1 files changed, 841 insertions, 0 deletions

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
new file mode 100644
index 000000000000..db0cc92cf2ea
--- /dev/null
+++ b/tools/perf/util/symbol-elf.c
@@ -0,0 +1,841 @@
+#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
+
+/**
+ * elf_symtab__for_each_symbol - iterate thru all the symbols
+ *
+ * @syms: struct elf_symtab instance to iterate
+ * @idx: uint32_t idx
+ * @sym: GElf_Sym iterator
+ */
+#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);
+}