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/security.h>
  11 #include <linux/module.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/rculist.h>
  14 #include <linux/error-injection.h>
  15
  16 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  17
  18 #include "trace_dynevent.h"
  19 #include "trace_kprobe_selftest.h"
  20 #include "trace_probe.h"
  21 #include "trace_probe_tmpl.h"
  22
  23 #define KPROBE_EVENT_SYSTEM "kprobes"
  24 #define KRETPROBE_MAXACTIVE_MAX 4096
  25
  26 /* Kprobe early definition from command line */
  27 static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
  28
  29 static int __init set_kprobe_boot_events(char *str)
  30 {
  31         strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
  32         disable_tracing_selftest("running kprobe events");
  33
  34         return 0;
  35 }
  36 __setup("kprobe_event=", set_kprobe_boot_events);
  37
  38 static int trace_kprobe_create(const char *raw_command);
  39 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
  40 static int trace_kprobe_release(struct dyn_event *ev);
  41 static bool trace_kprobe_is_busy(struct dyn_event *ev);
  42 static bool trace_kprobe_match(const char *system, const char *event,
  43                         int argc, const char **argv, struct dyn_event *ev);
  44
  45 static struct dyn_event_operations trace_kprobe_ops = {
  46         .create = trace_kprobe_create,
  47         .show = trace_kprobe_show,
  48         .is_busy = trace_kprobe_is_busy,
  49         .free = trace_kprobe_release,
  50         .match = trace_kprobe_match,
  51 };
  52
  53 /*
  54  * Kprobe event core functions
  55  */
  56 struct trace_kprobe {
  57         struct dyn_event        devent;
  58         struct kretprobe        rp;     /* Use rp.kp for kprobe use */
  59         unsigned long __percpu *nhit;
  60         const char              *symbol;        /* symbol name */
  61         struct trace_probe      tp;
  62 };
  63
  64 static bool is_trace_kprobe(struct dyn_event *ev)
  65 {
  66         return ev->ops == &trace_kprobe_ops;
  67 }
  68
  69 static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
  70 {
  71         return container_of(ev, struct trace_kprobe, devent);
  72 }
  73
  74 /**
  75  * for_each_trace_kprobe - iterate over the trace_kprobe list
  76  * @pos:        the struct trace_kprobe * for each entry
  77  * @dpos:       the struct dyn_event * to use as a loop cursor
  78  */
  79 #define for_each_trace_kprobe(pos, dpos)        \
  80         for_each_dyn_event(dpos)                \
  81                 if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
  82
  83 #define SIZEOF_TRACE_KPROBE(n)                          \
  84         (offsetof(struct trace_kprobe, tp.args) +       \
  85         (sizeof(struct probe_arg) * (n)))
  86
  87 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
  88 {
  89         return tk->rp.handler != NULL;
  90 }
  91
  92 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
  93 {
  94         return tk->symbol ? tk->symbol : "unknown";
  95 }
  96
  97 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
  98 {
  99         return tk->rp.kp.offset;
 100 }
 101
 102 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
 103 {
 104         return !!(kprobe_gone(&tk->rp.kp));
 105 }
 106
 107 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
 108                                                  struct module *mod)
 109 {
 110         int len = strlen(module_name(mod));
 111         const char *name = trace_kprobe_symbol(tk);
 112
 113         return strncmp(module_name(mod), name, len) == 0 && name[len] == ':';
 114 }
 115
 116 static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
 117 {
 118         char *p;
 119         bool ret;
 120
 121         if (!tk->symbol)
 122                 return false;
 123         p = strchr(tk->symbol, ':');
 124         if (!p)
 125                 return true;
 126         *p = '\0';
 127         rcu_read_lock_sched();
 128         ret = !!find_module(tk->symbol);
 129         rcu_read_unlock_sched();
 130         *p = ':';
 131
 132         return ret;
 133 }
 134
 135 static bool trace_kprobe_is_busy(struct dyn_event *ev)
 136 {
 137         struct trace_kprobe *tk = to_trace_kprobe(ev);
 138
 139         return trace_probe_is_enabled(&tk->tp);
 140 }
 141
 142 static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
 143                                             int argc, const char **argv)
 144 {
 145         char buf[MAX_ARGSTR_LEN + 1];
 146
 147         if (!argc)
 148                 return true;
 149
 150         if (!tk->symbol)
 151                 snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr);
 152         else if (tk->rp.kp.offset)
 153                 snprintf(buf, sizeof(buf), "%s+%u",
 154                          trace_kprobe_symbol(tk), tk->rp.kp.offset);
 155         else
 156                 snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk));
 157         if (strcmp(buf, argv[0]))
 158                 return false;
 159         argc--; argv++;
 160
 161         return trace_probe_match_command_args(&tk->tp, argc, argv);
 162 }
 163
 164 static bool trace_kprobe_match(const char *system, const char *event,
 165                         int argc, const char **argv, struct dyn_event *ev)
 166 {
 167         struct trace_kprobe *tk = to_trace_kprobe(ev);
 168
 169         return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
 170             (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
 171             trace_kprobe_match_command_head(tk, argc, argv);
 172 }
 173
 174 static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
 175 {
 176         unsigned long nhit = 0;
 177         int cpu;
 178
 179         for_each_possible_cpu(cpu)
 180                 nhit += *per_cpu_ptr(tk->nhit, cpu);
 181
 182         return nhit;
 183 }
 184
 185 static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk)
 186 {
 187         return !(list_empty(&tk->rp.kp.list) &&
 188                  hlist_unhashed(&tk->rp.kp.hlist));
 189 }
 190
 191 /* Return 0 if it fails to find the symbol address */
 192 static nokprobe_inline
 193 unsigned long trace_kprobe_address(struct trace_kprobe *tk)
 194 {
 195         unsigned long addr;
 196
 197         if (tk->symbol) {
 198                 addr = (unsigned long)
 199                         kallsyms_lookup_name(trace_kprobe_symbol(tk));
 200                 if (addr)
 201                         addr += tk->rp.kp.offset;
 202         } else {
 203                 addr = (unsigned long)tk->rp.kp.addr;
 204         }
 205         return addr;
 206 }
 207
 208 static nokprobe_inline struct trace_kprobe *
 209 trace_kprobe_primary_from_call(struct trace_event_call *call)
 210 {
 211         struct trace_probe *tp;
 212
 213         tp = trace_probe_primary_from_call(call);
 214         if (WARN_ON_ONCE(!tp))
 215                 return NULL;
 216
 217         return container_of(tp, struct trace_kprobe, tp);
 218 }
 219
 220 bool trace_kprobe_on_func_entry(struct trace_event_call *call)
 221 {
 222         struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
 223
 224         return tk ? (kprobe_on_func_entry(tk->rp.kp.addr,
 225                         tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
 226                         tk->rp.kp.addr ? 0 : tk->rp.kp.offset) == 0) : false;
 227 }
 228
 229 bool trace_kprobe_error_injectable(struct trace_event_call *call)
 230 {
 231         struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
 232
 233         return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
 234                false;
 235 }
 236
 237 static int register_kprobe_event(struct trace_kprobe *tk);
 238 static int unregister_kprobe_event(struct trace_kprobe *tk);
 239
 240 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 241 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
 242                                 struct pt_regs *regs);
 243
 244 static void free_trace_kprobe(struct trace_kprobe *tk)
 245 {
 246         if (tk) {
 247                 trace_probe_cleanup(&tk->tp);
 248                 kfree(tk->symbol);
 249                 free_percpu(tk->nhit);
 250                 kfree(tk);
 251         }
 252 }
 253
 254 /*
 255  * Allocate new trace_probe and initialize it (including kprobes).
