kernel/trace/trace_kprobe.c

   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 */
  29 static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
  30
  31 static 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
  40 static int trace_kprobe_create(const char *raw_command);
  41 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
  42 static int trace_kprobe_release(struct dyn_event *ev);
  43 static bool trace_kprobe_is_busy(struct dyn_event *ev);
  44 static bool trace_kprobe_match(const char *system, const char *event,
  45                         int argc, const char **argv, struct dyn_event *ev);
  46
  47 static 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  */
  58 struct 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
  66 static bool is_trace_kprobe(struct dyn_event *ev)
  67 {
  68         return ev->ops == &trace_kprobe_ops;
  69 }
  70
  71 static 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
  85 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
  86 {
  87         return tk->rp.handler != NULL;
  88 }
  89
  90 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
  91 {
  92         return tk->symbol ? tk->symbol : "unknown";
  93 }
  94
  95 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
  96 {
  97         return tk->rp.kp.offset;
  98 }
  99
 100 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
 101 {
 102         return kprobe_gone(&tk->rp.kp);
 103 }
 104
 105 static 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
 114 static 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
 133 static 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
 140 static 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
 162 static 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
 173 static 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
 184 static 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 */
 191 static nokprobe_inline
 192 unsigned 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
 207 static nokprobe_inline struct trace_kprobe *
 208 trace_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
 219 bool 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
 228 bool 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
 236 static int register_kprobe_event(struct trace_kprobe *tk);
 237 static int unregister_kprobe_event(struct trace_kprobe *tk);
 238
 239 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 240 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
 241                                 struct pt_regs *regs);
 242
 243 static 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  */
 256 static 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;
 299 error:
 300         free_trace_kprobe(tk);
 301         return ERR_PTR(ret);
 302 }
 303
 304 static 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
 317 static 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
 331 static 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  */
 349 static 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  */
 399 static 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)
 435 static 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
 452 static 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 */
 478 static 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 %s\n",
 491                         trace_kprobe_symbol(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 */
 516 static 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 */
 532 static 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
 550 unreg:
 551         __unregister_trace_kprobe(tk);
 552         dyn_event_remove(&tk->devent);
 553         trace_probe_unlink(&tk->tp);
 554
 555         return 0;
 556 }
 557
 558 static 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
 587 static 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 */
 625 static 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
 668 end:
 669         mutex_unlock(&event_mutex);
 670         return ret;
 671 }
 672
 673 /* Module notifier call back, checking event on the module */
 674 static 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
 703 static struct notifier_block trace_kprobe_module_nb = {
 704         .notifier_call = trace_kprobe_module_callback,
 705         .priority = 1   /* Invoked after kprobe module callback */
 706 };
 707
 708 static int count_symbols(void *data, unsigned long unused)
 709 {
 710         unsigned int *count = data;
 711
 712         (*count)++;
 713
 714         return 0;
 715 }
 716
 717 static unsigned int number_of_same_symbols(char *func_name)
 718 {
 719         unsigned int count;
 720
 721         count = 0;
 722         kallsyms_on_each_match_symbol(count_symbols, func_name, &count);
 723
 724         return count;
 725 }
 726
 727 static int __trace_kprobe_create(int argc, const char *argv[])
 728 {
 729         /*
 730          * Argument syntax:
 731          *  - Add kprobe:
 732          *      p[:[GRP/][EVENT]] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
 733          *  - Add kretprobe:
 734          *      r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]KSYM[+0] [FETCHARGS]
 735          *    Or
 736          *      p[:[GRP/][EVENT]] [MOD:]KSYM[+0]%return [FETCHARGS]
 737          *
 738          * Fetch args:
 739          *  $retval     : fetch return value
 740          *  $stack      : fetch stack address
 741          *  $stackN     : fetch Nth of stack (N:0-)
 742          *  $comm       : fetch current task comm
 743          *  @ADDR       : fetch memory at ADDR (ADDR should be in kernel)
 744          *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
 745          *  %REG        : fetch register REG
 746          * Dereferencing memory fetch:
 747          *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
 748          * Alias name of args:
 749          *  NAME=FETCHARG : set NAME as alias of FETCHARG.
 750          * Type of args:
 751          *  FETCHARG:TYPE : use TYPE instead of unsigned long.
 752          */
 753         struct trace_kprobe *tk = NULL;
 754         int i, len, new_argc = 0, ret = 0;
 755         bool is_return = false;
 756         char *symbol = NULL, *tmp = NULL;
 757         const char **new_argv = NULL;
 758         const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
 759         enum probe_print_type ptype;
 760         int maxactive = 0;
 761         long offset = 0;
 762         void *addr = NULL;
 763         char buf[MAX_EVENT_NAME_LEN];
 764         char gbuf[MAX_EVENT_NAME_LEN];
 765         char abuf[MAX_BTF_ARGS_LEN];
 766         struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL };
 767
 768         switch (argv[0][0]) {
 769         case 'r':
 770                 is_return = true;
 771                 break;
 772         case 'p':
 773                 break;
 774         default:
 775                 return -ECANCELED;
 776         }
 777         if (argc < 2)
 778                 return -ECANCELED;
 779
 780         trace_probe_log_init("trace_kprobe", argc, argv);
 781
 782         event = strchr(&argv[0][1], ':');
 783         if (event)
 784                 event++;
 785
 786         if (isdigit(argv[0][1])) {
 787                 if (!is_return) {
 788                         trace_probe_log_err(1, BAD_MAXACT_TYPE);
 789                         goto parse_error;
 790                 }
 791                 if (event)
 792                         len = event - &argv[0][1] - 1;
 793                 else
 794                         len = strlen(&argv[0][1]);
 795                 if (len > MAX_EVENT_NAME_LEN - 1) {
 796                         trace_probe_log_err(1, BAD_MAXACT);
 797                         goto parse_error;
 798                 }
 799                 memcpy(buf, &argv[0][1], len);
 800                 buf[len] = '\0';
 801                 ret = kstrtouint(buf, 0, &maxactive);
 802                 if (ret || !maxactive) {
 803                         trace_probe_log_err(1, BAD_MAXACT);
 804                         goto parse_error;
 805                 }
 806                 /* kretprobes instances are iterated over via a list. The
 807                  * maximum should stay reasonable.
