Unverified Commit 1504d8c7 authored by Song Liu's avatar Song Liu Committed by Christian Brauner
Browse files

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: default avatarSong Liu <song@kernel.org>
Link: https://lore.kernel.org/20250623063854.1896364-4-song@kernel.org


Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 535b070f

kernel/bpf/verifier.c

+5 −0
Original line number Diff line number Diff line
@@ -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");









}