1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* Infrastructure for profiling code inserted by 'gcc -pg'.
4	*
5	* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
6	* Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7	*
8	* Originally ported from the -rt patch by:
9	* Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10	*
11	* Based on code in the latency_tracer, that is:
12	*
13	* Copyright (C) 2004-2006 Ingo Molnar
14	* Copyright (C) 2004 Nadia Yvette Chambers
15	*/
16
17	#include <linux/stop_machine.h>
18	#include <linux/clocksource.h>
19	#include <linux/sched/task.h>
20	#include <linux/kallsyms.h>
21	#include <linux/security.h>
22	#include <linux/seq_file.h>
23	#include <linux/tracefs.h>
24	#include <linux/hardirq.h>
25	#include <linux/kthread.h>
26	#include <linux/uaccess.h>
27	#include <linux/bsearch.h>
28	#include <linux/module.h>
29	#include <linux/ftrace.h>
30	#include <linux/sysctl.h>
31	#include <linux/slab.h>
32	#include <linux/ctype.h>
33	#include <linux/sort.h>
34	#include <linux/list.h>
35	#include <linux/hash.h>
36	#include <linux/rcupdate.h>
37	#include <linux/kprobes.h>
38
39	#include <trace/events/sched.h>
40
41	#include <asm/sections.h>
42	#include <asm/setup.h>
43
44	#include "ftrace_internal.h"
45	#include "trace_output.h"
46	#include "trace_stat.h"
47
48	/* Flags that do not get reset */
49	#define FTRACE_NOCLEAR_FLAGS (FTRACE_FL_DISABLED | FTRACE_FL_TOUCHED | \
50	FTRACE_FL_MODIFIED)
51
52	#define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__"
53
54	#define FTRACE_WARN_ON(cond) \
55	({ \
56	int ___r = cond; \
57	if (WARN_ON(___r)) \
58	ftrace_kill(); \
59	___r; \
60	})
61
62	#define FTRACE_WARN_ON_ONCE(cond) \
63	({ \
64	int ___r = cond; \
65	if (WARN_ON_ONCE(___r)) \
66	ftrace_kill(); \
67	___r; \
68	})
69
70	/* hash bits for specific function selection */
71	#define FTRACE_HASH_DEFAULT_BITS 10
72	#define FTRACE_HASH_MAX_BITS 12
73
74	#ifdef CONFIG_DYNAMIC_FTRACE
75	#define INIT_OPS_HASH(opsname) \
76	.func_hash = &opsname.local_hash, \
77	.local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
78	#else
79	#define INIT_OPS_HASH(opsname)
80	#endif
81
82	enum {
83	FTRACE_MODIFY_ENABLE_FL = (1 << 0),
84	FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1),
85	};
86
87	struct ftrace_ops ftrace_list_end __read_mostly = {
88	.func = ftrace_stub,
89	.flags = FTRACE_OPS_FL_STUB,
90	INIT_OPS_HASH(ftrace_list_end)
91	};
92
93	/* ftrace_enabled is a method to turn ftrace on or off */
94	int ftrace_enabled __read_mostly;
95	static int __maybe_unused last_ftrace_enabled;
96
97	/* Current function tracing op */
98	struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
99	/* What to set function_trace_op to */
100	static struct ftrace_ops *set_function_trace_op;
101
102	static bool ftrace_pids_enabled(struct ftrace_ops *ops)
103	{
104	struct trace_array *tr;
105
106	if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
107	return false;
108
109	tr = ops->private;
110
111	return tr->function_pids != NULL || tr->function_no_pids != NULL;
112	}
113
114	static void ftrace_update_trampoline(struct ftrace_ops *ops);
115
116	/*
117	* ftrace_disabled is set when an anomaly is discovered.
118	* ftrace_disabled is much stronger than ftrace_enabled.
119	*/
120	static int ftrace_disabled __read_mostly;
121
122	DEFINE_MUTEX(ftrace_lock);
123
124	struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
125	ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
126	struct ftrace_ops global_ops;
127
128	/* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */
129	void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
130	struct ftrace_ops *op, struct ftrace_regs *fregs);
131
132	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
133	/*
134	* Stub used to invoke the list ops without requiring a separate trampoline.
135	*/
136	const struct ftrace_ops ftrace_list_ops = {
137	.func = ftrace_ops_list_func,
138	.flags = FTRACE_OPS_FL_STUB,
139	};
140
141	static void ftrace_ops_nop_func(unsigned long ip, unsigned long parent_ip,
142	struct ftrace_ops *op,
143	struct ftrace_regs *fregs)
144	{
145	/* do nothing */
146	}
147
148	/*
149	* Stub used when a call site is disabled. May be called transiently by threads
150	* which have made it into ftrace_caller but haven't yet recovered the ops at
151	* the point the call site is disabled.
152	*/
153	const struct ftrace_ops ftrace_nop_ops = {
154	.func = ftrace_ops_nop_func,
155	.flags = FTRACE_OPS_FL_STUB,
156	};
157	#endif
158
159	static inline void ftrace_ops_init(struct ftrace_ops *ops)
160	{
161	#ifdef CONFIG_DYNAMIC_FTRACE
162	if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
163	mutex_init(&ops->local_hash.regex_lock);
164	ops->func_hash = &ops->local_hash;
165	ops->flags |= FTRACE_OPS_FL_INITIALIZED;
166	}
167	#endif
168	}
169
170	static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
171	struct ftrace_ops *op, struct ftrace_regs *fregs)
172	{
173	struct trace_array *tr = op->private;
174	int pid;
175
176	if (tr) {
177	pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid);
178	if (pid == FTRACE_PID_IGNORE)
179	return;
180	if (pid != FTRACE_PID_TRACE &&
181	pid != current->pid)
182	return;
183	}
184
185	op->saved_func(ip, parent_ip, op, fregs);
186	}
187
188	static void ftrace_sync_ipi(void *data)
189	{
190	/* Probably not needed, but do it anyway */
191	smp_rmb();
192	}
193
194	static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
195	{
196	/*
197	* If this is a dynamic or RCU ops, or we force list func,
198	* then it needs to call the list anyway.
199	*/
200	if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
201	FTRACE_FORCE_LIST_FUNC)
202	return ftrace_ops_list_func;
203
204	return ftrace_ops_get_func(ops);
205	}
206
207	static void update_ftrace_function(void)
208	{
209	ftrace_func_t func;
210
211	/*
212	* Prepare the ftrace_ops that the arch callback will use.
213	* If there's only one ftrace_ops registered, the ftrace_ops_list
214	* will point to the ops we want.
215	*/
216	set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
217	lockdep_is_held(&ftrace_lock));
218
219	/* If there's no ftrace_ops registered, just call the stub function */
220	if (set_function_trace_op == &ftrace_list_end) {
221	func = ftrace_stub;
222
223	/*
224	* If we are at the end of the list and this ops is
225	* recursion safe and not dynamic and the arch supports passing ops,
226	* then have the mcount trampoline call the function directly.
227	*/
228	} else if (rcu_dereference_protected(ftrace_ops_list->next,
229	lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
230	func = ftrace_ops_get_list_func(ops: ftrace_ops_list);
231
232	} else {
233	/* Just use the default ftrace_ops */
234	set_function_trace_op = &ftrace_list_end;
235	func = ftrace_ops_list_func;
236	}
237
238	update_function_graph_func();
239
240	/* If there's no change, then do nothing more here */
241	if (ftrace_trace_function == func)
242	return;
243
244	/*
245	* If we are using the list function, it doesn't care
246	* about the function_trace_ops.
247	*/
248	if (func == ftrace_ops_list_func) {
249	ftrace_trace_function = func;
250	/*
251	* Don't even bother setting function_trace_ops,
252	* it would be racy to do so anyway.
253	*/
254	return;
255	}
256
257	#ifndef CONFIG_DYNAMIC_FTRACE
258	/*
259	* For static tracing, we need to be a bit more careful.
260	* The function change takes affect immediately. Thus,
261	* we need to coordinate the setting of the function_trace_ops
262	* with the setting of the ftrace_trace_function.
263	*
264	* Set the function to the list ops, which will call the
265	* function we want, albeit indirectly, but it handles the
266	* ftrace_ops and doesn't depend on function_trace_op.
267	*/
268	ftrace_trace_function = ftrace_ops_list_func;
269	/*
270	* Make sure all CPUs see this. Yes this is slow, but static
271	* tracing is slow and nasty to have enabled.
272	*/
273	synchronize_rcu_tasks_rude();
274	/* Now all cpus are using the list ops. */
275	function_trace_op = set_function_trace_op;
276	/* Make sure the function_trace_op is visible on all CPUs */
277	smp_wmb();
278	/* Nasty way to force a rmb on all cpus */
279	smp_call_function(ftrace_sync_ipi, NULL, 1);
280	/* OK, we are all set to update the ftrace_trace_function now! */
281	#endif /* !CONFIG_DYNAMIC_FTRACE */
282
283	ftrace_trace_function = func;
284	}
285
286	static void add_ftrace_ops(struct ftrace_ops __rcu **list,
287	struct ftrace_ops *ops)
288	{
289	rcu_assign_pointer(ops->next, *list);
290
291	/*
292	* We are entering ops into the list but another
293	* CPU might be walking that list. We need to make sure
294	* the ops->next pointer is valid before another CPU sees
295	* the ops pointer included into the list.
296	*/
297	rcu_assign_pointer(*list, ops);
298	}
299
300	static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
301	struct ftrace_ops *ops)
302	{
303	struct ftrace_ops **p;
304
305	/*
306	* If we are removing the last function, then simply point
307	* to the ftrace_stub.
308	*/
309	if (rcu_dereference_protected(*list,
310	lockdep_is_held(&ftrace_lock)) == ops &&
311	rcu_dereference_protected(ops->next,
312	lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
313	*list = &ftrace_list_end;
314	return 0;
315	}
316
317	for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
318	if (*p == ops)
319	break;
320
321	if (*p != ops)
322	return -1;
323
324	*p = (*p)->next;
325	return 0;
326	}
327
328	static void ftrace_update_trampoline(struct ftrace_ops *ops);
329
330	int __register_ftrace_function(struct ftrace_ops *ops)
331	{
332	if (ops->flags & FTRACE_OPS_FL_DELETED)
333	return -EINVAL;
334
335	if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
336	return -EBUSY;
337
338	#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
339	/*
340	* If the ftrace_ops specifies SAVE_REGS, then it only can be used
341	* if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
342	* Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
343	*/
344	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
345	!(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
346	return -EINVAL;
347
348	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
349	ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
350	#endif
351	if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT))
352	return -EBUSY;
353
354	if (!is_kernel_core_data(addr: (unsigned long)ops))
355	ops->flags |= FTRACE_OPS_FL_DYNAMIC;
356
357	add_ftrace_ops(list: &ftrace_ops_list, ops);
358
359	/* Always save the function, and reset at unregistering */
360	ops->saved_func = ops->func;
361
362	if (ftrace_pids_enabled(ops))
363	ops->func = ftrace_pid_func;
364
365	ftrace_update_trampoline(ops);
366
367	if (ftrace_enabled)
368	update_ftrace_function();
369
370	return 0;
371	}
372
373	int __unregister_ftrace_function(struct ftrace_ops *ops)
374	{
375	int ret;
376
377	if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
378	return -EBUSY;
379
380	ret = remove_ftrace_ops(list: &ftrace_ops_list, ops);
381
382	if (ret < 0)
383	return ret;
384
385	if (ftrace_enabled)
386	update_ftrace_function();
387
388	ops->func = ops->saved_func;
389
390	return 0;
391	}
392
393	static void ftrace_update_pid_func(void)
394	{
395	struct ftrace_ops *op;
396
397	/* Only do something if we are tracing something */
398	if (ftrace_trace_function == ftrace_stub)
399	return;
400
401	do_for_each_ftrace_op(op, ftrace_ops_list) {
402	if (op->flags & FTRACE_OPS_FL_PID) {
403	op->func = ftrace_pids_enabled(ops: op) ?
404	ftrace_pid_func : op->saved_func;
405	ftrace_update_trampoline(ops: op);
406	}
407	} while_for_each_ftrace_op(op);
408
409	update_ftrace_function();
410	}
411
412	#ifdef CONFIG_FUNCTION_PROFILER
413	struct ftrace_profile {
414	struct hlist_node node;
415	unsigned long ip;
416	unsigned long counter;
417	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
418	unsigned long long time;
419	unsigned long long time_squared;
420	#endif
421	};
422
423	struct ftrace_profile_page {
424	struct ftrace_profile_page *next;
425	unsigned long index;
426	struct ftrace_profile records[];
427	};
428
429	struct ftrace_profile_stat {
430	atomic_t disabled;
431	struct hlist_head *hash;
432	struct ftrace_profile_page *pages;
433	struct ftrace_profile_page *start;
434	struct tracer_stat stat;
435	};
436
437	#define PROFILE_RECORDS_SIZE \
438	(PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
439
440	#define PROFILES_PER_PAGE \
441	(PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
442
443	static int ftrace_profile_enabled __read_mostly;
444
445	/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
446	static DEFINE_MUTEX(ftrace_profile_lock);
447
448	static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
449
450	#define FTRACE_PROFILE_HASH_BITS 10
451	#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
452
453	static void *
454	function_stat_next(void *v, int idx)
455	{
456	struct ftrace_profile *rec = v;
457	struct ftrace_profile_page *pg;
458
459	pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
460
461	again:
462	if (idx != 0)
463	rec++;
464
465	if ((void *)rec >= (void *)&pg->records[pg->index]) {
466	pg = pg->next;
467	if (!pg)
468	return NULL;
469	rec = &pg->records[0];
470	if (!rec->counter)
471	goto again;
472	}
473
474	return rec;
475	}
476
477	static void *function_stat_start(struct tracer_stat *trace)
478	{
479	struct ftrace_profile_stat *stat =
480	container_of(trace, struct ftrace_profile_stat, stat);
481
482	if (!stat || !stat->start)
483	return NULL;
484
485	return function_stat_next(v: &stat->start->records[0], idx: 0);
486	}
487
488	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
489	/* function graph compares on total time */
490	static int function_stat_cmp(const void *p1, const void *p2)
491	{
492	const struct ftrace_profile *a = p1;
493	const struct ftrace_profile *b = p2;
494
495	if (a->time < b->time)
496	return -1;
497	if (a->time > b->time)
498	return 1;
499	else
500	return 0;
501	}
502	#else
503	/* not function graph compares against hits */
504	static int function_stat_cmp(const void *p1, const void *p2)
505	{
506	const struct ftrace_profile *a = p1;
507	const struct ftrace_profile *b = p2;
508
509	if (a->counter < b->counter)
510	return -1;
511	if (a->counter > b->counter)
512	return 1;
513	else
514	return 0;
515	}
516	#endif
517
518	static int function_stat_headers(struct seq_file *m)
519	{
520	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
521	seq_puts(m, s: " Function "
522	"Hit Time Avg s^2\n"
523	" -------- "
524	"--- ---- --- ---\n");
525	#else
526	seq_puts(m, " Function Hit\n"
527	" -------- ---\n");
528	#endif
529	return 0;
530	}
531
532	static int function_stat_show(struct seq_file *m, void *v)
533	{
534	struct ftrace_profile *rec = v;
535	char str[KSYM_SYMBOL_LEN];
536	int ret = 0;
537	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
538	static struct trace_seq s;
539	unsigned long long avg;
540	unsigned long long stddev;
541	#endif
542	mutex_lock(&ftrace_profile_lock);
543
544	/* we raced with function_profile_reset() */
545	if (unlikely(rec->counter == 0)) {
546	ret = -EBUSY;
547	goto out;
548	}
549
550	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
551	avg = div64_ul(rec->time, rec->counter);
552	if (tracing_thresh && (avg < tracing_thresh))
553	goto out;
554	#endif
555
556	kallsyms_lookup(addr: rec->ip, NULL, NULL, NULL, namebuf: str);
557	seq_printf(m, fmt: " %-30.30s %10lu", str, rec->counter);
558
559	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
560	seq_puts(m, s: " ");
561
562	/* Sample standard deviation (s^2) */
563	if (rec->counter <= 1)
564	stddev = 0;
565	else {
566	/*
567	* Apply Welford's method:
568	* s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
569	*/
570	stddev = rec->counter * rec->time_squared -
571	rec->time * rec->time;
572
573	/*
574	* Divide only 1000 for ns^2 -> us^2 conversion.
575	* trace_print_graph_duration will divide 1000 again.
576	*/
577	stddev = div64_ul(stddev,
578	rec->counter * (rec->counter - 1) * 1000);
579	}
580
581	trace_seq_init(s: &s);
582	trace_print_graph_duration(duration: rec->time, s: &s);
583	trace_seq_puts(s: &s, str: " ");
584	trace_print_graph_duration(duration: avg, s: &s);
585	trace_seq_puts(s: &s, str: " ");
586	trace_print_graph_duration(duration: stddev, s: &s);
587	trace_print_seq(m, s: &s);
588	#endif
589	seq_putc(m, c: '\n');
590	out:
591	mutex_unlock(lock: &ftrace_profile_lock);
592
593	return ret;
594	}
595
596	static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
597	{
598	struct ftrace_profile_page *pg;
599
600	pg = stat->pages = stat->start;
601
602	while (pg) {
603	memset(pg->records, 0, PROFILE_RECORDS_SIZE);
604	pg->index = 0;
605	pg = pg->next;
606	}
607
608	memset(stat->hash, 0,
609	FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
610	}
611
612	static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
613	{
614	struct ftrace_profile_page *pg;
615	int functions;
616	int pages;
617	int i;
618
619	/* If we already allocated, do nothing */
620	if (stat->pages)
621	return 0;
622
623	stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
624	if (!stat->pages)
625	return -ENOMEM;
626
627	#ifdef CONFIG_DYNAMIC_FTRACE
628	functions = ftrace_update_tot_cnt;
629	#else
630	/*
631	* We do not know the number of functions that exist because
632	* dynamic tracing is what counts them. With past experience
633	* we have around 20K functions. That should be more than enough.
634	* It is highly unlikely we will execute every function in
635	* the kernel.
636	*/
637	functions = 20000;
638	#endif
639
640	pg = stat->start = stat->pages;
641
642	pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
643
644	for (i = 1; i < pages; i++) {
645	pg->next = (void *)get_zeroed_page(GFP_KERNEL);
646	if (!pg->next)
647	goto out_free;
648	pg = pg->next;
649	}
650
651	return 0;
652
653	out_free:
654	pg = stat->start;
655	while (pg) {
656	unsigned long tmp = (unsigned long)pg;
657
658	pg = pg->next;
659	free_page(tmp);
660	}
661
662	stat->pages = NULL;
663	stat->start = NULL;
664
665	return -ENOMEM;
666	}
667
668	static int ftrace_profile_init_cpu(int cpu)
669	{
670	struct ftrace_profile_stat *stat;
671	int size;
672
673	stat = &per_cpu(ftrace_profile_stats, cpu);
674
675	if (stat->hash) {
676	/* If the profile is already created, simply reset it */
677	ftrace_profile_reset(stat);
678	return 0;
679	}
680
681	/*
682	* We are profiling all functions, but usually only a few thousand
683	* functions are hit. We'll make a hash of 1024 items.
684	*/
685	size = FTRACE_PROFILE_HASH_SIZE;
686
687	stat->hash = kcalloc(n: size, size: sizeof(struct hlist_head), GFP_KERNEL);
688
689	if (!stat->hash)
690	return -ENOMEM;
691
692	/* Preallocate the function profiling pages */
693	if (ftrace_profile_pages_init(stat) < 0) {
694	kfree(objp: stat->hash);
695	stat->hash = NULL;
696	return -ENOMEM;
697	}
698
699	return 0;
700	}
701
702	static int ftrace_profile_init(void)
703	{
704	int cpu;
705	int ret = 0;
706
707	for_each_possible_cpu(cpu) {
708	ret = ftrace_profile_init_cpu(cpu);
709	if (ret)
710	break;
711	}
712
713	return ret;
714	}
715
716	/* interrupts must be disabled */
717	static struct ftrace_profile *
718	ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
719	{
720	struct ftrace_profile *rec;
721	struct hlist_head *hhd;
722	unsigned long key;
723
724	key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
725	hhd = &stat->hash[key];
726
727	if (hlist_empty(h: hhd))
728	return NULL;
729
730	hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
731	if (rec->ip == ip)
732	return rec;
733	}
734
735	return NULL;
736	}
737
738	static void ftrace_add_profile(struct ftrace_profile_stat *stat,
739	struct ftrace_profile *rec)
740	{
741	unsigned long key;
742
743	key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
744	hlist_add_head_rcu(n: &rec->node, h: &stat->hash[key]);
745	}
746
747	/*
748	* The memory is already allocated, this simply finds a new record to use.
749	*/
750	static struct ftrace_profile *
751	ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
752	{
753	struct ftrace_profile *rec = NULL;
754
755	/* prevent recursion (from NMIs) */
756	if (atomic_inc_return(v: &stat->disabled) != 1)
757	goto out;
758
759	/*
760	* Try to find the function again since an NMI
761	* could have added it
762	*/
763	rec = ftrace_find_profiled_func(stat, ip);
764	if (rec)
765	goto out;
766
767	if (stat->pages->index == PROFILES_PER_PAGE) {
768	if (!stat->pages->next)
769	goto out;
770	stat->pages = stat->pages->next;
771	}
772
773	rec = &stat->pages->records[stat->pages->index++];
774	rec->ip = ip;
775	ftrace_add_profile(stat, rec);
776
777	out:
778	atomic_dec(v: &stat->disabled);
779
780	return rec;
781	}
782
783	static void
784	function_profile_call(unsigned long ip, unsigned long parent_ip,
785	struct ftrace_ops *ops, struct ftrace_regs *fregs)
786	{
787	struct ftrace_profile_stat *stat;
788	struct ftrace_profile *rec;
789	unsigned long flags;
790
791	if (!ftrace_profile_enabled)
792	return;
793
794	local_irq_save(flags);
795
796	stat = this_cpu_ptr(&ftrace_profile_stats);
797	if (!stat->hash || !ftrace_profile_enabled)
798	goto out;
799
800	rec = ftrace_find_profiled_func(stat, ip);
801	if (!rec) {
802	rec = ftrace_profile_alloc(stat, ip);
803	if (!rec)
804	goto out;
805	}
806
807	rec->counter++;
808	out:
809	local_irq_restore(flags);
810	}
811
812	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
813	static bool fgraph_graph_time = true;
814
815	void ftrace_graph_graph_time_control(bool enable)
816	{
817	fgraph_graph_time = enable;
818	}
819
820	static int profile_graph_entry(struct ftrace_graph_ent *trace)
821	{
822	struct ftrace_ret_stack *ret_stack;
823
824	function_profile_call(ip: trace->func, parent_ip: 0, NULL, NULL);
825
826	/* If function graph is shutting down, ret_stack can be NULL */
827	if (!current->ret_stack)
828	return 0;
829
830	ret_stack = ftrace_graph_get_ret_stack(current, idx: 0);
831	if (ret_stack)
832	ret_stack->subtime = 0;
833
834	return 1;
835	}
836
837	static void profile_graph_return(struct ftrace_graph_ret *trace)
838	{
839	struct ftrace_ret_stack *ret_stack;
840	struct ftrace_profile_stat *stat;
841	unsigned long long calltime;
842	struct ftrace_profile *rec;
843	unsigned long flags;
844
845	local_irq_save(flags);
846	stat = this_cpu_ptr(&ftrace_profile_stats);
847	if (!stat->hash || !ftrace_profile_enabled)
848	goto out;
849
850	/* If the calltime was zero'd ignore it */
851	if (!trace->calltime)
852	goto out;
853
854	calltime = trace->rettime - trace->calltime;
855
856	if (!fgraph_graph_time) {
857
858	/* Append this call time to the parent time to subtract */
859	ret_stack = ftrace_graph_get_ret_stack(current, idx: 1);
860	if (ret_stack)
861	ret_stack->subtime += calltime;
862
863	ret_stack = ftrace_graph_get_ret_stack(current, idx: 0);
864	if (ret_stack && ret_stack->subtime < calltime)
865	calltime -= ret_stack->subtime;
866	else
867	calltime = 0;
868	}
869
870	rec = ftrace_find_profiled_func(stat, ip: trace->func);
871	if (rec) {
872	rec->time += calltime;
873	rec->time_squared += calltime * calltime;
874	}
875
876	out:
877	local_irq_restore(flags);
878	}
879
880	static struct fgraph_ops fprofiler_ops = {
881	.entryfunc = &profile_graph_entry,
882	.retfunc = &profile_graph_return,
883	};
884
885	static int register_ftrace_profiler(void)
886	{
887	return register_ftrace_graph(ops: &fprofiler_ops);
888	}
889
890	static void unregister_ftrace_profiler(void)
891	{
892	unregister_ftrace_graph(ops: &fprofiler_ops);
893	}
894	#else
895	static struct ftrace_ops ftrace_profile_ops __read_mostly = {
896	.func = function_profile_call,
897	.flags = FTRACE_OPS_FL_INITIALIZED,
898	INIT_OPS_HASH(ftrace_profile_ops)
899	};
900
901	static int register_ftrace_profiler(void)
902	{
903	return register_ftrace_function(&ftrace_profile_ops);
904	}
905
906	static void unregister_ftrace_profiler(void)
907	{
908	unregister_ftrace_function(&ftrace_profile_ops);
909	}
910	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
911
912	static ssize_t
913	ftrace_profile_write(struct file *filp, const char __user *ubuf,
914	size_t cnt, loff_t *ppos)
915	{
916	unsigned long val;
917	int ret;
918
919	ret = kstrtoul_from_user(s: ubuf, count: cnt, base: 10, res: &val);
920	if (ret)
921	return ret;
922
923	val = !!val;
924
925	mutex_lock(&ftrace_profile_lock);
926	if (ftrace_profile_enabled ^ val) {
927	if (val) {
928	ret = ftrace_profile_init();
929	if (ret < 0) {
930	cnt = ret;
931	goto out;
932	}
933
934	ret = register_ftrace_profiler();
935	if (ret < 0) {
936	cnt = ret;
937	goto out;
938	}
939	ftrace_profile_enabled = 1;
940	} else {
941	ftrace_profile_enabled = 0;
942	/*
943	* unregister_ftrace_profiler calls stop_machine
944	* so this acts like an synchronize_rcu.
945	*/
946	unregister_ftrace_profiler();
947	}
948	}
949	out:
950	mutex_unlock(lock: &ftrace_profile_lock);
951
952	*ppos += cnt;
953
954	return cnt;
955	}
956
957	static ssize_t
958	ftrace_profile_read(struct file *filp, char __user *ubuf,
959	size_t cnt, loff_t *ppos)
960	{
961	char buf[64]; /* big enough to hold a number */
962	int r;
963
964	r = sprintf(buf, fmt: "%u\n", ftrace_profile_enabled);
965	return simple_read_from_buffer(to: ubuf, count: cnt, ppos, from: buf, available: r);
966	}
967
968	static const struct file_operations ftrace_profile_fops = {
969	.open = tracing_open_generic,
970	.read = ftrace_profile_read,
971	.write = ftrace_profile_write,
972	.llseek = default_llseek,
973	};
974
975	/* used to initialize the real stat files */
976	static struct tracer_stat function_stats __initdata = {
977	.name = "functions",
978	.stat_start = function_stat_start,
979	.stat_next = function_stat_next,
980	.stat_cmp = function_stat_cmp,
981	.stat_headers = function_stat_headers,
982	.stat_show = function_stat_show
983	};
984
985	static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
986	{
987	struct ftrace_profile_stat *stat;
988	char *name;
989	int ret;
990	int cpu;
991
992	for_each_possible_cpu(cpu) {
993	stat = &per_cpu(ftrace_profile_stats, cpu);
994
995	name = kasprintf(GFP_KERNEL, fmt: "function%d", cpu);
996	if (!name) {
997	/*
998	* The files created are permanent, if something happens
999	* we still do not free memory.
1000	*/
1001	WARN(1,
1002	"Could not allocate stat file for cpu %d\n",
1003	cpu);
1004	return;
1005	}
1006	stat->stat = function_stats;
1007	stat->stat.name = name;
1008	ret = register_stat_tracer(trace: &stat->stat);
1009	if (ret) {
1010	WARN(1,
1011	"Could not register function stat for cpu %d\n",
1012	cpu);
1013	kfree(objp: name);
1014	return;
1015	}
1016	}
1017
1018	trace_create_file(name: "function_profile_enabled",
1019	TRACE_MODE_WRITE, parent: d_tracer, NULL,
1020	fops: &ftrace_profile_fops);
1021	}
1022
1023	#else /* CONFIG_FUNCTION_PROFILER */
1024	static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1025	{
1026	}
1027	#endif /* CONFIG_FUNCTION_PROFILER */
1028
1029	#ifdef CONFIG_DYNAMIC_FTRACE
1030
1031	static struct ftrace_ops *removed_ops;
1032
1033	/*
1034	* Set when doing a global update, like enabling all recs or disabling them.
1035	* It is not set when just updating a single ftrace_ops.
1036	*/
1037	static bool update_all_ops;
1038
1039	#ifndef CONFIG_FTRACE_MCOUNT_RECORD
1040	# error Dynamic ftrace depends on MCOUNT_RECORD
1041	#endif
1042
1043	struct ftrace_func_probe {
1044	struct ftrace_probe_ops *probe_ops;
1045	struct ftrace_ops ops;
1046	struct trace_array *tr;
1047	struct list_head list;
1048	void *data;
1049	int ref;
1050	};
1051
1052	/*
1053	* We make these constant because no one should touch them,
1054	* but they are used as the default "empty hash", to avoid allocating
1055	* it all the time. These are in a read only section such that if
1056	* anyone does try to modify it, it will cause an exception.
1057	*/
1058	static const struct hlist_head empty_buckets[1];
1059	static const struct ftrace_hash empty_hash = {
1060	.buckets = (struct hlist_head *)empty_buckets,
1061	};
1062	#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1063
1064	struct ftrace_ops global_ops = {
1065	.func = ftrace_stub,
1066	.local_hash.notrace_hash = EMPTY_HASH,
1067	.local_hash.filter_hash = EMPTY_HASH,
1068	INIT_OPS_HASH(global_ops)
1069	.flags = FTRACE_OPS_FL_INITIALIZED |
1070	FTRACE_OPS_FL_PID,
1071	};
1072
1073	/*
1074	* Used by the stack unwinder to know about dynamic ftrace trampolines.
1075	*/
1076	struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
1077	{
1078	struct ftrace_ops *op = NULL;
1079
1080	/*
1081	* Some of the ops may be dynamically allocated,
1082	* they are freed after a synchronize_rcu().
1083	*/
1084	preempt_disable_notrace();
1085
1086	do_for_each_ftrace_op(op, ftrace_ops_list) {
1087	/*
1088	* This is to check for dynamically allocated trampolines.
1089	* Trampolines that are in kernel text will have
1090	* core_kernel_text() return true.
1091	*/
1092	if (op->trampoline && op->trampoline_size)
1093	if (addr >= op->trampoline &&
1094	addr < op->trampoline + op->trampoline_size) {
1095	preempt_enable_notrace();
1096	return op;
1097	}
1098	} while_for_each_ftrace_op(op);
1099	preempt_enable_notrace();
1100
1101	return NULL;
1102	}
1103
1104	/*
1105	* This is used by __kernel_text_address() to return true if the
1106	* address is on a dynamically allocated trampoline that would
1107	* not return true for either core_kernel_text() or
1108	* is_module_text_address().
1109	*/
1110	bool is_ftrace_trampoline(unsigned long addr)
1111	{
1112	return ftrace_ops_trampoline(addr) != NULL;
1113	}
1114
1115	struct ftrace_page {
1116	struct ftrace_page *next;
1117	struct dyn_ftrace *records;
1118	int index;
1119	int order;
1120	};
1121
1122	#define ENTRY_SIZE sizeof(struct dyn_ftrace)
1123	#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1124
1125	static struct ftrace_page *ftrace_pages_start;
1126	static struct ftrace_page *ftrace_pages;
1127
1128	static __always_inline unsigned long
1129	ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1130	{
1131	if (hash->size_bits > 0)
1132	return hash_long(ip, hash->size_bits);
1133
1134	return 0;
1135	}
1136
1137	/* Only use this function if ftrace_hash_empty() has already been tested */
1138	static __always_inline struct ftrace_func_entry *
1139	__ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1140	{
1141	unsigned long key;
1142	struct ftrace_func_entry *entry;
1143	struct hlist_head *hhd;
1144
1145	key = ftrace_hash_key(hash, ip);
1146	hhd = &hash->buckets[key];
1147
1148	hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1149	if (entry->ip == ip)
1150	return entry;
1151	}
1152	return NULL;
1153	}
1154
1155	/**
1156	* ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1157	* @hash: The hash to look at
1158	* @ip: The instruction pointer to test
1159	*
1160	* Search a given @hash to see if a given instruction pointer (@ip)
1161	* exists in it.
