trace_uprobe.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * uprobes-based tracing events
   4  *
   5  * Copyright (C) IBM Corporation, 2010-2012
   6  * Author:      Srikar Dronamraju <srikar@linux.vnet.ibm.com>
   7  */
   8 #define pr_fmt(fmt)     "trace_uprobe: " fmt
   9
  10 #include <linux/security.h>
  11 #include <linux/ctype.h>
  12 #include <linux/module.h>
  13 #include <linux/uaccess.h>
  14 #include <linux/uprobes.h>
  15 #include <linux/namei.h>
  16 #include <linux/string.h>
  17 #include <linux/rculist.h>
  18
  19 #include "trace_dynevent.h"
  20 #include "trace_probe.h"
  21 #include "trace_probe_tmpl.h"
  22
  23 #define UPROBE_EVENT_SYSTEM     "uprobes"
  24
  25 struct uprobe_trace_entry_head {
  26         struct trace_entry      ent;
  27         unsigned long           vaddr[];
  28 };
  29
  30 #define SIZEOF_TRACE_ENTRY(is_return)                   \
  31         (sizeof(struct uprobe_trace_entry_head) +       \
  32          sizeof(unsigned long) * (is_return ? 2 : 1))
  33
  34 #define DATAOF_TRACE_ENTRY(entry, is_return)            \
  35         ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
  36
  37 static int trace_uprobe_create(const char *raw_command);
  38 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
  39 static int trace_uprobe_release(struct dyn_event *ev);
  40 static bool trace_uprobe_is_busy(struct dyn_event *ev);
  41 static bool trace_uprobe_match(const char *system, const char *event,
  42                         int argc, const char **argv, struct dyn_event *ev);
  43
  44 static struct dyn_event_operations trace_uprobe_ops = {
  45         .create = trace_uprobe_create,
  46         .show = trace_uprobe_show,
  47         .is_busy = trace_uprobe_is_busy,
  48         .free = trace_uprobe_release,
  49         .match = trace_uprobe_match,
  50 };
  51
  52 /*
  53  * uprobe event core functions
  54  */
  55 struct trace_uprobe {
  56         struct dyn_event                devent;
  57         struct uprobe_consumer          consumer;
  58         struct path                     path;
  59         struct inode                    *inode;
  60         char                            *filename;
  61         unsigned long                   offset;
  62         unsigned long                   ref_ctr_offset;
  63         unsigned long                   nhit;
  64         struct trace_probe              tp;
  65 };
  66
  67 static bool is_trace_uprobe(struct dyn_event *ev)
  68 {
  69         return ev->ops == &trace_uprobe_ops;
  70 }
  71
  72 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
  73 {
  74         return container_of(ev, struct trace_uprobe, devent);
  75 }
  76
  77 /**
  78  * for_each_trace_uprobe - iterate over the trace_uprobe list
  79  * @pos:        the struct trace_uprobe * for each entry
  80  * @dpos:       the struct dyn_event * to use as a loop cursor
  81  */
  82 #define for_each_trace_uprobe(pos, dpos)        \
  83         for_each_dyn_event(dpos)                \
  84                 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
  85
  86 static int register_uprobe_event(struct trace_uprobe *tu);
  87 static int unregister_uprobe_event(struct trace_uprobe *tu);
  88
  89 struct uprobe_dispatch_data {
  90         struct trace_uprobe     *tu;
  91         unsigned long           bp_addr;
  92 };
  93
  94 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
  95 static int uretprobe_dispatcher(struct uprobe_consumer *con,
  96                                 unsigned long func, struct pt_regs *regs);
  97
  98 #ifdef CONFIG_STACK_GROWSUP
  99 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 100 {
 101         return addr - (n * sizeof(long));
 102 }
 103 #else
 104 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 105 {
 106         return addr + (n * sizeof(long));
 107 }
 108 #endif
 109
 110 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
 111 {
 112         unsigned long ret;
 113         unsigned long addr = user_stack_pointer(regs);
 114
 115         addr = adjust_stack_addr(addr, n);
 116
 117         if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
 118                 return 0;
 119
 120         return ret;
 121 }
 122
 123 /*
 124  * Uprobes-specific fetch functions
 125  */
 126 static nokprobe_inline int
 127 probe_mem_read(void *dest, void *src, size_t size)
 128 {
 129         void __user *vaddr = (void __force __user *)src;
 130
 131         return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
 132 }
 133
 134 static nokprobe_inline int
 135 probe_mem_read_user(void *dest, void *src, size_t size)
 136 {
 137         return probe_mem_read(dest, src, size);
 138 }
 139
 140 /*
 141  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
 142  * length and relative data location.
 143  */
 144 static nokprobe_inline int
 145 fetch_store_string(unsigned long addr, void *dest, void *base)
 146 {
 147         long ret;
 148         u32 loc = *(u32 *)dest;
 149         int maxlen  = get_loc_len(loc);
 150         u8 *dst = get_loc_data(dest, base);
 151         void __user *src = (void __force __user *) addr;
 152
 153         if (unlikely(!maxlen))
 154                 return -ENOMEM;
 155
 156         if (addr == FETCH_TOKEN_COMM)
 157                 ret = strlcpy(dst, current->comm, maxlen);
 158         else
 159                 ret = strncpy_from_user(dst, src, maxlen);
 160         if (ret >= 0) {
 161                 if (ret == maxlen)
 162                         dst[ret - 1] = '\0';
 163                 else
 164                         /*
 165                          * Include the terminating null byte. In this case it
 166                          * was copied by strncpy_from_user but not accounted
 167                          * for in ret.
