1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_CGROUP_H
3 #define _LINUX_CGROUP_H
4 /*
5  *  cgroup interface
6  *
7  *  Copyright (C) 2003 BULL SA
8  *  Copyright (C) 2004-2006 Silicon Graphics, Inc.
9  *
10  */
11 
12 #include <linux/sched.h>
13 #include <linux/nodemask.h>
14 #include <linux/list.h>
15 #include <linux/rculist.h>
16 #include <linux/cgroupstats.h>
17 #include <linux/fs.h>
18 #include <linux/seq_file.h>
19 #include <linux/kernfs.h>
20 #include <linux/jump_label.h>
21 #include <linux/types.h>
22 #include <linux/ns_common.h>
23 #include <linux/nsproxy.h>
24 #include <linux/user_namespace.h>
25 #include <linux/refcount.h>
26 #include <linux/kernel_stat.h>
27 #include <linux/android_kabi.h>
28 
29 #include <linux/cgroup-defs.h>
30 
31 struct kernel_clone_args;
32 
33 /*
34  * All weight knobs on the default hierarchy should use the following min,
35  * default and max values.  The default value is the logarithmic center of
36  * MIN and MAX and allows 100x to be expressed in both directions.
37  */
38 #define CGROUP_WEIGHT_MIN		1
39 #define CGROUP_WEIGHT_DFL		100
40 #define CGROUP_WEIGHT_MAX		10000
41 
42 #ifdef CONFIG_CGROUPS
43 
44 enum {
45 	CSS_TASK_ITER_PROCS    = (1U << 0),  /* walk only threadgroup leaders */
46 	CSS_TASK_ITER_THREADED = (1U << 1),  /* walk all threaded css_sets in the domain */
47 	CSS_TASK_ITER_SKIPPED  = (1U << 16), /* internal flags */
48 };
49 
50 /* a css_task_iter should be treated as an opaque object */
51 struct css_task_iter {
52 	struct cgroup_subsys		*ss;
53 	unsigned int			flags;
54 
55 	struct list_head		*cset_pos;
56 	struct list_head		*cset_head;
57 
58 	struct list_head		*tcset_pos;
59 	struct list_head		*tcset_head;
60 
61 	struct list_head		*task_pos;
62 
63 	struct list_head		*cur_tasks_head;
64 	struct css_set			*cur_cset;
65 	struct css_set			*cur_dcset;
66 	struct task_struct		*cur_task;
67 	struct list_head		iters_node;	/* css_set->task_iters */
68 
69 	ANDROID_KABI_RESERVE(1);
70 };
71 
72 extern struct file_system_type cgroup_fs_type;
73 extern struct cgroup_root cgrp_dfl_root;
74 extern struct css_set init_css_set;
75 extern spinlock_t css_set_lock;
76 
77 #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;
78 #include <linux/cgroup_subsys.h>
79 #undef SUBSYS
80 
81 #define SUBSYS(_x)								\
82 	extern struct static_key_true _x ## _cgrp_subsys_enabled_key;		\
83 	extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key;
84 #include <linux/cgroup_subsys.h>
85 #undef SUBSYS
86 
87 /**
88  * cgroup_subsys_enabled - fast test on whether a subsys is enabled
89  * @ss: subsystem in question
90  */
91 #define cgroup_subsys_enabled(ss)						\
92 	static_branch_likely(&ss ## _enabled_key)
93 
94 /**
95  * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy
96  * @ss: subsystem in question
97  */
98 #define cgroup_subsys_on_dfl(ss)						\
99 	static_branch_likely(&ss ## _on_dfl_key)
100 
101 bool css_has_online_children(struct cgroup_subsys_state *css);
102 struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss);
103 struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgroup,
104 					 struct cgroup_subsys *ss);
105 struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup,
106 					     struct cgroup_subsys *ss);
107 struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
108 						       struct cgroup_subsys *ss);
109 
110 struct cgroup *cgroup_get_from_path(const char *path);
111 struct cgroup *cgroup_get_from_fd(int fd);
112 struct cgroup *cgroup_v1v2_get_from_fd(int fd);
113 
114 int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);
115 int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);
116 
117 int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
118 int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
119 int cgroup_rm_cftypes(struct cftype *cfts);
120 void cgroup_file_notify(struct cgroup_file *cfile);
121 void cgroup_file_show(struct cgroup_file *cfile, bool show);
122 
123 int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry);
124 int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
125 		     struct pid *pid, struct task_struct *tsk);
126 
127 void cgroup_fork(struct task_struct *p);
128 extern int cgroup_can_fork(struct task_struct *p,
129 			   struct kernel_clone_args *kargs);
130 extern void cgroup_cancel_fork(struct task_struct *p,
131 			       struct kernel_clone_args *kargs);
132 extern void cgroup_post_fork(struct task_struct *p,
133 			     struct kernel_clone_args *kargs);
134 void cgroup_exit(struct task_struct *p);
135 void cgroup_release(struct task_struct *p);
136 void cgroup_free(struct task_struct *p);
137 
138 int cgroup_init_early(void);
139 int cgroup_init(void);
140 
141 int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v);
142 
143 /*
144  * Iteration helpers and macros.
