kernel/trace/trace_uprobe.c

   1 /*
   2  * uprobes-based tracing events
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16  *
  17  * Copyright (C) IBM Corporation, 2010-2012
  18  * Author:      Srikar Dronamraju <srikar@linux.vnet.ibm.com>
  19  */
  20 #define pr_fmt(fmt)     "trace_uprobe: " fmt
  21
  22 #include <linux/module.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/uprobes.h>
  25 #include <linux/namei.h>
  26 #include <linux/string.h>
  27 #include <linux/rculist.h>
  28
  29 #include "trace_probe.h"
  30
  31 #define UPROBE_EVENT_SYSTEM     "uprobes"
  32
  33 struct uprobe_trace_entry_head {
  34         struct trace_entry      ent;
  35         unsigned long           vaddr[];
  36 };
  37
  38 #define SIZEOF_TRACE_ENTRY(is_return)                   \
  39         (sizeof(struct uprobe_trace_entry_head) +       \
  40          sizeof(unsigned long) * (is_return ? 2 : 1))
  41
  42 #define DATAOF_TRACE_ENTRY(entry, is_return)            \
  43         ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
  44
  45 struct trace_uprobe_filter {
  46         rwlock_t                rwlock;
  47         int                     nr_systemwide;
  48         struct list_head        perf_events;
  49 };
  50
  51 /*
  52  * uprobe event core functions
  53  */
  54 struct trace_uprobe {
  55         struct list_head                list;
  56         struct trace_uprobe_filter      filter;
  57         struct uprobe_consumer          consumer;
  58         struct path                     path;
  59         struct inode                    *inode;
  60         char                            *filename;
  61         unsigned long                   offset;
  62         unsigned long                   nhit;
  63         struct trace_probe              tp;
  64 };
  65
  66 #define SIZEOF_TRACE_UPROBE(n)                          \
  67         (offsetof(struct trace_uprobe, tp.args) +       \
  68         (sizeof(struct probe_arg) * (n)))
  69
  70 static int register_uprobe_event(struct trace_uprobe *tu);
  71 static int unregister_uprobe_event(struct trace_uprobe *tu);
  72
  73 static DEFINE_MUTEX(uprobe_lock);
  74 static LIST_HEAD(uprobe_list);
  75
  76 struct uprobe_dispatch_data {
  77         struct trace_uprobe     *tu;
  78         unsigned long           bp_addr;
  79 };
  80
  81 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
  82 static int uretprobe_dispatcher(struct uprobe_consumer *con,
  83                                 unsigned long func, struct pt_regs *regs);
  84
  85 #ifdef CONFIG_STACK_GROWSUP
  86 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
  87 {
  88         return addr - (n * sizeof(long));
  89 }
  90 #else
  91 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
  92 {
  93         return addr + (n * sizeof(long));
  94 }
  95 #endif
  96
  97 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
  98 {
  99         unsigned long ret;
 100         unsigned long addr = user_stack_pointer(regs);
 101
 102         addr = adjust_stack_addr(addr, n);
 103
 104         if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
 105                 return 0;
 106
 107         return ret;
 108 }
 109
 110 /*
 111  * Uprobes-specific fetch functions
 112  */
 113 #define DEFINE_FETCH_stack(type)                                        \
 114 static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,          \
 115                                          void *offset, void *dest)      \
 116 {                                                                       \
 117         *(type *)dest = (type)get_user_stack_nth(regs,                  \
 118                                               ((unsigned long)offset)); \
 119 }
 120 DEFINE_BASIC_FETCH_FUNCS(stack)
 121 /* No string on the stack entry */
 122 #define fetch_stack_string      NULL
 123 #define fetch_stack_string_size NULL
 124
 125 #define DEFINE_FETCH_memory(type)                                       \
 126 static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,         \
 127                                           void *addr, void *dest)       \
 128 {                                                                       \
 129         type retval;                                                    \
 130         void __user *vaddr = (void __force __user *) addr;              \
 131                                                                         \
 132         if (copy_from_user(&retval, vaddr, sizeof(type)))               \
 133                 *(type *)dest = 0;                                      \
 134         else                                                            \
 135                 *(type *) dest = retval;                                \
 136 }
 137 DEFINE_BASIC_FETCH_FUNCS(memory)
 138 /*
 139  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
 140  * length and relative data location.
 141  */
 142 static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
 143                                             void *addr, void *dest)
 144 {
 145         long ret;
 146         u32 rloc = *(u32 *)dest;
 147         int maxlen  = get_rloc_len(rloc);
 148         u8 *dst = get_rloc_data(dest);
 149         void __user *src = (void __force __user *) addr;
 150
 151         if (!maxlen)
 152                 return;
 153
 154         ret = strncpy_from_user(dst, src, maxlen);
 155         if (ret == maxlen)
 156                 dst[ret - 1] = '\0';
 157         else if (ret >= 0)
 158                 /*
 159                  * Include the terminating null byte. In this case it
 160                  * was copied by strncpy_from_user but not accounted
 161                  * for in ret.
