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);
 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_create(int argc, const char *argv[])
 744{
 745	/*
 746	 * Argument syntax:
 747	 *  - Add kprobe:
 748	 *      p[:[GRP/][EVENT]] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
 749	 *  - Add kretprobe:
 750	 *      r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]KSYM[+0] [FETCHARGS]
 751	 *    Or
 752	 *      p[:[GRP/][EVENT]] [MOD:]KSYM[+0]%return [FETCHARGS]
 753	 *
 754	 * Fetch args:
 755	 *  $retval	: fetch return value
 756	 *  $stack	: fetch stack address
 757	 *  $stackN	: fetch Nth of stack (N:0-)
 758	 *  $comm       : fetch current task comm
 759	 *  @ADDR	: fetch memory at ADDR (ADDR should be in kernel)
 760	 *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
 761	 *  %REG	: fetch register REG
 762	 * Dereferencing memory fetch:
 763	 *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
 764	 * Alias name of args:
 765	 *  NAME=FETCHARG : set NAME as alias of FETCHARG.
 766	 * Type of args:
 767	 *  FETCHARG:TYPE : use TYPE instead of unsigned long.
 768	 */
 769	struct trace_kprobe *tk = NULL;
 770	int i, len, new_argc = 0, ret = 0;
 771	bool is_return = false;
 772	char *symbol = NULL, *tmp = NULL;
 773	const char **new_argv = NULL;
 774	const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
 775	enum probe_print_type ptype;
 776	int maxactive = 0;
 777	long offset = 0;
 778	void *addr = NULL;
 779	char buf[MAX_EVENT_NAME_LEN];
 780	char gbuf[MAX_EVENT_NAME_LEN];
 781	char abuf[MAX_BTF_ARGS_LEN];
 782	struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL };
 783
 784	switch (argv[0][0]) {
 785	case 'r':
 786		is_return = true;
 787		break;
 788	case 'p':
 789		break;
 790	default:
 791		return -ECANCELED;
 792	}
 793	if (argc < 2)
 794		return -ECANCELED;
 795
 796	trace_probe_log_init("trace_kprobe", argc, argv);
 797
 798	event = strchr(&argv[0][1], ':');
 799	if (event)
 800		event++;
 801
 802	if (isdigit(argv[0][1])) {
 803		if (!is_return) {
 804			trace_probe_log_err(1, BAD_MAXACT_TYPE);
 805			goto parse_error;
 806		}
 807		if (event)
 808			len = event - &argv[0][1] - 1;
 809		else
 810			len = strlen(&argv[0][1]);
 811		if (len > MAX_EVENT_NAME_LEN - 1) {
 812			trace_probe_log_err(1, BAD_MAXACT);
 813			goto parse_error;
 814		}
 815		memcpy(buf, &argv[0][1], len);
 816		buf[len] = '\0';
 817		ret = kstrtouint(buf, 0, &maxactive);
 818		if (ret || !maxactive) {
 819			trace_probe_log_err(1, BAD_MAXACT);
 820			goto parse_error;
 821		}
 822		/* kretprobes instances are iterated over via a list. The
 823		 * maximum should stay reasonable.
 824		 */
 825		if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
 826			trace_probe_log_err(1, MAXACT_TOO_BIG);
 827			goto parse_error;
 828		}
 829	}
 830
 831	/* try to parse an address. if that fails, try to read the
 832	 * input as a symbol. */
 833	if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
 834		trace_probe_log_set_index(1);
 835		/* Check whether uprobe event specified */
 836		if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
 837			ret = -ECANCELED;
 838			goto error;
 839		}
 840		/* a symbol specified */
 841		symbol = kstrdup(argv[1], GFP_KERNEL);
 842		if (!symbol)
 843			return -ENOMEM;
 844
 845		tmp = strchr(symbol, '%');
 846		if (tmp) {
 847			if (!strcmp(tmp, "%return")) {
 848				*tmp = '\0';
 849				is_return = true;
 850			} else {
 851				trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
 852				goto parse_error;
 853			}
 854		}
 855
 856		/* TODO: support .init module functions */
 857		ret = traceprobe_split_symbol_offset(symbol, &offset);
 858		if (ret || offset < 0 || offset > UINT_MAX) {
 859			trace_probe_log_err(0, BAD_PROBE_ADDR);
 860			goto parse_error;
 861		}
 862		if (is_return)
 863			ctx.flags |= TPARG_FL_RETURN;
 864		ret = kprobe_on_func_entry(NULL, symbol, offset);
 865		if (ret == 0 && !is_return)
 866			ctx.flags |= TPARG_FL_FENTRY;
 867		/* Defer the ENOENT case until register kprobe */
 868		if (ret == -EINVAL && is_return) {
 869			trace_probe_log_err(0, BAD_RETPROBE);
 870			goto parse_error;
 871		}
 872	}
 873
 874	if (symbol && !strchr(symbol, ':')) {
 875		unsigned int count;
 876
 877		count = number_of_same_symbols(symbol);
 878		if (count > 1) {
 879			/*
 880			 * Users should use ADDR to remove the ambiguity of
 881			 * using KSYM only.
 882			 */
 883			trace_probe_log_err(0, NON_UNIQ_SYMBOL);
 884			ret = -EADDRNOTAVAIL;
 885
 886			goto error;
 887		} else if (count == 0) {
 888			/*
 889			 * We can return ENOENT earlier than when register the
 890			 * kprobe.
 891			 */
 892			trace_probe_log_err(0, BAD_PROBE_ADDR);
 893			ret = -ENOENT;
 894
 895			goto error;
 896		}
 897	}
 898
 899	trace_probe_log_set_index(0);
 900	if (event) {
 901		ret = traceprobe_parse_event_name(&event, &group, gbuf,
 902						  event - argv[0]);
 903		if (ret)
 904			goto parse_error;
 905	}
 906
 907	if (!event) {
 908		/* Make a new event name */
 909		if (symbol)
 910			snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
 911				 is_return ? 'r' : 'p', symbol, offset);
 912		else
 913			snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
 914				 is_return ? 'r' : 'p', addr);
 915		sanitize_event_name(buf);
 916		event = buf;
 917	}
 918
 919	argc -= 2; argv += 2;
 920	ctx.funcname = symbol;
 921	new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc,
 922					       abuf, MAX_BTF_ARGS_LEN, &ctx);
 923	if (IS_ERR(new_argv)) {
 924		ret = PTR_ERR(new_argv);
 925		new_argv = NULL;
 926		goto out;
 927	}
 928	if (new_argv) {
 929		argc = new_argc;
 930		argv = new_argv;
 931	}
 932
 933	/* setup a probe */
 934	tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
 935				argc, is_return);
 936	if (IS_ERR(tk)) {
 937		ret = PTR_ERR(tk);
 938		/* This must return -ENOMEM, else there is a bug */
 939		WARN_ON_ONCE(ret != -ENOMEM);
 940		goto out;	/* We know tk is not allocated */
 941	}
 
