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/security.h>
  11 #include <linux/ctype.h>
  12 #include <linux/module.h>
  13 #include <linux/uaccess.h>
  14 #include <linux/uprobes.h>
  15 #include <linux/namei.h>
  16 #include <linux/string.h>
  17 #include <linux/rculist.h>
  18
  19 #include "trace_dynevent.h"
  20 #include "trace_probe.h"
  21 #include "trace_probe_tmpl.h"
  22
  23 #define UPROBE_EVENT_SYSTEM     "uprobes"
  24
  25 struct uprobe_trace_entry_head {
  26         struct trace_entry      ent;
  27         unsigned long           vaddr[];
  28 };
  29
  30 #define SIZEOF_TRACE_ENTRY(is_return)                   \
  31         (sizeof(struct uprobe_trace_entry_head) +       \
  32          sizeof(unsigned long) * (is_return ? 2 : 1))
  33
  34 #define DATAOF_TRACE_ENTRY(entry, is_return)            \
  35         ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
  36
  37 struct trace_uprobe_filter {
  38         rwlock_t                rwlock;
  39         int                     nr_systemwide;
  40         struct list_head        perf_events;
  41 };
  42
  43 static int trace_uprobe_create(int argc, const char **argv);
  44 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
  45 static int trace_uprobe_release(struct dyn_event *ev);
  46 static bool trace_uprobe_is_busy(struct dyn_event *ev);
  47 static bool trace_uprobe_match(const char *system, const char *event,
  48                         int argc, const char **argv, struct dyn_event *ev);
  49
  50 static struct dyn_event_operations trace_uprobe_ops = {
  51         .create = trace_uprobe_create,
  52         .show = trace_uprobe_show,
  53         .is_busy = trace_uprobe_is_busy,
  54         .free = trace_uprobe_release,
  55         .match = trace_uprobe_match,
  56 };
  57
  58 /*
  59  * uprobe event core functions
  60  */
  61 struct trace_uprobe {
  62         struct dyn_event                devent;
  63         struct trace_uprobe_filter      filter;
  64         struct uprobe_consumer          consumer;
  65         struct path                     path;
  66         struct inode                    *inode;
  67         char                            *filename;
  68         unsigned long                   offset;
  69         unsigned long                   ref_ctr_offset;
  70         unsigned long                   nhit;
  71         struct trace_probe              tp;
  72 };
  73
  74 static bool is_trace_uprobe(struct dyn_event *ev)
  75 {
  76         return ev->ops == &trace_uprobe_ops;
  77 }
  78
  79 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
  80 {
  81         return container_of(ev, struct trace_uprobe, devent);
  82 }
  83
  84 /**
  85  * for_each_trace_uprobe - iterate over the trace_uprobe list
  86  * @pos:        the struct trace_uprobe * for each entry
  87  * @dpos:       the struct dyn_event * to use as a loop cursor
  88  */
  89 #define for_each_trace_uprobe(pos, dpos)        \
  90         for_each_dyn_event(dpos)                \
  91                 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
  92
  93 #define SIZEOF_TRACE_UPROBE(n)                          \
  94         (offsetof(struct trace_uprobe, tp.args) +       \
  95         (sizeof(struct probe_arg) * (n)))
  96
  97 static int register_uprobe_event(struct trace_uprobe *tu);
  98 static int unregister_uprobe_event(struct trace_uprobe *tu);
  99
 100 struct uprobe_dispatch_data {
 101         struct trace_uprobe     *tu;
 102         unsigned long           bp_addr;
 103 };
 104
 105 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
 106 static int uretprobe_dispatcher(struct uprobe_consumer *con,
 107                                 unsigned long func, struct pt_regs *regs);
 108
 109 #ifdef CONFIG_STACK_GROWSUP
 110 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 111 {
 112         return addr - (n * sizeof(long));
 113 }
 114 #else
 115 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 116 {
 117         return addr + (n * sizeof(long));
 118 }
 119 #endif
 120
 121 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
 122 {
 123         unsigned long ret;
 124         unsigned long addr = user_stack_pointer(regs);
 125
 126         addr = adjust_stack_addr(addr, n);
 127
 128         if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
 129                 return 0;
 130
 131         return ret;
 132 }
 133
 134 /*
 135  * Uprobes-specific fetch functions
 136  */
 137 static nokprobe_inline int
 138 probe_mem_read(void *dest, void *src, size_t size)
 139 {
 140         void __user *vaddr = (void __force __user *)src;
 141
 142         return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
 143 }
 144
 145 static nokprobe_inline int
 146 probe_mem_read_user(void *dest, void *src, size_t size)
 147 {
 148         return probe_mem_read(dest, src, size);
 149 }
 150
 151 /*
 152  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
 153  * length and relative data location.
 154  */
 155 static nokprobe_inline int
 156 fetch_store_string(unsigned long addr, void *dest, void *base)
 157 {
 158         long ret;
 159         u32 loc = *(u32 *)dest;
 160         int maxlen  = get_loc_len(loc);
 161         u8 *dst = get_loc_data(dest, base);
 162         void __user *src = (void __force __user *) addr;
 163
 164         if (unlikely(!maxlen))
 165                 return -ENOMEM;
 166
 167         if (addr == FETCH_TOKEN_COMM)
 168                 ret = strlcpy(dst, current->comm, maxlen);
 169         else
 170                 ret = strncpy_from_user(dst, src, maxlen);
 171         if (ret >= 0) {
 172                 if (ret == maxlen)
 173                         dst[ret - 1] = '\0';
 174                 else
 175                         /*
 176                          * Include the terminating null byte. In this case it
 177                          * was copied by strncpy_from_user but not accounted
 178                          * for in ret.
