kernel/trace/trace_kprobe.c

   1 /*
   2  * Kprobes-based tracing events
   3  *
   4  * Created by Masami Hiramatsu <mhiramat@redhat.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/uaccess.h>
  22
  23 #include "trace_probe.h"
  24
  25 #define KPROBE_EVENT_SYSTEM "kprobes"
  26
  27 /**
  28  * Kprobe event core functions
  29  */
  30 struct trace_probe {
  31         struct list_head        list;
  32         struct kretprobe        rp;     /* Use rp.kp for kprobe use */
  33         unsigned long           nhit;
  34         unsigned int            flags;  /* For TP_FLAG_* */
  35         const char              *symbol;        /* symbol name */
  36         struct ftrace_event_class       class;
  37         struct ftrace_event_call        call;
  38         struct list_head        files;
  39         ssize_t                 size;           /* trace entry size */
  40         unsigned int            nr_args;
  41         struct probe_arg        args[];
  42 };
  43
  44 struct event_file_link {
  45         struct ftrace_event_file        *file;
  46         struct list_head                list;
  47 };
  48
  49 #define SIZEOF_TRACE_PROBE(n)                   \
  50         (offsetof(struct trace_probe, args) +   \
  51         (sizeof(struct probe_arg) * (n)))
  52
  53
  54 static __kprobes bool trace_probe_is_return(struct trace_probe *tp)
  55 {
  56         return tp->rp.handler != NULL;
  57 }
  58
  59 static __kprobes const char *trace_probe_symbol(struct trace_probe *tp)
  60 {
  61         return tp->symbol ? tp->symbol : "unknown";
  62 }
  63
  64 static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp)
  65 {
  66         return tp->rp.kp.offset;
  67 }
  68
  69 static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp)
  70 {
  71         return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
  72 }
  73
  74 static __kprobes bool trace_probe_is_registered(struct trace_probe *tp)
  75 {
  76         return !!(tp->flags & TP_FLAG_REGISTERED);
  77 }
  78
  79 static __kprobes bool trace_probe_has_gone(struct trace_probe *tp)
  80 {
  81         return !!(kprobe_gone(&tp->rp.kp));
  82 }
  83
  84 static __kprobes bool trace_probe_within_module(struct trace_probe *tp,
  85                                                 struct module *mod)
  86 {
  87         int len = strlen(mod->name);
  88         const char *name = trace_probe_symbol(tp);
  89         return strncmp(mod->name, name, len) == 0 && name[len] == ':';
  90 }
  91
  92 static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
  93 {
  94         return !!strchr(trace_probe_symbol(tp), ':');
  95 }
  96
  97 static int register_probe_event(struct trace_probe *tp);
  98 static int unregister_probe_event(struct trace_probe *tp);
  99
 100 static DEFINE_MUTEX(probe_lock);
 101 static LIST_HEAD(probe_list);
 102
 103 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 104 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
 105                                 struct pt_regs *regs);
 106
 107 /*
 108  * Allocate new trace_probe and initialize it (including kprobes).
 109  */
 110 static struct trace_probe *alloc_trace_probe(const char *group,
 111                                              const char *event,
 112                                              void *addr,
 113                                              const char *symbol,
 114                                              unsigned long offs,
 115                                              int nargs, bool is_return)
 116 {
 117         struct trace_probe *tp;
 118         int ret = -ENOMEM;
 119
 120         tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
 121         if (!tp)
 122                 return ERR_PTR(ret);
 123
 124         if (symbol) {
 125                 tp->symbol = kstrdup(symbol, GFP_KERNEL);
 126                 if (!tp->symbol)
 127                         goto error;
 128                 tp->rp.kp.symbol_name = tp->symbol;
 129                 tp->rp.kp.offset = offs;
 130         } else
 131                 tp->rp.kp.addr = addr;
 132
 133         if (is_return)
 134                 tp->rp.handler = kretprobe_dispatcher;
 135         else
 136                 tp->rp.kp.pre_handler = kprobe_dispatcher;
 137
 138         if (!event || !is_good_name(event)) {
 139                 ret = -EINVAL;
 140                 goto error;
 141         }
 142
 143         tp->call.class = &tp->class;
 144         tp->call.name = kstrdup(event, GFP_KERNEL);
 145         if (!tp->call.name)
 146                 goto error;
 147
 148         if (!group || !is_good_name(group)) {
 149                 ret = -EINVAL;
 150                 goto error;
 151         }
 152
 153         tp->class.system = kstrdup(group, GFP_KERNEL);
 154         if (!tp->class.system)
 155                 goto error;
 156
 157         INIT_LIST_HEAD(&tp->list);
 158         INIT_LIST_HEAD(&tp->files);
 159         return tp;
 160 error:
 161         kfree(tp->call.name);
 162         kfree(tp->symbol);
 163         kfree(tp);
 164         return ERR_PTR(ret);
 165 }
 166
 167 static void free_trace_probe(struct trace_probe *tp)
 168 {
 169         int i;
 170
 171         for (i = 0; i < tp->nr_args; i++)
 172                 traceprobe_free_probe_arg(&tp->args[i]);
 173
 174         kfree(tp->call.class->system);
 175         kfree(tp->call.name);
 176         kfree(tp->symbol);
 177         kfree(tp);
 178 }
 179
 180 static struct trace_probe *find_trace_probe(const char *event,
 181                                             const char *group)
 182 {
 183         struct trace_probe *tp;
 184
 185         list_for_each_entry(tp, &probe_list, list)
 186                 if (strcmp(tp->call.name, event) == 0 &&
 187                     strcmp(tp->call.class->system, group) == 0)
 188                         return tp;
 189         return NULL;
 190 }
 191
 192 /*
 193  * Enable trace_probe
 194  * if the file is NULL, enable "perf" handler, or enable "trace" handler.
