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 static int trace_uprobe_create(const char *raw_command);
  38 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
  39 static int trace_uprobe_release(struct dyn_event *ev);
  40 static bool trace_uprobe_is_busy(struct dyn_event *ev);
  41 static bool trace_uprobe_match(const char *system, const char *event,
  42                         int argc, const char **argv, struct dyn_event *ev);
  43
  44 static struct dyn_event_operations trace_uprobe_ops = {
  45         .create = trace_uprobe_create,
  46         .show = trace_uprobe_show,
  47         .is_busy = trace_uprobe_is_busy,
  48         .free = trace_uprobe_release,
  49         .match = trace_uprobe_match,
  50 };
  51
  52 /*
  53  * uprobe event core functions
  54  */
  55 struct trace_uprobe {
  56         struct dyn_event                devent;
  57         struct uprobe_consumer          consumer;
  58         struct path                     path;
  59         struct inode                    *inode;
  60         char                            *filename;
  61         unsigned long                   offset;
  62         unsigned long                   ref_ctr_offset;
  63         unsigned long                   nhit;
  64         struct trace_probe              tp;
  65 };
  66
  67 static bool is_trace_uprobe(struct dyn_event *ev)
  68 {
  69         return ev->ops == &trace_uprobe_ops;
  70 }
  71
  72 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
  73 {
  74         return container_of(ev, struct trace_uprobe, devent);
  75 }
  76
  77 /**
  78  * for_each_trace_uprobe - iterate over the trace_uprobe list
  79  * @pos:        the struct trace_uprobe * for each entry
  80  * @dpos:       the struct dyn_event * to use as a loop cursor
  81  */
  82 #define for_each_trace_uprobe(pos, dpos)        \
  83         for_each_dyn_event(dpos)                \
  84                 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
  85
  86 static int register_uprobe_event(struct trace_uprobe *tu);
  87 static int unregister_uprobe_event(struct trace_uprobe *tu);
  88
  89 struct uprobe_dispatch_data {
  90         struct trace_uprobe     *tu;
  91         unsigned long           bp_addr;
  92 };
  93
  94 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
  95 static int uretprobe_dispatcher(struct uprobe_consumer *con,
  96                                 unsigned long func, struct pt_regs *regs);
  97
  98 #ifdef CONFIG_STACK_GROWSUP
  99 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 100 {
 101         return addr - (n * sizeof(long));
 102 }
 103 #else
 104 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 105 {
 106         return addr + (n * sizeof(long));
 107 }
 108 #endif
 109
 110 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
 111 {
 112         unsigned long ret;
 113         unsigned long addr = user_stack_pointer(regs);
 114
 115         addr = adjust_stack_addr(addr, n);
 116
 117         if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
 118                 return 0;
 119
 120         return ret;
 121 }
 122
 123 /*
 124  * Uprobes-specific fetch functions
 125  */
 126 static nokprobe_inline int
 127 probe_mem_read(void *dest, void *src, size_t size)
 128 {
 129         void __user *vaddr = (void __force __user *)src;
 130
 131         return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
 132 }
 133
 134 static nokprobe_inline int
 135 probe_mem_read_user(void *dest, void *src, size_t size)
 136 {
 137         return probe_mem_read(dest, src, size);
 138 }
 139
 140 /*
 141  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
 142  * length and relative data location.
 143  */
 144 static nokprobe_inline int
 145 fetch_store_string(unsigned long addr, void *dest, void *base)
 146 {
 147         long ret;
 148         u32 loc = *(u32 *)dest;
 149         int maxlen  = get_loc_len(loc);
 150         u8 *dst = get_loc_data(dest, base);
 151         void __user *src = (void __force __user *) addr;
 152
 153         if (unlikely(!maxlen))
 154                 return -ENOMEM;
 155
 156         if (addr == FETCH_TOKEN_COMM)
 157                 ret = strlcpy(dst, current->comm, maxlen);
 158         else
 159                 ret = strncpy_from_user(dst, src, maxlen);
 160         if (ret >= 0) {
 161                 if (ret == maxlen)
 162                         dst[ret - 1] = '\0';
 163                 else
 164                         /*
 165                          * Include the terminating null byte. In this case it
 166                          * was copied by strncpy_from_user but not accounted
 167                          * for in ret.
 168                          */
 169                         ret++;
 170                 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
 171         }
 172
 173         return ret;
 174 }
 175
 176 static nokprobe_inline int
 177 fetch_store_string_user(unsigned long addr, void *dest, void *base)
 178 {
 179         return fetch_store_string(addr, dest, base);
 180 }
 181
 182 /* Return the length of string -- including null terminal byte */
 183 static nokprobe_inline int
 184 fetch_store_strlen(unsigned long addr)
 185 {
 186         int len;
 187         void __user *vaddr = (void __force __user *) addr;
 188
 189         if (addr == FETCH_TOKEN_COMM)
 190                 len = strlen(current->comm) + 1;
 191         else
 192                 len = strnlen_user(vaddr, MAX_STRING_SIZE);
 193
 194         return (len > MAX_STRING_SIZE) ? 0 : len;
 195 }
 196
 197 static nokprobe_inline int
 198 fetch_store_strlen_user(unsigned long addr)
 199 {
 200         return fetch_store_strlen(addr);
 201 }
 202
 203 static unsigned long translate_user_vaddr(unsigned long file_offset)
 204 {
 205         unsigned long base_addr;
 206         struct uprobe_dispatch_data *udd;
 207
 208         udd = (void *) current->utask->vaddr;
 209
 210         base_addr = udd->bp_addr - udd->tu->offset;
 211         return base_addr + file_offset;
 212 }
 213
 214 /* Note that we don't verify it, since the code does not come from user space */
 215 static int
 216 process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 217                    void *base)
 218 {
 219         struct pt_regs *regs = rec;
 220         unsigned long val;
 221
 222         /* 1st stage: get value from context */
 223         switch (code->op) {
 224         case FETCH_OP_REG:
 225                 val = regs_get_register(regs, code->param);
 226                 break;
 227         case FETCH_OP_STACK:
 228                 val = get_user_stack_nth(regs, code->param);
