kernel/trace/trace_uprobe.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * uprobes-based tracing events
   4  *
   5  * Copyright (C) IBM Corporation, 2010-2012
   6  * Author:      Srikar Dronamraju <srikar@linux.vnet.ibm.com>
   7  */
   8 #define pr_fmt(fmt)     "trace_uprobe: " fmt
   9
  10 #include <linux/bpf-cgroup.h>
  11 #include <linux/security.h>
  12 #include <linux/ctype.h>
  13 #include <linux/module.h>
  14 #include <linux/uaccess.h>
  15 #include <linux/uprobes.h>
  16 #include <linux/namei.h>
  17 #include <linux/string.h>
  18 #include <linux/rculist.h>
  19 #include <linux/filter.h>
  20
  21 #include "trace_dynevent.h"
  22 #include "trace_probe.h"
  23 #include "trace_probe_tmpl.h"
  24
  25 #define UPROBE_EVENT_SYSTEM     "uprobes"
  26
  27 struct uprobe_trace_entry_head {
  28         struct trace_entry      ent;
  29         unsigned long           vaddr[];
  30 };
  31
  32 #define SIZEOF_TRACE_ENTRY(is_return)                   \
  33         (sizeof(struct uprobe_trace_entry_head) +       \
  34          sizeof(unsigned long) * (is_return ? 2 : 1))
  35
  36 #define DATAOF_TRACE_ENTRY(entry, is_return)            \
  37         ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
  38
  39 static int trace_uprobe_create(const char *raw_command);
  40 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
  41 static int trace_uprobe_release(struct dyn_event *ev);
  42 static bool trace_uprobe_is_busy(struct dyn_event *ev);
  43 static bool trace_uprobe_match(const char *system, const char *event,
  44                         int argc, const char **argv, struct dyn_event *ev);
  45
  46 static struct dyn_event_operations trace_uprobe_ops = {
  47         .create = trace_uprobe_create,
  48         .show = trace_uprobe_show,
  49         .is_busy = trace_uprobe_is_busy,
  50         .free = trace_uprobe_release,
  51         .match = trace_uprobe_match,
  52 };
  53
  54 /*
  55  * uprobe event core functions
  56  */
  57 struct trace_uprobe {
  58         struct dyn_event                devent;
  59         struct uprobe_consumer          consumer;
  60         struct path                     path;
  61         struct inode                    *inode;
  62         char                            *filename;
  63         unsigned long                   offset;
  64         unsigned long                   ref_ctr_offset;
  65         unsigned long                   nhit;
  66         struct trace_probe              tp;
  67 };
  68
  69 static bool is_trace_uprobe(struct dyn_event *ev)
  70 {
  71         return ev->ops == &trace_uprobe_ops;
  72 }
  73
  74 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
  75 {
  76         return container_of(ev, struct trace_uprobe, devent);
  77 }
  78
  79 /**
  80  * for_each_trace_uprobe - iterate over the trace_uprobe list
  81  * @pos:        the struct trace_uprobe * for each entry
  82  * @dpos:       the struct dyn_event * to use as a loop cursor
  83  */
  84 #define for_each_trace_uprobe(pos, dpos)        \
  85         for_each_dyn_event(dpos)                \
  86                 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
  87
  88 static int register_uprobe_event(struct trace_uprobe *tu);
  89 static int unregister_uprobe_event(struct trace_uprobe *tu);
  90
  91 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
  92 static int uretprobe_dispatcher(struct uprobe_consumer *con,
  93                                 unsigned long func, struct pt_regs *regs);
  94
  95 #ifdef CONFIG_STACK_GROWSUP
  96 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
  97 {
  98         return addr - (n * sizeof(long));
  99 }
 100 #else
 101 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
 102 {
 103         return addr + (n * sizeof(long));
 104 }
 105 #endif
 106
 107 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
 108 {
 109         unsigned long ret;
 110         unsigned long addr = user_stack_pointer(regs);
 111
 112         addr = adjust_stack_addr(addr, n);
 113
 114         if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
 115                 return 0;
 116
 117         return ret;
 118 }
 119
 120 /*
 121  * Uprobes-specific fetch functions
 122  */
 123 static nokprobe_inline int
 124 probe_mem_read(void *dest, void *src, size_t size)
 125 {
 126         void __user *vaddr = (void __force __user *)src;
 127
 128         return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
 129 }
 130
 131 static nokprobe_inline int
 132 probe_mem_read_user(void *dest, void *src, size_t size)
 133 {
 134         return probe_mem_read(dest, src, size);
 135 }
 136
 137 /*
 138  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
 139  * length and relative data location.
 140  */
 141 static nokprobe_inline int
 142 fetch_store_string(unsigned long addr, void *dest, void *base)
 143 {
 144         long ret;
 145         u32 loc = *(u32 *)dest;
 146         int maxlen  = get_loc_len(loc);
 147         u8 *dst = get_loc_data(dest, base);
 148         void __user *src = (void __force __user *) addr;
 149
 150         if (unlikely(!maxlen))
 151                 return -ENOMEM;
 152
 153         if (addr == FETCH_TOKEN_COMM)
 154                 ret = strlcpy(dst, current->comm, maxlen);
 155         else
 156                 ret = strncpy_from_user(dst, src, maxlen);
 157         if (ret >= 0) {
 158                 if (ret == maxlen)
 159                         dst[ret - 1] = '\0';
 160                 else
 161                         /*
 162                          * Include the terminating null byte. In this case it
 163                          * was copied by strncpy_from_user but not accounted
 164                          * for in ret.
