kernel/trace/trace_kprobe.c

   1 /*
   2  * kprobe based kernel tracer
   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 #include <linux/kprobes.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/slab.h>
  25 #include <linux/smp.h>
  26 #include <linux/debugfs.h>
  27 #include <linux/types.h>
  28 #include <linux/string.h>
  29 #include <linux/ctype.h>
  30 #include <linux/ptrace.h>
  31 #include <linux/perf_event.h>
  32
  33 #include "trace.h"
  34 #include "trace_output.h"
  35
  36 #define MAX_TRACE_ARGS 128
  37 #define MAX_ARGSTR_LEN 63
  38 #define MAX_EVENT_NAME_LEN 64
  39 #define KPROBE_EVENT_SYSTEM "kprobes"
  40
  41 /* currently, trace_kprobe only supports X86. */
  42
  43 struct fetch_func {
  44         unsigned long (*func)(struct pt_regs *, void *);
  45         void *data;
  46 };
  47
  48 static __kprobes unsigned long call_fetch(struct fetch_func *f,
  49                                           struct pt_regs *regs)
  50 {
  51         return f->func(regs, f->data);
  52 }
  53
  54 /* fetch handlers */
  55 static __kprobes unsigned long fetch_register(struct pt_regs *regs,
  56                                               void *offset)
  57 {
  58         return regs_get_register(regs, (unsigned int)((unsigned long)offset));
  59 }
  60
  61 static __kprobes unsigned long fetch_stack(struct pt_regs *regs,
  62                                            void *num)
  63 {
  64         return regs_get_kernel_stack_nth(regs,
  65                                          (unsigned int)((unsigned long)num));
  66 }
  67
  68 static __kprobes unsigned long fetch_memory(struct pt_regs *regs, void *addr)
  69 {
  70         unsigned long retval;
  71
  72         if (probe_kernel_address(addr, retval))
  73                 return 0;
  74         return retval;
  75 }
  76
  77 static __kprobes unsigned long fetch_argument(struct pt_regs *regs, void *num)
  78 {
  79         return regs_get_argument_nth(regs, (unsigned int)((unsigned long)num));
  80 }
  81
  82 static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs,
  83                                               void *dummy)
  84 {
  85         return regs_return_value(regs);
  86 }
  87
  88 static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs,
  89                                                    void *dummy)
  90 {
  91         return kernel_stack_pointer(regs);
  92 }
  93
  94 /* Memory fetching by symbol */
  95 struct symbol_cache {
  96         char *symbol;
  97         long offset;
  98         unsigned long addr;
  99 };
 100
 101 static unsigned long update_symbol_cache(struct symbol_cache *sc)
 102 {
 103         sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
 104         if (sc->addr)
 105                 sc->addr += sc->offset;
 106         return sc->addr;
 107 }
 108
 109 static void free_symbol_cache(struct symbol_cache *sc)
 110 {
 111         kfree(sc->symbol);
 112         kfree(sc);
 113 }
 114
 115 static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
 116 {
 117         struct symbol_cache *sc;
 118
 119         if (!sym || strlen(sym) == 0)
 120                 return NULL;
 121         sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
 122         if (!sc)
 123                 return NULL;
 124
 125         sc->symbol = kstrdup(sym, GFP_KERNEL);
 126         if (!sc->symbol) {
 127                 kfree(sc);
 128                 return NULL;
 129         }
 130         sc->offset = offset;
 131
 132         update_symbol_cache(sc);
 133         return sc;
 134 }
 135
 136 static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data)
 137 {
 138         struct symbol_cache *sc = data;
 139
 140         if (sc->addr)
 141                 return fetch_memory(regs, (void *)sc->addr);
 142         else
 143                 return 0;
 144 }
 145
 146 /* Special indirect memory access interface */
 147 struct indirect_fetch_data {
 148         struct fetch_func orig;
 149         long offset;
 150 };
 151
 152 static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data)
 153 {
 154         struct indirect_fetch_data *ind = data;
 155         unsigned long addr;
 156
 157         addr = call_fetch(&ind->orig, regs);
 158         if (addr) {
 159                 addr += ind->offset;
 160                 return fetch_memory(regs, (void *)addr);
 161         } else
 162                 return 0;
 163 }
 164
 165 static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data)
 166 {
 167         if (data->orig.func == fetch_indirect)
 168                 free_indirect_fetch_data(data->orig.data);
 169         else if (data->orig.func == fetch_symbol)
 170                 free_symbol_cache(data->orig.data);
 171         kfree(data);
 172 }
 173
 174 /**
 175  * Kprobe tracer core functions
 176  */
 177
 178 struct probe_arg {
 179         struct fetch_func       fetch;
 180         const char              *name;
 181 };
 182
 183 /* Flags for trace_probe */
 184 #define TP_FLAG_TRACE   1
 185 #define TP_FLAG_PROFILE 2
 186
 187 struct trace_probe {
 188         struct list_head        list;
 189         struct kretprobe        rp;     /* Use rp.kp for kprobe use */
 190         unsigned long           nhit;
 191         unsigned int            flags;  /* For TP_FLAG_* */
 192         const char              *symbol;        /* symbol name */
 193         struct ftrace_event_call        call;
 194         struct trace_event              event;
 195         unsigned int            nr_args;
 196         struct probe_arg        args[];
 197 };
 198
 199 #define SIZEOF_TRACE_PROBE(n)                   \
 200         (offsetof(struct trace_probe, args) +   \
 201         (sizeof(struct probe_arg) * (n)))
 202
 203 static __kprobes int probe_is_return(struct trace_probe *tp)
 204 {
 205         return tp->rp.handler != NULL;
 206 }
 207
 208 static __kprobes const char *probe_symbol(struct trace_probe *tp)
 209 {
 210         return tp->symbol ? tp->symbol : "unknown";
 211 }
 212
 213 static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff)
 214 {
 215         int ret = -EINVAL;
 216
 217         if (ff->func == fetch_argument)
 218                 ret = snprintf(buf, n, "$arg%lu", (unsigned long)ff->data);
 219         else if (ff->func == fetch_register) {
 220                 const char *name;
 221                 name = regs_query_register_name((unsigned int)((long)ff->data));