 229                 break;
 230         case FETCH_OP_STACKP:
 231                 val = user_stack_pointer(regs);
 232                 break;
 233         case FETCH_OP_RETVAL:
 234                 val = regs_return_value(regs);
 235                 break;
 236         case FETCH_OP_IMM:
 237                 val = code->immediate;
 238                 break;
 239         case FETCH_OP_COMM:
 240                 val = FETCH_TOKEN_COMM;
 241                 break;
 242         case FETCH_OP_DATA:
 243                 val = (unsigned long)code->data;
 244                 break;
 245         case FETCH_OP_FOFFS:
 246                 val = translate_user_vaddr(code->immediate);
 247                 break;
 248         default:
 249                 return -EILSEQ;
 250         }
 251         code++;
 252
 253         return process_fetch_insn_bottom(code, val, dest, base);
 254 }
 255 NOKPROBE_SYMBOL(process_fetch_insn)
 256
 257 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
 258 {
 259         rwlock_init(&filter->rwlock);
 260         filter->nr_systemwide = 0;
 261         INIT_LIST_HEAD(&filter->perf_events);
 262 }
 263
 264 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
 265 {
 266         return !filter->nr_systemwide && list_empty(&filter->perf_events);
 267 }
 268
 269 static inline bool is_ret_probe(struct trace_uprobe *tu)
 270 {
 271         return tu->consumer.ret_handler != NULL;
 272 }
 273
 274 static bool trace_uprobe_is_busy(struct dyn_event *ev)
 275 {
 276         struct trace_uprobe *tu = to_trace_uprobe(ev);
 277
 278         return trace_probe_is_enabled(&tu->tp);
 279 }
 280
 281 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
 282                                             int argc, const char **argv)
 283 {
 284         char buf[MAX_ARGSTR_LEN + 1];
 285         int len;
 286
 287         if (!argc)
 288                 return true;
 289
 290         len = strlen(tu->filename);
 291         if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
 292                 return false;
 293
 294         if (tu->ref_ctr_offset == 0)
 295                 snprintf(buf, sizeof(buf), "0x%0*lx",
 296                                 (int)(sizeof(void *) * 2), tu->offset);
 297         else
 298                 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
 299                                 (int)(sizeof(void *) * 2), tu->offset,
 300                                 tu->ref_ctr_offset);
 301         if (strcmp(buf, &argv[0][len + 1]))
 302                 return false;
 303
 304         argc--; argv++;
 305
 306         return trace_probe_match_command_args(&tu->tp, argc, argv);
 307 }
 308
 309 static bool trace_uprobe_match(const char *system, const char *event,
 310                         int argc, const char **argv, struct dyn_event *ev)
 311 {
 312         struct trace_uprobe *tu = to_trace_uprobe(ev);
 313
 314         return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 315            (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
 316            trace_uprobe_match_command_head(tu, argc, argv);
 317 }
 318
 319 static nokprobe_inline struct trace_uprobe *
 320 trace_uprobe_primary_from_call(struct trace_event_call *call)
 321 {
 322         struct trace_probe *tp;
 323
 324         tp = trace_probe_primary_from_call(call);
 325         if (WARN_ON_ONCE(!tp))
 326                 return NULL;
 327
 328         return container_of(tp, struct trace_uprobe, tp);
 329 }
 330
 331 /*
 332  * Allocate new trace_uprobe and initialize it (including uprobes).
 333  */
 334 static struct trace_uprobe *
 335 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 336 {
 337         struct trace_uprobe *tu;
 338         int ret;
 339
 340         tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL);
 341         if (!tu)
 342                 return ERR_PTR(-ENOMEM);
 343
 344         ret = trace_probe_init(&tu->tp, event, group, true);
 345         if (ret < 0)
 346                 goto error;
 347
 348         dyn_event_init(&tu->devent, &trace_uprobe_ops);
 349         tu->consumer.handler = uprobe_dispatcher;
 350         if (is_ret)
 351                 tu->consumer.ret_handler = uretprobe_dispatcher;
 352         init_trace_uprobe_filter(tu->tp.event->filter);
 353         return tu;
 354
 355 error:
 356         kfree(tu);
 357
 358         return ERR_PTR(ret);
 359 }
 360
 361 static void free_trace_uprobe(struct trace_uprobe *tu)
 362 {
 363         if (!tu)
 364                 return;
 365
 366         path_put(&tu->path);
 367         trace_probe_cleanup(&tu->tp);
 368         kfree(tu->filename);
 369         kfree(tu);
 370 }
 371
 372 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
 373 {
 374         struct dyn_event *pos;
 375         struct trace_uprobe *tu;
 376
 377         for_each_trace_uprobe(tu, pos)
 378                 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 379                     strcmp(trace_probe_group_name(&tu->tp), group) == 0)
 380                         return tu;
 381
 382         return NULL;
 383 }
 384
 385 /* Unregister a trace_uprobe and probe_event */
 386 static int unregister_trace_uprobe(struct trace_uprobe *tu)
 387 {
 388         int ret;
 389
 390         if (trace_probe_has_sibling(&tu->tp))
 391                 goto unreg;
 392
 393         /* If there's a reference to the dynamic event */
 394         if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp)))
 395                 return -EBUSY;
 396
 397         ret = unregister_uprobe_event(tu);
 398         if (ret)
 399                 return ret;
 400
 401 unreg:
 402         dyn_event_remove(&tu->devent);
 403         trace_probe_unlink(&tu->tp);
 404         free_trace_uprobe(tu);
 405         return 0;
 406 }
 407
 408 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
 409                                          struct trace_uprobe *comp)
 410 {
 411         struct trace_probe_event *tpe = orig->tp.event;
 412         struct trace_probe *pos;
 413         struct inode *comp_inode = d_real_inode(comp->path.dentry);
 414         int i;
 415
 416         list_for_each_entry(pos, &tpe->probes, list) {
 417                 orig = container_of(pos, struct trace_uprobe, tp);
 418                 if (comp_inode != d_real_inode(orig->path.dentry) ||
 419                     comp->offset != orig->offset)
 420                         continue;
 421
 422                 /*
 423                  * trace_probe_compare_arg_type() ensured that nr_args and
 424                  * each argument name and type are same. Let's compare comm.
