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 static bool kprobe_boot_events_enabled __initdata;
  29
  30 static int __init set_kprobe_boot_events(char *str)
  31 {
  32         strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
  33         return 0;
  34 }
  35 __setup("kprobe_event=", set_kprobe_boot_events);
  36
  37 static int trace_kprobe_create(int argc, const char **argv);
  38 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
  39 static int trace_kprobe_release(struct dyn_event *ev);
  40 static bool trace_kprobe_is_busy(struct dyn_event *ev);
  41 static bool trace_kprobe_match(const char *system, const char *event,
  42                         int argc, const char **argv, struct dyn_event *ev);
  43
  44 static struct dyn_event_operations trace_kprobe_ops = {
  45         .create = trace_kprobe_create,
  46         .show = trace_kprobe_show,
  47         .is_busy = trace_kprobe_is_busy,
  48         .free = trace_kprobe_release,
  49         .match = trace_kprobe_match,
  50 };
  51
  52 /*
  53  * Kprobe event core functions
  54  */
  55 struct trace_kprobe {
  56         struct dyn_event        devent;
  57         struct kretprobe        rp;     /* Use rp.kp for kprobe use */
  58         unsigned long __percpu *nhit;
  59         const char              *symbol;        /* symbol name */
  60         struct trace_probe      tp;
  61 };
  62
  63 static bool is_trace_kprobe(struct dyn_event *ev)
  64 {
  65         return ev->ops == &trace_kprobe_ops;
  66 }
  67
  68 static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
  69 {
  70         return container_of(ev, struct trace_kprobe, devent);
  71 }
  72
  73 /**
  74  * for_each_trace_kprobe - iterate over the trace_kprobe list
  75  * @pos:        the struct trace_kprobe * for each entry
  76  * @dpos:       the struct dyn_event * to use as a loop cursor
  77  */
  78 #define for_each_trace_kprobe(pos, dpos)        \
  79         for_each_dyn_event(dpos)                \
  80                 if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
  81
  82 #define SIZEOF_TRACE_KPROBE(n)                          \
  83         (offsetof(struct trace_kprobe, tp.args) +       \
  84         (sizeof(struct probe_arg) * (n)))
  85
  86 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
  87 {
  88         return tk->rp.handler != NULL;
  89 }
  90
  91 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
  92 {
  93         return tk->symbol ? tk->symbol : "unknown";
  94 }
  95
  96 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
  97 {
  98         return tk->rp.kp.offset;
  99 }
 100
 101 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
 102 {
 103         return !!(kprobe_gone(&tk->rp.kp));
 104 }
 105
 106 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
 107                                                  struct module *mod)
 108 {
 109         int len = strlen(module_name(mod));
 110         const char *name = trace_kprobe_symbol(tk);
 111
 112         return strncmp(module_name(mod), name, len) == 0 && name[len] == ':';
 113 }
 114
 115 static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
 116 {
 117         char *p;
 118         bool ret;
 119
 120         if (!tk->symbol)
 121                 return false;
 122         p = strchr(tk->symbol, ':');
 123         if (!p)
 124                 return true;
 125         *p = '\0';
 126         mutex_lock(&module_mutex);
 127         ret = !!find_module(tk->symbol);
 128         mutex_unlock(&module_mutex);
 129         *p = ':';
 130
 131         return ret;
 132 }
 133
 134 static bool trace_kprobe_is_busy(struct dyn_event *ev)
 135 {
 136         struct trace_kprobe *tk = to_trace_kprobe(ev);
 137
 138         return trace_probe_is_enabled(&tk->tp);
 139 }
 140
 141 static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
 142                                             int argc, const char **argv)
 143 {
 144         char buf[MAX_ARGSTR_LEN + 1];
 145
 146         if (!argc)
 147                 return true;
 148
 149         if (!tk->symbol)
 150                 snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr);
 151         else if (tk->rp.kp.offset)
 152                 snprintf(buf, sizeof(buf), "%s+%u",
 153                          trace_kprobe_symbol(tk), tk->rp.kp.offset);
 154         else
 155                 snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk));
 156         if (strcmp(buf, argv[0]))
 157                 return false;
 158         argc--; argv++;
 159
 160         return trace_probe_match_command_args(&tk->tp, argc, argv);
 161 }
 162
 163 static bool trace_kprobe_match(const char *system, const char *event,
 164                         int argc, const char **argv, struct dyn_event *ev)
 165 {
 166         struct trace_kprobe *tk = to_trace_kprobe(ev);
 167
 168         return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
 169             (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
 170             trace_kprobe_match_command_head(tk, argc, argv);
 171 }
 172
 173 static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
 174 {
 175         unsigned long nhit = 0;
 176         int cpu;
 177
 178         for_each_possible_cpu(cpu)
 179                 nhit += *per_cpu_ptr(tk->nhit, cpu);
 180
 181         return nhit;
 182 }
 183
 184 static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk)
 185 {
 186         return !(list_empty(&tk->rp.kp.list) &&
 187                  hlist_unhashed(&tk->rp.kp.hlist));
 188 }
 189
 190 /* Return 0 if it fails to find the symbol address */
 191 static nokprobe_inline
 192 unsigned long trace_kprobe_address(struct trace_kprobe *tk)
 193 {
 194         unsigned long addr;
 195
 196         if (tk->symbol) {
 197                 addr = (unsigned long)
 198                         kallsyms_lookup_name(trace_kprobe_symbol(tk));
 199                 if (addr)
 200                         addr += tk->rp.kp.offset;
 201         } else {
 202                 addr = (unsigned long)tk->rp.kp.addr;
 203         }
 204         return addr;
 205 }
 206
 207 static nokprobe_inline struct trace_kprobe *
 208 trace_kprobe_primary_from_call(struct trace_event_call *call)
 209 {
 210         struct trace_probe *tp;
 211
 212         tp = trace_probe_primary_from_call(call);
 213         if (WARN_ON_ONCE(!tp))
 214                 return NULL;
 215
 216         return container_of(tp, struct trace_kprobe, tp);
 217 }
 218
 219 bool trace_kprobe_on_func_entry(struct trace_event_call *call)
 220 {
 221         struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
 222
 223         return tk ? kprobe_on_func_entry(tk->rp.kp.addr,
 224                         tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
 225                         tk->rp.kp.addr ? 0 : tk->rp.kp.offset) : false;
 226 }
 227
 228 bool trace_kprobe_error_injectable(struct trace_event_call *call)
 229 {
 230         struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
 231
 232         return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
 233                false;
 234 }
 235
 236 static int register_kprobe_event(struct trace_kprobe *tk);
 237 static int unregister_kprobe_event(struct trace_kprobe *tk);
 238
 239 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 240 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
 241                                 struct pt_regs *regs);
 242
 243 static void free_trace_kprobe(struct trace_kprobe *tk)
 244 {
 245         if (tk) {
 246                 trace_probe_cleanup(&tk->tp);
 247                 kfree(tk->symbol);
 248                 free_percpu(tk->nhit);
 249                 kfree(tk);
 250         }
 251 }
 252
 253 /*
 254  * Allocate new trace_probe and initialize it (including kprobes).