 179                          */
 180                         ret++;
 181                 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
 182         }
 183
 184         return ret;
 185 }
 186
 187 static nokprobe_inline int
 188 fetch_store_string_user(unsigned long addr, void *dest, void *base)
 189 {
 190         return fetch_store_string(addr, dest, base);
 191 }
 192
 193 /* Return the length of string -- including null terminal byte */
 194 static nokprobe_inline int
 195 fetch_store_strlen(unsigned long addr)
 196 {
 197         int len;
 198         void __user *vaddr = (void __force __user *) addr;
 199
 200         if (addr == FETCH_TOKEN_COMM)
 201                 len = strlen(current->comm) + 1;
 202         else
 203                 len = strnlen_user(vaddr, MAX_STRING_SIZE);
 204
 205         return (len > MAX_STRING_SIZE) ? 0 : len;
 206 }
 207
 208 static nokprobe_inline int
 209 fetch_store_strlen_user(unsigned long addr)
 210 {
 211         return fetch_store_strlen(addr);
 212 }
 213
 214 static unsigned long translate_user_vaddr(unsigned long file_offset)
 215 {
 216         unsigned long base_addr;
 217         struct uprobe_dispatch_data *udd;
 218
 219         udd = (void *) current->utask->vaddr;
 220
 221         base_addr = udd->bp_addr - udd->tu->offset;
 222         return base_addr + file_offset;
 223 }
 224
 225 /* Note that we don't verify it, since the code does not come from user space */
 226 static int
 227 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 228                    void *base)
 229 {
 230         unsigned long val;
 231
 232         /* 1st stage: get value from context */
 233         switch (code->op) {
 234         case FETCH_OP_REG:
 235                 val = regs_get_register(regs, code->param);
 236                 break;
 237         case FETCH_OP_STACK:
 238                 val = get_user_stack_nth(regs, code->param);
 239                 break;
 240         case FETCH_OP_STACKP:
 241                 val = user_stack_pointer(regs);
 242                 break;
 243         case FETCH_OP_RETVAL:
 244                 val = regs_return_value(regs);
 245                 break;
 246         case FETCH_OP_IMM:
 247                 val = code->immediate;
 248                 break;
 249         case FETCH_OP_COMM:
 250                 val = FETCH_TOKEN_COMM;
 251                 break;
 252         case FETCH_OP_DATA:
 253                 val = (unsigned long)code->data;
 254                 break;
 255         case FETCH_OP_FOFFS:
 256                 val = translate_user_vaddr(code->immediate);
 257                 break;
 258         default:
 259                 return -EILSEQ;
 260         }
 261         code++;
 262
 263         return process_fetch_insn_bottom(code, val, dest, base);
 264 }
 265 NOKPROBE_SYMBOL(process_fetch_insn)
 266
 267 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
 268 {
 269         rwlock_init(&filter->rwlock);
 270         filter->nr_systemwide = 0;
 271         INIT_LIST_HEAD(&filter->perf_events);
 272 }
 273
 274 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
 275 {
 276         return !filter->nr_systemwide && list_empty(&filter->perf_events);
 277 }
 278
 279 static inline bool is_ret_probe(struct trace_uprobe *tu)
 280 {
 281         return tu->consumer.ret_handler != NULL;
 282 }
 283
 284 static bool trace_uprobe_is_busy(struct dyn_event *ev)
 285 {
 286         struct trace_uprobe *tu = to_trace_uprobe(ev);
 287
 288         return trace_probe_is_enabled(&tu->tp);
 289 }
 290
 291 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
 292                                             int argc, const char **argv)
 293 {
 294         char buf[MAX_ARGSTR_LEN + 1];
 295         int len;
 296
 297         if (!argc)
 298                 return true;
 299
 300         len = strlen(tu->filename);
 301         if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
 302                 return false;
 303
 304         if (tu->ref_ctr_offset == 0)
 305                 snprintf(buf, sizeof(buf), "0x%0*lx",
 306                                 (int)(sizeof(void *) * 2), tu->offset);
 307         else
 308                 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
 309                                 (int)(sizeof(void *) * 2), tu->offset,
 310                                 tu->ref_ctr_offset);
 311         if (strcmp(buf, &argv[0][len + 1]))
 312                 return false;
 313
 314         argc--; argv++;
 315
 316         return trace_probe_match_command_args(&tu->tp, argc, argv);
 317 }
 318
 319 static bool trace_uprobe_match(const char *system, const char *event,
 320                         int argc, const char **argv, struct dyn_event *ev)
 321 {
 322         struct trace_uprobe *tu = to_trace_uprobe(ev);
 323
 324         return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 325            (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
 326            trace_uprobe_match_command_head(tu, argc, argv);
 327 }
 328
 329 static nokprobe_inline struct trace_uprobe *
 330 trace_uprobe_primary_from_call(struct trace_event_call *call)
 331 {
 332         struct trace_probe *tp;
 333
 334         tp = trace_probe_primary_from_call(call);
 335         if (WARN_ON_ONCE(!tp))
 336                 return NULL;
 337
 338         return container_of(tp, struct trace_uprobe, tp);
 339 }
 340
 341 /*
 342  * Allocate new trace_uprobe and initialize it (including uprobes).
 343  */
 344 static struct trace_uprobe *
 345 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 346 {
 347         struct trace_uprobe *tu;
 348         int ret;
 349
 350         tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
 351         if (!tu)
 352                 return ERR_PTR(-ENOMEM);
 353
 354         ret = trace_probe_init(&tu->tp, event, group);
 355         if (ret < 0)
 356                 goto error;
 357
 358         dyn_event_init(&tu->devent, &trace_uprobe_ops);
 359         tu->consumer.handler = uprobe_dispatcher;
 360         if (is_ret)
 361                 tu->consumer.ret_handler = uretprobe_dispatcher;
 362         init_trace_uprobe_filter(&tu->filter);
 363         return tu;
 364
 365 error:
 366         kfree(tu);
 367
 368         return ERR_PTR(ret);
 369 }
 370
 371 static void free_trace_uprobe(struct trace_uprobe *tu)
 372 {
 373         if (!tu)
 374                 return;
 375
 376         path_put(&tu->path);
 377         trace_probe_cleanup(&tu->tp);
 378         kfree(tu->filename);
 379         kfree(tu);
 380 }
 381
 382 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
 383 {
 384         struct dyn_event *pos;
 385         struct trace_uprobe *tu;
 386
 387         for_each_trace_uprobe(tu, pos)
 388                 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 389                     strcmp(trace_probe_group_name(&tu->tp), group) == 0)
 390                         return tu;
 391
 392         return NULL;
 393 }
 394
 395 /* Unregister a trace_uprobe and probe_event */
 396 static int unregister_trace_uprobe(struct trace_uprobe *tu)
 397 {
 398         int ret;
 399
 400         if (trace_probe_has_sibling(&tu->tp))
 401                 goto unreg;
 402
 403         ret = unregister_uprobe_event(tu);
 404         if (ret)
 405                 return ret;
 406
 407 unreg:
 408         dyn_event_remove(&tu->devent);
 409         trace_probe_unlink(&tu->tp);
 410         free_trace_uprobe(tu);
 411         return 0;
 412 }
 413
 414 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
 415                                          struct trace_uprobe *comp)
 416 {
 417         struct trace_probe_event *tpe = orig->tp.event;
 418         struct trace_probe *pos;
 419         struct inode *comp_inode = d_real_inode(comp->path.dentry);
 420         int i;
 421
 422         list_for_each_entry(pos, &tpe->probes, list) {
 423                 orig = container_of(pos, struct trace_uprobe, tp);
 424                 if (comp_inode != d_real_inode(orig->path.dentry) ||
 425                     comp->offset != orig->offset)
 426                         continue;
 427
 428                 /*
 429                  * trace_probe_compare_arg_type() ensured that nr_args and
 430                  * each argument name and type are same. Let's compare comm.