 168                          */
 169                         ret++;
 170                 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
 171         } else
 172                 *(u32 *)dest = make_data_loc(0, (void *)dst - base);
 173
 174         return ret;
 175 }
 176
 177 static nokprobe_inline int
 178 fetch_store_string_user(unsigned long addr, void *dest, void *base)
 179 {
 180         return fetch_store_string(addr, dest, base);
 181 }
 182
 183 /* Return the length of string -- including null terminal byte */
 184 static nokprobe_inline int
 185 fetch_store_strlen(unsigned long addr)
 186 {
 187         int len;
 188         void __user *vaddr = (void __force __user *) addr;
 189
 190         if (addr == FETCH_TOKEN_COMM)
 191                 len = strlen(current->comm) + 1;
 192         else
 193                 len = strnlen_user(vaddr, MAX_STRING_SIZE);
 194
 195         return (len > MAX_STRING_SIZE) ? 0 : len;
 196 }
 197
 198 static nokprobe_inline int
 199 fetch_store_strlen_user(unsigned long addr)
 200 {
 201         return fetch_store_strlen(addr);
 202 }
 203
 204 static unsigned long translate_user_vaddr(unsigned long file_offset)
 205 {
 206         unsigned long base_addr;
 207         struct uprobe_dispatch_data *udd;
 208
 209         udd = (void *) current->utask->vaddr;
 210
 211         base_addr = udd->bp_addr - udd->tu->offset;
 212         return base_addr + file_offset;
 213 }
 214
 215 /* Note that we don't verify it, since the code does not come from user space */
 216 static int
 217 process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 218                    void *base)
 219 {
 220         struct pt_regs *regs = rec;
 221         unsigned long val;
 222
 223         /* 1st stage: get value from context */
 224         switch (code->op) {
 225         case FETCH_OP_REG:
 226                 val = regs_get_register(regs, code->param);
 227                 break;
 228         case FETCH_OP_STACK:
 229                 val = get_user_stack_nth(regs, code->param);
 230                 break;
 231         case FETCH_OP_STACKP:
 232                 val = user_stack_pointer(regs);
 233                 break;
 234         case FETCH_OP_RETVAL:
 235                 val = regs_return_value(regs);
 236                 break;
 237         case FETCH_OP_IMM:
 238                 val = code->immediate;
 239                 break;
 240         case FETCH_OP_COMM:
 241                 val = FETCH_TOKEN_COMM;
 242                 break;
 243         case FETCH_OP_DATA:
 244                 val = (unsigned long)code->data;
 245                 break;
 246         case FETCH_OP_FOFFS:
 247                 val = translate_user_vaddr(code->immediate);
 248                 break;
 249         default:
 250                 return -EILSEQ;
 251         }
 252         code++;
 253
 254         return process_fetch_insn_bottom(code, val, dest, base);
 255 }
 256 NOKPROBE_SYMBOL(process_fetch_insn)
 257
 258 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
 259 {
 260         rwlock_init(&filter->rwlock);
 261         filter->nr_systemwide = 0;
 262         INIT_LIST_HEAD(&filter->perf_events);
 263 }
 264
 265 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
 266 {
 267         return !filter->nr_systemwide && list_empty(&filter->perf_events);
 268 }
 269
 270 static inline bool is_ret_probe(struct trace_uprobe *tu)
 271 {
 272         return tu->consumer.ret_handler != NULL;
 273 }
 274
 275 static bool trace_uprobe_is_busy(struct dyn_event *ev)
 276 {
 277         struct trace_uprobe *tu = to_trace_uprobe(ev);
 278
 279         return trace_probe_is_enabled(&tu->tp);
 280 }
 281
 282 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
 283                                             int argc, const char **argv)
 284 {
 285         char buf[MAX_ARGSTR_LEN + 1];
 286         int len;
 287
 288         if (!argc)
 289                 return true;
 290
 291         len = strlen(tu->filename);
 292         if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
 293                 return false;
 294
 295         if (tu->ref_ctr_offset == 0)
 296                 snprintf(buf, sizeof(buf), "0x%0*lx",
 297                                 (int)(sizeof(void *) * 2), tu->offset);
 298         else
 299                 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
 300                                 (int)(sizeof(void *) * 2), tu->offset,
 301                                 tu->ref_ctr_offset);
 302         if (strcmp(buf, &argv[0][len + 1]))
 303                 return false;
 304
 305         argc--; argv++;
 306
 307         return trace_probe_match_command_args(&tu->tp, argc, argv);
 308 }
 309
 310 static bool trace_uprobe_match(const char *system, const char *event,
 311                         int argc, const char **argv, struct dyn_event *ev)
 312 {
 313         struct trace_uprobe *tu = to_trace_uprobe(ev);
 314
 315         return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 316            (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
 317            trace_uprobe_match_command_head(tu, argc, argv);
 318 }
 319
 320 static nokprobe_inline struct trace_uprobe *
 321 trace_uprobe_primary_from_call(struct trace_event_call *call)
 322 {
 323         struct trace_probe *tp;
 324
 325         tp = trace_probe_primary_from_call(call);
 326         if (WARN_ON_ONCE(!tp))
 327                 return NULL;
 328
 329         return container_of(tp, struct trace_uprobe, tp);
 330 }
 331
 332 /*
 333  * Allocate new trace_uprobe and initialize it (including uprobes).
