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 struct ftrace_func_entry *
1187	add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1188	{
1189	struct ftrace_func_entry *entry;
1190
1191	entry = kmalloc(size: sizeof(*entry), GFP_KERNEL);
1192	if (!entry)
1193	return NULL;
1194
1195	entry->ip = ip;
1196	__add_hash_entry(hash, entry);
1197
1198	return entry;
1199	}
1200
1201	static void
1202	free_hash_entry(struct ftrace_hash *hash,
1203	struct ftrace_func_entry *entry)
1204	{
1205	hlist_del(n: &entry->hlist);
1206	kfree(objp: entry);
1207	hash->count--;
1208	}
1209
1210	static void
1211	remove_hash_entry(struct ftrace_hash *hash,
1212	struct ftrace_func_entry *entry)
1213	{
1214	hlist_del_rcu(n: &entry->hlist);
1215	hash->count--;
1216	}
1217
1218	static void ftrace_hash_clear(struct ftrace_hash *hash)
1219	{
1220	struct hlist_head *hhd;
1221	struct hlist_node *tn;
1222	struct ftrace_func_entry *entry;
1223	int size = 1 << hash->size_bits;
1224	int i;
1225
1226	if (!hash->count)
1227	return;
1228
1229	for (i = 0; i < size; i++) {
1230	hhd = &hash->buckets[i];
1231	hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1232	free_hash_entry(hash, entry);
1233	}
1234	FTRACE_WARN_ON(hash->count);
1235	}
1236
1237	static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1238	{
1239	list_del(entry: &ftrace_mod->list);
1240	kfree(objp: ftrace_mod->module);
1241	kfree(objp: ftrace_mod->func);
1242	kfree(objp: ftrace_mod);
1243	}
1244
1245	static void clear_ftrace_mod_list(struct list_head *head)
1246	{
1247	struct ftrace_mod_load *p, *n;
1248
1249	/* stack tracer isn't supported yet */
1250	if (!head)
1251	return;
1252
1253	mutex_lock(&ftrace_lock);
1254	list_for_each_entry_safe(p, n, head, list)
1255	free_ftrace_mod(ftrace_mod: p);
1256	mutex_unlock(lock: &ftrace_lock);
1257	}
1258
1259	static void free_ftrace_hash(struct ftrace_hash *hash)
1260	{
1261	if (!hash || hash == EMPTY_HASH)
1262	return;
1263	ftrace_hash_clear(hash);
1264	kfree(objp: hash->buckets);
1265	kfree(objp: hash);
1266	}
1267
1268	static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1269	{
1270	struct ftrace_hash *hash;
1271
1272	hash = container_of(rcu, struct ftrace_hash, rcu);
1273	free_ftrace_hash(hash);
1274	}
1275
1276	static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1277	{
1278	if (!hash || hash == EMPTY_HASH)
1279	return;
1280	call_rcu(head: &hash->rcu, func: __free_ftrace_hash_rcu);
1281	}
1282
1283	/**
1284	* ftrace_free_filter - remove all filters for an ftrace_ops
1285	* @ops: the ops to remove the filters from
1286	*/
1287	void ftrace_free_filter(struct ftrace_ops *ops)
1288	{
1289	ftrace_ops_init(ops);
1290	free_ftrace_hash(hash: ops->func_hash->filter_hash);
1291	free_ftrace_hash(hash: ops->func_hash->notrace_hash);
1292	}
1293	EXPORT_SYMBOL_GPL(ftrace_free_filter);
1294
1295	static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1296	{
1297	struct ftrace_hash *hash;
1298	int size;
1299
1300	hash = kzalloc(size: sizeof(*hash), GFP_KERNEL);
1301	if (!hash)
1302	return NULL;
1303
1304	size = 1 << size_bits;
1305	hash->buckets = kcalloc(n: size, size: sizeof(*hash->buckets), GFP_KERNEL);
1306
1307	if (!hash->buckets) {
1308	kfree(objp: hash);
1309	return NULL;
1310	}
1311
1312	hash->size_bits = size_bits;
1313
1314	return hash;
1315	}
1316
1317
1318	static int ftrace_add_mod(struct trace_array *tr,
1319	const char *func, const char *module,
1320	int enable)
1321	{
1322	struct ftrace_mod_load *ftrace_mod;
1323	struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1324
1325	ftrace_mod = kzalloc(size: sizeof(*ftrace_mod), GFP_KERNEL);
1326	if (!ftrace_mod)
1327	return -ENOMEM;
1328
1329	INIT_LIST_HEAD(list: &ftrace_mod->list);
1330	ftrace_mod->func = kstrdup(s: func, GFP_KERNEL);
1331	ftrace_mod->module = kstrdup(s: module, GFP_KERNEL);
1332	ftrace_mod->enable = enable;
1333
1334	if (!ftrace_mod->func || !ftrace_mod->module)
1335	goto out_free;
1336
1337	list_add(new: &ftrace_mod->list, head: mod_head);
1338
1339	return 0;
1340
1341	out_free:
1342	free_ftrace_mod(ftrace_mod);
1343
1344	return -ENOMEM;
1345	}
1346
1347	static struct ftrace_hash *
1348	alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1349	{
1350	struct ftrace_func_entry *entry;
1351	struct ftrace_hash *new_hash;
1352	int size;
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	if (add_hash_entry(hash: new_hash, ip: entry->ip) == NULL)
1370	goto free_hash;
1371	}
1372	}
1373
1374	FTRACE_WARN_ON(new_hash->count != hash->count);
1375
1376	return new_hash;
1377
1378	free_hash:
1379	free_ftrace_hash(hash: new_hash);
1380	return NULL;
1381	}
1382
1383	static void
1384	ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1385	static void
1386	ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1387
1388	static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1389	struct ftrace_hash *new_hash);
1390
1391	static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size)
1392	{
1393	struct ftrace_func_entry *entry;
1394	struct ftrace_hash *new_hash;
1395	struct hlist_head *hhd;
1396	struct hlist_node *tn;
1397	int bits = 0;
1398	int i;
1399
1400	/*
1401	* Use around half the size (max bit of it), but
1402	* a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits).
1403	*/
1404	bits = fls(x: size / 2);
1405
1406	/* Don't allocate too much */
1407	if (bits > FTRACE_HASH_MAX_BITS)
1408	bits = FTRACE_HASH_MAX_BITS;
1409
1410	new_hash = alloc_ftrace_hash(size_bits: bits);
1411	if (!new_hash)
1412	return NULL;
1413
1414	new_hash->flags = src->flags;
1415
1416	size = 1 << src->size_bits;
1417	for (i = 0; i < size; i++) {
1418	hhd = &src->buckets[i];
1419	hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1420	remove_hash_entry(hash: src, entry);
1421	__add_hash_entry(hash: new_hash, entry);
1422	}
1423	}
1424	return new_hash;
1425	}
1426
1427	static struct ftrace_hash *
1428	__ftrace_hash_move(struct ftrace_hash *src)
1429	{
1430	int size = src->count;
1431
1432	/*
1433	* If the new source is empty, just return the empty_hash.
1434	*/
1435	if (ftrace_hash_empty(hash: src))
1436	return EMPTY_HASH;
1437
1438	return dup_hash(src, size);
1439	}
1440
1441	static int
1442	ftrace_hash_move(struct ftrace_ops *ops, int enable,
1443	struct ftrace_hash **dst, struct ftrace_hash *src)
1444	{
1445	struct ftrace_hash *new_hash;
1446	int ret;
1447
1448	/* Reject setting notrace hash on IPMODIFY ftrace_ops */
1449	if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1450	return -EINVAL;
1451
1452	new_hash = __ftrace_hash_move(src);
1453	if (!new_hash)
1454	return -ENOMEM;
1455
1456	/* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1457	if (enable) {
1458	/* IPMODIFY should be updated only when filter_hash updating */
1459	ret = ftrace_hash_ipmodify_update(ops, new_hash);
1460	if (ret < 0) {
1461	free_ftrace_hash(hash: new_hash);
1462	return ret;
1463	}
1464	}
1465
1466	/*
1467	* Remove the current set, update the hash and add
1468	* them back.
1469	*/
1470	ftrace_hash_rec_disable_modify(ops, filter_hash: enable);
1471
1472	rcu_assign_pointer(*dst, new_hash);
1473
1474	ftrace_hash_rec_enable_modify(ops, filter_hash: enable);
1475
1476	return 0;
1477	}
1478
1479	static bool hash_contains_ip(unsigned long ip,
1480	struct ftrace_ops_hash *hash)
1481	{
1482	/*
1483	* The function record is a match if it exists in the filter
1484	* hash and not in the notrace hash. Note, an empty hash is
1485	* considered a match for the filter hash, but an empty
1486	* notrace hash is considered not in the notrace hash.
1487	*/
1488	return (ftrace_hash_empty(hash: hash->filter_hash) ||
1489	__ftrace_lookup_ip(hash: hash->filter_hash, ip)) &&
1490	(ftrace_hash_empty(hash: hash->notrace_hash) ||
1491	!__ftrace_lookup_ip(hash: hash->notrace_hash, ip));
1492	}
1493
1494	/*
1495	* Test the hashes for this ops to see if we want to call
1496	* the ops->func or not.
1497	*
1498	* It's a match if the ip is in the ops->filter_hash or
1499	* the filter_hash does not exist or is empty,
1500	* AND
1501	* the ip is not in the ops->notrace_hash.
1502	*
1503	* This needs to be called with preemption disabled as
1504	* the hashes are freed with call_rcu().
1505	*/
1506	int
1507	ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1508	{
1509	struct ftrace_ops_hash hash;
1510	int ret;
1511
1512	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1513	/*
1514	* There's a small race when adding ops that the ftrace handler
1515	* that wants regs, may be called without them. We can not
1516	* allow that handler to be called if regs is NULL.
1517	*/
1518	if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1519	return 0;
1520	#endif
1521
1522	rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1523	rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1524
1525	if (hash_contains_ip(ip, hash: &hash))
1526	ret = 1;
1527	else
1528	ret = 0;
1529
1530	return ret;
1531	}
1532
1533	/*
1534	* This is a double for. Do not use 'break' to break out of the loop,
1535	* you must use a goto.
1536	*/
1537	#define do_for_each_ftrace_rec(pg, rec) \
1538	for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1539	int _____i; \
1540	for (_____i = 0; _____i < pg->index; _____i++) { \
1541	rec = &pg->records[_____i];
1542
1543	#define while_for_each_ftrace_rec() \
1544	} \
1545	}
1546
1547
1548	static int ftrace_cmp_recs(const void *a, const void *b)
1549	{
1550	const struct dyn_ftrace *key = a;
1551	const struct dyn_ftrace *rec = b;
1552
1553	if (key->flags < rec->ip)
1554	return -1;
1555	if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1556	return 1;
1557	return 0;
1558	}
1559
1560	static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)
1561	{
1562	struct ftrace_page *pg;
1563	struct dyn_ftrace *rec = NULL;
1564	struct dyn_ftrace key;
1565
1566	key.ip = start;
1567	key.flags = end; /* overload flags, as it is unsigned long */
1568
1569	for (pg = ftrace_pages_start; pg; pg = pg->next) {
1570	if (pg->index == 0 ||
1571	end < pg->records[0].ip ||
1572	start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1573	continue;
1574	rec = bsearch(key: &key, base: pg->records, num: pg->index,
1575	size: sizeof(struct dyn_ftrace),
1576	cmp: ftrace_cmp_recs);
1577	if (rec)
1578	break;
1579	}
1580	return rec;
1581	}
1582
1583	/**
1584	* ftrace_location_range - return the first address of a traced location
1585	* if it touches the given ip range
1586	* @start: start of range to search.
1587	* @end: end of range to search (inclusive). @end points to the last byte
1588	* to check.
1589	*
1590	* Returns: rec->ip if the related ftrace location is a least partly within
1591	* the given address range. That is, the first address of the instruction
1592	* that is either a NOP or call to the function tracer. It checks the ftrace
1593	* internal tables to determine if the address belongs or not.
1594	*/
1595	unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1596	{
1597	struct dyn_ftrace *rec;
1598
1599	rec = lookup_rec(start, end);
1600	if (rec)
1601	return rec->ip;
1602
1603	return 0;
1604	}
1605
1606	/**
1607	* ftrace_location - return the ftrace location
1608	* @ip: the instruction pointer to check
1609	*
1610	* Returns:
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 __rcu *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 void call_direct_funcs(unsigned long ip, unsigned long pip,
2559	struct ftrace_ops *ops, struct ftrace_regs *fregs)
2560	{
2561	unsigned long addr = READ_ONCE(ops->direct_call);
2562
2563	if (!addr)
2564	return;
2565
2566	arch_ftrace_set_direct_caller(fregs, addr);
2567	}
2568	#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
2569
2570	/**
2571	* ftrace_get_addr_new - Get the call address to set to
2572	* @rec: The ftrace record descriptor
2573	*
2574	* If the record has the FTRACE_FL_REGS set, that means that it
2575	* wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2576	* is not set, then it wants to convert to the normal callback.
2577	*
2578	* Returns: the address of the trampoline to set to
2579	*/
2580	unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2581	{
2582	struct ftrace_ops *ops;
2583	unsigned long addr;
2584
2585	if ((rec->flags & FTRACE_FL_DIRECT) &&
2586	(ftrace_rec_count(rec) == 1)) {
2587	addr = ftrace_find_rec_direct(ip: rec->ip);
2588	if (addr)
2589	return addr;
2590	WARN_ON_ONCE(1);
2591	}
2592
2593	/* Trampolines take precedence over regs */
2594	if (rec->flags & FTRACE_FL_TRAMP) {
2595	ops = ftrace_find_tramp_ops_new(rec);
2596	if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2597	pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2598	(void *)rec->ip, (void *)rec->ip, rec->flags);
2599	/* Ftrace is shutting down, return anything */
2600	return (unsigned long)FTRACE_ADDR;
2601	}
2602	return ops->trampoline;
2603	}
2604
2605	if (rec->flags & FTRACE_FL_REGS)
2606	return (unsigned long)FTRACE_REGS_ADDR;
2607	else
2608	return (unsigned long)FTRACE_ADDR;
2609	}
2610
2611	/**
2612	* ftrace_get_addr_curr - Get the call address that is already there
2613	* @rec: The ftrace record descriptor
2614	*
2615	* The FTRACE_FL_REGS_EN is set when the record already points to
2616	* a function that saves all the regs. Basically the '_EN' version
2617	* represents the current state of the function.
2618	*
2619	* Returns: the address of the trampoline that is currently being called
2620	*/
2621	unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2622	{
2623	struct ftrace_ops *ops;
2624	unsigned long addr;
2625
2626	/* Direct calls take precedence over trampolines */
2627	if (rec->flags & FTRACE_FL_DIRECT_EN) {
2628	addr = ftrace_find_rec_direct(ip: rec->ip);
2629	if (addr)
2630	return addr;
2631	WARN_ON_ONCE(1);
2632	}
2633
2634	/* Trampolines take precedence over regs */
2635	if (rec->flags & FTRACE_FL_TRAMP_EN) {
2636	ops = ftrace_find_tramp_ops_curr(rec);
2637	if (FTRACE_WARN_ON(!ops)) {
2638	pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2639	(void *)rec->ip, (void *)rec->ip);
2640	/* Ftrace is shutting down, return anything */
2641	return (unsigned long)FTRACE_ADDR;
2642	}
2643	return ops->trampoline;
2644	}
2645
2646	if (rec->flags & FTRACE_FL_REGS_EN)
2647	return (unsigned long)FTRACE_REGS_ADDR;
2648	else
2649	return (unsigned long)FTRACE_ADDR;
2650	}
2651
2652	static int
2653	__ftrace_replace_code(struct dyn_ftrace *rec, bool enable)
2654	{
2655	unsigned long ftrace_old_addr;
2656	unsigned long ftrace_addr;
2657	int ret;
2658
2659	ftrace_addr = ftrace_get_addr_new(rec);
2660
2661	/* This needs to be done before we call ftrace_update_record */
2662	ftrace_old_addr = ftrace_get_addr_curr(rec);
2663
2664	ret = ftrace_update_record(rec, enable);
2665
2666	ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2667
2668	switch (ret) {
2669	case FTRACE_UPDATE_IGNORE:
2670	return 0;
2671
2672	case FTRACE_UPDATE_MAKE_CALL:
2673	ftrace_bug_type = FTRACE_BUG_CALL;
2674	return ftrace_make_call(rec, addr: ftrace_addr);
2675
2676	case FTRACE_UPDATE_MAKE_NOP:
2677	ftrace_bug_type = FTRACE_BUG_NOP;
2678	return ftrace_make_nop(NULL, rec, addr: ftrace_old_addr);
2679
2680	case FTRACE_UPDATE_MODIFY_CALL:
2681	ftrace_bug_type = FTRACE_BUG_UPDATE;
2682	return ftrace_modify_call(rec, old_addr: ftrace_old_addr, addr: ftrace_addr);
2683	}
2684
2685	return -1; /* unknown ftrace bug */
2686	}
2687
2688	void __weak ftrace_replace_code(int mod_flags)
2689	{
2690	struct dyn_ftrace *rec;
2691	struct ftrace_page *pg;
2692	bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
2693	int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
2694	int failed;
2695
2696	if (unlikely(ftrace_disabled))
2697	return;
2698
2699	do_for_each_ftrace_rec(pg, rec) {
2700
2701	if (skip_record(rec))
2702	continue;
2703
2704	failed = __ftrace_replace_code(rec, enable);
2705	if (failed) {
2706	ftrace_bug(failed, rec);
2707	/* Stop processing */
2708	return;
2709	}
2710	if (schedulable)
2711	cond_resched();
2712	} while_for_each_ftrace_rec();
2713	}
2714
2715	struct ftrace_rec_iter {
2716	struct ftrace_page *pg;
2717	int index;
2718	};
2719
2720	/**
2721	* ftrace_rec_iter_start - start up iterating over traced functions
2722	*
2723	* Returns: an iterator handle that is used to iterate over all
2724	* the records that represent address locations where functions
2725	* are traced.
2726	*
2727	* May return NULL if no records are available.
2728	*/
2729	struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2730	{
2731	/*
2732	* We only use a single iterator.
2733	* Protected by the ftrace_lock mutex.
2734	*/
2735	static struct ftrace_rec_iter ftrace_rec_iter;
2736	struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2737
2738	iter->pg = ftrace_pages_start;
2739	iter->index = 0;
2740
2741	/* Could have empty pages */
2742	while (iter->pg && !iter->pg->index)
2743	iter->pg = iter->pg->next;
2744
2745	if (!iter->pg)
2746	return NULL;
2747
2748	return iter;
2749	}
2750
2751	/**
2752	* ftrace_rec_iter_next - get the next record to process.
2753	* @iter: The handle to the iterator.
2754	*
2755	* Returns: the next iterator after the given iterator @iter.
2756	*/
2757	struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2758	{
2759	iter->index++;
2760
2761	if (iter->index >= iter->pg->index) {
2762	iter->pg = iter->pg->next;
2763	iter->index = 0;
2764
2765	/* Could have empty pages */
2766	while (iter->pg && !iter->pg->index)
2767	iter->pg = iter->pg->next;
2768	}
2769
2770	if (!iter->pg)
2771	return NULL;
2772
2773	return iter;
2774	}
2775
2776	/**
2777	* ftrace_rec_iter_record - get the record at the iterator location
2778	* @iter: The current iterator location
2779	*
2780	* Returns: the record that the current @iter is at.
2781	*/
2782	struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2783	{
2784	return &iter->pg->records[iter->index];
2785	}
2786
2787	static int
2788	ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec)
2789	{
2790	int ret;
2791
2792	if (unlikely(ftrace_disabled))
2793	return 0;
2794
2795	ret = ftrace_init_nop(mod, rec);
2796	if (ret) {
2797	ftrace_bug_type = FTRACE_BUG_INIT;
2798	ftrace_bug(failed: ret, rec);
2799	return 0;
2800	}
2801	return 1;
2802	}
2803
2804	/*
2805	* archs can override this function if they must do something
2806	* before the modifying code is performed.
2807	*/
2808	void __weak ftrace_arch_code_modify_prepare(void)
2809	{
2810	}
2811
2812	/*
2813	* archs can override this function if they must do something
2814	* after the modifying code is performed.
2815	*/
2816	void __weak ftrace_arch_code_modify_post_process(void)
2817	{
2818	}
2819
2820	static int update_ftrace_func(ftrace_func_t func)
2821	{
2822	static ftrace_func_t save_func;
2823
2824	/* Avoid updating if it hasn't changed */
2825	if (func == save_func)
2826	return 0;
2827
2828	save_func = func;
2829
2830	return ftrace_update_ftrace_func(func);
2831	}
2832
2833	void ftrace_modify_all_code(int command)
2834	{
2835	int update = command & FTRACE_UPDATE_TRACE_FUNC;
2836	int mod_flags = 0;
2837	int err = 0;
2838
2839	if (command & FTRACE_MAY_SLEEP)
2840	mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
2841
2842	/*
2843	* If the ftrace_caller calls a ftrace_ops func directly,
2844	* we need to make sure that it only traces functions it
2845	* expects to trace. When doing the switch of functions,
2846	* we need to update to the ftrace_ops_list_func first
2847	* before the transition between old and new calls are set,
2848	* as the ftrace_ops_list_func will check the ops hashes
2849	* to make sure the ops are having the right functions
2850	* traced.
2851	*/
2852	if (update) {
2853	err = update_ftrace_func(func: ftrace_ops_list_func);
2854	if (FTRACE_WARN_ON(err))
2855	return;
2856	}
2857
2858	if (command & FTRACE_UPDATE_CALLS)
2859	ftrace_replace_code(mod_flags: mod_flags | FTRACE_MODIFY_ENABLE_FL);
2860	else if (command & FTRACE_DISABLE_CALLS)
2861	ftrace_replace_code(mod_flags);
2862
2863	if (update && ftrace_trace_function != ftrace_ops_list_func) {
2864	function_trace_op = set_function_trace_op;
2865	smp_wmb();
2866	/* If irqs are disabled, we are in stop machine */
2867	if (!irqs_disabled())
2868	smp_call_function(func: ftrace_sync_ipi, NULL, wait: 1);
2869	err = update_ftrace_func(func: ftrace_trace_function);
2870	if (FTRACE_WARN_ON(err))
2871	return;
2872	}
2873
2874	if (command & FTRACE_START_FUNC_RET)
2875	err = ftrace_enable_ftrace_graph_caller();
2876	else if (command & FTRACE_STOP_FUNC_RET)
2877	err = ftrace_disable_ftrace_graph_caller();
2878	FTRACE_WARN_ON(err);
2879	}
2880
2881	static int __ftrace_modify_code(void *data)
2882	{
2883	int *command = data;
2884
2885	ftrace_modify_all_code(command: *command);
2886
2887	return 0;
2888	}
2889
2890	/**
2891	* ftrace_run_stop_machine - go back to the stop machine method
2892	* @command: The command to tell ftrace what to do
2893	*
2894	* If an arch needs to fall back to the stop machine method, the
2895	* it can call this function.
2896	*/
2897	void ftrace_run_stop_machine(int command)
2898	{
2899	stop_machine(fn: __ftrace_modify_code, data: &command, NULL);
2900	}
2901
2902	/**
2903	* arch_ftrace_update_code - modify the code to trace or not trace
2904	* @command: The command that needs to be done
2905	*
2906	* Archs can override this function if it does not need to
2907	* run stop_machine() to modify code.
2908	*/
2909	void __weak arch_ftrace_update_code(int command)
2910	{
2911	ftrace_run_stop_machine(command);
2912	}
2913
2914	static void ftrace_run_update_code(int command)
2915	{
2916	ftrace_arch_code_modify_prepare();
2917
2918	/*
2919	* By default we use stop_machine() to modify the code.
2920	* But archs can do what ever they want as long as it
2921	* is safe. The stop_machine() is the safest, but also
2922	* produces the most overhead.
