/* SPDX-License-Identifier: LGPL-2.1+ */ #include #include #include "alloc-util.h" #include "blockdev-util.h" #include "bpf-firewall.h" #include "btrfs-util.h" #include "bpf-devices.h" #include "bus-error.h" #include "cgroup-util.h" #include "cgroup.h" #include "fd-util.h" #include "fileio.h" #include "fs-util.h" #include "parse-util.h" #include "path-util.h" #include "process-util.h" #include "procfs-util.h" #include "special.h" #include "stat-util.h" #include "stdio-util.h" #include "string-table.h" #include "string-util.h" #include "virt.h" #define CGROUP_CPU_QUOTA_PERIOD_USEC ((usec_t) 100 * USEC_PER_MSEC) /* Returns the log level to use when cgroup attribute writes fail. When an attribute is missing or we have access * problems we downgrade to LOG_DEBUG. This is supposed to be nice to container managers and kernels which want to mask * out specific attributes from us. */ #define LOG_LEVEL_CGROUP_WRITE(r) (IN_SET(abs(r), ENOENT, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING) bool manager_owns_host_root_cgroup(Manager *m) { assert(m); /* Returns true if we are managing the root cgroup. Note that it isn't sufficient to just check whether the * group root path equals "/" since that will also be the case if CLONE_NEWCGROUP is in the mix. Since there's * appears to be no nice way to detect whether we are in a CLONE_NEWCGROUP namespace we instead just check if * we run in any kind of container virtualization. */ if (MANAGER_IS_USER(m)) return false; if (detect_container() > 0) return false; return empty_or_root(m->cgroup_root); } bool unit_has_host_root_cgroup(Unit *u) { assert(u); /* Returns whether this unit manages the root cgroup. This will return true if this unit is the root slice and * the manager manages the root cgroup. */ if (!manager_owns_host_root_cgroup(u->manager)) return false; return unit_has_name(u, SPECIAL_ROOT_SLICE); } static int set_attribute_and_warn(Unit *u, const char *controller, const char *attribute, const char *value) { int r; r = cg_set_attribute(controller, u->cgroup_path, attribute, value); if (r < 0) log_unit_full(u, LOG_LEVEL_CGROUP_WRITE(r), r, "Failed to set '%s' attribute on '%s' to '%.*s': %m", strna(attribute), isempty(u->cgroup_path) ? "/" : u->cgroup_path, (int) strcspn(value, NEWLINE), value); return r; } static void cgroup_compat_warn(void) { static bool cgroup_compat_warned = false; if (cgroup_compat_warned) return; log_warning("cgroup compatibility translation between legacy and unified hierarchy settings activated. " "See cgroup-compat debug messages for details."); cgroup_compat_warned = true; } #define log_cgroup_compat(unit, fmt, ...) do { \ cgroup_compat_warn(); \ log_unit_debug(unit, "cgroup-compat: " fmt, ##__VA_ARGS__); \ } while (false) void cgroup_context_init(CGroupContext *c) { assert(c); /* Initialize everything to the kernel defaults. */ *c = (CGroupContext) { .cpu_weight = CGROUP_WEIGHT_INVALID, .startup_cpu_weight = CGROUP_WEIGHT_INVALID, .cpu_quota_per_sec_usec = USEC_INFINITY, .cpu_shares = CGROUP_CPU_SHARES_INVALID, .startup_cpu_shares = CGROUP_CPU_SHARES_INVALID, .memory_high = CGROUP_LIMIT_MAX, .memory_max = CGROUP_LIMIT_MAX, .memory_swap_max = CGROUP_LIMIT_MAX, .memory_limit = CGROUP_LIMIT_MAX, .io_weight = CGROUP_WEIGHT_INVALID, .startup_io_weight = CGROUP_WEIGHT_INVALID, .blockio_weight = CGROUP_BLKIO_WEIGHT_INVALID, .startup_blockio_weight = CGROUP_BLKIO_WEIGHT_INVALID, .tasks_max = CGROUP_LIMIT_MAX, }; } void cgroup_context_free_device_allow(CGroupContext *c, CGroupDeviceAllow *a) { assert(c); assert(a); LIST_REMOVE(device_allow, c->device_allow, a); free(a->path); free(a); } void cgroup_context_free_io_device_weight(CGroupContext *c, CGroupIODeviceWeight *w) { assert(c); assert(w); LIST_REMOVE(device_weights, c->io_device_weights, w); free(w->path); free(w); } void cgroup_context_free_io_device_latency(CGroupContext *c, CGroupIODeviceLatency *l) { assert(c); assert(l); LIST_REMOVE(device_latencies, c->io_device_latencies, l); free(l->path); free(l); } void cgroup_context_free_io_device_limit(CGroupContext *c, CGroupIODeviceLimit *l) { assert(c); assert(l); LIST_REMOVE(device_limits, c->io_device_limits, l); free(l->path); free(l); } void cgroup_context_free_blockio_device_weight(CGroupContext *c, CGroupBlockIODeviceWeight *w) { assert(c); assert(w); LIST_REMOVE(device_weights, c->blockio_device_weights, w); free(w->path); free(w); } void cgroup_context_free_blockio_device_bandwidth(CGroupContext *c, CGroupBlockIODeviceBandwidth *b) { assert(c); assert(b); LIST_REMOVE(device_bandwidths, c->blockio_device_bandwidths, b); free(b->path); free(b); } void cgroup_context_done(CGroupContext *c) { assert(c); while (c->io_device_weights) cgroup_context_free_io_device_weight(c, c->io_device_weights); while (c->io_device_latencies) cgroup_context_free_io_device_latency(c, c->io_device_latencies); while (c->io_device_limits) cgroup_context_free_io_device_limit(c, c->io_device_limits); while (c->blockio_device_weights) cgroup_context_free_blockio_device_weight(c, c->blockio_device_weights); while (c->blockio_device_bandwidths) cgroup_context_free_blockio_device_bandwidth(c, c->blockio_device_bandwidths); while (c->device_allow) cgroup_context_free_device_allow(c, c->device_allow); c->ip_address_allow = ip_address_access_free_all(c->ip_address_allow); c->ip_address_deny = ip_address_access_free_all(c->ip_address_deny); } void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) { CGroupIODeviceLimit *il; CGroupIODeviceWeight *iw; CGroupIODeviceLatency *l; CGroupBlockIODeviceBandwidth *b; CGroupBlockIODeviceWeight *w; CGroupDeviceAllow *a; IPAddressAccessItem *iaai; char u[FORMAT_TIMESPAN_MAX]; assert(c); assert(f); prefix = strempty(prefix); fprintf(f, "%sCPUAccounting=%s\n" "%sIOAccounting=%s\n" "%sBlockIOAccounting=%s\n" "%sMemoryAccounting=%s\n" "%sTasksAccounting=%s\n" "%sIPAccounting=%s\n" "%sCPUWeight=%" PRIu64 "\n" "%sStartupCPUWeight=%" PRIu64 "\n" "%sCPUShares=%" PRIu64 "\n" "%sStartupCPUShares=%" PRIu64 "\n" "%sCPUQuotaPerSecSec=%s\n" "%sIOWeight=%" PRIu64 "\n" "%sStartupIOWeight=%" PRIu64 "\n" "%sBlockIOWeight=%" PRIu64 "\n" "%sStartupBlockIOWeight=%" PRIu64 "\n" "%sMemoryMin=%" PRIu64 "\n" "%sMemoryLow=%" PRIu64 "\n" "%sMemoryHigh=%" PRIu64 "\n" "%sMemoryMax=%" PRIu64 "\n" "%sMemorySwapMax=%" PRIu64 "\n" "%sMemoryLimit=%" PRIu64 "\n" "%sTasksMax=%" PRIu64 "\n" "%sDevicePolicy=%s\n" "%sDelegate=%s\n", prefix, yes_no(c->cpu_accounting), prefix, yes_no(c->io_accounting), prefix, yes_no(c->blockio_accounting), prefix, yes_no(c->memory_accounting), prefix, yes_no(c->tasks_accounting), prefix, yes_no(c->ip_accounting), prefix, c->cpu_weight, prefix, c->startup_cpu_weight, prefix, c->cpu_shares, prefix, c->startup_cpu_shares, prefix, format_timespan(u, sizeof(u), c->cpu_quota_per_sec_usec, 1), prefix, c->io_weight, prefix, c->startup_io_weight, prefix, c->blockio_weight, prefix, c->startup_blockio_weight, prefix, c->memory_min, prefix, c->memory_low, prefix, c->memory_high, prefix, c->memory_max, prefix, c->memory_swap_max, prefix, c->memory_limit, prefix, c->tasks_max, prefix, cgroup_device_policy_to_string(c->device_policy), prefix, yes_no(c->delegate)); if (c->delegate) { _cleanup_free_ char *t = NULL; (void) cg_mask_to_string(c->delegate_controllers, &t); fprintf(f, "%sDelegateControllers=%s\n", prefix, strempty(t)); } LIST_FOREACH(device_allow, a, c->device_allow) fprintf(f, "%sDeviceAllow=%s %s%s%s\n", prefix, a->path, a->r ? "r" : "", a->w ? "w" : "", a->m ? "m" : ""); LIST_FOREACH(device_weights, iw, c->io_device_weights) fprintf(f, "%sIODeviceWeight=%s %" PRIu64 "\n", prefix, iw->path, iw->weight); LIST_FOREACH(device_latencies, l, c->io_device_latencies) fprintf(f, "%sIODeviceLatencyTargetSec=%s %s\n", prefix, l->path, format_timespan(u, sizeof(u), l->target_usec, 1)); LIST_FOREACH(device_limits, il, c->io_device_limits) { char buf[FORMAT_BYTES_MAX]; CGroupIOLimitType type; for (type = 0; type < _CGROUP_IO_LIMIT_TYPE_MAX; type++) if (il->limits[type] != cgroup_io_limit_defaults[type]) fprintf(f, "%s%s=%s %s\n", prefix, cgroup_io_limit_type_to_string(type), il->path, format_bytes(buf, sizeof(buf), il->limits[type])); } LIST_FOREACH(device_weights, w, c->blockio_device_weights) fprintf(f, "%sBlockIODeviceWeight=%s %" PRIu64, prefix, w->path, w->weight); LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) { char buf[FORMAT_BYTES_MAX]; if (b->rbps != CGROUP_LIMIT_MAX) fprintf(f, "%sBlockIOReadBandwidth=%s %s\n", prefix, b->path, format_bytes(buf, sizeof(buf), b->rbps)); if (b->wbps != CGROUP_LIMIT_MAX) fprintf(f, "%sBlockIOWriteBandwidth=%s %s\n", prefix, b->path, format_bytes(buf, sizeof(buf), b->wbps)); } LIST_FOREACH(items, iaai, c->ip_address_allow) { _cleanup_free_ char *k = NULL; (void) in_addr_to_string(iaai->family, &iaai->address, &k); fprintf(f, "%sIPAddressAllow=%s/%u\n", prefix, strnull(k), iaai->prefixlen); } LIST_FOREACH(items, iaai, c->ip_address_deny) { _cleanup_free_ char *k = NULL; (void) in_addr_to_string(iaai->family, &iaai->address, &k); fprintf(f, "%sIPAddressDeny=%s/%u\n", prefix, strnull(k), iaai->prefixlen); } } int cgroup_add_device_allow(CGroupContext *c, const char *dev, const char *mode) { _cleanup_free_ CGroupDeviceAllow *a = NULL; _cleanup_free_ char *d = NULL; assert(c); assert(dev); assert(isempty(mode) || in_charset(mode, "rwm")); a = new(CGroupDeviceAllow, 1); if (!a) return -ENOMEM; d = strdup(dev); if (!d) return -ENOMEM; *a = (CGroupDeviceAllow) { .path = TAKE_PTR(d), .r = isempty(mode) || strchr(mode, 'r'), .w = isempty(mode) || strchr(mode, 'w'), .m = isempty(mode) || strchr(mode, 'm'), }; LIST_PREPEND(device_allow, c->device_allow, a); TAKE_PTR(a); return 0; } static void cgroup_xattr_apply(Unit *u) { char ids[SD_ID128_STRING_MAX]; int r; assert(u); if (!MANAGER_IS_SYSTEM(u->manager)) return; if (sd_id128_is_null(u->invocation_id)) return; r = cg_set_xattr(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "trusted.invocation_id", sd_id128_to_string(u->invocation_id, ids), 32, 0); if (r < 0) log_unit_debug_errno(u, r, "Failed to set invocation ID on control group %s, ignoring: %m", u->cgroup_path); } static int lookup_block_device(const char *p, dev_t *ret) { struct stat st = {}; int r; assert(p); assert(ret); r = device_path_parse_major_minor(p, &st.st_mode, &st.st_rdev); if (r == -ENODEV) { /* not a parsable device node, need to go to disk */ if (stat(p, &st) < 0) return log_warning_errno(errno, "Couldn't stat device '%s': %m", p); } else if (r < 0) return