 195  */
 196 static int
 197 enable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
 198 {
 199         int ret = 0;
 200
 201         if (file) {
 202                 struct event_file_link *link;
 203
 204                 link = kmalloc(sizeof(*link), GFP_KERNEL);
 205                 if (!link) {
 206                         ret = -ENOMEM;
 207                         goto out;
 208                 }
 209
 210                 link->file = file;
 211                 list_add_tail_rcu(&link->list, &tp->files);
 212
 213                 tp->flags |= TP_FLAG_TRACE;
 214         } else
 215                 tp->flags |= TP_FLAG_PROFILE;
 216
 217         if (trace_probe_is_registered(tp) && !trace_probe_has_gone(tp)) {
 218                 if (trace_probe_is_return(tp))
 219                         ret = enable_kretprobe(&tp->rp);
 220                 else
 221                         ret = enable_kprobe(&tp->rp.kp);
 222         }
 223  out:
 224         return ret;
 225 }
 226
 227 static struct event_file_link *
 228 find_event_file_link(struct trace_probe *tp, struct ftrace_event_file *file)
 229 {
 230         struct event_file_link *link;
 231
 232         list_for_each_entry(link, &tp->files, list)
 233                 if (link->file == file)
 234                         return link;
 235
 236         return NULL;
 237 }
 238
 239 /*
 240  * Disable trace_probe
 241  * if the file is NULL, disable "perf" handler, or disable "trace" handler.
 242  */
 243 static int
 244 disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
 245 {
 246         struct event_file_link *link = NULL;
 247         int wait = 0;
 248         int ret = 0;
 249
 250         if (file) {
 251                 link = find_event_file_link(tp, file);
 252                 if (!link) {
 253                         ret = -EINVAL;
 254                         goto out;
 255                 }
 256
 257                 list_del_rcu(&link->list);
 258                 wait = 1;
 259                 if (!list_empty(&tp->files))
 260                         goto out;
 261
 262                 tp->flags &= ~TP_FLAG_TRACE;
 263         } else
 264                 tp->flags &= ~TP_FLAG_PROFILE;
 265
 266         if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) {
 267                 if (trace_probe_is_return(tp))
 268                         disable_kretprobe(&tp->rp);
 269                 else
 270                         disable_kprobe(&tp->rp.kp);
 271                 wait = 1;
 272         }
 273  out:
 274         if (wait) {
 275                 /*
 276                  * Synchronize with kprobe_trace_func/kretprobe_trace_func
 277                  * to ensure disabled (all running handlers are finished).
 278                  * This is not only for kfree(), but also the caller,
 279                  * trace_remove_event_call() supposes it for releasing
 280                  * event_call related objects, which will be accessed in
 281                  * the kprobe_trace_func/kretprobe_trace_func.
 282                  */
 283                 synchronize_sched();
 284                 kfree(link);    /* Ignored if link == NULL */
 285         }
 286
 287         return ret;
 288 }
 289
 290 /* Internal register function - just handle k*probes and flags */
 291 static int __register_trace_probe(struct trace_probe *tp)
 292 {
 293         int i, ret;
 294
 295         if (trace_probe_is_registered(tp))
 296                 return -EINVAL;
 297
 298         for (i = 0; i < tp->nr_args; i++)
 299                 traceprobe_update_arg(&tp->args[i]);
 300
 301         /* Set/clear disabled flag according to tp->flag */
 302         if (trace_probe_is_enabled(tp))
 303                 tp->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
 304         else
 305                 tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
 306
 307         if (trace_probe_is_return(tp))
 308                 ret = register_kretprobe(&tp->rp);
 309         else
 310                 ret = register_kprobe(&tp->rp.kp);
 311
 312         if (ret == 0)
 313                 tp->flags |= TP_FLAG_REGISTERED;
 314         else {
 315                 pr_warning("Could not insert probe at %s+%lu: %d\n",
 316                            trace_probe_symbol(tp), trace_probe_offset(tp), ret);
 317                 if (ret == -ENOENT && trace_probe_is_on_module(tp)) {
 318                         pr_warning("This probe might be able to register after"
 319                                    "target module is loaded. Continue.\n");
 320                         ret = 0;
 321                 } else if (ret == -EILSEQ) {
 322                         pr_warning("Probing address(0x%p) is not an "
 323                                    "instruction boundary.\n",
 324                                    tp->rp.kp.addr);
 325                         ret = -EINVAL;
 326                 }
 327         }
 328
 329         return ret;
 330 }
 331
 332 /* Internal unregister function - just handle k*probes and flags */
 333 static void __unregister_trace_probe(struct trace_probe *tp)
 334 {
 335         if (trace_probe_is_registered(tp)) {
 336                 if (trace_probe_is_return(tp))
 337                         unregister_kretprobe(&tp->rp);
 338                 else
 339                         unregister_kprobe(&tp->rp.kp);
 340                 tp->flags &= ~TP_FLAG_REGISTERED;
 341                 /* Cleanup kprobe for reuse */
 342                 if (tp->rp.kp.symbol_name)
 343                         tp->rp.kp.addr = NULL;
 344         }
 345 }
 346
 347 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
 348 static int unregister_trace_probe(struct trace_probe *tp)
 349 {
 350         /* Enabled event can not be unregistered */
 351         if (trace_probe_is_enabled(tp))
 352                 return -EBUSY;
 353
 354         /* Will fail if probe is being used by ftrace or perf */
 355         if (unregister_probe_event(tp))
 356                 return -EBUSY;
 357
 358         __unregister_trace_probe(tp);
 359         list_del(&tp->list);
 360
 361         return 0;
 362 }
 363
 364 /* Register a trace_probe and probe_event */
 365 static int register_trace_probe(struct trace_probe *tp)
 366 {
 367         struct trace_probe *old_tp;
 368         int ret;
 369
 370         mutex_lock(&probe_lock);
 371
 372         /* Delete old (same name) event if exist */
 373         old_tp = find_trace_probe(tp->call.name, tp->call.class->system);
 374         if (old_tp) {
 375                 ret = unregister_trace_probe(old_tp);
 376                 if (ret < 0)
 377                         goto end;
 378                 free_trace_probe(old_tp);
 379         }
 380
 381         /* Register new event */
 382         ret = register_probe_event(tp);
 383         if (ret) {
 384                 pr_warning("Failed to register probe event(%d)\n", ret);