 334  */
 335 static struct trace_uprobe *
 336 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 337 {
 338         struct trace_uprobe *tu;
 339         int ret;
 340
 341         tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL);
 342         if (!tu)
 343                 return ERR_PTR(-ENOMEM);
 344
 345         ret = trace_probe_init(&tu->tp, event, group, true);
 346         if (ret < 0)
 347                 goto error;
 348
 349         dyn_event_init(&tu->devent, &trace_uprobe_ops);
 350         tu->consumer.handler = uprobe_dispatcher;
 351         if (is_ret)
 352                 tu->consumer.ret_handler = uretprobe_dispatcher;
 353         init_trace_uprobe_filter(tu->tp.event->filter);
 354         return tu;
 355
 356 error:
 357         kfree(tu);
 358
 359         return ERR_PTR(ret);
 360 }
 361
 362 static void free_trace_uprobe(struct trace_uprobe *tu)
 363 {
 364         if (!tu)
 365                 return;
 366
 367         path_put(&tu->path);
 368         trace_probe_cleanup(&tu->tp);
 369         kfree(tu->filename);
 370         kfree(tu);
 371 }
 372
 373 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
 374 {
 375         struct dyn_event *pos;
 376         struct trace_uprobe *tu;
 377
 378         for_each_trace_uprobe(tu, pos)
 379                 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 380                     strcmp(trace_probe_group_name(&tu->tp), group) == 0)
 381                         return tu;
 382
 383         return NULL;
 384 }
 385
 386 /* Unregister a trace_uprobe and probe_event */
 387 static int unregister_trace_uprobe(struct trace_uprobe *tu)
 388 {
 389         int ret;
 390
 391         if (trace_probe_has_sibling(&tu->tp))
 392                 goto unreg;
 393
 394         /* If there's a reference to the dynamic event */
 395         if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp)))
 396                 return -EBUSY;
 397
 398         ret = unregister_uprobe_event(tu);
 399         if (ret)
 400                 return ret;
 401
 402 unreg:
 403         dyn_event_remove(&tu->devent);
 404         trace_probe_unlink(&tu->tp);
 405         free_trace_uprobe(tu);
 406         return 0;
 407 }
 408
 409 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
 410                                          struct trace_uprobe *comp)
 411 {
 412         struct trace_probe_event *tpe = orig->tp.event;
 413         struct trace_probe *pos;
 414         struct inode *comp_inode = d_real_inode(comp->path.dentry);
 415         int i;
 416
 417         list_for_each_entry(pos, &tpe->probes, list) {
 418                 orig = container_of(pos, struct trace_uprobe, tp);
 419                 if (comp_inode != d_real_inode(orig->path.dentry) ||
 420                     comp->offset != orig->offset)
 421                         continue;
 422
 423                 /*
 424                  * trace_probe_compare_arg_type() ensured that nr_args and
 425                  * each argument name and type are same. Let's compare comm.
 426                  */
 427                 for (i = 0; i < orig->tp.nr_args; i++) {
 428                         if (strcmp(orig->tp.args[i].comm,
 429                                    comp->tp.args[i].comm))
 430                                 break;
 431                 }
 432
 433                 if (i == orig->tp.nr_args)
 434                         return true;
 435         }
 436
 437         return false;
 438 }
 439
 440 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
 441 {
 442         int ret;
 443
 444         ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
 445         if (ret) {
 446                 /* Note that argument starts index = 2 */
 447                 trace_probe_log_set_index(ret + 1);
 448                 trace_probe_log_err(0, DIFF_ARG_TYPE);
 449                 return -EEXIST;
 450         }
 451         if (trace_uprobe_has_same_uprobe(to, tu)) {
 452                 trace_probe_log_set_index(0);
 453                 trace_probe_log_err(0, SAME_PROBE);
 454                 return -EEXIST;
 455         }
 456
 457         /* Append to existing event */
 458         ret = trace_probe_append(&tu->tp, &to->tp);
 459         if (!ret)
 460                 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
 461
 462         return ret;
 463 }
 464
 465 /*
 466  * Uprobe with multiple reference counter is not allowed. i.e.
 467  * If inode and offset matches, reference counter offset *must*
 468  * match as well. Though, there is one exception: If user is
 469  * replacing old trace_uprobe with new one(same group/event),
 470  * then we allow same uprobe with new reference counter as far
 471  * as the new one does not conflict with any other existing
 472  * ones.
