linux/tools/perf/util/symbol.c
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   1// SPDX-License-Identifier: GPL-2.0
   2#include <dirent.h>
   3#include <errno.h>
   4#include <stdlib.h>
   5#include <stdio.h>
   6#include <string.h>
   7#include <linux/capability.h>
   8#include <linux/kernel.h>
   9#include <linux/mman.h>
  10#include <linux/string.h>
  11#include <linux/time64.h>
  12#include <sys/types.h>
  13#include <sys/stat.h>
  14#include <sys/param.h>
  15#include <fcntl.h>
  16#include <unistd.h>
  17#include <inttypes.h>
  18#include "annotate.h"
  19#include "build-id.h"
  20#include "cap.h"
  21#include "dso.h"
  22#include "util.h" // lsdir()
  23#include "debug.h"
  24#include "event.h"
  25#include "machine.h"
  26#include "map.h"
  27#include "symbol.h"
  28#include "map_symbol.h"
  29#include "mem-events.h"
  30#include "symsrc.h"
  31#include "strlist.h"
  32#include "intlist.h"
  33#include "namespaces.h"
  34#include "header.h"
  35#include "path.h"
  36#include <linux/ctype.h>
  37#include <linux/zalloc.h>
  38
  39#include <elf.h>
  40#include <limits.h>
  41#include <symbol/kallsyms.h>
  42#include <sys/utsname.h>
  43
  44static int dso__load_kernel_sym(struct dso *dso, struct map *map);
  45static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
  46static bool symbol__is_idle(const char *name);
  47
  48int vmlinux_path__nr_entries;
  49char **vmlinux_path;
  50
  51struct symbol_conf symbol_conf = {
  52        .nanosecs               = false,
  53        .use_modules            = true,
  54        .try_vmlinux_path       = true,
  55        .demangle               = true,
  56        .demangle_kernel        = false,
  57        .cumulate_callchain     = true,
  58        .time_quantum           = 100 * NSEC_PER_MSEC, /* 100ms */
  59        .show_hist_headers      = true,
  60        .symfs                  = "",
  61        .event_group            = true,
  62        .inline_name            = true,
  63        .res_sample             = 0,
  64};
  65
  66static enum dso_binary_type binary_type_symtab[] = {
  67        DSO_BINARY_TYPE__KALLSYMS,
  68        DSO_BINARY_TYPE__GUEST_KALLSYMS,
  69        DSO_BINARY_TYPE__JAVA_JIT,
  70        DSO_BINARY_TYPE__DEBUGLINK,
  71        DSO_BINARY_TYPE__BUILD_ID_CACHE,
  72        DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO,
  73        DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
  74        DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
  75        DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
  76        DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
  77        DSO_BINARY_TYPE__GUEST_KMODULE,
  78        DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
  79        DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
  80        DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
  81        DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
  82        DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
  83        DSO_BINARY_TYPE__NOT_FOUND,
  84};
  85
  86#define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
  87
  88static bool symbol_type__filter(char symbol_type)
  89{
  90        symbol_type = toupper(symbol_type);
  91        return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B';
  92}
  93
  94static int prefix_underscores_count(const char *str)
  95{
  96        const char *tail = str;
  97
  98        while (*tail == '_')
  99                tail++;
 100
 101        return tail - str;
 102}
 103
 104void __weak arch__symbols__fixup_end(struct symbol *p, struct symbol *c)
 105{
 106        p->end = c->start;
 107}
 108
 109const char * __weak arch__normalize_symbol_name(const char *name)
 110{
 111        return name;
 112}
 113
 114int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
 115{
 116        return strcmp(namea, nameb);
 117}
 118
 119int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
 120                                        unsigned int n)
 121{
 122        return strncmp(namea, nameb, n);
 123}
 124
 125int __weak arch__choose_best_symbol(struct symbol *syma,
 126                                    struct symbol *symb __maybe_unused)
 127{
 128        /* Avoid "SyS" kernel syscall aliases */
 129        if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
 130                return SYMBOL_B;
 131        if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
 132                return SYMBOL_B;
 133
 134        return SYMBOL_A;
 135}
 136
 137static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
 138{
 139        s64 a;
 140        s64 b;
 141        size_t na, nb;
 142
 143        /* Prefer a symbol with non zero length */
 144        a = syma->end - syma->start;
 145        b = symb->end - symb->start;
 146        if ((b == 0) && (a > 0))
 147                return SYMBOL_A;
 148        else if ((a == 0) && (b > 0))
 149                return SYMBOL_B;
 150
 151        /* Prefer a non weak symbol over a weak one */
 152        a = syma->binding == STB_WEAK;
 153        b = symb->binding == STB_WEAK;
 154        if (b && !a)
 155                return SYMBOL_A;
 156        if (a && !b)
 157                return SYMBOL_B;
 158
 159        /* Prefer a global symbol over a non global one */
 160        a = syma->binding == STB_GLOBAL;
 161        b = symb->binding == STB_GLOBAL;
 162        if (a && !b)
 163                return SYMBOL_A;
 164        if (b && !a)
 165                return SYMBOL_B;
 166
 167        /* Prefer a symbol with less underscores */
 168        a = prefix_underscores_count(syma->name);
 169        b = prefix_underscores_count(symb->name);
 170        if (b > a)
 171                return SYMBOL_A;
 172        else if (a > b)
 173                return SYMBOL_B;
 174
 175        /* Choose the symbol with the longest name */
 176        na = strlen(syma->name);
 177        nb = strlen(symb->name);
 178        if (na > nb)
 179                return SYMBOL_A;
 180        else if (na < nb)
 181                return SYMBOL_B;
 182
 183        return arch__choose_best_symbol(syma, symb);
 184}
 185
 186void symbols__fixup_duplicate(struct rb_root_cached *symbols)
 187{
 188        struct rb_node *nd;
 189        struct symbol *curr, *next;
 190
 191        if (symbol_conf.allow_aliases)
 192                return;
 193
 194        nd = rb_first_cached(symbols);
 195
 196        while (nd) {
 197                curr = rb_entry(nd, struct symbol, rb_node);
 198again:
 199                nd = rb_next(&curr->rb_node);
 200                next = rb_entry(nd, struct symbol, rb_node);
 201
 202                if (!nd)
 203                        break;
 204
 205                if (curr->start != next->start)
 206                        continue;
 207
 208                if (choose_best_symbol(curr, next) == SYMBOL_A) {
 209                        rb_erase_cached(&next->rb_node, symbols);
 210                        symbol__delete(next);
 211                        goto again;
 212                } else {
 213                        nd = rb_next(&curr->rb_node);
 214                        rb_erase_cached(&curr->rb_node, symbols);
 215                        symbol__delete(curr);
 216                }
 217        }
 218}
 219
 220void symbols__fixup_end(struct rb_root_cached *symbols)
 221{
 222        struct rb_node *nd, *prevnd = rb_first_cached(symbols);
 223        struct symbol *curr, *prev;
 224
 225        if (prevnd == NULL)
 226                return;
 227
 228        curr = rb_entry(prevnd, struct symbol, rb_node);
 229
 230        for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
 231                prev = curr;
 232                curr = rb_entry(nd, struct symbol, rb_node);
 233
 234                if (prev->end == prev->start && prev->end != curr->start)
 235                        arch__symbols__fixup_end(prev, curr);
 236        }
 237
 238        /* Last entry */
 239        if (curr->end == curr->start)
 240                curr->end = roundup(curr->start, 4096) + 4096;
 241}
 242
 243void maps__fixup_end(struct maps *maps)
 244{
 245        struct map *prev = NULL, *curr;
 246
 247        down_write(&maps->lock);
 248
 249        maps__for_each_entry(maps, curr) {
 250                if (prev != NULL && !prev->end)
 251                        prev->end = curr->start;
 252
 253                prev = curr;
 254        }
 255
 256        /*
 257         * We still haven't the actual symbols, so guess the
 258         * last map final address.
 259         */
 260        if (curr && !curr->end)
 261                curr->end = ~0ULL;
 262
 263        up_write(&maps->lock);
 264}
 265
 266struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char *name)
 267{
 268        size_t namelen = strlen(name) + 1;
 269        struct symbol *sym = calloc(1, (symbol_conf.priv_size +
 270                                        sizeof(*sym) + namelen));
 271        if (sym == NULL)
 272                return NULL;
 273
 274        if (symbol_conf.priv_size) {
 275                if (symbol_conf.init_annotation) {
 276                        struct annotation *notes = (void *)sym;
 277                        pthread_mutex_init(&notes->lock, NULL);
 278                }
 279                sym = ((void *)sym) + symbol_conf.priv_size;
 280        }
 281
 282        sym->start   = start;
 283        sym->end     = len ? start + len : start;
 284        sym->type    = type;
 285        sym->binding = binding;
 286        sym->namelen = namelen - 1;
 287
 288        pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
 289                  __func__, name, start, sym->end);
 290        memcpy(sym->name, name, namelen);
 291
 292        return sym;
 293}
 294
 295void symbol__delete(struct symbol *sym)
 296{
 297        free(((void *)sym) - symbol_conf.priv_size);
 298}
 299
 300void symbols__delete(struct rb_root_cached *symbols)
 301{
 302        struct symbol *pos;
 303        struct rb_node *next = rb_first_cached(symbols);
 304
 305        while (next) {
 306                pos = rb_entry(next, struct symbol, rb_node);
 307                next = rb_next(&pos->rb_node);
 308                rb_erase_cached(&pos->rb_node, symbols);
 309                symbol__delete(pos);
 310        }
 311}
 312
 313void __symbols__insert(struct rb_root_cached *symbols,
 314                       struct symbol *sym, bool kernel)
 315{
 316        struct rb_node **p = &symbols->rb_root.rb_node;
 317        struct rb_node *parent = NULL;
 318        const u64 ip = sym->start;
 319        struct symbol *s;
 320        bool leftmost = true;
 321
 322        if (kernel) {
 323                const char *name = sym->name;
 324                /*
 325                 * ppc64 uses function descriptors and appends a '.' to the
 326                 * start of every instruction address. Remove it.