 385                 goto end;
 386         }
 387
 388         /* Register k*probe */
 389         ret = __register_trace_probe(tp);
 390         if (ret < 0)
 391                 unregister_probe_event(tp);
 392         else
 393                 list_add_tail(&tp->list, &probe_list);
 394
 395 end:
 396         mutex_unlock(&probe_lock);
 397         return ret;
 398 }
 399
 400 /* Module notifier call back, checking event on the module */
 401 static int trace_probe_module_callback(struct notifier_block *nb,
 402                                        unsigned long val, void *data)
 403 {
 404         struct module *mod = data;
 405         struct trace_probe *tp;
 406         int ret;
 407
 408         if (val != MODULE_STATE_COMING)
 409                 return NOTIFY_DONE;
 410
 411         /* Update probes on coming module */
 412         mutex_lock(&probe_lock);
 413         list_for_each_entry(tp, &probe_list, list) {
 414                 if (trace_probe_within_module(tp, mod)) {
 415                         /* Don't need to check busy - this should have gone. */
 416                         __unregister_trace_probe(tp);
 417                         ret = __register_trace_probe(tp);
 418                         if (ret)
 419                                 pr_warning("Failed to re-register probe %s on"
 420                                            "%s: %d\n",
 421                                            tp->call.name, mod->name, ret);
 422                 }
 423         }
 424         mutex_unlock(&probe_lock);
 425
 426         return NOTIFY_DONE;
 427 }
 428
 429 static struct notifier_block trace_probe_module_nb = {
 430         .notifier_call = trace_probe_module_callback,
 431         .priority = 1   /* Invoked after kprobe module callback */
 432 };
 433
 434 static int create_trace_probe(int argc, char **argv)
 435 {
 436         /*
 437          * Argument syntax:
 438          *  - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
 439          *  - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
 440          * Fetch args:
 441          *  $retval     : fetch return value
 442          *  $stack      : fetch stack address
 443          *  $stackN     : fetch Nth of stack (N:0-)
 444          *  @ADDR       : fetch memory at ADDR (ADDR should be in kernel)
 445          *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
 446          *  %REG        : fetch register REG
 447          * Dereferencing memory fetch:
 448          *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
 449          * Alias name of args:
 450          *  NAME=FETCHARG : set NAME as alias of FETCHARG.
 451          * Type of args:
 452          *  FETCHARG:TYPE : use TYPE instead of unsigned long.
 453          */
 454         struct trace_probe *tp;
 455         int i, ret = 0;
 456         bool is_return = false, is_delete = false;
 457         char *symbol = NULL, *event = NULL, *group = NULL;
 458         char *arg;
 459         unsigned long offset = 0;
 460         void *addr = NULL;
 461         char buf[MAX_EVENT_NAME_LEN];
 462
 463         /* argc must be >= 1 */
 464         if (argv[0][0] == 'p')
 465                 is_return = false;
 466         else if (argv[0][0] == 'r')
 467                 is_return = true;
 468         else if (argv[0][0] == '-')
 469                 is_delete = true;
 470         else {
 471                 pr_info("Probe definition must be started with 'p', 'r' or"
 472                         " '-'.\n");
 473                 return -EINVAL;
 474         }
 475
 476         if (argv[0][1] == ':') {
 477                 event = &argv[0][2];
 478                 if (strchr(event, '/')) {
 479                         group = event;
 480                         event = strchr(group, '/') + 1;
 481                         event[-1] = '\0';
 482                         if (strlen(group) == 0) {
 483                                 pr_info("Group name is not specified\n");
 484                                 return -EINVAL;
 485                         }
 486                 }
 487                 if (strlen(event) == 0) {
 488                         pr_info("Event name is not specified\n");
 489                         return -EINVAL;
 490                 }
 491         }
 492         if (!group)
 493                 group = KPROBE_EVENT_SYSTEM;
 494
 495         if (is_delete) {
 496                 if (!event) {
 497                         pr_info("Delete command needs an event name.\n");
 498                         return -EINVAL;
 499                 }
 500                 mutex_lock(&probe_lock);
 501                 tp = find_trace_probe(event, group);
 502                 if (!tp) {
 503                         mutex_unlock(&probe_lock);
 504                         pr_info("Event %s/%s doesn't exist.\n", group, event);
 505                         return -ENOENT;
 506                 }
 507                 /* delete an event */
 508                 ret = unregister_trace_probe(tp);
 509                 if (ret == 0)
 510                         free_trace_probe(tp);
 511                 mutex_unlock(&probe_lock);
 512                 return ret;
 513         }
 514
 515         if (argc < 2) {
 516                 pr_info("Probe point is not specified.\n");
 517                 return -EINVAL;
 518         }
 519         if (isdigit(argv[1][0])) {
 520                 if (is_return) {
 521                         pr_info("Return probe point must be a symbol.\n");
 522                         return -EINVAL;
 523                 }
 524                 /* an address specified */
 525                 ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr);
 526                 if (ret) {
 527                         pr_info("Failed to parse address.\n");
 528                         return ret;
 529                 }
 530         } else {
 531                 /* a symbol specified */
 532                 symbol = argv[1];
 533                 /* TODO: support .init module functions */
 534                 ret = traceprobe_split_symbol_offset(symbol, &offset);
 535                 if (ret) {
 536                         pr_info("Failed to parse symbol.\n");
 537                         return ret;
 538                 }
 539                 if (offset && is_return) {
 540                         pr_info("Return probe must be used without offset.\n");
 541                         return -EINVAL;
 542                 }
 543         }
 544         argc -= 2; argv += 2;
 545
 546         /* setup a probe */
 547         if (!event) {
 548                 /* Make a new event name */
 549                 if (symbol)
 550                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
 551                                  is_return ? 'r' : 'p', symbol, offset);
 552                 else
 553                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