 473  */
 474 static int validate_ref_ctr_offset(struct trace_uprobe *new)
 475 {
 476         struct dyn_event *pos;
 477         struct trace_uprobe *tmp;
 478         struct inode *new_inode = d_real_inode(new->path.dentry);
 479
 480         for_each_trace_uprobe(tmp, pos) {
 481                 if (new_inode == d_real_inode(tmp->path.dentry) &&
 482                     new->offset == tmp->offset &&
 483                     new->ref_ctr_offset != tmp->ref_ctr_offset) {
 484                         pr_warn("Reference counter offset mismatch.");
 485                         return -EINVAL;
 486                 }
 487         }
 488         return 0;
 489 }
 490
 491 /* Register a trace_uprobe and probe_event */
 492 static int register_trace_uprobe(struct trace_uprobe *tu)
 493 {
 494         struct trace_uprobe *old_tu;
 495         int ret;
 496
 497         mutex_lock(&event_mutex);
 498
 499         ret = validate_ref_ctr_offset(tu);
 500         if (ret)
 501                 goto end;
 502
 503         /* register as an event */
 504         old_tu = find_probe_event(trace_probe_name(&tu->tp),
 505                                   trace_probe_group_name(&tu->tp));
 506         if (old_tu) {
 507                 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
 508                         trace_probe_log_set_index(0);
 509                         trace_probe_log_err(0, DIFF_PROBE_TYPE);
 510                         ret = -EEXIST;
 511                 } else {
 512                         ret = append_trace_uprobe(tu, old_tu);
 513                 }
 514                 goto end;
 515         }
 516
 517         ret = register_uprobe_event(tu);
 518         if (ret) {
 519                 if (ret == -EEXIST) {
 520                         trace_probe_log_set_index(0);
 521                         trace_probe_log_err(0, EVENT_EXIST);
 522                 } else
 523                         pr_warn("Failed to register probe event(%d)\n", ret);
 524                 goto end;
 525         }
 526
 527         dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
 528
 529 end:
 530         mutex_unlock(&event_mutex);
 531
 532         return ret;
 533 }
 534
 535 /*
 536  * Argument syntax:
 537  *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET[%return][(REF)] [FETCHARGS]
 538  */
 539 static int __trace_uprobe_create(int argc, const char **argv)
 540 {
 541         struct trace_uprobe *tu;
 542         const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
 543         char *arg, *filename, *rctr, *rctr_end, *tmp;
 544         char buf[MAX_EVENT_NAME_LEN];
 545         enum probe_print_type ptype;
 546         struct path path;
 547         unsigned long offset, ref_ctr_offset;
 548         bool is_return = false;
 549         int i, ret;
 550
 551         ret = 0;
 552         ref_ctr_offset = 0;
 553
 554         switch (argv[0][0]) {
 555         case 'r':
 556                 is_return = true;
 557                 break;
 558         case 'p':
 559                 break;
 560         default:
 561                 return -ECANCELED;
 562         }
 563
 564         if (argc < 2)
 565                 return -ECANCELED;
 566
 567         if (argv[0][1] == ':')
 568                 event = &argv[0][2];
 569
 570         if (!strchr(argv[1], '/'))
 571                 return -ECANCELED;
 572
 573         filename = kstrdup(argv[1], GFP_KERNEL);
 574         if (!filename)
 575                 return -ENOMEM;
 576
 577         /* Find the last occurrence, in case the path contains ':' too. */
 578         arg = strrchr(filename, ':');
 579         if (!arg || !isdigit(arg[1])) {
 580                 kfree(filename);
 581                 return -ECANCELED;
 582         }
 583
 584         trace_probe_log_init("trace_uprobe", argc, argv);
 585         trace_probe_log_set_index(1);   /* filename is the 2nd argument */
 586
 587         *arg++ = '\0';
 588         ret = kern_path(filename, LOOKUP_FOLLOW, &path);
 589         if (ret) {
 590                 trace_probe_log_err(0, FILE_NOT_FOUND);
 591                 kfree(filename);
 592                 trace_probe_log_clear();
 593                 return ret;
 594         }
 595         if (!d_is_reg(path.dentry)) {
 596                 trace_probe_log_err(0, NO_REGULAR_FILE);
 597                 ret = -EINVAL;
 598                 goto fail_address_parse;
 599         }
 600
 601         /* Parse reference counter offset if specified. */
 602         rctr = strchr(arg, '(');
 603         if (rctr) {
 604                 rctr_end = strchr(rctr, ')');
 605                 if (!rctr_end) {
 606                         ret = -EINVAL;
 607                         rctr_end = rctr + strlen(rctr);
 608                         trace_probe_log_err(rctr_end - filename,
 609                                             REFCNT_OPEN_BRACE);
 610                         goto fail_address_parse;
 611                 } else if (rctr_end[1] != '\0') {
 612                         ret = -EINVAL;
 613                         trace_probe_log_err(rctr_end + 1 - filename,
 614                                             BAD_REFCNT_SUFFIX);
 615                         goto fail_address_parse;
 616                 }
 617
 618                 *rctr++ = '\0';
 619                 *rctr_end = '\0';
 620                 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
 621                 if (ret) {
 622                         trace_probe_log_err(rctr - filename, BAD_REFCNT);
 623                         goto fail_address_parse;
 624                 }
 625         }
 626
 627         /* Check if there is %return suffix */
 628         tmp = strchr(arg, '%');
 629         if (tmp) {
 630                 if (!strcmp(tmp, "%return")) {
 631                         *tmp = '\0';
 632                         is_return = true;
 633                 } else {
 634                         trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
 635                         ret = -EINVAL;
 636                         goto fail_address_parse;
 637                 }
 638         }
 639
 640         /* Parse uprobe offset. */
 641         ret = kstrtoul(arg, 0, &offset);
 642         if (ret) {
 643                 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
 644                 goto fail_address_parse;
 645         }
 646
