From: Song Liu Date: Mon, 23 Jun 2025 06:38:53 +0000 (-0700) Subject: bpf: Mark cgroup_subsys_state->cgroup RCU safe X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5bc9557c9f17c38ed8c9070c1d369d49eabea1a9;p=thirdparty%2Fkernel%2Flinux.git bpf: Mark cgroup_subsys_state->cgroup RCU safe Mark struct cgroup_subsys_state->cgroup as safe under RCU read lock. This will enable accessing css->cgroup from a bpf css iterator. Signed-off-by: Song Liu Link: https://lore.kernel.org/20250623063854.1896364-4-song@kernel.org Acked-by: Tejun Heo Signed-off-by: Christian Brauner --- diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index a7d6e0c5928bc..db01bf51c7923 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6993,6 +6993,10 @@ BTF_TYPE_SAFE_RCU(struct css_set) { struct cgroup *dfl_cgrp; }; +BTF_TYPE_SAFE_RCU(struct cgroup_subsys_state) { + struct cgroup *cgroup; +}; + /* RCU trusted: these fields are trusted in RCU CS and can be NULL */ BTF_TYPE_SAFE_RCU_OR_NULL(struct mm_struct) { struct file __rcu *exe_file; @@ -7043,6 +7047,7 @@ static bool type_is_rcu(struct bpf_verifier_env *env, BTF_TYPE_EMIT(BTF_TYPE_SAFE_RCU(struct task_struct)); BTF_TYPE_EMIT(BTF_TYPE_SAFE_RCU(struct cgroup)); BTF_TYPE_EMIT(BTF_TYPE_SAFE_RCU(struct css_set)); + BTF_TYPE_EMIT(BTF_TYPE_SAFE_RCU(struct cgroup_subsys_state)); return btf_nested_type_is_trusted(&env->log, reg, field_name, btf_id, "__safe_rcu"); }