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                         int argc, const char **argv, 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_DATA:
 252                 val = (unsigned long)code->data;
 253                 break;
 254         case FETCH_OP_FOFFS:
 255                 val = translate_user_vaddr(code->immediate);
 256                 break;
 257         default:
 258                 return -EILSEQ;
 259         }
 260         code++;
 261
 262         return process_fetch_insn_bottom(code, val, dest, base);
 263 }
 264 NOKPROBE_SYMBOL(process_fetch_insn)
 265
 266 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
 267 {
 268         rwlock_init(&filter->rwlock);
 269         filter->nr_systemwide = 0;
 270         INIT_LIST_HEAD(&filter->perf_events);
 271 }
 272
 273 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
 274 {
 275         return !filter->nr_systemwide && list_empty(&filter->perf_events);
 276 }
 277
 278 static inline bool is_ret_probe(struct trace_uprobe *tu)
 279 {
 280         return tu->consumer.ret_handler != NULL;
 281 }
 282
 283 static bool trace_uprobe_is_busy(struct dyn_event *ev)
 284 {
 285         struct trace_uprobe *tu = to_trace_uprobe(ev);
 286
 287         return trace_probe_is_enabled(&tu->tp);
 288 }
 289
 290 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
 291                                             int argc, const char **argv)
 292 {
 293         char buf[MAX_ARGSTR_LEN + 1];
 294         int len;
 295
 296         if (!argc)
 297                 return true;
 298
 299         len = strlen(tu->filename);
 300         if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
 301                 return false;
 302
 303         if (tu->ref_ctr_offset == 0)
 304                 snprintf(buf, sizeof(buf), "0x%0*lx",
 305                                 (int)(sizeof(void *) * 2), tu->offset);
 306         else
 307                 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
 308                                 (int)(sizeof(void *) * 2), tu->offset,
 309                                 tu->ref_ctr_offset);
 310         if (strcmp(buf, &argv[0][len + 1]))
 311                 return false;
 312
 313         argc--; argv++;
 314
 315         return trace_probe_match_command_args(&tu->tp, argc, argv);
 316 }
 317
 318 static bool trace_uprobe_match(const char *system, const char *event,
 319                         int argc, const char **argv, struct dyn_event *ev)
 320 {
 321         struct trace_uprobe *tu = to_trace_uprobe(ev);
 322
 323         return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 324            (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
 325            trace_uprobe_match_command_head(tu, argc, argv);
 326 }
 327
 328 static nokprobe_inline struct trace_uprobe *
 329 trace_uprobe_primary_from_call(struct trace_event_call *call)
 330 {
 331         struct trace_probe *tp;
 332
 333         tp = trace_probe_primary_from_call(call);
 334         if (WARN_ON_ONCE(!tp))
 335                 return NULL;
 336
 337         return container_of(tp, struct trace_uprobe, tp);
 338 }
 339
 340 /*
 341  * Allocate new trace_uprobe and initialize it (including uprobes).
 342  */
 343 static struct trace_uprobe *
 344 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 345 {
 346         struct trace_uprobe *tu;
 347         int ret;
 348
 349         tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
 350         if (!tu)
 351                 return ERR_PTR(-ENOMEM);
 352
 353         ret = trace_probe_init(&tu->tp, event, group);
 354         if (ret < 0)
 355                 goto error;
 356
 357         dyn_event_init(&tu->devent, &trace_uprobe_ops);
 358         tu->consumer.handler = uprobe_dispatcher;
 359         if (is_ret)
 360                 tu->consumer.ret_handler = uretprobe_dispatcher;
 361         init_trace_uprobe_filter(&tu->filter);
 362         return tu;
 363
 364 error:
 365         kfree(tu);
 366
 367         return ERR_PTR(ret);
 368 }
 369
 370 static void free_trace_uprobe(struct trace_uprobe *tu)
 371 {
 372         if (!tu)
 373                 return;
 374
 375         path_put(&tu->path);
 376         trace_probe_cleanup(&tu->tp);
 377         kfree(tu->filename);
 378         kfree(tu);
 379 }
 380
 381 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
 382 {
 383         struct dyn_event *pos;
 384         struct trace_uprobe *tu;
 385
 386         for_each_trace_uprobe(tu, pos)
 387                 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 388                     strcmp(trace_probe_group_name(&tu->tp), group) == 0)
 389                         return tu;
 390
 391         return NULL;
 392 }
 393
 394 /* Unregister a trace_uprobe and probe_event */
 395 static int unregister_trace_uprobe(struct trace_uprobe *tu)
 396 {
 397         int ret;
 398
 399         if (trace_probe_has_sibling(&tu->tp))
 400                 goto unreg;
 401
 402         ret = unregister_uprobe_event(tu);
 403         if (ret)
 404                 return ret;
 405
 406 unreg:
 407         dyn_event_remove(&tu->devent);
 408         trace_probe_unlink(&tu->tp);
 409         free_trace_uprobe(tu);
 410         return 0;
 411 }
 412
 413 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
 414                                          struct trace_uprobe *comp)
 415 {
 416         struct trace_probe_event *tpe = orig->tp.event;
 417         struct trace_probe *pos;
 418         struct inode *comp_inode = d_real_inode(comp->path.dentry);
 419         int i;
 420
 421         list_for_each_entry(pos, &tpe->probes, list) {
 422                 orig = container_of(pos, struct trace_uprobe, tp);
 423                 if (comp_inode != d_real_inode(orig->path.dentry) ||
 424                     comp->offset != orig->offset)
 425                         continue;
 426
 427                 /*
 428                  * trace_probe_compare_arg_type() ensured that nr_args and
 429                  * each argument name and type are same. Let's compare comm.