 255  */
 256 static struct trace_kprobe *alloc_trace_kprobe(const char *group,
 257                                              const char *event,
 258                                              void *addr,
 259                                              const char *symbol,
 260                                              unsigned long offs,
 261                                              int maxactive,
 262                                              int nargs, bool is_return)
 263 {
 264         struct trace_kprobe *tk;
 265         int ret = -ENOMEM;
 266
 267         tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
 268         if (!tk)
 269                 return ERR_PTR(ret);
 270
 271         tk->nhit = alloc_percpu(unsigned long);
 272         if (!tk->nhit)
 273                 goto error;
 274
 275         if (symbol) {
 276                 tk->symbol = kstrdup(symbol, GFP_KERNEL);
 277                 if (!tk->symbol)
 278                         goto error;
 279                 tk->rp.kp.symbol_name = tk->symbol;
 280                 tk->rp.kp.offset = offs;
 281         } else
 282                 tk->rp.kp.addr = addr;
 283
 284         if (is_return)
 285                 tk->rp.handler = kretprobe_dispatcher;
 286         else
 287                 tk->rp.kp.pre_handler = kprobe_dispatcher;
 288
 289         tk->rp.maxactive = maxactive;
 290         INIT_HLIST_NODE(&tk->rp.kp.hlist);
 291         INIT_LIST_HEAD(&tk->rp.kp.list);
 292
 293         ret = trace_probe_init(&tk->tp, event, group, false);
 294         if (ret < 0)
 295                 goto error;
 296
 297         dyn_event_init(&tk->devent, &trace_kprobe_ops);
 298         return tk;
 299 error:
 300         free_trace_kprobe(tk);
 301         return ERR_PTR(ret);
 302 }
 303
 304 static struct trace_kprobe *find_trace_kprobe(const char *event,
 305                                               const char *group)
 306 {
 307         struct dyn_event *pos;
 308         struct trace_kprobe *tk;
 309
 310         for_each_trace_kprobe(tk, pos)
 311                 if (strcmp(trace_probe_name(&tk->tp), event) == 0 &&
 312                     strcmp(trace_probe_group_name(&tk->tp), group) == 0)
 313                         return tk;
 314         return NULL;
 315 }
 316
 317 static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
 318 {
 319         int ret = 0;
 320
 321         if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) {
 322                 if (trace_kprobe_is_return(tk))
 323                         ret = enable_kretprobe(&tk->rp);
 324                 else
 325                         ret = enable_kprobe(&tk->rp.kp);
 326         }
 327
 328         return ret;
 329 }
 330
 331 static void __disable_trace_kprobe(struct trace_probe *tp)
 332 {
 333         struct trace_probe *pos;
 334         struct trace_kprobe *tk;
 335
 336         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
 337                 tk = container_of(pos, struct trace_kprobe, tp);
 338                 if (!trace_kprobe_is_registered(tk))
 339                         continue;
 340                 if (trace_kprobe_is_return(tk))
 341                         disable_kretprobe(&tk->rp);
 342                 else
 343                         disable_kprobe(&tk->rp.kp);
 344         }
 345 }
 346
 347 /*
 348  * Enable trace_probe
 349  * if the file is NULL, enable "perf" handler, or enable "trace" handler.
 350  */
 351 static int enable_trace_kprobe(struct trace_event_call *call,
 352                                 struct trace_event_file *file)
 353 {
 354         struct trace_probe *pos, *tp;
 355         struct trace_kprobe *tk;
 356         bool enabled;
 357         int ret = 0;
 358
 359         tp = trace_probe_primary_from_call(call);
 360         if (WARN_ON_ONCE(!tp))
 361                 return -ENODEV;
 362         enabled = trace_probe_is_enabled(tp);
 363
 364         /* This also changes "enabled" state */
 365         if (file) {
 366                 ret = trace_probe_add_file(tp, file);
 367                 if (ret)
 368                         return ret;
 369         } else
 370                 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
 371
 372         if (enabled)
 373                 return 0;
 374
 375         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
 376                 tk = container_of(pos, struct trace_kprobe, tp);
 377                 if (trace_kprobe_has_gone(tk))
 378                         continue;
 379                 ret = __enable_trace_kprobe(tk);
 380                 if (ret)
 381                         break;
 382                 enabled = true;
 383         }
 384
 385         if (ret) {
 386                 /* Failed to enable one of them. Roll back all */
 387                 if (enabled)
 388                         __disable_trace_kprobe(tp);
 389                 if (file)
 390                         trace_probe_remove_file(tp, file);
 391                 else
 392                         trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
 393         }
 394
 395         return ret;
 396 }
 397
 398 /*
 399  * Disable trace_probe
 400  * if the file is NULL, disable "perf" handler, or disable "trace" handler.
 401  */
 402 static int disable_trace_kprobe(struct trace_event_call *call,
 403                                 struct trace_event_file *file)
 404 {
 405         struct trace_probe *tp;
 406
 407         tp = trace_probe_primary_from_call(call);
 408         if (WARN_ON_ONCE(!tp))
 409                 return -ENODEV;
 410
 411         if (file) {
 412                 if (!trace_probe_get_file_link(tp, file))
 413                         return -ENOENT;
 414                 if (!trace_probe_has_single_file(tp))
 415                         goto out;
 416                 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
 417         } else
 418                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
 419
 420         if (!trace_probe_is_enabled(tp))
 421                 __disable_trace_kprobe(tp);
 422
 423  out:
 424         if (file)
 425                 /*
 426                  * Synchronization is done in below function. For perf event,
 427                  * file == NULL and perf_trace_event_unreg() calls
 428                  * tracepoint_synchronize_unregister() to ensure synchronize
 429                  * event. We don't need to care about it.
 430                  */
 431                 trace_probe_remove_file(tp, file);
 432
 433         return 0;
 434 }
 435
 436 #if defined(CONFIG_KPROBES_ON_FTRACE) && \
 437         !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
 438 static bool __within_notrace_func(unsigned long addr)
 439 {
 440         unsigned long offset, size;
 441
 442         if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
 443                 return false;
 444
 445         /* Get the entry address of the target function */
 446         addr -= offset;
 447
 448         /*
 449          * Since ftrace_location_range() does inclusive range check, we need
 450          * to subtract 1 byte from the end address.
 451          */
 452         return !ftrace_location_range(addr, addr + size - 1);
 453 }
 454
 455 static bool within_notrace_func(struct trace_kprobe *tk)
 456 {
 457         unsigned long addr = trace_kprobe_address(tk);
 458         char symname[KSYM_NAME_LEN], *p;
 459
 460         if (!__within_notrace_func(addr))
 461                 return false;
 462
 463         /* Check if the address is on a suffixed-symbol */
 464         if (!lookup_symbol_name(addr, symname)) {
 465                 p = strchr(symname, '.');
 466                 if (!p)
 467                         return true;
 468                 *p = '\0';
 469                 addr = (unsigned long)kprobe_lookup_name(symname, 0);
 470                 if (addr)
 471                         return __within_notrace_func(addr);
 472         }
 473
 474         return true;
 475 }
 476 #else
 477 #define within_notrace_func(tk) (false)
 478 #endif
 479
 480 /* Internal register function - just handle k*probes and flags */
 481 static int __register_trace_kprobe(struct trace_kprobe *tk)
 482 {
 483         int i, ret;
 484
 485         ret = security_locked_down(LOCKDOWN_KPROBES);
 486         if (ret)
 487                 return ret;
 488
 489         if (trace_kprobe_is_registered(tk))
 490                 return -EINVAL;
 491
 492         if (within_notrace_func(tk)) {
 493                 pr_warn("Could not probe notrace function %s\n",
 494                         trace_kprobe_symbol(tk));
 495                 return -EINVAL;
 496         }
 497
 498         for (i = 0; i < tk->tp.nr_args; i++) {
 499                 ret = traceprobe_update_arg(&tk->tp.args[i]);
 500                 if (ret)
 501                         return ret;
 502         }
 503
 504         /* Set/clear disabled flag according to tp->flag */
 505         if (trace_probe_is_enabled(&tk->tp))
 506                 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
 507         else
 508                 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
 509
 510         if (trace_kprobe_is_return(tk))
 511                 ret = register_kretprobe(&tk->rp);
 512         else
 513                 ret = register_kprobe(&tk->rp.kp);
 514
 515         return ret;
 516 }
 517
 518 /* Internal unregister function - just handle k*probes and flags */
 519 static void __unregister_trace_kprobe(struct trace_kprobe *tk)
 520 {
 521         if (trace_kprobe_is_registered(tk)) {
 522                 if (trace_kprobe_is_return(tk))
 523                         unregister_kretprobe(&tk->rp);
 524                 else
 525                         unregister_kprobe(&tk->rp.kp);
 526                 /* Cleanup kprobe for reuse and mark it unregistered */
 527                 INIT_HLIST_NODE(&tk->rp.kp.hlist);
 528                 INIT_LIST_HEAD(&tk->rp.kp.list);
 529                 if (tk->rp.kp.symbol_name)
 530                         tk->rp.kp.addr = NULL;
 531         }
 532 }
 533
 534 /* Unregister a trace_probe and probe_event */
 535 static int unregister_trace_kprobe(struct trace_kprobe *tk)
 536 {
 537         /* If other probes are on the event, just unregister kprobe */
 538         if (trace_probe_has_sibling(&tk->tp))
 539                 goto unreg;
 540
 541         /* Enabled event can not be unregistered */
 542         if (trace_probe_is_enabled(&tk->tp))
 543                 return -EBUSY;
 544
 545         /* Will fail if probe is being used by ftrace or perf */
 546         if (unregister_kprobe_event(tk))
 547                 return -EBUSY;
 548
 549 unreg:
 550         __unregister_trace_kprobe(tk);
 551         dyn_event_remove(&tk->devent);
 552         trace_probe_unlink(&tk->tp);
 553
 554         return 0;
 555 }
 556
 557 static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
 558                                          struct trace_kprobe *comp)
 559 {
 560         struct trace_probe_event *tpe = orig->tp.event;
 561         struct trace_probe *pos;
 562         int i;
 563
 564         list_for_each_entry(pos, &tpe->probes, list) {
 565                 orig = container_of(pos, struct trace_kprobe, tp);
 566                 if (strcmp(trace_kprobe_symbol(orig),
 567                            trace_kprobe_symbol(comp)) ||
 568                     trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
 569                         continue;
 570
 571                 /*
 572                  * trace_probe_compare_arg_type() ensured that nr_args and
 573                  * each argument name and type are same. Let's compare comm.
