert(ret_path);
if (!pidref_is_set(pidref))
return -ESRCH;
if (pidref_is_remote(pidref))
return -EREMOTE;
// XXX: Ideally we'd use pidfd_get_cgroupid() + cg_path_from_cgroupid() here, to extract this
// bit of information from pidfd directly. However, the latter requires privilege and it's
// not entirely clear how to handle cgroups from outer namespace.
r = cg_pid_get_path(controller, pidref->pid, &path);
if (r < 0)
return r;
/* Before we return the path, make sure the procfs entry for this pid still matches the pidref */
r = pidref_verify(pidref);
if (r < 0)
return r;
*ret_path = TAKE_PTR(path);
return 0;
}
int cg_is_empty(const char *controller, const char *path) {
_cleanup_free_ char *t = NULL;
int r;
/* Check if the cgroup hierarchy under 'path' is empty. On cgroup v2 it's exposed via the "populated"
* attribute of "cgroup.events". */
assert(path);
/* The root cgroup is always populated */
if (empty_or_root(path))
return false;
r = cg_get_keyed_attribute(SYSTEMD_CGROUP_CONTROLLER, path, "cgroup.events", STRV_MAKE("populated"), &t);
if (r == -ENOENT)
return true;
if (r < 0)
return r;
return streq(t, "0");
}
int cg_split_spec(const char *spec, char **ret_controller, char **ret_path) {
_cleanup_free_ char *controller = NULL, *path = NULL;
int r;
assert(spec);
if (*spec == '/') {
if (!path_is_normalized(spec))
return -EINVAL;
if (ret_path) {
r = path_simplify_alloc(spec, &path);
if (r < 0)
return r;
}
} else {
const char *e;
e = strchr(spec, ':');
if (e) {
controller = strndup(spec, e-spec);
if (!controller)
return -ENOMEM;
if (!cg_controller_is_valid(controller))
return -EINVAL;
if (!isempty(e + 1)) {
path = strdup(e+1);
if (!path)
return -ENOMEM;
if (!path_is_normalized(path) ||
!path_is_absolute(path))
return -EINVAL;
path_simplify(path);
}
} else {
if (!cg_controller_is_valid(spec))
return -EINVAL;
if (ret_controller) {
controller = strdup(spec);
if (!controller)
return -ENOMEM;
}
}
}
if (ret_controller)
*ret_controller = TAKE_PTR(controller);
if (ret_path)
*ret_path = TAKE_PTR(path);
return 0;
}
int cg_mangle_path(const char *path, char **ret) {
_cleanup_free_ char *c = NULL, *p = NULL;
int r;
assert(path);
assert(ret);
/* First, check if it already is a filesystem path */
if (path_startswith(path, "/sys/fs/cgroup"))
return path_simplify_alloc(path, ret);
/* Otherwise, treat it as cg spec */
r = cg_split_spec(path, &c, &p);
if (r < 0)
return r;
return cg_get_path(c ?: SYSTEMD_CGROUP_CONTROLLER, p ?: "/", NULL, ret);
}
int cg_get_root_path(char **ret_path) {
char *p, *e;
int r;
assert(ret_path);
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 1, &p);
if (r < 0)
return r;
e = endswith(p, "/" SPECIAL_INIT_SCOPE);
if (e)
*e = 0;
*ret_path = p;
return 0;
}
int cg_shift_path(const char *cgroup, const char *root, const char **ret_shifted) {
int r;
assert(cgroup);
assert(ret_shifted);
_cleanup_free_ char *rt = NULL;
if (!root) {
/* If the root was specified let's use that, otherwise
* let's determine it from PID 1 */
r = cg_get_root_path(&rt);
if (r < 0)
return r;
root = rt;
}
*ret_shifted = path_startswith_full(cgroup, root, PATH_STARTSWITH_RETURN_LEADING_SLASH|PATH_STARTSWITH_REFUSE_DOT_DOT) ?: cgroup;
return 0;
}
int cg_pid_get_path_shifted(pid_t pid, const char *root, char **ret_cgroup) {
_cleanup_free_ char *raw = NULL;
const char *c;
int r;
assert(pid >= 0);
assert(ret_cgroup);
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &raw);
if (r < 0)
return r;
r = cg_shift_path(raw, root, &c);
if (r < 0)
return r;
if (c == raw) {
*ret_cgroup = TAKE_PTR(raw);
return 0;
}
return strdup_to(ret_cgroup, c);
}
int cg_path_decode_unit(const char *cgroup, char **ret_unit) {
assert(cgroup);
size_t n = strcspn(cgroup, "/");
if (n < 3)
return -ENXIO;
char *c = strndupa_safe(cgroup, n);
c = cg_unescape(c);
if (!unit_name_is_valid(c, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE))
return -ENXIO;
if (ret_unit)
return strdup_to(ret_unit, c);