145  */
146 
147 struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos,
148 					   struct cgroup_subsys_state *parent);
149 struct cgroup_subsys_state *css_next_descendant_pre(struct cgroup_subsys_state *pos,
150 						    struct cgroup_subsys_state *css);
151 struct cgroup_subsys_state *css_rightmost_descendant(struct cgroup_subsys_state *pos);
152 struct cgroup_subsys_state *css_next_descendant_post(struct cgroup_subsys_state *pos,
153 						     struct cgroup_subsys_state *css);
154 
155 struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset,
156 					 struct cgroup_subsys_state **dst_cssp);
157 struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
158 					struct cgroup_subsys_state **dst_cssp);
159 
160 void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags,
161 			 struct css_task_iter *it);
162 struct task_struct *css_task_iter_next(struct css_task_iter *it);
163 void css_task_iter_end(struct css_task_iter *it);
164 
165 /**
166  * css_for_each_child - iterate through children of a css
167  * @pos: the css * to use as the loop cursor
168  * @parent: css whose children to walk
169  *
170  * Walk @parent's children.  Must be called under rcu_read_lock().
171  *
172  * If a subsystem synchronizes ->css_online() and the start of iteration, a
173  * css which finished ->css_online() is guaranteed to be visible in the
174  * future iterations and will stay visible until the last reference is put.
175  * A css which hasn't finished ->css_online() or already finished
176  * ->css_offline() may show up during traversal.  It's each subsystem's
177  * responsibility to synchronize against on/offlining.
178  *
179  * It is allowed to temporarily drop RCU read lock during iteration.  The
180  * caller is responsible for ensuring that @pos remains accessible until
181  * the start of the next iteration by, for example, bumping the css refcnt.
182  */
183 #define css_for_each_child(pos, parent)					\
184 	for ((pos) = css_next_child(NULL, (parent)); (pos);		\
185 	     (pos) = css_next_child((pos), (parent)))
186 
187 /**
188  * css_for_each_descendant_pre - pre-order walk of a css's descendants
189  * @pos: the css * to use as the loop cursor
190  * @root: css whose descendants to walk
191  *
192  * Walk @root's descendants.  @root is included in the iteration and the
193  * first node to be visited.  Must be called under rcu_read_lock().
194  *
195  * If a subsystem synchronizes ->css_online() and the start of iteration, a
196  * css which finished ->css_online() is guaranteed to be visible in the
197  * future iterations and will stay visible until the last reference is put.
198  * A css which hasn't finished ->css_online() or already finished
199  * ->css_offline() may show up during traversal.  It's each subsystem's
200  * responsibility to synchronize against on/offlining.
201  *
202  * For example, the following guarantees that a descendant can't escape
203  * state updates of its ancestors.
204  *
205  * my_online(@css)
206  * {
207  *	Lock @css's parent and @css;
208  *	Inherit state from the parent;
209  *	Unlock both.
210  * }
211  *
212  * my_update_state(@css)
213  * {
214  *	css_for_each_descendant_pre(@pos, @css) {
215  *		Lock @pos;
216  *		if (@pos == @css)
217  *			Update @css's state;
218  *		else
219  *			Verify @pos is alive and inherit state from its parent;
220  *		Unlock @pos;
221  *	}
222  * }
223  *
224  * As long as the inheriting step, including checking the parent state, is
225  * enclosed inside @pos locking, double-locking the parent isn't necessary
226  * while inheriting.  The state update to the parent is guaranteed to be
227  * visible by walking order and, as long as inheriting operations to the
228  * same @pos are atomic to each other, multiple updates racing each other
229  * still result in the correct state.  It's guaranateed that at least one
230  * inheritance happens for any css after the latest update to its parent.
231  *
232  * If checking parent's state requires locking the parent, each inheriting
233  * iteration should lock and unlock both @pos->parent and @pos.