2923	*/
2924	arch_ftrace_update_code(command);
2925
2926	ftrace_arch_code_modify_post_process();
2927	}
2928
2929	static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2930	struct ftrace_ops_hash *old_hash)
2931	{
2932	ops->flags |= FTRACE_OPS_FL_MODIFYING;
2933	ops->old_hash.filter_hash = old_hash->filter_hash;
2934	ops->old_hash.notrace_hash = old_hash->notrace_hash;
2935	ftrace_run_update_code(command);
2936	ops->old_hash.filter_hash = NULL;
2937	ops->old_hash.notrace_hash = NULL;
2938	ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2939	}
2940
2941	static ftrace_func_t saved_ftrace_func;
2942	static int ftrace_start_up;
2943
2944	void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2945	{
2946	}
2947
2948	/* List of trace_ops that have allocated trampolines */
2949	static LIST_HEAD(ftrace_ops_trampoline_list);
2950
2951	static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops)
2952	{
2953	lockdep_assert_held(&ftrace_lock);
2954	list_add_rcu(new: &ops->list, head: &ftrace_ops_trampoline_list);
2955	}
2956
2957	static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops)
2958	{
2959	lockdep_assert_held(&ftrace_lock);
2960	list_del_rcu(entry: &ops->list);
2961	synchronize_rcu();
2962	}
2963
2964	/*
2965	* "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols
2966	* for pages allocated for ftrace purposes, even though "__builtin__ftrace" is
2967	* not a module.
2968	*/
2969	#define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace"
2970	#define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline"
2971
2972	static void ftrace_trampoline_free(struct ftrace_ops *ops)
2973	{
2974	if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) &&
2975	ops->trampoline) {
2976	/*
2977	* Record the text poke event before the ksymbol unregister
2978	* event.
2979	*/
2980	perf_event_text_poke(addr: (void *)ops->trampoline,
2981	old_bytes: (void *)ops->trampoline,
2982	old_len: ops->trampoline_size, NULL, new_len: 0);
2983	perf_event_ksymbol(ksym_type: PERF_RECORD_KSYMBOL_TYPE_OOL,
2984	addr: ops->trampoline, len: ops->trampoline_size,
2985	unregister: true, FTRACE_TRAMPOLINE_SYM);
2986	/* Remove from kallsyms after the perf events */
2987	ftrace_remove_trampoline_from_kallsyms(ops);
2988	}
2989
2990	arch_ftrace_trampoline_free(ops);
2991	}
2992
2993	static void ftrace_startup_enable(int command)
2994	{
2995	if (saved_ftrace_func != ftrace_trace_function) {
2996	saved_ftrace_func = ftrace_trace_function;
2997	command |= FTRACE_UPDATE_TRACE_FUNC;
2998	}
2999
3000	if (!command || !ftrace_enabled)
3001	return;
3002
3003	ftrace_run_update_code(command);
3004	}
3005
3006	static void ftrace_startup_all(int command)
3007	{
3008	update_all_ops = true;
3009	ftrace_startup_enable(command);
3010	update_all_ops = false;
3011	}
3012
3013	int ftrace_startup(struct ftrace_ops *ops, int command)
3014	{
3015	int ret;
3016
3017	if (unlikely(ftrace_disabled))
3018	return -ENODEV;
3019
3020	ret = __register_ftrace_function(ops);
3021	if (ret)
3022	return ret;
3023
3024	ftrace_start_up++;
3025
3026	/*
3027	* Note that ftrace probes uses this to start up
3028	* and modify functions it will probe. But we still
3029	* set the ADDING flag for modification, as probes
3030	* do not have trampolines. If they add them in the
3031	* future, then the probes will need to distinguish
3032	* between adding and updating probes.
3033	*/
3034	ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
3035
3036	ret = ftrace_hash_ipmodify_enable(ops);
3037	if (ret < 0) {
3038	/* Rollback registration process */
3039	__unregister_ftrace_function(ops);
3040	ftrace_start_up--;
3041	ops->flags &= ~FTRACE_OPS_FL_ENABLED;
3042	if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
3043	ftrace_trampoline_free(ops);
3044	return ret;
3045	}
3046
3047	if (ftrace_hash_rec_enable(ops, filter_hash: 1))
3048	command |= FTRACE_UPDATE_CALLS;
3049
3050	ftrace_startup_enable(command);
3051
3052	/*
3053	* If ftrace is in an undefined state, we just remove ops from list
3054	* to prevent the NULL pointer, instead of totally rolling it back and
3055	* free trampoline, because those actions could cause further damage.
3056	*/
3057	if (unlikely(ftrace_disabled)) {
3058	__unregister_ftrace_function(ops);
3059	return -ENODEV;
3060	}
3061
3062	ops->flags &= ~FTRACE_OPS_FL_ADDING;
3063
3064	return 0;
3065	}
3066
3067	int ftrace_shutdown(struct ftrace_ops *ops, int command)
3068	{
3069	int ret;
3070
3071	if (unlikely(ftrace_disabled))
3072	return -ENODEV;
3073
3074	ret = __unregister_ftrace_function(ops);
3075	if (ret)
3076	return ret;
3077
3078	ftrace_start_up--;
3079	/*
3080	* Just warn in case of unbalance, no need to kill ftrace, it's not
3081	* critical but the ftrace_call callers may be never nopped again after
3082	* further ftrace uses.
3083	*/
3084	WARN_ON_ONCE(ftrace_start_up < 0);
3085
3086	/* Disabling ipmodify never fails */
3087	ftrace_hash_ipmodify_disable(ops);
3088
3089	if (ftrace_hash_rec_disable(ops, filter_hash: 1))
3090	command |= FTRACE_UPDATE_CALLS;
3091
3092	ops->flags &= ~FTRACE_OPS_FL_ENABLED;
3093
3094	if (saved_ftrace_func != ftrace_trace_function) {
3095	saved_ftrace_func = ftrace_trace_function;
3096	command |= FTRACE_UPDATE_TRACE_FUNC;
3097	}
3098
3099	if (!command || !ftrace_enabled)
3100	goto out;
3101
3102	/*
3103	* If the ops uses a trampoline, then it needs to be
3104	* tested first on update.
3105	*/
3106	ops->flags |= FTRACE_OPS_FL_REMOVING;
3107	removed_ops = ops;
3108
3109	/* The trampoline logic checks the old hashes */
3110	ops->old_hash.filter_hash = ops->func_hash->filter_hash;
3111	ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
3112
3113	ftrace_run_update_code(command);
3114
3115	/*
3116	* If there's no more ops registered with ftrace, run a
3117	* sanity check to make sure all rec flags are cleared.
3118	*/
3119	if (rcu_dereference_protected(ftrace_ops_list,
3120	lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
3121	struct ftrace_page *pg;
3122	struct dyn_ftrace *rec;
3123
3124	do_for_each_ftrace_rec(pg, rec) {
3125	if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_NOCLEAR_FLAGS))
3126	pr_warn(" %pS flags:%lx\n",
3127	(void *)rec->ip, rec->flags);
3128	} while_for_each_ftrace_rec();
3129	}
3130
3131	ops->old_hash.filter_hash = NULL;
3132	ops->old_hash.notrace_hash = NULL;
3133
3134	removed_ops = NULL;
3135	ops->flags &= ~FTRACE_OPS_FL_REMOVING;
3136
3137	out:
3138	/*
3139	* Dynamic ops may be freed, we must make sure that all
3140	* callers are done before leaving this function.
3141	*/
3142	if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
3143	/*
3144	* We need to do a hard force of sched synchronization.
3145	* This is because we use preempt_disable() to do RCU, but
3146	* the function tracers can be called where RCU is not watching
3147	* (like before user_exit()). We can not rely on the RCU
3148	* infrastructure to do the synchronization, thus we must do it
3149	* ourselves.
3150	*/
3151	synchronize_rcu_tasks_rude();
3152
3153	/*
3154	* When the kernel is preemptive, tasks can be preempted
3155	* while on a ftrace trampoline. Just scheduling a task on
3156	* a CPU is not good enough to flush them. Calling
3157	* synchronize_rcu_tasks() will wait for those tasks to
3158	* execute and either schedule voluntarily or enter user space.
3159	*/
3160	if (IS_ENABLED(CONFIG_PREEMPTION))
3161	synchronize_rcu_tasks();
3162
3163	ftrace_trampoline_free(ops);
3164	}
3165
3166	return 0;
3167	}
3168
3169	static u64 ftrace_update_time;
3170	unsigned long ftrace_update_tot_cnt;
3171	unsigned long ftrace_number_of_pages;
3172	unsigned long ftrace_number_of_groups;
3173
3174	static inline int ops_traces_mod(struct ftrace_ops *ops)
3175	{
3176	/*
3177	* Filter_hash being empty will default to trace module.
3178	* But notrace hash requires a test of individual module functions.
3179	*/
3180	return ftrace_hash_empty(hash: ops->func_hash->filter_hash) &&
3181	ftrace_hash_empty(hash: ops->func_hash->notrace_hash);
3182	}
3183
3184	static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
3185	{
3186	bool init_nop = ftrace_need_init_nop();
3187	struct ftrace_page *pg;
3188	struct dyn_ftrace *p;
3189	u64 start, stop;
3190	unsigned long update_cnt = 0;
3191	unsigned long rec_flags = 0;
3192	int i;
3193
3194	start = ftrace_now(raw_smp_processor_id());
3195
3196	/*
3197	* When a module is loaded, this function is called to convert
3198	* the calls to mcount in its text to nops, and also to create
3199	* an entry in the ftrace data. Now, if ftrace is activated
3200	* after this call, but before the module sets its text to
3201	* read-only, the modification of enabling ftrace can fail if
3202	* the read-only is done while ftrace is converting the calls.
3203	* To prevent this, the module's records are set as disabled
3204	* and will be enabled after the call to set the module's text
3205	* to read-only.
3206	*/
3207	if (mod)
3208	rec_flags |= FTRACE_FL_DISABLED;
3209
3210	for (pg = new_pgs; pg; pg = pg->next) {
3211
3212	for (i = 0; i < pg->index; i++) {
3213
3214	/* If something went wrong, bail without enabling anything */
3215	if (unlikely(ftrace_disabled))
3216	return -1;
3217
3218	p = &pg->records[i];
3219	p->flags = rec_flags;
3220
3221	/*
3222	* Do the initial record conversion from mcount jump
3223	* to the NOP instructions.
3224	*/
3225	if (init_nop && !ftrace_nop_initialize(mod, rec: p))
3226	break;
3227
3228	update_cnt++;
3229	}
3230	}
3231
3232	stop = ftrace_now(raw_smp_processor_id());
3233	ftrace_update_time = stop - start;
3234	ftrace_update_tot_cnt += update_cnt;
3235
3236	return 0;
3237	}
3238
3239	static int ftrace_allocate_records(struct ftrace_page *pg, int count)
3240	{
3241	int order;
3242	int pages;
3243	int cnt;
3244
3245	if (WARN_ON(!count))
3246	return -EINVAL;
3247
3248	/* We want to fill as much as possible, with no empty pages */
3249	pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE);
3250	order = fls(x: pages) - 1;
3251
3252	again:
3253	pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
3254
3255	if (!pg->records) {
3256	/* if we can't allocate this size, try something smaller */
3257	if (!order)
3258	return -ENOMEM;
3259	order--;
3260	goto again;
3261	}
3262
3263	ftrace_number_of_pages += 1 << order;
3264	ftrace_number_of_groups++;
3265
3266	cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3267	pg->order = order;
3268
3269	if (cnt > count)
3270	cnt = count;
3271
3272	return cnt;
3273	}
3274
3275	static void ftrace_free_pages(struct ftrace_page *pages)
3276	{
3277	struct ftrace_page *pg = pages;
3278
3279	while (pg) {
3280	if (pg->records) {
3281	free_pages(addr: (unsigned long)pg->records, order: pg->order);
3282	ftrace_number_of_pages -= 1 << pg->order;
3283	}
3284	pages = pg->next;
3285	kfree(objp: pg);
3286	pg = pages;
3287	ftrace_number_of_groups--;
3288	}
3289	}
3290
3291	static struct ftrace_page *
3292	ftrace_allocate_pages(unsigned long num_to_init)
3293	{
3294	struct ftrace_page *start_pg;
3295	struct ftrace_page *pg;
3296	int cnt;
3297
3298	if (!num_to_init)
3299	return NULL;
3300
3301	start_pg = pg = kzalloc(size: sizeof(*pg), GFP_KERNEL);
3302	if (!pg)
3303	return NULL;
3304
3305	/*
3306	* Try to allocate as much as possible in one continues
3307	* location that fills in all of the space. We want to
3308	* waste as little space as possible.
3309	*/
3310	for (;;) {
3311	cnt = ftrace_allocate_records(pg, count: num_to_init);
3312	if (cnt < 0)
3313	goto free_pages;
3314
3315	num_to_init -= cnt;
3316	if (!num_to_init)
3317	break;
3318
3319	pg->next = kzalloc(size: sizeof(*pg), GFP_KERNEL);
3320	if (!pg->next)
3321	goto free_pages;
3322
3323	pg = pg->next;
3324	}
3325
3326	return start_pg;
3327
3328	free_pages:
3329	ftrace_free_pages(pages: start_pg);
3330	pr_info("ftrace: FAILED to allocate memory for functions\n");
3331	return NULL;
3332	}
3333
3334	#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3335
3336	struct ftrace_iterator {
3337	loff_t pos;
3338	loff_t func_pos;
3339	loff_t mod_pos;
3340	struct ftrace_page *pg;
3341	struct dyn_ftrace *func;
3342	struct ftrace_func_probe *probe;
3343	struct ftrace_func_entry *probe_entry;
3344	struct trace_parser parser;
3345	struct ftrace_hash *hash;
3346	struct ftrace_ops *ops;
3347	struct trace_array *tr;
3348	struct list_head *mod_list;
3349	int pidx;
3350	int idx;
3351	unsigned flags;
3352	};
3353
3354	static void *
3355	t_probe_next(struct seq_file *m, loff_t *pos)
3356	{
3357	struct ftrace_iterator *iter = m->private;
3358	struct trace_array *tr = iter->ops->private;
3359	struct list_head *func_probes;
3360	struct ftrace_hash *hash;
3361	struct list_head *next;
3362	struct hlist_node *hnd = NULL;
3363	struct hlist_head *hhd;
3364	int size;
3365
3366	(*pos)++;
3367	iter->pos = *pos;
3368
3369	if (!tr)
3370	return NULL;
3371
3372	func_probes = &tr->func_probes;
3373	if (list_empty(head: func_probes))
3374	return NULL;
3375
3376	if (!iter->probe) {
3377	next = func_probes->next;
3378	iter->probe = list_entry(next, struct ftrace_func_probe, list);
3379	}
3380
3381	if (iter->probe_entry)
3382	hnd = &iter->probe_entry->hlist;
3383
3384	hash = iter->probe->ops.func_hash->filter_hash;
3385
3386	/*
3387	* A probe being registered may temporarily have an empty hash
3388	* and it's at the end of the func_probes list.
3389	*/
3390	if (!hash || hash == EMPTY_HASH)
3391	return NULL;
3392
3393	size = 1 << hash->size_bits;
3394
3395	retry:
3396	if (iter->pidx >= size) {
3397	if (iter->probe->list.next == func_probes)
3398	return NULL;
3399	next = iter->probe->list.next;
3400	iter->probe = list_entry(next, struct ftrace_func_probe, list);
3401	hash = iter->probe->ops.func_hash->filter_hash;
3402	size = 1 << hash->size_bits;
3403	iter->pidx = 0;
3404	}
3405
3406	hhd = &hash->buckets[iter->pidx];
3407
3408	if (hlist_empty(h: hhd)) {
3409	iter->pidx++;
3410	hnd = NULL;
3411	goto retry;
3412	}
3413
3414	if (!hnd)
3415	hnd = hhd->first;
3416	else {
3417	hnd = hnd->next;
3418	if (!hnd) {
3419	iter->pidx++;
3420	goto retry;
3421	}
3422	}
3423
3424	if (WARN_ON_ONCE(!hnd))
3425	return NULL;
3426
3427	iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3428
3429	return iter;
3430	}
3431
3432	static void *t_probe_start(struct seq_file *m, loff_t *pos)
3433	{
3434	struct ftrace_iterator *iter = m->private;
3435	void *p = NULL;
3436	loff_t l;
3437
3438	if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3439	return NULL;
3440
3441	if (iter->mod_pos > *pos)
3442	return NULL;
3443
3444	iter->probe = NULL;
3445	iter->probe_entry = NULL;
3446	iter->pidx = 0;
3447	for (l = 0; l <= (*pos - iter->mod_pos); ) {
3448	p = t_probe_next(m, pos: &l);
3449	if (!p)
3450	break;
3451	}
3452	if (!p)
3453	return NULL;
3454
3455	/* Only set this if we have an item */
3456	iter->flags |= FTRACE_ITER_PROBE;
3457
3458	return iter;
3459	}
3460
3461	static int
3462	t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3463	{
3464	struct ftrace_func_entry *probe_entry;
3465	struct ftrace_probe_ops *probe_ops;
3466	struct ftrace_func_probe *probe;
3467
3468	probe = iter->probe;
3469	probe_entry = iter->probe_entry;
3470
3471	if (WARN_ON_ONCE(!probe || !probe_entry))
3472	return -EIO;
3473
3474	probe_ops = probe->probe_ops;
3475
3476	if (probe_ops->print)
3477	return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3478
3479	seq_printf(m, fmt: "%ps:%ps\n", (void *)probe_entry->ip,
3480	(void *)probe_ops->func);
3481
3482	return 0;
3483	}
3484
3485	static void *
3486	t_mod_next(struct seq_file *m, loff_t *pos)
3487	{
3488	struct ftrace_iterator *iter = m->private;
3489	struct trace_array *tr = iter->tr;
3490
3491	(*pos)++;
3492	iter->pos = *pos;
3493
3494	iter->mod_list = iter->mod_list->next;
3495
3496	if (iter->mod_list == &tr->mod_trace ||
3497	iter->mod_list == &tr->mod_notrace) {
3498	iter->flags &= ~FTRACE_ITER_MOD;
3499	return NULL;
3500	}
3501
3502	iter->mod_pos = *pos;
3503
3504	return iter;
3505	}
3506
3507	static void *t_mod_start(struct seq_file *m, loff_t *pos)
3508	{
3509	struct ftrace_iterator *iter = m->private;
3510	void *p = NULL;
3511	loff_t l;
3512
3513	if (iter->func_pos > *pos)
3514	return NULL;
3515
3516	iter->mod_pos = iter->func_pos;
3517
3518	/* probes are only available if tr is set */
3519	if (!iter->tr)
3520	return NULL;
3521
3522	for (l = 0; l <= (*pos - iter->func_pos); ) {
3523	p = t_mod_next(m, pos: &l);
3524	if (!p)
3525	break;
3526	}
3527	if (!p) {
3528	iter->flags &= ~FTRACE_ITER_MOD;
3529	return t_probe_start(m, pos);
3530	}
3531
3532	/* Only set this if we have an item */
3533	iter->flags |= FTRACE_ITER_MOD;
3534
3535	return iter;
3536	}
3537
3538	static int
3539	t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3540	{
3541	struct ftrace_mod_load *ftrace_mod;
3542	struct trace_array *tr = iter->tr;
3543
3544	if (WARN_ON_ONCE(!iter->mod_list) ||
3545	iter->mod_list == &tr->mod_trace ||
3546	iter->mod_list == &tr->mod_notrace)
3547	return -EIO;
3548
3549	ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3550
3551	if (ftrace_mod->func)
3552	seq_printf(m, fmt: "%s", ftrace_mod->func);
3553	else
3554	seq_putc(m, c: '*');
3555
3556	seq_printf(m, fmt: ":mod:%s\n", ftrace_mod->module);
3557
3558	return 0;
3559	}
3560
3561	static void *
3562	t_func_next(struct seq_file *m, loff_t *pos)
3563	{
3564	struct ftrace_iterator *iter = m->private;
3565	struct dyn_ftrace *rec = NULL;
3566
3567	(*pos)++;
3568
3569	retry:
3570	if (iter->idx >= iter->pg->index) {
3571	if (iter->pg->next) {
3572	iter->pg = iter->pg->next;
3573	iter->idx = 0;
3574	goto retry;
3575	}
3576	} else {
3577	rec = &iter->pg->records[iter->idx++];
3578	if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3579	!ftrace_lookup_ip(hash: iter->hash, ip: rec->ip)) ||
3580
3581	((iter->flags & FTRACE_ITER_ENABLED) &&
3582	!(rec->flags & FTRACE_FL_ENABLED)) ||
3583
3584	((iter->flags & FTRACE_ITER_TOUCHED) &&
3585	!(rec->flags & FTRACE_FL_TOUCHED))) {
3586
3587	rec = NULL;
3588	goto retry;
3589	}
3590	}
3591
3592	if (!rec)
3593	return NULL;
3594
3595	iter->pos = iter->func_pos = *pos;
3596	iter->func = rec;
3597
3598	return iter;
3599	}
3600
3601	static void *
3602	t_next(struct seq_file *m, void *v, loff_t *pos)
3603	{
3604	struct ftrace_iterator *iter = m->private;
3605	loff_t l = *pos; /* t_probe_start() must use original pos */
3606	void *ret;
3607
3608	if (unlikely(ftrace_disabled))
3609	return NULL;
3610
3611	if (iter->flags & FTRACE_ITER_PROBE)
3612	return t_probe_next(m, pos);
3613
3614	if (iter->flags & FTRACE_ITER_MOD)
3615	return t_mod_next(m, pos);
3616
3617	if (iter->flags & FTRACE_ITER_PRINTALL) {
3618	/* next must increment pos, and t_probe_start does not */
3619	(*pos)++;
3620	return t_mod_start(m, pos: &l);
3621	}
3622
3623	ret = t_func_next(m, pos);
3624
3625	if (!ret)
3626	return t_mod_start(m, pos: &l);
3627
3628	return ret;
3629	}
3630
3631	static void reset_iter_read(struct ftrace_iterator *iter)
3632	{
3633	iter->pos = 0;
3634	iter->func_pos = 0;
3635	iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3636	}
3637
3638	static void *t_start(struct seq_file *m, loff_t *pos)
3639	{
3640	struct ftrace_iterator *iter = m->private;
3641	void *p = NULL;
3642	loff_t l;
3643
3644	mutex_lock(&ftrace_lock);
3645
3646	if (unlikely(ftrace_disabled))
3647	return NULL;
3648
3649	/*
3650	* If an lseek was done, then reset and start from beginning.
3651	*/
3652	if (*pos < iter->pos)
3653	reset_iter_read(iter);
3654
3655	/*
3656	* For set_ftrace_filter reading, if we have the filter
3657	* off, we can short cut and just print out that all
3658	* functions are enabled.
3659	*/
3660	if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3661	ftrace_hash_empty(hash: iter->hash)) {
3662	iter->func_pos = 1; /* Account for the message */
3663	if (*pos > 0)
3664	return t_mod_start(m, pos);
3665	iter->flags |= FTRACE_ITER_PRINTALL;
3666	/* reset in case of seek/pread */
3667	iter->flags &= ~FTRACE_ITER_PROBE;
3668	return iter;
3669	}
3670
3671	if (iter->flags & FTRACE_ITER_MOD)
3672	return t_mod_start(m, pos);
3673
3674	/*
3675	* Unfortunately, we need to restart at ftrace_pages_start
3676	* every time we let go of the ftrace_mutex. This is because
3677	* those pointers can change without the lock.
3678	*/
3679	iter->pg = ftrace_pages_start;
3680	iter->idx = 0;
3681	for (l = 0; l <= *pos; ) {
3682	p = t_func_next(m, pos: &l);
3683	if (!p)
3684	break;
3685	}
3686
3687	if (!p)
3688	return t_mod_start(m, pos);
3689
3690	return iter;
3691	}
3692
3693	static void t_stop(struct seq_file *m, void *p)
3694	{
3695	mutex_unlock(lock: &ftrace_lock);
3696	}
3697
3698	void * __weak
3699	arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3700	{
3701	return NULL;
3702	}
3703
3704	static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3705	struct dyn_ftrace *rec)
3706	{
3707	void *ptr;
3708
3709	ptr = arch_ftrace_trampoline_func(ops, rec);
3710	if (ptr)
3711	seq_printf(m, fmt: " ->%pS", ptr);
3712	}
3713
3714	#ifdef FTRACE_MCOUNT_MAX_OFFSET
3715	/*
3716	* Weak functions can still have an mcount/fentry that is saved in
3717	* the __mcount_loc section. These can be detected by having a
3718	* symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the
3719	* symbol found by kallsyms is not the function that the mcount/fentry
3720	* is part of. The offset is much greater in these cases.
3721	*
3722	* Test the record to make sure that the ip points to a valid kallsyms
3723	* and if not, mark it disabled.