log_warning_errno(r, "Failed to parse major/minor from path '%s': %m", p); if (S_ISCHR(st.st_mode)) { log_warning("Device node '%s' is a character device, but block device needed.", p); return -ENOTBLK; } else if (S_ISBLK(st.st_mode)) *ret = st.st_rdev; else if (major(st.st_dev) != 0) *ret = st.st_dev; /* If this is not a device node then use the block device this file is stored on */ else { /* If this is btrfs, getting the backing block device is a bit harder */ r = btrfs_get_block_device(p, ret); if (r < 0 && r != -ENOTTY) return log_warning_errno(r, "Failed to determine block device backing btrfs file system '%s': %m", p); if (r == -ENOTTY) { log_warning("'%s' is not a block device node, and file system block device cannot be determined or is not local.", p); return -ENODEV; } } /* If this is a LUKS device, try to get the originating block device */ (void) block_get_originating(*ret, ret); /* If this is a partition, try to get the originating block device */ (void) block_get_whole_disk(*ret, ret); return 0; } static int whitelist_device(BPFProgram *prog, const char *path, const char *node, const char *acc) { struct stat st = {}; int r; assert(path); assert(acc); /* Some special handling for /dev/block/%u:%u, /dev/char/%u:%u, /run/systemd/inaccessible/chr and * /run/systemd/inaccessible/blk paths. Instead of stat()ing these we parse out the major/minor directly. This * means clients can use these path without the device node actually around */ r = device_path_parse_major_minor(node, &st.st_mode, &st.st_rdev); if (r < 0) { if (r != -ENODEV) return log_warning_errno(r, "Couldn't parse major/minor from device path '%s': %m", node); if (stat(node, &st) < 0) return log_warning_errno(errno, "Couldn't stat device %s: %m", node); if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) { log_warning("%s is not a device.", node); return -ENODEV; } } if (cg_all_unified() > 0) { if (!prog) return 0; return cgroup_bpf_whitelist_device(prog, S_ISCHR(st.st_mode) ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK, major(st.st_rdev), minor(st.st_rdev), acc); } else { char buf[2+DECIMAL_STR_MAX(dev_t)*2+2+4]; sprintf(buf, "%c %u:%u %s", S_ISCHR(st.st_mode) ? 'c' : 'b', major(st.st_rdev), minor(st.st_rdev), acc); /* Changing the devices list of a populated cgroup might result in EINVAL, hence ignore EINVAL here. */ r = cg_set_attribute("devices", path, "devices.allow", buf); if (r < 0) return log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r, "Failed to set devices.allow on %s: %m", path); return 0; } } static int whitelist_major(BPFProgram *prog, const char *path, const char *name, char type, const char *acc) { _cleanup_fclose_ FILE *f = NULL; char buf[2+DECIMAL_STR_MAX(unsigned)+3+4]; bool good = false; unsigned maj; int r; assert(path); assert(acc); assert(IN_SET(type, 'b', 'c')); if (streq(name, "*")) { /* If the name is a wildcard, then apply this list to all devices of this type */ if (cg_all_unified() > 0) { if (!prog) return 0; (void) cgroup_bpf_whitelist_class(prog, type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK, acc); } else { xsprintf(buf, "%c *:* %s", type, acc); r = cg_set_attribute("devices", path, "devices.allow", buf); if (r < 0) log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES) ? LOG_DEBUG : LOG_WARNING, r, "Failed to set devices.allow on %s: %m", path); return 0; } } if (safe_atou(name, &maj) >= 0 && DEVICE_MAJOR_VALID(maj)) { /* The name is numeric and suitable as major. In that case, let's take is major, and create the entry * directly */ if (cg_all_unified() > 0) { if (!prog) return 0; (void) cgroup_bpf_whitelist_major(prog, type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK, maj, acc); } else { xsprintf(buf, "%c %u:* %s", type, maj, acc); r = cg_set_attribute("devices", path, "devices.allow", buf); if (r < 0) log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES) ? LOG_DEBUG : LOG_WARNING, r, "Failed to set devices.allow on %s: %m", path); } return 0; } f = fopen("/proc/devices", "re"); if (!f) return log_warning_errno(errno, "Cannot open /proc/devices to resolve %s (%c): %m", name, type); for (;;) { _cleanup_free_ char *line = NULL; char *w, *p; r = read_line(f, LONG_LINE_MAX, &line); if (r < 0) return log_warning_errno(r, "Failed to read /proc/devices: %m"); if (r == 0) break; if (type == 'c' && streq(line, "Character devices:")) { good = true; continue; } if (type == 'b' && streq(line, "Block devices:")) { good = true; continue; } if (isempty(line)) { good = false; continue; } if (!good) continue; p = strstrip(line); w = strpbrk(p, WHITESPACE); if (!w) continue; *w = 0; r = safe_atou(p, &maj); if (r < 0) continue; if (maj <= 0) continue; w++; w += strspn(w, WHITESPACE); if (fnmatch(name, w, 0) != 0) continue; if (cg_all_unified() > 0) { if (!prog) continue; (void) cgroup_bpf_whitelist_major(prog, type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK, maj, acc); } else { sprintf(buf, "%c %u:* %s", type, maj, acc); /* Changing the devices list of a populated cgroup might result in EINVAL, hence ignore EINVAL * here. */ r = cg_set_attribute("devices", path, "devices.allow", buf); if (r < 0) log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r, "Failed to set devices.allow on %s: %m", path); } } return 0; } static bool cgroup_context_has_cpu_weight(CGroupContext *c) { return c->cpu_weight != CGROUP_WEIGHT_INVALID || c->startup_cpu_weight != CGROUP_WEIGHT_INVALID; } static bool cgroup_context_has_cpu_shares(CGroupContext *c) { return c->cpu_shares != CGROUP_CPU_SHARES_INVALID || c->startup_cpu_shares != CGROUP_CPU_SHARES_INVALID; } static uint64_t cgroup_context_cpu_weight(CGroupContext *c, ManagerState state) { if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) && c->startup_cpu_weight != CGROUP_WEIGHT_INVALID) return c->startup_cpu_weight; else if (c->cpu_weight != CGROUP_WEIGHT_INVALID) return c->cpu_weight; else return CGROUP_WEIGHT_DEFAULT; } static uint64_t cgroup_context_cpu_shares(CGroupContext *c, ManagerState state) { if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) && c->startup_cpu_shares != CGROUP_CPU_SHARES_INVALID) return c->startup_cpu_shares; else if (c->cpu_shares != CGROUP_CPU_SHARES_INVALID) return c->cpu_shares; else return CGROUP_CPU_SHARES_DEFAULT; } static void cgroup_apply_unified_cpu_weight(Unit *u, uint64_t weight) { char buf[DECIMAL_STR_MAX(uint64_t) + 2]; xsprintf(buf, "%" PRIu64 "\n", weight); (void) set_attribute_and_warn(u, "cpu", "cpu.weight", buf); } static void cgroup_apply_unified_cpu_quota(Unit *u, usec_t quota) { char buf[(DECIMAL_STR_MAX(usec_t) + 1) * 2 + 1]; if (quota != USEC_INFINITY) xsprintf(buf, USEC_FMT " " USEC_FMT "\n", quota * CGROUP_CPU_QUOTA_PERIOD_USEC / USEC_PER_SEC, CGROUP_CPU_QUOTA_PERIOD_USEC); else xsprintf(buf, "max " USEC_FMT "\n", CGROUP_CPU_QUOTA_PERIOD_USEC); (void) set_attribute_and_warn(u, "cpu", "cpu.max", buf); } static void cgroup_apply_legacy_cpu_shares(Unit *u, uint64_t shares) { char buf[DECIMAL_STR_MAX(uint64_t) + 2]; xsprintf(buf, "%" PRIu64 "\n", shares); (void) set_attribute_and_warn(u, "cpu", "cpu.shares", buf); } static void cgroup_apply_legacy_cpu_quota(Unit *u, usec_t quota) { char buf[DECIMAL_STR_MAX(usec_t) + 2]; xsprintf(buf, USEC_FMT "\n", CGROUP_CPU_QUOTA_PERIOD_USEC); (void) set_attribute_and_warn(u, "cpu", "cpu.cfs_period_us", buf); if (quota != USEC_INFINITY) { xsprintf(buf, USEC_FMT "\n", quota * CGROUP_CPU_QUOTA_PERIOD_USEC / USEC_PER_SEC); (void) set_attribute_and_warn(u, "cpu", "cpu.cfs_quota_us", buf); } else (void) set_attribute_and_warn(u, "cpu", "cpu.cfs_quota_us", "-1\n"); } static uint64_t cgroup_cpu_shares_to_weight(uint64_t shares) { return CLAMP(shares * CGROUP_WEIGHT_DEFAULT / CGROUP_CPU_SHARES_DEFAULT, CGROUP_WEIGHT_MIN, CGROUP_WEIGHT_MAX); } static uint64_t cgroup_cpu_weight_to_shares(uint64_t weight) { return CLAMP(weight * CGROUP_CPU_SHARES_DEFAULT / CGROUP_WEIGHT_DEFAULT, CGROUP_CPU_SHARES_MIN, CGROUP_CPU_SHARES_MAX); } static bool cgroup_context_has_io_config(CGroupContext *c) { return c->io_accounting || c->io_weight != CGROUP_WEIGHT_INVALID || c->startup_io_weight != CGROUP_WEIGHT_INVALID || c->io_device_weights || c->io_device_latencies || c->io_device_limits; } static bool cgroup_context_has_blockio_config(CGroupContext *c) { return c->blockio_accounting || c->blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID || c->startup_blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID || c->blockio_device_weights || c->blockio_device_bandwidths; } static uint64_t cgroup_context_io_weight(CGroupContext *c, ManagerState state) { if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) && c->startup_io_weight != CGROUP_WEIGHT_INVALID) return c->startup_io_weight; else if (c->io_weight != CGROUP_WEIGHT_INVALID) return c->io_weight; else return CGROUP_WEIGHT_DEFAULT; } static uint64_t cgroup_context_blkio_weight(CGroupContext *c, ManagerState state) { if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) && c->startup_blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID) return c->startup_blockio_weight; else if (c->blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID) return c->blockio_weight; else return CGROUP_BLKIO_WEIGHT_DEFAULT; } static uint64_t cgroup_weight_blkio_to_io(uint64_t blkio_weight) { return CLAMP(blkio_weight * CGROUP_WEIGHT_DEFAULT / CGROUP_BLKIO_WEIGHT_DEFAULT, CGROUP_WEIGHT_MIN, CGROUP_WEIGHT_MAX); } static uint64_t cgroup_weight_io_to_blkio(uint64_t io_weight) { return CLAMP(io_weight * CGROUP_BLKIO_WEIGHT_DEFAULT / CGROUP_WEIGHT_DEFAULT, CGROUP_BLKIO_WEIGHT_MIN, CGROUP_BLKIO_WEIGHT_MAX); } static void cgroup_apply_io_device_weight(Unit *u, const char *dev_path, uint64_t io_weight) { char buf[DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1]; dev_t dev; int r; r = lookup_block_device(dev_path, &dev); if (r < 0) return; xsprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), io_weight); (void) set_attribute_and_warn(u, "io", "io.weight", buf); } static void cgroup_apply_blkio_device_weight(Unit *u, const char *dev_path, uint64_t blkio_weight) { char buf[DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1]; dev_t dev; int r; r = lookup_block_device(dev_path, &dev); if (r < 0) return; xsprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), blkio_weight); (void) set_attribute_and_warn(u, "blkio", "blkio.weight_device", buf); } static void cgroup_apply_io_device_latency(Unit *u, const char *dev_path, usec_t target) { char buf[DECIMAL_STR_MAX(dev_t)*2+2+7+DECIMAL_STR_MAX(uint64_t)+1]; dev_t