 430                  */
 431                 for (i = 0; i < orig->tp.nr_args; i++) {
 432                         if (strcmp(orig->tp.args[i].comm,
 433                                    comp->tp.args[i].comm))
 434                                 continue;
 435                 }
 436
 437                 return true;
 438         }
 439
 440         return false;
 441 }
 442
 443 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
 444 {
 445         int ret;
 446
 447         ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
 448         if (ret) {
 449                 /* Note that argument starts index = 2 */
 450                 trace_probe_log_set_index(ret + 1);
 451                 trace_probe_log_err(0, DIFF_ARG_TYPE);
 452                 return -EEXIST;
 453         }
 454         if (trace_uprobe_has_same_uprobe(to, tu)) {
 455                 trace_probe_log_set_index(0);
 456                 trace_probe_log_err(0, SAME_PROBE);
 457                 return -EEXIST;
 458         }
 459
 460         /* Append to existing event */
 461         ret = trace_probe_append(&tu->tp, &to->tp);
 462         if (!ret)
 463                 dyn_event_add(&tu->devent);
 464
 465         return ret;
 466 }
 467
 468 /*
 469  * Uprobe with multiple reference counter is not allowed. i.e.
 470  * If inode and offset matches, reference counter offset *must*
 471  * match as well. Though, there is one exception: If user is
 472  * replacing old trace_uprobe with new one(same group/event),
 473  * then we allow same uprobe with new reference counter as far
 474  * as the new one does not conflict with any other existing
 475  * ones.
 476  */
 477 static int validate_ref_ctr_offset(struct trace_uprobe *new)
 478 {
 479         struct dyn_event *pos;
 480         struct trace_uprobe *tmp;
 481         struct inode *new_inode = d_real_inode(new->path.dentry);
 482
 483         for_each_trace_uprobe(tmp, pos) {
 484                 if (new_inode == d_real_inode(tmp->path.dentry) &&
 485                     new->offset == tmp->offset &&
 486                     new->ref_ctr_offset != tmp->ref_ctr_offset) {
 487                         pr_warn("Reference counter offset mismatch.");
 488                         return -EINVAL;
 489                 }
 490         }
 491         return 0;
 492 }
 493
 494 /* Register a trace_uprobe and probe_event */
 495 static int register_trace_uprobe(struct trace_uprobe *tu)
 496 {
 497         struct trace_uprobe *old_tu;
 498         int ret;
 499
 500         mutex_lock(&event_mutex);
 501
 502         ret = validate_ref_ctr_offset(tu);
 503         if (ret)
 504                 goto end;
 505
 506         /* register as an event */
 507         old_tu = find_probe_event(trace_probe_name(&tu->tp),
 508                                   trace_probe_group_name(&tu->tp));
 509         if (old_tu) {
 510                 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
 511                         trace_probe_log_set_index(0);
 512                         trace_probe_log_err(0, DIFF_PROBE_TYPE);
 513                         ret = -EEXIST;
 514                 } else {
 515                         ret = append_trace_uprobe(tu, old_tu);
 516                 }
 517                 goto end;
 518         }
 519
 520         ret = register_uprobe_event(tu);
 521         if (ret) {
 522                 pr_warn("Failed to register probe event(%d)\n", ret);
 523                 goto end;
 524         }
 525
 526         dyn_event_add(&tu->devent);
 527
 528 end:
 529         mutex_unlock(&event_mutex);
 530
 531         return ret;
 532 }
 533
 534 /*
 535  * Argument syntax:
 536  *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
 537  */
 538 static int trace_uprobe_create(int argc, const char **argv)
 539 {
 540         struct trace_uprobe *tu;
 541         const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
 542         char *arg, *filename, *rctr, *rctr_end, *tmp;
 543         char buf[MAX_EVENT_NAME_LEN];
 544         struct path path;
 545         unsigned long offset, ref_ctr_offset;
 546         bool is_return = false;
 547         int i, ret;
 548
 549         ret = 0;
 550         ref_ctr_offset = 0;
 551
 552         switch (argv[0][0]) {
 553         case 'r':
 554                 is_return = true;
 555                 break;
 556         case 'p':
 557                 break;
 558         default:
 559                 return -ECANCELED;
 560         }
 561
 562         if (argc < 2)
 563                 return -ECANCELED;
 564
 565         if (argv[0][1] == ':')
 566                 event = &argv[0][2];
 567
 568         if (!strchr(argv[1], '/'))
 569                 return -ECANCELED;
 570
 571         filename = kstrdup(argv[1], GFP_KERNEL);
 572         if (!filename)
 573                 return -ENOMEM;
 574
 575         /* Find the last occurrence, in case the path contains ':' too. */
 576         arg = strrchr(filename, ':');
 577         if (!arg || !isdigit(arg[1])) {
 578                 kfree(filename);
 579                 return -ECANCELED;
 580         }
 581
 582         trace_probe_log_init("trace_uprobe", argc, argv);
 583         trace_probe_log_set_index(1);   /* filename is the 2nd argument */
 584
 585         *arg++ = '\0';
 586         ret = kern_path(filename, LOOKUP_FOLLOW, &path);
 587         if (ret) {
 588                 trace_probe_log_err(0, FILE_NOT_FOUND);
 589                 kfree(filename);