 808                  */
 809                 if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
 810                         trace_probe_log_err(1, MAXACT_TOO_BIG);
 811                         goto parse_error;
 812                 }
 813         }
 814
 815         /* try to parse an address. if that fails, try to read the
 816          * input as a symbol. */
 817         if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
 818                 trace_probe_log_set_index(1);
 819                 /* Check whether uprobe event specified */
 820                 if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
 821                         ret = -ECANCELED;
 822                         goto error;
 823                 }
 824                 /* a symbol specified */
 825                 symbol = kstrdup(argv[1], GFP_KERNEL);
 826                 if (!symbol)
 827                         return -ENOMEM;
 828
 829                 tmp = strchr(symbol, '%');
 830                 if (tmp) {
 831                         if (!strcmp(tmp, "%return")) {
 832                                 *tmp = '\0';
 833                                 is_return = true;
 834                         } else {
 835                                 trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
 836                                 goto parse_error;
 837                         }
 838                 }
 839
 840                 /* TODO: support .init module functions */
 841                 ret = traceprobe_split_symbol_offset(symbol, &offset);
 842                 if (ret || offset < 0 || offset > UINT_MAX) {
 843                         trace_probe_log_err(0, BAD_PROBE_ADDR);
 844                         goto parse_error;
 845                 }
 846                 if (is_return)
 847                         ctx.flags |= TPARG_FL_RETURN;
 848                 ret = kprobe_on_func_entry(NULL, symbol, offset);
 849                 if (ret == 0 && !is_return)
 850                         ctx.flags |= TPARG_FL_FENTRY;
 851                 /* Defer the ENOENT case until register kprobe */
 852                 if (ret == -EINVAL && is_return) {
 853                         trace_probe_log_err(0, BAD_RETPROBE);
 854                         goto parse_error;
 855                 }
 856         }
 857
 858         if (symbol && !strchr(symbol, ':')) {
 859                 unsigned int count;
 860
 861                 count = number_of_same_symbols(symbol);
 862                 if (count > 1) {
 863                         /*
 864                          * Users should use ADDR to remove the ambiguity of
 865                          * using KSYM only.
 866                          */
 867                         trace_probe_log_err(0, NON_UNIQ_SYMBOL);
 868                         ret = -EADDRNOTAVAIL;
 869
 870                         goto error;
 871                 } else if (count == 0) {
 872                         /*
 873                          * We can return ENOENT earlier than when register the
 874                          * kprobe.
 875                          */
 876                         trace_probe_log_err(0, BAD_PROBE_ADDR);
 877                         ret = -ENOENT;
 878
 879                         goto error;
 880                 }
 881         }
 882
 883         trace_probe_log_set_index(0);
 884         if (event) {
 885                 ret = traceprobe_parse_event_name(&event, &group, gbuf,
 886                                                   event - argv[0]);
 887                 if (ret)
 888                         goto parse_error;
 889         }
 890
 891         if (!event) {
 892                 /* Make a new event name */
 893                 if (symbol)
 894                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
 895                                  is_return ? 'r' : 'p', symbol, offset);
 896                 else
 897                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
 898                                  is_return ? 'r' : 'p', addr);
 899                 sanitize_event_name(buf);
 900                 event = buf;
 901         }
 902
 903         argc -= 2; argv += 2;
 904         ctx.funcname = symbol;
 905         new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc,
 906                                                abuf, MAX_BTF_ARGS_LEN, &ctx);
 907         if (IS_ERR(new_argv)) {
 908                 ret = PTR_ERR(new_argv);
 909                 new_argv = NULL;
 910                 goto out;
 911         }
 912         if (new_argv) {
 913                 argc = new_argc;
 914                 argv = new_argv;
 915         }
 916
 917         /* setup a probe */
 918         tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
 919                                 argc, is_return);
 920         if (IS_ERR(tk)) {
 921                 ret = PTR_ERR(tk);
 922                 /* This must return -ENOMEM, else there is a bug */
 923                 WARN_ON_ONCE(ret != -ENOMEM);
 924                 goto out;       /* We know tk is not allocated */
 925         }
 926
 927         /* parse arguments */
 928         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 929                 trace_probe_log_set_index(i + 2);
 930                 ctx.offset = 0;
 931                 ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], &ctx);
 932                 if (ret)
 933                         goto error;     /* This can be -ENOMEM */
 934         }
 935
 936         ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
 937         ret = traceprobe_set_print_fmt(&tk->tp, ptype);
 938         if (ret < 0)
 939                 goto error;
 940
 941         ret = register_trace_kprobe(tk);
 942         if (ret) {
 943                 trace_probe_log_set_index(1);
 944                 if (ret == -EILSEQ)
 945                         trace_probe_log_err(0, BAD_INSN_BNDRY);
 946                 else if (ret == -ENOENT)
 947                         trace_probe_log_err(0, BAD_PROBE_ADDR);
 948                 else if (ret != -ENOMEM && ret != -EEXIST)
 949                         trace_probe_log_err(0, FAIL_REG_PROBE);
 950                 goto error;
 951         }
 952
 953 out:
 954         traceprobe_finish_parse(&ctx);
 955         trace_probe_log_clear();
 956         kfree(new_argv);
 957         kfree(symbol);
 958         return ret;
 959
 960 parse_error:
 961         ret = -EINVAL;
 962 error:
 963         free_trace_kprobe(tk);
 964         goto out;
 965 }
 966
 967 static int trace_kprobe_create(const char *raw_command)
 968 {
 969         return trace_probe_create(raw_command, __trace_kprobe_create);
 970 }
 971
 972 static int create_or_delete_trace_kprobe(const char *raw_command)
 973 {
 974         int ret;
 975
 976         if (raw_command[0] == '-')
 977                 return dyn_event_release(raw_command, &trace_kprobe_ops);
 978
 979         ret = trace_kprobe_create(raw_command);
 980         return ret == -ECANCELED ? -EINVAL : ret;
 981 }
 982
 983 static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
 984 {
 985         return create_or_delete_trace_kprobe(cmd->seq.buffer);
 986 }
 987
 988 /**
 989  * kprobe_event_cmd_init - Initialize a kprobe event command object
 990  * @cmd: A pointer to the dynevent_cmd struct representing the new event
 991  * @buf: A pointer to the buffer used to build the command
 992  * @maxlen: The length of the buffer passed in @buf
 993  *
 994  * Initialize a synthetic event command object.  Use this before
 995  * calling any of the other kprobe_event functions.