 574                  */
 575                 for (i = 0; i < orig->tp.nr_args; i++) {
 576                         if (strcmp(orig->tp.args[i].comm,
 577                                    comp->tp.args[i].comm))
 578                                 break;
 579                 }
 580
 581                 if (i == orig->tp.nr_args)
 582                         return true;
 583         }
 584
 585         return false;
 586 }
 587
 588 static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
 589 {
 590         int ret;
 591
 592         ret = trace_probe_compare_arg_type(&tk->tp, &to->tp);
 593         if (ret) {
 594                 /* Note that argument starts index = 2 */
 595                 trace_probe_log_set_index(ret + 1);
 596                 trace_probe_log_err(0, DIFF_ARG_TYPE);
 597                 return -EEXIST;
 598         }
 599         if (trace_kprobe_has_same_kprobe(to, tk)) {
 600                 trace_probe_log_set_index(0);
 601                 trace_probe_log_err(0, SAME_PROBE);
 602                 return -EEXIST;
 603         }
 604
 605         /* Append to existing event */
 606         ret = trace_probe_append(&tk->tp, &to->tp);
 607         if (ret)
 608                 return ret;
 609
 610         /* Register k*probe */
 611         ret = __register_trace_kprobe(tk);
 612         if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
 613                 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
 614                 ret = 0;
 615         }
 616
 617         if (ret)
 618                 trace_probe_unlink(&tk->tp);
 619         else
 620                 dyn_event_add(&tk->devent);
 621
 622         return ret;
 623 }
 624
 625 /* Register a trace_probe and probe_event */
 626 static int register_trace_kprobe(struct trace_kprobe *tk)
 627 {
 628         struct trace_kprobe *old_tk;
 629         int ret;
 630
 631         mutex_lock(&event_mutex);
 632
 633         old_tk = find_trace_kprobe(trace_probe_name(&tk->tp),
 634                                    trace_probe_group_name(&tk->tp));
 635         if (old_tk) {
 636                 if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) {
 637                         trace_probe_log_set_index(0);
 638                         trace_probe_log_err(0, DIFF_PROBE_TYPE);
 639                         ret = -EEXIST;
 640                 } else {
 641                         ret = append_trace_kprobe(tk, old_tk);
 642                 }
 643                 goto end;
 644         }
 645
 646         /* Register new event */
 647         ret = register_kprobe_event(tk);
 648         if (ret) {
 649                 pr_warn("Failed to register probe event(%d)\n", ret);
 650                 goto end;
 651         }
 652
 653         /* Register k*probe */
 654         ret = __register_trace_kprobe(tk);
 655         if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
 656                 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
 657                 ret = 0;
 658         }
 659
 660         if (ret < 0)
 661                 unregister_kprobe_event(tk);
 662         else
 663                 dyn_event_add(&tk->devent);
 664
 665 end:
 666         mutex_unlock(&event_mutex);
 667         return ret;
 668 }
 669
 670 /* Module notifier call back, checking event on the module */
 671 static int trace_kprobe_module_callback(struct notifier_block *nb,
 672                                        unsigned long val, void *data)
 673 {
 674         struct module *mod = data;
 675         struct dyn_event *pos;
 676         struct trace_kprobe *tk;
 677         int ret;
 678
 679         if (val != MODULE_STATE_COMING)
 680                 return NOTIFY_DONE;
 681
 682         /* Update probes on coming module */
 683         mutex_lock(&event_mutex);
 684         for_each_trace_kprobe(tk, pos) {
 685                 if (trace_kprobe_within_module(tk, mod)) {
 686                         /* Don't need to check busy - this should have gone. */
 687                         __unregister_trace_kprobe(tk);
 688                         ret = __register_trace_kprobe(tk);
 689                         if (ret)
 690                                 pr_warn("Failed to re-register probe %s on %s: %d\n",
 691                                         trace_probe_name(&tk->tp),
 692                                         module_name(mod), ret);
 693                 }
 694         }
 695         mutex_unlock(&event_mutex);
 696
 697         return NOTIFY_DONE;
 698 }
 699
 700 static struct notifier_block trace_kprobe_module_nb = {
 701         .notifier_call = trace_kprobe_module_callback,
 702         .priority = 1   /* Invoked after kprobe module callback */
 703 };
 704
 705 /* Convert certain expected symbols into '_' when generating event names */
 706 static inline void sanitize_event_name(char *name)
 707 {
 708         while (*name++ != '\0')
 709                 if (*name == ':' || *name == '.')
 710                         *name = '_';
 711 }
 712
 713 static int trace_kprobe_create(int argc, const char *argv[])
 714 {
 715         /*
 716          * Argument syntax:
 717          *  - Add kprobe:
 718          *      p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
 719          *  - Add kretprobe:
 720          *      r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
 721          *    Or
 722          *      p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS]
 723          *
 724          * Fetch args:
 725          *  $retval     : fetch return value
 726          *  $stack      : fetch stack address
 727          *  $stackN     : fetch Nth of stack (N:0-)
 728          *  $comm       : fetch current task comm
 729          *  @ADDR       : fetch memory at ADDR (ADDR should be in kernel)
 730          *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
 731          *  %REG        : fetch register REG
 732          * Dereferencing memory fetch:
 733          *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
 734          * Alias name of args:
 735          *  NAME=FETCHARG : set NAME as alias of FETCHARG.
 736          * Type of args:
 737          *  FETCHARG:TYPE : use TYPE instead of unsigned long.
