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/* 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 {
__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 */
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