#define _GNU_SOURCE
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <libgen.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <fcntl.h>
#include <unistd.h>
#include "build-id.h"
#include "symbol.h"
#include "strlist.h"

#include <libelf.h>
#include <gelf.h>
#include <elf.h>
#include <limits.h>
#include <sys/utsname.h>

#ifndef NT_GNU_BUILD_ID
#define NT_GNU_BUILD_ID 3
#endif

static void dsos__add(struct list_head *head, struct dso *dso);
static struct map *map__new2(u64 start, struct dso *dso, enum map_type type);
static int dso__load_kernel_sym(struct dso *self, struct map *map,
                                symbol_filter_t filter);
static int dso__load_guest_kernel_sym(struct dso *self, struct map *map,
                        symbol_filter_t filter);
static int vmlinux_path__nr_entries;
static char **vmlinux_path;

struct symbol_conf symbol_conf = {
        .exclude_other    = true,
        .use_modules      = true,
        .try_vmlinux_path = true,
};

bool dso__loaded(const struct dso *self, enum map_type type)
{
        return self->loaded & (1 << type);
}

bool dso__sorted_by_name(const struct dso *self, enum map_type type)
{
        return self->sorted_by_name & (1 << type);
}

static void dso__set_sorted_by_name(struct dso *self, enum map_type type)
{
        self->sorted_by_name |= (1 << type);
}

bool symbol_type__is_a(char symbol_type, enum map_type map_type)
{
        switch (map_type) {
        case MAP__FUNCTION:
                return symbol_type == 'T' || symbol_type == 'W';
        case MAP__VARIABLE:
                return symbol_type == 'D' || symbol_type == 'd';
        default:
                return false;
        }
}

static void symbols__fixup_end(struct rb_root *self)
{
        struct rb_node *nd, *prevnd = rb_first(self);
        struct symbol *curr, *prev;

        if (prevnd == NULL)
                return;

        curr = rb_entry(prevnd, struct symbol, rb_node);

        for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
                prev = curr;
                curr = rb_entry(nd, struct symbol, rb_node);

                if (prev->end == prev->start)
                        prev->end = curr->start - 1;
        }

        /* Last entry */
        if (curr->end == curr->start)
                curr->end = roundup(curr->start, 4096);
}

static void __map_groups__fixup_end(struct map_groups *self, enum map_type type)
{
        struct map *prev, *curr;
        struct rb_node *nd, *prevnd = rb_first(&self->maps[type]);

        if (prevnd == NULL)
                return;

        curr = rb_entry(prevnd, struct map, rb_node);

        for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
                prev = curr;
                curr = rb_entry(nd, struct map, rb_node);
                prev->end = curr->start - 1;
        }

        /*
         * We still haven't the actual symbols, so guess the
         * last map final address.
         */
        curr->end = ~0UL;
}

static void map_groups__fixup_end(struct map_groups *self)
{
        int i;
        for (i = 0; i < MAP__NR_TYPES; ++i)
                __map_groups__fixup_end(self, i);
}

static struct symbol *symbol__new(u64 start, u64 len, const char *name)
{
        size_t namelen = strlen(name) + 1;
        struct symbol *self = calloc(1, (symbol_conf.priv_size +
                                         sizeof(*self) + namelen));
        if (self == NULL)
                return NULL;

        if (symbol_conf.priv_size)
                self = ((void *)self) + symbol_conf.priv_size;

        self->start   = start;
        self->end     = len ? start + len - 1 : start;
        self->namelen = namelen - 1;

        pr_debug4("%s: %s %#Lx-%#Lx\n", __func__, name, start, self->end);

        memcpy(self->name, name, namelen);

        return self;
}

void symbol__delete(struct symbol *self)
{
        free(((void *)self) - symbol_conf.priv_size);
}

static size_t symbol__fprintf(struct symbol *self, FILE *fp)
{
        return fprintf(fp, " %llx-%llx %s\n",
                       self->start, self->end, self->name);
}

void dso__set_long_name(struct dso *self, char *name)
{
        if (name == NULL)
                return;
        self->long_name = name;
        self->long_name_len = strlen(name);
}

static void dso__set_short_name(struct dso *self, const char *name)
{
        if (name == NULL)
                return;
        self->short_name = name;
        self->short_name_len = strlen(name);
}

static void dso__set_basename(struct dso *self)
{
        dso__set_short_name(self, basename(self->long_name));
}