234  *
235  * Alternatively, a subsystem may choose to use a single global lock to
236  * synchronize ->css_online() and ->css_offline() against tree-walking
237  * operations.
238  *
239  * It is allowed to temporarily drop RCU read lock during iteration.  The
240  * caller is responsible for ensuring that @pos remains accessible until
241  * the start of the next iteration by, for example, bumping the css refcnt.
242  */
243 #define css_for_each_descendant_pre(pos, css)				\
244 	for ((pos) = css_next_descendant_pre(NULL, (css)); (pos);	\
245 	     (pos) = css_next_descendant_pre((pos), (css)))
246 
247 /**
248  * css_for_each_descendant_post - post-order walk of a css's descendants
249  * @pos: the css * to use as the loop cursor
250  * @css: css whose descendants to walk
251  *
252  * Similar to css_for_each_descendant_pre() but performs post-order
253  * traversal instead.  @root is included in the iteration and the last
254  * node to be visited.
255  *
256  * If a subsystem synchronizes ->css_online() and the start of iteration, a
257  * css which finished ->css_online() is guaranteed to be visible in the
258  * future iterations and will stay visible until the last reference is put.
259  * A css which hasn't finished ->css_online() or already finished
260  * ->css_offline() may show up during traversal.  It's each subsystem's
261  * responsibility to synchronize against on/offlining.
262  *
263  * Note that the walk visibility guarantee example described in pre-order
264  * walk doesn't apply the same to post-order walks.
265  */
266 #define css_for_each_descendant_post(pos, css)				\
267 	for ((pos) = css_next_descendant_post(NULL, (css)); (pos);	\
268 	     (pos) = css_next_descendant_post((pos), (css)))
269 
270 /**
271  * cgroup_taskset_for_each - iterate cgroup_taskset
272  * @task: the loop cursor
273  * @dst_css: the destination css
274  * @tset: taskset to iterate
275  *
276  * @tset may contain multiple tasks and they may belong to multiple
277  * processes.
278  *
279  * On the v2 hierarchy, there may be tasks from multiple processes and they
280  * may not share the source or destination csses.
281  *
282  * On traditional hierarchies, when there are multiple tasks in @tset, if a
283  * task of a process is in @tset, all tasks of the process are in @tset.
284  * Also, all are guaranteed to share the same source and destination csses.
285  *
286  * Iteration is not in any specific order.
287  */
288 #define cgroup_taskset_for_each(task, dst_css, tset)			\
289 	for ((task) = cgroup_taskset_first((tset), &(dst_css));		\
290 	     (task);							\
291 	     (task) = cgroup_taskset_next((tset), &(dst_css)))
292 
293 /**
294  * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset
295  * @leader: the loop cursor
296  * @dst_css: the destination css
297  * @tset: taskset to iterate
298  *
299  * Iterate threadgroup leaders of @tset.  For single-task migrations, @tset
300  * may not contain any.
301  */
302 #define cgroup_taskset_for_each_leader(leader, dst_css, tset)		\
303 	for ((leader) = cgroup_taskset_first((tset), &(dst_css));	\
304 	     (leader);							\
305 	     (leader) = cgroup_taskset_next((tset), &(dst_css)))	\
306 		if ((leader) != (leader)->group_leader)			\
307 			;						\
308 		else
309 
310 /*
311  * Inline functions.
312  */
313 
314 #ifdef CONFIG_DEBUG_CGROUP_REF
315 void css_get(struct cgroup_subsys_state *css);
316 void css_get_many(struct cgroup_subsys_state *css, unsigned int n);
317 bool css_tryget(struct cgroup_subsys_state *css);
318 bool css_tryget_online(struct cgroup_subsys_state *css);
319 void css_put(struct cgroup_subsys_state *css);
320 void css_put_many(struct cgroup_subsys_state *css, unsigned int n);
321 #else
322 #define CGROUP_REF_FN_ATTRS	static inline
323 #define CGROUP_REF_EXPORT(fn)
324 #include <linux/cgroup_refcnt.h>
325 #endif
326 
cgroup_id(const struct cgroup * cgrp)327 static inline u64 cgroup_id(const struct cgroup *cgrp)
328 {
329 	return cgrp->kn->id;
330 }
331 
332 /**
333  * css_is_dying - test whether the specified css is dying
334  * @css: target css
335  *
336  * Test whether @css is in the process of offlining or already offline.  In
337  * most cases, ->css_online() and ->css_offline() callbacks should be
338  * enough; however, the actual offline operations are RCU delayed and this
339  * test returns %true also when @css is scheduled to be offlined.
