Commit 82648b8b authored by Tejun Heo's avatar Tejun Heo
Browse files

sched_ext: Convert cgroup BPF support to use cgroup_lifetime_notifier 



Replace explicit cgroup_bpf_inherit/offline() calls from cgroup
creation/destruction paths with notification callback registered on
cgroup_lifetime_notifier.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 9e8c67a9

include/linux/bpf-cgroup.h

+5 −4
Original line number Diff line number Diff line
@@ -114,8 +114,7 @@ struct bpf_prog_list { 
	u32 flags;

};



int cgroup_bpf_inherit(struct cgroup *cgrp);

void cgroup_bpf_offline(struct cgroup *cgrp);

void __init cgroup_bpf_lifetime_notifier_init(void);



int __cgroup_bpf_run_filter_skb(struct sock *sk,

				struct sk_buff *skb,
@@ -431,8 +430,10 @@ const struct bpf_func_proto * 
cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog);

#else



static inline int cgroup_bpf_inherit(struct cgroup *cgrp) { return 0; }

static inline void cgroup_bpf_offline(struct cgroup *cgrp) {}

static inline void cgroup_bpf_lifetime_notifier_init(void)

{

	return;

}



static inline int cgroup_bpf_prog_attach(const union bpf_attr *attr,

					 enum bpf_prog_type ptype,

kernel/bpf/cgroup.c

+36 −2
Original line number Diff line number Diff line
@@ -41,6 +41,19 @@ static int __init cgroup_bpf_wq_init(void) 
}

core_initcall(cgroup_bpf_wq_init);



static int cgroup_bpf_lifetime_notify(struct notifier_block *nb,

				      unsigned long action, void *data);



static struct notifier_block cgroup_bpf_lifetime_nb = {

	.notifier_call = cgroup_bpf_lifetime_notify,

};



void __init cgroup_bpf_lifetime_notifier_init(void)

{

	BUG_ON(blocking_notifier_chain_register(&cgroup_lifetime_notifier,

						&cgroup_bpf_lifetime_nb));

}



/* __always_inline is necessary to prevent indirect call through run_prog

 * function pointer.

 */
@@ -206,7 +219,7 @@ bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id) 
}

#endif /* CONFIG_BPF_LSM */



void cgroup_bpf_offline(struct cgroup *cgrp)

static void cgroup_bpf_offline(struct cgroup *cgrp)

{

	cgroup_get(cgrp);

	percpu_ref_kill(&cgrp->bpf.refcnt);
@@ -491,7 +504,7 @@ static void activate_effective_progs(struct cgroup *cgrp, 
 * cgroup_bpf_inherit() - inherit effective programs from parent

 * @cgrp: the cgroup to modify

 */

int cgroup_bpf_inherit(struct cgroup *cgrp)

static int cgroup_bpf_inherit(struct cgroup *cgrp)

{

/* has to use marco instead of const int, since compiler thinks

 * that array below is variable length
@@ -534,6 +547,27 @@ int cgroup_bpf_inherit(struct cgroup *cgrp) 
	return -ENOMEM;

}



static int cgroup_bpf_lifetime_notify(struct notifier_block *nb,

				      unsigned long action, void *data)

{

	struct cgroup *cgrp = data;

	int ret = 0;



	if (cgrp->root != &cgrp_dfl_root)

		return NOTIFY_OK;



	switch (action) {

	case CGROUP_LIFETIME_ONLINE:

		ret = cgroup_bpf_inherit(cgrp);

		break;

	case CGROUP_LIFETIME_OFFLINE:

		cgroup_bpf_offline(cgrp);

		break;

	}



	return notifier_from_errno(ret);

}



static int update_effective_progs(struct cgroup *cgrp,

				  enum cgroup_bpf_attach_type atype)

{

kernel/cgroup/cgroup.c

+3 −17
Original line number Diff line number Diff line
@@ -2143,11 +2143,6 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) 
	if (ret)

		goto exit_stats;



	if (root == &cgrp_dfl_root) {

		ret = cgroup_bpf_inherit(root_cgrp);

		WARN_ON_ONCE(ret);

	}



	ret = blocking_notifier_call_chain(&cgroup_lifetime_notifier,

					   CGROUP_LIFETIME_ONLINE, root_cgrp);

	WARN_ON_ONCE(notifier_to_errno(ret));
@@ -5739,20 +5734,12 @@ static struct cgroup *cgroup_create(struct cgroup *parent, const char *name, 


	cgrp->self.serial_nr = css_serial_nr_next++;



	if (cgrp->root == &cgrp_dfl_root) {

		ret = cgroup_bpf_inherit(cgrp);

		if (ret)

			goto out_psi_free;

	}



	ret = blocking_notifier_call_chain_robust(&cgroup_lifetime_notifier,

						  CGROUP_LIFETIME_ONLINE,

						  CGROUP_LIFETIME_OFFLINE, cgrp);

	ret = notifier_to_errno(ret);

	if (ret) {

		cgroup_bpf_offline(cgrp);

	if (ret)

		goto out_psi_free;

	}



	/* allocation complete, commit to creation */

	spin_lock_irq(&css_set_lock);
@@ -6045,9 +6032,6 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) 


	cgroup1_check_for_release(parent);



	if (cgrp->root == &cgrp_dfl_root)

		cgroup_bpf_offline(cgrp);



	ret = blocking_notifier_call_chain(&cgroup_lifetime_notifier,

					   CGROUP_LIFETIME_OFFLINE, cgrp);

	WARN_ON_ONCE(notifier_to_errno(ret));
@@ -6206,6 +6190,8 @@ int __init cgroup_init(void) 
	hash_add(css_set_table, &init_css_set.hlist,

		 css_set_hash(init_css_set.subsys));



	cgroup_bpf_lifetime_notifier_init();



	BUG_ON(cgroup_setup_root(&cgrp_dfl_root, 0));



	cgroup_unlock();