 647         /* setup a probe */
 648         trace_probe_log_set_index(0);
 649         if (event) {
 650                 ret = traceprobe_parse_event_name(&event, &group, buf,
 651                                                   event - argv[0]);
 652                 if (ret)
 653                         goto fail_address_parse;
 654         } else {
 655                 char *tail;
 656                 char *ptr;
 657
 658                 tail = kstrdup(kbasename(filename), GFP_KERNEL);
 659                 if (!tail) {
 660                         ret = -ENOMEM;
 661                         goto fail_address_parse;
 662                 }
 663
 664                 ptr = strpbrk(tail, ".-_");
 665                 if (ptr)
 666                         *ptr = '\0';
 667
 668                 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
 669                 event = buf;
 670                 kfree(tail);
 671         }
 672
 673         argc -= 2;
 674         argv += 2;
 675
 676         tu = alloc_trace_uprobe(group, event, argc, is_return);
 677         if (IS_ERR(tu)) {
 678                 ret = PTR_ERR(tu);
 679                 /* This must return -ENOMEM otherwise there is a bug */
 680                 WARN_ON_ONCE(ret != -ENOMEM);
 681                 goto fail_address_parse;
 682         }
 683         tu->offset = offset;
 684         tu->ref_ctr_offset = ref_ctr_offset;
 685         tu->path = path;
 686         tu->filename = filename;
 687
 688         /* parse arguments */
 689         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 690                 trace_probe_log_set_index(i + 2);
 691                 ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i],
 692                                         is_return ? TPARG_FL_RETURN : 0);
 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_buffer *buffer;
 954         struct ring_buffer_event *event;
 955         void *data;
 956         int size, esize;
 957         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
 958
 959         WARN_ON(call != trace_file->event_call);
 960
 961         if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
 962                 return;
 963
 964         if (trace_trigger_soft_disabled(trace_file))
 965                 return;
 966
 967         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 968         size = esize + tu->tp.size + dsize;
 969         event = trace_event_buffer_lock_reserve(&buffer, trace_file,
 970                                                 call->event.type, size, 0);
 971         if (!event)
 972                 return;
 973
 974         entry = ring_buffer_event_data(event);
 975         if (is_ret_probe(tu)) {
 976                 entry->vaddr[0] = func;
 977                 entry->vaddr[1] = instruction_pointer(regs);
 978                 data = DATAOF_TRACE_ENTRY(entry, true);
 979         } else {
 980                 entry->vaddr[0] = instruction_pointer(regs);
 981                 data = DATAOF_TRACE_ENTRY(entry, false);
 982         }
 983
 984         memcpy(data, ucb->buf, tu->tp.size + dsize);
 985
 986         event_trigger_unlock_commit(trace_file, buffer, event, entry, 0);
 987 }
 988
 989 /* uprobe handler */
 990 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
 991                              struct uprobe_cpu_buffer *ucb, int dsize)
 992 {
 993         struct event_file_link *link;
 994
 995         if (is_ret_probe(tu))
 996                 return 0;
 997
 998         rcu_read_lock();
 999         trace_probe_for_each_link_rcu(link, &tu->tp)
1000                 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
1001         rcu_read_unlock();
1002
1003         return 0;
1004 }
1005
1006 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
1007                                  struct pt_regs *regs,
1008                                  struct uprobe_cpu_buffer *ucb, int dsize)
1009 {
1010         struct event_file_link *link;
1011
1012         rcu_read_lock();
1013         trace_probe_for_each_link_rcu(link, &tu->tp)
1014                 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
1015         rcu_read_unlock();
1016 }
1017
1018 /* Event entry printers */
1019 static enum print_line_t
1020 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1021 {
1022         struct uprobe_trace_entry_head *entry;
1023         struct trace_seq *s = &iter->seq;
1024         struct trace_uprobe *tu;
1025         u8 *data;
1026
1027         entry = (struct uprobe_trace_entry_head *)iter->ent;
1028         tu = trace_uprobe_primary_from_call(
1029                 container_of(event, struct trace_event_call, event));
1030         if (unlikely(!tu))
1031                 goto out;
1032
1033         if (is_ret_probe(tu)) {
1034                 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1035                                  trace_probe_name(&tu->tp),
1036                                  entry->vaddr[1], entry->vaddr[0]);
1037                 data = DATAOF_TRACE_ENTRY(entry, true);
1038         } else {
1039                 trace_seq_printf(s, "%s: (0x%lx)",
1040                                  trace_probe_name(&tu->tp),
1041                                  entry->vaddr[0]);
1042                 data = DATAOF_TRACE_ENTRY(entry, false);
1043         }
1044
1045         if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1046                 goto out;
1047
1048         trace_seq_putc(s, '\n');
1049
1050  out:
1051         return trace_handle_return(s);
1052 }
1053
1054 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1055                                 enum uprobe_filter_ctx ctx,
1056                                 struct mm_struct *mm);
1057
1058 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1059 {
1060         int ret;
1061
1062         tu->consumer.filter = filter;
1063         tu->inode = d_real_inode(tu->path.dentry);
1064
1065         if (tu->ref_ctr_offset)
1066                 ret = uprobe_register_refctr(tu->inode, tu->offset,
1067                                 tu->ref_ctr_offset, &tu->consumer);
1068         else
1069                 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1070
1071         if (ret)
1072                 tu->inode = NULL;
1073
1074         return ret;
1075 }
1076
1077 static void __probe_event_disable(struct trace_probe *tp)
1078 {