 431                  */
 432                 for (i = 0; i < orig->tp.nr_args; i++) {
 433                         if (strcmp(orig->tp.args[i].comm,
 434                                    comp->tp.args[i].comm))
 435                                 break;
 436                 }
 437
 438                 if (i == orig->tp.nr_args)
 439                         return true;
 440         }
 441
 442         return false;
 443 }
 444
 445 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
 446 {
 447         int ret;
 448
 449         ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
 450         if (ret) {
 451                 /* Note that argument starts index = 2 */
 452                 trace_probe_log_set_index(ret + 1);
 453                 trace_probe_log_err(0, DIFF_ARG_TYPE);
 454                 return -EEXIST;
 455         }
 456         if (trace_uprobe_has_same_uprobe(to, tu)) {
 457                 trace_probe_log_set_index(0);
 458                 trace_probe_log_err(0, SAME_PROBE);
 459                 return -EEXIST;
 460         }
 461
 462         /* Append to existing event */
 463         ret = trace_probe_append(&tu->tp, &to->tp);
 464         if (!ret)
 465                 dyn_event_add(&tu->devent);
 466
 467         return ret;
 468 }
 469
 470 /*
 471  * Uprobe with multiple reference counter is not allowed. i.e.
 472  * If inode and offset matches, reference counter offset *must*
 473  * match as well. Though, there is one exception: If user is
 474  * replacing old trace_uprobe with new one(same group/event),
 475  * then we allow same uprobe with new reference counter as far
 476  * as the new one does not conflict with any other existing
 477  * ones.
 478  */
 479 static int validate_ref_ctr_offset(struct trace_uprobe *new)
 480 {
 481         struct dyn_event *pos;
 482         struct trace_uprobe *tmp;
 483         struct inode *new_inode = d_real_inode(new->path.dentry);
 484
 485         for_each_trace_uprobe(tmp, pos) {
 486                 if (new_inode == d_real_inode(tmp->path.dentry) &&
 487                     new->offset == tmp->offset &&
 488                     new->ref_ctr_offset != tmp->ref_ctr_offset) {
 489                         pr_warn("Reference counter offset mismatch.");
 490                         return -EINVAL;
 491                 }
 492         }
 493         return 0;
 494 }
 495
 496 /* Register a trace_uprobe and probe_event */
 497 static int register_trace_uprobe(struct trace_uprobe *tu)
 498 {
 499         struct trace_uprobe *old_tu;
 500         int ret;
 501
 502         mutex_lock(&event_mutex);
 503
 504         ret = validate_ref_ctr_offset(tu);
 505         if (ret)
 506                 goto end;
 507
 508         /* register as an event */
 509         old_tu = find_probe_event(trace_probe_name(&tu->tp),
 510                                   trace_probe_group_name(&tu->tp));
 511         if (old_tu) {
 512                 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
 513                         trace_probe_log_set_index(0);
 514                         trace_probe_log_err(0, DIFF_PROBE_TYPE);
 515                         ret = -EEXIST;
 516                 } else {
 517                         ret = append_trace_uprobe(tu, old_tu);
 518                 }
 519                 goto end;
 520         }
 521
 522         ret = register_uprobe_event(tu);
 523         if (ret) {
 524                 pr_warn("Failed to register probe event(%d)\n", ret);
 525                 goto end;
 526         }
 527
 528         dyn_event_add(&tu->devent);
 529
 530 end:
 531         mutex_unlock(&event_mutex);
 532
 533         return ret;
 534 }
 535
 536 /*
 537  * Argument syntax:
 538  *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
 539  */
 540 static int trace_uprobe_create(int argc, const char **argv)
 541 {
 542         struct trace_uprobe *tu;
 543         const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
 544         char *arg, *filename, *rctr, *rctr_end, *tmp;
 545         char buf[MAX_EVENT_NAME_LEN];
 546         struct path path;
 547         unsigned long offset, ref_ctr_offset;
 548         bool is_return = false;
 549         int i, ret;
 550
 551         ret = 0;
 552         ref_ctr_offset = 0;
 553
 554         switch (argv[0][0]) {
 555         case 'r':
 556                 is_return = true;
 557                 break;
 558         case 'p':
 559                 break;
 560         default:
 561                 return -ECANCELED;
 562         }
 563
 564         if (argc < 2)
 565                 return -ECANCELED;
 566
 567         if (argv[0][1] == ':')
 568                 event = &argv[0][2];
 569
 570         if (!strchr(argv[1], '/'))
 571                 return -ECANCELED;
 572
 573         filename = kstrdup(argv[1], GFP_KERNEL);
 574         if (!filename)
 575                 return -ENOMEM;
 576
 577         /* Find the last occurrence, in case the path contains ':' too. */
 578         arg = strrchr(filename, ':');
 579         if (!arg || !isdigit(arg[1])) {
 580                 kfree(filename);
 581                 return -ECANCELED;
 582         }
 583
 584         trace_probe_log_init("trace_uprobe", argc, argv);
 585         trace_probe_log_set_index(1);   /* filename is the 2nd argument */
 586
 587         *arg++ = '\0';
 588         ret = kern_path(filename, LOOKUP_FOLLOW, &path);
 589         if (ret) {
 590                 trace_probe_log_err(0, FILE_NOT_FOUND);
 591                 kfree(filename);
 592                 trace_probe_log_clear();
 593                 return ret;
