kernel/trace/trace_uprobe.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * uprobes-based tracing events
   4  *
   5  * Copyright (C) IBM Corporation, 2010-2012
   6  * Author:      Srikar Dronamraju <srikar@linux.vnet.ibm.com>
   7  */
   8 #define pr_fmt(fmt)     "trace_uprobe: " fmt
   9
  10 #include <linux/ctype.h>
  11 #include <linux/module.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/uprobes.h>
  14 #include <linux/namei.h>
  15 #include <linux/string.h>
  16 #include <linux/rculist.h>
  17
  18 #include "trace_dynevent.h"
  19 #include "trace_probe.h"
  20 #include "trace_probe_tmpl.h"
  21
  22 #define UPROBE_EVENT_SYSTEM     "uprobes"
  23
  24 struct uprobe_trace_entry_head {
  25         struct trace_entry      ent;
  26         unsigned long           vaddr[];
  27 };
  28
  29 #define SIZEOF_TRACE_ENTRY(is_return)                   \
  30         (sizeof(struct uprobe_trace_entry_head) +       \
  31          sizeof(unsigned long) * (is_return ? 2 : 1))
  32
  33 #define DATAOF_TRACE_ENTRY(entry, is_return)            \
  34         ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
  35
  36 struct trace_uprobe_filter {
  37         rwlock_t                rwlock;
  38         int                     nr_systemwide;
  39         struct list_head        perf_events;
  40 };
  41
  42 static int trace_uprobe_create(int argc, const char **argv);
  43 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
  44 static int trace_uprobe_release(struct dyn_event *ev);
  45 static bool trace_uprobe_is_busy(struct dyn_event *ev);
  46 static bool trace_uprobe_match(const char *system, const char *event,
  47                                struct dyn_event *ev);
  48
  49 static struct dyn_event_operations trace_uprobe_ops = {
  50         .create = trace_uprobe_create,
  51         .show = trace_uprobe_show,
  52         .is_busy = trace_uprobe_is_busy,
  53         .free = trace_uprobe_release,
  54         .match = trace_uprobe_match,
  55 };
  56
  57 /*
  58  * uprobe event core functions
  59  */
  60 struct trace_uprobe {
  61         struct dyn_event                devent;
  62         struct trace_uprobe_filter      filter;
  63         struct uprobe_consumer          consumer;
  64         struct path                     path;
  65         struct inode                    *inode;
  66         char                            *filename;
  67         unsigned long                   offset;
  68         unsigned long                   ref_ctr_offset;
  69         unsigned long                   nhit;
  70         struct trace_probe              tp;
  71 };
  72
  73 static bool is_trace_uprobe(struct dyn_event *ev)
  74 {
  75         return ev->ops == &trace_uprobe_ops;
  76 }
  77
  78 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
  79 {
  80         return container_of(ev, struct trace_uprobe, devent);
  81 }
  82
  83 /**
  84  * for_each_trace_uprobe - iterate over the trace_uprobe list
  85  * @pos:        the struct trace_uprobe * for each entry
  86  * @dpos:       the struct dyn_event * to use as a loop cursor
  87  */
  88 #define for_each_trace_uprobe(pos, dpos)        \
  89         for_each_dyn_event(dpos)                \
  90                 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
  91
  92 #define SIZEOF_TRACE_UPROBE(n)                          \
  93         (offsetof(struct trace_uprobe, tp.args) +       \
  94         (sizeof(struct probe_arg) * (n)))
  95
  96 static int register_uprobe_event(struct trace_uprobe *tu);
  97 static int unregister_uprobe_event(struct trace_uprobe *tu);
  98
  99 struct uprobe_dispatch_data {
 100         struct trace_uprobe     *tu;
 101         unsigned long           bp_addr;
 102 };
 103
 104 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
 105 static int uretprobe_dispatcher(struct uprobe_consumer *con,
 106                                 unsigned long func, struct pt_regs *regs);
 107
 108 #ifdef CONFIG_STACK_GROWSUP
 109 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 110 {
 111         return addr - (n * sizeof(long));
 112 }
 113 #else
 114 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 115 {
 116         return addr + (n * sizeof(long));
 117 }
 118 #endif
 119
 120 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
 121 {
 122         unsigned long ret;
 123         unsigned long addr = user_stack_pointer(regs);
 124
 125         addr = adjust_stack_addr(addr, n);
 126
 127         if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
 128                 return 0;
 129
 130         return ret;
 131 }
 132
 133 /*
 134  * Uprobes-specific fetch functions
 135  */
 136 static nokprobe_inline int
 137 probe_mem_read(void *dest, void *src, size_t size)
 138 {
 139         void __user *vaddr = (void __force __user *)src;
 140
 141         return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
 142 }
 143
 144 static nokprobe_inline int
 145 probe_mem_read_user(void *dest, void *src, size_t size)
 146 {
 147         return probe_mem_read(dest, src, size);
 148 }
 149
 150 /*
 151  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
 152  * length and relative data location.
 153  */
 154 static nokprobe_inline int
 155 fetch_store_string(unsigned long addr, void *dest, void *base)
 156 {
 157         long ret;
 158         u32 loc = *(u32 *)dest;
 159         int maxlen  = get_loc_len(loc);
 160         u8 *dst = get_loc_data(dest, base);
 161         void __user *src = (void __force __user *) addr;
 162
 163         if (unlikely(!maxlen))
 164                 return -ENOMEM;
 165
 166         if (addr == FETCH_TOKEN_COMM)
 167                 ret = strlcpy(dst, current->comm, maxlen);
 168         else
 169                 ret = strncpy_from_user(dst, src, maxlen);
 170         if (ret >= 0) {
 171                 if (ret == maxlen)
 172                         dst[ret - 1] = '\0';
 173                 else
 174                         /*
 175                          * Include the terminating null byte. In this case it
 176                          * was copied by strncpy_from_user but not accounted
 177                          * for in ret.