1079         struct trace_probe *pos;
1080         struct trace_uprobe *tu;
1081
1082         tu = container_of(tp, struct trace_uprobe, tp);
1083         WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1084
1085         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1086                 tu = container_of(pos, struct trace_uprobe, tp);
1087                 if (!tu->inode)
1088                         continue;
1089
1090                 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1091                 tu->inode = NULL;
1092         }
1093 }
1094
1095 static int probe_event_enable(struct trace_event_call *call,
1096                         struct trace_event_file *file, filter_func_t filter)
1097 {
1098         struct trace_probe *pos, *tp;
1099         struct trace_uprobe *tu;
1100         bool enabled;
1101         int ret;
1102
1103         tp = trace_probe_primary_from_call(call);
1104         if (WARN_ON_ONCE(!tp))
1105                 return -ENODEV;
1106         enabled = trace_probe_is_enabled(tp);
1107
1108         /* This may also change "enabled" state */
1109         if (file) {
1110                 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1111                         return -EINTR;
1112
1113                 ret = trace_probe_add_file(tp, file);
1114                 if (ret < 0)
1115                         return ret;
1116         } else {
1117                 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1118                         return -EINTR;
1119
1120                 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1121         }
1122
1123         tu = container_of(tp, struct trace_uprobe, tp);
1124         WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1125
1126         if (enabled)
1127                 return 0;
1128
1129         ret = uprobe_buffer_enable();
1130         if (ret)
1131                 goto err_flags;
1132
1133         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1134                 tu = container_of(pos, struct trace_uprobe, tp);
1135                 ret = trace_uprobe_enable(tu, filter);
1136                 if (ret) {
1137                         __probe_event_disable(tp);
1138                         goto err_buffer;
1139                 }
1140         }
1141
1142         return 0;
1143
1144  err_buffer:
1145         uprobe_buffer_disable();
1146
1147  err_flags:
1148         if (file)
1149                 trace_probe_remove_file(tp, file);
1150         else
1151                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1152
1153         return ret;
1154 }
1155
1156 static void probe_event_disable(struct trace_event_call *call,
1157                                 struct trace_event_file *file)
1158 {
1159         struct trace_probe *tp;
1160
1161         tp = trace_probe_primary_from_call(call);
1162         if (WARN_ON_ONCE(!tp))
1163                 return;
1164
1165         if (!trace_probe_is_enabled(tp))
1166                 return;
1167
1168         if (file) {
1169                 if (trace_probe_remove_file(tp, file) < 0)
1170                         return;
1171
1172                 if (trace_probe_is_enabled(tp))
1173                         return;
1174         } else
1175                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1176
1177         __probe_event_disable(tp);
1178         uprobe_buffer_disable();
1179 }
1180
1181 static int uprobe_event_define_fields(struct trace_event_call *event_call)
1182 {
1183         int ret, size;
1184         struct uprobe_trace_entry_head field;
1185         struct trace_uprobe *tu;
1186
1187         tu = trace_uprobe_primary_from_call(event_call);
1188         if (unlikely(!tu))
1189                 return -ENODEV;
1190
1191         if (is_ret_probe(tu)) {
1192                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1193                 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1194                 size = SIZEOF_TRACE_ENTRY(true);
1195         } else {
1196                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1197                 size = SIZEOF_TRACE_ENTRY(false);
1198         }
1199
1200         return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1201 }
1202
1203 #ifdef CONFIG_PERF_EVENTS
1204 static bool
1205 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1206 {
1207         struct perf_event *event;
1208
1209         if (filter->nr_systemwide)
1210                 return true;
1211
1212         list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1213                 if (event->hw.target->mm == mm)
1214                         return true;
1215         }
1216
1217         return false;
1218 }
1219
1220 static inline bool
1221 trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1222                           struct perf_event *event)
1223 {
1224         return __uprobe_perf_filter(filter, event->hw.target->mm);
1225 }
1226
1227 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1228                                        struct perf_event *event)
1229 {
1230         bool done;
1231
1232         write_lock(&filter->rwlock);
1233         if (event->hw.target) {
1234                 list_del(&event->hw.tp_list);
1235                 done = filter->nr_systemwide ||
1236                         (event->hw.target->flags & PF_EXITING) ||
1237                         trace_uprobe_filter_event(filter, event);
1238         } else {
1239                 filter->nr_systemwide--;
1240                 done = filter->nr_systemwide;
1241         }
1242         write_unlock(&filter->rwlock);
1243
1244         return done;
1245 }
1246
1247 /* This returns true if the filter always covers target mm */
1248 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1249                                     struct perf_event *event)
1250 {
1251         bool done;
1252
1253         write_lock(&filter->rwlock);
1254         if (event->hw.target) {
1255                 /*
1256                  * event->parent != NULL means copy_process(), we can avoid
1257                  * uprobe_apply(). current->mm must be probed and we can rely
1258                  * on dup_mmap() which preserves the already installed bp's.
1259                  *
1260                  * attr.enable_on_exec means that exec/mmap will install the
1261                  * breakpoints we need.