3724	*/
3725	static int test_for_valid_rec(struct dyn_ftrace *rec)
3726	{
3727	char str[KSYM_SYMBOL_LEN];
3728	unsigned long offset;
3729	const char *ret;
3730
3731	ret = kallsyms_lookup(addr: rec->ip, NULL, offset: &offset, NULL, namebuf: str);
3732
3733	/* Weak functions can cause invalid addresses */
3734	if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
3735	rec->flags |= FTRACE_FL_DISABLED;
3736	return 0;
3737	}
3738	return 1;
3739	}
3740
3741	static struct workqueue_struct *ftrace_check_wq __initdata;
3742	static struct work_struct ftrace_check_work __initdata;
3743
3744	/*
3745	* Scan all the mcount/fentry entries to make sure they are valid.
3746	*/
3747	static __init void ftrace_check_work_func(struct work_struct *work)
3748	{
3749	struct ftrace_page *pg;
3750	struct dyn_ftrace *rec;
3751
3752	mutex_lock(&ftrace_lock);
3753	do_for_each_ftrace_rec(pg, rec) {
3754	test_for_valid_rec(rec);
3755	} while_for_each_ftrace_rec();
3756	mutex_unlock(lock: &ftrace_lock);
3757	}
3758
3759	static int __init ftrace_check_for_weak_functions(void)
3760	{
3761	INIT_WORK(&ftrace_check_work, ftrace_check_work_func);
3762
3763	ftrace_check_wq = alloc_workqueue(fmt: "ftrace_check_wq", flags: WQ_UNBOUND, max_active: 0);
3764
3765	queue_work(wq: ftrace_check_wq, work: &ftrace_check_work);
3766	return 0;
3767	}
3768
3769	static int __init ftrace_check_sync(void)
3770	{
3771	/* Make sure the ftrace_check updates are finished */
3772	if (ftrace_check_wq)
3773	destroy_workqueue(wq: ftrace_check_wq);
3774	return 0;
3775	}
3776
3777	late_initcall_sync(ftrace_check_sync);
3778	subsys_initcall(ftrace_check_for_weak_functions);
3779
3780	static int print_rec(struct seq_file *m, unsigned long ip)
3781	{
3782	unsigned long offset;
3783	char str[KSYM_SYMBOL_LEN];
3784	char *modname;
3785	const char *ret;
3786
3787	ret = kallsyms_lookup(addr: ip, NULL, offset: &offset, modname: &modname, namebuf: str);
3788	/* Weak functions can cause invalid addresses */
3789	if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) {
3790	snprintf(buf: str, KSYM_SYMBOL_LEN, fmt: "%s_%ld",
3791	FTRACE_INVALID_FUNCTION, offset);
3792	ret = NULL;
3793	}
3794
3795	seq_puts(m, s: str);
3796	if (modname)
3797	seq_printf(m, fmt: " [%s]", modname);
3798	return ret == NULL ? -1 : 0;
3799	}
3800	#else
3801	static inline int test_for_valid_rec(struct dyn_ftrace *rec)
3802	{
3803	return 1;
3804	}
3805
3806	static inline int print_rec(struct seq_file *m, unsigned long ip)
3807	{
3808	seq_printf(m, "%ps", (void *)ip);
3809	return 0;
3810	}
3811	#endif
3812
3813	static int t_show(struct seq_file *m, void *v)
3814	{
3815	struct ftrace_iterator *iter = m->private;
3816	struct dyn_ftrace *rec;
3817
3818	if (iter->flags & FTRACE_ITER_PROBE)
3819	return t_probe_show(m, iter);
3820
3821	if (iter->flags & FTRACE_ITER_MOD)
3822	return t_mod_show(m, iter);
3823
3824	if (iter->flags & FTRACE_ITER_PRINTALL) {
3825	if (iter->flags & FTRACE_ITER_NOTRACE)
3826	seq_puts(m, s: "#### no functions disabled ####\n");
3827	else
3828	seq_puts(m, s: "#### all functions enabled ####\n");
3829	return 0;
3830	}
3831
3832	rec = iter->func;
3833
3834	if (!rec)
3835	return 0;
3836
3837	if (iter->flags & FTRACE_ITER_ADDRS)
3838	seq_printf(m, fmt: "%lx ", rec->ip);
3839
3840	if (print_rec(m, ip: rec->ip)) {
3841	/* This should only happen when a rec is disabled */
3842	WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED));
3843	seq_putc(m, c: '\n');
3844	return 0;
3845	}
3846
3847	if (iter->flags & (FTRACE_ITER_ENABLED | FTRACE_ITER_TOUCHED)) {
3848	struct ftrace_ops *ops;
3849
3850	seq_printf(m, fmt: " (%ld)%s%s%s%s%s",
3851	ftrace_rec_count(rec),
3852	rec->flags & FTRACE_FL_REGS ? " R" : " ",
3853	rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ",
3854	rec->flags & FTRACE_FL_DIRECT ? " D" : " ",
3855	rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ",
3856	rec->flags & FTRACE_FL_MODIFIED ? " M " : " ");
3857	if (rec->flags & FTRACE_FL_TRAMP_EN) {
3858	ops = ftrace_find_tramp_ops_any(rec);
3859	if (ops) {
3860	do {
3861	seq_printf(m, fmt: "\ttramp: %pS (%pS)",
3862	(void *)ops->trampoline,
3863	(void *)ops->func);
3864	add_trampoline_func(m, ops, rec);
3865	ops = ftrace_find_tramp_ops_next(rec, op: ops);
3866	} while (ops);
3867	} else
3868	seq_puts(m, s: "\ttramp: ERROR!");
3869	} else {
3870	add_trampoline_func(m, NULL, rec);
3871	}
3872	if (rec->flags & FTRACE_FL_CALL_OPS_EN) {
3873	ops = ftrace_find_unique_ops(rec);
3874	if (ops) {
3875	seq_printf(m, fmt: "\tops: %pS (%pS)",
3876	ops, ops->func);
3877	} else {
3878	seq_puts(m, s: "\tops: ERROR!");
3879	}
3880	}
3881	if (rec->flags & FTRACE_FL_DIRECT) {
3882	unsigned long direct;
3883
3884	direct = ftrace_find_rec_direct(ip: rec->ip);
3885	if (direct)
3886	seq_printf(m, fmt: "\n\tdirect-->%pS", (void *)direct);
3887	}
3888	}
3889
3890	seq_putc(m, c: '\n');
3891
3892	return 0;
3893	}
3894
3895	static const struct seq_operations show_ftrace_seq_ops = {
3896	.start = t_start,
3897	.next = t_next,
3898	.stop = t_stop,
3899	.show = t_show,
3900	};
3901
3902	static int
3903	ftrace_avail_open(struct inode *inode, struct file *file)
3904	{
3905	struct ftrace_iterator *iter;
3906	int ret;
3907
3908	ret = security_locked_down(what: LOCKDOWN_TRACEFS);
3909	if (ret)
3910	return ret;
3911
3912	if (unlikely(ftrace_disabled))
3913	return -ENODEV;
3914
3915	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3916	if (!iter)
3917	return -ENOMEM;
3918
3919	iter->pg = ftrace_pages_start;
3920	iter->ops = &global_ops;
3921
3922	return 0;
3923	}
3924
3925	static int
3926	ftrace_enabled_open(struct inode *inode, struct file *file)
3927	{
3928	struct ftrace_iterator *iter;
3929
3930	/*
3931	* This shows us what functions are currently being
3932	* traced and by what. Not sure if we want lockdown
3933	* to hide such critical information for an admin.
3934	* Although, perhaps it can show information we don't
3935	* want people to see, but if something is tracing
3936	* something, we probably want to know about it.
3937	*/
3938
3939	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3940	if (!iter)
3941	return -ENOMEM;
3942
3943	iter->pg = ftrace_pages_start;
3944	iter->flags = FTRACE_ITER_ENABLED;
3945	iter->ops = &global_ops;
3946
3947	return 0;
3948	}
3949
3950	static int
3951	ftrace_touched_open(struct inode *inode, struct file *file)
3952	{
3953	struct ftrace_iterator *iter;
3954
3955	/*
3956	* This shows us what functions have ever been enabled
3957	* (traced, direct, patched, etc). Not sure if we want lockdown
3958	* to hide such critical information for an admin.
3959	* Although, perhaps it can show information we don't
3960	* want people to see, but if something had traced
3961	* something, we probably want to know about it.
3962	*/
3963
3964	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3965	if (!iter)
3966	return -ENOMEM;
3967
3968	iter->pg = ftrace_pages_start;
3969	iter->flags = FTRACE_ITER_TOUCHED;
3970	iter->ops = &global_ops;
3971
3972	return 0;
3973	}
3974
3975	static int
3976	ftrace_avail_addrs_open(struct inode *inode, struct file *file)
3977	{
3978	struct ftrace_iterator *iter;
3979	int ret;
3980
3981	ret = security_locked_down(what: LOCKDOWN_TRACEFS);
3982	if (ret)
3983	return ret;
3984
3985	if (unlikely(ftrace_disabled))
3986	return -ENODEV;
3987
3988	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3989	if (!iter)
3990	return -ENOMEM;
3991
3992	iter->pg = ftrace_pages_start;
3993	iter->flags = FTRACE_ITER_ADDRS;
3994	iter->ops = &global_ops;
3995
3996	return 0;
3997	}
3998
3999	/**
4000	* ftrace_regex_open - initialize function tracer filter files
4001	* @ops: The ftrace_ops that hold the hash filters
4002	* @flag: The type of filter to process
4003	* @inode: The inode, usually passed in to your open routine
4004	* @file: The file, usually passed in to your open routine
4005	*
4006	* ftrace_regex_open() initializes the filter files for the
4007	* @ops. Depending on @flag it may process the filter hash or
4008	* the notrace hash of @ops. With this called from the open
4009	* routine, you can use ftrace_filter_write() for the write
4010	* routine if @flag has FTRACE_ITER_FILTER set, or
4011	* ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
4012	* tracing_lseek() should be used as the lseek routine, and
4013	* release must call ftrace_regex_release().
4014	*
4015	* Returns: 0 on success or a negative errno value on failure
4016	*/
4017	int
4018	ftrace_regex_open(struct ftrace_ops *ops, int flag,
4019	struct inode *inode, struct file *file)
4020	{
4021	struct ftrace_iterator *iter;
4022	struct ftrace_hash *hash;
4023	struct list_head *mod_head;
4024	struct trace_array *tr = ops->private;
4025	int ret = -ENOMEM;
4026
4027	ftrace_ops_init(ops);
4028
4029	if (unlikely(ftrace_disabled))
4030	return -ENODEV;
4031
4032	if (tracing_check_open_get_tr(tr))
4033	return -ENODEV;
4034
4035	iter = kzalloc(size: sizeof(*iter), GFP_KERNEL);
4036	if (!iter)
4037	goto out;
4038
4039	if (trace_parser_get_init(parser: &iter->parser, FTRACE_BUFF_MAX))
4040	goto out;
4041
4042	iter->ops = ops;
4043	iter->flags = flag;
4044	iter->tr = tr;
4045
4046	mutex_lock(&ops->func_hash->regex_lock);
4047
4048	if (flag & FTRACE_ITER_NOTRACE) {
4049	hash = ops->func_hash->notrace_hash;
4050	mod_head = tr ? &tr->mod_notrace : NULL;
4051	} else {
4052	hash = ops->func_hash->filter_hash;
4053	mod_head = tr ? &tr->mod_trace : NULL;
4054	}
4055
4056	iter->mod_list = mod_head;
4057
4058	if (file->f_mode & FMODE_WRITE) {
4059	const int size_bits = FTRACE_HASH_DEFAULT_BITS;
4060
4061	if (file->f_flags & O_TRUNC) {
4062	iter->hash = alloc_ftrace_hash(size_bits);
4063	clear_ftrace_mod_list(head: mod_head);
4064	} else {
4065	iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
4066	}
4067
4068	if (!iter->hash) {
4069	trace_parser_put(parser: &iter->parser);
4070	goto out_unlock;
4071	}
4072	} else
4073	iter->hash = hash;
4074
4075	ret = 0;
4076
4077	if (file->f_mode & FMODE_READ) {
4078	iter->pg = ftrace_pages_start;
4079
4080	ret = seq_open(file, &show_ftrace_seq_ops);
4081	if (!ret) {
4082	struct seq_file *m = file->private_data;
4083	m->private = iter;
4084	} else {
4085	/* Failed */
4086	free_ftrace_hash(hash: iter->hash);
4087	trace_parser_put(parser: &iter->parser);
4088	}
4089	} else
4090	file->private_data = iter;
4091
4092	out_unlock:
4093	mutex_unlock(lock: &ops->func_hash->regex_lock);
4094
4095	out:
4096	if (ret) {
4097	kfree(objp: iter);
4098	if (tr)
4099	trace_array_put(tr);
4100	}
4101
4102	return ret;
4103	}
4104
4105	static int
4106	ftrace_filter_open(struct inode *inode, struct file *file)
4107	{
4108	struct ftrace_ops *ops = inode->i_private;
4109
4110	/* Checks for tracefs lockdown */
4111	return ftrace_regex_open(ops,
4112	flag: FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
4113	inode, file);
4114	}
4115
4116	static int
4117	ftrace_notrace_open(struct inode *inode, struct file *file)
4118	{
4119	struct ftrace_ops *ops = inode->i_private;
4120
4121	/* Checks for tracefs lockdown */
4122	return ftrace_regex_open(ops, flag: FTRACE_ITER_NOTRACE,
4123	inode, file);
4124	}
4125
4126	/* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
4127	struct ftrace_glob {
4128	char *search;
4129	unsigned len;
4130	int type;
4131	};
4132
4133	/*
4134	* If symbols in an architecture don't correspond exactly to the user-visible
4135	* name of what they represent, it is possible to define this function to
4136	* perform the necessary adjustments.
4137	*/
4138	char * __weak arch_ftrace_match_adjust(char *str, const char *search)
4139	{
4140	return str;
4141	}
4142
4143	static int ftrace_match(char *str, struct ftrace_glob *g)
4144	{
4145	int matched = 0;
4146	int slen;
4147
4148	str = arch_ftrace_match_adjust(str, search: g->search);
4149
4150	switch (g->type) {
4151	case MATCH_FULL:
4152	if (strcmp(str, g->search) == 0)
4153	matched = 1;
4154	break;
4155	case MATCH_FRONT_ONLY:
4156	if (strncmp(str, g->search, g->len) == 0)
4157	matched = 1;
4158	break;
4159	case MATCH_MIDDLE_ONLY:
4160	if (strstr(str, g->search))
4161	matched = 1;
4162	break;
4163	case MATCH_END_ONLY:
4164	slen = strlen(str);
4165	if (slen >= g->len &&
4166	memcmp(p: str + slen - g->len, q: g->search, size: g->len) == 0)
4167	matched = 1;
4168	break;
4169	case MATCH_GLOB:
4170	if (glob_match(pat: g->search, str))
4171	matched = 1;
4172	break;
4173	}
4174
4175	return matched;
4176	}
4177
4178	static int
4179	enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
4180	{
4181	struct ftrace_func_entry *entry;
4182	int ret = 0;
4183
4184	entry = ftrace_lookup_ip(hash, ip: rec->ip);
4185	if (clear_filter) {
4186	/* Do nothing if it doesn't exist */
4187	if (!entry)
4188	return 0;
4189
4190	free_hash_entry(hash, entry);
4191	} else {
4192	/* Do nothing if it exists */
4193	if (entry)
4194	return 0;
4195	if (add_hash_entry(hash, ip: rec->ip) == NULL)
4196	ret = -ENOMEM;
4197	}
4198	return ret;
4199	}
4200
4201	static int
4202	add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
4203	int clear_filter)
4204	{
4205	long index = simple_strtoul(func_g->search, NULL, 0);
4206	struct ftrace_page *pg;
4207	struct dyn_ftrace *rec;
4208
4209	/* The index starts at 1 */
4210	if (--index < 0)
4211	return 0;
4212
4213	do_for_each_ftrace_rec(pg, rec) {
4214	if (pg->index <= index) {
4215	index -= pg->index;
4216	/* this is a double loop, break goes to the next page */
4217	break;
4218	}
4219	rec = &pg->records[index];
4220	enter_record(hash, rec, clear_filter);
4221	return 1;
4222	} while_for_each_ftrace_rec();
4223	return 0;
4224	}
4225
4226	#ifdef FTRACE_MCOUNT_MAX_OFFSET
4227	static int lookup_ip(unsigned long ip, char **modname, char *str)
4228	{
4229	unsigned long offset;
4230
4231	kallsyms_lookup(addr: ip, NULL, offset: &offset, modname, namebuf: str);
4232	if (offset > FTRACE_MCOUNT_MAX_OFFSET)
4233	return -1;
4234	return 0;
4235	}
4236	#else
4237	static int lookup_ip(unsigned long ip, char **modname, char *str)
4238	{
4239	kallsyms_lookup(ip, NULL, NULL, modname, str);
4240	return 0;
4241	}
4242	#endif
4243
4244	static int
4245	ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
4246	struct ftrace_glob *mod_g, int exclude_mod)
4247	{
4248	char str[KSYM_SYMBOL_LEN];
4249	char *modname;
4250
4251	if (lookup_ip(ip: rec->ip, modname: &modname, str)) {
4252	/* This should only happen when a rec is disabled */
4253	WARN_ON_ONCE(system_state == SYSTEM_RUNNING &&
4254	!(rec->flags & FTRACE_FL_DISABLED));
4255	return 0;
4256	}
4257
4258	if (mod_g) {
4259	int mod_matches = (modname) ? ftrace_match(str: modname, g: mod_g) : 0;
4260
4261	/* blank module name to match all modules */
4262	if (!mod_g->len) {
4263	/* blank module globbing: modname xor exclude_mod */
4264	if (!exclude_mod != !modname)
4265	goto func_match;
4266	return 0;
4267	}
4268
4269	/*
4270	* exclude_mod is set to trace everything but the given
4271	* module. If it is set and the module matches, then
4272	* return 0. If it is not set, and the module doesn't match
4273	* also return 0. Otherwise, check the function to see if
4274	* that matches.
4275	*/
4276	if (!mod_matches == !exclude_mod)
4277	return 0;
4278	func_match:
4279	/* blank search means to match all funcs in the mod */
4280	if (!func_g->len)
4281	return 1;
4282	}
4283
4284	return ftrace_match(str, g: func_g);
4285	}
4286
4287	static int
4288	match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
4289	{
4290	struct ftrace_page *pg;
4291	struct dyn_ftrace *rec;
4292	struct ftrace_glob func_g = { .type = MATCH_FULL };
4293	struct ftrace_glob mod_g = { .type = MATCH_FULL };
4294	struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
4295	int exclude_mod = 0;
4296	int found = 0;
4297	int ret;
4298	int clear_filter = 0;
4299
4300	if (func) {
4301	func_g.type = filter_parse_regex(buff: func, len, search: &func_g.search,
4302	not: &clear_filter);
4303	func_g.len = strlen(func_g.search);
4304	}
4305
4306	if (mod) {
4307	mod_g.type = filter_parse_regex(buff: mod, strlen(mod),
4308	search: &mod_g.search, not: &exclude_mod);
4309	mod_g.len = strlen(mod_g.search);
4310	}
4311
4312	mutex_lock(&ftrace_lock);
4313
4314	if (unlikely(ftrace_disabled))
4315	goto out_unlock;
4316
4317	if (func_g.type == MATCH_INDEX) {
4318	found = add_rec_by_index(hash, func_g: &func_g, clear_filter);
4319	goto out_unlock;
4320	}
4321
4322	do_for_each_ftrace_rec(pg, rec) {
4323
4324	if (rec->flags & FTRACE_FL_DISABLED)
4325	continue;
4326
4327	if (ftrace_match_record(rec, func_g: &func_g, mod_g: mod_match, exclude_mod)) {
4328	ret = enter_record(hash, rec, clear_filter);
4329	if (ret < 0) {
4330	found = ret;
4331	goto out_unlock;
4332	}
4333	found = 1;
4334	}
4335	cond_resched();
4336	} while_for_each_ftrace_rec();
4337	out_unlock:
4338	mutex_unlock(lock: &ftrace_lock);
4339
4340	return found;
4341	}
4342
4343	static int
4344	ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
4345	{
4346	return match_records(hash, func: buff, len, NULL);
4347	}
4348
4349	static void ftrace_ops_update_code(struct ftrace_ops *ops,
4350	struct ftrace_ops_hash *old_hash)
4351	{
4352	struct ftrace_ops *op;
4353
4354	if (!ftrace_enabled)
4355	return;
4356
4357	if (ops->flags & FTRACE_OPS_FL_ENABLED) {
4358	ftrace_run_modify_code(ops, command: FTRACE_UPDATE_CALLS, old_hash);
4359	return;
4360	}
4361
4362	/*
4363	* If this is the shared global_ops filter, then we need to
4364	* check if there is another ops that shares it, is enabled.
4365	* If so, we still need to run the modify code.
4366	*/
4367	if (ops->func_hash != &global_ops.local_hash)
4368	return;
4369
4370	do_for_each_ftrace_op(op, ftrace_ops_list) {
4371	if (op->func_hash == &global_ops.local_hash &&
4372	op->flags & FTRACE_OPS_FL_ENABLED) {
4373	ftrace_run_modify_code(ops: op, command: FTRACE_UPDATE_CALLS, old_hash);
4374	/* Only need to do this once */
4375	return;
4376	}
4377	} while_for_each_ftrace_op(op);
4378	}
4379
4380	static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
4381	struct ftrace_hash **orig_hash,
4382	struct ftrace_hash *hash,
4383	int enable)
4384	{
4385	struct ftrace_ops_hash old_hash_ops;
4386	struct ftrace_hash *old_hash;
4387	int ret;
4388
4389	old_hash = *orig_hash;
4390	old_hash_ops.filter_hash = ops->func_hash->filter_hash;
4391	old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
4392	ret = ftrace_hash_move(ops, enable, dst: orig_hash, src: hash);
4393	if (!ret) {
4394	ftrace_ops_update_code(ops, old_hash: &old_hash_ops);
4395	free_ftrace_hash_rcu(hash: old_hash);
4396	}
4397	return ret;
4398	}
4399
4400	static bool module_exists(const char *module)
4401	{
4402	/* All modules have the symbol __this_module */
4403	static const char this_mod[] = "__this_module";
4404	char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
4405	unsigned long val;
4406	int n;
4407
4408	n = snprintf(buf: modname, size: sizeof(modname), fmt: "%s:%s", module, this_mod);
4409
4410	if (n > sizeof(modname) - 1)
4411	return false;
4412
4413	val = module_kallsyms_lookup_name(name: modname);
4414	return val != 0;
4415	}
4416
4417	static int cache_mod(struct trace_array *tr,
4418	const char *func, char *module, int enable)
4419	{
4420	struct ftrace_mod_load *ftrace_mod, *n;
4421	struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
4422	int ret;
4423
4424	mutex_lock(&ftrace_lock);
4425
4426	/* We do not cache inverse filters */
4427	if (func[0] == '!') {
4428	func++;
4429	ret = -EINVAL;
4430
4431	/* Look to remove this hash */
4432	list_for_each_entry_safe(ftrace_mod, n, head, list) {
4433	if (strcmp(ftrace_mod->module, module) != 0)
4434	continue;
4435
4436	/* no func matches all */
4437	if (strcmp(func, "*") == 0 ||
4438	(ftrace_mod->func &&
4439	strcmp(ftrace_mod->func, func) == 0)) {
4440	ret = 0;
4441	free_ftrace_mod(ftrace_mod);
4442	continue;
4443	}
4444	}
4445	goto out;
4446	}
4447
4448	ret = -EINVAL;
4449	/* We only care about modules that have not been loaded yet */
4450	if (module_exists(module))
4451	goto out;
4452
4453	/* Save this string off, and execute it when the module is loaded */
4454	ret = ftrace_add_mod(tr, func, module, enable);
4455	out:
4456	mutex_unlock(lock: &ftrace_lock);
4457
4458	return ret;
4459	}
4460
4461	static int
4462	ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4463	int reset, int enable);
4464
4465	#ifdef CONFIG_MODULES
4466	static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
4467	char *mod, bool enable)
4468	{
4469	struct ftrace_mod_load *ftrace_mod, *n;
4470	struct ftrace_hash **orig_hash, *new_hash;
4471	LIST_HEAD(process_mods);
4472	char *func;
4473
4474	mutex_lock(&ops->func_hash->regex_lock);
4475
4476	if (enable)
4477	orig_hash = &ops->func_hash->filter_hash;
4478	else
4479	orig_hash = &ops->func_hash->notrace_hash;
4480
4481	new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
4482	hash: *orig_hash);
4483	if (!new_hash)
4484	goto out; /* warn? */
4485
4486	mutex_lock(&ftrace_lock);
4487
4488	list_for_each_entry_safe(ftrace_mod, n, head, list) {
4489
4490	if (strcmp(ftrace_mod->module, mod) != 0)
4491	continue;
4492
4493	if (ftrace_mod->func)
4494	func = kstrdup(s: ftrace_mod->func, GFP_KERNEL);
4495	else
4496	func = kstrdup(s: "*", GFP_KERNEL);
4497
4498	if (!func) /* warn? */
4499	continue;
4500
4501	list_move(list: &ftrace_mod->list, head: &process_mods);
4502
4503	/* Use the newly allocated func, as it may be "*" */
4504	kfree(objp: ftrace_mod->func);
4505	ftrace_mod->func = func;
4506	}
4507
4508	mutex_unlock(lock: &ftrace_lock);
4509
4510	list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
4511
4512	func = ftrace_mod->func;
4513
4514	/* Grabs ftrace_lock, which is why we have this extra step */
4515	match_records(hash: new_hash, func, strlen(func), mod);
4516	free_ftrace_mod(ftrace_mod);
4517	}
4518
4519	if (enable && list_empty(head))
4520	new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4521
4522	mutex_lock(&ftrace_lock);
4523
4524	ftrace_hash_move_and_update_ops(ops, orig_hash,
4525	hash: new_hash, enable);
4526	mutex_unlock(lock: &ftrace_lock);
4527
4528	out:
4529	mutex_unlock(lock: &ops->func_hash->regex_lock);
4530
4531	free_ftrace_hash(hash: new_hash);
4532	}
4533
4534	static void process_cached_mods(const char *mod_name)
4535	{
4536	struct trace_array *tr;
4537	char *mod;
4538
4539	mod = kstrdup(s: mod_name, GFP_KERNEL);
4540	if (!mod)
4541	return;
4542
4543	mutex_lock(&trace_types_lock);
4544	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4545	if (!list_empty(head: &tr->mod_trace))
4546	process_mod_list(head: &tr->mod_trace, ops: tr->ops, mod, enable: true);
4547	if (!list_empty(head: &tr->mod_notrace))
4548	process_mod_list(head: &tr->mod_notrace, ops: tr->ops, mod, enable: false);
4549	}
4550	mutex_unlock(lock: &trace_types_lock);
4551
4552	kfree(objp: mod);
4553	}
4554	#endif
4555
4556	/*
4557	* We register the module command as a template to show others how
4558	* to register the a command as well.