 942
 943	/* parse arguments */
 944	for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 
 
 
 
 
 
 945		trace_probe_log_set_index(i + 2);
 946		ctx.offset = 0;
 947		ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], &ctx);
 948		if (ret)
 949			goto error;	/* This can be -ENOMEM */
 950	}
 951
 952	ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
 953	ret = traceprobe_set_print_fmt(&tk->tp, ptype);
 954	if (ret < 0)
 955		goto error;
 956
 957	ret = register_trace_kprobe(tk);
 958	if (ret) {
 959		trace_probe_log_set_index(1);
 960		if (ret == -EILSEQ)
 961			trace_probe_log_err(0, BAD_INSN_BNDRY);
 962		else if (ret == -ENOENT)
 963			trace_probe_log_err(0, BAD_PROBE_ADDR);
 964		else if (ret != -ENOMEM && ret != -EEXIST)
 965			trace_probe_log_err(0, FAIL_REG_PROBE);
 966		goto error;
 967	}
 968
 969out:
 970	traceprobe_finish_parse(&ctx);
 971	trace_probe_log_clear();
 972	kfree(new_argv);
 973	kfree(symbol);
 974	return ret;
 975
 976parse_error:
 977	ret = -EINVAL;
 978error:
 979	free_trace_kprobe(tk);
 980	goto out;
 981}
 982
 983static int trace_kprobe_create(const char *raw_command)
 984{
 985	return trace_probe_create(raw_command, __trace_kprobe_create);
 986}
 987
 988static int create_or_delete_trace_kprobe(const char *raw_command)
 989{
 990	int ret;
 991
 992	if (raw_command[0] == '-')
 993		return dyn_event_release(raw_command, &trace_kprobe_ops);
 994
 995	ret = trace_kprobe_create(raw_command);
 996	return ret == -ECANCELED ? -EINVAL : ret;
 997}
 998
 999static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
1000{
1001	return create_or_delete_trace_kprobe(cmd->seq.buffer);
1002}
1003
1004/**
1005 * kprobe_event_cmd_init - Initialize a kprobe event command object
1006 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1007 * @buf: A pointer to the buffer used to build the command
1008 * @maxlen: The length of the buffer passed in @buf
1009 *
1010 * Initialize a synthetic event command object.  Use this before
1011 * calling any of the other kprobe_event functions.
1012 */
1013void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
1014{
1015	dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
1016			  trace_kprobe_run_command);
1017}
1018EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
1019
1020/**
1021 * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
1022 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1023 * @kretprobe: Is this a return probe?
1024 * @name: The name of the kprobe event
1025 * @loc: The location of the kprobe event
1026 * @...: Variable number of arg (pairs), one pair for each field
 