 327                 */
 328                if (name[0] == '.')
 329                        name++;
 330                sym->idle = symbol__is_idle(name);
 331        }
 332
 333        while (*p != NULL) {
 334                parent = *p;
 335                s = rb_entry(parent, struct symbol, rb_node);
 336                if (ip < s->start)
 337                        p = &(*p)->rb_left;
 338                else {
 339                        p = &(*p)->rb_right;
 340                        leftmost = false;
 341                }
 342        }
 343        rb_link_node(&sym->rb_node, parent, p);
 344        rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
 345}
 346
 347void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
 348{
 349        __symbols__insert(symbols, sym, false);
 350}
 351
 352static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
 353{
 354        struct rb_node *n;
 355
 356        if (symbols == NULL)
 357                return NULL;
 358
 359        n = symbols->rb_root.rb_node;
 360
 361        while (n) {
 362                struct symbol *s = rb_entry(n, struct symbol, rb_node);
 363
 364                if (ip < s->start)
 365                        n = n->rb_left;
 366                else if (ip > s->end || (ip == s->end && ip != s->start))
 367                        n = n->rb_right;
 368                else
 369                        return s;
 370        }
 371
 372        return NULL;
 373}
 374
 375static struct symbol *symbols__first(struct rb_root_cached *symbols)
 376{
 377        struct rb_node *n = rb_first_cached(symbols);
 378
 379        if (n)
 380                return rb_entry(n, struct symbol, rb_node);
 381
 382        return NULL;
 383}
 384
 385static struct symbol *symbols__last(struct rb_root_cached *symbols)
 386{
 387        struct rb_node *n = rb_last(&symbols->rb_root);
 388
 389        if (n)
 390                return rb_entry(n, struct symbol, rb_node);
 391
 392        return NULL;
 393}
 394
 395static struct symbol *symbols__next(struct symbol *sym)
 396{
 397        struct rb_node *n = rb_next(&sym->rb_node);
 398
 399        if (n)
 400                return rb_entry(n, struct symbol, rb_node);
 401
 402        return NULL;
 403}
 404
 405static void symbols__insert_by_name(struct rb_root_cached *symbols, struct symbol *sym)
 406{
 407        struct rb_node **p = &symbols->rb_root.rb_node;
 408        struct rb_node *parent = NULL;
 409        struct symbol_name_rb_node *symn, *s;
 410        bool leftmost = true;
 411
 412        symn = container_of(sym, struct symbol_name_rb_node, sym);
 413
 414        while (*p != NULL) {
 415                parent = *p;
 416                s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
 417                if (strcmp(sym->name, s->sym.name) < 0)
 418                        p = &(*p)->rb_left;
 419                else {
 420                        p = &(*p)->rb_right;
 421                        leftmost = false;
 422                }
 423        }
 424        rb_link_node(&symn->rb_node, parent, p);
 425        rb_insert_color_cached(&symn->rb_node, symbols, leftmost);
 426}
 427
 428static void symbols__sort_by_name(struct rb_root_cached *symbols,
 429                                  struct rb_root_cached *source)
 430{
 431        struct rb_node *nd;
 432
 433        for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
 434                struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
 435                symbols__insert_by_name(symbols, pos);
 436        }
 437}
 438
 439int symbol__match_symbol_name(const char *name, const char *str,
 440                              enum symbol_tag_include includes)
 441{
 442        const char *versioning;
 443
 444        if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
 445            (versioning = strstr(name, "@@"))) {
 446                int len = strlen(str);
 447
 448                if (len < versioning - name)
 449                        len = versioning - name;
 450
 451                return arch__compare_symbol_names_n(name, str, len);
 452        } else
 453                return arch__compare_symbol_names(name, str);
 454}
 455
 456static struct symbol *symbols__find_by_name(struct rb_root_cached *symbols,
 457                                            const char *name,
 458                                            enum symbol_tag_include includes)
 459{
 460        struct rb_node *n;
 461        struct symbol_name_rb_node *s = NULL;
 462
 463        if (symbols == NULL)
 464                return NULL;
 465
 466        n = symbols->rb_root.rb_node;
 467
 468        while (n) {
 469                int cmp;
 470
 471                s = rb_entry(n, struct symbol_name_rb_node, rb_node);
 472                cmp = symbol__match_symbol_name(s->sym.name, name, includes);
 473
 474                if (cmp > 0)
 475                        n = n->rb_left;
 476                else if (cmp < 0)
 477                        n = n->rb_right;
 478                else
 479                        break;
 480        }
 481
 482        if (n == NULL)
 483                return NULL;
 484
 485        if (includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY)
 486                /* return first symbol that has same name (if any) */
 487                for (n = rb_prev(n); n; n = rb_prev(n)) {
 488                        struct symbol_name_rb_node *tmp;
 489
 490                        tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
 491                        if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
 492                                break;
 493
 494                        s = tmp;
 495                }
 496
 497        return &s->sym;
 498}
 499
 500void dso__reset_find_symbol_cache(struct dso *dso)
 501{
 502        dso->last_find_result.addr   = 0;
 503        dso->last_find_result.symbol = NULL;
 504}
 505
 506void dso__insert_symbol(struct dso *dso, struct symbol *sym)
 507{
 508        __symbols__insert(&dso->symbols, sym, dso->kernel);
 509
 510        /* update the symbol cache if necessary */
 511        if (dso->last_find_result.addr >= sym->start &&
 512            (dso->last_find_result.addr < sym->end ||
 513            sym->start == sym->end)) {
 514                dso->last_find_result.symbol = sym;
 515        }
 516}
 517
 518void dso__delete_symbol(struct dso *dso, struct symbol *sym)
 519{
 520        rb_erase_cached(&sym->rb_node, &dso->symbols);
 521        symbol__delete(sym);
 522        dso__reset_find_symbol_cache(dso);
 523}
 524
 525struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
 526{
 527        if (dso->last_find_result.addr != addr || dso->last_find_result.symbol == NULL) {
 528                dso->last_find_result.addr   = addr;
 529                dso->last_find_result.symbol = symbols__find(&dso->symbols, addr);
 530        }
 531
 532        return dso->last_find_result.symbol;
 533}
 534
 535struct symbol *dso__first_symbol(struct dso *dso)
 536{
 537        return symbols__first(&dso->symbols);
 538}
 539
 540struct symbol *dso__last_symbol(struct dso *dso)
 541{
 542        return symbols__last(&dso->symbols);
 543}
 544
 545struct symbol *dso__next_symbol(struct symbol *sym)
 546{
 547        return symbols__next(sym);
 548}
 549
 550struct symbol *symbol__next_by_name(struct symbol *sym)
 551{
 552        struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
 553        struct rb_node *n = rb_next(&s->rb_node);
 554
 555        return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
 556}
 557
 558 /*
 559  * Returns first symbol that matched with @name.
 560  */
 561struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name)
 562{
 563        struct symbol *s = symbols__find_by_name(&dso->symbol_names, name,
 564                                                 SYMBOL_TAG_INCLUDE__NONE);
 565        if (!s)
 566                s = symbols__find_by_name(&dso->symbol_names, name,
 567                                          SYMBOL_TAG_INCLUDE__DEFAULT_ONLY);
 568        return s;
 569}
 570
 571void dso__sort_by_name(struct dso *dso)
 572{
 573        dso__set_sorted_by_name(dso);
 574        return symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
 575}
 576
 577/*
 578 * While we find nice hex chars, build a long_val.
 579 * Return number of chars processed.
 580 */
 581static int hex2u64(const char *ptr, u64 *long_val)
 582{
 583        char *p;
 584
 585        *long_val = strtoull(ptr, &p, 16);
 586
 587        return p - ptr;
 588}
 589
 590
 591int modules__parse(const char *filename, void *arg,
 592                   int (*process_module)(void *arg, const char *name,
 593                                         u64 start, u64 size))
 594{
 595        char *line = NULL;
 596        size_t n;
 597        FILE *file;
 598        int err = 0;
 599
 600        file = fopen(filename, "r");
 601        if (file == NULL)
 602                return -1;
 603
 604        while (1) {
 605                char name[PATH_MAX];
 606                u64 start, size;
 607                char *sep, *endptr;
 608                ssize_t line_len;
 609
 610                line_len = getline(&line, &n, file);
 611                if (line_len < 0) {
 612                        if (feof(file))
 613                                break;
 614                        err = -1;
 615                        goto out;
 616                }
 617
 618                if (!line) {
 619                        err = -1;
 620                        goto out;
 621                }
 622
 623                line[--line_len] = '\0'; /* \n */
 624
 625                sep = strrchr(line, 'x');
 626                if (sep == NULL)
 627                        continue;
 628
 629                hex2u64(sep + 1, &start);
 630
 631                sep = strchr(line, ' ');
 632                if (sep == NULL)
 633                        continue;
 634
 635                *sep = '\0';
 636
 637                scnprintf(name, sizeof(name), "[%s]", line);
 638
 639                size = strtoul(sep + 1, &endptr, 0);
 640                if (*endptr != ' ' && *endptr != '\t')
 641                        continue;
 642
 643                err = process_module(arg, name, start, size);
 644                if (err)
 645                        break;
 646        }
 647out:
 648        free(line);
 649        fclose(file);
 650        return err;
 651}
 652
 653/*
 654 * These are symbols in the kernel image, so make sure that
 655 * sym is from a kernel DSO.