struct dso *dso__new(const char *name)
{
        struct dso *self = calloc(1, sizeof(*self) + strlen(name) + 1);

        if (self != NULL) {
                int i;
                strcpy(self->name, name);
                dso__set_long_name(self, self->name);
                dso__set_short_name(self, self->name);
                for (i = 0; i < MAP__NR_TYPES; ++i)
                        self->symbols[i] = self->symbol_names[i] = RB_ROOT;
                self->slen_calculated = 0;
                self->origin = DSO__ORIG_NOT_FOUND;
                self->loaded = 0;
                self->sorted_by_name = 0;
                self->has_build_id = 0;
                self->kernel = DSO_TYPE_USER;
                INIT_LIST_HEAD(&self->node);
        }

        return self;
}

static void symbols__delete(struct rb_root *self)
{
        struct symbol *pos;
        struct rb_node *next = rb_first(self);

        while (next) {
                pos = rb_entry(next, struct symbol, rb_node);
                next = rb_next(&pos->rb_node);
                rb_erase(&pos->rb_node, self);
                symbol__delete(pos);
        }
}

void dso__delete(struct dso *self)
{
        int i;
        for (i = 0; i < MAP__NR_TYPES; ++i)
                symbols__delete(&self->symbols[i]);
        if (self->long_name != self->name)
                free(self->long_name);
        free(self);
}

void dso__set_build_id(struct dso *self, void *build_id)
{
        memcpy(self->build_id, build_id, sizeof(self->build_id));
        self->has_build_id = 1;
}

static void symbols__insert(struct rb_root *self, struct symbol *sym)
{
        struct rb_node **p = &self->rb_node;
        struct rb_node *parent = NULL;
        const u64 ip = sym->start;
        struct symbol *s;

        while (*p != NULL) {
                parent = *p;
                s = rb_entry(parent, struct symbol, rb_node);
                if (ip < s->start)
                        p = &(*p)->rb_left;
                else
                        p = &(*p)->rb_right;
        }
        rb_link_node(&sym->rb_node, parent, p);
        rb_insert_color(&sym->rb_node, self);
}

static struct symbol *symbols__find(struct rb_root *self, u64 ip)
{
        struct rb_node *n;

        if (self == NULL)
                return NULL;

        n = self->rb_node;

        while (n) {
                struct symbol *s = rb_entry(n, struct symbol, rb_node);

                if (ip < s->start)
                        n = n->rb_left;
                else if (ip > s->end)
                        n = n->rb_right;
                else
                        return s;
        }

        return NULL;
}

struct symbol_name_rb_node {
        struct rb_node  rb_node;
        struct symbol   sym;
};

static void symbols__insert_by_name(struct rb_root *self, struct symbol *sym)
{
        struct rb_node **p = &self->rb_node;
        struct rb_node *parent = NULL;
        struct symbol_name_rb_node *symn = ((void *)sym) - sizeof(*parent), *s;

        while (*p != NULL) {
                parent = *p;
                s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
                if (strcmp(sym->name, s->sym.name) < 0)
                        p = &(*p)->rb_left;
                else
                        p = &(*p)->rb_right;
        }
        rb_link_node(&symn->rb_node, parent, p);
        rb_insert_color(&symn->rb_node, self);
}

static void symbols__sort_by_name(struct rb_root *self, struct rb_root *source)
{
        struct rb_node *nd;

        for (nd = rb_first(source); nd; nd = rb_next(nd)) {
                struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
                symbols__insert_by_name(self, pos);
        }
}

static struct symbol *symbols__find_by_name(struct rb_root *self, const char *name)
{
        struct rb_node *n;

        if (self == NULL)
                return NULL;

        n = self->rb_node;

        while (n) {
                struct symbol_name_rb_node *s;
                int cmp;

                s = rb_entry(n, struct symbol_name_rb_node, rb_node);
                cmp = strcmp(name, s->sym.name);

                if (cmp < 0)
                        n = n->rb_left;
                else if (cmp > 0)
                        n = n->rb_right;
                else
                        return &s->sym;
        }

        return NULL;
}

struct symbol *dso__find_symbol(struct dso *self,
                                enum map_type type, u64 addr)
{
        return symbols__find(&self->symbols[type], addr);
}