340  *
341  * This is useful, for example, when the use case requires synchronous
342  * behavior with respect to cgroup removal.  cgroup removal schedules css
343  * offlining but the css can seem alive while the operation is being
344  * delayed.  If the delay affects user visible semantics, this test can be
345  * used to resolve the situation.
346  */
css_is_dying(struct cgroup_subsys_state * css)347 static inline bool css_is_dying(struct cgroup_subsys_state *css)
348 {
349 	return !(css->flags & CSS_NO_REF) && percpu_ref_is_dying(&css->refcnt);
350 }
351 
cgroup_get(struct cgroup * cgrp)352 static inline void cgroup_get(struct cgroup *cgrp)
353 {
354 	css_get(&cgrp->self);
355 }
356 
cgroup_tryget(struct cgroup * cgrp)357 static inline bool cgroup_tryget(struct cgroup *cgrp)
358 {
359 	return css_tryget(&cgrp->self);
360 }
361 
cgroup_put(struct cgroup * cgrp)362 static inline void cgroup_put(struct cgroup *cgrp)
363 {
364 	css_put(&cgrp->self);
365 }
366 
367 extern struct mutex cgroup_mutex;
368 
cgroup_lock(void)369 static inline void cgroup_lock(void)
370 {
371 	mutex_lock(&cgroup_mutex);
372 }
373 
cgroup_unlock(void)374 static inline void cgroup_unlock(void)
375 {
376 	mutex_unlock(&cgroup_mutex);
377 }
378 
379 /**
380  * task_css_set_check - obtain a task's css_set with extra access conditions
381  * @task: the task to obtain css_set for
382  * @__c: extra condition expression to be passed to rcu_dereference_check()
383  *
384  * A task's css_set is RCU protected, initialized and exited while holding
385  * task_lock(), and can only be modified while holding both cgroup_mutex
386  * and task_lock() while the task is alive.  This macro verifies that the
387  * caller is inside proper critical section and returns @task's css_set.
388  *
389  * The caller can also specify additional allowed conditions via @__c, such
390  * as locks used during the cgroup_subsys::attach() methods.
391  */
392 #ifdef CONFIG_PROVE_RCU
393 #define task_css_set_check(task, __c)					\
394 	rcu_dereference_check((task)->cgroups,				\
395 		rcu_read_lock_sched_held() ||				\
396 		lockdep_is_held(&cgroup_mutex) ||			\
397 		lockdep_is_held(&css_set_lock) ||			\
398 		((task)->flags & PF_EXITING) || (__c))
399 #else
400 #define task_css_set_check(task, __c)					\
401 	rcu_dereference((task)->cgroups)
402 #endif
403 
404 /**
405  * task_css_check - obtain css for (task, subsys) w/ extra access conds
406  * @task: the target task
407  * @subsys_id: the target subsystem ID
408  * @__c: extra condition expression to be passed to rcu_dereference_check()
409  *
410  * Return the cgroup_subsys_state for the (@task, @subsys_id) pair.  The
411  * synchronization rules are the same as task_css_set_check().
412  */
413 #define task_css_check(task, subsys_id, __c)				\
414 	task_css_set_check((task), (__c))->subsys[(subsys_id)]
415 
416 /**
417  * task_css_set - obtain a task's css_set
418  * @task: the task to obtain css_set for
419  *
420  * See task_css_set_check().
421  */
task_css_set(struct task_struct * task)422 static inline struct css_set *task_css_set(struct task_struct *task)
423 {
424 	return task_css_set_check(task, false);
425 }
426 
427 /**
428  * task_css - obtain css for (task, subsys)
429  * @task: the target task
430  * @subsys_id: the target subsystem ID
431  *
432  * See task_css_check().
433  */
task_css(struct task_struct * task,int subsys_id)434 static inline struct cgroup_subsys_state *task_css(struct task_struct *task,
435 						   int subsys_id)
436 {
437 	return task_css_check(task, subsys_id, false);
438 }
439 
440 /**
441  * task_get_css - find and get the css for (task, subsys)
442  * @task: the target task
443  * @subsys_id: the target subsystem ID
444  *
445  * Find the css for the (@task, @subsys_id) combination, increment a
446  * reference on and return it.  This function is guaranteed to return a
447  * valid css.  The returned css may already have been offlined.