4559	*/
4560
4561	static int
4562	ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4563	char *func_orig, char *cmd, char *module, int enable)
4564	{
4565	char *func;
4566	int ret;
4567
4568	/* match_records() modifies func, and we need the original */
4569	func = kstrdup(s: func_orig, GFP_KERNEL);
4570	if (!func)
4571	return -ENOMEM;
4572
4573	/*
4574	* cmd == 'mod' because we only registered this func
4575	* for the 'mod' ftrace_func_command.
4576	* But if you register one func with multiple commands,
4577	* you can tell which command was used by the cmd
4578	* parameter.
4579	*/
4580	ret = match_records(hash, func, strlen(func), mod: module);
4581	kfree(objp: func);
4582
4583	if (!ret)
4584	return cache_mod(tr, func: func_orig, module, enable);
4585	if (ret < 0)
4586	return ret;
4587	return 0;
4588	}
4589
4590	static struct ftrace_func_command ftrace_mod_cmd = {
4591	.name = "mod",
4592	.func = ftrace_mod_callback,
4593	};
4594
4595	static int __init ftrace_mod_cmd_init(void)
4596	{
4597	return register_ftrace_command(cmd: &ftrace_mod_cmd);
4598	}
4599	core_initcall(ftrace_mod_cmd_init);
4600
4601	static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4602	struct ftrace_ops *op, struct ftrace_regs *fregs)
4603	{
4604	struct ftrace_probe_ops *probe_ops;
4605	struct ftrace_func_probe *probe;
4606
4607	probe = container_of(op, struct ftrace_func_probe, ops);
4608	probe_ops = probe->probe_ops;
4609
4610	/*
4611	* Disable preemption for these calls to prevent a RCU grace
4612	* period. This syncs the hash iteration and freeing of items
4613	* on the hash. rcu_read_lock is too dangerous here.
4614	*/
4615	preempt_disable_notrace();
4616	probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4617	preempt_enable_notrace();
4618	}
4619
4620	struct ftrace_func_map {
4621	struct ftrace_func_entry entry;
4622	void *data;
4623	};
4624
4625	struct ftrace_func_mapper {
4626	struct ftrace_hash hash;
4627	};
4628
4629	/**
4630	* allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4631	*
4632	* Returns: a ftrace_func_mapper descriptor that can be used to map ips to data.
4633	*/
4634	struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4635	{
4636	struct ftrace_hash *hash;
4637
4638	/*
4639	* The mapper is simply a ftrace_hash, but since the entries
4640	* in the hash are not ftrace_func_entry type, we define it
4641	* as a separate structure.
4642	*/
4643	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4644	return (struct ftrace_func_mapper *)hash;
4645	}
4646
4647	/**
4648	* ftrace_func_mapper_find_ip - Find some data mapped to an ip
4649	* @mapper: The mapper that has the ip maps
4650	* @ip: the instruction pointer to find the data for
4651	*
4652	* Returns: the data mapped to @ip if found otherwise NULL. The return
4653	* is actually the address of the mapper data pointer. The address is
4654	* returned for use cases where the data is no bigger than a long, and
4655	* the user can use the data pointer as its data instead of having to
4656	* allocate more memory for the reference.
4657	*/
4658	void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4659	unsigned long ip)
4660	{
4661	struct ftrace_func_entry *entry;
4662	struct ftrace_func_map *map;
4663
4664	entry = ftrace_lookup_ip(hash: &mapper->hash, ip);
4665	if (!entry)
4666	return NULL;
4667
4668	map = (struct ftrace_func_map *)entry;
4669	return &map->data;
4670	}
4671
4672	/**
4673	* ftrace_func_mapper_add_ip - Map some data to an ip
4674	* @mapper: The mapper that has the ip maps
4675	* @ip: The instruction pointer address to map @data to
4676	* @data: The data to map to @ip
4677	*
4678	* Returns: 0 on success otherwise an error.
4679	*/
4680	int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4681	unsigned long ip, void *data)
4682	{
4683	struct ftrace_func_entry *entry;
4684	struct ftrace_func_map *map;
4685
4686	entry = ftrace_lookup_ip(hash: &mapper->hash, ip);
4687	if (entry)
4688	return -EBUSY;
4689
4690	map = kmalloc(size: sizeof(*map), GFP_KERNEL);
4691	if (!map)
4692	return -ENOMEM;
4693
4694	map->entry.ip = ip;
4695	map->data = data;
4696
4697	__add_hash_entry(hash: &mapper->hash, entry: &map->entry);
4698
4699	return 0;
4700	}
4701
4702	/**
4703	* ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4704	* @mapper: The mapper that has the ip maps
4705	* @ip: The instruction pointer address to remove the data from
4706	*
4707	* Returns: the data if it is found, otherwise NULL.
4708	* Note, if the data pointer is used as the data itself, (see
4709	* ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4710	* if the data pointer was set to zero.
4711	*/
4712	void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4713	unsigned long ip)
4714	{
4715	struct ftrace_func_entry *entry;
4716	struct ftrace_func_map *map;
4717	void *data;
4718
4719	entry = ftrace_lookup_ip(hash: &mapper->hash, ip);
4720	if (!entry)
4721	return NULL;
4722
4723	map = (struct ftrace_func_map *)entry;
4724	data = map->data;
4725
4726	remove_hash_entry(hash: &mapper->hash, entry);
4727	kfree(objp: entry);
4728
4729	return data;
4730	}
4731
4732	/**
4733	* free_ftrace_func_mapper - free a mapping of ips and data
4734	* @mapper: The mapper that has the ip maps
4735	* @free_func: A function to be called on each data item.
4736	*
4737	* This is used to free the function mapper. The @free_func is optional
4738	* and can be used if the data needs to be freed as well.
4739	*/
4740	void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4741	ftrace_mapper_func free_func)
4742	{
4743	struct ftrace_func_entry *entry;
4744	struct ftrace_func_map *map;
4745	struct hlist_head *hhd;
4746	int size, i;
4747
4748	if (!mapper)
4749	return;
4750
4751	if (free_func && mapper->hash.count) {
4752	size = 1 << mapper->hash.size_bits;
4753	for (i = 0; i < size; i++) {
4754	hhd = &mapper->hash.buckets[i];
4755	hlist_for_each_entry(entry, hhd, hlist) {
4756	map = (struct ftrace_func_map *)entry;
4757	free_func(map);
4758	}
4759	}
4760	}
4761	free_ftrace_hash(hash: &mapper->hash);
4762	}
4763
4764	static void release_probe(struct ftrace_func_probe *probe)
4765	{
4766	struct ftrace_probe_ops *probe_ops;
4767
4768	mutex_lock(&ftrace_lock);
4769
4770	WARN_ON(probe->ref <= 0);
4771
4772	/* Subtract the ref that was used to protect this instance */
4773	probe->ref--;
4774
4775	if (!probe->ref) {
4776	probe_ops = probe->probe_ops;
4777	/*
4778	* Sending zero as ip tells probe_ops to free
4779	* the probe->data itself
4780	*/
4781	if (probe_ops->free)
4782	probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4783	list_del(entry: &probe->list);
4784	kfree(objp: probe);
4785	}
4786	mutex_unlock(lock: &ftrace_lock);
4787	}
4788
4789	static void acquire_probe_locked(struct ftrace_func_probe *probe)
4790	{
4791	/*
4792	* Add one ref to keep it from being freed when releasing the
4793	* ftrace_lock mutex.
4794	*/
4795	probe->ref++;
4796	}
4797
4798	int
4799	register_ftrace_function_probe(char *glob, struct trace_array *tr,
4800	struct ftrace_probe_ops *probe_ops,
4801	void *data)
4802	{
4803	struct ftrace_func_probe *probe = NULL, *iter;
4804	struct ftrace_func_entry *entry;
4805	struct ftrace_hash **orig_hash;
4806	struct ftrace_hash *old_hash;
4807	struct ftrace_hash *hash;
4808	int count = 0;
4809	int size;
4810	int ret;
4811	int i;
4812
4813	if (WARN_ON(!tr))
4814	return -EINVAL;
4815
4816	/* We do not support '!' for function probes */
4817	if (WARN_ON(glob[0] == '!'))
4818	return -EINVAL;
4819
4820
4821	mutex_lock(&ftrace_lock);
4822	/* Check if the probe_ops is already registered */
4823	list_for_each_entry(iter, &tr->func_probes, list) {
4824	if (iter->probe_ops == probe_ops) {
4825	probe = iter;
4826	break;
4827	}
4828	}
4829	if (!probe) {
4830	probe = kzalloc(size: sizeof(*probe), GFP_KERNEL);
4831	if (!probe) {
4832	mutex_unlock(lock: &ftrace_lock);
4833	return -ENOMEM;
4834	}
4835	probe->probe_ops = probe_ops;
4836	probe->ops.func = function_trace_probe_call;
4837	probe->tr = tr;
4838	ftrace_ops_init(ops: &probe->ops);
4839	list_add(new: &probe->list, head: &tr->func_probes);
4840	}
4841
4842	acquire_probe_locked(probe);
4843
4844	mutex_unlock(lock: &ftrace_lock);
4845
4846	/*
4847	* Note, there's a small window here that the func_hash->filter_hash
4848	* may be NULL or empty. Need to be careful when reading the loop.
4849	*/
4850	mutex_lock(&probe->ops.func_hash->regex_lock);
4851
4852	orig_hash = &probe->ops.func_hash->filter_hash;
4853	old_hash = *orig_hash;
4854	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash: old_hash);
4855
4856	if (!hash) {
4857	ret = -ENOMEM;
4858	goto out;
4859	}
4860
4861	ret = ftrace_match_records(hash, buff: glob, strlen(glob));
4862
4863	/* Nothing found? */
4864	if (!ret)
4865	ret = -EINVAL;
4866
4867	if (ret < 0)
4868	goto out;
4869
4870	size = 1 << hash->size_bits;
4871	for (i = 0; i < size; i++) {
4872	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4873	if (ftrace_lookup_ip(hash: old_hash, ip: entry->ip))
4874	continue;
4875	/*
4876	* The caller might want to do something special
4877	* for each function we find. We call the callback
4878	* to give the caller an opportunity to do so.
4879	*/
4880	if (probe_ops->init) {
4881	ret = probe_ops->init(probe_ops, tr,
4882	entry->ip, data,
4883	&probe->data);
4884	if (ret < 0) {
4885	if (probe_ops->free && count)
4886	probe_ops->free(probe_ops, tr,
4887	0, probe->data);
4888	probe->data = NULL;
4889	goto out;
4890	}
4891	}
4892	count++;
4893	}
4894	}
4895
4896	mutex_lock(&ftrace_lock);
4897
4898	if (!count) {
4899	/* Nothing was added? */
4900	ret = -EINVAL;
4901	goto out_unlock;
4902	}
4903
4904	ret = ftrace_hash_move_and_update_ops(ops: &probe->ops, orig_hash,
4905	hash, enable: 1);
4906	if (ret < 0)
4907	goto err_unlock;
4908
4909	/* One ref for each new function traced */
4910	probe->ref += count;
4911
4912	if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4913	ret = ftrace_startup(ops: &probe->ops, command: 0);
4914
4915	out_unlock:
4916	mutex_unlock(lock: &ftrace_lock);
4917
4918	if (!ret)
4919	ret = count;
4920	out:
4921	mutex_unlock(lock: &probe->ops.func_hash->regex_lock);
4922	free_ftrace_hash(hash);
4923
4924	release_probe(probe);
4925
4926	return ret;
4927
4928	err_unlock:
4929	if (!probe_ops->free || !count)
4930	goto out_unlock;
4931
4932	/* Failed to do the move, need to call the free functions */
4933	for (i = 0; i < size; i++) {
4934	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4935	if (ftrace_lookup_ip(hash: old_hash, ip: entry->ip))
4936	continue;
4937	probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4938	}
4939	}
4940	goto out_unlock;
4941	}
4942
4943	int
4944	unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4945	struct ftrace_probe_ops *probe_ops)
4946	{
4947	struct ftrace_func_probe *probe = NULL, *iter;
4948	struct ftrace_ops_hash old_hash_ops;
4949	struct ftrace_func_entry *entry;
4950	struct ftrace_glob func_g;
4951	struct ftrace_hash **orig_hash;
4952	struct ftrace_hash *old_hash;
4953	struct ftrace_hash *hash = NULL;
4954	struct hlist_node *tmp;
4955	struct hlist_head hhd;
4956	char str[KSYM_SYMBOL_LEN];
4957	int count = 0;
4958	int i, ret = -ENODEV;
4959	int size;
4960
4961	if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4962	func_g.search = NULL;
4963	else {
4964	int not;
4965
4966	func_g.type = filter_parse_regex(buff: glob, strlen(glob),
4967	search: &func_g.search, not: &not);
4968	func_g.len = strlen(func_g.search);
4969
4970	/* we do not support '!' for function probes */
4971	if (WARN_ON(not))
4972	return -EINVAL;
4973	}
4974
4975	mutex_lock(&ftrace_lock);
4976	/* Check if the probe_ops is already registered */
4977	list_for_each_entry(iter, &tr->func_probes, list) {
4978	if (iter->probe_ops == probe_ops) {
4979	probe = iter;
4980	break;
4981	}
4982	}
4983	if (!probe)
4984	goto err_unlock_ftrace;
4985
4986	ret = -EINVAL;
4987	if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4988	goto err_unlock_ftrace;
4989
4990	acquire_probe_locked(probe);
4991
4992	mutex_unlock(lock: &ftrace_lock);
4993
4994	mutex_lock(&probe->ops.func_hash->regex_lock);
4995
4996	orig_hash = &probe->ops.func_hash->filter_hash;
4997	old_hash = *orig_hash;
4998
4999	if (ftrace_hash_empty(hash: old_hash))
5000	goto out_unlock;
5001
5002	old_hash_ops.filter_hash = old_hash;
5003	/* Probes only have filters */
5004	old_hash_ops.notrace_hash = NULL;
5005
5006	ret = -ENOMEM;
5007	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash: old_hash);
5008	if (!hash)
5009	goto out_unlock;
5010
5011	INIT_HLIST_HEAD(&hhd);
5012
5013	size = 1 << hash->size_bits;
5014	for (i = 0; i < size; i++) {
5015	hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
5016
5017	if (func_g.search) {
5018	kallsyms_lookup(addr: entry->ip, NULL, NULL,
5019	NULL, namebuf: str);
5020	if (!ftrace_match(str, g: &func_g))
5021	continue;
5022	}
5023	count++;
5024	remove_hash_entry(hash, entry);
5025	hlist_add_head(n: &entry->hlist, h: &hhd);
5026	}
5027	}
5028
5029	/* Nothing found? */
5030	if (!count) {
5031	ret = -EINVAL;
5032	goto out_unlock;
5033	}
5034
5035	mutex_lock(&ftrace_lock);
5036
5037	WARN_ON(probe->ref < count);
5038
5039	probe->ref -= count;
5040
5041	if (ftrace_hash_empty(hash))
5042	ftrace_shutdown(ops: &probe->ops, command: 0);
5043
5044	ret = ftrace_hash_move_and_update_ops(ops: &probe->ops, orig_hash,
5045	hash, enable: 1);
5046
5047	/* still need to update the function call sites */
5048	if (ftrace_enabled && !ftrace_hash_empty(hash))
5049	ftrace_run_modify_code(ops: &probe->ops, command: FTRACE_UPDATE_CALLS,
5050	old_hash: &old_hash_ops);
5051	synchronize_rcu();
5052
5053	hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
5054	hlist_del(n: &entry->hlist);
5055	if (probe_ops->free)
5056	probe_ops->free(probe_ops, tr, entry->ip, probe->data);
5057	kfree(objp: entry);
5058	}
5059	mutex_unlock(lock: &ftrace_lock);
5060
5061	out_unlock:
5062	mutex_unlock(lock: &probe->ops.func_hash->regex_lock);
5063	free_ftrace_hash(hash);
5064
5065	release_probe(probe);
5066
5067	return ret;
5068
5069	err_unlock_ftrace:
5070	mutex_unlock(lock: &ftrace_lock);
5071	return ret;
5072	}
5073
5074	void clear_ftrace_function_probes(struct trace_array *tr)
5075	{
5076	struct ftrace_func_probe *probe, *n;
5077
5078	list_for_each_entry_safe(probe, n, &tr->func_probes, list)
5079	unregister_ftrace_function_probe_func(NULL, tr, probe_ops: probe->probe_ops);
5080	}
5081
5082	static LIST_HEAD(ftrace_commands);
5083	static DEFINE_MUTEX(ftrace_cmd_mutex);
5084
5085	/*
5086	* Currently we only register ftrace commands from __init, so mark this
5087	* __init too.
5088	*/
5089	__init int register_ftrace_command(struct ftrace_func_command *cmd)
5090	{
5091	struct ftrace_func_command *p;
5092	int ret = 0;
5093
5094	mutex_lock(&ftrace_cmd_mutex);
5095	list_for_each_entry(p, &ftrace_commands, list) {
5096	if (strcmp(cmd->name, p->name) == 0) {
5097	ret = -EBUSY;
5098	goto out_unlock;
5099	}
5100	}
5101	list_add(new: &cmd->list, head: &ftrace_commands);
5102	out_unlock:
5103	mutex_unlock(lock: &ftrace_cmd_mutex);
5104
5105	return ret;
5106	}
5107
5108	/*
5109	* Currently we only unregister ftrace commands from __init, so mark
5110	* this __init too.
5111	*/
5112	__init int unregister_ftrace_command(struct ftrace_func_command *cmd)
5113	{
5114	struct ftrace_func_command *p, *n;
5115	int ret = -ENODEV;
5116
5117	mutex_lock(&ftrace_cmd_mutex);
5118	list_for_each_entry_safe(p, n, &ftrace_commands, list) {
5119	if (strcmp(cmd->name, p->name) == 0) {
5120	ret = 0;
5121	list_del_init(entry: &p->list);
5122	goto out_unlock;
5123	}
5124	}
5125	out_unlock:
5126	mutex_unlock(lock: &ftrace_cmd_mutex);
5127
5128	return ret;
5129	}
5130
5131	static int ftrace_process_regex(struct ftrace_iterator *iter,
5132	char *buff, int len, int enable)
5133	{
5134	struct ftrace_hash *hash = iter->hash;
5135	struct trace_array *tr = iter->ops->private;
5136	char *func, *command, *next = buff;
5137	struct ftrace_func_command *p;
5138	int ret = -EINVAL;
5139
5140	func = strsep(&next, ":");
5141
5142	if (!next) {
5143	ret = ftrace_match_records(hash, buff: func, len);
5144	if (!ret)
5145	ret = -EINVAL;
5146	if (ret < 0)
5147	return ret;
5148	return 0;
5149	}
5150
5151	/* command found */
5152
5153	command = strsep(&next, ":");
5154
5155	mutex_lock(&ftrace_cmd_mutex);
5156	list_for_each_entry(p, &ftrace_commands, list) {
5157	if (strcmp(p->name, command) == 0) {
5158	ret = p->func(tr, hash, func, command, next, enable);
5159	goto out_unlock;
5160	}
5161	}
5162	out_unlock:
5163	mutex_unlock(lock: &ftrace_cmd_mutex);
5164
5165	return ret;
5166	}
5167
5168	static ssize_t
5169	ftrace_regex_write(struct file *file, const char __user *ubuf,
5170	size_t cnt, loff_t *ppos, int enable)
5171	{
5172	struct ftrace_iterator *iter;
5173	struct trace_parser *parser;
5174	ssize_t ret, read;
5175
5176	if (!cnt)
5177	return 0;
5178
5179	if (file->f_mode & FMODE_READ) {
5180	struct seq_file *m = file->private_data;
5181	iter = m->private;
5182	} else
5183	iter = file->private_data;
5184
5185	if (unlikely(ftrace_disabled))
5186	return -ENODEV;
5187
5188	/* iter->hash is a local copy, so we don't need regex_lock */
5189
5190	parser = &iter->parser;
5191	read = trace_get_user(parser, ubuf, cnt, ppos);
5192
5193	if (read >= 0 && trace_parser_loaded(parser) &&
5194	!trace_parser_cont(parser)) {
5195	ret = ftrace_process_regex(iter, buff: parser->buffer,
5196	len: parser->idx, enable);
5197	trace_parser_clear(parser);
5198	if (ret < 0)
5199	goto out;
5200	}
5201
5202	ret = read;
5203	out:
5204	return ret;
5205	}
5206
5207	ssize_t
5208	ftrace_filter_write(struct file *file, const char __user *ubuf,
5209	size_t cnt, loff_t *ppos)
5210	{
5211	return ftrace_regex_write(file, ubuf, cnt, ppos, enable: 1);
5212	}
5213
5214	ssize_t
5215	ftrace_notrace_write(struct file *file, const char __user *ubuf,
5216	size_t cnt, loff_t *ppos)
5217	{
5218	return ftrace_regex_write(file, ubuf, cnt, ppos, enable: 0);
5219	}
5220
5221	static int
5222	__ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
5223	{
5224	struct ftrace_func_entry *entry;
5225
5226	ip = ftrace_location(ip);
5227	if (!ip)
5228	return -EINVAL;
5229
5230	if (remove) {
5231	entry = ftrace_lookup_ip(hash, ip);
5232	if (!entry)
5233	return -ENOENT;
5234	free_hash_entry(hash, entry);
5235	return 0;
5236	}
5237
5238	entry = add_hash_entry(hash, ip);
5239	return entry ? 0 : -ENOMEM;
5240	}
5241
5242	static int
5243	ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips,
5244	unsigned int cnt, int remove)
5245	{
5246	unsigned int i;
5247	int err;
5248
5249	for (i = 0; i < cnt; i++) {
5250	err = __ftrace_match_addr(hash, ip: ips[i], remove);
5251	if (err) {
5252	/*
5253	* This expects the @hash is a temporary hash and if this
5254	* fails the caller must free the @hash.