return 0;
}
static bool valid_slice_name(const char *p, size_t n) {
assert(p || n == 0);
if (n < STRLEN("x.slice"))
return false;
char *c = strndupa_safe(p, n);
if (!endswith(c, ".slice"))
return false;
return unit_name_is_valid(cg_unescape(c), UNIT_NAME_PLAIN);
}
static const char* skip_slices(const char *p) {
assert(p);
/* Skips over all slice assignments */
for (;;) {
size_t n;
p += strspn(p, "/");
n = strcspn(p, "/");
if (!valid_slice_name(p, n))
return p;
p += n;
}
}
int cg_path_get_unit(const char *path, char **ret) {
_cleanup_free_ char *unit = NULL;
const char *e;
int r;
assert(path);
e = skip_slices(path);
r = cg_path_decode_unit(e, &unit);
if (r < 0)
return r;
/* We skipped over the slices, don't accept any now */
if (endswith(unit, ".slice"))
return -ENXIO;
if (ret)
*ret = TAKE_PTR(unit);
return 0;
}
int cg_path_get_unit_path(const char *path, char **ret) {
_cleanup_free_ char *path_copy = NULL;
char *unit_name;
assert(path);
assert(ret);
path_copy = strdup(path);
if (!path_copy)
return -ENOMEM;
unit_name = (char*) skip_slices(path_copy);
unit_name[strcspn(unit_name, "/")] = 0;
if (!unit_name_is_valid(cg_unescape(unit_name), UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE))
return -ENXIO;
*ret = TAKE_PTR(path_copy);
return 0;
}
int cg_pid_get_unit(pid_t pid, char **ret_unit) {
_cleanup_free_ char *cgroup = NULL;
int r;
assert(ret_unit);
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_unit(cgroup, ret_unit);
}
int cg_pidref_get_unit(const PidRef *pidref, char **ret) {
_cleanup_free_ char *unit = NULL;
int r;
assert(ret);
if (!pidref_is_set(pidref))
return -ESRCH;
if (pidref_is_remote(pidref))
return -EREMOTE;
r = cg_pid_get_unit(pidref->pid, &unit);
if (r < 0)
return r;
r = pidref_verify(pidref);
if (r < 0)
return r;
*ret = TAKE_PTR(unit);
return 0;
}
static const char* skip_session(const char *p) {
size_t n;
/* Skip session-*.scope, but require it to be there. */
if (isempty(p))
return NULL;
p += strspn(p, "/");
n = strcspn(p, "/");
if (n < STRLEN("session-x.scope"))
return NULL;
const char *s = startswith(p, "session-");
if (!s)
return NULL;
/* Note that session scopes never need unescaping, since they cannot conflict with the kernel's
* own names, hence we don't need to call cg_unescape() here. */
char *f = strndupa_safe(s, p + n - s),
*e = endswith(f, ".scope");
if (!e)
return NULL;
*e = '\0';
if (!session_id_valid(f))
return NULL;
return skip_leading_slash(p + n);
}
static const char* skip_user_manager(const char *p) {
size_t n;
/* Skip user@*.service or capsule@*.service, but require either of them to be there. */
if (isempty(p))
return NULL;
p += strspn(p, "/");
n = strcspn(p, "/");
if (n < CONST_MIN(STRLEN("user@x.service"), STRLEN("capsule@x.service")))
return NULL;
/* Any possible errors from functions called below are converted to NULL return, so our callers won't
* resolve user/capsule name. */
_cleanup_free_ char *unit_name = strndup(p, n);
if (!unit_name)
return NULL;
_cleanup_free_ char *i = NULL;
UnitNameFlags type = unit_name_to_instance(unit_name, &i);
if (type != UNIT_NAME_INSTANCE)
return NULL;
/* Note that user manager services never need unescaping, since they cannot conflict with the
* kernel's own names, hence we don't need to call cg_unescape() here. Prudently check validity of
* instance names, they should be always valid as we validate them upon unit start. */
if (!(startswith(unit_name, "user@") && parse_uid(i, NULL) >= 0) &&
!(startswith(unit_name, "capsule@") && capsule_name_is_valid(i) > 0))
return NULL;
return skip_leading_slash(p + n);
}
static const char* skip_user_prefix(const char *path) {
const char *e, *t;
assert(path);
/* Skip slices, if there are any */
e = skip_slices(path);
/* Skip the user manager, if it's in the path now... */
t = skip_user_manager(e);
if (t)
return t;
/* Alternatively skip the user session if it is in the path... */
return skip_session(e);