 222                 ret = snprintf(buf, n, "%%%s", name);
 223         } else if (ff->func == fetch_stack)
 224                 ret = snprintf(buf, n, "$stack%lu", (unsigned long)ff->data);
 225         else if (ff->func == fetch_memory)
 226                 ret = snprintf(buf, n, "@0x%p", ff->data);
 227         else if (ff->func == fetch_symbol) {
 228                 struct symbol_cache *sc = ff->data;
 229                 ret = snprintf(buf, n, "@%s%+ld", sc->symbol, sc->offset);
 230         } else if (ff->func == fetch_retvalue)
 231                 ret = snprintf(buf, n, "$retval");
 232         else if (ff->func == fetch_stack_address)
 233                 ret = snprintf(buf, n, "$stack");
 234         else if (ff->func == fetch_indirect) {
 235                 struct indirect_fetch_data *id = ff->data;
 236                 size_t l = 0;
 237                 ret = snprintf(buf, n, "%+ld(", id->offset);
 238                 if (ret >= n)
 239                         goto end;
 240                 l += ret;
 241                 ret = probe_arg_string(buf + l, n - l, &id->orig);
 242                 if (ret < 0)
 243                         goto end;
 244                 l += ret;
 245                 ret = snprintf(buf + l, n - l, ")");
 246                 ret += l;
 247         }
 248 end:
 249         if (ret >= n)
 250                 return -ENOSPC;
 251         return ret;
 252 }
 253
 254 static int register_probe_event(struct trace_probe *tp);
 255 static void unregister_probe_event(struct trace_probe *tp);
 256
 257 static DEFINE_MUTEX(probe_lock);
 258 static LIST_HEAD(probe_list);
 259
 260 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 261 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
 262                                 struct pt_regs *regs);
 263
 264 /*
 265  * Allocate new trace_probe and initialize it (including kprobes).
 266  */
 267 static struct trace_probe *alloc_trace_probe(const char *group,
 268                                              const char *event,
 269                                              void *addr,
 270                                              const char *symbol,
 271                                              unsigned long offs,
 272                                              int nargs, int is_return)
 273 {
 274         struct trace_probe *tp;
 275
 276         tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
 277         if (!tp)
 278                 return ERR_PTR(-ENOMEM);
 279
 280         if (symbol) {
 281                 tp->symbol = kstrdup(symbol, GFP_KERNEL);
 282                 if (!tp->symbol)
 283                         goto error;
 284                 tp->rp.kp.symbol_name = tp->symbol;
 285                 tp->rp.kp.offset = offs;
 286         } else
 287                 tp->rp.kp.addr = addr;
 288
 289         if (is_return)
 290                 tp->rp.handler = kretprobe_dispatcher;
 291         else
 292                 tp->rp.kp.pre_handler = kprobe_dispatcher;
 293
 294         if (!event)
 295                 goto error;
 296         tp->call.name = kstrdup(event, GFP_KERNEL);
 297         if (!tp->call.name)
 298                 goto error;
 299
 300         if (!group)
 301                 goto error;
 302         tp->call.system = kstrdup(group, GFP_KERNEL);
 303         if (!tp->call.system)
 304                 goto error;
 305
 306         INIT_LIST_HEAD(&tp->list);
 307         return tp;
 308 error:
 309         kfree(tp->call.name);
 310         kfree(tp->symbol);
 311         kfree(tp);
 312         return ERR_PTR(-ENOMEM);
 313 }
 314
 315 static void free_probe_arg(struct probe_arg *arg)
 316 {
 317         if (arg->fetch.func == fetch_symbol)
 318                 free_symbol_cache(arg->fetch.data);
 319         else if (arg->fetch.func == fetch_indirect)
 320                 free_indirect_fetch_data(arg->fetch.data);
 321         kfree(arg->name);
 322 }
 323
 324 static void free_trace_probe(struct trace_probe *tp)
 325 {
 326         int i;
 327
 328         for (i = 0; i < tp->nr_args; i++)
 329                 free_probe_arg(&tp->args[i]);
 330
 331         kfree(tp->call.system);
 332         kfree(tp->call.name);
 333         kfree(tp->symbol);
 334         kfree(tp);
 335 }
 336
 337 static struct trace_probe *find_probe_event(const char *event)
 338 {
 339         struct trace_probe *tp;
 340
 341         list_for_each_entry(tp, &probe_list, list)
 342                 if (!strcmp(tp->call.name, event))
 343                         return tp;
 344         return NULL;
 345 }
 346
 347 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
 348 static void unregister_trace_probe(struct trace_probe *tp)
 349 {
 350         if (probe_is_return(tp))
 351                 unregister_kretprobe(&tp->rp);
 352         else
 353                 unregister_kprobe(&tp->rp.kp);
 354         list_del(&tp->list);
 355         unregister_probe_event(tp);
 356 }
 357
 358 /* Register a trace_probe and probe_event */
 359 static int register_trace_probe(struct trace_probe *tp)
 360 {
 361         struct trace_probe *old_tp;
 362         int ret;
 363
 364         mutex_lock(&probe_lock);
 365
 366         /* register as an event */
 367         old_tp = find_probe_event(tp->call.name);
 368         if (old_tp) {
 369                 /* delete old event */
 370                 unregister_trace_probe(old_tp);
 371                 free_trace_probe(old_tp);
 372         }
 373         ret = register_probe_event(tp);
 374         if (ret) {
 375                 pr_warning("Faild to register probe event(%d)\n", ret);
 376                 goto end;
 377         }
 378
 379         tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
 380         if (probe_is_return(tp))
 381                 ret = register_kretprobe(&tp->rp);
 382         else
 383                 ret = register_kprobe(&tp->rp.kp);
 384
 385         if (ret) {
 386                 pr_warning("Could not insert probe(%d)\n", ret);
 387                 if (ret == -EILSEQ) {
 388                         pr_warning("Probing address(0x%p) is not an "
 389                                    "instruction boundary.\n",
 390                                    tp->rp.kp.addr);
 391                         ret = -EINVAL;
 392                 }
 393                 unregister_probe_event(tp);
 394         } else
 395                 list_add_tail(&tp->list, &probe_list);
 396 end:
 397         mutex_unlock(&probe_lock);
