1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Kprobes-based tracing events
   4 *
   5 * Created by Masami Hiramatsu <mhiramat@redhat.com>
   6 *
   7 */
   8#define pr_fmt(fmt)	"trace_kprobe: " fmt
   9
  10#include <linux/bpf-cgroup.h>
  11#include <linux/security.h>
  12#include <linux/module.h>
  13#include <linux/uaccess.h>
  14#include <linux/rculist.h>
  15#include <linux/error-injection.h>
  16
  17#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  18
  19#include "trace_dynevent.h"
  20#include "trace_kprobe_selftest.h"
  21#include "trace_probe.h"
  22#include "trace_probe_tmpl.h"
  23#include "trace_probe_kernel.h"
  24
  25#define KPROBE_EVENT_SYSTEM "kprobes"
  26#define KRETPROBE_MAXACTIVE_MAX 4096
  27
  28/* Kprobe early definition from command line */
  29static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
  30
  31static int __init set_kprobe_boot_events(char *str)
  32{
  33	strscpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
  34	disable_tracing_selftest("running kprobe events");
  35
  36	return 1;
  37}
  38__setup("kprobe_event=", set_kprobe_boot_events);
  39
  40static int trace_kprobe_create(const char *raw_command);
  41static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
  42static int trace_kprobe_release(struct dyn_event *ev);
  43static bool trace_kprobe_is_busy(struct dyn_event *ev);
  44static bool trace_kprobe_match(const char *system, const char *event,
  45			int argc, const char **argv, struct dyn_event *ev);
  46
  47static struct dyn_event_operations trace_kprobe_ops = {
  48	.create = trace_kprobe_create,
  49	.show = trace_kprobe_show,
  50	.is_busy = trace_kprobe_is_busy,
  51	.free = trace_kprobe_release,
  52	.match = trace_kprobe_match,
  53};
  54
  55/*
  56 * Kprobe event core functions
  57 */
  58struct trace_kprobe {
  59	struct dyn_event	devent;
  60	struct kretprobe	rp;	/* Use rp.kp for kprobe use */
  61	unsigned long __percpu *nhit;
  62	const char		*symbol;	/* symbol name */
  63	struct trace_probe	tp;
  64};
  65
  66static bool is_trace_kprobe(struct dyn_event *ev)
  67{
  68	return ev->ops == &trace_kprobe_ops;
  69}
  70
  71static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
  72{
  73	return container_of(ev, struct trace_kprobe, devent);
  74}
  75
  76/**
  77 * for_each_trace_kprobe - iterate over the trace_kprobe list
  78 * @pos:	the struct trace_kprobe * for each entry
  79 * @dpos:	the struct dyn_event * to use as a loop cursor
  80 */
  81#define for_each_trace_kprobe(pos, dpos)	\
  82	for_each_dyn_event(dpos)		\
  83		if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
  84
  85static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
  86{
  87	return tk->rp.handler != NULL;
  88}
  89
  90static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
  91{
  92	return tk->symbol ? tk->symbol : "unknown";
  93}
  94
  95static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
  96{
  97	return tk->rp.kp.offset;
  98}
  99
 100static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
 101{
 102	return kprobe_gone(&tk->rp.kp);
 103}
 104
 105static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
 106						 struct module *mod)
 107{
 108	int len = strlen(module_name(mod));
 109	const char *name = trace_kprobe_symbol(tk);
 110
 111	return strncmp(module_name(mod), name, len) == 0 && name[len] == ':';
 112}
 113
 114static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
 115{
 116	char *p;
 117	bool ret;
 118
 119	if (!tk->symbol)
 120		return false;
 121	p = strchr(tk->symbol, ':');
 122	if (!p)
 123		return true;
 124	*p = '\0';
 125	rcu_read_lock_sched();
 126	ret = !!find_module(tk->symbol);
 127	rcu_read_unlock_sched();
 128	*p = ':';
 129
 130	return ret;
 131}
 132
 133static bool trace_kprobe_is_busy(struct dyn_event *ev)
 134{
 135	struct trace_kprobe *tk = to_trace_kprobe(ev);
 136
 137	return trace_probe_is_enabled(&tk->tp);
 138}
 139
 140static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
 141					    int argc, const char **argv)
 142{
 143	char buf[MAX_ARGSTR_LEN + 1];
 144
 145	if (!argc)
 146		return true;
 147
 148	if (!tk->symbol)
 149		snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr);
 150	else if (tk->rp.kp.offset)
 151		snprintf(buf, sizeof(buf), "%s+%u",
 152			 trace_kprobe_symbol(tk), tk->rp.kp.offset);
 153	else
 154		snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk));
 155	if (strcmp(buf, argv[0]))
 156		return false;
 157	argc--; argv++;
 158
 159	return trace_probe_match_command_args(&tk->tp, argc, argv);
 160}
 161
 162static bool trace_kprobe_match(const char *system, const char *event,
 163			int argc, const char **argv, struct dyn_event *ev)
 164{
 165	struct trace_kprobe *tk = to_trace_kprobe(ev);
 166
 167	return (event[0] == '\0' ||
 168		strcmp(trace_probe_name(&tk->tp), event) == 0) &&
 169	    (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
 170	    trace_kprobe_match_command_head(tk, argc, argv);
 171}
 172
 173static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
 174{
 175	unsigned long nhit = 0;
 176	int cpu;
 177
 178	for_each_possible_cpu(cpu)
 179		nhit += *per_cpu_ptr(tk->nhit, cpu);
 180
 181	return nhit;
 182}
 183
 184static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk)
 185{
 186	return !(list_empty(&tk->rp.kp.list) &&
 187		 hlist_unhashed(&tk->rp.kp.hlist));
 188}
 189
 190/* Return 0 if it fails to find the symbol address */
 191static nokprobe_inline
 192unsigned long trace_kprobe_address(struct trace_kprobe *tk)
 193{
 194	unsigned long addr;
 195
 196	if (tk->symbol) {
 197		addr = (unsigned long)
 198			kallsyms_lookup_name(trace_kprobe_symbol(tk));
 199		if (addr)
 200			addr += tk->rp.kp.offset;
 201	} else {
 202		addr = (unsigned long)tk->rp.kp.addr;
 203	}
 204	return addr;
 205}
 206
 207static nokprobe_inline struct trace_kprobe *
 208trace_kprobe_primary_from_call(struct trace_event_call *call)
 209{
 210	struct trace_probe *tp;
 211
 212	tp = trace_probe_primary_from_call(call);
 213	if (WARN_ON_ONCE(!tp))
 214		return NULL;
 215
 216	return container_of(tp, struct trace_kprobe, tp);
 217}
 218
 219bool trace_kprobe_on_func_entry(struct trace_event_call *call)
 220{
 221	struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
 222
 223	return tk ? (kprobe_on_func_entry(tk->rp.kp.addr,
 224			tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
 225			tk->rp.kp.addr ? 0 : tk->rp.kp.offset) == 0) : false;
 226}
 227
 228bool trace_kprobe_error_injectable(struct trace_event_call *call)
 229{
 230	struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
 231
 232	return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
 233	       false;
 234}
 235
 236static int register_kprobe_event(struct trace_kprobe *tk);
 237static int unregister_kprobe_event(struct trace_kprobe *tk);
 238
 239static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 240static int kretprobe_dispatcher(struct kretprobe_instance *ri,
 241				struct pt_regs *regs);
 242
 243static void free_trace_kprobe(struct trace_kprobe *tk)
 244{
 245	if (tk) {
 246		trace_probe_cleanup(&tk->tp);
 247		kfree(tk->symbol);
 248		free_percpu(tk->nhit);
 249		kfree(tk);
 250	}
 251}
 252
 253/*
 254 * Allocate new trace_probe and initialize it (including kprobes).
