symbol-elf.c

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#include <libelf.h>
#include <gelf.h>
#include <elf.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <inttypes.h>

#include "symbol.h"
#include "debug.h"

#ifndef NT_GNU_BUILD_ID
#define NT_GNU_BUILD_ID 3
#endif

#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
    for (idx = 0, gelf_getsym(syms, idx, &sym);\
         idx < nr_syms; \
         idx++, gelf_getsym(syms, idx, &sym))

static inline uint8_t elf_sym__type(const GElf_Sym *sym)
{
    return GELF_ST_TYPE(sym->st_info);
}

static inline int elf_sym__is_function(const GElf_Sym *sym)
{
    return elf_sym__type(sym) == STT_FUNC &&
           sym->st_name != 0 &&
           sym->st_shndx != SHN_UNDEF;
}

static inline bool elf_sym__is_object(const GElf_Sym *sym)
{
    return elf_sym__type(sym) == STT_OBJECT &&
        sym->st_name != 0 &&
        sym->st_shndx != SHN_UNDEF;
}

static inline int elf_sym__is_label(const GElf_Sym *sym)
{
    return elf_sym__type(sym) == STT_NOTYPE &&
        sym->st_name != 0 &&
        sym->st_shndx != SHN_UNDEF &&
        sym->st_shndx != SHN_ABS;
}

static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
{
    switch (type) {
    case MAP__FUNCTION:
        return elf_sym__is_function(sym);
    case MAP__VARIABLE:
        return elf_sym__is_object(sym);
    default:
        return false;
    }
}

static inline const char *elf_sym__name(const GElf_Sym *sym,
                    const Elf_Data *symstrs)
{
    return symstrs->d_buf + sym->st_name;
}

static inline const char *elf_sec__name(const GElf_Shdr *shdr,
                    const Elf_Data *secstrs)
{
    return secstrs->d_buf + shdr->sh_name;
}

static inline int elf_sec__is_text(const GElf_Shdr *shdr,
                    const Elf_Data *secstrs)
{
    return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
}

static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
                    const Elf_Data *secstrs)
{
    return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
}

static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
              enum map_type type)
{
    switch (type) {
    case MAP__FUNCTION:
        return elf_sec__is_text(shdr, secstrs);
    case MAP__VARIABLE:
        return elf_sec__is_data(shdr, secstrs);
    default:
        return false;
    }
}

static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
{
    Elf_Scn *sec = NULL;
    GElf_Shdr shdr;
    size_t cnt = 1;

    while ((sec = elf_nextscn(elf, sec)) != NULL) {
        gelf_getshdr(sec, &shdr);

        if ((addr >= shdr.sh_addr) &&
            (addr < (shdr.sh_addr + shdr.sh_size)))
            return cnt;

        ++cnt;
    }

    return -1;
}

static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
                    GElf_Shdr *shp, const char *name,
                    size_t *idx)
{
    Elf_Scn *sec = NULL;
    size_t cnt = 1;

    /* Elf is corrupted/truncated, avoid calling elf_strptr. */
    if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
        return NULL;

    while ((sec = elf_nextscn(elf, sec)) != NULL) {
        char *str;

        gelf_getshdr(sec, shp);
        str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
        if (!strcmp(name, str)) {
            if (idx)
                *idx = cnt;
            break;
        }
        ++cnt;
    }

    return sec;
}

#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
    for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
         idx < nr_entries; \
         ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))

#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
    for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
         idx < nr_entries; \
         ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))

/*
 * We need to check if we have a .dynsym, so that we can handle the
 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
 * .dynsym or .symtab).
 * And always look at the original dso, not at debuginfo packages, that
 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
 */
int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
                symbol_filter_t filter)
{
    uint32_t nr_rel_entries, idx;
    GElf_Sym sym;
    u64 plt_offset;
    GElf_Shdr shdr_plt;
    struct symbol *f;
    GElf_Shdr shdr_rel_plt, shdr_dynsym;
    Elf_Data *reldata, *syms, *symstrs;
    Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
    size_t dynsym_idx;
    GElf_Ehdr ehdr;
    char sympltname[1024];
    Elf *elf;
    int nr = 0, symidx, err = 0;

    if (!ss->dynsym)
        return 0;

    elf = ss->elf;
    ehdr = ss->ehdr;

    scn_dynsym = ss->dynsym;
    shdr_dynsym = ss->dynshdr;
    dynsym_idx = ss->dynsym_idx;

    if (scn_dynsym == NULL)
        goto out_elf_end;

    scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
                      ".rela.plt", NULL);
    if (scn_plt_rel == NULL) {
        scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
                          ".rel.plt", NULL);
        if (scn_plt_rel == NULL)
            goto out_elf_end;
    }

    err = -1;

    if (shdr_rel_plt.sh_link != dynsym_idx)
        goto out_elf_end;

    if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
        goto out_elf_end;