 996  */
 997 void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
 998 {
 999         dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
1000                           trace_kprobe_run_command);
1001 }
1002 EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
1003
1004 /**
1005  * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
1006  * @cmd: A pointer to the dynevent_cmd struct representing the new event
1007  * @name: The name of the kprobe event
1008  * @loc: The location of the kprobe event
1009  * @kretprobe: Is this a return probe?
1010  * @args: Variable number of arg (pairs), one pair for each field
1011  *
1012  * NOTE: Users normally won't want to call this function directly, but
1013  * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
1014  * adds a NULL to the end of the arg list.  If this function is used
1015  * directly, make sure the last arg in the variable arg list is NULL.
1016  *
1017  * Generate a kprobe event command to be executed by
1018  * kprobe_event_gen_cmd_end().  This function can be used to generate the
1019  * complete command or only the first part of it; in the latter case,
1020  * kprobe_event_add_fields() can be used to add more fields following this.
1021  *
1022  * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
1023  * returns -EINVAL if @loc == NULL.
1024  *
1025  * Return: 0 if successful, error otherwise.
1026  */
1027 int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
1028                                  const char *name, const char *loc, ...)
1029 {
1030         char buf[MAX_EVENT_NAME_LEN];
1031         struct dynevent_arg arg;
1032         va_list args;
1033         int ret;
1034
1035         if (cmd->type != DYNEVENT_TYPE_KPROBE)
1036                 return -EINVAL;
1037
1038         if (!loc)
1039                 return -EINVAL;
1040
1041         if (kretprobe)
1042                 snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
1043         else
1044                 snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
1045
1046         ret = dynevent_str_add(cmd, buf);
1047         if (ret)
1048                 return ret;
1049
1050         dynevent_arg_init(&arg, 0);
1051         arg.str = loc;
1052         ret = dynevent_arg_add(cmd, &arg, NULL);
1053         if (ret)
1054                 return ret;
1055
1056         va_start(args, loc);
1057         for (;;) {
1058                 const char *field;
1059
1060                 field = va_arg(args, const char *);
1061                 if (!field)
1062                         break;
1063
1064                 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1065                         ret = -EINVAL;
1066                         break;
1067                 }
1068
1069                 arg.str = field;
1070                 ret = dynevent_arg_add(cmd, &arg, NULL);
1071                 if (ret)
1072                         break;
1073         }
1074         va_end(args);
1075
1076         return ret;
1077 }
1078 EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
1079
1080 /**
1081  * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
1082  * @cmd: A pointer to the dynevent_cmd struct representing the new event
1083  * @args: Variable number of arg (pairs), one pair for each field
1084  *
1085  * NOTE: Users normally won't want to call this function directly, but
1086  * rather use the kprobe_event_add_fields() wrapper, which
1087  * automatically adds a NULL to the end of the arg list.  If this
1088  * function is used directly, make sure the last arg in the variable
1089  * arg list is NULL.
1090  *
1091  * Add probe fields to an existing kprobe command using a variable
1092  * list of args.  Fields are added in the same order they're listed.
1093  *
1094  * Return: 0 if successful, error otherwise.
1095  */
1096 int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
1097 {
1098         struct dynevent_arg arg;
1099         va_list args;
1100         int ret = 0;
1101
1102         if (cmd->type != DYNEVENT_TYPE_KPROBE)
1103                 return -EINVAL;
1104
1105         dynevent_arg_init(&arg, 0);
1106
1107         va_start(args, cmd);
1108         for (;;) {
1109                 const char *field;
1110
1111                 field = va_arg(args, const char *);
1112                 if (!field)
1113                         break;
1114
1115                 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1116                         ret = -EINVAL;
1117                         break;
1118                 }
1119
1120                 arg.str = field;
1121                 ret = dynevent_arg_add(cmd, &arg, NULL);
1122                 if (ret)
1123                         break;
1124         }
1125         va_end(args);
1126
1127         return ret;
1128 }
1129 EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
1130
1131 /**
1132  * kprobe_event_delete - Delete a kprobe event
1133  * @name: The name of the kprobe event to delete
1134  *
1135  * Delete a kprobe event with the give @name from kernel code rather
1136  * than directly from the command line.
1137  *
1138  * Return: 0 if successful, error otherwise.