 590                 trace_probe_log_clear();
 591                 return ret;
 592         }
 593         if (!d_is_reg(path.dentry)) {
 594                 trace_probe_log_err(0, NO_REGULAR_FILE);
 595                 ret = -EINVAL;
 596                 goto fail_address_parse;
 597         }
 598
 599         /* Parse reference counter offset if specified. */
 600         rctr = strchr(arg, '(');
 601         if (rctr) {
 602                 rctr_end = strchr(rctr, ')');
 603                 if (!rctr_end) {
 604                         ret = -EINVAL;
 605                         rctr_end = rctr + strlen(rctr);
 606                         trace_probe_log_err(rctr_end - filename,
 607                                             REFCNT_OPEN_BRACE);
 608                         goto fail_address_parse;
 609                 } else if (rctr_end[1] != '\0') {
 610                         ret = -EINVAL;
 611                         trace_probe_log_err(rctr_end + 1 - filename,
 612                                             BAD_REFCNT_SUFFIX);
 613                         goto fail_address_parse;
 614                 }
 615
 616                 *rctr++ = '\0';
 617                 *rctr_end = '\0';
 618                 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
 619                 if (ret) {
 620                         trace_probe_log_err(rctr - filename, BAD_REFCNT);
 621                         goto fail_address_parse;
 622                 }
 623         }
 624
 625         /* Parse uprobe offset. */
 626         ret = kstrtoul(arg, 0, &offset);
 627         if (ret) {
 628                 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
 629                 goto fail_address_parse;
 630         }
 631
 632         /* setup a probe */
 633         trace_probe_log_set_index(0);
 634         if (event) {
 635                 ret = traceprobe_parse_event_name(&event, &group, buf,
 636                                                   event - argv[0]);
 637                 if (ret)
 638                         goto fail_address_parse;
 639         } else {
 640                 char *tail;
 641                 char *ptr;
 642
 643                 tail = kstrdup(kbasename(filename), GFP_KERNEL);
 644                 if (!tail) {
 645                         ret = -ENOMEM;
 646                         goto fail_address_parse;
 647                 }
 648
 649                 ptr = strpbrk(tail, ".-_");
 650                 if (ptr)
 651                         *ptr = '\0';
 652
 653                 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
 654                 event = buf;
 655                 kfree(tail);
 656         }
 657
 658         argc -= 2;
 659         argv += 2;
 660
 661         tu = alloc_trace_uprobe(group, event, argc, is_return);
 662         if (IS_ERR(tu)) {
 663                 ret = PTR_ERR(tu);
 664                 /* This must return -ENOMEM otherwise there is a bug */
 665                 WARN_ON_ONCE(ret != -ENOMEM);
 666                 goto fail_address_parse;
 667         }
 668         tu->offset = offset;
 669         tu->ref_ctr_offset = ref_ctr_offset;
 670         tu->path = path;
 671         tu->filename = filename;
 672
 673         /* parse arguments */
 674         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 675                 tmp = kstrdup(argv[i], GFP_KERNEL);
 676                 if (!tmp) {
 677                         ret = -ENOMEM;
 678                         goto error;
 679                 }
 680
 681                 trace_probe_log_set_index(i + 2);
 682                 ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
 683                                         is_return ? TPARG_FL_RETURN : 0);
 684                 kfree(tmp);
 685                 if (ret)
 686                         goto error;
 687         }
 688
 689         ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu));
 690         if (ret < 0)
 691                 goto error;
 692
 693         ret = register_trace_uprobe(tu);
 694         if (!ret)
 695                 goto out;
 696
 697 error:
 698         free_trace_uprobe(tu);
 699 out:
 700         trace_probe_log_clear();
 701         return ret;
 702
 703 fail_address_parse:
 704         trace_probe_log_clear();
 705         path_put(&path);
 706         kfree(filename);
 707
 708         return ret;
 709 }
 710
 711 static int create_or_delete_trace_uprobe(int argc, char **argv)
 712 {
 713         int ret;
 714
 715         if (argv[0][0] == '-')
 716                 return dyn_event_release(argc, argv, &trace_uprobe_ops);
 717
 718         ret = trace_uprobe_create(argc, (const char **)argv);
 719         return ret == -ECANCELED ? -EINVAL : ret;
 720 }
 721
 722 static int trace_uprobe_release(struct dyn_event *ev)
 723 {
 724         struct trace_uprobe *tu = to_trace_uprobe(ev);
 725
 726         return unregister_trace_uprobe(tu);
 727 }
 728
 729 /* Probes listing interfaces */
 730 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
 731 {
 732         struct trace_uprobe *tu = to_trace_uprobe(ev);
 733         char c = is_ret_probe(tu) ? 'r' : 'p';
 734         int i;
 735
 736         seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
 737                         trace_probe_name(&tu->tp), tu->filename,
 738                         (int)(sizeof(void *) * 2), tu->offset);
 739
 740         if (tu->ref_ctr_offset)
 741                 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
