1 // SPDX-License-Identifier: GPL-2.0-only
9 #include "../cgroup/cgroup-internal.h"  /* cgroup_mutex and cgroup_is_dead */
13  *  1. Walk the descendants of a cgroup in pre-order.
14  *  2. Walk the descendants of a cgroup in post-order.
18  * For walking descendants, cgroup_iter can walk in either pre-order or
19  * post-order. For walking ancestors, the iter walks up from a cgroup to
25  * The prog can check (seq->num == 0) to determine whether this is
28  * do post-processing, such as outputting an epilogue.
59 	struct cgroup_iter_priv *p = seq->private;  in cgroup_iter_seq_start()
65 		if (p->visited_all)  in cgroup_iter_seq_start()
69 		 * return -EOPNOTSUPP to indicate incomplete iteration.  in cgroup_iter_seq_start()
71 		return ERR_PTR(-EOPNOTSUPP);  in cgroup_iter_seq_start()
75 	p->terminate = false;  in cgroup_iter_seq_start()
76 	p->visited_all = false;  in cgroup_iter_seq_start()
77 	if (p->order == BPF_CGROUP_ITER_DESCENDANTS_PRE)  in cgroup_iter_seq_start()
78 		return css_next_descendant_pre(NULL, p->start_css);  in cgroup_iter_seq_start()
79 	else if (p->order == BPF_CGROUP_ITER_DESCENDANTS_POST)  in cgroup_iter_seq_start()
80 		return css_next_descendant_post(NULL, p->start_css);  in cgroup_iter_seq_start()
82 		return p->start_css;  in cgroup_iter_seq_start()
90 	struct cgroup_iter_priv *p = seq->private;  in cgroup_iter_seq_stop()
94 	/* pass NULL to the prog for post-processing */  in cgroup_iter_seq_stop()
97 		p->visited_all = true;  in cgroup_iter_seq_stop()
104 	struct cgroup_iter_priv *p = seq->private;  in cgroup_iter_seq_next()
107 	if (p->terminate)  in cgroup_iter_seq_next()
110 	if (p->order == BPF_CGROUP_ITER_DESCENDANTS_PRE)  in cgroup_iter_seq_next()
111 		return css_next_descendant_pre(curr, p->start_css);  in cgroup_iter_seq_next()
112 	else if (p->order == BPF_CGROUP_ITER_DESCENDANTS_POST)  in cgroup_iter_seq_next()
113 		return css_next_descendant_post(curr, p->start_css);  in cgroup_iter_seq_next()
114 	else if (p->order == BPF_CGROUP_ITER_ANCESTORS_UP)  in cgroup_iter_seq_next()
115 		return curr->parent;  in cgroup_iter_seq_next()
123 	struct cgroup_iter_priv *p = seq->private;  in __cgroup_iter_seq_show()
130 	if (css && cgroup_is_dead(css->cgroup))  in __cgroup_iter_seq_show()
134 	ctx.cgroup = css ? css->cgroup : NULL;  in __cgroup_iter_seq_show()
142 		p->terminate = true;  in __cgroup_iter_seq_show()
165 	struct cgroup *cgrp = aux->cgroup.start;  in BTF_ID_LIST_GLOBAL_SINGLE()
172 	p->start_css = &cgrp->self;  in BTF_ID_LIST_GLOBAL_SINGLE()
173 	css_get(p->start_css);  in BTF_ID_LIST_GLOBAL_SINGLE()
174 	p->terminate = false;  in BTF_ID_LIST_GLOBAL_SINGLE()
175 	p->visited_all = false;  in BTF_ID_LIST_GLOBAL_SINGLE()
176 	p->order = aux->cgroup.order;  in BTF_ID_LIST_GLOBAL_SINGLE()
184 	css_put(p->start_css);  in cgroup_iter_seq_fini()
198 	int fd = linfo->cgroup.cgroup_fd;  in bpf_iter_attach_cgroup()
199 	u64 id = linfo->cgroup.cgroup_id;  in bpf_iter_attach_cgroup()
200 	int order = linfo->cgroup.order;  in bpf_iter_attach_cgroup()
207 		return -EINVAL;  in bpf_iter_attach_cgroup()
210 		return -EINVAL;  in bpf_iter_attach_cgroup()
222 	aux->cgroup.start = cgrp;  in bpf_iter_attach_cgroup()
223 	aux->cgroup.order = order;  in bpf_iter_attach_cgroup()
229 	cgroup_put(aux->cgroup.start);  in bpf_iter_detach_cgroup()
248 	cgroup_path_ns(aux->cgroup.start, buf, PATH_MAX,  in bpf_iter_cgroup_show_fdinfo()
249 		       current->nsproxy->cgroup_ns);  in bpf_iter_cgroup_show_fdinfo()
254 	if (aux->cgroup.order == BPF_CGROUP_ITER_DESCENDANTS_PRE)  in bpf_iter_cgroup_show_fdinfo()
256 	else if (aux->cgroup.order == BPF_CGROUP_ITER_DESCENDANTS_POST)  in bpf_iter_cgroup_show_fdinfo()
258 	else if (aux->cgroup.order == BPF_CGROUP_ITER_ANCESTORS_UP)  in bpf_iter_cgroup_show_fdinfo()
267 	info->iter.cgroup.order = aux->cgroup.order;  in bpf_iter_cgroup_fill_link_info()
268 	info->iter.cgroup.cgroup_id = cgroup_id(aux->cgroup.start);  in bpf_iter_cgroup_fill_link_info()
318 	kit->start = NULL;  in bpf_iter_css_new()
325 		return -EINVAL;  in bpf_iter_css_new()
328 	kit->start = start;  in bpf_iter_css_new()
329 	kit->pos = NULL;  in bpf_iter_css_new()
330 	kit->flags = flags;  in bpf_iter_css_new()
338 	if (!kit->start)  in bpf_iter_css_next()
341 	switch (kit->flags) {  in bpf_iter_css_next()
343 		kit->pos = css_next_descendant_pre(kit->pos, kit->start);  in bpf_iter_css_next()
346 		kit->pos = css_next_descendant_post(kit->pos, kit->start);  in bpf_iter_css_next()
349 		kit->pos = kit->pos ? kit->pos->parent : kit->start;  in bpf_iter_css_next()
352 	return kit->pos;  in bpf_iter_css_next()