5255	*/
5256	return err;
5257	}
5258	}
5259	return 0;
5260	}
5261
5262	static int
5263	ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
5264	unsigned long *ips, unsigned int cnt,
5265	int remove, int reset, int enable)
5266	{
5267	struct ftrace_hash **orig_hash;
5268	struct ftrace_hash *hash;
5269	int ret;
5270
5271	if (unlikely(ftrace_disabled))
5272	return -ENODEV;
5273
5274	mutex_lock(&ops->func_hash->regex_lock);
5275
5276	if (enable)
5277	orig_hash = &ops->func_hash->filter_hash;
5278	else
5279	orig_hash = &ops->func_hash->notrace_hash;
5280
5281	if (reset)
5282	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
5283	else
5284	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash: *orig_hash);
5285
5286	if (!hash) {
5287	ret = -ENOMEM;
5288	goto out_regex_unlock;
5289	}
5290
5291	if (buf && !ftrace_match_records(hash, buff: buf, len)) {
5292	ret = -EINVAL;
5293	goto out_regex_unlock;
5294	}
5295	if (ips) {
5296	ret = ftrace_match_addr(hash, ips, cnt, remove);
5297	if (ret < 0)
5298	goto out_regex_unlock;
5299	}
5300
5301	mutex_lock(&ftrace_lock);
5302	ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
5303	mutex_unlock(lock: &ftrace_lock);
5304
5305	out_regex_unlock:
5306	mutex_unlock(lock: &ops->func_hash->regex_lock);
5307
5308	free_ftrace_hash(hash);
5309	return ret;
5310	}
5311
5312	static int
5313	ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt,
5314	int remove, int reset, int enable)
5315	{
5316	return ftrace_set_hash(ops, NULL, len: 0, ips, cnt, remove, reset, enable);
5317	}
5318
5319	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
5320
5321	struct ftrace_direct_func {
5322	struct list_head next;
5323	unsigned long addr;
5324	int count;
5325	};
5326
5327	static LIST_HEAD(ftrace_direct_funcs);
5328
5329	static int register_ftrace_function_nolock(struct ftrace_ops *ops);
5330
5331	/*
5332	* If there are multiple ftrace_ops, use SAVE_REGS by default, so that direct
5333	* call will be jumped from ftrace_regs_caller. Only if the architecture does
5334	* not support ftrace_regs_caller but direct_call, use SAVE_ARGS so that it
5335	* jumps from ftrace_caller for multiple ftrace_ops.
5336	*/
5337	#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS
5338	#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_ARGS)
5339	#else
5340	#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS)
5341	#endif
5342
5343	static int check_direct_multi(struct ftrace_ops *ops)
5344	{
5345	if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
5346	return -EINVAL;
5347	if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS)
5348	return -EINVAL;
5349	return 0;
5350	}
5351
5352	static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr)
5353	{
5354	struct ftrace_func_entry *entry, *del;
5355	int size, i;
5356
5357	size = 1 << hash->size_bits;
5358	for (i = 0; i < size; i++) {
5359	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5360	del = __ftrace_lookup_ip(hash: direct_functions, ip: entry->ip);
5361	if (del && del->direct == addr) {
5362	remove_hash_entry(hash: direct_functions, entry: del);
5363	kfree(objp: del);
5364	}
5365	}
5366	}
5367	}
5368
5369	/**
5370	* register_ftrace_direct - Call a custom trampoline directly
5371	* for multiple functions registered in @ops
5372	* @ops: The address of the struct ftrace_ops object
5373	* @addr: The address of the trampoline to call at @ops functions
5374	*
5375	* This is used to connect a direct calls to @addr from the nop locations
5376	* of the functions registered in @ops (with by ftrace_set_filter_ip
5377	* function).
5378	*
5379	* The location that it calls (@addr) must be able to handle a direct call,
5380	* and save the parameters of the function being traced, and restore them
5381	* (or inject new ones if needed), before returning.
5382	*
5383	* Returns:
5384	* 0 on success
5385	* -EINVAL - The @ops object was already registered with this call or
5386	* when there are no functions in @ops object.
5387	* -EBUSY - Another direct function is already attached (there can be only one)
5388	* -ENODEV - @ip does not point to a ftrace nop location (or not supported)
5389	* -ENOMEM - There was an allocation failure.
5390	*/
5391	int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
5392	{
5393	struct ftrace_hash *hash, *new_hash = NULL, *free_hash = NULL;
5394	struct ftrace_func_entry *entry, *new;
5395	int err = -EBUSY, size, i;
5396
5397	if (ops->func || ops->trampoline)
5398	return -EINVAL;
5399	if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
5400	return -EINVAL;
5401	if (ops->flags & FTRACE_OPS_FL_ENABLED)
5402	return -EINVAL;
5403
5404	hash = ops->func_hash->filter_hash;
5405	if (ftrace_hash_empty(hash))
5406	return -EINVAL;
5407
5408	mutex_lock(&direct_mutex);
5409
5410	/* Make sure requested entries are not already registered.. */
5411	size = 1 << hash->size_bits;
5412	for (i = 0; i < size; i++) {
5413	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5414	if (ftrace_find_rec_direct(ip: entry->ip))
5415	goto out_unlock;
5416	}
5417	}
5418
5419	err = -ENOMEM;
5420
5421	/* Make a copy hash to place the new and the old entries in */
5422	size = hash->count + direct_functions->count;
5423	if (size > 32)
5424	size = 32;
5425	new_hash = alloc_ftrace_hash(size_bits: fls(x: size));
5426	if (!new_hash)
5427	goto out_unlock;
5428
5429	/* Now copy over the existing direct entries */
5430	size = 1 << direct_functions->size_bits;
5431	for (i = 0; i < size; i++) {
5432	hlist_for_each_entry(entry, &direct_functions->buckets[i], hlist) {
5433	new = add_hash_entry(hash: new_hash, ip: entry->ip);
5434	if (!new)
5435	goto out_unlock;
5436	new->direct = entry->direct;
5437	}
5438	}
5439
5440	/* ... and add the new entries */
5441	size = 1 << hash->size_bits;
5442	for (i = 0; i < size; i++) {
5443	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
5444	new = add_hash_entry(hash: new_hash, ip: entry->ip);
5445	if (!new)
5446	goto out_unlock;
5447	/* Update both the copy and the hash entry */
5448	new->direct = addr;
5449	entry->direct = addr;
5450	}
5451	}
5452
5453	free_hash = direct_functions;
5454	rcu_assign_pointer(direct_functions, new_hash);
5455	new_hash = NULL;
5456
5457	ops->func = call_direct_funcs;
5458	ops->flags = MULTI_FLAGS;
5459	ops->trampoline = FTRACE_REGS_ADDR;
5460	ops->direct_call = addr;
5461
5462	err = register_ftrace_function_nolock(ops);
5463
5464	out_unlock:
5465	mutex_unlock(lock: &direct_mutex);
5466
5467	if (free_hash && free_hash != EMPTY_HASH) {
5468	synchronize_rcu_tasks();
5469	free_ftrace_hash(hash: free_hash);
5470	}
5471
5472	if (new_hash)
5473	free_ftrace_hash(hash: new_hash);
5474
5475	return err;
5476	}
5477	EXPORT_SYMBOL_GPL(register_ftrace_direct);
5478
5479	/**
5480	* unregister_ftrace_direct - Remove calls to custom trampoline
5481	* previously registered by register_ftrace_direct for @ops object.
5482	* @ops: The address of the struct ftrace_ops object
5483	*
5484	* This is used to remove a direct calls to @addr from the nop locations
5485	* of the functions registered in @ops (with by ftrace_set_filter_ip
5486	* function).
5487	*
5488	* Returns:
5489	* 0 on success
5490	* -EINVAL - The @ops object was not properly registered.
5491	*/
5492	int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
5493	bool free_filters)
5494	{
5495	struct ftrace_hash *hash = ops->func_hash->filter_hash;
5496	int err;
5497
5498	if (check_direct_multi(ops))
5499	return -EINVAL;
5500	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
5501	return -EINVAL;
5502
5503	mutex_lock(&direct_mutex);
5504	err = unregister_ftrace_function(ops);
5505	remove_direct_functions_hash(hash, addr);
5506	mutex_unlock(lock: &direct_mutex);
5507
5508	/* cleanup for possible another register call */
5509	ops->func = NULL;
5510	ops->trampoline = 0;
5511
5512	if (free_filters)
5513	ftrace_free_filter(ops);
5514	return err;
5515	}
5516	EXPORT_SYMBOL_GPL(unregister_ftrace_direct);
5517
5518	static int
5519	__modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
5520	{
5521	struct ftrace_hash *hash;
5522	struct ftrace_func_entry *entry, *iter;
5523	static struct ftrace_ops tmp_ops = {
5524	.func = ftrace_stub,
5525	.flags = FTRACE_OPS_FL_STUB,
5526	};
5527	int i, size;
5528	int err;
5529
5530	lockdep_assert_held_once(&direct_mutex);
5531
5532	/* Enable the tmp_ops to have the same functions as the direct ops */
5533	ftrace_ops_init(ops: &tmp_ops);
5534	tmp_ops.func_hash = ops->func_hash;
5535	tmp_ops.direct_call = addr;
5536
5537	err = register_ftrace_function_nolock(ops: &tmp_ops);
5538	if (err)
5539	return err;
5540
5541	/*
5542	* Now the ftrace_ops_list_func() is called to do the direct callers.
5543	* We can safely change the direct functions attached to each entry.
5544	*/
5545	mutex_lock(&ftrace_lock);
5546
5547	hash = ops->func_hash->filter_hash;
5548	size = 1 << hash->size_bits;
5549	for (i = 0; i < size; i++) {
5550	hlist_for_each_entry(iter, &hash->buckets[i], hlist) {
5551	entry = __ftrace_lookup_ip(hash: direct_functions, ip: iter->ip);
5552	if (!entry)
5553	continue;
5554	entry->direct = addr;
5555	}
5556	}
5557	/* Prevent store tearing if a trampoline concurrently accesses the value */
5558	WRITE_ONCE(ops->direct_call, addr);
5559
5560	mutex_unlock(lock: &ftrace_lock);
5561
5562	/* Removing the tmp_ops will add the updated direct callers to the functions */
5563	unregister_ftrace_function(ops: &tmp_ops);
5564
5565	return err;
5566	}
5567
5568	/**
5569	* modify_ftrace_direct_nolock - Modify an existing direct 'multi' call
5570	* to call something else
5571	* @ops: The address of the struct ftrace_ops object
5572	* @addr: The address of the new trampoline to call at @ops functions
5573	*
5574	* This is used to unregister currently registered direct caller and
5575	* register new one @addr on functions registered in @ops object.
5576	*
5577	* Note there's window between ftrace_shutdown and ftrace_startup calls
5578	* where there will be no callbacks called.
5579	*
5580	* Caller should already have direct_mutex locked, so we don't lock
5581	* direct_mutex here.
5582	*
5583	* Returns: zero on success. Non zero on error, which includes:
5584	* -EINVAL - The @ops object was not properly registered.
5585	*/
5586	int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr)
5587	{
5588	if (check_direct_multi(ops))
5589	return -EINVAL;
5590	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
5591	return -EINVAL;
5592
5593	return __modify_ftrace_direct(ops, addr);
5594	}
5595	EXPORT_SYMBOL_GPL(modify_ftrace_direct_nolock);
5596
5597	/**
5598	* modify_ftrace_direct - Modify an existing direct 'multi' call
5599	* to call something else
5600	* @ops: The address of the struct ftrace_ops object
5601	* @addr: The address of the new trampoline to call at @ops functions
5602	*
5603	* This is used to unregister currently registered direct caller and
5604	* register new one @addr on functions registered in @ops object.
5605	*
5606	* Note there's window between ftrace_shutdown and ftrace_startup calls
5607	* where there will be no callbacks called.
5608	*
5609	* Returns: zero on success. Non zero on error, which includes:
5610	* -EINVAL - The @ops object was not properly registered.
5611	*/
5612	int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
5613	{
5614	int err;
5615
5616	if (check_direct_multi(ops))
5617	return -EINVAL;
5618	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
5619	return -EINVAL;
5620
5621	mutex_lock(&direct_mutex);
5622	err = __modify_ftrace_direct(ops, addr);
5623	mutex_unlock(lock: &direct_mutex);
5624	return err;
5625	}
5626	EXPORT_SYMBOL_GPL(modify_ftrace_direct);
5627	#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
5628
5629	/**
5630	* ftrace_set_filter_ip - set a function to filter on in ftrace by address
5631	* @ops: the ops to set the filter with
5632	* @ip: the address to add to or remove from the filter.
5633	* @remove: non zero to remove the ip from the filter
5634	* @reset: non zero to reset all filters before applying this filter.
5635	*
5636	* Filters denote which functions should be enabled when tracing is enabled
5637	* If @ip is NULL, it fails to update filter.
5638	*
5639	* This can allocate memory which must be freed before @ops can be freed,
5640	* either by removing each filtered addr or by using
5641	* ftrace_free_filter(@ops).
5642	*/
5643	int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
5644	int remove, int reset)
5645	{
5646	ftrace_ops_init(ops);
5647	return ftrace_set_addr(ops, ips: &ip, cnt: 1, remove, reset, enable: 1);
5648	}
5649	EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
5650
5651	/**
5652	* ftrace_set_filter_ips - set functions to filter on in ftrace by addresses
5653	* @ops: the ops to set the filter with
5654	* @ips: the array of addresses to add to or remove from the filter.
5655	* @cnt: the number of addresses in @ips
5656	* @remove: non zero to remove ips from the filter
5657	* @reset: non zero to reset all filters before applying this filter.
5658	*
5659	* Filters denote which functions should be enabled when tracing is enabled
5660	* If @ips array or any ip specified within is NULL , it fails to update filter.
5661	*
5662	* This can allocate memory which must be freed before @ops can be freed,
5663	* either by removing each filtered addr or by using
5664	* ftrace_free_filter(@ops).
5665	*/
5666	int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
5667	unsigned int cnt, int remove, int reset)
5668	{
5669	ftrace_ops_init(ops);
5670	return ftrace_set_addr(ops, ips, cnt, remove, reset, enable: 1);
5671	}
5672	EXPORT_SYMBOL_GPL(ftrace_set_filter_ips);
5673
5674	/**
5675	* ftrace_ops_set_global_filter - setup ops to use global filters
5676	* @ops: the ops which will use the global filters
5677	*
5678	* ftrace users who need global function trace filtering should call this.
5679	* It can set the global filter only if ops were not initialized before.
5680	*/
5681	void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
5682	{
5683	if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
5684	return;
5685
5686	ftrace_ops_init(ops);
5687	ops->func_hash = &global_ops.local_hash;
5688	}
5689	EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
5690
5691	static int
5692	ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
5693	int reset, int enable)
5694	{
5695	return ftrace_set_hash(ops, buf, len, NULL, cnt: 0, remove: 0, reset, enable);
5696	}
5697
5698	/**
5699	* ftrace_set_filter - set a function to filter on in ftrace
5700	* @ops: the ops to set the filter with
5701	* @buf: the string that holds the function filter text.
5702	* @len: the length of the string.
5703	* @reset: non-zero to reset all filters before applying this filter.
5704	*
5705	* Filters denote which functions should be enabled when tracing is enabled.
5706	* If @buf is NULL and reset is set, all functions will be enabled for tracing.
5707	*
5708	* This can allocate memory which must be freed before @ops can be freed,
5709	* either by removing each filtered addr or by using
5710	* ftrace_free_filter(@ops).
5711	*/
5712	int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
5713	int len, int reset)
5714	{
5715	ftrace_ops_init(ops);
5716	return ftrace_set_regex(ops, buf, len, reset, enable: 1);
5717	}
5718	EXPORT_SYMBOL_GPL(ftrace_set_filter);
5719
5720	/**
5721	* ftrace_set_notrace - set a function to not trace in ftrace
5722	* @ops: the ops to set the notrace filter with
5723	* @buf: the string that holds the function notrace text.
5724	* @len: the length of the string.
5725	* @reset: non-zero to reset all filters before applying this filter.
5726	*
5727	* Notrace Filters denote which functions should not be enabled when tracing
5728	* is enabled. If @buf is NULL and reset is set, all functions will be enabled
5729	* for tracing.
5730	*
5731	* This can allocate memory which must be freed before @ops can be freed,
5732	* either by removing each filtered addr or by using
5733	* ftrace_free_filter(@ops).
5734	*/
5735	int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
5736	int len, int reset)
5737	{
5738	ftrace_ops_init(ops);
5739	return ftrace_set_regex(ops, buf, len, reset, enable: 0);
5740	}
5741	EXPORT_SYMBOL_GPL(ftrace_set_notrace);
5742	/**
5743	* ftrace_set_global_filter - set a function to filter on with global tracers
5744	* @buf: the string that holds the function filter text.
5745	* @len: the length of the string.
5746	* @reset: non-zero to reset all filters before applying this filter.
5747	*
5748	* Filters denote which functions should be enabled when tracing is enabled.
5749	* If @buf is NULL and reset is set, all functions will be enabled for tracing.
5750	*/
5751	void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
5752	{
5753	ftrace_set_regex(ops: &global_ops, buf, len, reset, enable: 1);
5754	}
5755	EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
5756
5757	/**
5758	* ftrace_set_global_notrace - set a function to not trace with global tracers
5759	* @buf: the string that holds the function notrace text.
5760	* @len: the length of the string.
5761	* @reset: non-zero to reset all filters before applying this filter.
5762	*
5763	* Notrace Filters denote which functions should not be enabled when tracing
5764	* is enabled. If @buf is NULL and reset is set, all functions will be enabled
5765	* for tracing.
5766	*/
5767	void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
5768	{
5769	ftrace_set_regex(ops: &global_ops, buf, len, reset, enable: 0);
5770	}
5771	EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
5772
5773	/*
5774	* command line interface to allow users to set filters on boot up.
5775	*/
5776	#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
5777	static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
5778	static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
5779
5780	/* Used by function selftest to not test if filter is set */
5781	bool ftrace_filter_param __initdata;
5782
5783	static int __init set_ftrace_notrace(char *str)
5784	{
5785	ftrace_filter_param = true;
5786	strscpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
5787	return 1;
5788	}
5789	__setup("ftrace_notrace=", set_ftrace_notrace);
5790
5791	static int __init set_ftrace_filter(char *str)
5792	{
5793	ftrace_filter_param = true;
5794	strscpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
5795	return 1;
5796	}
5797	__setup("ftrace_filter=", set_ftrace_filter);
5798
5799	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
5800	static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
5801	static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
5802	static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
5803
5804	static int __init set_graph_function(char *str)
5805	{
5806	strscpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
5807	return 1;
5808	}
5809	__setup("ftrace_graph_filter=", set_graph_function);
5810
5811	static int __init set_graph_notrace_function(char *str)
5812	{
5813	strscpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
5814	return 1;
5815	}
5816	__setup("ftrace_graph_notrace=", set_graph_notrace_function);
5817
5818	static int __init set_graph_max_depth_function(char *str)
5819	{
5820	if (!str)
5821	return 0;
5822	fgraph_max_depth = simple_strtoul(str, NULL, 0);
5823	return 1;
5824	}
5825	__setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
5826
5827	static void __init set_ftrace_early_graph(char *buf, int enable)
5828	{
5829	int ret;
5830	char *func;
5831	struct ftrace_hash *hash;
5832
5833	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
5834	if (MEM_FAIL(!hash, "Failed to allocate hash\n"))
5835	return;
5836
5837	while (buf) {
5838	func = strsep(&buf, ",");
5839	/* we allow only one expression at a time */
5840	ret = ftrace_graph_set_hash(hash, buffer: func);
5841	if (ret)
5842	printk(KERN_DEBUG "ftrace: function %s not "
5843	"traceable\n", func);
5844	}
5845
5846	if (enable)
5847	ftrace_graph_hash = hash;
5848	else
5849	ftrace_graph_notrace_hash = hash;
5850	}
5851	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5852
5853	void __init
5854	ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
5855	{
5856	char *func;
5857
5858	ftrace_ops_init(ops);
5859
5860	while (buf) {
5861	func = strsep(&buf, ",");
5862	ftrace_set_regex(ops, buf: func, strlen(func), reset: 0, enable);
5863	}
5864	}
5865
5866	static void __init set_ftrace_early_filters(void)
5867	{
5868	if (ftrace_filter_buf[0])
5869	ftrace_set_early_filter(ops: &global_ops, buf: ftrace_filter_buf, enable: 1);
5870	if (ftrace_notrace_buf[0])
5871	ftrace_set_early_filter(ops: &global_ops, buf: ftrace_notrace_buf, enable: 0);
5872	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
5873	if (ftrace_graph_buf[0])
5874	set_ftrace_early_graph(buf: ftrace_graph_buf, enable: 1);
5875	if (ftrace_graph_notrace_buf[0])
5876	set_ftrace_early_graph(buf: ftrace_graph_notrace_buf, enable: 0);
5877	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5878	}
5879
5880	int ftrace_regex_release(struct inode *inode, struct file *file)
5881	{
5882	struct seq_file *m = (struct seq_file *)file->private_data;
5883	struct ftrace_iterator *iter;
5884	struct ftrace_hash **orig_hash;
5885	struct trace_parser *parser;
5886	int filter_hash;
5887
5888	if (file->f_mode & FMODE_READ) {
5889	iter = m->private;
5890	seq_release(inode, file);
5891	} else
5892	iter = file->private_data;
5893
5894	parser = &iter->parser;
5895	if (trace_parser_loaded(parser)) {
5896	int enable = !(iter->flags & FTRACE_ITER_NOTRACE);
5897
5898	ftrace_process_regex(iter, buff: parser->buffer,
5899	len: parser->idx, enable);
5900	}
5901
5902	trace_parser_put(parser);
5903
5904	mutex_lock(&iter->ops->func_hash->regex_lock);
5905
5906	if (file->f_mode & FMODE_WRITE) {
5907	filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5908
5909	if (filter_hash) {
5910	orig_hash = &iter->ops->func_hash->filter_hash;
5911	if (iter->tr) {
5912	if (list_empty(head: &iter->tr->mod_trace))
5913	iter->hash->flags &= ~FTRACE_HASH_FL_MOD;
5914	else
5915	iter->hash->flags |= FTRACE_HASH_FL_MOD;
5916	}
5917	} else
5918	orig_hash = &iter->ops->func_hash->notrace_hash;
5919
5920	mutex_lock(&ftrace_lock);
5921	ftrace_hash_move_and_update_ops(ops: iter->ops, orig_hash,
5922	hash: iter->hash, enable: filter_hash);
5923	mutex_unlock(lock: &ftrace_lock);
5924	} else {
5925	/* For read only, the hash is the ops hash */
5926	iter->hash = NULL;
5927	}
5928
5929	mutex_unlock(lock: &iter->ops->func_hash->regex_lock);
5930	free_ftrace_hash(hash: iter->hash);
5931	if (iter->tr)
5932	trace_array_put(tr: iter->tr);
5933	kfree(objp: iter);
5934
5935	return 0;
5936	}
5937
5938	static const struct file_operations ftrace_avail_fops = {
5939	.open = ftrace_avail_open,
5940	.read = seq_read,
5941	.llseek = seq_lseek,
5942	.release = seq_release_private,
5943	};
5944
5945	static const struct file_operations ftrace_enabled_fops = {
5946	.open = ftrace_enabled_open,
5947	.read = seq_read,
5948	.llseek = seq_lseek,
5949	.release = seq_release_private,
5950	};
5951
5952	static const struct file_operations ftrace_touched_fops = {
5953	.open = ftrace_touched_open,
5954	.read = seq_read,
5955	.llseek = seq_lseek,
5956	.release = seq_release_private,
5957	};
5958
5959	static const struct file_operations ftrace_avail_addrs_fops = {
5960	.open = ftrace_avail_addrs_open,
5961	.read = seq_read,
5962	.llseek = seq_lseek,
5963	.release = seq_release_private,
5964	};
5965
5966	static const struct file_operations ftrace_filter_fops = {
5967	.open = ftrace_filter_open,
5968	.read = seq_read,
5969	.write = ftrace_filter_write,
5970	.llseek = tracing_lseek,
5971	.release = ftrace_regex_release,
5972	};
5973
5974	static const struct file_operations ftrace_notrace_fops = {
5975	.open = ftrace_notrace_open,
5976	.read = seq_read,
5977	.write = ftrace_notrace_write,
5978	.llseek = tracing_lseek,
5979	.release = ftrace_regex_release,
5980	};
5981
5982	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
5983
5984	static DEFINE_MUTEX(graph_lock);
5985
5986	struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH;
5987	struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH;
5988
5989	enum graph_filter_type {
5990	GRAPH_FILTER_NOTRACE = 0,
5991	GRAPH_FILTER_FUNCTION,
5992	};
5993
5994	#define FTRACE_GRAPH_EMPTY ((void *)1)
5995
5996	struct ftrace_graph_data {
5997	struct ftrace_hash *hash;
5998	struct ftrace_func_entry *entry;
5999	int idx; /* for hash table iteration */
6000	enum graph_filter_type type;
6001	struct ftrace_hash *new_hash;
6002	const struct seq_operations *seq_ops;
6003	struct trace_parser parser;
6004	};
6005
6006	static void *
6007	__g_next(struct seq_file *m, loff_t *pos)
6008	{
6009	struct ftrace_graph_data *fgd = m->private;
6010	struct ftrace_func_entry *entry = fgd->entry;
6011	struct hlist_head *head;
6012	int i, idx = fgd->idx;
6013
6014	if (*pos >= fgd->hash->count)
6015	return NULL;
6016
6017	if (entry) {
6018	hlist_for_each_entry_continue(entry, hlist) {
6019	fgd->entry = entry;
6020	return entry;
6021	}
6022
6023	idx++;
6024	}
6025
6026	for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
6027	head = &fgd->hash->buckets[i];
6028	hlist_for_each_entry(entry, head, hlist) {
6029	fgd->entry = entry;
6030	fgd->idx = i;
6031	return entry;
6032	}
6033	}
6034	return NULL;
6035	}
6036
6037	static void *
6038	g_next(struct seq_file *m, void *v, loff_t *pos)
6039	{
6040	(*pos)++;
6041	return __g_next(m, pos);
6042	}
6043
6044	static void *g_start(struct seq_file *m, loff_t *pos)
6045	{
6046	struct ftrace_graph_data *fgd = m->private;
6047
6048	mutex_lock(&graph_lock);
6049
6050	if (fgd->type == GRAPH_FILTER_FUNCTION)
6051	fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
6052	lockdep_is_held(&graph_lock));
6053	else
6054	fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6055	lockdep_is_held(&graph_lock));
6056
6057	/* Nothing, tell g_show to print all functions are enabled */
6058	if (ftrace_hash_empty(hash: fgd->hash) && !*pos)
6059	return FTRACE_GRAPH_EMPTY;
6060
6061	fgd->idx = 0;
6062	fgd->entry = NULL;
6063	return __g_next(m, pos);
6064	}
6065
6066	static void g_stop(struct seq_file *m, void *p)
6067	{
6068	mutex_unlock(lock: &graph_lock);
6069	}
6070
6071	static int g_show(struct seq_file *m, void *v)
6072	{
6073	struct ftrace_func_entry *entry = v;
6074
6075	if (!entry)
6076	return 0;
6077
6078	if (entry == FTRACE_GRAPH_EMPTY) {
6079	struct ftrace_graph_data *fgd = m->private;
6080
6081	if (fgd->type == GRAPH_FILTER_FUNCTION)
6082	seq_puts(m, s: "#### all functions enabled ####\n");
6083	else
6084	seq_puts(m, s: "#### no functions disabled ####\n");
6085	return 0;
6086	}
6087
6088	seq_printf(m, fmt: "%ps\n", (void *)entry->ip);
6089
6090	return 0;
6091	}
6092
6093	static const struct seq_operations ftrace_graph_seq_ops = {
6094	.start = g_start,
6095	.next = g_next,
6096	.stop = g_stop,
6097	.show = g_show,
6098	};
6099
6100	static int
6101	__ftrace_graph_open(struct inode *inode, struct file *file,
6102	struct ftrace_graph_data *fgd)
6103	{
6104	int ret;
6105	struct ftrace_hash *new_hash = NULL;
6106
6107	ret = security_locked_down(what: LOCKDOWN_TRACEFS);
6108	if (ret)
6109	return ret;
6110
6111	if (file->f_mode & FMODE_WRITE) {
6112	const int size_bits = FTRACE_HASH_DEFAULT_BITS;
6113
6114	if (trace_parser_get_init(parser: &fgd->parser, FTRACE_BUFF_MAX))
6115	return -ENOMEM;
6116
6117	if (file->f_flags & O_TRUNC)
6118	new_hash = alloc_ftrace_hash(size_bits);
6119	else
6120	new_hash = alloc_and_copy_ftrace_hash(size_bits,
6121	hash: fgd->hash);
6122	if (!new_hash) {
6123	ret = -ENOMEM;
6124	goto out;
6125	}
6126	}
6127
6128	if (file->f_mode & FMODE_READ) {
6129	ret = seq_open(file, &ftrace_graph_seq_ops);
6130	if (!ret) {
6131	struct seq_file *m = file->private_data;
6132	m->private = fgd;
6133	} else {
6134	/* Failed */
6135	free_ftrace_hash(hash: new_hash);
6136	new_hash = NULL;
6137	}
6138	} else
6139	file->private_data = fgd;
6140
6141	out:
6142	if (ret < 0 && file->f_mode & FMODE_WRITE)
6143	trace_parser_put(parser: &fgd->parser);
6144
6145	fgd->new_hash = new_hash;
6146
6147	/*
6148	* All uses of fgd->hash must be taken with the graph_lock
6149	* held. The graph_lock is going to be released, so force
6150	* fgd->hash to be reinitialized when it is taken again.
