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