struct symbol *dso__find_symbol_by_name(struct dso *self, enum map_type type,
                                        const char *name)
{
        return symbols__find_by_name(&self->symbol_names[type], name);
}

void dso__sort_by_name(struct dso *self, enum map_type type)
{
        dso__set_sorted_by_name(self, type);
        return symbols__sort_by_name(&self->symbol_names[type],
                                     &self->symbols[type]);
}

int build_id__sprintf(const u8 *self, int len, char *bf)
{
        char *bid = bf;
        const u8 *raw = self;
        int i;

        for (i = 0; i < len; ++i) {
                sprintf(bid, "%02x", *raw);
                ++raw;
                bid += 2;
        }

        return raw - self;
}

size_t dso__fprintf_buildid(struct dso *self, FILE *fp)
{
        char sbuild_id[BUILD_ID_SIZE * 2 + 1];

        build_id__sprintf(self->build_id, sizeof(self->build_id), sbuild_id);
        return fprintf(fp, "%s", sbuild_id);
}

size_t dso__fprintf(struct dso *self, enum map_type type, FILE *fp)
{
        struct rb_node *nd;
        size_t ret = fprintf(fp, "dso: %s (", self->short_name);

        if (self->short_name != self->long_name)
                ret += fprintf(fp, "%s, ", self->long_name);
        ret += fprintf(fp, "%s, %sloaded, ", map_type__name[type],
                       self->loaded ? "" : "NOT ");
        ret += dso__fprintf_buildid(self, fp);
        ret += fprintf(fp, ")\n");
        for (nd = rb_first(&self->symbols[type]); nd; nd = rb_next(nd)) {
                struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
                ret += symbol__fprintf(pos, fp);
        }

        return ret;
}

int kallsyms__parse(const char *filename, void *arg,
                    int (*process_symbol)(void *arg, const char *name,
                                                     char type, u64 start))
{
        char *line = NULL;
        size_t n;
        int err = 0;
        FILE *file = fopen(filename, "r");

        if (file == NULL)
                goto out_failure;

        while (!feof(file)) {
                u64 start;
                int line_len, len;
                char symbol_type;
                char *symbol_name;

                line_len = getline(&line, &n, file);
                if (line_len < 0 || !line)
                        break;

                line[--line_len] = '\0'; /* \n */

                len = hex2u64(line, &start);

                len++;
                if (len + 2 >= line_len)
                        continue;

                symbol_type = toupper(line[len]);
                symbol_name = line + len + 2;

                err = process_symbol(arg, symbol_name, symbol_type, start);
                if (err)
                        break;
        }

        free(line);
        fclose(file);
        return err;

out_failure:
        return -1;
}

struct process_kallsyms_args {
        struct map *map;
        struct dso *dso;
};

static int map__process_kallsym_symbol(void *arg, const char *name,
                                       char type, u64 start)
{
        struct symbol *sym;
        struct process_kallsyms_args *a = arg;
        struct rb_root *root = &a->dso->symbols[a->map->type];

        if (!symbol_type__is_a(type, a->map->type))
                return 0;

        /*
         * Will fix up the end later, when we have all symbols sorted.
         */
        sym = symbol__new(start, 0, name);

        if (sym == NULL)
                return -ENOMEM;
        /*
         * We will pass the symbols to the filter later, in
         * map__split_kallsyms, when we have split the maps per module
         */
        symbols__insert(root, sym);

        return 0;
}

/*
 * Loads the function entries in /proc/kallsyms into kernel_map->dso,
 * so that we can in the next step set the symbol ->end address and then
 * call kernel_maps__split_kallsyms.
 */
static int dso__load_all_kallsyms(struct dso *self, const char *filename,
                                  struct map *map)
{
        struct process_kallsyms_args args = { .map = map, .dso = self, };
        return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
}

/*
 * Split the symbols into maps, making sure there are no overlaps, i.e. the
 * kernel range is broken in several maps, named [kernel].N, as we don't have
 * the original ELF section names vmlinux have.
 */
static int dso__split_kallsyms(struct dso *self, struct map *map,
                               symbol_filter_t filter)
{
        struct map_groups *kmaps = map__kmap(map)->kmaps;
        struct machine *machine = kmaps->machine;
        struct map *curr_map = map;
        struct symbol *pos;
        int count = 0;
        struct rb_root *root = &self->symbols[map->type];
        struct rb_node *next = rb_first(root);
        int kernel_range = 0;

        while (next) {
                char *module;

                pos = rb_entry(next, struct symbol, rb_node);
                next = rb_next(&pos->rb_node);

                module = strchr(pos->name, '\t');
                if (module) {
                        if (!symbol_conf.use_modules)
                                goto discard_symbol;