448  */
449 static inline struct cgroup_subsys_state *
task_get_css(struct task_struct * task,int subsys_id)450 task_get_css(struct task_struct *task, int subsys_id)
451 {
452 	struct cgroup_subsys_state *css;
453 
454 	rcu_read_lock();
455 	while (true) {
456 		css = task_css(task, subsys_id);
457 		/*
458 		 * Can't use css_tryget_online() here.  A task which has
459 		 * PF_EXITING set may stay associated with an offline css.
460 		 * If such task calls this function, css_tryget_online()
461 		 * will keep failing.
462 		 */
463 		if (likely(css_tryget(css)))
464 			break;
465 		cpu_relax();
466 	}
467 	rcu_read_unlock();
468 	return css;
469 }
470 
471 /**
472  * task_css_is_root - test whether a task belongs to the root css
473  * @task: the target task
474  * @subsys_id: the target subsystem ID
475  *
476  * Test whether @task belongs to the root css on the specified subsystem.
477  * May be invoked in any context.
478  */
task_css_is_root(struct task_struct * task,int subsys_id)479 static inline bool task_css_is_root(struct task_struct *task, int subsys_id)
480 {
481 	return task_css_check(task, subsys_id, true) ==
482 		init_css_set.subsys[subsys_id];
483 }
484 
task_cgroup(struct task_struct * task,int subsys_id)485 static inline struct cgroup *task_cgroup(struct task_struct *task,
486 					 int subsys_id)
487 {
488 	return task_css(task, subsys_id)->cgroup;
489 }
490 
task_dfl_cgroup(struct task_struct * task)491 static inline struct cgroup *task_dfl_cgroup(struct task_struct *task)
492 {
493 	return task_css_set(task)->dfl_cgrp;
494 }
495 
cgroup_parent(struct cgroup * cgrp)496 static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
497 {
498 	struct cgroup_subsys_state *parent_css = cgrp->self.parent;
499 
500 	if (parent_css)
501 		return container_of(parent_css, struct cgroup, self);
502 	return NULL;
503 }
504 
505 /**
506  * cgroup_is_descendant - test ancestry
507  * @cgrp: the cgroup to be tested
508  * @ancestor: possible ancestor of @cgrp
509  *
510  * Test whether @cgrp is a descendant of @ancestor.  It also returns %true
511  * if @cgrp == @ancestor.  This function is safe to call as long as @cgrp
512  * and @ancestor are accessible.
513  */
cgroup_is_descendant(struct cgroup * cgrp,struct cgroup * ancestor)514 static inline bool cgroup_is_descendant(struct cgroup *cgrp,
515 					struct cgroup *ancestor)
516 {
517 	if (cgrp->root != ancestor->root || cgrp->level < ancestor->level)
518 		return false;
519 	return cgrp->ancestors[ancestor->level] == ancestor;
520 }
521 
522 /**
523  * cgroup_ancestor - find ancestor of cgroup
524  * @cgrp: cgroup to find ancestor of
525  * @ancestor_level: level of ancestor to find starting from root
526  *
527  * Find ancestor of cgroup at specified level starting from root if it exists
528  * and return pointer to it. Return NULL if @cgrp doesn't have ancestor at
529  * @ancestor_level.
530  *
531  * This function is safe to call as long as @cgrp is accessible.
532  */
cgroup_ancestor(struct cgroup * cgrp,int ancestor_level)533 static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp,
534 					     int ancestor_level)
535 {
536 	if (ancestor_level < 0 || ancestor_level > cgrp->level)
537 		return NULL;
538 	return cgrp->ancestors[ancestor_level];
539 }
540 
541 /**
542  * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry
543  * @task: the task to be tested
544  * @ancestor: possible ancestor of @task's cgroup
545  *
546  * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
547  * It follows all the same rules as cgroup_is_descendant, and only applies
548  * to the default hierarchy.