1139  */
1140 int kprobe_event_delete(const char *name)
1141 {
1142         char buf[MAX_EVENT_NAME_LEN];
1143
1144         snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
1145
1146         return create_or_delete_trace_kprobe(buf);
1147 }
1148 EXPORT_SYMBOL_GPL(kprobe_event_delete);
1149
1150 static int trace_kprobe_release(struct dyn_event *ev)
1151 {
1152         struct trace_kprobe *tk = to_trace_kprobe(ev);
1153         int ret = unregister_trace_kprobe(tk);
1154
1155         if (!ret)
1156                 free_trace_kprobe(tk);
1157         return ret;
1158 }
1159
1160 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
1161 {
1162         struct trace_kprobe *tk = to_trace_kprobe(ev);
1163         int i;
1164
1165         seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
1166         if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
1167                 seq_printf(m, "%d", tk->rp.maxactive);
1168         seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
1169                                 trace_probe_name(&tk->tp));
1170
1171         if (!tk->symbol)
1172                 seq_printf(m, " 0x%p", tk->rp.kp.addr);
1173         else if (tk->rp.kp.offset)
1174                 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
1175                            tk->rp.kp.offset);
1176         else
1177                 seq_printf(m, " %s", trace_kprobe_symbol(tk));
1178
1179         for (i = 0; i < tk->tp.nr_args; i++)
1180                 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
1181         seq_putc(m, '\n');
1182
1183         return 0;
1184 }
1185
1186 static int probes_seq_show(struct seq_file *m, void *v)
1187 {
1188         struct dyn_event *ev = v;
1189
1190         if (!is_trace_kprobe(ev))
1191                 return 0;
1192
1193         return trace_kprobe_show(m, ev);
1194 }
1195
1196 static const struct seq_operations probes_seq_op = {
1197         .start  = dyn_event_seq_start,
1198         .next   = dyn_event_seq_next,
1199         .stop   = dyn_event_seq_stop,
1200         .show   = probes_seq_show
1201 };
1202
1203 static int probes_open(struct inode *inode, struct file *file)
1204 {
1205         int ret;
1206
1207         ret = security_locked_down(LOCKDOWN_TRACEFS);
1208         if (ret)
1209                 return ret;
1210
1211         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1212                 ret = dyn_events_release_all(&trace_kprobe_ops);
1213                 if (ret < 0)
1214                         return ret;
1215         }
1216
1217         return seq_open(file, &probes_seq_op);
1218 }
1219
1220 static ssize_t probes_write(struct file *file, const char __user *buffer,
1221                             size_t count, loff_t *ppos)
1222 {
1223         return trace_parse_run_command(file, buffer, count, ppos,
1224                                        create_or_delete_trace_kprobe);
1225 }
1226
1227 static const struct file_operations kprobe_events_ops = {
1228         .owner          = THIS_MODULE,
1229         .open           = probes_open,
1230         .read           = seq_read,
1231         .llseek         = seq_lseek,
1232         .release        = seq_release,
1233         .write          = probes_write,
1234 };
1235
1236 /* Probes profiling interfaces */
1237 static int probes_profile_seq_show(struct seq_file *m, void *v)
1238 {
1239         struct dyn_event *ev = v;
1240         struct trace_kprobe *tk;
1241         unsigned long nmissed;
1242
1243         if (!is_trace_kprobe(ev))
1244                 return 0;
1245
1246         tk = to_trace_kprobe(ev);
1247         nmissed = trace_kprobe_is_return(tk) ?
1248                 tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
1249         seq_printf(m, "  %-44s %15lu %15lu\n",
1250                    trace_probe_name(&tk->tp),
1251                    trace_kprobe_nhit(tk),
1252                    nmissed);
1253
1254         return 0;
1255 }
1256
1257 static const struct seq_operations profile_seq_op = {
1258         .start  = dyn_event_seq_start,
1259         .next   = dyn_event_seq_next,
1260         .stop   = dyn_event_seq_stop,
1261         .show   = probes_profile_seq_show
1262 };
1263
1264 static int profile_open(struct inode *inode, struct file *file)
1265 {
1266         int ret;
1267
1268         ret = security_locked_down(LOCKDOWN_TRACEFS);
1269         if (ret)
1270                 return ret;
1271
1272         return seq_open(file, &profile_seq_op);
1273 }
1274
1275 static const struct file_operations kprobe_profile_ops = {
1276         .owner          = THIS_MODULE,
1277         .open           = profile_open,
1278         .read           = seq_read,
1279         .llseek         = seq_lseek,
1280         .release        = seq_release,
1281 };
1282
1283 /* Note that we don't verify it, since the code does not come from user space */
1284 static int
1285 process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
1286                    void *base)
1287 {
1288         struct pt_regs *regs = rec;
1289         unsigned long val;
1290         int ret;
1291
1292 retry:
1293         /* 1st stage: get value from context */
1294         switch (code->op) {
1295         case FETCH_OP_REG:
1296                 val = regs_get_register(regs, code->param);
1297                 break;
1298         case FETCH_OP_STACK:
1299                 val = regs_get_kernel_stack_nth(regs, code->param);
1300                 break;
1301         case FETCH_OP_STACKP:
1302                 val = kernel_stack_pointer(regs);
1303                 break;
1304         case FETCH_OP_RETVAL:
1305                 val = regs_return_value(regs);
1306                 break;
1307 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1308         case FETCH_OP_ARG:
1309                 val = regs_get_kernel_argument(regs, code->param);
1310                 break;
1311 #endif
1312         case FETCH_NOP_SYMBOL:  /* Ignore a place holder */
1313                 code++;
1314                 goto retry;
1315         default:
1316                 ret = process_common_fetch_insn(code, &val);
1317                 if (ret < 0)
1318                         return ret;
1319         }
1320         code++;
1321
1322         return process_fetch_insn_bottom(code, val, dest, base);
1323 }
1324 NOKPROBE_SYMBOL(process_fetch_insn)
1325
1326 /* Kprobe handler */
1327 static nokprobe_inline void
1328 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1329                     struct trace_event_file *trace_file)
1330 {
1331         struct kprobe_trace_entry_head *entry;
1332         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1333         struct trace_event_buffer fbuffer;