 738          */
 739         struct trace_kprobe *tk = NULL;
 740         int i, len, ret = 0;
 741         bool is_return = false;
 742         char *symbol = NULL, *tmp = NULL;
 743         const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
 744         int maxactive = 0;
 745         long offset = 0;
 746         void *addr = NULL;
 747         char buf[MAX_EVENT_NAME_LEN];
 748         unsigned int flags = TPARG_FL_KERNEL;
 749
 750         switch (argv[0][0]) {
 751         case 'r':
 752                 is_return = true;
 753                 break;
 754         case 'p':
 755                 break;
 756         default:
 757                 return -ECANCELED;
 758         }
 759         if (argc < 2)
 760                 return -ECANCELED;
 761
 762         trace_probe_log_init("trace_kprobe", argc, argv);
 763
 764         event = strchr(&argv[0][1], ':');
 765         if (event)
 766                 event++;
 767
 768         if (isdigit(argv[0][1])) {
 769                 if (!is_return) {
 770                         trace_probe_log_err(1, MAXACT_NO_KPROBE);
 771                         goto parse_error;
 772                 }
 773                 if (event)
 774                         len = event - &argv[0][1] - 1;
 775                 else
 776                         len = strlen(&argv[0][1]);
 777                 if (len > MAX_EVENT_NAME_LEN - 1) {
 778                         trace_probe_log_err(1, BAD_MAXACT);
 779                         goto parse_error;
 780                 }
 781                 memcpy(buf, &argv[0][1], len);
 782                 buf[len] = '\0';
 783                 ret = kstrtouint(buf, 0, &maxactive);
 784                 if (ret || !maxactive) {
 785                         trace_probe_log_err(1, BAD_MAXACT);
 786                         goto parse_error;
 787                 }
 788                 /* kretprobes instances are iterated over via a list. The
 789                  * maximum should stay reasonable.
 790                  */
 791                 if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
 792                         trace_probe_log_err(1, MAXACT_TOO_BIG);
 793                         goto parse_error;
 794                 }
 795         }
 796
 797         /* try to parse an address. if that fails, try to read the
 798          * input as a symbol. */
 799         if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
 800                 trace_probe_log_set_index(1);
 801                 /* Check whether uprobe event specified */
 802                 if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
 803                         ret = -ECANCELED;
 804                         goto error;
 805                 }
 806                 /* a symbol specified */
 807                 symbol = kstrdup(argv[1], GFP_KERNEL);
 808                 if (!symbol)
 809                         return -ENOMEM;
 810
 811                 tmp = strchr(symbol, '%');
 812                 if (tmp) {
 813                         if (!strcmp(tmp, "%return")) {
 814                                 *tmp = '\0';
 815                                 is_return = true;
 816                         } else {
 817                                 trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
 818                                 goto parse_error;
 819                         }
 820                 }
 821
 822                 /* TODO: support .init module functions */
 823                 ret = traceprobe_split_symbol_offset(symbol, &offset);
 824                 if (ret || offset < 0 || offset > UINT_MAX) {
 825                         trace_probe_log_err(0, BAD_PROBE_ADDR);
 826                         goto parse_error;
 827                 }
 828                 if (is_return)
 829                         flags |= TPARG_FL_RETURN;
 830                 if (kprobe_on_func_entry(NULL, symbol, offset))
 831                         flags |= TPARG_FL_FENTRY;
 832                 if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
 833                         trace_probe_log_err(0, BAD_RETPROBE);
 834                         goto parse_error;
 835                 }
 836         }
 837
 838         trace_probe_log_set_index(0);
 839         if (event) {
 840                 ret = traceprobe_parse_event_name(&event, &group, buf,
 841                                                   event - argv[0]);
 842                 if (ret)
 843                         goto parse_error;
 844         } else {
 845                 /* Make a new event name */
 846                 if (symbol)
 847                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
 848                                  is_return ? 'r' : 'p', symbol, offset);
 849                 else
 850                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
 851                                  is_return ? 'r' : 'p', addr);
 852                 sanitize_event_name(buf);
 853                 event = buf;
 854         }
 855
 856         /* setup a probe */
 857         tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
 858                                argc - 2, is_return);
 859         if (IS_ERR(tk)) {
 860                 ret = PTR_ERR(tk);
 861                 /* This must return -ENOMEM, else there is a bug */
 862                 WARN_ON_ONCE(ret != -ENOMEM);
 863                 goto out;       /* We know tk is not allocated */
 864         }
 865         argc -= 2; argv += 2;
 866
 867         /* parse arguments */
 868         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 869                 tmp = kstrdup(argv[i], GFP_KERNEL);
 870                 if (!tmp) {
 871                         ret = -ENOMEM;
 872                         goto error;
 873                 }
 874
 875                 trace_probe_log_set_index(i + 2);
 876                 ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags);
 877                 kfree(tmp);
 878                 if (ret)
 879                         goto error;     /* This can be -ENOMEM */
 880         }
 881
 882         ret = traceprobe_set_print_fmt(&tk->tp, is_return);
 883         if (ret < 0)
 884                 goto error;
 885
 886         ret = register_trace_kprobe(tk);
 887         if (ret) {
 888                 trace_probe_log_set_index(1);
 889                 if (ret == -EILSEQ)
 890                         trace_probe_log_err(0, BAD_INSN_BNDRY);
 891                 else if (ret == -ENOENT)
 892                         trace_probe_log_err(0, BAD_PROBE_ADDR);
 893                 else if (ret != -ENOMEM && ret != -EEXIST)
 894                         trace_probe_log_err(0, FAIL_REG_PROBE);
 895                 goto error;
 896         }
 897
 898 out:
 899         trace_probe_log_clear();
 900         kfree(symbol);
 901         return ret;
 902
 903 parse_error:
 904         ret = -EINVAL;
 905 error:
 906         free_trace_kprobe(tk);
 907         goto out;
 908 }
 909
 910 static int create_or_delete_trace_kprobe(int argc, char **argv)
 911 {
 912         int ret;
 913
 914         if (argv[0][0] == '-')
 915                 return dyn_event_release(argc, argv, &trace_kprobe_ops);
 916
 917         ret = trace_kprobe_create(argc, (const char **)argv);
 918         return ret == -ECANCELED ? -EINVAL : ret;
 919 }
 920
 921 static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
 922 {
 923         return trace_run_command(cmd->seq.buffer, create_or_delete_trace_kprobe);
 924 }
 925
 926 /**
 927  * kprobe_event_cmd_init - Initialize a kprobe event command object
 928  * @cmd: A pointer to the dynevent_cmd struct representing the new event
 929  * @buf: A pointer to the buffer used to build the command
 930  * @maxlen: The length of the buffer passed in @buf
 931  *
 932  * Initialize a synthetic event command object.  Use this before
 933  * calling any of the other kprobe_event functions.
 934  */
 935 void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
 936 {
 937         dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
 938                           trace_kprobe_run_command);
 939 }
 940 EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
 941
 942 /**
 943  * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
 944  * @cmd: A pointer to the dynevent_cmd struct representing the new event
 945  * @name: The name of the kprobe event
 946  * @loc: The location of the kprobe event
 947  * @kretprobe: Is this a return probe?
 948  * @args: Variable number of arg (pairs), one pair for each field
 949  *
 950  * NOTE: Users normally won't want to call this function directly, but
 951  * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
 952  * adds a NULL to the end of the arg list.  If this function is used
 953  * directly, make sure the last arg in the variable arg list is NULL.
 954  *
 955  * Generate a kprobe event command to be executed by
 956  * kprobe_event_gen_cmd_end().  This function can be used to generate the
 957  * complete command or only the first part of it; in the latter case,
 958  * kprobe_event_add_fields() can be used to add more fields following this.
 959  *
 960  * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
 961  * returns -EINVAL if @loc == NULL.
 962  *
 963  * Return: 0 if successful, error otherwise.
 964  */
 965 int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
 966                                  const char *name, const char *loc, ...)