}
int cg_path_get_user_unit(const char *path, char **ret) {
const char *t;
assert(path);
t = skip_user_prefix(path);
if (!t)
return -ENXIO;
/* And from here on it looks pretty much the same as for a system unit, hence let's use the same
* parser. */
return cg_path_get_unit(t, ret);
}
int cg_pid_get_user_unit(pid_t pid, char **ret_unit) {
_cleanup_free_ char *cgroup = NULL;
int r;
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_user_unit(cgroup, ret_unit);
}
int cg_path_get_machine_name(const char *path, char **ret_machine) {
_cleanup_free_ char *u = NULL;
const char *sl;
int r;
r = cg_path_get_unit(path, &u);
if (r < 0)
return r;
sl = strjoina("/run/systemd/machines/unit:", u);
return readlink_malloc(sl, ret_machine);
}
int cg_pid_get_machine_name(pid_t pid, char **ret_machine) {
_cleanup_free_ char *cgroup = NULL;
int r;
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_machine_name(cgroup, ret_machine);
}
int cg_path_get_session(const char *path, char **ret_session) {
_cleanup_free_ char *unit = NULL;
char *start, *end;
int r;
assert(path);
r = cg_path_get_unit(path, &unit);
if (r < 0)
return r;
start = startswith(unit, "session-");
if (!start)
return -ENXIO;
end = endswith(start, ".scope");
if (!end)
return -ENXIO;
*end = 0;
if (!session_id_valid(start))
return -ENXIO;
if (!ret_session)
return 0;
return strdup_to(ret_session, start);
}
int cg_pid_get_session(pid_t pid, char **ret_session) {
_cleanup_free_ char *cgroup = NULL;
int r;
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_session(cgroup, ret_session);
}
int cg_pidref_get_session(const PidRef *pidref, char **ret) {
int r;
if (!pidref_is_set(pidref))
return -ESRCH;
if (pidref_is_remote(pidref))
return -EREMOTE;
_cleanup_free_ char *session = NULL;
r = cg_pid_get_session(pidref->pid, &session);
if (r < 0)
return r;
r = pidref_verify(pidref);
if (r < 0)
return r;
if (ret)
*ret = TAKE_PTR(session);
return 0;
}
int cg_path_get_owner_uid(const char *path, uid_t *ret_uid) {
_cleanup_free_ char *slice = NULL;
char *start, *end;
int r;
assert(path);
r = cg_path_get_slice(path, &slice);
if (r < 0)
return r;
start = startswith(slice, "user-");
if (!start)
return -ENXIO;
end = endswith(start, ".slice");
if (!end)
return -ENXIO;
*end = 0;
if (parse_uid(start, ret_uid) < 0)
return -ENXIO;
return 0;
}
int cg_pid_get_owner_uid(pid_t pid, uid_t *ret_uid) {
_cleanup_free_ char *cgroup = NULL;
int r;
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_owner_uid(cgroup, ret_uid);
}
int cg_pidref_get_owner_uid(const PidRef *pidref, uid_t *ret) {
int r;
if (!pidref_is_set(pidref))
return -ESRCH;
if (pidref_is_remote(pidref))
return -EREMOTE;
uid_t uid;
r = cg_pid_get_owner_uid(pidref->pid, &uid);
if (r < 0)
return r;
r = pidref_verify(pidref);
if (r < 0)
return r;
if (ret)
*ret = uid;
return 0;
}
int cg_path_get_slice(const char *p, char **ret_slice) {
const char *e = NULL;
assert(p);
/* Finds the right-most slice unit from the beginning, but stops before we come to
* the first non-slice unit. */
for (;;) {
const char *s;
int n;
n = path_find_first_component(&p, /* accept_dot_dot = */ false, &s);
if (n < 0)
return n;
if (!valid_slice_name(s, n))
break;
e = s;
}
if (e)
return cg_path_decode_unit(e, ret_slice);
if (ret_slice)
return strdup_to(ret_slice, SPECIAL_ROOT_SLICE);
return 0;
}
int cg_pid_get_slice(pid_t pid, char **ret_slice) {
_cleanup_free_ char *cgroup = NULL;
int r;
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_slice(cgroup, ret_slice);
}
int cg_path_get_user_slice(const char *p, char **ret_slice) {
const char *t;
assert(p);
t = skip_user_prefix(p);
if (!t)
return -ENXIO;
/* And now it looks pretty much the same as for a system slice, so let's just use the same parser
* from here on. */
return cg_path_get_slice(t, ret_slice);
}
int cg_pid_get_user_slice(pid_t pid, char **ret_slice) {
_cleanup_free_ char *cgroup = NULL;
int r;