                        *module++ = '\0';

                        if (strcmp(curr_map->dso->short_name, module)) {
                                if (curr_map != map &&
                                    self->kernel == DSO_TYPE_GUEST_KERNEL &&
                                    machine__is_default_guest(machine)) {
                                        /*
                                         * We assume all symbols of a module are
                                         * continuous in * kallsyms, so curr_map
                                         * points to a module and all its
                                         * symbols are in its kmap. Mark it as
                                         * loaded.
                                         */
                                        dso__set_loaded(curr_map->dso,
                                                        curr_map->type);
                                }

                                curr_map = map_groups__find_by_name(kmaps,
                                                        map->type, module);
                                if (curr_map == NULL) {
                                        pr_debug("%s/proc/{kallsyms,modules} "
                                                 "inconsistency while looking "
                                                 "for \"%s\" module!\n",
                                                 machine->root_dir, module);
                                        curr_map = map;
                                        goto discard_symbol;
                                }

                                if (curr_map->dso->loaded &&
                                    !machine__is_default_guest(machine))
                                        goto discard_symbol;
                        }
                        /*
                         * So that we look just like we get from .ko files,
                         * i.e. not prelinked, relative to map->start.
                         */
                        pos->start = curr_map->map_ip(curr_map, pos->start);
                        pos->end   = curr_map->map_ip(curr_map, pos->end);
                } else if (curr_map != map) {
                        char dso_name[PATH_MAX];
                        struct dso *dso;

                        if (self->kernel == DSO_TYPE_GUEST_KERNEL)
                                snprintf(dso_name, sizeof(dso_name),
                                        "[guest.kernel].%d",
                                        kernel_range++);
                        else
                                snprintf(dso_name, sizeof(dso_name),
                                        "[kernel].%d",
                                        kernel_range++);

                        dso = dso__new(dso_name);
                        if (dso == NULL)
                                return -1;

                        dso->kernel = self->kernel;

                        curr_map = map__new2(pos->start, dso, map->type);
                        if (curr_map == NULL) {
                                dso__delete(dso);
                                return -1;
                        }

                        curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
                        map_groups__insert(kmaps, curr_map);
                        ++kernel_range;
                }

                if (filter && filter(curr_map, pos)) {
discard_symbol:         rb_erase(&pos->rb_node, root);
                        symbol__delete(pos);
                } else {
                        if (curr_map != map) {
                                rb_erase(&pos->rb_node, root);
                                symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
                        }
                        count++;
                }
        }

        if (curr_map != map &&
            self->kernel == DSO_TYPE_GUEST_KERNEL &&
            machine__is_default_guest(kmaps->machine)) {
                dso__set_loaded(curr_map->dso, curr_map->type);
        }

        return count;
}

int dso__load_kallsyms(struct dso *self, const char *filename,
                       struct map *map, symbol_filter_t filter)
{
        if (dso__load_all_kallsyms(self, filename, map) < 0)
                return -1;

        symbols__fixup_end(&self->symbols[map->type]);
        if (self->kernel == DSO_TYPE_GUEST_KERNEL)
                self->origin = DSO__ORIG_GUEST_KERNEL;
        else
                self->origin = DSO__ORIG_KERNEL;

        return dso__split_kallsyms(self, map, filter);
}

static int dso__load_perf_map(struct dso *self, struct map *map,
                              symbol_filter_t filter)
{
        char *line = NULL;
        size_t n;
        FILE *file;
        int nr_syms = 0;

        file = fopen(self->long_name, "r");
        if (file == NULL)
                goto out_failure;

        while (!feof(file)) {
                u64 start, size;
                struct symbol *sym;
                int line_len, len;

                line_len = getline(&line, &n, file);
                if (line_len < 0)
                        break;

                if (!line)
                        goto out_failure;

                line[--line_len] = '\0'; /* \n */

                len = hex2u64(line, &start);

                len++;
                if (len + 2 >= line_len)
                        continue;

                len += hex2u64(line + len, &size);

                len++;
                if (len + 2 >= line_len)
                        continue;

                sym = symbol__new(start, size, line + len);

                if (sym == NULL)
                        goto out_delete_line;

                if (filter && filter(map, sym))
                        symbol__delete(sym);
                else {
                        symbols__insert(&self->symbols[map->type], sym);
                        nr_syms++;
                }
        }

        free(line);
        fclose(file);

        return nr_syms;

out_delete_line:
        free(line);
out_failure:
        return -1;
}

/**
 * elf_symtab__for_each_symbol - iterate thru all the symbols
 *
 * @self: 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 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 inline const char *elf_sym__name(const GElf_Sym *sym,
                                        const Elf_Data *symstrs)
{
        return symstrs->d_buf + sym->st_name;
}

