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1/* SPDX-License-Identifier: GPL-2.0 */2/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */3 4#ifndef _CGRP_KFUNC_COMMON_H5#define _CGRP_KFUNC_COMMON_H6 7#include <errno.h>8#include <vmlinux.h>9#include <bpf/bpf_helpers.h>10#include <bpf/bpf_tracing.h>11 12struct __cgrps_kfunc_map_value {13 struct cgroup __kptr * cgrp;14};15 16struct {17 __uint(type, BPF_MAP_TYPE_HASH);18 __type(key, int);19 __type(value, struct __cgrps_kfunc_map_value);20 __uint(max_entries, 1);21} __cgrps_kfunc_map SEC(".maps");22 23struct cgroup *bpf_cgroup_acquire(struct cgroup *p) __ksym;24void bpf_cgroup_release(struct cgroup *p) __ksym;25struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) __ksym;26struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym;27void bpf_rcu_read_lock(void) __ksym;28void bpf_rcu_read_unlock(void) __ksym;29 30static inline struct __cgrps_kfunc_map_value *cgrps_kfunc_map_value_lookup(struct cgroup *cgrp)31{32 s32 id;33 long status;34 35 status = bpf_probe_read_kernel(&id, sizeof(id), &cgrp->self.id);36 if (status)37 return NULL;38 39 return bpf_map_lookup_elem(&__cgrps_kfunc_map, &id);40}41 42static inline int cgrps_kfunc_map_insert(struct cgroup *cgrp)43{44 struct __cgrps_kfunc_map_value local, *v;45 long status;46 struct cgroup *acquired, *old;47 s32 id;48 49 status = bpf_probe_read_kernel(&id, sizeof(id), &cgrp->self.id);50 if (status)51 return status;52 53 local.cgrp = NULL;54 status = bpf_map_update_elem(&__cgrps_kfunc_map, &id, &local, BPF_NOEXIST);55 if (status)56 return status;57 58 v = bpf_map_lookup_elem(&__cgrps_kfunc_map, &id);59 if (!v) {60 bpf_map_delete_elem(&__cgrps_kfunc_map, &id);61 return -ENOENT;62 }63 64 acquired = bpf_cgroup_acquire(cgrp);65 if (!acquired) {66 bpf_map_delete_elem(&__cgrps_kfunc_map, &id);67 return -ENOENT;68 }69 70 old = bpf_kptr_xchg(&v->cgrp, acquired);71 if (old) {72 bpf_cgroup_release(old);73 return -EEXIST;74 }75 76 return 0;77}78 79#endif /* _CGRP_KFUNC_COMMON_H */80