 162                  */
 163                 ret++;
 164
 165         if (ret < 0) {  /* Failed to fetch string */
 166                 ((u8 *)get_rloc_data(dest))[0] = '\0';
 167                 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc));
 168         } else {
 169                 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc));
 170         }
 171 }
 172
 173 static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
 174                                                  void *addr, void *dest)
 175 {
 176         int len;
 177         void __user *vaddr = (void __force __user *) addr;
 178
 179         len = strnlen_user(vaddr, MAX_STRING_SIZE);
 180
 181         if (len == 0 || len > MAX_STRING_SIZE)  /* Failed to check length */
 182                 *(u32 *)dest = 0;
 183         else
 184                 *(u32 *)dest = len;
 185 }
 186
 187 static unsigned long translate_user_vaddr(void *file_offset)
 188 {
 189         unsigned long base_addr;
 190         struct uprobe_dispatch_data *udd;
 191
 192         udd = (void *) current->utask->vaddr;
 193
 194         base_addr = udd->bp_addr - udd->tu->offset;
 195         return base_addr + (unsigned long)file_offset;
 196 }
 197
 198 #define DEFINE_FETCH_file_offset(type)                                  \
 199 static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs,    \
 200                                                void *offset, void *dest)\
 201 {                                                                       \
 202         void *vaddr = (void *)translate_user_vaddr(offset);             \
 203                                                                         \
 204         FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest);               \
 205 }
 206 DEFINE_BASIC_FETCH_FUNCS(file_offset)
 207 DEFINE_FETCH_file_offset(string)
 208 DEFINE_FETCH_file_offset(string_size)
 209
 210 /* Fetch type information table */
 211 static const struct fetch_type uprobes_fetch_type_table[] = {
 212         /* Special types */
 213         [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
 214                                         sizeof(u32), 1, "__data_loc char[]"),
 215         [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
 216                                         string_size, sizeof(u32), 0, "u32"),
 217         /* Basic types */
 218         ASSIGN_FETCH_TYPE(u8,  u8,  0),
 219         ASSIGN_FETCH_TYPE(u16, u16, 0),
 220         ASSIGN_FETCH_TYPE(u32, u32, 0),
 221         ASSIGN_FETCH_TYPE(u64, u64, 0),
 222         ASSIGN_FETCH_TYPE(s8,  u8,  1),
 223         ASSIGN_FETCH_TYPE(s16, u16, 1),
 224         ASSIGN_FETCH_TYPE(s32, u32, 1),
 225         ASSIGN_FETCH_TYPE(s64, u64, 1),
 226         ASSIGN_FETCH_TYPE_ALIAS(x8,  u8,  u8,  0),
 227         ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
 228         ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
 229         ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
 230
 231         ASSIGN_FETCH_TYPE_END
 232 };
 233
 234 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
 235 {
 236         rwlock_init(&filter->rwlock);
 237         filter->nr_systemwide = 0;
 238         INIT_LIST_HEAD(&filter->perf_events);
 239 }
 240
 241 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
 242 {
 243         return !filter->nr_systemwide && list_empty(&filter->perf_events);
 244 }
 245
 246 static inline bool is_ret_probe(struct trace_uprobe *tu)
 247 {
 248         return tu->consumer.ret_handler != NULL;
 249 }
 250
 251 /*
 252  * Allocate new trace_uprobe and initialize it (including uprobes).
 253  */
 254 static struct trace_uprobe *
 255 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 256 {
 257         struct trace_uprobe *tu;
 258
 259         if (!event || !is_good_name(event))
 260                 return ERR_PTR(-EINVAL);
 261
 262         if (!group || !is_good_name(group))
 263                 return ERR_PTR(-EINVAL);
 264
 265         tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
 266         if (!tu)
 267                 return ERR_PTR(-ENOMEM);
 268
 269         tu->tp.call.class = &tu->tp.class;
 270         tu->tp.call.name = kstrdup(event, GFP_KERNEL);
 271         if (!tu->tp.call.name)
 272                 goto error;
 273
 274         tu->tp.class.system = kstrdup(group, GFP_KERNEL);
 275         if (!tu->tp.class.system)
 276                 goto error;
 277
 278         INIT_LIST_HEAD(&tu->list);
 279         INIT_LIST_HEAD(&tu->tp.files);
 280         tu->consumer.handler = uprobe_dispatcher;
 281         if (is_ret)
 282                 tu->consumer.ret_handler = uretprobe_dispatcher;
 283         init_trace_uprobe_filter(&tu->filter);
 284         return tu;
 285
 286 error:
 287         kfree(tu->tp.call.name);
 288         kfree(tu);
 289
 290         return ERR_PTR(-ENOMEM);
 291 }
 292
 293 static void free_trace_uprobe(struct trace_uprobe *tu)
 294 {
 295         int i;
 296
 297         for (i = 0; i < tu->tp.nr_args; i++)
 298                 traceprobe_free_probe_arg(&tu->tp.args[i]);
 299
 300         path_put(&tu->path);
 301         kfree(tu->tp.call.class->system);
 302         kfree(tu->tp.call.name);
 303         kfree(tu->filename);
 304         kfree(tu);
 305 }
 306
 307 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
 308 {
 309         struct trace_uprobe *tu;
 310
 311         list_for_each_entry(tu, &uprobe_list, list)
 312                 if (strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
 313                     strcmp(tu->tp.call.class->system, group) == 0)
 314                         return tu;
 315
 316         return NULL;
 317 }
 318
 319 /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
 320 static int unregister_trace_uprobe(struct trace_uprobe *tu)
 321 {
 322         int ret;
 323
 324         ret = unregister_uprobe_event(tu);
 325         if (ret)