549  */
task_under_cgroup_hierarchy(struct task_struct * task,struct cgroup * ancestor)550 static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
551 					       struct cgroup *ancestor)
552 {
553 	struct css_set *cset = task_css_set(task);
554 
555 	return cgroup_is_descendant(cset->dfl_cgrp, ancestor);
556 }
557 
558 /* no synchronization, the result can only be used as a hint */
cgroup_is_populated(struct cgroup * cgrp)559 static inline bool cgroup_is_populated(struct cgroup *cgrp)
560 {
561 	return cgrp->nr_populated_csets + cgrp->nr_populated_domain_children +
562 		cgrp->nr_populated_threaded_children;
563 }
564 
565 /* returns ino associated with a cgroup */
cgroup_ino(struct cgroup * cgrp)566 static inline ino_t cgroup_ino(struct cgroup *cgrp)
567 {
568 	return kernfs_ino(cgrp->kn);
569 }
570 
571 /* cft/css accessors for cftype->write() operation */
of_cft(struct kernfs_open_file * of)572 static inline struct cftype *of_cft(struct kernfs_open_file *of)
573 {
574 	return of->kn->priv;
575 }
576 
577 struct cgroup_subsys_state *of_css(struct kernfs_open_file *of);
578 
579 /* cft/css accessors for cftype->seq_*() operations */
seq_cft(struct seq_file * seq)580 static inline struct cftype *seq_cft(struct seq_file *seq)
581 {
582 	return of_cft(seq->private);
583 }
584 
seq_css(struct seq_file * seq)585 static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq)
586 {
587 	return of_css(seq->private);
588 }
589 
590 /*
591  * Name / path handling functions.  All are thin wrappers around the kernfs
592  * counterparts and can be called under any context.
593  */
594 
cgroup_name(struct cgroup * cgrp,char * buf,size_t buflen)595 static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen)
596 {
597 	return kernfs_name(cgrp->kn, buf, buflen);
598 }
599 
cgroup_path(struct cgroup * cgrp,char * buf,size_t buflen)600 static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen)
601 {
602 	return kernfs_path(cgrp->kn, buf, buflen);
603 }
604 
pr_cont_cgroup_name(struct cgroup * cgrp)605 static inline void pr_cont_cgroup_name(struct cgroup *cgrp)
606 {
607 	pr_cont_kernfs_name(cgrp->kn);
608 }
609 
pr_cont_cgroup_path(struct cgroup * cgrp)610 static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
611 {
612 	pr_cont_kernfs_path(cgrp->kn);
613 }
614 
615 bool cgroup_psi_enabled(void);
616 
cgroup_init_kthreadd(void)617 static inline void cgroup_init_kthreadd(void)
618 {
619 	/*
620 	 * kthreadd is inherited by all kthreads, keep it in the root so
621 	 * that the new kthreads are guaranteed to stay in the root until
622 	 * initialization is finished.
623 	 */
624 	current->no_cgroup_migration = 1;
625 }
626 
cgroup_kthread_ready(void)627 static inline void cgroup_kthread_ready(void)
628 {
629 	/*
630 	 * This kthread finished initialization.  The creator should have
631 	 * set PF_NO_SETAFFINITY if this kthread should stay in the root.
632 	 */
633 	current->no_cgroup_migration = 0;
634 }
635 
636 void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen);
637 struct cgroup *cgroup_get_from_id(u64 id);
638 #else /* !CONFIG_CGROUPS */
639 
640 struct cgroup_subsys_state;
641 struct cgroup;
642 
cgroup_id(const struct cgroup * cgrp)643 static inline u64 cgroup_id(const struct cgroup *cgrp) { return 1; }
css_get(struct cgroup_subsys_state * css)644 static inline void css_get(struct cgroup_subsys_state *css) {}
css_put(struct cgroup_subsys_state * css)645 static inline void css_put(struct cgroup_subsys_state *css) {}
cgroup_lock(void)646 static inline void cgroup_lock(void) {}
cgroup_unlock(void)647 static inline void cgroup_unlock(void) {}
cgroup_attach_task_all(struct task_struct * from,struct task_struct * t)648 static inline int cgroup_attach_task_all(struct task_struct *from,
649 					 struct task_struct *t) { return 0; }
cgroupstats_build(struct cgroupstats * stats,struct dentry * dentry)650 static inline int cgroupstats_build(struct cgroupstats *stats,
651 				    struct dentry *dentry) { return -EINVAL; }
652 
cgroup_fork(struct task_struct * p)653 static inline void cgroup_fork(struct task_struct *p) {}
cgroup_can_fork(struct task_struct * p,struct kernel_clone_args * kargs)654 static inline int cgroup_can_fork(struct task_struct *p,