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;

        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).
 */
static int dso__synthesize_plt_symbols(struct  dso *self, 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, fd, err = 0;

        fd = open(self->long_name, O_RDONLY);
        if (fd < 0)
                goto out;

        elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
        if (elf == NULL)
                goto out_close;

        if (gelf_getehdr(elf, &ehdr) == NULL)
                goto out_elf_end;

        scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym,
                                         ".dynsym", &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;

        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,
                                        sympltname);
                        if (!f)
                                goto out_elf_end;

                        if (filter && filter(map, f))
                                symbol__delete(f);
                        else {
                                symbols__insert(&self->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,
                                        sympltname);
                        if (!f)
                                goto out_elf_end;

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

        err = 0;
out_elf_end:
        elf_end(elf);
out_close:
        close(fd);

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

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

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

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

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

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

        sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
        if (sec == NULL) {
                sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL);
                if (sec == NULL)
                        goto out_elf_end;
        }

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

        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;

                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;

                sec = elf_getscn(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);

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

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

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

                        snprintf(dso_name, sizeof(dso_name),
                                 "%s%s", self->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 = self->kernel;
                                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->origin = self->origin;
                                map_groups__insert(kmap->kmaps, curr_map);
                                dsos__add(&self->node, curr_dso);
                                dso__set_loaded(curr_dso, map->type);
                        } else
                                curr_dso = curr_map->dso;

                        goto new_symbol;
                }

                if (curr_dso->adjust_symbols) {
                        pr_debug4("%s: adjusting symbol: st_value: %#Lx "
                                  "sh_addr: %#Lx sh_offset: %#Lx\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, 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_end(&self->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:
        elf_end(elf);
out_close:
        return err;
}

static bool dso__build_id_equal(const struct dso *self, u8 *build_id)
{
        return memcmp(self->build_id, build_id, sizeof(self->build_id)) == 0;
}

bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
{
        bool have_build_id = false;
        struct dso *pos;

        list_for_each_entry(pos, head, node) {
                if (with_hits && !pos->hit)
                        continue;
                if (pos->has_build_id) {
                        have_build_id = true;
                        continue;
                }
                if (filename__read_build_id(pos->long_name, pos->build_id,
                                            sizeof(pos->build_id)) > 0) {
                        have_build_id     = true;
                        pos->has_build_id = true;
                }
        }

        return have_build_id;
}

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

int filename__read_build_id(const char *filename, void *bf, size_t size)
{
        int fd, err = -1;
        GElf_Ehdr ehdr;
        GElf_Shdr shdr;
        Elf_Data *data;
        Elf_Scn *sec;
        Elf_Kind ek;
        void *ptr;
        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;
        }

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

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

        sec = elf_section_by_name(elf, &ehdr, &shdr,
                                  ".note.gnu.build-id", NULL);
        if (sec == NULL) {
                sec = elf_section_by_name(elf, &ehdr, &shdr,
                                          ".notes", NULL);
                if (sec == NULL)
                        goto out_elf_end;
        }

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

        ptr = data->d_buf;
        while (ptr < (data->d_buf + data->d_size)) {
                GElf_Nhdr *nhdr = ptr;
                int 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) {
                                memcpy(bf, ptr, BUILD_ID_SIZE);
                                err = BUILD_ID_SIZE;
                                break;
                        }
                }
                ptr += descsz;
        }
out_elf_end:
        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;
                int 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) != namesz)
                                break;
                        if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
                                if (read(fd, build_id,
                                    BUILD_ID_SIZE) == BUILD_ID_SIZE) {
                                        err = 0;
                                        break;
                                }
                        } else if (read(fd, bf, descsz) != descsz)
                                break;
                } else {
                        int n = namesz + descsz;
                        if (read(fd, bf, n) != n)
                                break;
                }
        }
        close(fd);
out:
        return err;
}