 398         return ret;
 399 }
 400
 401 /* Split symbol and offset. */
 402 static int split_symbol_offset(char *symbol, unsigned long *offset)
 403 {
 404         char *tmp;
 405         int ret;
 406
 407         if (!offset)
 408                 return -EINVAL;
 409
 410         tmp = strchr(symbol, '+');
 411         if (tmp) {
 412                 /* skip sign because strict_strtol doesn't accept '+' */
 413                 ret = strict_strtoul(tmp + 1, 0, offset);
 414                 if (ret)
 415                         return ret;
 416                 *tmp = '\0';
 417         } else
 418                 *offset = 0;
 419         return 0;
 420 }
 421
 422 #define PARAM_MAX_ARGS 16
 423 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
 424
 425 static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
 426 {
 427         int ret = 0;
 428         unsigned long param;
 429
 430         if (strcmp(arg, "retval") == 0) {
 431                 if (is_return) {
 432                         ff->func = fetch_retvalue;
 433                         ff->data = NULL;
 434                 } else
 435                         ret = -EINVAL;
 436         } else if (strncmp(arg, "stack", 5) == 0) {
 437                 if (arg[5] == '\0') {
 438                         ff->func = fetch_stack_address;
 439                         ff->data = NULL;
 440                 } else if (isdigit(arg[5])) {
 441                         ret = strict_strtoul(arg + 5, 10, &param);
 442                         if (ret || param > PARAM_MAX_STACK)
 443                                 ret = -EINVAL;
 444                         else {
 445                                 ff->func = fetch_stack;
 446                                 ff->data = (void *)param;
 447                         }
 448                 } else
 449                         ret = -EINVAL;
 450         } else if (strncmp(arg, "arg", 3) == 0 && isdigit(arg[3])) {
 451                 ret = strict_strtoul(arg + 3, 10, &param);
 452                 if (ret || param > PARAM_MAX_ARGS)
 453                         ret = -EINVAL;
 454                 else {
 455                         ff->func = fetch_argument;
 456                         ff->data = (void *)param;
 457                 }
 458         } else
 459                 ret = -EINVAL;
 460         return ret;
 461 }
 462
 463 static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
 464 {
 465         int ret = 0;
 466         unsigned long param;
 467         long offset;
 468         char *tmp;
 469
 470         switch (arg[0]) {
 471         case '$':
 472                 ret = parse_probe_vars(arg + 1, ff, is_return);
 473                 break;
 474         case '%':       /* named register */
 475                 ret = regs_query_register_offset(arg + 1);
 476                 if (ret >= 0) {
 477                         ff->func = fetch_register;
 478                         ff->data = (void *)(unsigned long)ret;
 479                         ret = 0;
 480                 }
 481                 break;
 482         case '@':       /* memory or symbol */
 483                 if (isdigit(arg[1])) {
 484                         ret = strict_strtoul(arg + 1, 0, &param);
 485                         if (ret)
 486                                 break;
 487                         ff->func = fetch_memory;
 488                         ff->data = (void *)param;
 489                 } else {
 490                         ret = split_symbol_offset(arg + 1, &offset);
 491                         if (ret)
 492                                 break;
 493                         ff->data = alloc_symbol_cache(arg + 1, offset);
 494                         if (ff->data)
 495                                 ff->func = fetch_symbol;
 496                         else
 497                                 ret = -EINVAL;
 498                 }
 499                 break;
 500         case '+':       /* indirect memory */
 501         case '-':
 502                 tmp = strchr(arg, '(');
 503                 if (!tmp) {
 504                         ret = -EINVAL;
 505                         break;
 506                 }
 507                 *tmp = '\0';
 508                 ret = strict_strtol(arg + 1, 0, &offset);
 509                 if (ret)
 510                         break;
 511                 if (arg[0] == '-')
 512                         offset = -offset;
 513                 arg = tmp + 1;
 514                 tmp = strrchr(arg, ')');
 515                 if (tmp) {
 516                         struct indirect_fetch_data *id;
 517                         *tmp = '\0';
 518                         id = kzalloc(sizeof(struct indirect_fetch_data),
 519                                      GFP_KERNEL);
 520                         if (!id)
 521                                 return -ENOMEM;
 522                         id->offset = offset;
 523                         ret = parse_probe_arg(arg, &id->orig, is_return);
 524                         if (ret)
 525                                 kfree(id);
 526                         else {
 527                                 ff->func = fetch_indirect;
 528                                 ff->data = (void *)id;
 529                         }
 530                 } else
 531                         ret = -EINVAL;
 532                 break;
 533         default:
 534                 /* TODO: support custom handler */
 535                 ret = -EINVAL;
 536         }
 537         return ret;
 538 }
 539
 540 static int create_trace_probe(int argc, char **argv)
 541 {
 542         /*
 543          * Argument syntax:
 544          *  - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
 545          *  - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
 546          * Fetch args:
 547          *  $argN       : fetch Nth of function argument. (N:0-)
 548          *  $retval     : fetch return value
 549          *  $stack      : fetch stack address
 550          *  $stackN     : fetch Nth of stack (N:0-)
 551          *  @ADDR       : fetch memory at ADDR (ADDR should be in kernel)
 552          *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
 553          *  %REG        : fetch register REG
 554          * Indirect memory fetch:
 555          *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
 556          * Alias name of args:
 557          *  NAME=FETCHARG : set NAME as alias of FETCHARG.