dev; int r; r = lookup_block_device(dev_path, &dev); if (r < 0) return; if (target != USEC_INFINITY) xsprintf(buf, "%u:%u target=%" PRIu64 "\n", major(dev), minor(dev), target); else xsprintf(buf, "%u:%u target=max\n", major(dev), minor(dev)); (void) set_attribute_and_warn(u, "io", "io.latency", buf); } static void cgroup_apply_io_device_limit(Unit *u, const char *dev_path, uint64_t *limits) { char limit_bufs[_CGROUP_IO_LIMIT_TYPE_MAX][DECIMAL_STR_MAX(uint64_t)]; char buf[DECIMAL_STR_MAX(dev_t)*2+2+(6+DECIMAL_STR_MAX(uint64_t)+1)*4]; CGroupIOLimitType type; dev_t dev; int r; r = lookup_block_device(dev_path, &dev); if (r < 0) return; for (type = 0; type < _CGROUP_IO_LIMIT_TYPE_MAX; type++) if (limits[type] != cgroup_io_limit_defaults[type]) xsprintf(limit_bufs[type], "%" PRIu64, limits[type]); else xsprintf(limit_bufs[type], "%s", limits[type] == CGROUP_LIMIT_MAX ? "max" : "0"); xsprintf(buf, "%u:%u rbps=%s wbps=%s riops=%s wiops=%s\n", major(dev), minor(dev), limit_bufs[CGROUP_IO_RBPS_MAX], limit_bufs[CGROUP_IO_WBPS_MAX], limit_bufs[CGROUP_IO_RIOPS_MAX], limit_bufs[CGROUP_IO_WIOPS_MAX]); (void) set_attribute_and_warn(u, "io", "io.max", buf); } static void cgroup_apply_blkio_device_limit(Unit *u, const char *dev_path, uint64_t rbps, uint64_t wbps) { char buf[DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1]; dev_t dev; int r; r = lookup_block_device(dev_path, &dev); if (r < 0) return; sprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), rbps); (void) set_attribute_and_warn(u, "blkio", "blkio.throttle.read_bps_device", buf); sprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), wbps); (void) set_attribute_and_warn(u, "blkio", "blkio.throttle.write_bps_device", buf); } static bool cgroup_context_has_unified_memory_config(CGroupContext *c) { return c->memory_min > 0 || c->memory_low > 0 || c->memory_high != CGROUP_LIMIT_MAX || c->memory_max != CGROUP_LIMIT_MAX || c->memory_swap_max != CGROUP_LIMIT_MAX; } static void cgroup_apply_unified_memory_limit(Unit *u, const char *file, uint64_t v) { char buf[DECIMAL_STR_MAX(uint64_t) + 1] = "max\n"; if (v != CGROUP_LIMIT_MAX) xsprintf(buf, "%" PRIu64 "\n", v); (void) set_attribute_and_warn(u, "memory", file, buf); } static void cgroup_apply_firewall(Unit *u) { assert(u); /* Best-effort: let's apply IP firewalling and/or accounting if that's enabled */ if (bpf_firewall_compile(u) < 0) return; (void) bpf_firewall_install(u); } static void cgroup_context_apply( Unit *u, CGroupMask apply_mask, ManagerState state) { const char *path; CGroupContext *c; bool is_host_root, is_local_root; int r; assert(u); /* Nothing to do? Exit early! */ if (apply_mask == 0) return; /* Some cgroup attributes are not supported on the host root cgroup, hence silently ignore them here. And other * attributes should only be managed for cgroups further down the tree. */ is_local_root = unit_has_name(u, SPECIAL_ROOT_SLICE); is_host_root = unit_has_host_root_cgroup(u); assert_se(c = unit_get_cgroup_context(u)); assert_se(path = u->cgroup_path); if (is_local_root) /* Make sure we don't try to display messages with an empty path. */ path = "/"; /* We generally ignore errors caused by read-only mounted cgroup trees (assuming we are running in a container * then), and missing cgroups, i.e. EROFS and ENOENT. */ /* In fully unified mode these attributes don't exist on the host cgroup root. On legacy the weights exist, but * setting the weight makes very little sense on the host root cgroup, as there are no other cgroups at this * level. The quota exists there too, but any attempt to write to it is refused with EINVAL. Inside of * containers we want to leave control of these to the container manager (and if cgroup v2 delegation is used * we couldn't even write to them if we wanted to). */ if ((apply_mask & CGROUP_MASK_CPU) && !is_local_root) { if (cg_all_unified() > 0) { uint64_t weight; if (cgroup_context_has_cpu_weight(c)) weight = cgroup_context_cpu_weight(c, state); else if (cgroup_context_has_cpu_shares(c)) { uint64_t shares; shares = cgroup_context_cpu_shares(c, state); weight = cgroup_cpu_shares_to_weight(shares); log_cgroup_compat(u, "Applying [Startup]CPUShares=%" PRIu64 " as [Startup]CPUWeight=%" PRIu64 " on %s", shares, weight, path); } else weight = CGROUP_WEIGHT_DEFAULT; cgroup_apply_unified_cpu_weight(u, weight); cgroup_apply_unified_cpu_quota(u, c->cpu_quota_per_sec_usec); } else { uint64_t shares; if (cgroup_context_has_cpu_weight(c)) { uint64_t weight; weight = cgroup_context_cpu_weight(c, state); shares = cgroup_cpu_weight_to_shares(weight); log_cgroup_compat(u, "Applying [Startup]CPUWeight=%" PRIu64 " as [Startup]CPUShares=%" PRIu64 " on %s", weight, shares, path); } else if (cgroup_context_has_cpu_shares(c)) shares = cgroup_context_cpu_shares(c, state); else shares = CGROUP_CPU_SHARES_DEFAULT; cgroup_apply_legacy_cpu_shares(u, shares); cgroup_apply_legacy_cpu_quota(u, c->cpu_quota_per_sec_usec); } } /* The 'io' controller attributes are not exported on the host's root cgroup (being a pure cgroup v2 * controller), and in case of containers we want to leave control of these attributes to the container manager * (and we couldn't access that stuff anyway, even if we tried if proper delegation is used). */ if ((apply_mask & CGROUP_MASK_IO) && !is_local_root) { char buf[8+DECIMAL_STR_MAX(uint64_t)+1]; bool has_io, has_blockio; uint64_t weight; has_io = cgroup_context_has_io_config(c); has_blockio = cgroup_context_has_blockio_config(c); if (has_io) weight = cgroup_context_io_weight(c, state); else if (has_blockio) { uint64_t blkio_weight; blkio_weight = cgroup_context_blkio_weight(c, state); weight = cgroup_weight_blkio_to_io(blkio_weight); log_cgroup_compat(u, "Applying [Startup]BlockIOWeight=%" PRIu64 " as [Startup]IOWeight=%" PRIu64, blkio_weight, weight); } else weight = CGROUP_WEIGHT_DEFAULT; xsprintf(buf, "default %" PRIu64 "\n", weight); (void) set_attribute_and_warn(u, "io", "io.weight", buf); if (has_io) { CGroupIODeviceLatency *latency; CGroupIODeviceLimit *limit; CGroupIODeviceWeight *w; LIST_FOREACH(device_weights, w, c->io_device_weights) cgroup_apply_io_device_weight(u, w->path, w->weight); LIST_FOREACH(device_limits, limit, c->io_device_limits) cgroup_apply_io_device_limit(u, limit->path, limit->limits); LIST_FOREACH(device_latencies, latency, c->io_device_latencies) cgroup_apply_io_device_latency(u, latency->path, latency->target_usec); } else if (has_blockio) { CGroupBlockIODeviceWeight *w; CGroupBlockIODeviceBandwidth *b; LIST_FOREACH(device_weights, w, c->blockio_device_weights) { weight = cgroup_weight_blkio_to_io(w->weight); log_cgroup_compat(u, "Applying BlockIODeviceWeight=%" PRIu64 " as IODeviceWeight=%" PRIu64 " for %s", w->weight, weight, w->path); cgroup_apply_io_device_weight(u, w->path, weight); } LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) { uint64_t limits[_CGROUP_IO_LIMIT_TYPE_MAX]; CGroupIOLimitType type; for (type = 0; type < _CGROUP_IO_LIMIT_TYPE_MAX; type++) limits[type] = cgroup_io_limit_defaults[type]; limits[CGROUP_IO_RBPS_MAX] = b->rbps; limits[CGROUP_IO_WBPS_MAX] = b->wbps; log_cgroup_compat(u, "Applying BlockIO{Read|Write}Bandwidth=%" PRIu64 " %" PRIu64 " as IO{Read|Write}BandwidthMax= for %s", b->rbps, b->wbps, b->path); cgroup_apply_io_device_limit(u, b->path, limits); } } } if (apply_mask & CGROUP_MASK_BLKIO) { bool has_io, has_blockio; has_io = cgroup_context_has_io_config(c); has_blockio = cgroup_context_has_blockio_config(c); /* Applying a 'weight' never makes sense for the host root cgroup, and for containers this should be * left to our container manager, too. */ if (!is_local_root) { char buf[DECIMAL_STR_MAX(uint64_t)+1]; uint64_t weight; if (has_io) { uint64_t io_weight; io_weight = cgroup_context_io_weight(c, state); weight = cgroup_weight_io_to_blkio(cgroup_context_io_weight(c, state)); log_cgroup_compat(u, "Applying [Startup]IOWeight=%" PRIu64 " as [Startup]BlockIOWeight=%" PRIu64, io_weight, weight); } else if (has_blockio) weight = cgroup_context_blkio_weight(c, state); else weight = CGROUP_BLKIO_WEIGHT_DEFAULT; xsprintf(buf, "%" PRIu64 "\n", weight); (void) set_attribute_and_warn(u, "blkio", "blkio.weight", buf); if (has_io) { CGroupIODeviceWeight *w; LIST_FOREACH(device_weights, w, c->io_device_weights) { weight = cgroup_weight_io_to_blkio(w->weight); log_cgroup_compat(u, "Applying IODeviceWeight=%" PRIu64 " as BlockIODeviceWeight=%" PRIu64 " for %s", w->weight, weight, w->path); cgroup_apply_blkio_device_weight(u, w->path, weight); } } else if (has_blockio) { CGroupBlockIODeviceWeight *w; LIST_FOREACH(device_weights, w, c->blockio_device_weights) cgroup_apply_blkio_device_weight(u, w->path, w->weight); } } /* The bandwith limits are something that make sense to be applied to the host's root but not container * roots, as there we want the container manager to handle it */ if (is_host_root || !is_local_root) { if (has_io) { CGroupIODeviceLimit *l; LIST_FOREACH(device_limits, l, c->io_device_limits) { log_cgroup_compat(u, "Applying IO{Read|Write}Bandwidth=%" PRIu64 " %" PRIu64 " as BlockIO{Read|Write}BandwidthMax= for %s", l->limits[CGROUP_IO_RBPS_MAX], l->limits[CGROUP_IO_WBPS_MAX], l->path); cgroup_apply_blkio_device_limit(u, l->path, l->limits[CGROUP_IO_RBPS_MAX], l->limits[CGROUP_IO_WBPS_MAX]); } } else if (has_blockio) { CGroupBlockIODeviceBandwidth *b; LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) cgroup_apply_blkio_device_limit(u, b->path, b->rbps, b->wbps); } } } /* In unified mode 'memory' attributes do not exist on the root cgroup. In legacy mode 'memory.limit_in_bytes' * exists on the root cgroup, but any writes to it are refused with EINVAL. And if we run in a container we * want to leave control to the container manager (and if proper cgroup v2 delegation is used we couldn't even * write to this if we wanted to.) */ if ((apply_mask & CGROUP_MASK_MEMORY) && !is_local_root) { if (cg_all_unified() > 0) { uint64_t max, swap_max = CGROUP_LIMIT_MAX; if (cgroup_context_has_unified_memory_config(c)) { max = c->memory_max; swap_max = c->memory_swap_max; } else { max = c->memory_limit; if (max != CGROUP_LIMIT_MAX) log_cgroup_compat(u, "Applying MemoryLimit=%" PRIu64 " as MemoryMax=", max); } cgroup_apply_unified_memory_limit(u, "memory.min", c->memory_min); cgroup_apply_unified_memory_limit(u, "memory.low", c->memory_low); cgroup_apply_unified_memory_limit(u, "memory.high", c->memory_high); cgroup_apply_unified_memory_limit(u, "memory.max", max); cgroup_apply_unified_memory_limit(u, "memory.swap.max", swap_max); } else { char buf[DECIMAL_STR_MAX(uint64_t) + 1]; uint64_t val; if (cgroup_context_has_unified_memory_config(c)) { val = c->memory_max; log_cgroup_compat(u, "Applying MemoryMax=%" PRIi64 " as MemoryLimit=", val); } else val = c->memory_limit; if (val == CGROUP_LIMIT_MAX) strncpy(buf, "-1\n", sizeof(buf)); else xsprintf(buf, "%" PRIu64 "\n", val); (void) set_attribute_and_warn(u, "memory", "memory.limit_in_bytes", buf); } } /* On cgroup v2 we can apply BPF everywhere. On cgroup v1 we apply it everywhere except for the root of * containers, where we leave this to the manager */ if ((apply_mask & (CGROUP_MASK_DEVICES | CGROUP_MASK_BPF_DEVICES)) && (is_host_root || cg_all_unified() > 0 || !is_local_root)) { _cleanup_(bpf_program_unrefp) BPFProgram *prog = NULL; CGroupDeviceAllow *a; if (cg_all_unified() > 0) { r = cgroup_init_device_bpf(&prog, c->device_policy, c->device_allow); if (r < 0) log_unit_warning_errno(u, r, "Failed to initialize device control bpf program: %m"); } else { /* Changing the devices list of a populated cgroup might result in EINVAL, hence ignore EINVAL * here. */ if (c->device_allow || c->device_policy != CGROUP_AUTO) r = cg_set_attribute("devices", path, "devices.deny", "a"); else r = cg_set_attribute("devices", path, "devices.allow", "a"); if (r < 0) log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r, "Failed to reset devices.allow/devices.deny: %m"); } if (c->device_policy == CGROUP_CLOSED || (c->device_policy == CGROUP_AUTO && c->device_allow)) { static const char auto_devices[] = "/dev/null\0" "rwm\0" "/dev/zero\0" "rwm\0" "/dev/full\0" "rwm\0" "/dev/random\0" "rwm\0" "/dev/urandom\0" "rwm\0" "/dev/tty\0" "rwm\0" "/dev/ptmx\0" "rwm\0" /* Allow /run/systemd/inaccessible/{chr,blk} devices for mapping InaccessiblePaths */ "/run/systemd/inaccessible/chr\0" "rwm\0" "/run/systemd/inaccessible/blk\0" "rwm\0"; const char *x, *y; NULSTR_FOREACH_PAIR(x, y, auto_devices) (void) whitelist_device(prog, path, x, y); /* PTS (/dev/pts) devices may not be duplicated, but accessed */ (void) whitelist_major(prog, path, "pts", 'c', "rw"); } LIST_FOREACH(device_allow, a, c->device_allow) { char acc[4], *val; unsigned k = 0; if (a->r) acc[k++] = 'r'; if (a->w) acc[k++] = 'w'; if (a->m) acc[k++] = 'm'; if (k == 0) continue; acc[k++] = 0; if (path_startswith(a->path, "/dev/")) (void) whitelist_device(prog, path, a->path, acc); else if ((val = startswith(a->path, "block-"))) (void) whitelist_major(prog, path, val, 'b', acc); else if ((val = startswith(a->path, "char-"))) (void) whitelist_major(prog, path, val, 'c', acc); else log_unit_debug(u, "Ignoring device '%s' while writing cgroup attribute.", a->path); } r = cgroup_apply_device_bpf(u, prog, c->device_policy, c->device_allow); if (r < 0) { static bool warned = false; log_full_errno(warned ? LOG_DEBUG : LOG_WARNING, r, "Unit %s configures device ACL, but the local system doesn't seem to support the BPF-based device controller.\n" "Proceeding WITHOUT applying ACL (all devices will be accessible)!\n" "(This warning is only shown for the first loaded unit using device ACL.)", u->id); warned = true; } } if (apply_mask & CGROUP_MASK_PIDS) { if (is_host_root) { /* So, the "pids" controller does not expose anything on the root cgroup, in order not to * replicate knobs exposed elsewhere needlessly. We abstract this away here however, and when * the knobs of the root cgroup are modified propagate this to the relevant sysctls. There's a * non-obvious asymmetry however: unlike the cgroup properties we don't really want to take * exclusive ownership of the sysctls, but we still want to honour things if the user sets * limits. Hence we employ sort of a one-way strategy: when the user sets a bounded limit * through us it counts. When the user afterwards unsets it again (i.e. sets it to unbounded) * it also counts. But if the user never set a limit through us (i.e. we are the default of * "unbounded") we leave things unmodified. For this we manage a global boolean that we turn on * the first time we set a limit. Note that this boolean is flushed out on manager reload, * which is desirable so that there's an offical way to release control of the sysctl from * systemd: set the limit to unbounded and reload. */ if (c->tasks_max != CGROUP_LIMIT_MAX) { u->manager->sysctl_pid_max_changed = true; r = procfs_tasks_set_limit(c->tasks_max); } else if (u->manager->sysctl_pid_max_changed) r = procfs_tasks_set_limit(TASKS_MAX); else r = 0; if (r < 0) log_unit_full(u, LOG_LEVEL_CGROUP_WRITE(r), r, "Failed to write to tasks limit sysctls: %m"); } /* The attribute itself is not available on the host root cgroup, and in the container case we want to * leave it for the container manager. */ if (!is_local_root) { if (c->tasks_max != CGROUP_LIMIT_MAX) { char buf[DECIMAL_STR_MAX(uint64_t) + 2]; sprintf(buf, "%" PRIu64 "\n", c->tasks_max); (void) set_attribute_and_warn(u, "pids", "pids.max", buf); } else (void) set_attribute_and_warn(u, "pids", "pids.max", "max\n"); } } if (apply_mask & CGROUP_MASK_BPF_FIREWALL) cgroup_apply_firewall(u); } static bool unit_get_needs_bpf_firewall(Unit *u) { CGroupContext *c; Unit *p; assert(u); c = unit_get_cgroup_context(u); if (!c) return false; if (c->ip_accounting || c->ip_address_allow || c->ip_address_deny) return true; /* If any parent slice has an IP access list defined, it applies too */ for (p = UNIT_DEREF(u->slice); p; p = UNIT_DEREF(p->slice)) { c = unit_get_cgroup_context(p); if (!c) return false; if (c->ip_address_allow || c->ip_address_deny) return true; } return false; } static CGroupMask cgroup_context_get_mask(CGroupContext *c) { CGroupMask mask = 0; /* Figure out which controllers we need, based on the cgroup context object */ if (c->cpu_accounting) mask |= get_cpu_accounting_mask(); if (cgroup_context_has_cpu_weight(c) || cgroup_context_has_cpu_shares(c) || c->cpu_quota_per_sec_usec != USEC_INFINITY) mask |= CGROUP_MASK_CPU; if (cgroup_context_has_io_config(c) || cgroup_context_has_blockio_config(c)) mask |= CGROUP_MASK_IO | CGROUP_MASK_BLKIO; if (c->memory_accounting || c->memory_limit != CGROUP_LIMIT_MAX || cgroup_context_has_unified_memory_config(c)) mask |= CGROUP_MASK_MEMORY; if (c->device_allow || c->device_policy != CGROUP_AUTO) mask |= CGROUP_MASK_DEVICES | CGROUP_MASK_BPF_DEVICES; if (c->tasks_accounting || c->tasks_max != CGROUP_LIMIT_MAX) mask |= CGROUP_MASK_PIDS; return CGROUP_MASK_EXTEND_JOINED(mask); } static CGroupMask unit_get_bpf_mask(Unit *u) { CGroupMask mask = 0; /* Figure out which controllers we need, based on the cgroup context, possibly taking into account children * too. */ if (unit_get_needs_bpf_firewall(u)) mask |= CGROUP_MASK_BPF_FIREWALL; return mask; } CGroupMask unit_get_own_mask(Unit *u) { CGroupContext *c; /* Returns the mask of controllers the unit needs for itself. If a unit is not properly loaded, return an empty * mask, as we shouldn't reflect it in the cgroup hierarchy then. */ if (u->load_state != UNIT_LOADED) return 0; c = unit_get_cgroup_context(u); if (!c) return 0; return (cgroup_context_get_mask(c) | unit_get_bpf_mask(u) | unit_get_delegate_mask(u)) & ~unit_get_ancestor_disable_mask(u); } CGroupMask unit_get_delegate_mask(Unit *u) { CGroupContext *c; /* If delegation is turned on, then turn on selected controllers, unless we are on the legacy hierarchy and the * process we fork into is known to drop privileges, and hence shouldn't get access to the controllers. * * Note that on the unified hierarchy it is safe to delegate controllers to unprivileged services. */ if (!unit_cgroup_delegate(u)) return 0; if (cg_all_unified() <= 0) { ExecContext *e; e = unit_get_exec_context(u); if (e && !exec_context_maintains_privileges(e)) return 0; } assert_se(c = unit_get_cgroup_context(u)); return CGROUP_MASK_EXTEND_JOINED(c->delegate_controllers); } CGroupMask unit_get_members_mask(Unit *u) { assert(u); /* Returns the mask of controllers all of the unit's children require, merged */ if (u->cgroup_members_mask_valid) return u->cgroup_members_mask; /* Use cached value if possible */ u->cgroup_members_mask = 0; if (u->type == UNIT_SLICE) { void *v; Unit *member; Iterator i; HASHMAP_FOREACH_KEY(v, member, u->dependencies[UNIT_BEFORE], i) { if (UNIT_DEREF(member->slice) == u) u->cgroup_members_mask |= unit_get_subtree_mask(member); /* note that this calls ourselves again, for the children */ } } u->cgroup_members_mask_valid = true; return u->cgroup_members_mask; } CGroupMask unit_get_siblings_mask(Unit *u) { assert(u); /* Returns the mask of controllers all of the unit's siblings * require, i.e. the members mask of the unit's parent slice * if there is one. */ if (UNIT_ISSET(u->slice)) return unit_get_members_mask(UNIT_DEREF(u->slice)); return unit_get_subtree_mask(u); /* we are the top-level slice */ } CGroupMask unit_get_disable_mask(Unit *u) { CGroupContext *c; c = unit_get_cgroup_context(u); if (!c) return 0; return c->disable_controllers; } CGroupMask unit_get_ancestor_disable_mask(Unit *u) { CGroupMask mask; assert(u); mask = unit_get_disable_mask(u); /* Returns the mask of controllers which are marked as forcibly * disabled in any ancestor unit or the unit in question. */ if (UNIT_ISSET(u->slice)) mask |= unit_get_ancestor_disable_mask(UNIT_DEREF(u->slice)); return mask; } CGroupMask unit_get_subtree_mask(Unit *u) { /* Returns the mask of this subtree, meaning of the group * itself and its children. */ return unit_get_own_mask(u) | unit_get_members_mask(u); } CGroupMask unit_get_target_mask(Unit *u) { CGroupMask mask; /* This returns the cgroup mask of all controllers to enable * for a specific cgroup, i.e. everything it needs itself, * plus all that its children need, plus all that its siblings * need. This is primarily useful on the legacy cgroup * hierarchy, where we need to duplicate each cgroup in each * hierarchy that shall be enabled for it. */ mask = unit_get_own_mask(u) | unit_get_members_mask(u) | unit_get_siblings_mask(u); mask &= u->manager->cgroup_supported; mask &= ~unit_get_ancestor_disable_mask(u); return mask; } CGroupMask unit_get_enable_mask(Unit *u) { CGroupMask mask; /* This returns the cgroup mask of all controllers to enable * for the children of a specific cgroup. This is primarily * useful for the unified cgroup hierarchy, where each cgroup * controls which controllers are enabled for its children. */ mask = unit_get_members_mask(u); mask &= u->manager->cgroup_supported; mask &= ~unit_get_ancestor_disable_mask(u); return mask; } void unit_invalidate_cgroup_members_masks(Unit *u) { assert(u); /* Recurse invalidate the member masks cache all the way up the tree */ u->cgroup_members_mask_valid = false; if (UNIT_ISSET(u->slice)) unit_invalidate_cgroup_members_masks(UNIT_DEREF(u->slice)); } const char *unit_get_realized_cgroup_path(Unit *u, CGroupMask mask) { /* Returns the realized cgroup path of the specified unit where all specified controllers are available. */ while (u) { if (u->cgroup_path && u->cgroup_realized && FLAGS_SET(u->cgroup_realized_mask, mask)) return u->cgroup_path; u = UNIT_DEREF(u->slice); } return NULL; } static const char *migrate_callback(CGroupMask mask, void *userdata) { return unit_get_realized_cgroup_path(userdata, mask); } char *unit_default_cgroup_path(const Unit *u) { _cleanup_free_ char *escaped = NULL, *slice = NULL; int r; assert(u); if (unit_has_name(u, SPECIAL_ROOT_SLICE)) return strdup(u->manager->cgroup_root); if (UNIT_ISSET(u->slice) && !unit_has_name(UNIT_DEREF(u->slice), SPECIAL_ROOT_SLICE)) { r = cg_slice_to_path(UNIT_DEREF(u->slice)->id, &slice); if (r < 0) return NULL; } escaped = cg_escape(u->id); if (!escaped) return NULL; if (slice) return strjoin(u->manager->cgroup_root, "/", slice, "/", escaped); else return strjoin(u->manager->cgroup_root, "/", escaped); } int unit_set_cgroup_path(Unit *u, const char *path) { _cleanup_free_ char *p = NULL; int r; assert(u); if (path) { p = strdup(path); if (!p) return -ENOMEM; } else p = NULL; if (streq_ptr(u->cgroup_path, p)) return 0; if (p) { r = hashmap_put(u->manager->cgroup_unit, p, u); if (r < 0) return r; } unit_release_cgroup(u); u->cgroup_path = TAKE_PTR(p); return 1; } int unit_watch_cgroup(Unit *u) { _cleanup_free_ char *events = NULL; int r; assert(u); if (!u->cgroup_path) return 0; if (u->cgroup_inotify_wd >= 0) return 0; /* Only applies to the unified hierarchy */ r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); if (r < 0) return log_error_errno(r, "Failed to determine whether the name=systemd hierarchy is unified: %m"); if (r == 0) return 0; /* Don't watch the root slice, it's pointless. */ if (unit_has_name(u, SPECIAL_ROOT_SLICE)) return 0; r = hashmap_ensure_allocated(&u->manager->cgroup_inotify_wd_unit, &trivial_hash_ops); if (r < 0) return log_oom(); r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "cgroup.events", &events); if (r < 0) return log_oom(); u->cgroup_inotify_wd = inotify_add_watch(u->manager->cgroup_inotify_fd, events, IN_MODIFY); if (u->cgroup_inotify_wd < 0) { if (errno == ENOENT) /* If the directory is already * gone we don't need to track * it, so this is not an error */ return 0; return log_unit_error_errno(u, errno, "Failed to add inotify watch descriptor for control group %s: %m", u->cgroup_path); } r = hashmap_put(u->manager->cgroup_inotify_wd_unit, INT_TO_PTR(u->cgroup_inotify_wd), u); if (r < 0) return log_unit_error_errno(u, r, "Failed to add inotify watch descriptor to hash map: %m"); return 0; } int unit_pick_cgroup_path(Unit *u) { _cleanup_free_ char *path = NULL; int r; assert(u); if (u->cgroup_path) return 0; if (!UNIT_HAS_CGROUP_CONTEXT(u)) return -EINVAL; path = unit_default_cgroup_path(u); if (!path) return log_oom(); r = unit_set_cgroup_path(u, path); if (r == -EEXIST) return log_unit_error_errno(u, r, "Control group %s exists already.", path); if (r < 0) return log_unit_error_errno(u, r, "Failed to set unit's control group path to %s: %m", path); return 0; } static int unit_create_cgroup( Unit *u, CGroupMask target_mask, CGroupMask enable_mask, ManagerState state) { bool created; int r; assert(u); if (!UNIT_HAS_CGROUP_CONTEXT(u)) return 0; /* Figure out our cgroup path */ r = unit_pick_cgroup_path(u); if (r < 0) return r; /* First, create our own group */ r = cg_create_everywhere(u->manager->cgroup_supported, target_mask, u->cgroup_path); if (r < 0) return log_unit_error_errno(u, r, "Failed to create cgroup %s: %m", u->cgroup_path); created = r; /* Start watching it */ (void) unit_watch_cgroup(u); /* Preserve enabled controllers in delegated units, adjust others. */ if (created || !u->cgroup_realized || !unit_cgroup_delegate(u)) { CGroupMask result_mask = 0; /* Enable all controllers we need */ r = cg_enable_everywhere(u->manager->cgroup_supported, enable_mask, u->cgroup_path, &result_mask); if (r < 0) log_unit_warning_errno(u, r, "Failed to enable/disable controllers on cgroup %s, ignoring: %m", u->cgroup_path); /* If we just turned off a controller, this might release the controller for our parent too, let's * enqueue the parent for re-realization in that case again. */ if (UNIT_ISSET(u->slice)) { CGroupMask turned_off; turned_off = (u->cgroup_realized ? u->cgroup_enabled_mask & ~result_mask : 0); if (turned_off != 0) { Unit *parent; /* Force the parent to propagate the enable mask to the kernel again, by invalidating * the controller we just turned off. */ for (parent = UNIT_DEREF(u->slice); parent; parent = UNIT_DEREF(parent->slice)) unit_invalidate_cgroup(parent, turned_off); } } /* Remember what's actually enabled now */ u->cgroup_enabled_mask = result_mask; } /* Keep track that this is now realized */ u->cgroup_realized = true; u->cgroup_realized_mask = target_mask; if (u->type != UNIT_SLICE && !unit_cgroup_delegate(u)) { /* Then, possibly move things over, but not if * subgroups may contain processes, which is the case * for slice and delegation units. */ r = cg_migrate_everywhere(u->manager->cgroup_supported, u->cgroup_path, u->cgroup_path, migrate_callback, u); if (r < 0) log_unit_warning_errno(u, r, "Failed to migrate cgroup from to %s, ignoring: %m", u->cgroup_path); } /* Set attributes */ cgroup_context_apply(u, target_mask, state); cgroup_xattr_apply(u); return 0; } static int unit_attach_pid_to_cgroup_via_bus(Unit *u, pid_t pid, const char *suffix_path) { _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; char *pp; int r; assert(u); if (MANAGER_IS_SYSTEM(u->manager)) return -EINVAL; if (!u->manager->system_bus) return -EIO; if (!u->cgroup_path) return -EINVAL; /* Determine this unit's cgroup path relative to our cgroup root */ pp = path_startswith(u->cgroup_path, u->manager->cgroup_root); if (!pp) return -EINVAL; pp = strjoina("/", pp, suffix_path); path_simplify(pp, false); r = sd_bus_call_method(u->manager->system_bus, "org.freedesktop.systemd1", "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "AttachProcessesToUnit", &error, NULL, "ssau", NULL /* empty unit name means client's unit, i.e. us */, pp, 1, (uint32_t) pid); if (r < 0) return log_unit_debug_errno(u, r, "Failed to attach unit process " PID_FMT " via the bus: %s", pid, bus_error_message(&error, r)); return 0; } int unit_attach_pids_to_cgroup(Unit *u, Set *pids, const char *suffix_path) { CGroupMask delegated_mask; const char *p; Iterator i; void *pidp; int r, q; assert(u); if (!UNIT_HAS_CGROUP_CONTEXT(u)) return -EINVAL; if (set_isempty(pids)) return 0; r = unit_realize_cgroup(u); if (r < 0) return r; if (isempty(suffix_path)) p = u->cgroup_path; else p = strjoina(u->cgroup_path, "/", suffix_path); delegated_mask = unit_get_delegate_mask(u); r = 0; SET_FOREACH(pidp, pids, i) { pid_t pid = PTR_TO_PID(pidp); CGroupController c; /* First, attach the PID to the main cgroup hierarchy */ q = cg_attach(SYSTEMD_CGROUP_CONTROLLER, p, pid); if (q < 0) { log_unit_debug_errno(u, q, "Couldn't move process " PID_FMT " to requested cgroup '%s': %m", pid, p); if (MANAGER_IS_USER(u->manager) && IN_SET(q, -EPERM, -EACCES)) { int z; /* If we are in a user instance, and we can't move the process ourselves due to * permission problems, let's ask the system instance about it instead. Since it's more * privileged it might be able to move the process across the leaves of a subtree who's * top node is not owned by us. */ z = unit_attach_pid_to_cgroup_via_bus(u, pid, suffix_path); if (z < 0) log_unit_debug_errno(u, z, "Couldn't move process " PID_FMT " to requested cgroup '%s' via the system bus either: %m", pid, p); else continue; /* When the bus thing worked via the bus we are fully done for this PID. */ } if (r >= 0) r = q; /* Remember first error */ continue; } q = cg_all_unified(); if (q < 0) return q; if (q > 0) continue; /* In the legacy hierarchy, attach the process to the request cgroup if possible, and if not to the * innermost realized one */ for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); const char *realized; if (!(u->manager->cgroup_supported & bit)) continue; /* If this controller is delegated and realized, honour the caller's request for the cgroup suffix. */ if (delegated_mask & u->cgroup_realized_mask & bit) { q = cg_attach(cgroup_controller_to_string(c), p, pid); if (q >= 0) continue; /* Success! */ log_unit_debug_errno(u, q, "Failed to attach PID " PID_FMT " to requested cgroup %s in controller %s, falling back to unit's cgroup: %m", pid, p, cgroup_controller_to_string(c)); } /* So this controller is either not delegate or realized, or something else weird happened. In * that case let's attach the PID at least to the closest cgroup up the tree that is * realized. */ realized = unit_get_realized_cgroup_path(u, bit); if (!realized) continue; /* Not even realized in the root slice? Then let's not bother */ q = cg_attach(cgroup_controller_to_string(c), realized, pid); if (q < 0) log_unit_debug_errno(u, q, "Failed to attach PID " PID_FMT " to realized cgroup %s in controller %s, ignoring: %m", pid, realized, cgroup_controller_to_string(c)); } } return r; } static bool unit_has_mask_realized( Unit *u, CGroupMask target_mask, CGroupMask enable_mask) { assert(u); /* Returns true if this unit is fully realized. We check four things: * * 1. Whether the cgroup was created at all * 2. Whether the cgroup was created in all the hierarchies we need it to be created in (in case of cgroup v1) * 3. Whether the cgroup has all the right controllers enabled (in case of cgroup v2) * 4. Whether the invalidation mask is currently zero * * If you wonder why we mask the target realization and enable mask with CGROUP_MASK_V1/CGROUP_MASK_V2: note * that there are three sets of bitmasks: CGROUP_MASK_V1 (for real cgroup v1 controllers), CGROUP_MASK_V2 (for * real cgroup v2 controllers) and CGROUP_MASK_BPF (for BPF-based pseudo-controllers). Now, cgroup_realized_mask * is only matters for cgroup v1 controllers, and cgroup_enabled_mask only used for cgroup v2, and if they * differ in the others, we don't really care. (After all, the cgroup_enabled_mask tracks with controllers