 326                 return ret;
 327
 328         list_del(&tu->list);
 329         free_trace_uprobe(tu);
 330         return 0;
 331 }
 332
 333 /* Register a trace_uprobe and probe_event */
 334 static int register_trace_uprobe(struct trace_uprobe *tu)
 335 {
 336         struct trace_uprobe *old_tu;
 337         int ret;
 338
 339         mutex_lock(&uprobe_lock);
 340
 341         /* register as an event */
 342         old_tu = find_probe_event(trace_event_name(&tu->tp.call),
 343                         tu->tp.call.class->system);
 344         if (old_tu) {
 345                 /* delete old event */
 346                 ret = unregister_trace_uprobe(old_tu);
 347                 if (ret)
 348                         goto end;
 349         }
 350
 351         ret = register_uprobe_event(tu);
 352         if (ret) {
 353                 pr_warn("Failed to register probe event(%d)\n", ret);
 354                 goto end;
 355         }
 356
 357         list_add_tail(&tu->list, &uprobe_list);
 358
 359 end:
 360         mutex_unlock(&uprobe_lock);
 361
 362         return ret;
 363 }
 364
 365 /*
 366  * Argument syntax:
 367  *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
 368  *
 369  *  - Remove uprobe: -:[GRP/]EVENT
 370  */
 371 static int create_trace_uprobe(int argc, char **argv)
 372 {
 373         struct trace_uprobe *tu;
 374         char *arg, *event, *group, *filename;
 375         char buf[MAX_EVENT_NAME_LEN];
 376         struct path path;
 377         unsigned long offset;
 378         bool is_delete, is_return;
 379         int i, ret;
 380
 381         ret = 0;
 382         is_delete = false;
 383         is_return = false;
 384         event = NULL;
 385         group = NULL;
 386
 387         /* argc must be >= 1 */
 388         if (argv[0][0] == '-')
 389                 is_delete = true;
 390         else if (argv[0][0] == 'r')
 391                 is_return = true;
 392         else if (argv[0][0] != 'p') {
 393                 pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
 394                 return -EINVAL;
 395         }
 396
 397         if (argv[0][1] == ':') {
 398                 event = &argv[0][2];
 399                 arg = strchr(event, '/');
 400
 401                 if (arg) {
 402                         group = event;
 403                         event = arg + 1;
 404                         event[-1] = '\0';
 405
 406                         if (strlen(group) == 0) {
 407                                 pr_info("Group name is not specified\n");
 408                                 return -EINVAL;
 409                         }
 410                 }
 411                 if (strlen(event) == 0) {
 412                         pr_info("Event name is not specified\n");
 413                         return -EINVAL;
 414                 }
 415         }
 416         if (!group)
 417                 group = UPROBE_EVENT_SYSTEM;
 418
 419         if (is_delete) {
 420                 int ret;
 421
 422                 if (!event) {
 423                         pr_info("Delete command needs an event name.\n");
 424                         return -EINVAL;
 425                 }
 426                 mutex_lock(&uprobe_lock);
 427                 tu = find_probe_event(event, group);
 428
 429                 if (!tu) {
 430                         mutex_unlock(&uprobe_lock);
 431                         pr_info("Event %s/%s doesn't exist.\n", group, event);
 432                         return -ENOENT;
 433                 }
 434                 /* delete an event */
 435                 ret = unregister_trace_uprobe(tu);
 436                 mutex_unlock(&uprobe_lock);
 437                 return ret;
 438         }
 439
 440         if (argc < 2) {
 441                 pr_info("Probe point is not specified.\n");
 442                 return -EINVAL;
 443         }
 444         /* Find the last occurrence, in case the path contains ':' too. */
 445         arg = strrchr(argv[1], ':');
 446         if (!arg)
 447                 return -EINVAL;
 448
 449         *arg++ = '\0';
 450         filename = argv[1];
 451         ret = kern_path(filename, LOOKUP_FOLLOW, &path);
 452         if (ret)
 453                 return ret;
 454
 455         if (!d_is_reg(path.dentry)) {
 456                 ret = -EINVAL;
 457                 goto fail_address_parse;
 458         }
 459
 460         ret = kstrtoul(arg, 0, &offset);
 461         if (ret)
 462                 goto fail_address_parse;
 463
 464         argc -= 2;
 465         argv += 2;
 466
 467         /* setup a probe */
 468         if (!event) {
 469                 char *tail;
 470                 char *ptr;
 471
 472                 tail = kstrdup(kbasename(filename), GFP_KERNEL);
 473                 if (!tail) {
 474                         ret = -ENOMEM;
 475                         goto fail_address_parse;
 476                 }
 477
 478                 ptr = strpbrk(tail, ".-_");
 479                 if (ptr)
 480                         *ptr = '\0';
 481
 482                 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
 483                 event = buf;
 484                 kfree(tail);
 485         }
 486
 487         tu = alloc_trace_uprobe(group, event, argc, is_return);
 488         if (IS_ERR(tu)) {
 489                 pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
 490                 ret = PTR_ERR(tu);
 491                 goto fail_address_parse;
 492         }
 493         tu->offset = offset;
 494         tu->path = path;
 495         tu->filename = kstrdup(filename, GFP_KERNEL);
 496
 497         if (!tu->filename) {
 498                 pr_info("Failed to allocate filename.\n");
 499                 ret = -ENOMEM;
 500                 goto error;
 501         }
 502
 503         /* parse arguments */
 504         ret = 0;
 505         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 506                 struct probe_arg *parg = &tu->tp.args[i];