 558          */
 559         struct trace_probe *tp;
 560         int i, ret = 0;
 561         int is_return = 0;
 562         char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL;
 563         unsigned long offset = 0;
 564         void *addr = NULL;
 565         char buf[MAX_EVENT_NAME_LEN];
 566
 567         if (argc < 2)
 568                 return -EINVAL;
 569
 570         if (argv[0][0] == 'p')
 571                 is_return = 0;
 572         else if (argv[0][0] == 'r')
 573                 is_return = 1;
 574         else
 575                 return -EINVAL;
 576
 577         if (argv[0][1] == ':') {
 578                 event = &argv[0][2];
 579                 if (strchr(event, '/')) {
 580                         group = event;
 581                         event = strchr(group, '/') + 1;
 582                         event[-1] = '\0';
 583                         if (strlen(group) == 0) {
 584                                 pr_info("Group name is not specifiled\n");
 585                                 return -EINVAL;
 586                         }
 587                 }
 588                 if (strlen(event) == 0) {
 589                         pr_info("Event name is not specifiled\n");
 590                         return -EINVAL;
 591                 }
 592         }
 593
 594         if (isdigit(argv[1][0])) {
 595                 if (is_return)
 596                         return -EINVAL;
 597                 /* an address specified */
 598                 ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr);
 599                 if (ret)
 600                         return ret;
 601         } else {
 602                 /* a symbol specified */
 603                 symbol = argv[1];
 604                 /* TODO: support .init module functions */
 605                 ret = split_symbol_offset(symbol, &offset);
 606                 if (ret)
 607                         return ret;
 608                 if (offset && is_return)
 609                         return -EINVAL;
 610         }
 611         argc -= 2; argv += 2;
 612
 613         /* setup a probe */
 614         if (!group)
 615                 group = KPROBE_EVENT_SYSTEM;
 616         if (!event) {
 617                 /* Make a new event name */
 618                 if (symbol)
 619                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c@%s%+ld",
 620                                  is_return ? 'r' : 'p', symbol, offset);
 621                 else
 622                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c@0x%p",
 623                                  is_return ? 'r' : 'p', addr);
 624                 event = buf;
 625         }
 626         tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
 627                                is_return);
 628         if (IS_ERR(tp))
 629                 return PTR_ERR(tp);
 630
 631         /* parse arguments */
 632         ret = 0;
 633         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 634                 /* Parse argument name */
 635                 arg = strchr(argv[i], '=');
 636                 if (arg)
 637                         *arg++ = '\0';
 638                 else
 639                         arg = argv[i];
 640                 tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
 641
 642                 /* Parse fetch argument */
 643                 if (strlen(arg) > MAX_ARGSTR_LEN) {
 644                         pr_info("Argument%d(%s) is too long.\n", i, arg);
 645                         ret = -ENOSPC;
 646                         goto error;
 647                 }
 648                 ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return);
 649                 if (ret)
 650                         goto error;
 651         }
 652         tp->nr_args = i;
 653
 654         ret = register_trace_probe(tp);
 655         if (ret)
 656                 goto error;
 657         return 0;
 658
 659 error:
 660         free_trace_probe(tp);
 661         return ret;
 662 }
 663
 664 static void cleanup_all_probes(void)
 665 {
 666         struct trace_probe *tp;
 667
 668         mutex_lock(&probe_lock);
 669         /* TODO: Use batch unregistration */
 670         while (!list_empty(&probe_list)) {
 671                 tp = list_entry(probe_list.next, struct trace_probe, list);
 672                 unregister_trace_probe(tp);
 673                 free_trace_probe(tp);
 674         }
 675         mutex_unlock(&probe_lock);
 676 }
 677
 678
 679 /* Probes listing interfaces */
 680 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
 681 {
 682         mutex_lock(&probe_lock);
 683         return seq_list_start(&probe_list, *pos);
 684 }
 685
 686 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
 687 {
 688         return seq_list_next(v, &probe_list, pos);
 689 }
 690
 691 static void probes_seq_stop(struct seq_file *m, void *v)
 692 {
 693         mutex_unlock(&probe_lock);
 694 }
 695
 696 static int probes_seq_show(struct seq_file *m, void *v)
 697 {
 698         struct trace_probe *tp = v;
 699         int i, ret;
 700         char buf[MAX_ARGSTR_LEN + 1];
 701
 702         seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
 703         seq_printf(m, ":%s", tp->call.name);
 704
 705         if (tp->symbol)
 706                 seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
 707         else
 708                 seq_printf(m, " 0x%p", tp->rp.kp.addr);
 709
 710         for (i = 0; i < tp->nr_args; i++) {
 711                 ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);
 712                 if (ret < 0) {
 713                         pr_warning("Argument%d decoding error(%d).\n", i, ret);
 714                         return ret;
 715                 }
 716                 seq_printf(m, " %s=%s", tp->args[i].name, buf);
 717         }
 718         seq_printf(m, "\n");
 719         return 0;
 720 }
 721
 722 static const struct seq_operations probes_seq_op = {
 723         .start  = probes_seq_start,
 724         .next   = probes_seq_next,
 725         .stop   = probes_seq_stop,
 726         .show   = probes_seq_show
 727 };
 728
 729 static int probes_open(struct inode *inode, struct file *file)
 730 {
 731         if ((file->f_mode & FMODE_WRITE) &&
 732             (file->f_flags & O_TRUNC))
 733                 cleanup_all_probes();