1027 *
1028 * NOTE: Users normally won't want to call this function directly, but
1029 * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
1030 * adds a NULL to the end of the arg list.  If this function is used
1031 * directly, make sure the last arg in the variable arg list is NULL.
1032 *
1033 * Generate a kprobe event command to be executed by
1034 * kprobe_event_gen_cmd_end().  This function can be used to generate the
1035 * complete command or only the first part of it; in the latter case,
1036 * kprobe_event_add_fields() can be used to add more fields following this.
1037 *
1038 * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
1039 * returns -EINVAL if @loc == NULL.
1040 *
1041 * Return: 0 if successful, error otherwise.
1042 */
1043int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
1044				 const char *name, const char *loc, ...)
1045{
1046	char buf[MAX_EVENT_NAME_LEN];
1047	struct dynevent_arg arg;
1048	va_list args;
1049	int ret;
1050
1051	if (cmd->type != DYNEVENT_TYPE_KPROBE)
1052		return -EINVAL;
1053
1054	if (!loc)
1055		return -EINVAL;
1056
1057	if (kretprobe)
1058		snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
1059	else
1060		snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
1061
1062	ret = dynevent_str_add(cmd, buf);
1063	if (ret)
1064		return ret;
1065
1066	dynevent_arg_init(&arg, 0);
1067	arg.str = loc;
1068	ret = dynevent_arg_add(cmd, &arg, NULL);
1069	if (ret)
1070		return ret;
1071
1072	va_start(args, loc);
1073	for (;;) {
1074		const char *field;
1075
1076		field = va_arg(args, const char *);
1077		if (!field)
1078			break;
1079
1080		if (++cmd->n_fields > MAX_TRACE_ARGS) {
1081			ret = -EINVAL;
1082			break;
1083		}
1084
1085		arg.str = field;
1086		ret = dynevent_arg_add(cmd, &arg, NULL);
1087		if (ret)
1088			break;
1089	}
1090	va_end(args);
1091
1092	return ret;
1093}
1094EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
1095
1096/**
1097 * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
1098 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1099 * @...: Variable number of arg (pairs), one pair for each field
1100 *
1101 * NOTE: Users normally won't want to call this function directly, but
1102 * rather use the kprobe_event_add_fields() wrapper, which
1103 * automatically adds a NULL to the end of the arg list.  If this
1104 * function is used directly, make sure the last arg in the variable
1105 * arg list is NULL.
1106 *
1107 * Add probe fields to an existing kprobe command using a variable
1108 * list of args.  Fields are added in the same order they're listed.
1109 *
1110 * Return: 0 if successful, error otherwise.
1111 */
1112int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
1113{
1114	struct dynevent_arg arg;
1115	va_list args;
1116	int ret = 0;
1117
1118	if (cmd->type != DYNEVENT_TYPE_KPROBE)
1119		return -EINVAL;
1120
1121	dynevent_arg_init(&arg, 0);
1122
1123	va_start(args, cmd);
1124	for (;;) {
1125		const char *field;
1126
1127		field = va_arg(args, const char *);
1128		if (!field)
1129			break;
1130
1131		if (++cmd->n_fields > MAX_TRACE_ARGS) {
1132			ret = -EINVAL;
1133			break;
1134		}
1135
1136		arg.str = field;
1137		ret = dynevent_arg_add(cmd, &arg, NULL);
1138		if (ret)
1139			break;
1140	}
1141	va_end(args);
1142
1143	return ret;
1144}
1145EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
1146
1147/**
1148 * kprobe_event_delete - Delete a kprobe event
1149 * @name: The name of the kprobe event to delete
1150 *
1151 * Delete a kprobe event with the give @name from kernel code rather
1152 * than directly from the command line.
1153 *
1154 * Return: 0 if successful, error otherwise.
1155 */
1156int kprobe_event_delete(const char *name)
1157{
1158	char buf[MAX_EVENT_NAME_LEN];
1159
1160	snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
1161
1162	return create_or_delete_trace_kprobe(buf);
1163}
1164EXPORT_SYMBOL_GPL(kprobe_event_delete);
1165
1166static int trace_kprobe_release(struct dyn_event *ev)
1167{
1168	struct trace_kprobe *tk = to_trace_kprobe(ev);
1169	int ret = unregister_trace_kprobe(tk);
1170
1171	if (!ret)
1172		free_trace_kprobe(tk);
1173	return ret;
1174}
1175
1176static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