655 				  struct kernel_clone_args *kargs) { return 0; }
cgroup_cancel_fork(struct task_struct * p,struct kernel_clone_args * kargs)656 static inline void cgroup_cancel_fork(struct task_struct *p,
657 				      struct kernel_clone_args *kargs) {}
cgroup_post_fork(struct task_struct * p,struct kernel_clone_args * kargs)658 static inline void cgroup_post_fork(struct task_struct *p,
659 				    struct kernel_clone_args *kargs) {}
cgroup_exit(struct task_struct * p)660 static inline void cgroup_exit(struct task_struct *p) {}
cgroup_release(struct task_struct * p)661 static inline void cgroup_release(struct task_struct *p) {}
cgroup_free(struct task_struct * p)662 static inline void cgroup_free(struct task_struct *p) {}
663 
cgroup_init_early(void)664 static inline int cgroup_init_early(void) { return 0; }
cgroup_init(void)665 static inline int cgroup_init(void) { return 0; }
cgroup_init_kthreadd(void)666 static inline void cgroup_init_kthreadd(void) {}
cgroup_kthread_ready(void)667 static inline void cgroup_kthread_ready(void) {}
668 
cgroup_parent(struct cgroup * cgrp)669 static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
670 {
671 	return NULL;
672 }
673 
cgroup_psi_enabled(void)674 static inline bool cgroup_psi_enabled(void)
675 {
676 	return false;
677 }
678 
task_under_cgroup_hierarchy(struct task_struct * task,struct cgroup * ancestor)679 static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
680 					       struct cgroup *ancestor)
681 {
682 	return true;
683 }
684 
cgroup_path_from_kernfs_id(u64 id,char * buf,size_t buflen)685 static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen)
686 {}
687 #endif /* !CONFIG_CGROUPS */
688 
689 #ifdef CONFIG_CGROUPS
690 /*
691  * cgroup scalable recursive statistics.
692  */
693 void cgroup_rstat_updated(struct cgroup *cgrp, int cpu);
694 void cgroup_rstat_flush(struct cgroup *cgrp);
695 void cgroup_rstat_flush_hold(struct cgroup *cgrp);
696 void cgroup_rstat_flush_release(struct cgroup *cgrp);
697 
698 /*
699  * Basic resource stats.
700  */
701 #ifdef CONFIG_CGROUP_CPUACCT
702 void cpuacct_charge(struct task_struct *tsk, u64 cputime);
703 void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
704 #else
cpuacct_charge(struct task_struct * tsk,u64 cputime)705 static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
cpuacct_account_field(struct task_struct * tsk,int index,u64 val)706 static inline void cpuacct_account_field(struct task_struct *tsk, int index,
707 					 u64 val) {}
708 #endif
709 
710 void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec);
711 void __cgroup_account_cputime_field(struct cgroup *cgrp,
712 				    enum cpu_usage_stat index, u64 delta_exec);
713 
cgroup_account_cputime(struct task_struct * task,u64 delta_exec)714 static inline void cgroup_account_cputime(struct task_struct *task,
715 					  u64 delta_exec)
716 {
717 	struct cgroup *cgrp;
718 
719 	cpuacct_charge(task, delta_exec);
720 
721 	cgrp = task_dfl_cgroup(task);
722 	if (cgroup_parent(cgrp))
723 		__cgroup_account_cputime(cgrp, delta_exec);
724 }
725 
cgroup_account_cputime_field(struct task_struct * task,enum cpu_usage_stat index,u64 delta_exec)726 static inline void cgroup_account_cputime_field(struct task_struct *task,
727 						enum cpu_usage_stat index,
728 						u64 delta_exec)
729 {
730 	struct cgroup *cgrp;
731 
732 	cpuacct_account_field(task, index, delta_exec);
733 
734 	cgrp = task_dfl_cgroup(task);
735 	if (cgroup_parent(cgrp))
736 		__cgroup_account_cputime_field(cgrp, index, delta_exec);
737 }
738 
739 #else	/* CONFIG_CGROUPS */
740 
cgroup_account_cputime(struct task_struct * task,u64 delta_exec)741 static inline void cgroup_account_cputime(struct task_struct *task,
742 					  u64 delta_exec) {}
cgroup_account_cputime_field(struct task_struct * task,enum cpu_usage_stat index,u64 delta_exec)743 static inline void cgroup_account_cputime_field(struct task_struct *task,
744 						enum cpu_usage_stat index,
745 						u64 delta_exec) {}
746 
747 #endif	/* CONFIG_CGROUPS */
748 
749 /*
750  * sock->sk_cgrp_data handling.  For more info, see sock_cgroup_data
751  * definition in cgroup-defs.h.