 255 */
 256static struct trace_kprobe *alloc_trace_kprobe(const char *group,
 257					     const char *event,
 258					     void *addr,
 259					     const char *symbol,
 260					     unsigned long offs,
 261					     int maxactive,
 262					     int nargs, bool is_return)
 263{
 264	struct trace_kprobe *tk;
 265	int ret = -ENOMEM;
 266
 267	tk = kzalloc(struct_size(tk, tp.args, nargs), GFP_KERNEL);
 268	if (!tk)
 269		return ERR_PTR(ret);
 270
 271	tk->nhit = alloc_percpu(unsigned long);
 272	if (!tk->nhit)
 273		goto error;
 274
 275	if (symbol) {
 276		tk->symbol = kstrdup(symbol, GFP_KERNEL);
 277		if (!tk->symbol)
 278			goto error;
 279		tk->rp.kp.symbol_name = tk->symbol;
 280		tk->rp.kp.offset = offs;
 281	} else
 282		tk->rp.kp.addr = addr;
 283
 284	if (is_return)
 285		tk->rp.handler = kretprobe_dispatcher;
 286	else
 287		tk->rp.kp.pre_handler = kprobe_dispatcher;
 288
 289	tk->rp.maxactive = maxactive;
 290	INIT_HLIST_NODE(&tk->rp.kp.hlist);
 291	INIT_LIST_HEAD(&tk->rp.kp.list);
 292
 293	ret = trace_probe_init(&tk->tp, event, group, false, nargs);
 294	if (ret < 0)
 295		goto error;
 296
 297	dyn_event_init(&tk->devent, &trace_kprobe_ops);
 298	return tk;
 299error:
 300	free_trace_kprobe(tk);
 301	return ERR_PTR(ret);
 302}
 303
 304static struct trace_kprobe *find_trace_kprobe(const char *event,
 305					      const char *group)
 306{
 307	struct dyn_event *pos;
 308	struct trace_kprobe *tk;
 309
 310	for_each_trace_kprobe(tk, pos)
 311		if (strcmp(trace_probe_name(&tk->tp), event) == 0 &&
 312		    strcmp(trace_probe_group_name(&tk->tp), group) == 0)
 313			return tk;
 314	return NULL;
 315}
 316
 317static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
 318{
 319	int ret = 0;
 320
 321	if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) {
 322		if (trace_kprobe_is_return(tk))
 323			ret = enable_kretprobe(&tk->rp);
 324		else
 325			ret = enable_kprobe(&tk->rp.kp);
 326	}
 327
 328	return ret;
 329}
 330
 331static void __disable_trace_kprobe(struct trace_probe *tp)
 332{
 333	struct trace_kprobe *tk;
 334
 335	list_for_each_entry(tk, trace_probe_probe_list(tp), tp.list) {
 336		if (!trace_kprobe_is_registered(tk))
 337			continue;
 338		if (trace_kprobe_is_return(tk))
 339			disable_kretprobe(&tk->rp);
 340		else
 341			disable_kprobe(&tk->rp.kp);
 342	}
 343}
 344
 345/*
 346 * Enable trace_probe
 347 * if the file is NULL, enable "perf" handler, or enable "trace" handler.
 348 */
 349static int enable_trace_kprobe(struct trace_event_call *call,
 350				struct trace_event_file *file)
 351{
 352	struct trace_probe *tp;
 353	struct trace_kprobe *tk;
 354	bool enabled;
 355	int ret = 0;
 356
 357	tp = trace_probe_primary_from_call(call);
 358	if (WARN_ON_ONCE(!tp))
 359		return -ENODEV;
 360	enabled = trace_probe_is_enabled(tp);
 361
 362	/* This also changes "enabled" state */
 363	if (file) {
 364		ret = trace_probe_add_file(tp, file);
 365		if (ret)
 366			return ret;
 367	} else
 368		trace_probe_set_flag(tp, TP_FLAG_PROFILE);
 369
 370	if (enabled)
 371		return 0;
 372
 373	list_for_each_entry(tk, trace_probe_probe_list(tp), tp.list) {
 374		if (trace_kprobe_has_gone(tk))
 375			continue;
 376		ret = __enable_trace_kprobe(tk);
 377		if (ret)
 378			break;
 379		enabled = true;
 380	}
 381
 382	if (ret) {
 383		/* Failed to enable one of them. Roll back all */
 384		if (enabled)
 385			__disable_trace_kprobe(tp);
 386		if (file)
 387			trace_probe_remove_file(tp, file);
 388		else
 389			trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
 390	}
 391
 392	return ret;
 393}
 394
 395/*
 396 * Disable trace_probe
 397 * if the file is NULL, disable "perf" handler, or disable "trace" handler.
 398 */
 399static int disable_trace_kprobe(struct trace_event_call *call,
 400				struct trace_event_file *file)
 401{
 402	struct trace_probe *tp;
 403
 404	tp = trace_probe_primary_from_call(call);
 405	if (WARN_ON_ONCE(!tp))
 406		return -ENODEV;
 407
 408	if (file) {
 409		if (!trace_probe_get_file_link(tp, file))
 410			return -ENOENT;
 411		if (!trace_probe_has_single_file(tp))
 412			goto out;
 413		trace_probe_clear_flag(tp, TP_FLAG_TRACE);
 414	} else
 415		trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
 416
 417	if (!trace_probe_is_enabled(tp))
 418		__disable_trace_kprobe(tp);
 419
 420 out:
 421	if (file)
 422		/*
 423		 * Synchronization is done in below function. For perf event,
 424		 * file == NULL and perf_trace_event_unreg() calls
 425		 * tracepoint_synchronize_unregister() to ensure synchronize
 426		 * event. We don't need to care about it.
 427		 */
 428		trace_probe_remove_file(tp, file);
 429
 430	return 0;
 431}
 432
 433#if defined(CONFIG_DYNAMIC_FTRACE) && \
 434	!defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
 435static bool __within_notrace_func(unsigned long addr)
 436{
 437	unsigned long offset, size;
 438
 439	if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
 440		return false;
 441
 442	/* Get the entry address of the target function */
 443	addr -= offset;
 444
 445	/*
 446	 * Since ftrace_location_range() does inclusive range check, we need
 447	 * to subtract 1 byte from the end address.
 448	 */
 449	return !ftrace_location_range(addr, addr + size - 1);
 450}
 451
 452static bool within_notrace_func(struct trace_kprobe *tk)
 453{
 454	unsigned long addr = trace_kprobe_address(tk);
 455	char symname[KSYM_NAME_LEN], *p;
 456
 457	if (!__within_notrace_func(addr))
 458		return false;
 459
 460	/* Check if the address is on a suffixed-symbol */
 461	if (!lookup_symbol_name(addr, symname)) {
 462		p = strchr(symname, '.');
 463		if (!p)
 464			return true;
 465		*p = '\0';
 466		addr = (unsigned long)kprobe_lookup_name(symname, 0);
 467		if (addr)
 468			return __within_notrace_func(addr);
 469	}
 470
 471	return true;
 472}
 473#else
 474#define within_notrace_func(tk)	(false)
 475#endif
 476
 477/* Internal register function - just handle k*probes and flags */
 478static int __register_trace_kprobe(struct trace_kprobe *tk)
 479{
 480	int i, ret;
 481
 482	ret = security_locked_down(LOCKDOWN_KPROBES);
 483	if (ret)
 484		return ret;
 485
 486	if (trace_kprobe_is_registered(tk))
 487		return -EINVAL;
 488
 489	if (within_notrace_func(tk)) {
 490		pr_warn("Could not probe notrace function %ps\n",
 491			(void *)trace_kprobe_address(tk));
 492		return -EINVAL;
 493	}
 494
 495	for (i = 0; i < tk->tp.nr_args; i++) {
 496		ret = traceprobe_update_arg(&tk->tp.args[i]);
 497		if (ret)
 498			return ret;
 499	}
 500
 501	/* Set/clear disabled flag according to tp->flag */
 502	if (trace_probe_is_enabled(&tk->tp))
 503		tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
 504	else
 505		tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
 506
 507	if (trace_kprobe_is_return(tk))
 508		ret = register_kretprobe(&tk->rp);
 509	else
 510		ret = register_kprobe(&tk->rp.kp);
 511
 512	return ret;
 513}
 514
 515/* Internal unregister function - just handle k*probes and flags */
 516static void __unregister_trace_kprobe(struct trace_kprobe *tk)
 517{
 518	if (trace_kprobe_is_registered(tk)) {
 519		if (trace_kprobe_is_return(tk))
 520			unregister_kretprobe(&tk->rp);
 521		else
 522			unregister_kprobe(&tk->rp.kp);
 523		/* Cleanup kprobe for reuse and mark it unregistered */
 524		INIT_HLIST_NODE(&tk->rp.kp.hlist);
 525		INIT_LIST_HEAD(&tk->rp.kp.list);
 526		if (tk->rp.kp.symbol_name)
 527			tk->rp.kp.addr = NULL;
 528	}
 529}
 530
 531/* Unregister a trace_probe and probe_event */
 532static int unregister_trace_kprobe(struct trace_kprobe *tk)
 533{
 534	/* If other probes are on the event, just unregister kprobe */
 535	if (trace_probe_has_sibling(&tk->tp))
 536		goto unreg;
 537
 538	/* Enabled event can not be unregistered */
 539	if (trace_probe_is_enabled(&tk->tp))
 540		return -EBUSY;
 541
 542	/* If there's a reference to the dynamic event */
 543	if (trace_event_dyn_busy(trace_probe_event_call(&tk->tp)))
 544		return -EBUSY;
 545
 546	/* Will fail if probe is being used by ftrace or perf */
 547	if (unregister_kprobe_event(tk))
 548		return -EBUSY;
 549
 550unreg:
 551	__unregister_trace_kprobe(tk);
 552	dyn_event_remove(&tk->devent);
 553	trace_probe_unlink(&tk->tp);
 554
 555	return 0;
 556}
 557
 558static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
 559					 struct trace_kprobe *comp)
 560{
 561	struct trace_probe_event *tpe = orig->tp.event;
 562	int i;
 563
 564	list_for_each_entry(orig, &tpe->probes, tp.list) {
 565		if (strcmp(trace_kprobe_symbol(orig),
 566			   trace_kprobe_symbol(comp)) ||
 567		    trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
 568			continue;
 569
 570		/*
 571		 * trace_probe_compare_arg_type() ensured that nr_args and
 572		 * each argument name and type are same. Let's compare comm.