1162	*
1163	* Returns the entry that holds the @ip if found. NULL otherwise.
1164	*/
1165	struct ftrace_func_entry *
1166	ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1167	{
1168	if (ftrace_hash_empty(hash))
1169	return NULL;
1170
1171	return __ftrace_lookup_ip(hash, ip);
1172	}
1173
1174	static void __add_hash_entry(struct ftrace_hash *hash,
1175	struct ftrace_func_entry *entry)
1176	{
1177	struct hlist_head *hhd;
1178	unsigned long key;
1179
1180	key = ftrace_hash_key(hash, ip: entry->ip);
1181	hhd = &hash->buckets[key];
1182	hlist_add_head(n: &entry->hlist, h: hhd);
1183	hash->count++;
1184	}
1185
1186	static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1187	{
1188	struct ftrace_func_entry *entry;
1189
1190	entry = kmalloc(size: sizeof(*entry), GFP_KERNEL);
1191	if (!entry)
1192	return -ENOMEM;
1193
1194	entry->ip = ip;
1195	__add_hash_entry(hash, entry);
1196
1197	return 0;
1198	}
1199
1200	static void
1201	free_hash_entry(struct ftrace_hash *hash,
1202	struct ftrace_func_entry *entry)
1203	{
1204	hlist_del(n: &entry->hlist);
1205	kfree(objp: entry);
1206	hash->count--;
1207	}
1208
1209	static void
1210	remove_hash_entry(struct ftrace_hash *hash,
1211	struct ftrace_func_entry *entry)
1212	{
1213	hlist_del_rcu(n: &entry->hlist);
1214	hash->count--;
1215	}
1216
1217	static void ftrace_hash_clear(struct ftrace_hash *hash)
1218	{
1219	struct hlist_head *hhd;
1220	struct hlist_node *tn;
1221	struct ftrace_func_entry *entry;
1222	int size = 1 << hash->size_bits;
1223	int i;
1224
1225	if (!hash->count)
1226	return;
1227
1228	for (i = 0; i < size; i++) {
1229	hhd = &hash->buckets[i];
1230	hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1231	free_hash_entry(hash, entry);
1232	}
1233	FTRACE_WARN_ON(hash->count);
1234	}
1235
1236	static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1237	{
1238	list_del(entry: &ftrace_mod->list);
1239	kfree(objp: ftrace_mod->module);
1240	kfree(objp: ftrace_mod->func);
1241	kfree(objp: ftrace_mod);
1242	}
1243
1244	static void clear_ftrace_mod_list(struct list_head *head)
1245	{
1246	struct ftrace_mod_load *p, *n;
1247
1248	/* stack tracer isn't supported yet */
1249	if (!head)
1250	return;
1251
1252	mutex_lock(&ftrace_lock);
1253	list_for_each_entry_safe(p, n, head, list)
1254	free_ftrace_mod(ftrace_mod: p);
1255	mutex_unlock(lock: &ftrace_lock);
1256	}
1257
1258	static void free_ftrace_hash(struct ftrace_hash *hash)
1259	{
1260	if (!hash || hash == EMPTY_HASH)
1261	return;
1262	ftrace_hash_clear(hash);
1263	kfree(objp: hash->buckets);
1264	kfree(objp: hash);
1265	}
1266
1267	static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1268	{
1269	struct ftrace_hash *hash;
1270
1271	hash = container_of(rcu, struct ftrace_hash, rcu);
1272	free_ftrace_hash(hash);
1273	}
1274
1275	static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1276	{
1277	if (!hash || hash == EMPTY_HASH)
1278	return;
1279	call_rcu(head: &hash->rcu, func: __free_ftrace_hash_rcu);
1280	}
1281
1282	/**
1283	* ftrace_free_filter - remove all filters for an ftrace_ops
1284	* @ops - the ops to remove the filters from
1285	*/
1286	void ftrace_free_filter(struct ftrace_ops *ops)
1287	{
1288	ftrace_ops_init(ops);
1289	free_ftrace_hash(hash: ops->func_hash->filter_hash);
1290	free_ftrace_hash(hash: ops->func_hash->notrace_hash);
1291	}
1292	EXPORT_SYMBOL_GPL(ftrace_free_filter);
1293
1294	static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1295	{
1296	struct ftrace_hash *hash;
1297	int size;
1298
1299	hash = kzalloc(size: sizeof(*hash), GFP_KERNEL);
1300	if (!hash)
1301	return NULL;
1302
1303	size = 1 << size_bits;
1304	hash->buckets = kcalloc(n: size, size: sizeof(*hash->buckets), GFP_KERNEL);
1305
1306	if (!hash->buckets) {
1307	kfree(objp: hash);
1308	return NULL;
1309	}
1310
1311	hash->size_bits = size_bits;
1312
1313	return hash;
1314	}
1315
1316
1317	static int ftrace_add_mod(struct trace_array *tr,
1318	const char *func, const char *module,
1319	int enable)
1320	{
1321	struct ftrace_mod_load *ftrace_mod;
1322	struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1323
1324	ftrace_mod = kzalloc(size: sizeof(*ftrace_mod), GFP_KERNEL);
1325	if (!ftrace_mod)
1326	return -ENOMEM;
1327
1328	INIT_LIST_HEAD(list: &ftrace_mod->list);
1329	ftrace_mod->func = kstrdup(s: func, GFP_KERNEL);
1330	ftrace_mod->module = kstrdup(s: module, GFP_KERNEL);
1331	ftrace_mod->enable = enable;
1332
1333	if (!ftrace_mod->func || !ftrace_mod->module)
1334	goto out_free;
1335
1336	list_add(new: &ftrace_mod->list, head: mod_head);
1337
1338	return 0;
1339
1340	out_free:
1341	free_ftrace_mod(ftrace_mod);
1342
1343	return -ENOMEM;
1344	}
1345
1346	static struct ftrace_hash *
1347	alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1348	{
1349	struct ftrace_func_entry *entry;
1350	struct ftrace_hash *new_hash;
1351	int size;
1352	int ret;
1353	int i;
1354
1355	new_hash = alloc_ftrace_hash(size_bits);
1356	if (!new_hash)
1357	return NULL;
1358
1359	if (hash)
1360	new_hash->flags = hash->flags;
1361
1362	/* Empty hash? */
1363	if (ftrace_hash_empty(hash))
1364	return new_hash;
1365
1366	size = 1 << hash->size_bits;
1367	for (i = 0; i < size; i++) {
1368	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1369	ret = add_hash_entry(hash: new_hash, ip: entry->ip);
1370	if (ret < 0)
1371	goto free_hash;
1372	}
1373	}
1374
1375	FTRACE_WARN_ON(new_hash->count != hash->count);
1376
1377	return new_hash;
1378
1379	free_hash:
1380	free_ftrace_hash(hash: new_hash);
1381	return NULL;
1382	}
1383
1384	static void
1385	ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1386	static void
1387	ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1388
1389	static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1390	struct ftrace_hash *new_hash);
1391
1392	static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size)
1393	{
1394	struct ftrace_func_entry *entry;
1395	struct ftrace_hash *new_hash;
1396	struct hlist_head *hhd;
1397	struct hlist_node *tn;
1398	int bits = 0;
1399	int i;
1400
1401	/*
1402	* Use around half the size (max bit of it), but
1403	* a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits).
1404	*/
1405	bits = fls(x: size / 2);
1406
1407	/* Don't allocate too much */
1408	if (bits > FTRACE_HASH_MAX_BITS)
1409	bits = FTRACE_HASH_MAX_BITS;
1410
1411	new_hash = alloc_ftrace_hash(size_bits: bits);
1412	if (!new_hash)
1413	return NULL;
1414
1415	new_hash->flags = src->flags;
1416
1417	size = 1 << src->size_bits;
1418	for (i = 0; i < size; i++) {
1419	hhd = &src->buckets[i];
1420	hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1421	remove_hash_entry(hash: src, entry);
1422	__add_hash_entry(hash: new_hash, entry);
1423	}
1424	}
1425	return new_hash;
1426	}
1427
1428	static struct ftrace_hash *
1429	__ftrace_hash_move(struct ftrace_hash *src)
1430	{
1431	int size = src->count;
1432
1433	/*
1434	* If the new source is empty, just return the empty_hash.
1435	*/
1436	if (ftrace_hash_empty(hash: src))
1437	return EMPTY_HASH;
1438
1439	return dup_hash(src, size);
1440	}
1441
1442	static int
1443	ftrace_hash_move(struct ftrace_ops *ops, int enable,
1444	struct ftrace_hash **dst, struct ftrace_hash *src)
1445	{
1446	struct ftrace_hash *new_hash;
1447	int ret;
1448
1449	/* Reject setting notrace hash on IPMODIFY ftrace_ops */
1450	if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1451	return -EINVAL;
1452
1453	new_hash = __ftrace_hash_move(src);
1454	if (!new_hash)
1455	return -ENOMEM;
1456
1457	/* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1458	if (enable) {
1459	/* IPMODIFY should be updated only when filter_hash updating */
1460	ret = ftrace_hash_ipmodify_update(ops, new_hash);
1461	if (ret < 0) {
1462	free_ftrace_hash(hash: new_hash);
1463	return ret;
1464	}
1465	}
1466
1467	/*
1468	* Remove the current set, update the hash and add
1469	* them back.
1470	*/
1471	ftrace_hash_rec_disable_modify(ops, filter_hash: enable);
1472
1473	rcu_assign_pointer(*dst, new_hash);
1474
1475	ftrace_hash_rec_enable_modify(ops, filter_hash: enable);
1476
1477	return 0;
1478	}
1479
1480	static bool hash_contains_ip(unsigned long ip,
1481	struct ftrace_ops_hash *hash)
1482	{
1483	/*
1484	* The function record is a match if it exists in the filter
1485	* hash and not in the notrace hash. Note, an empty hash is
1486	* considered a match for the filter hash, but an empty
1487	* notrace hash is considered not in the notrace hash.
1488	*/
1489	return (ftrace_hash_empty(hash: hash->filter_hash) ||
1490	__ftrace_lookup_ip(hash: hash->filter_hash, ip)) &&
1491	(ftrace_hash_empty(hash: hash->notrace_hash) ||
1492	!__ftrace_lookup_ip(hash: hash->notrace_hash, ip));
1493	}
1494
1495	/*
1496	* Test the hashes for this ops to see if we want to call
1497	* the ops->func or not.
1498	*
1499	* It's a match if the ip is in the ops->filter_hash or
1500	* the filter_hash does not exist or is empty,
1501	* AND
1502	* the ip is not in the ops->notrace_hash.
1503	*
1504	* This needs to be called with preemption disabled as
1505	* the hashes are freed with call_rcu().
1506	*/
1507	int
1508	ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1509	{
1510	struct ftrace_ops_hash hash;
1511	int ret;
1512
1513	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1514	/*
1515	* There's a small race when adding ops that the ftrace handler
1516	* that wants regs, may be called without them. We can not
1517	* allow that handler to be called if regs is NULL.
1518	*/
1519	if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1520	return 0;
1521	#endif
1522
1523	rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1524	rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1525
1526	if (hash_contains_ip(ip, hash: &hash))
1527	ret = 1;
1528	else
1529	ret = 0;
1530
1531	return ret;
1532	}
1533
1534	/*
1535	* This is a double for. Do not use 'break' to break out of the loop,
1536	* you must use a goto.
1537	*/
1538	#define do_for_each_ftrace_rec(pg, rec) \
1539	for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1540	int _____i; \
1541	for (_____i = 0; _____i < pg->index; _____i++) { \
1542	rec = &pg->records[_____i];
1543
1544	#define while_for_each_ftrace_rec() \
1545	} \
1546	}
1547
1548
1549	static int ftrace_cmp_recs(const void *a, const void *b)
1550	{
1551	const struct dyn_ftrace *key = a;
1552	const struct dyn_ftrace *rec = b;
1553
1554	if (key->flags < rec->ip)
1555	return -1;
1556	if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1557	return 1;
1558	return 0;
1559	}
1560
1561	static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)
1562	{
1563	struct ftrace_page *pg;
1564	struct dyn_ftrace *rec = NULL;
1565	struct dyn_ftrace key;
1566
1567	key.ip = start;
1568	key.flags = end; /* overload flags, as it is unsigned long */
1569
1570	for (pg = ftrace_pages_start; pg; pg = pg->next) {
1571	if (pg->index == 0 ||
1572	end < pg->records[0].ip ||
1573	start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1574	continue;
1575	rec = bsearch(key: &key, base: pg->records, num: pg->index,
1576	size: sizeof(struct dyn_ftrace),
1577	cmp: ftrace_cmp_recs);
1578	if (rec)
1579	break;
1580	}
1581	return rec;
1582	}
1583
1584	/**
1585	* ftrace_location_range - return the first address of a traced location
1586	* if it touches the given ip range
1587	* @start: start of range to search.
1588	* @end: end of range to search (inclusive). @end points to the last byte
1589	* to check.
1590	*
1591	* Returns rec->ip if the related ftrace location is a least partly within
1592	* the given address range. That is, the first address of the instruction
1593	* that is either a NOP or call to the function tracer. It checks the ftrace
1594	* internal tables to determine if the address belongs or not.
1595	*/
1596	unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1597	{
1598	struct dyn_ftrace *rec;
1599
1600	rec = lookup_rec(start, end);
1601	if (rec)
1602	return rec->ip;
1603
1604	return 0;
1605	}
1606
1607	/**
1608	* ftrace_location - return the ftrace location
1609	* @ip: the instruction pointer to check
1610	*
1611	* If @ip matches the ftrace location, return @ip.
1612	* If @ip matches sym+0, return sym's ftrace location.
1613	* Otherwise, return 0.
1614	*/
1615	unsigned long ftrace_location(unsigned long ip)
1616	{
1617	struct dyn_ftrace *rec;
1618	unsigned long offset;
1619	unsigned long size;
1620
1621	rec = lookup_rec(start: ip, end: ip);
1622	if (!rec) {
1623	if (!kallsyms_lookup_size_offset(addr: ip, symbolsize: &size, offset: &offset))
1624	goto out;
1625
1626	/* map sym+0 to __fentry__ */
1627	if (!offset)
1628	rec = lookup_rec(start: ip, end: ip + size - 1);
1629	}
1630
1631	if (rec)
1632	return rec->ip;
1633
1634	out:
1635	return 0;
1636	}
1637
1638	/**
1639	* ftrace_text_reserved - return true if range contains an ftrace location
1640	* @start: start of range to search
1641	* @end: end of range to search (inclusive). @end points to the last byte to check.
1642	*
1643	* Returns 1 if @start and @end contains a ftrace location.
1644	* That is, the instruction that is either a NOP or call to
1645	* the function tracer. It checks the ftrace internal tables to
1646	* determine if the address belongs or not.
1647	*/
1648	int ftrace_text_reserved(const void *start, const void *end)
1649	{
1650	unsigned long ret;
1651
1652	ret = ftrace_location_range(start: (unsigned long)start,
1653	end: (unsigned long)end);
1654
1655	return (int)!!ret;
1656	}
1657
1658	/* Test if ops registered to this rec needs regs */
1659	static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1660	{
1661	struct ftrace_ops *ops;
1662	bool keep_regs = false;
1663
1664	for (ops = ftrace_ops_list;
1665	ops != &ftrace_list_end; ops = ops->next) {
1666	/* pass rec in as regs to have non-NULL val */
1667	if (ftrace_ops_test(ops, ip: rec->ip, regs: rec)) {
1668	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1669	keep_regs = true;
1670	break;
1671	}
1672	}
1673	}
1674
1675	return keep_regs;
1676	}
1677
1678	static struct ftrace_ops *
1679	ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
1680	static struct ftrace_ops *
1681	ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude);
1682	static struct ftrace_ops *
1683	ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
1684
1685	static bool skip_record(struct dyn_ftrace *rec)
1686	{
1687	/*
1688	* At boot up, weak functions are set to disable. Function tracing
1689	* can be enabled before they are, and they still need to be disabled now.
1690	* If the record is disabled, still continue if it is marked as already
1691	* enabled (this is needed to keep the accounting working).
1692	*/
1693	return rec->flags & FTRACE_FL_DISABLED &&
1694	!(rec->flags & FTRACE_FL_ENABLED);
1695	}
1696
1697	static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1698	int filter_hash,
1699	bool inc)
1700	{
1701	struct ftrace_hash *hash;
1702	struct ftrace_hash *other_hash;
1703	struct ftrace_page *pg;
1704	struct dyn_ftrace *rec;
1705	bool update = false;
1706	int count = 0;
1707	int all = false;
1708
1709	/* Only update if the ops has been registered */
1710	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1711	return false;
1712
1713	/*
1714	* In the filter_hash case:
1715	* If the count is zero, we update all records.
1716	* Otherwise we just update the items in the hash.
1717	*
1718	* In the notrace_hash case:
1719	* We enable the update in the hash.
1720	* As disabling notrace means enabling the tracing,
1721	* and enabling notrace means disabling, the inc variable
1722	* gets inversed.
1723	*/
1724	if (filter_hash) {
1725	hash = ops->func_hash->filter_hash;
1726	other_hash = ops->func_hash->notrace_hash;
1727	if (ftrace_hash_empty(hash))
1728	all = true;
1729	} else {
1730	inc = !inc;
1731	hash = ops->func_hash->notrace_hash;
1732	other_hash = ops->func_hash->filter_hash;
1733	/*
1734	* If the notrace hash has no items,
1735	* then there's nothing to do.
1736	*/
1737	if (ftrace_hash_empty(hash))
1738	return false;
1739	}
1740
1741	do_for_each_ftrace_rec(pg, rec) {
1742	int in_other_hash = 0;
1743	int in_hash = 0;
1744	int match = 0;
1745
1746	if (skip_record(rec))
1747	continue;
1748
1749	if (all) {
1750	/*
1751	* Only the filter_hash affects all records.
1752	* Update if the record is not in the notrace hash.
1753	*/
1754	if (!other_hash || !ftrace_lookup_ip(hash: other_hash, ip: rec->ip))
1755	match = 1;
1756	} else {
1757	in_hash = !!ftrace_lookup_ip(hash, ip: rec->ip);
1758	in_other_hash = !!ftrace_lookup_ip(hash: other_hash, ip: rec->ip);
1759
1760	/*
1761	* If filter_hash is set, we want to match all functions
1762	* that are in the hash but not in the other hash.
1763	*
1764	* If filter_hash is not set, then we are decrementing.
1765	* That means we match anything that is in the hash
1766	* and also in the other_hash. That is, we need to turn
1767	* off functions in the other hash because they are disabled
1768	* by this hash.
1769	*/
1770	if (filter_hash && in_hash && !in_other_hash)
1771	match = 1;
1772	else if (!filter_hash && in_hash &&
1773	(in_other_hash || ftrace_hash_empty(hash: other_hash)))
1774	match = 1;
1775	}
1776	if (!match)
1777	continue;
1778
1779	if (inc) {
1780	rec->flags++;
1781	if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1782	return false;
1783
1784	if (ops->flags & FTRACE_OPS_FL_DIRECT)
1785	rec->flags |= FTRACE_FL_DIRECT;
1786
1787	/*
1788	* If there's only a single callback registered to a
1789	* function, and the ops has a trampoline registered
1790	* for it, then we can call it directly.
1791	*/
1792	if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1793	rec->flags |= FTRACE_FL_TRAMP;
1794	else
1795	/*
1796	* If we are adding another function callback
1797	* to this function, and the previous had a
1798	* custom trampoline in use, then we need to go
1799	* back to the default trampoline.
1800	*/
1801	rec->flags &= ~FTRACE_FL_TRAMP;
1802
1803	/*
1804	* If any ops wants regs saved for this function
1805	* then all ops will get saved regs.
1806	*/
1807	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1808	rec->flags |= FTRACE_FL_REGS;
1809	} else {
1810	if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1811	return false;
1812	rec->flags--;
1813
1814	/*
1815	* Only the internal direct_ops should have the
1816	* DIRECT flag set. Thus, if it is removing a
1817	* function, then that function should no longer
1818	* be direct.
1819	*/
1820	if (ops->flags & FTRACE_OPS_FL_DIRECT)
1821	rec->flags &= ~FTRACE_FL_DIRECT;
1822
1823	/*
1824	* If the rec had REGS enabled and the ops that is
1825	* being removed had REGS set, then see if there is
1826	* still any ops for this record that wants regs.
1827	* If not, we can stop recording them.
1828	*/
1829	if (ftrace_rec_count(rec) > 0 &&
1830	rec->flags & FTRACE_FL_REGS &&
1831	ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1832	if (!test_rec_ops_needs_regs(rec))
1833	rec->flags &= ~FTRACE_FL_REGS;
1834	}
1835
1836	/*
1837	* The TRAMP needs to be set only if rec count
1838	* is decremented to one, and the ops that is
1839	* left has a trampoline. As TRAMP can only be
1840	* enabled if there is only a single ops attached
1841	* to it.
1842	*/
1843	if (ftrace_rec_count(rec) == 1 &&
1844	ftrace_find_tramp_ops_any_other(rec, op_exclude: ops))
1845	rec->flags |= FTRACE_FL_TRAMP;
1846	else
1847	rec->flags &= ~FTRACE_FL_TRAMP;
1848
1849	/*
1850	* flags will be cleared in ftrace_check_record()
1851	* if rec count is zero.
1852	*/
1853	}
1854
1855	/*
1856	* If the rec has a single associated ops, and ops->func can be
1857	* called directly, allow the call site to call via the ops.
1858	*/
1859	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) &&
1860	ftrace_rec_count(rec) == 1 &&
1861	ftrace_ops_get_func(ops) == ops->func)
1862	rec->flags |= FTRACE_FL_CALL_OPS;
1863	else
1864	rec->flags &= ~FTRACE_FL_CALL_OPS;
1865
1866	count++;
1867
1868	/* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1869	update |= ftrace_test_record(rec, enable: true) != FTRACE_UPDATE_IGNORE;
1870
1871	/* Shortcut, if we handled all records, we are done. */
1872	if (!all && count == hash->count)
1873	return update;
1874	} while_for_each_ftrace_rec();
1875
1876	return update;
1877	}
1878
1879	static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1880	int filter_hash)
1881	{
1882	return __ftrace_hash_rec_update(ops, filter_hash, inc: 0);
1883	}
1884
1885	static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1886	int filter_hash)
1887	{
1888	return __ftrace_hash_rec_update(ops, filter_hash, inc: 1);
1889	}
1890
1891	static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1892	int filter_hash, int inc)
1893	{
1894	struct ftrace_ops *op;
1895
1896	__ftrace_hash_rec_update(ops, filter_hash, inc);
1897
1898	if (ops->func_hash != &global_ops.local_hash)
1899	return;
1900
1901	/*
1902	* If the ops shares the global_ops hash, then we need to update
1903	* all ops that are enabled and use this hash.
1904	*/
1905	do_for_each_ftrace_op(op, ftrace_ops_list) {
1906	/* Already done */
1907	if (op == ops)
1908	continue;
1909	if (op->func_hash == &global_ops.local_hash)
1910	__ftrace_hash_rec_update(ops: op, filter_hash, inc);
1911	} while_for_each_ftrace_op(op);
1912	}
1913
1914	static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1915	int filter_hash)
1916	{
1917	ftrace_hash_rec_update_modify(ops, filter_hash, inc: 0);
1918	}
1919
1920	static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1921	int filter_hash)
1922	{
1923	ftrace_hash_rec_update_modify(ops, filter_hash, inc: 1);
1924	}
1925
1926	/*
1927	* Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1928	* or no-needed to update, -EBUSY if it detects a conflict of the flag
1929	* on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1930	* Note that old_hash and new_hash has below meanings
1931	* - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1932	* - If the hash is EMPTY_HASH, it hits nothing
1933	* - Anything else hits the recs which match the hash entries.
1934	*
1935	* DIRECT ops does not have IPMODIFY flag, but we still need to check it
1936	* against functions with FTRACE_FL_IPMODIFY. If there is any overlap, call
1937	* ops_func(SHARE_IPMODIFY_SELF) to make sure current ops can share with
1938	* IPMODIFY. If ops_func(SHARE_IPMODIFY_SELF) returns non-zero, propagate
1939	* the return value to the caller and eventually to the owner of the DIRECT
1940	* ops.
1941	*/
1942	static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1943	struct ftrace_hash *old_hash,
1944	struct ftrace_hash *new_hash)
1945	{
1946	struct ftrace_page *pg;
1947	struct dyn_ftrace *rec, *end = NULL;
1948	int in_old, in_new;
1949	bool is_ipmodify, is_direct;
1950
1951	/* Only update if the ops has been registered */
1952	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1953	return 0;
1954
1955	is_ipmodify = ops->flags & FTRACE_OPS_FL_IPMODIFY;
1956	is_direct = ops->flags & FTRACE_OPS_FL_DIRECT;
1957
1958	/* neither IPMODIFY nor DIRECT, skip */
1959	if (!is_ipmodify && !is_direct)
1960	return 0;
1961
1962	if (WARN_ON_ONCE(is_ipmodify && is_direct))
1963	return 0;
1964
1965	/*
1966	* Since the IPMODIFY and DIRECT are very address sensitive
1967	* actions, we do not allow ftrace_ops to set all functions to new
1968	* hash.
1969	*/
1970	if (!new_hash || !old_hash)
1971	return -EINVAL;
1972
1973	/* Update rec->flags */
1974	do_for_each_ftrace_rec(pg, rec) {
1975
1976	if (rec->flags & FTRACE_FL_DISABLED)
1977	continue;
1978
1979	/* We need to update only differences of filter_hash */
1980	in_old = !!ftrace_lookup_ip(hash: old_hash, ip: rec->ip);
1981	in_new = !!ftrace_lookup_ip(hash: new_hash, ip: rec->ip);
1982	if (in_old == in_new)
1983	continue;
1984
1985	if (in_new) {
1986	if (rec->flags & FTRACE_FL_IPMODIFY) {
1987	int ret;
1988
1989	/* Cannot have two ipmodify on same rec */
1990	if (is_ipmodify)
1991	goto rollback;
1992
1993	FTRACE_WARN_ON(rec->flags & FTRACE_FL_DIRECT);
1994
1995	/*
1996	* Another ops with IPMODIFY is already
1997	* attached. We are now attaching a direct
1998	* ops. Run SHARE_IPMODIFY_SELF, to check
1999	* whether sharing is supported.
2000	*/
2001	if (!ops->ops_func)
2002	return -EBUSY;
2003	ret = ops->ops_func(ops, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF);
2004	if (ret)
2005	return ret;
2006	} else if (is_ipmodify) {
2007	rec->flags |= FTRACE_FL_IPMODIFY;
2008	}
2009	} else if (is_ipmodify) {
2010	rec->flags &= ~FTRACE_FL_IPMODIFY;
2011	}
2012	} while_for_each_ftrace_rec();
2013
2014	return 0;
2015
2016	rollback:
2017	end = rec;
2018
2019	/* Roll back what we did above */
2020	do_for_each_ftrace_rec(pg, rec) {
2021
2022	if (rec->flags & FTRACE_FL_DISABLED)
2023	continue;
2024
2025	if (rec == end)
2026	goto err_out;
2027
2028	in_old = !!ftrace_lookup_ip(hash: old_hash, ip: rec->ip);
2029	in_new = !!ftrace_lookup_ip(hash: new_hash, ip: rec->ip);
2030	if (in_old == in_new)
2031	continue;
2032
2033	if (in_new)
2034	rec->flags &= ~FTRACE_FL_IPMODIFY;
2035	else
2036	rec->flags |= FTRACE_FL_IPMODIFY;
2037	} while_for_each_ftrace_rec();
2038
2039	err_out:
2040	return -EBUSY;
2041	}
2042
2043	static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
2044	{
2045	struct ftrace_hash *hash = ops->func_hash->filter_hash;
2046
2047	if (ftrace_hash_empty(hash))
2048	hash = NULL;
2049
2050	return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, new_hash: hash);
2051	}
2052
2053	/* Disabling always succeeds */
2054	static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
2055	{
2056	struct ftrace_hash *hash = ops->func_hash->filter_hash;
2057
2058	if (ftrace_hash_empty(hash))
2059	hash = NULL;
2060
2061	__ftrace_hash_update_ipmodify(ops, old_hash: hash, EMPTY_HASH);
2062	}
2063
2064	static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
2065	struct ftrace_hash *new_hash)
2066	{
2067	struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
2068
2069	if (ftrace_hash_empty(hash: old_hash))
2070	old_hash = NULL;
2071
2072	if (ftrace_hash_empty(hash: new_hash))
2073	new_hash = NULL;
2074
2075	return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
2076	}
2077
2078	static void print_ip_ins(const char *fmt, const unsigned char *p)
2079	{
2080	char ins[MCOUNT_INSN_SIZE];
2081
2082	if (copy_from_kernel_nofault(dst: ins, src: p, MCOUNT_INSN_SIZE)) {
2083	printk(KERN_CONT "%s[FAULT] %px\n", fmt, p);
2084	return;
2085	}
2086
2087	printk(KERN_CONT "%s", fmt);
2088	pr_cont("%*phC", MCOUNT_INSN_SIZE, ins);
2089	}
2090
2091	enum ftrace_bug_type ftrace_bug_type;
2092	const void *ftrace_expected;
2093
2094	static void print_bug_type(void)
2095	{
2096	switch (ftrace_bug_type) {
2097	case FTRACE_BUG_UNKNOWN:
2098	break;
2099	case FTRACE_BUG_INIT:
2100	pr_info("Initializing ftrace call sites\n");
2101	break;
2102	case FTRACE_BUG_NOP:
2103	pr_info("Setting ftrace call site to NOP\n");
2104	break;
2105	case FTRACE_BUG_CALL:
2106	pr_info("Setting ftrace call site to call ftrace function\n");
2107	break;
2108	case FTRACE_BUG_UPDATE:
2109	pr_info("Updating ftrace call site to call a different ftrace function\n");
2110	break;
2111	}
2112	}
2113
2114	/**
2115	* ftrace_bug - report and shutdown function tracer
2116	* @failed: The failed type (EFAULT, EINVAL, EPERM)
2117	* @rec: The record that failed
2118	*
2119	* The arch code that enables or disables the function tracing
2120	* can call ftrace_bug() when it has detected a problem in
2121	* modifying the code. @failed should be one of either:
2122	* EFAULT - if the problem happens on reading the @ip address
2123	* EINVAL - if what is read at @ip is not what was expected
2124	* EPERM - if the problem happens on writing to the @ip address
2125	*/
2126	void ftrace_bug(int failed, struct dyn_ftrace *rec)
2127	{
2128	unsigned long ip = rec ? rec->ip : 0;
2129
2130	pr_info("------------[ ftrace bug ]------------\n");
2131
2132	switch (failed) {
2133	case -EFAULT:
2134	pr_info("ftrace faulted on modifying ");
2135	print_ip_sym(KERN_INFO, ip);
2136	break;
2137	case -EINVAL:
2138	pr_info("ftrace failed to modify ");
2139	print_ip_sym(KERN_INFO, ip);
2140	print_ip_ins(fmt: " actual: ", p: (unsigned char *)ip);
2141	pr_cont("\n");
2142	if (ftrace_expected) {
2143	print_ip_ins(fmt: " expected: ", p: ftrace_expected);
2144	pr_cont("\n");
2145	}
2146	break;
2147	case -EPERM:
2148	pr_info("ftrace faulted on writing ");
2149	print_ip_sym(KERN_INFO, ip);
2150	break;
2151	default:
2152	pr_info("ftrace faulted on unknown error ");
2153	print_ip_sym(KERN_INFO, ip);
2154	}
2155	print_bug_type();
2156	if (rec) {
2157	struct ftrace_ops *ops = NULL;
2158
2159	pr_info("ftrace record flags: %lx\n", rec->flags);
2160	pr_cont(" (%ld)%s%s", ftrace_rec_count(rec),
2161	rec->flags & FTRACE_FL_REGS ? " R" : " ",
2162	rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ");
2163	if (rec->flags & FTRACE_FL_TRAMP_EN) {
2164	ops = ftrace_find_tramp_ops_any(rec);
2165	if (ops) {
2166	do {
2167	pr_cont("\ttramp: %pS (%pS)",
2168	(void *)ops->trampoline,
2169	(void *)ops->func);
2170	ops = ftrace_find_tramp_ops_next(rec, ops);
2171	} while (ops);
2172	} else
2173	pr_cont("\ttramp: ERROR!");
2174
2175	}
2176	ip = ftrace_get_addr_curr(rec);
2177	pr_cont("\n expected tramp: %lx\n", ip);
2178	}
2179
2180	FTRACE_WARN_ON_ONCE(1);
2181	}
2182
2183	static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
2184	{
2185	unsigned long flag = 0UL;
2186
2187	ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2188
2189	if (skip_record(rec))
2190	return FTRACE_UPDATE_IGNORE;
2191
2192	/*
2193	* If we are updating calls:
2194	*
2195	* If the record has a ref count, then we need to enable it
2196	* because someone is using it.