 425                  */
 426                 for (i = 0; i < orig->tp.nr_args; i++) {
 427                         if (strcmp(orig->tp.args[i].comm,
 428                                    comp->tp.args[i].comm))
 429                                 break;
 430                 }
 431
 432                 if (i == orig->tp.nr_args)
 433                         return true;
 434         }
 435
 436         return false;
 437 }
 438
 439 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
 440 {
 441         int ret;
 442
 443         ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
 444         if (ret) {
 445                 /* Note that argument starts index = 2 */
 446                 trace_probe_log_set_index(ret + 1);
 447                 trace_probe_log_err(0, DIFF_ARG_TYPE);
 448                 return -EEXIST;
 449         }
 450         if (trace_uprobe_has_same_uprobe(to, tu)) {
 451                 trace_probe_log_set_index(0);
 452                 trace_probe_log_err(0, SAME_PROBE);
 453                 return -EEXIST;
 454         }
 455
 456         /* Append to existing event */
 457         ret = trace_probe_append(&tu->tp, &to->tp);
 458         if (!ret)
 459                 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
 460
 461         return ret;
 462 }
 463
 464 /*
 465  * Uprobe with multiple reference counter is not allowed. i.e.
 466  * If inode and offset matches, reference counter offset *must*
 467  * match as well. Though, there is one exception: If user is
 468  * replacing old trace_uprobe with new one(same group/event),
 469  * then we allow same uprobe with new reference counter as far
 470  * as the new one does not conflict with any other existing
 471  * ones.
 472  */
 473 static int validate_ref_ctr_offset(struct trace_uprobe *new)
 474 {
 475         struct dyn_event *pos;
 476         struct trace_uprobe *tmp;
 477         struct inode *new_inode = d_real_inode(new->path.dentry);
 478
 479         for_each_trace_uprobe(tmp, pos) {
 480                 if (new_inode == d_real_inode(tmp->path.dentry) &&
 481                     new->offset == tmp->offset &&
 482                     new->ref_ctr_offset != tmp->ref_ctr_offset) {
 483                         pr_warn("Reference counter offset mismatch.");
 484                         return -EINVAL;
 485                 }
 486         }
 487         return 0;
 488 }
 489
 490 /* Register a trace_uprobe and probe_event */
 491 static int register_trace_uprobe(struct trace_uprobe *tu)
 492 {
 493         struct trace_uprobe *old_tu;
 494         int ret;
 495
 496         mutex_lock(&event_mutex);
 497
 498         ret = validate_ref_ctr_offset(tu);
 499         if (ret)
 500                 goto end;
 501
 502         /* register as an event */
 503         old_tu = find_probe_event(trace_probe_name(&tu->tp),
 504                                   trace_probe_group_name(&tu->tp));
 505         if (old_tu) {
 506                 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
 507                         trace_probe_log_set_index(0);
 508                         trace_probe_log_err(0, DIFF_PROBE_TYPE);
 509                         ret = -EEXIST;
 510                 } else {
 511                         ret = append_trace_uprobe(tu, old_tu);
 512                 }
 513                 goto end;
 514         }
 515
 516         ret = register_uprobe_event(tu);
 517         if (ret) {
 518                 if (ret == -EEXIST) {
 519                         trace_probe_log_set_index(0);
 520                         trace_probe_log_err(0, EVENT_EXIST);
 521                 } else
 522                         pr_warn("Failed to register probe event(%d)\n", ret);
 523                 goto end;
 524         }
 525
 526         dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
 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[%return][(REF)] [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         enum probe_print_type ptype;
 545         struct path path;
 546         unsigned long offset, ref_ctr_offset;
 547         bool is_return = false;
 548         int i, ret;
 549
 550         ret = 0;
 551         ref_ctr_offset = 0;
 552
 553         switch (argv[0][0]) {
 554         case 'r':
 555                 is_return = true;
 556                 break;
 557         case 'p':
 558                 break;
 559         default:
 560                 return -ECANCELED;
 561         }
 562
 563         if (argc < 2)
 564                 return -ECANCELED;
 565
 566         if (argv[0][1] == ':')
 567                 event = &argv[0][2];
 568
 569         if (!strchr(argv[1], '/'))
 570                 return -ECANCELED;
 571
 572         filename = kstrdup(argv[1], GFP_KERNEL);
 573         if (!filename)
 574                 return -ENOMEM;
 575
 576         /* Find the last occurrence, in case the path contains ':' too. */
 577         arg = strrchr(filename, ':');
 578         if (!arg || !isdigit(arg[1])) {
 579                 kfree(filename);
 580                 return -ECANCELED;
 581         }
 582
 583         trace_probe_log_init("trace_uprobe", argc, argv);
 584         trace_probe_log_set_index(1);   /* filename is the 2nd argument */
 585
 586         *arg++ = '\0';
 587         ret = kern_path(filename, LOOKUP_FOLLOW, &path);
 588         if (ret) {
 589                 trace_probe_log_err(0, FILE_NOT_FOUND);
 590                 kfree(filename);
 591                 trace_probe_log_clear();
 592                 return ret;
 593         }
 594         if (!d_is_reg(path.dentry)) {
 595                 trace_probe_log_err(0, NO_REGULAR_FILE);
 596                 ret = -EINVAL;
 597                 goto fail_address_parse;
 598         }
 599
 600         /* Parse reference counter offset if specified. */
 601         rctr = strchr(arg, '(');
 602         if (rctr) {
 603                 rctr_end = strchr(rctr, ')');
 604                 if (!rctr_end) {
 605                         ret = -EINVAL;
 606                         rctr_end = rctr + strlen(rctr);
 607                         trace_probe_log_err(rctr_end - filename,
 608                                             REFCNT_OPEN_BRACE);
 609                         goto fail_address_parse;
 610                 } else if (rctr_end[1] != '\0') {
 611                         ret = -EINVAL;
 612                         trace_probe_log_err(rctr_end + 1 - filename,
 613                                             BAD_REFCNT_SUFFIX);
 614                         goto fail_address_parse;
 615                 }
 616
 617                 *rctr++ = '\0';
 618                 *rctr_end = '\0';
 619                 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
 620                 if (ret) {
 621                         trace_probe_log_err(rctr - filename, BAD_REFCNT);
 622                         goto fail_address_parse;
 623                 }
 624         }
 625
 626         /* Check if there is %return suffix */
 627         tmp = strchr(arg, '%');
 628         if (tmp) {
 629                 if (!strcmp(tmp, "%return")) {