    /*
     * Fetch the relocation section to find the idxes to the GOT
     * and the symbols in the .dynsym they refer to.
     */
    reldata = elf_getdata(scn_plt_rel, NULL);
    if (reldata == NULL)
        goto out_elf_end;

    syms = elf_getdata(scn_dynsym, NULL);
    if (syms == NULL)
        goto out_elf_end;

    scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
    if (scn_symstrs == NULL)
        goto out_elf_end;

    symstrs = elf_getdata(scn_symstrs, NULL);
    if (symstrs == NULL)
        goto out_elf_end;

    if (symstrs->d_size == 0)
        goto out_elf_end;

    nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
    plt_offset = shdr_plt.sh_offset;

    if (shdr_rel_plt.sh_type == SHT_RELA) {
        GElf_Rela pos_mem, *pos;

        elf_section__for_each_rela(reldata, pos, pos_mem, idx,
                       nr_rel_entries) {
            symidx = GELF_R_SYM(pos->r_info);
            plt_offset += shdr_plt.sh_entsize;
            gelf_getsym(syms, symidx, &sym);
            snprintf(sympltname, sizeof(sympltname),
                 "%s@plt", elf_sym__name(&sym, symstrs));

            f = symbol__new(plt_offset, shdr_plt.sh_entsize,
                    STB_GLOBAL, sympltname);
            if (!f)
                goto out_elf_end;

            if (filter && filter(map, f))
                symbol__delete(f);
            else {
                symbols__insert(&dso->symbols[map->type], f);
                ++nr;
            }
        }
    } else if (shdr_rel_plt.sh_type == SHT_REL) {
        GElf_Rel pos_mem, *pos;
        elf_section__for_each_rel(reldata, pos, pos_mem, idx,
                      nr_rel_entries) {
            symidx = GELF_R_SYM(pos->r_info);
            plt_offset += shdr_plt.sh_entsize;
            gelf_getsym(syms, symidx, &sym);
            snprintf(sympltname, sizeof(sympltname),
                 "%s@plt", elf_sym__name(&sym, symstrs));

            f = symbol__new(plt_offset, shdr_plt.sh_entsize,
                    STB_GLOBAL, sympltname);
            if (!f)
                goto out_elf_end;

            if (filter && filter(map, f))
                symbol__delete(f);
            else {
                symbols__insert(&dso->symbols[map->type], f);
                ++nr;
            }
        }
    }

    err = 0;
out_elf_end:
    if (err == 0)
        return nr;
    pr_debug("%s: problems reading %s PLT info.\n",
         __func__, dso->long_name);
    return 0;
}

/*
 * Align offset to 4 bytes as needed for note name and descriptor data.
 */
#define NOTE_ALIGN(n) (((n) + 3) & -4U)

static int elf_read_build_id(Elf *elf, void *bf, size_t size)
{
    int err = -1;
    GElf_Ehdr ehdr;
    GElf_Shdr shdr;
    Elf_Data *data;
    Elf_Scn *sec;
    Elf_Kind ek;
    void *ptr;

    if (size < BUILD_ID_SIZE)
        goto out;

    ek = elf_kind(elf);
    if (ek != ELF_K_ELF)
        goto out;

    if (gelf_getehdr(elf, &ehdr) == NULL) {
        pr_err("%s: cannot get elf header.\n", __func__);
        goto out;
    }

    /*
     * Check following sections for notes:
     *   '.note.gnu.build-id'
     *   '.notes'
     *   '.note' (VDSO specific)
     */
    do {
        sec = elf_section_by_name(elf, &ehdr, &shdr,
                      ".note.gnu.build-id", NULL);
        if (sec)
            break;

        sec = elf_section_by_name(elf, &ehdr, &shdr,
                      ".notes", NULL);
        if (sec)
            break;

        sec = elf_section_by_name(elf, &ehdr, &shdr,
                      ".note", NULL);
        if (sec)
            break;

        return err;