 573		 */
 574		for (i = 0; i < orig->tp.nr_args; i++) {
 575			if (strcmp(orig->tp.args[i].comm,
 576				   comp->tp.args[i].comm))
 577				break;
 578		}
 579
 580		if (i == orig->tp.nr_args)
 581			return true;
 582	}
 583
 584	return false;
 585}
 586
 587static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
 588{
 589	int ret;
 590
 591	ret = trace_probe_compare_arg_type(&tk->tp, &to->tp);
 592	if (ret) {
 593		/* Note that argument starts index = 2 */
 594		trace_probe_log_set_index(ret + 1);
 595		trace_probe_log_err(0, DIFF_ARG_TYPE);
 596		return -EEXIST;
 597	}
 598	if (trace_kprobe_has_same_kprobe(to, tk)) {
 599		trace_probe_log_set_index(0);
 600		trace_probe_log_err(0, SAME_PROBE);
 601		return -EEXIST;
 602	}
 603
 604	/* Append to existing event */
 605	ret = trace_probe_append(&tk->tp, &to->tp);
 606	if (ret)
 607		return ret;
 608
 609	/* Register k*probe */
 610	ret = __register_trace_kprobe(tk);
 611	if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
 612		pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
 613		ret = 0;
 614	}
 615
 616	if (ret)
 617		trace_probe_unlink(&tk->tp);
 618	else
 619		dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp));
 620
 621	return ret;
 622}
 623
 624/* Register a trace_probe and probe_event */
 625static int register_trace_kprobe(struct trace_kprobe *tk)
 626{
 627	struct trace_kprobe *old_tk;
 628	int ret;
 629
 630	mutex_lock(&event_mutex);
 631
 632	old_tk = find_trace_kprobe(trace_probe_name(&tk->tp),
 633				   trace_probe_group_name(&tk->tp));
 634	if (old_tk) {
 635		if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) {
 636			trace_probe_log_set_index(0);
 637			trace_probe_log_err(0, DIFF_PROBE_TYPE);
 638			ret = -EEXIST;
 639		} else {
 640			ret = append_trace_kprobe(tk, old_tk);
 641		}
 642		goto end;
 643	}
 644
 645	/* Register new event */
 646	ret = register_kprobe_event(tk);
 647	if (ret) {
 648		if (ret == -EEXIST) {
 649			trace_probe_log_set_index(0);
 650			trace_probe_log_err(0, EVENT_EXIST);
 651		} else
 652			pr_warn("Failed to register probe event(%d)\n", ret);
 653		goto end;
 654	}
 655
 656	/* Register k*probe */
 657	ret = __register_trace_kprobe(tk);
 658	if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
 659		pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
 660		ret = 0;
 661	}
 662
 663	if (ret < 0)
 664		unregister_kprobe_event(tk);
 665	else
 666		dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp));
 667
 668end:
 669	mutex_unlock(&event_mutex);
 670	return ret;
 671}
 672
 673/* Module notifier call back, checking event on the module */
 674static int trace_kprobe_module_callback(struct notifier_block *nb,
 675				       unsigned long val, void *data)
 676{
 677	struct module *mod = data;
 678	struct dyn_event *pos;
 679	struct trace_kprobe *tk;
 680	int ret;
 681
 682	if (val != MODULE_STATE_COMING)
 683		return NOTIFY_DONE;
 684
 685	/* Update probes on coming module */
 686	mutex_lock(&event_mutex);
 687	for_each_trace_kprobe(tk, pos) {
 688		if (trace_kprobe_within_module(tk, mod)) {
 689			/* Don't need to check busy - this should have gone. */
 690			__unregister_trace_kprobe(tk);
 691			ret = __register_trace_kprobe(tk);
 692			if (ret)
 693				pr_warn("Failed to re-register probe %s on %s: %d\n",
 694					trace_probe_name(&tk->tp),
 695					module_name(mod), ret);
 696		}
 697	}
 698	mutex_unlock(&event_mutex);
 699
 700	return NOTIFY_DONE;
 701}
 702
 703static struct notifier_block trace_kprobe_module_nb = {
 704	.notifier_call = trace_kprobe_module_callback,
 705	.priority = 1	/* Invoked after kprobe module callback */
 706};
 707
 708static int count_symbols(void *data, unsigned long unused)
 709{
 710	unsigned int *count = data;
 711
 712	(*count)++;
 713
 714	return 0;
 715}
 716
 717struct sym_count_ctx {
 718	unsigned int count;
 719	const char *name;
 720};
 721
 722static int count_mod_symbols(void *data, const char *name, unsigned long unused)
 723{
 724	struct sym_count_ctx *ctx = data;
 725
 726	if (strcmp(name, ctx->name) == 0)
 727		ctx->count++;
 728
 729	return 0;
 730}
 731
 732static unsigned int number_of_same_symbols(char *func_name)
 733{
 734	struct sym_count_ctx ctx = { .count = 0, .name = func_name };
 735
 736	kallsyms_on_each_match_symbol(count_symbols, func_name, &ctx.count);
 737
 738	module_kallsyms_on_each_symbol(NULL, count_mod_symbols, &ctx);
 739
 740	return ctx.count;
 741}
 742
 743static int trace_kprobe_entry_handler(struct kretprobe_instance *ri,
 744				      struct pt_regs *regs);
 745
 746static int __trace_kprobe_create(int argc, const char *argv[])
 747{
 748	/*
 749	 * Argument syntax:
 750	 *  - Add kprobe:
 751	 *      p[:[GRP/][EVENT]] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
 752	 *  - Add kretprobe:
 753	 *      r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]KSYM[+0] [FETCHARGS]
 754	 *    Or
 755	 *      p[:[GRP/][EVENT]] [MOD:]KSYM[+0]%return [FETCHARGS]
 756	 *
 757	 * Fetch args:
 758	 *  $retval	: fetch return value
 759	 *  $stack	: fetch stack address
 760	 *  $stackN	: fetch Nth of stack (N:0-)
 761	 *  $comm       : fetch current task comm
 762	 *  @ADDR	: fetch memory at ADDR (ADDR should be in kernel)
 763	 *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
 764	 *  %REG	: fetch register REG
 765	 * Dereferencing memory fetch:
 766	 *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
 767	 * Alias name of args:
 768	 *  NAME=FETCHARG : set NAME as alias of FETCHARG.
 769	 * Type of args:
 770	 *  FETCHARG:TYPE : use TYPE instead of unsigned long.