 594         }
 595         if (!d_is_reg(path.dentry)) {
 596                 trace_probe_log_err(0, NO_REGULAR_FILE);
 597                 ret = -EINVAL;
 598                 goto fail_address_parse;
 599         }
 600
 601         /* Parse reference counter offset if specified. */
 602         rctr = strchr(arg, '(');
 603         if (rctr) {
 604                 rctr_end = strchr(rctr, ')');
 605                 if (!rctr_end) {
 606                         ret = -EINVAL;
 607                         rctr_end = rctr + strlen(rctr);
 608                         trace_probe_log_err(rctr_end - filename,
 609                                             REFCNT_OPEN_BRACE);
 610                         goto fail_address_parse;
 611                 } else if (rctr_end[1] != '\0') {
 612                         ret = -EINVAL;
 613                         trace_probe_log_err(rctr_end + 1 - filename,
 614                                             BAD_REFCNT_SUFFIX);
 615                         goto fail_address_parse;
 616                 }
 617
 618                 *rctr++ = '\0';
 619                 *rctr_end = '\0';
 620                 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
 621                 if (ret) {
 622                         trace_probe_log_err(rctr - filename, BAD_REFCNT);
 623                         goto fail_address_parse;
 624                 }
 625         }
 626
 627         /* Parse uprobe offset. */
 628         ret = kstrtoul(arg, 0, &offset);
 629         if (ret) {
 630                 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
 631                 goto fail_address_parse;
 632         }
 633
 634         /* setup a probe */
 635         trace_probe_log_set_index(0);
 636         if (event) {
 637                 ret = traceprobe_parse_event_name(&event, &group, buf,
 638                                                   event - argv[0]);
 639                 if (ret)
 640                         goto fail_address_parse;
 641         } else {
 642                 char *tail;
 643                 char *ptr;
 644
 645                 tail = kstrdup(kbasename(filename), GFP_KERNEL);
 646                 if (!tail) {
 647                         ret = -ENOMEM;
 648                         goto fail_address_parse;
 649                 }
 650
 651                 ptr = strpbrk(tail, ".-_");
 652                 if (ptr)
 653                         *ptr = '\0';
 654
 655                 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
 656                 event = buf;
 657                 kfree(tail);
 658         }
 659
 660         argc -= 2;
 661         argv += 2;
 662
 663         tu = alloc_trace_uprobe(group, event, argc, is_return);
 664         if (IS_ERR(tu)) {
 665                 ret = PTR_ERR(tu);
 666                 /* This must return -ENOMEM otherwise there is a bug */
 667                 WARN_ON_ONCE(ret != -ENOMEM);
 668                 goto fail_address_parse;
 669         }
 670         tu->offset = offset;
 671         tu->ref_ctr_offset = ref_ctr_offset;
 672         tu->path = path;
 673         tu->filename = filename;
 674
 675         /* parse arguments */
 676         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 677                 tmp = kstrdup(argv[i], GFP_KERNEL);
 678                 if (!tmp) {
 679                         ret = -ENOMEM;
 680                         goto error;
 681                 }
 682
 683                 trace_probe_log_set_index(i + 2);
 684                 ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
 685                                         is_return ? TPARG_FL_RETURN : 0);
 686                 kfree(tmp);
 687                 if (ret)
 688                         goto error;
 689         }
 690
 691         ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu));
 692         if (ret < 0)
 693                 goto error;
 694
 695         ret = register_trace_uprobe(tu);
 696         if (!ret)
 697                 goto out;
 698
 699 error:
 700         free_trace_uprobe(tu);
 701 out:
 702         trace_probe_log_clear();
 703         return ret;
 704
 705 fail_address_parse:
 706         trace_probe_log_clear();
 707         path_put(&path);
 708         kfree(filename);
 709
 710         return ret;
 711 }
 712
 713 static int create_or_delete_trace_uprobe(int argc, char **argv)
 714 {
 715         int ret;
 716
 717         if (argv[0][0] == '-')
 718                 return dyn_event_release(argc, argv, &trace_uprobe_ops);
 719
 720         ret = trace_uprobe_create(argc, (const char **)argv);
 721         return ret == -ECANCELED ? -EINVAL : ret;
 722 }
 723
 724 static int trace_uprobe_release(struct dyn_event *ev)
 725 {
 726         struct trace_uprobe *tu = to_trace_uprobe(ev);
 727
 728         return unregister_trace_uprobe(tu);
 729 }
 730
 731 /* Probes listing interfaces */
 732 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
 733 {
 734         struct trace_uprobe *tu = to_trace_uprobe(ev);
 735         char c = is_ret_probe(tu) ? 'r' : 'p';
 736         int i;
 737
 738         seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
 739                         trace_probe_name(&tu->tp), tu->filename,
 740                         (int)(sizeof(void *) * 2), tu->offset);
 741
 742         if (tu->ref_ctr_offset)
 743                 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
 744
 745         for (i = 0; i < tu->tp.nr_args; i++)
 746                 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
 747