 178                          */
 179                         ret++;
 180                 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
 181         }
 182
 183         return ret;
 184 }
 185
 186 static nokprobe_inline int
 187 fetch_store_string_user(unsigned long addr, void *dest, void *base)
 188 {
 189         return fetch_store_string(addr, dest, base);
 190 }
 191
 192 /* Return the length of string -- including null terminal byte */
 193 static nokprobe_inline int
 194 fetch_store_strlen(unsigned long addr)
 195 {
 196         int len;
 197         void __user *vaddr = (void __force __user *) addr;
 198
 199         if (addr == FETCH_TOKEN_COMM)
 200                 len = strlen(current->comm) + 1;
 201         else
 202                 len = strnlen_user(vaddr, MAX_STRING_SIZE);
 203
 204         return (len > MAX_STRING_SIZE) ? 0 : len;
 205 }
 206
 207 static nokprobe_inline int
 208 fetch_store_strlen_user(unsigned long addr)
 209 {
 210         return fetch_store_strlen(addr);
 211 }
 212
 213 static unsigned long translate_user_vaddr(unsigned long file_offset)
 214 {
 215         unsigned long base_addr;
 216         struct uprobe_dispatch_data *udd;
 217
 218         udd = (void *) current->utask->vaddr;
 219
 220         base_addr = udd->bp_addr - udd->tu->offset;
 221         return base_addr + file_offset;
 222 }
 223
 224 /* Note that we don't verify it, since the code does not come from user space */
 225 static int
 226 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 227                    void *base)
 228 {
 229         unsigned long val;
 230
 231         /* 1st stage: get value from context */
 232         switch (code->op) {
 233         case FETCH_OP_REG:
 234                 val = regs_get_register(regs, code->param);
 235                 break;
 236         case FETCH_OP_STACK:
 237                 val = get_user_stack_nth(regs, code->param);
 238                 break;
 239         case FETCH_OP_STACKP:
 240                 val = user_stack_pointer(regs);
 241                 break;
 242         case FETCH_OP_RETVAL:
 243                 val = regs_return_value(regs);
 244                 break;
 245         case FETCH_OP_IMM:
 246                 val = code->immediate;
 247                 break;
 248         case FETCH_OP_COMM:
 249                 val = FETCH_TOKEN_COMM;
 250                 break;
 251         case FETCH_OP_FOFFS:
 252                 val = translate_user_vaddr(code->immediate);
 253                 break;
 254         default:
 255                 return -EILSEQ;
 256         }
 257         code++;
 258
 259         return process_fetch_insn_bottom(code, val, dest, base);
 260 }
 261 NOKPROBE_SYMBOL(process_fetch_insn)
 262
 263 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
 264 {
 265         rwlock_init(&filter->rwlock);
 266         filter->nr_systemwide = 0;
 267         INIT_LIST_HEAD(&filter->perf_events);
 268 }
 269
 270 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
 271 {
 272         return !filter->nr_systemwide && list_empty(&filter->perf_events);
 273 }
 274
 275 static inline bool is_ret_probe(struct trace_uprobe *tu)
 276 {
 277         return tu->consumer.ret_handler != NULL;
 278 }
 279
 280 static bool trace_uprobe_is_busy(struct dyn_event *ev)
 281 {
 282         struct trace_uprobe *tu = to_trace_uprobe(ev);
 283
 284         return trace_probe_is_enabled(&tu->tp);
 285 }
 286
 287 static bool trace_uprobe_match(const char *system, const char *event,
 288                                struct dyn_event *ev)
 289 {
 290         struct trace_uprobe *tu = to_trace_uprobe(ev);
 291
 292         return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 293             (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0);
 294 }
 295
 296 /*
 297  * Allocate new trace_uprobe and initialize it (including uprobes).
 298  */
 299 static struct trace_uprobe *
 300 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 301 {
 302         struct trace_uprobe *tu;
 303         int ret;
 304
 305         tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
 306         if (!tu)
 307                 return ERR_PTR(-ENOMEM);
 308
 309         ret = trace_probe_init(&tu->tp, event, group);
 310         if (ret < 0)
 311                 goto error;
 312
 313         dyn_event_init(&tu->devent, &trace_uprobe_ops);
 314         tu->consumer.handler = uprobe_dispatcher;
 315         if (is_ret)
 316                 tu->consumer.ret_handler = uretprobe_dispatcher;
 317         init_trace_uprobe_filter(&tu->filter);
 318         return tu;
 319
 320 error:
 321         kfree(tu);
 322
 323         return ERR_PTR(ret);
 324 }
 325
 326 static void free_trace_uprobe(struct trace_uprobe *tu)
 327 {
 328         if (!tu)
 329                 return;
 330
 331         path_put(&tu->path);
 332         trace_probe_cleanup(&tu->tp);
 333         kfree(tu->filename);
 334         kfree(tu);
 335 }
 336
 337 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
 338 {
 339         struct dyn_event *pos;
 340         struct trace_uprobe *tu;
 341
 342         for_each_trace_uprobe(tu, pos)
 343                 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 344                     strcmp(trace_probe_group_name(&tu->tp), group) == 0)
 345                         return tu;
 346
 347         return NULL;
 348 }
 349
 350 /* Unregister a trace_uprobe and probe_event */
 351 static int unregister_trace_uprobe(struct trace_uprobe *tu)
 352 {
 353         int ret;
 354
 355         ret = unregister_uprobe_event(tu);
 356         if (ret)
 357                 return ret;
 358
 359         dyn_event_remove(&tu->devent);
 360         free_trace_uprobe(tu);
 361         return 0;
 362 }
 363
 364 /*
 365  * Uprobe with multiple reference counter is not allowed. i.e.