 656 */
 657static bool symbol__is_idle(const char *name)
 658{
 659        const char * const idle_symbols[] = {
 660                "acpi_idle_do_entry",
 661                "acpi_processor_ffh_cstate_enter",
 662                "arch_cpu_idle",
 663                "cpu_idle",
 664                "cpu_startup_entry",
 665                "idle_cpu",
 666                "intel_idle",
 667                "default_idle",
 668                "native_safe_halt",
 669                "enter_idle",
 670                "exit_idle",
 671                "mwait_idle",
 672                "mwait_idle_with_hints",
 673                "mwait_idle_with_hints.constprop.0",
 674                "poll_idle",
 675                "ppc64_runlatch_off",
 676                "pseries_dedicated_idle_sleep",
 677                "psw_idle",
 678                "psw_idle_exit",
 679                NULL
 680        };
 681        int i;
 682        static struct strlist *idle_symbols_list;
 683
 684        if (idle_symbols_list)
 685                return strlist__has_entry(idle_symbols_list, name);
 686
 687        idle_symbols_list = strlist__new(NULL, NULL);
 688
 689        for (i = 0; idle_symbols[i]; i++)
 690                strlist__add(idle_symbols_list, idle_symbols[i]);
 691
 692        return strlist__has_entry(idle_symbols_list, name);
 693}
 694
 695static int map__process_kallsym_symbol(void *arg, const char *name,
 696                                       char type, u64 start)
 697{
 698        struct symbol *sym;
 699        struct dso *dso = arg;
 700        struct rb_root_cached *root = &dso->symbols;
 701
 702        if (!symbol_type__filter(type))
 703                return 0;
 704
 705        /*
 706         * module symbols are not sorted so we add all
 707         * symbols, setting length to 0, and rely on
 708         * symbols__fixup_end() to fix it up.
 709         */
 710        sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
 711        if (sym == NULL)
 712                return -ENOMEM;
 713        /*
 714         * We will pass the symbols to the filter later, in
 715         * map__split_kallsyms, when we have split the maps per module
 716         */
 717        __symbols__insert(root, sym, !strchr(name, '['));
 718
 719        return 0;
 720}
 721
 722/*
 723 * Loads the function entries in /proc/kallsyms into kernel_map->dso,
 724 * so that we can in the next step set the symbol ->end address and then
 725 * call kernel_maps__split_kallsyms.
 726 */
 727static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
 728{
 729        return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
 730}
 731
 732static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
 733{
 734        struct map *curr_map;
 735        struct symbol *pos;
 736        int count = 0;
 737        struct rb_root_cached old_root = dso->symbols;
 738        struct rb_root_cached *root = &dso->symbols;
 739        struct rb_node *next = rb_first_cached(root);
 740
 741        if (!kmaps)
 742                return -1;
 743
 744        *root = RB_ROOT_CACHED;
 745
 746        while (next) {
 747                char *module;
 748
 749                pos = rb_entry(next, struct symbol, rb_node);
 750                next = rb_next(&pos->rb_node);
 751
 752                rb_erase_cached(&pos->rb_node, &old_root);
 753                RB_CLEAR_NODE(&pos->rb_node);
 754                module = strchr(pos->name, '\t');
 755                if (module)
 756                        *module = '\0';
 757
 758                curr_map = maps__find(kmaps, pos->start);
 759
 760                if (!curr_map) {
 761                        symbol__delete(pos);
 762                        continue;
 763                }
 764
 765                pos->start -= curr_map->start - curr_map->pgoff;
 766                if (pos->end > curr_map->end)
 767                        pos->end = curr_map->end;
 768                if (pos->end)
 769                        pos->end -= curr_map->start - curr_map->pgoff;
 770                symbols__insert(&curr_map->dso->symbols, pos);
 771                ++count;
 772        }
 773
 774        /* Symbols have been adjusted */
 775        dso->adjust_symbols = 1;
 776
 777        return count;
 778}
 779
 780/*
 781 * Split the symbols into maps, making sure there are no overlaps, i.e. the
 782 * kernel range is broken in several maps, named [kernel].N, as we don't have
 783 * the original ELF section names vmlinux have.
 784 */
 785static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
 786                                struct map *initial_map)
 787{
 788        struct machine *machine;
 789        struct map *curr_map = initial_map;
 790        struct symbol *pos;
 791        int count = 0, moved = 0;
 792        struct rb_root_cached *root = &dso->symbols;
 793        struct rb_node *next = rb_first_cached(root);
 794        int kernel_range = 0;
 795        bool x86_64;
 796
 797        if (!kmaps)
 798                return -1;
 799
 800        machine = kmaps->machine;
 801
 802        x86_64 = machine__is(machine, "x86_64");
 803
 804        while (next) {
 805                char *module;
 806
 807                pos = rb_entry(next, struct symbol, rb_node);
 808                next = rb_next(&pos->rb_node);
 809
 810                module = strchr(pos->name, '\t');
 811                if (module) {
 812                        if (!symbol_conf.use_modules)
 813                                goto discard_symbol;
 814
 815                        *module++ = '\0';
 816
 817                        if (strcmp(curr_map->dso->short_name, module)) {
 818                                if (curr_map != initial_map &&
 819                                    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
 820                                    machine__is_default_guest(machine)) {
 821                                        /*
 822                                         * We assume all symbols of a module are
 823                                         * continuous in * kallsyms, so curr_map
 824                                         * points to a module and all its
 825                                         * symbols are in its kmap. Mark it as
 826                                         * loaded.
 827                                         */
 828                                        dso__set_loaded(curr_map->dso);
 829                                }
 830
 831                                curr_map = maps__find_by_name(kmaps, module);
 832                                if (curr_map == NULL) {
 833                                        pr_debug("%s/proc/{kallsyms,modules} "
 834                                                 "inconsistency while looking "
 835                                                 "for \"%s\" module!\n",
 836                                                 machine->root_dir, module);
 837                                        curr_map = initial_map;
 838                                        goto discard_symbol;
 839                                }
 840
 841                                if (curr_map->dso->loaded &&
 842                                    !machine__is_default_guest(machine))
 843                                        goto discard_symbol;
 844                        }
 845                        /*
 846                         * So that we look just like we get from .ko files,
 847                         * i.e. not prelinked, relative to initial_map->start.
 848                         */
 849                        pos->start = curr_map->map_ip(curr_map, pos->start);
 850                        pos->end   = curr_map->map_ip(curr_map, pos->end);
 851                } else if (x86_64 && is_entry_trampoline(pos->name)) {
 852                        /*
 853                         * These symbols are not needed anymore since the
 854                         * trampoline maps refer to the text section and it's
 855                         * symbols instead. Avoid having to deal with
 856                         * relocations, and the assumption that the first symbol
 857                         * is the start of kernel text, by simply removing the
 858                         * symbols at this point.
 859                         */
 860                        goto discard_symbol;
 861                } else if (curr_map != initial_map) {
 862                        char dso_name[PATH_MAX];
 863                        struct dso *ndso;
 864
 865                        if (delta) {
 866                                /* Kernel was relocated at boot time */
 867                                pos->start -= delta;
 868                                pos->end -= delta;
 869                        }
 870
 871                        if (count == 0) {
 872                                curr_map = initial_map;
 873                                goto add_symbol;
 874                        }
 875
 876                        if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
 877                                snprintf(dso_name, sizeof(dso_name),
 878                                        "[guest.kernel].%d",
 879                                        kernel_range++);
 880                        else
 881                                snprintf(dso_name, sizeof(dso_name),
 882                                        "[kernel].%d",
 883                                        kernel_range++);
 884
 885                        ndso = dso__new(dso_name);
 886                        if (ndso == NULL)
 887                                return -1;
 888
 889                        ndso->kernel = dso->kernel;
 890
 891                        curr_map = map__new2(pos->start, ndso);
 892                        if (curr_map == NULL) {
 893                                dso__put(ndso);
 894                                return -1;
 895                        }
 896
 897                        curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
 898                        maps__insert(kmaps, curr_map);
 899                        ++kernel_range;
 900                } else if (delta) {
 901                        /* Kernel was relocated at boot time */
 902                        pos->start -= delta;
 903                        pos->end -= delta;
 904                }
 905add_symbol:
 906                if (curr_map != initial_map) {
 907                        rb_erase_cached(&pos->rb_node, root);
 908                        symbols__insert(&curr_map->dso->symbols, pos);
 909                        ++moved;
 910                } else
 911                        ++count;
 912
 913                continue;
 914discard_symbol:
 915                rb_erase_cached(&pos->rb_node, root);
 916                symbol__delete(pos);
 917        }
 918
 919        if (curr_map != initial_map &&
 920            dso->kernel == DSO_SPACE__KERNEL_GUEST &&
 921            machine__is_default_guest(kmaps->machine)) {
 922                dso__set_loaded(curr_map->dso);
 923        }
 924
 925        return count + moved;
 926}
 927
 928bool symbol__restricted_filename(const char *filename,
 929                                 const char *restricted_filename)
 930{
 931        bool restricted = false;
 932
 933        if (symbol_conf.kptr_restrict) {
 934                char *r = realpath(filename, NULL);
 935
 936                if (r != NULL) {
 937                        restricted = strcmp(r, restricted_filename) == 0;
 938                        free(r);
 939                        return restricted;
 940                }
 941        }
 942
 943        return restricted;
 944}
 945
 946struct module_info {
 947        struct rb_node rb_node;
 948        char *name;
 949        u64 start;
 950};
 951
 952static void add_module(struct module_info *mi, struct rb_root *modules)
 953{
 954        struct rb_node **p = &modules->rb_node;
 955        struct rb_node *parent = NULL;
 956        struct module_info *m;
 957
 958        while (*p != NULL) {
 959                parent = *p;
 960                m = rb_entry(parent, struct module_info, rb_node);
 961                if (strcmp(mi->name, m->name) < 0)
 962                        p = &(*p)->rb_left;
 963                else
 964                        p = &(*p)->rb_right;
 965        }
 966        rb_link_node(&mi->rb_node, parent, p);
 967        rb_insert_color(&mi->rb_node, modules);