 554                                  is_return ? 'r' : 'p', addr);
 555                 event = buf;
 556         }
 557         tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
 558                                is_return);
 559         if (IS_ERR(tp)) {
 560                 pr_info("Failed to allocate trace_probe.(%d)\n",
 561                         (int)PTR_ERR(tp));
 562                 return PTR_ERR(tp);
 563         }
 564
 565         /* parse arguments */
 566         ret = 0;
 567         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 568                 /* Increment count for freeing args in error case */
 569                 tp->nr_args++;
 570
 571                 /* Parse argument name */
 572                 arg = strchr(argv[i], '=');
 573                 if (arg) {
 574                         *arg++ = '\0';
 575                         tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
 576                 } else {
 577                         arg = argv[i];
 578                         /* If argument name is omitted, set "argN" */
 579                         snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
 580                         tp->args[i].name = kstrdup(buf, GFP_KERNEL);
 581                 }
 582
 583                 if (!tp->args[i].name) {
 584                         pr_info("Failed to allocate argument[%d] name.\n", i);
 585                         ret = -ENOMEM;
 586                         goto error;
 587                 }
 588
 589                 if (!is_good_name(tp->args[i].name)) {
 590                         pr_info("Invalid argument[%d] name: %s\n",
 591                                 i, tp->args[i].name);
 592                         ret = -EINVAL;
 593                         goto error;
 594                 }
 595
 596                 if (traceprobe_conflict_field_name(tp->args[i].name,
 597                                                         tp->args, i)) {
 598                         pr_info("Argument[%d] name '%s' conflicts with "
 599                                 "another field.\n", i, argv[i]);
 600                         ret = -EINVAL;
 601                         goto error;
 602                 }
 603
 604                 /* Parse fetch argument */
 605                 ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i],
 606                                                 is_return, true);
 607                 if (ret) {
 608                         pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
 609                         goto error;
 610                 }
 611         }
 612
 613         ret = register_trace_probe(tp);
 614         if (ret)
 615                 goto error;
 616         return 0;
 617
 618 error:
 619         free_trace_probe(tp);
 620         return ret;
 621 }
 622
 623 static int release_all_trace_probes(void)
 624 {
 625         struct trace_probe *tp;
 626         int ret = 0;
 627
 628         mutex_lock(&probe_lock);
 629         /* Ensure no probe is in use. */
 630         list_for_each_entry(tp, &probe_list, list)
 631                 if (trace_probe_is_enabled(tp)) {
 632                         ret = -EBUSY;
 633                         goto end;
 634                 }
 635         /* TODO: Use batch unregistration */
 636         while (!list_empty(&probe_list)) {
 637                 tp = list_entry(probe_list.next, struct trace_probe, list);
 638                 ret = unregister_trace_probe(tp);
 639                 if (ret)
 640                         goto end;
 641                 free_trace_probe(tp);
 642         }
 643
 644 end:
 645         mutex_unlock(&probe_lock);
 646
 647         return ret;
 648 }
 649
 650 /* Probes listing interfaces */
 651 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
 652 {
 653         mutex_lock(&probe_lock);
 654         return seq_list_start(&probe_list, *pos);
 655 }
 656
 657 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
 658 {
 659         return seq_list_next(v, &probe_list, pos);
 660 }
 661
 662 static void probes_seq_stop(struct seq_file *m, void *v)
 663 {
 664         mutex_unlock(&probe_lock);
 665 }
 666
 667 static int probes_seq_show(struct seq_file *m, void *v)
 668 {
 669         struct trace_probe *tp = v;
 670         int i;
 671
 672         seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p');
 673         seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name);
 674
 675         if (!tp->symbol)
 676                 seq_printf(m, " 0x%p", tp->rp.kp.addr);
 677         else if (tp->rp.kp.offset)
 678                 seq_printf(m, " %s+%u", trace_probe_symbol(tp),
 679                            tp->rp.kp.offset);
 680         else
 681                 seq_printf(m, " %s", trace_probe_symbol(tp));
 682
 683         for (i = 0; i < tp->nr_args; i++)
 684                 seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm);
 685         seq_printf(m, "\n");
 686
 687         return 0;
 688 }
 689
 690 static const struct seq_operations probes_seq_op = {
 691         .start  = probes_seq_start,
 692         .next   = probes_seq_next,
 693         .stop   = probes_seq_stop,
 694         .show   = probes_seq_show
 695 };
 696
 697 static int probes_open(struct inode *inode, struct file *file)
 698 {
 699         int ret;
 700
 701         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 702                 ret = release_all_trace_probes();
 703                 if (ret < 0)
 704                         return ret;
 705         }
 706
 707         return seq_open(file, &probes_seq_op);
 708 }
 709
 710 static ssize_t probes_write(struct file *file, const char __user *buffer,
 711                             size_t count, loff_t *ppos)
 712 {
 713         return traceprobe_probes_write(file, buffer, count, ppos,
 714                         create_trace_probe);
 715 }
 716
 717 static const struct file_operations kprobe_events_ops = {
 718         .owner          = THIS_MODULE,
 719         .open           = probes_open,
 720         .read           = seq_read,
 721         .llseek         = seq_lseek,
 722         .release        = seq_release,
 723         .write          = probes_write,
 724 };
 725
 726 /* Probes profiling interfaces */
 727 static int probes_profile_seq_show(struct seq_file *m, void *v)
 728 {
 729         struct trace_probe *tp = v;
 730
 731         seq_printf(m, "  %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
 732                    tp->rp.kp.nmissed);
 733
 734         return 0;
 735 }
 736
 737 static const struct seq_operations profile_seq_op = {
 738         .start  = probes_seq_start,
 739         .next   = probes_seq_next,
 740         .stop   = probes_seq_stop,
 741         .show   = probes_profile_seq_show
 742 };
 743
 744 static int profile_open(struct inode *inode, struct file *file)
 745 {