 771	 */
 772	struct trace_kprobe *tk = NULL;
 773	int i, len, new_argc = 0, ret = 0;
 774	bool is_return = false;
 775	char *symbol = NULL, *tmp = NULL;
 776	const char **new_argv = NULL;
 777	const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
 778	enum probe_print_type ptype;
 779	int maxactive = 0;
 780	long offset = 0;
 781	void *addr = NULL;
 782	char buf[MAX_EVENT_NAME_LEN];
 783	char gbuf[MAX_EVENT_NAME_LEN];
 784	char abuf[MAX_BTF_ARGS_LEN];
 785	struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL };
 786
 787	switch (argv[0][0]) {
 788	case 'r':
 789		is_return = true;
 790		break;
 791	case 'p':
 792		break;
 793	default:
 794		return -ECANCELED;
 795	}
 796	if (argc < 2)
 797		return -ECANCELED;
 798
 799	trace_probe_log_init("trace_kprobe", argc, argv);
 800
 801	event = strchr(&argv[0][1], ':');
 802	if (event)
 803		event++;
 804
 805	if (isdigit(argv[0][1])) {
 806		if (!is_return) {
 807			trace_probe_log_err(1, BAD_MAXACT_TYPE);
 808			goto parse_error;
 809		}
 810		if (event)
 811			len = event - &argv[0][1] - 1;
 812		else
 813			len = strlen(&argv[0][1]);
 814		if (len > MAX_EVENT_NAME_LEN - 1) {
 815			trace_probe_log_err(1, BAD_MAXACT);
 816			goto parse_error;
 817		}
 818		memcpy(buf, &argv[0][1], len);
 819		buf[len] = '\0';
 820		ret = kstrtouint(buf, 0, &maxactive);
 821		if (ret || !maxactive) {
 822			trace_probe_log_err(1, BAD_MAXACT);
 823			goto parse_error;
 824		}
 825		/* kretprobes instances are iterated over via a list. The
 826		 * maximum should stay reasonable.
 827		 */
 828		if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
 829			trace_probe_log_err(1, MAXACT_TOO_BIG);
 830			goto parse_error;
 831		}
 832	}
 833
 834	/* try to parse an address. if that fails, try to read the
 835	 * input as a symbol. */
 836	if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
 837		trace_probe_log_set_index(1);
 838		/* Check whether uprobe event specified */
 839		if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
 840			ret = -ECANCELED;
 841			goto error;
 842		}
 843		/* a symbol specified */
 844		symbol = kstrdup(argv[1], GFP_KERNEL);
 845		if (!symbol)
 846			return -ENOMEM;
 847
 848		tmp = strchr(symbol, '%');
 849		if (tmp) {
 850			if (!strcmp(tmp, "%return")) {
 851				*tmp = '\0';
 852				is_return = true;
 853			} else {
 854				trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
 855				goto parse_error;
 856			}
 857		}
 858
 859		/* TODO: support .init module functions */
 860		ret = traceprobe_split_symbol_offset(symbol, &offset);
 861		if (ret || offset < 0 || offset > UINT_MAX) {
 862			trace_probe_log_err(0, BAD_PROBE_ADDR);
 863			goto parse_error;
 864		}
 865		if (is_return)
 866			ctx.flags |= TPARG_FL_RETURN;
 867		ret = kprobe_on_func_entry(NULL, symbol, offset);
 868		if (ret == 0 && !is_return)
 869			ctx.flags |= TPARG_FL_FENTRY;
 870		/* Defer the ENOENT case until register kprobe */
 871		if (ret == -EINVAL && is_return) {
 872			trace_probe_log_err(0, BAD_RETPROBE);
 873			goto parse_error;
 874		}
 875	}
 876
 877	if (symbol && !strchr(symbol, ':')) {
 878		unsigned int count;
 879
 880		count = number_of_same_symbols(symbol);
 881		if (count > 1) {
 882			/*
 883			 * Users should use ADDR to remove the ambiguity of
 884			 * using KSYM only.
 885			 */
 886			trace_probe_log_err(0, NON_UNIQ_SYMBOL);
 887			ret = -EADDRNOTAVAIL;
 888
 889			goto error;
 890		} else if (count == 0) {
 891			/*
 892			 * We can return ENOENT earlier than when register the
 893			 * kprobe.
 894			 */
 895			trace_probe_log_err(0, BAD_PROBE_ADDR);
 896			ret = -ENOENT;
 897
 898			goto error;
 899		}
 900	}
 901
 902	trace_probe_log_set_index(0);
 903	if (event) {
 904		ret = traceprobe_parse_event_name(&event, &group, gbuf,
 905						  event - argv[0]);
 906		if (ret)
 907			goto parse_error;
 908	}
 909
 910	if (!event) {
 911		/* Make a new event name */
 912		if (symbol)
 913			snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
 914				 is_return ? 'r' : 'p', symbol, offset);
 915		else
 916			snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
 917				 is_return ? 'r' : 'p', addr);
 918		sanitize_event_name(buf);
 919		event = buf;
 920	}
 921
 922	argc -= 2; argv += 2;
 923	ctx.funcname = symbol;
 924	new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc,
 925					       abuf, MAX_BTF_ARGS_LEN, &ctx);
 926	if (IS_ERR(new_argv)) {
 927		ret = PTR_ERR(new_argv);
 928		new_argv = NULL;
 929		goto out;
 930	}
 931	if (new_argv) {
 932		argc = new_argc;
 933		argv = new_argv;
 934	}
 935
 936	/* setup a probe */
 937	tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
 938				argc, is_return);
 939	if (IS_ERR(tk)) {
 940		ret = PTR_ERR(tk);
 941		/* This must return -ENOMEM, else there is a bug */
 942		WARN_ON_ONCE(ret != -ENOMEM);
 943		goto out;	/* We know tk is not allocated */
 944	}
 
 945
 946	/* parse arguments */
 947	for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 948		trace_probe_log_set_index(i + 2);
 949		ctx.offset = 0;
 950		ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], &ctx);
 951		if (ret)
 952			goto error;	/* This can be -ENOMEM */
 953	}
 954	/* entry handler for kretprobe */
 955	if (is_return && tk->tp.entry_arg) {
 956		tk->rp.entry_handler = trace_kprobe_entry_handler;
 957		tk->rp.data_size = traceprobe_get_entry_data_size(&tk->tp);
 958	}
 959
 960	ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
 961	ret = traceprobe_set_print_fmt(&tk->tp, ptype);
 962	if (ret < 0)
 963		goto error;
 964
 965	ret = register_trace_kprobe(tk);
 966	if (ret) {
 967		trace_probe_log_set_index(1);
 968		if (ret == -EILSEQ)
 969			trace_probe_log_err(0, BAD_INSN_BNDRY);
 970		else if (ret == -ENOENT)
 971			trace_probe_log_err(0, BAD_PROBE_ADDR);
 972		else if (ret != -ENOMEM && ret != -EEXIST)
 973			trace_probe_log_err(0, FAIL_REG_PROBE);
 974		goto error;
 975	}
 976
 977out:
 978	traceprobe_finish_parse(&ctx);
 979	trace_probe_log_clear();
 980	kfree(new_argv);
 981	kfree(symbol);
 982	return ret;
 983
 984parse_error:
 985	ret = -EINVAL;
 986error:
 987	free_trace_kprobe(tk);
 988	goto out;
 989}
 990
 991static int trace_kprobe_create(const char *raw_command)
 992{
 993	return trace_probe_create(raw_command, __trace_kprobe_create);
 994}
 995
 996static int create_or_delete_trace_kprobe(const char *raw_command)
 997{
 998	int ret;
 999
1000	if (raw_command[0] == '-')
1001		return dyn_event_release(raw_command, &trace_kprobe_ops);
1002
1003	ret = trace_kprobe_create(raw_command);
1004	return ret == -ECANCELED ? -EINVAL : ret;
1005}
1006
1007static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
1008{
1009	return create_or_delete_trace_kprobe(cmd->seq.buffer);
1010}
1011
1012/**
1013 * kprobe_event_cmd_init - Initialize a kprobe event command object
1014 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1015 * @buf: A pointer to the buffer used to build the command
1016 * @maxlen: The length of the buffer passed in @buf
1017 *
1018 * Initialize a synthetic event command object.  Use this before
1019 * calling any of the other kprobe_event functions.
1020 */
1021void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
1022{
1023	dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
1024			  trace_kprobe_run_command);
1025}
1026EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
1027
1028/**
1029 * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
1030 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1031 * @kretprobe: Is this a return probe?
1032 * @name: The name of the kprobe event
1033 * @loc: The location of the kprobe event
1034 * @...: Variable number of arg (pairs), one pair for each field
 
1035 *
1036 * NOTE: Users normally won't want to call this function directly, but
1037 * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
1038 * adds a NULL to the end of the arg list.  If this function is used
1039 * directly, make sure the last arg in the variable arg list is NULL.
1040 *
1041 * Generate a kprobe event command to be executed by
1042 * kprobe_event_gen_cmd_end().  This function can be used to generate the
1043 * complete command or only the first part of it; in the latter case,
1044 * kprobe_event_add_fields() can be used to add more fields following this.
1045 *
1046 * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
1047 * returns -EINVAL if @loc == NULL.