char dso__symtab_origin(const struct dso *self)
{
        static const char origin[] = {
                [DSO__ORIG_KERNEL] =   'k',
                [DSO__ORIG_JAVA_JIT] = 'j',
                [DSO__ORIG_BUILD_ID_CACHE] = 'B',
                [DSO__ORIG_FEDORA] =   'f',
                [DSO__ORIG_UBUNTU] =   'u',
                [DSO__ORIG_BUILDID] =  'b',
                [DSO__ORIG_DSO] =      'd',
                [DSO__ORIG_KMODULE] =  'K',
                [DSO__ORIG_GUEST_KERNEL] =  'g',
                [DSO__ORIG_GUEST_KMODULE] =  'G',
        };

        if (self == NULL || self->origin == DSO__ORIG_NOT_FOUND)
                return '!';
        return origin[self->origin];
}

int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
{
        int size = PATH_MAX;
        char *name;
        u8 build_id[BUILD_ID_SIZE];
        int ret = -1;
        int fd;
        struct machine *machine;
        const char *root_dir;

        dso__set_loaded(self, map->type);

        if (self->kernel == DSO_TYPE_KERNEL)
                return dso__load_kernel_sym(self, map, filter);
        else if (self->kernel == DSO_TYPE_GUEST_KERNEL)
                return dso__load_guest_kernel_sym(self, map, filter);

        if (map->groups && map->groups->machine)
                machine = map->groups->machine;
        else
                machine = NULL;

        name = malloc(size);
        if (!name)
                return -1;

        self->adjust_symbols = 0;

        if (strncmp(self->name, "/tmp/perf-", 10) == 0) {
                ret = dso__load_perf_map(self, map, filter);
                self->origin = ret > 0 ? DSO__ORIG_JAVA_JIT :
                                         DSO__ORIG_NOT_FOUND;
                return ret;
        }

        self->origin = DSO__ORIG_BUILD_ID_CACHE;
        if (dso__build_id_filename(self, name, size) != NULL)
                goto open_file;
more:
        do {
                self->origin++;
                switch (self->origin) {
                case DSO__ORIG_FEDORA:
                        snprintf(name, size, "/usr/lib/debug%s.debug",
                                 self->long_name);
                        break;
                case DSO__ORIG_UBUNTU:
                        snprintf(name, size, "/usr/lib/debug%s",
                                 self->long_name);
                        break;
                case DSO__ORIG_BUILDID:
                        if (filename__read_build_id(self->long_name, build_id,
                                                    sizeof(build_id))) {
                                char build_id_hex[BUILD_ID_SIZE * 2 + 1];
                                build_id__sprintf(build_id, sizeof(build_id),
                                                  build_id_hex);
                                snprintf(name, size,
                                         "/usr/lib/debug/.build-id/%.2s/%s.debug",
                                        build_id_hex, build_id_hex + 2);
                                if (self->has_build_id)
                                        goto compare_build_id;
                                break;
                        }
                        self->origin++;
                        /* Fall thru */
                case DSO__ORIG_DSO:
                        snprintf(name, size, "%s", self->long_name);
                        break;
                case DSO__ORIG_GUEST_KMODULE:
                        if (map->groups && map->groups->machine)
                                root_dir = map->groups->machine->root_dir;
                        else
                                root_dir = "";
                        snprintf(name, size, "%s%s", root_dir, self->long_name);
                        break;

                default:
                        goto out;
                }

                if (self->has_build_id) {
                        if (filename__read_build_id(name, build_id,
                                                    sizeof(build_id)) < 0)
                                goto more;
compare_build_id:
                        if (!dso__build_id_equal(self, build_id))
                                goto more;
                }
open_file:
                fd = open(name, O_RDONLY);
        } while (fd < 0);

        ret = dso__load_sym(self, map, name, fd, filter, 0);
        close(fd);