 507
 508                 /* Increment count for freeing args in error case */
 509                 tu->tp.nr_args++;
 510
 511                 /* Parse argument name */
 512                 arg = strchr(argv[i], '=');
 513                 if (arg) {
 514                         *arg++ = '\0';
 515                         parg->name = kstrdup(argv[i], GFP_KERNEL);
 516                 } else {
 517                         arg = argv[i];
 518                         /* If argument name is omitted, set "argN" */
 519                         snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
 520                         parg->name = kstrdup(buf, GFP_KERNEL);
 521                 }
 522
 523                 if (!parg->name) {
 524                         pr_info("Failed to allocate argument[%d] name.\n", i);
 525                         ret = -ENOMEM;
 526                         goto error;
 527                 }
 528
 529                 if (!is_good_name(parg->name)) {
 530                         pr_info("Invalid argument[%d] name: %s\n", i, parg->name);
 531                         ret = -EINVAL;
 532                         goto error;
 533                 }
 534
 535                 if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) {
 536                         pr_info("Argument[%d] name '%s' conflicts with "
 537                                 "another field.\n", i, argv[i]);
 538                         ret = -EINVAL;
 539                         goto error;
 540                 }
 541
 542                 /* Parse fetch argument */
 543                 ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
 544                                                  is_return, false,
 545                                                  uprobes_fetch_type_table);
 546                 if (ret) {
 547                         pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
 548                         goto error;
 549                 }
 550         }
 551
 552         ret = register_trace_uprobe(tu);
 553         if (ret)
 554                 goto error;
 555         return 0;
 556
 557 error:
 558         free_trace_uprobe(tu);
 559         return ret;
 560
 561 fail_address_parse:
 562         path_put(&path);
 563
 564         pr_info("Failed to parse address or file.\n");
 565
 566         return ret;
 567 }
 568
 569 static int cleanup_all_probes(void)
 570 {
 571         struct trace_uprobe *tu;
 572         int ret = 0;
 573
 574         mutex_lock(&uprobe_lock);
 575         while (!list_empty(&uprobe_list)) {
 576                 tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
 577                 ret = unregister_trace_uprobe(tu);
 578                 if (ret)
 579                         break;
 580         }
 581         mutex_unlock(&uprobe_lock);
 582         return ret;
 583 }
 584
 585 /* Probes listing interfaces */
 586 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
 587 {
 588         mutex_lock(&uprobe_lock);
 589         return seq_list_start(&uprobe_list, *pos);
 590 }
 591
 592 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
 593 {
 594         return seq_list_next(v, &uprobe_list, pos);
 595 }
 596
 597 static void probes_seq_stop(struct seq_file *m, void *v)
 598 {
 599         mutex_unlock(&uprobe_lock);
 600 }
 601
 602 static int probes_seq_show(struct seq_file *m, void *v)
 603 {
 604         struct trace_uprobe *tu = v;
 605         char c = is_ret_probe(tu) ? 'r' : 'p';
 606         int i;
 607
 608         seq_printf(m, "%c:%s/%s", c, tu->tp.call.class->system,
 609                         trace_event_name(&tu->tp.call));
 610         seq_printf(m, " %s:", tu->filename);
 611
 612         /* Don't print "0x  (null)" when offset is 0 */
 613         if (tu->offset) {
 614                 seq_printf(m, "0x%p", (void *)tu->offset);
 615         } else {
 616                 switch (sizeof(void *)) {
 617                 case 4:
 618                         seq_printf(m, "0x00000000");
 619                         break;
 620                 case 8:
 621                 default:
 622                         seq_printf(m, "0x0000000000000000");
 623                         break;
 624                 }
 625         }
 626
 627         for (i = 0; i < tu->tp.nr_args; i++)
 628                 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
 629
 630         seq_putc(m, '\n');
 631         return 0;
 632 }
 633
 634 static const struct seq_operations probes_seq_op = {
 635         .start  = probes_seq_start,
 636         .next   = probes_seq_next,
 637         .stop   = probes_seq_stop,
 638         .show   = probes_seq_show
 639 };
 640
 641 static int probes_open(struct inode *inode, struct file *file)
 642 {
 643         int ret;
 644
 645         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 646                 ret = cleanup_all_probes();
 647                 if (ret)
 648                         return ret;
 649         }
 650
 651         return seq_open(file, &probes_seq_op);
 652 }
 653
 654 static ssize_t probes_write(struct file *file, const char __user *buffer,
 655                             size_t count, loff_t *ppos)
 656 {
 657         return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe);
 658 }
 659
 660 static const struct file_operations uprobe_events_ops = {
 661         .owner          = THIS_MODULE,
 662         .open           = probes_open,
 663         .read           = seq_read,
 664         .llseek         = seq_lseek,
 665         .release        = seq_release,
 666         .write          = probes_write,
 667 };
 668
 669 /* Probes profiling interfaces */
 670 static int probes_profile_seq_show(struct seq_file *m, void *v)
 671 {
 672         struct trace_uprobe *tu = v;
 673
 674         seq_printf(m, "  %s %-44s %15lu\n", tu->filename,