 165                          */
 166                         ret++;
 167                 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
 168         } else
 169                 *(u32 *)dest = make_data_loc(0, (void *)dst - base);
 170
 171         return ret;
 172 }
 173
 174 static nokprobe_inline int
 175 fetch_store_string_user(unsigned long addr, void *dest, void *base)
 176 {
 177         return fetch_store_string(addr, dest, base);
 178 }
 179
 180 /* Return the length of string -- including null terminal byte */
 181 static nokprobe_inline int
 182 fetch_store_strlen(unsigned long addr)
 183 {
 184         int len;
 185         void __user *vaddr = (void __force __user *) addr;
 186
 187         if (addr == FETCH_TOKEN_COMM)
 188                 len = strlen(current->comm) + 1;
 189         else
 190                 len = strnlen_user(vaddr, MAX_STRING_SIZE);
 191
 192         return (len > MAX_STRING_SIZE) ? 0 : len;
 193 }
 194
 195 static nokprobe_inline int
 196 fetch_store_strlen_user(unsigned long addr)
 197 {
 198         return fetch_store_strlen(addr);
 199 }
 200
 201 static unsigned long translate_user_vaddr(unsigned long file_offset)
 202 {
 203         unsigned long base_addr;
 204         struct uprobe_dispatch_data *udd;
 205
 206         udd = (void *) current->utask->vaddr;
 207
 208         base_addr = udd->bp_addr - udd->tu->offset;
 209         return base_addr + file_offset;
 210 }
 211
 212 /* Note that we don't verify it, since the code does not come from user space */
 213 static int
 214 process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 215                    void *base)
 216 {
 217         struct pt_regs *regs = rec;
 218         unsigned long val;
 219         int ret;
 220
 221         /* 1st stage: get value from context */
 222         switch (code->op) {
 223         case FETCH_OP_REG:
 224                 val = regs_get_register(regs, code->param);
 225                 break;
 226         case FETCH_OP_STACK:
 227                 val = get_user_stack_nth(regs, code->param);
 228                 break;
 229         case FETCH_OP_STACKP:
 230                 val = user_stack_pointer(regs);
 231                 break;
 232         case FETCH_OP_RETVAL:
 233                 val = regs_return_value(regs);
 234                 break;
 235         case FETCH_OP_COMM:
 236                 val = FETCH_TOKEN_COMM;
 237                 break;
 238         case FETCH_OP_FOFFS:
 239                 val = translate_user_vaddr(code->immediate);
 240                 break;
 241         default:
 242                 ret = process_common_fetch_insn(code, &val);
 243                 if (ret < 0)
 244                         return ret;
 245         }
 246         code++;
 247
 248         return process_fetch_insn_bottom(code, val, dest, base);
 249 }
 250 NOKPROBE_SYMBOL(process_fetch_insn)
 251
 252 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
 253 {
 254         rwlock_init(&filter->rwlock);
 255         filter->nr_systemwide = 0;
 256         INIT_LIST_HEAD(&filter->perf_events);
 257 }
 258
 259 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
 260 {
 261         return !filter->nr_systemwide && list_empty(&filter->perf_events);
 262 }
 263
 264 static inline bool is_ret_probe(struct trace_uprobe *tu)
 265 {
 266         return tu->consumer.ret_handler != NULL;
 267 }
 268
 269 static bool trace_uprobe_is_busy(struct dyn_event *ev)
 270 {
 271         struct trace_uprobe *tu = to_trace_uprobe(ev);
 272
 273         return trace_probe_is_enabled(&tu->tp);
 274 }
 275
 276 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
 277                                             int argc, const char **argv)
 278 {
 279         char buf[MAX_ARGSTR_LEN + 1];
 280         int len;
 281
 282         if (!argc)
 283                 return true;
 284
 285         len = strlen(tu->filename);
 286         if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
 287                 return false;
 288
 289         if (tu->ref_ctr_offset == 0)
 290                 snprintf(buf, sizeof(buf), "0x%0*lx",
 291                                 (int)(sizeof(void *) * 2), tu->offset);
 292         else
 293                 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
 294                                 (int)(sizeof(void *) * 2), tu->offset,
 295                                 tu->ref_ctr_offset);
 296         if (strcmp(buf, &argv[0][len + 1]))
 297                 return false;
 298
 299         argc--; argv++;
 300
 301         return trace_probe_match_command_args(&tu->tp, argc, argv);
 302 }
 303
 304 static bool trace_uprobe_match(const char *system, const char *event,
 305                         int argc, const char **argv, struct dyn_event *ev)
 306 {
 307         struct trace_uprobe *tu = to_trace_uprobe(ev);
 308
 309         return (event[0] == '\0' ||
 310                 strcmp(trace_probe_name(&tu->tp), event) == 0) &&
 311            (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
 312            trace_uprobe_match_command_head(tu, argc, argv);
 313 }
 314
 315 static nokprobe_inline struct trace_uprobe *
 316 trace_uprobe_primary_from_call(struct trace_event_call *call)
 317 {
 318         struct trace_probe *tp;
 319
 320         tp = trace_probe_primary_from_call(call);
 321         if (WARN_ON_ONCE(!tp))
 322                 return NULL;
 323
 324         return container_of(tp, struct trace_uprobe, tp);
 325 }
 326
 327 /*
 328  * Allocate new trace_uprobe and initialize it (including uprobes).
 329  */
 330 static struct trace_uprobe *
 331 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 332 {
 333         struct trace_uprobe *tu;
 334         int ret;
 335
 336         tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL);
 337         if (!tu)
 338                 return ERR_PTR(-ENOMEM);
 339
 340         ret = trace_probe_init(&tu->tp, event, group, true);
 341         if (ret < 0)
 342                 goto error;
 343
 344         dyn_event_init(&tu->devent, &trace_uprobe_ops);
 345         tu->consumer.handler = uprobe_dispatcher;
 346         if (is_ret)
 347                 tu->consumer.ret_handler = uretprobe_dispatcher;
 348         init_trace_uprobe_filter(tu->tp.event->filter);
 349         return tu;
 350
 351 error:
 352         kfree(tu);
 353
 354         return ERR_PTR(ret);
 355 }
 356
 357 static void free_trace_uprobe(struct trace_uprobe *tu)
 358 {
 359         if (!tu)
 360                 return;
 361
 362         path_put(&tu->path);
 363         trace_probe_cleanup(&tu->tp);
 364         kfree(tu->filename);
 365         kfree(tu);
 366 }
 367
 368 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
 369 {
 370         struct dyn_event *pos;
 371         struct trace_uprobe *tu;
 372
 373         for_each_trace_uprobe(tu, pos)
 374                 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
 375                     strcmp(trace_probe_group_name(&tu->tp), group) == 0)
 376                         return tu;
 377
 378         return NULL;
 379 }
 380
 381 /* Unregister a trace_uprobe and probe_event */
 382 static int unregister_trace_uprobe(struct trace_uprobe *tu)
 383 {
 384         int ret;
 385
 386         if (trace_probe_has_sibling(&tu->tp))
 387                 goto unreg;
 388
 389         /* If there's a reference to the dynamic event */
 390         if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp)))
 391                 return -EBUSY;
 392
 393         ret = unregister_uprobe_event(tu);
 394         if (ret)
 395                 return ret;
 396
 397 unreg:
 398         dyn_event_remove(&tu->devent);
 399         trace_probe_unlink(&tu->tp);
 400         free_trace_uprobe(tu);
 401         return 0;
 402 }
 403
 404 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
 405                                          struct trace_uprobe *comp)
 406 {
 407         struct trace_probe_event *tpe = orig->tp.event;
 408         struct inode *comp_inode = d_real_inode(comp->path.dentry);
 409         int i;
 410
 411         list_for_each_entry(orig, &tpe->probes, tp.list) {
 412                 if (comp_inode != d_real_inode(orig->path.dentry) ||
 413                     comp->offset != orig->offset)
 414                         continue;
 415
 416                 /*
 417                  * trace_probe_compare_arg_type() ensured that nr_args and
 418                  * each argument name and type are same. Let's compare comm.