 748         seq_putc(m, '\n');
 749         return 0;
 750 }
 751
 752 static int probes_seq_show(struct seq_file *m, void *v)
 753 {
 754         struct dyn_event *ev = v;
 755
 756         if (!is_trace_uprobe(ev))
 757                 return 0;
 758
 759         return trace_uprobe_show(m, ev);
 760 }
 761
 762 static const struct seq_operations probes_seq_op = {
 763         .start  = dyn_event_seq_start,
 764         .next   = dyn_event_seq_next,
 765         .stop   = dyn_event_seq_stop,
 766         .show   = probes_seq_show
 767 };
 768
 769 static int probes_open(struct inode *inode, struct file *file)
 770 {
 771         int ret;
 772
 773         ret = security_locked_down(LOCKDOWN_TRACEFS);
 774         if (ret)
 775                 return ret;
 776
 777         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 778                 ret = dyn_events_release_all(&trace_uprobe_ops);
 779                 if (ret)
 780                         return ret;
 781         }
 782
 783         return seq_open(file, &probes_seq_op);
 784 }
 785
 786 static ssize_t probes_write(struct file *file, const char __user *buffer,
 787                             size_t count, loff_t *ppos)
 788 {
 789         return trace_parse_run_command(file, buffer, count, ppos,
 790                                         create_or_delete_trace_uprobe);
 791 }
 792
 793 static const struct file_operations uprobe_events_ops = {
 794         .owner          = THIS_MODULE,
 795         .open           = probes_open,
 796         .read           = seq_read,
 797         .llseek         = seq_lseek,
 798         .release        = seq_release,
 799         .write          = probes_write,
 800 };
 801
 802 /* Probes profiling interfaces */
 803 static int probes_profile_seq_show(struct seq_file *m, void *v)
 804 {
 805         struct dyn_event *ev = v;
 806         struct trace_uprobe *tu;
 807
 808         if (!is_trace_uprobe(ev))
 809                 return 0;
 810
 811         tu = to_trace_uprobe(ev);
 812         seq_printf(m, "  %s %-44s %15lu\n", tu->filename,
 813                         trace_probe_name(&tu->tp), tu->nhit);
 814         return 0;
 815 }
 816
 817 static const struct seq_operations profile_seq_op = {
 818         .start  = dyn_event_seq_start,
 819         .next   = dyn_event_seq_next,
 820         .stop   = dyn_event_seq_stop,
 821         .show   = probes_profile_seq_show
 822 };
 823
 824 static int profile_open(struct inode *inode, struct file *file)
 825 {
 826         int ret;
 827
 828         ret = security_locked_down(LOCKDOWN_TRACEFS);
 829         if (ret)
 830                 return ret;
 831
 832         return seq_open(file, &profile_seq_op);
 833 }
 834
 835 static const struct file_operations uprobe_profile_ops = {
 836         .owner          = THIS_MODULE,
 837         .open           = profile_open,
 838         .read           = seq_read,
 839         .llseek         = seq_lseek,
 840         .release        = seq_release,
 841 };
 842
 843 struct uprobe_cpu_buffer {
 844         struct mutex mutex;
 845         void *buf;
 846 };
 847 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
 848 static int uprobe_buffer_refcnt;
 849
 850 static int uprobe_buffer_init(void)
 851 {
 852         int cpu, err_cpu;
 853
 854         uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
 855         if (uprobe_cpu_buffer == NULL)
 856                 return -ENOMEM;
 857
 858         for_each_possible_cpu(cpu) {
 859                 struct page *p = alloc_pages_node(cpu_to_node(cpu),
 860                                                   GFP_KERNEL, 0);
 861                 if (p == NULL) {
 862                         err_cpu = cpu;
 863                         goto err;
 864                 }
 865                 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
 866                 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
 867         }
 868
 869         return 0;
 870
 871 err:
 872         for_each_possible_cpu(cpu) {
 873                 if (cpu == err_cpu)
 874                         break;
 875                 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
 876         }
 877
 878         free_percpu(uprobe_cpu_buffer);
 879         return -ENOMEM;
 880 }
 881
 882 static int uprobe_buffer_enable(void)
 883 {
 884         int ret = 0;
 885
 886         BUG_ON(!mutex_is_locked(&event_mutex));
 887
 888         if (uprobe_buffer_refcnt++ == 0) {
 889                 ret = uprobe_buffer_init();
 890                 if (ret < 0)
 891                         uprobe_buffer_refcnt--;
 892         }
 893
 894         return ret;
 895 }
 896
 897 static void uprobe_buffer_disable(void)
 898 {
 899         int cpu;
 900
 901         BUG_ON(!mutex_is_locked(&event_mutex));
 902
 903         if (--uprobe_buffer_refcnt == 0) {
 904                 for_each_possible_cpu(cpu)
 905                         free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
 906                                                              cpu)->buf);
 907
 908                 free_percpu(uprobe_cpu_buffer);
 909                 uprobe_cpu_buffer = NULL;
 910         }
 911 }
 912
 913 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
 914 {
 915         struct uprobe_cpu_buffer *ucb;
 916         int cpu;
 917
 918         cpu = raw_smp_processor_id();
 919         ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
 920
 921         /*
 922          * Use per-cpu buffers for fastest access, but we might migrate
 923          * so the mutex makes sure we have sole access to it.