1048 *
1049 * Return: 0 if successful, error otherwise.
1050 */
1051int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
1052				 const char *name, const char *loc, ...)
1053{
1054	char buf[MAX_EVENT_NAME_LEN];
1055	struct dynevent_arg arg;
1056	va_list args;
1057	int ret;
1058
1059	if (cmd->type != DYNEVENT_TYPE_KPROBE)
1060		return -EINVAL;
1061
1062	if (!loc)
1063		return -EINVAL;
1064
1065	if (kretprobe)
1066		snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
1067	else
1068		snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
1069
1070	ret = dynevent_str_add(cmd, buf);
1071	if (ret)
1072		return ret;
1073
1074	dynevent_arg_init(&arg, 0);
1075	arg.str = loc;
1076	ret = dynevent_arg_add(cmd, &arg, NULL);
1077	if (ret)
1078		return ret;
1079
1080	va_start(args, loc);
1081	for (;;) {
1082		const char *field;
1083
1084		field = va_arg(args, const char *);
1085		if (!field)
1086			break;
1087
1088		if (++cmd->n_fields > MAX_TRACE_ARGS) {
1089			ret = -EINVAL;
1090			break;
1091		}
1092
1093		arg.str = field;
1094		ret = dynevent_arg_add(cmd, &arg, NULL);
1095		if (ret)
1096			break;
1097	}
1098	va_end(args);
1099
1100	return ret;
1101}
1102EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
1103
1104/**
1105 * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
1106 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1107 * @...: Variable number of arg (pairs), one pair for each field
1108 *
1109 * NOTE: Users normally won't want to call this function directly, but
1110 * rather use the kprobe_event_add_fields() wrapper, which
1111 * automatically adds a NULL to the end of the arg list.  If this
1112 * function is used directly, make sure the last arg in the variable
1113 * arg list is NULL.
1114 *
1115 * Add probe fields to an existing kprobe command using a variable
1116 * list of args.  Fields are added in the same order they're listed.
1117 *
1118 * Return: 0 if successful, error otherwise.
1119 */
1120int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
1121{
1122	struct dynevent_arg arg;
1123	va_list args;
1124	int ret = 0;
1125
1126	if (cmd->type != DYNEVENT_TYPE_KPROBE)
1127		return -EINVAL;
1128
1129	dynevent_arg_init(&arg, 0);
1130
1131	va_start(args, cmd);
1132	for (;;) {
1133		const char *field;
1134
1135		field = va_arg(args, const char *);
1136		if (!field)
1137			break;
1138
1139		if (++cmd->n_fields > MAX_TRACE_ARGS) {
1140			ret = -EINVAL;
1141			break;
1142		}
1143
1144		arg.str = field;
1145		ret = dynevent_arg_add(cmd, &arg, NULL);
1146		if (ret)
1147			break;
1148	}
1149	va_end(args);
1150
1151	return ret;
1152}
1153EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
1154
1155/**
1156 * kprobe_event_delete - Delete a kprobe event
1157 * @name: The name of the kprobe event to delete
1158 *
1159 * Delete a kprobe event with the give @name from kernel code rather
1160 * than directly from the command line.
1161 *
1162 * Return: 0 if successful, error otherwise.
1163 */
1164int kprobe_event_delete(const char *name)
1165{
1166	char buf[MAX_EVENT_NAME_LEN];
1167
1168	snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
1169
1170	return create_or_delete_trace_kprobe(buf);
1171}
1172EXPORT_SYMBOL_GPL(kprobe_event_delete);
1173
1174static int trace_kprobe_release(struct dyn_event *ev)
1175{
1176	struct trace_kprobe *tk = to_trace_kprobe(ev);
1177	int ret = unregister_trace_kprobe(tk);
1178
1179	if (!ret)
1180		free_trace_kprobe(tk);
1181	return ret;
1182}
1183
1184static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
1185{
1186	struct trace_kprobe *tk = to_trace_kprobe(ev);
1187	int i;
1188
1189	seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
1190	if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
1191		seq_printf(m, "%d", tk->rp.maxactive);
1192	seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
1193				trace_probe_name(&tk->tp));
1194
1195	if (!tk->symbol)
1196		seq_printf(m, " 0x%p", tk->rp.kp.addr);
1197	else if (tk->rp.kp.offset)
1198		seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
1199			   tk->rp.kp.offset);
1200	else
1201		seq_printf(m, " %s", trace_kprobe_symbol(tk));
1202
1203	for (i = 0; i < tk->tp.nr_args; i++)
1204		seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
1205	seq_putc(m, '\n');
1206
1207	return 0;
1208}
1209
1210static int probes_seq_show(struct seq_file *m, void *v)
1211{
1212	struct dyn_event *ev = v;
1213
1214	if (!is_trace_kprobe(ev))
1215		return 0;
1216
1217	return trace_kprobe_show(m, ev);
1218}
1219
1220static const struct seq_operations probes_seq_op = {
1221	.start  = dyn_event_seq_start,
1222	.next   = dyn_event_seq_next,
1223	.stop   = dyn_event_seq_stop,
1224	.show   = probes_seq_show
1225};
1226
1227static int probes_open(struct inode *inode, struct file *file)
1228{
1229	int ret;
1230
1231	ret = security_locked_down(LOCKDOWN_TRACEFS);
1232	if (ret)
1233		return ret;
1234
1235	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1236		ret = dyn_events_release_all(&trace_kprobe_ops);
1237		if (ret < 0)
1238			return ret;
1239	}
1240
1241	return seq_open(file, &probes_seq_op);
1242}
1243
1244static ssize_t probes_write(struct file *file, const char __user *buffer,
1245			    size_t count, loff_t *ppos)
1246{
1247	return trace_parse_run_command(file, buffer, count, ppos,
1248				       create_or_delete_trace_kprobe);
1249}
1250
1251static const struct file_operations kprobe_events_ops = {
1252	.owner          = THIS_MODULE,
1253	.open           = probes_open,
1254	.read           = seq_read,
1255	.llseek         = seq_lseek,
1256	.release        = seq_release,
1257	.write		= probes_write,
1258};
1259
1260static unsigned long trace_kprobe_missed(struct trace_kprobe *tk)
1261{
1262	return trace_kprobe_is_return(tk) ?