 256  */
 257 static struct trace_kprobe *alloc_trace_kprobe(const char *group,
 258                                              const char *event,
 259                                              void *addr,
 260                                              const char *symbol,
 261                                              unsigned long offs,
 262                                              int maxactive,
 263                                              int nargs, bool is_return)
 264 {
 265         struct trace_kprobe *tk;
 266         int ret = -ENOMEM;
 267
 268         tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
 269         if (!tk)
 270                 return ERR_PTR(ret);
 271
 272         tk->nhit = alloc_percpu(unsigned long);
 273         if (!tk->nhit)
 274                 goto error;
 275
 276         if (symbol) {
 277                 tk->symbol = kstrdup(symbol, GFP_KERNEL);
 278                 if (!tk->symbol)
 279                         goto error;
 280                 tk->rp.kp.symbol_name = tk->symbol;
 281                 tk->rp.kp.offset = offs;
 282         } else
 283                 tk->rp.kp.addr = addr;
 284
 285         if (is_return)
 286                 tk->rp.handler = kretprobe_dispatcher;
 287         else
 288                 tk->rp.kp.pre_handler = kprobe_dispatcher;
 289
 290         tk->rp.maxactive = maxactive;
 291         INIT_HLIST_NODE(&tk->rp.kp.hlist);
 292         INIT_LIST_HEAD(&tk->rp.kp.list);
 293
 294         ret = trace_probe_init(&tk->tp, event, group, false);
 295         if (ret < 0)
 296                 goto error;
 297
 298         dyn_event_init(&tk->devent, &trace_kprobe_ops);
 299         return tk;
 300 error:
 301         free_trace_kprobe(tk);
 302         return ERR_PTR(ret);
 303 }
 304
 305 static struct trace_kprobe *find_trace_kprobe(const char *event,
 306                                               const char *group)
 307 {
 308         struct dyn_event *pos;
 309         struct trace_kprobe *tk;
 310
 311         for_each_trace_kprobe(tk, pos)
 312                 if (strcmp(trace_probe_name(&tk->tp), event) == 0 &&
 313                     strcmp(trace_probe_group_name(&tk->tp), group) == 0)
 314                         return tk;
 315         return NULL;
 316 }
 317
 318 static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
 319 {
 320         int ret = 0;
 321
 322         if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) {
 323                 if (trace_kprobe_is_return(tk))
 324                         ret = enable_kretprobe(&tk->rp);
 325                 else
 326                         ret = enable_kprobe(&tk->rp.kp);
 327         }
 328
 329         return ret;
 330 }
 331
 332 static void __disable_trace_kprobe(struct trace_probe *tp)
 333 {
 334         struct trace_probe *pos;
 335         struct trace_kprobe *tk;
 336
 337         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
 338                 tk = container_of(pos, struct trace_kprobe, tp);
 339                 if (!trace_kprobe_is_registered(tk))
 340                         continue;
 341                 if (trace_kprobe_is_return(tk))
 342                         disable_kretprobe(&tk->rp);
 343                 else
 344                         disable_kprobe(&tk->rp.kp);
 345         }
 346 }
 347
 348 /*
 349  * Enable trace_probe
 350  * if the file is NULL, enable "perf" handler, or enable "trace" handler.
 351  */
 352 static int enable_trace_kprobe(struct trace_event_call *call,
 353                                 struct trace_event_file *file)
 354 {
 355         struct trace_probe *pos, *tp;
 356         struct trace_kprobe *tk;
 357         bool enabled;
 358         int ret = 0;
 359
 360         tp = trace_probe_primary_from_call(call);
 361         if (WARN_ON_ONCE(!tp))
 362                 return -ENODEV;
 363         enabled = trace_probe_is_enabled(tp);
 364
 365         /* This also changes "enabled" state */
 366         if (file) {
 367                 ret = trace_probe_add_file(tp, file);
 368                 if (ret)
 369                         return ret;
 370         } else
 371                 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
 372
 373         if (enabled)
 374                 return 0;
 375
 376         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
 377                 tk = container_of(pos, struct trace_kprobe, tp);
 378                 if (trace_kprobe_has_gone(tk))
 379                         continue;
 380                 ret = __enable_trace_kprobe(tk);
 381                 if (ret)
 382                         break;
 383                 enabled = true;
 384         }
 385
 386         if (ret) {
 387                 /* Failed to enable one of them. Roll back all */
 388                 if (enabled)
 389                         __disable_trace_kprobe(tp);
 390                 if (file)
 391                         trace_probe_remove_file(tp, file);
 392                 else
 393                         trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
 394         }
 395
 396         return ret;
 397 }
 398
 399 /*
 400  * Disable trace_probe
 401  * if the file is NULL, disable "perf" handler, or disable "trace" handler.
 402  */
 403 static int disable_trace_kprobe(struct trace_event_call *call,
 404                                 struct trace_event_file *file)
 405 {
 406         struct trace_probe *tp;
 407
 408         tp = trace_probe_primary_from_call(call);
 409         if (WARN_ON_ONCE(!tp))
 410                 return -ENODEV;
 411
 412         if (file) {
 413                 if (!trace_probe_get_file_link(tp, file))
 414                         return -ENOENT;
 415                 if (!trace_probe_has_single_file(tp))
 416                         goto out;
 417                 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
 418         } else
 419                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
 420
 421         if (!trace_probe_is_enabled(tp))
 422                 __disable_trace_kprobe(tp);
 423
 424  out:
 425         if (file)
 426                 /*
 427                  * Synchronization is done in below function. For perf event,
 428                  * file == NULL and perf_trace_event_unreg() calls
 429                  * tracepoint_synchronize_unregister() to ensure synchronize
 430                  * event. We don't need to care about it.
 431                  */
 432                 trace_probe_remove_file(tp, file);
 433
 434         return 0;
 435 }
 436
 437 #if defined(CONFIG_DYNAMIC_FTRACE) && \
 438         !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
 439 static bool __within_notrace_func(unsigned long addr)
 440 {
 441         unsigned long offset, size;
 442
 443         if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
 444                 return false;
 445
 446         /* Get the entry address of the target function */
 447         addr -= offset;
 448
 449         /*
 450          * Since ftrace_location_range() does inclusive range check, we need
 451          * to subtract 1 byte from the end address.
 452          */
 453         return !ftrace_location_range(addr, addr + size - 1);
 454 }
 455
 456 static bool within_notrace_func(struct trace_kprobe *tk)
 457 {
 458         unsigned long addr = trace_kprobe_address(tk);
 459         char symname[KSYM_NAME_LEN], *p;
 460
 461         if (!__within_notrace_func(addr))
 462                 return false;
 463
 464         /* Check if the address is on a suffixed-symbol */
 465         if (!lookup_symbol_name(addr, symname)) {
 466                 p = strchr(symname, '.');
 467                 if (!p)
 468                         return true;
 469                 *p = '\0';
 470                 addr = (unsigned long)kprobe_lookup_name(symname, 0);
 471                 if (addr)
 472                         return __within_notrace_func(addr);
 473         }
 474
 475         return true;
 476 }
 477 #else
 478 #define within_notrace_func(tk) (false)
 479 #endif
 480
 481 /* Internal register function - just handle k*probes and flags */
 482 static int __register_trace_kprobe(struct trace_kprobe *tk)
 483 {
 484         int i, ret;
 485
 486         ret = security_locked_down(LOCKDOWN_KPROBES);
 487         if (ret)
 488                 return ret;
 489
 490         if (trace_kprobe_is_registered(tk))
 491                 return -EINVAL;
 492
 493         if (within_notrace_func(tk)) {
 494                 pr_warn("Could not probe notrace function %s\n",
 495                         trace_kprobe_symbol(tk));
 496                 return -EINVAL;
 497         }
 498
 499         for (i = 0; i < tk->tp.nr_args; i++) {
 500                 ret = traceprobe_update_arg(&tk->tp.args[i]);
 501                 if (ret)
 502                         return ret;
 503         }
 504
 505         /* Set/clear disabled flag according to tp->flag */
 506         if (trace_probe_is_enabled(&tk->tp))
 507                 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
 508         else
 509                 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
 510
 511         if (trace_kprobe_is_return(tk))
 512                 ret = register_kretprobe(&tk->rp);
 513         else
 514                 ret = register_kprobe(&tk->rp.kp);
 515
 516         return ret;
 517 }
 518
 519 /* Internal unregister function - just handle k*probes and flags */
 520 static void __unregister_trace_kprobe(struct trace_kprobe *tk)
 521 {
 522         if (trace_kprobe_is_registered(tk)) {
 523                 if (trace_kprobe_is_return(tk))
 524                         unregister_kretprobe(&tk->rp);
 525                 else
 526                         unregister_kprobe(&tk->rp.kp);
 527                 /* Cleanup kprobe for reuse and mark it unregistered */
 528                 INIT_HLIST_NODE(&tk->rp.kp.hlist);
 529                 INIT_LIST_HEAD(&tk->rp.kp.list);
 530                 if (tk->rp.kp.symbol_name)
 531                         tk->rp.kp.addr = NULL;
 532         }
 533 }
 534
 535 /* Unregister a trace_probe and probe_event */
 536 static int unregister_trace_kprobe(struct trace_kprobe *tk)
 537 {
 538         /* If other probes are on the event, just unregister kprobe */
 539         if (trace_probe_has_sibling(&tk->tp))
 540                 goto unreg;
 541
 542         /* Enabled event can not be unregistered */
 543         if (trace_probe_is_enabled(&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         struct trace_probe *pos;
 563         int i;
 564
 565         list_for_each_entry(pos, &tpe->probes, list) {
 566                 orig = container_of(pos, struct trace_kprobe, tp);
 567                 if (strcmp(trace_kprobe_symbol(orig),
 568                            trace_kprobe_symbol(comp)) ||
 569                     trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
 570                         continue;
 571
 572                 /*
 573                  * trace_probe_compare_arg_type() ensured that nr_args and
 574                  * each argument name and type are same. Let's compare comm.