 968}
 969
 970static void delete_modules(struct rb_root *modules)
 971{
 972        struct module_info *mi;
 973        struct rb_node *next = rb_first(modules);
 974
 975        while (next) {
 976                mi = rb_entry(next, struct module_info, rb_node);
 977                next = rb_next(&mi->rb_node);
 978                rb_erase(&mi->rb_node, modules);
 979                zfree(&mi->name);
 980                free(mi);
 981        }
 982}
 983
 984static struct module_info *find_module(const char *name,
 985                                       struct rb_root *modules)
 986{
 987        struct rb_node *n = modules->rb_node;
 988
 989        while (n) {
 990                struct module_info *m;
 991                int cmp;
 992
 993                m = rb_entry(n, struct module_info, rb_node);
 994                cmp = strcmp(name, m->name);
 995                if (cmp < 0)
 996                        n = n->rb_left;
 997                else if (cmp > 0)
 998                        n = n->rb_right;
 999                else
1000                        return m;
1001        }
1002
1003        return NULL;
1004}
1005
1006static int __read_proc_modules(void *arg, const char *name, u64 start,
1007                               u64 size __maybe_unused)
1008{
1009        struct rb_root *modules = arg;
1010        struct module_info *mi;
1011
1012        mi = zalloc(sizeof(struct module_info));
1013        if (!mi)
1014                return -ENOMEM;
1015
1016        mi->name = strdup(name);
1017        mi->start = start;
1018
1019        if (!mi->name) {
1020                free(mi);
1021                return -ENOMEM;
1022        }
1023
1024        add_module(mi, modules);
1025
1026        return 0;
1027}
1028
1029static int read_proc_modules(const char *filename, struct rb_root *modules)
1030{
1031        if (symbol__restricted_filename(filename, "/proc/modules"))
1032                return -1;
1033
1034        if (modules__parse(filename, modules, __read_proc_modules)) {
1035                delete_modules(modules);
1036                return -1;
1037        }
1038
1039        return 0;
1040}
1041
1042int compare_proc_modules(const char *from, const char *to)
1043{
1044        struct rb_root from_modules = RB_ROOT;
1045        struct rb_root to_modules = RB_ROOT;
1046        struct rb_node *from_node, *to_node;
1047        struct module_info *from_m, *to_m;
1048        int ret = -1;
1049
1050        if (read_proc_modules(from, &from_modules))
1051                return -1;
1052
1053        if (read_proc_modules(to, &to_modules))
1054                goto out_delete_from;
1055
1056        from_node = rb_first(&from_modules);
1057        to_node = rb_first(&to_modules);
1058        while (from_node) {
1059                if (!to_node)
1060                        break;
1061
1062                from_m = rb_entry(from_node, struct module_info, rb_node);
1063                to_m = rb_entry(to_node, struct module_info, rb_node);
1064
1065                if (from_m->start != to_m->start ||
1066                    strcmp(from_m->name, to_m->name))
1067                        break;
1068
1069                from_node = rb_next(from_node);
1070                to_node = rb_next(to_node);
1071        }
1072
1073        if (!from_node && !to_node)
1074                ret = 0;
1075
1076        delete_modules(&to_modules);
1077out_delete_from:
1078        delete_modules(&from_modules);
1079
1080        return ret;
1081}
1082
1083static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1084{
1085        struct rb_root modules = RB_ROOT;
1086        struct map *old_map;
1087        int err;
1088
1089        err = read_proc_modules(filename, &modules);
1090        if (err)
1091                return err;
1092
1093        maps__for_each_entry(kmaps, old_map) {
1094                struct module_info *mi;
1095
1096                if (!__map__is_kmodule(old_map)) {
1097                        continue;
1098                }
1099
1100                /* Module must be in memory at the same address */
1101                mi = find_module(old_map->dso->short_name, &modules);
1102                if (!mi || mi->start != old_map->start) {
1103                        err = -EINVAL;
1104                        goto out;
1105                }
1106        }
1107out:
1108        delete_modules(&modules);
1109        return err;
1110}
1111
1112/*
1113 * If kallsyms is referenced by name then we look for filename in the same
1114 * directory.
1115 */
1116static bool filename_from_kallsyms_filename(char *filename,
1117                                            const char *base_name,
1118                                            const char *kallsyms_filename)
1119{
1120        char *name;
1121
1122        strcpy(filename, kallsyms_filename);
1123        name = strrchr(filename, '/');
1124        if (!name)
1125                return false;
1126
1127        name += 1;
1128
1129        if (!strcmp(name, "kallsyms")) {
1130                strcpy(name, base_name);
1131                return true;
1132        }
1133
1134        return false;
1135}
1136
1137static int validate_kcore_modules(const char *kallsyms_filename,
1138                                  struct map *map)
1139{
1140        struct maps *kmaps = map__kmaps(map);
1141        char modules_filename[PATH_MAX];
1142
1143        if (!kmaps)
1144                return -EINVAL;
1145
1146        if (!filename_from_kallsyms_filename(modules_filename, "modules",
1147                                             kallsyms_filename))
1148                return -EINVAL;
1149
1150        if (do_validate_kcore_modules(modules_filename, kmaps))
1151                return -EINVAL;
1152
1153        return 0;
1154}
1155
1156static int validate_kcore_addresses(const char *kallsyms_filename,
1157                                    struct map *map)
1158{
1159        struct kmap *kmap = map__kmap(map);
1160
1161        if (!kmap)
1162                return -EINVAL;
1163
1164        if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1165                u64 start;
1166
1167                if (kallsyms__get_function_start(kallsyms_filename,
1168                                                 kmap->ref_reloc_sym->name, &start))
1169                        return -ENOENT;
1170                if (start != kmap->ref_reloc_sym->addr)
1171                        return -EINVAL;
1172        }
1173
1174        return validate_kcore_modules(kallsyms_filename, map);
1175}
1176
1177struct kcore_mapfn_data {
1178        struct dso *dso;
1179        struct list_head maps;
1180};
1181
1182static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1183{
1184        struct kcore_mapfn_data *md = data;
1185        struct map *map;
1186
1187        map = map__new2(start, md->dso);
1188        if (map == NULL)
1189                return -ENOMEM;
1190
1191        map->end = map->start + len;
1192        map->pgoff = pgoff;
1193
1194        list_add(&map->node, &md->maps);
1195
1196        return 0;
1197}
1198
1199/*
1200 * Merges map into maps by splitting the new map within the existing map
1201 * regions.
1202 */
1203int maps__merge_in(struct maps *kmaps, struct map *new_map)
1204{
1205        struct map *old_map;
1206        LIST_HEAD(merged);
1207
1208        maps__for_each_entry(kmaps, old_map) {
1209                /* no overload with this one */
1210                if (new_map->end < old_map->start ||
1211                    new_map->start >= old_map->end)
1212                        continue;
1213
1214                if (new_map->start < old_map->start) {
1215                        /*
1216                         * |new......
1217                         *       |old....
1218                         */
1219                        if (new_map->end < old_map->end) {
1220                                /*
1221                                 * |new......|     -> |new..|
1222                                 *       |old....| ->       |old....|
1223                                 */
1224                                new_map->end = old_map->start;
1225                        } else {
1226                                /*
1227                                 * |new.............| -> |new..|       |new..|
1228                                 *       |old....|    ->       |old....|
1229                                 */
1230                                struct map *m = map__clone(new_map);
1231
1232                                if (!m)
1233                                        return -ENOMEM;
1234
1235                                m->end = old_map->start;
1236                                list_add_tail(&m->node, &merged);
1237                                new_map->pgoff += old_map->end - new_map->start;
1238                                new_map->start = old_map->end;
1239                        }
1240                } else {
1241                        /*
1242                         *      |new......
1243                         * |old....
1244                         */
1245                        if (new_map->end < old_map->end) {
1246                                /*
1247                                 *      |new..|   -> x
1248                                 * |old.........| -> |old.........|
1249                                 */
1250                                map__put(new_map);
1251                                new_map = NULL;
1252                                break;
1253                        } else {
1254                                /*
1255                                 *      |new......| ->         |new...|
1256                                 * |old....|        -> |old....|
1257                                 */
1258                                new_map->pgoff += old_map->end - new_map->start;
1259                                new_map->start = old_map->end;
1260                        }
1261                }
1262        }
1263
1264        while (!list_empty(&merged)) {
1265                old_map = list_entry(merged.next, struct map, node);
1266                list_del_init(&old_map->node);
1267                maps__insert(kmaps, old_map);
1268                map__put(old_map);
1269        }
1270
1271        if (new_map) {
1272                maps__insert(kmaps, new_map);
1273                map__put(new_map);
1274        }
1275        return 0;
1276}
1277
1278static int dso__load_kcore(struct dso *dso, struct map *map,
1279                           const char *kallsyms_filename)
1280{
1281        struct maps *kmaps = map__kmaps(map);
1282        struct kcore_mapfn_data md;
1283        struct map *old_map, *new_map, *replacement_map = NULL, *next;
1284        struct machine *machine;
1285        bool is_64_bit;
1286        int err, fd;
1287        char kcore_filename[PATH_MAX];
1288        u64 stext;
1289
1290        if (!kmaps)
1291                return -EINVAL;
1292
1293        machine = kmaps->machine;
1294
1295        /* This function requires that the map is the kernel map */
1296        if (!__map__is_kernel(map))
1297                return -EINVAL;
1298
1299        if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1300                                             kallsyms_filename))
1301                return -EINVAL;
1302
1303        /* Modules and kernel must be present at their original addresses */
1304        if (validate_kcore_addresses(kallsyms_filename, map))
1305                return -EINVAL;
1306
1307        md.dso = dso;
1308        INIT_LIST_HEAD(&md.maps);
1309
1310        fd = open(kcore_filename, O_RDONLY);
1311        if (fd < 0) {
1312                pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1313                         kcore_filename);
1314                return -EINVAL;
1315        }
1316
1317        /* Read new maps into temporary lists */
1318        err = file__read_maps(fd, map->prot & PROT_EXEC, kcore_mapfn, &md,
1319                              &is_64_bit);
1320        if (err)
1321                goto out_err;
1322        dso->is_64_bit = is_64_bit;
1323
1324        if (list_empty(&md.maps)) {
1325                err = -EINVAL;
1326                goto out_err;
1327        }
1328
1329        /* Remove old maps */
1330        maps__for_each_entry_safe(kmaps, old_map, next) {
1331                /*
1332                 * We need to preserve eBPF maps even if they are
1333                 * covered by kcore, because we need to access
1334                 * eBPF dso for source data.