 366  * If inode and offset matches, reference counter offset *must*
 367  * match as well. Though, there is one exception: If user is
 368  * replacing old trace_uprobe with new one(same group/event),
 369  * then we allow same uprobe with new reference counter as far
 370  * as the new one does not conflict with any other existing
 371  * ones.
 372  */
 373 static struct trace_uprobe *find_old_trace_uprobe(struct trace_uprobe *new)
 374 {
 375         struct dyn_event *pos;
 376         struct trace_uprobe *tmp, *old = NULL;
 377         struct inode *new_inode = d_real_inode(new->path.dentry);
 378
 379         old = find_probe_event(trace_probe_name(&new->tp),
 380                                 trace_probe_group_name(&new->tp));
 381
 382         for_each_trace_uprobe(tmp, pos) {
 383                 if ((old ? old != tmp : true) &&
 384                     new_inode == d_real_inode(tmp->path.dentry) &&
 385                     new->offset == tmp->offset &&
 386                     new->ref_ctr_offset != tmp->ref_ctr_offset) {
 387                         pr_warn("Reference counter offset mismatch.");
 388                         return ERR_PTR(-EINVAL);
 389                 }
 390         }
 391         return old;
 392 }
 393
 394 /* Register a trace_uprobe and probe_event */
 395 static int register_trace_uprobe(struct trace_uprobe *tu)
 396 {
 397         struct trace_uprobe *old_tu;
 398         int ret;
 399
 400         mutex_lock(&event_mutex);
 401
 402         /* register as an event */
 403         old_tu = find_old_trace_uprobe(tu);
 404         if (IS_ERR(old_tu)) {
 405                 ret = PTR_ERR(old_tu);
 406                 goto end;
 407         }
 408
 409         if (old_tu) {
 410                 /* delete old event */
 411                 ret = unregister_trace_uprobe(old_tu);
 412                 if (ret)
 413                         goto end;
 414         }
 415
 416         ret = register_uprobe_event(tu);
 417         if (ret) {
 418                 pr_warn("Failed to register probe event(%d)\n", ret);
 419                 goto end;
 420         }
 421
 422         dyn_event_add(&tu->devent);
 423
 424 end:
 425         mutex_unlock(&event_mutex);
 426
 427         return ret;
 428 }
 429
 430 /*
 431  * Argument syntax:
 432  *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
 433  */
 434 static int trace_uprobe_create(int argc, const char **argv)
 435 {
 436         struct trace_uprobe *tu;
 437         const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
 438         char *arg, *filename, *rctr, *rctr_end, *tmp;
 439         char buf[MAX_EVENT_NAME_LEN];
 440         struct path path;
 441         unsigned long offset, ref_ctr_offset;
 442         bool is_return = false;
 443         int i, ret;
 444
 445         ret = 0;
 446         ref_ctr_offset = 0;
 447
 448         switch (argv[0][0]) {
 449         case 'r':
 450                 is_return = true;
 451                 break;
 452         case 'p':
 453                 break;
 454         default:
 455                 return -ECANCELED;
 456         }
 457
 458         if (argc < 2)
 459                 return -ECANCELED;
 460
 461         if (argv[0][1] == ':')
 462                 event = &argv[0][2];
 463
 464         if (!strchr(argv[1], '/'))
 465                 return -ECANCELED;
 466
 467         filename = kstrdup(argv[1], GFP_KERNEL);
 468         if (!filename)
 469                 return -ENOMEM;
 470
 471         /* Find the last occurrence, in case the path contains ':' too. */
 472         arg = strrchr(filename, ':');
 473         if (!arg || !isdigit(arg[1])) {
 474                 kfree(filename);
 475                 return -ECANCELED;
 476         }
 477
 478         trace_probe_log_init("trace_uprobe", argc, argv);
 479         trace_probe_log_set_index(1);   /* filename is the 2nd argument */
 480
 481         *arg++ = '\0';
 482         ret = kern_path(filename, LOOKUP_FOLLOW, &path);
 483         if (ret) {
 484                 trace_probe_log_err(0, FILE_NOT_FOUND);
 485                 kfree(filename);
 486                 trace_probe_log_clear();
 487                 return ret;
 488         }
 489         if (!d_is_reg(path.dentry)) {
 490                 trace_probe_log_err(0, NO_REGULAR_FILE);
 491                 ret = -EINVAL;
 492                 goto fail_address_parse;
 493         }
 494
 495         /* Parse reference counter offset if specified. */
 496         rctr = strchr(arg, '(');
 497         if (rctr) {
 498                 rctr_end = strchr(rctr, ')');
 499                 if (!rctr_end) {
 500                         ret = -EINVAL;
 501                         rctr_end = rctr + strlen(rctr);
 502                         trace_probe_log_err(rctr_end - filename,
 503                                             REFCNT_OPEN_BRACE);
 504                         goto fail_address_parse;
 505                 } else if (rctr_end[1] != '\0') {
 506                         ret = -EINVAL;
 507                         trace_probe_log_err(rctr_end + 1 - filename,
 508                                             BAD_REFCNT_SUFFIX);
 509                         goto fail_address_parse;
 510                 }
 511
 512                 *rctr++ = '\0';
 513                 *rctr_end = '\0';
 514                 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
 515                 if (ret) {
 516                         trace_probe_log_err(rctr - filename, BAD_REFCNT);
 517                         goto fail_address_parse;
 518                 }
 519         }
 520
 521         /* Parse uprobe offset. */
 522         ret = kstrtoul(arg, 0, &offset);
 523         if (ret) {
 524                 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
 525                 goto fail_address_parse;
 526         }
 527
 528         /* setup a probe */
 529         trace_probe_log_set_index(0);
 530         if (event) {
 531                 ret = traceprobe_parse_event_name(&event, &group, buf,
 532                                                   event - argv[0]);
 533                 if (ret)