        /*
         * Some people seem to have debuginfo files _WITHOUT_ debug info!?!?
         */
        if (!ret)
                goto more;

        if (ret > 0) {
                int nr_plt = dso__synthesize_plt_symbols(self, map, filter);
                if (nr_plt > 0)
                        ret += nr_plt;
        }
out:
        free(name);
        if (ret < 0 && strstr(self->name, " (deleted)") != NULL)
                return 0;
        return ret;
}

struct map *map_groups__find_by_name(struct map_groups *self,
                                     enum map_type type, const char *name)
{
        struct rb_node *nd;

        for (nd = rb_first(&self->maps[type]); nd; nd = rb_next(nd)) {
                struct map *map = rb_entry(nd, struct map, rb_node);

                if (map->dso && strcmp(map->dso->short_name, name) == 0)
                        return map;
        }

        return NULL;
}

static int dso__kernel_module_get_build_id(struct dso *self,
                                const char *root_dir)
{
        char filename[PATH_MAX];
        /*
         * kernel module short names are of the form "[module]" and
         * we need just "module" here.
         */
        const char *name = self->short_name + 1;

        snprintf(filename, sizeof(filename),
                 "%s/sys/module/%.*s/notes/.note.gnu.build-id",
                 root_dir, (int)strlen(name) - 1, name);

        if (sysfs__read_build_id(filename, self->build_id,
                                 sizeof(self->build_id)) == 0)
                self->has_build_id = true;

        return 0;
}

static int map_groups__set_modules_path_dir(struct map_groups *self,
                                const char *dir_name)
{
        struct dirent *dent;
        DIR *dir = opendir(dir_name);
        int ret = 0;

        if (!dir) {
                pr_debug("%s: cannot open %s dir\n", __func__, dir_name);
                return -1;
        }

        while ((dent = readdir(dir)) != NULL) {
                char path[PATH_MAX];
                struct stat st;

                /*sshfs might return bad dent->d_type, so we have to stat*/
                sprintf(path, "%s/%s", dir_name, dent->d_name);
                if (stat(path, &st))
                        continue;

                if (S_ISDIR(st.st_mode)) {
                        if (!strcmp(dent->d_name, ".") ||
                            !strcmp(dent->d_name, ".."))
                                continue;

                        snprintf(path, sizeof(path), "%s/%s",
                                 dir_name, dent->d_name);
                        ret = map_groups__set_modules_path_dir(self, path);
                        if (ret < 0)
                                goto out;
                } else {
                        char *dot = strrchr(dent->d_name, '.'),
                             dso_name[PATH_MAX];
                        struct map *map;
                        char *long_name;

                        if (dot == NULL || strcmp(dot, ".ko"))
                                continue;
                        snprintf(dso_name, sizeof(dso_name), "[%.*s]",
                                 (int)(dot - dent->d_name), dent->d_name);

                        strxfrchar(dso_name, '-', '_');
                        map = map_groups__find_by_name(self, MAP__FUNCTION, dso_name);
                        if (map == NULL)
                                continue;

                        snprintf(path, sizeof(path), "%s/%s",
                                 dir_name, dent->d_name);

                        long_name = strdup(path);
                        if (long_name == NULL) {
                                ret = -1;
                                goto out;
                        }
                        dso__set_long_name(map->dso, long_name);
                        dso__kernel_module_get_build_id(map->dso, "");
                }
        }

out:
        closedir(dir);
        return ret;
}

static char *get_kernel_version(const char *root_dir)
{
        char version[PATH_MAX];
        FILE *file;
        char *name, *tmp;
        const char *prefix = "Linux version ";

        sprintf(version, "%s/proc/version", root_dir);
        file = fopen(version, "r");
        if (!file)
                return NULL;

        version[0] = '\0';
        tmp = fgets(version, sizeof(version), file);
        fclose(file);

        name = strstr(version, prefix);
        if (!name)
                return NULL;
        name += strlen(prefix);
        tmp = strchr(name, ' ');
        if (tmp)
                *tmp = '\0';

        return strdup(name);
}

static int machine__set_modules_path(struct machine *self)
{
        char *version;
        char modules_path[PATH_MAX];

        version = get_kernel_version(self->root_dir);
        if (!version)
                return -1;

        snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s/kernel",
                 self->root_dir, version);
        free(version);

        return map_groups__set_modules_path_dir(&self->kmaps, modules_path);
}

/*
 * Constructor variant for modules (where we know from /proc/modules where
 * they are loaded) and for vmlinux, where only after we load all the
 * symbols we'll know where it starts and ends.
 */
static struct map *map__new2(u64 start, struct dso *dso, enum map_type type)
{
        struct map *self = calloc(1, (sizeof(*self) +
                                      (dso->kernel ? sizeof(struct kmap) : 0)));
        if (self != NULL) {
                /*
                 * ->end will be filled after we load all the symbols
                 */
                map__init(self, type, start, 0, 0, dso);
        }