 675                         trace_event_name(&tu->tp.call), tu->nhit);
 676         return 0;
 677 }
 678
 679 static const struct seq_operations profile_seq_op = {
 680         .start  = probes_seq_start,
 681         .next   = probes_seq_next,
 682         .stop   = probes_seq_stop,
 683         .show   = probes_profile_seq_show
 684 };
 685
 686 static int profile_open(struct inode *inode, struct file *file)
 687 {
 688         return seq_open(file, &profile_seq_op);
 689 }
 690
 691 static const struct file_operations uprobe_profile_ops = {
 692         .owner          = THIS_MODULE,
 693         .open           = profile_open,
 694         .read           = seq_read,
 695         .llseek         = seq_lseek,
 696         .release        = seq_release,
 697 };
 698
 699 struct uprobe_cpu_buffer {
 700         struct mutex mutex;
 701         void *buf;
 702 };
 703 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
 704 static int uprobe_buffer_refcnt;
 705
 706 static int uprobe_buffer_init(void)
 707 {
 708         int cpu, err_cpu;
 709
 710         uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
 711         if (uprobe_cpu_buffer == NULL)
 712                 return -ENOMEM;
 713
 714         for_each_possible_cpu(cpu) {
 715                 struct page *p = alloc_pages_node(cpu_to_node(cpu),
 716                                                   GFP_KERNEL, 0);
 717                 if (p == NULL) {
 718                         err_cpu = cpu;
 719                         goto err;
 720                 }
 721                 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
 722                 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
 723         }
 724
 725         return 0;
 726
 727 err:
 728         for_each_possible_cpu(cpu) {
 729                 if (cpu == err_cpu)
 730                         break;
 731                 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
 732         }
 733
 734         free_percpu(uprobe_cpu_buffer);
 735         return -ENOMEM;
 736 }
 737
 738 static int uprobe_buffer_enable(void)
 739 {
 740         int ret = 0;
 741
 742         BUG_ON(!mutex_is_locked(&event_mutex));
 743
 744         if (uprobe_buffer_refcnt++ == 0) {
 745                 ret = uprobe_buffer_init();
 746                 if (ret < 0)
 747                         uprobe_buffer_refcnt--;
 748         }
 749
 750         return ret;
 751 }
 752
 753 static void uprobe_buffer_disable(void)
 754 {
 755         int cpu;
 756
 757         BUG_ON(!mutex_is_locked(&event_mutex));
 758
 759         if (--uprobe_buffer_refcnt == 0) {
 760                 for_each_possible_cpu(cpu)
 761                         free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
 762                                                              cpu)->buf);
 763
 764                 free_percpu(uprobe_cpu_buffer);
 765                 uprobe_cpu_buffer = NULL;
 766         }
 767 }
 768
 769 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
 770 {
 771         struct uprobe_cpu_buffer *ucb;
 772         int cpu;
 773
 774         cpu = raw_smp_processor_id();
 775         ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
 776
 777         /*
 778          * Use per-cpu buffers for fastest access, but we might migrate
 779          * so the mutex makes sure we have sole access to it.
 780          */
 781         mutex_lock(&ucb->mutex);
 782
 783         return ucb;
 784 }
 785
 786 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
 787 {
 788         mutex_unlock(&ucb->mutex);
 789 }
 790
 791 static void __uprobe_trace_func(struct trace_uprobe *tu,
 792                                 unsigned long func, struct pt_regs *regs,
 793                                 struct uprobe_cpu_buffer *ucb, int dsize,
 794                                 struct trace_event_file *trace_file)
 795 {
 796         struct uprobe_trace_entry_head *entry;
 797         struct ring_buffer_event *event;
 798         struct ring_buffer *buffer;
 799         void *data;
 800         int size, esize;
 801         struct trace_event_call *call = &tu->tp.call;
 802
 803         WARN_ON(call != trace_file->event_call);
 804
 805         if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
 806                 return;
 807
 808         if (trace_trigger_soft_disabled(trace_file))
 809                 return;
 810
 811         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 812         size = esize + tu->tp.size + dsize;
 813         event = trace_event_buffer_lock_reserve(&buffer, trace_file,
 814                                                 call->event.type, size, 0, 0);
 815         if (!event)
 816                 return;
 817
 818         entry = ring_buffer_event_data(event);
 819         if (is_ret_probe(tu)) {
 820                 entry->vaddr[0] = func;
 821                 entry->vaddr[1] = instruction_pointer(regs);
 822                 data = DATAOF_TRACE_ENTRY(entry, true);
 823         } else {
 824                 entry->vaddr[0] = instruction_pointer(regs);
 825                 data = DATAOF_TRACE_ENTRY(entry, false);
 826         }
 827
 828         memcpy(data, ucb->buf, tu->tp.size + dsize);
 829
 830         event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
 831 }
 832
 833 /* uprobe handler */
 834 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
 835                              struct uprobe_cpu_buffer *ucb, int dsize)
 836 {
 837         struct event_file_link *link;
 838
 839         if (is_ret_probe(tu))
 840                 return 0;
 841
 842         rcu_read_lock();
 843         list_for_each_entry_rcu(link, &tu->tp.files, list)
 844                 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
 845         rcu_read_unlock();
 846
 847         return 0;
 848 }
 849
 850 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
 851                                  struct pt_regs *regs,