    } while (0);

    data = elf_getdata(sec, NULL);
    if (data == NULL)
        goto out;

    ptr = data->d_buf;
    while (ptr < (data->d_buf + data->d_size)) {
        GElf_Nhdr *nhdr = ptr;
        size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
               descsz = NOTE_ALIGN(nhdr->n_descsz);
        const char *name;

        ptr += sizeof(*nhdr);
        name = ptr;
        ptr += namesz;
        if (nhdr->n_type == NT_GNU_BUILD_ID &&
            nhdr->n_namesz == sizeof("GNU")) {
            if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
                size_t sz = min(size, descsz);
                memcpy(bf, ptr, sz);
                memset(bf + sz, 0, size - sz);
                err = descsz;
                break;
            }
        }
        ptr += descsz;
    }

out:
    return err;
}

int filename__read_build_id(const char *filename, void *bf, size_t size)
{
    int fd, err = -1;
    Elf *elf;

    if (size < BUILD_ID_SIZE)
        goto out;

    fd = open(filename, O_RDONLY);
    if (fd < 0)
        goto out;

    elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
    if (elf == NULL) {
        pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
        goto out_close;
    }

    err = elf_read_build_id(elf, bf, size);

    elf_end(elf);
out_close:
    close(fd);
out:
    return err;
}

int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
{
    int fd, err = -1;

    if (size < BUILD_ID_SIZE)
        goto out;

    fd = open(filename, O_RDONLY);
    if (fd < 0)
        goto out;

    while (1) {
        char bf[BUFSIZ];
        GElf_Nhdr nhdr;
        size_t namesz, descsz;

        if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
            break;

        namesz = NOTE_ALIGN(nhdr.n_namesz);
        descsz = NOTE_ALIGN(nhdr.n_descsz);
        if (nhdr.n_type == NT_GNU_BUILD_ID &&
            nhdr.n_namesz == sizeof("GNU")) {
            if (read(fd, bf, namesz) != (ssize_t)namesz)
                break;
            if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
                size_t sz = min(descsz, size);
                if (read(fd, build_id, sz) == (ssize_t)sz) {
                    memset(build_id + sz, 0, size - sz);
                    err = 0;
                    break;
                }
            } else if (read(fd, bf, descsz) != (ssize_t)descsz)
                break;
        } else {
            int n = namesz + descsz;
            if (read(fd, bf, n) != n)
                break;
        }
    }
    close(fd);
out:
    return err;
}

int filename__read_debuglink(const char *filename, char *debuglink,
                 size_t size)
{
    int fd, err = -1;
    Elf *elf;
    GElf_Ehdr ehdr;
    GElf_Shdr shdr;
    Elf_Data *data;
    Elf_Scn *sec;
    Elf_Kind ek;

    fd = open(filename, O_RDONLY);
    if (fd < 0)
        goto out;

    elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
    if (elf == NULL) {
        pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
        goto out_close;
    }

    ek = elf_kind(elf);
    if (ek != ELF_K_ELF)
        goto out_close;

    if (gelf_getehdr(elf, &ehdr) == NULL) {
        pr_err("%s: cannot get elf header.\n", __func__);
        goto out_close;
    }

    sec = elf_section_by_name(elf, &ehdr, &shdr,
                  ".gnu_debuglink", NULL);
    if (sec == NULL)
        goto out_close;

    data = elf_getdata(sec, NULL);
    if (data == NULL)
        goto out_close;

    /* the start of this section is a zero-terminated string */
    strncpy(debuglink, data->d_buf, size);

    elf_end(elf);

out_close:
    close(fd);
out:
    return err;
}

static int dso__swap_init(struct dso *dso, unsigned char eidata)
{
    static unsigned int const endian = 1;

    dso->needs_swap = DSO_SWAP__NO;

    switch (eidata) {
    case ELFDATA2LSB:
        /* We are big endian, DSO is little endian. */
        if (*(unsigned char const *)&endian != 1)
            dso->needs_swap = DSO_SWAP__YES;
        break;

    case ELFDATA2MSB:
        /* We are little endian, DSO is big endian. */
        if (*(unsigned char const *)&endian != 0)
            dso->needs_swap = DSO_SWAP__YES;
        break;