 967 {
 968         char buf[MAX_EVENT_NAME_LEN];
 969         struct dynevent_arg arg;
 970         va_list args;
 971         int ret;
 972
 973         if (cmd->type != DYNEVENT_TYPE_KPROBE)
 974                 return -EINVAL;
 975
 976         if (!loc)
 977                 return -EINVAL;
 978
 979         if (kretprobe)
 980                 snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
 981         else
 982                 snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
 983
 984         ret = dynevent_str_add(cmd, buf);
 985         if (ret)
 986                 return ret;
 987
 988         dynevent_arg_init(&arg, 0);
 989         arg.str = loc;
 990         ret = dynevent_arg_add(cmd, &arg, NULL);
 991         if (ret)
 992                 return ret;
 993
 994         va_start(args, loc);
 995         for (;;) {
 996                 const char *field;
 997
 998                 field = va_arg(args, const char *);
 999                 if (!field)
1000                         break;
1001
1002                 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1003                         ret = -EINVAL;
1004                         break;
1005                 }
1006
1007                 arg.str = field;
1008                 ret = dynevent_arg_add(cmd, &arg, NULL);
1009                 if (ret)
1010                         break;
1011         }
1012         va_end(args);
1013
1014         return ret;
1015 }
1016 EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
1017
1018 /**
1019  * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
1020  * @cmd: A pointer to the dynevent_cmd struct representing the new event
1021  * @args: Variable number of arg (pairs), one pair for each field
1022  *
1023  * NOTE: Users normally won't want to call this function directly, but
1024  * rather use the kprobe_event_add_fields() wrapper, which
1025  * automatically adds a NULL to the end of the arg list.  If this
1026  * function is used directly, make sure the last arg in the variable
1027  * arg list is NULL.
1028  *
1029  * Add probe fields to an existing kprobe command using a variable
1030  * list of args.  Fields are added in the same order they're listed.
1031  *
1032  * Return: 0 if successful, error otherwise.
1033  */
1034 int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
1035 {
1036         struct dynevent_arg arg;
1037         va_list args;
1038         int ret = 0;
1039
1040         if (cmd->type != DYNEVENT_TYPE_KPROBE)
1041                 return -EINVAL;
1042
1043         dynevent_arg_init(&arg, 0);
1044
1045         va_start(args, cmd);
1046         for (;;) {
1047                 const char *field;
1048
1049                 field = va_arg(args, const char *);
1050                 if (!field)
1051                         break;
1052
1053                 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1054                         ret = -EINVAL;
1055                         break;
1056                 }
1057
1058                 arg.str = field;
1059                 ret = dynevent_arg_add(cmd, &arg, NULL);
1060                 if (ret)
1061                         break;
1062         }
1063         va_end(args);
1064
1065         return ret;
1066 }
1067 EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
1068
1069 /**
1070  * kprobe_event_delete - Delete a kprobe event
1071  * @name: The name of the kprobe event to delete
1072  *
1073  * Delete a kprobe event with the give @name from kernel code rather
1074  * than directly from the command line.
1075  *
1076  * Return: 0 if successful, error otherwise.
1077  */
1078 int kprobe_event_delete(const char *name)
1079 {
1080         char buf[MAX_EVENT_NAME_LEN];
1081
1082         snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
1083
1084         return trace_run_command(buf, create_or_delete_trace_kprobe);
1085 }
1086 EXPORT_SYMBOL_GPL(kprobe_event_delete);
1087
1088 static int trace_kprobe_release(struct dyn_event *ev)
1089 {
1090         struct trace_kprobe *tk = to_trace_kprobe(ev);
1091         int ret = unregister_trace_kprobe(tk);
1092
1093         if (!ret)
1094                 free_trace_kprobe(tk);
1095         return ret;
1096 }
1097
1098 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
1099 {
1100         struct trace_kprobe *tk = to_trace_kprobe(ev);
1101         int i;
1102
1103         seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
1104         if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
1105                 seq_printf(m, "%d", tk->rp.maxactive);
1106         seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
1107                                 trace_probe_name(&tk->tp));
1108
1109         if (!tk->symbol)
1110                 seq_printf(m, " 0x%p", tk->rp.kp.addr);
1111         else if (tk->rp.kp.offset)
1112                 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
1113                            tk->rp.kp.offset);
1114         else
1115                 seq_printf(m, " %s", trace_kprobe_symbol(tk));
1116
1117         for (i = 0; i < tk->tp.nr_args; i++)
1118                 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
1119         seq_putc(m, '\n');
1120
1121         return 0;
1122 }
1123
1124 static int probes_seq_show(struct seq_file *m, void *v)
1125 {
1126         struct dyn_event *ev = v;
1127
1128         if (!is_trace_kprobe(ev))
1129                 return 0;
1130
1131         return trace_kprobe_show(m, ev);
1132 }
1133
1134 static const struct seq_operations probes_seq_op = {
1135         .start  = dyn_event_seq_start,
1136         .next   = dyn_event_seq_next,
1137         .stop   = dyn_event_seq_stop,
1138         .show   = probes_seq_show
1139 };
1140
1141 static int probes_open(struct inode *inode, struct file *file)
1142 {
1143         int ret;
1144
1145         ret = security_locked_down(LOCKDOWN_TRACEFS);
1146         if (ret)
1147                 return ret;
1148
1149         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1150                 ret = dyn_events_release_all(&trace_kprobe_ops);
1151                 if (ret < 0)
1152                         return ret;
1153         }
1154
1155         return seq_open(file, &probes_seq_op);
1156 }
1157
1158 static ssize_t probes_write(struct file *file, const char __user *buffer,
1159                             size_t count, loff_t *ppos)
1160 {
1161         return trace_parse_run_command(file, buffer, count, ppos,
1162                                        create_or_delete_trace_kprobe);
1163 }
1164
1165 static const struct file_operations kprobe_events_ops = {
1166         .owner          = THIS_MODULE,
1167         .open           = probes_open,
1168         .read           = seq_read,
1169         .llseek         = seq_lseek,
1170         .release        = seq_release,
1171         .write          = probes_write,
1172 };
1173
1174 /* Probes profiling interfaces */
1175 static int probes_profile_seq_show(struct seq_file *m, void *v)
1176 {
1177         struct dyn_event *ev = v;
1178         struct trace_kprobe *tk;
1179
1180         if (!is_trace_kprobe(ev))
1181                 return 0;
1182
1183         tk = to_trace_kprobe(ev);
1184         seq_printf(m, "  %-44s %15lu %15lu\n",
1185                    trace_probe_name(&tk->tp),
1186                    trace_kprobe_nhit(tk),
1187                    tk->rp.kp.nmissed);
1188
1189         return 0;
1190 }
1191
1192 static const struct seq_operations profile_seq_op = {
1193         .start  = dyn_event_seq_start,
1194         .next   = dyn_event_seq_next,
1195         .stop   = dyn_event_seq_stop,
1196         .show   = probes_profile_seq_show
1197 };
1198
1199 static int profile_open(struct inode *inode, struct file *file)
1200 {
1201         int ret;
1202
1203         ret = security_locked_down(LOCKDOWN_TRACEFS);
1204         if (ret)
1205                 return ret;
1206
1207         return seq_open(file, &profile_seq_op);
1208 }
1209
1210 static const struct file_operations kprobe_profile_ops = {
1211         .owner          = THIS_MODULE,
1212         .open           = profile_open,
1213         .read           = seq_read,
1214         .llseek         = seq_lseek,
1215         .release        = seq_release,
1216 };
1217
1218 /* Kprobe specific fetch functions */
1219
1220 /* Return the length of string -- including null terminal byte */
1221 static nokprobe_inline int
1222 fetch_store_strlen_user(unsigned long addr)
1223 {
1224         const void __user *uaddr =  (__force const void __user *)addr;
1225
1226         return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
1227 }
1228
1229 /* Return the length of string -- including null terminal byte */
1230 static nokprobe_inline int
1231 fetch_store_strlen(unsigned long addr)
1232 {
1233         int ret, len = 0;
1234         u8 c;
1235
1236 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1237         if (addr < TASK_SIZE)
1238                 return fetch_store_strlen_user(addr);
1239 #endif
1240
1241         do {
1242                 ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1);
1243                 len++;
1244         } while (c && ret == 0 && len < MAX_STRING_SIZE);
1245
1246         return (ret < 0) ? ret : len;
1247 }
1248
1249 /*
1250  * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
1251  * with max length and relative data location.