 534                         goto fail_address_parse;
 535         } else {
 536                 char *tail;
 537                 char *ptr;
 538
 539                 tail = kstrdup(kbasename(filename), GFP_KERNEL);
 540                 if (!tail) {
 541                         ret = -ENOMEM;
 542                         goto fail_address_parse;
 543                 }
 544
 545                 ptr = strpbrk(tail, ".-_");
 546                 if (ptr)
 547                         *ptr = '\0';
 548
 549                 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
 550                 event = buf;
 551                 kfree(tail);
 552         }
 553
 554         argc -= 2;
 555         argv += 2;
 556
 557         tu = alloc_trace_uprobe(group, event, argc, is_return);
 558         if (IS_ERR(tu)) {
 559                 ret = PTR_ERR(tu);
 560                 /* This must return -ENOMEM otherwise there is a bug */
 561                 WARN_ON_ONCE(ret != -ENOMEM);
 562                 goto fail_address_parse;
 563         }
 564         tu->offset = offset;
 565         tu->ref_ctr_offset = ref_ctr_offset;
 566         tu->path = path;
 567         tu->filename = filename;
 568
 569         /* parse arguments */
 570         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 571                 tmp = kstrdup(argv[i], GFP_KERNEL);
 572                 if (!tmp) {
 573                         ret = -ENOMEM;
 574                         goto error;
 575                 }
 576
 577                 trace_probe_log_set_index(i + 2);
 578                 ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
 579                                         is_return ? TPARG_FL_RETURN : 0);
 580                 kfree(tmp);
 581                 if (ret)
 582                         goto error;
 583         }
 584
 585         ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu));
 586         if (ret < 0)
 587                 goto error;
 588
 589         ret = register_trace_uprobe(tu);
 590         if (!ret)
 591                 goto out;
 592
 593 error:
 594         free_trace_uprobe(tu);
 595 out:
 596         trace_probe_log_clear();
 597         return ret;
 598
 599 fail_address_parse:
 600         trace_probe_log_clear();
 601         path_put(&path);
 602         kfree(filename);
 603
 604         return ret;
 605 }
 606
 607 static int create_or_delete_trace_uprobe(int argc, char **argv)
 608 {
 609         int ret;
 610
 611         if (argv[0][0] == '-')
 612                 return dyn_event_release(argc, argv, &trace_uprobe_ops);
 613
 614         ret = trace_uprobe_create(argc, (const char **)argv);
 615         return ret == -ECANCELED ? -EINVAL : ret;
 616 }
 617
 618 static int trace_uprobe_release(struct dyn_event *ev)
 619 {
 620         struct trace_uprobe *tu = to_trace_uprobe(ev);
 621
 622         return unregister_trace_uprobe(tu);
 623 }
 624
 625 /* Probes listing interfaces */
 626 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
 627 {
 628         struct trace_uprobe *tu = to_trace_uprobe(ev);
 629         char c = is_ret_probe(tu) ? 'r' : 'p';
 630         int i;
 631
 632         seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
 633                         trace_probe_name(&tu->tp), tu->filename,
 634                         (int)(sizeof(void *) * 2), tu->offset);
 635
 636         if (tu->ref_ctr_offset)
 637                 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
 638
 639         for (i = 0; i < tu->tp.nr_args; i++)
 640                 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
 641
 642         seq_putc(m, '\n');
 643         return 0;
 644 }
 645
 646 static int probes_seq_show(struct seq_file *m, void *v)
 647 {
 648         struct dyn_event *ev = v;
 649
 650         if (!is_trace_uprobe(ev))
 651                 return 0;
 652
 653         return trace_uprobe_show(m, ev);
 654 }
 655
 656 static const struct seq_operations probes_seq_op = {
 657         .start  = dyn_event_seq_start,
 658         .next   = dyn_event_seq_next,
 659         .stop   = dyn_event_seq_stop,
 660         .show   = probes_seq_show
 661 };
 662
 663 static int probes_open(struct inode *inode, struct file *file)
 664 {
 665         int ret;
 666
 667         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 668                 ret = dyn_events_release_all(&trace_uprobe_ops);
 669                 if (ret)
 670                         return ret;
 671         }
 672
 673         return seq_open(file, &probes_seq_op);
 674 }
 675
 676 static ssize_t probes_write(struct file *file, const char __user *buffer,
 677                             size_t count, loff_t *ppos)
 678 {
 679         return trace_parse_run_command(file, buffer, count, ppos,
 680                                         create_or_delete_trace_uprobe);
 681 }
 682
 683 static const struct file_operations uprobe_events_ops = {
 684         .owner          = THIS_MODULE,
 685         .open           = probes_open,
 686         .read           = seq_read,
 687         .llseek         = seq_lseek,
 688         .release        = seq_release,
 689         .write          = probes_write,
 690 };
 691
 692 /* Probes profiling interfaces */
 693 static int probes_profile_seq_show(struct seq_file *m, void *v)
 694 {
 695         struct dyn_event *ev = v;
 696         struct trace_uprobe *tu;
 697
 698         if (!is_trace_uprobe(ev))
 699                 return 0;
 700
 701         tu = to_trace_uprobe(ev);
 702         seq_printf(m, "  %s %-44s %15lu\n", tu->filename,
 703                         trace_probe_name(&tu->tp), tu->nhit);
 704         return 0;
 705 }
 706
 707 static const struct seq_operations profile_seq_op = {
 708         .start  = dyn_event_seq_start,
 709         .next   = dyn_event_seq_next,
 710         .stop   = dyn_event_seq_stop,
 711         .show   = probes_profile_seq_show
 712 };
 713
 714 static int profile_open(struct inode *inode, struct file *file)
 715 {
 716         return seq_open(file, &profile_seq_op);
 717 }
 718
 719 static const struct file_operations uprobe_profile_ops = {