 419                  */
 420                 for (i = 0; i < orig->tp.nr_args; i++) {
 421                         if (strcmp(orig->tp.args[i].comm,
 422                                    comp->tp.args[i].comm))
 423                                 break;
 424                 }
 425
 426                 if (i == orig->tp.nr_args)
 427                         return true;
 428         }
 429
 430         return false;
 431 }
 432
 433 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
 434 {
 435         int ret;
 436
 437         ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
 438         if (ret) {
 439                 /* Note that argument starts index = 2 */
 440                 trace_probe_log_set_index(ret + 1);
 441                 trace_probe_log_err(0, DIFF_ARG_TYPE);
 442                 return -EEXIST;
 443         }
 444         if (trace_uprobe_has_same_uprobe(to, tu)) {
 445                 trace_probe_log_set_index(0);
 446                 trace_probe_log_err(0, SAME_PROBE);
 447                 return -EEXIST;
 448         }
 449
 450         /* Append to existing event */
 451         ret = trace_probe_append(&tu->tp, &to->tp);
 452         if (!ret)
 453                 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
 454
 455         return ret;
 456 }
 457
 458 /*
 459  * Uprobe with multiple reference counter is not allowed. i.e.
 460  * If inode and offset matches, reference counter offset *must*
 461  * match as well. Though, there is one exception: If user is
 462  * replacing old trace_uprobe with new one(same group/event),
 463  * then we allow same uprobe with new reference counter as far
 464  * as the new one does not conflict with any other existing
 465  * ones.
 466  */
 467 static int validate_ref_ctr_offset(struct trace_uprobe *new)
 468 {
 469         struct dyn_event *pos;
 470         struct trace_uprobe *tmp;
 471         struct inode *new_inode = d_real_inode(new->path.dentry);
 472
 473         for_each_trace_uprobe(tmp, pos) {
 474                 if (new_inode == d_real_inode(tmp->path.dentry) &&
 475                     new->offset == tmp->offset &&
 476                     new->ref_ctr_offset != tmp->ref_ctr_offset) {
 477                         pr_warn("Reference counter offset mismatch.");
 478                         return -EINVAL;
 479                 }
 480         }
 481         return 0;
 482 }
 483
 484 /* Register a trace_uprobe and probe_event */
 485 static int register_trace_uprobe(struct trace_uprobe *tu)
 486 {
 487         struct trace_uprobe *old_tu;
 488         int ret;
 489
 490         mutex_lock(&event_mutex);
 491
 492         ret = validate_ref_ctr_offset(tu);
 493         if (ret)
 494                 goto end;
 495
 496         /* register as an event */
 497         old_tu = find_probe_event(trace_probe_name(&tu->tp),
 498                                   trace_probe_group_name(&tu->tp));
 499         if (old_tu) {
 500                 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
 501                         trace_probe_log_set_index(0);
 502                         trace_probe_log_err(0, DIFF_PROBE_TYPE);
 503                         ret = -EEXIST;
 504                 } else {
 505                         ret = append_trace_uprobe(tu, old_tu);
 506                 }
 507                 goto end;
 508         }
 509
 510         ret = register_uprobe_event(tu);
 511         if (ret) {
 512                 if (ret == -EEXIST) {
 513                         trace_probe_log_set_index(0);
 514                         trace_probe_log_err(0, EVENT_EXIST);
 515                 } else
 516                         pr_warn("Failed to register probe event(%d)\n", ret);
 517                 goto end;
 518         }
 519
 520         dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
 521
 522 end:
 523         mutex_unlock(&event_mutex);
 524
 525         return ret;
 526 }
 527
 528 /*
 529  * Argument syntax:
 530  *  - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS]
 531  */
 532 static int __trace_uprobe_create(int argc, const char **argv)
 533 {
 534         struct trace_uprobe *tu;
 535         const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
 536         char *arg, *filename, *rctr, *rctr_end, *tmp;
 537         char buf[MAX_EVENT_NAME_LEN];
 538         char gbuf[MAX_EVENT_NAME_LEN];
 539         enum probe_print_type ptype;
 540         struct path path;
 541         unsigned long offset, ref_ctr_offset;
 542         bool is_return = false;
 543         int i, ret;
 544
 545         ref_ctr_offset = 0;
 546
 547         switch (argv[0][0]) {
 548         case 'r':
 549                 is_return = true;
 550                 break;
 551         case 'p':
 552                 break;
 553         default:
 554                 return -ECANCELED;
 555         }
 556
 557         if (argc < 2)
 558                 return -ECANCELED;
 559
 560         if (argv[0][1] == ':')
 561                 event = &argv[0][2];
 562
 563         if (!strchr(argv[1], '/'))
 564                 return -ECANCELED;
 565
 566         filename = kstrdup(argv[1], GFP_KERNEL);
 567         if (!filename)
 568                 return -ENOMEM;
 569
 570         /* Find the last occurrence, in case the path contains ':' too. */
 571         arg = strrchr(filename, ':');
 572         if (!arg || !isdigit(arg[1])) {
 573                 kfree(filename);
 574                 return -ECANCELED;
 575         }
 576
 577         trace_probe_log_init("trace_uprobe", argc, argv);
 578         trace_probe_log_set_index(1);   /* filename is the 2nd argument */
 579
 580         *arg++ = '\0';
 581         ret = kern_path(filename, LOOKUP_FOLLOW, &path);
 582         if (ret) {
 583                 trace_probe_log_err(0, FILE_NOT_FOUND);
 584                 kfree(filename);
 585                 trace_probe_log_clear();
 586                 return ret;
 587         }
 588         if (!d_is_reg(path.dentry)) {
 589                 trace_probe_log_err(0, NO_REGULAR_FILE);
 590                 ret = -EINVAL;
 591                 goto fail_address_parse;
 592         }
 593
 594         /* Parse reference counter offset if specified. */
 595         rctr = strchr(arg, '(');
 596         if (rctr) {
 597                 rctr_end = strchr(rctr, ')');
 598                 if (!rctr_end) {
 599                         ret = -EINVAL;
 600                         rctr_end = rctr + strlen(rctr);
 601                         trace_probe_log_err(rctr_end - filename,
 602                                             REFCNT_OPEN_BRACE);
 603                         goto fail_address_parse;
 604                 } else if (rctr_end[1] != '\0') {
 605                         ret = -EINVAL;
 606                         trace_probe_log_err(rctr_end + 1 - filename,
 607                                             BAD_REFCNT_SUFFIX);
 608                         goto fail_address_parse;
 609                 }
 610
 611                 *rctr++ = '\0';
 612                 *rctr_end = '\0';
 613                 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
 614                 if (ret) {