1262                  */
1263                 done = filter->nr_systemwide ||
1264                         event->parent || event->attr.enable_on_exec ||
1265                         trace_uprobe_filter_event(filter, event);
1266                 list_add(&event->hw.tp_list, &filter->perf_events);
1267         } else {
1268                 done = filter->nr_systemwide;
1269                 filter->nr_systemwide++;
1270         }
1271         write_unlock(&filter->rwlock);
1272
1273         return done;
1274 }
1275
1276 static int uprobe_perf_close(struct trace_event_call *call,
1277                              struct perf_event *event)
1278 {
1279         struct trace_probe *pos, *tp;
1280         struct trace_uprobe *tu;
1281         int ret = 0;
1282
1283         tp = trace_probe_primary_from_call(call);
1284         if (WARN_ON_ONCE(!tp))
1285                 return -ENODEV;
1286
1287         tu = container_of(tp, struct trace_uprobe, tp);
1288         if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1289                 return 0;
1290
1291         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1292                 tu = container_of(pos, struct trace_uprobe, tp);
1293                 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1294                 if (ret)
1295                         break;
1296         }
1297
1298         return ret;
1299 }
1300
1301 static int uprobe_perf_open(struct trace_event_call *call,
1302                             struct perf_event *event)
1303 {
1304         struct trace_probe *pos, *tp;
1305         struct trace_uprobe *tu;
1306         int err = 0;
1307
1308         tp = trace_probe_primary_from_call(call);
1309         if (WARN_ON_ONCE(!tp))
1310                 return -ENODEV;
1311
1312         tu = container_of(tp, struct trace_uprobe, tp);
1313         if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1314                 return 0;
1315
1316         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1317                 tu = container_of(pos, struct trace_uprobe, tp);
1318                 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1319                 if (err) {
1320                         uprobe_perf_close(call, event);
1321                         break;
1322                 }
1323         }
1324
1325         return err;
1326 }
1327
1328 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1329                                 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1330 {
1331         struct trace_uprobe_filter *filter;
1332         struct trace_uprobe *tu;
1333         int ret;
1334
1335         tu = container_of(uc, struct trace_uprobe, consumer);
1336         filter = tu->tp.event->filter;
1337
1338         read_lock(&filter->rwlock);
1339         ret = __uprobe_perf_filter(filter, mm);
1340         read_unlock(&filter->rwlock);
1341
1342         return ret;
1343 }
1344
1345 static void __uprobe_perf_func(struct trace_uprobe *tu,
1346                                unsigned long func, struct pt_regs *regs,
1347                                struct uprobe_cpu_buffer *ucb, int dsize)
1348 {
1349         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1350         struct uprobe_trace_entry_head *entry;
1351         struct hlist_head *head;
1352         void *data;
1353         int size, esize;
1354         int rctx;
1355
1356         if (bpf_prog_array_valid(call)) {
1357                 u32 ret;
1358
1359                 preempt_disable();
1360                 ret = trace_call_bpf(call, regs);
1361                 preempt_enable();
1362                 if (!ret)
1363                         return;
1364         }
1365
1366         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1367
1368         size = esize + tu->tp.size + dsize;
1369         size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1370         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1371                 return;
1372
1373         preempt_disable();
1374         head = this_cpu_ptr(call->perf_events);
1375         if (hlist_empty(head))
1376                 goto out;
1377
1378         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1379         if (!entry)
1380                 goto out;
1381
1382         if (is_ret_probe(tu)) {
1383                 entry->vaddr[0] = func;
1384                 entry->vaddr[1] = instruction_pointer(regs);
1385                 data = DATAOF_TRACE_ENTRY(entry, true);
1386         } else {
1387                 entry->vaddr[0] = instruction_pointer(regs);
1388                 data = DATAOF_TRACE_ENTRY(entry, false);
1389         }
1390
1391         memcpy(data, ucb->buf, tu->tp.size + dsize);
1392
1393         if (size - esize > tu->tp.size + dsize) {
1394                 int len = tu->tp.size + dsize;
1395
1396                 memset(data + len, 0, size - esize - len);
1397         }
1398
1399         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1400                               head, NULL);
1401  out:
1402         preempt_enable();
1403 }
1404
1405 /* uprobe profile handler */
1406 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1407                             struct uprobe_cpu_buffer *ucb, int dsize)
1408 {
1409         if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1410                 return UPROBE_HANDLER_REMOVE;
1411
1412         if (!is_ret_probe(tu))
1413                 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1414         return 0;
1415 }
1416
1417 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1418                                 struct pt_regs *regs,
1419                                 struct uprobe_cpu_buffer *ucb, int dsize)
1420 {
1421         __uprobe_perf_func(tu, func, regs, ucb, dsize);
1422 }
1423
1424 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1425                         const char **filename, u64 *probe_offset,
1426                         u64 *probe_addr, bool perf_type_tracepoint)
1427 {
1428         const char *pevent = trace_event_name(event->tp_event);
1429         const char *group = event->tp_event->class->system;
1430         struct trace_uprobe *tu;
1431
1432         if (perf_type_tracepoint)
1433                 tu = find_probe_event(pevent, group);
1434         else
1435                 tu = trace_uprobe_primary_from_call(event->tp_event);
1436         if (!tu)
1437                 return -EINVAL;
1438
1439         *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1440                                     : BPF_FD_TYPE_UPROBE;
1441         *filename = tu->filename;
1442         *probe_offset = tu->offset;
1443         *probe_addr = 0;
1444         return 0;
1445 }
1446 #endif  /* CONFIG_PERF_EVENTS */
1447
1448 static int
1449 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1450                       void *data)
1451 {
1452         struct trace_event_file *file = data;
1453
1454         switch (type) {
1455         case TRACE_REG_REGISTER:
1456                 return probe_event_enable(event, file, NULL);
1457
1458         case TRACE_REG_UNREGISTER:
1459                 probe_event_disable(event, file);