1263		tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
1264}
1265
1266/* Probes profiling interfaces */
1267static int probes_profile_seq_show(struct seq_file *m, void *v)
1268{
1269	struct dyn_event *ev = v;
1270	struct trace_kprobe *tk;
1271	unsigned long nmissed;
1272
1273	if (!is_trace_kprobe(ev))
1274		return 0;
1275
1276	tk = to_trace_kprobe(ev);
1277	nmissed = trace_kprobe_missed(tk);
 
1278	seq_printf(m, "  %-44s %15lu %15lu\n",
1279		   trace_probe_name(&tk->tp),
1280		   trace_kprobe_nhit(tk),
1281		   nmissed);
1282
1283	return 0;
1284}
1285
1286static const struct seq_operations profile_seq_op = {
1287	.start  = dyn_event_seq_start,
1288	.next   = dyn_event_seq_next,
1289	.stop   = dyn_event_seq_stop,
1290	.show   = probes_profile_seq_show
1291};
1292
1293static int profile_open(struct inode *inode, struct file *file)
1294{
1295	int ret;
1296
1297	ret = security_locked_down(LOCKDOWN_TRACEFS);
1298	if (ret)
1299		return ret;
1300
1301	return seq_open(file, &profile_seq_op);
1302}
1303
1304static const struct file_operations kprobe_profile_ops = {
1305	.owner          = THIS_MODULE,
1306	.open           = profile_open,
1307	.read           = seq_read,
1308	.llseek         = seq_lseek,
1309	.release        = seq_release,
1310};
1311
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1312/* Note that we don't verify it, since the code does not come from user space */
1313static int
1314process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
1315		   void *dest, void *base)
1316{
1317	struct pt_regs *regs = rec;
1318	unsigned long val;
1319	int ret;
1320
1321retry:
1322	/* 1st stage: get value from context */
1323	switch (code->op) {
1324	case FETCH_OP_REG:
1325		val = regs_get_register(regs, code->param);
1326		break;
1327	case FETCH_OP_STACK:
1328		val = regs_get_kernel_stack_nth(regs, code->param);
1329		break;
1330	case FETCH_OP_STACKP:
1331		val = kernel_stack_pointer(regs);
1332		break;
1333	case FETCH_OP_RETVAL:
1334		val = regs_return_value(regs);
1335		break;
 
 
 
 
 
 
 
 
 
1336#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1337	case FETCH_OP_ARG:
1338		val = regs_get_kernel_argument(regs, code->param);
1339		break;
1340	case FETCH_OP_EDATA:
1341		val = *(unsigned long *)((unsigned long)edata + code->offset);
1342		break;
1343#endif
1344	case FETCH_NOP_SYMBOL:	/* Ignore a place holder */
1345		code++;
1346		goto retry;
1347	default:
1348		ret = process_common_fetch_insn(code, &val);
1349		if (ret < 0)
1350			return ret;
1351	}
1352	code++;
1353
1354	return process_fetch_insn_bottom(code, val, dest, base);
1355}
1356NOKPROBE_SYMBOL(process_fetch_insn)
1357
1358/* Kprobe handler */
1359static nokprobe_inline void
1360__kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1361		    struct trace_event_file *trace_file)
1362{
1363	struct kprobe_trace_entry_head *entry;
1364	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1365	struct trace_event_buffer fbuffer;
1366	int dsize;
1367
1368	WARN_ON(call != trace_file->event_call);
1369
1370	if (trace_trigger_soft_disabled(trace_file))
1371		return;
1372
1373	dsize = __get_data_size(&tk->tp, regs, NULL);
1374
1375	entry = trace_event_buffer_reserve(&fbuffer, trace_file,
1376					   sizeof(*entry) + tk->tp.size + dsize);
1377	if (!entry)
1378		return;
1379
1380	fbuffer.regs = regs;
1381	entry->ip = (unsigned long)tk->rp.kp.addr;
1382	store_trace_args(&entry[1], &tk->tp, regs, NULL, sizeof(*entry), dsize);
1383
1384	trace_event_buffer_commit(&fbuffer);
1385}
1386
1387static void
1388kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1389{
1390	struct event_file_link *link;
1391
1392	trace_probe_for_each_link_rcu(link, &tk->tp)
1393		__kprobe_trace_func(tk, regs, link->file);
1394}
1395NOKPROBE_SYMBOL(kprobe_trace_func);
1396
1397/* Kretprobe handler */
1398
1399static int trace_kprobe_entry_handler(struct kretprobe_instance *ri,
1400				      struct pt_regs *regs)
1401{
1402	struct kretprobe *rp = get_kretprobe(ri);
1403	struct trace_kprobe *tk;
1404
1405	/*
1406	 * There is a small chance that get_kretprobe(ri) returns NULL when
1407	 * the kretprobe is unregister on another CPU between kretprobe's
1408	 * trampoline_handler and this function.
1409	 */
1410	if (unlikely(!rp))
1411		return -ENOENT;
1412
1413	tk = container_of(rp, struct trace_kprobe, rp);
1414
1415	/* store argument values into ri->data as entry data */
1416	if (tk->tp.entry_arg)
1417		store_trace_entry_data(ri->data, &tk->tp, regs);
1418
1419	return 0;
1420}
1421
1422
1423static nokprobe_inline void
1424__kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1425		       struct pt_regs *regs,
1426		       struct trace_event_file *trace_file)
1427{
1428	struct kretprobe_trace_entry_head *entry;
1429	struct trace_event_buffer fbuffer;
1430	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1431	int dsize;
1432
1433	WARN_ON(call != trace_file->event_call);
1434
1435	if (trace_trigger_soft_disabled(trace_file))
1436		return;
1437
1438	dsize = __get_data_size(&tk->tp, regs, ri->data);
1439
1440	entry = trace_event_buffer_reserve(&fbuffer, trace_file,
1441					   sizeof(*entry) + tk->tp.size + dsize);
1442	if (!entry)
1443		return;
1444
1445	fbuffer.regs = regs;
1446	entry->func = (unsigned long)tk->rp.kp.addr;
1447	entry->ret_ip = get_kretprobe_retaddr(ri);
1448	store_trace_args(&entry[1], &tk->tp, regs, ri->data, sizeof(*entry), dsize);
1449
1450	trace_event_buffer_commit(&fbuffer);
1451}
1452
1453static void
1454kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1455		     struct pt_regs *regs)
1456{
1457	struct event_file_link *link;
1458
1459	trace_probe_for_each_link_rcu(link, &tk->tp)
1460		__kretprobe_trace_func(tk, ri, regs, link->file);
1461}
1462NOKPROBE_SYMBOL(kretprobe_trace_func);
1463
1464/* Event entry printers */
1465static enum print_line_t
1466print_kprobe_event(struct trace_iterator *iter, int flags,
1467		   struct trace_event *event)
1468{
1469	struct kprobe_trace_entry_head *field;
1470	struct trace_seq *s = &iter->seq;
1471	struct trace_probe *tp;
1472
1473	field = (struct kprobe_trace_entry_head *)iter->ent;
1474	tp = trace_probe_primary_from_call(
1475		container_of(event, struct trace_event_call, event));
1476	if (WARN_ON_ONCE(!tp))
1477		goto out;
1478
1479	trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1480
1481	if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1482		goto out;
1483
1484	trace_seq_putc(s, ')');
1485
1486	if (trace_probe_print_args(s, tp->args, tp->nr_args,
1487			     (u8 *)&field[1], field) < 0)
1488		goto out;
1489
1490	trace_seq_putc(s, '\n');
1491 out:
1492	return trace_handle_return(s);
1493}
1494
1495static enum print_line_t
1496print_kretprobe_event(struct trace_iterator *iter, int flags,
1497		      struct trace_event *event)
1498{
1499	struct kretprobe_trace_entry_head *field;
1500	struct trace_seq *s = &iter->seq;
1501	struct trace_probe *tp;
1502
1503	field = (struct kretprobe_trace_entry_head *)iter->ent;
1504	tp = trace_probe_primary_from_call(
1505		container_of(event, struct trace_event_call, event));
1506	if (WARN_ON_ONCE(!tp))
1507		goto out;
1508
1509	trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1510
1511	if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1512		goto out;
1513
1514	trace_seq_puts(s, " <- ");
1515
1516	if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1517		goto out;
1518
1519	trace_seq_putc(s, ')');
1520
1521	if (trace_probe_print_args(s, tp->args, tp->nr_args,
1522			     (u8 *)&field[1], field) < 0)
1523		goto out;
1524
1525	trace_seq_putc(s, '\n');
1526
1527 out:
1528	return trace_handle_return(s);
1529}
1530
1531
1532static int kprobe_event_define_fields(struct trace_event_call *event_call)
1533{
1534	int ret;
1535	struct kprobe_trace_entry_head field;
1536	struct trace_probe *tp;
1537
1538	tp = trace_probe_primary_from_call(event_call);
1539	if (WARN_ON_ONCE(!tp))
1540		return -ENOENT;
1541
1542	DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1543
1544	return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1545}
1546
1547static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1548{
1549	int ret;
1550	struct kretprobe_trace_entry_head field;
1551	struct trace_probe *tp;
1552
1553	tp = trace_probe_primary_from_call(event_call);
1554	if (WARN_ON_ONCE(!tp))
1555		return -ENOENT;
1556
1557	DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1558	DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1559
1560	return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1561}
1562
1563#ifdef CONFIG_PERF_EVENTS
1564
1565/* Kprobe profile handler */
1566static int
1567kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1568{
1569	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1570	struct kprobe_trace_entry_head *entry;
1571	struct hlist_head *head;
1572	int size, __size, dsize;
1573	int rctx;
1574
1575	if (bpf_prog_array_valid(call)) {
1576		unsigned long orig_ip = instruction_pointer(regs);
1577		int ret;
1578
1579		ret = trace_call_bpf(call, regs);
1580
1581		/*
1582		 * We need to check and see if we modified the pc of the
1583		 * pt_regs, and if so return 1 so that we don't do the
1584		 * single stepping.