 575                  */
 576                 for (i = 0; i < orig->tp.nr_args; i++) {
 577                         if (strcmp(orig->tp.args[i].comm,
 578                                    comp->tp.args[i].comm))
 579                                 break;
 580                 }
 581
 582                 if (i == orig->tp.nr_args)
 583                         return true;
 584         }
 585
 586         return false;
 587 }
 588
 589 static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
 590 {
 591         int ret;
 592
 593         ret = trace_probe_compare_arg_type(&tk->tp, &to->tp);
 594         if (ret) {
 595                 /* Note that argument starts index = 2 */
 596                 trace_probe_log_set_index(ret + 1);
 597                 trace_probe_log_err(0, DIFF_ARG_TYPE);
 598                 return -EEXIST;
 599         }
 600         if (trace_kprobe_has_same_kprobe(to, tk)) {
 601                 trace_probe_log_set_index(0);
 602                 trace_probe_log_err(0, SAME_PROBE);
 603                 return -EEXIST;
 604         }
 605
 606         /* Append to existing event */
 607         ret = trace_probe_append(&tk->tp, &to->tp);
 608         if (ret)
 609                 return ret;
 610
 611         /* Register k*probe */
 612         ret = __register_trace_kprobe(tk);
 613         if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
 614                 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
 615                 ret = 0;
 616         }
 617
 618         if (ret)
 619                 trace_probe_unlink(&tk->tp);
 620         else
 621                 dyn_event_add(&tk->devent);
 622
 623         return ret;
 624 }
 625
 626 /* Register a trace_probe and probe_event */
 627 static int register_trace_kprobe(struct trace_kprobe *tk)
 628 {
 629         struct trace_kprobe *old_tk;
 630         int ret;
 631
 632         mutex_lock(&event_mutex);
 633
 634         old_tk = find_trace_kprobe(trace_probe_name(&tk->tp),
 635                                    trace_probe_group_name(&tk->tp));
 636         if (old_tk) {
 637                 if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) {
 638                         trace_probe_log_set_index(0);
 639                         trace_probe_log_err(0, DIFF_PROBE_TYPE);
 640                         ret = -EEXIST;
 641                 } else {
 642                         ret = append_trace_kprobe(tk, old_tk);
 643                 }
 644                 goto end;
 645         }
 646
 647         /* Register new event */
 648         ret = register_kprobe_event(tk);
 649         if (ret) {
 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);
 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 /* Convert certain expected symbols into '_' when generating event names */
 707 static inline void sanitize_event_name(char *name)
 708 {
 709         while (*name++ != '\0')
 710                 if (*name == ':' || *name == '.')
 711                         *name = '_';
 712 }
 713
 714 static int __trace_kprobe_create(int argc, const char *argv[])
 715 {
 716         /*
 717          * Argument syntax:
 718          *  - Add kprobe:
 719          *      p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
 720          *  - Add kretprobe:
 721          *      r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
 722          *    Or
 723          *      p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS]
 724          *
 725          * Fetch args:
 726          *  $retval     : fetch return value
 727          *  $stack      : fetch stack address
 728          *  $stackN     : fetch Nth of stack (N:0-)
 729          *  $comm       : fetch current task comm
 730          *  @ADDR       : fetch memory at ADDR (ADDR should be in kernel)
 731          *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
 732          *  %REG        : fetch register REG
 733          * Dereferencing memory fetch:
 734          *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
 735          * Alias name of args:
 736          *  NAME=FETCHARG : set NAME as alias of FETCHARG.
 737          * Type of args:
 738          *  FETCHARG:TYPE : use TYPE instead of unsigned long.
 739          */
 740         struct trace_kprobe *tk = NULL;
 741         int i, len, ret = 0;
 742         bool is_return = false;
 743         char *symbol = NULL, *tmp = NULL;
 744         const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
 745         int maxactive = 0;
 746         long offset = 0;
 747         void *addr = NULL;
 748         char buf[MAX_EVENT_NAME_LEN];
 749         unsigned int flags = TPARG_FL_KERNEL;
 750
 751         switch (argv[0][0]) {
 752         case 'r':
 753                 is_return = true;
 754                 break;
 755         case 'p':
 756                 break;
 757         default:
 758                 return -ECANCELED;
 759         }
 760         if (argc < 2)
 761                 return -ECANCELED;
 762
 763         trace_probe_log_init("trace_kprobe", argc, argv);
 764
 765         event = strchr(&argv[0][1], ':');
 766         if (event)
 767                 event++;
 768
 769         if (isdigit(argv[0][1])) {
 770                 if (!is_return) {
 771                         trace_probe_log_err(1, MAXACT_NO_KPROBE);
 772                         goto parse_error;
 773                 }
 774                 if (event)
 775                         len = event - &argv[0][1] - 1;
 776                 else
 777                         len = strlen(&argv[0][1]);
 778                 if (len > MAX_EVENT_NAME_LEN - 1) {
 779                         trace_probe_log_err(1, BAD_MAXACT);
 780                         goto parse_error;
 781                 }
 782                 memcpy(buf, &argv[0][1], len);
 783                 buf[len] = '\0';
 784                 ret = kstrtouint(buf, 0, &maxactive);
 785                 if (ret || !maxactive) {
 786                         trace_probe_log_err(1, BAD_MAXACT);
 787                         goto parse_error;
 788                 }
 789                 /* kretprobes instances are iterated over via a list. The
 790                  * maximum should stay reasonable.