 746         return seq_open(file, &profile_seq_op);
 747 }
 748
 749 static const struct file_operations kprobe_profile_ops = {
 750         .owner          = THIS_MODULE,
 751         .open           = profile_open,
 752         .read           = seq_read,
 753         .llseek         = seq_lseek,
 754         .release        = seq_release,
 755 };
 756
 757 /* Sum up total data length for dynamic arraies (strings) */
 758 static __kprobes int __get_data_size(struct trace_probe *tp,
 759                                      struct pt_regs *regs)
 760 {
 761         int i, ret = 0;
 762         u32 len;
 763
 764         for (i = 0; i < tp->nr_args; i++)
 765                 if (unlikely(tp->args[i].fetch_size.fn)) {
 766                         call_fetch(&tp->args[i].fetch_size, regs, &len);
 767                         ret += len;
 768                 }
 769
 770         return ret;
 771 }
 772
 773 /* Store the value of each argument */
 774 static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp,
 775                                        struct pt_regs *regs,
 776                                        u8 *data, int maxlen)
 777 {
 778         int i;
 779         u32 end = tp->size;
 780         u32 *dl;        /* Data (relative) location */
 781
 782         for (i = 0; i < tp->nr_args; i++) {
 783                 if (unlikely(tp->args[i].fetch_size.fn)) {
 784                         /*
 785                          * First, we set the relative location and
 786                          * maximum data length to *dl
 787                          */
 788                         dl = (u32 *)(data + tp->args[i].offset);
 789                         *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
 790                         /* Then try to fetch string or dynamic array data */
 791                         call_fetch(&tp->args[i].fetch, regs, dl);
 792                         /* Reduce maximum length */
 793                         end += get_rloc_len(*dl);
 794                         maxlen -= get_rloc_len(*dl);
 795                         /* Trick here, convert data_rloc to data_loc */
 796                         *dl = convert_rloc_to_loc(*dl,
 797                                  ent_size + tp->args[i].offset);
 798                 } else
 799                         /* Just fetching data normally */
 800                         call_fetch(&tp->args[i].fetch, regs,
 801                                    data + tp->args[i].offset);
 802         }
 803 }
 804
 805 /* Kprobe handler */
 806 static __kprobes void
 807 __kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs,
 808                     struct ftrace_event_file *ftrace_file)
 809 {
 810         struct kprobe_trace_entry_head *entry;
 811         struct ring_buffer_event *event;
 812         struct ring_buffer *buffer;
 813         int size, dsize, pc;
 814         unsigned long irq_flags;
 815         struct ftrace_event_call *call = &tp->call;
 816
 817         WARN_ON(call != ftrace_file->event_call);
 818
 819         if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
 820                 return;
 821
 822         local_save_flags(irq_flags);
 823         pc = preempt_count();
 824
 825         dsize = __get_data_size(tp, regs);
 826         size = sizeof(*entry) + tp->size + dsize;
 827
 828         event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
 829                                                 call->event.type,
 830                                                 size, irq_flags, pc);
 831         if (!event)
 832                 return;
 833
 834         entry = ring_buffer_event_data(event);
 835         entry->ip = (unsigned long)tp->rp.kp.addr;
 836         store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
 837
 838         if (!filter_current_check_discard(buffer, call, entry, event))
 839                 trace_buffer_unlock_commit_regs(buffer, event,
 840                                                 irq_flags, pc, regs);
 841 }
 842
 843 static __kprobes void
 844 kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs)
 845 {
 846         struct event_file_link *link;
 847
 848         list_for_each_entry_rcu(link, &tp->files, list)
 849                 __kprobe_trace_func(tp, regs, link->file);
 850 }
 851
 852 /* Kretprobe handler */
 853 static __kprobes void
 854 __kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
 855                        struct pt_regs *regs,
 856                        struct ftrace_event_file *ftrace_file)
 857 {
 858         struct kretprobe_trace_entry_head *entry;
 859         struct ring_buffer_event *event;
 860         struct ring_buffer *buffer;
 861         int size, pc, dsize;
 862         unsigned long irq_flags;
 863         struct ftrace_event_call *call = &tp->call;
 864
 865         WARN_ON(call != ftrace_file->event_call);
 866
 867         if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
 868                 return;
 869
 870         local_save_flags(irq_flags);
 871         pc = preempt_count();
 872
 873         dsize = __get_data_size(tp, regs);
 874         size = sizeof(*entry) + tp->size + dsize;
 875
 876         event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
 877                                                 call->event.type,
 878                                                 size, irq_flags, pc);
 879         if (!event)
 880                 return;
 881
 882         entry = ring_buffer_event_data(event);
 883         entry->func = (unsigned long)tp->rp.kp.addr;
 884         entry->ret_ip = (unsigned long)ri->ret_addr;
 885         store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
 886
 887         if (!filter_current_check_discard(buffer, call, entry, event))
 888                 trace_buffer_unlock_commit_regs(buffer, event,
 889                                                 irq_flags, pc, regs);
 890 }
 891
 892 static __kprobes void
 893 kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
 894                      struct pt_regs *regs)
 895 {
 896         struct event_file_link *link;
 897
 898         list_for_each_entry_rcu(link, &tp->files, list)
 899                 __kretprobe_trace_func(tp, ri, regs, link->file);
 900 }
 901
 902 /* Event entry printers */
 903 static enum print_line_t
 904 print_kprobe_event(struct trace_iterator *iter, int flags,
 905                    struct trace_event *event)
 906 {
 907         struct kprobe_trace_entry_head *field;
 908         struct trace_seq *s = &iter->seq;
 909         struct trace_probe *tp;
 910         u8 *data;
 911         int i;
 912
 913         field = (struct kprobe_trace_entry_head *)iter->ent;
 914         tp = container_of(event, struct trace_probe, call.event);
 915
 916         if (!trace_seq_printf(s, "%s: (", tp->call.name))
 917                 goto partial;
 918
 919         if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