1585		 */
1586		if (orig_ip != instruction_pointer(regs))
1587			return 1;
1588		if (!ret)
1589			return 0;
1590	}
1591
1592	head = this_cpu_ptr(call->perf_events);
1593	if (hlist_empty(head))
1594		return 0;
1595
1596	dsize = __get_data_size(&tk->tp, regs, NULL);
1597	__size = sizeof(*entry) + tk->tp.size + dsize;
1598	size = ALIGN(__size + sizeof(u32), sizeof(u64));
1599	size -= sizeof(u32);
1600
1601	entry = perf_trace_buf_alloc(size, NULL, &rctx);
1602	if (!entry)
1603		return 0;
1604
1605	entry->ip = (unsigned long)tk->rp.kp.addr;
1606	memset(&entry[1], 0, dsize);
1607	store_trace_args(&entry[1], &tk->tp, regs, NULL, sizeof(*entry), dsize);
1608	perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1609			      head, NULL);
1610	return 0;
1611}
1612NOKPROBE_SYMBOL(kprobe_perf_func);
1613
1614/* Kretprobe profile handler */
1615static void
1616kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1617		    struct pt_regs *regs)
1618{
1619	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1620	struct kretprobe_trace_entry_head *entry;
1621	struct hlist_head *head;
1622	int size, __size, dsize;
1623	int rctx;
1624
1625	if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1626		return;
1627
1628	head = this_cpu_ptr(call->perf_events);
1629	if (hlist_empty(head))
1630		return;
1631
1632	dsize = __get_data_size(&tk->tp, regs, ri->data);
1633	__size = sizeof(*entry) + tk->tp.size + dsize;
1634	size = ALIGN(__size + sizeof(u32), sizeof(u64));
1635	size -= sizeof(u32);
1636
1637	entry = perf_trace_buf_alloc(size, NULL, &rctx);
1638	if (!entry)
1639		return;
1640
1641	entry->func = (unsigned long)tk->rp.kp.addr;
1642	entry->ret_ip = get_kretprobe_retaddr(ri);
1643	store_trace_args(&entry[1], &tk->tp, regs, ri->data, sizeof(*entry), dsize);
1644	perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1645			      head, NULL);
1646}
1647NOKPROBE_SYMBOL(kretprobe_perf_func);
1648
1649int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1650			const char **symbol, u64 *probe_offset,
1651			u64 *probe_addr, unsigned long *missed,
1652			bool perf_type_tracepoint)
1653{
1654	const char *pevent = trace_event_name(event->tp_event);
1655	const char *group = event->tp_event->class->system;
1656	struct trace_kprobe *tk;
1657
1658	if (perf_type_tracepoint)
1659		tk = find_trace_kprobe(pevent, group);
1660	else
1661		tk = trace_kprobe_primary_from_call(event->tp_event);
1662	if (!tk)
1663		return -EINVAL;
1664
1665	*fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1666					      : BPF_FD_TYPE_KPROBE;
1667	*probe_offset = tk->rp.kp.offset;
1668	*probe_addr = kallsyms_show_value(current_cred()) ?
1669		      (unsigned long)tk->rp.kp.addr : 0;
1670	*symbol = tk->symbol;
1671	if (missed)
1672		*missed = trace_kprobe_missed(tk);
 
 
 
1673	return 0;
1674}
1675#endif	/* CONFIG_PERF_EVENTS */
1676
1677/*
1678 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1679 *
1680 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1681 * lockless, but we can't race with this __init function.
1682 */
1683static int kprobe_register(struct trace_event_call *event,
1684			   enum trace_reg type, void *data)
1685{
1686	struct trace_event_file *file = data;
1687
1688	switch (type) {
1689	case TRACE_REG_REGISTER:
1690		return enable_trace_kprobe(event, file);
1691	case TRACE_REG_UNREGISTER:
1692		return disable_trace_kprobe(event, file);
1693
1694#ifdef CONFIG_PERF_EVENTS
1695	case TRACE_REG_PERF_REGISTER:
1696		return enable_trace_kprobe(event, NULL);
1697	case TRACE_REG_PERF_UNREGISTER:
1698		return disable_trace_kprobe(event, NULL);
1699	case TRACE_REG_PERF_OPEN:
1700	case TRACE_REG_PERF_CLOSE:
1701	case TRACE_REG_PERF_ADD:
1702	case TRACE_REG_PERF_DEL:
1703		return 0;
1704#endif
1705	}
1706	return 0;
1707}
1708
1709static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1710{
1711	struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1712	int ret = 0;
1713
1714	raw_cpu_inc(*tk->nhit);
1715
1716	if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1717		kprobe_trace_func(tk, regs);
1718#ifdef CONFIG_PERF_EVENTS
1719	if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1720		ret = kprobe_perf_func(tk, regs);
1721#endif
1722	return ret;
1723}
1724NOKPROBE_SYMBOL(kprobe_dispatcher);
1725
1726static int
1727kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1728{
1729	struct kretprobe *rp = get_kretprobe(ri);
1730	struct trace_kprobe *tk;
1731
1732	/*
1733	 * There is a small chance that get_kretprobe(ri) returns NULL when
1734	 * the kretprobe is unregister on another CPU between kretprobe's
1735	 * trampoline_handler and this function.
1736	 */
1737	if (unlikely(!rp))
1738		return 0;
1739
1740	tk = container_of(rp, struct trace_kprobe, rp);
1741	raw_cpu_inc(*tk->nhit);
1742
1743	if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1744		kretprobe_trace_func(tk, ri, regs);
1745#ifdef CONFIG_PERF_EVENTS
1746	if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1747		kretprobe_perf_func(tk, ri, regs);
1748#endif
1749	return 0;	/* We don't tweak kernel, so just return 0 */
1750}
1751NOKPROBE_SYMBOL(kretprobe_dispatcher);
1752
1753static struct trace_event_functions kretprobe_funcs = {
1754	.trace		= print_kretprobe_event
1755};
1756
1757static struct trace_event_functions kprobe_funcs = {
1758	.trace		= print_kprobe_event
1759};
1760
1761static struct trace_event_fields kretprobe_fields_array[] = {
1762	{ .type = TRACE_FUNCTION_TYPE,
1763	  .define_fields = kretprobe_event_define_fields },
1764	{}
1765};
1766
1767static struct trace_event_fields kprobe_fields_array[] = {
1768	{ .type = TRACE_FUNCTION_TYPE,
1769	  .define_fields = kprobe_event_define_fields },
1770	{}
1771};
1772
1773static inline void init_trace_event_call(struct trace_kprobe *tk)
1774{
1775	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1776
1777	if (trace_kprobe_is_return(tk)) {
1778		call->event.funcs = &kretprobe_funcs;
1779		call->class->fields_array = kretprobe_fields_array;
1780	} else {
1781		call->event.funcs = &kprobe_funcs;
1782		call->class->fields_array = kprobe_fields_array;
1783	}
1784
1785	call->flags = TRACE_EVENT_FL_KPROBE;
1786	call->class->reg = kprobe_register;
1787}
1788
1789static int register_kprobe_event(struct trace_kprobe *tk)
1790{
1791	init_trace_event_call(tk);
1792
1793	return trace_probe_register_event_call(&tk->tp);
1794}
1795
1796static int unregister_kprobe_event(struct trace_kprobe *tk)
1797{
1798	return trace_probe_unregister_event_call(&tk->tp);
1799}
1800
1801#ifdef CONFIG_PERF_EVENTS
1802
1803/* create a trace_kprobe, but don't add it to global lists */
1804struct trace_event_call *
1805create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1806			  bool is_return)
1807{
1808	enum probe_print_type ptype;
1809	struct trace_kprobe *tk;
1810	int ret;
1811	char *event;
1812
1813	if (func) {
1814		unsigned int count;
1815
1816		count = number_of_same_symbols(func);
1817		if (count > 1)
1818			/*
1819			 * Users should use addr to remove the ambiguity of
1820			 * using func only.
1821			 */
1822			return ERR_PTR(-EADDRNOTAVAIL);
1823		else if (count == 0)
1824			/*
1825			 * We can return ENOENT earlier than when register the
1826			 * kprobe.
1827			 */
1828			return ERR_PTR(-ENOENT);
1829	}
1830
1831	/*
1832	 * local trace_kprobes are not added to dyn_event, so they are never
1833	 * searched in find_trace_kprobe(). Therefore, there is no concern of
1834	 * duplicated name here.
1835	 */
1836	event = func ? func : "DUMMY_EVENT";
1837
1838	tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1839				offs, 0 /* maxactive */, 0 /* nargs */,
1840				is_return);
1841
1842	if (IS_ERR(tk)) {
1843		pr_info("Failed to allocate trace_probe.(%d)\n",
1844			(int)PTR_ERR(tk));
1845		return ERR_CAST(tk);
1846	}
1847
1848	init_trace_event_call(tk);
1849
1850	ptype = trace_kprobe_is_return(tk) ?