2197	*
2198	* Otherwise we make sure its disabled.
2199	*
2200	* If we are disabling calls, then disable all records that
2201	* are enabled.
2202	*/
2203	if (enable && ftrace_rec_count(rec))
2204	flag = FTRACE_FL_ENABLED;
2205
2206	/*
2207	* If enabling and the REGS flag does not match the REGS_EN, or
2208	* the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2209	* this record. Set flags to fail the compare against ENABLED.
2210	* Same for direct calls.
2211	*/
2212	if (flag) {
2213	if (!(rec->flags & FTRACE_FL_REGS) !=
2214	!(rec->flags & FTRACE_FL_REGS_EN))
2215	flag |= FTRACE_FL_REGS;
2216
2217	if (!(rec->flags & FTRACE_FL_TRAMP) !=
2218	!(rec->flags & FTRACE_FL_TRAMP_EN))
2219	flag |= FTRACE_FL_TRAMP;
2220
2221	/*
2222	* Direct calls are special, as count matters.
2223	* We must test the record for direct, if the
2224	* DIRECT and DIRECT_EN do not match, but only
2225	* if the count is 1. That's because, if the
2226	* count is something other than one, we do not
2227	* want the direct enabled (it will be done via the
2228	* direct helper). But if DIRECT_EN is set, and
2229	* the count is not one, we need to clear it.
2230	*
2231	*/
2232	if (ftrace_rec_count(rec) == 1) {
2233	if (!(rec->flags & FTRACE_FL_DIRECT) !=
2234	!(rec->flags & FTRACE_FL_DIRECT_EN))
2235	flag |= FTRACE_FL_DIRECT;
2236	} else if (rec->flags & FTRACE_FL_DIRECT_EN) {
2237	flag |= FTRACE_FL_DIRECT;
2238	}
2239
2240	/*
2241	* Ops calls are special, as count matters.
2242	* As with direct calls, they must only be enabled when count
2243	* is one, otherwise they'll be handled via the list ops.
2244	*/
2245	if (ftrace_rec_count(rec) == 1) {
2246	if (!(rec->flags & FTRACE_FL_CALL_OPS) !=
2247	!(rec->flags & FTRACE_FL_CALL_OPS_EN))
2248	flag |= FTRACE_FL_CALL_OPS;
2249	} else if (rec->flags & FTRACE_FL_CALL_OPS_EN) {
2250	flag |= FTRACE_FL_CALL_OPS;
2251	}
2252	}
2253
2254	/* If the state of this record hasn't changed, then do nothing */
2255	if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2256	return FTRACE_UPDATE_IGNORE;
2257
2258	if (flag) {
2259	/* Save off if rec is being enabled (for return value) */
2260	flag ^= rec->flags & FTRACE_FL_ENABLED;
2261
2262	if (update) {
2263	rec->flags |= FTRACE_FL_ENABLED | FTRACE_FL_TOUCHED;
2264	if (flag & FTRACE_FL_REGS) {
2265	if (rec->flags & FTRACE_FL_REGS)
2266	rec->flags |= FTRACE_FL_REGS_EN;
2267	else
2268	rec->flags &= ~FTRACE_FL_REGS_EN;
2269	}
2270	if (flag & FTRACE_FL_TRAMP) {
2271	if (rec->flags & FTRACE_FL_TRAMP)
2272	rec->flags |= FTRACE_FL_TRAMP_EN;
2273	else
2274	rec->flags &= ~FTRACE_FL_TRAMP_EN;
2275	}
2276
2277	/* Keep track of anything that modifies the function */
2278	if (rec->flags & (FTRACE_FL_DIRECT | FTRACE_FL_IPMODIFY))
2279	rec->flags |= FTRACE_FL_MODIFIED;
2280
2281	if (flag & FTRACE_FL_DIRECT) {
2282	/*
2283	* If there's only one user (direct_ops helper)
2284	* then we can call the direct function
2285	* directly (no ftrace trampoline).
2286	*/
2287	if (ftrace_rec_count(rec) == 1) {
2288	if (rec->flags & FTRACE_FL_DIRECT)
2289	rec->flags |= FTRACE_FL_DIRECT_EN;
2290	else
2291	rec->flags &= ~FTRACE_FL_DIRECT_EN;
2292	} else {
2293	/*
2294	* Can only call directly if there's
2295	* only one callback to the function.
2296	*/
2297	rec->flags &= ~FTRACE_FL_DIRECT_EN;
2298	}
2299	}
2300
2301	if (flag & FTRACE_FL_CALL_OPS) {
2302	if (ftrace_rec_count(rec) == 1) {
2303	if (rec->flags & FTRACE_FL_CALL_OPS)
2304	rec->flags |= FTRACE_FL_CALL_OPS_EN;
2305	else
2306	rec->flags &= ~FTRACE_FL_CALL_OPS_EN;
2307	} else {
2308	/*
2309	* Can only call directly if there's
2310	* only one set of associated ops.
2311	*/
2312	rec->flags &= ~FTRACE_FL_CALL_OPS_EN;
2313	}
2314	}
2315	}
2316
2317	/*
2318	* If this record is being updated from a nop, then
2319	* return UPDATE_MAKE_CALL.
2320	* Otherwise,
2321	* return UPDATE_MODIFY_CALL to tell the caller to convert
2322	* from the save regs, to a non-save regs function or
2323	* vice versa, or from a trampoline call.
2324	*/
2325	if (flag & FTRACE_FL_ENABLED) {
2326	ftrace_bug_type = FTRACE_BUG_CALL;
2327	return FTRACE_UPDATE_MAKE_CALL;
2328	}
2329
2330	ftrace_bug_type = FTRACE_BUG_UPDATE;
2331	return FTRACE_UPDATE_MODIFY_CALL;
2332	}
2333
2334	if (update) {
2335	/* If there's no more users, clear all flags */
2336	if (!ftrace_rec_count(rec))
2337	rec->flags &= FTRACE_NOCLEAR_FLAGS;
2338	else
2339	/*
2340	* Just disable the record, but keep the ops TRAMP
2341	* and REGS states. The _EN flags must be disabled though.
2342	*/
2343	rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2344	FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN |
2345	FTRACE_FL_CALL_OPS_EN);
2346	}
2347
2348	ftrace_bug_type = FTRACE_BUG_NOP;
2349	return FTRACE_UPDATE_MAKE_NOP;
2350	}
2351
2352	/**
2353	* ftrace_update_record - set a record that now is tracing or not
2354	* @rec: the record to update
2355	* @enable: set to true if the record is tracing, false to force disable
2356	*
2357	* The records that represent all functions that can be traced need
2358	* to be updated when tracing has been enabled.
2359	*/
2360	int ftrace_update_record(struct dyn_ftrace *rec, bool enable)
2361	{
2362	return ftrace_check_record(rec, enable, update: true);
2363	}
2364
2365	/**
2366	* ftrace_test_record - check if the record has been enabled or not
2367	* @rec: the record to test
2368	* @enable: set to true to check if enabled, false if it is disabled
2369	*
2370	* The arch code may need to test if a record is already set to
2371	* tracing to determine how to modify the function code that it
2372	* represents.
2373	*/
2374	int ftrace_test_record(struct dyn_ftrace *rec, bool enable)
2375	{
2376	return ftrace_check_record(rec, enable, update: false);
2377	}
2378
2379	static struct ftrace_ops *
2380	ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2381	{
2382	struct ftrace_ops *op;
2383	unsigned long ip = rec->ip;
2384
2385	do_for_each_ftrace_op(op, ftrace_ops_list) {
2386
2387	if (!op->trampoline)
2388	continue;
2389
2390	if (hash_contains_ip(ip, hash: op->func_hash))
2391	return op;
2392	} while_for_each_ftrace_op(op);
2393
2394	return NULL;
2395	}
2396
2397	static struct ftrace_ops *
2398	ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude)
2399	{
2400	struct ftrace_ops *op;
2401	unsigned long ip = rec->ip;
2402
2403	do_for_each_ftrace_op(op, ftrace_ops_list) {
2404
2405	if (op == op_exclude || !op->trampoline)
2406	continue;
2407
2408	if (hash_contains_ip(ip, hash: op->func_hash))
2409	return op;
2410	} while_for_each_ftrace_op(op);
2411
2412	return NULL;
2413	}
2414
2415	static struct ftrace_ops *
2416	ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2417	struct ftrace_ops *op)
2418	{
2419	unsigned long ip = rec->ip;
2420
2421	while_for_each_ftrace_op(op) {
2422
2423	if (!op->trampoline)
2424	continue;
2425
2426	if (hash_contains_ip(ip, hash: op->func_hash))
2427	return op;
2428	}
2429
2430	return NULL;
2431	}
2432
2433	static struct ftrace_ops *
2434	ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2435	{
2436	struct ftrace_ops *op;
2437	unsigned long ip = rec->ip;
2438
2439	/*
2440	* Need to check removed ops first.
2441	* If they are being removed, and this rec has a tramp,
2442	* and this rec is in the ops list, then it would be the
2443	* one with the tramp.
2444	*/
2445	if (removed_ops) {
2446	if (hash_contains_ip(ip, hash: &removed_ops->old_hash))
2447	return removed_ops;
2448	}
2449
2450	/*
2451	* Need to find the current trampoline for a rec.
2452	* Now, a trampoline is only attached to a rec if there
2453	* was a single 'ops' attached to it. But this can be called
2454	* when we are adding another op to the rec or removing the
2455	* current one. Thus, if the op is being added, we can
2456	* ignore it because it hasn't attached itself to the rec
2457	* yet.
2458	*
2459	* If an ops is being modified (hooking to different functions)
2460	* then we don't care about the new functions that are being
2461	* added, just the old ones (that are probably being removed).
2462	*
2463	* If we are adding an ops to a function that already is using
2464	* a trampoline, it needs to be removed (trampolines are only
2465	* for single ops connected), then an ops that is not being
2466	* modified also needs to be checked.
2467	*/
2468	do_for_each_ftrace_op(op, ftrace_ops_list) {
2469
2470	if (!op->trampoline)
2471	continue;
2472
2473	/*
2474	* If the ops is being added, it hasn't gotten to
2475	* the point to be removed from this tree yet.
2476	*/
2477	if (op->flags & FTRACE_OPS_FL_ADDING)
2478	continue;
2479
2480
2481	/*
2482	* If the ops is being modified and is in the old
2483	* hash, then it is probably being removed from this
2484	* function.
2485	*/
2486	if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2487	hash_contains_ip(ip, hash: &op->old_hash))
2488	return op;
2489	/*
2490	* If the ops is not being added or modified, and it's
2491	* in its normal filter hash, then this must be the one
2492	* we want!
2493	*/
2494	if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2495	hash_contains_ip(ip, hash: op->func_hash))
2496	return op;
2497
2498	} while_for_each_ftrace_op(op);
2499
2500	return NULL;
2501	}
2502
2503	static struct ftrace_ops *
2504	ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2505	{
2506	struct ftrace_ops *op;
2507	unsigned long ip = rec->ip;
2508
2509	do_for_each_ftrace_op(op, ftrace_ops_list) {
2510	/* pass rec in as regs to have non-NULL val */
2511	if (hash_contains_ip(ip, hash: op->func_hash))
2512	return op;
2513	} while_for_each_ftrace_op(op);
2514
2515	return NULL;
2516	}
2517
2518	struct ftrace_ops *
2519	ftrace_find_unique_ops(struct dyn_ftrace *rec)
2520	{
2521	struct ftrace_ops *op, *found = NULL;
2522	unsigned long ip = rec->ip;
2523
2524	do_for_each_ftrace_op(op, ftrace_ops_list) {
2525
2526	if (hash_contains_ip(ip, hash: op->func_hash)) {
2527	if (found)
2528	return NULL;
2529	found = op;
2530	}
2531
2532	} while_for_each_ftrace_op(op);
2533
2534	return found;
2535	}
2536
2537	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
2538	/* Protected by rcu_tasks for reading, and direct_mutex for writing */
2539	static struct ftrace_hash *direct_functions = EMPTY_HASH;
2540	static DEFINE_MUTEX(direct_mutex);
2541	int ftrace_direct_func_count;
2542
2543	/*
2544	* Search the direct_functions hash to see if the given instruction pointer
2545	* has a direct caller attached to it.
2546	*/
2547	unsigned long ftrace_find_rec_direct(unsigned long ip)
2548	{
2549	struct ftrace_func_entry *entry;
2550
2551	entry = __ftrace_lookup_ip(hash: direct_functions, ip);
2552	if (!entry)
2553	return 0;
2554
2555	return entry->direct;
2556	}
2557
2558	static struct ftrace_func_entry*
2559	ftrace_add_rec_direct(unsigned long ip, unsigned long addr,
2560	struct ftrace_hash **free_hash)
2561	{
2562	struct ftrace_func_entry *entry;
2563
2564	if (ftrace_hash_empty(hash: direct_functions) ||
2565	direct_functions->count > 2 * (1 << direct_functions->size_bits)) {
2566	struct ftrace_hash *new_hash;
2567	int size = ftrace_hash_empty(hash: direct_functions) ? 0 :
2568	direct_functions->count + 1;
2569
2570	if (size < 32)
2571	size = 32;
2572
2573	new_hash = dup_hash(src: direct_functions, size);
2574	if (!new_hash)
2575	return NULL;
2576
2577	*free_hash = direct_functions;
2578	direct_functions = new_hash;
2579	}
2580
2581	entry = kmalloc(size: sizeof(*entry), GFP_KERNEL);
2582	if (!entry)
2583	return NULL;
2584
2585	entry->ip = ip;
2586	entry->direct = addr;
2587	__add_hash_entry(hash: direct_functions, entry);
2588	return entry;
2589	}
2590
2591	static void call_direct_funcs(unsigned long ip, unsigned long pip,
2592	struct ftrace_ops *ops, struct ftrace_regs *fregs)
2593	{
2594	unsigned long addr = READ_ONCE(ops->direct_call);
2595
2596	if (!addr)
2597	return;
2598
2599	arch_ftrace_set_direct_caller(fregs, addr);
2600	}
2601	#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
2602
2603	/**
2604	* ftrace_get_addr_new - Get the call address to set to
2605	* @rec: The ftrace record descriptor
2606	*
2607	* If the record has the FTRACE_FL_REGS set, that means that it
2608	* wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2609	* is not set, then it wants to convert to the normal callback.
2610	*
2611	* Returns the address of the trampoline to set to
2612	*/
2613	unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2614	{
2615	struct ftrace_ops *ops;
2616	unsigned long addr;
2617
2618	if ((rec->flags & FTRACE_FL_DIRECT) &&
2619	(ftrace_rec_count(rec) == 1)) {
2620	addr = ftrace_find_rec_direct(ip: rec->ip);
2621	if (addr)
2622	return addr;
2623	WARN_ON_ONCE(1);
2624	}
2625
2626	/* Trampolines take precedence over regs */
2627	if (rec->flags & FTRACE_FL_TRAMP) {
2628	ops = ftrace_find_tramp_ops_new(rec);
2629	if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2630	pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2631	(void *)rec->ip, (void *)rec->ip, rec->flags);
2632	/* Ftrace is shutting down, return anything */
2633	return (unsigned long)FTRACE_ADDR;
2634	}
2635	return ops->trampoline;
2636	}
2637
2638	if (rec->flags & FTRACE_FL_REGS)
2639	return (unsigned long)FTRACE_REGS_ADDR;
2640	else
2641	return (unsigned long)FTRACE_ADDR;
2642	}
2643
2644	/**
2645	* ftrace_get_addr_curr - Get the call address that is already there
2646	* @rec: The ftrace record descriptor
2647	*
2648	* The FTRACE_FL_REGS_EN is set when the record already points to
2649	* a function that saves all the regs. Basically the '_EN' version
2650	* represents the current state of the function.
2651	*
2652	* Returns the address of the trampoline that is currently being called
2653	*/
2654	unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2655	{
2656	struct ftrace_ops *ops;
2657	unsigned long addr;
2658
2659	/* Direct calls take precedence over trampolines */
2660	if (rec->flags & FTRACE_FL_DIRECT_EN) {
2661	addr = ftrace_find_rec_direct(ip: rec->ip);
2662	if (addr)
2663	return addr;
2664	WARN_ON_ONCE(1);
2665	}
2666
2667	/* Trampolines take precedence over regs */
2668	if (rec->flags & FTRACE_FL_TRAMP_EN) {
2669	ops = ftrace_find_tramp_ops_curr(rec);
2670	if (FTRACE_WARN_ON(!ops)) {
2671	pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2672	(void *)rec->ip, (void *)rec->ip);
2673	/* Ftrace is shutting down, return anything */
2674	return (unsigned long)FTRACE_ADDR;
2675	}
2676	return ops->trampoline;
2677	}
2678
2679	if (rec->flags & FTRACE_FL_REGS_EN)
2680	return (unsigned long)FTRACE_REGS_ADDR;
2681	else
2682	return (unsigned long)FTRACE_ADDR;
2683	}
2684
2685	static int
2686	__ftrace_replace_code(struct dyn_ftrace *rec, bool enable)
2687	{
2688	unsigned long ftrace_old_addr;
2689	unsigned long ftrace_addr;
2690	int ret;
2691
2692	ftrace_addr = ftrace_get_addr_new(rec);
2693
2694	/* This needs to be done before we call ftrace_update_record */
2695	ftrace_old_addr = ftrace_get_addr_curr(rec);
2696
2697	ret = ftrace_update_record(rec, enable);
2698
2699	ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2700
2701	switch (ret) {
2702	case FTRACE_UPDATE_IGNORE:
2703	return 0;
2704
2705	case FTRACE_UPDATE_MAKE_CALL:
2706	ftrace_bug_type = FTRACE_BUG_CALL;
2707	return ftrace_make_call(rec, addr: ftrace_addr);
2708
2709	case FTRACE_UPDATE_MAKE_NOP:
2710	ftrace_bug_type = FTRACE_BUG_NOP;
2711	return ftrace_make_nop(NULL, rec, addr: ftrace_old_addr);
2712
2713	case FTRACE_UPDATE_MODIFY_CALL:
2714	ftrace_bug_type = FTRACE_BUG_UPDATE;
2715	return ftrace_modify_call(rec, old_addr: ftrace_old_addr, addr: ftrace_addr);
2716	}
2717
2718	return -1; /* unknown ftrace bug */
2719	}
2720
2721	void __weak ftrace_replace_code(int mod_flags)
2722	{
2723	struct dyn_ftrace *rec;
2724	struct ftrace_page *pg;
2725	bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
2726	int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
2727	int failed;
2728
2729	if (unlikely(ftrace_disabled))
2730	return;
2731
2732	do_for_each_ftrace_rec(pg, rec) {
2733
2734	if (skip_record(rec))
2735	continue;
2736
2737	failed = __ftrace_replace_code(rec, enable);
2738	if (failed) {
2739	ftrace_bug(failed, rec);
2740	/* Stop processing */
2741	return;
2742	}
2743	if (schedulable)
2744	cond_resched();
2745	} while_for_each_ftrace_rec();
2746	}
2747
2748	struct ftrace_rec_iter {
2749	struct ftrace_page *pg;
2750	int index;
2751	};
2752
2753	/**
2754	* ftrace_rec_iter_start - start up iterating over traced functions
2755	*
2756	* Returns an iterator handle that is used to iterate over all
2757	* the records that represent address locations where functions
2758	* are traced.
2759	*
2760	* May return NULL if no records are available.
2761	*/
2762	struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2763	{
2764	/*
2765	* We only use a single iterator.
2766	* Protected by the ftrace_lock mutex.
2767	*/
2768	static struct ftrace_rec_iter ftrace_rec_iter;
2769	struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2770
2771	iter->pg = ftrace_pages_start;
2772	iter->index = 0;
2773
2774	/* Could have empty pages */
2775	while (iter->pg && !iter->pg->index)
2776	iter->pg = iter->pg->next;
2777
2778	if (!iter->pg)
2779	return NULL;
2780
2781	return iter;
2782	}
2783
2784	/**
2785	* ftrace_rec_iter_next - get the next record to process.
2786	* @iter: The handle to the iterator.
2787	*
2788	* Returns the next iterator after the given iterator @iter.
2789	*/
2790	struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2791	{
2792	iter->index++;
2793
2794	if (iter->index >= iter->pg->index) {
2795	iter->pg = iter->pg->next;
2796	iter->index = 0;
2797
2798	/* Could have empty pages */
2799	while (iter->pg && !iter->pg->index)
2800	iter->pg = iter->pg->next;
2801	}
2802
2803	if (!iter->pg)
2804	return NULL;
2805
2806	return iter;
2807	}
2808
2809	/**
2810	* ftrace_rec_iter_record - get the record at the iterator location
2811	* @iter: The current iterator location
2812	*
2813	* Returns the record that the current @iter is at.
2814	*/
2815	struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2816	{
2817	return &iter->pg->records[iter->index];
2818	}
2819
2820	static int
2821	ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec)
2822	{
2823	int ret;
2824
2825	if (unlikely(ftrace_disabled))
2826	return 0;
2827
2828	ret = ftrace_init_nop(mod, rec);
2829	if (ret) {
2830	ftrace_bug_type = FTRACE_BUG_INIT;
2831	ftrace_bug(failed: ret, rec);
2832	return 0;
2833	}
2834	return 1;
2835	}
2836
2837	/*
2838	* archs can override this function if they must do something
2839	* before the modifying code is performed.
2840	*/
2841	void __weak ftrace_arch_code_modify_prepare(void)
2842	{
2843	}
2844
2845	/*
2846	* archs can override this function if they must do something
2847	* after the modifying code is performed.
2848	*/
2849	void __weak ftrace_arch_code_modify_post_process(void)
2850	{
2851	}
2852
2853	static int update_ftrace_func(ftrace_func_t func)
2854	{
2855	static ftrace_func_t save_func;
2856
2857	/* Avoid updating if it hasn't changed */
2858	if (func == save_func)
2859	return 0;
2860
2861	save_func = func;
2862
2863	return ftrace_update_ftrace_func(func);
2864	}
2865
2866	void ftrace_modify_all_code(int command)
2867	{
2868	int update = command & FTRACE_UPDATE_TRACE_FUNC;
2869	int mod_flags = 0;
2870	int err = 0;
2871
2872	if (command & FTRACE_MAY_SLEEP)
2873	mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
2874
2875	/*
2876	* If the ftrace_caller calls a ftrace_ops func directly,
2877	* we need to make sure that it only traces functions it
2878	* expects to trace. When doing the switch of functions,
2879	* we need to update to the ftrace_ops_list_func first
2880	* before the transition between old and new calls are set,
2881	* as the ftrace_ops_list_func will check the ops hashes
2882	* to make sure the ops are having the right functions
2883	* traced.
2884	*/
2885	if (update) {
2886	err = update_ftrace_func(func: ftrace_ops_list_func);
2887	if (FTRACE_WARN_ON(err))
2888	return;
2889	}
2890
2891	if (command & FTRACE_UPDATE_CALLS)
2892	ftrace_replace_code(mod_flags: mod_flags | FTRACE_MODIFY_ENABLE_FL);
2893	else if (command & FTRACE_DISABLE_CALLS)
2894	ftrace_replace_code(mod_flags);
2895
2896	if (update && ftrace_trace_function != ftrace_ops_list_func) {
2897	function_trace_op = set_function_trace_op;
2898	smp_wmb();
2899	/* If irqs are disabled, we are in stop machine */
2900	if (!irqs_disabled())
2901	smp_call_function(func: ftrace_sync_ipi, NULL, wait: 1);
2902	err = update_ftrace_func(func: ftrace_trace_function);
2903	if (FTRACE_WARN_ON(err))
2904	return;
2905	}
2906
2907	if (command & FTRACE_START_FUNC_RET)
2908	err = ftrace_enable_ftrace_graph_caller();
2909	else if (command & FTRACE_STOP_FUNC_RET)
2910	err = ftrace_disable_ftrace_graph_caller();
2911	FTRACE_WARN_ON(err);
2912	}
2913
2914	static int __ftrace_modify_code(void *data)
2915	{
2916	int *command = data;
2917
2918	ftrace_modify_all_code(command: *command);
2919
2920	return 0;
2921	}
2922
2923	/**
2924	* ftrace_run_stop_machine - go back to the stop machine method
2925	* @command: The command to tell ftrace what to do
2926	*
2927	* If an arch needs to fall back to the stop machine method, the
2928	* it can call this function.
2929	*/
2930	void ftrace_run_stop_machine(int command)
2931	{
2932	stop_machine(fn: __ftrace_modify_code, data: &command, NULL);
2933	}
2934
2935	/**
2936	* arch_ftrace_update_code - modify the code to trace or not trace
2937	* @command: The command that needs to be done
2938	*
2939	* Archs can override this function if it does not need to
2940	* run stop_machine() to modify code.
2941	*/
2942	void __weak arch_ftrace_update_code(int command)
2943	{
2944	ftrace_run_stop_machine(command);
2945	}
2946
2947	static void ftrace_run_update_code(int command)
2948	{
2949	ftrace_arch_code_modify_prepare();
2950
2951	/*
2952	* By default we use stop_machine() to modify the code.
2953	* But archs can do what ever they want as long as it
2954	* is safe. The stop_machine() is the safest, but also
2955	* produces the most overhead.
2956	*/
2957	arch_ftrace_update_code(command);
2958
2959	ftrace_arch_code_modify_post_process();
2960	}
2961
2962	static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2963	struct ftrace_ops_hash *old_hash)
2964	{
2965	ops->flags |= FTRACE_OPS_FL_MODIFYING;
2966	ops->old_hash.filter_hash = old_hash->filter_hash;
2967	ops->old_hash.notrace_hash = old_hash->notrace_hash;
2968	ftrace_run_update_code(command);
2969	ops->old_hash.filter_hash = NULL;
2970	ops->old_hash.notrace_hash = NULL;
2971	ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2972	}
2973
2974	static ftrace_func_t saved_ftrace_func;
2975	static int ftrace_start_up;
2976
2977	void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2978	{
2979	}
2980
2981	/* List of trace_ops that have allocated trampolines */
2982	static LIST_HEAD(ftrace_ops_trampoline_list);
2983
2984	static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops)
2985	{
2986	lockdep_assert_held(&ftrace_lock);
2987	list_add_rcu(new: &ops->list, head: &ftrace_ops_trampoline_list);
2988	}
2989
2990	static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops)
2991	{
2992	lockdep_assert_held(&ftrace_lock);
2993	list_del_rcu(entry: &ops->list);
2994	synchronize_rcu();
2995	}
2996
2997	/*
2998	* "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols
2999	* for pages allocated for ftrace purposes, even though "__builtin__ftrace" is
3000	* not a module.
3001	*/
3002	#define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace"
3003	#define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline"
3004
3005	static void ftrace_trampoline_free(struct ftrace_ops *ops)
3006	{
3007	if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) &&
3008	ops->trampoline) {
3009	/*
3010	* Record the text poke event before the ksymbol unregister
3011	* event.
3012	*/
3013	perf_event_text_poke(addr: (void *)ops->trampoline,
3014	old_bytes: (void *)ops->trampoline,
3015	old_len: ops->trampoline_size, NULL, new_len: 0);
3016	perf_event_ksymbol(ksym_type: PERF_RECORD_KSYMBOL_TYPE_OOL,
3017	addr: ops->trampoline, len: ops->trampoline_size,
3018	unregister: true, FTRACE_TRAMPOLINE_SYM);
3019	/* Remove from kallsyms after the perf events */
3020	ftrace_remove_trampoline_from_kallsyms(ops);
3021	}
3022
3023	arch_ftrace_trampoline_free(ops);
3024	}
3025
3026	static void ftrace_startup_enable(int command)
3027	{
3028	if (saved_ftrace_func != ftrace_trace_function) {
3029	saved_ftrace_func = ftrace_trace_function;
3030	command |= FTRACE_UPDATE_TRACE_FUNC;
3031	}
3032
3033	if (!command || !ftrace_enabled)
3034	return;
3035
3036	ftrace_run_update_code(command);
3037	}
3038
3039	static void ftrace_startup_all(int command)
3040	{
3041	update_all_ops = true;
3042	ftrace_startup_enable(command);
3043	update_all_ops = false;
3044	}
3045
3046	int ftrace_startup(struct ftrace_ops *ops, int command)
3047	{
3048	int ret;
3049
3050	if (unlikely(ftrace_disabled))
3051	return -ENODEV;
3052
3053	ret = __register_ftrace_function(ops);
3054	if (ret)
3055	return ret;
3056
3057	ftrace_start_up++;
3058
3059	/*
3060	* Note that ftrace probes uses this to start up
3061	* and modify functions it will probe. But we still
3062	* set the ADDING flag for modification, as probes
3063	* do not have trampolines. If they add them in the
3064	* future, then the probes will need to distinguish
3065	* between adding and updating probes.
3066	*/
3067	ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
3068
3069	ret = ftrace_hash_ipmodify_enable(ops);
3070	if (ret < 0) {
3071	/* Rollback registration process */
3072	__unregister_ftrace_function(ops);
3073	ftrace_start_up--;
3074	ops->flags &= ~FTRACE_OPS_FL_ENABLED;
3075	if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
3076	ftrace_trampoline_free(ops);
3077	return ret;
3078	}
3079
3080	if (ftrace_hash_rec_enable(ops, filter_hash: 1))
3081	command |= FTRACE_UPDATE_CALLS;
3082
3083	ftrace_startup_enable(command);
3084
3085	/*
3086	* If ftrace is in an undefined state, we just remove ops from list
3087	* to prevent the NULL pointer, instead of totally rolling it back and
3088	* free trampoline, because those actions could cause further damage.
3089	*/
3090	if (unlikely(ftrace_disabled)) {
3091	__unregister_ftrace_function(ops);
3092	return -ENODEV;
3093	}
3094
3095	ops->flags &= ~FTRACE_OPS_FL_ADDING;
3096
3097	return 0;
3098	}
3099
3100	int ftrace_shutdown(struct ftrace_ops *ops, int command)
3101	{
3102	int ret;
3103
3104	if (unlikely(ftrace_disabled))
3105	return -ENODEV;
3106
3107	ret = __unregister_ftrace_function(ops);
3108	if (ret)
3109	return ret;
3110
3111	ftrace_start_up--;
3112	/*
3113	* Just warn in case of unbalance, no need to kill ftrace, it's not
3114	* critical but the ftrace_call callers may be never nopped again after
3115	* further ftrace uses.
3116	*/
3117	WARN_ON_ONCE(ftrace_start_up < 0);
3118
3119	/* Disabling ipmodify never fails */
3120	ftrace_hash_ipmodify_disable(ops);
3121
3122	if (ftrace_hash_rec_disable(ops, filter_hash: 1))
3123	command |= FTRACE_UPDATE_CALLS;
3124
3125	ops->flags &= ~FTRACE_OPS_FL_ENABLED;
3126
3127	if (saved_ftrace_func != ftrace_trace_function) {
3128	saved_ftrace_func = ftrace_trace_function;
3129	command |= FTRACE_UPDATE_TRACE_FUNC;
3130	}
3131
3132	if (!command || !ftrace_enabled)
3133	goto out;
3134
3135	/*
3136	* If the ops uses a trampoline, then it needs to be
3137	* tested first on update.
3138	*/
3139	ops->flags |= FTRACE_OPS_FL_REMOVING;
3140	removed_ops = ops;
3141
3142	/* The trampoline logic checks the old hashes */
3143	ops->old_hash.filter_hash = ops->func_hash->filter_hash;
3144	ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
3145
3146	ftrace_run_update_code(command);
3147
3148	/*
3149	* If there's no more ops registered with ftrace, run a
3150	* sanity check to make sure all rec flags are cleared.
3151	*/
3152	if (rcu_dereference_protected(ftrace_ops_list,
3153	lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
3154	struct ftrace_page *pg;
3155	struct dyn_ftrace *rec;
3156
3157	do_for_each_ftrace_rec(pg, rec) {
3158	if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_NOCLEAR_FLAGS))
3159	pr_warn(" %pS flags:%lx\n",
3160	(void *)rec->ip, rec->flags);
3161	} while_for_each_ftrace_rec();
3162	}
3163
3164	ops->old_hash.filter_hash = NULL;
3165	ops->old_hash.notrace_hash = NULL;
3166
3167	removed_ops = NULL;
3168	ops->flags &= ~FTRACE_OPS_FL_REMOVING;
3169
3170	out:
3171	/*
3172	* Dynamic ops may be freed, we must make sure that all
3173	* callers are done before leaving this function.