 791                  */
 792                 if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
 793                         trace_probe_log_err(1, MAXACT_TOO_BIG);
 794                         goto parse_error;
 795                 }
 796         }
 797
 798         /* try to parse an address. if that fails, try to read the
 799          * input as a symbol. */
 800         if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
 801                 trace_probe_log_set_index(1);
 802                 /* Check whether uprobe event specified */
 803                 if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
 804                         ret = -ECANCELED;
 805                         goto error;
 806                 }
 807                 /* a symbol specified */
 808                 symbol = kstrdup(argv[1], GFP_KERNEL);
 809                 if (!symbol)
 810                         return -ENOMEM;
 811
 812                 tmp = strchr(symbol, '%');
 813                 if (tmp) {
 814                         if (!strcmp(tmp, "%return")) {
 815                                 *tmp = '\0';
 816                                 is_return = true;
 817                         } else {
 818                                 trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
 819                                 goto parse_error;
 820                         }
 821                 }
 822
 823                 /* TODO: support .init module functions */
 824                 ret = traceprobe_split_symbol_offset(symbol, &offset);
 825                 if (ret || offset < 0 || offset > UINT_MAX) {
 826                         trace_probe_log_err(0, BAD_PROBE_ADDR);
 827                         goto parse_error;
 828                 }
 829                 if (is_return)
 830                         flags |= TPARG_FL_RETURN;
 831                 ret = kprobe_on_func_entry(NULL, symbol, offset);
 832                 if (ret == 0)
 833                         flags |= TPARG_FL_FENTRY;
 834                 /* Defer the ENOENT case until register kprobe */
 835                 if (ret == -EINVAL && is_return) {
 836                         trace_probe_log_err(0, BAD_RETPROBE);
 837                         goto parse_error;
 838                 }
 839         }
 840
 841         trace_probe_log_set_index(0);
 842         if (event) {
 843                 ret = traceprobe_parse_event_name(&event, &group, buf,
 844                                                   event - argv[0]);
 845                 if (ret)
 846                         goto parse_error;
 847         } else {
 848                 /* Make a new event name */
 849                 if (symbol)
 850                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
 851                                  is_return ? 'r' : 'p', symbol, offset);
 852                 else
 853                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
 854                                  is_return ? 'r' : 'p', addr);
 855                 sanitize_event_name(buf);
 856                 event = buf;
 857         }
 858
 859         /* setup a probe */
 860         tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
 861                                argc - 2, is_return);
 862         if (IS_ERR(tk)) {
 863                 ret = PTR_ERR(tk);
 864                 /* This must return -ENOMEM, else there is a bug */
 865                 WARN_ON_ONCE(ret != -ENOMEM);
 866                 goto out;       /* We know tk is not allocated */
 867         }
 868         argc -= 2; argv += 2;
 869
 870         /* parse arguments */
 871         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 872                 tmp = kstrdup(argv[i], GFP_KERNEL);
 873                 if (!tmp) {
 874                         ret = -ENOMEM;
 875                         goto error;
 876                 }
 877
 878                 trace_probe_log_set_index(i + 2);
 879                 ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags);
 880                 kfree(tmp);
 881                 if (ret)
 882                         goto error;     /* This can be -ENOMEM */
 883         }
 884
 885         ret = traceprobe_set_print_fmt(&tk->tp, is_return);
 886         if (ret < 0)
 887                 goto error;
 888
 889         ret = register_trace_kprobe(tk);
 890         if (ret) {
 891                 trace_probe_log_set_index(1);
 892                 if (ret == -EILSEQ)
 893                         trace_probe_log_err(0, BAD_INSN_BNDRY);
 894                 else if (ret == -ENOENT)
 895                         trace_probe_log_err(0, BAD_PROBE_ADDR);
 896                 else if (ret != -ENOMEM && ret != -EEXIST)
 897                         trace_probe_log_err(0, FAIL_REG_PROBE);
 898                 goto error;
 899         }
 900
 901 out:
 902         trace_probe_log_clear();
 903         kfree(symbol);
 904         return ret;
 905
 906 parse_error:
 907         ret = -EINVAL;
 908 error:
 909         free_trace_kprobe(tk);
 910         goto out;
 911 }
 912
 913 static int trace_kprobe_create(const char *raw_command)
 914 {
 915         return trace_probe_create(raw_command, __trace_kprobe_create);
 916 }
 917
 918 static int create_or_delete_trace_kprobe(const char *raw_command)
 919 {
 920         int ret;
 921
 922         if (raw_command[0] == '-')
 923                 return dyn_event_release(raw_command, &trace_kprobe_ops);
 924
 925         ret = trace_kprobe_create(raw_command);
 926         return ret == -ECANCELED ? -EINVAL : ret;
 927 }
 928
 929 static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
 930 {
 931         return create_or_delete_trace_kprobe(cmd->seq.buffer);
 932 }
 933
 934 /**
 935  * kprobe_event_cmd_init - Initialize a kprobe event command object
 936  * @cmd: A pointer to the dynevent_cmd struct representing the new event
 937  * @buf: A pointer to the buffer used to build the command
 938  * @maxlen: The length of the buffer passed in @buf
 939  *
 940  * Initialize a synthetic event command object.  Use this before
 941  * calling any of the other kprobe_event functions.
 942  */
 943 void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
 944 {
 945         dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
 946                           trace_kprobe_run_command);
 947 }
 948 EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
 949
 950 /**
 951  * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
 952  * @cmd: A pointer to the dynevent_cmd struct representing the new event
 953  * @name: The name of the kprobe event
 954  * @loc: The location of the kprobe event
 955  * @kretprobe: Is this a return probe?
 956  * @args: Variable number of arg (pairs), one pair for each field
 957  *
 958  * NOTE: Users normally won't want to call this function directly, but
 959  * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
 960  * adds a NULL to the end of the arg list.  If this function is used
 961  * directly, make sure the last arg in the variable arg list is NULL.
 962  *
 963  * Generate a kprobe event command to be executed by
 964  * kprobe_event_gen_cmd_end().  This function can be used to generate the
 965  * complete command or only the first part of it; in the latter case,
 966  * kprobe_event_add_fields() can be used to add more fields following this.
 967  *
 968  * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
 969  * returns -EINVAL if @loc == NULL.
 970  *
 971  * Return: 0 if successful, error otherwise.
 972  */
 973 int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
 974                                  const char *name, const char *loc, ...)
 975 {
 976         char buf[MAX_EVENT_NAME_LEN];
 977         struct dynevent_arg arg;
 978         va_list args;
 979         int ret;
 980
 981         if (cmd->type != DYNEVENT_TYPE_KPROBE)
 982                 return -EINVAL;
 983
 984         if (!loc)
 985                 return -EINVAL;
 986
 987         if (kretprobe)
 988                 snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
 989         else
 990                 snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
 991
 992         ret = dynevent_str_add(cmd, buf);
 993         if (ret)
 994                 return ret;
 995
 996         dynevent_arg_init(&arg, 0);
 997         arg.str = loc;
 998         ret = dynevent_arg_add(cmd, &arg, NULL);
 999         if (ret)
1000                 return ret;
1001
1002         va_start(args, loc);
1003         for (;;) {
1004                 const char *field;
1005
1006                 field = va_arg(args, const char *);
1007                 if (!field)
1008                         break;
1009
1010                 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1011                         ret = -EINVAL;
1012                         break;
1013                 }
1014
1015                 arg.str = field;
1016                 ret = dynevent_arg_add(cmd, &arg, NULL);
1017                 if (ret)
1018                         break;
1019         }
1020         va_end(args);
1021
1022         return ret;
1023 }
1024 EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
1025
1026 /**
1027  * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
1028  * @cmd: A pointer to the dynevent_cmd struct representing the new event
1029  * @args: Variable number of arg (pairs), one pair for each field
1030  *
1031  * NOTE: Users normally won't want to call this function directly, but
1032  * rather use the kprobe_event_add_fields() wrapper, which
1033  * automatically adds a NULL to the end of the arg list.  If this
1034  * function is used directly, make sure the last arg in the variable
1035  * arg list is NULL.
1036  *
1037  * Add probe fields to an existing kprobe command using a variable
1038  * list of args.  Fields are added in the same order they're listed.
1039  *
1040  * Return: 0 if successful, error otherwise.
1041  */
1042 int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
1043 {
1044         struct dynevent_arg arg;
1045         va_list args;
1046         int ret = 0;
1047
1048         if (cmd->type != DYNEVENT_TYPE_KPROBE)
1049                 return -EINVAL;
1050
1051         dynevent_arg_init(&arg, 0);
1052
1053         va_start(args, cmd);
1054         for (;;) {
1055                 const char *field;
1056
1057                 field = va_arg(args, const char *);
1058                 if (!field)
1059                         break;
1060
1061                 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1062                         ret = -EINVAL;
1063                         break;
1064                 }
1065
1066                 arg.str = field;
1067                 ret = dynevent_arg_add(cmd, &arg, NULL);
1068                 if (ret)
1069                         break;
1070         }
1071         va_end(args);
1072
1073         return ret;
1074 }
1075 EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
1076
1077 /**
1078  * kprobe_event_delete - Delete a kprobe event
1079  * @name: The name of the kprobe event to delete
1080  *
1081  * Delete a kprobe event with the give @name from kernel code rather
1082  * than directly from the command line.
