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| author | Tejun Heo <tj@kernel.org> | 2023-02-22 15:29:12 -1000 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-02-23 08:33:05 -0800 |
| commit | 332ea1f697be148bd5e66475d82b5ecc5084da65 (patch) | |
| tree | 91c5b5b1138cc7fd1d210dfbaa161af0c9e0054e /kernel/bpf/helpers.c | |
| parent | 746ce767128598711a00d8df5713d4c3b3d9e9a7 (diff) | |
| download | lwn-332ea1f697be148bd5e66475d82b5ecc5084da65.tar.gz lwn-332ea1f697be148bd5e66475d82b5ecc5084da65.zip | |
bpf: Add bpf_cgroup_from_id() kfunc
cgroup ID is an userspace-visible 64bit value uniquely identifying a given
cgroup. As the IDs are used widely, it's useful to be able to look up the
matching cgroups. Add bpf_cgroup_from_id().
v2: Separate out selftest into its own patch as suggested by Alexei.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/Y/bBaG96t0/gQl9/@slm.duckdns.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/helpers.c')
| -rw-r--r-- | kernel/bpf/helpers.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 5b278a38ae58..a784be6f8bac 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2101,6 +2101,23 @@ __bpf_kfunc struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) cgroup_get(ancestor); return ancestor; } + +/** + * bpf_cgroup_from_id - Find a cgroup from its ID. A cgroup returned by this + * kfunc which is not subsequently stored in a map, must be released by calling + * bpf_cgroup_release(). + * @cgrp: The cgroup for which we're performing a lookup. + * @level: The level of ancestor to look up. + */ +__bpf_kfunc struct cgroup *bpf_cgroup_from_id(u64 cgid) +{ + struct cgroup *cgrp; + + cgrp = cgroup_get_from_id(cgid); + if (IS_ERR(cgrp)) + return NULL; + return cgrp; +} #endif /* CONFIG_CGROUPS */ /** @@ -2167,6 +2184,7 @@ BTF_ID_FLAGS(func, bpf_cgroup_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS) BTF_ID_FLAGS(func, bpf_cgroup_kptr_get, KF_ACQUIRE | KF_KPTR_GET | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE) BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_TRUSTED_ARGS | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL) #endif BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL) BTF_SET8_END(generic_btf_ids) |