3174	*/
3175	if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
3176	/*
3177	* We need to do a hard force of sched synchronization.
3178	* This is because we use preempt_disable() to do RCU, but
3179	* the function tracers can be called where RCU is not watching
3180	* (like before user_exit()). We can not rely on the RCU
3181	* infrastructure to do the synchronization, thus we must do it
3182	* ourselves.
3183	*/
3184	synchronize_rcu_tasks_rude();
3185
3186	/*
3187	* When the kernel is preemptive, tasks can be preempted
3188	* while on a ftrace trampoline. Just scheduling a task on
3189	* a CPU is not good enough to flush them. Calling
3190	* synchronize_rcu_tasks() will wait for those tasks to
3191	* execute and either schedule voluntarily or enter user space.
3192	*/
3193	if (IS_ENABLED(CONFIG_PREEMPTION))
3194	synchronize_rcu_tasks();
3195
3196	ftrace_trampoline_free(ops);
3197	}
3198
3199	return 0;
3200	}
3201
3202	static u64 ftrace_update_time;
3203	unsigned long ftrace_update_tot_cnt;
3204	unsigned long ftrace_number_of_pages;
3205	unsigned long ftrace_number_of_groups;
3206
3207	static inline int ops_traces_mod(struct ftrace_ops *ops)
3208	{
3209	/*
3210	* Filter_hash being empty will default to trace module.
3211	* But notrace hash requires a test of individual module functions.
3212	*/
3213	return ftrace_hash_empty(hash: ops->func_hash->filter_hash) &&
3214	ftrace_hash_empty(hash: ops->func_hash->notrace_hash);
3215	}
3216
3217	static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
3218	{
3219	bool init_nop = ftrace_need_init_nop();
3220	struct ftrace_page *pg;
3221	struct dyn_ftrace *p;
3222	u64 start, stop;
3223	unsigned long update_cnt = 0;
3224	unsigned long rec_flags = 0;
3225	int i;
3226
3227	start = ftrace_now(raw_smp_processor_id());
3228
3229	/*
3230	* When a module is loaded, this function is called to convert
3231	* the calls to mcount in its text to nops, and also to create
3232	* an entry in the ftrace data. Now, if ftrace is activated
3233	* after this call, but before the module sets its text to
3234	* read-only, the modification of enabling ftrace can fail if
3235	* the read-only is done while ftrace is converting the calls.
3236	* To prevent this, the module's records are set as disabled
3237	* and will be enabled after the call to set the module's text
3238	* to read-only.
3239	*/
3240	if (mod)
3241	rec_flags |= FTRACE_FL_DISABLED;
3242
3243	for (pg = new_pgs; pg; pg = pg->next) {
3244
3245	for (i = 0; i < pg->index; i++) {
3246
3247	/* If something went wrong, bail without enabling anything */
3248	if (unlikely(ftrace_disabled))
3249	return -1;
3250
3251	p = &pg->records[i];
3252	p->flags = rec_flags;
3253
3254	/*
3255	* Do the initial record conversion from mcount jump
3256	* to the NOP instructions.
3257	*/
3258	if (init_nop && !ftrace_nop_initialize(mod, rec: p))
3259	break;
3260
3261	update_cnt++;
3262	}
3263	}
3264
3265	stop = ftrace_now(raw_smp_processor_id());
3266	ftrace_update_time = stop - start;
3267	ftrace_update_tot_cnt += update_cnt;
3268
3269	return 0;
3270	}
3271
3272	static int ftrace_allocate_records(struct ftrace_page *pg, int count)
3273	{
3274	int order;
3275	int pages;
3276	int cnt;
3277
3278	if (WARN_ON(!count))
3279	return -EINVAL;
3280
3281	/* We want to fill as much as possible, with no empty pages */
3282	pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE);
3283	order = fls(x: pages) - 1;
3284
3285	again:
3286	pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
3287
3288	if (!pg->records) {
3289	/* if we can't allocate this size, try something smaller */
3290	if (!order)
3291	return -ENOMEM;
3292	order--;
3293	goto again;
3294	}
3295
3296	ftrace_number_of_pages += 1 << order;
3297	ftrace_number_of_groups++;
3298
3299	cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3300	pg->order = order;
3301
3302	if (cnt > count)
3303	cnt = count;
3304
3305	return cnt;
3306	}
3307
3308	static void ftrace_free_pages(struct ftrace_page *pages)
3309	{
3310	struct ftrace_page *pg = pages;
3311
3312	while (pg) {
3313	if (pg->records) {
3314	free_pages(addr: (unsigned long)pg->records, order: pg->order);
3315	ftrace_number_of_pages -= 1 << pg->order;
3316	}
3317	pages = pg->next;
3318	kfree(objp: pg);
3319	pg = pages;
3320	ftrace_number_of_groups--;
3321	}
3322	}
3323
3324	static struct ftrace_page *
3325	ftrace_allocate_pages(unsigned long num_to_init)
3326	{
3327	struct ftrace_page *start_pg;
3328	struct ftrace_page *pg;
3329	int cnt;
3330
3331	if (!num_to_init)
3332	return NULL;
3333
3334	start_pg = pg = kzalloc(size: sizeof(*pg), GFP_KERNEL);
3335	if (!pg)
3336	return NULL;
3337
3338	/*
3339	* Try to allocate as much as possible in one continues
3340	* location that fills in all of the space. We want to
3341	* waste as little space as possible.
3342	*/
3343	for (;;) {
3344	cnt = ftrace_allocate_records(pg, count: num_to_init);
3345	if (cnt < 0)
3346	goto free_pages;
3347
3348	num_to_init -= cnt;
3349	if (!num_to_init)
3350	break;
3351
3352	pg->next = kzalloc(size: sizeof(*pg), GFP_KERNEL);
3353	if (!pg->next)
3354	goto free_pages;
3355
3356	pg = pg->next;
3357	}
3358
3359	return start_pg;
3360
3361	free_pages:
3362	ftrace_free_pages(pages: start_pg);
3363	pr_info("ftrace: FAILED to allocate memory for functions\n");
3364	return NULL;
3365	}
3366
3367	#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3368
3369	struct ftrace_iterator {
3370	loff_t pos;
3371	loff_t func_pos;
3372	loff_t mod_pos;
3373	struct ftrace_page *pg;
3374	struct dyn_ftrace *func;
3375	struct ftrace_func_probe *probe;
3376	struct ftrace_func_entry *probe_entry;
3377	struct trace_parser parser;
3378	struct ftrace_hash *hash;
3379	struct ftrace_ops *ops;
3380	struct trace_array *tr;
3381	struct list_head *mod_list;
3382	int pidx;
3383	int idx;
3384	unsigned flags;
3385	};
3386
3387	static void *
3388	t_probe_next(struct seq_file *m, loff_t *pos)
3389	{
3390	struct ftrace_iterator *iter = m->private;
3391	struct trace_array *tr = iter->ops->private;
3392	struct list_head *func_probes;
3393	struct ftrace_hash *hash;
3394	struct list_head *next;
3395	struct hlist_node *hnd = NULL;
3396	struct hlist_head *hhd;
3397	int size;
3398
3399	(*pos)++;
3400	iter->pos = *pos;
3401
3402	if (!tr)
3403	return NULL;
3404
3405	func_probes = &tr->func_probes;
3406	if (list_empty(head: func_probes))
3407	return NULL;
3408
3409	if (!iter->probe) {
3410	next = func_probes->next;
3411	iter->probe = list_entry(next, struct ftrace_func_probe, list);
3412	}
3413
3414	if (iter->probe_entry)
3415	hnd = &iter->probe_entry->hlist;
3416
3417	hash = iter->probe->ops.func_hash->filter_hash;
3418
3419	/*
3420	* A probe being registered may temporarily have an empty hash
3421	* and it's at the end of the func_probes list.
3422	*/
3423	if (!hash || hash == EMPTY_HASH)
3424	return NULL;
3425
3426	size = 1 << hash->size_bits;
3427
3428	retry:
3429	if (iter->pidx >= size) {
3430	if (iter->probe->list.next == func_probes)
3431	return NULL;
3432	next = iter->probe->list.next;
3433	iter->probe = list_entry(next, struct ftrace_func_probe, list);
3434	hash = iter->probe->ops.func_hash->filter_hash;
3435	size = 1 << hash->size_bits;
3436	iter->pidx = 0;
3437	}
3438
3439	hhd = &hash->buckets[iter->pidx];
3440
3441	if (hlist_empty(h: hhd)) {
3442	iter->pidx++;
3443	hnd = NULL;
3444	goto retry;
3445	}
3446
3447	if (!hnd)
3448	hnd = hhd->first;
3449	else {
3450	hnd = hnd->next;
3451	if (!hnd) {
3452	iter->pidx++;
3453	goto retry;
3454	}
3455	}
3456
3457	if (WARN_ON_ONCE(!hnd))
3458	return NULL;
3459
3460	iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3461
3462	return iter;
3463	}
3464
3465	static void *t_probe_start(struct seq_file *m, loff_t *pos)
3466	{
3467	struct ftrace_iterator *iter = m->private;
3468	void *p = NULL;
3469	loff_t l;
3470
3471	if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3472	return NULL;
3473
3474	if (iter->mod_pos > *pos)
3475	return NULL;
3476
3477	iter->probe = NULL;
3478	iter->probe_entry = NULL;
3479	iter->pidx = 0;
3480	for (l = 0; l <= (*pos - iter->mod_pos); ) {
3481	p = t_probe_next(m, pos: &l);
3482	if (!p)
3483	break;
3484	}
3485	if (!p)
3486	return NULL;
3487
3488	/* Only set this if we have an item */
3489	iter->flags |= FTRACE_ITER_PROBE;
3490
3491	return iter;
3492	}
3493
3494	static int
3495	t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3496	{
3497	struct ftrace_func_entry *probe_entry;
3498	struct ftrace_probe_ops *probe_ops;
3499	struct ftrace_func_probe *probe;
3500
3501	probe = iter->probe;
3502	probe_entry = iter->probe_entry;
3503
3504	if (WARN_ON_ONCE(!probe || !probe_entry))
3505	return -EIO;
3506
3507	probe_ops = probe->probe_ops;
3508
3509	if (probe_ops->print)
3510	return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3511
3512	seq_printf(m, fmt: "%ps:%ps\n", (void *)probe_entry->ip,
3513	(void *)probe_ops->func);
3514
3515	return 0;
3516	}
3517
3518	static void *
3519	t_mod_next(struct seq_file *m, loff_t *pos)
3520	{
3521	struct ftrace_iterator *iter = m->private;
3522	struct trace_array *tr = iter->tr;
3523
3524	(*pos)++;
3525	iter->pos = *pos;
3526
3527	iter->mod_list = iter->mod_list->next;
3528
3529	if (iter->mod_list == &tr->mod_trace ||
3530	iter->mod_list == &tr->mod_notrace) {
3531	iter->flags &= ~FTRACE_ITER_MOD;
3532	return NULL;
3533	}
3534
3535	iter->mod_pos = *pos;
3536
3537	return iter;
3538	}
3539
3540	static void *t_mod_start(struct seq_file *m, loff_t *pos)
3541	{
3542	struct ftrace_iterator *iter = m->private;
3543	void *p = NULL;
3544	loff_t l;
3545
3546	if (iter->func_pos > *pos)
3547	return NULL;
3548
3549	iter->mod_pos = iter->func_pos;
3550
3551	/* probes are only available if tr is set */
3552	if (!iter->tr)
3553	return NULL;
3554
3555	for (l = 0; l <= (*pos - iter->func_pos); ) {
3556	p = t_mod_next(m, pos: &l);
3557	if (!p)
3558	break;
3559	}
3560	if (!p) {
3561	iter->flags &= ~FTRACE_ITER_MOD;
3562	return t_probe_start(m, pos);
3563	}
3564
3565	/* Only set this if we have an item */
3566	iter->flags |= FTRACE_ITER_MOD;
3567
3568	return iter;
3569	}
3570
3571	static int
3572	t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3573	{
3574	struct ftrace_mod_load *ftrace_mod;
3575	struct trace_array *tr = iter->tr;
3576
3577	if (WARN_ON_ONCE(!iter->mod_list) ||
3578	iter->mod_list == &tr->mod_trace ||
3579	iter->mod_list == &tr->mod_notrace)
3580	return -EIO;
3581
3582	ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3583
3584	if (ftrace_mod->func)
3585	seq_printf(m, fmt: "%s", ftrace_mod->func);
3586	else
3587	seq_putc(m, c: '*');
3588
3589	seq_printf(m, fmt: ":mod:%s\n", ftrace_mod->module);
3590
3591	return 0;
3592	}
3593
3594	static void *
3595	t_func_next(struct seq_file *m, loff_t *pos)
3596	{
3597	struct ftrace_iterator *iter = m->private;
3598	struct dyn_ftrace *rec = NULL;
3599
3600	(*pos)++;
3601
3602	retry:
3603	if (iter->idx >= iter->pg->index) {
3604	if (iter->pg->next) {
3605	iter->pg = iter->pg->next;
3606	iter->idx = 0;
3607	goto retry;
3608	}
3609	} else {
3610	rec = &iter->pg->records[iter->idx++];
3611	if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3612	!ftrace_lookup_ip(hash: iter->hash, ip: rec->ip)) ||
3613
3614	((iter->flags & FTRACE_ITER_ENABLED) &&
3615	!(rec->flags & FTRACE_FL_ENABLED)) ||
3616
3617	((iter->flags & FTRACE_ITER_TOUCHED) &&
3618	!(rec->flags & FTRACE_FL_TOUCHED))) {
3619
3620	rec = NULL;
3621	goto retry;
3622	}
3623	}
3624
3625	if (!rec)
3626	return NULL;
3627
3628	iter->pos = iter->func_pos = *pos;
3629	iter->func = rec;
3630
3631	return iter;
3632	}
3633
3634	static void *
3635	t_next(struct seq_file *m, void *v, loff_t *pos)
3636	{
3637	struct ftrace_iterator *iter = m->private;
3638	loff_t l = *pos; /* t_probe_start() must use original pos */
3639	void *ret;
3640
3641	if (unlikely(ftrace_disabled))
3642	return NULL;
3643
3644	if (iter->flags & FTRACE_ITER_PROBE)
3645	return t_probe_next(m, pos);
3646
3647	if (iter->flags & FTRACE_ITER_MOD)
3648	return t_mod_next(m, pos);
3649
3650	if (iter->flags & FTRACE_ITER_PRINTALL) {
3651	/* next must increment pos, and t_probe_start does not */
3652	(*pos)++;
3653	return t_mod_start(m, pos: &l);
3654	}
3655
3656	ret = t_func_next(m, pos);
3657
3658	if (!ret)
3659	return t_mod_start(m, pos: &l);
3660
3661	return ret;
3662	}
3663
3664	static void reset_iter_read(struct ftrace_iterator *iter)
3665	{
3666	iter->pos = 0;
3667	iter->func_pos = 0;
3668	iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3669	}
3670
3671	static void *t_start(struct seq_file *m, loff_t *pos)
3672	{
3673	struct ftrace_iterator *iter = m->private;
3674	void *p = NULL;
3675	loff_t l;
3676
3677	mutex_lock(&ftrace_lock);
3678
3679	if (unlikely(ftrace_disabled))
3680	return NULL;
3681
3682	/*
3683	* If an lseek was done, then reset and start from beginning.
3684	*/
3685	if (*pos < iter->pos)
3686	reset_iter_read(iter);
3687
3688	/*
3689	* For set_ftrace_filter reading, if we have the filter
3690	* off, we can short cut and just print out that all
3691	* functions are enabled.
3692	*/
3693	if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3694	ftrace_hash_empty(hash: iter->hash)) {
3695	iter->func_pos = 1; /* Account for the message */
3696	if (*pos > 0)
3697	return t_mod_start(m, pos);
3698	iter->flags |= FTRACE_ITER_PRINTALL;
3699	/* reset in case of seek/pread */
3700	iter->flags &= ~FTRACE_ITER_PROBE;
3701	return iter;
3702	}
3703
3704	if (iter->flags & FTRACE_ITER_MOD)
3705	return t_mod_start(m, pos);
3706
3707	/*
3708	* Unfortunately, we need to restart at ftrace_pages_start
3709	* every time we let go of the ftrace_mutex. This is because
3710	* those pointers can change without the lock.
3711	*/
3712	iter->pg = ftrace_pages_start;
3713	iter->idx = 0;
3714	for (l = 0; l <= *pos; ) {
3715	p = t_func_next(m, pos: &l);
3716	if (!p)
3717	break;
3718	}
3719
3720	if (!p)
3721	return t_mod_start(m, pos);
3722
3723	return iter;
3724	}
3725
3726	static void t_stop(struct seq_file *m, void *p)
3727	{
3728	mutex_unlock(lock: &ftrace_lock);
3729	}
3730
3731	void * __weak
3732	arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3733	{
3734	return NULL;
3735	}
3736
3737	static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3738	struct dyn_ftrace *rec)
3739	{
3740	void *ptr;
3741
3742	ptr = arch_ftrace_trampoline_func(ops, rec);
3743	if (ptr)
3744	seq_printf(m, fmt: " ->%pS", ptr);
3745	}
3746
3747	#ifdef FTRACE_MCOUNT_MAX_OFFSET
3748	/*
3749	* Weak functions can still have an mcount/fentry that is saved in
3750	* the __mcount_loc section. These can be detected by having a
3751	* symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the
3752	* symbol found by kallsyms is not the function that the mcount/fentry
3753	* is part of. The offset is much greater in these cases.
3754	*
3755	* Test the record to make sure that the ip points to a valid kallsyms
3756	* and if not, mark it disabled.
3757	*/
3758	static int test_for_valid_rec(struct dyn_ftrace *rec)
3759	{
3760	char str[KSYM_SYMBOL_LEN];
3761	unsigned long offset;
3762	const char *ret;
3763
3764	ret = kallsyms_lookup(addr: rec->ip, NULL, offset: &offset, NULL, namebuf: str);
3765
3766	/* Weak functions can cause invalid addresses */
3767	if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
3768	rec->flags |= FTRACE_FL_DISABLED;
3769	return 0;
3770	}
3771	return 1;
3772	}
3773
3774	static struct workqueue_struct *ftrace_check_wq __initdata;
3775	static struct work_struct ftrace_check_work __initdata;
3776
3777	/*
3778	* Scan all the mcount/fentry entries to make sure they are valid.
3779	*/
3780	static __init void ftrace_check_work_func(struct work_struct *work)
3781	{
3782	struct ftrace_page *pg;
3783	struct dyn_ftrace *rec;
3784
3785	mutex_lock(&ftrace_lock);
3786	do_for_each_ftrace_rec(pg, rec) {
3787	test_for_valid_rec(rec);
3788	} while_for_each_ftrace_rec();
3789	mutex_unlock(lock: &ftrace_lock);
3790	}
3791
3792	static int __init ftrace_check_for_weak_functions(void)
3793	{
3794	INIT_WORK(&ftrace_check_work, ftrace_check_work_func);
3795
3796	ftrace_check_wq = alloc_workqueue(fmt: "ftrace_check_wq", flags: WQ_UNBOUND, max_active: 0);
3797
3798	queue_work(wq: ftrace_check_wq, work: &ftrace_check_work);
3799	return 0;
3800	}
3801
3802	static int __init ftrace_check_sync(void)
3803	{
3804	/* Make sure the ftrace_check updates are finished */
3805	if (ftrace_check_wq)
3806	destroy_workqueue(wq: ftrace_check_wq);
3807	return 0;
3808	}
3809
3810	late_initcall_sync(ftrace_check_sync);
3811	subsys_initcall(ftrace_check_for_weak_functions);
3812
3813	static int print_rec(struct seq_file *m, unsigned long ip)
3814	{
3815	unsigned long offset;
3816	char str[KSYM_SYMBOL_LEN];
3817	char *modname;
3818	const char *ret;
3819
3820	ret = kallsyms_lookup(addr: ip, NULL, offset: &offset, modname: &modname, namebuf: str);
3821	/* Weak functions can cause invalid addresses */
3822	if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
3823	snprintf(buf: str, KSYM_SYMBOL_LEN, fmt: "%s_%ld",
3824	FTRACE_INVALID_FUNCTION, offset);
3825	ret = NULL;
3826	}
3827
3828	seq_puts(m, s: str);
3829	if (modname)
3830	seq_printf(m, fmt: " [%s]", modname);
3831	return ret == NULL ? -1 : 0;
3832	}
3833	#else
3834	static inline int test_for_valid_rec(struct dyn_ftrace *rec)
3835	{
3836	return 1;
3837	}
3838
3839	static inline int print_rec(struct seq_file *m, unsigned long ip)
3840	{
3841	seq_printf(m, "%ps", (void *)ip);
3842	return 0;
3843	}
3844	#endif
3845
3846	static int t_show(struct seq_file *m, void *v)
3847	{
3848	struct ftrace_iterator *iter = m->private;
3849	struct dyn_ftrace *rec;
3850
3851	if (iter->flags & FTRACE_ITER_PROBE)
3852	return t_probe_show(m, iter);
3853
3854	if (iter->flags & FTRACE_ITER_MOD)
3855	return t_mod_show(m, iter);
3856
3857	if (iter->flags & FTRACE_ITER_PRINTALL) {
3858	if (iter->flags & FTRACE_ITER_NOTRACE)
3859	seq_puts(m, s: "#### no functions disabled ####\n");
3860	else
3861	seq_puts(m, s: "#### all functions enabled ####\n");
3862	return 0;
3863	}
3864
3865	rec = iter->func;
3866
3867	if (!rec)
3868	return 0;
3869
3870	if (iter->flags & FTRACE_ITER_ADDRS)
3871	seq_printf(m, fmt: "%lx ", rec->ip);
3872
3873	if (print_rec(m, ip: rec->ip)) {
3874	/* This should only happen when a rec is disabled */
3875	WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED));
3876	seq_putc(m, c: '\n');
3877	return 0;
3878	}
3879
3880	if (iter->flags & (FTRACE_ITER_ENABLED | FTRACE_ITER_TOUCHED)) {
3881	struct ftrace_ops *ops;
3882
3883	seq_printf(m, fmt: " (%ld)%s%s%s%s%s",
3884	ftrace_rec_count(rec),
3885	rec->flags & FTRACE_FL_REGS ? " R" : " ",
3886	rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ",
3887	rec->flags & FTRACE_FL_DIRECT ? " D" : " ",
3888	rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ",
3889	rec->flags & FTRACE_FL_MODIFIED ? " M " : " ");
3890	if (rec->flags & FTRACE_FL_TRAMP_EN) {
3891	ops = ftrace_find_tramp_ops_any(rec);
3892	if (ops) {
3893	do {
3894	seq_printf(m, fmt: "\ttramp: %pS (%pS)",
3895	(void *)ops->trampoline,
3896	(void *)ops->func);
3897	add_trampoline_func(m, ops, rec);
3898	ops = ftrace_find_tramp_ops_next(rec, op: ops);
3899	} while (ops);
3900	} else
3901	seq_puts(m, s: "\ttramp: ERROR!");
3902	} else {
3903	add_trampoline_func(m, NULL, rec);
3904	}
3905	if (rec->flags & FTRACE_FL_CALL_OPS_EN) {
3906	ops = ftrace_find_unique_ops(rec);
3907	if (ops) {
3908	seq_printf(m, fmt: "\tops: %pS (%pS)",
3909	ops, ops->func);
3910	} else {
3911	seq_puts(m, s: "\tops: ERROR!");
3912	}
3913	}
3914	if (rec->flags & FTRACE_FL_DIRECT) {
3915	unsigned long direct;
3916
3917	direct = ftrace_find_rec_direct(ip: rec->ip);
3918	if (direct)
3919	seq_printf(m, fmt: "\n\tdirect-->%pS", (void *)direct);
3920	}
3921	}
3922
3923	seq_putc(m, c: '\n');
3924
3925	return 0;
3926	}
3927
3928	static const struct seq_operations show_ftrace_seq_ops = {
3929	.start = t_start,
3930	.next = t_next,
3931	.stop = t_stop,
3932	.show = t_show,
3933	};
3934
3935	static int
3936	ftrace_avail_open(struct inode *inode, struct file *file)
3937	{
3938	struct ftrace_iterator *iter;
3939	int ret;
3940
3941	ret = security_locked_down(what: LOCKDOWN_TRACEFS);
3942	if (ret)
3943	return ret;
3944
3945	if (unlikely(ftrace_disabled))
3946	return -ENODEV;
3947
3948	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3949	if (!iter)
3950	return -ENOMEM;
3951
3952	iter->pg = ftrace_pages_start;
3953	iter->ops = &global_ops;
3954
3955	return 0;
3956	}
3957
3958	static int
3959	ftrace_enabled_open(struct inode *inode, struct file *file)
3960	{
3961	struct ftrace_iterator *iter;
3962
3963	/*
3964	* This shows us what functions are currently being
3965	* traced and by what. Not sure if we want lockdown
3966	* to hide such critical information for an admin.
3967	* Although, perhaps it can show information we don't
3968	* want people to see, but if something is tracing
3969	* something, we probably want to know about it.
3970	*/
3971
3972	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3973	if (!iter)
3974	return -ENOMEM;
3975
3976	iter->pg = ftrace_pages_start;
3977	iter->flags = FTRACE_ITER_ENABLED;
3978	iter->ops = &global_ops;
3979
3980	return 0;
3981	}
3982
3983	static int
3984	ftrace_touched_open(struct inode *inode, struct file *file)
3985	{
3986	struct ftrace_iterator *iter;
3987
3988	/*
3989	* This shows us what functions have ever been enabled
3990	* (traced, direct, patched, etc). Not sure if we want lockdown
3991	* to hide such critical information for an admin.
3992	* Although, perhaps it can show information we don't
3993	* want people to see, but if something had traced
3994	* something, we probably want to know about it.
3995	*/
3996
3997	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3998	if (!iter)
3999	return -ENOMEM;
4000
4001	iter->pg = ftrace_pages_start;
4002	iter->flags = FTRACE_ITER_TOUCHED;
4003	iter->ops = &global_ops;
4004
4005	return 0;
4006	}
4007
4008	static int
4009	ftrace_avail_addrs_open(struct inode *inode, struct file *file)
4010	{
4011	struct ftrace_iterator *iter;
4012	int ret;
4013
4014	ret = security_locked_down(what: LOCKDOWN_TRACEFS);
4015	if (ret)
4016	return ret;
4017
4018	if (unlikely(ftrace_disabled))
4019	return -ENODEV;
4020
4021	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
4022	if (!iter)
4023	return -ENOMEM;
4024
4025	iter->pg = ftrace_pages_start;
4026	iter->flags = FTRACE_ITER_ADDRS;
4027	iter->ops = &global_ops;
4028
4029	return 0;
4030	}
4031
4032	/**
4033	* ftrace_regex_open - initialize function tracer filter files
4034	* @ops: The ftrace_ops that hold the hash filters
4035	* @flag: The type of filter to process
4036	* @inode: The inode, usually passed in to your open routine
4037	* @file: The file, usually passed in to your open routine
4038	*
4039	* ftrace_regex_open() initializes the filter files for the
4040	* @ops. Depending on @flag it may process the filter hash or
4041	* the notrace hash of @ops. With this called from the open
4042	* routine, you can use ftrace_filter_write() for the write
4043	* routine if @flag has FTRACE_ITER_FILTER set, or
4044	* ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
4045	* tracing_lseek() should be used as the lseek routine, and
4046	* release must call ftrace_regex_release().
4047	*/
4048	int
4049	ftrace_regex_open(struct ftrace_ops *ops, int flag,
4050	struct inode *inode, struct file *file)
4051	{
4052	struct ftrace_iterator *iter;
4053	struct ftrace_hash *hash;
4054	struct list_head *mod_head;
4055	struct trace_array *tr = ops->private;
4056	int ret = -ENOMEM;
4057
4058	ftrace_ops_init(ops);
4059
4060	if (unlikely(ftrace_disabled))
4061	return -ENODEV;
4062
4063	if (tracing_check_open_get_tr(tr))
4064	return -ENODEV;
4065
4066	iter = kzalloc(size: sizeof(*iter), GFP_KERNEL);
4067	if (!iter)
4068	goto out;
4069
4070	if (trace_parser_get_init(parser: &iter->parser, FTRACE_BUFF_MAX))
4071	goto out;
4072
4073	iter->ops = ops;
4074	iter->flags = flag;
4075	iter->tr = tr;
4076
4077	mutex_lock(&ops->func_hash->regex_lock);
4078
4079	if (flag & FTRACE_ITER_NOTRACE) {
4080	hash = ops->func_hash->notrace_hash;
4081	mod_head = tr ? &tr->mod_notrace : NULL;
4082	} else {
4083	hash = ops->func_hash->filter_hash;
4084	mod_head = tr ? &tr->mod_trace : NULL;
4085	}
4086
4087	iter->mod_list = mod_head;
4088
4089	if (file->f_mode & FMODE_WRITE) {
4090	const int size_bits = FTRACE_HASH_DEFAULT_BITS;
4091
4092	if (file->f_flags & O_TRUNC) {
4093	iter->hash = alloc_ftrace_hash(size_bits);
4094	clear_ftrace_mod_list(head: mod_head);
4095	} else {
4096	iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
4097	}
4098
4099	if (!iter->hash) {
4100	trace_parser_put(parser: &iter->parser);
4101	goto out_unlock;
4102	}
4103	} else
4104	iter->hash = hash;
4105
4106	ret = 0;
4107
4108	if (file->f_mode & FMODE_READ) {
4109	iter->pg = ftrace_pages_start;
4110
4111	ret = seq_open(file, &show_ftrace_seq_ops);
4112	if (!ret) {
4113	struct seq_file *m = file->private_data;
4114	m->private = iter;
4115	} else {
4116	/* Failed */
4117	free_ftrace_hash(hash: iter->hash);
4118	trace_parser_put(parser: &iter->parser);
4119	}
4120	} else
4121	file->private_data = iter;
4122
4123	out_unlock:
4124	mutex_unlock(lock: &ops->func_hash->regex_lock);
4125
4126	out:
4127	if (ret) {
4128	kfree(objp: iter);
4129	if (tr)
4130	trace_array_put(tr);
4131	}
4132
4133	return ret;
4134	}
4135
4136	static int
4137	ftrace_filter_open(struct inode *inode, struct file *file)
4138	{
4139	struct ftrace_ops *ops = inode->i_private;
4140
4141	/* Checks for tracefs lockdown */
4142	return ftrace_regex_open(ops,
4143	flag: FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
4144	inode, file);
4145	}
4146
4147	static int
4148	ftrace_notrace_open(struct inode *inode, struct file *file)
4149	{
4150	struct ftrace_ops *ops = inode->i_private;
4151
4152	/* Checks for tracefs lockdown */
4153	return ftrace_regex_open(ops, flag: FTRACE_ITER_NOTRACE,
4154	inode, file);
4155	}
4156
4157	/* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
4158	struct ftrace_glob {
4159	char *search;
4160	unsigned len;
4161	int type;
4162	};
4163
4164	/*
4165	* If symbols in an architecture don't correspond exactly to the user-visible
4166	* name of what they represent, it is possible to define this function to
4167	* perform the necessary adjustments.