1083  *
1084  * Return: 0 if successful, error otherwise.
1085  */
1086 int kprobe_event_delete(const char *name)
1087 {
1088         char buf[MAX_EVENT_NAME_LEN];
1089
1090         snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
1091
1092         return create_or_delete_trace_kprobe(buf);
1093 }
1094 EXPORT_SYMBOL_GPL(kprobe_event_delete);
1095
1096 static int trace_kprobe_release(struct dyn_event *ev)
1097 {
1098         struct trace_kprobe *tk = to_trace_kprobe(ev);
1099         int ret = unregister_trace_kprobe(tk);
1100
1101         if (!ret)
1102                 free_trace_kprobe(tk);
1103         return ret;
1104 }
1105
1106 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
1107 {
1108         struct trace_kprobe *tk = to_trace_kprobe(ev);
1109         int i;
1110
1111         seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
1112         if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
1113                 seq_printf(m, "%d", tk->rp.maxactive);
1114         seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
1115                                 trace_probe_name(&tk->tp));
1116
1117         if (!tk->symbol)
1118                 seq_printf(m, " 0x%p", tk->rp.kp.addr);
1119         else if (tk->rp.kp.offset)
1120                 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
1121                            tk->rp.kp.offset);
1122         else
1123                 seq_printf(m, " %s", trace_kprobe_symbol(tk));
1124
1125         for (i = 0; i < tk->tp.nr_args; i++)
1126                 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
1127         seq_putc(m, '\n');
1128
1129         return 0;
1130 }
1131
1132 static int probes_seq_show(struct seq_file *m, void *v)
1133 {
1134         struct dyn_event *ev = v;
1135
1136         if (!is_trace_kprobe(ev))
1137                 return 0;
1138
1139         return trace_kprobe_show(m, ev);
1140 }
1141
1142 static const struct seq_operations probes_seq_op = {
1143         .start  = dyn_event_seq_start,
1144         .next   = dyn_event_seq_next,
1145         .stop   = dyn_event_seq_stop,
1146         .show   = probes_seq_show
1147 };
1148
1149 static int probes_open(struct inode *inode, struct file *file)
1150 {
1151         int ret;
1152
1153         ret = security_locked_down(LOCKDOWN_TRACEFS);
1154         if (ret)
1155                 return ret;
1156
1157         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1158                 ret = dyn_events_release_all(&trace_kprobe_ops);
1159                 if (ret < 0)
1160                         return ret;
1161         }
1162
1163         return seq_open(file, &probes_seq_op);
1164 }
1165
1166 static ssize_t probes_write(struct file *file, const char __user *buffer,
1167                             size_t count, loff_t *ppos)
1168 {
1169         return trace_parse_run_command(file, buffer, count, ppos,
1170                                        create_or_delete_trace_kprobe);
1171 }
1172
1173 static const struct file_operations kprobe_events_ops = {
1174         .owner          = THIS_MODULE,
1175         .open           = probes_open,
1176         .read           = seq_read,
1177         .llseek         = seq_lseek,
1178         .release        = seq_release,
1179         .write          = probes_write,
1180 };
1181
1182 /* Probes profiling interfaces */
1183 static int probes_profile_seq_show(struct seq_file *m, void *v)
1184 {
1185         struct dyn_event *ev = v;
1186         struct trace_kprobe *tk;
1187
1188         if (!is_trace_kprobe(ev))
1189                 return 0;
1190
1191         tk = to_trace_kprobe(ev);
1192         seq_printf(m, "  %-44s %15lu %15lu\n",
1193                    trace_probe_name(&tk->tp),
1194                    trace_kprobe_nhit(tk),
1195                    tk->rp.kp.nmissed);
1196
1197         return 0;
1198 }
1199
1200 static const struct seq_operations profile_seq_op = {
1201         .start  = dyn_event_seq_start,
1202         .next   = dyn_event_seq_next,
1203         .stop   = dyn_event_seq_stop,
1204         .show   = probes_profile_seq_show
1205 };
1206
1207 static int profile_open(struct inode *inode, struct file *file)
1208 {
1209         int ret;
1210
1211         ret = security_locked_down(LOCKDOWN_TRACEFS);
1212         if (ret)
1213                 return ret;
1214
1215         return seq_open(file, &profile_seq_op);
1216 }
1217
1218 static const struct file_operations kprobe_profile_ops = {
1219         .owner          = THIS_MODULE,
1220         .open           = profile_open,
1221         .read           = seq_read,
1222         .llseek         = seq_lseek,
1223         .release        = seq_release,
1224 };
1225
1226 /* Kprobe specific fetch functions */
1227
1228 /* Return the length of string -- including null terminal byte */
1229 static nokprobe_inline int
1230 fetch_store_strlen_user(unsigned long addr)
1231 {
1232         const void __user *uaddr =  (__force const void __user *)addr;
1233
1234         return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
1235 }
1236
1237 /* Return the length of string -- including null terminal byte */
1238 static nokprobe_inline int
1239 fetch_store_strlen(unsigned long addr)
1240 {
1241         int ret, len = 0;
1242         u8 c;
1243
1244 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1245         if (addr < TASK_SIZE)
1246                 return fetch_store_strlen_user(addr);
1247 #endif
1248
1249         do {
1250                 ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1);
1251                 len++;
1252         } while (c && ret == 0 && len < MAX_STRING_SIZE);
1253
1254         return (ret < 0) ? ret : len;
1255 }
1256
1257 /*
1258  * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
1259  * with max length and relative data location.
1260  */
1261 static nokprobe_inline int
1262 fetch_store_string_user(unsigned long addr, void *dest, void *base)
1263 {
1264         const void __user *uaddr =  (__force const void __user *)addr;
1265         int maxlen = get_loc_len(*(u32 *)dest);
1266         void *__dest;
1267         long ret;
1268
1269         if (unlikely(!maxlen))
1270                 return -ENOMEM;
1271
1272         __dest = get_loc_data(dest, base);
1273
1274         ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
1275         if (ret >= 0)
1276                 *(u32 *)dest = make_data_loc(ret, __dest - base);
1277
1278         return ret;
1279 }
1280
1281 /*
1282  * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
1283  * length and relative data location.
1284  */
1285 static nokprobe_inline int
1286 fetch_store_string(unsigned long addr, void *dest, void *base)
1287 {
1288         int maxlen = get_loc_len(*(u32 *)dest);
1289         void *__dest;
1290         long ret;
1291
1292 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1293         if ((unsigned long)addr < TASK_SIZE)
1294                 return fetch_store_string_user(addr, dest, base);
1295 #endif
1296
1297         if (unlikely(!maxlen))
1298                 return -ENOMEM;
1299
1300         __dest = get_loc_data(dest, base);
1301
1302         /*
1303          * Try to get string again, since the string can be changed while
1304          * probing.