are * enabled through cgroup.subtree_control, and since the BPF pseudo-controllers don't show up there, they * simply don't matter. */ return u->cgroup_realized && ((u->cgroup_realized_mask ^ target_mask) & CGROUP_MASK_V1) == 0 && ((u->cgroup_enabled_mask ^ enable_mask) & CGROUP_MASK_V2) == 0 && u->cgroup_invalidated_mask == 0; } static bool unit_has_mask_disables_realized( Unit *u, CGroupMask target_mask, CGroupMask enable_mask) { assert(u); /* Returns true if all controllers which should be disabled are indeed disabled. * * Unlike unit_has_mask_realized, we don't care what was enabled, only that anything we want to remove is * already removed. */ return !u->cgroup_realized || (FLAGS_SET(u->cgroup_realized_mask, target_mask & CGROUP_MASK_V1) && FLAGS_SET(u->cgroup_enabled_mask, enable_mask & CGROUP_MASK_V2)); } static bool unit_has_mask_enables_realized( Unit *u, CGroupMask target_mask, CGroupMask enable_mask) { assert(u); /* Returns true if all controllers which should be enabled are indeed enabled. * * Unlike unit_has_mask_realized, we don't care about the controllers that are not present, only that anything * we want to add is already added. */ return u->cgroup_realized && ((u->cgroup_realized_mask | target_mask) & CGROUP_MASK_V1) == (u->cgroup_realized_mask & CGROUP_MASK_V1) && ((u->cgroup_enabled_mask | enable_mask) & CGROUP_MASK_V2) == (u->cgroup_enabled_mask & CGROUP_MASK_V2); } void unit_add_to_cgroup_realize_queue(Unit *u) { assert(u); if (u->in_cgroup_realize_queue) return; LIST_PREPEND(cgroup_realize_queue, u->manager->cgroup_realize_queue, u); u->in_cgroup_realize_queue = true; } static void unit_remove_from_cgroup_realize_queue(Unit *u) { assert(u); if (!u->in_cgroup_realize_queue) return; LIST_REMOVE(cgroup_realize_queue, u->manager->cgroup_realize_queue, u); u->in_cgroup_realize_queue = false; } /* Controllers can only be enabled breadth-first, from the root of the * hierarchy downwards to the unit in question. */ static int unit_realize_cgroup_now_enable(Unit *u, ManagerState state) { CGroupMask target_mask, enable_mask, new_target_mask, new_enable_mask; int r; assert(u); /* First go deal with this unit's parent, or we won't be able to enable * any new controllers at this layer. */ if (UNIT_ISSET(u->slice)) { r = unit_realize_cgroup_now_enable(UNIT_DEREF(u->slice), state); if (r < 0) return r; } target_mask = unit_get_target_mask(u); enable_mask = unit_get_enable_mask(u); /* We can only enable in this direction, don't try to disable anything. */ if (unit_has_mask_enables_realized(u, target_mask, enable_mask)) return 0; new_target_mask = u->cgroup_realized_mask | target_mask; new_enable_mask = u->cgroup_enabled_mask | enable_mask; return unit_create_cgroup(u, new_target_mask, new_enable_mask, state); } /* Controllers can only be disabled depth-first, from the leaves of the * hierarchy upwards to the unit in question. */ static int unit_realize_cgroup_now_disable(Unit *u, ManagerState state) { Iterator i; Unit *m; void *v; assert(u); if (u->type != UNIT_SLICE) return 0; HASHMAP_FOREACH_KEY(v, m, u->dependencies[UNIT_BEFORE], i) { CGroupMask target_mask, enable_mask, new_target_mask, new_enable_mask; int r; if (UNIT_DEREF(m->slice) != u) continue; /* The cgroup for this unit might not actually be fully * realised yet, in which case it isn't holding any controllers * open anyway. */ if (!m->cgroup_path) continue; /* We must disable those below us first in order to release the * controller. */ if (m->type == UNIT_SLICE) (void) unit_realize_cgroup_now_disable(m, state); target_mask = unit_get_target_mask(m); enable_mask = unit_get_enable_mask(m); /* We can only disable in this direction, don't try to enable * anything. */ if (unit_has_mask_disables_realized(m, target_mask, enable_mask)) continue; new_target_mask = m->cgroup_realized_mask & target_mask; new_enable_mask = m->cgroup_enabled_mask & enable_mask; r = unit_create_cgroup(m, new_target_mask, new_enable_mask, state); if (r < 0) return r; } return 0; } /* Check if necessary controllers and attributes for a unit are in place. * * - If so, do nothing. * - If not, create paths, move processes over, and set attributes. * * Controllers can only be *enabled* in a breadth-first way, and *disabled* in * a depth-first way. As such the process looks like this: * * Suppose we have a cgroup hierarchy which looks like this: * * root * / \ * / \ * / \ * a b * / \ / \ * / \ / \ * c d e f * / \ / \ / \ / \ * h i j k l m n o * * 1. We want to realise cgroup "d" now. * 2. cgroup "a" has DisableControllers=cpu in the associated unit. * 3. cgroup "k" just started requesting the memory controller. * * To make this work we must do the following in order: * * 1. Disable CPU controller in k, j * 2. Disable CPU controller in d * 3. Enable memory controller in root * 4. Enable memory controller in a * 5. Enable memory controller in d * 6. Enable memory controller in k * * Notice that we need to touch j in one direction, but not the other. We also * don't go beyond d when disabling -- it's up to "a" to get realized if it * wants to disable further. The basic rules are therefore: * * - If you're disabling something, you need to realise all of the cgroups from * your recursive descendants to the root. This starts from the leaves. * - If you're enabling something, you need to realise from the root cgroup * downwards, but you don't need to iterate your recursive descendants. * * Returns 0 on success and < 0 on failure. */ static int unit_realize_cgroup_now(Unit *u, ManagerState state) { CGroupMask target_mask, enable_mask; int r; assert(u); unit_remove_from_cgroup_realize_queue(u); target_mask = unit_get_target_mask(u); enable_mask = unit_get_enable_mask(u); if (unit_has_mask_realized(u, target_mask, enable_mask)) return 0; /* Disable controllers below us, if there are any */ r = unit_realize_cgroup_now_disable(u, state); if (r < 0) return r; /* Enable controllers above us, if there are any */ if (UNIT_ISSET(u->slice)) { r = unit_realize_cgroup_now_enable(UNIT_DEREF(u->slice), state); if (r < 0) return r; } /* Now actually deal with the cgroup we were trying to realise and set attributes */ r = unit_create_cgroup(u, target_mask, enable_mask, state); if (r < 0) return r; /* Now, reset the invalidation mask */ u->cgroup_invalidated_mask = 0; return 0; } unsigned manager_dispatch_cgroup_realize_queue(Manager *m) { ManagerState state; unsigned n = 0; Unit *i; int r; assert(m); state = manager_state(m); while ((i = m->cgroup_realize_queue)) { assert(i->in_cgroup_realize_queue); if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(i))) { /* Maybe things changed, and the unit is not actually active anymore? */ unit_remove_from_cgroup_realize_queue(i); continue; } r = unit_realize_cgroup_now(i, state); if (r < 0) log_warning_errno(r, "Failed to realize cgroups for queued unit %s, ignoring: %m", i->id); n++; } return n; } static void unit_add_siblings_to_cgroup_realize_queue(Unit *u) { Unit *slice; /* This adds the siblings of the specified unit and the * siblings of all parent units to the cgroup queue. (But * neither the specified unit itself nor the parents.) */ while ((slice = UNIT_DEREF(u->slice))) { Iterator i; Unit *m; void *v; HASHMAP_FOREACH_KEY(v, m, u->dependencies[UNIT_BEFORE], i) { /* Skip units that have a dependency on the slice * but aren't actually in it. */ if (UNIT_DEREF(m->slice) != slice) continue; /* No point in doing cgroup application for units * without active processes. */ if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(m))) continue; /* If the unit doesn't need any new controllers * and has current ones realized, it doesn't need * any changes. */ if (unit_has_mask_realized(m, unit_get_target_mask(m), unit_get_enable_mask(m))) continue; unit_add_to_cgroup_realize_queue(m); } u = slice; } } int unit_realize_cgroup(Unit *u) { assert(u); if (!UNIT_HAS_CGROUP_CONTEXT(u)) return 0; /* So, here's the deal: when realizing the cgroups for this * unit, we need to first create all parents, but there's more * actually: for the weight-based controllers we also need to * make sure that all our siblings (i.e. units that are in the * same slice as we are) have cgroups, too. Otherwise, things * would become very uneven as each of their processes would * get as much resources as all our group together. This call * will synchronously create the parent cgroups, but will * defer work on the siblings to the next event loop * iteration. */ /* Add all sibling slices to the cgroup queue. */ unit_add_siblings_to_cgroup_realize_queue(u); /* And realize this one now (and apply the values) */ return unit_realize_cgroup_now(u, manager_state(u->manager)); } void unit_release_cgroup(Unit *u) { assert(u); /* Forgets all cgroup details for this cgroup — but does *not* destroy the cgroup. This is hence OK to call * when we close down everything for reexecution, where we really want to leave the cgroup in place. */ if (u->cgroup_path) { (void) hashmap_remove(u->manager->cgroup_unit, u->cgroup_path); u->cgroup_path = mfree(u->cgroup_path); } if (u->cgroup_inotify_wd >= 0) { if (inotify_rm_watch(u->manager->cgroup_inotify_fd, u->cgroup_inotify_wd) < 0) log_unit_debug_errno(u, errno, "Failed to remove cgroup inotify watch %i for %s, ignoring: %m", u->cgroup_inotify_wd, u->id); (void) hashmap_remove(u->manager->cgroup_inotify_wd_unit, INT_TO_PTR(u->cgroup_inotify_wd)); u->cgroup_inotify_wd = -1; } } void unit_prune_cgroup(Unit *u) { int r; bool is_root_slice; assert(u); /* Removes the cgroup, if empty and possible, and stops watching it. */ if (!u->cgroup_path) return; (void) unit_get_cpu_usage(u, NULL); /* Cache the last CPU usage value before we destroy the cgroup */ is_root_slice = unit_has_name(u, SPECIAL_ROOT_SLICE); r = cg_trim_everywhere(u->manager->cgroup_supported, u->cgroup_path, !is_root_slice); if (r < 0) { log_unit_debug_errno(u, r, "Failed to destroy cgroup %s, ignoring: %m", u->cgroup_path); return; } if (is_root_slice) return; unit_release_cgroup(u); u->cgroup_realized = false; u->cgroup_realized_mask = 0; u->cgroup_enabled_mask = 0; u->bpf_device_control_installed = bpf_program_unref(u->bpf_device_control_installed); } int unit_search_main_pid(Unit *u, pid_t *ret) { _cleanup_fclose_ FILE *f = NULL; pid_t pid = 0, npid, mypid; int r; assert(u); assert(ret); if (!u->cgroup_path) return -ENXIO; r = cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, &f); if (r < 0) return r; mypid = getpid_cached(); while (cg_read_pid(f, &npid) > 0) { pid_t