    default:
        pr_err("unrecognized DSO data encoding %d\n", eidata);
        return -EINVAL;
    }

    return 0;
}

bool symsrc__possibly_runtime(struct symsrc *ss)
{
    return ss->dynsym || ss->opdsec;
}

bool symsrc__has_symtab(struct symsrc *ss)
{
    return ss->symtab != NULL;
}

void symsrc__destroy(struct symsrc *ss)
{
    free(ss->name);
    elf_end(ss->elf);
    close(ss->fd);
}

int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
         enum dso_binary_type type)
{
    int err = -1;
    GElf_Ehdr ehdr;
    Elf *elf;
    int fd;

    fd = open(name, O_RDONLY);
    if (fd < 0)
        return -1;

    elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
    if (elf == NULL) {
        pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
        goto out_close;
    }

    if (gelf_getehdr(elf, &ehdr) == NULL) {
        pr_debug("%s: cannot get elf header.\n", __func__);
        goto out_elf_end;
    }

    if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
        goto out_elf_end;

    /* Always reject images with a mismatched build-id: */
    if (dso->has_build_id) {
        u8 build_id[BUILD_ID_SIZE];

        if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
            goto out_elf_end;

        if (!dso__build_id_equal(dso, build_id))
            goto out_elf_end;
    }

    ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
            NULL);
    if (ss->symshdr.sh_type != SHT_SYMTAB)
        ss->symtab = NULL;

    ss->dynsym_idx = 0;
    ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
            &ss->dynsym_idx);
    if (ss->dynshdr.sh_type != SHT_DYNSYM)
        ss->dynsym = NULL;

    ss->opdidx = 0;
    ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
            &ss->opdidx);
    if (ss->opdshdr.sh_type != SHT_PROGBITS)
        ss->opdsec = NULL;

    if (dso->kernel == DSO_TYPE_USER) {
        GElf_Shdr shdr;
        ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
                elf_section_by_name(elf, &ehdr, &shdr,
                             ".gnu.prelink_undo",
                             NULL) != NULL);
    } else {
        ss->adjust_symbols = 0;
    }

    ss->name   = strdup(name);
    if (!ss->name)
        goto out_elf_end;

    ss->elf    = elf;
    ss->fd     = fd;
    ss->ehdr   = ehdr;
    ss->type   = type;

    return 0;

out_elf_end:
    elf_end(elf);
out_close:
    close(fd);
    return err;
}

int dso__load_sym(struct dso *dso, struct map *map,
          struct symsrc *syms_ss, struct symsrc *runtime_ss,
          symbol_filter_t filter, int kmodule)
{
    struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
    struct map *curr_map = map;
    struct dso *curr_dso = dso;
    Elf_Data *symstrs, *secstrs;
    uint32_t nr_syms;
    int err = -1;
    uint32_t idx;
    GElf_Ehdr ehdr;
    GElf_Shdr shdr;
    Elf_Data *syms, *opddata = NULL;
    GElf_Sym sym;
    Elf_Scn *sec, *sec_strndx;
    Elf *elf;
    int nr = 0;

    dso->symtab_type = syms_ss->type;

    if (!syms_ss->symtab) {
        syms_ss->symtab  = syms_ss->dynsym;
        syms_ss->symshdr = syms_ss->dynshdr;
    }

    elf = syms_ss->elf;
    ehdr = syms_ss->ehdr;
    sec = syms_ss->symtab;
    shdr = syms_ss->symshdr;

    if (runtime_ss->opdsec)
        opddata = elf_rawdata(runtime_ss->opdsec, NULL);

    syms = elf_getdata(sec, NULL);
    if (syms == NULL)
        goto out_elf_end;

    sec = elf_getscn(elf, shdr.sh_link);
    if (sec == NULL)
        goto out_elf_end;

    symstrs = elf_getdata(sec, NULL);
    if (symstrs == NULL)
        goto out_elf_end;

    sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
    if (sec_strndx == NULL)
        goto out_elf_end;

    secstrs = elf_getdata(sec_strndx, NULL);
    if (secstrs == NULL)
        goto out_elf_end;

    nr_syms = shdr.sh_size / shdr.sh_entsize;

    memset(&sym, 0, sizeof(sym));
    dso->adjust_symbols = runtime_ss->adjust_symbols;
    elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
        struct symbol *f;
        const char *elf_name = elf_sym__name(&sym, symstrs);
        char *demangled = NULL;
        int is_label = elf_sym__is_label(&sym);
        const char *section_name;
        bool used_opd = false;

        if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
            strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
            kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;

        if (!is_label && !elf_sym__is_a(&sym, map->type))
            continue;

