1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ 3 4 #ifndef _CGRP_KFUNC_COMMON_H 5 #define _CGRP_KFUNC_COMMON_H 6 7 #include <errno.h> 8 #include <vmlinux.h> 9 #include <bpf/bpf_helpers.h> 10 #include <bpf/bpf_tracing.h> 11 12 struct __cgrps_kfunc_map_value { 13 struct cgroup __kptr * cgrp; 14 }; 15 16 struct hash_map { 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 23 struct cgroup *bpf_cgroup_acquire(struct cgroup *p) __ksym; 24 struct cgroup *bpf_cgroup_kptr_get(struct cgroup **pp) __ksym; 25 void bpf_cgroup_release(struct cgroup *p) __ksym; 26 struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) __ksym; 27 struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym; 28 29 static inline struct __cgrps_kfunc_map_value *cgrps_kfunc_map_value_lookup(struct cgroup *cgrp) 30 { 31 s32 id; 32 long status; 33 34 status = bpf_probe_read_kernel(&id, sizeof(id), &cgrp->self.id); 35 if (status) 36 return NULL; 37 38 return bpf_map_lookup_elem(&__cgrps_kfunc_map, &id); 39 } 40 41 static inline int cgrps_kfunc_map_insert(struct cgroup *cgrp) 42 { 43 struct __cgrps_kfunc_map_value local, *v; 44 long status; 45 struct cgroup *acquired, *old; 46 s32 id; 47 48 status = bpf_probe_read_kernel(&id, sizeof(id), &cgrp->self.id); 49 if (status) 50 return status; 51 52 local.cgrp = NULL; 53 status = bpf_map_update_elem(&__cgrps_kfunc_map, &id, &local, BPF_NOEXIST); 54 if (status) 55 return status; 56 57 v = bpf_map_lookup_elem(&__cgrps_kfunc_map, &id); 58 if (!v) { 59 bpf_map_delete_elem(&__cgrps_kfunc_map, &id); 60 return -ENOENT; 61 } 62 63 acquired = bpf_cgroup_acquire(cgrp); 64 old = bpf_kptr_xchg(&v->cgrp, acquired); 65 if (old) { 66 bpf_cgroup_release(old); 67 return -EEXIST; 68 } 69 70 return 0; 71 } 72 73 #endif /* _CGRP_KFUNC_COMMON_H */ 74