 615                         trace_probe_log_err(rctr - filename, BAD_REFCNT);
 616                         goto fail_address_parse;
 617                 }
 618         }
 619
 620         /* Check if there is %return suffix */
 621         tmp = strchr(arg, '%');
 622         if (tmp) {
 623                 if (!strcmp(tmp, "%return")) {
 624                         *tmp = '\0';
 625                         is_return = true;
 626                 } else {
 627                         trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
 628                         ret = -EINVAL;
 629                         goto fail_address_parse;
 630                 }
 631         }
 632
 633         /* Parse uprobe offset. */
 634         ret = kstrtoul(arg, 0, &offset);
 635         if (ret) {
 636                 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
 637                 goto fail_address_parse;
 638         }
 639
 640         /* setup a probe */
 641         trace_probe_log_set_index(0);
 642         if (event) {
 643                 ret = traceprobe_parse_event_name(&event, &group, gbuf,
 644                                                   event - argv[0]);
 645                 if (ret)
 646                         goto fail_address_parse;
 647         }
 648
 649         if (!event) {
 650                 char *tail;
 651                 char *ptr;
 652
 653                 tail = kstrdup(kbasename(filename), GFP_KERNEL);
 654                 if (!tail) {
 655                         ret = -ENOMEM;
 656                         goto fail_address_parse;
 657                 }
 658
 659                 ptr = strpbrk(tail, ".-_");
 660                 if (ptr)
 661                         *ptr = '\0';
 662
 663                 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
 664                 event = buf;
 665                 kfree(tail);
 666         }
 667
 668         argc -= 2;
 669         argv += 2;
 670
 671         tu = alloc_trace_uprobe(group, event, argc, is_return);
 672         if (IS_ERR(tu)) {
 673                 ret = PTR_ERR(tu);
 674                 /* This must return -ENOMEM otherwise there is a bug */
 675                 WARN_ON_ONCE(ret != -ENOMEM);
 676                 goto fail_address_parse;
 677         }
 678         tu->offset = offset;
 679         tu->ref_ctr_offset = ref_ctr_offset;
 680         tu->path = path;
 681         tu->filename = filename;
 682
 683         /* parse arguments */
 684         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
 685                 struct traceprobe_parse_context ctx = {
 686                         .flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER,
 687                 };
 688
 689                 trace_probe_log_set_index(i + 2);
 690                 ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], &ctx);
 691                 traceprobe_finish_parse(&ctx);
 692                 if (ret)
 693                         goto error;
 694         }
 695
 696         ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
 697         ret = traceprobe_set_print_fmt(&tu->tp, ptype);
 698         if (ret < 0)
 699                 goto error;
 700
 701         ret = register_trace_uprobe(tu);
 702         if (!ret)
 703                 goto out;
 704
 705 error:
 706         free_trace_uprobe(tu);
 707 out:
 708         trace_probe_log_clear();
 709         return ret;
 710
 711 fail_address_parse:
 712         trace_probe_log_clear();
 713         path_put(&path);
 714         kfree(filename);
 715
 716         return ret;
 717 }
 718
 719 int trace_uprobe_create(const char *raw_command)
 720 {
 721         return trace_probe_create(raw_command, __trace_uprobe_create);
 722 }
 723
 724 static int create_or_delete_trace_uprobe(const char *raw_command)
 725 {
 726         int ret;
 727
 728         if (raw_command[0] == '-')
 729                 return dyn_event_release(raw_command, &trace_uprobe_ops);
 730
 731         ret = trace_uprobe_create(raw_command);
 732         return ret == -ECANCELED ? -EINVAL : ret;
 733 }
 734
 735 static int trace_uprobe_release(struct dyn_event *ev)
 736 {
 737         struct trace_uprobe *tu = to_trace_uprobe(ev);
 738
 739         return unregister_trace_uprobe(tu);
 740 }
 741
 742 /* Probes listing interfaces */
 743 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
 744 {
 745         struct trace_uprobe *tu = to_trace_uprobe(ev);
 746         char c = is_ret_probe(tu) ? 'r' : 'p';
 747         int i;
 748
 749         seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
 750                         trace_probe_name(&tu->tp), tu->filename,
 751                         (int)(sizeof(void *) * 2), tu->offset);
 752
 753         if (tu->ref_ctr_offset)
 754                 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
 755
 756         for (i = 0; i < tu->tp.nr_args; i++)
 757                 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
 758
 759         seq_putc(m, '\n');
 760         return 0;
 761 }
 762
 763 static int probes_seq_show(struct seq_file *m, void *v)
 764 {
 765         struct dyn_event *ev = v;
 766
 767         if (!is_trace_uprobe(ev))
 768                 return 0;
 769
 770         return trace_uprobe_show(m, ev);
 771 }
 772
 773 static const struct seq_operations probes_seq_op = {
 774         .start  = dyn_event_seq_start,
 775         .next   = dyn_event_seq_next,
 776         .stop   = dyn_event_seq_stop,
 777         .show   = probes_seq_show
 778 };
 779
 780 static int probes_open(struct inode *inode, struct file *file)
 781 {
 782         int ret;
 783
 784         ret = security_locked_down(LOCKDOWN_TRACEFS);
 785         if (ret)
 786                 return ret;
 787
 788         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 789                 ret = dyn_events_release_all(&trace_uprobe_ops);
 790                 if (ret)
 791                         return ret;
 792         }
 793
 794         return seq_open(file, &probes_seq_op);
 795 }
 796
 797 static ssize_t probes_write(struct file *file, const char __user *buffer,
 798                             size_t count, loff_t *ppos)
 799 {
 800         return trace_parse_run_command(file, buffer, count, ppos,
 801                                         create_or_delete_trace_uprobe);
 802 }
 803
 804 static const struct file_operations uprobe_events_ops = {
 805         .owner          = THIS_MODULE,
 806         .open           = probes_open,
 807         .read           = seq_read,
 808         .llseek         = seq_lseek,
 809         .release        = seq_release,
 810         .write          = probes_write,
 811 };
 812
 813 /* Probes profiling interfaces */
 814 static int probes_profile_seq_show(struct seq_file *m, void *v)
 815 {
 816         struct dyn_event *ev = v;
 817         struct trace_uprobe *tu;
 818
 819         if (!is_trace_uprobe(ev))
 820                 return 0;
 821
 822         tu = to_trace_uprobe(ev);
 823         seq_printf(m, "  %s %-44s %15lu\n", tu->filename,
 824                         trace_probe_name(&tu->tp), tu->nhit);
 825         return 0;
 826 }
 827