 720         .owner          = THIS_MODULE,
 721         .open           = profile_open,
 722         .read           = seq_read,
 723         .llseek         = seq_lseek,
 724         .release        = seq_release,
 725 };
 726
 727 struct uprobe_cpu_buffer {
 728         struct mutex mutex;
 729         void *buf;
 730 };
 731 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
 732 static int uprobe_buffer_refcnt;
 733
 734 static int uprobe_buffer_init(void)
 735 {
 736         int cpu, err_cpu;
 737
 738         uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
 739         if (uprobe_cpu_buffer == NULL)
 740                 return -ENOMEM;
 741
 742         for_each_possible_cpu(cpu) {
 743                 struct page *p = alloc_pages_node(cpu_to_node(cpu),
 744                                                   GFP_KERNEL, 0);
 745                 if (p == NULL) {
 746                         err_cpu = cpu;
 747                         goto err;
 748                 }
 749                 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
 750                 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
 751         }
 752
 753         return 0;
 754
 755 err:
 756         for_each_possible_cpu(cpu) {
 757                 if (cpu == err_cpu)
 758                         break;
 759                 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
 760         }
 761
 762         free_percpu(uprobe_cpu_buffer);
 763         return -ENOMEM;
 764 }
 765
 766 static int uprobe_buffer_enable(void)
 767 {
 768         int ret = 0;
 769
 770         BUG_ON(!mutex_is_locked(&event_mutex));
 771
 772         if (uprobe_buffer_refcnt++ == 0) {
 773                 ret = uprobe_buffer_init();
 774                 if (ret < 0)
 775                         uprobe_buffer_refcnt--;
 776         }
 777
 778         return ret;
 779 }
 780
 781 static void uprobe_buffer_disable(void)
 782 {
 783         int cpu;
 784
 785         BUG_ON(!mutex_is_locked(&event_mutex));
 786
 787         if (--uprobe_buffer_refcnt == 0) {
 788                 for_each_possible_cpu(cpu)
 789                         free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
 790                                                              cpu)->buf);
 791
 792                 free_percpu(uprobe_cpu_buffer);
 793                 uprobe_cpu_buffer = NULL;
 794         }
 795 }
 796
 797 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
 798 {
 799         struct uprobe_cpu_buffer *ucb;
 800         int cpu;
 801
 802         cpu = raw_smp_processor_id();
 803         ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
 804
 805         /*
 806          * Use per-cpu buffers for fastest access, but we might migrate
 807          * so the mutex makes sure we have sole access to it.
 808          */
 809         mutex_lock(&ucb->mutex);
 810
 811         return ucb;
 812 }
 813
 814 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
 815 {
 816         mutex_unlock(&ucb->mutex);
 817 }
 818
 819 static void __uprobe_trace_func(struct trace_uprobe *tu,
 820                                 unsigned long func, struct pt_regs *regs,
 821                                 struct uprobe_cpu_buffer *ucb, int dsize,
 822                                 struct trace_event_file *trace_file)
 823 {
 824         struct uprobe_trace_entry_head *entry;
 825         struct ring_buffer_event *event;
 826         struct ring_buffer *buffer;
 827         void *data;
 828         int size, esize;
 829         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
 830
 831         WARN_ON(call != trace_file->event_call);
 832
 833         if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
 834                 return;
 835
 836         if (trace_trigger_soft_disabled(trace_file))
 837                 return;
 838
 839         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 840         size = esize + tu->tp.size + dsize;
 841         event = trace_event_buffer_lock_reserve(&buffer, trace_file,
 842                                                 call->event.type, size, 0, 0);
 843         if (!event)
 844                 return;
 845
 846         entry = ring_buffer_event_data(event);
 847         if (is_ret_probe(tu)) {
 848                 entry->vaddr[0] = func;
 849                 entry->vaddr[1] = instruction_pointer(regs);
 850                 data = DATAOF_TRACE_ENTRY(entry, true);
 851         } else {
 852                 entry->vaddr[0] = instruction_pointer(regs);
 853                 data = DATAOF_TRACE_ENTRY(entry, false);
 854         }
 855
 856         memcpy(data, ucb->buf, tu->tp.size + dsize);
 857
 858         event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
 859 }
 860
 861 /* uprobe handler */
 862 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
 863                              struct uprobe_cpu_buffer *ucb, int dsize)
 864 {
 865         struct event_file_link *link;
 866
 867         if (is_ret_probe(tu))
 868                 return 0;
 869
 870         rcu_read_lock();
 871         trace_probe_for_each_link_rcu(link, &tu->tp)
 872                 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
 873         rcu_read_unlock();
 874
 875         return 0;
 876 }
 877
 878 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
 879                                  struct pt_regs *regs,
 880                                  struct uprobe_cpu_buffer *ucb, int dsize)
 881 {
 882         struct event_file_link *link;
 883
 884         rcu_read_lock();
 885         trace_probe_for_each_link_rcu(link, &tu->tp)
 886                 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
 887         rcu_read_unlock();
 888 }
 889
 890 /* Event entry printers */
 891 static enum print_line_t
 892 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
 893 {
 894         struct uprobe_trace_entry_head *entry;
 895         struct trace_seq *s = &iter->seq;
 896         struct trace_uprobe *tu;
 897         u8 *data;
 898
 899         entry = (struct uprobe_trace_entry_head *)iter->ent;