 920                 goto partial;
 921
 922         if (!trace_seq_puts(s, ")"))
 923                 goto partial;
 924
 925         data = (u8 *)&field[1];
 926         for (i = 0; i < tp->nr_args; i++)
 927                 if (!tp->args[i].type->print(s, tp->args[i].name,
 928                                              data + tp->args[i].offset, field))
 929                         goto partial;
 930
 931         if (!trace_seq_puts(s, "\n"))
 932                 goto partial;
 933
 934         return TRACE_TYPE_HANDLED;
 935 partial:
 936         return TRACE_TYPE_PARTIAL_LINE;
 937 }
 938
 939 static enum print_line_t
 940 print_kretprobe_event(struct trace_iterator *iter, int flags,
 941                       struct trace_event *event)
 942 {
 943         struct kretprobe_trace_entry_head *field;
 944         struct trace_seq *s = &iter->seq;
 945         struct trace_probe *tp;
 946         u8 *data;
 947         int i;
 948
 949         field = (struct kretprobe_trace_entry_head *)iter->ent;
 950         tp = container_of(event, struct trace_probe, call.event);
 951
 952         if (!trace_seq_printf(s, "%s: (", tp->call.name))
 953                 goto partial;
 954
 955         if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
 956                 goto partial;
 957
 958         if (!trace_seq_puts(s, " <- "))
 959                 goto partial;
 960
 961         if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
 962                 goto partial;
 963
 964         if (!trace_seq_puts(s, ")"))
 965                 goto partial;
 966
 967         data = (u8 *)&field[1];
 968         for (i = 0; i < tp->nr_args; i++)
 969                 if (!tp->args[i].type->print(s, tp->args[i].name,
 970                                              data + tp->args[i].offset, field))
 971                         goto partial;
 972
 973         if (!trace_seq_puts(s, "\n"))
 974                 goto partial;
 975
 976         return TRACE_TYPE_HANDLED;
 977 partial:
 978         return TRACE_TYPE_PARTIAL_LINE;
 979 }
 980
 981
 982 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
 983 {
 984         int ret, i;
 985         struct kprobe_trace_entry_head field;
 986         struct trace_probe *tp = (struct trace_probe *)event_call->data;
 987
 988         DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
 989         /* Set argument names as fields */
 990         for (i = 0; i < tp->nr_args; i++) {
 991                 ret = trace_define_field(event_call, tp->args[i].type->fmttype,
 992                                          tp->args[i].name,
 993                                          sizeof(field) + tp->args[i].offset,
 994                                          tp->args[i].type->size,
 995                                          tp->args[i].type->is_signed,
 996                                          FILTER_OTHER);
 997                 if (ret)
 998                         return ret;
 999         }
1000         return 0;
1001 }
1002
1003 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1004 {
1005         int ret, i;
1006         struct kretprobe_trace_entry_head field;
1007         struct trace_probe *tp = (struct trace_probe *)event_call->data;
1008
1009         DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1010         DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1011         /* Set argument names as fields */
1012         for (i = 0; i < tp->nr_args; i++) {
1013                 ret = trace_define_field(event_call, tp->args[i].type->fmttype,
1014                                          tp->args[i].name,
1015                                          sizeof(field) + tp->args[i].offset,
1016                                          tp->args[i].type->size,
1017                                          tp->args[i].type->is_signed,
1018                                          FILTER_OTHER);
1019                 if (ret)
1020                         return ret;
1021         }
1022         return 0;
1023 }
1024
1025 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
1026 {
1027         int i;
1028         int pos = 0;
1029
1030         const char *fmt, *arg;
1031
1032         if (!trace_probe_is_return(tp)) {
1033                 fmt = "(%lx)";
1034                 arg = "REC->" FIELD_STRING_IP;
1035         } else {
1036                 fmt = "(%lx <- %lx)";
1037                 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
1038         }
1039
1040         /* When len=0, we just calculate the needed length */
1041 #define LEN_OR_ZERO (len ? len - pos : 0)
1042
1043         pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1044
1045         for (i = 0; i < tp->nr_args; i++) {
1046                 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
1047                                 tp->args[i].name, tp->args[i].type->fmt);
1048         }
1049
1050         pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
1051
1052         for (i = 0; i < tp->nr_args; i++) {
1053                 if (strcmp(tp->args[i].type->name, "string") == 0)
1054                         pos += snprintf(buf + pos, LEN_OR_ZERO,
1055                                         ", __get_str(%s)",
1056                                         tp->args[i].name);
1057                 else
1058                         pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
1059                                         tp->args[i].name);
1060         }
1061
1062 #undef LEN_OR_ZERO
1063
1064         /* return the length of print_fmt */
1065         return pos;
1066 }
1067
1068 static int set_print_fmt(struct trace_probe *tp)
1069 {
1070         int len;
1071         char *print_fmt;
1072
1073         /* First: called with 0 length to calculate the needed length */
1074         len = __set_print_fmt(tp, NULL, 0);
1075         print_fmt = kmalloc(len + 1, GFP_KERNEL);
1076         if (!print_fmt)
1077                 return -ENOMEM;
1078
1079         /* Second: actually write the @print_fmt */
1080         __set_print_fmt(tp, print_fmt, len + 1);
1081         tp->call.print_fmt = print_fmt;
1082
1083         return 0;
1084 }
1085
1086 #ifdef CONFIG_PERF_EVENTS
1087
1088 /* Kprobe profile handler */
1089 static __kprobes void
1090 kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs)
1091 {
1092         struct ftrace_event_call *call = &tp->call;
1093         struct kprobe_trace_entry_head *entry;
1094         struct hlist_head *head;
1095         int size, __size, dsize;
1096         int rctx;
1097
1098         head = this_cpu_ptr(call->perf_events);
1099         if (hlist_empty(head))
1100                 return;
1101
1102         dsize = __get_data_size(tp, regs);
1103         __size = sizeof(*entry) + tp->size + dsize;
1104         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1105         size -= sizeof(u32);
1106