 828 static const struct seq_operations profile_seq_op = {
 829         .start  = dyn_event_seq_start,
 830         .next   = dyn_event_seq_next,
 831         .stop   = dyn_event_seq_stop,
 832         .show   = probes_profile_seq_show
 833 };
 834
 835 static int profile_open(struct inode *inode, struct file *file)
 836 {
 837         int ret;
 838
 839         ret = security_locked_down(LOCKDOWN_TRACEFS);
 840         if (ret)
 841                 return ret;
 842
 843         return seq_open(file, &profile_seq_op);
 844 }
 845
 846 static const struct file_operations uprobe_profile_ops = {
 847         .owner          = THIS_MODULE,
 848         .open           = profile_open,
 849         .read           = seq_read,
 850         .llseek         = seq_lseek,
 851         .release        = seq_release,
 852 };
 853
 854 struct uprobe_cpu_buffer {
 855         struct mutex mutex;
 856         void *buf;
 857 };
 858 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
 859 static int uprobe_buffer_refcnt;
 860
 861 static int uprobe_buffer_init(void)
 862 {
 863         int cpu, err_cpu;
 864
 865         uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
 866         if (uprobe_cpu_buffer == NULL)
 867                 return -ENOMEM;
 868
 869         for_each_possible_cpu(cpu) {
 870                 struct page *p = alloc_pages_node(cpu_to_node(cpu),
 871                                                   GFP_KERNEL, 0);
 872                 if (p == NULL) {
 873                         err_cpu = cpu;
 874                         goto err;
 875                 }
 876                 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
 877                 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
 878         }
 879
 880         return 0;
 881
 882 err:
 883         for_each_possible_cpu(cpu) {
 884                 if (cpu == err_cpu)
 885                         break;
 886                 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
 887         }
 888
 889         free_percpu(uprobe_cpu_buffer);
 890         return -ENOMEM;
 891 }
 892
 893 static int uprobe_buffer_enable(void)
 894 {
 895         int ret = 0;
 896
 897         BUG_ON(!mutex_is_locked(&event_mutex));
 898
 899         if (uprobe_buffer_refcnt++ == 0) {
 900                 ret = uprobe_buffer_init();
 901                 if (ret < 0)
 902                         uprobe_buffer_refcnt--;
 903         }
 904
 905         return ret;
 906 }
 907
 908 static void uprobe_buffer_disable(void)
 909 {
 910         int cpu;
 911
 912         BUG_ON(!mutex_is_locked(&event_mutex));
 913
 914         if (--uprobe_buffer_refcnt == 0) {
 915                 for_each_possible_cpu(cpu)
 916                         free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
 917                                                              cpu)->buf);
 918
 919                 free_percpu(uprobe_cpu_buffer);
 920                 uprobe_cpu_buffer = NULL;
 921         }
 922 }
 923
 924 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
 925 {
 926         struct uprobe_cpu_buffer *ucb;
 927         int cpu;
 928
 929         cpu = raw_smp_processor_id();
 930         ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
 931
 932         /*
 933          * Use per-cpu buffers for fastest access, but we might migrate
 934          * so the mutex makes sure we have sole access to it.
 935          */
 936         mutex_lock(&ucb->mutex);
 937
 938         return ucb;
 939 }
 940
 941 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
 942 {
 943         mutex_unlock(&ucb->mutex);
 944 }
 945
 946 static void __uprobe_trace_func(struct trace_uprobe *tu,
 947                                 unsigned long func, struct pt_regs *regs,
 948                                 struct uprobe_cpu_buffer *ucb, int dsize,
 949                                 struct trace_event_file *trace_file)
 950 {
 951         struct uprobe_trace_entry_head *entry;
 952         struct trace_event_buffer fbuffer;
 953         void *data;
 954         int size, esize;
 955         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
 956
 957         WARN_ON(call != trace_file->event_call);
 958
 959         if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
 960                 return;
 961
 962         if (trace_trigger_soft_disabled(trace_file))
 963                 return;
 964
 965         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 966         size = esize + tu->tp.size + dsize;
 967         entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
 968         if (!entry)
 969                 return;
 970
 971         if (is_ret_probe(tu)) {
 972                 entry->vaddr[0] = func;
 973                 entry->vaddr[1] = instruction_pointer(regs);
 974                 data = DATAOF_TRACE_ENTRY(entry, true);
 975         } else {
 976                 entry->vaddr[0] = instruction_pointer(regs);
 977                 data = DATAOF_TRACE_ENTRY(entry, false);
 978         }
 979
 980         memcpy(data, ucb->buf, tu->tp.size + dsize);
 981
 982         trace_event_buffer_commit(&fbuffer);
 983 }
 984
 985 /* uprobe handler */
 986 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
 987                              struct uprobe_cpu_buffer *ucb, int dsize)
 988 {
 989         struct event_file_link *link;
 990
 991         if (is_ret_probe(tu))
 992                 return 0;
 993
 994         rcu_read_lock();
 995         trace_probe_for_each_link_rcu(link, &tu->tp)
 996                 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
 997         rcu_read_unlock();
 998
 999         return 0;
1000 }
1001
1002 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
1003                                  struct pt_regs *regs,
1004                                  struct uprobe_cpu_buffer *ucb, int dsize)
1005 {
1006         struct event_file_link *link;
1007
1008         rcu_read_lock();
1009         trace_probe_for_each_link_rcu(link, &tu->tp)
1010                 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
1011         rcu_read_unlock();
1012 }
1013
1014 /* Event entry printers */
1015 static enum print_line_t
1016 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1017 {
1018         struct uprobe_trace_entry_head *entry;
1019         struct trace_seq *s = &iter->seq;
1020         struct trace_uprobe *tu;
1021         u8 *data;
1022
1023         entry = (struct uprobe_trace_entry_head *)iter->ent;
1024         tu = trace_uprobe_primary_from_call(
1025                 container_of(event, struct trace_event_call, event));
1026         if (unlikely(!tu))
1027                 goto out;
1028
1029         if (is_ret_probe(tu)) {
1030                 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1031                                  trace_probe_name(&tu->tp),
1032                                  entry->vaddr[1], entry->vaddr[0]);
1033                 data = DATAOF_TRACE_ENTRY(entry, true);
1034         } else {
1035                 trace_seq_printf(s, "%s: (0x%lx)",
1036                                  trace_probe_name(&tu->tp),
1037                                  entry->vaddr[0]);