 734
 735         return seq_open(file, &probes_seq_op);
 736 }
 737
 738 static int command_trace_probe(const char *buf)
 739 {
 740         char **argv;
 741         int argc = 0, ret = 0;
 742
 743         argv = argv_split(GFP_KERNEL, buf, &argc);
 744         if (!argv)
 745                 return -ENOMEM;
 746
 747         if (argc)
 748                 ret = create_trace_probe(argc, argv);
 749
 750         argv_free(argv);
 751         return ret;
 752 }
 753
 754 #define WRITE_BUFSIZE 128
 755
 756 static ssize_t probes_write(struct file *file, const char __user *buffer,
 757                             size_t count, loff_t *ppos)
 758 {
 759         char *kbuf, *tmp;
 760         int ret;
 761         size_t done;
 762         size_t size;
 763
 764         kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
 765         if (!kbuf)
 766                 return -ENOMEM;
 767
 768         ret = done = 0;
 769         while (done < count) {
 770                 size = count - done;
 771                 if (size >= WRITE_BUFSIZE)
 772                         size = WRITE_BUFSIZE - 1;
 773                 if (copy_from_user(kbuf, buffer + done, size)) {
 774                         ret = -EFAULT;
 775                         goto out;
 776                 }
 777                 kbuf[size] = '\0';
 778                 tmp = strchr(kbuf, '\n');
 779                 if (tmp) {
 780                         *tmp = '\0';
 781                         size = tmp - kbuf + 1;
 782                 } else if (done + size < count) {
 783                         pr_warning("Line length is too long: "
 784                                    "Should be less than %d.", WRITE_BUFSIZE);
 785                         ret = -EINVAL;
 786                         goto out;
 787                 }
 788                 done += size;
 789                 /* Remove comments */
 790                 tmp = strchr(kbuf, '#');
 791                 if (tmp)
 792                         *tmp = '\0';
 793
 794                 ret = command_trace_probe(kbuf);
 795                 if (ret)
 796                         goto out;
 797         }
 798         ret = done;
 799 out:
 800         kfree(kbuf);
 801         return ret;
 802 }
 803
 804 static const struct file_operations kprobe_events_ops = {
 805         .owner          = THIS_MODULE,
 806         .open           = probes_open,
 807         .read           = seq_read,
 808         .llseek         = seq_lseek,
 809         .release        = seq_release,
 810         .write          = probes_write,
 811 };
 812
 813 /* Probes profiling interfaces */
 814 static int probes_profile_seq_show(struct seq_file *m, void *v)
 815 {
 816         struct trace_probe *tp = v;
 817
 818         seq_printf(m, "  %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
 819                    tp->rp.kp.nmissed);
 820
 821         return 0;
 822 }
 823
 824 static const struct seq_operations profile_seq_op = {
 825         .start  = probes_seq_start,
 826         .next   = probes_seq_next,
 827         .stop   = probes_seq_stop,
 828         .show   = probes_profile_seq_show
 829 };
 830
 831 static int profile_open(struct inode *inode, struct file *file)
 832 {
 833         return seq_open(file, &profile_seq_op);
 834 }
 835
 836 static const struct file_operations kprobe_profile_ops = {
 837         .owner          = THIS_MODULE,
 838         .open           = profile_open,
 839         .read           = seq_read,
 840         .llseek         = seq_lseek,
 841         .release        = seq_release,
 842 };
 843
 844 /* Kprobe handler */
 845 static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
 846 {
 847         struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
 848         struct kprobe_trace_entry *entry;
 849         struct ring_buffer_event *event;
 850         struct ring_buffer *buffer;
 851         int size, i, pc;
 852         unsigned long irq_flags;
 853         struct ftrace_event_call *call = &tp->call;
 854
 855         tp->nhit++;
 856
 857         local_save_flags(irq_flags);
 858         pc = preempt_count();
 859
 860         size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
 861
 862         event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
 863                                                   irq_flags, pc);
 864         if (!event)
 865                 return 0;
 866
 867         entry = ring_buffer_event_data(event);
 868         entry->nargs = tp->nr_args;
 869         entry->ip = (unsigned long)kp->addr;
 870         for (i = 0; i < tp->nr_args; i++)
 871                 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
 872
 873         if (!filter_current_check_discard(buffer, call, entry, event))
 874                 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
 875         return 0;
 876 }
 877
 878 /* Kretprobe handler */
 879 static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri,
 880                                           struct pt_regs *regs)
 881 {
 882         struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
 883         struct kretprobe_trace_entry *entry;
 884         struct ring_buffer_event *event;
 885         struct ring_buffer *buffer;
 886         int size, i, pc;
 887         unsigned long irq_flags;
 888         struct ftrace_event_call *call = &tp->call;
 889
 890         local_save_flags(irq_flags);
 891         pc = preempt_count();
 892
 893         size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
 894
 895         event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
 896                                                   irq_flags, pc);
 897         if (!event)
 898                 return 0;
 899
 900         entry = ring_buffer_event_data(event);
 901         entry->nargs = tp->nr_args;
 902         entry->func = (unsigned long)tp->rp.kp.addr;
 903         entry->ret_ip = (unsigned long)ri->ret_addr;
 904         for (i = 0; i < tp->nr_args; i++)
 905                 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
 906
 907         if (!filter_current_check_discard(buffer, call, entry, event))
 908                 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
 909
 910         return 0;
 911 }
 912
 913 /* Event entry printers */
 914 enum print_line_t