 924          */
 925         mutex_lock(&ucb->mutex);
 926
 927         return ucb;
 928 }
 929
 930 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
 931 {
 932         mutex_unlock(&ucb->mutex);
 933 }
 934
 935 static void __uprobe_trace_func(struct trace_uprobe *tu,
 936                                 unsigned long func, struct pt_regs *regs,
 937                                 struct uprobe_cpu_buffer *ucb, int dsize,
 938                                 struct trace_event_file *trace_file)
 939 {
 940         struct uprobe_trace_entry_head *entry;
 941         struct ring_buffer_event *event;
 942         struct ring_buffer *buffer;
 943         void *data;
 944         int size, esize;
 945         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
 946
 947         WARN_ON(call != trace_file->event_call);
 948
 949         if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
 950                 return;
 951
 952         if (trace_trigger_soft_disabled(trace_file))
 953                 return;
 954
 955         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 956         size = esize + tu->tp.size + dsize;
 957         event = trace_event_buffer_lock_reserve(&buffer, trace_file,
 958                                                 call->event.type, size, 0, 0);
 959         if (!event)
 960                 return;
 961
 962         entry = ring_buffer_event_data(event);
 963         if (is_ret_probe(tu)) {
 964                 entry->vaddr[0] = func;
 965                 entry->vaddr[1] = instruction_pointer(regs);
 966                 data = DATAOF_TRACE_ENTRY(entry, true);
 967         } else {
 968                 entry->vaddr[0] = instruction_pointer(regs);
 969                 data = DATAOF_TRACE_ENTRY(entry, false);
 970         }
 971
 972         memcpy(data, ucb->buf, tu->tp.size + dsize);
 973
 974         event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
 975 }
 976
 977 /* uprobe handler */
 978 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
 979                              struct uprobe_cpu_buffer *ucb, int dsize)
 980 {
 981         struct event_file_link *link;
 982
 983         if (is_ret_probe(tu))
 984                 return 0;
 985
 986         rcu_read_lock();
 987         trace_probe_for_each_link_rcu(link, &tu->tp)
 988                 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
 989         rcu_read_unlock();
 990
 991         return 0;
 992 }
 993
 994 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
 995                                  struct pt_regs *regs,
 996                                  struct uprobe_cpu_buffer *ucb, int dsize)
 997 {
 998         struct event_file_link *link;
 999
1000         rcu_read_lock();
1001         trace_probe_for_each_link_rcu(link, &tu->tp)
1002                 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
1003         rcu_read_unlock();
1004 }
1005
1006 /* Event entry printers */
1007 static enum print_line_t
1008 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1009 {
1010         struct uprobe_trace_entry_head *entry;
1011         struct trace_seq *s = &iter->seq;
1012         struct trace_uprobe *tu;
1013         u8 *data;
1014
1015         entry = (struct uprobe_trace_entry_head *)iter->ent;
1016         tu = trace_uprobe_primary_from_call(
1017                 container_of(event, struct trace_event_call, event));
1018         if (unlikely(!tu))
1019                 goto out;
1020
1021         if (is_ret_probe(tu)) {
1022                 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1023                                  trace_probe_name(&tu->tp),
1024                                  entry->vaddr[1], entry->vaddr[0]);
1025                 data = DATAOF_TRACE_ENTRY(entry, true);
1026         } else {
1027                 trace_seq_printf(s, "%s: (0x%lx)",
1028                                  trace_probe_name(&tu->tp),
1029                                  entry->vaddr[0]);
1030                 data = DATAOF_TRACE_ENTRY(entry, false);
1031         }
1032
1033         if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1034                 goto out;
1035
1036         trace_seq_putc(s, '\n');
1037
1038  out:
1039         return trace_handle_return(s);
1040 }
1041
1042 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1043                                 enum uprobe_filter_ctx ctx,
1044                                 struct mm_struct *mm);
1045
1046 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1047 {
1048         int ret;
1049
1050         tu->consumer.filter = filter;
1051         tu->inode = d_real_inode(tu->path.dentry);
1052
1053         if (tu->ref_ctr_offset)
1054                 ret = uprobe_register_refctr(tu->inode, tu->offset,
1055                                 tu->ref_ctr_offset, &tu->consumer);
1056         else
1057                 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1058
1059         if (ret)
1060                 tu->inode = NULL;
1061
1062         return ret;
1063 }
1064
1065 static void __probe_event_disable(struct trace_probe *tp)
1066 {
1067         struct trace_probe *pos;
1068         struct trace_uprobe *tu;
1069
1070         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1071                 tu = container_of(pos, struct trace_uprobe, tp);
1072                 if (!tu->inode)
1073                         continue;
1074
1075                 WARN_ON(!uprobe_filter_is_empty(&tu->filter));
1076
1077                 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1078                 tu->inode = NULL;
1079         }
1080 }
1081
1082 static int probe_event_enable(struct trace_event_call *call,
1083                         struct trace_event_file *file, filter_func_t filter)
1084 {
1085         struct trace_probe *pos, *tp;
1086         struct trace_uprobe *tu;
1087         bool enabled;
1088         int ret;
1089
1090         tp = trace_probe_primary_from_call(call);
1091         if (WARN_ON_ONCE(!tp))
1092                 return -ENODEV;
1093         enabled = trace_probe_is_enabled(tp);
1094
1095         /* This may also change "enabled" state */
1096         if (file) {
1097                 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1098                         return -EINTR;
1099
1100                 ret = trace_probe_add_file(tp, file);
1101                 if (ret < 0)
1102                         return ret;
1103         } else {
1104                 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1105                         return -EINTR;
1106
1107                 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1108         }
1109
1110         tu = container_of(tp, struct trace_uprobe, tp);
1111         WARN_ON(!uprobe_filter_is_empty(&tu->filter));
1112
1113         if (enabled)
1114                 return 0;
1115
1116         ret = uprobe_buffer_enable();
1117         if (ret)
1118                 goto err_flags;
1119
1120         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1121                 tu = container_of(pos, struct trace_uprobe, tp);
1122                 ret = trace_uprobe_enable(tu, filter);
1123                 if (ret) {
1124                         __probe_event_disable(tp);
1125                         goto err_buffer;
1126                 }
1127         }
1128
1129         return 0;
1130
1131  err_buffer:
1132         uprobe_buffer_disable();
1133
1134  err_flags:
1135         if (file)
1136                 trace_probe_remove_file(tp, file);
1137         else
1138                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1139
1140         return ret;
1141 }
1142
1143 static void probe_event_disable(struct trace_event_call *call,
1144                                 struct trace_event_file *file)
1145 {
1146         struct trace_probe *tp;
1147
1148         tp = trace_probe_primary_from_call(call);
1149         if (WARN_ON_ONCE(!tp))
1150                 return;
1151
1152         if (!trace_probe_is_enabled(tp))
1153                 return;
1154
1155         if (file) {
1156                 if (trace_probe_remove_file(tp, file) < 0)
1157                         return;
1158
1159                 if (trace_probe_is_enabled(tp))
1160                         return;
1161         } else
1162                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1163
1164         __probe_event_disable(tp);
1165         uprobe_buffer_disable();
1166 }
1167
1168 static int uprobe_event_define_fields(struct trace_event_call *event_call)
1169 {
1170         int ret, size;
1171         struct uprobe_trace_entry_head field;
1172         struct trace_uprobe *tu;
1173
1174         tu = trace_uprobe_primary_from_call(event_call);
1175         if (unlikely(!tu))
1176                 return -ENODEV;
1177
1178         if (is_ret_probe(tu)) {
1179                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1180                 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1181                 size = SIZEOF_TRACE_ENTRY(true);
1182         } else {
1183                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1184                 size = SIZEOF_TRACE_ENTRY(false);
1185         }
1186
1187         return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1188 }
1189
1190 #ifdef CONFIG_PERF_EVENTS
1191 static bool
1192 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1193 {
1194         struct perf_event *event;
1195
1196         if (filter->nr_systemwide)
1197                 return true;
1198
1199         list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1200                 if (event->hw.target->mm == mm)
1201                         return true;
1202         }
1203
1204         return false;
1205 }
1206
1207 static inline bool
1208 uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
1209 {
1210         return __uprobe_perf_filter(&tu->filter, event->hw.target->mm);
1211 }
1212
1213 static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
1214 {
1215         bool done;
1216
1217         write_lock(&tu->filter.rwlock);
1218         if (event->hw.target) {
1219                 list_del(&event->hw.tp_list);
1220                 done = tu->filter.nr_systemwide ||
1221                         (event->hw.target->flags & PF_EXITING) ||
1222                         uprobe_filter_event(tu, event);
1223         } else {
1224                 tu->filter.nr_systemwide--;
1225                 done = tu->filter.nr_systemwide;
1226         }
1227         write_unlock(&tu->filter.rwlock);
1228
1229         if (!done)
1230                 return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1231
1232         return 0;
1233 }
1234
1235 static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
1236 {
1237         bool done;
1238         int err;
1239
1240         write_lock(&tu->filter.rwlock);
1241         if (event->hw.target) {
1242                 /*
1243                  * event->parent != NULL means copy_process(), we can avoid
1244                  * uprobe_apply(). current->mm must be probed and we can rely
1245                  * on dup_mmap() which preserves the already installed bp's.
