Documentation/bpf/map_cgroup_storage.rst

11 storage is identified by the cgroup the program is attached to.
13 The map provide a local storage at the cgroup that the BPF program is attached
34 ``attach_type`` is the program's attach type.
42 To access the storage in a program, use ``bpf_get_local_storage``::
67     int program(struct __sk_buff *skb)
102     int program(struct __sk_buff *skb)
131 for a single ``CGROUP_STORAGE`` map, there can be at most one program loaded
132 that uses the map. A program may be attached to multiple cgroups or have
137 non-per-CPU) and the BPF program during load verification time. As a result,
138 each map can only be used by one BPF program and each BPF program can only use
140 program, sharing of this cgroup's storage with other BPF programs were
143 Since Linux 5.9, storage can be shared by multiple programs. When a program is
152 The map is not associated with any BPF program, thus making sharing possible.
153 However, the BPF program can still only associate with one map of each type
154 (per-CPU and non-per-CPU). A BPF program cannot use more than one
165 The storage is bound at attach time. Even if the program is attached to parent
169 Program test runs always use a temporary storage.