1305          */
1306         ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
1307         if (ret >= 0)
1308                 *(u32 *)dest = make_data_loc(ret, __dest - base);
1309
1310         return ret;
1311 }
1312
1313 static nokprobe_inline int
1314 probe_mem_read_user(void *dest, void *src, size_t size)
1315 {
1316         const void __user *uaddr =  (__force const void __user *)src;
1317
1318         return copy_from_user_nofault(dest, uaddr, size);
1319 }
1320
1321 static nokprobe_inline int
1322 probe_mem_read(void *dest, void *src, size_t size)
1323 {
1324 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1325         if ((unsigned long)src < TASK_SIZE)
1326                 return probe_mem_read_user(dest, src, size);
1327 #endif
1328         return copy_from_kernel_nofault(dest, src, size);
1329 }
1330
1331 /* Note that we don't verify it, since the code does not come from user space */
1332 static int
1333 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
1334                    void *base)
1335 {
1336         unsigned long val;
1337
1338 retry:
1339         /* 1st stage: get value from context */
1340         switch (code->op) {
1341         case FETCH_OP_REG:
1342                 val = regs_get_register(regs, code->param);
1343                 break;
1344         case FETCH_OP_STACK:
1345                 val = regs_get_kernel_stack_nth(regs, code->param);
1346                 break;
1347         case FETCH_OP_STACKP:
1348                 val = kernel_stack_pointer(regs);
1349                 break;
1350         case FETCH_OP_RETVAL:
1351                 val = regs_return_value(regs);
1352                 break;
1353         case FETCH_OP_IMM:
1354                 val = code->immediate;
1355                 break;
1356         case FETCH_OP_COMM:
1357                 val = (unsigned long)current->comm;
1358                 break;
1359         case FETCH_OP_DATA:
1360                 val = (unsigned long)code->data;
1361                 break;
1362 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1363         case FETCH_OP_ARG:
1364                 val = regs_get_kernel_argument(regs, code->param);
1365                 break;
1366 #endif
1367         case FETCH_NOP_SYMBOL:  /* Ignore a place holder */
1368                 code++;
1369                 goto retry;
1370         default:
1371                 return -EILSEQ;
1372         }
1373         code++;
1374
1375         return process_fetch_insn_bottom(code, val, dest, base);
1376 }
1377 NOKPROBE_SYMBOL(process_fetch_insn)
1378
1379 /* Kprobe handler */
1380 static nokprobe_inline void
1381 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1382                     struct trace_event_file *trace_file)
1383 {
1384         struct kprobe_trace_entry_head *entry;
1385         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1386         struct trace_event_buffer fbuffer;
1387         int dsize;
1388
1389         WARN_ON(call != trace_file->event_call);
1390
1391         if (trace_trigger_soft_disabled(trace_file))
1392                 return;
1393
1394         fbuffer.trace_ctx = tracing_gen_ctx();
1395         fbuffer.trace_file = trace_file;
1396
1397         dsize = __get_data_size(&tk->tp, regs);
1398
1399         fbuffer.event =
1400                 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
1401                                         call->event.type,
1402                                         sizeof(*entry) + tk->tp.size + dsize,
1403                                         fbuffer.trace_ctx);
1404         if (!fbuffer.event)
1405                 return;
1406
1407         fbuffer.regs = regs;
1408         entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
1409         entry->ip = (unsigned long)tk->rp.kp.addr;
1410         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1411
1412         trace_event_buffer_commit(&fbuffer);
1413 }
1414
1415 static void
1416 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1417 {
1418         struct event_file_link *link;
1419
1420         trace_probe_for_each_link_rcu(link, &tk->tp)
1421                 __kprobe_trace_func(tk, regs, link->file);
1422 }
1423 NOKPROBE_SYMBOL(kprobe_trace_func);
1424
1425 /* Kretprobe handler */
1426 static nokprobe_inline void
1427 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1428                        struct pt_regs *regs,
1429                        struct trace_event_file *trace_file)
1430 {
1431         struct kretprobe_trace_entry_head *entry;
1432         struct trace_event_buffer fbuffer;
1433         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1434         int dsize;
1435
1436         WARN_ON(call != trace_file->event_call);
1437
1438         if (trace_trigger_soft_disabled(trace_file))
1439                 return;
1440
1441         fbuffer.trace_ctx = tracing_gen_ctx();
1442         fbuffer.trace_file = trace_file;
1443
1444         dsize = __get_data_size(&tk->tp, regs);
1445         fbuffer.event =
1446                 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
1447                                         call->event.type,
1448                                         sizeof(*entry) + tk->tp.size + dsize,
1449                                         fbuffer.trace_ctx);
1450         if (!fbuffer.event)
1451                 return;
1452
1453         fbuffer.regs = regs;
1454         entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
1455         entry->func = (unsigned long)tk->rp.kp.addr;
1456         entry->ret_ip = (unsigned long)ri->ret_addr;
1457         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1458
1459         trace_event_buffer_commit(&fbuffer);
1460 }
1461
1462 static void
1463 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1464                      struct pt_regs *regs)
1465 {
1466         struct event_file_link *link;
1467
1468         trace_probe_for_each_link_rcu(link, &tk->tp)
1469                 __kretprobe_trace_func(tk, ri, regs, link->file);
1470 }
1471 NOKPROBE_SYMBOL(kretprobe_trace_func);
1472
1473 /* Event entry printers */
1474 static enum print_line_t
1475 print_kprobe_event(struct trace_iterator *iter, int flags,
1476                    struct trace_event *event)
1477 {
1478         struct kprobe_trace_entry_head *field;
1479         struct trace_seq *s = &iter->seq;
1480         struct trace_probe *tp;
1481
1482         field = (struct kprobe_trace_entry_head *)iter->ent;
1483         tp = trace_probe_primary_from_call(
1484                 container_of(event, struct trace_event_call, event));
1485         if (WARN_ON_ONCE(!tp))
1486                 goto out;
1487
1488         trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1489
1490         if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1491                 goto out;
1492
1493         trace_seq_putc(s, ')');
1494
1495         if (print_probe_args(s, tp->args, tp->nr_args,
1496                              (u8 *)&field[1], field) < 0)
1497                 goto out;
1498
1499         trace_seq_putc(s, '\n');
1500  out:
1501         return trace_handle_return(s);
1502 }
1503
1504 static enum print_line_t
1505 print_kretprobe_event(struct trace_iterator *iter, int flags,
1506                       struct trace_event *event)
1507 {
1508         struct kretprobe_trace_entry_head *field;
1509         struct trace_seq *s = &iter->seq;
1510         struct trace_probe *tp;
1511
1512         field = (struct kretprobe_trace_entry_head *)iter->ent;
1513         tp = trace_probe_primary_from_call(
1514                 container_of(event, struct trace_event_call, event));
1515         if (WARN_ON_ONCE(!tp))
1516                 goto out;
1517
1518         trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1519
1520         if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1521                 goto out;
1522
1523         trace_seq_puts(s, " <- ");
1524
1525         if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1526                 goto out;
1527
1528         trace_seq_putc(s, ')');
1529
1530         if (print_probe_args(s, tp->args, tp->nr_args,
1531                              (u8 *)&field[1], field) < 0)
1532                 goto out;
1533
1534         trace_seq_putc(s, '\n');
1535
1536  out:
1537         return trace_handle_return(s);
1538 }
1539
1540
1541 static int kprobe_event_define_fields(struct trace_event_call *event_call)
1542 {
1543         int ret;
1544         struct kprobe_trace_entry_head field;
1545         struct trace_probe *tp;
1546
1547         tp = trace_probe_primary_from_call(event_call);
1548         if (WARN_ON_ONCE(!tp))
1549                 return -ENOENT;
1550
1551         DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1552
1553         return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1554 }
1555
1556 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1557 {
1558         int ret;
1559         struct kretprobe_trace_entry_head field;
1560         struct trace_probe *tp;
1561
1562         tp = trace_probe_primary_from_call(event_call);
1563         if (WARN_ON_ONCE(!tp))
1564                 return -ENOENT;
1565
1566         DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1567         DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1568
1569         return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1570 }
1571
1572 #ifdef CONFIG_PERF_EVENTS
1573
1574 /* Kprobe profile handler */
1575 static int
1576 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1577 {
1578         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1579         struct kprobe_trace_entry_head *entry;
1580         struct hlist_head *head;
1581         int size, __size, dsize;
1582         int rctx;
1583
1584         if (bpf_prog_array_valid(call)) {
1585                 unsigned long orig_ip = instruction_pointer(regs);
1586                 int ret;
1587
1588                 ret = trace_call_bpf(call, regs);
1589
1590                 /*
1591                  * We need to check and see if we modified the pc of the
1592                  * pt_regs, and if so return 1 so that we don't do the
1593                  * single stepping.