1252  */
1253 static nokprobe_inline int
1254 fetch_store_string_user(unsigned long addr, void *dest, void *base)
1255 {
1256         const void __user *uaddr =  (__force const void __user *)addr;
1257         int maxlen = get_loc_len(*(u32 *)dest);
1258         void *__dest;
1259         long ret;
1260
1261         if (unlikely(!maxlen))
1262                 return -ENOMEM;
1263
1264         __dest = get_loc_data(dest, base);
1265
1266         ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
1267         if (ret >= 0)
1268                 *(u32 *)dest = make_data_loc(ret, __dest - base);
1269
1270         return ret;
1271 }
1272
1273 /*
1274  * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
1275  * length and relative data location.
1276  */
1277 static nokprobe_inline int
1278 fetch_store_string(unsigned long addr, void *dest, void *base)
1279 {
1280         int maxlen = get_loc_len(*(u32 *)dest);
1281         void *__dest;
1282         long ret;
1283
1284 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1285         if ((unsigned long)addr < TASK_SIZE)
1286                 return fetch_store_string_user(addr, dest, base);
1287 #endif
1288
1289         if (unlikely(!maxlen))
1290                 return -ENOMEM;
1291
1292         __dest = get_loc_data(dest, base);
1293
1294         /*
1295          * Try to get string again, since the string can be changed while
1296          * probing.
1297          */
1298         ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
1299         if (ret >= 0)
1300                 *(u32 *)dest = make_data_loc(ret, __dest - base);
1301
1302         return ret;
1303 }
1304
1305 static nokprobe_inline int
1306 probe_mem_read_user(void *dest, void *src, size_t size)
1307 {
1308         const void __user *uaddr =  (__force const void __user *)src;
1309
1310         return copy_from_user_nofault(dest, uaddr, size);
1311 }
1312
1313 static nokprobe_inline int
1314 probe_mem_read(void *dest, void *src, size_t size)
1315 {
1316 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1317         if ((unsigned long)src < TASK_SIZE)
1318                 return probe_mem_read_user(dest, src, size);
1319 #endif
1320         return copy_from_kernel_nofault(dest, src, size);
1321 }
1322
1323 /* Note that we don't verify it, since the code does not come from user space */
1324 static int
1325 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
1326                    void *base)
1327 {
1328         unsigned long val;
1329
1330 retry:
1331         /* 1st stage: get value from context */
1332         switch (code->op) {
1333         case FETCH_OP_REG:
1334                 val = regs_get_register(regs, code->param);
1335                 break;
1336         case FETCH_OP_STACK:
1337                 val = regs_get_kernel_stack_nth(regs, code->param);
1338                 break;
1339         case FETCH_OP_STACKP:
1340                 val = kernel_stack_pointer(regs);
1341                 break;
1342         case FETCH_OP_RETVAL:
1343                 val = regs_return_value(regs);
1344                 break;
1345         case FETCH_OP_IMM:
1346                 val = code->immediate;
1347                 break;
1348         case FETCH_OP_COMM:
1349                 val = (unsigned long)current->comm;
1350                 break;
1351         case FETCH_OP_DATA:
1352                 val = (unsigned long)code->data;
1353                 break;
1354 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1355         case FETCH_OP_ARG:
1356                 val = regs_get_kernel_argument(regs, code->param);
1357                 break;
1358 #endif
1359         case FETCH_NOP_SYMBOL:  /* Ignore a place holder */
1360                 code++;
1361                 goto retry;
1362         default:
1363                 return -EILSEQ;
1364         }
1365         code++;
1366
1367         return process_fetch_insn_bottom(code, val, dest, base);
1368 }
1369 NOKPROBE_SYMBOL(process_fetch_insn)
1370
1371 /* Kprobe handler */
1372 static nokprobe_inline void
1373 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1374                     struct trace_event_file *trace_file)
1375 {
1376         struct kprobe_trace_entry_head *entry;
1377         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1378         struct trace_event_buffer fbuffer;
1379         int dsize;
1380
1381         WARN_ON(call != trace_file->event_call);
1382
1383         if (trace_trigger_soft_disabled(trace_file))
1384                 return;
1385
1386         local_save_flags(fbuffer.flags);
1387         fbuffer.pc = preempt_count();
1388         fbuffer.trace_file = trace_file;
1389
1390         dsize = __get_data_size(&tk->tp, regs);
1391
1392         fbuffer.event =
1393                 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
1394                                         call->event.type,
1395                                         sizeof(*entry) + tk->tp.size + dsize,
1396                                         fbuffer.flags, fbuffer.pc);
1397         if (!fbuffer.event)
1398                 return;
1399
1400         fbuffer.regs = regs;
1401         entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
1402         entry->ip = (unsigned long)tk->rp.kp.addr;
1403         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1404
1405         trace_event_buffer_commit(&fbuffer);
1406 }
1407
1408 static void
1409 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1410 {
1411         struct event_file_link *link;
1412
1413         trace_probe_for_each_link_rcu(link, &tk->tp)
1414                 __kprobe_trace_func(tk, regs, link->file);
1415 }
1416 NOKPROBE_SYMBOL(kprobe_trace_func);
1417
1418 /* Kretprobe handler */
1419 static nokprobe_inline void
1420 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1421                        struct pt_regs *regs,
1422                        struct trace_event_file *trace_file)
1423 {
1424         struct kretprobe_trace_entry_head *entry;
1425         struct trace_event_buffer fbuffer;
1426         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1427         int dsize;
1428
1429         WARN_ON(call != trace_file->event_call);
1430
1431         if (trace_trigger_soft_disabled(trace_file))
1432                 return;
1433
1434         local_save_flags(fbuffer.flags);
1435         fbuffer.pc = preempt_count();
1436         fbuffer.trace_file = trace_file;
1437
1438         dsize = __get_data_size(&tk->tp, regs);
1439         fbuffer.event =
1440                 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
1441                                         call->event.type,
1442                                         sizeof(*entry) + tk->tp.size + dsize,
1443                                         fbuffer.flags, fbuffer.pc);
1444         if (!fbuffer.event)
1445                 return;
1446
1447         fbuffer.regs = regs;
1448         entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
1449         entry->func = (unsigned long)tk->rp.kp.addr;
1450         entry->ret_ip = (unsigned long)ri->ret_addr;
1451         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1452
1453         trace_event_buffer_commit(&fbuffer);
1454 }
1455
1456 static void
1457 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1458                      struct pt_regs *regs)
1459 {
1460         struct event_file_link *link;
1461
1462         trace_probe_for_each_link_rcu(link, &tk->tp)
1463                 __kretprobe_trace_func(tk, ri, regs, link->file);
1464 }
1465 NOKPROBE_SYMBOL(kretprobe_trace_func);
1466
1467 /* Event entry printers */
1468 static enum print_line_t
1469 print_kprobe_event(struct trace_iterator *iter, int flags,
1470                    struct trace_event *event)
1471 {
1472         struct kprobe_trace_entry_head *field;
1473         struct trace_seq *s = &iter->seq;
1474         struct trace_probe *tp;
1475
1476         field = (struct kprobe_trace_entry_head *)iter->ent;
1477         tp = trace_probe_primary_from_call(
1478                 container_of(event, struct trace_event_call, event));
1479         if (WARN_ON_ONCE(!tp))
1480                 goto out;
1481
1482         trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1483
1484         if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1485                 goto out;
1486
1487         trace_seq_putc(s, ')');
1488
1489         if (print_probe_args(s, tp->args, tp->nr_args,
1490                              (u8 *)&field[1], field) < 0)
1491                 goto out;
1492
1493         trace_seq_putc(s, '\n');
1494  out:
1495         return trace_handle_return(s);
1496 }
1497
1498 static enum print_line_t
1499 print_kretprobe_event(struct trace_iterator *iter, int flags,
1500                       struct trace_event *event)
1501 {
1502         struct kretprobe_trace_entry_head *field;
1503         struct trace_seq *s = &iter->seq;
1504         struct trace_probe *tp;
1505
1506         field = (struct kretprobe_trace_entry_head *)iter->ent;
1507         tp = trace_probe_primary_from_call(
1508                 container_of(event, struct trace_event_call, event));
1509         if (WARN_ON_ONCE(!tp))
1510                 goto out;
1511
1512         trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1513
1514         if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1515                 goto out;
1516
1517         trace_seq_puts(s, " <- ");
1518
1519         if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1520                 goto out;
1521
1522         trace_seq_putc(s, ')');
1523
1524         if (print_probe_args(s, tp->args, tp->nr_args,
1525                              (u8 *)&field[1], field) < 0)
1526                 goto out;
1527
1528         trace_seq_putc(s, '\n');
1529
1530  out:
1531         return trace_handle_return(s);
1532 }
1533
1534
1535 static int kprobe_event_define_fields(struct trace_event_call *event_call)
1536 {
1537         int ret;
1538         struct kprobe_trace_entry_head field;
1539         struct trace_probe *tp;
1540
1541         tp = trace_probe_primary_from_call(event_call);
1542         if (WARN_ON_ONCE(!tp))
1543                 return -ENOENT;
1544
1545         DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1546
1547         return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1548 }
1549
1550 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1551 {
1552         int ret;
1553         struct kretprobe_trace_entry_head field;
1554         struct trace_probe *tp;
1555
1556         tp = trace_probe_primary_from_call(event_call);
1557         if (WARN_ON_ONCE(!tp))
1558                 return -ENOENT;
1559
1560         DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1561         DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1562
1563         return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1564 }
1565
1566 #ifdef CONFIG_PERF_EVENTS
1567
1568 /* Kprobe profile handler */
1569 static int
1570 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1571 {
1572         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1573         struct kprobe_trace_entry_head *entry;
1574         struct hlist_head *head;
1575         int size, __size, dsize;
1576         int rctx;
1577
1578         if (bpf_prog_array_valid(call)) {
1579                 unsigned long orig_ip = instruction_pointer(regs);
1580                 int ret;
1581
1582                 ret = trace_call_bpf(call, regs);
1583
1584                 /*
1585                  * We need to check and see if we modified the pc of the
1586                  * pt_regs, and if so return 1 so that we don't do the
1587                  * single stepping.