 915 print_kprobe_event(struct trace_iterator *iter, int flags)
 916 {
 917         struct kprobe_trace_entry *field;
 918         struct trace_seq *s = &iter->seq;
 919         struct trace_event *event;
 920         struct trace_probe *tp;
 921         int i;
 922
 923         field = (struct kprobe_trace_entry *)iter->ent;
 924         event = ftrace_find_event(field->ent.type);
 925         tp = container_of(event, struct trace_probe, event);
 926
 927         if (!trace_seq_printf(s, "%s: (", tp->call.name))
 928                 goto partial;
 929
 930         if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
 931                 goto partial;
 932
 933         if (!trace_seq_puts(s, ")"))
 934                 goto partial;
 935
 936         for (i = 0; i < field->nargs; i++)
 937                 if (!trace_seq_printf(s, " %s=%lx",
 938                                       tp->args[i].name, field->args[i]))
 939                         goto partial;
 940
 941         if (!trace_seq_puts(s, "\n"))
 942                 goto partial;
 943
 944         return TRACE_TYPE_HANDLED;
 945 partial:
 946         return TRACE_TYPE_PARTIAL_LINE;
 947 }
 948
 949 enum print_line_t
 950 print_kretprobe_event(struct trace_iterator *iter, int flags)
 951 {
 952         struct kretprobe_trace_entry *field;
 953         struct trace_seq *s = &iter->seq;
 954         struct trace_event *event;
 955         struct trace_probe *tp;
 956         int i;
 957
 958         field = (struct kretprobe_trace_entry *)iter->ent;
 959         event = ftrace_find_event(field->ent.type);
 960         tp = container_of(event, struct trace_probe, event);
 961
 962         if (!trace_seq_printf(s, "%s: (", tp->call.name))
 963                 goto partial;
 964
 965         if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
 966                 goto partial;
 967
 968         if (!trace_seq_puts(s, " <- "))
 969                 goto partial;
 970
 971         if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
 972                 goto partial;
 973
 974         if (!trace_seq_puts(s, ")"))
 975                 goto partial;
 976
 977         for (i = 0; i < field->nargs; i++)
 978                 if (!trace_seq_printf(s, " %s=%lx",
 979                                       tp->args[i].name, field->args[i]))
 980                         goto partial;
 981
 982         if (!trace_seq_puts(s, "\n"))
 983                 goto partial;
 984
 985         return TRACE_TYPE_HANDLED;
 986 partial:
 987         return TRACE_TYPE_PARTIAL_LINE;
 988 }
 989
 990 static int probe_event_enable(struct ftrace_event_call *call)
 991 {
 992         struct trace_probe *tp = (struct trace_probe *)call->data;
 993
 994         tp->flags |= TP_FLAG_TRACE;
 995         if (probe_is_return(tp))
 996                 return enable_kretprobe(&tp->rp);
 997         else
 998                 return enable_kprobe(&tp->rp.kp);
 999 }
1000
1001 static void probe_event_disable(struct ftrace_event_call *call)
1002 {
1003         struct trace_probe *tp = (struct trace_probe *)call->data;
1004
1005         tp->flags &= ~TP_FLAG_TRACE;
1006         if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) {
1007                 if (probe_is_return(tp))
1008                         disable_kretprobe(&tp->rp);
1009                 else
1010                         disable_kprobe(&tp->rp.kp);
1011         }
1012 }
1013
1014 static int probe_event_raw_init(struct ftrace_event_call *event_call)
1015 {
1016         INIT_LIST_HEAD(&event_call->fields);
1017
1018         return 0;
1019 }
1020
1021 #undef DEFINE_FIELD
1022 #define DEFINE_FIELD(type, item, name, is_signed)                       \
1023         do {                                                            \
1024                 ret = trace_define_field(event_call, #type, name,       \
1025                                          offsetof(typeof(field), item), \
1026                                          sizeof(field.item), is_signed, \
1027                                          FILTER_OTHER);                 \
1028                 if (ret)                                                \
1029                         return ret;                                     \
1030         } while (0)
1031
1032 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
1033 {
1034         int ret, i;
1035         struct kprobe_trace_entry field;
1036         struct trace_probe *tp = (struct trace_probe *)event_call->data;
1037
1038         ret = trace_define_common_fields(event_call);
1039         if (!ret)
1040                 return ret;
1041
1042         DEFINE_FIELD(unsigned long, ip, "ip", 0);
1043         DEFINE_FIELD(int, nargs, "nargs", 1);
1044         /* Set argument names as fields */
1045         for (i = 0; i < tp->nr_args; i++)
1046                 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1047         return 0;
1048 }
1049
1050 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1051 {
1052         int ret, i;
1053         struct kretprobe_trace_entry field;
1054         struct trace_probe *tp = (struct trace_probe *)event_call->data;
1055
1056         ret = trace_define_common_fields(event_call);
1057         if (!ret)
1058                 return ret;
1059
1060         DEFINE_FIELD(unsigned long, func, "func", 0);
1061         DEFINE_FIELD(unsigned long, ret_ip, "ret_ip", 0);
1062         DEFINE_FIELD(int, nargs, "nargs", 1);
1063         /* Set argument names as fields */
1064         for (i = 0; i < tp->nr_args; i++)
1065                 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1066         return 0;
1067 }
1068
1069 static int __probe_event_show_format(struct trace_seq *s,
1070                                      struct trace_probe *tp, const char *fmt,
1071                                      const char *arg)
1072 {
1073         int i;
1074
1075         /* Show format */
1076         if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt))
1077                 return 0;
1078
1079         for (i = 0; i < tp->nr_args; i++)
1080                 if (!trace_seq_printf(s, " %s=%%lx", tp->args[i].name))
1081                         return 0;
1082
1083         if (!trace_seq_printf(s, "\", %s", arg))
1084                 return 0;
1085
1086         for (i = 0; i < tp->nr_args; i++)