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_user_slice(cgroup, ret_slice);
}
bool cg_needs_escape(const char *p) {
/* Checks if the specified path is a valid cgroup name by our rules, or if it must be escaped. Note
* that we consider escaped cgroup names invalid here, as they need to be escaped a second time if
* they shall be used. Also note that various names cannot be made valid by escaping even if we
* return true here (because too long, or contain the forbidden character "/"). */
if (!filename_is_valid(p))
return true;
if (IN_SET(p[0], '_', '.'))
return true;
if (STR_IN_SET(p, "notify_on_release", "release_agent", "tasks"))
return true;
if (startswith(p, "cgroup."))
return true;
for (CGroupController c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
const char *q;
q = startswith(p, cgroup_controller_to_string(c));
if (!q)
continue;
if (q[0] == '.')
return true;
}
return false;
}
int cg_escape(const char *p, char **ret) {
_cleanup_free_ char *n = NULL;
/* This implements very minimal escaping for names to be used as file names in the cgroup tree: any
* name which might conflict with a kernel name or is prefixed with '_' is prefixed with a '_'. That
* way, when reading cgroup names it is sufficient to remove a single prefixing underscore if there
* is one. */
/* The return value of this function (unlike cg_unescape()) needs free()! */
if (cg_needs_escape(p)) {
n = strjoin("_", p);
if (!n)
return -ENOMEM;
if (!filename_is_valid(n)) /* became invalid due to the prefixing? Or contained things like a slash that cannot be fixed by prefixing? */
return -EINVAL;
} else {
n = strdup(p);
if (!n)
return -ENOMEM;
}
*ret = TAKE_PTR(n);
return 0;
}
char* cg_unescape(const char *p) {
assert(p);
/* The return value of this function (unlike cg_escape())
* doesn't need free()! */
if (p[0] == '_')
return (char*) p+1;
return (char*) p;
}
#define CONTROLLER_VALID \
DIGITS LETTERS \
"_"
bool cg_controller_is_valid(const char *p) {
const char *t, *s;
if (!p)
return false;
if (streq(p, SYSTEMD_CGROUP_CONTROLLER))
return true;
s = startswith(p, "name=");
if (s)
p = s;
if (IN_SET(*p, 0, '_'))
return false;
for (t = p; *t; t++)
if (!strchr(CONTROLLER_VALID, *t))
return false;
if (t - p > NAME_MAX)
return false;
return true;
}
int cg_slice_to_path(const char *unit, char **ret) {
_cleanup_free_ char *p = NULL, *s = NULL, *e = NULL;
const char *dash;
int r;
assert(unit);
assert(ret);
if (streq(unit, SPECIAL_ROOT_SLICE))
return strdup_to(ret, "");
if (!unit_name_is_valid(unit, UNIT_NAME_PLAIN))
return -EINVAL;
if (!endswith(unit, ".slice"))
return -EINVAL;
r = unit_name_to_prefix(unit, &p);
if (r < 0)
return r;
dash = strchr(p, '-');
/* Don't allow initial dashes */
if (dash == p)
return -EINVAL;
while (dash) {
_cleanup_free_ char *escaped = NULL;
char n[dash - p + sizeof(".slice")];
#if HAS_FEATURE_MEMORY_SANITIZER
/* msan doesn't instrument stpncpy, so it thinks
* n is later used uninitialized:
* https://github.com/google/sanitizers/issues/926
*/
zero(n);
#endif
/* Don't allow trailing or double dashes */
if (IN_SET(dash[1], 0, '-'))
return -EINVAL;
strcpy(stpncpy(n, p, dash - p), ".slice");
if (!unit_name_is_valid(n, UNIT_NAME_PLAIN))
return -EINVAL;
r = cg_escape(n, &escaped);
if (r < 0)
return r;
if (!strextend(&s, escaped, "/"))
return -ENOMEM;
dash = strchr(dash+1, '-');
}
r = cg_escape(unit, &e);
if (r < 0)
return r;
if (!strextend(&s, e))
return -ENOMEM;
*ret = TAKE_PTR(s);
return 0;
}
int cg_is_threaded(const char *path) {
_cleanup_free_ char *fs = NULL, *contents = NULL;
_cleanup_strv_free_ char **v = NULL;
int r;
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, "cgroup.type", &fs);
if (r < 0)
return r;
r = read_full_virtual_file(fs, &contents, NULL);
if (r == -ENOENT)
return false; /* Assume no. */
if (r < 0)
return r;
v = strv_split(contents, NULL);
if (!v)
return -ENOMEM;
/* If the cgroup is in the threaded mode, it contains "threaded".
