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/bpf-cgroup.h>
  11 #include <linux/security.h>
  12 #include <linux/ctype.h>
  13 #include <linux/module.h>
  14 #include <linux/uaccess.h>
  15 #include <linux/uprobes.h>
  16 #include <linux/namei.h>
  17 #include <linux/string.h>
  18 #include <linux/rculist.h>
  19 #include <linux/filter.h>
  20
  21 #include "trace_dynevent.h"
  22 #include "trace_probe.h"
  23 #include "trace_probe_tmpl.h"
  24
  25 #define UPROBE_EVENT_SYSTEM     "uprobes"
  26
  27 struct uprobe_trace_entry_head {
  28         struct trace_entry      ent;
  29         unsigned long           vaddr[];
  30 };
  31
  32 #define SIZEOF_TRACE_ENTRY(is_return)                   \
  33         (sizeof(struct uprobe_trace_entry_head) +       \
  34          sizeof(unsigned long) * (is_return ? 2 : 1))
  35
  36 #define DATAOF_TRACE_ENTRY(entry, is_return)            \
  37         ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
  38
  39 static int trace_uprobe_create(const char *raw_command);
  40 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
  41 static int trace_uprobe_release(struct dyn_event *ev);
  42 static bool trace_uprobe_is_busy(struct dyn_event *ev);
  43 static bool trace_uprobe_match(const char *system, const char *event,
  44                         int argc, const char **argv, struct dyn_event *ev);
  45
  46 static struct dyn_event_operations trace_uprobe_ops = {
  47         .create = trace_uprobe_create,
  48         .show = trace_uprobe_show,
  49         .is_busy = trace_uprobe_is_busy,
  50         .free = trace_uprobe_release,
  51         .match = trace_uprobe_match,
  52 };
  53
  54 /*
  55  * uprobe event core functions
  56  */
  57 struct trace_uprobe {
  58         struct dyn_event                devent;
  59         struct uprobe_consumer          consumer;
  60         struct path                     path;
  61         struct inode                    *inode;
  62         char                            *filename;
  63         unsigned long                   offset;
  64         unsigned long                   ref_ctr_offset;
  65         unsigned long                   nhit;
  66         struct trace_probe              tp;
  67 };
  68
  69 static bool is_trace_uprobe(struct dyn_event *ev)
  70 {
  71         return ev->ops == &trace_uprobe_ops;
  72 }
  73
  74 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
  75 {
  76         return container_of(ev, struct trace_uprobe, devent);
  77 }
  78
  79 /**
  80  * for_each_trace_uprobe - iterate over the trace_uprobe list
  81  * @pos:        the struct trace_uprobe * for each entry
  82  * @dpos:       the struct dyn_event * to use as a loop cursor
  83  */
  84 #define for_each_trace_uprobe(pos, dpos)        \
  85         for_each_dyn_event(dpos)                \
  86                 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
  87
  88 static int register_uprobe_event(struct trace_uprobe *tu);
  89 static int unregister_uprobe_event(struct trace_uprobe *tu);
  90
  91 struct uprobe_dispatch_data {
  92         struct trace_uprobe     *tu;
  93         unsigned long           bp_addr;
  94 };
  95
  96 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
  97 static int uretprobe_dispatcher(struct uprobe_consumer *con,
  98                                 unsigned long func, struct pt_regs *regs);
  99
 100 #ifdef CONFIG_STACK_GROWSUP
 101 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 102 {
 103         return addr - (n * sizeof(long));
 104 }
 105 #else
 106 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 107 {
 108         return addr + (n * sizeof(long));
 109 }
 110 #endif
 111
 112 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
 113 {
 114         unsigned long ret;
 115         unsigned long addr = user_stack_pointer(regs);
 116
 117         addr = adjust_stack_addr(addr, n);
 118
 119         if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
 120                 return 0;
 121
 122         return ret;
 123 }
 124
 125 /*
 126  * Uprobes-specific fetch functions
 127  */
 128 static nokprobe_inline int
 129 probe_mem_read(void *dest, void *src, size_t size)
 130 {
 131         void __user *vaddr = (void __force __user *)src;
 132
 133         return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
 134 }
 135
 136 static nokprobe_inline int
 137 probe_mem_read_user(void *dest, void *src, size_t size)
 138 {
 139         return probe_mem_read(dest, src, size);
 140 }
 141
 142 /*
 143  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
 144  * length and relative data location.
 145  */
 146 static nokprobe_inline int
 147 fetch_store_string(unsigned long addr, void *dest, void *base)
 148 {
 149         long ret;
 150         u32 loc = *(u32 *)dest;
 151         int maxlen  = get_loc_len(loc);
 152         u8 *dst = get_loc_data(dest, base);
 153         void __user *src = (void __force __user *) addr;
 154
 155         if (unlikely(!maxlen))
 156                 return -ENOMEM;
 157
 158         if (addr == FETCH_TOKEN_COMM)
 159                 ret = strlcpy(dst, current->comm, maxlen);
 160         else
 161                 ret = strncpy_from_user(dst, src, maxlen);
 162         if (ret >= 0) {
 163                 if (ret == maxlen)
 164                         dst[ret - 1] = '\0';
 165                 else
 166                         /*
 167                          * Include the terminating null byte. In this case it
 168                          * was copied by strncpy_from_user but not accounted
 169                          * for in ret.
 170                          */
 171                         ret++;
 172                 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
 173         }
 174
 175         return ret;
 176 }
 177
 178 static nokprobe_inline int
 179 fetch_store_string_user(unsigned long addr, void *dest, void *base)
 180 {
 181         return fetch_store_string(addr, dest, base);
 182 }
 183
 184 /* Return the length of string -- including null terminal byte */
 185 static nokprobe_inline int
 186 fetch_store_strlen(unsigned long addr)
 187 {
 188         int len;
 189         void __user *vaddr = (void __force __user *) addr;
 190
 191         if (addr == FETCH_TOKEN_COMM)
 192                 len = strlen(current->comm) + 1;
 193         else
 194                 len = strnlen_user(vaddr, MAX_STRING_SIZE);
 195
 196         return (len > MAX_STRING_SIZE) ? 0 : len;
 197 }
 198
 199 static nokprobe_inline int
 200 fetch_store_strlen_user(unsigned long addr)
 201 {
 202         return fetch_store_strlen(addr);
 203 }
 204
 205 static unsigned long translate_user_vaddr(unsigned long file_offset)
 206 {
 207         unsigned long base_addr;
 208         struct uprobe_dispatch_data *udd;
 209
 210         udd = (void *) current->utask->vaddr;
 211
 212         base_addr = udd->bp_addr - udd->tu->offset;
 213         return base_addr + file_offset;
 214 }
 215
 216 /* Note that we don't verify it, since the code does not come from user space */
 217 static int
 218 process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 219                    void *base)
 220 {
 221         struct pt_regs *regs = rec;
 222         unsigned long val;
 223         int ret;
 224
 225         /* 1st stage: get value from context */
 226         switch (code->op) {
 227         case FETCH_OP_REG:
 228                 val = regs_get_register(regs, code->param);
 229                 break;
 230         case FETCH_OP_STACK:
 231                 val = get_user_stack_nth(regs, code->param);
 232                 break;
 233         case FETCH_OP_STACKP:
 234                 val = user_stack_pointer(regs);
 235                 break;
 236         case FETCH_OP_RETVAL:
 237                 val = regs_return_value(regs);
 238                 break;
 239         case FETCH_OP_COMM:
 240                 val = FETCH_TOKEN_COMM;
 241                 break;
 242         case FETCH_OP_FOFFS:
 243                 val = translate_user_vaddr(code->immediate);
 244                 break;
 245         default:
 246                 ret = process_common_fetch_insn(code, &val);
 247                 if (ret < 0)
 248                         return ret;
 249         }
 250         code++;
 251
 252         return process_fetch_insn_bottom(code, val, dest, base);
 253 }
 254 NOKPROBE_SYMBOL(process_fetch_insn)
 255
 256 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
 257 {
 258         rwlock_init(&filter->rwlock);
 259         filter->nr_systemwide = 0;
 260         INIT_LIST_HEAD(&filter->perf_events);
 261 }
 262
 263 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
 264 {
 265         return !filter->nr_systemwide && list_empty(&filter->perf_events);
 266 }
 267
 268 static inline bool is_ret_probe(struct trace_uprobe *tu)
 269 {
 270         return tu->consumer.ret_handler != NULL;
 271 }
 272
 273 static bool trace_uprobe_is_busy(struct dyn_event *ev)
 274 {
 275         struct trace_uprobe *tu = to_trace_uprobe(ev);
 276
 277         return trace_probe_is_enabled(&tu->tp);
 278 }
 279
 280 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
 281                                             int argc, const char **argv)
 282 {
 283         char buf[MAX_ARGSTR_LEN + 1];
 284         int len;
 285
 286         if (!argc)
 287                 return true;
 288
 289         len = strlen(tu->filename);
 290         if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
 291                 return false;
 292
 293         if (tu->ref_ctr_offset == 0)
 294                 snprintf(buf, sizeof(buf), "0x%0*lx",
 295                                 (int)(sizeof(void *) * 2), tu->offset);
 296         else
 297                 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
 298                                 (int)(sizeof(void *) * 2), tu->offset,
 299                                 tu->ref_ctr_offset);
 300         if (strcmp(buf, &argv[0][len + 1]))
 301                 return false;
 302
 303         argc--; argv++;
 304
 305         return trace_probe_match_command_args(&tu->tp, argc, argv);
 306 }
 307
 308 static bool trace_uprobe_match(const char *system, const char *event,
 309                         int argc, const char **argv, struct dyn_event *ev)
 310 {
 311         struct trace_uprobe *tu = to_trace_uprobe(ev);
 312
 313         return (event[0] == '\0' ||
 314                 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 inode *comp_inode = d_real_inode(comp->path.dentry);
 413         int i;
 414
 415         list_for_each_entry(orig, &tpe->probes, tp.list) {
 416                 if (comp_inode != d_real_inode(orig->path.dentry) ||
 417                     comp->offset != orig->offset)
 418                         continue;
 419
 420                 /*
 421                  * trace_probe_compare_arg_type() ensured that nr_args and
 422                  * each argument name and type are same. Let's compare comm.
 423                  */
 424                 for (i = 0; i < orig->tp.nr_args; i++) {
 425                         if (strcmp(orig->tp.args[i].comm,
 426                                    comp->tp.args[i].comm))
 427                                 break;
 428                 }
 429
 430                 if (i == orig->tp.nr_args)
 431                         return true;
 432         }
 433
 434         return false;
 435 }
 436
 437 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
 438 {
 439         int ret;
 440
 441         ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
 442         if (ret) {
 443                 /* Note that argument starts index = 2 */
 444                 trace_probe_log_set_index(ret + 1);
 445                 trace_probe_log_err(0, DIFF_ARG_TYPE);
 446                 return -EEXIST;
 447         }
 448         if (trace_uprobe_has_same_uprobe(to, tu)) {
 449                 trace_probe_log_set_index(0);
 450                 trace_probe_log_err(0, SAME_PROBE);
 451                 return -EEXIST;
 452         }
 453
 454         /* Append to existing event */
 455         ret = trace_probe_append(&tu->tp, &to->tp);
 456         if (!ret)
 457                 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
 458
 459         return ret;
 460 }
 461
 462 /*
 463  * Uprobe with multiple reference counter is not allowed. i.e.
 464  * If inode and offset matches, reference counter offset *must*
 465  * match as well. Though, there is one exception: If user is
 466  * replacing old trace_uprobe with new one(same group/event),
 467  * then we allow same uprobe with new reference counter as far
 468  * as the new one does not conflict with any other existing
 469  * ones.
 470  */
 471 static int validate_ref_ctr_offset(struct trace_uprobe *new)
 472 {
 473         struct dyn_event *pos;
 474         struct trace_uprobe *tmp;
 475         struct inode *new_inode = d_real_inode(new->path.dentry);
 476
 477         for_each_trace_uprobe(tmp, pos) {
 478                 if (new_inode == d_real_inode(tmp->path.dentry) &&
 479                     new->offset == tmp->offset &&
 480                     new->ref_ctr_offset != tmp->ref_ctr_offset) {
 481                         pr_warn("Reference counter offset mismatch.");
 482                         return -EINVAL;
 483                 }
 484         }
 485         return 0;
 486 }
 487
 488 /* Register a trace_uprobe and probe_event */
 489 static int register_trace_uprobe(struct trace_uprobe *tu)
 490 {
 491         struct trace_uprobe *old_tu;
 492         int ret;
 493
 494         mutex_lock(&event_mutex);
 495
 496         ret = validate_ref_ctr_offset(tu);
 497         if (ret)
 498                 goto end;
 499
 500         /* register as an event */
 501         old_tu = find_probe_event(trace_probe_name(&tu->tp),
 502                                   trace_probe_group_name(&tu->tp));
 503         if (old_tu) {
 504                 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
 505                         trace_probe_log_set_index(0);
 506                         trace_probe_log_err(0, DIFF_PROBE_TYPE);
 507                         ret = -EEXIST;
 508                 } else {
 509                         ret = append_trace_uprobe(tu, old_tu);
 510                 }
 511                 goto end;
 512         }
 513
 514         ret = register_uprobe_event(tu);
 515         if (ret) {
 516                 if (ret == -EEXIST) {
 517                         trace_probe_log_set_index(0);
 518                         trace_probe_log_err(0, EVENT_EXIST);
 519                 } else
 520                         pr_warn("Failed to register probe event(%d)\n", ret);
 521                 goto end;
 522         }
 523
 524         dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
 525
 526 end:
 527         mutex_unlock(&event_mutex);
 528
 529         return ret;
 530 }
 531
 532 /*
 533  * Argument syntax:
 534  *  - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS]
 535  */
 536 static int __trace_uprobe_create(int argc, const char **argv)
 537 {
 538         struct trace_uprobe *tu;
 539         const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
 540         char *arg, *filename, *rctr, *rctr_end, *tmp;
 541         char buf[MAX_EVENT_NAME_LEN];
 542         char gbuf[MAX_EVENT_NAME_LEN];
 543         enum probe_print_type ptype;
 544         struct path path;
 545         unsigned long offset, ref_ctr_offset;
 546         bool is_return = false;
 547         int i, ret;
 548
 549         ref_ctr_offset = 0;
 550
 551         switch (argv[0][0]) {
 552         case 'r':
 553                 is_return = true;
 554                 break;
 555         case 'p':
 556                 break;
 557         default:
 558                 return -ECANCELED;
 559         }
 560
 561         if (argc < 2)
 562                 return -ECANCELED;
 563
 564         if (argv[0][1] == ':')
 565                 event = &argv[0][2];
 566
 567         if (!strchr(argv[1], '/'))
 568                 return -ECANCELED;
 569
 570         filename = kstrdup(argv[1], GFP_KERNEL);
 571         if (!filename)
 572                 return -ENOMEM;
 573
 574         /* Find the last occurrence, in case the path contains ':' too. */
 575         arg = strrchr(filename, ':');
 576         if (!arg || !isdigit(arg[1])) {
 577                 kfree(filename);
 578                 return -ECANCELED;
 579         }
 580
 581         trace_probe_log_init("trace_uprobe", argc, argv);
 582         trace_probe_log_set_index(1);   /* filename is the 2nd argument */
 583
 584         *arg++ = '\0';
 585         ret = kern_path(filename, LOOKUP_FOLLOW, &path);
 586         if (ret) {
 587                 trace_probe_log_err(0, FILE_NOT_FOUND);
 588                 kfree(filename);
 589                 trace_probe_log_clear();
 590                 return ret;
 591         }
 592         if (!d_is_reg(path.dentry)) {
 593                 trace_probe_log_err(0, NO_REGULAR_FILE);
 594                 ret = -EINVAL;
 595                 goto fail_address_parse;
 596         }
 597
 598         /* Parse reference counter offset if specified. */
 599         rctr = strchr(arg, '(');
 600         if (rctr) {
 601                 rctr_end = strchr(rctr, ')');
 602                 if (!rctr_end) {
 603                         ret = -EINVAL;
 604                         rctr_end = rctr + strlen(rctr);
 605                         trace_probe_log_err(rctr_end - filename,
 606                                             REFCNT_OPEN_BRACE);
 607                         goto fail_address_parse;
 608                 } else if (rctr_end[1] != '\0') {
 609                         ret = -EINVAL;
 610                         trace_probe_log_err(rctr_end + 1 - filename,
 611                                             BAD_REFCNT_SUFFIX);
 612                         goto fail_address_parse;
 613                 }
 614
 615                 *rctr++ = '\0';
 616                 *rctr_end = '\0';
 617                 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
 618                 if (ret) {
 619                         trace_probe_log_err(rctr - filename, BAD_REFCNT);
 620                         goto fail_address_parse;
 621                 }
 622         }
 623
 624         /* Check if there is %return suffix */
 625         tmp = strchr(arg, '%');
 626         if (tmp) {
 627                 if (!strcmp(tmp, "%return")) {
 628                         *tmp = '\0';
 629                         is_return = true;
 630                 } else {
 631                         trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
 632                         ret = -EINVAL;
 633                         goto fail_address_parse;
 634                 }
 635         }
 636
 637         /* Parse uprobe offset. */
 638         ret = kstrtoul(arg, 0, &offset);
 639         if (ret) {
 640                 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
 641                 goto fail_address_parse;
 642         }
 643
 644         /* setup a probe */
 645         trace_probe_log_set_index(0);
 646         if (event) {
 647                 ret = traceprobe_parse_event_name(&event, &group, gbuf,
 648                                                   event - argv[0]);
 649                 if (ret)
 650                         goto fail_address_parse;
 651         }
 652
 653         if (!event) {
 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                                         TPARG_FL_USER);
 693                 if (ret)
 694                         goto error;
 695         }
 696
 697         ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
 698         ret = traceprobe_set_print_fmt(&tu->tp, ptype);
 699         if (ret < 0)
 700                 goto error;
 701
 702         ret = register_trace_uprobe(tu);
 703         if (!ret)
 704                 goto out;
 705
 706 error:
 707         free_trace_uprobe(tu);
 708 out:
 709         trace_probe_log_clear();
 710         return ret;
 711
 712 fail_address_parse:
 713         trace_probe_log_clear();
 714         path_put(&path);
 715         kfree(filename);
 716
 717         return ret;
 718 }
 719
 720 int trace_uprobe_create(const char *raw_command)
 721 {
 722         return trace_probe_create(raw_command, __trace_uprobe_create);
 723 }
 724
 725 static int create_or_delete_trace_uprobe(const char *raw_command)
 726 {
 727         int ret;
 728
 729         if (raw_command[0] == '-')
 730                 return dyn_event_release(raw_command, &trace_uprobe_ops);
 731
 732         ret = trace_uprobe_create(raw_command);
 733         return ret == -ECANCELED ? -EINVAL : ret;
 734 }
 735
 736 static int trace_uprobe_release(struct dyn_event *ev)
 737 {
 738         struct trace_uprobe *tu = to_trace_uprobe(ev);
 739
 740         return unregister_trace_uprobe(tu);
 741 }
 742
 743 /* Probes listing interfaces */
 744 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
 745 {
 746         struct trace_uprobe *tu = to_trace_uprobe(ev);
 747         char c = is_ret_probe(tu) ? 'r' : 'p';
 748         int i;
 749
 750         seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
 751                         trace_probe_name(&tu->tp), tu->filename,
 752                         (int)(sizeof(void *) * 2), tu->offset);
 753
 754         if (tu->ref_ctr_offset)
 755                 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
 756
 757         for (i = 0; i < tu->tp.nr_args; i++)
 758                 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
 759
 760         seq_putc(m, '\n');
 761         return 0;
 762 }
 763
 764 static int probes_seq_show(struct seq_file *m, void *v)
 765 {
 766         struct dyn_event *ev = v;
 767
 768         if (!is_trace_uprobe(ev))
 769                 return 0;
 770
 771         return trace_uprobe_show(m, ev);
 772 }
 773
 774 static const struct seq_operations probes_seq_op = {
 775         .start  = dyn_event_seq_start,
 776         .next   = dyn_event_seq_next,
 777         .stop   = dyn_event_seq_stop,
 778         .show   = probes_seq_show
 779 };
 780
 781 static int probes_open(struct inode *inode, struct file *file)
 782 {
 783         int ret;
 784
 785         ret = security_locked_down(LOCKDOWN_TRACEFS);
 786         if (ret)
 787                 return ret;
 788
 789         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 790                 ret = dyn_events_release_all(&trace_uprobe_ops);
 791                 if (ret)
 792                         return ret;
 793         }
 794
 795         return seq_open(file, &probes_seq_op);
 796 }
 797
 798 static ssize_t probes_write(struct file *file, const char __user *buffer,
 799                             size_t count, loff_t *ppos)
 800 {
 801         return trace_parse_run_command(file, buffer, count, ppos,
 802                                         create_or_delete_trace_uprobe);
 803 }
 804
 805 static const struct file_operations uprobe_events_ops = {
 806         .owner          = THIS_MODULE,
 807         .open           = probes_open,
 808         .read           = seq_read,
 809         .llseek         = seq_lseek,
 810         .release        = seq_release,
 811         .write          = probes_write,
 812 };
 813
 814 /* Probes profiling interfaces */
 815 static int probes_profile_seq_show(struct seq_file *m, void *v)
 816 {
 817         struct dyn_event *ev = v;
 818         struct trace_uprobe *tu;
 819
 820         if (!is_trace_uprobe(ev))
 821                 return 0;
 822
 823         tu = to_trace_uprobe(ev);
 824         seq_printf(m, "  %s %-44s %15lu\n", tu->filename,
 825                         trace_probe_name(&tu->tp), tu->nhit);
 826         return 0;
 827 }
 828
 829 static const struct seq_operations profile_seq_op = {
 830         .start  = dyn_event_seq_start,
 831         .next   = dyn_event_seq_next,
 832         .stop   = dyn_event_seq_stop,
 833         .show   = probes_profile_seq_show
 834 };
 835
 836 static int profile_open(struct inode *inode, struct file *file)
 837 {
 838         int ret;
 839
 840         ret = security_locked_down(LOCKDOWN_TRACEFS);
 841         if (ret)
 842                 return ret;
 843
 844         return seq_open(file, &profile_seq_op);
 845 }
 846
 847 static const struct file_operations uprobe_profile_ops = {
 848         .owner          = THIS_MODULE,
 849         .open           = profile_open,
 850         .read           = seq_read,
 851         .llseek         = seq_lseek,
 852         .release        = seq_release,
 853 };
 854
 855 struct uprobe_cpu_buffer {
 856         struct mutex mutex;
 857         void *buf;
 858 };
 859 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
 860 static int uprobe_buffer_refcnt;
 861
 862 static int uprobe_buffer_init(void)
 863 {
 864         int cpu, err_cpu;
 865
 866         uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
 867         if (uprobe_cpu_buffer == NULL)
 868                 return -ENOMEM;
 869
 870         for_each_possible_cpu(cpu) {
 871                 struct page *p = alloc_pages_node(cpu_to_node(cpu),
 872                                                   GFP_KERNEL, 0);
 873                 if (p == NULL) {
 874                         err_cpu = cpu;
 875                         goto err;
 876                 }
 877                 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
 878                 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
 879         }
 880
 881         return 0;
 882
 883 err:
 884         for_each_possible_cpu(cpu) {
 885                 if (cpu == err_cpu)
 886                         break;
 887                 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
 888         }
 889
 890         free_percpu(uprobe_cpu_buffer);
 891         return -ENOMEM;
 892 }
 893
 894 static int uprobe_buffer_enable(void)
 895 {
 896         int ret = 0;
 897
 898         BUG_ON(!mutex_is_locked(&event_mutex));
 899
 900         if (uprobe_buffer_refcnt++ == 0) {
 901                 ret = uprobe_buffer_init();
 902                 if (ret < 0)
 903                         uprobe_buffer_refcnt--;
 904         }
 905
 906         return ret;
 907 }
 908
 909 static void uprobe_buffer_disable(void)
 910 {
 911         int cpu;
 912
 913         BUG_ON(!mutex_is_locked(&event_mutex));
 914
 915         if (--uprobe_buffer_refcnt == 0) {
 916                 for_each_possible_cpu(cpu)
 917                         free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
 918                                                              cpu)->buf);
 919
 920                 free_percpu(uprobe_cpu_buffer);
 921                 uprobe_cpu_buffer = NULL;
 922         }
 923 }
 924
 925 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
 926 {
 927         struct uprobe_cpu_buffer *ucb;
 928         int cpu;
 929
 930         cpu = raw_smp_processor_id();
 931         ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
 932
 933         /*
 934          * Use per-cpu buffers for fastest access, but we might migrate
 935          * so the mutex makes sure we have sole access to it.
 936          */
 937         mutex_lock(&ucb->mutex);
 938
 939         return ucb;
 940 }
 941
 942 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
 943 {
 944         mutex_unlock(&ucb->mutex);
 945 }
 946
 947 static void __uprobe_trace_func(struct trace_uprobe *tu,
 948                                 unsigned long func, struct pt_regs *regs,
 949                                 struct uprobe_cpu_buffer *ucb, int dsize,
 950                                 struct trace_event_file *trace_file)
 951 {
 952         struct uprobe_trace_entry_head *entry;
 953         struct trace_event_buffer fbuffer;
 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         entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
 969         if (!entry)
 970                 return;
 971
 972         if (is_ret_probe(tu)) {
 973                 entry->vaddr[0] = func;
 974                 entry->vaddr[1] = instruction_pointer(regs);
 975                 data = DATAOF_TRACE_ENTRY(entry, true);
 976         } else {
 977                 entry->vaddr[0] = instruction_pointer(regs);
 978                 data = DATAOF_TRACE_ENTRY(entry, false);
 979         }
 980
 981         memcpy(data, ucb->buf, tu->tp.size + dsize);
 982
 983         trace_event_buffer_commit(&fbuffer);
 984 }
 985
 986 /* uprobe handler */
 987 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
 988                              struct uprobe_cpu_buffer *ucb, int dsize)
 989 {
 990         struct event_file_link *link;
 991
 992         if (is_ret_probe(tu))
 993                 return 0;
 994
 995         rcu_read_lock();
 996         trace_probe_for_each_link_rcu(link, &tu->tp)
 997                 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
 998         rcu_read_unlock();
 999
1000         return 0;
1001 }
1002
1003 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
1004                                  struct pt_regs *regs,
1005                                  struct uprobe_cpu_buffer *ucb, int dsize)
1006 {
1007         struct event_file_link *link;
1008
1009         rcu_read_lock();
1010         trace_probe_for_each_link_rcu(link, &tu->tp)
1011                 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
1012         rcu_read_unlock();
1013 }
1014
1015 /* Event entry printers */
1016 static enum print_line_t
1017 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1018 {
1019         struct uprobe_trace_entry_head *entry;
1020         struct trace_seq *s = &iter->seq;
1021         struct trace_uprobe *tu;
1022         u8 *data;
1023
1024         entry = (struct uprobe_trace_entry_head *)iter->ent;
1025         tu = trace_uprobe_primary_from_call(
1026                 container_of(event, struct trace_event_call, event));
1027         if (unlikely(!tu))
1028                 goto out;
1029
1030         if (is_ret_probe(tu)) {
1031                 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1032                                  trace_probe_name(&tu->tp),
1033                                  entry->vaddr[1], entry->vaddr[0]);
1034                 data = DATAOF_TRACE_ENTRY(entry, true);
1035         } else {
1036                 trace_seq_printf(s, "%s: (0x%lx)",
1037                                  trace_probe_name(&tu->tp),
1038                                  entry->vaddr[0]);
1039                 data = DATAOF_TRACE_ENTRY(entry, false);
1040         }
1041
1042         if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1043                 goto out;
1044
1045         trace_seq_putc(s, '\n');
1046
1047  out:
1048         return trace_handle_return(s);
1049 }
1050
1051 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1052                                 enum uprobe_filter_ctx ctx,
1053                                 struct mm_struct *mm);
1054
1055 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1056 {
1057         int ret;
1058
1059         tu->consumer.filter = filter;
1060         tu->inode = d_real_inode(tu->path.dentry);
1061
1062         if (tu->ref_ctr_offset)
1063                 ret = uprobe_register_refctr(tu->inode, tu->offset,
1064                                 tu->ref_ctr_offset, &tu->consumer);
1065         else
1066                 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1067
1068         if (ret)
1069                 tu->inode = NULL;
1070
1071         return ret;
1072 }
1073
1074 static void __probe_event_disable(struct trace_probe *tp)
1075 {
1076         struct trace_uprobe *tu;
1077
1078         tu = container_of(tp, struct trace_uprobe, tp);
1079         WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1080
1081         list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1082                 if (!tu->inode)
1083                         continue;
1084
1085                 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1086                 tu->inode = NULL;
1087         }
1088 }
1089
1090 static int probe_event_enable(struct trace_event_call *call,
1091                         struct trace_event_file *file, filter_func_t filter)
1092 {
1093         struct trace_probe *tp;
1094         struct trace_uprobe *tu;
1095         bool enabled;
1096         int ret;
1097
1098         tp = trace_probe_primary_from_call(call);
1099         if (WARN_ON_ONCE(!tp))
1100                 return -ENODEV;
1101         enabled = trace_probe_is_enabled(tp);
1102
1103         /* This may also change "enabled" state */
1104         if (file) {
1105                 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1106                         return -EINTR;
1107
1108                 ret = trace_probe_add_file(tp, file);
1109                 if (ret < 0)
1110                         return ret;
1111         } else {
1112                 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1113                         return -EINTR;
1114
1115                 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1116         }
1117
1118         tu = container_of(tp, struct trace_uprobe, tp);
1119         WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1120
1121         if (enabled)
1122                 return 0;
1123
1124         ret = uprobe_buffer_enable();
1125         if (ret)
1126                 goto err_flags;
1127
1128         list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1129                 ret = trace_uprobe_enable(tu, filter);
1130                 if (ret) {
1131                         __probe_event_disable(tp);
1132                         goto err_buffer;
1133                 }
1134         }
1135
1136         return 0;
1137
1138  err_buffer:
1139         uprobe_buffer_disable();
1140
1141  err_flags:
1142         if (file)
1143                 trace_probe_remove_file(tp, file);
1144         else
1145                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1146
1147         return ret;
1148 }
1149
1150 static void probe_event_disable(struct trace_event_call *call,
1151                                 struct trace_event_file *file)
1152 {
1153         struct trace_probe *tp;
1154
1155         tp = trace_probe_primary_from_call(call);
1156         if (WARN_ON_ONCE(!tp))
1157                 return;
1158
1159         if (!trace_probe_is_enabled(tp))
1160                 return;
1161
1162         if (file) {
1163                 if (trace_probe_remove_file(tp, file) < 0)
1164                         return;
1165
1166                 if (trace_probe_is_enabled(tp))
1167                         return;
1168         } else
1169                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1170
1171         __probe_event_disable(tp);
1172         uprobe_buffer_disable();
1173 }
1174
1175 static int uprobe_event_define_fields(struct trace_event_call *event_call)
1176 {
1177         int ret, size;
1178         struct uprobe_trace_entry_head field;
1179         struct trace_uprobe *tu;
1180
1181         tu = trace_uprobe_primary_from_call(event_call);
1182         if (unlikely(!tu))
1183                 return -ENODEV;
1184
1185         if (is_ret_probe(tu)) {
1186                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1187                 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1188                 size = SIZEOF_TRACE_ENTRY(true);
1189         } else {
1190                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1191                 size = SIZEOF_TRACE_ENTRY(false);
1192         }
1193
1194         return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1195 }
1196
1197 #ifdef CONFIG_PERF_EVENTS
1198 static bool
1199 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1200 {
1201         struct perf_event *event;
1202
1203         if (filter->nr_systemwide)
1204                 return true;
1205
1206         list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1207                 if (event->hw.target->mm == mm)
1208                         return true;
1209         }
1210
1211         return false;
1212 }
1213
1214 static inline bool
1215 trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1216                           struct perf_event *event)
1217 {
1218         return __uprobe_perf_filter(filter, event->hw.target->mm);
1219 }
1220
1221 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1222                                        struct perf_event *event)
1223 {
1224         bool done;
1225
1226         write_lock(&filter->rwlock);
1227         if (event->hw.target) {
1228                 list_del(&event->hw.tp_list);
1229                 done = filter->nr_systemwide ||
1230                         (event->hw.target->flags & PF_EXITING) ||
1231                         trace_uprobe_filter_event(filter, event);
1232         } else {
1233                 filter->nr_systemwide--;
1234                 done = filter->nr_systemwide;
1235         }
1236         write_unlock(&filter->rwlock);
1237
1238         return done;
1239 }
1240
1241 /* This returns true if the filter always covers target mm */
1242 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1243                                     struct perf_event *event)
1244 {
1245         bool done;
1246
1247         write_lock(&filter->rwlock);
1248         if (event->hw.target) {
1249                 /*
1250                  * event->parent != NULL means copy_process(), we can avoid
1251                  * uprobe_apply(). current->mm must be probed and we can rely
1252                  * on dup_mmap() which preserves the already installed bp's.
1253                  *
1254                  * attr.enable_on_exec means that exec/mmap will install the
1255                  * breakpoints we need.
1256                  */
1257                 done = filter->nr_systemwide ||
1258                         event->parent || event->attr.enable_on_exec ||
1259                         trace_uprobe_filter_event(filter, event);
1260                 list_add(&event->hw.tp_list, &filter->perf_events);
1261         } else {
1262                 done = filter->nr_systemwide;
1263                 filter->nr_systemwide++;
1264         }
1265         write_unlock(&filter->rwlock);
1266
1267         return done;
1268 }
1269
1270 static int uprobe_perf_close(struct trace_event_call *call,
1271                              struct perf_event *event)
1272 {
1273         struct trace_probe *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         tu = container_of(tp, struct trace_uprobe, tp);
1282         if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1283                 return 0;
1284
1285         list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1286                 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1287                 if (ret)
1288                         break;
1289         }
1290
1291         return ret;
1292 }
1293
1294 static int uprobe_perf_open(struct trace_event_call *call,
1295                             struct perf_event *event)
1296 {
1297         struct trace_probe *tp;
1298         struct trace_uprobe *tu;
1299         int err = 0;
1300
1301         tp = trace_probe_primary_from_call(call);
1302         if (WARN_ON_ONCE(!tp))
1303                 return -ENODEV;
1304
1305         tu = container_of(tp, struct trace_uprobe, tp);
1306         if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1307                 return 0;
1308
1309         list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1310                 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1311                 if (err) {
1312                         uprobe_perf_close(call, event);
1313                         break;
1314                 }
1315         }
1316
1317         return err;
1318 }
1319
1320 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1321                                 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1322 {
1323         struct trace_uprobe_filter *filter;
1324         struct trace_uprobe *tu;
1325         int ret;
1326
1327         tu = container_of(uc, struct trace_uprobe, consumer);
1328         filter = tu->tp.event->filter;
1329
1330         read_lock(&filter->rwlock);
1331         ret = __uprobe_perf_filter(filter, mm);
1332         read_unlock(&filter->rwlock);
1333
1334         return ret;
1335 }
1336
1337 static void __uprobe_perf_func(struct trace_uprobe *tu,
1338                                unsigned long func, struct pt_regs *regs,
1339                                struct uprobe_cpu_buffer *ucb, int dsize)
1340 {
1341         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1342         struct uprobe_trace_entry_head *entry;
1343         struct hlist_head *head;
1344         void *data;
1345         int size, esize;
1346         int rctx;
1347
1348 #ifdef CONFIG_BPF_EVENTS
1349         if (bpf_prog_array_valid(call)) {
1350                 u32 ret;
1351
1352                 ret = bpf_prog_run_array_sleepable(call->prog_array, regs, bpf_prog_run);
1353                 if (!ret)
1354                         return;
1355         }
1356 #endif /* CONFIG_BPF_EVENTS */
1357
1358         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1359
1360         size = esize + tu->tp.size + dsize;
1361         size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1362         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1363                 return;
1364
1365         preempt_disable();
1366         head = this_cpu_ptr(call->perf_events);
1367         if (hlist_empty(head))
1368                 goto out;
1369
1370         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1371         if (!entry)
1372                 goto out;
1373
1374         if (is_ret_probe(tu)) {
1375                 entry->vaddr[0] = func;
1376                 entry->vaddr[1] = instruction_pointer(regs);
1377                 data = DATAOF_TRACE_ENTRY(entry, true);
1378         } else {
1379                 entry->vaddr[0] = instruction_pointer(regs);
1380                 data = DATAOF_TRACE_ENTRY(entry, false);
1381         }
1382
1383         memcpy(data, ucb->buf, tu->tp.size + dsize);
1384
1385         if (size - esize > tu->tp.size + dsize) {
1386                 int len = tu->tp.size + dsize;
1387
1388                 memset(data + len, 0, size - esize - len);
1389         }
1390
1391         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1392                               head, NULL);
1393  out:
1394         preempt_enable();
1395 }
1396
1397 /* uprobe profile handler */
1398 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1399                             struct uprobe_cpu_buffer *ucb, int dsize)
1400 {
1401         if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1402                 return UPROBE_HANDLER_REMOVE;
1403
1404         if (!is_ret_probe(tu))
1405                 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1406         return 0;
1407 }
1408
1409 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1410                                 struct pt_regs *regs,
1411                                 struct uprobe_cpu_buffer *ucb, int dsize)
1412 {
1413         __uprobe_perf_func(tu, func, regs, ucb, dsize);
1414 }
1415
1416 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1417                         const char **filename, u64 *probe_offset,
1418                         bool perf_type_tracepoint)
1419 {
1420         const char *pevent = trace_event_name(event->tp_event);
1421         const char *group = event->tp_event->class->system;
1422         struct trace_uprobe *tu;
1423
1424         if (perf_type_tracepoint)
1425                 tu = find_probe_event(pevent, group);
1426         else
1427                 tu = trace_uprobe_primary_from_call(event->tp_event);
1428         if (!tu)
1429                 return -EINVAL;
1430
1431         *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1432                                     : BPF_FD_TYPE_UPROBE;
1433         *filename = tu->filename;
1434         *probe_offset = tu->offset;
1435         return 0;
1436 }
1437 #endif  /* CONFIG_PERF_EVENTS */
1438
1439 static int
1440 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1441                       void *data)
1442 {
1443         struct trace_event_file *file = data;
1444
1445         switch (type) {
1446         case TRACE_REG_REGISTER:
1447                 return probe_event_enable(event, file, NULL);
1448
1449         case TRACE_REG_UNREGISTER:
1450                 probe_event_disable(event, file);
1451                 return 0;
1452
1453 #ifdef CONFIG_PERF_EVENTS
1454         case TRACE_REG_PERF_REGISTER:
1455                 return probe_event_enable(event, NULL, uprobe_perf_filter);
1456
1457         case TRACE_REG_PERF_UNREGISTER:
1458                 probe_event_disable(event, NULL);
1459                 return 0;
1460
1461         case TRACE_REG_PERF_OPEN:
1462                 return uprobe_perf_open(event, data);
1463
1464         case TRACE_REG_PERF_CLOSE:
1465                 return uprobe_perf_close(event, data);
1466
1467 #endif
1468         default:
1469                 return 0;
1470         }
1471 }
1472
1473 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1474 {
1475         struct trace_uprobe *tu;
1476         struct uprobe_dispatch_data udd;
1477         struct uprobe_cpu_buffer *ucb;
1478         int dsize, esize;
1479         int ret = 0;
1480
1481
1482         tu = container_of(con, struct trace_uprobe, consumer);
1483         tu->nhit++;
1484
1485         udd.tu = tu;
1486         udd.bp_addr = instruction_pointer(regs);
1487
1488         current->utask->vaddr = (unsigned long) &udd;
1489
1490         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1491                 return 0;
1492
1493         dsize = __get_data_size(&tu->tp, regs);
1494         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1495
1496         ucb = uprobe_buffer_get();
1497         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1498
1499         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1500                 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1501
1502 #ifdef CONFIG_PERF_EVENTS
1503         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1504                 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1505 #endif
1506         uprobe_buffer_put(ucb);
1507         return ret;
1508 }
1509
1510 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1511                                 unsigned long func, struct pt_regs *regs)
1512 {
1513         struct trace_uprobe *tu;
1514         struct uprobe_dispatch_data udd;
1515         struct uprobe_cpu_buffer *ucb;
1516         int dsize, esize;
1517
1518         tu = container_of(con, struct trace_uprobe, consumer);
1519
1520         udd.tu = tu;
1521         udd.bp_addr = func;
1522
1523         current->utask->vaddr = (unsigned long) &udd;
1524
1525         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1526                 return 0;
1527
1528         dsize = __get_data_size(&tu->tp, regs);
1529         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1530
1531         ucb = uprobe_buffer_get();
1532         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1533
1534         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1535                 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1536
1537 #ifdef CONFIG_PERF_EVENTS
1538         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1539                 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1540 #endif
1541         uprobe_buffer_put(ucb);
1542         return 0;
1543 }
1544
1545 static struct trace_event_functions uprobe_funcs = {
1546         .trace          = print_uprobe_event
1547 };
1548
1549 static struct trace_event_fields uprobe_fields_array[] = {
1550         { .type = TRACE_FUNCTION_TYPE,
1551           .define_fields = uprobe_event_define_fields },
1552         {}
1553 };
1554
1555 static inline void init_trace_event_call(struct trace_uprobe *tu)
1556 {
1557         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1558         call->event.funcs = &uprobe_funcs;
1559         call->class->fields_array = uprobe_fields_array;
1560
1561         call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1562         call->class->reg = trace_uprobe_register;
1563 }
1564
1565 static int register_uprobe_event(struct trace_uprobe *tu)
1566 {
1567         init_trace_event_call(tu);
1568
1569         return trace_probe_register_event_call(&tu->tp);
1570 }
1571
1572 static int unregister_uprobe_event(struct trace_uprobe *tu)
1573 {
1574         return trace_probe_unregister_event_call(&tu->tp);
1575 }
1576
1577 #ifdef CONFIG_PERF_EVENTS
1578 struct trace_event_call *
1579 create_local_trace_uprobe(char *name, unsigned long offs,
1580                           unsigned long ref_ctr_offset, bool is_return)
1581 {
1582         enum probe_print_type ptype;
1583         struct trace_uprobe *tu;
1584         struct path path;
1585         int ret;
1586
1587         ret = kern_path(name, LOOKUP_FOLLOW, &path);
1588         if (ret)
1589                 return ERR_PTR(ret);
1590
1591         if (!d_is_reg(path.dentry)) {
1592                 path_put(&path);
1593                 return ERR_PTR(-EINVAL);
1594         }
1595
1596         /*
1597          * local trace_kprobes are not added to dyn_event, so they are never
1598          * searched in find_trace_kprobe(). Therefore, there is no concern of
1599          * duplicated name "DUMMY_EVENT" here.
1600          */
1601         tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1602                                 is_return);
1603
1604         if (IS_ERR(tu)) {
1605                 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1606                         (int)PTR_ERR(tu));
1607                 path_put(&path);
1608                 return ERR_CAST(tu);
1609         }
1610
1611         tu->offset = offs;
1612         tu->path = path;
1613         tu->ref_ctr_offset = ref_ctr_offset;
1614         tu->filename = kstrdup(name, GFP_KERNEL);
1615         if (!tu->filename) {
1616                 ret = -ENOMEM;
1617                 goto error;
1618         }
1619
1620         init_trace_event_call(tu);
1621
1622         ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1623         if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
1624                 ret = -ENOMEM;
1625                 goto error;
1626         }
1627
1628         return trace_probe_event_call(&tu->tp);
1629 error:
1630         free_trace_uprobe(tu);
1631         return ERR_PTR(ret);
1632 }
1633
1634 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1635 {
1636         struct trace_uprobe *tu;
1637
1638         tu = trace_uprobe_primary_from_call(event_call);
1639
1640         free_trace_uprobe(tu);
1641 }
1642 #endif /* CONFIG_PERF_EVENTS */
1643
1644 /* Make a trace interface for controlling probe points */
1645 static __init int init_uprobe_trace(void)
1646 {
1647         int ret;
1648
1649         ret = dyn_event_register(&trace_uprobe_ops);
1650         if (ret)
1651                 return ret;
1652
1653         ret = tracing_init_dentry();
1654         if (ret)
1655                 return 0;
1656
1657         trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL,
1658                                     NULL, &uprobe_events_ops);
1659         /* Profile interface */
1660         trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
1661                                     NULL, &uprobe_profile_ops);
1662         return 0;
1663 }
1664
1665 fs_initcall(init_uprobe_trace);