 852                                  struct uprobe_cpu_buffer *ucb, int dsize)
 853 {
 854         struct event_file_link *link;
 855
 856         rcu_read_lock();
 857         list_for_each_entry_rcu(link, &tu->tp.files, list)
 858                 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
 859         rcu_read_unlock();
 860 }
 861
 862 /* Event entry printers */
 863 static enum print_line_t
 864 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
 865 {
 866         struct uprobe_trace_entry_head *entry;
 867         struct trace_seq *s = &iter->seq;
 868         struct trace_uprobe *tu;
 869         u8 *data;
 870         int i;
 871
 872         entry = (struct uprobe_trace_entry_head *)iter->ent;
 873         tu = container_of(event, struct trace_uprobe, tp.call.event);
 874
 875         if (is_ret_probe(tu)) {
 876                 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
 877                                  trace_event_name(&tu->tp.call),
 878                                  entry->vaddr[1], entry->vaddr[0]);
 879                 data = DATAOF_TRACE_ENTRY(entry, true);
 880         } else {
 881                 trace_seq_printf(s, "%s: (0x%lx)",
 882                                  trace_event_name(&tu->tp.call),
 883                                  entry->vaddr[0]);
 884                 data = DATAOF_TRACE_ENTRY(entry, false);
 885         }
 886
 887         for (i = 0; i < tu->tp.nr_args; i++) {
 888                 struct probe_arg *parg = &tu->tp.args[i];
 889
 890                 if (!parg->type->print(s, parg->name, data + parg->offset, entry))
 891                         goto out;
 892         }
 893
 894         trace_seq_putc(s, '\n');
 895
 896  out:
 897         return trace_handle_return(s);
 898 }
 899
 900 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
 901                                 enum uprobe_filter_ctx ctx,
 902                                 struct mm_struct *mm);
 903
 904 static int
 905 probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
 906                    filter_func_t filter)
 907 {
 908         bool enabled = trace_probe_is_enabled(&tu->tp);
 909         struct event_file_link *link = NULL;
 910         int ret;
 911
 912         if (file) {
 913                 if (tu->tp.flags & TP_FLAG_PROFILE)
 914                         return -EINTR;
 915
 916                 link = kmalloc(sizeof(*link), GFP_KERNEL);
 917                 if (!link)
 918                         return -ENOMEM;
 919
 920                 link->file = file;
 921                 list_add_tail_rcu(&link->list, &tu->tp.files);
 922
 923                 tu->tp.flags |= TP_FLAG_TRACE;
 924         } else {
 925                 if (tu->tp.flags & TP_FLAG_TRACE)
 926                         return -EINTR;
 927
 928                 tu->tp.flags |= TP_FLAG_PROFILE;
 929         }
 930
 931         WARN_ON(!uprobe_filter_is_empty(&tu->filter));
 932
 933         if (enabled)
 934                 return 0;
 935
 936         ret = uprobe_buffer_enable();
 937         if (ret)
 938                 goto err_flags;
 939
 940         tu->consumer.filter = filter;
 941         tu->inode = d_real_inode(tu->path.dentry);
 942         ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
 943         if (ret)
 944                 goto err_buffer;
 945
 946         return 0;
 947
 948  err_buffer:
 949         uprobe_buffer_disable();
 950
 951  err_flags:
 952         if (file) {
 953                 list_del(&link->list);
 954                 kfree(link);
 955                 tu->tp.flags &= ~TP_FLAG_TRACE;
 956         } else {
 957                 tu->tp.flags &= ~TP_FLAG_PROFILE;
 958         }
 959         return ret;
 960 }
 961
 962 static void
 963 probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
 964 {
 965         if (!trace_probe_is_enabled(&tu->tp))
 966                 return;
 967
 968         if (file) {
 969                 struct event_file_link *link;
 970
 971                 link = find_event_file_link(&tu->tp, file);
 972                 if (!link)
 973                         return;
 974
 975                 list_del_rcu(&link->list);
 976                 /* synchronize with u{,ret}probe_trace_func */
 977                 synchronize_rcu();
 978                 kfree(link);
 979
 980                 if (!list_empty(&tu->tp.files))
 981                         return;
 982         }
 983
 984         WARN_ON(!uprobe_filter_is_empty(&tu->filter));
 985
 986         uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
 987         tu->inode = NULL;
 988         tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
 989
 990         uprobe_buffer_disable();
 991 }
 992
 993 static int uprobe_event_define_fields(struct trace_event_call *event_call)
 994 {
 995         int ret, i, size;
 996         struct uprobe_trace_entry_head field;
 997         struct trace_uprobe *tu = event_call->data;
 998
 999         if (is_ret_probe(tu)) {
1000                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1001                 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1002                 size = SIZEOF_TRACE_ENTRY(true);
1003         } else {
1004                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1005                 size = SIZEOF_TRACE_ENTRY(false);
1006         }
1007         /* Set argument names as fields */
1008         for (i = 0; i < tu->tp.nr_args; i++) {
1009                 struct probe_arg *parg = &tu->tp.args[i];
1010
1011                 ret = trace_define_field(event_call, parg->type->fmttype,
1012                                          parg->name, size + parg->offset,
1013                                          parg->type->size, parg->type->is_signed,
1014                                          FILTER_OTHER);
1015
1016                 if (ret)
1017                         return ret;
1018         }
1019         return 0;