1334         int dsize;
1335
1336         WARN_ON(call != trace_file->event_call);
1337
1338         if (trace_trigger_soft_disabled(trace_file))
1339                 return;
1340
1341         dsize = __get_data_size(&tk->tp, regs);
1342
1343         entry = trace_event_buffer_reserve(&fbuffer, trace_file,
1344                                            sizeof(*entry) + tk->tp.size + dsize);
1345         if (!entry)
1346                 return;
1347
1348         fbuffer.regs = regs;
1349         entry->ip = (unsigned long)tk->rp.kp.addr;
1350         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1351
1352         trace_event_buffer_commit(&fbuffer);
1353 }
1354
1355 static void
1356 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1357 {
1358         struct event_file_link *link;
1359
1360         trace_probe_for_each_link_rcu(link, &tk->tp)
1361                 __kprobe_trace_func(tk, regs, link->file);
1362 }
1363 NOKPROBE_SYMBOL(kprobe_trace_func);
1364
1365 /* Kretprobe handler */
1366 static nokprobe_inline void
1367 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1368                        struct pt_regs *regs,
1369                        struct trace_event_file *trace_file)
1370 {
1371         struct kretprobe_trace_entry_head *entry;
1372         struct trace_event_buffer fbuffer;
1373         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1374         int dsize;
1375
1376         WARN_ON(call != trace_file->event_call);
1377
1378         if (trace_trigger_soft_disabled(trace_file))
1379                 return;
1380
1381         dsize = __get_data_size(&tk->tp, regs);
1382
1383         entry = trace_event_buffer_reserve(&fbuffer, trace_file,
1384                                            sizeof(*entry) + tk->tp.size + dsize);
1385         if (!entry)
1386                 return;
1387
1388         fbuffer.regs = regs;
1389         entry->func = (unsigned long)tk->rp.kp.addr;
1390         entry->ret_ip = get_kretprobe_retaddr(ri);
1391         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1392
1393         trace_event_buffer_commit(&fbuffer);
1394 }
1395
1396 static void
1397 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1398                      struct pt_regs *regs)
1399 {
1400         struct event_file_link *link;
1401
1402         trace_probe_for_each_link_rcu(link, &tk->tp)
1403                 __kretprobe_trace_func(tk, ri, regs, link->file);
1404 }
1405 NOKPROBE_SYMBOL(kretprobe_trace_func);
1406
1407 /* Event entry printers */
1408 static enum print_line_t
1409 print_kprobe_event(struct trace_iterator *iter, int flags,
1410                    struct trace_event *event)
1411 {
1412         struct kprobe_trace_entry_head *field;
1413         struct trace_seq *s = &iter->seq;
1414         struct trace_probe *tp;
1415
1416         field = (struct kprobe_trace_entry_head *)iter->ent;
1417         tp = trace_probe_primary_from_call(
1418                 container_of(event, struct trace_event_call, event));
1419         if (WARN_ON_ONCE(!tp))
1420                 goto out;
1421
1422         trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1423
1424         if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1425                 goto out;
1426
1427         trace_seq_putc(s, ')');
1428
1429         if (trace_probe_print_args(s, tp->args, tp->nr_args,
1430                              (u8 *)&field[1], field) < 0)
1431                 goto out;
1432
1433         trace_seq_putc(s, '\n');
1434  out:
1435         return trace_handle_return(s);
1436 }
1437
1438 static enum print_line_t
1439 print_kretprobe_event(struct trace_iterator *iter, int flags,
1440                       struct trace_event *event)
1441 {
1442         struct kretprobe_trace_entry_head *field;
1443         struct trace_seq *s = &iter->seq;
1444         struct trace_probe *tp;
1445
1446         field = (struct kretprobe_trace_entry_head *)iter->ent;
1447         tp = trace_probe_primary_from_call(
1448                 container_of(event, struct trace_event_call, event));
1449         if (WARN_ON_ONCE(!tp))
1450                 goto out;
1451
1452         trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1453
1454         if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1455                 goto out;
1456
1457         trace_seq_puts(s, " <- ");
1458
1459         if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1460                 goto out;
1461
1462         trace_seq_putc(s, ')');
1463
1464         if (trace_probe_print_args(s, tp->args, tp->nr_args,
1465                              (u8 *)&field[1], field) < 0)
1466                 goto out;
1467
1468         trace_seq_putc(s, '\n');
1469
1470  out:
1471         return trace_handle_return(s);
1472 }
1473
1474
1475 static int kprobe_event_define_fields(struct trace_event_call *event_call)
1476 {
1477         int ret;
1478         struct kprobe_trace_entry_head field;
1479         struct trace_probe *tp;
1480
1481         tp = trace_probe_primary_from_call(event_call);
1482         if (WARN_ON_ONCE(!tp))
1483                 return -ENOENT;
1484
1485         DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1486
1487         return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1488 }
1489
1490 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1491 {
1492         int ret;
1493         struct kretprobe_trace_entry_head field;
1494         struct trace_probe *tp;
1495
1496         tp = trace_probe_primary_from_call(event_call);
1497         if (WARN_ON_ONCE(!tp))
1498                 return -ENOENT;
1499
1500         DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1501         DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1502
1503         return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1504 }
1505
1506 #ifdef CONFIG_PERF_EVENTS
1507
1508 /* Kprobe profile handler */
1509 static int
1510 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1511 {
1512         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1513         struct kprobe_trace_entry_head *entry;
1514         struct hlist_head *head;
1515         int size, __size, dsize;
1516         int rctx;
1517
1518         if (bpf_prog_array_valid(call)) {
1519                 unsigned long orig_ip = instruction_pointer(regs);
1520                 int ret;
1521
1522                 ret = trace_call_bpf(call, regs);
1523
1524                 /*
1525                  * We need to check and see if we modified the pc of the
1526                  * pt_regs, and if so return 1 so that we don't do the
1527                  * single stepping.