 630                         *tmp = '\0';
 631                         is_return = true;
 632                 } else {
 633                         trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
 634                         ret = -EINVAL;
 635                         goto fail_address_parse;
 636                 }
 637         }
 638
 639         /* Parse uprobe offset. */
 640         ret = kstrtoul(arg, 0, &offset);
 641         if (ret) {
 642                 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
 643                 goto fail_address_parse;
 644         }
 645
 646         /* setup a probe */
 647         trace_probe_log_set_index(0);
 648         if (event) {
 649                 ret = traceprobe_parse_event_name(&event, &group, buf,
 650                                                   event - argv[0]);
 651                 if (ret)
 652                         goto fail_address_parse;
 653         } else {
 654                 char *tail;
 655                 char *ptr;
 656
 657                 tail = kstrdup(kbasename(filename), GFP_KERNEL);
 658                 if (!tail) {
 659                         ret = -ENOMEM;
 660                         goto fail_address_parse;
 661                 }
 662
 663                 ptr = strpbrk(tail, ".-_");
 664                 if (ptr)
 665                         *ptr = '\0';
 666
 667                 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
 668                 event = buf;
 669                 kfree(tail);
 670         }
 671
 672         argc -= 2;
 673         argv += 2;
 674
 675         tu = alloc_trace_uprobe(group, event, argc, is_return);
 676         if (IS_ERR(tu)) {
 677                 ret = PTR_ERR(tu);
 678                 /* This must return -ENOMEM otherwise there is a bug */
 679                 WARN_ON_ONCE(ret != -ENOMEM);
 680                 goto fail_address_parse;
 681         }
 682         tu->offset = offset;
 683         tu->ref_ctr_offset = ref_ctr_offset;
 684         tu->path = path;
 685         tu->filename = filename;
 686
 687         /* parse arguments */
 688         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 689                 trace_probe_log_set_index(i + 2);
 690                 ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i],
 691                                         is_return ? TPARG_FL_RETURN : 0);
 692                 if (ret)
 693                         goto error;
 694         }
 695
 696         ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
 697         ret = traceprobe_set_print_fmt(&tu->tp, ptype);
 698         if (ret < 0)
 699                 goto error;
 700
 701         ret = register_trace_uprobe(tu);
 702         if (!ret)
 703                 goto out;
 704
 705 error:
 706         free_trace_uprobe(tu);
 707 out:
 708         trace_probe_log_clear();
 709         return ret;
 710
 711 fail_address_parse:
 712         trace_probe_log_clear();
 713         path_put(&path);
 714         kfree(filename);
 715
 716         return ret;
 717 }
 718
 719 int trace_uprobe_create(const char *raw_command)
 720 {
 721         return trace_probe_create(raw_command, __trace_uprobe_create);
 722 }
 723
 724 static int create_or_delete_trace_uprobe(const char *raw_command)
 725 {
 726         int ret;
 727
 728         if (raw_command[0] == '-')
 729                 return dyn_event_release(raw_command, &trace_uprobe_ops);
 730
 731         ret = trace_uprobe_create(raw_command);
 732         return ret == -ECANCELED ? -EINVAL : ret;
 733 }
 734
 735 static int trace_uprobe_release(struct dyn_event *ev)
 736 {
 737         struct trace_uprobe *tu = to_trace_uprobe(ev);
 738
 739         return unregister_trace_uprobe(tu);
 740 }
 741
 742 /* Probes listing interfaces */
 743 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
 744 {
 745         struct trace_uprobe *tu = to_trace_uprobe(ev);
 746         char c = is_ret_probe(tu) ? 'r' : 'p';
 747         int i;
 748
 749         seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
 750                         trace_probe_name(&tu->tp), tu->filename,
 751                         (int)(sizeof(void *) * 2), tu->offset);
 752
 753         if (tu->ref_ctr_offset)
 754                 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
 755
 756         for (i = 0; i < tu->tp.nr_args; i++)
 757                 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
 758
 759         seq_putc(m, '\n');
 760         return 0;
 761 }
 762
 763 static int probes_seq_show(struct seq_file *m, void *v)
 764 {
 765         struct dyn_event *ev = v;
 766
 767         if (!is_trace_uprobe(ev))
 768                 return 0;
 769
 770         return trace_uprobe_show(m, ev);
 771 }
 772
 773 static const struct seq_operations probes_seq_op = {
 774         .start  = dyn_event_seq_start,
 775         .next   = dyn_event_seq_next,
 776         .stop   = dyn_event_seq_stop,
 777         .show   = probes_seq_show
 778 };
 779
 780 static int probes_open(struct inode *inode, struct file *file)
 781 {
 782         int ret;
 783
 784         ret = security_locked_down(LOCKDOWN_TRACEFS);
 785         if (ret)
 786                 return ret;
 787
 788         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 789                 ret = dyn_events_release_all(&trace_uprobe_ops);
 790                 if (ret)
 791                         return ret;
 792         }
 793
 794         return seq_open(file, &probes_seq_op);
 795 }
 796
 797 static ssize_t probes_write(struct file *file, const char __user *buffer,
 798                             size_t count, loff_t *ppos)
 799 {
 800         return trace_parse_run_command(file, buffer, count, ppos,
 801                                         create_or_delete_trace_uprobe);
 802 }
 803
 804 static const struct file_operations uprobe_events_ops = {
 805         .owner          = THIS_MODULE,
 806         .open           = probes_open,
 807         .read           = seq_read,
 808         .llseek         = seq_lseek,
 809         .release        = seq_release,
 810         .write          = probes_write,
 811 };
 812
 813 /* Probes profiling interfaces */
 814 static int probes_profile_seq_show(struct seq_file *m, void *v)
 815 {
 816         struct dyn_event *ev = v;
 817         struct trace_uprobe *tu;
 818
 819         if (!is_trace_uprobe(ev))
 820                 return 0;
 821
 822         tu = to_trace_uprobe(ev);
 823         seq_printf(m, "  %s %-44s %15lu\n", tu->filename,
 824                         trace_probe_name(&tu->tp), tu->nhit);
 825         return 0;
 826 }
 827
 828 static const struct seq_operations profile_seq_op = {
 829         .start  = dyn_event_seq_start,
 830         .next   = dyn_event_seq_next,
 831         .stop   = dyn_event_seq_stop,
 832         .show   = probes_profile_seq_show
 833 };
 834
 835 static int profile_open(struct inode *inode, struct file *file)
 836 {
 837         int ret;
 838
 839         ret = security_locked_down(LOCKDOWN_TRACEFS);
 840         if (ret)
 841                 return ret;
 842
 843         return seq_open(file, &profile_seq_op);
 844 }
 845
 846 static const struct file_operations uprobe_profile_ops = {
 847         .owner          = THIS_MODULE,
 848         .open           = profile_open,
 849         .read           = seq_read,
 850         .llseek         = seq_lseek,
 851         .release        = seq_release,
 852 };
 853
 854 struct uprobe_cpu_buffer {
 855         struct mutex mutex;
 856         void *buf;
 857 };
 858 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
 859 static int uprobe_buffer_refcnt;
 860
 861 static int uprobe_buffer_init(void)
 862 {
 863         int cpu, err_cpu;
 864
 865         uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
 866         if (uprobe_cpu_buffer == NULL)
 867                 return -ENOMEM;
 868
 869         for_each_possible_cpu(cpu) {
 870                 struct page *p = alloc_pages_node(cpu_to_node(cpu),
 871                                                   GFP_KERNEL, 0);
 872                 if (p == NULL) {
 873                         err_cpu = cpu;
 874                         goto err;
 875                 }
 876                 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
 877                 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
 878         }
 879
 880         return 0;
 881
 882 err:
 883         for_each_possible_cpu(cpu) {
 884                 if (cpu == err_cpu)
 885                         break;
 886                 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
 887         }
 888
 889         free_percpu(uprobe_cpu_buffer);
 890         return -ENOMEM;
 891 }
 892
 893 static int uprobe_buffer_enable(void)
 894 {
 895         int ret = 0;
 896
 897         BUG_ON(!mutex_is_locked(&event_mutex));
 898
 899         if (uprobe_buffer_refcnt++ == 0) {
 900                 ret = uprobe_buffer_init();
 901                 if (ret < 0)
 902                         uprobe_buffer_refcnt--;
 903         }
 904
 905         return ret;
 906 }
 907
 908 static void uprobe_buffer_disable(void)
 909 {
 910         int cpu;
 911
 912         BUG_ON(!mutex_is_locked(&event_mutex));
 913
 914         if (--uprobe_buffer_refcnt == 0) {
 915                 for_each_possible_cpu(cpu)
 916                         free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
 917                                                              cpu)->buf);
 918
 919                 free_percpu(uprobe_cpu_buffer);
 920                 uprobe_cpu_buffer = NULL;
 921         }
 922 }
 923
 924 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
 925 {
 926         struct uprobe_cpu_buffer *ucb;
 927         int cpu;
 928
 929         cpu = raw_smp_processor_id();
 930         ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
 931
 932         /*
 933          * Use per-cpu buffers for fastest access, but we might migrate
 934          * so the mutex makes sure we have sole access to it.
 935          */
 936         mutex_lock(&ucb->mutex);
 937
 938         return ucb;
 939 }
 940
 941 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
 942 {
 943         mutex_unlock(&ucb->mutex);
 944 }
 945
 946 static void __uprobe_trace_func(struct trace_uprobe *tu,
 947                                 unsigned long func, struct pt_regs *regs,
 948                                 struct uprobe_cpu_buffer *ucb, int dsize,
 949                                 struct trace_event_file *trace_file)
 950 {
 951         struct uprobe_trace_entry_head *entry;
 952         struct trace_buffer *buffer;
 953         struct ring_buffer_event *event;
 954         void *data;
 955         int size, esize;
 956         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
 957
 958         WARN_ON(call != trace_file->event_call);
 959
 960         if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
 961                 return;
 962
 963         if (trace_trigger_soft_disabled(trace_file))
 964                 return;
 965
 966         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 967         size = esize + tu->tp.size + dsize;
 968         event = trace_event_buffer_lock_reserve(&buffer, trace_file,
 969                                                 call->event.type, size, 0);
 970         if (!event)
 971                 return;
 972
 973         entry = ring_buffer_event_data(event);
 974         if (is_ret_probe(tu)) {
 975                 entry->vaddr[0] = func;
 976                 entry->vaddr[1] = instruction_pointer(regs);
 977                 data = DATAOF_TRACE_ENTRY(entry, true);
 978         } else {
 979                 entry->vaddr[0] = instruction_pointer(regs);
 980                 data = DATAOF_TRACE_ENTRY(entry, false);
 981         }
 982
 983         memcpy(data, ucb->buf, tu->tp.size + dsize);
 984
 985         event_trigger_unlock_commit(trace_file, buffer, event, entry, 0);
 986 }
 987
 988 /* uprobe handler */
 989 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
 990                              struct uprobe_cpu_buffer *ucb, int dsize)
 991 {
 992         struct event_file_link *link;
 993
 994         if (is_ret_probe(tu))
 995                 return 0;
 996
 997         rcu_read_lock();
 998         trace_probe_for_each_link_rcu(link, &tu->tp)
 999                 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
1000         rcu_read_unlock();
1001
1002         return 0;
1003 }
1004
1005 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
1006                                  struct pt_regs *regs,
1007                                  struct uprobe_cpu_buffer *ucb, int dsize)
1008 {
1009         struct event_file_link *link;
1010
1011         rcu_read_lock();
1012         trace_probe_for_each_link_rcu(link, &tu->tp)
1013                 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
1014         rcu_read_unlock();
1015 }
1016
1017 /* Event entry printers */
1018 static enum print_line_t
1019 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1020 {
1021         struct uprobe_trace_entry_head *entry;
1022         struct trace_seq *s = &iter->seq;
1023         struct trace_uprobe *tu;
1024         u8 *data;
1025
1026         entry = (struct uprobe_trace_entry_head *)iter->ent;
1027         tu = trace_uprobe_primary_from_call(
1028                 container_of(event, struct trace_event_call, event));
1029         if (unlikely(!tu))
1030                 goto out;
1031
1032         if (is_ret_probe(tu)) {
1033                 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1034                                  trace_probe_name(&tu->tp),
1035                                  entry->vaddr[1], entry->vaddr[0]);
1036                 data = DATAOF_TRACE_ENTRY(entry, true);
1037         } else {
1038                 trace_seq_printf(s, "%s: (0x%lx)",
1039                                  trace_probe_name(&tu->tp),
1040                                  entry->vaddr[0]);
1041                 data = DATAOF_TRACE_ENTRY(entry, false);
1042         }
1043
1044         if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1045                 goto out;
1046
1047         trace_seq_putc(s, '\n');
1048
1049  out:
1050         return trace_handle_return(s);
1051 }
1052
1053 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1054                                 enum uprobe_filter_ctx ctx,
1055                                 struct mm_struct *mm);
1056
1057 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1058 {
1059         int ret;
1060
1061         tu->consumer.filter = filter;
1062         tu->inode = d_real_inode(tu->path.dentry);
1063
1064         if (tu->ref_ctr_offset)
1065                 ret = uprobe_register_refctr(tu->inode, tu->offset,
1066                                 tu->ref_ctr_offset, &tu->consumer);
1067         else
1068                 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1069
1070         if (ret)
1071                 tu->inode = NULL;
1072
1073         return ret;
1074 }
1075
1076 static void __probe_event_disable(struct trace_probe *tp)
1077 {
1078         struct trace_probe *pos;
1079         struct trace_uprobe *tu;
1080
1081         tu = container_of(tp, struct trace_uprobe, tp);
1082         WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1083
1084         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1085                 tu = container_of(pos, struct trace_uprobe, tp);
1086                 if (!tu->inode)
1087                         continue;
1088
1089                 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1090                 tu->inode = NULL;
1091         }
1092 }
1093
1094 static int probe_event_enable(struct trace_event_call *call,
1095                         struct trace_event_file *file, filter_func_t filter)
1096 {
1097         struct trace_probe *pos, *tp;
1098         struct trace_uprobe *tu;
1099         bool enabled;
1100         int ret;
1101
1102         tp = trace_probe_primary_from_call(call);
1103         if (WARN_ON_ONCE(!tp))
1104                 return -ENODEV;
1105         enabled = trace_probe_is_enabled(tp);
1106
1107         /* This may also change "enabled" state */
1108         if (file) {
1109                 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1110                         return -EINTR;
1111
1112                 ret = trace_probe_add_file(tp, file);
1113                 if (ret < 0)
1114                         return ret;
1115         } else {
1116                 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1117                         return -EINTR;
1118
1119                 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1120         }
1121
1122         tu = container_of(tp, struct trace_uprobe, tp);
1123         WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1124
1125         if (enabled)
1126                 return 0;
1127
1128         ret = uprobe_buffer_enable();
1129         if (ret)
1130                 goto err_flags;
1131
1132         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1133                 tu = container_of(pos, struct trace_uprobe, tp);
1134                 ret = trace_uprobe_enable(tu, filter);
1135                 if (ret) {
1136                         __probe_event_disable(tp);
1137                         goto err_buffer;
1138                 }
1139         }
1140
1141         return 0;
1142
1143  err_buffer:
1144         uprobe_buffer_disable();
1145
1146  err_flags:
1147         if (file)
1148                 trace_probe_remove_file(tp, file);
1149         else
1150                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1151
1152         return ret;
1153 }
1154
1155 static void probe_event_disable(struct trace_event_call *call,
1156                                 struct trace_event_file *file)
1157 {
1158         struct trace_probe *tp;
1159
1160         tp = trace_probe_primary_from_call(call);
1161         if (WARN_ON_ONCE(!tp))
1162                 return;
1163
1164         if (!trace_probe_is_enabled(tp))
1165                 return;
1166
1167         if (file) {
1168                 if (trace_probe_remove_file(tp, file) < 0)
1169                         return;
1170
1171                 if (trace_probe_is_enabled(tp))
1172                         return;
1173         } else
1174                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1175
1176         __probe_event_disable(tp);
1177         uprobe_buffer_disable();
1178 }
1179
1180 static int uprobe_event_define_fields(struct trace_event_call *event_call)
1181 {
1182         int ret, size;
1183         struct uprobe_trace_entry_head field;
1184         struct trace_uprobe *tu;
1185
1186         tu = trace_uprobe_primary_from_call(event_call);
1187         if (unlikely(!tu))
1188                 return -ENODEV;
1189
1190         if (is_ret_probe(tu)) {
1191                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1192                 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1193                 size = SIZEOF_TRACE_ENTRY(true);
1194         } else {
1195                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1196                 size = SIZEOF_TRACE_ENTRY(false);
1197         }
1198
1199         return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1200 }
1201
1202 #ifdef CONFIG_PERF_EVENTS
1203 static bool
1204 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1205 {
1206         struct perf_event *event;
1207
1208         if (filter->nr_systemwide)
1209                 return true;
1210
1211         list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1212                 if (event->hw.target->mm == mm)
1213                         return true;
1214         }
1215
1216         return false;
1217 }
1218
1219 static inline bool
1220 trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1221                           struct perf_event *event)
1222 {
1223         return __uprobe_perf_filter(filter, event->hw.target->mm);
1224 }
1225
1226 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1227                                        struct perf_event *event)
1228 {
1229         bool done;
1230
1231         write_lock(&filter->rwlock);
1232         if (event->hw.target) {
1233                 list_del(&event->hw.tp_list);
1234                 done = filter->nr_systemwide ||
1235                         (event->hw.target->flags & PF_EXITING) ||
1236                         trace_uprobe_filter_event(filter, event);
1237         } else {
1238                 filter->nr_systemwide--;
1239                 done = filter->nr_systemwide;
1240         }
1241         write_unlock(&filter->rwlock);
1242
1243         return done;
1244 }
1245
1246 /* This returns true if the filter always covers target mm */
1247 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1248                                     struct perf_event *event)
1249 {
1250         bool done;
1251
1252         write_lock(&filter->rwlock);
1253         if (event->hw.target) {
1254                 /*
1255                  * event->parent != NULL means copy_process(), we can avoid
1256                  * uprobe_apply(). current->mm must be probed and we can rely
1257                  * on dup_mmap() which preserves the already installed bp's.