 900         tu = container_of(event, struct trace_uprobe, tp.call.event);
 901
 902         if (is_ret_probe(tu)) {
 903                 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
 904                                  trace_probe_name(&tu->tp),
 905                                  entry->vaddr[1], entry->vaddr[0]);
 906                 data = DATAOF_TRACE_ENTRY(entry, true);
 907         } else {
 908                 trace_seq_printf(s, "%s: (0x%lx)",
 909                                  trace_probe_name(&tu->tp),
 910                                  entry->vaddr[0]);
 911                 data = DATAOF_TRACE_ENTRY(entry, false);
 912         }
 913
 914         if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
 915                 goto out;
 916
 917         trace_seq_putc(s, '\n');
 918
 919  out:
 920         return trace_handle_return(s);
 921 }
 922
 923 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
 924                                 enum uprobe_filter_ctx ctx,
 925                                 struct mm_struct *mm);
 926
 927 static int
 928 probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
 929                    filter_func_t filter)
 930 {
 931         bool enabled = trace_probe_is_enabled(&tu->tp);
 932         int ret;
 933
 934         if (file) {
 935                 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
 936                         return -EINTR;
 937
 938                 ret = trace_probe_add_file(&tu->tp, file);
 939                 if (ret < 0)
 940                         return ret;
 941         } else {
 942                 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
 943                         return -EINTR;
 944
 945                 trace_probe_set_flag(&tu->tp, TP_FLAG_PROFILE);
 946         }
 947
 948         WARN_ON(!uprobe_filter_is_empty(&tu->filter));
 949
 950         if (enabled)
 951                 return 0;
 952
 953         ret = uprobe_buffer_enable();
 954         if (ret)
 955                 goto err_flags;
 956
 957         tu->consumer.filter = filter;
 958         tu->inode = d_real_inode(tu->path.dentry);
 959         if (tu->ref_ctr_offset) {
 960                 ret = uprobe_register_refctr(tu->inode, tu->offset,
 961                                 tu->ref_ctr_offset, &tu->consumer);
 962         } else {
 963                 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
 964         }
 965
 966         if (ret)
 967                 goto err_buffer;
 968
 969         return 0;
 970
 971  err_buffer:
 972         uprobe_buffer_disable();
 973
 974  err_flags:
 975         if (file)
 976                 trace_probe_remove_file(&tu->tp, file);
 977         else
 978                 trace_probe_clear_flag(&tu->tp, TP_FLAG_PROFILE);
 979
 980         return ret;
 981 }
 982
 983 static void
 984 probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
 985 {
 986         if (!trace_probe_is_enabled(&tu->tp))
 987                 return;
 988
 989         if (file) {
 990                 if (trace_probe_remove_file(&tu->tp, file) < 0)
 991                         return;
 992
 993                 if (trace_probe_is_enabled(&tu->tp))
 994                         return;
 995         } else
 996                 trace_probe_clear_flag(&tu->tp, TP_FLAG_PROFILE);
 997
 998         WARN_ON(!uprobe_filter_is_empty(&tu->filter));
 999
1000         uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1001         tu->inode = NULL;
1002
1003         uprobe_buffer_disable();
1004 }
1005
1006 static int uprobe_event_define_fields(struct trace_event_call *event_call)
1007 {
1008         int ret, size;
1009         struct uprobe_trace_entry_head field;
1010         struct trace_uprobe *tu = event_call->data;
1011
1012         if (is_ret_probe(tu)) {
1013                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1014                 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1015                 size = SIZEOF_TRACE_ENTRY(true);
1016         } else {
1017                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1018                 size = SIZEOF_TRACE_ENTRY(false);
1019         }
1020
1021         return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1022 }
1023
1024 #ifdef CONFIG_PERF_EVENTS
1025 static bool
1026 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1027 {
1028         struct perf_event *event;
1029
1030         if (filter->nr_systemwide)
1031                 return true;
1032
1033         list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1034                 if (event->hw.target->mm == mm)
1035                         return true;
1036         }
1037
1038         return false;
1039 }
1040
1041 static inline bool
1042 uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
1043 {
1044         return __uprobe_perf_filter(&tu->filter, event->hw.target->mm);
1045 }
1046
1047 static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
1048 {
1049         bool done;
1050
1051         write_lock(&tu->filter.rwlock);
1052         if (event->hw.target) {
1053                 list_del(&event->hw.tp_list);
1054                 done = tu->filter.nr_systemwide ||
1055                         (event->hw.target->flags & PF_EXITING) ||
1056                         uprobe_filter_event(tu, event);
1057         } else {
1058                 tu->filter.nr_systemwide--;
1059                 done = tu->filter.nr_systemwide;
1060         }
1061         write_unlock(&tu->filter.rwlock);
1062
1063         if (!done)
1064                 return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1065
1066         return 0;
1067 }
1068
1069 static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
1070 {
1071         bool done;
1072         int err;
1073
1074         write_lock(&tu->filter.rwlock);
1075         if (event->hw.target) {
1076                 /*
1077                  * event->parent != NULL means copy_process(), we can avoid
1078                  * uprobe_apply(). current->mm must be probed and we can rely
1079                  * on dup_mmap() which preserves the already installed bp's.