1588                  */
1589                 if (orig_ip != instruction_pointer(regs))
1590                         return 1;
1591                 if (!ret)
1592                         return 0;
1593         }
1594
1595         head = this_cpu_ptr(call->perf_events);
1596         if (hlist_empty(head))
1597                 return 0;
1598
1599         dsize = __get_data_size(&tk->tp, regs);
1600         __size = sizeof(*entry) + tk->tp.size + dsize;
1601         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1602         size -= sizeof(u32);
1603
1604         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1605         if (!entry)
1606                 return 0;
1607
1608         entry->ip = (unsigned long)tk->rp.kp.addr;
1609         memset(&entry[1], 0, dsize);
1610         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1611         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1612                               head, NULL);
1613         return 0;
1614 }
1615 NOKPROBE_SYMBOL(kprobe_perf_func);
1616
1617 /* Kretprobe profile handler */
1618 static void
1619 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1620                     struct pt_regs *regs)
1621 {
1622         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1623         struct kretprobe_trace_entry_head *entry;
1624         struct hlist_head *head;
1625         int size, __size, dsize;
1626         int rctx;
1627
1628         if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1629                 return;
1630
1631         head = this_cpu_ptr(call->perf_events);
1632         if (hlist_empty(head))
1633                 return;
1634
1635         dsize = __get_data_size(&tk->tp, regs);
1636         __size = sizeof(*entry) + tk->tp.size + dsize;
1637         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1638         size -= sizeof(u32);
1639
1640         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1641         if (!entry)
1642                 return;
1643
1644         entry->func = (unsigned long)tk->rp.kp.addr;
1645         entry->ret_ip = (unsigned long)ri->ret_addr;
1646         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1647         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1648                               head, NULL);
1649 }
1650 NOKPROBE_SYMBOL(kretprobe_perf_func);
1651
1652 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1653                         const char **symbol, u64 *probe_offset,
1654                         u64 *probe_addr, bool perf_type_tracepoint)
1655 {
1656         const char *pevent = trace_event_name(event->tp_event);
1657         const char *group = event->tp_event->class->system;
1658         struct trace_kprobe *tk;
1659
1660         if (perf_type_tracepoint)
1661                 tk = find_trace_kprobe(pevent, group);
1662         else
1663                 tk = trace_kprobe_primary_from_call(event->tp_event);
1664         if (!tk)
1665                 return -EINVAL;
1666
1667         *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1668                                               : BPF_FD_TYPE_KPROBE;
1669         if (tk->symbol) {
1670                 *symbol = tk->symbol;
1671                 *probe_offset = tk->rp.kp.offset;
1672                 *probe_addr = 0;
1673         } else {
1674                 *symbol = NULL;
1675                 *probe_offset = 0;
1676                 *probe_addr = (unsigned long)tk->rp.kp.addr;
1677         }
1678         return 0;
1679 }
1680 #endif  /* CONFIG_PERF_EVENTS */
1681
1682 /*
1683  * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1684  *
1685  * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1686  * lockless, but we can't race with this __init function.
1687  */
1688 static int kprobe_register(struct trace_event_call *event,
1689                            enum trace_reg type, void *data)
1690 {
1691         struct trace_event_file *file = data;
1692
1693         switch (type) {
1694         case TRACE_REG_REGISTER:
1695                 return enable_trace_kprobe(event, file);
1696         case TRACE_REG_UNREGISTER:
1697                 return disable_trace_kprobe(event, file);
1698
1699 #ifdef CONFIG_PERF_EVENTS
1700         case TRACE_REG_PERF_REGISTER:
1701                 return enable_trace_kprobe(event, NULL);
1702         case TRACE_REG_PERF_UNREGISTER:
1703                 return disable_trace_kprobe(event, NULL);
1704         case TRACE_REG_PERF_OPEN:
1705         case TRACE_REG_PERF_CLOSE:
1706         case TRACE_REG_PERF_ADD:
1707         case TRACE_REG_PERF_DEL:
1708                 return 0;
1709 #endif
1710         }
1711         return 0;
1712 }
1713
1714 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1715 {
1716         struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1717         int ret = 0;
1718
1719         raw_cpu_inc(*tk->nhit);
1720
1721         if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1722                 kprobe_trace_func(tk, regs);
1723 #ifdef CONFIG_PERF_EVENTS
1724         if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1725                 ret = kprobe_perf_func(tk, regs);
1726 #endif
1727         return ret;
1728 }
1729 NOKPROBE_SYMBOL(kprobe_dispatcher);
1730
1731 static int
1732 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1733 {
1734         struct kretprobe *rp = get_kretprobe(ri);
1735         struct trace_kprobe *tk = container_of(rp, struct trace_kprobe, rp);
1736
1737         raw_cpu_inc(*tk->nhit);
1738
1739         if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1740                 kretprobe_trace_func(tk, ri, regs);
1741 #ifdef CONFIG_PERF_EVENTS
1742         if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1743                 kretprobe_perf_func(tk, ri, regs);
1744 #endif
1745         return 0;       /* We don't tweek kernel, so just return 0 */
1746 }
1747 NOKPROBE_SYMBOL(kretprobe_dispatcher);
1748
1749 static struct trace_event_functions kretprobe_funcs = {
1750         .trace          = print_kretprobe_event
1751 };
1752
1753 static struct trace_event_functions kprobe_funcs = {
1754         .trace          = print_kprobe_event
1755 };
1756
1757 static struct trace_event_fields kretprobe_fields_array[] = {
1758         { .type = TRACE_FUNCTION_TYPE,
1759           .define_fields = kretprobe_event_define_fields },
1760         {}
1761 };
1762
1763 static struct trace_event_fields kprobe_fields_array[] = {
1764         { .type = TRACE_FUNCTION_TYPE,
1765           .define_fields = kprobe_event_define_fields },
1766         {}
1767 };
1768
1769 static inline void init_trace_event_call(struct trace_kprobe *tk)
1770 {
1771         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1772
1773         if (trace_kprobe_is_return(tk)) {
1774                 call->event.funcs = &kretprobe_funcs;
1775                 call->class->fields_array = kretprobe_fields_array;
1776         } else {
1777                 call->event.funcs = &kprobe_funcs;
1778                 call->class->fields_array = kprobe_fields_array;
1779         }
1780
1781         call->flags = TRACE_EVENT_FL_KPROBE;
1782         call->class->reg = kprobe_register;
1783 }
1784
1785 static int register_kprobe_event(struct trace_kprobe *tk)
1786 {
1787         init_trace_event_call(tk);
1788
1789         return trace_probe_register_event_call(&tk->tp);
1790 }
1791
1792 static int unregister_kprobe_event(struct trace_kprobe *tk)
1793 {
1794         return trace_probe_unregister_event_call(&tk->tp);
1795 }
1796
1797 #ifdef CONFIG_PERF_EVENTS
1798 /* create a trace_kprobe, but don't add it to global lists */
1799 struct trace_event_call *
1800 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1801                           bool is_return)
1802 {
1803         struct trace_kprobe *tk;
1804         int ret;
1805         char *event;
1806
1807         /*
1808          * local trace_kprobes are not added to dyn_event, so they are never
1809          * searched in find_trace_kprobe(). Therefore, there is no concern of
1810          * duplicated name here.