* If one of the parents or siblings is in the threaded mode, it may contain "invalid". */
return strv_contains(v, "threaded") || strv_contains(v, "invalid");
}
int cg_set_attribute(const char *controller, const char *path, const char *attribute, const char *value) {
_cleanup_free_ char *p = NULL;
int r;
assert(attribute);
r = cg_get_path(controller, path, attribute, &p);
if (r < 0)
return r;
/* https://lore.kernel.org/all/20250419183545.1982187-1-shakeel.butt@linux.dev/ adds O_NONBLOCK
* semantics to memory.max and memory.high to skip synchronous memory reclaim when O_NONBLOCK is
* enabled. Let's always open cgroupv2 attribute files in nonblocking mode to immediately take
* advantage of this and any other asynchronous resource reclaim that's added to the cgroupv2 API in
* the future. */
return write_string_file(p, value, WRITE_STRING_FILE_DISABLE_BUFFER|WRITE_STRING_FILE_OPEN_NONBLOCKING);
}
int cg_get_attribute(const char *controller, const char *path, const char *attribute, char **ret) {
_cleanup_free_ char *p = NULL;
int r;
assert(attribute);
r = cg_get_path(controller, path, attribute, &p);
if (r < 0)
return r;
return read_one_line_file(p, ret);
}
int cg_get_attribute_as_uint64(const char *controller, const char *path, const char *attribute, uint64_t *ret) {
_cleanup_free_ char *value = NULL;
uint64_t v;
int r;
assert(ret);
r = cg_get_attribute(controller, path, attribute, &value);
if (r == -ENOENT)
return -ENODATA;
if (r < 0)
return r;
if (streq(value, "max")) {
*ret = CGROUP_LIMIT_MAX;
return 0;
}
r = safe_atou64(value, &v);
if (r < 0)
return r;
*ret = v;
return 0;
}
int cg_get_attribute_as_bool(const char *controller, const char *path, const char *attribute) {
_cleanup_free_ char *value = NULL;
int r;
r = cg_get_attribute(controller, path, attribute, &value);
if (r == -ENOENT)
return -ENODATA;
if (r < 0)
return r;
return parse_boolean(value);
}
int cg_get_owner(const char *path, uid_t *ret_uid) {
_cleanup_free_ char *f = NULL;
struct stat stats;
int r;
assert(ret_uid);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &f);
if (r < 0)
return r;
if (stat(f, &stats) < 0)
return -errno;
r = stat_verify_directory(&stats);
if (r < 0)
return r;
*ret_uid = stats.st_uid;
return 0;
}
int cg_get_keyed_attribute(
const char *controller,
const char *path,
const char *attribute,
char * const *keys,
char **values) {
_cleanup_free_ char *filename = NULL, *contents = NULL;
size_t n;
int r;
assert(path);
assert(attribute);
/* Reads one or more fields of a cgroup v2 keyed attribute file. The 'keys' parameter should be an strv with
* all keys to retrieve. The 'values' parameter should be passed as string size with the same number of
* entries as 'keys'. On success each entry will be set to the value of the matching key.