4168	*/
4169	char * __weak arch_ftrace_match_adjust(char *str, const char *search)
4170	{
4171	return str;
4172	}
4173
4174	static int ftrace_match(char *str, struct ftrace_glob *g)
4175	{
4176	int matched = 0;
4177	int slen;
4178
4179	str = arch_ftrace_match_adjust(str, search: g->search);
4180
4181	switch (g->type) {
4182	case MATCH_FULL:
4183	if (strcmp(str, g->search) == 0)
4184	matched = 1;
4185	break;
4186	case MATCH_FRONT_ONLY:
4187	if (strncmp(str, g->search, g->len) == 0)
4188	matched = 1;
4189	break;
4190	case MATCH_MIDDLE_ONLY:
4191	if (strstr(str, g->search))
4192	matched = 1;
4193	break;
4194	case MATCH_END_ONLY:
4195	slen = strlen(str);
4196	if (slen >= g->len &&
4197	memcmp(p: str + slen - g->len, q: g->search, size: g->len) == 0)
4198	matched = 1;
4199	break;
4200	case MATCH_GLOB:
4201	if (glob_match(pat: g->search, str))
4202	matched = 1;
4203	break;
4204	}
4205
4206	return matched;
4207	}
4208
4209	static int
4210	enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
4211	{
4212	struct ftrace_func_entry *entry;
4213	int ret = 0;
4214
4215	entry = ftrace_lookup_ip(hash, ip: rec->ip);
4216	if (clear_filter) {
4217	/* Do nothing if it doesn't exist */
4218	if (!entry)
4219	return 0;
4220
4221	free_hash_entry(hash, entry);
4222	} else {
4223	/* Do nothing if it exists */
4224	if (entry)
4225	return 0;
4226
4227	ret = add_hash_entry(hash, ip: rec->ip);
4228	}
4229	return ret;
4230	}
4231
4232	static int
4233	add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
4234	int clear_filter)
4235	{
4236	long index = simple_strtoul(func_g->search, NULL, 0);
4237	struct ftrace_page *pg;
4238	struct dyn_ftrace *rec;
4239
4240	/* The index starts at 1 */
4241	if (--index < 0)
4242	return 0;
4243
4244	do_for_each_ftrace_rec(pg, rec) {
4245	if (pg->index <= index) {
4246	index -= pg->index;
4247	/* this is a double loop, break goes to the next page */
4248	break;
4249	}
4250	rec = &pg->records[index];
4251	enter_record(hash, rec, clear_filter);
4252	return 1;
4253	} while_for_each_ftrace_rec();
4254	return 0;
4255	}
4256
4257	#ifdef FTRACE_MCOUNT_MAX_OFFSET
4258	static int lookup_ip(unsigned long ip, char **modname, char *str)
4259	{
4260	unsigned long offset;
4261
4262	kallsyms_lookup(addr: ip, NULL, offset: &offset, modname, namebuf: str);
4263	if (offset > FTRACE_MCOUNT_MAX_OFFSET)
4264	return -1;
4265	return 0;
4266	}
4267	#else
4268	static int lookup_ip(unsigned long ip, char **modname, char *str)
4269	{
4270	kallsyms_lookup(ip, NULL, NULL, modname, str);
4271	return 0;
4272	}
4273	#endif
4274
4275	static int
4276	ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
4277	struct ftrace_glob *mod_g, int exclude_mod)
4278	{
4279	char str[KSYM_SYMBOL_LEN];
4280	char *modname;
4281
4282	if (lookup_ip(ip: rec->ip, modname: &modname, str)) {
4283	/* This should only happen when a rec is disabled */
4284	WARN_ON_ONCE(system_state == SYSTEM_RUNNING &&
4285	!(rec->flags & FTRACE_FL_DISABLED));
4286	return 0;
4287	}
4288
4289	if (mod_g) {
4290	int mod_matches = (modname) ? ftrace_match(str: modname, g: mod_g) : 0;
4291
4292	/* blank module name to match all modules */
4293	if (!mod_g->len) {
4294	/* blank module globbing: modname xor exclude_mod */
4295	if (!exclude_mod != !modname)
4296	goto func_match;
4297	return 0;
4298	}
4299
4300	/*
4301	* exclude_mod is set to trace everything but the given
4302	* module. If it is set and the module matches, then
4303	* return 0. If it is not set, and the module doesn't match
4304	* also return 0. Otherwise, check the function to see if
4305	* that matches.
4306	*/
4307	if (!mod_matches == !exclude_mod)
4308	return 0;
4309	func_match:
4310	/* blank search means to match all funcs in the mod */
4311	if (!func_g->len)
4312	return 1;
4313	}
4314
4315	return ftrace_match(str, g: func_g);
4316	}
4317
4318	static int
4319	match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
4320	{
4321	struct ftrace_page *pg;
4322	struct dyn_ftrace *rec;
4323	struct ftrace_glob func_g = { .type = MATCH_FULL };
4324	struct ftrace_glob mod_g = { .type = MATCH_FULL };
4325	struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
4326	int exclude_mod = 0;
4327	int found = 0;
4328	int ret;
4329	int clear_filter = 0;
4330
4331	if (func) {
4332	func_g.type = filter_parse_regex(buff: func, len, search: &func_g.search,
4333	not: &clear_filter);
4334	func_g.len = strlen(func_g.search);
4335	}
4336
4337	if (mod) {
4338	mod_g.type = filter_parse_regex(buff: mod, strlen(mod),
4339	search: &mod_g.search, not: &exclude_mod);
4340	mod_g.len = strlen(mod_g.search);
4341	}
4342
4343	mutex_lock(&ftrace_lock);
4344
4345	if (unlikely(ftrace_disabled))
4346	goto out_unlock;
4347
4348	if (func_g.type == MATCH_INDEX) {
4349	found = add_rec_by_index(hash, func_g: &func_g, clear_filter);
4350	goto out_unlock;
4351	}
4352
4353	do_for_each_ftrace_rec(pg, rec) {
4354
4355	if (rec->flags & FTRACE_FL_DISABLED)
4356	continue;
4357
4358	if (ftrace_match_record(rec, func_g: &func_g, mod_g: mod_match, exclude_mod)) {
4359	ret = enter_record(hash, rec, clear_filter);
4360	if (ret < 0) {
4361	found = ret;
4362	goto out_unlock;
4363	}
4364	found = 1;
4365	}
4366	cond_resched();
4367	} while_for_each_ftrace_rec();
4368	out_unlock:
4369	mutex_unlock(lock: &ftrace_lock);
4370
4371	return found;
4372	}
4373
4374	static int
4375	ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
4376	{
4377	return match_records(hash, func: buff, len, NULL);
4378	}
4379
4380	static void ftrace_ops_update_code(struct ftrace_ops *ops,
4381	struct ftrace_ops_hash *old_hash)
4382	{
4383	struct ftrace_ops *op;
4384
4385	if (!ftrace_enabled)
4386	return;
4387
4388	if (ops->flags & FTRACE_OPS_FL_ENABLED) {
4389	ftrace_run_modify_code(ops, command: FTRACE_UPDATE_CALLS, old_hash);
4390	return;
4391	}
4392
4393	/*
4394	* If this is the shared global_ops filter, then we need to
4395	* check if there is another ops that shares it, is enabled.
4396	* If so, we still need to run the modify code.
4397	*/
4398	if (ops->func_hash != &global_ops.local_hash)
4399	return;
4400
4401	do_for_each_ftrace_op(op, ftrace_ops_list) {
4402	if (op->func_hash == &global_ops.local_hash &&
4403	op->flags & FTRACE_OPS_FL_ENABLED) {
4404	ftrace_run_modify_code(ops: op, command: FTRACE_UPDATE_CALLS, old_hash);
4405	/* Only need to do this once */
4406	return;
4407	}
4408	} while_for_each_ftrace_op(op);
4409	}
4410
4411	static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
4412	struct ftrace_hash **orig_hash,
4413	struct ftrace_hash *hash,
4414	int enable)
4415	{
4416	struct ftrace_ops_hash old_hash_ops;
4417	struct ftrace_hash *old_hash;
4418	int ret;
4419
4420	old_hash = *orig_hash;
4421	old_hash_ops.filter_hash = ops->func_hash->filter_hash;
4422	old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
4423	ret = ftrace_hash_move(ops, enable, dst: orig_hash, src: hash);
4424	if (!ret) {
4425	ftrace_ops_update_code(ops, old_hash: &old_hash_ops);
4426	free_ftrace_hash_rcu(hash: old_hash);
4427	}
4428	return ret;
4429	}
4430
4431	static bool module_exists(const char *module)
4432	{
4433	/* All modules have the symbol __this_module */
4434	static const char this_mod[] = "__this_module";
4435	char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
4436	unsigned long val;
4437	int n;
4438
4439	n = snprintf(buf: modname, size: sizeof(modname), fmt: "%s:%s", module, this_mod);
4440
4441	if (n > sizeof(modname) - 1)
4442	return false;
4443
4444	val = module_kallsyms_lookup_name(name: modname);
4445	return val != 0;
4446	}
4447
4448	static int cache_mod(struct trace_array *tr,
4449	const char *func, char *module, int enable)
4450	{
4451	struct ftrace_mod_load *ftrace_mod, *n;
4452	struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
4453	int ret;
4454
4455	mutex_lock(&ftrace_lock);
4456
4457	/* We do not cache inverse filters */
4458	if (func[0] == '!') {
4459	func++;
4460	ret = -EINVAL;
4461
4462	/* Look to remove this hash */
4463	list_for_each_entry_safe(ftrace_mod, n, head, list) {
4464	if (strcmp(ftrace_mod->module, module) != 0)
4465	continue;
4466
4467	/* no func matches all */
4468	if (strcmp(func, "*") == 0 ||
4469	(ftrace_mod->func &&
4470	strcmp(ftrace_mod->func, func) == 0)) {
4471	ret = 0;
4472	free_ftrace_mod(ftrace_mod);
4473	continue;
4474	}
4475	}
4476	goto out;
4477	}
4478
4479	ret = -EINVAL;
4480	/* We only care about modules that have not been loaded yet */
4481	if (module_exists(module))
4482	goto out;
4483
4484	/* Save this string off, and execute it when the module is loaded */
4485	ret = ftrace_add_mod(tr, func, module, enable);
4486	out:
4487	mutex_unlock(lock: &ftrace_lock);
4488
4489	return ret;
4490	}
4491
4492	static int
4493	ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4494	int reset, int enable);
4495
4496	#ifdef CONFIG_MODULES
4497	static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
4498	char *mod, bool enable)
4499	{
4500	struct ftrace_mod_load *ftrace_mod, *n;
4501	struct ftrace_hash **orig_hash, *new_hash;
4502	LIST_HEAD(process_mods);
4503	char *func;
4504
4505	mutex_lock(&ops->func_hash->regex_lock);
4506
4507	if (enable)
4508	orig_hash = &ops->func_hash->filter_hash;
4509	else
4510	orig_hash = &ops->func_hash->notrace_hash;
4511
4512	new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
4513	hash: *orig_hash);
4514	if (!new_hash)
4515	goto out; /* warn? */
4516
4517	mutex_lock(&ftrace_lock);
4518
4519	list_for_each_entry_safe(ftrace_mod, n, head, list) {
4520
4521	if (strcmp(ftrace_mod->module, mod) != 0)
4522	continue;
4523
4524	if (ftrace_mod->func)
4525	func = kstrdup(s: ftrace_mod->func, GFP_KERNEL);
4526	else
4527	func = kstrdup(s: "*", GFP_KERNEL);
4528
4529	if (!func) /* warn? */
4530	continue;
4531
4532	list_move(list: &ftrace_mod->list, head: &process_mods);
4533
4534	/* Use the newly allocated func, as it may be "*" */
4535	kfree(objp: ftrace_mod->func);
4536	ftrace_mod->func = func;
4537	}
4538
4539	mutex_unlock(lock: &ftrace_lock);
4540
4541	list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
4542
4543	func = ftrace_mod->func;
4544
4545	/* Grabs ftrace_lock, which is why we have this extra step */
4546	match_records(hash: new_hash, func, strlen(func), mod);
4547	free_ftrace_mod(ftrace_mod);
4548	}
4549
4550	if (enable && list_empty(head))
4551	new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4552
4553	mutex_lock(&ftrace_lock);
4554
4555	ftrace_hash_move_and_update_ops(ops, orig_hash,
4556	hash: new_hash, enable);
4557	mutex_unlock(lock: &ftrace_lock);
4558
4559	out:
4560	mutex_unlock(lock: &ops->func_hash->regex_lock);
4561
4562	free_ftrace_hash(hash: new_hash);
4563	}
4564
4565	static void process_cached_mods(const char *mod_name)
4566	{
4567	struct trace_array *tr;
4568	char *mod;
4569
4570	mod = kstrdup(s: mod_name, GFP_KERNEL);
4571	if (!mod)
4572	return;
4573
4574	mutex_lock(&trace_types_lock);
4575	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4576	if (!list_empty(head: &tr->mod_trace))
4577	process_mod_list(head: &tr->mod_trace, ops: tr->ops, mod, enable: true);
4578	if (!list_empty(head: &tr->mod_notrace))
4579	process_mod_list(head: &tr->mod_notrace, ops: tr->ops, mod, enable: false);
4580	}
4581	mutex_unlock(lock: &trace_types_lock);
4582
4583	kfree(objp: mod);
4584	}
4585	#endif
4586
4587	/*
4588	* We register the module command as a template to show others how
4589	* to register the a command as well.
4590	*/
4591
4592	static int
4593	ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4594	char *func_orig, char *cmd, char *module, int enable)
4595	{
4596	char *func;
4597	int ret;
4598
4599	/* match_records() modifies func, and we need the original */
4600	func = kstrdup(s: func_orig, GFP_KERNEL);
4601	if (!func)
4602	return -ENOMEM;
4603
4604	/*
4605	* cmd == 'mod' because we only registered this func
4606	* for the 'mod' ftrace_func_command.
4607	* But if you register one func with multiple commands,
4608	* you can tell which command was used by the cmd
4609	* parameter.
4610	*/
4611	ret = match_records(hash, func, strlen(func), mod: module);
4612	kfree(objp: func);
4613
4614	if (!ret)
4615	return cache_mod(tr, func: func_orig, module, enable);
4616	if (ret < 0)
4617	return ret;
4618	return 0;
4619	}
4620
4621	static struct ftrace_func_command ftrace_mod_cmd = {
4622	.name = "mod",
4623	.func = ftrace_mod_callback,
4624	};
4625
4626	static int __init ftrace_mod_cmd_init(void)
4627	{
4628	return register_ftrace_command(cmd: &ftrace_mod_cmd);
4629	}
4630	core_initcall(ftrace_mod_cmd_init);
4631
4632	static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4633	struct ftrace_ops *op, struct ftrace_regs *fregs)
4634	{
4635	struct ftrace_probe_ops *probe_ops;
4636	struct ftrace_func_probe *probe;
4637
4638	probe = container_of(op, struct ftrace_func_probe, ops);
4639	probe_ops = probe->probe_ops;
4640
4641	/*
4642	* Disable preemption for these calls to prevent a RCU grace
4643	* period. This syncs the hash iteration and freeing of items
4644	* on the hash. rcu_read_lock is too dangerous here.
4645	*/
4646	preempt_disable_notrace();
4647	probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4648	preempt_enable_notrace();
4649	}
4650
4651	struct ftrace_func_map {
4652	struct ftrace_func_entry entry;
4653	void *data;
4654	};
4655
4656	struct ftrace_func_mapper {
4657	struct ftrace_hash hash;
4658	};
4659
4660	/**
4661	* allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4662	*
4663	* Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4664	*/
4665	struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4666	{
4667	struct ftrace_hash *hash;
4668
4669	/*
4670	* The mapper is simply a ftrace_hash, but since the entries
4671	* in the hash are not ftrace_func_entry type, we define it
4672	* as a separate structure.
4673	*/
4674	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4675	return (struct ftrace_func_mapper *)hash;
4676	}
4677
4678	/**
4679	* ftrace_func_mapper_find_ip - Find some data mapped to an ip
4680	* @mapper: The mapper that has the ip maps
4681	* @ip: the instruction pointer to find the data for
4682	*
4683	* Returns the data mapped to @ip if found otherwise NULL. The return
4684	* is actually the address of the mapper data pointer. The address is
4685	* returned for use cases where the data is no bigger than a long, and
4686	* the user can use the data pointer as its data instead of having to
4687	* allocate more memory for the reference.
4688	*/
4689	void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4690	unsigned long ip)
4691	{
4692	struct ftrace_func_entry *entry;
4693	struct ftrace_func_map *map;
4694
4695	entry = ftrace_lookup_ip(hash: &mapper->hash, ip);
4696	if (!entry)
4697	return NULL;
4698
4699	map = (struct ftrace_func_map *)entry;
4700	return &map->data;
4701	}
4702
4703	/**
4704	* ftrace_func_mapper_add_ip - Map some data to an ip
4705	* @mapper: The mapper that has the ip maps
4706	* @ip: The instruction pointer address to map @data to
4707	* @data: The data to map to @ip
4708	*
4709	* Returns 0 on success otherwise an error.
4710	*/
4711	int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4712	unsigned long ip, void *data)
4713	{
4714	struct ftrace_func_entry *entry;
4715	struct ftrace_func_map *map;
4716
4717	entry = ftrace_lookup_ip(hash: &mapper->hash, ip);
4718	if (entry)
4719	return -EBUSY;
4720
4721	map = kmalloc(size: sizeof(*map), GFP_KERNEL);
4722	if (!map)
4723	return -ENOMEM;
4724
4725	map->entry.ip = ip;
4726	map->data = data;
4727
4728	__add_hash_entry(hash: &mapper->hash, entry: &map->entry);
4729
4730	return 0;
4731	}
4732
4733	/**
4734	* ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4735	* @mapper: The mapper that has the ip maps
4736	* @ip: The instruction pointer address to remove the data from
4737	*
4738	* Returns the data if it is found, otherwise NULL.
4739	* Note, if the data pointer is used as the data itself, (see
4740	* ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4741	* if the data pointer was set to zero.
4742	*/
4743	void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4744	unsigned long ip)
4745	{
4746	struct ftrace_func_entry *entry;
4747	struct ftrace_func_map *map;
4748	void *data;
4749
4750	entry = ftrace_lookup_ip(hash: &mapper->hash, ip);
4751	if (!entry)
4752	return NULL;
4753
4754	map = (struct ftrace_func_map *)entry;
4755	data = map->data;
4756
4757	remove_hash_entry(hash: &mapper->hash, entry);
4758	kfree(objp: entry);
4759
4760	return data;
4761	}
4762
4763	/**
4764	* free_ftrace_func_mapper - free a mapping of ips and data
4765	* @mapper: The mapper that has the ip maps
4766	* @free_func: A function to be called on each data item.
4767	*
4768	* This is used to free the function mapper. The @free_func is optional
4769	* and can be used if the data needs to be freed as well.
4770	*/
4771	void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4772	ftrace_mapper_func free_func)
4773	{
4774	struct ftrace_func_entry *entry;
4775	struct ftrace_func_map *map;
4776	struct hlist_head *hhd;
4777	int size, i;
4778
4779	if (!mapper)
4780	return;
4781
4782	if (free_func && mapper->hash.count) {
4783	size = 1 << mapper->hash.size_bits;
4784	for (i = 0; i < size; i++) {
4785	hhd = &mapper->hash.buckets[i];
4786	hlist_for_each_entry(entry, hhd, hlist) {
4787	map = (struct ftrace_func_map *)entry;
4788	free_func(map);
4789	}
4790	}
4791	}
4792	free_ftrace_hash(hash: &mapper->hash);
4793	}
4794
4795	static void release_probe(struct ftrace_func_probe *probe)
4796	{
4797	struct ftrace_probe_ops *probe_ops;
4798
4799	mutex_lock(&ftrace_lock);
4800
4801	WARN_ON(probe->ref <= 0);
4802
4803	/* Subtract the ref that was used to protect this instance */
4804	probe->ref--;
4805
4806	if (!probe->ref) {
4807	probe_ops = probe->probe_ops;
4808	/*
4809	* Sending zero as ip tells probe_ops to free
4810	* the probe->data itself
4811	*/
4812	if (probe_ops->free)
4813	probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4814	list_del(entry: &probe->list);
4815	kfree(objp: probe);
4816	}
4817	mutex_unlock(lock: &ftrace_lock);
4818	}
4819
4820	static void acquire_probe_locked(struct ftrace_func_probe *probe)
4821	{
4822	/*
4823	* Add one ref to keep it from being freed when releasing the
4824	* ftrace_lock mutex.
4825	*/
4826	probe->ref++;
4827	}
4828
4829	int
4830	register_ftrace_function_probe(char *glob, struct trace_array *tr,
4831	struct ftrace_probe_ops *probe_ops,
4832	void *data)
4833	{
4834	struct ftrace_func_probe *probe = NULL, *iter;
4835	struct ftrace_func_entry *entry;
4836	struct ftrace_hash **orig_hash;
4837	struct ftrace_hash *old_hash;
4838	struct ftrace_hash *hash;
4839	int count = 0;
4840	int size;
4841	int ret;
4842	int i;
4843
4844	if (WARN_ON(!tr))
4845	return -EINVAL;
4846
4847	/* We do not support '!' for function probes */
4848	if (WARN_ON(glob[0] == '!'))
4849	return -EINVAL;
4850
4851
4852	mutex_lock(&ftrace_lock);
4853	/* Check if the probe_ops is already registered */
4854	list_for_each_entry(iter, &tr->func_probes, list) {
4855	if (iter->probe_ops == probe_ops) {
4856	probe = iter;
4857	break;
4858	}
4859	}
4860	if (!probe) {
4861	probe = kzalloc(size: sizeof(*probe), GFP_KERNEL);
4862	if (!probe) {
4863	mutex_unlock(lock: &ftrace_lock);
4864	return -ENOMEM;
4865	}
4866	probe->probe_ops = probe_ops;
4867	probe->ops.func = function_trace_probe_call;
4868	probe->tr = tr;
4869	ftrace_ops_init(ops: &probe->ops);
4870	list_add(new: &probe->list, head: &tr->func_probes);
4871	}
4872
4873	acquire_probe_locked(probe);
4874
4875	mutex_unlock(lock: &ftrace_lock);
4876
4877	/*
4878	* Note, there's a small window here that the func_hash->filter_hash
4879	* may be NULL or empty. Need to be careful when reading the loop.
4880	*/
4881	mutex_lock(&probe->ops.func_hash->regex_lock);
4882
4883	orig_hash = &probe->ops.func_hash->filter_hash;
4884	old_hash = *orig_hash;
4885	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash: old_hash);
4886
4887	if (!hash) {
4888	ret = -ENOMEM;
4889	goto out;
4890	}
4891
4892	ret = ftrace_match_records(hash, buff: glob, strlen(glob));
4893
4894	/* Nothing found? */
4895	if (!ret)
4896	ret = -EINVAL;
4897
4898	if (ret < 0)
4899	goto out;
4900
4901	size = 1 << hash->size_bits;
4902	for (i = 0; i < size; i++) {
4903	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4904	if (ftrace_lookup_ip(hash: old_hash, ip: entry->ip))
4905	continue;
4906	/*
4907	* The caller might want to do something special
4908	* for each function we find. We call the callback
4909	* to give the caller an opportunity to do so.
4910	*/
4911	if (probe_ops->init) {
4912	ret = probe_ops->init(probe_ops, tr,
4913	entry->ip, data,
4914	&probe->data);
4915	if (ret < 0) {
4916	if (probe_ops->free && count)
4917	probe_ops->free(probe_ops, tr,
4918	0, probe->data);
4919	probe->data = NULL;
4920	goto out;
4921	}
4922	}
4923	count++;
4924	}
4925	}
4926
4927	mutex_lock(&ftrace_lock);
4928
4929	if (!count) {
4930	/* Nothing was added? */
4931	ret = -EINVAL;
4932	goto out_unlock;
4933	}
4934
4935	ret = ftrace_hash_move_and_update_ops(ops: &probe->ops, orig_hash,
4936	hash, enable: 1);
4937	if (ret < 0)
4938	goto err_unlock;
4939
4940	/* One ref for each new function traced */
4941	probe->ref += count;
4942
4943	if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4944	ret = ftrace_startup(ops: &probe->ops, command: 0);
4945
4946	out_unlock:
4947	mutex_unlock(lock: &ftrace_lock);
4948
4949	if (!ret)
4950	ret = count;
4951	out:
4952	mutex_unlock(lock: &probe->ops.func_hash->regex_lock);
4953	free_ftrace_hash(hash);
4954
4955	release_probe(probe);
4956
4957	return ret;
4958
4959	err_unlock:
4960	if (!probe_ops->free || !count)
4961	goto out_unlock;
4962
4963	/* Failed to do the move, need to call the free functions */
4964	for (i = 0; i < size; i++) {
4965	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4966	if (ftrace_lookup_ip(hash: old_hash, ip: entry->ip))
4967	continue;
4968	probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4969	}
4970	}
4971	goto out_unlock;
4972	}
4973
4974	int
4975	unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4976	struct ftrace_probe_ops *probe_ops)
4977	{
4978	struct ftrace_func_probe *probe = NULL, *iter;
4979	struct ftrace_ops_hash old_hash_ops;
4980	struct ftrace_func_entry *entry;
4981	struct ftrace_glob func_g;
4982	struct ftrace_hash **orig_hash;
4983	struct ftrace_hash *old_hash;
4984	struct ftrace_hash *hash = NULL;
4985	struct hlist_node *tmp;
4986	struct hlist_head hhd;
4987	char str[KSYM_SYMBOL_LEN];
4988	int count = 0;
4989	int i, ret = -ENODEV;
4990	int size;
4991
4992	if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4993	func_g.search = NULL;
4994	else {
4995	int not;
4996
4997	func_g.type = filter_parse_regex(buff: glob, strlen(glob),
4998	search: &func_g.search, not: &not);
4999	func_g.len = strlen(func_g.search);
5000
5001	/* we do not support '!' for function probes */
5002	if (WARN_ON(not))
5003	return -EINVAL;
5004	}
5005
5006	mutex_lock(&ftrace_lock);
5007	/* Check if the probe_ops is already registered */
5008	list_for_each_entry(iter, &tr->func_probes, list) {
5009	if (iter->probe_ops == probe_ops) {
5010	probe = iter;
5011	break;
5012	}
5013	}
5014	if (!probe)
5015	goto err_unlock_ftrace;
5016
5017	ret = -EINVAL;
5018	if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
5019	goto err_unlock_ftrace;
5020
5021	acquire_probe_locked(probe);
5022
5023	mutex_unlock(lock: &ftrace_lock);
5024
5025	mutex_lock(&probe->ops.func_hash->regex_lock);
5026
5027	orig_hash = &probe->ops.func_hash->filter_hash;
5028	old_hash = *orig_hash;
5029
5030	if (ftrace_hash_empty(hash: old_hash))
5031	goto out_unlock;
5032
5033	old_hash_ops.filter_hash = old_hash;
5034	/* Probes only have filters */
5035	old_hash_ops.notrace_hash = NULL;
5036
5037	ret = -ENOMEM;
5038	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash: old_hash);
5039	if (!hash)
5040	goto out_unlock;
5041
5042	INIT_HLIST_HEAD(&hhd);
5043
5044	size = 1 << hash->size_bits;
5045	for (i = 0; i < size; i++) {
5046	hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
5047
5048	if (func_g.search) {
5049	kallsyms_lookup(addr: entry->ip, NULL, NULL,
5050	NULL, namebuf: str);
5051	if (!ftrace_match(str, g: &func_g))
5052	continue;
5053	}
5054	count++;
5055	remove_hash_entry(hash, entry);
5056	hlist_add_head(n: &entry->hlist, h: &hhd);
5057	}
5058	}
5059
5060	/* Nothing found? */
5061	if (!count) {
5062	ret = -EINVAL;
5063	goto out_unlock;
5064	}
5065
5066	mutex_lock(&ftrace_lock);
5067
5068	WARN_ON(probe->ref < count);
5069
5070	probe->ref -= count;
5071
5072	if (ftrace_hash_empty(hash))
5073	ftrace_shutdown(ops: &probe->ops, command: 0);
5074
5075	ret = ftrace_hash_move_and_update_ops(ops: &probe->ops, orig_hash,
5076	hash, enable: 1);
5077
5078	/* still need to update the function call sites */
5079	if (ftrace_enabled && !ftrace_hash_empty(hash))
5080	ftrace_run_modify_code(ops: &probe->ops, command: FTRACE_UPDATE_CALLS,
5081	old_hash: &old_hash_ops);
5082	synchronize_rcu();
5083
5084	hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
5085	hlist_del(n: &entry->hlist);
5086	if (probe_ops->free)
5087	probe_ops->free(probe_ops, tr, entry->ip, probe->data);
5088	kfree(objp: entry);
5089	}
5090	mutex_unlock(lock: &ftrace_lock);
5091
5092	out_unlock:
5093	mutex_unlock(lock: &probe->ops.func_hash->regex_lock);
5094	free_ftrace_hash(hash);
5095
5096	release_probe(probe);
5097
5098	return ret;
5099
5100	err_unlock_ftrace:
5101	mutex_unlock(lock: &ftrace_lock);
5102	return ret;
5103	}
5104
5105	void clear_ftrace_function_probes(struct trace_array *tr)
5106	{
5107	struct ftrace_func_probe *probe, *n;
5108
5109	list_for_each_entry_safe(probe, n, &tr->func_probes, list)
5110	unregister_ftrace_function_probe_func(NULL, tr, probe_ops: probe->probe_ops);
5111	}
5112
5113	static LIST_HEAD(ftrace_commands);
5114	static DEFINE_MUTEX(ftrace_cmd_mutex);
5115
5116	/*
5117	* Currently we only register ftrace commands from __init, so mark this
5118	* __init too.
5119	*/
5120	__init int register_ftrace_command(struct ftrace_func_command *cmd)
5121	{
5122	struct ftrace_func_command *p;
5123	int ret = 0;
5124
5125	mutex_lock(&ftrace_cmd_mutex);
5126	list_for_each_entry(p, &ftrace_commands, list) {
5127	if (strcmp(cmd->name, p->name) == 0) {
5128	ret = -EBUSY;
5129	goto out_unlock;
5130	}
5131	}
5132	list_add(new: &cmd->list, head: &ftrace_commands);
5133	out_unlock:
5134	mutex_unlock(lock: &ftrace_cmd_mutex);
5135
5136	return ret;
5137	}
5138
5139	/*
5140	* Currently we only unregister ftrace commands from __init, so mark
5141	* this __init too.
5142	*/
5143	__init int unregister_ftrace_command(struct ftrace_func_command *cmd)
5144	{
5145	struct ftrace_func_command *p, *n;
5146	int ret = -ENODEV;
5147
5148	mutex_lock(&ftrace_cmd_mutex);
5149	list_for_each_entry_safe(p, n, &ftrace_commands, list) {
5150	if (strcmp(cmd->name, p->name) == 0) {
5151	ret = 0;
5152	list_del_init(entry: &p->list);
5153	goto out_unlock;
5154	}
5155	}
5156	out_unlock:
5157	mutex_unlock(lock: &ftrace_cmd_mutex);
5158
5159	return ret;
5160	}
5161
5162	static int ftrace_process_regex(struct ftrace_iterator *iter,
5163	char *buff, int len, int enable)
5164	{
5165	struct ftrace_hash *hash = iter->hash;
5166	struct trace_array *tr = iter->ops->private;
5167	char *func, *command, *next = buff;
5168	struct ftrace_func_command *p;
5169	int ret = -EINVAL;
5170
5171	func = strsep(&next, ":");
5172
5173	if (!next) {
5174	ret = ftrace_match_records(hash, buff: func, len);
5175	if (!ret)
5176	ret = -EINVAL;
5177	if (ret < 0)
5178	return ret;
5179	return 0;
5180	}
5181
5182	/* command found */
5183
5184	command = strsep(&next, ":");
5185
5186	mutex_lock(&ftrace_cmd_mutex);
5187	list_for_each_entry(p, &ftrace_commands, list) {
5188	if (strcmp(p->name, command) == 0) {
5189	ret = p->func(tr, hash, func, command, next, enable);
5190	goto out_unlock;
5191	}
5192	}
5193	out_unlock:
5194	mutex_unlock(lock: &ftrace_cmd_mutex);
5195
5196	return ret;
5197	}
5198
5199	static ssize_t
5200	ftrace_regex_write(struct file *file, const char __user *ubuf,
5201	size_t cnt, loff_t *ppos, int enable)
5202	{
5203	struct ftrace_iterator *iter;
5204	struct trace_parser *parser;
5205	ssize_t ret, read;
5206
5207	if (!cnt)
5208	return 0;
5209
5210	if (file->f_mode & FMODE_READ) {
5211	struct seq_file *m = file->private_data;
5212	iter = m->private;
5213	} else
5214	iter = file->private_data;
5215
5216	if (unlikely(ftrace_disabled))
5217	return -ENODEV;
5218
5219	/* iter->hash is a local copy, so we don't need regex_lock */
5220
5221	parser = &iter->parser;
5222	read = trace_get_user(parser, ubuf, cnt, ppos);
5223
5224	if (read >= 0 && trace_parser_loaded(parser) &&
5225	!trace_parser_cont(parser)) {
5226	ret = ftrace_process_regex(iter, buff: parser->buffer,
5227	len: parser->idx, enable);
5228	trace_parser_clear(parser);
5229	if (ret < 0)
5230	goto out;
5231	}
5232
5233	ret = read;
5234	out:
5235	return ret;
5236	}
5237
5238	ssize_t
5239	ftrace_filter_write(struct file *file, const char __user *ubuf,
5240	size_t cnt, loff_t *ppos)
5241	{
5242	return ftrace_regex_write(file, ubuf, cnt, ppos, enable: 1);
5243	}
5244
5245	ssize_t
5246	ftrace_notrace_write(struct file *file, const char __user *ubuf,
5247	size_t cnt, loff_t *ppos)
5248	{
5249	return ftrace_regex_write(file, ubuf, cnt, ppos, enable: 0);
5250	}
5251
5252	static int
5253	__ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
5254	{
5255	struct ftrace_func_entry *entry;
5256
5257	ip = ftrace_location(ip);
5258	if (!ip)
5259	return -EINVAL;
5260
5261	if (remove) {
5262	entry = ftrace_lookup_ip(hash, ip);
5263	if (!entry)
5264	return -ENOENT;
5265	free_hash_entry(hash, entry);
5266	return 0;
5267	}
5268
5269	return add_hash_entry(hash, ip);
5270	}
5271
5272	static int
5273	ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips,
5274	unsigned int cnt, int remove)
5275	{
5276	unsigned int i;
5277	int err;
5278
5279	for (i = 0; i < cnt; i++) {
5280	err = __ftrace_match_addr(hash, ip: ips[i], remove);
5281	if (err) {
5282	/*
5283	* This expects the @hash is a temporary hash and if this
5284	* fails the caller must free the @hash.