 742
 743         for (i = 0; i < tu->tp.nr_args; i++)
 744                 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
 745
 746         seq_putc(m, '\n');
 747         return 0;
 748 }
 749
 750 static int probes_seq_show(struct seq_file *m, void *v)
 751 {
 752         struct dyn_event *ev = v;
 753
 754         if (!is_trace_uprobe(ev))
 755                 return 0;
 756
 757         return trace_uprobe_show(m, ev);
 758 }
 759
 760 static const struct seq_operations probes_seq_op = {
 761         .start  = dyn_event_seq_start,
 762         .next   = dyn_event_seq_next,
 763         .stop   = dyn_event_seq_stop,
 764         .show   = probes_seq_show
 765 };
 766
 767 static int probes_open(struct inode *inode, struct file *file)
 768 {
 769         int ret;
 770
 771         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 772                 ret = dyn_events_release_all(&trace_uprobe_ops);
 773                 if (ret)
 774                         return ret;
 775         }
 776
 777         return seq_open(file, &probes_seq_op);
 778 }
 779
 780 static ssize_t probes_write(struct file *file, const char __user *buffer,
 781                             size_t count, loff_t *ppos)
 782 {
 783         return trace_parse_run_command(file, buffer, count, ppos,
 784                                         create_or_delete_trace_uprobe);
 785 }
 786
 787 static const struct file_operations uprobe_events_ops = {
 788         .owner          = THIS_MODULE,
 789         .open           = probes_open,
 790         .read           = seq_read,
 791         .llseek         = seq_lseek,
 792         .release        = seq_release,
 793         .write          = probes_write,
 794 };
 795
 796 /* Probes profiling interfaces */
 797 static int probes_profile_seq_show(struct seq_file *m, void *v)
 798 {
 799         struct dyn_event *ev = v;
 800         struct trace_uprobe *tu;
 801
 802         if (!is_trace_uprobe(ev))
 803                 return 0;
 804
 805         tu = to_trace_uprobe(ev);
 806         seq_printf(m, "  %s %-44s %15lu\n", tu->filename,
 807                         trace_probe_name(&tu->tp), tu->nhit);
 808         return 0;
 809 }
 810
 811 static const struct seq_operations profile_seq_op = {
 812         .start  = dyn_event_seq_start,
 813         .next   = dyn_event_seq_next,
 814         .stop   = dyn_event_seq_stop,
 815         .show   = probes_profile_seq_show
 816 };
 817
 818 static int profile_open(struct inode *inode, struct file *file)
 819 {
 820         return seq_open(file, &profile_seq_op);
 821 }
 822
 823 static const struct file_operations uprobe_profile_ops = {
 824         .owner          = THIS_MODULE,
 825         .open           = profile_open,
 826         .read           = seq_read,
 827         .llseek         = seq_lseek,
 828         .release        = seq_release,
 829 };
 830
 831 struct uprobe_cpu_buffer {
 832         struct mutex mutex;
 833         void *buf;
 834 };
 835 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
 836 static int uprobe_buffer_refcnt;
 837
 838 static int uprobe_buffer_init(void)
 839 {
 840         int cpu, err_cpu;
 841
 842         uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
 843         if (uprobe_cpu_buffer == NULL)
 844                 return -ENOMEM;
 845
 846         for_each_possible_cpu(cpu) {
 847                 struct page *p = alloc_pages_node(cpu_to_node(cpu),
 848                                                   GFP_KERNEL, 0);
 849                 if (p == NULL) {
 850                         err_cpu = cpu;
 851                         goto err;
 852                 }
 853                 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
 854                 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
 855         }
 856
 857         return 0;
 858
 859 err:
 860         for_each_possible_cpu(cpu) {
 861                 if (cpu == err_cpu)
 862                         break;
 863                 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
 864         }
 865
 866         free_percpu(uprobe_cpu_buffer);
 867         return -ENOMEM;
 868 }
 869
 870 static int uprobe_buffer_enable(void)
 871 {
 872         int ret = 0;
 873
 874         BUG_ON(!mutex_is_locked(&event_mutex));
 875
 876         if (uprobe_buffer_refcnt++ == 0) {
 877                 ret = uprobe_buffer_init();
 878                 if (ret < 0)
 879                         uprobe_buffer_refcnt--;
 880         }
 881
 882         return ret;
 883 }
 884
 885 static void uprobe_buffer_disable(void)
 886 {
 887         int cpu;
 888
 889         BUG_ON(!mutex_is_locked(&event_mutex));
 890
 891         if (--uprobe_buffer_refcnt == 0) {
 892                 for_each_possible_cpu(cpu)
 893                         free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
 894                                                              cpu)->buf);
 895
 896                 free_percpu(uprobe_cpu_buffer);
 897                 uprobe_cpu_buffer = NULL;
 898         }
 899 }
 900
 901 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
 902 {
 903         struct uprobe_cpu_buffer *ucb;
 904         int cpu;
 905
 906         cpu = raw_smp_processor_id();
 907         ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
 908
 909         /*
 910          * Use per-cpu buffers for fastest access, but we might migrate
 911          * so the mutex makes sure we have sole access to it.