1335                 */
1336                if (old_map != map && !__map__is_bpf_prog(old_map))
1337                        maps__remove(kmaps, old_map);
1338        }
1339        machine->trampolines_mapped = false;
1340
1341        /* Find the kernel map using the '_stext' symbol */
1342        if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1343                list_for_each_entry(new_map, &md.maps, node) {
1344                        if (stext >= new_map->start && stext < new_map->end) {
1345                                replacement_map = new_map;
1346                                break;
1347                        }
1348                }
1349        }
1350
1351        if (!replacement_map)
1352                replacement_map = list_entry(md.maps.next, struct map, node);
1353
1354        /* Add new maps */
1355        while (!list_empty(&md.maps)) {
1356                new_map = list_entry(md.maps.next, struct map, node);
1357                list_del_init(&new_map->node);
1358                if (new_map == replacement_map) {
1359                        map->start      = new_map->start;
1360                        map->end        = new_map->end;
1361                        map->pgoff      = new_map->pgoff;
1362                        map->map_ip     = new_map->map_ip;
1363                        map->unmap_ip   = new_map->unmap_ip;
1364                        /* Ensure maps are correctly ordered */
1365                        map__get(map);
1366                        maps__remove(kmaps, map);
1367                        maps__insert(kmaps, map);
1368                        map__put(map);
1369                        map__put(new_map);
1370                } else {
1371                        /*
1372                         * Merge kcore map into existing maps,
1373                         * and ensure that current maps (eBPF)
1374                         * stay intact.
1375                         */
1376                        if (maps__merge_in(kmaps, new_map))
1377                                goto out_err;
1378                }
1379        }
1380
1381        if (machine__is(machine, "x86_64")) {
1382                u64 addr;
1383
1384                /*
1385                 * If one of the corresponding symbols is there, assume the
1386                 * entry trampoline maps are too.
1387                 */
1388                if (!kallsyms__get_function_start(kallsyms_filename,
1389                                                  ENTRY_TRAMPOLINE_NAME,
1390                                                  &addr))
1391                        machine->trampolines_mapped = true;
1392        }
1393
1394        /*
1395         * Set the data type and long name so that kcore can be read via
1396         * dso__data_read_addr().
1397         */
1398        if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1399                dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1400        else
1401                dso->binary_type = DSO_BINARY_TYPE__KCORE;
1402        dso__set_long_name(dso, strdup(kcore_filename), true);
1403
1404        close(fd);
1405
1406        if (map->prot & PROT_EXEC)
1407                pr_debug("Using %s for kernel object code\n", kcore_filename);
1408        else
1409                pr_debug("Using %s for kernel data\n", kcore_filename);
1410
1411        return 0;
1412
1413out_err:
1414        while (!list_empty(&md.maps)) {
1415                map = list_entry(md.maps.next, struct map, node);
1416                list_del_init(&map->node);
1417                map__put(map);
1418        }
1419        close(fd);
1420        return -EINVAL;
1421}
1422
1423/*
1424 * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1425 * delta based on the relocation reference symbol.
1426 */
1427static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1428{
1429        u64 addr;
1430
1431        if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1432                return 0;
1433
1434        if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1435                return -1;
1436
1437        *delta = addr - kmap->ref_reloc_sym->addr;
1438        return 0;
1439}
1440
1441int __dso__load_kallsyms(struct dso *dso, const char *filename,
1442                         struct map *map, bool no_kcore)
1443{
1444        struct kmap *kmap = map__kmap(map);
1445        u64 delta = 0;
1446
1447        if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1448                return -1;
1449
1450        if (!kmap || !kmap->kmaps)
1451                return -1;
1452
1453        if (dso__load_all_kallsyms(dso, filename) < 0)
1454                return -1;
1455
1456        if (kallsyms__delta(kmap, filename, &delta))
1457                return -1;
1458
1459        symbols__fixup_end(&dso->symbols);
1460        symbols__fixup_duplicate(&dso->symbols);
1461
1462        if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1463                dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1464        else
1465                dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1466
1467        if (!no_kcore && !dso__load_kcore(dso, map, filename))
1468                return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1469        else
1470                return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1471}
1472
1473int dso__load_kallsyms(struct dso *dso, const char *filename,
1474                       struct map *map)
1475{
1476        return __dso__load_kallsyms(dso, filename, map, false);
1477}
1478
1479static int dso__load_perf_map(const char *map_path, struct dso *dso)
1480{
1481        char *line = NULL;
1482        size_t n;
1483        FILE *file;
1484        int nr_syms = 0;
1485
1486        file = fopen(map_path, "r");
1487        if (file == NULL)
1488                goto out_failure;
1489
1490        while (!feof(file)) {
1491                u64 start, size;
1492                struct symbol *sym;
1493                int line_len, len;
1494
1495                line_len = getline(&line, &n, file);
1496                if (line_len < 0)
1497                        break;
1498
1499                if (!line)
1500                        goto out_failure;
1501
1502                line[--line_len] = '\0'; /* \n */
1503
1504                len = hex2u64(line, &start);
1505
1506                len++;
1507                if (len + 2 >= line_len)
1508                        continue;
1509
1510                len += hex2u64(line + len, &size);
1511
1512                len++;
1513                if (len + 2 >= line_len)
1514                        continue;
1515
1516                sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1517
1518                if (sym == NULL)
1519                        goto out_delete_line;
1520
1521                symbols__insert(&dso->symbols, sym);
1522                nr_syms++;
1523        }
1524
1525        free(line);
1526        fclose(file);
1527
1528        return nr_syms;
1529
1530out_delete_line:
1531        free(line);
1532out_failure:
1533        return -1;
1534}
1535
1536#ifdef HAVE_LIBBFD_SUPPORT
1537#define PACKAGE 'perf'
1538#include <bfd.h>
1539
1540static int bfd_symbols__cmpvalue(const void *a, const void *b)
1541{
1542        const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1543
1544        if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1545                return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1546
1547        return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1548}
1549
1550static int bfd2elf_binding(asymbol *symbol)
1551{
1552        if (symbol->flags & BSF_WEAK)
1553                return STB_WEAK;
1554        if (symbol->flags & BSF_GLOBAL)
1555                return STB_GLOBAL;
1556        if (symbol->flags & BSF_LOCAL)
1557                return STB_LOCAL;
1558        return -1;
1559}
1560
1561int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1562{
1563        int err = -1;
1564        long symbols_size, symbols_count, i;
1565        asection *section;
1566        asymbol **symbols, *sym;
1567        struct symbol *symbol;
1568        bfd *abfd;
1569        u64 start, len;
1570
1571        abfd = bfd_openr(debugfile, NULL);
1572        if (!abfd)
1573                return -1;
1574
1575        if (!bfd_check_format(abfd, bfd_object)) {
1576                pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1577                          dso->long_name);
1578                goto out_close;
1579        }
1580
1581        if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1582                goto out_close;
1583
1584        symbols_size = bfd_get_symtab_upper_bound(abfd);
1585        if (symbols_size == 0) {
1586                bfd_close(abfd);
1587                return 0;
1588        }
1589
1590        if (symbols_size < 0)
1591                goto out_close;
1592
1593        symbols = malloc(symbols_size);
1594        if (!symbols)
1595                goto out_close;
1596
1597        symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1598        if (symbols_count < 0)
1599                goto out_free;
1600
1601        section = bfd_get_section_by_name(abfd, ".text");
1602        if (section) {
1603                for (i = 0; i < symbols_count; ++i) {
1604                        if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
1605                            !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
1606                                break;
1607                }
1608                if (i < symbols_count) {
1609                        /* PE symbols can only have 4 bytes, so use .text high bits */
1610                        dso->text_offset = section->vma - (u32)section->vma;
1611                        dso->text_offset += (u32)bfd_asymbol_value(symbols[i]);
1612                } else {
1613                        dso->text_offset = section->vma - section->filepos;
1614                }
1615        }
1616
1617        qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1618
1619#ifdef bfd_get_section
1620#define bfd_asymbol_section bfd_get_section
1621#endif
1622        for (i = 0; i < symbols_count; ++i) {
1623                sym = symbols[i];
1624                section = bfd_asymbol_section(sym);
1625                if (bfd2elf_binding(sym) < 0)
1626                        continue;
1627
1628                while (i + 1 < symbols_count &&
1629                       bfd_asymbol_section(symbols[i + 1]) == section &&
1630                       bfd2elf_binding(symbols[i + 1]) < 0)
1631                        i++;
1632
1633                if (i + 1 < symbols_count &&
1634                    bfd_asymbol_section(symbols[i + 1]) == section)
1635                        len = symbols[i + 1]->value - sym->value;
1636                else
1637                        len = section->size - sym->value;
1638
1639                start = bfd_asymbol_value(sym) - dso->text_offset;
1640                symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1641                                     bfd_asymbol_name(sym));
1642                if (!symbol)
1643                        goto out_free;
1644
1645                symbols__insert(&dso->symbols, symbol);
1646        }
1647#ifdef bfd_get_section
1648#undef bfd_asymbol_section
1649#endif
1650
1651        symbols__fixup_end(&dso->symbols);
1652        symbols__fixup_duplicate(&dso->symbols);
1653        dso->adjust_symbols = 1;
1654
1655        err = 0;
1656out_free:
1657        free(symbols);
1658out_close:
1659        bfd_close(abfd);
1660        return err;
1661}
1662#endif
1663
1664static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1665                                           enum dso_binary_type type)
1666{
1667        switch (type) {
1668        case DSO_BINARY_TYPE__JAVA_JIT:
1669        case DSO_BINARY_TYPE__DEBUGLINK:
1670        case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1671        case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1672        case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1673        case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1674        case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1675        case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1676                return !kmod && dso->kernel == DSO_SPACE__USER;
1677
1678        case DSO_BINARY_TYPE__KALLSYMS:
1679        case DSO_BINARY_TYPE__VMLINUX:
1680        case DSO_BINARY_TYPE__KCORE:
1681                return dso->kernel == DSO_SPACE__KERNEL;
1682
1683        case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1684        case DSO_BINARY_TYPE__GUEST_VMLINUX:
1685        case DSO_BINARY_TYPE__GUEST_KCORE:
1686                return dso->kernel == DSO_SPACE__KERNEL_GUEST;
1687
1688        case DSO_BINARY_TYPE__GUEST_KMODULE:
1689        case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1690        case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1691        case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1692                /*
1693                 * kernel modules know their symtab type - it's set when
1694                 * creating a module dso in machine__addnew_module_map().
