/* SPDX-License-Identifier: GPL-2.0 */ /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ #ifndef _CGRP_KFUNC_COMMON_H #define _CGRP_KFUNC_COMMON_H #include <errno.h> #include <vmlinux.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> struct __cgrps_kfunc_map_value { struct cgroup __kptr * cgrp; }; struct hash_map { __uint(type, BPF_MAP_TYPE_HASH); __type(key, int); __type(value, struct __cgrps_kfunc_map_value); __uint(max_entries, 1); } __cgrps_kfunc_map SEC(".maps"); struct cgroup *bpf_cgroup_acquire(struct cgroup *p) __ksym; void bpf_cgroup_release(struct cgroup *p) __ksym; struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) __ksym; struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym; void bpf_rcu_read_lock(void) __ksym; void bpf_rcu_read_unlock(void) __ksym; static inline struct __cgrps_kfunc_map_value *cgrps_kfunc_map_value_lookup(struct cgroup *cgrp) { s32 id; long status; status = bpf_probe_read_kernel(&id, sizeof(id), &cgrp->self.id); if (status) return NULL; return bpf_map_lookup_elem(&__cgrps_kfunc_map, &id); } static inline int cgrps_kfunc_map_insert(struct cgroup *cgrp) { struct __cgrps_kfunc_map_value local, *v; long status; struct cgroup *acquired, *old; s32 id; status = bpf_probe_read_kernel(&id, sizeof(id), &cgrp->self.id); if (status) return status; local.cgrp = NULL; status = bpf_map_update_elem(&__cgrps_kfunc_map, &id, &local, BPF_NOEXIST); if (status) return status; v = bpf_map_lookup_elem(&__cgrps_kfunc_map, &id); if (!v) { bpf_map_delete_elem(&__cgrps_kfunc_map, &id); return -ENOENT; } acquired = bpf_cgroup_acquire(cgrp); if (!acquired) { bpf_map_delete_elem(&__cgrps_kfunc_map, &id); return -ENOENT; } old = bpf_kptr_xchg(&v->cgrp, acquired); if (old) { bpf_cgroup_release(old); return -EEXIST; } return 0; } #endif /* _CGRP_KFUNC_COMMON_H */