6151	*/
6152	fgd->hash = NULL;
6153
6154	return ret;
6155	}
6156
6157	static int
6158	ftrace_graph_open(struct inode *inode, struct file *file)
6159	{
6160	struct ftrace_graph_data *fgd;
6161	int ret;
6162
6163	if (unlikely(ftrace_disabled))
6164	return -ENODEV;
6165
6166	fgd = kmalloc(size: sizeof(*fgd), GFP_KERNEL);
6167	if (fgd == NULL)
6168	return -ENOMEM;
6169
6170	mutex_lock(&graph_lock);
6171
6172	fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
6173	lockdep_is_held(&graph_lock));
6174	fgd->type = GRAPH_FILTER_FUNCTION;
6175	fgd->seq_ops = &ftrace_graph_seq_ops;
6176
6177	ret = __ftrace_graph_open(inode, file, fgd);
6178	if (ret < 0)
6179	kfree(objp: fgd);
6180
6181	mutex_unlock(lock: &graph_lock);
6182	return ret;
6183	}
6184
6185	static int
6186	ftrace_graph_notrace_open(struct inode *inode, struct file *file)
6187	{
6188	struct ftrace_graph_data *fgd;
6189	int ret;
6190
6191	if (unlikely(ftrace_disabled))
6192	return -ENODEV;
6193
6194	fgd = kmalloc(size: sizeof(*fgd), GFP_KERNEL);
6195	if (fgd == NULL)
6196	return -ENOMEM;
6197
6198	mutex_lock(&graph_lock);
6199
6200	fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6201	lockdep_is_held(&graph_lock));
6202	fgd->type = GRAPH_FILTER_NOTRACE;
6203	fgd->seq_ops = &ftrace_graph_seq_ops;
6204
6205	ret = __ftrace_graph_open(inode, file, fgd);
6206	if (ret < 0)
6207	kfree(objp: fgd);
6208
6209	mutex_unlock(lock: &graph_lock);
6210	return ret;
6211	}
6212
6213	static int
6214	ftrace_graph_release(struct inode *inode, struct file *file)
6215	{
6216	struct ftrace_graph_data *fgd;
6217	struct ftrace_hash *old_hash, *new_hash;
6218	struct trace_parser *parser;
6219	int ret = 0;
6220
6221	if (file->f_mode & FMODE_READ) {
6222	struct seq_file *m = file->private_data;
6223
6224	fgd = m->private;
6225	seq_release(inode, file);
6226	} else {
6227	fgd = file->private_data;
6228	}
6229
6230
6231	if (file->f_mode & FMODE_WRITE) {
6232
6233	parser = &fgd->parser;
6234
6235	if (trace_parser_loaded((parser))) {
6236	ret = ftrace_graph_set_hash(hash: fgd->new_hash,
6237	buffer: parser->buffer);
6238	}
6239
6240	trace_parser_put(parser);
6241
6242	new_hash = __ftrace_hash_move(src: fgd->new_hash);
6243	if (!new_hash) {
6244	ret = -ENOMEM;
6245	goto out;
6246	}
6247
6248	mutex_lock(&graph_lock);
6249
6250	if (fgd->type == GRAPH_FILTER_FUNCTION) {
6251	old_hash = rcu_dereference_protected(ftrace_graph_hash,
6252	lockdep_is_held(&graph_lock));
6253	rcu_assign_pointer(ftrace_graph_hash, new_hash);
6254	} else {
6255	old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
6256	lockdep_is_held(&graph_lock));
6257	rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
6258	}
6259
6260	mutex_unlock(lock: &graph_lock);
6261
6262	/*
6263	* We need to do a hard force of sched synchronization.
6264	* This is because we use preempt_disable() to do RCU, but
6265	* the function tracers can be called where RCU is not watching
6266	* (like before user_exit()). We can not rely on the RCU
6267	* infrastructure to do the synchronization, thus we must do it
6268	* ourselves.
6269	*/
6270	if (old_hash != EMPTY_HASH)
6271	synchronize_rcu_tasks_rude();
6272
6273	free_ftrace_hash(hash: old_hash);
6274	}
6275
6276	out:
6277	free_ftrace_hash(hash: fgd->new_hash);
6278	kfree(objp: fgd);
6279
6280	return ret;
6281	}
6282
6283	static int
6284	ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
6285	{
6286	struct ftrace_glob func_g;
6287	struct dyn_ftrace *rec;
6288	struct ftrace_page *pg;
6289	struct ftrace_func_entry *entry;
6290	int fail = 1;
6291	int not;
6292
6293	/* decode regex */
6294	func_g.type = filter_parse_regex(buff: buffer, strlen(buffer),
6295	search: &func_g.search, not: &not);
6296
6297	func_g.len = strlen(func_g.search);
6298
6299	mutex_lock(&ftrace_lock);
6300
6301	if (unlikely(ftrace_disabled)) {
6302	mutex_unlock(lock: &ftrace_lock);
6303	return -ENODEV;
6304	}
6305
6306	do_for_each_ftrace_rec(pg, rec) {
6307
6308	if (rec->flags & FTRACE_FL_DISABLED)
6309	continue;
6310
6311	if (ftrace_match_record(rec, func_g: &func_g, NULL, exclude_mod: 0)) {
6312	entry = ftrace_lookup_ip(hash, ip: rec->ip);
6313
6314	if (!not) {
6315	fail = 0;
6316
6317	if (entry)
6318	continue;
6319	if (add_hash_entry(hash, ip: rec->ip) == NULL)
6320	goto out;
6321	} else {
6322	if (entry) {
6323	free_hash_entry(hash, entry);
6324	fail = 0;
6325	}
6326	}
6327	}
6328	} while_for_each_ftrace_rec();
6329	out:
6330	mutex_unlock(lock: &ftrace_lock);
6331
6332	if (fail)
6333	return -EINVAL;
6334
6335	return 0;
6336	}
6337
6338	static ssize_t
6339	ftrace_graph_write(struct file *file, const char __user *ubuf,
6340	size_t cnt, loff_t *ppos)
6341	{
6342	ssize_t read, ret = 0;
6343	struct ftrace_graph_data *fgd = file->private_data;
6344	struct trace_parser *parser;
6345
6346	if (!cnt)
6347	return 0;
6348
6349	/* Read mode uses seq functions */
6350	if (file->f_mode & FMODE_READ) {
6351	struct seq_file *m = file->private_data;
6352	fgd = m->private;
6353	}
6354
6355	parser = &fgd->parser;
6356
6357	read = trace_get_user(parser, ubuf, cnt, ppos);
6358
6359	if (read >= 0 && trace_parser_loaded(parser) &&
6360	!trace_parser_cont(parser)) {
6361
6362	ret = ftrace_graph_set_hash(hash: fgd->new_hash,
6363	buffer: parser->buffer);
6364	trace_parser_clear(parser);
6365	}
6366
6367	if (!ret)
6368	ret = read;
6369
6370	return ret;
6371	}
6372
6373	static const struct file_operations ftrace_graph_fops = {
6374	.open = ftrace_graph_open,
6375	.read = seq_read,
6376	.write = ftrace_graph_write,
6377	.llseek = tracing_lseek,
6378	.release = ftrace_graph_release,
6379	};
6380
6381	static const struct file_operations ftrace_graph_notrace_fops = {
6382	.open = ftrace_graph_notrace_open,
6383	.read = seq_read,
6384	.write = ftrace_graph_write,
6385	.llseek = tracing_lseek,
6386	.release = ftrace_graph_release,
6387	};
6388	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
6389
6390	void ftrace_create_filter_files(struct ftrace_ops *ops,
6391	struct dentry *parent)
6392	{
6393
6394	trace_create_file(name: "set_ftrace_filter", TRACE_MODE_WRITE, parent,
6395	data: ops, fops: &ftrace_filter_fops);
6396
6397	trace_create_file(name: "set_ftrace_notrace", TRACE_MODE_WRITE, parent,
6398	data: ops, fops: &ftrace_notrace_fops);
6399	}
6400
6401	/*
6402	* The name "destroy_filter_files" is really a misnomer. Although
6403	* in the future, it may actually delete the files, but this is
6404	* really intended to make sure the ops passed in are disabled
6405	* and that when this function returns, the caller is free to
6406	* free the ops.
6407	*
6408	* The "destroy" name is only to match the "create" name that this
6409	* should be paired with.
6410	*/
6411	void ftrace_destroy_filter_files(struct ftrace_ops *ops)
6412	{
6413	mutex_lock(&ftrace_lock);
6414	if (ops->flags & FTRACE_OPS_FL_ENABLED)
6415	ftrace_shutdown(ops, command: 0);
6416	ops->flags |= FTRACE_OPS_FL_DELETED;
6417	ftrace_free_filter(ops);
6418	mutex_unlock(lock: &ftrace_lock);
6419	}
6420
6421	static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
6422	{
6423
6424	trace_create_file(name: "available_filter_functions", TRACE_MODE_READ,
6425	parent: d_tracer, NULL, fops: &ftrace_avail_fops);
6426
6427	trace_create_file(name: "available_filter_functions_addrs", TRACE_MODE_READ,
6428	parent: d_tracer, NULL, fops: &ftrace_avail_addrs_fops);
6429
6430	trace_create_file(name: "enabled_functions", TRACE_MODE_READ,
6431	parent: d_tracer, NULL, fops: &ftrace_enabled_fops);
6432
6433	trace_create_file(name: "touched_functions", TRACE_MODE_READ,
6434	parent: d_tracer, NULL, fops: &ftrace_touched_fops);
6435
6436	ftrace_create_filter_files(ops: &global_ops, parent: d_tracer);
6437
6438	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
6439	trace_create_file(name: "set_graph_function", TRACE_MODE_WRITE, parent: d_tracer,
6440	NULL,
6441	fops: &ftrace_graph_fops);
6442	trace_create_file(name: "set_graph_notrace", TRACE_MODE_WRITE, parent: d_tracer,
6443	NULL,
6444	fops: &ftrace_graph_notrace_fops);
6445	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
6446
6447	return 0;
6448	}
6449
6450	static int ftrace_cmp_ips(const void *a, const void *b)
6451	{
6452	const unsigned long *ipa = a;
6453	const unsigned long *ipb = b;
6454
6455	if (*ipa > *ipb)
6456	return 1;
6457	if (*ipa < *ipb)
6458	return -1;
6459	return 0;
6460	}
6461
6462	#ifdef CONFIG_FTRACE_SORT_STARTUP_TEST
6463	static void test_is_sorted(unsigned long *start, unsigned long count)
6464	{
6465	int i;
6466
6467	for (i = 1; i < count; i++) {
6468	if (WARN(start[i - 1] > start[i],
6469	"[%d] %pS at %lx is not sorted with %pS at %lx\n", i,
6470	(void *)start[i - 1], start[i - 1],
6471	(void *)start[i], start[i]))
6472	break;
6473	}
6474	if (i == count)
6475	pr_info("ftrace section at %px sorted properly\n", start);
6476	}
6477	#else
6478	static void test_is_sorted(unsigned long *start, unsigned long count)
6479	{
6480	}
6481	#endif
6482
6483	static int ftrace_process_locs(struct module *mod,
6484	unsigned long *start,
6485	unsigned long *end)
6486	{
6487	struct ftrace_page *pg_unuse = NULL;
6488	struct ftrace_page *start_pg;
6489	struct ftrace_page *pg;
6490	struct dyn_ftrace *rec;
6491	unsigned long skipped = 0;
6492	unsigned long count;
6493	unsigned long *p;
6494	unsigned long addr;
6495	unsigned long flags = 0; /* Shut up gcc */
6496	int ret = -ENOMEM;
6497
6498	count = end - start;
6499
6500	if (!count)
6501	return 0;
6502
6503	/*
6504	* Sorting mcount in vmlinux at build time depend on
6505	* CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in
6506	* modules can not be sorted at build time.
6507	*/
6508	if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) {
6509	sort(base: start, num: count, size: sizeof(*start),
6510	cmp_func: ftrace_cmp_ips, NULL);
6511	} else {
6512	test_is_sorted(start, count);
6513	}
6514
6515	start_pg = ftrace_allocate_pages(num_to_init: count);
6516	if (!start_pg)
6517	return -ENOMEM;
6518
6519	mutex_lock(&ftrace_lock);
6520
6521	/*
6522	* Core and each module needs their own pages, as
6523	* modules will free them when they are removed.
6524	* Force a new page to be allocated for modules.
6525	*/
6526	if (!mod) {
6527	WARN_ON(ftrace_pages || ftrace_pages_start);
6528	/* First initialization */
6529	ftrace_pages = ftrace_pages_start = start_pg;
6530	} else {
6531	if (!ftrace_pages)
6532	goto out;
6533
6534	if (WARN_ON(ftrace_pages->next)) {
6535	/* Hmm, we have free pages? */
6536	while (ftrace_pages->next)
6537	ftrace_pages = ftrace_pages->next;
6538	}
6539
6540	ftrace_pages->next = start_pg;
6541	}
6542
6543	p = start;
6544	pg = start_pg;
6545	while (p < end) {
6546	unsigned long end_offset;
6547	addr = ftrace_call_adjust(addr: *p++);
6548	/*
6549	* Some architecture linkers will pad between
6550	* the different mcount_loc sections of different
6551	* object files to satisfy alignments.
6552	* Skip any NULL pointers.
6553	*/
6554	if (!addr) {
6555	skipped++;
6556	continue;
6557	}
6558
6559	end_offset = (pg->index+1) * sizeof(pg->records[0]);
6560	if (end_offset > PAGE_SIZE << pg->order) {
6561	/* We should have allocated enough */
6562	if (WARN_ON(!pg->next))
6563	break;
6564	pg = pg->next;
6565	}
6566
6567	rec = &pg->records[pg->index++];
6568	rec->ip = addr;
6569	}
6570
6571	if (pg->next) {
6572	pg_unuse = pg->next;
6573	pg->next = NULL;
6574	}
6575
6576	/* Assign the last page to ftrace_pages */
6577	ftrace_pages = pg;
6578
6579	/*
6580	* We only need to disable interrupts on start up
6581	* because we are modifying code that an interrupt
6582	* may execute, and the modification is not atomic.
6583	* But for modules, nothing runs the code we modify
6584	* until we are finished with it, and there's no
6585	* reason to cause large interrupt latencies while we do it.
6586	*/
6587	if (!mod)
6588	local_irq_save(flags);
6589	ftrace_update_code(mod, new_pgs: start_pg);
6590	if (!mod)
6591	local_irq_restore(flags);
6592	ret = 0;
6593	out:
6594	mutex_unlock(lock: &ftrace_lock);
6595
6596	/* We should have used all pages unless we skipped some */
6597	if (pg_unuse) {
6598	WARN_ON(!skipped);
6599	ftrace_free_pages(pages: pg_unuse);
6600	}
6601	return ret;
6602	}
6603
6604	struct ftrace_mod_func {
6605	struct list_head list;
6606	char *name;
6607	unsigned long ip;
6608	unsigned int size;
6609	};
6610
6611	struct ftrace_mod_map {
6612	struct rcu_head rcu;
6613	struct list_head list;
6614	struct module *mod;
6615	unsigned long start_addr;
6616	unsigned long end_addr;
6617	struct list_head funcs;
6618	unsigned int num_funcs;
6619	};
6620
6621	static int ftrace_get_trampoline_kallsym(unsigned int symnum,
6622	unsigned long *value, char *type,
6623	char *name, char *module_name,
6624	int *exported)
6625	{
6626	struct ftrace_ops *op;
6627
6628	list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) {
6629	if (!op->trampoline || symnum--)
6630	continue;
6631	*value = op->trampoline;
6632	*type = 't';
6633	strscpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
6634	strscpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);
6635	*exported = 0;
6636	return 0;
6637	}
6638
6639	return -ERANGE;
6640	}
6641
6642	#if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) || defined(CONFIG_MODULES)
6643	/*
6644	* Check if the current ops references the given ip.
6645	*
6646	* If the ops traces all functions, then it was already accounted for.
6647	* If the ops does not trace the current record function, skip it.
6648	* If the ops ignores the function via notrace filter, skip it.
6649	*/
6650	static bool
6651	ops_references_ip(struct ftrace_ops *ops, unsigned long ip)
6652	{
6653	/* If ops isn't enabled, ignore it */
6654	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
6655	return false;
6656
6657	/* If ops traces all then it includes this function */
6658	if (ops_traces_mod(ops))
6659	return true;
6660
6661	/* The function must be in the filter */
6662	if (!ftrace_hash_empty(hash: ops->func_hash->filter_hash) &&
6663	!__ftrace_lookup_ip(hash: ops->func_hash->filter_hash, ip))
6664	return false;
6665
6666	/* If in notrace hash, we ignore it too */
6667	if (ftrace_lookup_ip(hash: ops->func_hash->notrace_hash, ip))
6668	return false;
6669
6670	return true;
6671	}
6672	#endif
6673
6674	#ifdef CONFIG_MODULES
6675
6676	#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
6677
6678	static LIST_HEAD(ftrace_mod_maps);
6679
6680	static int referenced_filters(struct dyn_ftrace *rec)
6681	{
6682	struct ftrace_ops *ops;
6683	int cnt = 0;
6684
6685	for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
6686	if (ops_references_ip(ops, ip: rec->ip)) {
6687	if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT))
6688	continue;
6689	if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY))
6690	continue;
6691	cnt++;
6692	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
6693	rec->flags |= FTRACE_FL_REGS;
6694	if (cnt == 1 && ops->trampoline)
6695	rec->flags |= FTRACE_FL_TRAMP;
6696	else
6697	rec->flags &= ~FTRACE_FL_TRAMP;
6698	}
6699	}
6700
6701	return cnt;
6702	}
6703
6704	static void
6705	clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
6706	{
6707	struct ftrace_func_entry *entry;
6708	struct dyn_ftrace *rec;
6709	int i;
6710
6711	if (ftrace_hash_empty(hash))
6712	return;
6713
6714	for (i = 0; i < pg->index; i++) {
6715	rec = &pg->records[i];
6716	entry = __ftrace_lookup_ip(hash, ip: rec->ip);
6717	/*
6718	* Do not allow this rec to match again.
6719	* Yeah, it may waste some memory, but will be removed
6720	* if/when the hash is modified again.
6721	*/
6722	if (entry)
6723	entry->ip = 0;
6724	}
6725	}
6726
6727	/* Clear any records from hashes */
6728	static void clear_mod_from_hashes(struct ftrace_page *pg)
6729	{
6730	struct trace_array *tr;
6731
6732	mutex_lock(&trace_types_lock);
6733	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
6734	if (!tr->ops || !tr->ops->func_hash)
6735	continue;
6736	mutex_lock(&tr->ops->func_hash->regex_lock);
6737	clear_mod_from_hash(pg, hash: tr->ops->func_hash->filter_hash);
6738	clear_mod_from_hash(pg, hash: tr->ops->func_hash->notrace_hash);
6739	mutex_unlock(lock: &tr->ops->func_hash->regex_lock);
6740	}
6741	mutex_unlock(lock: &trace_types_lock);
6742	}
6743
6744	static void ftrace_free_mod_map(struct rcu_head *rcu)
6745	{
6746	struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
6747	struct ftrace_mod_func *mod_func;
6748	struct ftrace_mod_func *n;
6749
6750	/* All the contents of mod_map are now not visible to readers */
6751	list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
6752	kfree(objp: mod_func->name);
6753	list_del(entry: &mod_func->list);
6754	kfree(objp: mod_func);
6755	}
6756
6757	kfree(objp: mod_map);
6758	}
6759
6760	void ftrace_release_mod(struct module *mod)
6761	{
6762	struct ftrace_mod_map *mod_map;
6763	struct ftrace_mod_map *n;
6764	struct dyn_ftrace *rec;
6765	struct ftrace_page **last_pg;
6766	struct ftrace_page *tmp_page = NULL;
6767	struct ftrace_page *pg;
6768
6769	mutex_lock(&ftrace_lock);
6770
6771	if (ftrace_disabled)
6772	goto out_unlock;
6773
6774	list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
6775	if (mod_map->mod == mod) {
6776	list_del_rcu(entry: &mod_map->list);
6777	call_rcu(head: &mod_map->rcu, func: ftrace_free_mod_map);
6778	break;
6779	}
6780	}
6781
6782	/*
6783	* Each module has its own ftrace_pages, remove
6784	* them from the list.