1695                 */
1696                return kmod && dso->symtab_type == type;
1697
1698        case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1699        case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1700                return true;
1701
1702        case DSO_BINARY_TYPE__BPF_PROG_INFO:
1703        case DSO_BINARY_TYPE__BPF_IMAGE:
1704        case DSO_BINARY_TYPE__OOL:
1705        case DSO_BINARY_TYPE__NOT_FOUND:
1706        default:
1707                return false;
1708        }
1709}
1710
1711/* Checks for the existence of the perf-<pid>.map file in two different
1712 * locations.  First, if the process is a separate mount namespace, check in
1713 * that namespace using the pid of the innermost pid namespace.  If's not in a
1714 * namespace, or the file can't be found there, try in the mount namespace of
1715 * the tracing process using our view of its pid.
1716 */
1717static int dso__find_perf_map(char *filebuf, size_t bufsz,
1718                              struct nsinfo **nsip)
1719{
1720        struct nscookie nsc;
1721        struct nsinfo *nsi;
1722        struct nsinfo *nnsi;
1723        int rc = -1;
1724
1725        nsi = *nsip;
1726
1727        if (nsi->need_setns) {
1728                snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsi->nstgid);
1729                nsinfo__mountns_enter(nsi, &nsc);
1730                rc = access(filebuf, R_OK);
1731                nsinfo__mountns_exit(&nsc);
1732                if (rc == 0)
1733                        return rc;
1734        }
1735
1736        nnsi = nsinfo__copy(nsi);
1737        if (nnsi) {
1738                nsinfo__put(nsi);
1739
1740                nnsi->need_setns = false;
1741                snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nnsi->tgid);
1742                *nsip = nnsi;
1743                rc = 0;
1744        }
1745
1746        return rc;
1747}
1748
1749int dso__load(struct dso *dso, struct map *map)
1750{
1751        char *name;
1752        int ret = -1;
1753        u_int i;
1754        struct machine *machine = NULL;
1755        char *root_dir = (char *) "";
1756        int ss_pos = 0;
1757        struct symsrc ss_[2];
1758        struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1759        bool kmod;
1760        bool perfmap;
1761        struct build_id bid;
1762        struct nscookie nsc;
1763        char newmapname[PATH_MAX];
1764        const char *map_path = dso->long_name;
1765
1766        perfmap = strncmp(dso->name, "/tmp/perf-", 10) == 0;
1767        if (perfmap) {
1768                if (dso->nsinfo && (dso__find_perf_map(newmapname,
1769                    sizeof(newmapname), &dso->nsinfo) == 0)) {
1770                        map_path = newmapname;
1771                }
1772        }
1773
1774        nsinfo__mountns_enter(dso->nsinfo, &nsc);
1775        pthread_mutex_lock(&dso->lock);
1776
1777        /* check again under the dso->lock */
1778        if (dso__loaded(dso)) {
1779                ret = 1;
1780                goto out;
1781        }
1782
1783        kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1784                dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1785                dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1786                dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1787
1788        if (dso->kernel && !kmod) {
1789                if (dso->kernel == DSO_SPACE__KERNEL)
1790                        ret = dso__load_kernel_sym(dso, map);
1791                else if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1792                        ret = dso__load_guest_kernel_sym(dso, map);
1793
1794                machine = map__kmaps(map)->machine;
1795                if (machine__is(machine, "x86_64"))
1796                        machine__map_x86_64_entry_trampolines(machine, dso);
1797                goto out;
1798        }
1799
1800        dso->adjust_symbols = 0;
1801
1802        if (perfmap) {
1803                ret = dso__load_perf_map(map_path, dso);
1804                dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1805                                             DSO_BINARY_TYPE__NOT_FOUND;
1806                goto out;
1807        }
1808
1809        if (machine)
1810                root_dir = machine->root_dir;
1811
1812        name = malloc(PATH_MAX);
1813        if (!name)
1814                goto out;
1815
1816        /*
1817         * Read the build id if possible. This is required for
1818         * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1819         */
1820        if (!dso->has_build_id &&
1821            is_regular_file(dso->long_name)) {
1822            __symbol__join_symfs(name, PATH_MAX, dso->long_name);
1823                if (filename__read_build_id(name, &bid) > 0)
1824                        dso__set_build_id(dso, &bid);
1825        }
1826
1827        /*
1828         * Iterate over candidate debug images.
1829         * Keep track of "interesting" ones (those which have a symtab, dynsym,
1830         * and/or opd section) for processing.
1831         */
1832        for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1833                struct symsrc *ss = &ss_[ss_pos];
1834                bool next_slot = false;
1835                bool is_reg;
1836                bool nsexit;
1837                int bfdrc = -1;
1838                int sirc = -1;
1839
1840                enum dso_binary_type symtab_type = binary_type_symtab[i];
1841
1842                nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1843                    symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1844
1845                if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1846                        continue;
1847
1848                if (dso__read_binary_type_filename(dso, symtab_type,
1849                                                   root_dir, name, PATH_MAX))
1850                        continue;
1851
1852                if (nsexit)
1853                        nsinfo__mountns_exit(&nsc);
1854
1855                is_reg = is_regular_file(name);
1856#ifdef HAVE_LIBBFD_SUPPORT
1857                if (is_reg)
1858                        bfdrc = dso__load_bfd_symbols(dso, name);
1859#endif
1860                if (is_reg && bfdrc < 0)
1861                        sirc = symsrc__init(ss, dso, name, symtab_type);
1862
1863                if (nsexit)
1864                        nsinfo__mountns_enter(dso->nsinfo, &nsc);
1865
1866                if (bfdrc == 0) {
1867                        ret = 0;
1868                        break;
1869                }
1870
1871                if (!is_reg || sirc < 0)
1872                        continue;
1873
1874                if (!syms_ss && symsrc__has_symtab(ss)) {
1875                        syms_ss = ss;
1876                        next_slot = true;
1877                        if (!dso->symsrc_filename)
1878                                dso->symsrc_filename = strdup(name);
1879                }
1880
1881                if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1882                        runtime_ss = ss;
1883                        next_slot = true;
1884                }
1885
1886                if (next_slot) {
1887                        ss_pos++;
1888
1889                        if (syms_ss && runtime_ss)
1890                                break;
1891                } else {
1892                        symsrc__destroy(ss);
1893                }
1894
1895        }
1896
1897        if (!runtime_ss && !syms_ss)
1898                goto out_free;
1899
1900        if (runtime_ss && !syms_ss) {
1901                syms_ss = runtime_ss;
1902        }
1903
1904        /* We'll have to hope for the best */
1905        if (!runtime_ss && syms_ss)
1906                runtime_ss = syms_ss;
1907
1908        if (syms_ss)
1909                ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
1910        else
1911                ret = -1;
1912
1913        if (ret > 0) {
1914                int nr_plt;
1915
1916                nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
1917                if (nr_plt > 0)
1918                        ret += nr_plt;
1919        }
1920
1921        for (; ss_pos > 0; ss_pos--)
1922                symsrc__destroy(&ss_[ss_pos - 1]);
1923out_free:
1924        free(name);
1925        if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1926                ret = 0;
1927out:
1928        dso__set_loaded(dso);
1929        pthread_mutex_unlock(&dso->lock);
1930        nsinfo__mountns_exit(&nsc);
1931
1932        return ret;
1933}
1934
1935static int map__strcmp(const void *a, const void *b)
1936{
1937        const struct map *ma = *(const struct map **)a, *mb = *(const struct map **)b;
1938        return strcmp(ma->dso->short_name, mb->dso->short_name);
1939}
1940
1941static int map__strcmp_name(const void *name, const void *b)
1942{
1943        const struct map *map = *(const struct map **)b;
1944        return strcmp(name, map->dso->short_name);
1945}
1946
1947void __maps__sort_by_name(struct maps *maps)
1948{
1949        qsort(maps->maps_by_name, maps->nr_maps, sizeof(struct map *), map__strcmp);
1950}
1951
1952static int map__groups__sort_by_name_from_rbtree(struct maps *maps)
1953{
1954        struct map *map;
1955        struct map **maps_by_name = realloc(maps->maps_by_name, maps->nr_maps * sizeof(map));
1956        int i = 0;
1957
1958        if (maps_by_name == NULL)
1959                return -1;
1960
1961        maps->maps_by_name = maps_by_name;
1962        maps->nr_maps_allocated = maps->nr_maps;
1963
1964        maps__for_each_entry(maps, map)
1965                maps_by_name[i++] = map;
1966
1967        __maps__sort_by_name(maps);
1968        return 0;
1969}
1970
1971static struct map *__maps__find_by_name(struct maps *maps, const char *name)
1972{
1973        struct map **mapp;
1974
1975        if (maps->maps_by_name == NULL &&
1976            map__groups__sort_by_name_from_rbtree(maps))
1977                return NULL;
1978
1979        mapp = bsearch(name, maps->maps_by_name, maps->nr_maps, sizeof(*mapp), map__strcmp_name);
1980        if (mapp)
1981                return *mapp;
1982        return NULL;
1983}
1984
1985struct map *maps__find_by_name(struct maps *maps, const char *name)
1986{
1987        struct map *map;
1988
1989        down_read(&maps->lock);
1990
1991        if (maps->last_search_by_name && strcmp(maps->last_search_by_name->dso->short_name, name) == 0) {
1992                map = maps->last_search_by_name;
1993                goto out_unlock;
1994        }
1995        /*
1996         * If we have maps->maps_by_name, then the name isn't in the rbtree,
1997         * as maps->maps_by_name mirrors the rbtree when lookups by name are
1998         * made.