1038                 data = DATAOF_TRACE_ENTRY(entry, false);
1039         }
1040
1041         if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1042                 goto out;
1043
1044         trace_seq_putc(s, '\n');
1045
1046  out:
1047         return trace_handle_return(s);
1048 }
1049
1050 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1051                                 enum uprobe_filter_ctx ctx,
1052                                 struct mm_struct *mm);
1053
1054 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1055 {
1056         int ret;
1057
1058         tu->consumer.filter = filter;
1059         tu->inode = d_real_inode(tu->path.dentry);
1060
1061         if (tu->ref_ctr_offset)
1062                 ret = uprobe_register_refctr(tu->inode, tu->offset,
1063                                 tu->ref_ctr_offset, &tu->consumer);
1064         else
1065                 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1066
1067         if (ret)
1068                 tu->inode = NULL;
1069
1070         return ret;
1071 }
1072
1073 static void __probe_event_disable(struct trace_probe *tp)
1074 {
1075         struct trace_uprobe *tu;
1076
1077         tu = container_of(tp, struct trace_uprobe, tp);
1078         WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1079
1080         list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1081                 if (!tu->inode)
1082                         continue;
1083
1084                 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1085                 tu->inode = NULL;
1086         }
1087 }
1088
1089 static int probe_event_enable(struct trace_event_call *call,
1090                         struct trace_event_file *file, filter_func_t filter)
1091 {
1092         struct trace_probe *tp;
1093         struct trace_uprobe *tu;
1094         bool enabled;
1095         int ret;
1096
1097         tp = trace_probe_primary_from_call(call);
1098         if (WARN_ON_ONCE(!tp))
1099                 return -ENODEV;
1100         enabled = trace_probe_is_enabled(tp);
1101
1102         /* This may also change "enabled" state */
1103         if (file) {
1104                 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1105                         return -EINTR;
1106
1107                 ret = trace_probe_add_file(tp, file);
1108                 if (ret < 0)
1109                         return ret;
1110         } else {
1111                 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1112                         return -EINTR;
1113
1114                 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1115         }
1116
1117         tu = container_of(tp, struct trace_uprobe, tp);
1118         WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1119
1120         if (enabled)
1121                 return 0;
1122
1123         ret = uprobe_buffer_enable();
1124         if (ret)
1125                 goto err_flags;
1126
1127         list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1128                 ret = trace_uprobe_enable(tu, filter);
1129                 if (ret) {
1130                         __probe_event_disable(tp);
1131                         goto err_buffer;
1132                 }
1133         }
1134
1135         return 0;
1136
1137  err_buffer:
1138         uprobe_buffer_disable();
1139
1140  err_flags:
1141         if (file)
1142                 trace_probe_remove_file(tp, file);
1143         else
1144                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1145
1146         return ret;
1147 }
1148
1149 static void probe_event_disable(struct trace_event_call *call,
1150                                 struct trace_event_file *file)
1151 {
1152         struct trace_probe *tp;
1153
1154         tp = trace_probe_primary_from_call(call);
1155         if (WARN_ON_ONCE(!tp))
1156                 return;
1157
1158         if (!trace_probe_is_enabled(tp))
1159                 return;
1160
1161         if (file) {
1162                 if (trace_probe_remove_file(tp, file) < 0)
1163                         return;
1164
1165                 if (trace_probe_is_enabled(tp))
1166                         return;
1167         } else
1168                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1169
1170         __probe_event_disable(tp);
1171         uprobe_buffer_disable();
1172 }
1173
1174 static int uprobe_event_define_fields(struct trace_event_call *event_call)
1175 {
1176         int ret, size;
1177         struct uprobe_trace_entry_head field;
1178         struct trace_uprobe *tu;
1179
1180         tu = trace_uprobe_primary_from_call(event_call);
1181         if (unlikely(!tu))
1182                 return -ENODEV;
1183
1184         if (is_ret_probe(tu)) {
1185                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1186                 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1187                 size = SIZEOF_TRACE_ENTRY(true);
1188         } else {
1189                 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1190                 size = SIZEOF_TRACE_ENTRY(false);
1191         }
1192
1193         return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1194 }
1195
1196 #ifdef CONFIG_PERF_EVENTS
1197 static bool
1198 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1199 {
1200         struct perf_event *event;
1201
1202         if (filter->nr_systemwide)
1203                 return true;
1204
1205         list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1206                 if (event->hw.target->mm == mm)
1207                         return true;
1208         }
1209
1210         return false;
1211 }
1212
1213 static inline bool
1214 trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1215                           struct perf_event *event)
1216 {
1217         return __uprobe_perf_filter(filter, event->hw.target->mm);
1218 }
1219
1220 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1221                                        struct perf_event *event)
1222 {
1223         bool done;
1224
1225         write_lock(&filter->rwlock);
1226         if (event->hw.target) {
1227                 list_del(&event->hw.tp_list);
1228                 done = filter->nr_systemwide ||
1229                         (event->hw.target->flags & PF_EXITING) ||
1230                         trace_uprobe_filter_event(filter, event);
1231         } else {
1232                 filter->nr_systemwide--;
1233                 done = filter->nr_systemwide;
1234         }
1235         write_unlock(&filter->rwlock);
1236
1237         return done;
1238 }
1239
1240 /* This returns true if the filter always covers target mm */
1241 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1242                                     struct perf_event *event)
1243 {
1244         bool done;
1245
1246         write_lock(&filter->rwlock);
1247         if (event->hw.target) {
1248                 /*
1249                  * event->parent != NULL means copy_process(), we can avoid
1250                  * uprobe_apply(). current->mm must be probed and we can rely
1251                  * on dup_mmap() which preserves the already installed bp's.