6785	*/
6786	last_pg = &ftrace_pages_start;
6787	for (pg = ftrace_pages_start; pg; pg = *last_pg) {
6788	rec = &pg->records[0];
6789	if (within_module(addr: rec->ip, mod)) {
6790	/*
6791	* As core pages are first, the first
6792	* page should never be a module page.
6793	*/
6794	if (WARN_ON(pg == ftrace_pages_start))
6795	goto out_unlock;
6796
6797	/* Check if we are deleting the last page */
6798	if (pg == ftrace_pages)
6799	ftrace_pages = next_to_ftrace_page(last_pg);
6800
6801	ftrace_update_tot_cnt -= pg->index;
6802	*last_pg = pg->next;
6803
6804	pg->next = tmp_page;
6805	tmp_page = pg;
6806	} else
6807	last_pg = &pg->next;
6808	}
6809	out_unlock:
6810	mutex_unlock(lock: &ftrace_lock);
6811
6812	for (pg = tmp_page; pg; pg = tmp_page) {
6813
6814	/* Needs to be called outside of ftrace_lock */
6815	clear_mod_from_hashes(pg);
6816
6817	if (pg->records) {
6818	free_pages(addr: (unsigned long)pg->records, order: pg->order);
6819	ftrace_number_of_pages -= 1 << pg->order;
6820	}
6821	tmp_page = pg->next;
6822	kfree(objp: pg);
6823	ftrace_number_of_groups--;
6824	}
6825	}
6826
6827	void ftrace_module_enable(struct module *mod)
6828	{
6829	struct dyn_ftrace *rec;
6830	struct ftrace_page *pg;
6831
6832	mutex_lock(&ftrace_lock);
6833
6834	if (ftrace_disabled)
6835	goto out_unlock;
6836
6837	/*
6838	* If the tracing is enabled, go ahead and enable the record.
6839	*
6840	* The reason not to enable the record immediately is the
6841	* inherent check of ftrace_make_nop/ftrace_make_call for
6842	* correct previous instructions. Making first the NOP
6843	* conversion puts the module to the correct state, thus
6844	* passing the ftrace_make_call check.
6845	*
6846	* We also delay this to after the module code already set the
6847	* text to read-only, as we now need to set it back to read-write
6848	* so that we can modify the text.
6849	*/
6850	if (ftrace_start_up)
6851	ftrace_arch_code_modify_prepare();
6852
6853	do_for_each_ftrace_rec(pg, rec) {
6854	int cnt;
6855	/*
6856	* do_for_each_ftrace_rec() is a double loop.
6857	* module text shares the pg. If a record is
6858	* not part of this module, then skip this pg,
6859	* which the "break" will do.
6860	*/
6861	if (!within_module(addr: rec->ip, mod))
6862	break;
6863
6864	/* Weak functions should still be ignored */
6865	if (!test_for_valid_rec(rec)) {
6866	/* Clear all other flags. Should not be enabled anyway */
6867	rec->flags = FTRACE_FL_DISABLED;
6868	continue;
6869	}
6870
6871	cnt = 0;
6872
6873	/*
6874	* When adding a module, we need to check if tracers are
6875	* currently enabled and if they are, and can trace this record,
6876	* we need to enable the module functions as well as update the
6877	* reference counts for those function records.
6878	*/
6879	if (ftrace_start_up)
6880	cnt += referenced_filters(rec);
6881
6882	rec->flags &= ~FTRACE_FL_DISABLED;
6883	rec->flags += cnt;
6884
6885	if (ftrace_start_up && cnt) {
6886	int failed = __ftrace_replace_code(rec, enable: 1);
6887	if (failed) {
6888	ftrace_bug(failed, rec);
6889	goto out_loop;
6890	}
6891	}
6892
6893	} while_for_each_ftrace_rec();
6894
6895	out_loop:
6896	if (ftrace_start_up)
6897	ftrace_arch_code_modify_post_process();
6898
6899	out_unlock:
6900	mutex_unlock(lock: &ftrace_lock);
6901
6902	process_cached_mods(mod_name: mod->name);
6903	}
6904
6905	void ftrace_module_init(struct module *mod)
6906	{
6907	int ret;
6908
6909	if (ftrace_disabled || !mod->num_ftrace_callsites)
6910	return;
6911
6912	ret = ftrace_process_locs(mod, start: mod->ftrace_callsites,
6913	end: mod->ftrace_callsites + mod->num_ftrace_callsites);
6914	if (ret)
6915	pr_warn("ftrace: failed to allocate entries for module '%s' functions\n",
6916	mod->name);
6917	}
6918
6919	static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6920	struct dyn_ftrace *rec)
6921	{
6922	struct ftrace_mod_func *mod_func;
6923	unsigned long symsize;
6924	unsigned long offset;
6925	char str[KSYM_SYMBOL_LEN];
6926	char *modname;
6927	const char *ret;
6928
6929	ret = kallsyms_lookup(addr: rec->ip, symbolsize: &symsize, offset: &offset, modname: &modname, namebuf: str);
6930	if (!ret)
6931	return;
6932
6933	mod_func = kmalloc(size: sizeof(*mod_func), GFP_KERNEL);
6934	if (!mod_func)
6935	return;
6936
6937	mod_func->name = kstrdup(s: str, GFP_KERNEL);
6938	if (!mod_func->name) {
6939	kfree(objp: mod_func);
6940	return;
6941	}
6942
6943	mod_func->ip = rec->ip - offset;
6944	mod_func->size = symsize;
6945
6946	mod_map->num_funcs++;
6947
6948	list_add_rcu(new: &mod_func->list, head: &mod_map->funcs);
6949	}
6950
6951	static struct ftrace_mod_map *
6952	allocate_ftrace_mod_map(struct module *mod,
6953	unsigned long start, unsigned long end)
6954	{
6955	struct ftrace_mod_map *mod_map;
6956
6957	mod_map = kmalloc(size: sizeof(*mod_map), GFP_KERNEL);
6958	if (!mod_map)
6959	return NULL;
6960
6961	mod_map->mod = mod;
6962	mod_map->start_addr = start;
6963	mod_map->end_addr = end;
6964	mod_map->num_funcs = 0;
6965
6966	INIT_LIST_HEAD_RCU(list: &mod_map->funcs);
6967
6968	list_add_rcu(new: &mod_map->list, head: &ftrace_mod_maps);
6969
6970	return mod_map;
6971	}
6972
6973	static const char *
6974	ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
6975	unsigned long addr, unsigned long *size,
6976	unsigned long *off, char *sym)
6977	{
6978	struct ftrace_mod_func *found_func = NULL;
6979	struct ftrace_mod_func *mod_func;
6980
6981	list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
6982	if (addr >= mod_func->ip &&
6983	addr < mod_func->ip + mod_func->size) {
6984	found_func = mod_func;
6985	break;
6986	}
6987	}
6988
6989	if (found_func) {
6990	if (size)
6991	*size = found_func->size;
6992	if (off)
6993	*off = addr - found_func->ip;
6994	if (sym)
6995	strscpy(sym, found_func->name, KSYM_NAME_LEN);
6996
6997	return found_func->name;
6998	}
6999
7000	return NULL;
7001	}
7002
7003	const char *
7004	ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
7005	unsigned long *off, char **modname, char *sym)
7006	{
7007	struct ftrace_mod_map *mod_map;
7008	const char *ret = NULL;
7009
7010	/* mod_map is freed via call_rcu() */
7011	preempt_disable();
7012	list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
7013	ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
7014	if (ret) {
7015	if (modname)
7016	*modname = mod_map->mod->name;
7017	break;
7018	}
7019	}
7020	preempt_enable();
7021
7022	return ret;
7023	}
7024
7025	int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
7026	char *type, char *name,
7027	char *module_name, int *exported)
7028	{
7029	struct ftrace_mod_map *mod_map;
7030	struct ftrace_mod_func *mod_func;
7031	int ret;
7032
7033	preempt_disable();
7034	list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
7035
7036	if (symnum >= mod_map->num_funcs) {
7037	symnum -= mod_map->num_funcs;
7038	continue;
7039	}
7040
7041	list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
7042	if (symnum > 1) {
7043	symnum--;
7044	continue;
7045	}
7046
7047	*value = mod_func->ip;
7048	*type = 'T';
7049	strscpy(name, mod_func->name, KSYM_NAME_LEN);
7050	strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
7051	*exported = 1;
7052	preempt_enable();
7053	return 0;
7054	}
7055	WARN_ON(1);
7056	break;
7057	}
7058	ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
7059	module_name, exported);
7060	preempt_enable();
7061	return ret;
7062	}
7063
7064	#else
7065	static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
7066	struct dyn_ftrace *rec) { }
7067	static inline struct ftrace_mod_map *
7068	allocate_ftrace_mod_map(struct module *mod,
7069	unsigned long start, unsigned long end)
7070	{
7071	return NULL;
7072	}
7073	int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
7074	char *type, char *name, char *module_name,
7075	int *exported)
7076	{
7077	int ret;
7078
7079	preempt_disable();
7080	ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
7081	module_name, exported);
7082	preempt_enable();
7083	return ret;
7084	}
7085	#endif /* CONFIG_MODULES */
7086
7087	struct ftrace_init_func {
7088	struct list_head list;
7089	unsigned long ip;
7090	};
7091
7092	/* Clear any init ips from hashes */
7093	static void
7094	clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
7095	{
7096	struct ftrace_func_entry *entry;
7097
7098	entry = ftrace_lookup_ip(hash, ip: func->ip);
7099	/*
7100	* Do not allow this rec to match again.
7101	* Yeah, it may waste some memory, but will be removed
7102	* if/when the hash is modified again.
7103	*/
7104	if (entry)
7105	entry->ip = 0;
7106	}
7107
7108	static void
7109	clear_func_from_hashes(struct ftrace_init_func *func)
7110	{
7111	struct trace_array *tr;
7112
7113	mutex_lock(&trace_types_lock);
7114	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
7115	if (!tr->ops || !tr->ops->func_hash)
7116	continue;
7117	mutex_lock(&tr->ops->func_hash->regex_lock);
7118	clear_func_from_hash(func, hash: tr->ops->func_hash->filter_hash);
7119	clear_func_from_hash(func, hash: tr->ops->func_hash->notrace_hash);
7120	mutex_unlock(lock: &tr->ops->func_hash->regex_lock);
7121	}
7122	mutex_unlock(lock: &trace_types_lock);
7123	}
7124
7125	static void add_to_clear_hash_list(struct list_head *clear_list,
7126	struct dyn_ftrace *rec)
7127	{
7128	struct ftrace_init_func *func;
7129
7130	func = kmalloc(size: sizeof(*func), GFP_KERNEL);
7131	if (!func) {
7132	MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n");
7133	return;
7134	}
7135
7136	func->ip = rec->ip;
7137	list_add(new: &func->list, head: clear_list);
7138	}
7139
7140	void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
7141	{
7142	unsigned long start = (unsigned long)(start_ptr);
7143	unsigned long end = (unsigned long)(end_ptr);
7144	struct ftrace_page **last_pg = &ftrace_pages_start;
7145	struct ftrace_page *pg;
7146	struct dyn_ftrace *rec;
7147	struct dyn_ftrace key;
7148	struct ftrace_mod_map *mod_map = NULL;
7149	struct ftrace_init_func *func, *func_next;
7150	LIST_HEAD(clear_hash);
7151
7152	key.ip = start;
7153	key.flags = end; /* overload flags, as it is unsigned long */
7154
7155	mutex_lock(&ftrace_lock);
7156
7157	/*
7158	* If we are freeing module init memory, then check if
7159	* any tracer is active. If so, we need to save a mapping of
7160	* the module functions being freed with the address.
7161	*/
7162	if (mod && ftrace_ops_list != &ftrace_list_end)
7163	mod_map = allocate_ftrace_mod_map(mod, start, end);
7164
7165	for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
7166	if (end < pg->records[0].ip ||
7167	start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
7168	continue;
7169	again:
7170	rec = bsearch(key: &key, base: pg->records, num: pg->index,
7171	size: sizeof(struct dyn_ftrace),
7172	cmp: ftrace_cmp_recs);
7173	if (!rec)
7174	continue;
7175
7176	/* rec will be cleared from hashes after ftrace_lock unlock */
7177	add_to_clear_hash_list(clear_list: &clear_hash, rec);
7178
7179	if (mod_map)
7180	save_ftrace_mod_rec(mod_map, rec);
7181
7182	pg->index--;
7183	ftrace_update_tot_cnt--;
7184	if (!pg->index) {
7185	*last_pg = pg->next;
7186	if (pg->records) {
7187	free_pages(addr: (unsigned long)pg->records, order: pg->order);
7188	ftrace_number_of_pages -= 1 << pg->order;
7189	}
7190	ftrace_number_of_groups--;
7191	kfree(objp: pg);
7192	pg = container_of(last_pg, struct ftrace_page, next);
7193	if (!(*last_pg))
7194	ftrace_pages = pg;
7195	continue;
7196	}
7197	memmove(rec, rec + 1,
7198	(pg->index - (rec - pg->records)) * sizeof(*rec));
7199	/* More than one function may be in this block */
7200	goto again;
7201	}
7202	mutex_unlock(lock: &ftrace_lock);
7203
7204	list_for_each_entry_safe(func, func_next, &clear_hash, list) {
7205	clear_func_from_hashes(func);
7206	kfree(objp: func);
7207	}
7208	}
7209
7210	void __init ftrace_free_init_mem(void)
7211	{
7212	void *start = (void *)(&__init_begin);
7213	void *end = (void *)(&__init_end);
7214
7215	ftrace_boot_snapshot();
7216
7217	ftrace_free_mem(NULL, start_ptr: start, end_ptr: end);
7218	}
7219
7220	int __init __weak ftrace_dyn_arch_init(void)
7221	{
7222	return 0;
7223	}
7224
7225	void __init ftrace_init(void)
7226	{
7227	extern unsigned long __start_mcount_loc[];
7228	extern unsigned long __stop_mcount_loc[];
7229	unsigned long count, flags;
7230	int ret;
7231
7232	local_irq_save(flags);
7233	ret = ftrace_dyn_arch_init();
7234	local_irq_restore(flags);
7235	if (ret)
7236	goto failed;
7237
7238	count = __stop_mcount_loc - __start_mcount_loc;
7239	if (!count) {
7240	pr_info("ftrace: No functions to be traced?\n");
7241	goto failed;
7242	}
7243
7244	pr_info("ftrace: allocating %ld entries in %ld pages\n",
7245	count, DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
7246
7247	ret = ftrace_process_locs(NULL,
7248	start: __start_mcount_loc,
7249	end: __stop_mcount_loc);
7250	if (ret) {
7251	pr_warn("ftrace: failed to allocate entries for functions\n");
7252	goto failed;
7253	}
7254
7255	pr_info("ftrace: allocated %ld pages with %ld groups\n",
7256	ftrace_number_of_pages, ftrace_number_of_groups);
7257
7258	last_ftrace_enabled = ftrace_enabled = 1;
7259
7260	set_ftrace_early_filters();
7261
7262	return;
7263	failed:
7264	ftrace_disabled = 1;
7265	}
7266
7267	/* Do nothing if arch does not support this */
7268	void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
7269	{
7270	}
7271
7272	static void ftrace_update_trampoline(struct ftrace_ops *ops)
7273	{
7274	unsigned long trampoline = ops->trampoline;
7275
7276	arch_ftrace_update_trampoline(ops);
7277	if (ops->trampoline && ops->trampoline != trampoline &&
7278	(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) {
7279	/* Add to kallsyms before the perf events */
7280	ftrace_add_trampoline_to_kallsyms(ops);
7281	perf_event_ksymbol(ksym_type: PERF_RECORD_KSYMBOL_TYPE_OOL,
7282	addr: ops->trampoline, len: ops->trampoline_size, unregister: false,
7283	FTRACE_TRAMPOLINE_SYM);
7284	/*
7285	* Record the perf text poke event after the ksymbol register
7286	* event.
7287	*/
7288	perf_event_text_poke(addr: (void *)ops->trampoline, NULL, old_len: 0,
7289	new_bytes: (void *)ops->trampoline,
7290	new_len: ops->trampoline_size);
7291	}
7292	}
7293
7294	void ftrace_init_trace_array(struct trace_array *tr)
7295	{
7296	INIT_LIST_HEAD(list: &tr->func_probes);
7297	INIT_LIST_HEAD(list: &tr->mod_trace);
7298	INIT_LIST_HEAD(list: &tr->mod_notrace);
7299	}
7300	#else
7301
7302	struct ftrace_ops global_ops = {
7303	.func = ftrace_stub,
7304	.flags = FTRACE_OPS_FL_INITIALIZED |
7305	FTRACE_OPS_FL_PID,
7306	};
7307
7308	static int __init ftrace_nodyn_init(void)
7309	{
7310	ftrace_enabled = 1;
7311	return 0;
7312	}
7313	core_initcall(ftrace_nodyn_init);
7314
7315	static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
7316	static inline void ftrace_startup_all(int command) { }
7317
7318	static void ftrace_update_trampoline(struct ftrace_ops *ops)
7319	{
7320	}
7321
7322	#endif /* CONFIG_DYNAMIC_FTRACE */
7323
7324	__init void ftrace_init_global_array_ops(struct trace_array *tr)
7325	{
7326	tr->ops = &global_ops;
7327	tr->ops->private = tr;
7328	ftrace_init_trace_array(tr);
7329	}
7330
7331	void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
7332	{
7333	/* If we filter on pids, update to use the pid function */
7334	if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
7335	if (WARN_ON(tr->ops->func != ftrace_stub))
7336	printk("ftrace ops had %pS for function\n",
7337	tr->ops->func);
7338	}
7339	tr->ops->func = func;
7340	tr->ops->private = tr;
7341	}
7342
7343	void ftrace_reset_array_ops(struct trace_array *tr)
7344	{
7345	tr->ops->func = ftrace_stub;
7346	}
7347
7348	static nokprobe_inline void
7349	__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
7350	struct ftrace_ops *ignored, struct ftrace_regs *fregs)
7351	{
7352	struct pt_regs *regs = ftrace_get_regs(fregs);
7353	struct ftrace_ops *op;
7354	int bit;
7355
7356	/*
7357	* The ftrace_test_and_set_recursion() will disable preemption,
7358	* which is required since some of the ops may be dynamically
7359	* allocated, they must be freed after a synchronize_rcu().
7360	*/
7361	bit = trace_test_and_set_recursion(ip, pip: parent_ip, TRACE_LIST_START);
7362	if (bit < 0)
7363	return;
7364
7365	do_for_each_ftrace_op(op, ftrace_ops_list) {
7366	/* Stub functions don't need to be called nor tested */
7367	if (op->flags & FTRACE_OPS_FL_STUB)
7368	continue;
7369	/*
7370	* Check the following for each ops before calling their func:
7371	* if RCU flag is set, then rcu_is_watching() must be true
7372	* Otherwise test if the ip matches the ops filter
7373	*
7374	* If any of the above fails then the op->func() is not executed.
7375	*/
7376	if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
7377	ftrace_ops_test(ops: op, ip, regs)) {
7378	if (FTRACE_WARN_ON(!op->func)) {
7379	pr_warn("op=%p %pS\n", op, op);
7380	goto out;
7381	}
7382	op->func(ip, parent_ip, op, fregs);
7383	}
7384	} while_for_each_ftrace_op(op);
7385	out:
7386	trace_clear_recursion(bit);
7387	}
7388
7389	/*
7390	* Some archs only support passing ip and parent_ip. Even though
7391	* the list function ignores the op parameter, we do not want any
7392	* C side effects, where a function is called without the caller
7393	* sending a third parameter.
7394	* Archs are to support both the regs and ftrace_ops at the same time.
7395	* If they support ftrace_ops, it is assumed they support regs.
7396	* If call backs want to use regs, they must either check for regs
7397	* being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
7398	* Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
7399	* An architecture can pass partial regs with ftrace_ops and still
7400	* set the ARCH_SUPPORTS_FTRACE_OPS.
7401	*
7402	* In vmlinux.lds.h, ftrace_ops_list_func() is defined to be
7403	* arch_ftrace_ops_list_func.
7404	*/
7405	#if ARCH_SUPPORTS_FTRACE_OPS
7406	void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
7407	struct ftrace_ops *op, struct ftrace_regs *fregs)
7408	{
7409	__ftrace_ops_list_func(ip, parent_ip, NULL, fregs);
7410	}
7411	#else
7412	void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
7413	{
7414	__ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
7415	}
7416	#endif
7417	NOKPROBE_SYMBOL(arch_ftrace_ops_list_func);
7418
7419	/*
7420	* If there's only one function registered but it does not support
7421	* recursion, needs RCU protection, then this function will be called
7422	* by the mcount trampoline.
7423	*/
7424	static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
7425	struct ftrace_ops *op, struct ftrace_regs *fregs)
7426	{
7427	int bit;
7428
7429	bit = trace_test_and_set_recursion(ip, pip: parent_ip, TRACE_LIST_START);
7430	if (bit < 0)
7431	return;
7432
7433	if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching())
7434	op->func(ip, parent_ip, op, fregs);
7435
7436	trace_clear_recursion(bit);
7437	}
7438	NOKPROBE_SYMBOL(ftrace_ops_assist_func);
7439
7440	/**
7441	* ftrace_ops_get_func - get the function a trampoline should call
7442	* @ops: the ops to get the function for
7443	*
7444	* Normally the mcount trampoline will call the ops->func, but there
7445	* are times that it should not. For example, if the ops does not
7446	* have its own recursion protection, then it should call the
7447	* ftrace_ops_assist_func() instead.
7448	*
7449	* Returns: the function that the trampoline should call for @ops.
7450	*/
7451	ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
7452	{
7453	/*
7454	* If the function does not handle recursion or needs to be RCU safe,
7455	* then we need to call the assist handler.