1999         */
2000        map = __maps__find_by_name(maps, name);
2001        if (map || maps->maps_by_name != NULL)
2002                goto out_unlock;
2003
2004        /* Fallback to traversing the rbtree... */
2005        maps__for_each_entry(maps, map)
2006                if (strcmp(map->dso->short_name, name) == 0) {
2007                        maps->last_search_by_name = map;
2008                        goto out_unlock;
2009                }
2010
2011        map = NULL;
2012
2013out_unlock:
2014        up_read(&maps->lock);
2015        return map;
2016}
2017
2018int dso__load_vmlinux(struct dso *dso, struct map *map,
2019                      const char *vmlinux, bool vmlinux_allocated)
2020{
2021        int err = -1;
2022        struct symsrc ss;
2023        char symfs_vmlinux[PATH_MAX];
2024        enum dso_binary_type symtab_type;
2025
2026        if (vmlinux[0] == '/')
2027                snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
2028        else
2029                symbol__join_symfs(symfs_vmlinux, vmlinux);
2030
2031        if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2032                symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2033        else
2034                symtab_type = DSO_BINARY_TYPE__VMLINUX;
2035
2036        if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
2037                return -1;
2038
2039        err = dso__load_sym(dso, map, &ss, &ss, 0);
2040        symsrc__destroy(&ss);
2041
2042        if (err > 0) {
2043                if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2044                        dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2045                else
2046                        dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
2047                dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2048                dso__set_loaded(dso);
2049                pr_debug("Using %s for symbols\n", symfs_vmlinux);
2050        }
2051
2052        return err;
2053}
2054
2055int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2056{
2057        int i, err = 0;
2058        char *filename = NULL;
2059
2060        pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2061                 vmlinux_path__nr_entries + 1);
2062
2063        for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2064                err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2065                if (err > 0)
2066                        goto out;
2067        }
2068
2069        if (!symbol_conf.ignore_vmlinux_buildid)
2070                filename = dso__build_id_filename(dso, NULL, 0, false);
2071        if (filename != NULL) {
2072                err = dso__load_vmlinux(dso, map, filename, true);
2073                if (err > 0)
2074                        goto out;
2075                free(filename);
2076        }
2077out:
2078        return err;
2079}
2080
2081static bool visible_dir_filter(const char *name, struct dirent *d)
2082{
2083        if (d->d_type != DT_DIR)
2084                return false;
2085        return lsdir_no_dot_filter(name, d);
2086}
2087
2088static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2089{
2090        char kallsyms_filename[PATH_MAX];
2091        int ret = -1;
2092        struct strlist *dirs;
2093        struct str_node *nd;
2094
2095        dirs = lsdir(dir, visible_dir_filter);
2096        if (!dirs)
2097                return -1;
2098
2099        strlist__for_each_entry(nd, dirs) {
2100                scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2101                          "%s/%s/kallsyms", dir, nd->s);
2102                if (!validate_kcore_addresses(kallsyms_filename, map)) {
2103                        strlcpy(dir, kallsyms_filename, dir_sz);
2104                        ret = 0;
2105                        break;
2106                }
2107        }
2108
2109        strlist__delete(dirs);
2110
2111        return ret;
2112}
2113
2114/*
2115 * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2116 * since access(R_OK) only checks with real UID/GID but open() use effective
2117 * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2118 */
2119static bool filename__readable(const char *file)
2120{
2121        int fd = open(file, O_RDONLY);
2122        if (fd < 0)
2123                return false;
2124        close(fd);
2125        return true;
2126}
2127
2128static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2129{
2130        struct build_id bid;
2131        char sbuild_id[SBUILD_ID_SIZE];
2132        bool is_host = false;
2133        char path[PATH_MAX];
2134
2135        if (!dso->has_build_id) {
2136                /*
2137                 * Last resort, if we don't have a build-id and couldn't find
2138                 * any vmlinux file, try the running kernel kallsyms table.
2139                 */
2140                goto proc_kallsyms;
2141        }
2142
2143        if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2144                is_host = dso__build_id_equal(dso, &bid);
2145
2146        /* Try a fast path for /proc/kallsyms if possible */
2147        if (is_host) {
2148                /*
2149                 * Do not check the build-id cache, unless we know we cannot use
2150                 * /proc/kcore or module maps don't match to /proc/kallsyms.
2151                 * To check readability of /proc/kcore, do not use access(R_OK)
2152                 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2153                 * can't check it.
2154                 */
2155                if (filename__readable("/proc/kcore") &&
2156                    !validate_kcore_addresses("/proc/kallsyms", map))
2157                        goto proc_kallsyms;
2158        }
2159
2160        build_id__sprintf(&dso->bid, sbuild_id);
2161
2162        /* Find kallsyms in build-id cache with kcore */
2163        scnprintf(path, sizeof(path), "%s/%s/%s",
2164                  buildid_dir, DSO__NAME_KCORE, sbuild_id);
2165
2166        if (!find_matching_kcore(map, path, sizeof(path)))
2167                return strdup(path);
2168
2169        /* Use current /proc/kallsyms if possible */
2170        if (is_host) {
2171proc_kallsyms:
2172                return strdup("/proc/kallsyms");
2173        }
2174
2175        /* Finally, find a cache of kallsyms */
2176        if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2177                pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2178                       sbuild_id);
2179                return NULL;
2180        }
2181
2182        return strdup(path);
2183}
2184
2185static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2186{
2187        int err;
2188        const char *kallsyms_filename = NULL;
2189        char *kallsyms_allocated_filename = NULL;
2190        char *filename = NULL;
2191
2192        /*
2193         * Step 1: if the user specified a kallsyms or vmlinux filename, use
2194         * it and only it, reporting errors to the user if it cannot be used.
2195         *
2196         * For instance, try to analyse an ARM perf.data file _without_ a
2197         * build-id, or if the user specifies the wrong path to the right
2198         * vmlinux file, obviously we can't fallback to another vmlinux (a
2199         * x86_86 one, on the machine where analysis is being performed, say),
2200         * or worse, /proc/kallsyms.
2201         *
2202         * If the specified file _has_ a build-id and there is a build-id
2203         * section in the perf.data file, we will still do the expected
2204         * validation in dso__load_vmlinux and will bail out if they don't
2205         * match.
2206         */
2207        if (symbol_conf.kallsyms_name != NULL) {
2208                kallsyms_filename = symbol_conf.kallsyms_name;
2209                goto do_kallsyms;
2210        }
2211
2212        if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2213                return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2214        }
2215
2216        /*
2217         * Before checking on common vmlinux locations, check if it's
2218         * stored as standard build id binary (not kallsyms) under
2219         * .debug cache.
2220         */
2221        if (!symbol_conf.ignore_vmlinux_buildid)
2222                filename = __dso__build_id_filename(dso, NULL, 0, false, false);
2223        if (filename != NULL) {
2224                err = dso__load_vmlinux(dso, map, filename, true);
2225                if (err > 0)
2226                        return err;
2227                free(filename);
2228        }
2229
2230        if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2231                err = dso__load_vmlinux_path(dso, map);
2232                if (err > 0)
2233                        return err;
2234        }
2235
2236        /* do not try local files if a symfs was given */
2237        if (symbol_conf.symfs[0] != 0)
2238                return -1;
2239
2240        kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2241        if (!kallsyms_allocated_filename)
2242                return -1;
2243
2244        kallsyms_filename = kallsyms_allocated_filename;
2245
2246do_kallsyms:
2247        err = dso__load_kallsyms(dso, kallsyms_filename, map);
2248        if (err > 0)
2249                pr_debug("Using %s for symbols\n", kallsyms_filename);
2250        free(kallsyms_allocated_filename);
2251
2252        if (err > 0 && !dso__is_kcore(dso)) {
2253                dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
2254                dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2255                map__fixup_start(map);
2256                map__fixup_end(map);
2257        }
2258
2259        return err;
2260}
2261
2262static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2263{
2264        int err;
2265        const char *kallsyms_filename = NULL;
2266        struct machine *machine = map__kmaps(map)->machine;
2267        char path[PATH_MAX];
2268
2269        if (machine__is_default_guest(machine)) {
2270                /*
2271                 * if the user specified a vmlinux filename, use it and only
2272                 * it, reporting errors to the user if it cannot be used.