752  */
753 #ifdef CONFIG_SOCK_CGROUP_DATA
754 
755 void cgroup_sk_alloc(struct sock_cgroup_data *skcd);
756 void cgroup_sk_clone(struct sock_cgroup_data *skcd);
757 void cgroup_sk_free(struct sock_cgroup_data *skcd);
758 
sock_cgroup_ptr(struct sock_cgroup_data * skcd)759 static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd)
760 {
761 	return skcd->cgroup;
762 }
763 
764 #else	/* CONFIG_CGROUP_DATA */
765 
cgroup_sk_alloc(struct sock_cgroup_data * skcd)766 static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {}
cgroup_sk_clone(struct sock_cgroup_data * skcd)767 static inline void cgroup_sk_clone(struct sock_cgroup_data *skcd) {}
cgroup_sk_free(struct sock_cgroup_data * skcd)768 static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {}
769 
770 #endif	/* CONFIG_CGROUP_DATA */
771 
772 struct cgroup_namespace {
773 	struct ns_common	ns;
774 	struct user_namespace	*user_ns;
775 	struct ucounts		*ucounts;
776 	struct css_set          *root_cset;
777 };
778 
779 extern struct cgroup_namespace init_cgroup_ns;
780 
781 #ifdef CONFIG_CGROUPS
782 
783 void free_cgroup_ns(struct cgroup_namespace *ns);
784 
785 struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
786 					struct user_namespace *user_ns,
787 					struct cgroup_namespace *old_ns);
788 
789 int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
790 		   struct cgroup_namespace *ns);
791 
792 #else /* !CONFIG_CGROUPS */
793 
free_cgroup_ns(struct cgroup_namespace * ns)794 static inline void free_cgroup_ns(struct cgroup_namespace *ns) { }
795 static inline struct cgroup_namespace *
copy_cgroup_ns(unsigned long flags,struct user_namespace * user_ns,struct cgroup_namespace * old_ns)796 copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns,
797 	       struct cgroup_namespace *old_ns)
798 {
799 	return old_ns;
800 }
801 
802 #endif /* !CONFIG_CGROUPS */
803 
get_cgroup_ns(struct cgroup_namespace * ns)804 static inline void get_cgroup_ns(struct cgroup_namespace *ns)
805 {
806 	if (ns)
807 		refcount_inc(&ns->ns.count);
808 }
809 
put_cgroup_ns(struct cgroup_namespace * ns)810 static inline void put_cgroup_ns(struct cgroup_namespace *ns)
811 {
812 	if (ns && refcount_dec_and_test(&ns->ns.count))
813 		free_cgroup_ns(ns);
814 }
815 
816 #ifdef CONFIG_CGROUPS
817 
818 void cgroup_enter_frozen(void);
819 void cgroup_leave_frozen(bool always_leave);
820 void cgroup_update_frozen(struct cgroup *cgrp);
821 void cgroup_freeze(struct cgroup *cgrp, bool freeze);
822 void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src,
823 				 struct cgroup *dst);
824 
cgroup_task_frozen(struct task_struct * task)825 static inline bool cgroup_task_frozen(struct task_struct *task)
826 {
827 	return task->frozen;
828 }
829 
830 #else /* !CONFIG_CGROUPS */
831 
cgroup_enter_frozen(void)832 static inline void cgroup_enter_frozen(void) { }
cgroup_leave_frozen(bool always_leave)833 static inline void cgroup_leave_frozen(bool always_leave) { }
cgroup_task_frozen(struct task_struct * task)834 static inline bool cgroup_task_frozen(struct task_struct *task)
835 {
836 	return false;
837 }
838 
839 #endif /* !CONFIG_CGROUPS */
840 
841 #ifdef CONFIG_CGROUP_BPF
cgroup_bpf_get(struct cgroup * cgrp)842 static inline void cgroup_bpf_get(struct cgroup *cgrp)
843 {
844 	percpu_ref_get(&cgrp->bpf.refcnt);
845 }
846 
cgroup_bpf_put(struct cgroup * cgrp)847 static inline void cgroup_bpf_put(struct cgroup *cgrp)
848 {
849 	percpu_ref_put(&cgrp->bpf.refcnt);
850 }
851 
852 #else /* CONFIG_CGROUP_BPF */
853 
cgroup_bpf_get(struct cgroup * cgrp)854 static inline void cgroup_bpf_get(struct cgroup *cgrp) {}
cgroup_bpf_put(struct cgroup * cgrp)855 static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
856 
857 #endif /* CONFIG_CGROUP_BPF */
858 
859 struct cgroup *task_get_cgroup1(struct task_struct *tsk, int hierarchy_id);
860 
861 struct cgroup_of_peak *of_peak(struct kernfs_open_file *of);
862 
863 #endif /* _LINUX_CGROUP_H */
864