ppid; if (npid == pid) continue; /* Ignore processes that aren't our kids */ if (get_process_ppid(npid, &ppid) >= 0 && ppid != mypid) continue; if (pid != 0) /* Dang, there's more than one daemonized PID in this group, so we don't know what process is the main process. */ return -ENODATA; pid = npid; } *ret = pid; return 0; } static int unit_watch_pids_in_path(Unit *u, const char *path) { _cleanup_closedir_ DIR *d = NULL; _cleanup_fclose_ FILE *f = NULL; int ret = 0, r; assert(u); assert(path); r = cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, path, &f); if (r < 0) ret = r; else { pid_t pid; while ((r = cg_read_pid(f, &pid)) > 0) { r = unit_watch_pid(u, pid); if (r < 0 && ret >= 0) ret = r; } if (r < 0 && ret >= 0) ret = r; } r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, path, &d); if (r < 0) { if (ret >= 0) ret = r; } else { char *fn; while ((r = cg_read_subgroup(d, &fn)) > 0) { _cleanup_free_ char *p = NULL; p = strjoin(path, "/", fn); free(fn); if (!p) return -ENOMEM; r = unit_watch_pids_in_path(u, p); if (r < 0 && ret >= 0) ret = r; } if (r < 0 && ret >= 0) ret = r; } return ret; } int unit_synthesize_cgroup_empty_event(Unit *u) { int r; assert(u); /* Enqueue a synthetic cgroup empty event if this unit doesn't watch any PIDs anymore. This is compatibility * support for non-unified systems where notifications aren't reliable, and hence need to take whatever we can * get as notification source as soon as we stopped having any useful PIDs to watch for. */ if (!u->cgroup_path) return -ENOENT; r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); if (r < 0) return r; if (r > 0) /* On unified we have reliable notifications, and don't need this */ return 0; if (!set_isempty(u->pids)) return 0; unit_add_to_cgroup_empty_queue(u); return 0; } int unit_watch_all_pids(Unit *u) { int r; assert(u); /* Adds all PIDs from our cgroup to the set of PIDs we * watch. This is a fallback logic for cases where we do not * get reliable cgroup empty notifications: we try to use * SIGCHLD as replacement. */ if (!u->cgroup_path) return -ENOENT; r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); if (r < 0) return r; if (r > 0) /* On unified we can use proper notifications */ return 0; return unit_watch_pids_in_path(u, u->cgroup_path); } static int on_cgroup_empty_event(sd_event_source *s, void *userdata) { Manager *m = userdata; Unit *u; int r; assert(s); assert(m); u = m->cgroup_empty_queue; if (!u) return 0; assert(u->in_cgroup_empty_queue); u->in_cgroup_empty_queue = false; LIST_REMOVE(cgroup_empty_queue, m->cgroup_empty_queue, u); if (m->cgroup_empty_queue) { /* More stuff queued, let's make sure we remain enabled */ r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT); if (r < 0) log_debug_errno(r, "Failed to reenable cgroup empty event source, ignoring: %m"); } unit_add_to_gc_queue(u); if (UNIT_VTABLE(u)->notify_cgroup_empty) UNIT_VTABLE(u)->notify_cgroup_empty(u); return 0; } void unit_add_to_cgroup_empty_queue(Unit *u) { int r; assert(u); /* Note that there are four different ways how cgroup empty events reach us: * * 1. On the unified hierarchy we get an inotify event on the cgroup * * 2. On the legacy hierarchy, when running in system mode, we get a datagram on the cgroup agent socket * * 3. On the legacy hierarchy, when running in user mode, we get a D-Bus signal on the system bus * * 4. On the legacy hierarchy, in service units we start watching all processes of the cgroup for SIGCHLD as * soon as we get one SIGCHLD, to deal with unreliable cgroup notifications. * * Regardless which way we got the notification, we'll verify it here, and then add it to a separate * queue. This queue will be dispatched at a lower priority than the SIGCHLD handler, so that we always use * SIGCHLD if we can get it first, and only use the cgroup empty notifications if there's no SIGCHLD pending * (which might happen if the cgroup doesn't contain processes that are our own child, which is typically the * case for scope units). */ if (u->in_cgroup_empty_queue) return; /* Let's verify that the cgroup is really empty */ if (!u->cgroup_path) return; r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path); if (r < 0) { log_unit_debug_errno(u, r, "Failed to determine whether cgroup %s is empty: %m", u->cgroup_path); return; } if (r == 0) return; LIST_PREPEND(cgroup_empty_queue, u->manager->cgroup_empty_queue, u); u->in_cgroup_empty_queue = true; /* Trigger the defer event */ r = sd_event_source_set_enabled(u->manager->cgroup_empty_event_source, SD_EVENT_ONESHOT); if (r < 0) log_debug_errno(r, "Failed to enable cgroup empty event source: %m"); } static int on_cgroup_inotify_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) { Manager *m = userdata; assert(s); assert(fd >= 0); assert(m); for (;;) { union inotify_event_buffer buffer; struct inotify_event *e; ssize_t l; l = read(fd, &buffer, sizeof(buffer)); if (l < 0) { if (IN_SET(errno, EINTR, EAGAIN)) return 0; return log_error_errno(errno, "Failed to read control group inotify events: %m"); } FOREACH_INOTIFY_EVENT(e, buffer, l) { Unit *u; if (e->wd < 0) /* Queue overflow has no watch descriptor */ continue; if (e->mask & IN_IGNORED) /* The watch was just removed */ continue; u = hashmap_get(m->cgroup_inotify_wd_unit, INT_TO_PTR(e->wd)); if (!u) /* Not that inotify might deliver * events for a watch even after it * was removed, because it was queued * before the removal. Let's ignore * this here safely. */ continue; unit_add_to_cgroup_empty_queue(u); } } } static int cg_bpf_mask_supported(CGroupMask *ret) { CGroupMask mask = 0; int r; /* BPF-based firewall */ r = bpf_firewall_supported(); if (r > 0) mask |= CGROUP_MASK_BPF_FIREWALL; /* BPF-based device access control */ r = bpf_devices_supported(); if (r > 0) mask |= CGROUP_MASK_BPF_DEVICES; *ret = mask; return 0; } int manager_setup_cgroup(Manager *m) { _cleanup_free_ char *path = NULL; const char *scope_path; CGroupController c; int r, all_unified; CGroupMask mask; char *e; assert(m); /* 1. Determine hierarchy */ m->cgroup_root = mfree(m->cgroup_root); r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &m->cgroup_root); if (r < 0) return log_error_errno(r, "Cannot determine cgroup we are running in: %m"); /* Chop off the init scope, if we are already located in it */ e = endswith(m->cgroup_root, "/" SPECIAL_INIT_SCOPE); /* LEGACY: Also chop off the system slice if we are in * it. This is to support live upgrades from older systemd * versions where PID 1 was moved there. Also see * cg_get_root_path(). */ if (!e && MANAGER_IS_SYSTEM(m)) { e = endswith(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE); if (!e) e = endswith(m->cgroup_root, "/system"); /* even more legacy */ } if (e) *e = 0; /* And make sure to store away the root value without trailing slash, even for the root dir, so that we can * easily prepend it everywhere. */ delete_trailing_chars(m->cgroup_root, "/"); /* 2. Show data */ r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, NULL, &path); if (r < 0) return log_error_errno(r, "Cannot find cgroup mount point: %m"); r = cg_unified_flush(); if (r < 0) return log_error_errno(r, "Couldn't determine if we are running in the unified hierarchy: %m"); all_unified = cg_all_unified(); if (all_unified < 0) return log_error_errno(all_unified, "Couldn't determine whether we are in all unified mode: %m"); if (all_unified > 0) log_debug("Unified cgroup hierarchy is located at %s.", path); else { r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); if (r < 0) return log_error_errno(r, "Failed to determine whether systemd's own controller is in unified mode: %m"); if (r > 0) log_debug("Unified cgroup hierarchy is located at %s. Controllers are on legacy hierarchies.", path); else log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER_LEGACY ". File system hierarchy is at %s.", path); } /* 3. Allocate cgroup empty defer event source */ m->cgroup_empty_event_source = sd_event_source_unref(m->cgroup_empty_event_source); r = sd_event_add_defer(m->event, &m->cgroup_empty_event_source, on_cgroup_empty_event, m); if (r < 0) return log_error_errno(r, "Failed to create cgroup empty event source: %m"); r = sd_event_source_set_priority(m->cgroup_empty_event_source, SD_EVENT_PRIORITY_NORMAL-5); if (r < 0) return log_error_errno(r, "Failed to set priority of cgroup empty event source: %m"); r = sd_event_source_set_enabled(m->cgroup_empty_event_source, SD_EVENT_OFF); if (r < 0) return log_error_errno(r, "Failed to disable cgroup empty event source: %m"); (void) sd_event_source_set_description(m->cgroup_empty_event_source, "cgroup-empty"); /* 4. Install notifier inotify object, or agent */ if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0) { /* In the unified hierarchy we can get cgroup empty notifications via inotify. */ m->cgroup_inotify_event_source = sd_event_source_unref(m->cgroup_inotify_event_source); safe_close(m->cgroup_inotify_fd); m->cgroup_inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC); if (m->cgroup_inotify_fd < 0) return log_error_errno(errno, "Failed to create control group inotify object: %m"); r = sd_event_add_io(m->event, &m->cgroup_inotify_event_source, m->cgroup_inotify_fd, EPOLLIN, on_cgroup_inotify_event, m); if (r < 0) return log_error_errno(r, "Failed to watch control group inotify object: %m"); /* Process cgroup empty notifications early, but after service notifications and SIGCHLD. Also * see handling of cgroup agent notifications, for the classic cgroup hierarchy support. */ r = sd_event_source_set_priority(m->cgroup_inotify_event_source, SD_EVENT_PRIORITY_NORMAL-4); if (r < 0) return log_error_errno(r, "Failed to set priority of inotify event source: %m"); (void) sd_event_source_set_description(m->cgroup_inotify_event_source, "cgroup-inotify"); } else if (MANAGER_IS_SYSTEM(m) && manager_owns_host_root_cgroup(m) && !MANAGER_IS_TEST_RUN(m)) { /* On the legacy hierarchy we only get notifications via cgroup agents. (Which isn't really reliable, * since it does not generate events when control groups with children run empty. */ r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_CGROUP_AGENT_PATH); if (r < 0) log_warning_errno(r, "Failed to install release agent, ignoring: %m"); else if (r > 0) log_debug("Installed release agent."); else if (r == 0) log_debug("Release agent already installed."); } /* 5. Make sure we are in the special "init.scope" unit in the root slice. */ scope_path = strjoina(m->cgroup_root, "/" SPECIAL_INIT_SCOPE); r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, scope_path, 0); if (r >= 0) { /* Also, move all other userspace processes remaining in the root cgroup into that scope. */ r = cg_migrate(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, SYSTEMD_CGROUP_CONTROLLER, scope_path, 0); if (r < 0) log_warning_errno(r, "Couldn't move remaining userspace processes, ignoring: %m"); /* 6. And pin it, so that it cannot be unmounted */ safe_close(m->pin_cgroupfs_fd); m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK); if (m->pin_cgroupfs_fd < 0) return log_error_errno(errno, "Failed to open pin file: %m"); } else if (!MANAGER_IS_TEST_RUN(m)) return log_error_errno(r, "Failed to create %s control group: %m", scope_path); /* 7. Always enable hierarchical support if it exists... */ if (!all_unified && !MANAGER_IS_TEST_RUN(m)) (void) cg_set_attribute("memory", "/", "memory.use_hierarchy", "1"); /* 8. Figure out which controllers are supported */ r = cg_mask_supported(&m->cgroup_supported); if (r < 0) return log_error_errno(r, "Failed to determine supported controllers: %m"); /* 9. Figure out which bpf-based pseudo-controllers are supported */ r = cg_bpf_mask_supported(&mask); if (r < 0) return log_error_errno(r, "Failed to determine supported bpf-based pseudo-controllers: %m"); m->cgroup_supported |= mask; /* 10. Log which controllers are supported */ for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) log_debug("Controller '%s' supported: %s", cgroup_controller_to_string(c), yes_no(m->cgroup_supported & CGROUP_CONTROLLER_TO_MASK(c))); return 0; } void manager_shutdown_cgroup(Manager *m, bool delete) { assert(m); /* We can't really delete the group, since we are in it. But * let's trim it. */ if (delete && m->cgroup_root && m->test_run_flags != MANAGER_TEST_RUN_MINIMAL) (void) cg_trim(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, false); m->cgroup_empty_event_source = sd_event_source_unref(m->cgroup_empty_event_source); m->cgroup_inotify_wd_unit = hashmap_free(m->cgroup_inotify_wd_unit); m->cgroup_inotify_event_source = sd_event_source_unref(m->cgroup_inotify_event_source); m->cgroup_inotify_fd = safe_close(m->cgroup_inotify_fd); m->pin_cgroupfs_fd = safe_close(m->pin_cgroupfs_fd); m->cgroup_root = mfree(m->cgroup_root); } Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) { char *p; Unit *u; assert(m); assert(cgroup); u = hashmap_get(m->cgroup_unit, cgroup); if (u) return u; p = strdupa(cgroup); for (;;) { char *e; e = strrchr(p, '/'); if (!e || e == p) return hashmap_get(m->cgroup_unit, SPECIAL_ROOT_SLICE); *e = 0; u = hashmap_get(m->cgroup_unit, p); if (u) return u; } } Unit *manager_get_unit_by_pid_cgroup(Manager *m, pid_t pid) { _cleanup_free_ char *cgroup = NULL; assert(m); if (!pid_is_valid(pid)) return NULL; if (cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup) < 0) return NULL; return manager_get_unit_by_cgroup(m, cgroup); } Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) { Unit *u, **array; assert(m); /* Note that a process might be owned by multiple units, we return only one here, which is good enough for most * cases, though not strictly correct. We prefer the one reported by cgroup membership, as that's the most * relevant one as children of the process will be assigned to that one, too, before all else. */ if (!pid_is_valid(pid)) return NULL; if (pid == getpid_cached()) return hashmap_get(m->units, SPECIAL_INIT_SCOPE); u = manager_get_unit_by_pid_cgroup(m, pid); if (u) return u; u = hashmap_get(m->watch_pids, PID_TO_PTR(pid)); if (u) return u; array = hashmap_get(m->watch_pids, PID_TO_PTR(-pid)); if (array) return array[0]; return NULL; } int manager_notify_cgroup_empty(Manager *m, const char *cgroup) { Unit *u; assert(m); assert(cgroup); /* Called on the legacy hierarchy whenever we get an explicit cgroup notification from the cgroup agent process * or from the --system instance */ log_debug("Got cgroup empty notification for: %s", cgroup); u = manager_get_unit_by_cgroup(m, cgroup); if (!u) return 0; unit_add_to_cgroup_empty_queue(u); return 1; } int unit_get_memory_current(Unit *u, uint64_t *ret) { _cleanup_free_ char *v = NULL; int r; assert(u); assert(ret); if (!UNIT_CGROUP_BOOL(u, memory_accounting)) return -ENODATA; if (!u->cgroup_path) return -ENODATA; /* The root cgroup doesn't expose this information, let's get it from /proc instead */ if (unit_has_host_root_cgroup(u)) return procfs_memory_get_current(ret); if ((u->cgroup_realized_mask & CGROUP_MASK_MEMORY) == 0) return -ENODATA; r = cg_all_unified(); if (r < 0) return r; if (r > 0) r = cg_get_attribute("memory", u->cgroup_path, "memory.current", &v); else r = cg_get_attribute("memory", u->cgroup_path, "memory.usage_in_bytes", &v); if (r == -ENOENT) return -ENODATA; if (r < 0) return r; return safe_atou64(v, ret); } int unit_get_tasks_current(Unit *u, uint64_t *ret) { _cleanup_free_ char *v = NULL; int r; assert(u); assert(ret); if (!UNIT_CGROUP_BOOL(u, tasks_accounting)) return -ENODATA; if (!u->cgroup_path) return -ENODATA; /* The root cgroup doesn't expose this information, let's get it from /proc instead */ if (unit_has_host_root_cgroup(u)) return procfs_tasks_get_current(ret); if ((u->cgroup_realized_mask & CGROUP_MASK_PIDS) == 0) return -ENODATA; r = cg_get_attribute("pids", u->cgroup_path, "pids.current", &v); if (r == -ENOENT) return -ENODATA; if (r < 0) return r; return safe_atou64(v, ret); } static int unit_get_cpu_usage_raw(Unit *u, nsec_t *ret) { _cleanup_free_ char *v = NULL; uint64_t ns; int r; assert(u); assert(ret); if (!u->cgroup_path) return -ENODATA; /* The root cgroup doesn't expose this information, let's get it from /proc instead */ if (unit_has_host_root_cgroup(u)) return procfs_cpu_get_usage(ret); /* Requisite controllers for CPU accounting are not enabled */ if ((get_cpu_accounting_mask() & ~u->cgroup_realized_mask) != 0) return -ENODATA; r = cg_all_unified(); if (r < 0) return r; if (r > 0) { _cleanup_free_ char *val = NULL; uint64_t us; r = cg_get_keyed_attribute("cpu", u->cgroup_path, "cpu.stat", STRV_MAKE("usage_usec"), &val); if (IN_SET(r, -ENOENT, -ENXIO)) return -ENODATA; if (r < 0) return r; r = safe_atou64(val, &us); if (r < 0) return r; ns = us * NSEC_PER_USEC; } else { r = cg_get_attribute("cpuacct", u->cgroup_path, "cpuacct.usage", &v); if (r == -ENOENT) return -ENODATA; if (r < 0) return r; r = safe_atou64(v, &ns); if (r < 0) return r; } *ret = ns; return 0; } int unit_get_cpu_usage(Unit *u, nsec_t *ret) { nsec_t ns; int r; assert(u); /* Retrieve the current CPU usage counter. This will subtract the CPU counter taken when the unit was * started. If the cgroup has been removed already, returns the last cached value. To cache the value, simply * call this function with a NULL return value. */ if (!UNIT_CGROUP_BOOL(u, cpu_accounting)) return -ENODATA; r = unit_get_cpu_usage_raw(u, &ns); if (r == -ENODATA && u->cpu_usage_last != NSEC_INFINITY) { /* If we can't get the CPU usage anymore (because the cgroup was already removed, for example), use our * cached value. */ if (ret) *ret = u->cpu_usage_last; return 0; } if (r < 0) return r; if (ns > u->cpu_usage_base) ns -= u->cpu_usage_base; else ns = 0; u->cpu_usage_last = ns; if (ret) *ret = ns; return 0; } int unit_get_ip_accounting( Unit *u, CGroupIPAccountingMetric metric, uint64_t *ret) { uint64_t value; int fd, r; assert(u); assert(metric >= 0); assert(metric < _CGROUP_IP_ACCOUNTING_METRIC_MAX); assert(ret); if (!UNIT_CGROUP_BOOL(u, ip_accounting)) return -ENODATA; fd = IN_SET(metric, CGROUP_IP_INGRESS_BYTES, CGROUP_IP_INGRESS_PACKETS) ? u->ip_accounting_ingress_map_fd : u->ip_accounting_egress_map_fd; if (fd < 0) return -ENODATA; if (IN_SET(metric, CGROUP_IP_INGRESS_BYTES, CGROUP_IP_EGRESS_BYTES)) r = bpf_firewall_read_accounting(fd, &value, NULL); else r = bpf_firewall_read_accounting(fd, NULL, &value); if (r < 0) return r; /* Add in additional metrics from a previous runtime. Note that when reexecing/reloading the daemon we compile * all BPF programs and maps anew, but serialize the old counters. When deserializing we store them in the * ip_accounting_extra[] field, and add them in here transparently. */ *ret = value + u->ip_accounting_extra[metric]; return r; } int unit_reset_cpu_accounting(Unit *u) { nsec_t ns; int r; assert(u); u->cpu_usage_last = NSEC_INFINITY; r = unit_get_cpu_usage_raw(u, &ns); if (r < 0) { u->cpu_usage_base = 0; return r; } u->cpu_usage_base = ns; return 0; } int unit_reset_ip_accounting(Unit *u) { int r = 0, q = 0; assert(u); if (u->ip_accounting_ingress_map_fd >= 0) r = bpf_firewall_reset_accounting(u->ip_accounting_ingress_map_fd); if (u->ip_accounting_egress_map_fd >= 0) q = bpf_firewall_reset_accounting(u->ip_accounting_egress_map_fd); zero(u->ip_accounting_extra); return r < 0 ? r : q; } void unit_invalidate_cgroup(Unit *u, CGroupMask m) { assert(u); if (!UNIT_HAS_CGROUP_CONTEXT(u)) return; if (m == 0) return; /* always invalidate compat pairs together */ if (m & (CGROUP_MASK_IO | CGROUP_MASK_BLKIO)) m |= CGROUP_MASK_IO | CGROUP_MASK_BLKIO; if (m & (CGROUP_MASK_CPU | CGROUP_MASK_CPUACCT)) m |= CGROUP_MASK_CPU | CGROUP_MASK_CPUACCT; if (FLAGS_SET(u->cgroup_invalidated_mask, m)) /* NOP? */ return; u->cgroup_invalidated_mask |= m; unit_add_to_cgroup_realize_queue(u); } void unit_invalidate_cgroup_bpf(Unit *u) { assert(u); if (!UNIT_HAS_CGROUP_CONTEXT(u)) return; if (u->cgroup_invalidated_mask & CGROUP_MASK_BPF_FIREWALL) /* NOP? */ return; u->cgroup_invalidated_mask |= CGROUP_MASK_BPF_FIREWALL; unit_add_to_cgroup_realize_queue(u); /* If we are a slice unit, we also need to put compile a new BPF program for all our children, as the IP access * list of our children includes our own. */ if (u->type == UNIT_SLICE) { Unit *member; Iterator i; void *v; HASHMAP_FOREACH_KEY(v, member, u->dependencies[UNIT_BEFORE], i) { if (UNIT_DEREF(member->slice) == u) unit_invalidate_cgroup_bpf(member); } } } bool unit_cgroup_delegate(Unit *u) { CGroupContext *c; assert(u); if (!UNIT_VTABLE(u)->can_delegate) return false; c = unit_get_cgroup_context(u); if (!c) return false; return c->delegate; } void manager_invalidate_startup_units(Manager *m) { Iterator i; Unit *u; assert(m); SET_FOREACH(u, m->startup_units, i) unit_invalidate_cgroup(u, CGROUP_MASK_CPU|CGROUP_MASK_IO|CGROUP_MASK_BLKIO); } static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = { [CGROUP_AUTO] = "auto", [CGROUP_CLOSED] = "closed", [CGROUP_STRICT] = "strict", }; DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy);