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(int argc, const char **argv);
  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 #define SIZEOF_TRACE_UPROBE(n)                          \
  87         (offsetof(struct trace_uprobe, tp.args) +       \
  88         (sizeof(struct probe_arg) * (n)))
  89
  90 static int register_uprobe_event(struct trace_uprobe *tu);
  91 static int unregister_uprobe_event(struct trace_uprobe *tu);
  92
  93 struct uprobe_dispatch_data {
  94         struct trace_uprobe     *tu;
  95         unsigned long           bp_addr;
  96 };
  97
  98 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
  99 static int uretprobe_dispatcher(struct uprobe_consumer *con,
 100                                 unsigned long func, struct pt_regs *regs);
 101
 102 #ifdef CONFIG_STACK_GROWSUP
 103 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 104 {
 105         return addr - (n * sizeof(long));
 106 }
 107 #else
 108 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 109 {
 110         return addr + (n * sizeof(long));
 111 }
 112 #endif
 113
 114 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
 115 {
 116         unsigned long ret;
 117         unsigned long addr = user_stack_pointer(regs);
 118
 119         addr = adjust_stack_addr(addr, n);
 120
 121         if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
 122                 return 0;
 123
 124         return ret;
 125 }
 126
 127 /*
 128  * Uprobes-specific fetch functions
 129  */
 130 static nokprobe_inline int
 131 probe_mem_read(void *dest, void *src, size_t size)
 132 {
 133         void __user *vaddr = (void __force __user *)src;
 134
 135         return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
 136 }
 137
 138 static nokprobe_inline int
 139 probe_mem_read_user(void *dest, void *src, size_t size)
 140 {
 141         return probe_mem_read(dest, src, size);
 142 }
 143
 144 /*
 145  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
 146  * length and relative data location.
 147  */
 148 static nokprobe_inline int
 149 fetch_store_string(unsigned long addr, void *dest, void *base)
 150 {
 151         long ret;
 152         u32 loc = *(u32 *)dest;
 153         int maxlen  = get_loc_len(loc);
 154         u8 *dst = get_loc_data(dest, base);
 155         void __user *src = (void __force __user *) addr;
 156
 157         if (unlikely(!maxlen))
 158                 return -ENOMEM;
 159
 160         if (addr == FETCH_TOKEN_COMM)
 161                 ret = strlcpy(dst, current->comm, maxlen);
 162         else
 163                 ret = strncpy_from_user(dst, src, maxlen);
 164         if (ret >= 0) {
 165                 if (ret == maxlen)
 166                         dst[ret - 1] = '\0';
 167                 else
 168                         /*
 169                          * Include the terminating null byte. In this case it
 170                          * was copied by strncpy_from_user but not accounted
 171                          * for in ret.
 172                          */
 173                         ret++;
 174                 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
 175         }
 176
 177         return ret;
 178 }
 179
 180 static nokprobe_inline int
 181 fetch_store_string_user(unsigned long addr, void *dest, void *base)
 182 {
 183         return fetch_store_string(addr, dest, base);
 184 }
 185
 186 /* Return the length of string -- including null terminal byte */
 187 static nokprobe_inline int
 188 fetch_store_strlen(unsigned long addr)
 189 {
 190         int len;
 191         void __user *vaddr = (void __force __user *) addr;
 192
 193         if (addr == FETCH_TOKEN_COMM)
 194                 len = strlen(current->comm) + 1;
 195         else
 196                 len = strnlen_user(vaddr, MAX_STRING_SIZE);
 197
 198         return (len > MAX_STRING_SIZE) ? 0 : len;
 199 }
 200
 201 static nokprobe_inline int
 202 fetch_store_strlen_user(unsigned long addr)
 203 {
 204         return fetch_store_strlen(addr);
 205 }
 206
 207 static unsigned long translate_user_vaddr(unsigned long file_offset)
 208 {
 209         unsigned long base_addr;
 210         struct uprobe_dispatch_data *udd;
 211
 212         udd = (void *) current->utask->vaddr;
 213
 214         base_addr = udd->bp_addr - udd->tu->offset;
 215         return base_addr + file_offset;
 216 }
 217
 218 /* Note that we don't verify it, since the code does not come from user space */
 219 static int
 220 process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 221                    void *base)
 222 {
 223         struct pt_regs *regs = rec;
 224         unsigned long val;
 225
 226         /* 1st stage: get value from context */
 227         switch (code->op) {
 228         case FETCH_OP_REG:
 229                 val = regs_get_register(regs, code->param);
 230                 break;
 231         case FETCH_OP_STACK:
 232                 val = get_user_stack_nth(regs, code->param);
 233                 break;
 234         case FETCH_OP_STACKP:
 235                 val = user_stack_pointer(regs);
 236                 break;
 237         case FETCH_OP_RETVAL:
 238                 val = regs_return_value(regs);
 239                 break;
 240         case FETCH_OP_IMM:
 241                 val = code->immediate;
 242                 break;
 243         case FETCH_OP_COMM:
 244                 val = FETCH_TOKEN_COMM;
 245                 break;
 246         case FETCH_OP_DATA:
 247                 val = (unsigned long)code->data;
 248                 break;
 249         case FETCH_OP_FOFFS:
 250                 val = translate_user_vaddr(code->immediate);
 251                 break;
 252         default:
 253                 return -EILSEQ;
 254         }
 255         code++;
 256
 257         return process_fetch_insn_bottom(code, val, dest, base);
 258 }
 259 NOKPROBE_SYMBOL(process_fetch_insn)
 260
 261 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
 262 {
 263         rwlock_init(&filter->rwlock);
 264         filter->nr_systemwide = 0;
 265         INIT_LIST_HEAD(&filter->perf_events);
 266 }
 267
 268 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
 269 {
 270         return !filter->nr_systemwide && list_empty(&filter->perf_events);
 271 }
 272
 273 static inline bool is_ret_probe(struct trace_uprobe *tu)
 274 {
 275         return tu->consumer.ret_handler != NULL;
 276 }
 277
 278 static bool trace_uprobe_is_busy(struct dyn_event *ev)
 279 {
 280         struct trace_uprobe *tu = to_trace_uprobe(ev);
 281
 282         return trace_probe_is_enabled(&tu->tp);
 283 }
 284
 285 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
 286                                             int argc, const char **argv)
 287 {
 288         char buf[MAX_ARGSTR_LEN + 1];
 289         int len;
 290
 291         if (!argc)
 292                 return true;
 293
 294         len = strlen(tu->filename);
 295         if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
 296                 return false;
 297
 298         if (tu->ref_ctr_offset == 0)
 299                 snprintf(buf, sizeof(buf), "0x%0*lx",
 300                                 (int)(sizeof(void *) * 2), tu->offset);
 301         else
 302                 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
 303                                 (int)(sizeof(void *) * 2), tu->offset,
 304                                 tu->ref_ctr_offset);
 305         if (strcmp(buf, &argv[0][len + 1]))
 306                 return false;
 307
 308         argc--; argv++;
 309
 310         return trace_probe_match_command_args(&tu->tp, argc, argv);
 311 }
 312
 313 static bool trace_uprobe_match(const char *system, const char *event,
 314                         int argc, const char **argv, struct dyn_event *ev)
 315 {
 316         struct trace_uprobe *tu = to_trace_uprobe(ev);
 317
 318         return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 319            (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
 320            trace_uprobe_match_command_head(tu, argc, argv);
 321 }
 322
 323 static nokprobe_inline struct trace_uprobe *
 324 trace_uprobe_primary_from_call(struct trace_event_call *call)
 325 {
 326         struct trace_probe *tp;
 327
 328         tp = trace_probe_primary_from_call(call);
 329         if (WARN_ON_ONCE(!tp))
 330                 return NULL;
 331
 332         return container_of(tp, struct trace_uprobe, tp);
 333 }
 334
 335 /*
 336  * Allocate new trace_uprobe and initialize it (including uprobes).
 337  */
 338 static struct trace_uprobe *
 339 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 340 {
 341         struct trace_uprobe *tu;
 342         int ret;
 343
 344         tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
 345         if (!tu)
 346                 return ERR_PTR(-ENOMEM);
 347
 348         ret = trace_probe_init(&tu->tp, event, group, true);
 349         if (ret < 0)
 350                 goto error;
 351
 352         dyn_event_init(&tu->devent, &trace_uprobe_ops);
 353         tu->consumer.handler = uprobe_dispatcher;
 354         if (is_ret)
 355                 tu->consumer.ret_handler = uretprobe_dispatcher;
 356         init_trace_uprobe_filter(tu->tp.event->filter);
 357         return tu;
 358
 359 error:
 360         kfree(tu);
 361
 362         return ERR_PTR(ret);
 363 }
 364
 365 static void free_trace_uprobe(struct trace_uprobe *tu)
 366 {
 367         if (!tu)
 368                 return;
 369
 370         path_put(&tu->path);
 371         trace_probe_cleanup(&tu->tp);
 372         kfree(tu->filename);
 373         kfree(tu);
 374 }
 375
 376 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
 377 {
 378         struct dyn_event *pos;
 379         struct trace_uprobe *tu;
 380
 381         for_each_trace_uprobe(tu, pos)
 382                 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 383                     strcmp(trace_probe_group_name(&tu->tp), group) == 0)
 384                         return tu;
 385
 386         return NULL;
 387 }
 388
 389 /* Unregister a trace_uprobe and probe_event */
 390 static int unregister_trace_uprobe(struct trace_uprobe *tu)
 391 {
 392         int ret;
 393
 394         if (trace_probe_has_sibling(&tu->tp))
 395                 goto unreg;
 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);
 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);
 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         struct path path;
 545         unsigned long offset, ref_ctr_offset;
 546         bool is_return = false;
 547         int i, ret;
 548
 549         ret = 0;
 550         ref_ctr_offset = 0;
 551
 552         switch (argv[0][0]) {
 553         case 'r':
 554                 is_return = true;
 555                 break;
 556         case 'p':
 557                 break;
 558         default:
 559                 return -ECANCELED;
 560         }
 561
 562         if (argc < 2)
 563                 return -ECANCELED;
 564
 565         if (argv[0][1] == ':')
 566                 event = &argv[0][2];
 567
 568         if (!strchr(argv[1], '/'))
 569                 return -ECANCELED;
 570
 571         filename = kstrdup(argv[1], GFP_KERNEL);
 572         if (!filename)
 573                 return -ENOMEM;
 574
 575         /* Find the last occurrence, in case the path contains ':' too. */
 576         arg = strrchr(filename, ':');
 577         if (!arg || !isdigit(arg[1])) {
 578                 kfree(filename);
 579                 return -ECANCELED;
 580         }
 581
 582         trace_probe_log_init("trace_uprobe", argc, argv);
 583         trace_probe_log_set_index(1);   /* filename is the 2nd argument */
 584
 585         *arg++ = '\0';
 586         ret = kern_path(filename, LOOKUP_FOLLOW, &path);
 587         if (ret) {
 588                 trace_probe_log_err(0, FILE_NOT_FOUND);
 589                 kfree(filename);
 590                 trace_probe_log_clear();
 591                 return ret;
 592         }
 593         if (!d_is_reg(path.dentry)) {
 594                 trace_probe_log_err(0, NO_REGULAR_FILE);
 595                 ret = -EINVAL;
 596                 goto fail_address_parse;
 597         }
 598
 599         /* Parse reference counter offset if specified. */
 600         rctr = strchr(arg, '(');
 601         if (rctr) {
 602                 rctr_end = strchr(rctr, ')');
 603                 if (!rctr_end) {
 604                         ret = -EINVAL;
 605                         rctr_end = rctr + strlen(rctr);
 606                         trace_probe_log_err(rctr_end - filename,
 607                                             REFCNT_OPEN_BRACE);
 608                         goto fail_address_parse;
 609                 } else if (rctr_end[1] != '\0') {
 610                         ret = -EINVAL;
 611                         trace_probe_log_err(rctr_end + 1 - filename,
 612                                             BAD_REFCNT_SUFFIX);
 613                         goto fail_address_parse;
 614                 }
 615
 616                 *rctr++ = '\0';
 617                 *rctr_end = '\0';
 618                 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
 619                 if (ret) {
 620                         trace_probe_log_err(rctr - filename, BAD_REFCNT);
 621                         goto fail_address_parse;
 622                 }
 623         }
 624
 625         /* Check if there is %return suffix */
 626         tmp = strchr(arg, '%');
 627         if (tmp) {
 628                 if (!strcmp(tmp, "%return")) {
 629                         *tmp = '\0';
 630                         is_return = true;
 631                 } else {
 632                         trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
 633                         ret = -EINVAL;
 634                         goto fail_address_parse;
 635                 }
 636         }
 637
 638         /* Parse uprobe offset. */
 639         ret = kstrtoul(arg, 0, &offset);
 640         if (ret) {
 641                 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
 642                 goto fail_address_parse;
 643         }
 644
 645         /* setup a probe */
 646         trace_probe_log_set_index(0);
 647         if (event) {
 648                 ret = traceprobe_parse_event_name(&event, &group, buf,
 649                                                   event - argv[0]);
 650                 if (ret)
 651                         goto fail_address_parse;
 652         } else {
 653                 char *tail;
 654                 char *ptr;
 655
 656                 tail = kstrdup(kbasename(filename), GFP_KERNEL);
 657                 if (!tail) {
 658                         ret = -ENOMEM;
 659                         goto fail_address_parse;
 660                 }
 661
 662                 ptr = strpbrk(tail, ".-_");
 663                 if (ptr)
 664                         *ptr = '\0';
 665
 666                 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
 667                 event = buf;
 668                 kfree(tail);
 669         }
 670
 671         argc -= 2;
 672         argv += 2;
 673
 674         tu = alloc_trace_uprobe(group, event, argc, is_return);
 675         if (IS_ERR(tu)) {
 676                 ret = PTR_ERR(tu);
 677                 /* This must return -ENOMEM otherwise there is a bug */
 678                 WARN_ON_ONCE(ret != -ENOMEM);
 679                 goto fail_address_parse;
 680         }
 681         tu->offset = offset;
 682         tu->ref_ctr_offset = ref_ctr_offset;
 683         tu->path = path;
 684         tu->filename = filename;
 685
 686         /* parse arguments */
 687         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 688                 tmp = kstrdup(argv[i], GFP_KERNEL);
 689                 if (!tmp) {
 690                         ret = -ENOMEM;
 691                         goto error;
 692                 }
 693
 694                 trace_probe_log_set_index(i + 2);
 695                 ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
 696                                         is_return ? TPARG_FL_RETURN : 0);
 697                 kfree(tmp);
 698                 if (ret)
 699                         goto error;
 700         }
 701
 702         ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu));
 703         if (ret < 0)
 704                 goto error;
 705
 706         ret = register_trace_uprobe(tu);
 707         if (!ret)
 708                 goto out;
 709
 710 error:
 711         free_trace_uprobe(tu);
 712 out:
 713         trace_probe_log_clear();
 714         return ret;
 715
 716 fail_address_parse:
 717         trace_probe_log_clear();
 718         path_put(&path);
 719         kfree(filename);
 720
 721         return ret;
 722 }
 723
 724 static int create_or_delete_trace_uprobe(int argc, char **argv)
 725 {
 726         int ret;
 727
 728         if (argv[0][0] == '-')
 729                 return dyn_event_release(argc, argv, &trace_uprobe_ops);
 730
 731         ret = trace_uprobe_create(argc, (const char **)argv);
 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, 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, 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                 tu = container_of(pos, struct trace_uprobe, tp);
1317                 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1318                 if (err) {
1319                         uprobe_perf_close(call, event);
1320                         break;
1321                 }
1322         }
1323
1324         return err;
1325 }
1326
1327 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1328                                 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1329 {
1330         struct trace_uprobe_filter *filter;
1331         struct trace_uprobe *tu;
1332         int ret;
1333
1334         tu = container_of(uc, struct trace_uprobe, consumer);
1335         filter = tu->tp.event->filter;
1336
1337         read_lock(&filter->rwlock);
1338         ret = __uprobe_perf_filter(filter, mm);
1339         read_unlock(&filter->rwlock);
1340
1341         return ret;
1342 }
1343
1344 static void __uprobe_perf_func(struct trace_uprobe *tu,
1345                                unsigned long func, struct pt_regs *regs,
1346                                struct uprobe_cpu_buffer *ucb, int dsize)
1347 {
1348         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1349         struct uprobe_trace_entry_head *entry;
1350         struct hlist_head *head;
1351         void *data;
1352         int size, esize;
1353         int rctx;
1354
1355         if (bpf_prog_array_valid(call)) {
1356                 u32 ret;
1357
1358                 preempt_disable();
1359                 ret = trace_call_bpf(call, regs);
1360                 preempt_enable();
1361                 if (!ret)
1362                         return;
1363         }
1364
1365         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1366
1367         size = esize + tu->tp.size + dsize;
1368         size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1369         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1370                 return;
1371
1372         preempt_disable();
1373         head = this_cpu_ptr(call->perf_events);
1374         if (hlist_empty(head))
1375                 goto out;
1376
1377         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1378         if (!entry)
1379                 goto out;
1380
1381         if (is_ret_probe(tu)) {
1382                 entry->vaddr[0] = func;
1383                 entry->vaddr[1] = instruction_pointer(regs);
1384                 data = DATAOF_TRACE_ENTRY(entry, true);
1385         } else {
1386                 entry->vaddr[0] = instruction_pointer(regs);
1387                 data = DATAOF_TRACE_ENTRY(entry, false);
1388         }
1389
1390         memcpy(data, ucb->buf, tu->tp.size + dsize);
1391
1392         if (size - esize > tu->tp.size + dsize) {
1393                 int len = tu->tp.size + dsize;
1394
1395                 memset(data + len, 0, size - esize - len);
1396         }
1397
1398         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1399                               head, NULL);
1400  out:
1401         preempt_enable();
1402 }
1403
1404 /* uprobe profile handler */
1405 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1406                             struct uprobe_cpu_buffer *ucb, int dsize)
1407 {
1408         if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1409                 return UPROBE_HANDLER_REMOVE;
1410
1411         if (!is_ret_probe(tu))
1412                 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1413         return 0;
1414 }
1415
1416 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1417                                 struct pt_regs *regs,
1418                                 struct uprobe_cpu_buffer *ucb, int dsize)
1419 {
1420         __uprobe_perf_func(tu, func, regs, ucb, dsize);
1421 }
1422
1423 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1424                         const char **filename, u64 *probe_offset,
1425                         u64 *probe_addr, bool perf_type_tracepoint)
1426 {
1427         const char *pevent = trace_event_name(event->tp_event);
1428         const char *group = event->tp_event->class->system;
1429         struct trace_uprobe *tu;
1430
1431         if (perf_type_tracepoint)
1432                 tu = find_probe_event(pevent, group);
1433         else
1434                 tu = trace_uprobe_primary_from_call(event->tp_event);
1435         if (!tu)
1436                 return -EINVAL;
1437
1438         *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1439                                     : BPF_FD_TYPE_UPROBE;
1440         *filename = tu->filename;
1441         *probe_offset = tu->offset;
1442         *probe_addr = 0;
1443         return 0;
1444 }
1445 #endif  /* CONFIG_PERF_EVENTS */
1446
1447 static int
1448 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1449                       void *data)
1450 {
1451         struct trace_event_file *file = data;
1452
1453         switch (type) {
1454         case TRACE_REG_REGISTER:
1455                 return probe_event_enable(event, file, NULL);
1456
1457         case TRACE_REG_UNREGISTER:
1458                 probe_event_disable(event, file);
1459                 return 0;
1460
1461 #ifdef CONFIG_PERF_EVENTS
1462         case TRACE_REG_PERF_REGISTER:
1463                 return probe_event_enable(event, NULL, uprobe_perf_filter);
1464
1465         case TRACE_REG_PERF_UNREGISTER:
1466                 probe_event_disable(event, NULL);
1467                 return 0;
1468
1469         case TRACE_REG_PERF_OPEN:
1470                 return uprobe_perf_open(event, data);
1471
1472         case TRACE_REG_PERF_CLOSE:
1473                 return uprobe_perf_close(event, data);
1474
1475 #endif
1476         default:
1477                 return 0;
1478         }
1479 }
1480
1481 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1482 {
1483         struct trace_uprobe *tu;
1484         struct uprobe_dispatch_data udd;
1485         struct uprobe_cpu_buffer *ucb;
1486         int dsize, esize;
1487         int ret = 0;
1488
1489
1490         tu = container_of(con, struct trace_uprobe, consumer);
1491         tu->nhit++;
1492
1493         udd.tu = tu;
1494         udd.bp_addr = instruction_pointer(regs);
1495
1496         current->utask->vaddr = (unsigned long) &udd;
1497
1498         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1499                 return 0;
1500
1501         dsize = __get_data_size(&tu->tp, regs);
1502         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1503
1504         ucb = uprobe_buffer_get();
1505         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1506
1507         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1508                 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1509
1510 #ifdef CONFIG_PERF_EVENTS
1511         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1512                 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1513 #endif
1514         uprobe_buffer_put(ucb);
1515         return ret;
1516 }
1517
1518 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1519                                 unsigned long func, struct pt_regs *regs)
1520 {
1521         struct trace_uprobe *tu;
1522         struct uprobe_dispatch_data udd;
1523         struct uprobe_cpu_buffer *ucb;
1524         int dsize, esize;
1525
1526         tu = container_of(con, struct trace_uprobe, consumer);
1527
1528         udd.tu = tu;
1529         udd.bp_addr = func;
1530
1531         current->utask->vaddr = (unsigned long) &udd;
1532
1533         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1534                 return 0;
1535
1536         dsize = __get_data_size(&tu->tp, regs);
1537         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1538
1539         ucb = uprobe_buffer_get();
1540         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1541
1542         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1543                 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1544
1545 #ifdef CONFIG_PERF_EVENTS
1546         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1547                 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1548 #endif
1549         uprobe_buffer_put(ucb);
1550         return 0;
1551 }
1552
1553 static struct trace_event_functions uprobe_funcs = {
1554         .trace          = print_uprobe_event
1555 };
1556
1557 static struct trace_event_fields uprobe_fields_array[] = {
1558         { .type = TRACE_FUNCTION_TYPE,
1559           .define_fields = uprobe_event_define_fields },
1560         {}
1561 };
1562
1563 static inline void init_trace_event_call(struct trace_uprobe *tu)
1564 {
1565         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1566         call->event.funcs = &uprobe_funcs;
1567         call->class->fields_array = uprobe_fields_array;
1568
1569         call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1570         call->class->reg = trace_uprobe_register;
1571 }
1572
1573 static int register_uprobe_event(struct trace_uprobe *tu)
1574 {
1575         init_trace_event_call(tu);
1576
1577         return trace_probe_register_event_call(&tu->tp);
1578 }
1579
1580 static int unregister_uprobe_event(struct trace_uprobe *tu)
1581 {
1582         return trace_probe_unregister_event_call(&tu->tp);
1583 }
1584
1585 #ifdef CONFIG_PERF_EVENTS
1586 struct trace_event_call *
1587 create_local_trace_uprobe(char *name, unsigned long offs,
1588                           unsigned long ref_ctr_offset, bool is_return)
1589 {
1590         struct trace_uprobe *tu;
1591         struct path path;
1592         int ret;
1593
1594         ret = kern_path(name, LOOKUP_FOLLOW, &path);
1595         if (ret)
1596                 return ERR_PTR(ret);
1597
1598         if (!d_is_reg(path.dentry)) {
1599                 path_put(&path);
1600                 return ERR_PTR(-EINVAL);
1601         }
1602
1603         /*
1604          * local trace_kprobes are not added to dyn_event, so they are never
1605          * searched in find_trace_kprobe(). Therefore, there is no concern of
1606          * duplicated name "DUMMY_EVENT" here.
1607          */
1608         tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1609                                 is_return);
1610
1611         if (IS_ERR(tu)) {
1612                 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1613                         (int)PTR_ERR(tu));
1614                 path_put(&path);
1615                 return ERR_CAST(tu);
1616         }
1617
1618         tu->offset = offs;
1619         tu->path = path;
1620         tu->ref_ctr_offset = ref_ctr_offset;
1621         tu->filename = kstrdup(name, GFP_KERNEL);
1622         init_trace_event_call(tu);
1623
1624         if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 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 controling 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);