        /* Reject ARM ELF "mapping symbols": these aren't unique and
         * don't identify functions, so will confuse the profile
         * output: */
        if (ehdr.e_machine == EM_ARM) {
            if (!strcmp(elf_name, "$a") ||
                !strcmp(elf_name, "$d") ||
                !strcmp(elf_name, "$t"))
                continue;
        }

        if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
            u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
            u64 *opd = opddata->d_buf + offset;
            sym.st_value = DSO__SWAP(dso, u64, *opd);
            sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
                    sym.st_value);
            used_opd = true;
        }

        sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
        if (!sec)
            goto out_elf_end;

        gelf_getshdr(sec, &shdr);

        if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
            continue;

        section_name = elf_sec__name(&shdr, secstrs);

        /* On ARM, symbols for thumb functions have 1 added to
         * the symbol address as a flag - remove it */
        if ((ehdr.e_machine == EM_ARM) &&
            (map->type == MAP__FUNCTION) &&
            (sym.st_value & 1))
            --sym.st_value;

        if (dso->kernel != DSO_TYPE_USER || kmodule) {
            char dso_name[PATH_MAX];

            if (strcmp(section_name,
                   (curr_dso->short_name +
                    dso->short_name_len)) == 0)
                goto new_symbol;

            if (strcmp(section_name, ".text") == 0) {
                curr_map = map;
                curr_dso = dso;
                goto new_symbol;
            }

            snprintf(dso_name, sizeof(dso_name),
                 "%s%s", dso->short_name, section_name);

            curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
            if (curr_map == NULL) {
                u64 start = sym.st_value;

                if (kmodule)
                    start += map->start + shdr.sh_offset;

                curr_dso = dso__new(dso_name);
                if (curr_dso == NULL)
                    goto out_elf_end;
                curr_dso->kernel = dso->kernel;
                curr_dso->long_name = dso->long_name;
                curr_dso->long_name_len = dso->long_name_len;
                curr_map = map__new2(start, curr_dso,
                             map->type);
                if (curr_map == NULL) {
                    dso__delete(curr_dso);
                    goto out_elf_end;
                }
                curr_map->map_ip = identity__map_ip;
                curr_map->unmap_ip = identity__map_ip;
                curr_dso->symtab_type = dso->symtab_type;
                map_groups__insert(kmap->kmaps, curr_map);
                dsos__add(&dso->node, curr_dso);
                dso__set_loaded(curr_dso, map->type);
            } else
                curr_dso = curr_map->dso;

            goto new_symbol;
        }

        if ((used_opd && runtime_ss->adjust_symbols)
                || (!used_opd && syms_ss->adjust_symbols)) {
            pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
                  "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
                  (u64)sym.st_value, (u64)shdr.sh_addr,
                  (u64)shdr.sh_offset);
            sym.st_value -= shdr.sh_addr - shdr.sh_offset;
        }
        /*
         * We need to figure out if the object was created from C++ sources
         * DWARF DW_compile_unit has this, but we don't always have access
         * to it...
         */
        demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
        if (demangled != NULL)
            elf_name = demangled;
new_symbol:
        f = symbol__new(sym.st_value, sym.st_size,
                GELF_ST_BIND(sym.st_info), elf_name);
        free(demangled);
        if (!f)
            goto out_elf_end;

        if (filter && filter(curr_map, f))
            symbol__delete(f);
        else {
            symbols__insert(&curr_dso->symbols[curr_map->type], f);
            nr++;
        }
    }

    /*
     * For misannotated, zeroed, ASM function sizes.
     */
    if (nr > 0) {
        symbols__fixup_duplicate(&dso->symbols[map->type]);
        symbols__fixup_end(&dso->symbols[map->type]);
        if (kmap) {
            /*
             * We need to fixup this here too because we create new
             * maps here, for things like vsyscall sections.
             */
            __map_groups__fixup_end(kmap->kmaps, map->type);
        }
    }
    err = nr;
out_elf_end:
    return err;
}

void symbol__elf_init(void)
{
    elf_version(EV_CURRENT);
}