1594                  */
1595                 if (orig_ip != instruction_pointer(regs))
1596                         return 1;
1597                 if (!ret)
1598                         return 0;
1599         }
1600
1601         head = this_cpu_ptr(call->perf_events);
1602         if (hlist_empty(head))
1603                 return 0;
1604
1605         dsize = __get_data_size(&tk->tp, regs);
1606         __size = sizeof(*entry) + tk->tp.size + dsize;
1607         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1608         size -= sizeof(u32);
1609
1610         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1611         if (!entry)
1612                 return 0;
1613
1614         entry->ip = (unsigned long)tk->rp.kp.addr;
1615         memset(&entry[1], 0, dsize);
1616         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1617         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1618                               head, NULL);
1619         return 0;
1620 }
1621 NOKPROBE_SYMBOL(kprobe_perf_func);
1622
1623 /* Kretprobe profile handler */
1624 static void
1625 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1626                     struct pt_regs *regs)
1627 {
1628         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1629         struct kretprobe_trace_entry_head *entry;
1630         struct hlist_head *head;
1631         int size, __size, dsize;
1632         int rctx;
1633
1634         if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1635                 return;
1636
1637         head = this_cpu_ptr(call->perf_events);
1638         if (hlist_empty(head))
1639                 return;
1640
1641         dsize = __get_data_size(&tk->tp, regs);
1642         __size = sizeof(*entry) + tk->tp.size + dsize;
1643         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1644         size -= sizeof(u32);
1645
1646         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1647         if (!entry)
1648                 return;
1649
1650         entry->func = (unsigned long)tk->rp.kp.addr;
1651         entry->ret_ip = (unsigned long)ri->ret_addr;
1652         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1653         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1654                               head, NULL);
1655 }
1656 NOKPROBE_SYMBOL(kretprobe_perf_func);
1657
1658 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1659                         const char **symbol, u64 *probe_offset,
1660                         u64 *probe_addr, bool perf_type_tracepoint)
1661 {
1662         const char *pevent = trace_event_name(event->tp_event);
1663         const char *group = event->tp_event->class->system;
1664         struct trace_kprobe *tk;
1665
1666         if (perf_type_tracepoint)
1667                 tk = find_trace_kprobe(pevent, group);
1668         else
1669                 tk = trace_kprobe_primary_from_call(event->tp_event);
1670         if (!tk)
1671                 return -EINVAL;
1672
1673         *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1674                                               : BPF_FD_TYPE_KPROBE;
1675         if (tk->symbol) {
1676                 *symbol = tk->symbol;
1677                 *probe_offset = tk->rp.kp.offset;
1678                 *probe_addr = 0;
1679         } else {
1680                 *symbol = NULL;
1681                 *probe_offset = 0;
1682                 *probe_addr = (unsigned long)tk->rp.kp.addr;
1683         }
1684         return 0;
1685 }
1686 #endif  /* CONFIG_PERF_EVENTS */
1687
1688 /*
1689  * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1690  *
1691  * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1692  * lockless, but we can't race with this __init function.
1693  */
1694 static int kprobe_register(struct trace_event_call *event,
1695                            enum trace_reg type, void *data)
1696 {
1697         struct trace_event_file *file = data;
1698
1699         switch (type) {
1700         case TRACE_REG_REGISTER:
1701                 return enable_trace_kprobe(event, file);
1702         case TRACE_REG_UNREGISTER:
1703                 return disable_trace_kprobe(event, file);
1704
1705 #ifdef CONFIG_PERF_EVENTS
1706         case TRACE_REG_PERF_REGISTER:
1707                 return enable_trace_kprobe(event, NULL);
1708         case TRACE_REG_PERF_UNREGISTER:
1709                 return disable_trace_kprobe(event, NULL);
1710         case TRACE_REG_PERF_OPEN:
1711         case TRACE_REG_PERF_CLOSE:
1712         case TRACE_REG_PERF_ADD:
1713         case TRACE_REG_PERF_DEL:
1714                 return 0;
1715 #endif
1716         }
1717         return 0;
1718 }
1719
1720 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1721 {
1722         struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1723         int ret = 0;
1724
1725         raw_cpu_inc(*tk->nhit);
1726
1727         if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1728                 kprobe_trace_func(tk, regs);
1729 #ifdef CONFIG_PERF_EVENTS
1730         if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1731                 ret = kprobe_perf_func(tk, regs);
1732 #endif
1733         return ret;
1734 }
1735 NOKPROBE_SYMBOL(kprobe_dispatcher);
1736
1737 static int
1738 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1739 {
1740         struct kretprobe *rp = get_kretprobe(ri);
1741         struct trace_kprobe *tk = container_of(rp, struct trace_kprobe, rp);
1742
1743         raw_cpu_inc(*tk->nhit);
1744
1745         if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1746                 kretprobe_trace_func(tk, ri, regs);
1747 #ifdef CONFIG_PERF_EVENTS
1748         if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1749                 kretprobe_perf_func(tk, ri, regs);
1750 #endif
1751         return 0;       /* We don't tweek kernel, so just return 0 */
1752 }
1753 NOKPROBE_SYMBOL(kretprobe_dispatcher);
1754
1755 static struct trace_event_functions kretprobe_funcs = {
1756         .trace          = print_kretprobe_event
1757 };
1758
1759 static struct trace_event_functions kprobe_funcs = {
1760         .trace          = print_kprobe_event
1761 };
1762
1763 static struct trace_event_fields kretprobe_fields_array[] = {
1764         { .type = TRACE_FUNCTION_TYPE,
1765           .define_fields = kretprobe_event_define_fields },
1766         {}
1767 };
1768
1769 static struct trace_event_fields kprobe_fields_array[] = {
1770         { .type = TRACE_FUNCTION_TYPE,
1771           .define_fields = kprobe_event_define_fields },
1772         {}
1773 };
1774
1775 static inline void init_trace_event_call(struct trace_kprobe *tk)
1776 {
1777         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1778
1779         if (trace_kprobe_is_return(tk)) {
1780                 call->event.funcs = &kretprobe_funcs;
1781                 call->class->fields_array = kretprobe_fields_array;
1782         } else {
1783                 call->event.funcs = &kprobe_funcs;
1784                 call->class->fields_array = kprobe_fields_array;
1785         }
1786
1787         call->flags = TRACE_EVENT_FL_KPROBE;
1788         call->class->reg = kprobe_register;
1789 }
1790
1791 static int register_kprobe_event(struct trace_kprobe *tk)
1792 {
1793         init_trace_event_call(tk);
1794
1795         return trace_probe_register_event_call(&tk->tp);
1796 }
1797
1798 static int unregister_kprobe_event(struct trace_kprobe *tk)
1799 {
1800         return trace_probe_unregister_event_call(&tk->tp);
1801 }
1802
1803 #ifdef CONFIG_PERF_EVENTS
1804 /* create a trace_kprobe, but don't add it to global lists */
1805 struct trace_event_call *
1806 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1807                           bool is_return)
1808 {
1809         struct trace_kprobe *tk;
1810         int ret;
1811         char *event;
1812
1813         /*
1814          * local trace_kprobes are not added to dyn_event, so they are never
1815          * searched in find_trace_kprobe(). Therefore, there is no concern of
1816          * duplicated name here.
1817          */
1818         event = func ? func : "DUMMY_EVENT";
1819
1820         tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1821                                 offs, 0 /* maxactive */, 0 /* nargs */,
1822                                 is_return);
1823
1824         if (IS_ERR(tk)) {
1825                 pr_info("Failed to allocate trace_probe.(%d)\n",
1826                         (int)PTR_ERR(tk));
1827                 return ERR_CAST(tk);
1828         }
1829
1830         init_trace_event_call(tk);
1831
1832         if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
1833                 ret = -ENOMEM;
1834                 goto error;
1835         }
1836
1837         ret = __register_trace_kprobe(tk);
1838         if (ret < 0)
1839                 goto error;
1840
1841         return trace_probe_event_call(&tk->tp);
1842 error:
1843         free_trace_kprobe(tk);
1844         return ERR_PTR(ret);
1845 }
1846
1847 void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1848 {
1849         struct trace_kprobe *tk;
1850
1851         tk = trace_kprobe_primary_from_call(event_call);
1852         if (unlikely(!tk))
1853                 return;
1854
1855         if (trace_probe_is_enabled(&tk->tp)) {
1856                 WARN_ON(1);
1857                 return;
1858         }
1859
1860         __unregister_trace_kprobe(tk);
1861
1862         free_trace_kprobe(tk);
1863 }
1864 #endif /* CONFIG_PERF_EVENTS */
1865
1866 static __init void enable_boot_kprobe_events(void)
1867 {
1868         struct trace_array *tr = top_trace_array();
1869         struct trace_event_file *file;
1870         struct trace_kprobe *tk;
1871         struct dyn_event *pos;
1872
1873         mutex_lock(&event_mutex);
1874         for_each_trace_kprobe(tk, pos) {
1875                 list_for_each_entry(file, &tr->events, list)
1876                         if (file->event_call == trace_probe_event_call(&tk->tp))
1877                                 trace_event_enable_disable(file, 1, 0);
1878         }
1879         mutex_unlock(&event_mutex);
1880 }
1881
1882 static __init void setup_boot_kprobe_events(void)
1883 {
1884         char *p, *cmd = kprobe_boot_events_buf;
1885         int ret;
1886
1887         strreplace(kprobe_boot_events_buf, ',', ' ');
1888
1889         while (cmd && *cmd != '\0') {
1890                 p = strchr(cmd, ';');
1891                 if (p)
1892                         *p++ = '\0';
1893
1894                 ret = create_or_delete_trace_kprobe(cmd);
1895                 if (ret)
1896                         pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1897
1898                 cmd = p;
1899         }
1900
1901         enable_boot_kprobe_events();
1902 }
1903
1904 /*
1905  * Register dynevent at core_initcall. This allows kernel to setup kprobe
1906  * events in postcore_initcall without tracefs.