1177{
1178	struct trace_kprobe *tk = to_trace_kprobe(ev);
1179	int i;
1180
1181	seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
1182	if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
1183		seq_printf(m, "%d", tk->rp.maxactive);
1184	seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
1185				trace_probe_name(&tk->tp));
1186
1187	if (!tk->symbol)
1188		seq_printf(m, " 0x%p", tk->rp.kp.addr);
1189	else if (tk->rp.kp.offset)
1190		seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
1191			   tk->rp.kp.offset);
1192	else
1193		seq_printf(m, " %s", trace_kprobe_symbol(tk));
1194
1195	for (i = 0; i < tk->tp.nr_args; i++)
1196		seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
1197	seq_putc(m, '\n');
1198
1199	return 0;
1200}
1201
1202static int probes_seq_show(struct seq_file *m, void *v)
1203{
1204	struct dyn_event *ev = v;
1205
1206	if (!is_trace_kprobe(ev))
1207		return 0;
1208
1209	return trace_kprobe_show(m, ev);
1210}
1211
1212static const struct seq_operations probes_seq_op = {
1213	.start  = dyn_event_seq_start,
1214	.next   = dyn_event_seq_next,
1215	.stop   = dyn_event_seq_stop,
1216	.show   = probes_seq_show
1217};
1218
1219static int probes_open(struct inode *inode, struct file *file)
1220{
1221	int ret;
1222
1223	ret = security_locked_down(LOCKDOWN_TRACEFS);
1224	if (ret)
1225		return ret;
1226
1227	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1228		ret = dyn_events_release_all(&trace_kprobe_ops);
1229		if (ret < 0)
1230			return ret;
1231	}
1232
1233	return seq_open(file, &probes_seq_op);
1234}
1235
1236static ssize_t probes_write(struct file *file, const char __user *buffer,
1237			    size_t count, loff_t *ppos)
1238{
1239	return trace_parse_run_command(file, buffer, count, ppos,
1240				       create_or_delete_trace_kprobe);
1241}
1242
1243static const struct file_operations kprobe_events_ops = {
1244	.owner          = THIS_MODULE,
1245	.open           = probes_open,
1246	.read           = seq_read,
1247	.llseek         = seq_lseek,
1248	.release        = seq_release,
1249	.write		= probes_write,
1250};
1251
1252static unsigned long trace_kprobe_missed(struct trace_kprobe *tk)
1253{
1254	return trace_kprobe_is_return(tk) ?
1255		tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
1256}
1257
1258/* Probes profiling interfaces */
1259static int probes_profile_seq_show(struct seq_file *m, void *v)
1260{
1261	struct dyn_event *ev = v;
1262	struct trace_kprobe *tk;
1263	unsigned long nmissed;
1264
1265	if (!is_trace_kprobe(ev))
1266		return 0;
1267
1268	tk = to_trace_kprobe(ev);
1269	nmissed = trace_kprobe_missed(tk);
1270	seq_printf(m, "  %-44s %15lu %15lu\n",
1271		   trace_probe_name(&tk->tp),
1272		   trace_kprobe_nhit(tk),
1273		   nmissed);
1274
1275	return 0;
1276}
1277
1278static const struct seq_operations profile_seq_op = {
1279	.start  = dyn_event_seq_start,
1280	.next   = dyn_event_seq_next,
1281	.stop   = dyn_event_seq_stop,
1282	.show   = probes_profile_seq_show
1283};
1284
1285static int profile_open(struct inode *inode, struct file *file)
1286{
1287	int ret;
1288
1289	ret = security_locked_down(LOCKDOWN_TRACEFS);
1290	if (ret)
1291		return ret;
1292
1293	return seq_open(file, &profile_seq_op);
1294}
1295
1296static const struct file_operations kprobe_profile_ops = {
1297	.owner          = THIS_MODULE,
1298	.open           = profile_open,
1299	.read           = seq_read,
1300	.llseek         = seq_lseek,
1301	.release        = seq_release,
1302};
1303
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1304/* Note that we don't verify it, since the code does not come from user space */
1305static int
1306process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
1307		   void *base)
1308{
1309	struct pt_regs *regs = rec;
1310	unsigned long val;
1311	int ret;
1312
1313retry:
1314	/* 1st stage: get value from context */
1315	switch (code->op) {
1316	case FETCH_OP_REG:
1317		val = regs_get_register(regs, code->param);
1318		break;
1319	case FETCH_OP_STACK:
1320		val = regs_get_kernel_stack_nth(regs, code->param);
1321		break;
1322	case FETCH_OP_STACKP:
1323		val = kernel_stack_pointer(regs);
1324		break;
1325	case FETCH_OP_RETVAL:
1326		val = regs_return_value(regs);
1327		break;
 