1528                  */
1529                 if (orig_ip != instruction_pointer(regs))
1530                         return 1;
1531                 if (!ret)
1532                         return 0;
1533         }
1534
1535         head = this_cpu_ptr(call->perf_events);
1536         if (hlist_empty(head))
1537                 return 0;
1538
1539         dsize = __get_data_size(&tk->tp, regs);
1540         __size = sizeof(*entry) + tk->tp.size + dsize;
1541         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1542         size -= sizeof(u32);
1543
1544         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1545         if (!entry)
1546                 return 0;
1547
1548         entry->ip = (unsigned long)tk->rp.kp.addr;
1549         memset(&entry[1], 0, dsize);
1550         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1551         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1552                               head, NULL);
1553         return 0;
1554 }
1555 NOKPROBE_SYMBOL(kprobe_perf_func);
1556
1557 /* Kretprobe profile handler */
1558 static void
1559 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1560                     struct pt_regs *regs)
1561 {
1562         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1563         struct kretprobe_trace_entry_head *entry;
1564         struct hlist_head *head;
1565         int size, __size, dsize;
1566         int rctx;
1567
1568         if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1569                 return;
1570
1571         head = this_cpu_ptr(call->perf_events);
1572         if (hlist_empty(head))
1573                 return;
1574
1575         dsize = __get_data_size(&tk->tp, regs);
1576         __size = sizeof(*entry) + tk->tp.size + dsize;
1577         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1578         size -= sizeof(u32);
1579
1580         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1581         if (!entry)
1582                 return;
1583
1584         entry->func = (unsigned long)tk->rp.kp.addr;
1585         entry->ret_ip = get_kretprobe_retaddr(ri);
1586         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1587         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1588                               head, NULL);
1589 }
1590 NOKPROBE_SYMBOL(kretprobe_perf_func);
1591
1592 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1593                         const char **symbol, u64 *probe_offset,
1594                         u64 *probe_addr, bool perf_type_tracepoint)
1595 {
1596         const char *pevent = trace_event_name(event->tp_event);
1597         const char *group = event->tp_event->class->system;
1598         struct trace_kprobe *tk;
1599
1600         if (perf_type_tracepoint)
1601                 tk = find_trace_kprobe(pevent, group);
1602         else
1603                 tk = trace_kprobe_primary_from_call(event->tp_event);
1604         if (!tk)
1605                 return -EINVAL;
1606
1607         *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1608                                               : BPF_FD_TYPE_KPROBE;
1609         *probe_offset = tk->rp.kp.offset;
1610         *probe_addr = kallsyms_show_value(current_cred()) ?
1611                       (unsigned long)tk->rp.kp.addr : 0;
1612         *symbol = tk->symbol;
1613         return 0;
1614 }
1615 #endif  /* CONFIG_PERF_EVENTS */
1616
1617 /*
1618  * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1619  *
1620  * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1621  * lockless, but we can't race with this __init function.
1622  */
1623 static int kprobe_register(struct trace_event_call *event,
1624                            enum trace_reg type, void *data)
1625 {
1626         struct trace_event_file *file = data;
1627
1628         switch (type) {
1629         case TRACE_REG_REGISTER:
1630                 return enable_trace_kprobe(event, file);
1631         case TRACE_REG_UNREGISTER:
1632                 return disable_trace_kprobe(event, file);
1633
1634 #ifdef CONFIG_PERF_EVENTS
1635         case TRACE_REG_PERF_REGISTER:
1636                 return enable_trace_kprobe(event, NULL);
1637         case TRACE_REG_PERF_UNREGISTER:
1638                 return disable_trace_kprobe(event, NULL);
1639         case TRACE_REG_PERF_OPEN:
1640         case TRACE_REG_PERF_CLOSE:
1641         case TRACE_REG_PERF_ADD:
1642         case TRACE_REG_PERF_DEL:
1643                 return 0;
1644 #endif
1645         }
1646         return 0;
1647 }
1648
1649 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1650 {
1651         struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1652         int ret = 0;
1653
1654         raw_cpu_inc(*tk->nhit);
1655
1656         if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1657                 kprobe_trace_func(tk, regs);
1658 #ifdef CONFIG_PERF_EVENTS
1659         if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1660                 ret = kprobe_perf_func(tk, regs);
1661 #endif
1662         return ret;
1663 }
1664 NOKPROBE_SYMBOL(kprobe_dispatcher);
1665
1666 static int
1667 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1668 {
1669         struct kretprobe *rp = get_kretprobe(ri);
1670         struct trace_kprobe *tk;
1671
1672         /*
1673          * There is a small chance that get_kretprobe(ri) returns NULL when
1674          * the kretprobe is unregister on another CPU between kretprobe's
1675          * trampoline_handler and this function.