1811          */
1812         event = func ? func : "DUMMY_EVENT";
1813
1814         tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1815                                 offs, 0 /* maxactive */, 0 /* nargs */,
1816                                 is_return);
1817
1818         if (IS_ERR(tk)) {
1819                 pr_info("Failed to allocate trace_probe.(%d)\n",
1820                         (int)PTR_ERR(tk));
1821                 return ERR_CAST(tk);
1822         }
1823
1824         init_trace_event_call(tk);
1825
1826         if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
1827                 ret = -ENOMEM;
1828                 goto error;
1829         }
1830
1831         ret = __register_trace_kprobe(tk);
1832         if (ret < 0)
1833                 goto error;
1834
1835         return trace_probe_event_call(&tk->tp);
1836 error:
1837         free_trace_kprobe(tk);
1838         return ERR_PTR(ret);
1839 }
1840
1841 void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1842 {
1843         struct trace_kprobe *tk;
1844
1845         tk = trace_kprobe_primary_from_call(event_call);
1846         if (unlikely(!tk))
1847                 return;
1848
1849         if (trace_probe_is_enabled(&tk->tp)) {
1850                 WARN_ON(1);
1851                 return;
1852         }
1853
1854         __unregister_trace_kprobe(tk);
1855
1856         free_trace_kprobe(tk);
1857 }
1858 #endif /* CONFIG_PERF_EVENTS */
1859
1860 static __init void enable_boot_kprobe_events(void)
1861 {
1862         struct trace_array *tr = top_trace_array();
1863         struct trace_event_file *file;
1864         struct trace_kprobe *tk;
1865         struct dyn_event *pos;
1866
1867         mutex_lock(&event_mutex);
1868         for_each_trace_kprobe(tk, pos) {
1869                 list_for_each_entry(file, &tr->events, list)
1870                         if (file->event_call == trace_probe_event_call(&tk->tp))
1871                                 trace_event_enable_disable(file, 1, 0);
1872         }
1873         mutex_unlock(&event_mutex);
1874 }
1875
1876 static __init void setup_boot_kprobe_events(void)
1877 {
1878         char *p, *cmd = kprobe_boot_events_buf;
1879         int ret;
1880
1881         strreplace(kprobe_boot_events_buf, ',', ' ');
1882
1883         while (cmd && *cmd != '\0') {
1884                 p = strchr(cmd, ';');
1885                 if (p)
1886                         *p++ = '\0';
1887
1888                 ret = trace_run_command(cmd, create_or_delete_trace_kprobe);
1889                 if (ret)
1890                         pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1891                 else
1892                         kprobe_boot_events_enabled = true;
1893
1894                 cmd = p;
1895         }
1896
1897         enable_boot_kprobe_events();
1898 }
1899
1900 /*
1901  * Register dynevent at subsys_initcall. This allows kernel to setup kprobe
1902  * events in fs_initcall without tracefs.
1903  */
1904 static __init int init_kprobe_trace_early(void)
1905 {
1906         int ret;
1907
1908         ret = dyn_event_register(&trace_kprobe_ops);
1909         if (ret)
1910                 return ret;
1911
1912         if (register_module_notifier(&trace_kprobe_module_nb))
1913                 return -EINVAL;
1914
1915         return 0;
1916 }
1917 subsys_initcall(init_kprobe_trace_early);
1918
1919 /* Make a tracefs interface for controlling probe points */
1920 static __init int init_kprobe_trace(void)
1921 {
1922         int ret;
1923         struct dentry *entry;
1924
1925         ret = tracing_init_dentry();
1926         if (ret)
1927                 return 0;
1928
1929         entry = tracefs_create_file("kprobe_events", 0644, NULL,
1930                                     NULL, &kprobe_events_ops);
1931
1932         /* Event list interface */
1933         if (!entry)
1934                 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1935
1936         /* Profile interface */
1937         entry = tracefs_create_file("kprobe_profile", 0444, NULL,
1938                                     NULL, &kprobe_profile_ops);
1939
1940         if (!entry)
1941                 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1942
1943         setup_boot_kprobe_events();
1944
1945         return 0;
1946 }
1947 fs_initcall(init_kprobe_trace);
1948
1949
1950 #ifdef CONFIG_FTRACE_STARTUP_TEST
1951 static __init struct trace_event_file *
1952 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1953 {
1954         struct trace_event_file *file;
1955
1956         list_for_each_entry(file, &tr->events, list)
1957                 if (file->event_call == trace_probe_event_call(&tk->tp))
1958                         return file;
1959
1960         return NULL;
1961 }
1962
1963 /*
1964  * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1965  * stage, we can do this lockless.
1966  */
1967 static __init int kprobe_trace_self_tests_init(void)
1968 {
1969         int ret, warn = 0;
1970         int (*target)(int, int, int, int, int, int);
1971         struct trace_kprobe *tk;
1972         struct trace_event_file *file;
1973
1974         if (tracing_is_disabled())
1975                 return -ENODEV;
1976
1977         if (kprobe_boot_events_enabled) {
1978                 pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n");
1979                 return 0;
1980         }
1981
1982         target = kprobe_trace_selftest_target;
1983
1984         pr_info("Testing kprobe tracing: ");
1985
1986         ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)",
1987                                 create_or_delete_trace_kprobe);
1988         if (WARN_ON_ONCE(ret)) {
1989                 pr_warn("error on probing function entry.\n");
1990                 warn++;
1991         } else {
1992                 /* Enable trace point */
1993                 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1994                 if (WARN_ON_ONCE(tk == NULL)) {
1995                         pr_warn("error on getting new probe.\n");
1996                         warn++;
1997                 } else {
1998                         file = find_trace_probe_file(tk, top_trace_array());
1999                         if (WARN_ON_ONCE(file == NULL)) {
2000                                 pr_warn("error on getting probe file.\n");
2001                                 warn++;
2002                         } else
2003                                 enable_trace_kprobe(
2004                                         trace_probe_event_call(&tk->tp), file);
2005                 }
2006         }
2007
2008         ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval",
2009                                 create_or_delete_trace_kprobe);
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 = trace_run_command("-:testprobe", create_or_delete_trace_kprobe);
2083         if (WARN_ON_ONCE(ret)) {
2084                 pr_warn("error on deleting a probe.\n");
2085                 warn++;
2086         }
2087
2088         ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe);
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