1087                 if (!trace_seq_printf(s, ", REC->%s", tp->args[i].name))
1088                         return 0;
1089
1090         return trace_seq_puts(s, "\n");
1091 }
1092
1093 #undef SHOW_FIELD
1094 #define SHOW_FIELD(type, item, name)                                    \
1095         do {                                                            \
1096                 ret = trace_seq_printf(s, "\tfield: " #type " %s;\t"    \
1097                                 "offset:%u;\tsize:%u;\n", name,         \
1098                                 (unsigned int)offsetof(typeof(field), item),\
1099                                 (unsigned int)sizeof(type));            \
1100                 if (!ret)                                               \
1101                         return 0;                                       \
1102         } while (0)
1103
1104 static int kprobe_event_show_format(struct ftrace_event_call *call,
1105                                     struct trace_seq *s)
1106 {
1107         struct kprobe_trace_entry field __attribute__((unused));
1108         int ret, i;
1109         struct trace_probe *tp = (struct trace_probe *)call->data;
1110
1111         SHOW_FIELD(unsigned long, ip, "ip");
1112         SHOW_FIELD(int, nargs, "nargs");
1113
1114         /* Show fields */
1115         for (i = 0; i < tp->nr_args; i++)
1116                 SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
1117         trace_seq_puts(s, "\n");
1118
1119         return __probe_event_show_format(s, tp, "(%lx)", "REC->ip");
1120 }
1121
1122 static int kretprobe_event_show_format(struct ftrace_event_call *call,
1123                                        struct trace_seq *s)
1124 {
1125         struct kretprobe_trace_entry field __attribute__((unused));
1126         int ret, i;
1127         struct trace_probe *tp = (struct trace_probe *)call->data;
1128
1129         SHOW_FIELD(unsigned long, func, "func");
1130         SHOW_FIELD(unsigned long, ret_ip, "ret_ip");
1131         SHOW_FIELD(int, nargs, "nargs");
1132
1133         /* Show fields */
1134         for (i = 0; i < tp->nr_args; i++)
1135                 SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
1136         trace_seq_puts(s, "\n");
1137
1138         return __probe_event_show_format(s, tp, "(%lx <- %lx)",
1139                                           "REC->func, REC->ret_ip");
1140 }
1141
1142 #ifdef CONFIG_EVENT_PROFILE
1143
1144 /* Kprobe profile handler */
1145 static __kprobes int kprobe_profile_func(struct kprobe *kp,
1146                                          struct pt_regs *regs)
1147 {
1148         struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1149         struct ftrace_event_call *call = &tp->call;
1150         struct kprobe_trace_entry *entry;
1151         struct trace_entry *ent;
1152         int size, __size, i, pc, __cpu;
1153         unsigned long irq_flags;
1154         char *raw_data;
1155
1156         pc = preempt_count();
1157         __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
1158         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1159         size -= sizeof(u32);
1160         if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
1161                      "profile buffer not large enough"))
1162                 return 0;
1163
1164         /*
1165          * Protect the non nmi buffer
1166          * This also protects the rcu read side
1167          */
1168         local_irq_save(irq_flags);
1169         __cpu = smp_processor_id();
1170
1171         if (in_nmi())
1172                 raw_data = rcu_dereference(trace_profile_buf_nmi);
1173         else
1174                 raw_data = rcu_dereference(trace_profile_buf);
1175
1176         if (!raw_data)
1177                 goto end;
1178
1179         raw_data = per_cpu_ptr(raw_data, __cpu);
1180         /* Zero dead bytes from alignment to avoid buffer leak to userspace */
1181         *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
1182         entry = (struct kprobe_trace_entry *)raw_data;
1183         ent = &entry->ent;
1184
1185         tracing_generic_entry_update(ent, irq_flags, pc);
1186         ent->type = call->id;
1187         entry->nargs = tp->nr_args;
1188         entry->ip = (unsigned long)kp->addr;
1189         for (i = 0; i < tp->nr_args; i++)
1190                 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1191         perf_tp_event(call->id, entry->ip, 1, entry, size);
1192 end:
1193         local_irq_restore(irq_flags);
1194         return 0;
1195 }
1196
1197 /* Kretprobe profile handler */
1198 static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
1199                                             struct pt_regs *regs)
1200 {
1201         struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1202         struct ftrace_event_call *call = &tp->call;
1203         struct kretprobe_trace_entry *entry;
1204         struct trace_entry *ent;
1205         int size, __size, i, pc, __cpu;
1206         unsigned long irq_flags;
1207         char *raw_data;
1208
1209         pc = preempt_count();
1210         __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
1211         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1212         size -= sizeof(u32);
1213         if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
1214                      "profile buffer not large enough"))
1215                 return 0;
1216
1217         /*
1218          * Protect the non nmi buffer
1219          * This also protects the rcu read side
1220          */
1221         local_irq_save(irq_flags);
1222         __cpu = smp_processor_id();
1223
1224         if (in_nmi())
1225                 raw_data = rcu_dereference(trace_profile_buf_nmi);
1226         else
1227                 raw_data = rcu_dereference(trace_profile_buf);
1228
1229         if (!raw_data)
1230                 goto end;
1231
1232         raw_data = per_cpu_ptr(raw_data, __cpu);
1233         /* Zero dead bytes from alignment to avoid buffer leak to userspace */
1234         *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
1235         entry = (struct kretprobe_trace_entry *)raw_data;
1236         ent = &entry->ent;
1237
1238         tracing_generic_entry_update(ent, irq_flags, pc);
1239         ent->type = call->id;
1240         entry->nargs = tp->nr_args;