 912          */
 913         mutex_lock(&ucb->mutex);
 914
 915         return ucb;
 916 }
 917
 918 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
 919 {
 920         mutex_unlock(&ucb->mutex);
 921 }
 922
 923 static void __uprobe_trace_func(struct trace_uprobe *tu,
 924                                 unsigned long func, struct pt_regs *regs,
 925                                 struct uprobe_cpu_buffer *ucb, int dsize,
 926                                 struct trace_event_file *trace_file)
 927 {
 928         struct uprobe_trace_entry_head *entry;
 929         struct ring_buffer_event *event;
 930         struct ring_buffer *buffer;
 931         void *data;
 932         int size, esize;
 933         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
 934
 935         WARN_ON(call != trace_file->event_call);
 936
 937         if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
 938                 return;
 939
 940         if (trace_trigger_soft_disabled(trace_file))
 941                 return;
 942
 943         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 944         size = esize + tu->tp.size + dsize;
 945         event = trace_event_buffer_lock_reserve(&buffer, trace_file,
 946                                                 call->event.type, size, 0, 0);
 947         if (!event)
 948                 return;
 949
 950         entry = ring_buffer_event_data(event);
 951         if (is_ret_probe(tu)) {
 952                 entry->vaddr[0] = func;
 953                 entry->vaddr[1] = instruction_pointer(regs);
 954                 data = DATAOF_TRACE_ENTRY(entry, true);
 955         } else {
 956                 entry->vaddr[0] = instruction_pointer(regs);
 957                 data = DATAOF_TRACE_ENTRY(entry, false);
 958         }
 959
 960         memcpy(data, ucb->buf, tu->tp.size + dsize);
 961
 962         event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
 963 }
 964
 965 /* uprobe handler */
 966 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
 967                              struct uprobe_cpu_buffer *ucb, int dsize)
 968 {
 969         struct event_file_link *link;
 970
 971         if (is_ret_probe(tu))
 972                 return 0;
 973
 974         rcu_read_lock();
 975         trace_probe_for_each_link_rcu(link, &tu->tp)
 976                 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
 977         rcu_read_unlock();
 978
 979         return 0;
 980 }
 981
 982 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
 983                                  struct pt_regs *regs,
 984                                  struct uprobe_cpu_buffer *ucb, int dsize)
 985 {
 986         struct event_file_link *link;
 987
 988         rcu_read_lock();
 989         trace_probe_for_each_link_rcu(link, &tu->tp)
 990                 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
 991         rcu_read_unlock();
 992 }
 993
 994 /* Event entry printers */
 995 static enum print_line_t
 996 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
 997 {
 998         struct uprobe_trace_entry_head *entry;
 999         struct trace_seq *s = &iter->seq;
1000         struct trace_uprobe *tu;
1001         u8 *data;
1002
1003         entry = (struct uprobe_trace_entry_head *)iter->ent;
1004         tu = trace_uprobe_primary_from_call(
1005                 container_of(event, struct trace_event_call, event));
1006         if (unlikely(!tu))
1007                 goto out;
1008
1009         if (is_ret_probe(tu)) {
1010                 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1011                                  trace_probe_name(&tu->tp),
1012                                  entry->vaddr[1], entry->vaddr[0]);
1013                 data = DATAOF_TRACE_ENTRY(entry, true);
1014         } else {
1015                 trace_seq_printf(s, "%s: (0x%lx)",
1016                                  trace_probe_name(&tu->tp),
1017                                  entry->vaddr[0]);
1018                 data = DATAOF_TRACE_ENTRY(entry, false);
1019         }
1020
1021         if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1022                 goto out;
1023
1024         trace_seq_putc(s, '\n');
1025
1026  out:
1027         return trace_handle_return(s);
1028 }
1029
1030 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1031                                 enum uprobe_filter_ctx ctx,
1032                                 struct mm_struct *mm);
1033
1034 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1035 {
1036         int ret;
1037
1038         tu->consumer.filter = filter;
1039         tu->inode = d_real_inode(tu->path.dentry);
1040
1041         if (tu->ref_ctr_offset)
1042                 ret = uprobe_register_refctr(tu->inode, tu->offset,
1043                                 tu->ref_ctr_offset, &tu->consumer);
1044         else
1045                 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1046
1047         if (ret)
1048                 tu->inode = NULL;
1049
1050         return ret;
1051 }
1052
1053 static void __probe_event_disable(struct trace_probe *tp)
1054 {
1055         struct trace_probe *pos;
1056         struct trace_uprobe *tu;
1057
1058         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1059                 tu = container_of(pos, struct trace_uprobe, tp);
1060                 if (!tu->inode)
1061                         continue;
1062
1063                 WARN_ON(!uprobe_filter_is_empty(&tu->filter));
1064
1065                 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1066                 tu->inode = NULL;
1067         }
1068 }
1069