1246                  *
1247                  * attr.enable_on_exec means that exec/mmap will install the
1248                  * breakpoints we need.
1249                  */
1250                 done = tu->filter.nr_systemwide ||
1251                         event->parent || event->attr.enable_on_exec ||
1252                         uprobe_filter_event(tu, event);
1253                 list_add(&event->hw.tp_list, &tu->filter.perf_events);
1254         } else {
1255                 done = tu->filter.nr_systemwide;
1256                 tu->filter.nr_systemwide++;
1257         }
1258         write_unlock(&tu->filter.rwlock);
1259
1260         err = 0;
1261         if (!done) {
1262                 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1263                 if (err)
1264                         uprobe_perf_close(tu, event);
1265         }
1266         return err;
1267 }
1268
1269 static int uprobe_perf_multi_call(struct trace_event_call *call,
1270                                   struct perf_event *event,
1271                 int (*op)(struct trace_uprobe *tu, struct perf_event *event))
1272 {
1273         struct trace_probe *pos, *tp;
1274         struct trace_uprobe *tu;
1275         int ret = 0;
1276
1277         tp = trace_probe_primary_from_call(call);
1278         if (WARN_ON_ONCE(!tp))
1279                 return -ENODEV;
1280
1281         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1282                 tu = container_of(pos, struct trace_uprobe, tp);
1283                 ret = op(tu, event);
1284                 if (ret)
1285                         break;
1286         }
1287
1288         return ret;
1289 }
1290 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1291                                 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1292 {
1293         struct trace_uprobe *tu;
1294         int ret;
1295
1296         tu = container_of(uc, struct trace_uprobe, consumer);
1297         read_lock(&tu->filter.rwlock);
1298         ret = __uprobe_perf_filter(&tu->filter, mm);
1299         read_unlock(&tu->filter.rwlock);
1300
1301         return ret;
1302 }
1303
1304 static void __uprobe_perf_func(struct trace_uprobe *tu,
1305                                unsigned long func, struct pt_regs *regs,
1306                                struct uprobe_cpu_buffer *ucb, int dsize)
1307 {
1308         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1309         struct uprobe_trace_entry_head *entry;
1310         struct hlist_head *head;
1311         void *data;
1312         int size, esize;
1313         int rctx;
1314
1315         if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1316                 return;
1317
1318         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1319
1320         size = esize + tu->tp.size + dsize;
1321         size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1322         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1323                 return;
1324
1325         preempt_disable();
1326         head = this_cpu_ptr(call->perf_events);
1327         if (hlist_empty(head))
1328                 goto out;
1329
1330         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1331         if (!entry)
1332                 goto out;
1333
1334         if (is_ret_probe(tu)) {
1335                 entry->vaddr[0] = func;
1336                 entry->vaddr[1] = instruction_pointer(regs);
1337                 data = DATAOF_TRACE_ENTRY(entry, true);
1338         } else {
1339                 entry->vaddr[0] = instruction_pointer(regs);
1340                 data = DATAOF_TRACE_ENTRY(entry, false);
1341         }
1342
1343         memcpy(data, ucb->buf, tu->tp.size + dsize);
1344
1345         if (size - esize > tu->tp.size + dsize) {
1346                 int len = tu->tp.size + dsize;
1347
1348                 memset(data + len, 0, size - esize - len);
1349         }
1350
1351         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1352                               head, NULL);
1353  out:
1354         preempt_enable();
1355 }
1356
1357 /* uprobe profile handler */
1358 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1359                             struct uprobe_cpu_buffer *ucb, int dsize)
1360 {
1361         if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1362                 return UPROBE_HANDLER_REMOVE;
1363
1364         if (!is_ret_probe(tu))
1365                 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1366         return 0;
1367 }
1368
1369 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1370                                 struct pt_regs *regs,
1371                                 struct uprobe_cpu_buffer *ucb, int dsize)
1372 {
1373         __uprobe_perf_func(tu, func, regs, ucb, dsize);
1374 }
1375
1376 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1377                         const char **filename, u64 *probe_offset,
1378                         bool perf_type_tracepoint)
1379 {
1380         const char *pevent = trace_event_name(event->tp_event);
1381         const char *group = event->tp_event->class->system;
1382         struct trace_uprobe *tu;
1383
1384         if (perf_type_tracepoint)
1385                 tu = find_probe_event(pevent, group);
1386         else
1387                 tu = event->tp_event->data;
1388         if (!tu)
1389                 return -EINVAL;
1390
1391         *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1392                                     : BPF_FD_TYPE_UPROBE;
1393         *filename = tu->filename;
1394         *probe_offset = tu->offset;
1395         return 0;
1396 }
1397 #endif  /* CONFIG_PERF_EVENTS */
1398
1399 static int
1400 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1401                       void *data)
1402 {
1403         struct trace_event_file *file = data;
1404
1405         switch (type) {
1406         case TRACE_REG_REGISTER:
1407                 return probe_event_enable(event, file, NULL);
1408
1409         case TRACE_REG_UNREGISTER:
1410                 probe_event_disable(event, file);
1411                 return 0;
1412
1413 #ifdef CONFIG_PERF_EVENTS
1414         case TRACE_REG_PERF_REGISTER:
1415                 return probe_event_enable(event, NULL, uprobe_perf_filter);
1416
1417         case TRACE_REG_PERF_UNREGISTER:
1418                 probe_event_disable(event, NULL);
1419                 return 0;
1420
1421         case TRACE_REG_PERF_OPEN:
1422                 return uprobe_perf_multi_call(event, data, uprobe_perf_open);
1423
1424         case TRACE_REG_PERF_CLOSE:
1425                 return uprobe_perf_multi_call(event, data, uprobe_perf_close);
1426
1427 #endif
1428         default:
1429                 return 0;
1430         }
1431         return 0;
1432 }
1433
1434 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1435 {
1436         struct trace_uprobe *tu;
1437         struct uprobe_dispatch_data udd;
1438         struct uprobe_cpu_buffer *ucb;
1439         int dsize, esize;
1440         int ret = 0;
1441
1442
1443         tu = container_of(con, struct trace_uprobe, consumer);
1444         tu->nhit++;
1445
1446         udd.tu = tu;
1447         udd.bp_addr = instruction_pointer(regs);
1448
1449         current->utask->vaddr = (unsigned long) &udd;
1450
1451         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1452                 return 0;
1453
1454         dsize = __get_data_size(&tu->tp, regs);
1455         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1456
1457         ucb = uprobe_buffer_get();
1458         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1459
1460         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1461                 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1462
1463 #ifdef CONFIG_PERF_EVENTS
1464         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1465                 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1466 #endif
1467         uprobe_buffer_put(ucb);
1468         return ret;
1469 }
1470
1471 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1472                                 unsigned long func, struct pt_regs *regs)
1473 {
1474         struct trace_uprobe *tu;
1475         struct uprobe_dispatch_data udd;
1476         struct uprobe_cpu_buffer *ucb;
1477         int dsize, esize;
1478
1479         tu = container_of(con, struct trace_uprobe, consumer);
1480
1481         udd.tu = tu;
1482         udd.bp_addr = func;
1483
1484         current->utask->vaddr = (unsigned long) &udd;
1485
1486         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1487                 return 0;
1488
1489         dsize = __get_data_size(&tu->tp, regs);
1490         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1491
1492         ucb = uprobe_buffer_get();
1493         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1494
1495         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1496                 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1497
1498 #ifdef CONFIG_PERF_EVENTS
1499         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1500                 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1501 #endif
1502         uprobe_buffer_put(ucb);
1503         return 0;
1504 }
1505
1506 static struct trace_event_functions uprobe_funcs = {
1507         .trace          = print_uprobe_event
1508 };
1509
1510 static inline void init_trace_event_call(struct trace_uprobe *tu)
1511 {
1512         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1513
1514         call->event.funcs = &uprobe_funcs;
1515         call->class->define_fields = uprobe_event_define_fields;
1516
1517         call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1518         call->class->reg = trace_uprobe_register;
1519 }
1520
1521 static int register_uprobe_event(struct trace_uprobe *tu)
1522 {
1523         init_trace_event_call(tu);
1524
1525         return trace_probe_register_event_call(&tu->tp);
1526 }
1527
1528 static int unregister_uprobe_event(struct trace_uprobe *tu)
1529 {
1530         return trace_probe_unregister_event_call(&tu->tp);
1531 }
1532
1533 #ifdef CONFIG_PERF_EVENTS
1534 struct trace_event_call *
1535 create_local_trace_uprobe(char *name, unsigned long offs,
1536                           unsigned long ref_ctr_offset, bool is_return)
1537 {
1538         struct trace_uprobe *tu;
1539         struct path path;
1540         int ret;
1541
1542         ret = kern_path(name, LOOKUP_FOLLOW, &path);
1543         if (ret)
1544                 return ERR_PTR(ret);
1545
1546         if (!d_is_reg(path.dentry)) {
1547                 path_put(&path);
1548                 return ERR_PTR(-EINVAL);
1549         }
1550
1551         /*
1552          * local trace_kprobes are not added to dyn_event, so they are never
1553          * searched in find_trace_kprobe(). Therefore, there is no concern of
1554          * duplicated name "DUMMY_EVENT" here.
1555          */
1556         tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1557                                 is_return);
1558
1559         if (IS_ERR(tu)) {
1560                 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1561                         (int)PTR_ERR(tu));
1562                 path_put(&path);
1563                 return ERR_CAST(tu);
1564         }
1565
1566         tu->offset = offs;
1567         tu->path = path;
1568         tu->ref_ctr_offset = ref_ctr_offset;
1569         tu->filename = kstrdup(name, GFP_KERNEL);
1570         init_trace_event_call(tu);
1571
1572         if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
1573                 ret = -ENOMEM;
1574                 goto error;
1575         }
1576
1577         return trace_probe_event_call(&tu->tp);
1578 error:
1579         free_trace_uprobe(tu);
1580         return ERR_PTR(ret);
1581 }
1582
1583 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1584 {
1585         struct trace_uprobe *tu;
1586
1587         tu = trace_uprobe_primary_from_call(event_call);
1588
1589         free_trace_uprobe(tu);
1590 }
1591 #endif /* CONFIG_PERF_EVENTS */
1592
1593 /* Make a trace interface for controling probe points */
1594 static __init int init_uprobe_trace(void)
1595 {
1596         struct dentry *d_tracer;
1597         int ret;
1598
1599         ret = dyn_event_register(&trace_uprobe_ops);
1600         if (ret)
1601                 return ret;
1602
1603         d_tracer = tracing_init_dentry();
1604         if (IS_ERR(d_tracer))
1605                 return 0;
1606
1607         trace_create_file("uprobe_events", 0644, d_tracer,
1608                                     NULL, &uprobe_events_ops);
1609         /* Profile interface */
1610         trace_create_file("uprobe_profile", 0444, d_tracer,
1611                                     NULL, &uprobe_profile_ops);
1612         return 0;
1613 }
1614
1615 fs_initcall(init_uprobe_trace);