 
 
 
 
 
 
 
 
1328#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1329	case FETCH_OP_ARG:
1330		val = regs_get_kernel_argument(regs, code->param);
1331		break;
1332#endif
1333	case FETCH_NOP_SYMBOL:	/* Ignore a place holder */
1334		code++;
1335		goto retry;
1336	default:
1337		ret = process_common_fetch_insn(code, &val);
1338		if (ret < 0)
1339			return ret;
1340	}
1341	code++;
1342
1343	return process_fetch_insn_bottom(code, val, dest, base);
1344}
1345NOKPROBE_SYMBOL(process_fetch_insn)
1346
1347/* Kprobe handler */
1348static nokprobe_inline void
1349__kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1350		    struct trace_event_file *trace_file)
1351{
1352	struct kprobe_trace_entry_head *entry;
1353	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1354	struct trace_event_buffer fbuffer;
1355	int dsize;
1356
1357	WARN_ON(call != trace_file->event_call);
1358
1359	if (trace_trigger_soft_disabled(trace_file))
1360		return;
1361
 
 
 
1362	dsize = __get_data_size(&tk->tp, regs);
1363
1364	entry = trace_event_buffer_reserve(&fbuffer, trace_file,
1365					   sizeof(*entry) + tk->tp.size + dsize);
1366	if (!entry)
 
 
 
1367		return;
1368
1369	fbuffer.regs = regs;
 
1370	entry->ip = (unsigned long)tk->rp.kp.addr;
1371	store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1372
1373	trace_event_buffer_commit(&fbuffer);
1374}
1375
1376static void
1377kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1378{
1379	struct event_file_link *link;
1380
1381	trace_probe_for_each_link_rcu(link, &tk->tp)
1382		__kprobe_trace_func(tk, regs, link->file);
1383}
1384NOKPROBE_SYMBOL(kprobe_trace_func);
1385
1386/* Kretprobe handler */
1387static nokprobe_inline void
1388__kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1389		       struct pt_regs *regs,
1390		       struct trace_event_file *trace_file)
1391{
1392	struct kretprobe_trace_entry_head *entry;
1393	struct trace_event_buffer fbuffer;
1394	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1395	int dsize;
1396
1397	WARN_ON(call != trace_file->event_call);
1398
1399	if (trace_trigger_soft_disabled(trace_file))
1400		return;
1401
1402	dsize = __get_data_size(&tk->tp, regs);
 
1403
1404	entry = trace_event_buffer_reserve(&fbuffer, trace_file,
1405					   sizeof(*entry) + tk->tp.size + dsize);
1406	if (!entry)
 
 
 
 
1407		return;
1408
1409	fbuffer.regs = regs;
 