1676          */
1677         if (unlikely(!rp))
1678                 return 0;
1679
1680         tk = container_of(rp, struct trace_kprobe, rp);
1681         raw_cpu_inc(*tk->nhit);
1682
1683         if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1684                 kretprobe_trace_func(tk, ri, regs);
1685 #ifdef CONFIG_PERF_EVENTS
1686         if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1687                 kretprobe_perf_func(tk, ri, regs);
1688 #endif
1689         return 0;       /* We don't tweak kernel, so just return 0 */
1690 }
1691 NOKPROBE_SYMBOL(kretprobe_dispatcher);
1692
1693 static struct trace_event_functions kretprobe_funcs = {
1694         .trace          = print_kretprobe_event
1695 };
1696
1697 static struct trace_event_functions kprobe_funcs = {
1698         .trace          = print_kprobe_event
1699 };
1700
1701 static struct trace_event_fields kretprobe_fields_array[] = {
1702         { .type = TRACE_FUNCTION_TYPE,
1703           .define_fields = kretprobe_event_define_fields },
1704         {}
1705 };
1706
1707 static struct trace_event_fields kprobe_fields_array[] = {
1708         { .type = TRACE_FUNCTION_TYPE,
1709           .define_fields = kprobe_event_define_fields },
1710         {}
1711 };
1712
1713 static inline void init_trace_event_call(struct trace_kprobe *tk)
1714 {
1715         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1716
1717         if (trace_kprobe_is_return(tk)) {
1718                 call->event.funcs = &kretprobe_funcs;
1719                 call->class->fields_array = kretprobe_fields_array;
1720         } else {
1721                 call->event.funcs = &kprobe_funcs;
1722                 call->class->fields_array = kprobe_fields_array;
1723         }
1724
1725         call->flags = TRACE_EVENT_FL_KPROBE;
1726         call->class->reg = kprobe_register;
1727 }
1728
1729 static int register_kprobe_event(struct trace_kprobe *tk)
1730 {
1731         init_trace_event_call(tk);
1732
1733         return trace_probe_register_event_call(&tk->tp);
1734 }
1735
1736 static int unregister_kprobe_event(struct trace_kprobe *tk)
1737 {
1738         return trace_probe_unregister_event_call(&tk->tp);
1739 }
1740
1741 #ifdef CONFIG_PERF_EVENTS
1742
1743 /* create a trace_kprobe, but don't add it to global lists */
1744 struct trace_event_call *
1745 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1746                           bool is_return)
1747 {
1748         enum probe_print_type ptype;
1749         struct trace_kprobe *tk;
1750         int ret;
1751         char *event;
1752
1753         if (func) {
1754                 unsigned int count;
1755
1756                 count = number_of_same_symbols(func);
1757                 if (count > 1)
1758                         /*
1759                          * Users should use addr to remove the ambiguity of
1760                          * using func only.
1761                          */
1762                         return ERR_PTR(-EADDRNOTAVAIL);
1763                 else if (count == 0)
1764                         /*
1765                          * We can return ENOENT earlier than when register the
1766                          * kprobe.
1767                          */
1768                         return ERR_PTR(-ENOENT);
1769         }
1770
1771         /*
1772          * local trace_kprobes are not added to dyn_event, so they are never
1773          * searched in find_trace_kprobe(). Therefore, there is no concern of
1774          * duplicated name here.
1775          */
1776         event = func ? func : "DUMMY_EVENT";
1777
1778         tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1779                                 offs, 0 /* maxactive */, 0 /* nargs */,
1780                                 is_return);
1781
1782         if (IS_ERR(tk)) {
1783                 pr_info("Failed to allocate trace_probe.(%d)\n",
1784                         (int)PTR_ERR(tk));
1785                 return ERR_CAST(tk);
1786         }
1787
1788         init_trace_event_call(tk);
1789
1790         ptype = trace_kprobe_is_return(tk) ?
1791                 PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1792         if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) {
1793                 ret = -ENOMEM;
1794                 goto error;
1795         }
1796
1797         ret = __register_trace_kprobe(tk);
1798         if (ret < 0)
1799                 goto error;
1800
1801         return trace_probe_event_call(&tk->tp);
1802 error:
1803         free_trace_kprobe(tk);
1804         return ERR_PTR(ret);
1805 }
1806
1807 void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1808 {
1809         struct trace_kprobe *tk;
1810
1811         tk = trace_kprobe_primary_from_call(event_call);
1812         if (unlikely(!tk))
1813                 return;
1814
1815         if (trace_probe_is_enabled(&tk->tp)) {
1816                 WARN_ON(1);
1817                 return;
1818         }
1819
1820         __unregister_trace_kprobe(tk);
1821
1822         free_trace_kprobe(tk);
1823 }
1824 #endif /* CONFIG_PERF_EVENTS */
1825
1826 static __init void enable_boot_kprobe_events(void)
1827 {
1828         struct trace_array *tr = top_trace_array();
1829         struct trace_event_file *file;
1830         struct trace_kprobe *tk;
1831         struct dyn_event *pos;
1832
1833         mutex_lock(&event_mutex);
1834         for_each_trace_kprobe(tk, pos) {
1835                 list_for_each_entry(file, &tr->events, list)
1836                         if (file->event_call == trace_probe_event_call(&tk->tp))
1837                                 trace_event_enable_disable(file, 1, 0);
1838         }
1839         mutex_unlock(&event_mutex);
1840 }
1841
1842 static __init void setup_boot_kprobe_events(void)
1843 {
1844         char *p, *cmd = kprobe_boot_events_buf;
1845         int ret;
1846
1847         strreplace(kprobe_boot_events_buf, ',', ' ');
1848
1849         while (cmd && *cmd != '\0') {
1850                 p = strchr(cmd, ';');
1851                 if (p)
1852                         *p++ = '\0';
1853
1854                 ret = create_or_delete_trace_kprobe(cmd);
1855                 if (ret)
1856                         pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1857
1858                 cmd = p;
1859         }
1860
1861         enable_boot_kprobe_events();
1862 }
1863
1864 /*
1865  * Register dynevent at core_initcall. This allows kernel to setup kprobe
1866  * events in postcore_initcall without tracefs.
1867  */
1868 static __init int init_kprobe_trace_early(void)
1869 {
1870         int ret;
1871
1872         ret = dyn_event_register(&trace_kprobe_ops);
1873         if (ret)
1874                 return ret;
1875
1876         if (register_module_notifier(&trace_kprobe_module_nb))
1877                 return -EINVAL;
1878
1879         return 0;
1880 }
1881 core_initcall(init_kprobe_trace_early);
1882
1883 /* Make a tracefs interface for controlling probe points */
1884 static __init int init_kprobe_trace(void)
1885 {
1886         int ret;
1887
1888         ret = tracing_init_dentry();
1889         if (ret)
1890                 return 0;
1891
1892         /* Event list interface */
1893         trace_create_file("kprobe_events", TRACE_MODE_WRITE,
1894                           NULL, NULL, &kprobe_events_ops);
1895
1896         /* Profile interface */
1897         trace_create_file("kprobe_profile", TRACE_MODE_READ,
1898                           NULL, NULL, &kprobe_profile_ops);
1899
1900         setup_boot_kprobe_events();
1901
1902         return 0;
1903 }
1904 fs_initcall(init_kprobe_trace);
1905
1906
1907 #ifdef CONFIG_FTRACE_STARTUP_TEST
1908 static __init struct trace_event_file *
1909 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1910 {
1911         struct trace_event_file *file;
1912
1913         list_for_each_entry(file, &tr->events, list)
1914                 if (file->event_call == trace_probe_event_call(&tk->tp))
1915                         return file;
1916
1917         return NULL;
1918 }
1919
1920 /*
1921  * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1922  * stage, we can do this lockless.