*
* If the attribute file doesn't exist at all returns ENOENT, if any key is not found returns ENXIO. */
r = cg_get_path(controller, path, attribute, &filename);
if (r < 0)
return r;
r = read_full_file(filename, &contents, /* ret_size = */ NULL);
if (r < 0)
return r;
n = strv_length(keys);
if (n == 0) /* No keys to retrieve? That's easy, we are done then */
return 0;
assert(strv_is_uniq(keys));
/* Let's build this up in a temporary array for now in order not to clobber the return parameter on failure */
char **v = newa0(char*, n);
size_t n_done = 0;
for (const char *p = contents; *p;) {
const char *w;
size_t i;
for (i = 0; i < n; i++) {
w = first_word(p, keys[i]);
if (w)
break;
}
if (w) {
if (v[i]) { /* duplicate entry? */
r = -EBADMSG;
goto fail;
}
size_t l = strcspn(w, NEWLINE);
v[i] = strndup(w, l);
if (!v[i]) {
r = -ENOMEM;
goto fail;
}
n_done++;
if (n_done >= n)
break;
p = w + l;
} else
p += strcspn(p, NEWLINE);
p += strspn(p, NEWLINE);
}
if (n_done < n) {
r = -ENXIO;
goto fail;
}
memcpy(values, v, sizeof(char*) * n);
return 0;
fail:
free_many_charp(v, n);
return r;
}
int cg_mask_to_string(CGroupMask mask, char **ret) {
_cleanup_free_ char *s = NULL;
bool space = false;
CGroupController c;
size_t n = 0;
assert(ret);
if (mask == 0) {
*ret = NULL;
return 0;
}
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
const char *k;
size_t l;
if (!FLAGS_SET(mask, CGROUP_CONTROLLER_TO_MASK(c)))
continue;
k = cgroup_controller_to_string(c);
l = strlen(k);
if (!GREEDY_REALLOC(s, n + space + l + 1))
return -ENOMEM;
if (space)
s[n] = ' ';
memcpy(s + n + space, k, l);
n += space + l;
space = true;
}
assert(s);
s[n] = 0;
*ret = TAKE_PTR(s);
return 0;
}
int cg_mask_from_string(const char *value, CGroupMask *ret) {
CGroupMask m = 0;
assert(ret);
assert(value);
for (;;) {
_cleanup_free_ char *n = NULL;
CGroupController v;
int r;
r = extract_first_word(&value, &n, NULL, 0);
if (r < 0)
return r;
if (r == 0)
break;
v = cgroup_controller_from_string(n);
if (v < 0)
continue;
m |= CGROUP_CONTROLLER_TO_MASK(v);
}
*ret = m;
return 0;
}
int cg_mask_supported_subtree(const char *root, CGroupMask *ret) {
CGroupMask mask;
int r;
/* Determines the mask of supported cgroup controllers. Only includes controllers we can make sense of and that
* are actually accessible. Only covers real controllers, i.e. not the CGROUP_CONTROLLER_BPF_xyz
* pseudo-controllers. */
r = cg_all_unified();
if (r < 0)
return r;
if (r > 0) {
_cleanup_free_ char *controllers = NULL, *path = NULL;
/* In the unified hierarchy we can read the supported and accessible controllers from
* the top-level cgroup attribute */
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, root, "cgroup.controllers", &path);
if (r < 0)
return r;
r = read_one_line_file(path, &controllers);
if (r < 0)
return r;
r = cg_mask_from_string(controllers, &mask);
if (r < 0)
return r;
/* Mask controllers that are not supported in unified hierarchy. */
mask &= CGROUP_MASK_V2;
} else {
CGroupController c;
/* In the legacy hierarchy, we check which hierarchies are accessible. */
mask = 0;
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
const char *n;
if (!FLAGS_SET(CGROUP_MASK_V1, bit))
continue;
n = cgroup_controller_to_string(c);
if (controller_is_v1_accessible(root, n) >= 0)
mask |= bit;
}
}
*ret = mask;
return 0;
}
int cg_mask_supported(CGroupMask *ret) {
_cleanup_free_ char *root = NULL;
int r;
r = cg_get_root_path(&root);
if (r < 0)
return r;
return cg_mask_supported_subtree(root, ret);
}
/* The hybrid mode was initially implemented in v232 and simply mounted cgroup2 on
* /sys/fs/cgroup/systemd. This unfortunately broke other tools (such as docker) which expected the v1
* "name=systemd" hierarchy on /sys/fs/cgroup/systemd. From v233 and on, the hybrid mode mounts v2 on
* /sys/fs/cgroup/unified and maintains "name=systemd" hierarchy on /sys/fs/cgroup/systemd for compatibility
* with other tools.