1080                  *
1081                  * attr.enable_on_exec means that exec/mmap will install the
1082                  * breakpoints we need.
1083                  */
1084                 done = tu->filter.nr_systemwide ||
1085                         event->parent || event->attr.enable_on_exec ||
1086                         uprobe_filter_event(tu, event);
1087                 list_add(&event->hw.tp_list, &tu->filter.perf_events);
1088         } else {
1089                 done = tu->filter.nr_systemwide;
1090                 tu->filter.nr_systemwide++;
1091         }
1092         write_unlock(&tu->filter.rwlock);
1093
1094         err = 0;
1095         if (!done) {
1096                 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1097                 if (err)
1098                         uprobe_perf_close(tu, event);
1099         }
1100         return err;
1101 }
1102
1103 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1104                                 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1105 {
1106         struct trace_uprobe *tu;
1107         int ret;
1108
1109         tu = container_of(uc, struct trace_uprobe, consumer);
1110         read_lock(&tu->filter.rwlock);
1111         ret = __uprobe_perf_filter(&tu->filter, mm);
1112         read_unlock(&tu->filter.rwlock);
1113
1114         return ret;
1115 }
1116
1117 static void __uprobe_perf_func(struct trace_uprobe *tu,
1118                                unsigned long func, struct pt_regs *regs,
1119                                struct uprobe_cpu_buffer *ucb, int dsize)
1120 {
1121         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1122         struct uprobe_trace_entry_head *entry;
1123         struct hlist_head *head;
1124         void *data;
1125         int size, esize;
1126         int rctx;
1127
1128         if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1129                 return;
1130
1131         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1132
1133         size = esize + tu->tp.size + dsize;
1134         size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1135         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1136                 return;
1137
1138         preempt_disable();
1139         head = this_cpu_ptr(call->perf_events);
1140         if (hlist_empty(head))
1141                 goto out;
1142
1143         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1144         if (!entry)
1145                 goto out;
1146
1147         if (is_ret_probe(tu)) {
1148                 entry->vaddr[0] = func;
1149                 entry->vaddr[1] = instruction_pointer(regs);
1150                 data = DATAOF_TRACE_ENTRY(entry, true);
1151         } else {
1152                 entry->vaddr[0] = instruction_pointer(regs);
1153                 data = DATAOF_TRACE_ENTRY(entry, false);
1154         }
1155
1156         memcpy(data, ucb->buf, tu->tp.size + dsize);
1157
1158         if (size - esize > tu->tp.size + dsize) {
1159                 int len = tu->tp.size + dsize;
1160
1161                 memset(data + len, 0, size - esize - len);
1162         }
1163
1164         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1165                               head, NULL);
1166  out:
1167         preempt_enable();
1168 }
1169
1170 /* uprobe profile handler */
1171 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1172                             struct uprobe_cpu_buffer *ucb, int dsize)
1173 {
1174         if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1175                 return UPROBE_HANDLER_REMOVE;
1176
1177         if (!is_ret_probe(tu))
1178                 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1179         return 0;
1180 }
1181
1182 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1183                                 struct pt_regs *regs,
1184                                 struct uprobe_cpu_buffer *ucb, int dsize)
1185 {
1186         __uprobe_perf_func(tu, func, regs, ucb, dsize);
1187 }
1188
1189 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1190                         const char **filename, u64 *probe_offset,
1191                         bool perf_type_tracepoint)
1192 {
1193         const char *pevent = trace_event_name(event->tp_event);
1194         const char *group = event->tp_event->class->system;
1195         struct trace_uprobe *tu;
1196
1197         if (perf_type_tracepoint)
1198                 tu = find_probe_event(pevent, group);
1199         else
1200                 tu = event->tp_event->data;
1201         if (!tu)
1202                 return -EINVAL;
1203
1204         *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1205                                     : BPF_FD_TYPE_UPROBE;
1206         *filename = tu->filename;
1207         *probe_offset = tu->offset;
1208         return 0;
1209 }
1210 #endif  /* CONFIG_PERF_EVENTS */
1211
1212 static int
1213 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1214                       void *data)
1215 {
1216         struct trace_uprobe *tu = event->data;
1217         struct trace_event_file *file = data;
1218
1219         switch (type) {
1220         case TRACE_REG_REGISTER:
1221                 return probe_event_enable(tu, file, NULL);
1222
1223         case TRACE_REG_UNREGISTER:
1224                 probe_event_disable(tu, file);
1225                 return 0;
1226
1227 #ifdef CONFIG_PERF_EVENTS
1228         case TRACE_REG_PERF_REGISTER:
1229                 return probe_event_enable(tu, NULL, uprobe_perf_filter);
1230
1231         case TRACE_REG_PERF_UNREGISTER:
1232                 probe_event_disable(tu, NULL);
1233                 return 0;
1234
1235         case TRACE_REG_PERF_OPEN:
1236                 return uprobe_perf_open(tu, data);
1237
1238         case TRACE_REG_PERF_CLOSE:
1239                 return uprobe_perf_close(tu, data);
1240
1241 #endif
1242         default:
1243                 return 0;
1244         }
1245         return 0;
1246 }
1247
1248 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1249 {