1410	entry->func = (unsigned long)tk->rp.kp.addr;
1411	entry->ret_ip = get_kretprobe_retaddr(ri);
1412	store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1413
1414	trace_event_buffer_commit(&fbuffer);
1415}
1416
1417static void
1418kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1419		     struct pt_regs *regs)
1420{
1421	struct event_file_link *link;
1422
1423	trace_probe_for_each_link_rcu(link, &tk->tp)
1424		__kretprobe_trace_func(tk, ri, regs, link->file);
1425}
1426NOKPROBE_SYMBOL(kretprobe_trace_func);
1427
1428/* Event entry printers */
1429static enum print_line_t
1430print_kprobe_event(struct trace_iterator *iter, int flags,
1431		   struct trace_event *event)
1432{
1433	struct kprobe_trace_entry_head *field;
1434	struct trace_seq *s = &iter->seq;
1435	struct trace_probe *tp;
1436
1437	field = (struct kprobe_trace_entry_head *)iter->ent;
1438	tp = trace_probe_primary_from_call(
1439		container_of(event, struct trace_event_call, event));
1440	if (WARN_ON_ONCE(!tp))
1441		goto out;
1442
1443	trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1444
1445	if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1446		goto out;
1447
1448	trace_seq_putc(s, ')');
1449
1450	if (trace_probe_print_args(s, tp->args, tp->nr_args,
1451			     (u8 *)&field[1], field) < 0)
1452		goto out;
1453
1454	trace_seq_putc(s, '\n');
1455 out:
1456	return trace_handle_return(s);
1457}
1458
1459static enum print_line_t
1460print_kretprobe_event(struct trace_iterator *iter, int flags,
1461		      struct trace_event *event)
1462{
1463	struct kretprobe_trace_entry_head *field;
1464	struct trace_seq *s = &iter->seq;
1465	struct trace_probe *tp;
1466
1467	field = (struct kretprobe_trace_entry_head *)iter->ent;
1468	tp = trace_probe_primary_from_call(
1469		container_of(event, struct trace_event_call, event));
1470	if (WARN_ON_ONCE(!tp))
1471		goto out;
1472
1473	trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1474
1475	if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1476		goto out;
1477
1478	trace_seq_puts(s, " <- ");
1479
1480	if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1481		goto out;
1482
1483	trace_seq_putc(s, ')');
1484
1485	if (trace_probe_print_args(s, tp->args, tp->nr_args,
1486			     (u8 *)&field[1], field) < 0)
1487		goto out;
1488
1489	trace_seq_putc(s, '\n');
1490
1491 out:
1492	return trace_handle_return(s);
1493}
1494
1495
1496static int kprobe_event_define_fields(struct trace_event_call *event_call)
1497{
1498	int ret;
1499	struct kprobe_trace_entry_head field;
1500	struct trace_probe *tp;
1501
1502	tp = trace_probe_primary_from_call(event_call);
1503	if (WARN_ON_ONCE(!tp))
1504		return -ENOENT;
1505
1506	DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1507
1508	return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1509}
1510
1511static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1512{
1513	int ret;
1514	struct kretprobe_trace_entry_head field;
1515	struct trace_probe *tp;
1516
1517	tp = trace_probe_primary_from_call(event_call);
1518	if (WARN_ON_ONCE(!tp))
1519		return -ENOENT;
1520
1521	DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1522	DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1523
1524	return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1525}
1526
1527#ifdef CONFIG_PERF_EVENTS
1528
1529/* Kprobe profile handler */
1530static int
1531kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1532{
1533	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1534	struct kprobe_trace_entry_head *entry;
1535	struct hlist_head *head;
1536	int size, __size, dsize;
1537	int rctx;
1538
1539	if (bpf_prog_array_valid(call)) {
1540		unsigned long orig_ip = instruction_pointer(regs);
1541		int ret;
1542
1543		ret = trace_call_bpf(call, regs);
1544
1545		/*
1546		 * We need to check and see if we modified the pc of the
1547		 * pt_regs, and if so return 1 so that we don't do the
1548		 * single stepping.
1549		 */
1550		if (orig_ip != instruction_pointer(regs))
1551			return 1;
1552		if (!ret)
1553			return 0;
1554	}
1555
1556	head = this_cpu_ptr(call->perf_events);
1557	if (hlist_empty(head))
1558		return 0;
1559
1560	dsize = __get_data_size(&tk->tp, regs);
1561	__size = sizeof(*entry) + tk->tp.size + dsize;
1562	size = ALIGN(__size + sizeof(u32), sizeof(u64));
1563	size -= sizeof(u32);
1564
1565	entry = perf_trace_buf_alloc(size, NULL, &rctx);
1566	if (!entry)
1567		return 0;
1568
1569	entry->ip = (unsigned long)tk->rp.kp.addr;
1570	memset(&entry[1], 0, dsize);
1571	store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1572	perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1573			      head, NULL);
1574	return 0;
1575}
1576NOKPROBE_SYMBOL(kprobe_perf_func);
1577
1578/* Kretprobe profile handler */
1579static void
1580kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1581		    struct pt_regs *regs)
1582{
1583	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1584	struct kretprobe_trace_entry_head *entry;
1585	struct hlist_head *head;
1586	int size, __size, dsize;
1587	int rctx;
1588
1589	if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1590		return;
1591
1592	head = this_cpu_ptr(call->perf_events);
1593	if (hlist_empty(head))
1594		return;
1595
1596	dsize = __get_data_size(&tk->tp, regs);
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;
1604
1605	entry->func = (unsigned long)tk->rp.kp.addr;
1606	entry->ret_ip = get_kretprobe_retaddr(ri);
1607	store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1608	perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1609			      head, NULL);
1610}
1611NOKPROBE_SYMBOL(kretprobe_perf_func);
1612
1613int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1614			const char **symbol, u64 *probe_offset,
1615			u64 *probe_addr, unsigned long *missed,
1616			bool perf_type_tracepoint)
1617{
1618	const char *pevent = trace_event_name(event->tp_event);
1619	const char *group = event->tp_event->class->system;
1620	struct trace_kprobe *tk;
1621
1622	if (perf_type_tracepoint)
1623		tk = find_trace_kprobe(pevent, group);
1624	else
1625		tk = trace_kprobe_primary_from_call(event->tp_event);
1626	if (!tk)
1627		return -EINVAL;
1628
1629	*fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1630					      : BPF_FD_TYPE_KPROBE;
1631	*probe_offset = tk->rp.kp.offset;
1632	*probe_addr = kallsyms_show_value(current_cred()) ?
1633		      (unsigned long)tk->rp.kp.addr : 0;
1634	*symbol = tk->symbol;
1635	if (missed)
1636		*missed = trace_kprobe_missed(tk);
 