*
* To keep live upgrade working, we detect and support v232 layout. When v232 layout is detected, to keep
* cgroup v2 process management but disable the compat dual layout, we return true on
* cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) and false on cg_hybrid_unified().
*/
static thread_local bool unified_systemd_v232;
int cg_unified_cached(bool flush) {
static thread_local CGroupUnified unified_cache = CGROUP_UNIFIED_UNKNOWN;
struct statfs fs;
/* Checks if we support the unified hierarchy. Returns an
* error when the cgroup hierarchies aren't mounted yet or we
* have any other trouble determining if the unified hierarchy
* is supported. */
if (flush)
unified_cache = CGROUP_UNIFIED_UNKNOWN;
else if (unified_cache >= CGROUP_UNIFIED_NONE)
return unified_cache;
if (statfs("/sys/fs/cgroup/", &fs) < 0)
return log_debug_errno(errno, "statfs(\"/sys/fs/cgroup/\") failed: %m");
if (F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC)) {
log_debug("Found cgroup2 on /sys/fs/cgroup/, full unified hierarchy");
unified_cache = CGROUP_UNIFIED_ALL;
} else if (F_TYPE_EQUAL(fs.f_type, TMPFS_MAGIC)) {
if (statfs("/sys/fs/cgroup/unified/", &fs) == 0 &&
F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC)) {
log_debug("Found cgroup2 on /sys/fs/cgroup/unified, unified hierarchy for systemd controller");
unified_cache = CGROUP_UNIFIED_SYSTEMD;
unified_systemd_v232 = false;
} else {
if (statfs("/sys/fs/cgroup/systemd/", &fs) < 0) {
if (errno == ENOENT) {
/* Some other software may have set up /sys/fs/cgroup in a configuration we do not recognize. */
log_debug_errno(errno, "Unsupported cgroupsv1 setup detected: name=systemd hierarchy not found.");
return -ENOMEDIUM;
}
return log_debug_errno(errno, "statfs(\"/sys/fs/cgroup/systemd\" failed: %m");
}
if (F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC)) {
log_debug("Found cgroup2 on /sys/fs/cgroup/systemd, unified hierarchy for systemd controller (v232 variant)");
unified_cache = CGROUP_UNIFIED_SYSTEMD;
unified_systemd_v232 = true;
} else if (F_TYPE_EQUAL(fs.f_type, CGROUP_SUPER_MAGIC)) {
log_debug("Found cgroup on /sys/fs/cgroup/systemd, legacy hierarchy");
unified_cache = CGROUP_UNIFIED_NONE;
} else {
log_debug("Unexpected filesystem type %llx mounted on /sys/fs/cgroup/systemd, assuming legacy hierarchy",
(unsigned long long) fs.f_type);
unified_cache = CGROUP_UNIFIED_NONE;
}
}
} else if (F_TYPE_EQUAL(fs.f_type, SYSFS_MAGIC)) {
return log_debug_errno(SYNTHETIC_ERRNO(ENOMEDIUM),
"No filesystem is currently mounted on /sys/fs/cgroup.");
} else
return log_debug_errno(SYNTHETIC_ERRNO(ENOMEDIUM),
"Unknown filesystem type %llx mounted on /sys/fs/cgroup.",
(unsigned long long)fs.f_type);
return unified_cache;
}
int cg_unified_controller(const char *controller) {
int r;
r = cg_unified_cached(false);
if (r < 0)
return r;
if (r == CGROUP_UNIFIED_NONE)
return false;
if (r >= CGROUP_UNIFIED_ALL)
return true;
return streq_ptr(controller, SYSTEMD_CGROUP_CONTROLLER);
}
int cg_all_unified(void) {
int r;
r = cg_unified_cached(false);
if (r < 0)
return r;
return r >= CGROUP_UNIFIED_ALL;
}