1107         entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1108         if (!entry)
1109                 return;
1110
1111         entry->ip = (unsigned long)tp->rp.kp.addr;
1112         memset(&entry[1], 0, dsize);
1113         store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1114         perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
1115 }
1116
1117 /* Kretprobe profile handler */
1118 static __kprobes void
1119 kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri,
1120                     struct pt_regs *regs)
1121 {
1122         struct ftrace_event_call *call = &tp->call;
1123         struct kretprobe_trace_entry_head *entry;
1124         struct hlist_head *head;
1125         int size, __size, dsize;
1126         int rctx;
1127
1128         head = this_cpu_ptr(call->perf_events);
1129         if (hlist_empty(head))
1130                 return;
1131
1132         dsize = __get_data_size(tp, regs);
1133         __size = sizeof(*entry) + tp->size + dsize;
1134         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1135         size -= sizeof(u32);
1136
1137         entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1138         if (!entry)
1139                 return;
1140
1141         entry->func = (unsigned long)tp->rp.kp.addr;
1142         entry->ret_ip = (unsigned long)ri->ret_addr;
1143         store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1144         perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
1145 }
1146 #endif  /* CONFIG_PERF_EVENTS */
1147
1148 /*
1149  * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1150  *
1151  * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1152  * lockless, but we can't race with this __init function.
1153  */
1154 static __kprobes
1155 int kprobe_register(struct ftrace_event_call *event,
1156                     enum trace_reg type, void *data)
1157 {
1158         struct trace_probe *tp = (struct trace_probe *)event->data;
1159         struct ftrace_event_file *file = data;
1160
1161         switch (type) {
1162         case TRACE_REG_REGISTER:
1163                 return enable_trace_probe(tp, file);
1164         case TRACE_REG_UNREGISTER:
1165                 return disable_trace_probe(tp, file);
1166
1167 #ifdef CONFIG_PERF_EVENTS
1168         case TRACE_REG_PERF_REGISTER:
1169                 return enable_trace_probe(tp, NULL);
1170         case TRACE_REG_PERF_UNREGISTER:
1171                 return disable_trace_probe(tp, NULL);
1172         case TRACE_REG_PERF_OPEN:
1173         case TRACE_REG_PERF_CLOSE:
1174         case TRACE_REG_PERF_ADD:
1175         case TRACE_REG_PERF_DEL:
1176                 return 0;
1177 #endif
1178         }
1179         return 0;
1180 }
1181
1182 static __kprobes
1183 int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1184 {
1185         struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1186
1187         tp->nhit++;
1188
1189         if (tp->flags & TP_FLAG_TRACE)
1190                 kprobe_trace_func(tp, regs);
1191 #ifdef CONFIG_PERF_EVENTS
1192         if (tp->flags & TP_FLAG_PROFILE)
1193                 kprobe_perf_func(tp, regs);
1194 #endif
1195         return 0;       /* We don't tweek kernel, so just return 0 */
1196 }
1197
1198 static __kprobes
1199 int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1200 {
1201         struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1202
1203         tp->nhit++;
1204
1205         if (tp->flags & TP_FLAG_TRACE)
1206                 kretprobe_trace_func(tp, ri, regs);
1207 #ifdef CONFIG_PERF_EVENTS
1208         if (tp->flags & TP_FLAG_PROFILE)
1209                 kretprobe_perf_func(tp, ri, regs);
1210 #endif
1211         return 0;       /* We don't tweek kernel, so just return 0 */
1212 }
1213
1214 static struct trace_event_functions kretprobe_funcs = {
1215         .trace          = print_kretprobe_event
1216 };
1217
1218 static struct trace_event_functions kprobe_funcs = {
1219         .trace          = print_kprobe_event
1220 };
1221
1222 static int register_probe_event(struct trace_probe *tp)
1223 {
1224         struct ftrace_event_call *call = &tp->call;
1225         int ret;
1226
1227         /* Initialize ftrace_event_call */
1228         INIT_LIST_HEAD(&call->class->fields);
1229         if (trace_probe_is_return(tp)) {
1230                 call->event.funcs = &kretprobe_funcs;
1231                 call->class->define_fields = kretprobe_event_define_fields;
1232         } else {
1233                 call->event.funcs = &kprobe_funcs;
1234                 call->class->define_fields = kprobe_event_define_fields;
1235         }
1236         if (set_print_fmt(tp) < 0)
1237                 return -ENOMEM;
1238         ret = register_ftrace_event(&call->event);
1239         if (!ret) {
1240                 kfree(call->print_fmt);
1241                 return -ENODEV;
1242         }
1243         call->flags = 0;
1244         call->class->reg = kprobe_register;
1245         call->data = tp;
1246         ret = trace_add_event_call(call);
1247         if (ret) {
1248                 pr_info("Failed to register kprobe event: %s\n", call->name);
1249                 kfree(call->print_fmt);
1250                 unregister_ftrace_event(&call->event);
1251         }
1252         return ret;
1253 }
1254
1255 static int unregister_probe_event(struct trace_probe *tp)
1256 {
1257         int ret;
1258
1259         /* tp->event is unregistered in trace_remove_event_call() */
1260         ret = trace_remove_event_call(&tp->call);
1261         if (!ret)
1262                 kfree(tp->call.print_fmt);
1263         return ret;
1264 }
1265
1266 /* Make a debugfs interface for controlling probe points */
1267 static __init int init_kprobe_trace(void)
1268 {
1269         struct dentry *d_tracer;
1270         struct dentry *entry;
1271
1272         if (register_module_notifier(&trace_probe_module_nb))
1273                 return -EINVAL;
1274
1275         d_tracer = tracing_init_dentry();
1276         if (!d_tracer)
1277                 return 0;
1278
1279         entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
1280                                     NULL, &kprobe_events_ops);
1281
1282         /* Event list interface */
1283         if (!entry)
1284                 pr_warning("Could not create debugfs "
1285                            "'kprobe_events' entry\n");
1286
1287         /* Profile interface */
1288         entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
1289                                     NULL, &kprobe_profile_ops);
1290
1291         if (!entry)
1292                 pr_warning("Could not create debugfs "
1293                            "'kprobe_profile' entry\n");
1294         return 0;
1295 }
1296 fs_initcall(init_kprobe_trace);
1297
1298
1299 #ifdef CONFIG_FTRACE_STARTUP_TEST
1300
1301 /*
1302  * The "__used" keeps gcc from removing the function symbol
1303  * from the kallsyms table.