1258                  *
1259                  * attr.enable_on_exec means that exec/mmap will install the
1260                  * breakpoints we need.
1261                  */
1262                 done = filter->nr_systemwide ||
1263                         event->parent || event->attr.enable_on_exec ||
1264                         trace_uprobe_filter_event(filter, event);
1265                 list_add(&event->hw.tp_list, &filter->perf_events);
1266         } else {
1267                 done = filter->nr_systemwide;
1268                 filter->nr_systemwide++;
1269         }
1270         write_unlock(&filter->rwlock);
1271
1272         return done;
1273 }
1274
1275 static int uprobe_perf_close(struct trace_event_call *call,
1276                              struct perf_event *event)
1277 {
1278         struct trace_probe *pos, *tp;
1279         struct trace_uprobe *tu;
1280         int ret = 0;
1281
1282         tp = trace_probe_primary_from_call(call);
1283         if (WARN_ON_ONCE(!tp))
1284                 return -ENODEV;
1285
1286         tu = container_of(tp, struct trace_uprobe, tp);
1287         if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1288                 return 0;
1289
1290         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1291                 tu = container_of(pos, struct trace_uprobe, tp);
1292                 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1293                 if (ret)
1294                         break;
1295         }
1296
1297         return ret;
1298 }
1299
1300 static int uprobe_perf_open(struct trace_event_call *call,
1301                             struct perf_event *event)
1302 {
1303         struct trace_probe *pos, *tp;
1304         struct trace_uprobe *tu;
1305         int err = 0;
1306
1307         tp = trace_probe_primary_from_call(call);
1308         if (WARN_ON_ONCE(!tp))
1309                 return -ENODEV;
1310
1311         tu = container_of(tp, struct trace_uprobe, tp);
1312         if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1313                 return 0;
1314
1315         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1316                 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1317                 if (err) {
1318                         uprobe_perf_close(call, event);
1319                         break;
1320                 }
1321         }
1322
1323         return err;
1324 }
1325
1326 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1327                                 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1328 {
1329         struct trace_uprobe_filter *filter;
1330         struct trace_uprobe *tu;
1331         int ret;
1332
1333         tu = container_of(uc, struct trace_uprobe, consumer);
1334         filter = tu->tp.event->filter;
1335
1336         read_lock(&filter->rwlock);
1337         ret = __uprobe_perf_filter(filter, mm);
1338         read_unlock(&filter->rwlock);
1339
1340         return ret;
1341 }
1342
1343 static void __uprobe_perf_func(struct trace_uprobe *tu,
1344                                unsigned long func, struct pt_regs *regs,
1345                                struct uprobe_cpu_buffer *ucb, int dsize)
1346 {
1347         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1348         struct uprobe_trace_entry_head *entry;
1349         struct hlist_head *head;
1350         void *data;
1351         int size, esize;
1352         int rctx;
1353
1354         if (bpf_prog_array_valid(call)) {
1355                 u32 ret;
1356
1357                 preempt_disable();
1358                 ret = trace_call_bpf(call, regs);
1359                 preempt_enable();
1360                 if (!ret)
1361                         return;
1362         }
1363
1364         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1365
1366         size = esize + tu->tp.size + dsize;
1367         size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1368         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1369                 return;
1370
1371         preempt_disable();
1372         head = this_cpu_ptr(call->perf_events);
1373         if (hlist_empty(head))
1374                 goto out;
1375
1376         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1377         if (!entry)
1378                 goto out;
1379
1380         if (is_ret_probe(tu)) {
1381                 entry->vaddr[0] = func;
1382                 entry->vaddr[1] = instruction_pointer(regs);
1383                 data = DATAOF_TRACE_ENTRY(entry, true);
1384         } else {
1385                 entry->vaddr[0] = instruction_pointer(regs);
1386                 data = DATAOF_TRACE_ENTRY(entry, false);
1387         }
1388
1389         memcpy(data, ucb->buf, tu->tp.size + dsize);
1390
1391         if (size - esize > tu->tp.size + dsize) {
1392                 int len = tu->tp.size + dsize;
1393
1394                 memset(data + len, 0, size - esize - len);
1395         }
1396
1397         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1398                               head, NULL);
1399  out:
1400         preempt_enable();
1401 }
1402
1403 /* uprobe profile handler */
1404 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1405                             struct uprobe_cpu_buffer *ucb, int dsize)
1406 {
1407         if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1408                 return UPROBE_HANDLER_REMOVE;
1409
1410         if (!is_ret_probe(tu))
1411                 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1412         return 0;
1413 }
1414
1415 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1416                                 struct pt_regs *regs,
1417                                 struct uprobe_cpu_buffer *ucb, int dsize)
1418 {
1419         __uprobe_perf_func(tu, func, regs, ucb, dsize);
1420 }
1421
1422 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1423                         const char **filename, u64 *probe_offset,
1424                         bool perf_type_tracepoint)
1425 {
1426         const char *pevent = trace_event_name(event->tp_event);
1427         const char *group = event->tp_event->class->system;
1428         struct trace_uprobe *tu;
1429
1430         if (perf_type_tracepoint)
1431                 tu = find_probe_event(pevent, group);
1432         else
1433                 tu = trace_uprobe_primary_from_call(event->tp_event);
1434         if (!tu)
1435                 return -EINVAL;
1436
1437         *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1438                                     : BPF_FD_TYPE_UPROBE;
1439         *filename = tu->filename;
1440         *probe_offset = tu->offset;
1441         return 0;
1442 }
1443 #endif  /* CONFIG_PERF_EVENTS */
1444
1445 static int
1446 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1447                       void *data)
1448 {
1449         struct trace_event_file *file = data;
1450
1451         switch (type) {
1452         case TRACE_REG_REGISTER:
1453                 return probe_event_enable(event, file, NULL);
1454
1455         case TRACE_REG_UNREGISTER:
1456                 probe_event_disable(event, file);
1457                 return 0;
1458
1459 #ifdef CONFIG_PERF_EVENTS
1460         case TRACE_REG_PERF_REGISTER:
1461                 return probe_event_enable(event, NULL, uprobe_perf_filter);
1462
1463         case TRACE_REG_PERF_UNREGISTER:
1464                 probe_event_disable(event, NULL);
1465                 return 0;
1466
1467         case TRACE_REG_PERF_OPEN:
1468                 return uprobe_perf_open(event, data);
1469
1470         case TRACE_REG_PERF_CLOSE:
1471                 return uprobe_perf_close(event, data);
1472
1473 #endif
1474         default:
1475                 return 0;
1476         }
1477 }
1478
1479 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1480 {
1481         struct trace_uprobe *tu;
1482         struct uprobe_dispatch_data udd;
1483         struct uprobe_cpu_buffer *ucb;
1484         int dsize, esize;
1485         int ret = 0;
1486
1487
1488         tu = container_of(con, struct trace_uprobe, consumer);
1489         tu->nhit++;
1490
1491         udd.tu = tu;
1492         udd.bp_addr = instruction_pointer(regs);
1493
1494         current->utask->vaddr = (unsigned long) &udd;
1495
1496         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1497                 return 0;
1498
1499         dsize = __get_data_size(&tu->tp, regs);
1500         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1501
1502         ucb = uprobe_buffer_get();
1503         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1504
1505         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1506                 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1507
1508 #ifdef CONFIG_PERF_EVENTS
1509         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1510                 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1511 #endif
1512         uprobe_buffer_put(ucb);
1513         return ret;
1514 }
1515
1516 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1517                                 unsigned long func, struct pt_regs *regs)
1518 {
1519         struct trace_uprobe *tu;
1520         struct uprobe_dispatch_data udd;
1521         struct uprobe_cpu_buffer *ucb;
1522         int dsize, esize;
1523
1524         tu = container_of(con, struct trace_uprobe, consumer);
1525
1526         udd.tu = tu;
1527         udd.bp_addr = func;
1528
1529         current->utask->vaddr = (unsigned long) &udd;
1530
1531         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1532                 return 0;
1533
1534         dsize = __get_data_size(&tu->tp, regs);
1535         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1536
1537         ucb = uprobe_buffer_get();
1538         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1539
1540         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1541                 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1542
1543 #ifdef CONFIG_PERF_EVENTS
1544         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1545                 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1546 #endif
1547         uprobe_buffer_put(ucb);
1548         return 0;
1549 }
1550
1551 static struct trace_event_functions uprobe_funcs = {
1552         .trace          = print_uprobe_event
1553 };
1554
1555 static struct trace_event_fields uprobe_fields_array[] = {
1556         { .type = TRACE_FUNCTION_TYPE,
1557           .define_fields = uprobe_event_define_fields },
1558         {}
1559 };
1560
1561 static inline void init_trace_event_call(struct trace_uprobe *tu)
1562 {
1563         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1564         call->event.funcs = &uprobe_funcs;
1565         call->class->fields_array = uprobe_fields_array;
1566
1567         call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1568         call->class->reg = trace_uprobe_register;
1569 }
1570
1571 static int register_uprobe_event(struct trace_uprobe *tu)
1572 {
1573         init_trace_event_call(tu);
1574
1575         return trace_probe_register_event_call(&tu->tp);
1576 }
1577
1578 static int unregister_uprobe_event(struct trace_uprobe *tu)
1579 {
1580         return trace_probe_unregister_event_call(&tu->tp);
1581 }
1582
1583 #ifdef CONFIG_PERF_EVENTS
1584 struct trace_event_call *
1585 create_local_trace_uprobe(char *name, unsigned long offs,
1586                           unsigned long ref_ctr_offset, bool is_return)
1587 {
1588         enum probe_print_type ptype;
1589         struct trace_uprobe *tu;
1590         struct path path;
1591         int ret;
1592
1593         ret = kern_path(name, LOOKUP_FOLLOW, &path);
1594         if (ret)
1595                 return ERR_PTR(ret);
1596
1597         if (!d_is_reg(path.dentry)) {
1598                 path_put(&path);
1599                 return ERR_PTR(-EINVAL);
1600         }
1601
1602         /*
1603          * local trace_kprobes are not added to dyn_event, so they are never
1604          * searched in find_trace_kprobe(). Therefore, there is no concern of
1605          * duplicated name "DUMMY_EVENT" here.
1606          */
1607         tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1608                                 is_return);
1609
1610         if (IS_ERR(tu)) {
1611                 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1612                         (int)PTR_ERR(tu));
1613                 path_put(&path);
1614                 return ERR_CAST(tu);
1615         }
1616
1617         tu->offset = offs;
1618         tu->path = path;
1619         tu->ref_ctr_offset = ref_ctr_offset;
1620         tu->filename = kstrdup(name, GFP_KERNEL);
1621         init_trace_event_call(tu);
1622
1623         ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1624         if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
1625                 ret = -ENOMEM;
1626                 goto error;
1627         }
1628
1629         return trace_probe_event_call(&tu->tp);
1630 error:
1631         free_trace_uprobe(tu);
1632         return ERR_PTR(ret);
1633 }
1634
1635 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1636 {
1637         struct trace_uprobe *tu;
1638
1639         tu = trace_uprobe_primary_from_call(event_call);
1640
1641         free_trace_uprobe(tu);
1642 }
1643 #endif /* CONFIG_PERF_EVENTS */
1644
1645 /* Make a trace interface for controlling probe points */
1646 static __init int init_uprobe_trace(void)
1647 {
1648         int ret;
1649
1650         ret = dyn_event_register(&trace_uprobe_ops);
1651         if (ret)
1652                 return ret;
1653
1654         ret = tracing_init_dentry();
1655         if (ret)
1656                 return 0;
1657
1658         trace_create_file("uprobe_events", 0644, NULL,
1659                                     NULL, &uprobe_events_ops);
1660         /* Profile interface */
1661         trace_create_file("uprobe_profile", 0444, NULL,
1662                                     NULL, &uprobe_profile_ops);
1663         return 0;
1664 }
1665
1666 fs_initcall(init_uprobe_trace);