2273                 * Or use file guest_kallsyms inputted by user on commandline
2274                 */
2275                if (symbol_conf.default_guest_vmlinux_name != NULL) {
2276                        err = dso__load_vmlinux(dso, map,
2277                                                symbol_conf.default_guest_vmlinux_name,
2278                                                false);
2279                        return err;
2280                }
2281
2282                kallsyms_filename = symbol_conf.default_guest_kallsyms;
2283                if (!kallsyms_filename)
2284                        return -1;
2285        } else {
2286                sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2287                kallsyms_filename = path;
2288        }
2289
2290        err = dso__load_kallsyms(dso, kallsyms_filename, map);
2291        if (err > 0)
2292                pr_debug("Using %s for symbols\n", kallsyms_filename);
2293        if (err > 0 && !dso__is_kcore(dso)) {
2294                dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
2295                dso__set_long_name(dso, machine->mmap_name, false);
2296                map__fixup_start(map);
2297                map__fixup_end(map);
2298        }
2299
2300        return err;
2301}
2302
2303static void vmlinux_path__exit(void)
2304{
2305        while (--vmlinux_path__nr_entries >= 0)
2306                zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2307        vmlinux_path__nr_entries = 0;
2308
2309        zfree(&vmlinux_path);
2310}
2311
2312static const char * const vmlinux_paths[] = {
2313        "vmlinux",
2314        "/boot/vmlinux"
2315};
2316
2317static const char * const vmlinux_paths_upd[] = {
2318        "/boot/vmlinux-%s",
2319        "/usr/lib/debug/boot/vmlinux-%s",
2320        "/lib/modules/%s/build/vmlinux",
2321        "/usr/lib/debug/lib/modules/%s/vmlinux",
2322        "/usr/lib/debug/boot/vmlinux-%s.debug"
2323};
2324
2325static int vmlinux_path__add(const char *new_entry)
2326{
2327        vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2328        if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2329                return -1;
2330        ++vmlinux_path__nr_entries;
2331
2332        return 0;
2333}
2334
2335static int vmlinux_path__init(struct perf_env *env)
2336{
2337        struct utsname uts;
2338        char bf[PATH_MAX];
2339        char *kernel_version;
2340        unsigned int i;
2341
2342        vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2343                              ARRAY_SIZE(vmlinux_paths_upd)));
2344        if (vmlinux_path == NULL)
2345                return -1;
2346
2347        for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2348                if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2349                        goto out_fail;
2350
2351        /* only try kernel version if no symfs was given */
2352        if (symbol_conf.symfs[0] != 0)
2353                return 0;
2354
2355        if (env) {
2356                kernel_version = env->os_release;
2357        } else {
2358                if (uname(&uts) < 0)
2359                        goto out_fail;
2360
2361                kernel_version = uts.release;
2362        }
2363
2364        for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2365                snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2366                if (vmlinux_path__add(bf) < 0)
2367                        goto out_fail;
2368        }
2369
2370        return 0;
2371
2372out_fail:
2373        vmlinux_path__exit();
2374        return -1;
2375}
2376
2377int setup_list(struct strlist **list, const char *list_str,
2378                      const char *list_name)
2379{
2380        if (list_str == NULL)
2381                return 0;
2382
2383        *list = strlist__new(list_str, NULL);
2384        if (!*list) {
2385                pr_err("problems parsing %s list\n", list_name);
2386                return -1;
2387        }
2388
2389        symbol_conf.has_filter = true;
2390        return 0;
2391}
2392
2393int setup_intlist(struct intlist **list, const char *list_str,
2394                  const char *list_name)
2395{
2396        if (list_str == NULL)
2397                return 0;
2398
2399        *list = intlist__new(list_str);
2400        if (!*list) {
2401                pr_err("problems parsing %s list\n", list_name);
2402                return -1;
2403        }
2404        return 0;
2405}
2406
2407static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
2408{
2409        struct str_node *pos, *tmp;
2410        unsigned long val;
2411        char *sep;
2412        const char *end;
2413        int i = 0, err;
2414
2415        *addr_list = intlist__new(NULL);
2416        if (!*addr_list)
2417                return -1;
2418
2419        strlist__for_each_entry_safe(pos, tmp, sym_list) {
2420                errno = 0;
2421                val = strtoul(pos->s, &sep, 16);
2422                if (errno || (sep == pos->s))
2423                        continue;
2424
2425                if (*sep != '\0') {
2426                        end = pos->s + strlen(pos->s) - 1;
2427                        while (end >= sep && isspace(*end))
2428                                end--;
2429
2430                        if (end >= sep)
2431                                continue;
2432                }
2433
2434                err = intlist__add(*addr_list, val);
2435                if (err)
2436                        break;
2437
2438                strlist__remove(sym_list, pos);
2439                i++;
2440        }
2441
2442        if (i == 0) {
2443                intlist__delete(*addr_list);
2444                *addr_list = NULL;
2445        }
2446
2447        return 0;
2448}
2449
2450static bool symbol__read_kptr_restrict(void)
2451{
2452        bool value = false;
2453        FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2454
2455        if (fp != NULL) {
2456                char line[8];
2457
2458                if (fgets(line, sizeof(line), fp) != NULL)
2459                        value = perf_cap__capable(CAP_SYSLOG) ?
2460                                        (atoi(line) >= 2) :
2461                                        (atoi(line) != 0);
2462
2463                fclose(fp);
2464        }
2465
2466        /* Per kernel/kallsyms.c:
2467         * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2468         */
2469        if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))
2470                value = true;
2471
2472        return value;
2473}
2474
2475int symbol__annotation_init(void)
2476{
2477        if (symbol_conf.init_annotation)
2478                return 0;
2479
2480        if (symbol_conf.initialized) {
2481                pr_err("Annotation needs to be init before symbol__init()\n");
2482                return -1;
2483        }
2484
2485        symbol_conf.priv_size += sizeof(struct annotation);
2486        symbol_conf.init_annotation = true;
2487        return 0;
2488}
2489
2490int symbol__init(struct perf_env *env)
2491{
2492        const char *symfs;
2493
2494        if (symbol_conf.initialized)
2495                return 0;
2496
2497        symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2498
2499        symbol__elf_init();
2500
2501        if (symbol_conf.sort_by_name)
2502                symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
2503                                          sizeof(struct symbol));
2504
2505        if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2506                return -1;
2507
2508        if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2509                pr_err("'.' is the only non valid --field-separator argument\n");
2510                return -1;
2511        }
2512
2513        if (setup_list(&symbol_conf.dso_list,
2514                       symbol_conf.dso_list_str, "dso") < 0)
2515                return -1;
2516
2517        if (setup_list(&symbol_conf.comm_list,
2518                       symbol_conf.comm_list_str, "comm") < 0)
2519                goto out_free_dso_list;
2520
2521        if (setup_intlist(&symbol_conf.pid_list,
2522                       symbol_conf.pid_list_str, "pid") < 0)
2523                goto out_free_comm_list;
2524
2525        if (setup_intlist(&symbol_conf.tid_list,
2526                       symbol_conf.tid_list_str, "tid") < 0)
2527                goto out_free_pid_list;
2528
2529        if (setup_list(&symbol_conf.sym_list,
2530                       symbol_conf.sym_list_str, "symbol") < 0)
2531                goto out_free_tid_list;
2532
2533        if (symbol_conf.sym_list &&
2534            setup_addrlist(&symbol_conf.addr_list, symbol_conf.sym_list) < 0)
2535                goto out_free_sym_list;
2536
2537        if (setup_list(&symbol_conf.bt_stop_list,
2538                       symbol_conf.bt_stop_list_str, "symbol") < 0)
2539                goto out_free_sym_list;
2540
2541        /*
2542         * A path to symbols of "/" is identical to ""
2543         * reset here for simplicity.
2544         */
2545        symfs = realpath(symbol_conf.symfs, NULL);
2546        if (symfs == NULL)
2547                symfs = symbol_conf.symfs;
2548        if (strcmp(symfs, "/") == 0)
2549                symbol_conf.symfs = "";
2550        if (symfs != symbol_conf.symfs)
2551                free((void *)symfs);
2552
2553        symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2554
2555        symbol_conf.initialized = true;
2556        return 0;
2557
2558out_free_sym_list:
2559        strlist__delete(symbol_conf.sym_list);
2560        intlist__delete(symbol_conf.addr_list);
2561out_free_tid_list:
2562        intlist__delete(symbol_conf.tid_list);
2563out_free_pid_list:
2564        intlist__delete(symbol_conf.pid_list);
2565out_free_comm_list:
2566        strlist__delete(symbol_conf.comm_list);
2567out_free_dso_list:
2568        strlist__delete(symbol_conf.dso_list);
2569        return -1;
2570}
2571
2572void symbol__exit(void)
2573{
2574        if (!symbol_conf.initialized)
2575                return;
2576        strlist__delete(symbol_conf.bt_stop_list);
2577        strlist__delete(symbol_conf.sym_list);
2578        strlist__delete(symbol_conf.dso_list);
2579        strlist__delete(symbol_conf.comm_list);
2580        intlist__delete(symbol_conf.tid_list);
2581        intlist__delete(symbol_conf.pid_list);
2582        intlist__delete(symbol_conf.addr_list);
2583        vmlinux_path__exit();
2584        symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2585        symbol_conf.bt_stop_list = NULL;
2586        symbol_conf.initialized = false;
2587}
2588
2589int symbol__config_symfs(const struct option *opt __maybe_unused,
2590                         const char *dir, int unset __maybe_unused)
2591{
2592        char *bf = NULL;
2593        int ret;
2594
2595        symbol_conf.symfs = strdup(dir);
2596        if (symbol_conf.symfs == NULL)
2597                return -ENOMEM;
2598
2599        /* skip the locally configured cache if a symfs is given, and
2600         * config buildid dir to symfs/.debug
2601         */
2602        ret = asprintf(&bf, "%s/%s", dir, ".debug");
2603        if (ret < 0)
2604                return -ENOMEM;
2605
2606        set_buildid_dir(bf);
2607
2608        free(bf);
2609        return 0;
2610}
2611
2612struct mem_info *mem_info__get(struct mem_info *mi)
2613{
2614        if (mi)
2615                refcount_inc(&mi->refcnt);
2616        return mi;
2617}
2618
2619void mem_info__put(struct mem_info *mi)
2620{
2621        if (mi && refcount_dec_and_test(&mi->refcnt))
2622                free(mi);
2623}
2624
2625struct mem_info *mem_info__new(void)
2626{
2627        struct mem_info *mi = zalloc(sizeof(*mi));
2628
2629        if (mi)
2630                refcount_set(&mi->refcnt, 1);
2631        return mi;
2632}
2633