 
 
1637	return 0;
1638}
1639#endif	/* CONFIG_PERF_EVENTS */
1640
1641/*
1642 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1643 *
1644 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1645 * lockless, but we can't race with this __init function.
1646 */
1647static int kprobe_register(struct trace_event_call *event,
1648			   enum trace_reg type, void *data)
1649{
1650	struct trace_event_file *file = data;
1651
1652	switch (type) {
1653	case TRACE_REG_REGISTER:
1654		return enable_trace_kprobe(event, file);
1655	case TRACE_REG_UNREGISTER:
1656		return disable_trace_kprobe(event, file);
1657
1658#ifdef CONFIG_PERF_EVENTS
1659	case TRACE_REG_PERF_REGISTER:
1660		return enable_trace_kprobe(event, NULL);
1661	case TRACE_REG_PERF_UNREGISTER:
1662		return disable_trace_kprobe(event, NULL);
1663	case TRACE_REG_PERF_OPEN:
1664	case TRACE_REG_PERF_CLOSE:
1665	case TRACE_REG_PERF_ADD:
1666	case TRACE_REG_PERF_DEL:
1667		return 0;
1668#endif
1669	}
1670	return 0;
1671}
1672
1673static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1674{
1675	struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1676	int ret = 0;
1677
1678	raw_cpu_inc(*tk->nhit);
1679
1680	if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1681		kprobe_trace_func(tk, regs);
1682#ifdef CONFIG_PERF_EVENTS
1683	if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1684		ret = kprobe_perf_func(tk, regs);
1685#endif
1686	return ret;
1687}
1688NOKPROBE_SYMBOL(kprobe_dispatcher);
1689
1690static int
1691kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1692{
1693	struct kretprobe *rp = get_kretprobe(ri);
1694	struct trace_kprobe *tk;
1695
1696	/*
1697	 * There is a small chance that get_kretprobe(ri) returns NULL when
1698	 * the kretprobe is unregister on another CPU between kretprobe's
1699	 * trampoline_handler and this function.
1700	 */
1701	if (unlikely(!rp))
1702		return 0;
1703
1704	tk = container_of(rp, struct trace_kprobe, rp);
1705	raw_cpu_inc(*tk->nhit);
1706
1707	if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1708		kretprobe_trace_func(tk, ri, regs);
1709#ifdef CONFIG_PERF_EVENTS
1710	if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1711		kretprobe_perf_func(tk, ri, regs);
1712#endif
1713	return 0;	/* We don't tweak kernel, so just return 0 */
1714}
1715NOKPROBE_SYMBOL(kretprobe_dispatcher);
1716
1717static struct trace_event_functions kretprobe_funcs = {
1718	.trace		= print_kretprobe_event
1719};
1720
1721static struct trace_event_functions kprobe_funcs = {
1722	.trace		= print_kprobe_event
1723};
1724
1725static struct trace_event_fields kretprobe_fields_array[] = {
1726	{ .type = TRACE_FUNCTION_TYPE,
1727	  .define_fields = kretprobe_event_define_fields },
1728	{}
1729};
1730
1731static struct trace_event_fields kprobe_fields_array[] = {
1732	{ .type = TRACE_FUNCTION_TYPE,
1733	  .define_fields = kprobe_event_define_fields },
1734	{}
1735};
1736
1737static inline void init_trace_event_call(struct trace_kprobe *tk)
1738{
1739	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1740
1741	if (trace_kprobe_is_return(tk)) {
1742		call->event.funcs = &kretprobe_funcs;
1743		call->class->fields_array = kretprobe_fields_array;
1744	} else {
1745		call->event.funcs = &kprobe_funcs;
1746		call->class->fields_array = kprobe_fields_array;
1747	}
1748
1749	call->flags = TRACE_EVENT_FL_KPROBE;
1750	call->class->reg = kprobe_register;
1751}
1752
1753static int register_kprobe_event(struct trace_kprobe *tk)
1754{
1755	init_trace_event_call(tk);
1756
1757	return trace_probe_register_event_call(&tk->tp);
1758}
1759
1760static int unregister_kprobe_event(struct trace_kprobe *tk)
1761{
1762	return trace_probe_unregister_event_call(&tk->tp);
1763}
1764
1765#ifdef CONFIG_PERF_EVENTS
1766
1767/* create a trace_kprobe, but don't add it to global lists */
1768struct trace_event_call *
1769create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1770			  bool is_return)
1771{
1772	enum probe_print_type ptype;
1773	struct trace_kprobe *tk;
1774	int ret;
1775	char *event;
1776
1777	if (func) {
1778		unsigned int count;
1779
1780		count = number_of_same_symbols(func);
1781		if (count > 1)
1782			/*
1783			 * Users should use addr to remove the ambiguity of
1784			 * using func only.
1785			 */
1786			return ERR_PTR(-EADDRNOTAVAIL);
1787		else if (count == 0)
1788			/*
1789			 * We can return ENOENT earlier than when register the
1790			 * kprobe.
1791			 */
1792			return ERR_PTR(-ENOENT);
1793	}
1794
1795	/*
1796	 * local trace_kprobes are not added to dyn_event, so they are never
1797	 * searched in find_trace_kprobe(). Therefore, there is no concern of
1798	 * duplicated name here.
1799	 */
1800	event = func ? func : "DUMMY_EVENT";
1801
1802	tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1803				offs, 0 /* maxactive */, 0 /* nargs */,
1804				is_return);
1805
1806	if (IS_ERR(tk)) {
1807		pr_info("Failed to allocate trace_probe.(%d)\n",
1808			(int)PTR_ERR(tk));
1809		return ERR_CAST(tk);
1810	}
1811
1812	init_trace_event_call(tk);
1813
1814	ptype = trace_kprobe_is_return(tk) ?
1815		PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1816	if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) {
1817		ret = -ENOMEM;
1818		goto error;
1819	}
1820
1821	ret = __register_trace_kprobe(tk);
1822	if (ret < 0)
1823		goto error;
1824
1825	return trace_probe_event_call(&tk->tp);
1826error:
1827	free_trace_kprobe(tk);
1828	return ERR_PTR(ret);
1829}
1830
1831void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1832{
1833	struct trace_kprobe *tk;
1834
1835	tk = trace_kprobe_primary_from_call(event_call);
1836	if (unlikely(!tk))
1837		return;
1838
1839	if (trace_probe_is_enabled(&tk->tp)) {
1840		WARN_ON(1);
1841		return;
1842	}
1843
1844	__unregister_trace_kprobe(tk);
1845
1846	free_trace_kprobe(tk);
1847}
1848#endif /* CONFIG_PERF_EVENTS */
1849
1850static __init void enable_boot_kprobe_events(void)
1851{
1852	struct trace_array *tr = top_trace_array();
1853	struct trace_event_file *file;
1854	struct trace_kprobe *tk;
1855	struct dyn_event *pos;
1856
1857	mutex_lock(&event_mutex);
1858	for_each_trace_kprobe(tk, pos) {
1859		list_for_each_entry(file, &tr->events, list)
1860			if (file->event_call == trace_probe_event_call(&tk->tp))
1861				trace_event_enable_disable(file, 1, 0);
1862	}
1863	mutex_unlock(&event_mutex);
1864}
1865
1866static __init void setup_boot_kprobe_events(void)
1867{
1868	char *p, *cmd = kprobe_boot_events_buf;
1869	int ret;
1870
1871	strreplace(kprobe_boot_events_buf, ',', ' ');
1872
1873	while (cmd && *cmd != '\0') {
1874		p = strchr(cmd, ';');
1875		if (p)
1876			*p++ = '\0';
1877
1878		ret = create_or_delete_trace_kprobe(cmd);
1879		if (ret)
1880			pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1881
1882		cmd = p;
1883	}
1884
1885	enable_boot_kprobe_events();
1886}
1887
1888/*
1889 * Register dynevent at core_initcall. This allows kernel to setup kprobe
1890 * events in postcore_initcall without tracefs.
1891 */
1892static __init int init_kprobe_trace_early(void)
1893{
1894	int ret;
1895
1896	ret = dyn_event_register(&trace_kprobe_ops);
1897	if (ret)
1898		return ret;
1899
1900	if (register_module_notifier(&trace_kprobe_module_nb))
1901		return -EINVAL;
1902
1903	return 0;
1904}
1905core_initcall(init_kprobe_trace_early);
1906
1907/* Make a tracefs interface for controlling probe points */
1908static __init int init_kprobe_trace(void)
1909{
1910	int ret;
 
1911
1912	ret = tracing_init_dentry();
1913	if (ret)
1914		return 0;
1915
 
 
 
1916	/* Event list interface */
1917	trace_create_file("kprobe_events", TRACE_MODE_WRITE,
1918			  NULL, NULL, &kprobe_events_ops);
1919
1920	/* Profile interface */
1921	trace_create_file("kprobe_profile", TRACE_MODE_READ,
1922			  NULL, NULL, &kprobe_profile_ops);
 
 
 