1252                  *
1253                  * attr.enable_on_exec means that exec/mmap will install the
1254                  * breakpoints we need.
1255                  */
1256                 done = filter->nr_systemwide ||
1257                         event->parent || event->attr.enable_on_exec ||
1258                         trace_uprobe_filter_event(filter, event);
1259                 list_add(&event->hw.tp_list, &filter->perf_events);
1260         } else {
1261                 done = filter->nr_systemwide;
1262                 filter->nr_systemwide++;
1263         }
1264         write_unlock(&filter->rwlock);
1265
1266         return done;
1267 }
1268
1269 static int uprobe_perf_close(struct trace_event_call *call,
1270                              struct perf_event *event)
1271 {
1272         struct trace_probe *tp;
1273         struct trace_uprobe *tu;
1274         int ret = 0;
1275
1276         tp = trace_probe_primary_from_call(call);
1277         if (WARN_ON_ONCE(!tp))
1278                 return -ENODEV;
1279
1280         tu = container_of(tp, struct trace_uprobe, tp);
1281         if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1282                 return 0;
1283
1284         list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1285                 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1286                 if (ret)
1287                         break;
1288         }
1289
1290         return ret;
1291 }
1292
1293 static int uprobe_perf_open(struct trace_event_call *call,
1294                             struct perf_event *event)
1295 {
1296         struct trace_probe *tp;
1297         struct trace_uprobe *tu;
1298         int err = 0;
1299
1300         tp = trace_probe_primary_from_call(call);
1301         if (WARN_ON_ONCE(!tp))
1302                 return -ENODEV;
1303
1304         tu = container_of(tp, struct trace_uprobe, tp);
1305         if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1306                 return 0;
1307
1308         list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1309                 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1310                 if (err) {
1311                         uprobe_perf_close(call, event);
1312                         break;
1313                 }
1314         }
1315
1316         return err;
1317 }
1318
1319 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1320                                 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1321 {
1322         struct trace_uprobe_filter *filter;
1323         struct trace_uprobe *tu;
1324         int ret;
1325
1326         tu = container_of(uc, struct trace_uprobe, consumer);
1327         filter = tu->tp.event->filter;
1328
1329         read_lock(&filter->rwlock);
1330         ret = __uprobe_perf_filter(filter, mm);
1331         read_unlock(&filter->rwlock);
1332
1333         return ret;
1334 }
1335
1336 static void __uprobe_perf_func(struct trace_uprobe *tu,
1337                                unsigned long func, struct pt_regs *regs,
1338                                struct uprobe_cpu_buffer *ucb, int dsize)
1339 {
1340         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1341         struct uprobe_trace_entry_head *entry;
1342         struct hlist_head *head;
1343         void *data;
1344         int size, esize;
1345         int rctx;
1346
1347 #ifdef CONFIG_BPF_EVENTS
1348         if (bpf_prog_array_valid(call)) {
1349                 u32 ret;
1350
1351                 ret = bpf_prog_run_array_uprobe(call->prog_array, regs, bpf_prog_run);
1352                 if (!ret)
1353                         return;
1354         }
1355 #endif /* CONFIG_BPF_EVENTS */
1356
1357         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1358
1359         size = esize + tu->tp.size + dsize;
1360         size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1361         if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1362                 return;
1363
1364         preempt_disable();
1365         head = this_cpu_ptr(call->perf_events);
1366         if (hlist_empty(head))
1367                 goto out;
1368
1369         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1370         if (!entry)
1371                 goto out;
1372
1373         if (is_ret_probe(tu)) {
1374                 entry->vaddr[0] = func;
1375                 entry->vaddr[1] = instruction_pointer(regs);
1376                 data = DATAOF_TRACE_ENTRY(entry, true);
1377         } else {
1378                 entry->vaddr[0] = instruction_pointer(regs);
1379                 data = DATAOF_TRACE_ENTRY(entry, false);
1380         }
1381
1382         memcpy(data, ucb->buf, tu->tp.size + dsize);
1383
1384         if (size - esize > tu->tp.size + dsize) {
1385                 int len = tu->tp.size + dsize;
1386
1387                 memset(data + len, 0, size - esize - len);
1388         }
1389
1390         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1391                               head, NULL);
1392  out:
1393         preempt_enable();
1394 }
1395
1396 /* uprobe profile handler */
1397 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1398                             struct uprobe_cpu_buffer *ucb, int dsize)
1399 {
1400         if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1401                 return UPROBE_HANDLER_REMOVE;
1402
1403         if (!is_ret_probe(tu))
1404                 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1405         return 0;
1406 }
1407
1408 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1409                                 struct pt_regs *regs,
1410                                 struct uprobe_cpu_buffer *ucb, int dsize)
1411 {
1412         __uprobe_perf_func(tu, func, regs, ucb, dsize);
1413 }
1414
1415 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1416                         const char **filename, u64 *probe_offset,
1417                         u64 *probe_addr, bool perf_type_tracepoint)
1418 {
1419         const char *pevent = trace_event_name(event->tp_event);
1420         const char *group = event->tp_event->class->system;
1421         struct trace_uprobe *tu;
1422
1423         if (perf_type_tracepoint)
1424                 tu = find_probe_event(pevent, group);
1425         else
1426                 tu = trace_uprobe_primary_from_call(event->tp_event);
1427         if (!tu)
1428                 return -EINVAL;
1429
1430         *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1431                                     : BPF_FD_TYPE_UPROBE;
1432         *filename = tu->filename;
1433         *probe_offset = tu->offset;
1434         *probe_addr = 0;
1435         return 0;
1436 }
1437 #endif  /* CONFIG_PERF_EVENTS */
1438
1439 static int
1440 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1441                       void *data)
1442 {
1443         struct trace_event_file *file = data;
1444
1445         switch (type) {
1446         case TRACE_REG_REGISTER:
1447                 return probe_event_enable(event, file, NULL);
1448
1449         case TRACE_REG_UNREGISTER:
1450                 probe_event_disable(event, file);