int cg_hybrid_unified(void) {
int r;
r = cg_unified_cached(false);
if (r < 0)
return r;
return r == CGROUP_UNIFIED_SYSTEMD && !unified_systemd_v232;
}
int cg_is_delegated(const char *path) {
int r;
assert(path);
r = cg_get_xattr_bool(path, "trusted.delegate");
if (!ERRNO_IS_NEG_XATTR_ABSENT(r))
return r;
/* If the trusted xattr isn't set (preferred), then check the untrusted one. Under the assumption
* that whoever is trusted enough to own the cgroup, is also trusted enough to decide if it is
* delegated or not this should be safe. */
r = cg_get_xattr_bool(path, "user.delegate");
return ERRNO_IS_NEG_XATTR_ABSENT(r) ? false : r;
}
int cg_is_delegated_fd(int fd) {
int r;
assert(fd >= 0);
r = getxattr_at_bool(fd, /* path= */ NULL, "trusted.delegate", /* at_flags= */ 0);
if (!ERRNO_IS_NEG_XATTR_ABSENT(r))
return r;
r = getxattr_at_bool(fd, /* path= */ NULL, "user.delegate", /* at_flags= */ 0);
return ERRNO_IS_NEG_XATTR_ABSENT(r) ? false : r;
}
int cg_has_coredump_receive(const char *path) {
int r;
assert(path);
r = cg_get_xattr_bool(path, "user.coredump_receive");
if (ERRNO_IS_NEG_XATTR_ABSENT(r))
return false;
return r;
}
const uint64_t cgroup_io_limit_defaults[_CGROUP_IO_LIMIT_TYPE_MAX] = {
[CGROUP_IO_RBPS_MAX] = CGROUP_LIMIT_MAX,
[CGROUP_IO_WBPS_MAX] = CGROUP_LIMIT_MAX,
[CGROUP_IO_RIOPS_MAX] = CGROUP_LIMIT_MAX,
[CGROUP_IO_WIOPS_MAX] = CGROUP_LIMIT_MAX,
};
static const char* const cgroup_io_limit_type_table[_CGROUP_IO_LIMIT_TYPE_MAX] = {
[CGROUP_IO_RBPS_MAX] = "IOReadBandwidthMax",
[CGROUP_IO_WBPS_MAX] = "IOWriteBandwidthMax",
[CGROUP_IO_RIOPS_MAX] = "IOReadIOPSMax",
[CGROUP_IO_WIOPS_MAX] = "IOWriteIOPSMax",
};
DEFINE_STRING_TABLE_LOOKUP(cgroup_io_limit_type, CGroupIOLimitType);
void cgroup_io_limits_list(void) {
DUMP_STRING_TABLE(cgroup_io_limit_type, CGroupIOLimitType, _CGROUP_IO_LIMIT_TYPE_MAX);
}
static const char *const cgroup_controller_table[_CGROUP_CONTROLLER_MAX] = {
[CGROUP_CONTROLLER_CPU] = "cpu",
[CGROUP_CONTROLLER_CPUACCT] = "cpuacct",
[CGROUP_CONTROLLER_CPUSET] = "cpuset",
[CGROUP_CONTROLLER_IO] = "io",
[CGROUP_CONTROLLER_BLKIO] = "blkio",
[CGROUP_CONTROLLER_MEMORY] = "memory",
[CGROUP_CONTROLLER_DEVICES] = "devices",
[CGROUP_CONTROLLER_PIDS] = "pids",
[CGROUP_CONTROLLER_BPF_FIREWALL] = "bpf-firewall",
[CGROUP_CONTROLLER_BPF_DEVICES] = "bpf-devices",
[CGROUP_CONTROLLER_BPF_FOREIGN] = "bpf-foreign",
[CGROUP_CONTROLLER_BPF_SOCKET_BIND] = "bpf-socket-bind",
[CGROUP_CONTROLLER_BPF_RESTRICT_NETWORK_INTERFACES] = "bpf-restrict-network-interfaces",
};
DEFINE_STRING_TABLE_LOOKUP(cgroup_controller, CGroupController);
static const char* const managed_oom_mode_table[_MANAGED_OOM_MODE_MAX] = {
[MANAGED_OOM_AUTO] = "auto",
[MANAGED_OOM_KILL] = "kill",
};
DEFINE_STRING_TABLE_LOOKUP(managed_oom_mode, ManagedOOMMode);
static const char* const managed_oom_preference_table[_MANAGED_OOM_PREFERENCE_MAX] = {
[MANAGED_OOM_PREFERENCE_NONE] = "none",
[MANAGED_OOM_PREFERENCE_AVOID] = "avoid",
[MANAGED_OOM_PREFERENCE_OMIT] = "omit",
};
DEFINE_STRING_TABLE_LOOKUP(managed_oom_preference, ManagedOOMPreference);
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