7456	*/
7457	if (ops->flags & (FTRACE_OPS_FL_RECURSION |
7458	FTRACE_OPS_FL_RCU))
7459	return ftrace_ops_assist_func;
7460
7461	return ops->func;
7462	}
7463
7464	static void
7465	ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
7466	struct task_struct *prev,
7467	struct task_struct *next,
7468	unsigned int prev_state)
7469	{
7470	struct trace_array *tr = data;
7471	struct trace_pid_list *pid_list;
7472	struct trace_pid_list *no_pid_list;
7473
7474	pid_list = rcu_dereference_sched(tr->function_pids);
7475	no_pid_list = rcu_dereference_sched(tr->function_no_pids);
7476
7477	if (trace_ignore_this_task(filtered_pids: pid_list, filtered_no_pids: no_pid_list, task: next))
7478	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7479	FTRACE_PID_IGNORE);
7480	else
7481	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7482	next->pid);
7483	}
7484
7485	static void
7486	ftrace_pid_follow_sched_process_fork(void *data,
7487	struct task_struct *self,
7488	struct task_struct *task)
7489	{
7490	struct trace_pid_list *pid_list;
7491	struct trace_array *tr = data;
7492
7493	pid_list = rcu_dereference_sched(tr->function_pids);
7494	trace_filter_add_remove_task(pid_list, self, task);
7495
7496	pid_list = rcu_dereference_sched(tr->function_no_pids);
7497	trace_filter_add_remove_task(pid_list, self, task);
7498	}
7499
7500	static void
7501	ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
7502	{
7503	struct trace_pid_list *pid_list;
7504	struct trace_array *tr = data;
7505
7506	pid_list = rcu_dereference_sched(tr->function_pids);
7507	trace_filter_add_remove_task(pid_list, NULL, task);
7508
7509	pid_list = rcu_dereference_sched(tr->function_no_pids);
7510	trace_filter_add_remove_task(pid_list, NULL, task);
7511	}
7512
7513	void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
7514	{
7515	if (enable) {
7516	register_trace_sched_process_fork(probe: ftrace_pid_follow_sched_process_fork,
7517	data: tr);
7518	register_trace_sched_process_free(probe: ftrace_pid_follow_sched_process_exit,
7519	data: tr);
7520	} else {
7521	unregister_trace_sched_process_fork(probe: ftrace_pid_follow_sched_process_fork,
7522	data: tr);
7523	unregister_trace_sched_process_free(probe: ftrace_pid_follow_sched_process_exit,
7524	data: tr);
7525	}
7526	}
7527
7528	static void clear_ftrace_pids(struct trace_array *tr, int type)
7529	{
7530	struct trace_pid_list *pid_list;
7531	struct trace_pid_list *no_pid_list;
7532	int cpu;
7533
7534	pid_list = rcu_dereference_protected(tr->function_pids,
7535	lockdep_is_held(&ftrace_lock));
7536	no_pid_list = rcu_dereference_protected(tr->function_no_pids,
7537	lockdep_is_held(&ftrace_lock));
7538
7539	/* Make sure there's something to do */
7540	if (!pid_type_enabled(type, pid_list, no_pid_list))
7541	return;
7542
7543	/* See if the pids still need to be checked after this */
7544	if (!still_need_pid_events(type, pid_list, no_pid_list)) {
7545	unregister_trace_sched_switch(probe: ftrace_filter_pid_sched_switch_probe, data: tr);
7546	for_each_possible_cpu(cpu)
7547	per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE;
7548	}
7549
7550	if (type & TRACE_PIDS)
7551	rcu_assign_pointer(tr->function_pids, NULL);
7552
7553	if (type & TRACE_NO_PIDS)
7554	rcu_assign_pointer(tr->function_no_pids, NULL);
7555
7556	/* Wait till all users are no longer using pid filtering */
7557	synchronize_rcu();
7558
7559	if ((type & TRACE_PIDS) && pid_list)
7560	trace_pid_list_free(pid_list);
7561
7562	if ((type & TRACE_NO_PIDS) && no_pid_list)
7563	trace_pid_list_free(pid_list: no_pid_list);
7564	}
7565
7566	void ftrace_clear_pids(struct trace_array *tr)
7567	{
7568	mutex_lock(&ftrace_lock);
7569
7570	clear_ftrace_pids(tr, type: TRACE_PIDS | TRACE_NO_PIDS);
7571
7572	mutex_unlock(lock: &ftrace_lock);
7573	}
7574
7575	static void ftrace_pid_reset(struct trace_array *tr, int type)
7576	{
7577	mutex_lock(&ftrace_lock);
7578	clear_ftrace_pids(tr, type);
7579
7580	ftrace_update_pid_func();
7581	ftrace_startup_all(command: 0);
7582
7583	mutex_unlock(lock: &ftrace_lock);
7584	}
7585
7586	/* Greater than any max PID */
7587	#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
7588
7589	static void *fpid_start(struct seq_file *m, loff_t *pos)
7590	__acquires(RCU)
7591	{
7592	struct trace_pid_list *pid_list;
7593	struct trace_array *tr = m->private;
7594
7595	mutex_lock(&ftrace_lock);
7596	rcu_read_lock_sched();
7597
7598	pid_list = rcu_dereference_sched(tr->function_pids);
7599
7600	if (!pid_list)
7601	return !(*pos) ? FTRACE_NO_PIDS : NULL;
7602
7603	return trace_pid_start(pid_list, pos);
7604	}
7605
7606	static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
7607	{
7608	struct trace_array *tr = m->private;
7609	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
7610
7611	if (v == FTRACE_NO_PIDS) {
7612	(*pos)++;
7613	return NULL;
7614	}
7615	return trace_pid_next(pid_list, v, pos);
7616	}
7617
7618	static void fpid_stop(struct seq_file *m, void *p)
7619	__releases(RCU)
7620	{
7621	rcu_read_unlock_sched();
7622	mutex_unlock(lock: &ftrace_lock);
7623	}
7624
7625	static int fpid_show(struct seq_file *m, void *v)
7626	{
7627	if (v == FTRACE_NO_PIDS) {
7628	seq_puts(m, s: "no pid\n");
7629	return 0;
7630	}
7631
7632	return trace_pid_show(m, v);
7633	}
7634
7635	static const struct seq_operations ftrace_pid_sops = {
7636	.start = fpid_start,
7637	.next = fpid_next,
7638	.stop = fpid_stop,
7639	.show = fpid_show,
7640	};
7641
7642	static void *fnpid_start(struct seq_file *m, loff_t *pos)
7643	__acquires(RCU)
7644	{
7645	struct trace_pid_list *pid_list;
7646	struct trace_array *tr = m->private;
7647
7648	mutex_lock(&ftrace_lock);
7649	rcu_read_lock_sched();
7650
7651	pid_list = rcu_dereference_sched(tr->function_no_pids);
7652
7653	if (!pid_list)
7654	return !(*pos) ? FTRACE_NO_PIDS : NULL;
7655
7656	return trace_pid_start(pid_list, pos);
7657	}
7658
7659	static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos)
7660	{
7661	struct trace_array *tr = m->private;
7662	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids);
7663
7664	if (v == FTRACE_NO_PIDS) {
7665	(*pos)++;
7666	return NULL;
7667	}
7668	return trace_pid_next(pid_list, v, pos);
7669	}
7670
7671	static const struct seq_operations ftrace_no_pid_sops = {
7672	.start = fnpid_start,
7673	.next = fnpid_next,
7674	.stop = fpid_stop,
7675	.show = fpid_show,
7676	};
7677
7678	static int pid_open(struct inode *inode, struct file *file, int type)
7679	{
7680	const struct seq_operations *seq_ops;
7681	struct trace_array *tr = inode->i_private;
7682	struct seq_file *m;
7683	int ret = 0;
7684
7685	ret = tracing_check_open_get_tr(tr);
7686	if (ret)
7687	return ret;
7688
7689	if ((file->f_mode & FMODE_WRITE) &&
7690	(file->f_flags & O_TRUNC))
7691	ftrace_pid_reset(tr, type);
7692
7693	switch (type) {
7694	case TRACE_PIDS:
7695	seq_ops = &ftrace_pid_sops;
7696	break;
7697	case TRACE_NO_PIDS:
7698	seq_ops = &ftrace_no_pid_sops;
7699	break;
7700	default:
7701	trace_array_put(tr);
7702	WARN_ON_ONCE(1);
7703	return -EINVAL;
7704	}
7705
7706	ret = seq_open(file, seq_ops);
7707	if (ret < 0) {
7708	trace_array_put(tr);
7709	} else {
7710	m = file->private_data;
7711	/* copy tr over to seq ops */
7712	m->private = tr;
7713	}
7714
7715	return ret;
7716	}
7717
7718	static int
7719	ftrace_pid_open(struct inode *inode, struct file *file)
7720	{
7721	return pid_open(inode, file, type: TRACE_PIDS);
7722	}
7723
7724	static int
7725	ftrace_no_pid_open(struct inode *inode, struct file *file)
7726	{
7727	return pid_open(inode, file, type: TRACE_NO_PIDS);
7728	}
7729
7730	static void ignore_task_cpu(void *data)
7731	{
7732	struct trace_array *tr = data;
7733	struct trace_pid_list *pid_list;
7734	struct trace_pid_list *no_pid_list;
7735
7736	/*
7737	* This function is called by on_each_cpu() while the
7738	* event_mutex is held.
7739	*/
7740	pid_list = rcu_dereference_protected(tr->function_pids,
7741	mutex_is_locked(&ftrace_lock));
7742	no_pid_list = rcu_dereference_protected(tr->function_no_pids,
7743	mutex_is_locked(&ftrace_lock));
7744
7745	if (trace_ignore_this_task(filtered_pids: pid_list, filtered_no_pids: no_pid_list, current))
7746	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7747	FTRACE_PID_IGNORE);
7748	else
7749	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
7750	current->pid);
7751	}
7752
7753	static ssize_t
7754	pid_write(struct file *filp, const char __user *ubuf,
7755	size_t cnt, loff_t *ppos, int type)
7756	{
7757	struct seq_file *m = filp->private_data;
7758	struct trace_array *tr = m->private;
7759	struct trace_pid_list *filtered_pids;
7760	struct trace_pid_list *other_pids;
7761	struct trace_pid_list *pid_list;
7762	ssize_t ret;
7763
7764	if (!cnt)
7765	return 0;
7766
7767	mutex_lock(&ftrace_lock);
7768
7769	switch (type) {
7770	case TRACE_PIDS:
7771	filtered_pids = rcu_dereference_protected(tr->function_pids,
7772	lockdep_is_held(&ftrace_lock));
7773	other_pids = rcu_dereference_protected(tr->function_no_pids,
7774	lockdep_is_held(&ftrace_lock));
7775	break;
7776	case TRACE_NO_PIDS:
7777	filtered_pids = rcu_dereference_protected(tr->function_no_pids,
7778	lockdep_is_held(&ftrace_lock));
7779	other_pids = rcu_dereference_protected(tr->function_pids,
7780	lockdep_is_held(&ftrace_lock));
7781	break;
7782	default:
7783	ret = -EINVAL;
7784	WARN_ON_ONCE(1);
7785	goto out;
7786	}
7787
7788	ret = trace_pid_write(filtered_pids, new_pid_list: &pid_list, ubuf, cnt);
7789	if (ret < 0)
7790	goto out;
7791
7792	switch (type) {
7793	case TRACE_PIDS:
7794	rcu_assign_pointer(tr->function_pids, pid_list);
7795	break;
7796	case TRACE_NO_PIDS:
7797	rcu_assign_pointer(tr->function_no_pids, pid_list);
7798	break;
7799	}
7800
7801
7802	if (filtered_pids) {
7803	synchronize_rcu();
7804	trace_pid_list_free(pid_list: filtered_pids);
7805	} else if (pid_list && !other_pids) {
7806	/* Register a probe to set whether to ignore the tracing of a task */
7807	register_trace_sched_switch(probe: ftrace_filter_pid_sched_switch_probe, data: tr);
7808	}
7809
7810	/*
7811	* Ignoring of pids is done at task switch. But we have to
7812	* check for those tasks that are currently running.
7813	* Always do this in case a pid was appended or removed.
7814	*/
7815	on_each_cpu(func: ignore_task_cpu, info: tr, wait: 1);
7816
7817	ftrace_update_pid_func();
7818	ftrace_startup_all(command: 0);
7819	out:
7820	mutex_unlock(lock: &ftrace_lock);
7821
7822	if (ret > 0)
7823	*ppos += ret;
7824
7825	return ret;
7826	}
7827
7828	static ssize_t
7829	ftrace_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_PIDS);
7833	}
7834
7835	static ssize_t
7836	ftrace_no_pid_write(struct file *filp, const char __user *ubuf,
7837	size_t cnt, loff_t *ppos)
7838	{
7839	return pid_write(filp, ubuf, cnt, ppos, type: TRACE_NO_PIDS);
7840	}
7841
7842	static int
7843	ftrace_pid_release(struct inode *inode, struct file *file)
7844	{
7845	struct trace_array *tr = inode->i_private;
7846
7847	trace_array_put(tr);
7848
7849	return seq_release(inode, file);
7850	}
7851
7852	static const struct file_operations ftrace_pid_fops = {
7853	.open = ftrace_pid_open,
7854	.write = ftrace_pid_write,
7855	.read = seq_read,
7856	.llseek = tracing_lseek,
7857	.release = ftrace_pid_release,
7858	};
7859
7860	static const struct file_operations ftrace_no_pid_fops = {
7861	.open = ftrace_no_pid_open,
7862	.write = ftrace_no_pid_write,
7863	.read = seq_read,
7864	.llseek = tracing_lseek,
7865	.release = ftrace_pid_release,
7866	};
7867
7868	void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
7869	{
7870	trace_create_file(name: "set_ftrace_pid", TRACE_MODE_WRITE, parent: d_tracer,
7871	data: tr, fops: &ftrace_pid_fops);
7872	trace_create_file(name: "set_ftrace_notrace_pid", TRACE_MODE_WRITE,
7873	parent: d_tracer, data: tr, fops: &ftrace_no_pid_fops);
7874	}
7875
7876	void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
7877	struct dentry *d_tracer)
7878	{
7879	/* Only the top level directory has the dyn_tracefs and profile */
7880	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
7881
7882	ftrace_init_dyn_tracefs(d_tracer);
7883	ftrace_profile_tracefs(d_tracer);
7884	}
7885
7886	/**
7887	* ftrace_kill - kill ftrace
7888	*
7889	* This function should be used by panic code. It stops ftrace
7890	* but in a not so nice way. If you need to simply kill ftrace
7891	* from a non-atomic section, use ftrace_kill.
7892	*/
7893	void ftrace_kill(void)
7894	{
7895	ftrace_disabled = 1;
7896	ftrace_enabled = 0;
7897	ftrace_trace_function = ftrace_stub;
7898	}
7899
7900	/**
7901	* ftrace_is_dead - Test if ftrace is dead or not.
7902	*
7903	* Returns: 1 if ftrace is "dead", zero otherwise.
7904	*/
7905	int ftrace_is_dead(void)
7906	{
7907	return ftrace_disabled;
7908	}
7909
7910	#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
7911	/*
7912	* When registering ftrace_ops with IPMODIFY, it is necessary to make sure
7913	* it doesn't conflict with any direct ftrace_ops. If there is existing
7914	* direct ftrace_ops on a kernel function being patched, call
7915	* FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER on it to enable sharing.
7916	*
7917	* @ops: ftrace_ops being registered.
7918	*
7919	* Returns:
7920	* 0 on success;
7921	* Negative on failure.
7922	*/
7923	static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops)
7924	{
7925	struct ftrace_func_entry *entry;
7926	struct ftrace_hash *hash;
7927	struct ftrace_ops *op;
7928	int size, i, ret;
7929
7930	lockdep_assert_held_once(&direct_mutex);
7931
7932	if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
7933	return 0;
7934
7935	hash = ops->func_hash->filter_hash;
7936	size = 1 << hash->size_bits;
7937	for (i = 0; i < size; i++) {
7938	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
7939	unsigned long ip = entry->ip;
7940	bool found_op = false;
7941
7942	mutex_lock(&ftrace_lock);
7943	do_for_each_ftrace_op(op, ftrace_ops_list) {
7944	if (!(op->flags & FTRACE_OPS_FL_DIRECT))
7945	continue;
7946	if (ops_references_ip(ops: op, ip)) {
7947	found_op = true;
7948	break;
7949	}
7950	} while_for_each_ftrace_op(op);
7951	mutex_unlock(lock: &ftrace_lock);
7952
7953	if (found_op) {
7954	if (!op->ops_func)
7955	return -EBUSY;
7956
7957	ret = op->ops_func(op, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER);
7958	if (ret)
7959	return ret;
7960	}
7961	}
7962	}
7963
7964	return 0;
7965	}
7966
7967	/*
7968	* Similar to prepare_direct_functions_for_ipmodify, clean up after ops
7969	* with IPMODIFY is unregistered. The cleanup is optional for most DIRECT
7970	* ops.
7971	*/
7972	static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
7973	{
7974	struct ftrace_func_entry *entry;
7975	struct ftrace_hash *hash;
7976	struct ftrace_ops *op;
7977	int size, i;
7978
7979	if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
7980	return;
7981
7982	mutex_lock(&direct_mutex);
7983
7984	hash = ops->func_hash->filter_hash;
7985	size = 1 << hash->size_bits;
7986	for (i = 0; i < size; i++) {
7987	hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
7988	unsigned long ip = entry->ip;
7989	bool found_op = false;
7990
7991	mutex_lock(&ftrace_lock);
7992	do_for_each_ftrace_op(op, ftrace_ops_list) {
7993	if (!(op->flags & FTRACE_OPS_FL_DIRECT))
7994	continue;
7995	if (ops_references_ip(ops: op, ip)) {
7996	found_op = true;
7997	break;
7998	}
7999	} while_for_each_ftrace_op(op);
8000	mutex_unlock(lock: &ftrace_lock);
8001
8002	/* The cleanup is optional, ignore any errors */
8003	if (found_op && op->ops_func)
8004	op->ops_func(op, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER);
8005	}
8006	}
8007	mutex_unlock(lock: &direct_mutex);
8008	}
8009
8010	#define lock_direct_mutex() mutex_lock(&direct_mutex)
8011	#define unlock_direct_mutex() mutex_unlock(&direct_mutex)
8012
8013	#else /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
8014
8015	static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops)
8016	{
8017	return 0;
8018	}
8019
8020	static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops)
8021	{
8022	}
8023
8024	#define lock_direct_mutex() do { } while (0)
8025	#define unlock_direct_mutex() do { } while (0)
8026
8027	#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
8028
8029	/*
8030	* Similar to register_ftrace_function, except we don't lock direct_mutex.
8031	*/
8032	static int register_ftrace_function_nolock(struct ftrace_ops *ops)
8033	{
8034	int ret;
8035
8036	ftrace_ops_init(ops);
8037
8038	mutex_lock(&ftrace_lock);
8039
8040	ret = ftrace_startup(ops, command: 0);
8041
8042	mutex_unlock(lock: &ftrace_lock);
8043
8044	return ret;
8045	}
8046
8047	/**
8048	* register_ftrace_function - register a function for profiling
8049	* @ops: ops structure that holds the function for profiling.
8050	*
8051	* Register a function to be called by all functions in the
8052	* kernel.
8053	*
8054	* Note: @ops->func and all the functions it calls must be labeled
8055	* with "notrace", otherwise it will go into a
8056	* recursive loop.
8057	*/
8058	int register_ftrace_function(struct ftrace_ops *ops)
8059	{
8060	int ret;
8061
8062	lock_direct_mutex();
8063	ret = prepare_direct_functions_for_ipmodify(ops);
8064	if (ret < 0)
8065	goto out_unlock;
8066
8067	ret = register_ftrace_function_nolock(ops);
8068
8069	out_unlock:
8070	unlock_direct_mutex();
8071	return ret;
8072	}
8073	EXPORT_SYMBOL_GPL(register_ftrace_function);
8074
8075	/**
8076	* unregister_ftrace_function - unregister a function for profiling.
8077	* @ops: ops structure that holds the function to unregister
8078	*
8079	* Unregister a function that was added to be called by ftrace profiling.
8080	*/
8081	int unregister_ftrace_function(struct ftrace_ops *ops)
8082	{
8083	int ret;
8084
8085	mutex_lock(&ftrace_lock);
8086	ret = ftrace_shutdown(ops, command: 0);
8087	mutex_unlock(lock: &ftrace_lock);
8088
8089	cleanup_direct_functions_after_ipmodify(ops);
8090	return ret;
8091	}
8092	EXPORT_SYMBOL_GPL(unregister_ftrace_function);
8093
8094	static int symbols_cmp(const void *a, const void *b)
8095	{
8096	const char **str_a = (const char **) a;
8097	const char **str_b = (const char **) b;
8098
8099	return strcmp(*str_a, *str_b);
8100	}
8101
8102	struct kallsyms_data {
8103	unsigned long *addrs;
8104	const char **syms;
8105	size_t cnt;
8106	size_t found;
8107	};
8108
8109	/* This function gets called for all kernel and module symbols
8110	* and returns 1 in case we resolved all the requested symbols,
8111	* 0 otherwise.
8112	*/
8113	static int kallsyms_callback(void *data, const char *name, unsigned long addr)
8114	{
8115	struct kallsyms_data *args = data;
8116	const char **sym;
8117	int idx;
8118
8119	sym = bsearch(key: &name, base: args->syms, num: args->cnt, size: sizeof(*args->syms), cmp: symbols_cmp);
8120	if (!sym)
8121	return 0;
8122
8123	idx = sym - args->syms;
8124	if (args->addrs[idx])
8125	return 0;
8126
8127	if (!ftrace_location(ip: addr))
8128	return 0;
8129
8130	args->addrs[idx] = addr;
8131	args->found++;
8132	return args->found == args->cnt ? 1 : 0;
8133	}
8134
8135	/**
8136	* ftrace_lookup_symbols - Lookup addresses for array of symbols
8137	*
8138	* @sorted_syms: array of symbols pointers symbols to resolve,
8139	* must be alphabetically sorted
8140	* @cnt: number of symbols/addresses in @syms/@addrs arrays
8141	* @addrs: array for storing resulting addresses
8142	*
8143	* This function looks up addresses for array of symbols provided in
8144	* @syms array (must be alphabetically sorted) and stores them in
8145	* @addrs array, which needs to be big enough to store at least @cnt
8146	* addresses.
8147	*
8148	* Returns: 0 if all provided symbols are found, -ESRCH otherwise.
8149	*/
8150	int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
8151	{
8152	struct kallsyms_data args;
8153	int found_all;
8154
8155	memset(addrs, 0, sizeof(*addrs) * cnt);
8156	args.addrs = addrs;
8157	args.syms = sorted_syms;
8158	args.cnt = cnt;
8159	args.found = 0;
8160
8161	found_all = kallsyms_on_each_symbol(fn: kallsyms_callback, data: &args);
8162	if (found_all)
8163	return 0;
8164	found_all = module_kallsyms_on_each_symbol(NULL, fn: kallsyms_callback, data: &args);
8165	return found_all ? 0 : -ESRCH;
8166	}
8167
8168	#ifdef CONFIG_SYSCTL
8169
8170	#ifdef CONFIG_DYNAMIC_FTRACE
8171	static void ftrace_startup_sysctl(void)
8172	{
8173	int command;
8174
8175	if (unlikely(ftrace_disabled))
8176	return;
8177
8178	/* Force update next time */
8179	saved_ftrace_func = NULL;
8180	/* ftrace_start_up is true if we want ftrace running */
8181	if (ftrace_start_up) {
8182	command = FTRACE_UPDATE_CALLS;
8183	if (ftrace_graph_active)
8184	command |= FTRACE_START_FUNC_RET;
8185	ftrace_startup_enable(command);
8186	}
8187	}
8188
8189	static void ftrace_shutdown_sysctl(void)
8190	{
8191	int command;
8192
8193	if (unlikely(ftrace_disabled))
8194	return;
8195
8196	/* ftrace_start_up is true if ftrace is running */
8197	if (ftrace_start_up) {
8198	command = FTRACE_DISABLE_CALLS;
8199	if (ftrace_graph_active)
8200	command |= FTRACE_STOP_FUNC_RET;
8201	ftrace_run_update_code(command);
8202	}
8203	}
8204	#else
8205	# define ftrace_startup_sysctl() do { } while (0)
8206	# define ftrace_shutdown_sysctl() do { } while (0)
8207	#endif /* CONFIG_DYNAMIC_FTRACE */
8208
8209	static bool is_permanent_ops_registered(void)
8210	{
8211	struct ftrace_ops *op;
8212
8213	do_for_each_ftrace_op(op, ftrace_ops_list) {
8214	if (op->flags & FTRACE_OPS_FL_PERMANENT)
8215	return true;
8216	} while_for_each_ftrace_op(op);
8217
8218	return false;
8219	}
8220
8221	static int
8222	ftrace_enable_sysctl(struct ctl_table *table, int write,
8223	void *buffer, size_t *lenp, loff_t *ppos)
8224	{
8225	int ret = -ENODEV;
8226
8227	mutex_lock(&ftrace_lock);
8228
8229	if (unlikely(ftrace_disabled))
8230	goto out;
8231
8232	ret = proc_dointvec(table, write, buffer, lenp, ppos);
8233
8234	if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
8235	goto out;
8236
8237	if (ftrace_enabled) {
8238
8239	/* we are starting ftrace again */
8240	if (rcu_dereference_protected(ftrace_ops_list,
8241	lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
8242	update_ftrace_function();
8243
8244	ftrace_startup_sysctl();
8245
8246	} else {
8247	if (is_permanent_ops_registered()) {
8248	ftrace_enabled = true;
8249	ret = -EBUSY;
8250	goto out;
8251	}
8252
8253	/* stopping ftrace calls (just send to ftrace_stub) */
8254	ftrace_trace_function = ftrace_stub;
8255
8256	ftrace_shutdown_sysctl();
8257	}
8258
8259	last_ftrace_enabled = !!ftrace_enabled;
8260	out:
8261	mutex_unlock(lock: &ftrace_lock);
8262	return ret;
8263	}
8264
8265	static struct ctl_table ftrace_sysctls[] = {
8266	{
8267	.procname = "ftrace_enabled",
8268	.data = &ftrace_enabled,
8269	.maxlen = sizeof(int),
8270	.mode = 0644,
8271	.proc_handler = ftrace_enable_sysctl,
8272	},
8273	{}
8274	};
8275
8276	static int __init ftrace_sysctl_init(void)
8277	{
8278	register_sysctl_init("kernel", ftrace_sysctls);
8279	return 0;
8280	}
8281	late_initcall(ftrace_sysctl_init);
8282	#endif
8283