5285	*/
5286	return err;
5287	}
5288	}
5289	return 0;
5290	}
5291
5292	static int
5293	ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
5294	unsigned long *ips, unsigned int cnt,
5295	int remove, int reset, int enable)
5296	{
5297	struct ftrace_hash **orig_hash;
5298	struct ftrace_hash *hash;
5299	int ret;
5300
5301	if (unlikely(ftrace_disabled))
5302	return -ENODEV;
5303
5304	mutex_lock(&ops->func_hash->regex_lock);
5305
5306	if (enable)
5307	orig_hash = &ops->func_hash->filter_hash;
5308	else
5309	orig_hash = &ops->func_hash->notrace_hash;
5310
5311	if (reset)
5312	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
5313	else
5314	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash: *orig_hash);
5315
5316	if (!hash) {
5317	ret = -ENOMEM;
5318	goto out_regex_unlock;
5319	}
5320
5321	if (buf && !ftrace_match_records(hash, buff: buf, len)) {
5322	ret = -EINVAL;
5323	goto out_regex_unlock;
5324	}
5325	if (ips) {
5326	ret = ftrace_match_addr(hash, ips, cnt, remove);
5327	if (ret < 0)
5328	goto out_regex_unlock;
5329	}
5330
5331	mutex_lock(&ftrace_lock);
5332	ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
5333	mutex_unlock(lock: &ftrace_lock);
5334
5335	out_regex_unlock:
5336	mutex_unlock(lock: &ops->func_hash->regex_lock);
5337
5338	free_ftrace_hash(hash);
5339	return ret;
5340	}
5341
5342	static int
5343	ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt,
5344	int remove, int reset, int enable)
5345	{
5346	return ftrace_set_hash(ops, NULL, len: 0, ips, cnt, remove, reset, enable);
5347	}
5348
5349	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
5350
5351	struct ftrace_direct_func {
5352	struct list_head next;
5353	unsigned long addr;
5354	int count;
5355	};
5356
5357	static LIST_HEAD(ftrace_direct_funcs);
5358
5359	static int register_ftrace_function_nolock(struct ftrace_ops *ops);
5360
5361	#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_ARGS)
5362
5363	static int check_direct_multi(struct ftrace_ops *ops)
5364	{
5365	if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
5366	return -EINVAL;
5367	if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS)
5368	return -EINVAL;
5369	return 0;
5370	}
5371
5372	static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr)
5373	{
5374	struct ftrace_func_entry *entry, *del;
5375	int size, i;
5376
5377	size = 1 << hash->size_bits;
5378	for (i = 0; i < size; i++) {
5379	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5380	del = __ftrace_lookup_ip(hash: direct_functions, ip: entry->ip);
5381	if (del && del->direct == addr) {
5382	remove_hash_entry(hash: direct_functions, entry: del);
5383	kfree(objp: del);
5384	}
5385	}
5386	}
5387	}
5388
5389	/**
5390	* register_ftrace_direct - Call a custom trampoline directly
5391	* for multiple functions registered in @ops
5392	* @ops: The address of the struct ftrace_ops object
5393	* @addr: The address of the trampoline to call at @ops functions
5394	*
5395	* This is used to connect a direct calls to @addr from the nop locations
5396	* of the functions registered in @ops (with by ftrace_set_filter_ip
5397	* function).
5398	*
5399	* The location that it calls (@addr) must be able to handle a direct call,
5400	* and save the parameters of the function being traced, and restore them
5401	* (or inject new ones if needed), before returning.
5402	*
5403	* Returns:
5404	* 0 on success
5405	* -EINVAL - The @ops object was already registered with this call or
5406	* when there are no functions in @ops object.
5407	* -EBUSY - Another direct function is already attached (there can be only one)
5408	* -ENODEV - @ip does not point to a ftrace nop location (or not supported)
5409	* -ENOMEM - There was an allocation failure.
5410	*/
5411	int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
5412	{
5413	struct ftrace_hash *hash, *free_hash = NULL;
5414	struct ftrace_func_entry *entry, *new;
5415	int err = -EBUSY, size, i;
5416
5417	if (ops->func || ops->trampoline)
5418	return -EINVAL;
5419	if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
5420	return -EINVAL;
5421	if (ops->flags & FTRACE_OPS_FL_ENABLED)
5422	return -EINVAL;
5423
5424	hash = ops->func_hash->filter_hash;
5425	if (ftrace_hash_empty(hash))
5426	return -EINVAL;
5427
5428	mutex_lock(&direct_mutex);
5429
5430	/* Make sure requested entries are not already registered.. */
5431	size = 1 << hash->size_bits;
5432	for (i = 0; i < size; i++) {
5433	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5434	if (ftrace_find_rec_direct(ip: entry->ip))
5435	goto out_unlock;
5436	}
5437	}
5438
5439	/* ... and insert them to direct_functions hash. */
5440	err = -ENOMEM;
5441	for (i = 0; i < size; i++) {
5442	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5443	new = ftrace_add_rec_direct(ip: entry->ip, addr, free_hash: &free_hash);
5444	if (!new)
5445	goto out_remove;
5446	entry->direct = addr;
5447	}
5448	}
5449
5450	ops->func = call_direct_funcs;
5451	ops->flags = MULTI_FLAGS;
5452	ops->trampoline = FTRACE_REGS_ADDR;
5453	ops->direct_call = addr;
5454
5455	err = register_ftrace_function_nolock(ops);
5456
5457	out_remove:
5458	if (err)
5459	remove_direct_functions_hash(hash, addr);
5460
5461	out_unlock:
5462	mutex_unlock(lock: &direct_mutex);
5463
5464	if (free_hash) {
5465	synchronize_rcu_tasks();
5466	free_ftrace_hash(hash: free_hash);
5467	}
5468	return err;
5469	}
5470	EXPORT_SYMBOL_GPL(register_ftrace_direct);
5471
5472	/**
5473	* unregister_ftrace_direct - Remove calls to custom trampoline
5474	* previously registered by register_ftrace_direct for @ops object.
5475	* @ops: The address of the struct ftrace_ops object
5476	*
5477	* This is used to remove a direct calls to @addr from the nop locations
5478	* of the functions registered in @ops (with by ftrace_set_filter_ip
5479	* function).
5480	*
5481	* Returns:
5482	* 0 on success
5483	* -EINVAL - The @ops object was not properly registered.
5484	*/
5485	int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
5486	bool free_filters)
5487	{
5488	struct ftrace_hash *hash = ops->func_hash->filter_hash;
5489	int err;
5490
5491	if (check_direct_multi(ops))
5492	return -EINVAL;
5493	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
5494	return -EINVAL;
5495
5496	mutex_lock(&direct_mutex);
5497	err = unregister_ftrace_function(ops);
5498	remove_direct_functions_hash(hash, addr);
5499	mutex_unlock(lock: &direct_mutex);
5500
5501	/* cleanup for possible another register call */
5502	ops->func = NULL;
5503	ops->trampoline = 0;
5504
5505	if (free_filters)
5506	ftrace_free_filter(ops);
5507	return err;
5508	}
5509	EXPORT_SYMBOL_GPL(unregister_ftrace_direct);
5510
5511	static int
5512	__modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
5513	{
5514	struct ftrace_hash *hash;
5515	struct ftrace_func_entry *entry, *iter;
5516	static struct ftrace_ops tmp_ops = {
5517	.func = ftrace_stub,
5518	.flags = FTRACE_OPS_FL_STUB,
5519	};
5520	int i, size;
5521	int err;
5522
5523	lockdep_assert_held_once(&direct_mutex);
5524
5525	/* Enable the tmp_ops to have the same functions as the direct ops */
5526	ftrace_ops_init(ops: &tmp_ops);
5527	tmp_ops.func_hash = ops->func_hash;
5528	tmp_ops.direct_call = addr;
5529
5530	err = register_ftrace_function_nolock(ops: &tmp_ops);
5531	if (err)
5532	return err;
5533
5534	/*
5535	* Now the ftrace_ops_list_func() is called to do the direct callers.
5536	* We can safely change the direct functions attached to each entry.
5537	*/
5538	mutex_lock(&ftrace_lock);
5539
5540	hash = ops->func_hash->filter_hash;
5541	size = 1 << hash->size_bits;
5542	for (i = 0; i < size; i++) {
5543	hlist_for_each_entry(iter, &hash->buckets[i], hlist) {
5544	entry = __ftrace_lookup_ip(hash: direct_functions, ip: iter->ip);
5545	if (!entry)
5546	continue;
5547	entry->direct = addr;
5548	}
5549	}
5550	/* Prevent store tearing if a trampoline concurrently accesses the value */
5551	WRITE_ONCE(ops->direct_call, addr);
5552
5553	mutex_unlock(lock: &ftrace_lock);
5554
5555	/* Removing the tmp_ops will add the updated direct callers to the functions */
5556	unregister_ftrace_function(ops: &tmp_ops);
5557
5558	return err;
5559	}
5560
5561	/**
5562	* modify_ftrace_direct_nolock - Modify an existing direct 'multi' call
5563	* to call something else
5564	* @ops: The address of the struct ftrace_ops object
5565	* @addr: The address of the new trampoline to call at @ops functions
5566	*
5567	* This is used to unregister currently registered direct caller and
5568	* register new one @addr on functions registered in @ops object.
5569	*
5570	* Note there's window between ftrace_shutdown and ftrace_startup calls
5571	* where there will be no callbacks called.
5572	*
5573	* Caller should already have direct_mutex locked, so we don't lock
5574	* direct_mutex here.
5575	*
5576	* Returns: zero on success. Non zero on error, which includes:
5577	* -EINVAL - The @ops object was not properly registered.
5578	*/
5579	int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr)
5580	{
5581	if (check_direct_multi(ops))
5582	return -EINVAL;
5583	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
5584	return -EINVAL;
5585
5586	return __modify_ftrace_direct(ops, addr);
5587	}
5588	EXPORT_SYMBOL_GPL(modify_ftrace_direct_nolock);
5589
5590	/**
5591	* modify_ftrace_direct - Modify an existing direct 'multi' call
5592	* to call something else
5593	* @ops: The address of the struct ftrace_ops object
5594	* @addr: The address of the new trampoline to call at @ops functions
5595	*
5596	* This is used to unregister currently registered direct caller and
5597	* register new one @addr on functions registered in @ops object.
5598	*
5599	* Note there's window between ftrace_shutdown and ftrace_startup calls
5600	* where there will be no callbacks called.
5601	*
5602	* Returns: zero on success. Non zero on error, which includes:
5603	* -EINVAL - The @ops object was not properly registered.
5604	*/
5605	int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
5606	{
5607	int err;
5608
5609	if (check_direct_multi(ops))
5610	return -EINVAL;
5611	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
5612	return -EINVAL;
5613
5614	mutex_lock(&direct_mutex);
5615	err = __modify_ftrace_direct(ops, addr);
5616	mutex_unlock(lock: &direct_mutex);
5617	return err;
5618	}
5619	EXPORT_SYMBOL_GPL(modify_ftrace_direct);
5620	#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
5621
5622	/**
5623	* ftrace_set_filter_ip - set a function to filter on in ftrace by address
5624	* @ops - the ops to set the filter with
5625	* @ip - the address to add to or remove from the filter.
5626	* @remove - non zero to remove the ip from the filter
5627	* @reset - non zero to reset all filters before applying this filter.
5628	*
5629	* Filters denote which functions should be enabled when tracing is enabled
5630	* If @ip is NULL, it fails to update filter.
5631	*
5632	* This can allocate memory which must be freed before @ops can be freed,
5633	* either by removing each filtered addr or by using
5634	* ftrace_free_filter(@ops).
5635	*/
5636	int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
5637	int remove, int reset)
5638	{
5639	ftrace_ops_init(ops);
5640	return ftrace_set_addr(ops, ips: &ip, cnt: 1, remove, reset, enable: 1);
5641	}
5642	EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
5643
5644	/**
5645	* ftrace_set_filter_ips - set functions to filter on in ftrace by addresses
5646	* @ops - the ops to set the filter with
5647	* @ips - the array of addresses to add to or remove from the filter.
5648	* @cnt - the number of addresses in @ips
5649	* @remove - non zero to remove ips from the filter
5650	* @reset - non zero to reset all filters before applying this filter.
5651	*
5652	* Filters denote which functions should be enabled when tracing is enabled
5653	* If @ips array or any ip specified within is NULL , it fails to update filter.
5654	*
5655	* This can allocate memory which must be freed before @ops can be freed,
5656	* either by removing each filtered addr or by using
5657	* ftrace_free_filter(@ops).
5658	*/
5659	int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
5660	unsigned int cnt, int remove, int reset)
5661	{
5662	ftrace_ops_init(ops);
5663	return ftrace_set_addr(ops, ips, cnt, remove, reset, enable: 1);
5664	}
5665	EXPORT_SYMBOL_GPL(ftrace_set_filter_ips);
5666
5667	/**
5668	* ftrace_ops_set_global_filter - setup ops to use global filters
5669	* @ops - the ops which will use the global filters
5670	*
5671	* ftrace users who need global function trace filtering should call this.
5672	* It can set the global filter only if ops were not initialized before.
5673	*/
5674	void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
5675	{
5676	if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
5677	return;
5678
5679	ftrace_ops_init(ops);
5680	ops->func_hash = &global_ops.local_hash;
5681	}
5682	EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
5683
5684	static int
5685	ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
5686	int reset, int enable)
5687	{
5688	return ftrace_set_hash(ops, buf, len, NULL, cnt: 0, remove: 0, reset, enable);
5689	}
5690
5691	/**
5692	* ftrace_set_filter - set a function to filter on in ftrace
5693	* @ops - the ops to set the filter with
5694	* @buf - the string that holds the function filter text.
5695	* @len - the length of the string.
5696	* @reset - non zero to reset all filters before applying this filter.
5697	*
5698	* Filters denote which functions should be enabled when tracing is enabled.
5699	* If @buf is NULL and reset is set, all functions will be enabled for tracing.
5700	*
5701	* This can allocate memory which must be freed before @ops can be freed,
5702	* either by removing each filtered addr or by using
5703	* ftrace_free_filter(@ops).
5704	*/
5705	int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
5706	int len, int reset)
5707	{
5708	ftrace_ops_init(ops);
5709	return ftrace_set_regex(ops, buf, len, reset, enable: 1);
5710	}
5711	EXPORT_SYMBOL_GPL(ftrace_set_filter);
5712
5713	/**
5714	* ftrace_set_notrace - set a function to not trace in ftrace
5715	* @ops - the ops to set the notrace filter with
5716	* @buf - the string that holds the function notrace text.
5717	* @len - the length of the string.
5718	* @reset - non zero to reset all filters before applying this filter.
5719	*
5720	* Notrace Filters denote which functions should not be enabled when tracing
5721	* is enabled. If @buf is NULL and reset is set, all functions will be enabled
5722	* for tracing.
5723	*
5724	* This can allocate memory which must be freed before @ops can be freed,
5725	* either by removing each filtered addr or by using
5726	* ftrace_free_filter(@ops).
5727	*/
5728	int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
5729	int len, int reset)
5730	{
5731	ftrace_ops_init(ops);
5732	return ftrace_set_regex(ops, buf, len, reset, enable: 0);
5733	}
5734	EXPORT_SYMBOL_GPL(ftrace_set_notrace);
5735	/**
5736	* ftrace_set_global_filter - set a function to filter on with global tracers
5737	* @buf - the string that holds the function filter text.
5738	* @len - the length of the string.
5739	* @reset - non zero to reset all filters before applying this filter.
5740	*
5741	* Filters denote which functions should be enabled when tracing is enabled.
5742	* If @buf is NULL and reset is set, all functions will be enabled for tracing.
5743	*/
5744	void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
5745	{
5746	ftrace_set_regex(ops: &global_ops, buf, len, reset, enable: 1);
5747	}
5748	EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
5749
5750	/**
5751	* ftrace_set_global_notrace - set a function to not trace with global tracers
5752	* @buf - the string that holds the function notrace text.
5753	* @len - the length of the string.
5754	* @reset - non zero to reset all filters before applying this filter.
5755	*
5756	* Notrace Filters denote which functions should not be enabled when tracing
5757	* is enabled. If @buf is NULL and reset is set, all functions will be enabled
5758	* for tracing.
5759	*/
5760	void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
5761	{
5762	ftrace_set_regex(ops: &global_ops, buf, len, reset, enable: 0);
5763	}
5764	EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
5765
5766	/*
5767	* command line interface to allow users to set filters on boot up.
5768	*/
5769	#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
5770	static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
5771	static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
5772
5773	/* Used by function selftest to not test if filter is set */
5774	bool ftrace_filter_param __initdata;
5775
5776	static int __init set_ftrace_notrace(char *str)
5777	{
5778	ftrace_filter_param = true;
5779	strscpy(p: ftrace_notrace_buf, q: str, FTRACE_FILTER_SIZE);
5780	return 1;
5781	}
5782	__setup("ftrace_notrace=", set_ftrace_notrace);
5783
5784	static int __init set_ftrace_filter(char *str)
5785	{
5786	ftrace_filter_param = true;
5787	strscpy(p: ftrace_filter_buf, q: str, FTRACE_FILTER_SIZE);
5788	return 1;
5789	}
5790	__setup("ftrace_filter=", set_ftrace_filter);
5791
5792	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
5793	static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
5794	static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
5795	static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
5796
5797	static int __init set_graph_function(char *str)
5798	{
5799	strscpy(p: ftrace_graph_buf, q: str, FTRACE_FILTER_SIZE);
5800	return 1;
5801	}
5802	__setup("ftrace_graph_filter=", set_graph_function);
5803
5804	static int __init set_graph_notrace_function(char *str)
5805	{
5806	strscpy(p: ftrace_graph_notrace_buf, q: str, FTRACE_FILTER_SIZE);
5807	return 1;
5808	}
5809	__setup("ftrace_graph_notrace=", set_graph_notrace_function);
5810
5811	static int __init set_graph_max_depth_function(char *str)
5812	{
5813	if (!str)
5814	return 0;
5815	fgraph_max_depth = simple_strtoul(str, NULL, 0);
5816	return 1;
5817	}
5818	__setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
5819
5820	static void __init set_ftrace_early_graph(char *buf, int enable)
5821	{
5822	int ret;
5823	char *func;
5824	struct ftrace_hash *hash;
5825
5826	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
5827	if (MEM_FAIL(!hash, "Failed to allocate hash\n"))
5828	return;
5829
5830	while (buf) {
5831	func = strsep(&buf, ",");
5832	/* we allow only one expression at a time */
5833	ret = ftrace_graph_set_hash(hash, buffer: func);
5834	if (ret)
5835	printk(KERN_DEBUG "ftrace: function %s not "
5836	"traceable\n", func);
5837	}
5838
5839	if (enable)
5840	ftrace_graph_hash = hash;
5841	else
5842	ftrace_graph_notrace_hash = hash;
5843	}
5844	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5845
5846	void __init
5847	ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
5848	{
5849	char *func;
5850
5851	ftrace_ops_init(ops);
5852
5853	while (buf) {
5854	func = strsep(&buf, ",");
5855	ftrace_set_regex(ops, buf: func, strlen(func), reset: 0, enable);
5856	}
5857	}
5858
5859	static void __init set_ftrace_early_filters(void)
5860	{
5861	if (ftrace_filter_buf[0])
5862	ftrace_set_early_filter(ops: &global_ops, buf: ftrace_filter_buf, enable: 1);
5863	if (ftrace_notrace_buf[0])
5864	ftrace_set_early_filter(ops: &global_ops, buf: ftrace_notrace_buf, enable: 0);
5865	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
5866	if (ftrace_graph_buf[0])
5867	set_ftrace_early_graph(buf: ftrace_graph_buf, enable: 1);
5868	if (ftrace_graph_notrace_buf[0])
5869	set_ftrace_early_graph(buf: ftrace_graph_notrace_buf, enable: 0);
5870	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5871	}
5872
5873	int ftrace_regex_release(struct inode *inode, struct file *file)
5874	{
5875	struct seq_file *m = (struct seq_file *)file->private_data;
5876	struct ftrace_iterator *iter;
5877	struct ftrace_hash **orig_hash;
5878	struct trace_parser *parser;
5879	int filter_hash;
5880
5881	if (file->f_mode & FMODE_READ) {
5882	iter = m->private;
5883	seq_release(inode, file);
5884	} else
5885	iter = file->private_data;
5886
5887	parser = &iter->parser;
5888	if (trace_parser_loaded(parser)) {
5889	int enable = !(iter->flags & FTRACE_ITER_NOTRACE);
5890
5891	ftrace_process_regex(iter, buff: parser->buffer,
5892	len: parser->idx, enable);
5893	}
5894
5895	trace_parser_put(parser);
5896
5897	mutex_lock(&iter->ops->func_hash->regex_lock);
5898
5899	if (file->f_mode & FMODE_WRITE) {
5900	filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5901
5902	if (filter_hash) {
5903	orig_hash = &iter->ops->func_hash->filter_hash;
5904	if (iter->tr) {
5905	if (list_empty(head: &iter->tr->mod_trace))
5906	iter->hash->flags &= ~FTRACE_HASH_FL_MOD;
5907	else
5908	iter->hash->flags |= FTRACE_HASH_FL_MOD;
5909	}
5910	} else
5911	orig_hash = &iter->ops->func_hash->notrace_hash;
5912
5913	mutex_lock(&ftrace_lock);
5914	ftrace_hash_move_and_update_ops(ops: iter->ops, orig_hash,
5915	hash: iter->hash, enable: filter_hash);
5916	mutex_unlock(lock: &ftrace_lock);
5917	} else {
5918	/* For read only, the hash is the ops hash */
5919	iter->hash = NULL;
5920	}
5921
5922	mutex_unlock(lock: &iter->ops->func_hash->regex_lock);
5923	free_ftrace_hash(hash: iter->hash);
5924	if (iter->tr)
5925	trace_array_put(tr: iter->tr);
5926	kfree(objp: iter);
5927
5928	return 0;
5929	}
5930
5931	static const struct file_operations ftrace_avail_fops = {
5932	.open = ftrace_avail_open,
5933	.read = seq_read,
5934	.llseek = seq_lseek,
5935	.release = seq_release_private,
5936	};
5937
5938	static const struct file_operations ftrace_enabled_fops = {
5939	.open = ftrace_enabled_open,
5940	.read = seq_read,
5941	.llseek = seq_lseek,
5942	.release = seq_release_private,
5943	};
5944
5945	static const struct file_operations ftrace_touched_fops = {
5946	.open = ftrace_touched_open,
5947	.read = seq_read,
5948	.llseek = seq_lseek,
5949	.release = seq_release_private,
5950	};
5951
5952	static const struct file_operations ftrace_avail_addrs_fops = {
5953	.open = ftrace_avail_addrs_open,
5954	.read = seq_read,
5955	.llseek = seq_lseek,
5956	.release = seq_release_private,
5957	};
5958
5959	static const struct file_operations ftrace_filter_fops = {
5960	.open = ftrace_filter_open,
5961	.read = seq_read,
5962	.write = ftrace_filter_write,
5963	.llseek = tracing_lseek,
5964	.release = ftrace_regex_release,
5965	};
5966
5967	static const struct file_operations ftrace_notrace_fops = {
5968	.open = ftrace_notrace_open,
5969	.read = seq_read,
5970	.write = ftrace_notrace_write,
5971	.llseek = tracing_lseek,
5972	.release = ftrace_regex_release,
5973	};
5974
5975	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
5976
5977	static DEFINE_MUTEX(graph_lock);
5978
5979	struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH;
5980	struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH;
5981
5982	enum graph_filter_type {
5983	GRAPH_FILTER_NOTRACE = 0,
5984	GRAPH_FILTER_FUNCTION,
5985	};
5986
5987	#define FTRACE_GRAPH_EMPTY ((void *)1)
5988
5989	struct ftrace_graph_data {
5990	struct ftrace_hash *hash;
5991	struct ftrace_func_entry *entry;
5992	int idx; /* for hash table iteration */
5993	enum graph_filter_type type;
5994	struct ftrace_hash *new_hash;
5995	const struct seq_operations *seq_ops;
5996	struct trace_parser parser;
5997	};
5998
5999	static void *
6000	__g_next(struct seq_file *m, loff_t *pos)
6001	{
6002	struct ftrace_graph_data *fgd = m->private;
6003	struct ftrace_func_entry *entry = fgd->entry;
6004	struct hlist_head *head;
6005	int i, idx = fgd->idx;
6006
6007	if (*pos >= fgd->hash->count)
6008	return NULL;
6009
6010	if (entry) {
6011	hlist_for_each_entry_continue(entry, hlist) {
6012	fgd->entry = entry;
6013	return entry;
6014	}
6015
6016	idx++;
6017	}
6018
6019	for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
6020	head = &fgd->hash->buckets[i];
6021	hlist_for_each_entry(entry, head, hlist) {
6022	fgd->entry = entry;
6023	fgd->idx = i;
6024	return entry;
6025	}
6026	}
6027	return NULL;
6028	}
6029
6030	static void *
6031	g_next(struct seq_file *m, void *v, loff_t *pos)
6032	{
6033	(*pos)++;
6034	return __g_next(m, pos);
6035	}
6036
6037	static void *g_start(struct seq_file *m, loff_t *pos)
6038	{
6039	struct ftrace_graph_data *fgd = m->private;
6040
6041	mutex_lock(&graph_lock);
6042
6043	if (fgd->type == GRAPH_FILTER_FUNCTION)
6044	fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
6045	lockdep_is_held(&graph_lock));
6046	else
6047	fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6048	lockdep_is_held(&graph_lock));
6049
6050	/* Nothing, tell g_show to print all functions are enabled */
6051	if (ftrace_hash_empty(hash: fgd->hash) && !*pos)
6052	return FTRACE_GRAPH_EMPTY;
6053
6054	fgd->idx = 0;
6055	fgd->entry = NULL;
6056	return __g_next(m, pos);
6057	}
6058
6059	static void g_stop(struct seq_file *m, void *p)
6060	{
6061	mutex_unlock(lock: &graph_lock);
6062	}
6063
6064	static int g_show(struct seq_file *m, void *v)
6065	{
6066	struct ftrace_func_entry *entry = v;
6067
6068	if (!entry)
6069	return 0;
6070
6071	if (entry == FTRACE_GRAPH_EMPTY) {
6072	struct ftrace_graph_data *fgd = m->private;
6073
6074	if (fgd->type == GRAPH_FILTER_FUNCTION)
6075	seq_puts(m, s: "#### all functions enabled ####\n");
6076	else
6077	seq_puts(m, s: "#### no functions disabled ####\n");
6078	return 0;
6079	}
6080
6081	seq_printf(m, fmt: "%ps\n", (void *)entry->ip);
6082
6083	return 0;
6084	}
6085
6086	static const struct seq_operations ftrace_graph_seq_ops = {
6087	.start = g_start,
6088	.next = g_next,
6089	.stop = g_stop,
6090	.show = g_show,
6091	};
6092
6093	static int
6094	__ftrace_graph_open(struct inode *inode, struct file *file,
6095	struct ftrace_graph_data *fgd)
6096	{
6097	int ret;
6098	struct ftrace_hash *new_hash = NULL;
6099
6100	ret = security_locked_down(what: LOCKDOWN_TRACEFS);
6101	if (ret)
6102	return ret;
6103
6104	if (file->f_mode & FMODE_WRITE) {
6105	const int size_bits = FTRACE_HASH_DEFAULT_BITS;
6106
6107	if (trace_parser_get_init(parser: &fgd->parser, FTRACE_BUFF_MAX))
6108	return -ENOMEM;
6109
6110	if (file->f_flags & O_TRUNC)
6111	new_hash = alloc_ftrace_hash(size_bits);
6112	else
6113	new_hash = alloc_and_copy_ftrace_hash(size_bits,
6114	hash: fgd->hash);
6115	if (!new_hash) {
6116	ret = -ENOMEM;
6117	goto out;
6118	}
6119	}
6120
6121	if (file->f_mode & FMODE_READ) {
6122	ret = seq_open(file, &ftrace_graph_seq_ops);
6123	if (!ret) {
6124	struct seq_file *m = file->private_data;
6125	m->private = fgd;
6126	} else {
6127	/* Failed */
6128	free_ftrace_hash(hash: new_hash);
6129	new_hash = NULL;
6130	}
6131	} else
6132	file->private_data = fgd;
6133
6134	out:
6135	if (ret < 0 && file->f_mode & FMODE_WRITE)
6136	trace_parser_put(parser: &fgd->parser);
6137
6138	fgd->new_hash = new_hash;
6139
6140	/*
6141	* All uses of fgd->hash must be taken with the graph_lock
6142	* held. The graph_lock is going to be released, so force
6143	* fgd->hash to be reinitialized when it is taken again.
6144	*/
6145	fgd->hash = NULL;
6146
6147	return ret;
6148	}
6149
6150	static int
6151	ftrace_graph_open(struct inode *inode, struct file *file)
6152	{
6153	struct ftrace_graph_data *fgd;
6154	int ret;
6155
6156	if (unlikely(ftrace_disabled))
6157	return -ENODEV;
6158
6159	fgd = kmalloc(size: sizeof(*fgd), GFP_KERNEL);
6160	if (fgd == NULL)
6161	return -ENOMEM;
6162
6163	mutex_lock(&graph_lock);
6164
6165	fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
6166	lockdep_is_held(&graph_lock));
6167	fgd->type = GRAPH_FILTER_FUNCTION;
6168	fgd->seq_ops = &ftrace_graph_seq_ops;
6169
6170	ret = __ftrace_graph_open(inode, file, fgd);
6171	if (ret < 0)
6172	kfree(objp: fgd);
6173
6174	mutex_unlock(lock: &graph_lock);
6175	return ret;
6176	}
6177
6178	static int
6179	ftrace_graph_notrace_open(struct inode *inode, struct file *file)
6180	{
6181	struct ftrace_graph_data *fgd;
6182	int ret;
6183
6184	if (unlikely(ftrace_disabled))
6185	return -ENODEV;
6186
6187	fgd = kmalloc(size: sizeof(*fgd), GFP_KERNEL);
6188	if (fgd == NULL)
6189	return -ENOMEM;
6190
6191	mutex_lock(&graph_lock);
6192
6193	fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6194	lockdep_is_held(&graph_lock));
6195	fgd->type = GRAPH_FILTER_NOTRACE;
6196	fgd->seq_ops = &ftrace_graph_seq_ops;
6197
6198	ret = __ftrace_graph_open(inode, file, fgd);
6199	if (ret < 0)
6200	kfree(objp: fgd);
6201
6202	mutex_unlock(lock: &graph_lock);
6203	return ret;
6204	}
6205
6206	static int
6207	ftrace_graph_release(struct inode *inode, struct file *file)
6208	{
6209	struct ftrace_graph_data *fgd;
6210	struct ftrace_hash *old_hash, *new_hash;
6211	struct trace_parser *parser;
6212	int ret = 0;
6213
6214	if (file->f_mode & FMODE_READ) {
6215	struct seq_file *m = file->private_data;
6216
6217	fgd = m->private;
6218	seq_release(inode, file);
6219	} else {
6220	fgd = file->private_data;
6221	}
6222
6223
6224	if (file->f_mode & FMODE_WRITE) {
6225
6226	parser = &fgd->parser;
6227
6228	if (trace_parser_loaded((parser))) {
6229	ret = ftrace_graph_set_hash(hash: fgd->new_hash,
6230	buffer: parser->buffer);
6231	}
6232
6233	trace_parser_put(parser);
6234
6235	new_hash = __ftrace_hash_move(src: fgd->new_hash);
6236	if (!new_hash) {
6237	ret = -ENOMEM;
6238	goto out;
6239	}
6240
6241	mutex_lock(&graph_lock);
6242
6243	if (fgd->type == GRAPH_FILTER_FUNCTION) {
6244	old_hash = rcu_dereference_protected(ftrace_graph_hash,
6245	lockdep_is_held(&graph_lock));
6246	rcu_assign_pointer(ftrace_graph_hash, new_hash);
6247	} else {
6248	old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6249	lockdep_is_held(&graph_lock));
6250	rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
6251	}
6252
6253	mutex_unlock(lock: &graph_lock);
6254
6255	/*
6256	* We need to do a hard force of sched synchronization.