1304  */
1305 static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
1306                                                int a4, int a5, int a6)
1307 {
1308         return a1 + a2 + a3 + a4 + a5 + a6;
1309 }
1310
1311 static struct ftrace_event_file *
1312 find_trace_probe_file(struct trace_probe *tp, struct trace_array *tr)
1313 {
1314         struct ftrace_event_file *file;
1315
1316         list_for_each_entry(file, &tr->events, list)
1317                 if (file->event_call == &tp->call)
1318                         return file;
1319
1320         return NULL;
1321 }
1322
1323 /*
1324  * Nobody but us can call enable_trace_probe/disable_trace_probe at this
1325  * stage, we can do this lockless.
1326  */
1327 static __init int kprobe_trace_self_tests_init(void)
1328 {
1329         int ret, warn = 0;
1330         int (*target)(int, int, int, int, int, int);
1331         struct trace_probe *tp;
1332         struct ftrace_event_file *file;
1333
1334         target = kprobe_trace_selftest_target;
1335
1336         pr_info("Testing kprobe tracing: ");
1337
1338         ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target "
1339                                   "$stack $stack0 +0($stack)",
1340                                   create_trace_probe);
1341         if (WARN_ON_ONCE(ret)) {
1342                 pr_warn("error on probing function entry.\n");
1343                 warn++;
1344         } else {
1345                 /* Enable trace point */
1346                 tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
1347                 if (WARN_ON_ONCE(tp == NULL)) {
1348                         pr_warn("error on getting new probe.\n");
1349                         warn++;
1350                 } else {
1351                         file = find_trace_probe_file(tp, top_trace_array());
1352                         if (WARN_ON_ONCE(file == NULL)) {
1353                                 pr_warn("error on getting probe file.\n");
1354                                 warn++;
1355                         } else
1356                                 enable_trace_probe(tp, file);
1357                 }
1358         }
1359
1360         ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "
1361                                   "$retval", create_trace_probe);
1362         if (WARN_ON_ONCE(ret)) {
1363                 pr_warn("error on probing function return.\n");
1364                 warn++;
1365         } else {
1366                 /* Enable trace point */
1367                 tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
1368                 if (WARN_ON_ONCE(tp == NULL)) {
1369                         pr_warn("error on getting 2nd new probe.\n");
1370                         warn++;
1371                 } else {
1372                         file = find_trace_probe_file(tp, top_trace_array());
1373                         if (WARN_ON_ONCE(file == NULL)) {
1374                                 pr_warn("error on getting probe file.\n");
1375                                 warn++;
1376                         } else
1377                                 enable_trace_probe(tp, file);
1378                 }
1379         }
1380
1381         if (warn)
1382                 goto end;
1383
1384         ret = target(1, 2, 3, 4, 5, 6);
1385
1386         /* Disable trace points before removing it */
1387         tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
1388         if (WARN_ON_ONCE(tp == NULL)) {
1389                 pr_warn("error on getting test probe.\n");
1390                 warn++;
1391         } else {
1392                 file = find_trace_probe_file(tp, top_trace_array());
1393                 if (WARN_ON_ONCE(file == NULL)) {
1394                         pr_warn("error on getting probe file.\n");
1395                         warn++;
1396                 } else
1397                         disable_trace_probe(tp, file);
1398         }
1399
1400         tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
1401         if (WARN_ON_ONCE(tp == NULL)) {
1402                 pr_warn("error on getting 2nd test probe.\n");
1403                 warn++;
1404         } else {
1405                 file = find_trace_probe_file(tp, top_trace_array());
1406                 if (WARN_ON_ONCE(file == NULL)) {
1407                         pr_warn("error on getting probe file.\n");
1408                         warn++;
1409                 } else
1410                         disable_trace_probe(tp, file);
1411         }
1412
1413         ret = traceprobe_command("-:testprobe", create_trace_probe);
1414         if (WARN_ON_ONCE(ret)) {
1415                 pr_warn("error on deleting a probe.\n");
1416                 warn++;
1417         }
1418
1419         ret = traceprobe_command("-:testprobe2", create_trace_probe);
1420         if (WARN_ON_ONCE(ret)) {
1421                 pr_warn("error on deleting a probe.\n");
1422                 warn++;
1423         }
1424
1425 end:
1426         release_all_trace_probes();
1427         if (warn)
1428                 pr_cont("NG: Some tests are failed. Please check them.\n");
1429         else
1430                 pr_cont("OK\n");
1431         return 0;
1432 }
1433
1434 late_initcall(kprobe_trace_self_tests_init);
1435
1436 #endif