1070 static int probe_event_enable(struct trace_event_call *call,
1071                         struct trace_event_file *file, filter_func_t filter)
1072 {
1073         struct trace_probe *pos, *tp;
1074         struct trace_uprobe *tu;
1075         bool enabled;
1076         int ret;
1077
1078         tp = trace_probe_primary_from_call(call);
1079         if (WARN_ON_ONCE(!tp))
1080                 return -ENODEV;
1081         enabled = trace_probe_is_enabled(tp);
1082
1083         /* This may also change "enabled" state */
1084         if (file) {
1085                 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1086                         return -EINTR;
1087
1088                 ret = trace_probe_add_file(tp, file);
1089                 if (ret < 0)
1090                         return ret;
1091         } else {
1092                 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1093                         return -EINTR;
1094
1095                 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1096         }
1097
1098         tu = container_of(tp, struct trace_uprobe, tp);
1099         WARN_ON(!uprobe_filter_is_empty(&tu->filter));
1100
1101         if (enabled)
1102                 return 0;
1103
1104         ret = uprobe_buffer_enable();
1105         if (ret)
1106                 goto err_flags;
1107
1108         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1109                 tu = container_of(pos, struct trace_uprobe, tp);
1110                 ret = trace_uprobe_enable(tu, filter);
1111                 if (ret) {
1112                         __probe_event_disable(tp);
1113                         goto err_buffer;
1114                 }
1115         }
1116
1117         return 0;
1118
1119  err_buffer:
1120         uprobe_buffer_disable();
1121
1122  err_flags:
1123         if (file)
1124                 trace_probe_remove_file(tp, file);
1125         else
1126                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1127
1128         return ret;
1129 }
1130
1131 static void probe_event_disable(struct trace_event_call *call,
1132                                 struct trace_event_file *file)
1133 {
1134         struct trace_probe *tp;
1135
1136         tp = trace_probe_primary_from_call(call);
1137         if (WARN_ON_ONCE(!tp))
1138                 return;
1139
1140         if (!trace_probe_is_enabled(tp))
1141                 return;
1142
1143         if (file) {
1144                 if (trace_probe_remove_file(tp, file) < 0)
1145                         return;
1146
1147                 if (trace_probe_is_enabled(tp))
1148                         return;
1149         } else
1150                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1151
1152         __probe_event_disable(tp);
1153         uprobe_buffer_disable();
1154 }
1155
1156 static int uprobe_event_define_fields(struct trace_event_call *event_call)
1157 {
1158         int ret, size;
1159         struct uprobe_trace_entry_head field;
1160         struct trace_uprobe *tu;
1161
1162         tu = trace_uprobe_primary_from_call(event_call);
1163         if (unlikely(!tu))
1164                 return -ENODEV;
1165
1166         if (is_ret_probe(tu)) {
1167                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1168                 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1169                 size = SIZEOF_TRACE_ENTRY(true);
1170         } else {
1171                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1172                 size = SIZEOF_TRACE_ENTRY(false);
1173         }
1174
1175         return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1176 }
1177
1178 #ifdef CONFIG_PERF_EVENTS
1179 static bool
1180 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1181 {
1182         struct perf_event *event;
1183
1184         if (filter->nr_systemwide)
1185                 return true;
1186
1187         list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1188                 if (event->hw.target->mm == mm)
1189                         return true;
1190         }
1191
1192         return false;
1193 }
1194
1195 static inline bool
1196 uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
1197 {
1198         return __uprobe_perf_filter(&tu->filter, event->hw.target->mm);
1199 }
1200
1201 static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
1202 {
1203         bool done;
1204
1205         write_lock(&tu->filter.rwlock);
1206         if (event->hw.target) {
1207                 list_del(&event->hw.tp_list);
1208                 done = tu->filter.nr_systemwide ||
1209                         (event->hw.target->flags & PF_EXITING) ||
1210                         uprobe_filter_event(tu, event);
1211         } else {
1212                 tu->filter.nr_systemwide--;
1213                 done = tu->filter.nr_systemwide;
1214         }
1215         write_unlock(&tu->filter.rwlock);
1216
1217         if (!done)
1218                 return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1219
1220         return 0;
1221 }
1222
1223 static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
1224 {
1225         bool done;
1226         int err;
1227
1228         write_lock(&tu->filter.rwlock);
1229         if (event->hw.target) {
1230                 /*
1231                  * event->parent != NULL means copy_process(), we can avoid
1232                  * uprobe_apply(). current->mm must be probed and we can rely
1233                  * on dup_mmap() which preserves the already installed bp's.
1234                  *
1235                  * attr.enable_on_exec means that exec/mmap will install the
1236                  * breakpoints we need.