1907  */
1908 static __init int init_kprobe_trace_early(void)
1909 {
1910         int ret;
1911
1912         ret = dyn_event_register(&trace_kprobe_ops);
1913         if (ret)
1914                 return ret;
1915
1916         if (register_module_notifier(&trace_kprobe_module_nb))
1917                 return -EINVAL;
1918
1919         return 0;
1920 }
1921 core_initcall(init_kprobe_trace_early);
1922
1923 /* Make a tracefs interface for controlling probe points */
1924 static __init int init_kprobe_trace(void)
1925 {
1926         int ret;
1927         struct dentry *entry;
1928
1929         ret = tracing_init_dentry();
1930         if (ret)
1931                 return 0;
1932
1933         entry = tracefs_create_file("kprobe_events", 0644, NULL,
1934                                     NULL, &kprobe_events_ops);
1935
1936         /* Event list interface */
1937         if (!entry)
1938                 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1939
1940         /* Profile interface */
1941         entry = tracefs_create_file("kprobe_profile", 0444, NULL,
1942                                     NULL, &kprobe_profile_ops);
1943
1944         if (!entry)
1945                 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1946
1947         setup_boot_kprobe_events();
1948
1949         return 0;
1950 }
1951 fs_initcall(init_kprobe_trace);
1952
1953
1954 #ifdef CONFIG_FTRACE_STARTUP_TEST
1955 static __init struct trace_event_file *
1956 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1957 {
1958         struct trace_event_file *file;
1959
1960         list_for_each_entry(file, &tr->events, list)
1961                 if (file->event_call == trace_probe_event_call(&tk->tp))
1962                         return file;
1963
1964         return NULL;
1965 }
1966
1967 /*
1968  * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1969  * stage, we can do this lockless.
1970  */
1971 static __init int kprobe_trace_self_tests_init(void)
1972 {
1973         int ret, warn = 0;
1974         int (*target)(int, int, int, int, int, int);
1975         struct trace_kprobe *tk;
1976         struct trace_event_file *file;
1977
1978         if (tracing_is_disabled())
1979                 return -ENODEV;
1980
1981         if (tracing_selftest_disabled)
1982                 return 0;
1983
1984         target = kprobe_trace_selftest_target;
1985
1986         pr_info("Testing kprobe tracing: ");
1987
1988         ret = create_or_delete_trace_kprobe("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)");
1989         if (WARN_ON_ONCE(ret)) {
1990                 pr_warn("error on probing function entry.\n");
1991                 warn++;
1992         } else {
1993                 /* Enable trace point */
1994                 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1995                 if (WARN_ON_ONCE(tk == NULL)) {
1996                         pr_warn("error on getting new probe.\n");
1997                         warn++;
1998                 } else {
1999                         file = find_trace_probe_file(tk, top_trace_array());
2000                         if (WARN_ON_ONCE(file == NULL)) {
2001                                 pr_warn("error on getting probe file.\n");
2002                                 warn++;
2003                         } else
2004                                 enable_trace_kprobe(
2005                                         trace_probe_event_call(&tk->tp), file);
2006                 }
2007         }
2008
2009         ret = create_or_delete_trace_kprobe("r:testprobe2 kprobe_trace_selftest_target $retval");
2010         if (WARN_ON_ONCE(ret)) {
2011                 pr_warn("error on probing function return.\n");
2012                 warn++;
2013         } else {
2014                 /* Enable trace point */
2015                 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2016                 if (WARN_ON_ONCE(tk == NULL)) {
2017                         pr_warn("error on getting 2nd new probe.\n");
2018                         warn++;
2019                 } else {
2020                         file = find_trace_probe_file(tk, top_trace_array());
2021                         if (WARN_ON_ONCE(file == NULL)) {
2022                                 pr_warn("error on getting probe file.\n");
2023                                 warn++;
2024                         } else
2025                                 enable_trace_kprobe(
2026                                         trace_probe_event_call(&tk->tp), file);
2027                 }
2028         }
2029
2030         if (warn)
2031                 goto end;
2032
2033         ret = target(1, 2, 3, 4, 5, 6);
2034
2035         /*
2036          * Not expecting an error here, the check is only to prevent the
2037          * optimizer from removing the call to target() as otherwise there
2038          * are no side-effects and the call is never performed.
2039          */
2040         if (ret != 21)
2041                 warn++;
2042
2043         /* Disable trace points before removing it */
2044         tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
2045         if (WARN_ON_ONCE(tk == NULL)) {
2046                 pr_warn("error on getting test probe.\n");
2047                 warn++;
2048         } else {
2049                 if (trace_kprobe_nhit(tk) != 1) {
2050                         pr_warn("incorrect number of testprobe hits\n");
2051                         warn++;
2052                 }
2053
2054                 file = find_trace_probe_file(tk, top_trace_array());
2055                 if (WARN_ON_ONCE(file == NULL)) {
2056                         pr_warn("error on getting probe file.\n");
2057                         warn++;
2058                 } else
2059                         disable_trace_kprobe(
2060                                 trace_probe_event_call(&tk->tp), file);
2061         }
2062
2063         tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2064         if (WARN_ON_ONCE(tk == NULL)) {
2065                 pr_warn("error on getting 2nd test probe.\n");
2066                 warn++;
2067         } else {
2068                 if (trace_kprobe_nhit(tk) != 1) {
2069                         pr_warn("incorrect number of testprobe2 hits\n");
2070                         warn++;
2071                 }
2072
2073                 file = find_trace_probe_file(tk, top_trace_array());
2074                 if (WARN_ON_ONCE(file == NULL)) {
2075                         pr_warn("error on getting probe file.\n");
2076                         warn++;
2077                 } else
2078                         disable_trace_kprobe(
2079                                 trace_probe_event_call(&tk->tp), file);
2080         }
2081
2082         ret = create_or_delete_trace_kprobe("-:testprobe");
2083         if (WARN_ON_ONCE(ret)) {
2084                 pr_warn("error on deleting a probe.\n");
2085                 warn++;
2086         }
2087
2088         ret = create_or_delete_trace_kprobe("-:testprobe2");
2089         if (WARN_ON_ONCE(ret)) {
2090                 pr_warn("error on deleting a probe.\n");
2091                 warn++;
2092         }
2093
2094 end:
2095         ret = dyn_events_release_all(&trace_kprobe_ops);
2096         if (WARN_ON_ONCE(ret)) {
2097                 pr_warn("error on cleaning up probes.\n");
2098                 warn++;
2099         }
2100         /*
2101          * Wait for the optimizer work to finish. Otherwise it might fiddle
2102          * with probes in already freed __init text.
2103          */
2104         wait_for_kprobe_optimizer();
2105         if (warn)
2106                 pr_cont("NG: Some tests are failed. Please check them.\n");
2107         else
2108                 pr_cont("OK\n");
2109         return 0;
2110 }
2111
2112 late_initcall(kprobe_trace_self_tests_init);
2113
2114 #endif