1923
1924	setup_boot_kprobe_events();
1925
1926	return 0;
1927}
1928fs_initcall(init_kprobe_trace);
1929
1930
1931#ifdef CONFIG_FTRACE_STARTUP_TEST
1932static __init struct trace_event_file *
1933find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1934{
1935	struct trace_event_file *file;
1936
1937	list_for_each_entry(file, &tr->events, list)
1938		if (file->event_call == trace_probe_event_call(&tk->tp))
1939			return file;
1940
1941	return NULL;
1942}
1943
1944/*
1945 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1946 * stage, we can do this lockless.
1947 */
1948static __init int kprobe_trace_self_tests_init(void)
1949{
1950	int ret, warn = 0;
1951	int (*target)(int, int, int, int, int, int);
1952	struct trace_kprobe *tk;
1953	struct trace_event_file *file;
1954
1955	if (tracing_is_disabled())
1956		return -ENODEV;
1957
1958	if (tracing_selftest_disabled)
1959		return 0;
1960
1961	target = kprobe_trace_selftest_target;
1962
1963	pr_info("Testing kprobe tracing: ");
1964
1965	ret = create_or_delete_trace_kprobe("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)");
1966	if (WARN_ON_ONCE(ret)) {
1967		pr_warn("error on probing function entry.\n");
1968		warn++;
1969	} else {
1970		/* Enable trace point */
1971		tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1972		if (WARN_ON_ONCE(tk == NULL)) {
1973			pr_warn("error on getting new probe.\n");
1974			warn++;
1975		} else {
1976			file = find_trace_probe_file(tk, top_trace_array());
1977			if (WARN_ON_ONCE(file == NULL)) {
1978				pr_warn("error on getting probe file.\n");
1979				warn++;
1980			} else
1981				enable_trace_kprobe(
1982					trace_probe_event_call(&tk->tp), file);
1983		}
1984	}
1985
1986	ret = create_or_delete_trace_kprobe("r:testprobe2 kprobe_trace_selftest_target $retval");
1987	if (WARN_ON_ONCE(ret)) {
1988		pr_warn("error on probing function return.\n");
1989		warn++;
1990	} else {
1991		/* Enable trace point */
1992		tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1993		if (WARN_ON_ONCE(tk == NULL)) {
1994			pr_warn("error on getting 2nd new probe.\n");
1995			warn++;
1996		} else {
1997			file = find_trace_probe_file(tk, top_trace_array());
1998			if (WARN_ON_ONCE(file == NULL)) {
1999				pr_warn("error on getting probe file.\n");
2000				warn++;
2001			} else
2002				enable_trace_kprobe(
2003					trace_probe_event_call(&tk->tp), file);
2004		}
2005	}
2006
2007	if (warn)
2008		goto end;
2009
2010	ret = target(1, 2, 3, 4, 5, 6);
2011
2012	/*
2013	 * Not expecting an error here, the check is only to prevent the
2014	 * optimizer from removing the call to target() as otherwise there
2015	 * are no side-effects and the call is never performed.
2016	 */
2017	if (ret != 21)
2018		warn++;
2019
2020	/* Disable trace points before removing it */
2021	tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
2022	if (WARN_ON_ONCE(tk == NULL)) {
2023		pr_warn("error on getting test probe.\n");
2024		warn++;
2025	} else {
2026		if (trace_kprobe_nhit(tk) != 1) {
2027			pr_warn("incorrect number of testprobe hits\n");
2028			warn++;
2029		}
2030
2031		file = find_trace_probe_file(tk, top_trace_array());
2032		if (WARN_ON_ONCE(file == NULL)) {
2033			pr_warn("error on getting probe file.\n");
2034			warn++;
2035		} else
2036			disable_trace_kprobe(
2037				trace_probe_event_call(&tk->tp), file);
2038	}
2039
2040	tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2041	if (WARN_ON_ONCE(tk == NULL)) {
2042		pr_warn("error on getting 2nd test probe.\n");
2043		warn++;
2044	} else {
2045		if (trace_kprobe_nhit(tk) != 1) {
2046			pr_warn("incorrect number of testprobe2 hits\n");
2047			warn++;
2048		}
2049
2050		file = find_trace_probe_file(tk, top_trace_array());
2051		if (WARN_ON_ONCE(file == NULL)) {
2052			pr_warn("error on getting probe file.\n");
2053			warn++;
2054		} else
2055			disable_trace_kprobe(
2056				trace_probe_event_call(&tk->tp), file);
2057	}
2058
2059	ret = create_or_delete_trace_kprobe("-:testprobe");
2060	if (WARN_ON_ONCE(ret)) {
2061		pr_warn("error on deleting a probe.\n");
2062		warn++;
2063	}
2064
2065	ret = create_or_delete_trace_kprobe("-:testprobe2");
2066	if (WARN_ON_ONCE(ret)) {
2067		pr_warn("error on deleting a probe.\n");
2068		warn++;
2069	}
2070
2071end:
2072	ret = dyn_events_release_all(&trace_kprobe_ops);
2073	if (WARN_ON_ONCE(ret)) {
2074		pr_warn("error on cleaning up probes.\n");
2075		warn++;
2076	}
2077	/*
2078	 * Wait for the optimizer work to finish. Otherwise it might fiddle
2079	 * with probes in already freed __init text.
2080	 */
2081	wait_for_kprobe_optimizer();
2082	if (warn)
2083		pr_cont("NG: Some tests are failed. Please check them.\n");
2084	else
2085		pr_cont("OK\n");
2086	return 0;
2087}
2088
2089late_initcall(kprobe_trace_self_tests_init);
2090
2091#endif