1237                  */
1238                 done = tu->filter.nr_systemwide ||
1239                         event->parent || event->attr.enable_on_exec ||
1240                         uprobe_filter_event(tu, event);
1241                 list_add(&event->hw.tp_list, &tu->filter.perf_events);
1242         } else {
1243                 done = tu->filter.nr_systemwide;
1244                 tu->filter.nr_systemwide++;
1245         }
1246         write_unlock(&tu->filter.rwlock);
1247
1248         err = 0;
1249         if (!done) {
1250                 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1251                 if (err)
1252                         uprobe_perf_close(tu, event);
1253         }
1254         return err;
1255 }
1256
1257 static int uprobe_perf_multi_call(struct trace_event_call *call,
1258                                   struct perf_event *event,
1259                 int (*op)(struct trace_uprobe *tu, struct perf_event *event))
1260 {
1261         struct trace_probe *pos, *tp;
1262         struct trace_uprobe *tu;
1263         int ret = 0;
1264
1265         tp = trace_probe_primary_from_call(call);
1266         if (WARN_ON_ONCE(!tp))
1267                 return -ENODEV;
1268
1269         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1270                 tu = container_of(pos, struct trace_uprobe, tp);
1271                 ret = op(tu, event);
1272                 if (ret)
1273                         break;
1274         }
1275
1276         return ret;
1277 }
1278 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1279                                 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1280 {
1281         struct trace_uprobe *tu;
1282         int ret;
1283
1284         tu = container_of(uc, struct trace_uprobe, consumer);
1285         read_lock(&tu->filter.rwlock);
1286         ret = __uprobe_perf_filter(&tu->filter, mm);
1287         read_unlock(&tu->filter.rwlock);
1288
1289         return ret;
1290 }
1291
1292 static void __uprobe_perf_func(struct trace_uprobe *tu,
1293                                unsigned long func, struct pt_regs *regs,
1294                                struct uprobe_cpu_buffer *ucb, int dsize)
1295 {
1296         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1297         struct uprobe_trace_entry_head *entry;
1298         struct hlist_head *head;
1299         void *data;
1300         int size, esize;
1301         int rctx;
1302
1303         if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1304                 return;
1305
1306         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1307
1308         size = esize + tu->tp.size + dsize;
1309         size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1310         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1311                 return;
1312
1313         preempt_disable();
1314         head = this_cpu_ptr(call->perf_events);
1315         if (hlist_empty(head))
1316                 goto out;
1317
1318         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1319         if (!entry)
1320                 goto out;
1321
1322         if (is_ret_probe(tu)) {
1323                 entry->vaddr[0] = func;
1324                 entry->vaddr[1] = instruction_pointer(regs);
1325                 data = DATAOF_TRACE_ENTRY(entry, true);
1326         } else {
1327                 entry->vaddr[0] = instruction_pointer(regs);
1328                 data = DATAOF_TRACE_ENTRY(entry, false);
1329         }
1330
1331         memcpy(data, ucb->buf, tu->tp.size + dsize);
1332
1333         if (size - esize > tu->tp.size + dsize) {
1334                 int len = tu->tp.size + dsize;
1335
1336                 memset(data + len, 0, size - esize - len);
1337         }
1338
1339         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1340                               head, NULL);
1341  out:
1342         preempt_enable();
1343 }
1344
1345 /* uprobe profile handler */
1346 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1347                             struct uprobe_cpu_buffer *ucb, int dsize)
1348 {
1349         if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1350                 return UPROBE_HANDLER_REMOVE;
1351
1352         if (!is_ret_probe(tu))
1353                 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1354         return 0;
1355 }
1356
1357 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1358                                 struct pt_regs *regs,
1359                                 struct uprobe_cpu_buffer *ucb, int dsize)
1360 {
1361         __uprobe_perf_func(tu, func, regs, ucb, dsize);
1362 }
1363
1364 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1365                         const char **filename, u64 *probe_offset,
1366                         bool perf_type_tracepoint)
1367 {
1368         const char *pevent = trace_event_name(event->tp_event);
1369         const char *group = event->tp_event->class->system;
1370         struct trace_uprobe *tu;
1371
1372         if (perf_type_tracepoint)
1373                 tu = find_probe_event(pevent, group);
1374         else
1375                 tu = event->tp_event->data;
1376         if (!tu)
1377                 return -EINVAL;
1378
1379         *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1380                                     : BPF_FD_TYPE_UPROBE;
1381         *filename = tu->filename;
1382         *probe_offset = tu->offset;
1383         return 0;
1384 }
1385 #endif  /* CONFIG_PERF_EVENTS */
1386
1387 static int
1388 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1389                       void *data)
1390 {
1391         struct trace_event_file *file = data;
1392
1393         switch (type) {
1394         case TRACE_REG_REGISTER:
1395                 return probe_event_enable(event, file, NULL);
1396
1397         case TRACE_REG_UNREGISTER:
1398                 probe_event_disable(event, file);
1399                 return 0;
1400
1401 #ifdef CONFIG_PERF_EVENTS
1402         case TRACE_REG_PERF_REGISTER:
1403                 return probe_event_enable(event, NULL, uprobe_perf_filter);
1404
1405         case TRACE_REG_PERF_UNREGISTER:
1406                 probe_event_disable(event, NULL);
1407                 return 0;
1408
1409         case TRACE_REG_PERF_OPEN:
1410                 return uprobe_perf_multi_call(event, data, uprobe_perf_open);