1241         entry->func = (unsigned long)tp->rp.kp.addr;
1242         entry->ret_ip = (unsigned long)ri->ret_addr;
1243         for (i = 0; i < tp->nr_args; i++)
1244                 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1245         perf_tp_event(call->id, entry->ret_ip, 1, entry, size);
1246 end:
1247         local_irq_restore(irq_flags);
1248         return 0;
1249 }
1250
1251 static int probe_profile_enable(struct ftrace_event_call *call)
1252 {
1253         struct trace_probe *tp = (struct trace_probe *)call->data;
1254
1255         tp->flags |= TP_FLAG_PROFILE;
1256
1257         if (probe_is_return(tp))
1258                 return enable_kretprobe(&tp->rp);
1259         else
1260                 return enable_kprobe(&tp->rp.kp);
1261 }
1262
1263 static void probe_profile_disable(struct ftrace_event_call *call)
1264 {
1265         struct trace_probe *tp = (struct trace_probe *)call->data;
1266
1267         tp->flags &= ~TP_FLAG_PROFILE;
1268
1269         if (!(tp->flags & TP_FLAG_TRACE)) {
1270                 if (probe_is_return(tp))
1271                         disable_kretprobe(&tp->rp);
1272                 else
1273                         disable_kprobe(&tp->rp.kp);
1274         }
1275 }
1276 #endif  /* CONFIG_EVENT_PROFILE */
1277
1278
1279 static __kprobes
1280 int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1281 {
1282         struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1283
1284         if (tp->flags & TP_FLAG_TRACE)
1285                 kprobe_trace_func(kp, regs);
1286 #ifdef CONFIG_EVENT_PROFILE
1287         if (tp->flags & TP_FLAG_PROFILE)
1288                 kprobe_profile_func(kp, regs);
1289 #endif  /* CONFIG_EVENT_PROFILE */
1290         return 0;       /* We don't tweek kernel, so just return 0 */
1291 }
1292
1293 static __kprobes
1294 int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1295 {
1296         struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1297
1298         if (tp->flags & TP_FLAG_TRACE)
1299                 kretprobe_trace_func(ri, regs);
1300 #ifdef CONFIG_EVENT_PROFILE
1301         if (tp->flags & TP_FLAG_PROFILE)
1302                 kretprobe_profile_func(ri, regs);
1303 #endif  /* CONFIG_EVENT_PROFILE */
1304         return 0;       /* We don't tweek kernel, so just return 0 */
1305 }
1306
1307 static int register_probe_event(struct trace_probe *tp)
1308 {
1309         struct ftrace_event_call *call = &tp->call;
1310         int ret;
1311
1312         /* Initialize ftrace_event_call */
1313         if (probe_is_return(tp)) {
1314                 tp->event.trace = print_kretprobe_event;
1315                 call->raw_init = probe_event_raw_init;
1316                 call->show_format = kretprobe_event_show_format;
1317                 call->define_fields = kretprobe_event_define_fields;
1318         } else {
1319                 tp->event.trace = print_kprobe_event;
1320                 call->raw_init = probe_event_raw_init;
1321                 call->show_format = kprobe_event_show_format;
1322                 call->define_fields = kprobe_event_define_fields;
1323         }
1324         call->event = &tp->event;
1325         call->id = register_ftrace_event(&tp->event);
1326         if (!call->id)
1327                 return -ENODEV;
1328         call->enabled = 0;
1329         call->regfunc = probe_event_enable;
1330         call->unregfunc = probe_event_disable;
1331
1332 #ifdef CONFIG_EVENT_PROFILE
1333         atomic_set(&call->profile_count, -1);
1334         call->profile_enable = probe_profile_enable;
1335         call->profile_disable = probe_profile_disable;
1336 #endif
1337         call->data = tp;
1338         ret = trace_add_event_call(call);
1339         if (ret) {
1340                 pr_info("Failed to register kprobe event: %s\n", call->name);
1341                 unregister_ftrace_event(&tp->event);
1342         }
1343         return ret;
1344 }
1345
1346 static void unregister_probe_event(struct trace_probe *tp)
1347 {
1348         /* tp->event is unregistered in trace_remove_event_call() */
1349         trace_remove_event_call(&tp->call);
1350 }
1351
1352 /* Make a debugfs interface for controling probe points */
1353 static __init int init_kprobe_trace(void)
1354 {
1355         struct dentry *d_tracer;
1356         struct dentry *entry;
1357
1358         d_tracer = tracing_init_dentry();
1359         if (!d_tracer)
1360                 return 0;
1361
1362         entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
1363                                     NULL, &kprobe_events_ops);
1364
1365         /* Event list interface */
1366         if (!entry)
1367                 pr_warning("Could not create debugfs "
1368                            "'kprobe_events' entry\n");
1369
1370         /* Profile interface */
1371         entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
1372                                     NULL, &kprobe_profile_ops);
1373
1374         if (!entry)
1375                 pr_warning("Could not create debugfs "
1376                            "'kprobe_profile' entry\n");
1377         return 0;
1378 }
1379 fs_initcall(init_kprobe_trace);
1380
1381
1382 #ifdef CONFIG_FTRACE_STARTUP_TEST
1383
1384 static int kprobe_trace_selftest_target(int a1, int a2, int a3,
1385                                         int a4, int a5, int a6)
1386 {
1387         return a1 + a2 + a3 + a4 + a5 + a6;
1388 }
1389
1390 static __init int kprobe_trace_self_tests_init(void)
1391 {
1392         int ret;
1393         int (*target)(int, int, int, int, int, int);
1394
1395         target = kprobe_trace_selftest_target;
1396
1397         pr_info("Testing kprobe tracing: ");
1398
1399         ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
1400                                   "a1 a2 a3 a4 a5 a6");
1401         if (WARN_ON_ONCE(ret))
1402                 pr_warning("error enabling function entry\n");
1403
1404         ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
1405                                   "ra rv");
1406         if (WARN_ON_ONCE(ret))
1407                 pr_warning("error enabling function return\n");
1408
1409         ret = target(1, 2, 3, 4, 5, 6);
1410
1411         cleanup_all_probes();
1412
1413         pr_cont("OK\n");
1414         return 0;
1415 }
1416
1417 late_initcall(kprobe_trace_self_tests_init);
1418
1419 #endif