1020 }
1021
1022 #ifdef CONFIG_PERF_EVENTS
1023 static bool
1024 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1025 {
1026         struct perf_event *event;
1027
1028         if (filter->nr_systemwide)
1029                 return true;
1030
1031         list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1032                 if (event->hw.target->mm == mm)
1033                         return true;
1034         }
1035
1036         return false;
1037 }
1038
1039 static inline bool
1040 uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
1041 {
1042         return __uprobe_perf_filter(&tu->filter, event->hw.target->mm);
1043 }
1044
1045 static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
1046 {
1047         bool done;
1048
1049         write_lock(&tu->filter.rwlock);
1050         if (event->hw.target) {
1051                 list_del(&event->hw.tp_list);
1052                 done = tu->filter.nr_systemwide ||
1053                         (event->hw.target->flags & PF_EXITING) ||
1054                         uprobe_filter_event(tu, event);
1055         } else {
1056                 tu->filter.nr_systemwide--;
1057                 done = tu->filter.nr_systemwide;
1058         }
1059         write_unlock(&tu->filter.rwlock);
1060
1061         if (!done)
1062                 return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1063
1064         return 0;
1065 }
1066
1067 static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
1068 {
1069         bool done;
1070         int err;
1071
1072         write_lock(&tu->filter.rwlock);
1073         if (event->hw.target) {
1074                 /*
1075                  * event->parent != NULL means copy_process(), we can avoid
1076                  * uprobe_apply(). current->mm must be probed and we can rely
1077                  * on dup_mmap() which preserves the already installed bp's.
1078                  *
1079                  * attr.enable_on_exec means that exec/mmap will install the
1080                  * breakpoints we need.
1081                  */
1082                 done = tu->filter.nr_systemwide ||
1083                         event->parent || event->attr.enable_on_exec ||
1084                         uprobe_filter_event(tu, event);
1085                 list_add(&event->hw.tp_list, &tu->filter.perf_events);
1086         } else {
1087                 done = tu->filter.nr_systemwide;
1088                 tu->filter.nr_systemwide++;
1089         }
1090         write_unlock(&tu->filter.rwlock);
1091
1092         err = 0;
1093         if (!done) {
1094                 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1095                 if (err)
1096                         uprobe_perf_close(tu, event);
1097         }
1098         return err;
1099 }
1100
1101 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1102                                 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1103 {
1104         struct trace_uprobe *tu;
1105         int ret;
1106
1107         tu = container_of(uc, struct trace_uprobe, consumer);
1108         read_lock(&tu->filter.rwlock);
1109         ret = __uprobe_perf_filter(&tu->filter, mm);
1110         read_unlock(&tu->filter.rwlock);
1111
1112         return ret;
1113 }
1114
1115 static void __uprobe_perf_func(struct trace_uprobe *tu,
1116                                unsigned long func, struct pt_regs *regs,
1117                                struct uprobe_cpu_buffer *ucb, int dsize)
1118 {
1119         struct trace_event_call *call = &tu->tp.call;
1120         struct uprobe_trace_entry_head *entry;
1121         struct bpf_prog *prog = call->prog;
1122         struct hlist_head *head;
1123         void *data;
1124         int size, esize;
1125         int rctx;
1126
1127         if (prog && !trace_call_bpf(prog, regs))
1128                 return;
1129
1130         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1131
1132         size = esize + tu->tp.size + dsize;
1133         size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1134         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1135                 return;
1136
1137         preempt_disable();
1138         head = this_cpu_ptr(call->perf_events);
1139         if (hlist_empty(head))
1140                 goto out;
1141
1142         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1143         if (!entry)
1144                 goto out;
1145
1146         if (is_ret_probe(tu)) {
1147                 entry->vaddr[0] = func;
1148                 entry->vaddr[1] = instruction_pointer(regs);
1149                 data = DATAOF_TRACE_ENTRY(entry, true);
1150         } else {
1151                 entry->vaddr[0] = instruction_pointer(regs);
1152                 data = DATAOF_TRACE_ENTRY(entry, false);
1153         }
1154
1155         memcpy(data, ucb->buf, tu->tp.size + dsize);
1156
1157         if (size - esize > tu->tp.size + dsize) {
1158                 int len = tu->tp.size + dsize;
1159
1160                 memset(data + len, 0, size - esize - len);
1161         }
1162
1163         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1164                               head, NULL, NULL);
1165  out:
1166         preempt_enable();
1167 }
1168
1169 /* uprobe profile handler */
1170 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1171                             struct uprobe_cpu_buffer *ucb, int dsize)
1172 {
1173         if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1174                 return UPROBE_HANDLER_REMOVE;
1175
1176         if (!is_ret_probe(tu))
1177                 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1178         return 0;
1179 }
1180
1181 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1182                                 struct pt_regs *regs,
1183                                 struct uprobe_cpu_buffer *ucb, int dsize)
1184 {
1185         __uprobe_perf_func(tu, func, regs, ucb, dsize);