1250         struct trace_uprobe *tu;
1251         struct uprobe_dispatch_data udd;
1252         struct uprobe_cpu_buffer *ucb;
1253         int dsize, esize;
1254         int ret = 0;
1255
1256
1257         tu = container_of(con, struct trace_uprobe, consumer);
1258         tu->nhit++;
1259
1260         udd.tu = tu;
1261         udd.bp_addr = instruction_pointer(regs);
1262
1263         current->utask->vaddr = (unsigned long) &udd;
1264
1265         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1266                 return 0;
1267
1268         dsize = __get_data_size(&tu->tp, regs);
1269         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1270
1271         ucb = uprobe_buffer_get();
1272         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1273
1274         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1275                 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1276
1277 #ifdef CONFIG_PERF_EVENTS
1278         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1279                 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1280 #endif
1281         uprobe_buffer_put(ucb);
1282         return ret;
1283 }
1284
1285 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1286                                 unsigned long func, struct pt_regs *regs)
1287 {
1288         struct trace_uprobe *tu;
1289         struct uprobe_dispatch_data udd;
1290         struct uprobe_cpu_buffer *ucb;
1291         int dsize, esize;
1292
1293         tu = container_of(con, struct trace_uprobe, consumer);
1294
1295         udd.tu = tu;
1296         udd.bp_addr = func;
1297
1298         current->utask->vaddr = (unsigned long) &udd;
1299
1300         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1301                 return 0;
1302
1303         dsize = __get_data_size(&tu->tp, regs);
1304         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1305
1306         ucb = uprobe_buffer_get();
1307         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1308
1309         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1310                 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1311
1312 #ifdef CONFIG_PERF_EVENTS
1313         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1314                 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1315 #endif
1316         uprobe_buffer_put(ucb);
1317         return 0;
1318 }
1319
1320 static struct trace_event_functions uprobe_funcs = {
1321         .trace          = print_uprobe_event
1322 };
1323
1324 static inline void init_trace_event_call(struct trace_uprobe *tu)
1325 {
1326         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1327
1328         call->event.funcs = &uprobe_funcs;
1329         call->class->define_fields = uprobe_event_define_fields;
1330
1331         call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1332         call->class->reg = trace_uprobe_register;
1333         call->data = tu;
1334 }
1335
1336 static int register_uprobe_event(struct trace_uprobe *tu)
1337 {
1338         init_trace_event_call(tu);
1339
1340         return trace_probe_register_event_call(&tu->tp);
1341 }
1342
1343 static int unregister_uprobe_event(struct trace_uprobe *tu)
1344 {
1345         return trace_probe_unregister_event_call(&tu->tp);
1346 }
1347
1348 #ifdef CONFIG_PERF_EVENTS
1349 struct trace_event_call *
1350 create_local_trace_uprobe(char *name, unsigned long offs,
1351                           unsigned long ref_ctr_offset, bool is_return)
1352 {
1353         struct trace_uprobe *tu;
1354         struct path path;
1355         int ret;
1356
1357         ret = kern_path(name, LOOKUP_FOLLOW, &path);
1358         if (ret)
1359                 return ERR_PTR(ret);
1360
1361         if (!d_is_reg(path.dentry)) {
1362                 path_put(&path);
1363                 return ERR_PTR(-EINVAL);
1364         }
1365
1366         /*
1367          * local trace_kprobes are not added to dyn_event, so they are never
1368          * searched in find_trace_kprobe(). Therefore, there is no concern of
1369          * duplicated name "DUMMY_EVENT" here.
1370          */
1371         tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1372                                 is_return);
1373
1374         if (IS_ERR(tu)) {
1375                 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1376                         (int)PTR_ERR(tu));
1377                 path_put(&path);
1378                 return ERR_CAST(tu);
1379         }
1380
1381         tu->offset = offs;
1382         tu->path = path;
1383         tu->ref_ctr_offset = ref_ctr_offset;
1384         tu->filename = kstrdup(name, GFP_KERNEL);
1385         init_trace_event_call(tu);
1386
1387         if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
1388                 ret = -ENOMEM;
1389                 goto error;
1390         }
1391
1392         return trace_probe_event_call(&tu->tp);
1393 error:
1394         free_trace_uprobe(tu);
1395         return ERR_PTR(ret);
1396 }
1397
1398 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1399 {
1400         struct trace_uprobe *tu;
1401
1402         tu = container_of(event_call, struct trace_uprobe, tp.call);
1403
1404         free_trace_uprobe(tu);
1405 }
1406 #endif /* CONFIG_PERF_EVENTS */
1407
1408 /* Make a trace interface for controling probe points */
1409 static __init int init_uprobe_trace(void)
1410 {
1411         struct dentry *d_tracer;
1412         int ret;
1413
1414         ret = dyn_event_register(&trace_uprobe_ops);
1415         if (ret)
1416                 return ret;
1417
1418         d_tracer = tracing_init_dentry();
1419         if (IS_ERR(d_tracer))
1420                 return 0;
1421
1422         trace_create_file("uprobe_events", 0644, d_tracer,
1423                                     NULL, &uprobe_events_ops);
1424         /* Profile interface */
1425         trace_create_file("uprobe_profile", 0444, d_tracer,
1426                                     NULL, &uprobe_profile_ops);
1427         return 0;
1428 }
1429
1430 fs_initcall(init_uprobe_trace);