1460                 return 0;
1461
1462 #ifdef CONFIG_PERF_EVENTS
1463         case TRACE_REG_PERF_REGISTER:
1464                 return probe_event_enable(event, NULL, uprobe_perf_filter);
1465
1466         case TRACE_REG_PERF_UNREGISTER:
1467                 probe_event_disable(event, NULL);
1468                 return 0;
1469
1470         case TRACE_REG_PERF_OPEN:
1471                 return uprobe_perf_open(event, data);
1472
1473         case TRACE_REG_PERF_CLOSE:
1474                 return uprobe_perf_close(event, data);
1475
1476 #endif
1477         default:
1478                 return 0;
1479         }
1480 }
1481
1482 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1483 {
1484         struct trace_uprobe *tu;
1485         struct uprobe_dispatch_data udd;
1486         struct uprobe_cpu_buffer *ucb;
1487         int dsize, esize;
1488         int ret = 0;
1489
1490
1491         tu = container_of(con, struct trace_uprobe, consumer);
1492         tu->nhit++;
1493
1494         udd.tu = tu;
1495         udd.bp_addr = instruction_pointer(regs);
1496
1497         current->utask->vaddr = (unsigned long) &udd;
1498
1499         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1500                 return 0;
1501
1502         dsize = __get_data_size(&tu->tp, regs);
1503         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1504
1505         ucb = uprobe_buffer_get();
1506         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1507
1508         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1509                 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1510
1511 #ifdef CONFIG_PERF_EVENTS
1512         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1513                 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1514 #endif
1515         uprobe_buffer_put(ucb);
1516         return ret;
1517 }
1518
1519 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1520                                 unsigned long func, struct pt_regs *regs)
1521 {
1522         struct trace_uprobe *tu;
1523         struct uprobe_dispatch_data udd;
1524         struct uprobe_cpu_buffer *ucb;
1525         int dsize, esize;
1526
1527         tu = container_of(con, struct trace_uprobe, consumer);
1528
1529         udd.tu = tu;
1530         udd.bp_addr = func;
1531
1532         current->utask->vaddr = (unsigned long) &udd;
1533
1534         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1535                 return 0;
1536
1537         dsize = __get_data_size(&tu->tp, regs);
1538         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1539
1540         ucb = uprobe_buffer_get();
1541         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1542
1543         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1544                 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1545
1546 #ifdef CONFIG_PERF_EVENTS
1547         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1548                 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1549 #endif
1550         uprobe_buffer_put(ucb);
1551         return 0;
1552 }
1553
1554 static struct trace_event_functions uprobe_funcs = {
1555         .trace          = print_uprobe_event
1556 };
1557
1558 static struct trace_event_fields uprobe_fields_array[] = {
1559         { .type = TRACE_FUNCTION_TYPE,
1560           .define_fields = uprobe_event_define_fields },
1561         {}
1562 };
1563
1564 static inline void init_trace_event_call(struct trace_uprobe *tu)
1565 {
1566         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1567         call->event.funcs = &uprobe_funcs;
1568         call->class->fields_array = uprobe_fields_array;
1569
1570         call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1571         call->class->reg = trace_uprobe_register;
1572 }
1573
1574 static int register_uprobe_event(struct trace_uprobe *tu)
1575 {
1576         init_trace_event_call(tu);
1577
1578         return trace_probe_register_event_call(&tu->tp);
1579 }
1580
1581 static int unregister_uprobe_event(struct trace_uprobe *tu)
1582 {
1583         return trace_probe_unregister_event_call(&tu->tp);
1584 }
1585
1586 #ifdef CONFIG_PERF_EVENTS
1587 struct trace_event_call *
1588 create_local_trace_uprobe(char *name, unsigned long offs,
1589                           unsigned long ref_ctr_offset, bool is_return)
1590 {
1591         enum probe_print_type ptype;
1592         struct trace_uprobe *tu;
1593         struct path path;
1594         int ret;
1595
1596         ret = kern_path(name, LOOKUP_FOLLOW, &path);
1597         if (ret)
1598                 return ERR_PTR(ret);
1599
1600         if (!d_is_reg(path.dentry)) {
1601                 path_put(&path);
1602                 return ERR_PTR(-EINVAL);
1603         }
1604
1605         /*
1606          * local trace_kprobes are not added to dyn_event, so they are never
1607          * searched in find_trace_kprobe(). Therefore, there is no concern of
1608          * duplicated name "DUMMY_EVENT" here.
1609          */
1610         tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1611                                 is_return);
1612
1613         if (IS_ERR(tu)) {
1614                 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1615                         (int)PTR_ERR(tu));
1616                 path_put(&path);
1617                 return ERR_CAST(tu);
1618         }
1619
1620         tu->offset = offs;
1621         tu->path = path;
1622         tu->ref_ctr_offset = ref_ctr_offset;
1623         tu->filename = kstrdup(name, GFP_KERNEL);
1624         if (!tu->filename) {
1625                 ret = -ENOMEM;
1626                 goto error;
1627         }
1628
1629         init_trace_event_call(tu);
1630
1631         ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1632         if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
1633                 ret = -ENOMEM;
1634                 goto error;
1635         }
1636
1637         return trace_probe_event_call(&tu->tp);
1638 error:
1639         free_trace_uprobe(tu);
1640         return ERR_PTR(ret);
1641 }
1642
1643 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1644 {
1645         struct trace_uprobe *tu;
1646
1647         tu = trace_uprobe_primary_from_call(event_call);
1648
1649         free_trace_uprobe(tu);
1650 }
1651 #endif /* CONFIG_PERF_EVENTS */
1652
1653 /* Make a trace interface for controlling probe points */
1654 static __init int init_uprobe_trace(void)
1655 {
1656         int ret;
1657
1658         ret = dyn_event_register(&trace_uprobe_ops);
1659         if (ret)
1660                 return ret;
1661
1662         ret = tracing_init_dentry();
1663         if (ret)
1664                 return 0;
1665
1666         trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL,
1667                                     NULL, &uprobe_events_ops);
1668         /* Profile interface */
1669         trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
1670                                     NULL, &uprobe_profile_ops);
1671         return 0;
1672 }
1673
1674 fs_initcall(init_uprobe_trace);