1186 }
1187 #endif  /* CONFIG_PERF_EVENTS */
1188
1189 static int
1190 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1191                       void *data)
1192 {
1193         struct trace_uprobe *tu = event->data;
1194         struct trace_event_file *file = data;
1195
1196         switch (type) {
1197         case TRACE_REG_REGISTER:
1198                 return probe_event_enable(tu, file, NULL);
1199
1200         case TRACE_REG_UNREGISTER:
1201                 probe_event_disable(tu, file);
1202                 return 0;
1203
1204 #ifdef CONFIG_PERF_EVENTS
1205         case TRACE_REG_PERF_REGISTER:
1206                 return probe_event_enable(tu, NULL, uprobe_perf_filter);
1207
1208         case TRACE_REG_PERF_UNREGISTER:
1209                 probe_event_disable(tu, NULL);
1210                 return 0;
1211
1212         case TRACE_REG_PERF_OPEN:
1213                 return uprobe_perf_open(tu, data);
1214
1215         case TRACE_REG_PERF_CLOSE:
1216                 return uprobe_perf_close(tu, data);
1217
1218 #endif
1219         default:
1220                 return 0;
1221         }
1222         return 0;
1223 }
1224
1225 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1226 {
1227         struct trace_uprobe *tu;
1228         struct uprobe_dispatch_data udd;
1229         struct uprobe_cpu_buffer *ucb;
1230         int dsize, esize;
1231         int ret = 0;
1232
1233
1234         tu = container_of(con, struct trace_uprobe, consumer);
1235         tu->nhit++;
1236
1237         udd.tu = tu;
1238         udd.bp_addr = instruction_pointer(regs);
1239
1240         current->utask->vaddr = (unsigned long) &udd;
1241
1242         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1243                 return 0;
1244
1245         dsize = __get_data_size(&tu->tp, regs);
1246         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1247
1248         ucb = uprobe_buffer_get();
1249         store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
1250
1251         if (tu->tp.flags & TP_FLAG_TRACE)
1252                 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1253
1254 #ifdef CONFIG_PERF_EVENTS
1255         if (tu->tp.flags & TP_FLAG_PROFILE)
1256                 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1257 #endif
1258         uprobe_buffer_put(ucb);
1259         return ret;
1260 }
1261
1262 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1263                                 unsigned long func, struct pt_regs *regs)
1264 {
1265         struct trace_uprobe *tu;
1266         struct uprobe_dispatch_data udd;
1267         struct uprobe_cpu_buffer *ucb;
1268         int dsize, esize;
1269
1270         tu = container_of(con, struct trace_uprobe, consumer);
1271
1272         udd.tu = tu;
1273         udd.bp_addr = func;
1274
1275         current->utask->vaddr = (unsigned long) &udd;
1276
1277         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1278                 return 0;
1279
1280         dsize = __get_data_size(&tu->tp, regs);
1281         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1282
1283         ucb = uprobe_buffer_get();
1284         store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
1285
1286         if (tu->tp.flags & TP_FLAG_TRACE)
1287                 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1288
1289 #ifdef CONFIG_PERF_EVENTS
1290         if (tu->tp.flags & TP_FLAG_PROFILE)
1291                 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1292 #endif
1293         uprobe_buffer_put(ucb);
1294         return 0;
1295 }
1296
1297 static struct trace_event_functions uprobe_funcs = {
1298         .trace          = print_uprobe_event
1299 };
1300
1301 static int register_uprobe_event(struct trace_uprobe *tu)
1302 {
1303         struct trace_event_call *call = &tu->tp.call;
1304         int ret;
1305
1306         /* Initialize trace_event_call */
1307         INIT_LIST_HEAD(&call->class->fields);
1308         call->event.funcs = &uprobe_funcs;
1309         call->class->define_fields = uprobe_event_define_fields;
1310
1311         if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
1312                 return -ENOMEM;
1313
1314         ret = register_trace_event(&call->event);
1315         if (!ret) {
1316                 kfree(call->print_fmt);
1317                 return -ENODEV;
1318         }
1319
1320         call->flags = TRACE_EVENT_FL_UPROBE;
1321         call->class->reg = trace_uprobe_register;
1322         call->data = tu;
1323         ret = trace_add_event_call(call);
1324
1325         if (ret) {
1326                 pr_info("Failed to register uprobe event: %s\n",
1327                         trace_event_name(call));
1328                 kfree(call->print_fmt);
1329                 unregister_trace_event(&call->event);
1330         }
1331
1332         return ret;
1333 }
1334
1335 static int unregister_uprobe_event(struct trace_uprobe *tu)
1336 {
1337         int ret;
1338
1339         /* tu->event is unregistered in trace_remove_event_call() */
1340         ret = trace_remove_event_call(&tu->tp.call);
1341         if (ret)
1342                 return ret;
1343         kfree(tu->tp.call.print_fmt);
1344         tu->tp.call.print_fmt = NULL;
1345         return 0;
1346 }
1347
1348 /* Make a trace interface for controling probe points */
1349 static __init int init_uprobe_trace(void)
1350 {
1351         struct dentry *d_tracer;
1352
1353         d_tracer = tracing_init_dentry();
1354         if (IS_ERR(d_tracer))
1355                 return 0;
1356
1357         trace_create_file("uprobe_events", 0644, d_tracer,
1358                                     NULL, &uprobe_events_ops);
1359         /* Profile interface */
1360         trace_create_file("uprobe_profile", 0444, d_tracer,
1361                                     NULL, &uprobe_profile_ops);
1362         return 0;
1363 }
1364
1365 fs_initcall(init_uprobe_trace);