1851		PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1852	if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) {
1853		ret = -ENOMEM;
1854		goto error;
1855	}
1856
1857	ret = __register_trace_kprobe(tk);
1858	if (ret < 0)
1859		goto error;
1860
1861	return trace_probe_event_call(&tk->tp);
1862error:
1863	free_trace_kprobe(tk);
1864	return ERR_PTR(ret);
1865}
1866
1867void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1868{
1869	struct trace_kprobe *tk;
1870
1871	tk = trace_kprobe_primary_from_call(event_call);
1872	if (unlikely(!tk))
1873		return;
1874
1875	if (trace_probe_is_enabled(&tk->tp)) {
1876		WARN_ON(1);
1877		return;
1878	}
1879
1880	__unregister_trace_kprobe(tk);
1881
1882	free_trace_kprobe(tk);
1883}
1884#endif /* CONFIG_PERF_EVENTS */
1885
1886static __init void enable_boot_kprobe_events(void)
1887{
1888	struct trace_array *tr = top_trace_array();
1889	struct trace_event_file *file;
1890	struct trace_kprobe *tk;
1891	struct dyn_event *pos;
1892
1893	mutex_lock(&event_mutex);
1894	for_each_trace_kprobe(tk, pos) {
1895		list_for_each_entry(file, &tr->events, list)
1896			if (file->event_call == trace_probe_event_call(&tk->tp))
1897				trace_event_enable_disable(file, 1, 0);
1898	}
1899	mutex_unlock(&event_mutex);
1900}
1901
1902static __init void setup_boot_kprobe_events(void)
1903{
1904	char *p, *cmd = kprobe_boot_events_buf;
1905	int ret;
1906
1907	strreplace(kprobe_boot_events_buf, ',', ' ');
1908
1909	while (cmd && *cmd != '\0') {
1910		p = strchr(cmd, ';');
1911		if (p)
1912			*p++ = '\0';
1913
1914		ret = create_or_delete_trace_kprobe(cmd);
1915		if (ret)
1916			pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1917
1918		cmd = p;
1919	}
1920
1921	enable_boot_kprobe_events();
1922}
1923
1924/*
1925 * Register dynevent at core_initcall. This allows kernel to setup kprobe
1926 * events in postcore_initcall without tracefs.
1927 */
1928static __init int init_kprobe_trace_early(void)
1929{
1930	int ret;
1931
1932	ret = dyn_event_register(&trace_kprobe_ops);
1933	if (ret)
1934		return ret;
1935
1936	if (register_module_notifier(&trace_kprobe_module_nb))
1937		return -EINVAL;
1938
1939	return 0;
1940}
1941core_initcall(init_kprobe_trace_early);
1942
1943/* Make a tracefs interface for controlling probe points */
1944static __init int init_kprobe_trace(void)
1945{
1946	int ret;
1947
1948	ret = tracing_init_dentry();
1949	if (ret)
1950		return 0;
1951
1952	/* Event list interface */
1953	trace_create_file("kprobe_events", TRACE_MODE_WRITE,
1954			  NULL, NULL, &kprobe_events_ops);
1955
1956	/* Profile interface */
1957	trace_create_file("kprobe_profile", TRACE_MODE_READ,
1958			  NULL, NULL, &kprobe_profile_ops);
1959
1960	setup_boot_kprobe_events();
1961
1962	return 0;
1963}
1964fs_initcall(init_kprobe_trace);
1965
1966
1967#ifdef CONFIG_FTRACE_STARTUP_TEST
1968static __init struct trace_event_file *
1969find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1970{
1971	struct trace_event_file *file;
1972
1973	list_for_each_entry(file, &tr->events, list)
1974		if (file->event_call == trace_probe_event_call(&tk->tp))
1975			return file;
1976
1977	return NULL;
1978}
1979
1980/*
1981 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1982 * stage, we can do this lockless.
1983 */
1984static __init int kprobe_trace_self_tests_init(void)
1985{
1986	int ret, warn = 0;
1987	int (*target)(int, int, int, int, int, int);
1988	struct trace_kprobe *tk;
1989	struct trace_event_file *file;
1990
1991	if (tracing_is_disabled())
1992		return -ENODEV;
1993
1994	if (tracing_selftest_disabled)
1995		return 0;
1996
1997	target = kprobe_trace_selftest_target;
1998
1999	pr_info("Testing kprobe tracing: ");
2000
2001	ret = create_or_delete_trace_kprobe("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)");
2002	if (WARN_ON_ONCE(ret)) {
2003		pr_warn("error on probing function entry.\n");
2004		warn++;
2005	} else {
2006		/* Enable trace point */
2007		tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
2008		if (WARN_ON_ONCE(tk == NULL)) {
2009			pr_warn("error on getting new probe.\n");
2010			warn++;
2011		} else {
2012			file = find_trace_probe_file(tk, top_trace_array());
2013			if (WARN_ON_ONCE(file == NULL)) {
2014				pr_warn("error on getting probe file.\n");
2015				warn++;
2016			} else
2017				enable_trace_kprobe(
2018					trace_probe_event_call(&tk->tp), file);
2019		}
2020	}
2021
2022	ret = create_or_delete_trace_kprobe("r:testprobe2 kprobe_trace_selftest_target $retval");
2023	if (WARN_ON_ONCE(ret)) {
2024		pr_warn("error on probing function return.\n");
2025		warn++;
2026	} else {
2027		/* Enable trace point */
2028		tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2029		if (WARN_ON_ONCE(tk == NULL)) {
2030			pr_warn("error on getting 2nd new probe.\n");
2031			warn++;
2032		} else {
2033			file = find_trace_probe_file(tk, top_trace_array());
2034			if (WARN_ON_ONCE(file == NULL)) {
2035				pr_warn("error on getting probe file.\n");
2036				warn++;
2037			} else
2038				enable_trace_kprobe(
2039					trace_probe_event_call(&tk->tp), file);
2040		}
2041	}
2042
2043	if (warn)
2044		goto end;
2045
2046	ret = target(1, 2, 3, 4, 5, 6);
2047
2048	/*
2049	 * Not expecting an error here, the check is only to prevent the
2050	 * optimizer from removing the call to target() as otherwise there
2051	 * are no side-effects and the call is never performed.
2052	 */
2053	if (ret != 21)
2054		warn++;
2055
2056	/* Disable trace points before removing it */
2057	tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
2058	if (WARN_ON_ONCE(tk == NULL)) {
2059		pr_warn("error on getting test probe.\n");
2060		warn++;
2061	} else {
2062		if (trace_kprobe_nhit(tk) != 1) {
2063			pr_warn("incorrect number of testprobe hits\n");
2064			warn++;
2065		}
2066
2067		file = find_trace_probe_file(tk, top_trace_array());
2068		if (WARN_ON_ONCE(file == NULL)) {
2069			pr_warn("error on getting probe file.\n");
2070			warn++;
2071		} else
2072			disable_trace_kprobe(
2073				trace_probe_event_call(&tk->tp), file);
2074	}
2075
2076	tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2077	if (WARN_ON_ONCE(tk == NULL)) {
2078		pr_warn("error on getting 2nd test probe.\n");
2079		warn++;
2080	} else {
2081		if (trace_kprobe_nhit(tk) != 1) {
2082			pr_warn("incorrect number of testprobe2 hits\n");
2083			warn++;
2084		}
2085
2086		file = find_trace_probe_file(tk, top_trace_array());
2087		if (WARN_ON_ONCE(file == NULL)) {
2088			pr_warn("error on getting probe file.\n");
2089			warn++;
2090		} else
2091			disable_trace_kprobe(
2092				trace_probe_event_call(&tk->tp), file);
2093	}
2094
2095	ret = create_or_delete_trace_kprobe("-:testprobe");
2096	if (WARN_ON_ONCE(ret)) {
2097		pr_warn("error on deleting a probe.\n");
2098		warn++;
2099	}
2100
2101	ret = create_or_delete_trace_kprobe("-:testprobe2");
2102	if (WARN_ON_ONCE(ret)) {
2103		pr_warn("error on deleting a probe.\n");
2104		warn++;
2105	}
2106
2107end:
2108	ret = dyn_events_release_all(&trace_kprobe_ops);
2109	if (WARN_ON_ONCE(ret)) {
2110		pr_warn("error on cleaning up probes.\n");
2111		warn++;
2112	}
2113	/*
2114	 * Wait for the optimizer work to finish. Otherwise it might fiddle
2115	 * with probes in already freed __init text.
2116	 */
2117	wait_for_kprobe_optimizer();
2118	if (warn)
2119		pr_cont("NG: Some tests are failed. Please check them.\n");
2120	else
2121		pr_cont("OK\n");
2122	return 0;
2123}
2124
2125late_initcall(kprobe_trace_self_tests_init);
2126
2127#endif