1451                 return 0;
1452
1453 #ifdef CONFIG_PERF_EVENTS
1454         case TRACE_REG_PERF_REGISTER:
1455                 return probe_event_enable(event, NULL, uprobe_perf_filter);
1456
1457         case TRACE_REG_PERF_UNREGISTER:
1458                 probe_event_disable(event, NULL);
1459                 return 0;
1460
1461         case TRACE_REG_PERF_OPEN:
1462                 return uprobe_perf_open(event, data);
1463
1464         case TRACE_REG_PERF_CLOSE:
1465                 return uprobe_perf_close(event, data);
1466
1467 #endif
1468         default:
1469                 return 0;
1470         }
1471 }
1472
1473 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1474 {
1475         struct trace_uprobe *tu;
1476         struct uprobe_dispatch_data udd;
1477         struct uprobe_cpu_buffer *ucb;
1478         int dsize, esize;
1479         int ret = 0;
1480
1481
1482         tu = container_of(con, struct trace_uprobe, consumer);
1483         tu->nhit++;
1484
1485         udd.tu = tu;
1486         udd.bp_addr = instruction_pointer(regs);
1487
1488         current->utask->vaddr = (unsigned long) &udd;
1489
1490         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1491                 return 0;
1492
1493         dsize = __get_data_size(&tu->tp, regs);
1494         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1495
1496         ucb = uprobe_buffer_get();
1497         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1498
1499         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1500                 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1501
1502 #ifdef CONFIG_PERF_EVENTS
1503         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1504                 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1505 #endif
1506         uprobe_buffer_put(ucb);
1507         return ret;
1508 }
1509
1510 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1511                                 unsigned long func, struct pt_regs *regs)
1512 {
1513         struct trace_uprobe *tu;
1514         struct uprobe_dispatch_data udd;
1515         struct uprobe_cpu_buffer *ucb;
1516         int dsize, esize;
1517
1518         tu = container_of(con, struct trace_uprobe, consumer);
1519
1520         udd.tu = tu;
1521         udd.bp_addr = func;
1522
1523         current->utask->vaddr = (unsigned long) &udd;
1524
1525         if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1526                 return 0;
1527
1528         dsize = __get_data_size(&tu->tp, regs);
1529         esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1530
1531         ucb = uprobe_buffer_get();
1532         store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1533
1534         if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1535                 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1536
1537 #ifdef CONFIG_PERF_EVENTS
1538         if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1539                 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1540 #endif
1541         uprobe_buffer_put(ucb);
1542         return 0;
1543 }
1544
1545 static struct trace_event_functions uprobe_funcs = {
1546         .trace          = print_uprobe_event
1547 };
1548
1549 static struct trace_event_fields uprobe_fields_array[] = {
1550         { .type = TRACE_FUNCTION_TYPE,
1551           .define_fields = uprobe_event_define_fields },
1552         {}
1553 };
1554
1555 static inline void init_trace_event_call(struct trace_uprobe *tu)
1556 {
1557         struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1558         call->event.funcs = &uprobe_funcs;
1559         call->class->fields_array = uprobe_fields_array;
1560
1561         call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1562         call->class->reg = trace_uprobe_register;
1563 }
1564
1565 static int register_uprobe_event(struct trace_uprobe *tu)
1566 {
1567         init_trace_event_call(tu);
1568
1569         return trace_probe_register_event_call(&tu->tp);
1570 }
1571
1572 static int unregister_uprobe_event(struct trace_uprobe *tu)
1573 {
1574         return trace_probe_unregister_event_call(&tu->tp);
1575 }
1576
1577 #ifdef CONFIG_PERF_EVENTS
1578 struct trace_event_call *
1579 create_local_trace_uprobe(char *name, unsigned long offs,
1580                           unsigned long ref_ctr_offset, bool is_return)
1581 {
1582         enum probe_print_type ptype;
1583         struct trace_uprobe *tu;
1584         struct path path;
1585         int ret;
1586
1587         ret = kern_path(name, LOOKUP_FOLLOW, &path);
1588         if (ret)
1589                 return ERR_PTR(ret);
1590
1591         if (!d_is_reg(path.dentry)) {
1592                 path_put(&path);
1593                 return ERR_PTR(-EINVAL);
1594         }
1595
1596         /*
1597          * local trace_kprobes are not added to dyn_event, so they are never
1598          * searched in find_trace_kprobe(). Therefore, there is no concern of
1599          * duplicated name "DUMMY_EVENT" here.
1600          */
1601         tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1602                                 is_return);
1603
1604         if (IS_ERR(tu)) {
1605                 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1606                         (int)PTR_ERR(tu));
1607                 path_put(&path);
1608                 return ERR_CAST(tu);
1609         }
1610
1611         tu->offset = offs;
1612         tu->path = path;
1613         tu->ref_ctr_offset = ref_ctr_offset;
1614         tu->filename = kstrdup(name, GFP_KERNEL);
1615         if (!tu->filename) {
1616                 ret = -ENOMEM;
1617                 goto error;
1618         }
1619
1620         init_trace_event_call(tu);
1621
1622         ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1623         if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
1624                 ret = -ENOMEM;
1625                 goto error;
1626         }
1627
1628         return trace_probe_event_call(&tu->tp);
1629 error:
1630         free_trace_uprobe(tu);
1631         return ERR_PTR(ret);
1632 }
1633
1634 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1635 {
1636         struct trace_uprobe *tu;
1637
1638         tu = trace_uprobe_primary_from_call(event_call);
1639
1640         free_trace_uprobe(tu);
1641 }
1642 #endif /* CONFIG_PERF_EVENTS */
1643
1644 /* Make a trace interface for controlling probe points */
1645 static __init int init_uprobe_trace(void)
1646 {
1647         int ret;
1648
1649         ret = dyn_event_register(&trace_uprobe_ops);
1650         if (ret)
1651                 return ret;
1652
1653         ret = tracing_init_dentry();
1654         if (ret)
1655                 return 0;
1656
1657         trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL,
1658                                     NULL, &uprobe_events_ops);
1659         /* Profile interface */
1660         trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
1661                                     NULL, &uprobe_profile_ops);
1662         return 0;
1663 }
1664
1665 fs_initcall(init_uprobe_trace);