6257	* This is because we use preempt_disable() to do RCU, but
6258	* the function tracers can be called where RCU is not watching
6259	* (like before user_exit()). We can not rely on the RCU
6260	* infrastructure to do the synchronization, thus we must do it
6261	* ourselves.
6262	*/
6263	if (old_hash != EMPTY_HASH)
6264	synchronize_rcu_tasks_rude();
6265
6266	free_ftrace_hash(hash: old_hash);
6267	}
6268
6269	out:
6270	free_ftrace_hash(hash: fgd->new_hash);
6271	kfree(objp: fgd);
6272
6273	return ret;
6274	}
6275
6276	static int
6277	ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
6278	{
6279	struct ftrace_glob func_g;
6280	struct dyn_ftrace *rec;
6281	struct ftrace_page *pg;
6282	struct ftrace_func_entry *entry;
6283	int fail = 1;
6284	int not;
6285
6286	/* decode regex */
6287	func_g.type = filter_parse_regex(buff: buffer, strlen(buffer),
6288	search: &func_g.search, not: &not);
6289
6290	func_g.len = strlen(func_g.search);
6291
6292	mutex_lock(&ftrace_lock);
6293
6294	if (unlikely(ftrace_disabled)) {
6295	mutex_unlock(lock: &ftrace_lock);
6296	return -ENODEV;
6297	}
6298
6299	do_for_each_ftrace_rec(pg, rec) {
6300
6301	if (rec->flags & FTRACE_FL_DISABLED)
6302	continue;
6303
6304	if (ftrace_match_record(rec, func_g: &func_g, NULL, exclude_mod: 0)) {
6305	entry = ftrace_lookup_ip(hash, ip: rec->ip);
6306
6307	if (!not) {
6308	fail = 0;
6309
6310	if (entry)
6311	continue;
6312	if (add_hash_entry(hash, ip: rec->ip) < 0)
6313	goto out;
6314	} else {
6315	if (entry) {
6316	free_hash_entry(hash, entry);
6317	fail = 0;
6318	}
6319	}
6320	}
6321	} while_for_each_ftrace_rec();
6322	out:
6323	mutex_unlock(lock: &ftrace_lock);
6324
6325	if (fail)
6326	return -EINVAL;
6327
6328	return 0;
6329	}
6330
6331	static ssize_t
6332	ftrace_graph_write(struct file *file, const char __user *ubuf,
6333	size_t cnt, loff_t *ppos)
6334	{
6335	ssize_t read, ret = 0;
6336	struct ftrace_graph_data *fgd = file->private_data;
6337	struct trace_parser *parser;
6338
6339	if (!cnt)
6340	return 0;
6341
6342	/* Read mode uses seq functions */
6343	if (file->f_mode & FMODE_READ) {
6344	struct seq_file *m = file->private_data;
6345	fgd = m->private;
6346	}
6347
6348	parser = &fgd->parser;
6349
6350	read = trace_get_user(parser, ubuf, cnt, ppos);
6351
6352	if (read >= 0 && trace_parser_loaded(parser) &&
6353	!trace_parser_cont(parser)) {
6354
6355	ret = ftrace_graph_set_hash(hash: fgd->new_hash,
6356	buffer: parser->buffer);
6357	trace_parser_clear(parser);
6358	}
6359
6360	if (!ret)
6361	ret = read;
6362
6363	return ret;
6364	}
6365
6366	static const struct file_operations ftrace_graph_fops = {
6367	.open = ftrace_graph_open,
6368	.read = seq_read,
6369	.write = ftrace_graph_write,
6370	.llseek = tracing_lseek,
6371	.release = ftrace_graph_release,
6372	};
6373
6374	static const struct file_operations ftrace_graph_notrace_fops = {
6375	.open = ftrace_graph_notrace_open,
6376	.read = seq_read,
6377	.write = ftrace_graph_write,
6378	.llseek = tracing_lseek,
6379	.release = ftrace_graph_release,
6380	};
6381	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
6382
6383	void ftrace_create_filter_files(struct ftrace_ops *ops,
6384	struct dentry *parent)
6385	{
6386
6387	trace_create_file(name: "set_ftrace_filter", TRACE_MODE_WRITE, parent,
6388	data: ops, fops: &ftrace_filter_fops);
6389
6390	trace_create_file(name: "set_ftrace_notrace", TRACE_MODE_WRITE, parent,
6391	data: ops, fops: &ftrace_notrace_fops);
6392	}
6393
6394	/*
6395	* The name "destroy_filter_files" is really a misnomer. Although
6396	* in the future, it may actually delete the files, but this is
6397	* really intended to make sure the ops passed in are disabled
6398	* and that when this function returns, the caller is free to
6399	* free the ops.
6400	*
6401	* The "destroy" name is only to match the "create" name that this
6402	* should be paired with.
6403	*/
6404	void ftrace_destroy_filter_files(struct ftrace_ops *ops)
6405	{
6406	mutex_lock(&ftrace_lock);
6407	if (ops->flags & FTRACE_OPS_FL_ENABLED)
6408	ftrace_shutdown(ops, command: 0);
6409	ops->flags |= FTRACE_OPS_FL_DELETED;
6410	ftrace_free_filter(ops);
6411	mutex_unlock(lock: &ftrace_lock);
6412	}
6413
6414	static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
6415	{
6416
6417	trace_create_file(name: "available_filter_functions", TRACE_MODE_READ,
6418	parent: d_tracer, NULL, fops: &ftrace_avail_fops);
6419
6420	trace_create_file(name: "available_filter_functions_addrs", TRACE_MODE_READ,
6421	parent: d_tracer, NULL, fops: &ftrace_avail_addrs_fops);
6422
6423	trace_create_file(name: "enabled_functions", TRACE_MODE_READ,
6424	parent: d_tracer, NULL, fops: &ftrace_enabled_fops);
6425
6426	trace_create_file(name: "touched_functions", TRACE_MODE_READ,
6427	parent: d_tracer, NULL, fops: &ftrace_touched_fops);
6428
6429	ftrace_create_filter_files(ops: &global_ops, parent: d_tracer);
6430
6431	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
6432	trace_create_file(name: "set_graph_function", TRACE_MODE_WRITE, parent: d_tracer,
6433	NULL,
6434	fops: &ftrace_graph_fops);
6435	trace_create_file(name: "set_graph_notrace", TRACE_MODE_WRITE, parent: d_tracer,
6436	NULL,
6437	fops: &ftrace_graph_notrace_fops);
6438	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
6439
6440	return 0;
6441	}
6442
6443	static int ftrace_cmp_ips(const void *a, const void *b)
6444	{
6445	const unsigned long *ipa = a;
6446	const unsigned long *ipb = b;
6447
6448	if (*ipa > *ipb)
6449	return 1;
6450	if (*ipa < *ipb)
6451	return -1;
6452	return 0;
6453	}
6454
6455	#ifdef CONFIG_FTRACE_SORT_STARTUP_TEST
6456	static void test_is_sorted(unsigned long *start, unsigned long count)
6457	{
6458	int i;
6459
6460	for (i = 1; i < count; i++) {
6461	if (WARN(start[i - 1] > start[i],
6462	"[%d] %pS at %lx is not sorted with %pS at %lx\n", i,
6463	(void *)start[i - 1], start[i - 1],
6464	(void *)start[i], start[i]))
6465	break;
6466	}
6467	if (i == count)
6468	pr_info("ftrace section at %px sorted properly\n", start);
6469	}
6470	#else
6471	static void test_is_sorted(unsigned long *start, unsigned long count)
6472	{
6473	}
6474	#endif
6475
6476	static int ftrace_process_locs(struct module *mod,
6477	unsigned long *start,
6478	unsigned long *end)
6479	{
6480	struct ftrace_page *pg_unuse = NULL;
6481	struct ftrace_page *start_pg;
6482	struct ftrace_page *pg;
6483	struct dyn_ftrace *rec;
6484	unsigned long skipped = 0;
6485	unsigned long count;
6486	unsigned long *p;
6487	unsigned long addr;
6488	unsigned long flags = 0; /* Shut up gcc */
6489	int ret = -ENOMEM;
6490
6491	count = end - start;
6492
6493	if (!count)
6494	return 0;
6495
6496	/*
6497	* Sorting mcount in vmlinux at build time depend on
6498	* CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in
6499	* modules can not be sorted at build time.
6500	*/
6501	if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) {
6502	sort(base: start, num: count, size: sizeof(*start),
6503	cmp_func: ftrace_cmp_ips, NULL);
6504	} else {
6505	test_is_sorted(start, count);
6506	}
6507
6508	start_pg = ftrace_allocate_pages(num_to_init: count);
6509	if (!start_pg)
6510	return -ENOMEM;
6511
6512	mutex_lock(&ftrace_lock);
6513
6514	/*
6515	* Core and each module needs their own pages, as
6516	* modules will free them when they are removed.
6517	* Force a new page to be allocated for modules.
6518	*/
6519	if (!mod) {
6520	WARN_ON(ftrace_pages || ftrace_pages_start);
6521	/* First initialization */
6522	ftrace_pages = ftrace_pages_start = start_pg;
6523	} else {
6524	if (!ftrace_pages)
6525	goto out;
6526
6527	if (WARN_ON(ftrace_pages->next)) {
6528	/* Hmm, we have free pages? */
6529	while (ftrace_pages->next)
6530	ftrace_pages = ftrace_pages->next;
6531	}
6532
6533	ftrace_pages->next = start_pg;
6534	}
6535
6536	p = start;
6537	pg = start_pg;
6538	while (p < end) {
6539	unsigned long end_offset;
6540	addr = ftrace_call_adjust(addr: *p++);
6541	/*
6542	* Some architecture linkers will pad between
6543	* the different mcount_loc sections of different
6544	* object files to satisfy alignments.
6545	* Skip any NULL pointers.
6546	*/
6547	if (!addr) {
6548	skipped++;
6549	continue;
6550	}
6551
6552	end_offset = (pg->index+1) * sizeof(pg->records[0]);
6553	if (end_offset > PAGE_SIZE << pg->order) {
6554	/* We should have allocated enough */
6555	if (WARN_ON(!pg->next))
6556	break;
6557	pg = pg->next;
6558	}
6559
6560	rec = &pg->records[pg->index++];
6561	rec->ip = addr;
6562	}
6563
6564	if (pg->next) {
6565	pg_unuse = pg->next;
6566	pg->next = NULL;
6567	}
6568
6569	/* Assign the last page to ftrace_pages */
6570	ftrace_pages = pg;
6571
6572	/*
6573	* We only need to disable interrupts on start up
6574	* because we are modifying code that an interrupt
6575	* may execute, and the modification is not atomic.
6576	* But for modules, nothing runs the code we modify
6577	* until we are finished with it, and there's no
6578	* reason to cause large interrupt latencies while we do it.
6579	*/
6580	if (!mod)
6581	local_irq_save(flags);
6582	ftrace_update_code(mod, new_pgs: start_pg);
6583	if (!mod)
6584	local_irq_restore(flags);
6585	ret = 0;
6586	out:
6587	mutex_unlock(lock: &ftrace_lock);
6588
6589	/* We should have used all pages unless we skipped some */
6590	if (pg_unuse) {
6591	WARN_ON(!skipped);
6592	ftrace_free_pages(pages: pg_unuse);
6593	}
6594	return ret;
6595	}
6596
6597	struct ftrace_mod_func {
6598	struct list_head list;
6599	char *name;
6600	unsigned long ip;
6601	unsigned int size;
6602	};
6603
6604	struct ftrace_mod_map {
6605	struct rcu_head rcu;
6606	struct list_head list;
6607	struct module *mod;
6608	unsigned long start_addr;
6609	unsigned long end_addr;
6610	struct list_head funcs;
6611	unsigned int num_funcs;
6612	};
6613
6614	static int ftrace_get_trampoline_kallsym(unsigned int symnum,
6615	unsigned long *value, char *type,
6616	char *name, char *module_name,
6617	int *exported)
6618	{
6619	struct ftrace_ops *op;
6620
6621	list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) {
6622	if (!op->trampoline || symnum--)
6623	continue;
6624	*value = op->trampoline;
6625	*type = 't';
6626	strscpy(p: name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
6627	strscpy(p: module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);
6628	*exported = 0;
6629	return 0;
6630	}
6631
6632	return -ERANGE;
6633	}
6634
6635	#if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) || defined(CONFIG_MODULES)
6636	/*
6637	* Check if the current ops references the given ip.
6638	*
6639	* If the ops traces all functions, then it was already accounted for.
6640	* If the ops does not trace the current record function, skip it.
6641	* If the ops ignores the function via notrace filter, skip it.
6642	*/
6643	static bool
6644	ops_references_ip(struct ftrace_ops *ops, unsigned long ip)
6645	{
6646	/* If ops isn't enabled, ignore it */
6647	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
6648	return false;
6649
6650	/* If ops traces all then it includes this function */
6651	if (ops_traces_mod(ops))
6652	return true;
6653
6654	/* The function must be in the filter */
6655	if (!ftrace_hash_empty(hash: ops->func_hash->filter_hash) &&
6656	!__ftrace_lookup_ip(hash: ops->func_hash->filter_hash, ip))
6657	return false;
6658
6659	/* If in notrace hash, we ignore it too */
6660	if (ftrace_lookup_ip(hash: ops->func_hash->notrace_hash, ip))
6661	return false;
6662
6663	return true;
6664	}
6665	#endif
6666
6667	#ifdef CONFIG_MODULES
6668
6669	#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
6670
6671	static LIST_HEAD(ftrace_mod_maps);
6672
6673	static int referenced_filters(struct dyn_ftrace *rec)
6674	{
6675	struct ftrace_ops *ops;
6676	int cnt = 0;
6677
6678	for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
6679	if (ops_references_ip(ops, ip: rec->ip)) {
6680	if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT))
6681	continue;
6682	if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY))
6683	continue;
6684	cnt++;
6685	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
6686	rec->flags |= FTRACE_FL_REGS;
6687	if (cnt == 1 && ops->trampoline)
6688	rec->flags |= FTRACE_FL_TRAMP;
6689	else
6690	rec->flags &= ~FTRACE_FL_TRAMP;
6691	}
6692	}
6693
6694	return cnt;
6695	}
6696
6697	static void
6698	clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
6699	{
6700	struct ftrace_func_entry *entry;
6701	struct dyn_ftrace *rec;
6702	int i;
6703
6704	if (ftrace_hash_empty(hash))
6705	return;
6706
6707	for (i = 0; i < pg->index; i++) {
6708	rec = &pg->records[i];
6709	entry = __ftrace_lookup_ip(hash, ip: rec->ip);
6710	/*
6711	* Do not allow this rec to match again.
6712	* Yeah, it may waste some memory, but will be removed
6713	* if/when the hash is modified again.
6714	*/
6715	if (entry)
6716	entry->ip = 0;
6717	}
6718	}
6719
6720	/* Clear any records from hashes */
6721	static void clear_mod_from_hashes(struct ftrace_page *pg)
6722	{
6723	struct trace_array *tr;
6724
6725	mutex_lock(&trace_types_lock);
6726	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
6727	if (!tr->ops || !tr->ops->func_hash)
6728	continue;
6729	mutex_lock(&tr->ops->func_hash->regex_lock);
6730	clear_mod_from_hash(pg, hash: tr->ops->func_hash->filter_hash);
6731	clear_mod_from_hash(pg, hash: tr->ops->func_hash->notrace_hash);
6732	mutex_unlock(lock: &tr->ops->func_hash->regex_lock);
6733	}
6734	mutex_unlock(lock: &trace_types_lock);
6735	}
6736
6737	static void ftrace_free_mod_map(struct rcu_head *rcu)
6738	{
6739	struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
6740	struct ftrace_mod_func *mod_func;
6741	struct ftrace_mod_func *n;
6742
6743	/* All the contents of mod_map are now not visible to readers */
6744	list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
6745	kfree(objp: mod_func->name);
6746	list_del(entry: &mod_func->list);
6747	kfree(objp: mod_func);
6748	}
6749
6750	kfree(objp: mod_map);
6751	}
6752
6753	void ftrace_release_mod(struct module *mod)
6754	{
6755	struct ftrace_mod_map *mod_map;
6756	struct ftrace_mod_map *n;
6757	struct dyn_ftrace *rec;
6758	struct ftrace_page **last_pg;
6759	struct ftrace_page *tmp_page = NULL;
6760	struct ftrace_page *pg;
6761
6762	mutex_lock(&ftrace_lock);
6763
6764	if (ftrace_disabled)
6765	goto out_unlock;
6766
6767	list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
6768	if (mod_map->mod == mod) {
6769	list_del_rcu(entry: &mod_map->list);
6770	call_rcu(head: &mod_map->rcu, func: ftrace_free_mod_map);
6771	break;
6772	}
6773	}
6774
6775	/*
6776	* Each module has its own ftrace_pages, remove
6777	* them from the list.
6778	*/
6779	last_pg = &ftrace_pages_start;
6780	for (pg = ftrace_pages_start; pg; pg = *last_pg) {
6781	rec = &pg->records[0];
6782	if (within_module(addr: rec->ip, mod)) {
6783	/*
6784	* As core pages are first, the first
6785	* page should never be a module page.
6786	*/
6787	if (WARN_ON(pg == ftrace_pages_start))
6788	goto out_unlock;
6789
6790	/* Check if we are deleting the last page */
6791	if (pg == ftrace_pages)
6792	ftrace_pages = next_to_ftrace_page(last_pg);
6793
6794	ftrace_update_tot_cnt -= pg->index;
6795	*last_pg = pg->next;
6796
6797	pg->next = tmp_page;
6798	tmp_page = pg;
6799	} else
6800	last_pg = &pg->next;
6801	}
6802	out_unlock:
6803	mutex_unlock(lock: &ftrace_lock);
6804
6805	for (pg = tmp_page; pg; pg = tmp_page) {
6806
6807	/* Needs to be called outside of ftrace_lock */
6808	clear_mod_from_hashes(pg);
6809
6810	if (pg->records) {
6811	free_pages(addr: (unsigned long)pg->records, order: pg->order);
6812	ftrace_number_of_pages -= 1 << pg->order;
6813	}
6814	tmp_page = pg->next;
6815	kfree(objp: pg);
6816	ftrace_number_of_groups--;
6817	}
6818	}
6819
6820	void ftrace_module_enable(struct module *mod)
6821	{
6822	struct dyn_ftrace *rec;
6823	struct ftrace_page *pg;
6824
6825	mutex_lock(&ftrace_lock);
6826
6827	if (ftrace_disabled)
6828	goto out_unlock;
6829
6830	/*
6831	* If the tracing is enabled, go ahead and enable the record.
6832	*
6833	* The reason not to enable the record immediately is the
6834	* inherent check of ftrace_make_nop/ftrace_make_call for
6835	* correct previous instructions. Making first the NOP
6836	* conversion puts the module to the correct state, thus
6837	* passing the ftrace_make_call check.
6838	*
6839	* We also delay this to after the module code already set the
6840	* text to read-only, as we now need to set it back to read-write
6841	* so that we can modify the text.
6842	*/
6843	if (ftrace_start_up)
6844	ftrace_arch_code_modify_prepare();
6845
6846	do_for_each_ftrace_rec(pg, rec) {
6847	int cnt;
6848	/*
6849	* do_for_each_ftrace_rec() is a double loop.
6850	* module text shares the pg. If a record is
6851	* not part of this module, then skip this pg,
6852	* which the "break" will do.
6853	*/
6854	if (!within_module(addr: rec->ip, mod))
6855	break;
6856
6857	/* Weak functions should still be ignored */
6858	if (!test_for_valid_rec(rec)) {
6859	/* Clear all other flags. Should not be enabled anyway */
6860	rec->flags = FTRACE_FL_DISABLED;
6861	continue;
6862	}
6863
6864	cnt = 0;
6865
6866	/*
6867	* When adding a module, we need to check if tracers are
6868	* currently enabled and if they are, and can trace this record,
6869	* we need to enable the module functions as well as update the
6870	* reference counts for those function records.
6871	*/
6872	if (ftrace_start_up)
6873	cnt += referenced_filters(rec);
6874
6875	rec->flags &= ~FTRACE_FL_DISABLED;
6876	rec->flags += cnt;
6877
6878	if (ftrace_start_up && cnt) {
6879	int failed = __ftrace_replace_code(rec, enable: 1);
6880	if (failed) {
6881	ftrace_bug(failed, rec);
6882	goto out_loop;
6883	}
6884	}
6885
6886	} while_for_each_ftrace_rec();
6887
6888	out_loop:
6889	if (ftrace_start_up)
6890	ftrace_arch_code_modify_post_process();
6891
6892	out_unlock:
6893	mutex_unlock(lock: &ftrace_lock);
6894
6895	process_cached_mods(mod_name: mod->name);
6896	}
6897
6898	void ftrace_module_init(struct module *mod)
6899	{
6900	int ret;
6901
6902	if (ftrace_disabled || !mod->num_ftrace_callsites)
6903	return;
6904
6905	ret = ftrace_process_locs(mod, start: mod->ftrace_callsites,
6906	end: mod->ftrace_callsites + mod->num_ftrace_callsites);
6907	if (ret)
6908	pr_warn("ftrace: failed to allocate entries for module '%s' functions\n",
6909	mod->name);
6910	}
6911
6912	static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6913	struct dyn_ftrace *rec)
6914	{
6915	struct ftrace_mod_func *mod_func;
6916	unsigned long symsize;
6917	unsigned long offset;
6918	char str[KSYM_SYMBOL_LEN];
6919	char *modname;
6920	const char *ret;
6921
6922	ret = kallsyms_lookup(addr: rec->ip, symbolsize: &symsize, offset: &offset, modname: &modname, namebuf: str);
6923	if (!ret)
6924	return;
6925
6926	mod_func = kmalloc(size: sizeof(*mod_func), GFP_KERNEL);
6927	if (!mod_func)
6928	return;
6929
6930	mod_func->name = kstrdup(s: str, GFP_KERNEL);
6931	if (!mod_func->name) {
6932	kfree(objp: mod_func);
6933	return;
6934	}
6935
6936	mod_func->ip = rec->ip - offset;
6937	mod_func->size = symsize;
6938
6939	mod_map->num_funcs++;
6940
6941	list_add_rcu(new: &mod_func->list, head: &mod_map->funcs);
6942	}
6943
6944	static struct ftrace_mod_map *
6945	allocate_ftrace_mod_map(struct module *mod,
6946	unsigned long start, unsigned long end)
6947	{
6948	struct ftrace_mod_map *mod_map;
6949
6950	mod_map = kmalloc(size: sizeof(*mod_map), GFP_KERNEL);
6951	if (!mod_map)
6952	return NULL;
6953
6954	mod_map->mod = mod;
6955	mod_map->start_addr = start;
6956	mod_map->end_addr = end;
6957	mod_map->num_funcs = 0;
6958
6959	INIT_LIST_HEAD_RCU(list: &mod_map->funcs);
6960
6961	list_add_rcu(new: &mod_map->list, head: &ftrace_mod_maps);
6962
6963	return mod_map;
6964	}
6965
6966	static const char *
6967	ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
6968	unsigned long addr, unsigned long *size,
6969	unsigned long *off, char *sym)
6970	{
6971	struct ftrace_mod_func *found_func = NULL;
6972	struct ftrace_mod_func *mod_func;
6973
6974	list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
6975	if (addr >= mod_func->ip &&
6976	addr < mod_func->ip + mod_func->size) {
6977	found_func = mod_func;
6978	break;
6979	}
6980	}
6981
6982	if (found_func) {
6983	if (size)
6984	*size = found_func->size;
6985	if (off)
6986	*off = addr - found_func->ip;
6987	if (sym)
6988	strscpy(p: sym, q: found_func->name, KSYM_NAME_LEN);
6989
6990	return found_func->name;
6991	}
6992
6993	return NULL;
6994	}
6995
6996	const char *
6997	ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
6998	unsigned long *off, char **modname, char *sym)
6999	{
7000	struct ftrace_mod_map *mod_map;
7001	const char *ret = NULL;
7002
7003	/* mod_map is freed via call_rcu() */
7004	preempt_disable();
7005	list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
7006	ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
7007	if (ret) {
7008	if (modname)
7009	*modname = mod_map->mod->name;
7010	break;
7011	}
7012	}
7013	preempt_enable();
7014
7015	return ret;
7016	}
7017
7018	int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
7019	char *type, char *name,
7020	char *module_name, int *exported)
7021	{
7022	struct ftrace_mod_map *mod_map;
7023	struct ftrace_mod_func *mod_func;
7024	int ret;
7025
7026	preempt_disable();
7027	list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
7028
7029	if (symnum >= mod_map->num_funcs) {
7030	symnum -= mod_map->num_funcs;
7031	continue;
7032	}
7033
7034	list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
7035	if (symnum > 1) {
7036	symnum--;
7037	continue;
7038	}
7039
7040	*value = mod_func->ip;
7041	*type = 'T';
7042	strscpy(p: name, q: mod_func->name, KSYM_NAME_LEN);
7043	strscpy(p: module_name, q: mod_map->mod->name, MODULE_NAME_LEN);
7044	*exported = 1;
7045	preempt_enable();
7046	return 0;
7047	}
7048	WARN_ON(1);
7049	break;
7050	}
7051	ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
7052	module_name, exported);
7053	preempt_enable();
7054	return ret;
7055	}
7056
7057	#else
7058	static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
7059	struct dyn_ftrace *rec) { }
7060	static inline struct ftrace_mod_map *
7061	allocate_ftrace_mod_map(struct module *mod,
7062	unsigned long start, unsigned long end)
7063	{
7064	return NULL;
7065	}
7066	int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
7067	char *type, char *name, char *module_name,
7068	int *exported)
7069	{
7070	int ret;
7071
7072	preempt_disable();
7073	ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
7074	module_name, exported);
7075	preempt_enable();
7076	return ret;
7077	}
7078	#endif /* CONFIG_MODULES */
7079
7080	struct ftrace_init_func {
7081	struct list_head list;
7082	unsigned long ip;
7083	};
7084
7085	/* Clear any init ips from hashes */
7086	static void
7087	clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
7088	{
7089	struct ftrace_func_entry *entry;
7090
7091	entry = ftrace_lookup_ip(hash, ip: func->ip);
7092	/*
7093	* Do not allow this rec to match again.
7094	* Yeah, it may waste some memory, but will be removed
7095	* if/when the hash is modified again.
7096	*/
7097	if (entry)
7098	entry->ip = 0;
7099	}
7100
7101	static void
7102	clear_func_from_hashes(struct ftrace_init_func *func)
7103	{
7104	struct trace_array *tr;
7105
7106	mutex_lock(&trace_types_lock);
7107	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
7108	if (!tr->ops || !tr->ops->func_hash)
7109	continue;
7110	mutex_lock(&tr->ops->func_hash->regex_lock);
7111	clear_func_from_hash(func, hash: tr->ops->func_hash->filter_hash);
7112	clear_func_from_hash(func, hash: tr->ops->func_hash->notrace_hash);
7113	mutex_unlock(lock: &tr->ops->func_hash->regex_lock);
7114	}
7115	mutex_unlock(lock: &trace_types_lock);
7116	}
7117
7118	static void add_to_clear_hash_list(struct list_head *clear_list,
7119	struct dyn_ftrace *rec)
7120	{
7121	struct ftrace_init_func *func;
7122
7123	func = kmalloc(size: sizeof(*func), GFP_KERNEL);
7124	if (!func) {
7125	MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n");
7126	return;
7127	}
7128
7129	func->ip = rec->ip;
7130	list_add(new: &func->list, head: clear_list);
7131	}
7132
7133	void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
7134	{
7135	unsigned long start = (unsigned long)(start_ptr);
7136	unsigned long end = (unsigned long)(end_ptr);
7137	struct ftrace_page **last_pg = &ftrace_pages_start;
7138	struct ftrace_page *pg;
7139	struct dyn_ftrace *rec;
7140	struct dyn_ftrace key;
7141	struct ftrace_mod_map *mod_map = NULL;
7142	struct ftrace_init_func *func, *func_next;
7143	LIST_HEAD(clear_hash);
7144
7145	key.ip = start;
7146	key.flags = end; /* overload flags, as it is unsigned long */
7147
7148	mutex_lock(&ftrace_lock);
7149
7150	/*
7151	* If we are freeing module init memory, then check if
7152	* any tracer is active. If so, we need to save a mapping of
7153	* the module functions being freed with the address.
7154	*/
7155	if (mod && ftrace_ops_list != &ftrace_list_end)
7156	mod_map = allocate_ftrace_mod_map(mod, start, end);
7157
7158	for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
7159	if (end < pg->records[0].ip ||
7160	start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
7161	continue;
7162	again:
7163	rec = bsearch(key: &key, base: pg->records, num: pg->index,
7164	size: sizeof(struct dyn_ftrace),
7165	cmp: ftrace_cmp_recs);
7166	if (!rec)
7167	continue;
7168
7169	/* rec will be cleared from hashes after ftrace_lock unlock */
7170	add_to_clear_hash_list(clear_list: &clear_hash, rec);
7171
7172	if (mod_map)
7173	save_ftrace_mod_rec(mod_map, rec);
7174
7175	pg->index--;
7176	ftrace_update_tot_cnt--;
7177	if (!pg->index) {
7178	*last_pg = pg->next;
7179	if (pg->records) {
7180	free_pages(addr: (unsigned long)pg->records, order: pg->order);
7181	ftrace_number_of_pages -= 1 << pg->order;
7182	}
7183	ftrace_number_of_groups--;
7184	kfree(objp: pg);
7185	pg = container_of(last_pg, struct ftrace_page, next);
7186	if (!(*last_pg))
7187	ftrace_pages = pg;
7188	continue;
7189	}
7190	memmove(rec, rec + 1,
7191	(pg->index - (rec - pg->records)) * sizeof(*rec));
7192	/* More than one function may be in this block */
7193	goto again;
7194	}
7195	mutex_unlock(lock: &ftrace_lock);
7196
7197	list_for_each_entry_safe(func, func_next, &clear_hash, list) {
7198	clear_func_from_hashes(func);
7199	kfree(objp: func);
7200	}
7201	}
7202
7203	void __init ftrace_free_init_mem(void)
7204	{
7205	void *start = (void *)(&__init_begin);
7206	void *end = (void *)(&__init_end);
7207
7208	ftrace_boot_snapshot();
7209
7210	ftrace_free_mem(NULL, start_ptr: start, end_ptr: end);
7211	}
7212
7213	int __init __weak ftrace_dyn_arch_init(void)
7214	{
7215	return 0;
7216	}
7217
7218	void __init ftrace_init(void)
7219	{
7220	extern unsigned long __start_mcount_loc[];
7221	extern unsigned long __stop_mcount_loc[];
7222	unsigned long count, flags;
7223	int ret;
7224
7225	local_irq_save(flags);
7226	ret = ftrace_dyn_arch_init();
7227	local_irq_restore(flags);
7228	if (ret)
7229	goto failed;
7230
7231	count = __stop_mcount_loc - __start_mcount_loc;
7232	if (!count) {
7233	pr_info("ftrace: No functions to be traced?\n");
7234	goto failed;
7235	}
7236
7237	pr_info("ftrace: allocating %ld entries in %ld pages\n",
7238	count, DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
7239
7240	ret = ftrace_process_locs(NULL,
7241	start: __start_mcount_loc,
7242	end: __stop_mcount_loc);
7243	if (ret) {
7244	pr_warn("ftrace: failed to allocate entries for functions\n");
7245	goto failed;
7246	}
7247
7248	pr_info("ftrace: allocated %ld pages with %ld groups\n",
7249	ftrace_number_of_pages, ftrace_number_of_groups);
7250
7251	last_ftrace_enabled = ftrace_enabled = 1;
7252
7253	set_ftrace_early_filters();
7254
7255	return;
7256	failed:
7257	ftrace_disabled = 1;
7258	}
7259
7260	/* Do nothing if arch does not support this */
7261	void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
7262	{
7263	}
7264
7265	static void ftrace_update_trampoline(struct ftrace_ops *ops)
7266	{
7267	unsigned long trampoline = ops->trampoline;
7268
7269	arch_ftrace_update_trampoline(ops);
7270	if (ops->trampoline && ops->trampoline != trampoline &&
7271	(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) {
7272	/* Add to kallsyms before the perf events */
7273	ftrace_add_trampoline_to_kallsyms(ops);
7274	perf_event_ksymbol(ksym_type: PERF_RECORD_KSYMBOL_TYPE_OOL,
7275	addr: ops->trampoline, len: ops->trampoline_size, unregister: false,
7276	FTRACE_TRAMPOLINE_SYM);
7277	/*
7278	* Record the perf text poke event after the ksymbol register
7279	* event.