1411
1412         case TRACE_REG_PERF_CLOSE:
1413                 return uprobe_perf_multi_call(event, data, uprobe_perf_close);
1414
1415 #endif
1416         default:
1417                 return 0;
1418         }
1419         return 0;
1420 }
1421
1422 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1423 {
1424         struct trace_uprobe *tu;
1425         struct uprobe_dispatch_data udd;
1426         struct uprobe_cpu_buffer *ucb;
1427         int dsize, esize;
1428         int ret = 0;
1429
1430
1431         tu = container_of(con, struct trace_uprobe, consumer);
1432         tu->nhit++;
1433
1434         udd.tu = tu;
1435         udd.bp_addr = instruction_pointer(regs);
1436
1437         current->utask->vaddr = (unsigned long) &udd;
1438
1439         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1440                 return 0;
1441
1442         dsize = __get_data_size(&tu->tp, regs);
1443         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1444
1445         ucb = uprobe_buffer_get();
1446         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1447
1448         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1449                 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1450
1451 #ifdef CONFIG_PERF_EVENTS
1452         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1453                 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1454 #endif
1455         uprobe_buffer_put(ucb);
1456         return ret;
1457 }
1458
1459 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1460                                 unsigned long func, struct pt_regs *regs)
1461 {
1462         struct trace_uprobe *tu;
1463         struct uprobe_dispatch_data udd;
1464         struct uprobe_cpu_buffer *ucb;
1465         int dsize, esize;
1466
1467         tu = container_of(con, struct trace_uprobe, consumer);
1468
1469         udd.tu = tu;
1470         udd.bp_addr = func;
1471
1472         current->utask->vaddr = (unsigned long) &udd;
1473
1474         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1475                 return 0;
1476
1477         dsize = __get_data_size(&tu->tp, regs);
1478         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1479
1480         ucb = uprobe_buffer_get();
1481         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1482
1483         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1484                 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1485
1486 #ifdef CONFIG_PERF_EVENTS
1487         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1488                 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1489 #endif
1490         uprobe_buffer_put(ucb);
1491         return 0;
1492 }
1493
1494 static struct trace_event_functions uprobe_funcs = {
1495         .trace          = print_uprobe_event
1496 };
1497
1498 static inline void init_trace_event_call(struct trace_uprobe *tu)
1499 {
1500         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1501
1502         call->event.funcs = &uprobe_funcs;
1503         call->class->define_fields = uprobe_event_define_fields;
1504
1505         call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1506         call->class->reg = trace_uprobe_register;
1507 }
1508
1509 static int register_uprobe_event(struct trace_uprobe *tu)
1510 {
1511         init_trace_event_call(tu);
1512
1513         return trace_probe_register_event_call(&tu->tp);
1514 }
1515
1516 static int unregister_uprobe_event(struct trace_uprobe *tu)
1517 {
1518         return trace_probe_unregister_event_call(&tu->tp);
1519 }
1520
1521 #ifdef CONFIG_PERF_EVENTS
1522 struct trace_event_call *
1523 create_local_trace_uprobe(char *name, unsigned long offs,
1524                           unsigned long ref_ctr_offset, bool is_return)
1525 {
1526         struct trace_uprobe *tu;
1527         struct path path;
1528         int ret;
1529
1530         ret = kern_path(name, LOOKUP_FOLLOW, &path);
1531         if (ret)
1532                 return ERR_PTR(ret);
1533
1534         if (!d_is_reg(path.dentry)) {
1535                 path_put(&path);
1536                 return ERR_PTR(-EINVAL);
1537         }
1538
1539         /*
1540          * local trace_kprobes are not added to dyn_event, so they are never
1541          * searched in find_trace_kprobe(). Therefore, there is no concern of
1542          * duplicated name "DUMMY_EVENT" here.
1543          */
1544         tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1545                                 is_return);
1546
1547         if (IS_ERR(tu)) {
1548                 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1549                         (int)PTR_ERR(tu));
1550                 path_put(&path);
1551                 return ERR_CAST(tu);
1552         }
1553
1554         tu->offset = offs;
1555         tu->path = path;
1556         tu->ref_ctr_offset = ref_ctr_offset;
1557         tu->filename = kstrdup(name, GFP_KERNEL);
1558         init_trace_event_call(tu);
1559
1560         if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
1561                 ret = -ENOMEM;
1562                 goto error;
1563         }
1564
1565         return trace_probe_event_call(&tu->tp);
1566 error:
1567         free_trace_uprobe(tu);
1568         return ERR_PTR(ret);
1569 }
1570
1571 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1572 {
1573         struct trace_uprobe *tu;
1574
1575         tu = trace_uprobe_primary_from_call(event_call);
1576
1577         free_trace_uprobe(tu);
1578 }
1579 #endif /* CONFIG_PERF_EVENTS */
1580
1581 /* Make a trace interface for controling probe points */
1582 static __init int init_uprobe_trace(void)
1583 {
1584         struct dentry *d_tracer;
1585         int ret;
1586
1587         ret = dyn_event_register(&trace_uprobe_ops);
1588         if (ret)
1589                 return ret;
1590
1591         d_tracer = tracing_init_dentry();
1592         if (IS_ERR(d_tracer))
1593                 return 0;
1594
1595         trace_create_file("uprobe_events", 0644, d_tracer,
1596                                     NULL, &uprobe_events_ops);
1597         /* Profile interface */
1598         trace_create_file("uprobe_profile", 0444, d_tracer,
1599                                     NULL, &uprobe_profile_ops);
1600         return 0;
1601 }
1602
1603 fs_initcall(init_uprobe_trace);