1923  */
1924 static __init int kprobe_trace_self_tests_init(void)
1925 {
1926         int ret, warn = 0;
1927         int (*target)(int, int, int, int, int, int);
1928         struct trace_kprobe *tk;
1929         struct trace_event_file *file;
1930
1931         if (tracing_is_disabled())
1932                 return -ENODEV;
1933
1934         if (tracing_selftest_disabled)
1935                 return 0;
1936
1937         target = kprobe_trace_selftest_target;
1938
1939         pr_info("Testing kprobe tracing: ");
1940
1941         ret = create_or_delete_trace_kprobe("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)");
1942         if (WARN_ON_ONCE(ret)) {
1943                 pr_warn("error on probing function entry.\n");
1944                 warn++;
1945         } else {
1946                 /* Enable trace point */
1947                 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1948                 if (WARN_ON_ONCE(tk == NULL)) {
1949                         pr_warn("error on getting new probe.\n");
1950                         warn++;
1951                 } else {
1952                         file = find_trace_probe_file(tk, top_trace_array());
1953                         if (WARN_ON_ONCE(file == NULL)) {
1954                                 pr_warn("error on getting probe file.\n");
1955                                 warn++;
1956                         } else
1957                                 enable_trace_kprobe(
1958                                         trace_probe_event_call(&tk->tp), file);
1959                 }
1960         }
1961
1962         ret = create_or_delete_trace_kprobe("r:testprobe2 kprobe_trace_selftest_target $retval");
1963         if (WARN_ON_ONCE(ret)) {
1964                 pr_warn("error on probing function return.\n");
1965                 warn++;
1966         } else {
1967                 /* Enable trace point */
1968                 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1969                 if (WARN_ON_ONCE(tk == NULL)) {
1970                         pr_warn("error on getting 2nd new probe.\n");
1971                         warn++;
1972                 } else {
1973                         file = find_trace_probe_file(tk, top_trace_array());
1974                         if (WARN_ON_ONCE(file == NULL)) {
1975                                 pr_warn("error on getting probe file.\n");
1976                                 warn++;
1977                         } else
1978                                 enable_trace_kprobe(
1979                                         trace_probe_event_call(&tk->tp), file);
1980                 }
1981         }
1982
1983         if (warn)
1984                 goto end;
1985
1986         ret = target(1, 2, 3, 4, 5, 6);
1987
1988         /*
1989          * Not expecting an error here, the check is only to prevent the
1990          * optimizer from removing the call to target() as otherwise there
1991          * are no side-effects and the call is never performed.
1992          */
1993         if (ret != 21)
1994                 warn++;
1995
1996         /* Disable trace points before removing it */
1997         tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1998         if (WARN_ON_ONCE(tk == NULL)) {
1999                 pr_warn("error on getting test probe.\n");
2000                 warn++;
2001         } else {
2002                 if (trace_kprobe_nhit(tk) != 1) {
2003                         pr_warn("incorrect number of testprobe hits\n");
2004                         warn++;
2005                 }
2006
2007                 file = find_trace_probe_file(tk, top_trace_array());
2008                 if (WARN_ON_ONCE(file == NULL)) {
2009                         pr_warn("error on getting probe file.\n");
2010                         warn++;
2011                 } else
2012                         disable_trace_kprobe(
2013                                 trace_probe_event_call(&tk->tp), file);
2014         }
2015
2016         tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2017         if (WARN_ON_ONCE(tk == NULL)) {
2018                 pr_warn("error on getting 2nd test probe.\n");
2019                 warn++;
2020         } else {
2021                 if (trace_kprobe_nhit(tk) != 1) {
2022                         pr_warn("incorrect number of testprobe2 hits\n");
2023                         warn++;
2024                 }
2025
2026                 file = find_trace_probe_file(tk, top_trace_array());
2027                 if (WARN_ON_ONCE(file == NULL)) {
2028                         pr_warn("error on getting probe file.\n");
2029                         warn++;
2030                 } else
2031                         disable_trace_kprobe(
2032                                 trace_probe_event_call(&tk->tp), file);
2033         }
2034
2035         ret = create_or_delete_trace_kprobe("-:testprobe");
2036         if (WARN_ON_ONCE(ret)) {
2037                 pr_warn("error on deleting a probe.\n");
2038                 warn++;
2039         }
2040
2041         ret = create_or_delete_trace_kprobe("-:testprobe2");
2042         if (WARN_ON_ONCE(ret)) {
2043                 pr_warn("error on deleting a probe.\n");
2044                 warn++;
2045         }
2046
2047 end:
2048         ret = dyn_events_release_all(&trace_kprobe_ops);
2049         if (WARN_ON_ONCE(ret)) {
2050                 pr_warn("error on cleaning up probes.\n");
2051                 warn++;
2052         }
2053         /*
2054          * Wait for the optimizer work to finish. Otherwise it might fiddle
2055          * with probes in already freed __init text.
2056          */
2057         wait_for_kprobe_optimizer();
2058         if (warn)
2059                 pr_cont("NG: Some tests are failed. Please check them.\n");
2060         else
2061                 pr_cont("OK\n");
2062         return 0;
2063 }
2064
2065 late_initcall(kprobe_trace_self_tests_init);
2066
2067 #endif