7280	*/
7281	perf_event_text_poke(addr: (void *)ops->trampoline, NULL, old_len: 0,
7282	new_bytes: (void *)ops->trampoline,
7283	new_len: ops->trampoline_size);
7284	}
7285	}
7286
7287	void ftrace_init_trace_array(struct trace_array *tr)
7288	{
7289	INIT_LIST_HEAD(list: &tr->func_probes);
7290	INIT_LIST_HEAD(list: &tr->mod_trace);
7291	INIT_LIST_HEAD(list: &tr->mod_notrace);
7292	}
7293	#else
7294
7295	struct ftrace_ops global_ops = {
7296	.func = ftrace_stub,
7297	.flags = FTRACE_OPS_FL_INITIALIZED |
7298	FTRACE_OPS_FL_PID,
7299	};
7300
7301	static int __init ftrace_nodyn_init(void)
7302	{
7303	ftrace_enabled = 1;
7304	return 0;
7305	}
7306	core_initcall(ftrace_nodyn_init);
7307
7308	static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
7309	static inline void ftrace_startup_all(int command) { }
7310
7311	static void ftrace_update_trampoline(struct ftrace_ops *ops)
7312	{
7313	}
7314
7315	#endif /* CONFIG_DYNAMIC_FTRACE */
7316
7317	__init void ftrace_init_global_array_ops(struct trace_array *tr)
7318	{
7319	tr->ops = &global_ops;
7320	tr->ops->private = tr;
7321	ftrace_init_trace_array(tr);
7322	}
7323
7324	void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
7325	{
7326	/* If we filter on pids, update to use the pid function */
7327	if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
7328	if (WARN_ON(tr->ops->func != ftrace_stub))
7329	printk("ftrace ops had %pS for function\n",
7330	tr->ops->func);
7331	}
7332	tr->ops->func = func;
7333	tr->ops->private = tr;
7334	}
7335
7336	void ftrace_reset_array_ops(struct trace_array *tr)
7337	{
7338	tr->ops->func = ftrace_stub;
7339	}
7340
7341	static nokprobe_inline void
7342	__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
7343	struct ftrace_ops *ignored, struct ftrace_regs *fregs)
7344	{
7345	struct pt_regs *regs = ftrace_get_regs(fregs);
7346	struct ftrace_ops *op;
7347	int bit;
7348
7349	/*
7350	* The ftrace_test_and_set_recursion() will disable preemption,
7351	* which is required since some of the ops may be dynamically
7352	* allocated, they must be freed after a synchronize_rcu().
7353	*/
7354	bit = trace_test_and_set_recursion(ip, pip: parent_ip, TRACE_LIST_START);
7355	if (bit < 0)
7356	return;
7357
7358	do_for_each_ftrace_op(op, ftrace_ops_list) {
7359	/* Stub functions don't need to be called nor tested */
7360	if (op->flags & FTRACE_OPS_FL_STUB)
7361	continue;
7362	/*
7363	* Check the following for each ops before calling their func:
7364	* if RCU flag is set, then rcu_is_watching() must be true
7365	* Otherwise test if the ip matches the ops filter
7366	*
7367	* If any of the above fails then the op->func() is not executed.
7368	*/
7369	if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
7370	ftrace_ops_test(ops: op, ip, regs)) {
7371	if (FTRACE_WARN_ON(!op->func)) {
7372	pr_warn("op=%p %pS\n", op, op);
7373	goto out;
7374	}
7375	op->func(ip, parent_ip, op, fregs);
7376	}
7377	} while_for_each_ftrace_op(op);
7378	out:
7379	trace_clear_recursion(bit);
7380	}
7381
7382	/*
7383	* Some archs only support passing ip and parent_ip. Even though
7384	* the list function ignores the op parameter, we do not want any
7385	* C side effects, where a function is called without the caller
7386	* sending a third parameter.
7387	* Archs are to support both the regs and ftrace_ops at the same time.
7388	* If they support ftrace_ops, it is assumed they support regs.
7389	* If call backs want to use regs, they must either check for regs
7390	* being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
7391	* Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
7392	* An architecture can pass partial regs with ftrace_ops and still
7393	* set the ARCH_SUPPORTS_FTRACE_OPS.
7394	*
7395	* In vmlinux.lds.h, ftrace_ops_list_func() is defined to be
7396	* arch_ftrace_ops_list_func.
7397	*/
7398	#if ARCH_SUPPORTS_FTRACE_OPS
7399	void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
7400	struct ftrace_ops *op, struct ftrace_regs *fregs)
7401	{
7402	__ftrace_ops_list_func(ip, parent_ip, NULL, fregs);
7403	}
7404	#else
7405	void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
7406	{
7407	__ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
7408	}
7409	#endif
7410	NOKPROBE_SYMBOL(arch_ftrace_ops_list_func);
7411
7412	/*
7413	* If there's only one function registered but it does not support
7414	* recursion, needs RCU protection, then this function will be called
7415	* by the mcount trampoline.
7416	*/
7417	static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
7418	struct ftrace_ops *op, struct ftrace_regs *fregs)
7419	{
7420	int bit;
7421
7422	bit = trace_test_and_set_recursion(ip, pip: parent_ip, TRACE_LIST_START);
7423	if (bit < 0)
7424	return;
7425
7426	if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching())
7427	op->func(ip, parent_ip, op, fregs);
7428
7429	trace_clear_recursion(bit);
7430	}
7431	NOKPROBE_SYMBOL(ftrace_ops_assist_func);
7432
7433	/**
7434	* ftrace_ops_get_func - get the function a trampoline should call
7435	* @ops: the ops to get the function for
7436	*
7437	* Normally the mcount trampoline will call the ops->func, but there
7438	* are times that it should not. For example, if the ops does not
7439	* have its own recursion protection, then it should call the
7440	* ftrace_ops_assist_func() instead.
7441	*
7442	* Returns the function that the trampoline should call for @ops.
7443	*/
7444	ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
7445	{
7446	/*
7447	* If the function does not handle recursion or needs to be RCU safe,
7448	* then we need to call the assist handler.
7449	*/
7450	if (ops->flags & (FTRACE_OPS_FL_RECURSION |
7451	FTRACE_OPS_FL_RCU))
7452	return ftrace_ops_assist_func;
7453
7454	return ops->func;
7455	}
7456
7457	static void
7458	ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
7459	struct task_struct *prev,
7460	struct task_struct *next,
7461	unsigned int prev_state)
7462	{
7463	struct trace_array *tr = data;
7464	struct trace_pid_list *pid_list;
7465	struct trace_pid_list *no_pid_list;
7466
7467	pid_list = rcu_dereference_sched(tr->function_pids);
7468	no_pid_list = rcu_dereference_sched(tr->function_no_pids);
7469
7470	if (trace_ignore_this_task(filtered_pids: pid_list, filtered_no_pids: no_pid_list, task: next))
7471	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7472	FTRACE_PID_IGNORE);
7473	else
7474	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7475	next->pid);
7476	}
7477
7478	static void
7479	ftrace_pid_follow_sched_process_fork(void *data,
7480	struct task_struct *self,
7481	struct task_struct *task)
7482	{
7483	struct trace_pid_list *pid_list;
7484	struct trace_array *tr = data;
7485
7486	pid_list = rcu_dereference_sched(tr->function_pids);
7487	trace_filter_add_remove_task(pid_list, self, task);
7488
7489	pid_list = rcu_dereference_sched(tr->function_no_pids);
7490	trace_filter_add_remove_task(pid_list, self, task);
7491	}
7492
7493	static void
7494	ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
7495	{
7496	struct trace_pid_list *pid_list;
7497	struct trace_array *tr = data;
7498
7499	pid_list = rcu_dereference_sched(tr->function_pids);
7500	trace_filter_add_remove_task(pid_list, NULL, task);
7501
7502	pid_list = rcu_dereference_sched(tr->function_no_pids);
7503	trace_filter_add_remove_task(pid_list, NULL, task);
7504	}
7505
7506	void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
7507	{
7508	if (enable) {
7509	register_trace_sched_process_fork(probe: ftrace_pid_follow_sched_process_fork,
7510	data: tr);
7511	register_trace_sched_process_free(probe: ftrace_pid_follow_sched_process_exit,
7512	data: tr);
7513	} else {
7514	unregister_trace_sched_process_fork(probe: ftrace_pid_follow_sched_process_fork,
7515	data: tr);
7516	unregister_trace_sched_process_free(probe: ftrace_pid_follow_sched_process_exit,
7517	data: tr);
7518	}
7519	}
7520
7521	static void clear_ftrace_pids(struct trace_array *tr, int type)
7522	{
7523	struct trace_pid_list *pid_list;
7524	struct trace_pid_list *no_pid_list;
7525	int cpu;
7526
7527	pid_list = rcu_dereference_protected(tr->function_pids,
7528	lockdep_is_held(&ftrace_lock));
7529	no_pid_list = rcu_dereference_protected(tr->function_no_pids,
7530	lockdep_is_held(&ftrace_lock));
7531
7532	/* Make sure there's something to do */
7533	if (!pid_type_enabled(type, pid_list, no_pid_list))
7534	return;
7535
7536	/* See if the pids still need to be checked after this */
7537	if (!still_need_pid_events(type, pid_list, no_pid_list)) {
7538	unregister_trace_sched_switch(probe: ftrace_filter_pid_sched_switch_probe, data: tr);
7539	for_each_possible_cpu(cpu)
7540	per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE;
7541	}
7542
7543	if (type & TRACE_PIDS)
7544	rcu_assign_pointer(tr->function_pids, NULL);
7545
7546	if (type & TRACE_NO_PIDS)
7547	rcu_assign_pointer(tr->function_no_pids, NULL);
7548
7549	/* Wait till all users are no longer using pid filtering */
7550	synchronize_rcu();
7551
7552	if ((type & TRACE_PIDS) && pid_list)
7553	trace_pid_list_free(pid_list);
7554
7555	if ((type & TRACE_NO_PIDS) && no_pid_list)
7556	trace_pid_list_free(pid_list: no_pid_list);
7557	}
7558
7559	void ftrace_clear_pids(struct trace_array *tr)
7560	{
7561	mutex_lock(&ftrace_lock);
7562
7563	clear_ftrace_pids(tr, type: TRACE_PIDS | TRACE_NO_PIDS);
7564
7565	mutex_unlock(lock: &ftrace_lock);
7566	}
7567
7568	static void ftrace_pid_reset(struct trace_array *tr, int type)
7569	{
7570	mutex_lock(&ftrace_lock);
7571	clear_ftrace_pids(tr, type);
7572
7573	ftrace_update_pid_func();
7574	ftrace_startup_all(command: 0);
7575
7576	mutex_unlock(lock: &ftrace_lock);
7577	}
7578
7579	/* Greater than any max PID */
7580	#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
7581
7582	static void *fpid_start(struct seq_file *m, loff_t *pos)
7583	__acquires(RCU)
7584	{
7585	struct trace_pid_list *pid_list;
7586	struct trace_array *tr = m->private;
7587
7588	mutex_lock(&ftrace_lock);
7589	rcu_read_lock_sched();
7590
7591	pid_list = rcu_dereference_sched(tr->function_pids);
7592
7593	if (!pid_list)
7594	return !(*pos) ? FTRACE_NO_PIDS : NULL;
7595
7596	return trace_pid_start(pid_list, pos);
7597	}
7598
7599	static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
7600	{
7601	struct trace_array *tr = m->private;
7602	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
7603
7604	if (v == FTRACE_NO_PIDS) {
7605	(*pos)++;
7606	return NULL;
7607	}
7608	return trace_pid_next(pid_list, v, pos);
7609	}
7610
7611	static void fpid_stop(struct seq_file *m, void *p)
7612	__releases(RCU)
7613	{
7614	rcu_read_unlock_sched();
7615	mutex_unlock(lock: &ftrace_lock);
7616	}
7617
7618	static int fpid_show(struct seq_file *m, void *v)
7619	{
7620	if (v == FTRACE_NO_PIDS) {
7621	seq_puts(m, s: "no pid\n");
7622	return 0;
7623	}
7624
7625	return trace_pid_show(m, v);
7626	}
7627
7628	static const struct seq_operations ftrace_pid_sops = {
7629	.start = fpid_start,
7630	.next = fpid_next,
7631	.stop = fpid_stop,
7632	.show = fpid_show,
7633	};
7634
7635	static void *fnpid_start(struct seq_file *m, loff_t *pos)
7636	__acquires(RCU)
7637	{
7638	struct trace_pid_list *pid_list;
7639	struct trace_array *tr = m->private;
7640
7641	mutex_lock(&ftrace_lock);
7642	rcu_read_lock_sched();
7643
7644	pid_list = rcu_dereference_sched(tr->function_no_pids);
7645
7646	if (!pid_list)
7647	return !(*pos) ? FTRACE_NO_PIDS : NULL;
7648
7649	return trace_pid_start(pid_list, pos);
7650	}
7651
7652	static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos)
7653	{
7654	struct trace_array *tr = m->private;
7655	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids);
7656
7657	if (v == FTRACE_NO_PIDS) {
7658	(*pos)++;
7659	return NULL;
7660	}
7661	return trace_pid_next(pid_list, v, pos);
7662	}
7663
7664	static const struct seq_operations ftrace_no_pid_sops = {
7665	.start = fnpid_start,
7666	.next = fnpid_next,
7667	.stop = fpid_stop,
7668	.show = fpid_show,
7669	};
7670
7671	static int pid_open(struct inode *inode, struct file *file, int type)
7672	{
7673	const struct seq_operations *seq_ops;
7674	struct trace_array *tr = inode->i_private;
7675	struct seq_file *m;
7676	int ret = 0;
7677
7678	ret = tracing_check_open_get_tr(tr);
7679	if (ret)
7680	return ret;
7681
7682	if ((file->f_mode & FMODE_WRITE) &&
7683	(file->f_flags & O_TRUNC))
7684	ftrace_pid_reset(tr, type);
7685
7686	switch (type) {
7687	case TRACE_PIDS:
7688	seq_ops = &ftrace_pid_sops;
7689	break;
7690	case TRACE_NO_PIDS:
7691	seq_ops = &ftrace_no_pid_sops;
7692	break;
7693	default:
7694	trace_array_put(tr);
7695	WARN_ON_ONCE(1);
7696	return -EINVAL;
7697	}
7698
7699	ret = seq_open(file, seq_ops);
7700	if (ret < 0) {
7701	trace_array_put(tr);
7702	} else {
7703	m = file->private_data;
7704	/* copy tr over to seq ops */
7705	m->private = tr;
7706	}
7707
7708	return ret;
7709	}
7710
7711	static int
7712	ftrace_pid_open(struct inode *inode, struct file *file)
7713	{
7714	return pid_open(inode, file, type: TRACE_PIDS);
7715	}
7716
7717	static int
7718	ftrace_no_pid_open(struct inode *inode, struct file *file)
7719	{
7720	return pid_open(inode, file, type: TRACE_NO_PIDS);
7721	}
7722
7723	static void ignore_task_cpu(void *data)
7724	{
7725	struct trace_array *tr = data;
7726	struct trace_pid_list *pid_list;
7727	struct trace_pid_list *no_pid_list;
7728
7729	/*
7730	* This function is called by on_each_cpu() while the
7731	* event_mutex is held.
7732	*/
7733	pid_list = rcu_dereference_protected(tr->function_pids,
7734	mutex_is_locked(&ftrace_lock));
7735	no_pid_list = rcu_dereference_protected(tr->function_no_pids,
7736	mutex_is_locked(&ftrace_lock));
7737
7738	if (trace_ignore_this_task(filtered_pids: pid_list, filtered_no_pids: no_pid_list, current))
7739	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7740	FTRACE_PID_IGNORE);
7741	else
7742	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7743	current->pid);
7744	}
7745
7746	static ssize_t
7747	pid_write(struct file *filp, const char __user *ubuf,
7748	size_t cnt, loff_t *ppos, int type)
7749	{
7750	struct seq_file *m = filp->private_data;
7751	struct trace_array *tr = m->private;
7752	struct trace_pid_list *filtered_pids;
7753	struct trace_pid_list *other_pids;
7754	struct trace_pid_list *pid_list;
7755	ssize_t ret;
7756
7757	if (!cnt)
7758	return 0;
7759
7760	mutex_lock(&ftrace_lock);
7761
7762	switch (type) {
7763	case TRACE_PIDS:
7764	filtered_pids = rcu_dereference_protected(tr->function_pids,
7765	lockdep_is_held(&ftrace_lock));
7766	other_pids = rcu_dereference_protected(tr->function_no_pids,
7767	lockdep_is_held(&ftrace_lock));
7768	break;
7769	case TRACE_NO_PIDS:
7770	filtered_pids = rcu_dereference_protected(tr->function_no_pids,
7771	lockdep_is_held(&ftrace_lock));
7772	other_pids = rcu_dereference_protected(tr->function_pids,
7773	lockdep_is_held(&ftrace_lock));
7774	break;
7775	default:
7776	ret = -EINVAL;
7777	WARN_ON_ONCE(1);
7778	goto out;
7779	}
7780
7781	ret = trace_pid_write(filtered_pids, new_pid_list: &pid_list, ubuf, cnt);
7782	if (ret < 0)
7783	goto out;
7784
7785	switch (type) {
7786	case TRACE_PIDS:
7787	rcu_assign_pointer(tr->function_pids, pid_list);
7788	break;
7789	case TRACE_NO_PIDS:
7790	rcu_assign_pointer(tr->function_no_pids, pid_list);
7791	break;
7792	}
7793
7794
7795	if (filtered_pids) {
7796	synchronize_rcu();
7797	trace_pid_list_free(pid_list: filtered_pids);
7798	} else if (pid_list && !other_pids) {
7799	/* Register a probe to set whether to ignore the tracing of a task */
7800	register_trace_sched_switch(probe: ftrace_filter_pid_sched_switch_probe, data: tr);
7801	}
7802
7803	/*
7804	* Ignoring of pids is done at task switch. But we have to
7805	* check for those tasks that are currently running.
7806	* Always do this in case a pid was appended or removed.
7807	*/
7808	on_each_cpu(func: ignore_task_cpu, info: tr, wait: 1);
7809
7810	ftrace_update_pid_func();
7811	ftrace_startup_all(command: 0);
7812	out:
7813	mutex_unlock(lock: &ftrace_lock);
7814
7815	if (ret > 0)
7816	*ppos += ret;
7817
7818	return ret;
7819	}
7820
7821	static ssize_t
7822	ftrace_pid_write(struct file *filp, const char __user *ubuf,
7823	size_t cnt, loff_t *ppos)
7824	{
7825	return pid_write(filp, ubuf, cnt, ppos, type: TRACE_PIDS);
7826	}
7827
7828	static ssize_t
7829	ftrace_no_pid_write(struct file *filp, const char __user *ubuf,
7830	size_t cnt, loff_t *ppos)
7831	{
7832	return pid_write(filp, ubuf, cnt, ppos, type: TRACE_NO_PIDS);
7833	}
7834
7835	static int
7836	ftrace_pid_release(struct inode *inode, struct file *file)
7837	{
7838	struct trace_array *tr = inode->i_private;
7839
7840	trace_array_put(tr);
7841
7842	return seq_release(inode, file);
7843	}
7844
7845	static const struct file_operations ftrace_pid_fops = {
7846	.open = ftrace_pid_open,
7847	.write = ftrace_pid_write,
7848	.read = seq_read,
7849	.llseek = tracing_lseek,
7850	.release = ftrace_pid_release,
7851	};
7852
7853	static const struct file_operations ftrace_no_pid_fops = {
7854	.open = ftrace_no_pid_open,
7855	.write = ftrace_no_pid_write,
7856	.read = seq_read,
7857	.llseek = tracing_lseek,
7858	.release = ftrace_pid_release,
7859	};
7860
7861	void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
7862	{
7863	trace_create_file(name: "set_ftrace_pid", TRACE_MODE_WRITE, parent: d_tracer,
7864	data: tr, fops: &ftrace_pid_fops);
7865	trace_create_file(name: "set_ftrace_notrace_pid", TRACE_MODE_WRITE,
7866	parent: d_tracer, data: tr, fops: &ftrace_no_pid_fops);
7867	}
7868
7869	void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
7870	struct dentry *d_tracer)
7871	{
7872	/* Only the top level directory has the dyn_tracefs and profile */
7873	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
7874
7875	ftrace_init_dyn_tracefs(d_tracer);
7876	ftrace_profile_tracefs(d_tracer);
7877	}
7878
7879	/**
7880	* ftrace_kill - kill ftrace
7881	*
7882	* This function should be used by panic code. It stops ftrace
7883	* but in a not so nice way. If you need to simply kill ftrace
7884	* from a non-atomic section, use ftrace_kill.
7885	*/
7886	void ftrace_kill(void)
7887	{
7888	ftrace_disabled = 1;
7889	ftrace_enabled = 0;
7890	ftrace_trace_function = ftrace_stub;
7891	}
7892
7893	/**
7894	* ftrace_is_dead - Test if ftrace is dead or not.
7895	*
7896	* Returns 1 if ftrace is "dead", zero otherwise.
7897	*/
7898	int ftrace_is_dead(void)
7899	{
7900	return ftrace_disabled;
7901	}
7902
7903	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
7904	/*
7905	* When registering ftrace_ops with IPMODIFY, it is necessary to make sure
7906	* it doesn't conflict with any direct ftrace_ops. If there is existing
7907	* direct ftrace_ops on a kernel function being patched, call
7908	* FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER on it to enable sharing.
7909	*
7910	* @ops: ftrace_ops being registered.
7911	*
7912	* Returns:
7913	* 0 on success;
7914	* Negative on failure.
7915	*/
7916	static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops)
7917	{
7918	struct ftrace_func_entry *entry;
7919	struct ftrace_hash *hash;
7920	struct ftrace_ops *op;
7921	int size, i, ret;
7922
7923	lockdep_assert_held_once(&direct_mutex);
7924
7925	if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
7926	return 0;
7927
7928	hash = ops->func_hash->filter_hash;
7929	size = 1 << hash->size_bits;
7930	for (i = 0; i < size; i++) {
7931	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
7932	unsigned long ip = entry->ip;
7933	bool found_op = false;
7934
7935	mutex_lock(&ftrace_lock);
7936	do_for_each_ftrace_op(op, ftrace_ops_list) {
7937	if (!(op->flags & FTRACE_OPS_FL_DIRECT))
7938	continue;
7939	if (ops_references_ip(ops: op, ip)) {
7940	found_op = true;
7941	break;
7942	}
7943	} while_for_each_ftrace_op(op);
7944	mutex_unlock(lock: &ftrace_lock);
7945
7946	if (found_op) {
7947	if (!op->ops_func)
7948	return -EBUSY;
7949
7950	ret = op->ops_func(op, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER);
7951	if (ret)
7952	return ret;
7953	}
7954	}
7955	}
7956
7957	return 0;
7958	}
7959
7960	/*
7961	* Similar to prepare_direct_functions_for_ipmodify, clean up after ops
7962	* with IPMODIFY is unregistered. The cleanup is optional for most DIRECT
7963	* ops.
7964	*/
7965	static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
7966	{
7967	struct ftrace_func_entry *entry;
7968	struct ftrace_hash *hash;
7969	struct ftrace_ops *op;
7970	int size, i;
7971
7972	if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
7973	return;
7974
7975	mutex_lock(&direct_mutex);
7976
7977	hash = ops->func_hash->filter_hash;
7978	size = 1 << hash->size_bits;
7979	for (i = 0; i < size; i++) {
7980	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
7981	unsigned long ip = entry->ip;
7982	bool found_op = false;
7983
7984	mutex_lock(&ftrace_lock);
7985	do_for_each_ftrace_op(op, ftrace_ops_list) {
7986	if (!(op->flags & FTRACE_OPS_FL_DIRECT))
7987	continue;
7988	if (ops_references_ip(ops: op, ip)) {
7989	found_op = true;
7990	break;
7991	}
7992	} while_for_each_ftrace_op(op);
7993	mutex_unlock(lock: &ftrace_lock);
7994
7995	/* The cleanup is optional, ignore any errors */
7996	if (found_op && op->ops_func)
7997	op->ops_func(op, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER);
7998	}
7999	}
8000	mutex_unlock(lock: &direct_mutex);
8001	}
8002
8003	#define lock_direct_mutex() mutex_lock(&direct_mutex)
8004	#define unlock_direct_mutex() mutex_unlock(&direct_mutex)
8005
8006	#else /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
8007
8008	static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops)
8009	{
8010	return 0;
8011	}
8012
8013	static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
8014	{
8015	}
8016
8017	#define lock_direct_mutex() do { } while (0)
8018	#define unlock_direct_mutex() do { } while (0)
8019
8020	#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
8021
8022	/*
8023	* Similar to register_ftrace_function, except we don't lock direct_mutex.
8024	*/
8025	static int register_ftrace_function_nolock(struct ftrace_ops *ops)
8026	{
8027	int ret;
8028
8029	ftrace_ops_init(ops);
8030
8031	mutex_lock(&ftrace_lock);
8032
8033	ret = ftrace_startup(ops, command: 0);
8034
8035	mutex_unlock(lock: &ftrace_lock);
8036
8037	return ret;
8038	}
8039
8040	/**
8041	* register_ftrace_function - register a function for profiling
8042	* @ops: ops structure that holds the function for profiling.
8043	*
8044	* Register a function to be called by all functions in the
8045	* kernel.
8046	*
8047	* Note: @ops->func and all the functions it calls must be labeled
8048	* with "notrace", otherwise it will go into a
8049	* recursive loop.
8050	*/
8051	int register_ftrace_function(struct ftrace_ops *ops)
8052	{
8053	int ret;
8054
8055	lock_direct_mutex();
8056	ret = prepare_direct_functions_for_ipmodify(ops);
8057	if (ret < 0)
8058	goto out_unlock;
8059
8060	ret = register_ftrace_function_nolock(ops);
8061
8062	out_unlock:
8063	unlock_direct_mutex();
8064	return ret;
8065	}
8066	EXPORT_SYMBOL_GPL(register_ftrace_function);
8067
8068	/**
8069	* unregister_ftrace_function - unregister a function for profiling.
8070	* @ops: ops structure that holds the function to unregister
8071	*
8072	* Unregister a function that was added to be called by ftrace profiling.
8073	*/
8074	int unregister_ftrace_function(struct ftrace_ops *ops)
8075	{
8076	int ret;
8077
8078	mutex_lock(&ftrace_lock);
8079	ret = ftrace_shutdown(ops, command: 0);
8080	mutex_unlock(lock: &ftrace_lock);
8081
8082	cleanup_direct_functions_after_ipmodify(ops);
8083	return ret;
8084	}
8085	EXPORT_SYMBOL_GPL(unregister_ftrace_function);
8086
8087	static int symbols_cmp(const void *a, const void *b)
8088	{
8089	const char **str_a = (const char **) a;
8090	const char **str_b = (const char **) b;
8091
8092	return strcmp(*str_a, *str_b);
8093	}
8094
8095	struct kallsyms_data {
8096	unsigned long *addrs;
8097	const char **syms;
8098	size_t cnt;
8099	size_t found;
8100	};
8101
8102	/* This function gets called for all kernel and module symbols
8103	* and returns 1 in case we resolved all the requested symbols,
8104	* 0 otherwise.
8105	*/
8106	static int kallsyms_callback(void *data, const char *name, unsigned long addr)
8107	{
8108	struct kallsyms_data *args = data;
8109	const char **sym;
8110	int idx;
8111
8112	sym = bsearch(key: &name, base: args->syms, num: args->cnt, size: sizeof(*args->syms), cmp: symbols_cmp);
8113	if (!sym)
8114	return 0;
8115
8116	idx = sym - args->syms;
8117	if (args->addrs[idx])
8118	return 0;
8119
8120	if (!ftrace_location(ip: addr))
8121	return 0;
8122
8123	args->addrs[idx] = addr;
8124	args->found++;
8125	return args->found == args->cnt ? 1 : 0;
8126	}
8127
8128	/**
8129	* ftrace_lookup_symbols - Lookup addresses for array of symbols
8130	*
8131	* @sorted_syms: array of symbols pointers symbols to resolve,
8132	* must be alphabetically sorted
8133	* @cnt: number of symbols/addresses in @syms/@addrs arrays
8134	* @addrs: array for storing resulting addresses
8135	*
8136	* This function looks up addresses for array of symbols provided in
8137	* @syms array (must be alphabetically sorted) and stores them in
8138	* @addrs array, which needs to be big enough to store at least @cnt
8139	* addresses.
8140	*
8141	* This function returns 0 if all provided symbols are found,
8142	* -ESRCH otherwise.
8143	*/
8144	int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
8145	{
8146	struct kallsyms_data args;
8147	int found_all;
8148
8149	memset(addrs, 0, sizeof(*addrs) * cnt);
8150	args.addrs = addrs;
8151	args.syms = sorted_syms;
8152	args.cnt = cnt;
8153	args.found = 0;
8154
8155	found_all = kallsyms_on_each_symbol(fn: kallsyms_callback, data: &args);
8156	if (found_all)
8157	return 0;
8158	found_all = module_kallsyms_on_each_symbol(NULL, fn: kallsyms_callback, data: &args);
8159	return found_all ? 0 : -ESRCH;
8160	}
8161
8162	#ifdef CONFIG_SYSCTL
8163
8164	#ifdef CONFIG_DYNAMIC_FTRACE
8165	static void ftrace_startup_sysctl(void)
8166	{
8167	int command;
8168
8169	if (unlikely(ftrace_disabled))
8170	return;
8171
8172	/* Force update next time */
8173	saved_ftrace_func = NULL;
8174	/* ftrace_start_up is true if we want ftrace running */
8175	if (ftrace_start_up) {
8176	command = FTRACE_UPDATE_CALLS;
8177	if (ftrace_graph_active)
8178	command |= FTRACE_START_FUNC_RET;
8179	ftrace_startup_enable(command);
8180	}
8181	}
8182
8183	static void ftrace_shutdown_sysctl(void)
8184	{
8185	int command;
8186
8187	if (unlikely(ftrace_disabled))
8188	return;
8189
8190	/* ftrace_start_up is true if ftrace is running */
8191	if (ftrace_start_up) {
8192	command = FTRACE_DISABLE_CALLS;
8193	if (ftrace_graph_active)
8194	command |= FTRACE_STOP_FUNC_RET;
8195	ftrace_run_update_code(command);
8196	}
8197	}
8198	#else
8199	# define ftrace_startup_sysctl() do { } while (0)
8200	# define ftrace_shutdown_sysctl() do { } while (0)
8201	#endif /* CONFIG_DYNAMIC_FTRACE */
8202
8203	static bool is_permanent_ops_registered(void)
8204	{
8205	struct ftrace_ops *op;
8206
8207	do_for_each_ftrace_op(op, ftrace_ops_list) {
8208	if (op->flags & FTRACE_OPS_FL_PERMANENT)
8209	return true;
8210	} while_for_each_ftrace_op(op);
8211
8212	return false;
8213	}
8214
8215	static int
8216	ftrace_enable_sysctl(struct ctl_table *table, int write,
8217	void *buffer, size_t *lenp, loff_t *ppos)
8218	{
8219	int ret = -ENODEV;
8220
8221	mutex_lock(&ftrace_lock);
8222
8223	if (unlikely(ftrace_disabled))
8224	goto out;
8225
8226	ret = proc_dointvec(table, write, buffer, lenp, ppos);
8227
8228	if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
8229	goto out;
8230
8231	if (ftrace_enabled) {
8232
8233	/* we are starting ftrace again */
8234	if (rcu_dereference_protected(ftrace_ops_list,
8235	lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
8236	update_ftrace_function();
8237
8238	ftrace_startup_sysctl();
8239
8240	} else {
8241	if (is_permanent_ops_registered()) {
8242	ftrace_enabled = true;
8243	ret = -EBUSY;
8244	goto out;
8245	}
8246
8247	/* stopping ftrace calls (just send to ftrace_stub) */
8248	ftrace_trace_function = ftrace_stub;
8249
8250	ftrace_shutdown_sysctl();
8251	}
8252
8253	last_ftrace_enabled = !!ftrace_enabled;
8254	out:
8255	mutex_unlock(lock: &ftrace_lock);
8256	return ret;
8257	}
8258
8259	static struct ctl_table ftrace_sysctls[] = {
8260	{
8261	.procname = "ftrace_enabled",
8262	.data = &ftrace_enabled,
8263	.maxlen = sizeof(int),
8264	.mode = 0644,
8265	.proc_handler = ftrace_enable_sysctl,
8266	},
8267	{}
8268	};
8269
8270	static int __init ftrace_sysctl_init(void)
8271	{
8272	register_sysctl_init("kernel", ftrace_sysctls);
8273	return 0;
8274	}
8275	late_initcall(ftrace_sysctl_init);
8276	#endif
8277