        return self;
}

struct map *machine__new_module(struct machine *self, u64 start,
                                const char *filename)
{
        struct map *map;
        struct dso *dso = __dsos__findnew(&self->kernel_dsos, filename);

        if (dso == NULL)
                return NULL;

        map = map__new2(start, dso, MAP__FUNCTION);
        if (map == NULL)
                return NULL;

        if (machine__is_host(self))
                dso->origin = DSO__ORIG_KMODULE;
        else
                dso->origin = DSO__ORIG_GUEST_KMODULE;
        map_groups__insert(&self->kmaps, map);
        return map;
}

static int machine__create_modules(struct machine *self)
{
        char *line = NULL;
        size_t n;
        FILE *file;
        struct map *map;
        const char *modules;
        char path[PATH_MAX];

        if (machine__is_default_guest(self))
                modules = symbol_conf.default_guest_modules;
        else {
                sprintf(path, "%s/proc/modules", self->root_dir);
                modules = path;
        }

        file = fopen(modules, "r");
        if (file == NULL)
                return -1;

        while (!feof(file)) {
                char name[PATH_MAX];
                u64 start;
                char *sep;
                int line_len;

                line_len = getline(&line, &n, file);
                if (line_len < 0)
                        break;

                if (!line)
                        goto out_failure;

                line[--line_len] = '\0'; /* \n */

                sep = strrchr(line, 'x');
                if (sep == NULL)
                        continue;

                hex2u64(sep + 1, &start);

                sep = strchr(line, ' ');
                if (sep == NULL)
                        continue;

                *sep = '\0';

                snprintf(name, sizeof(name), "[%s]", line);
                map = machine__new_module(self, start, name);
                if (map == NULL)
                        goto out_delete_line;
                dso__kernel_module_get_build_id(map->dso, self->root_dir);
        }

        free(line);
        fclose(file);

        return machine__set_modules_path(self);

out_delete_line:
        free(line);
out_failure:
        return -1;
}

static int dso__load_vmlinux(struct dso *self, struct map *map,
                             const char *vmlinux, symbol_filter_t filter)
{
        int err = -1, fd;

        if (self->has_build_id) {
                u8 build_id[BUILD_ID_SIZE];

                if (filename__read_build_id(vmlinux, build_id,
                                            sizeof(build_id)) < 0) {
                        pr_debug("No build_id in %s, ignoring it\n", vmlinux);
                        return -1;
                }
                if (!dso__build_id_equal(self, build_id)) {
                        char expected_build_id[BUILD_ID_SIZE * 2 + 1],
                             vmlinux_build_id[BUILD_ID_SIZE * 2 + 1];

                        build_id__sprintf(self->build_id,
                                          sizeof(self->build_id),
                                          expected_build_id);
                        build_id__sprintf(build_id, sizeof(build_id),
                                          vmlinux_build_id);
                        pr_debug("build_id in %s is %s while expected is %s, "
                                 "ignoring it\n", vmlinux, vmlinux_build_id,
                                 expected_build_id);
                        return -1;
                }
        }

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

        dso__set_loaded(self, map->type);
        err = dso__load_sym(self, map, vmlinux, fd, filter, 0);
        close(fd);

        if (err > 0)
                pr_debug("Using %s for symbols\n", vmlinux);

        return err;
}

int dso__load_vmlinux_path(struct dso *self, struct map *map,
                           symbol_filter_t filter)
{
        int i, err = 0;
        char *filename;

        pr_debug("Looking at the vmlinux_path (%d entries long)\n",
                 vmlinux_path__nr_entries + 1);

        filename = dso__build_id_filename(self, NULL, 0);
        if (filename != NULL) {
                err = dso__load_vmlinux(self, map, filename, filter);
                if (err > 0) {
                        dso__set_long_name(self, filename);
                        goto out;
                }
                free(filename);
        }

        for (i = 0; i < vmlinux_path__nr_entries; ++i) {
                err = dso__load_vmlinux(self, map, vmlinux_path[i], filter);
                if (err > 0) {
                        dso__set_long_name(self, strdup(vmlinux_path[i]));
                        break;
                }
        }
out:
        return err;
}

static int dso__load_kernel_sym(struct dso *self, struct map *map,
                                symbol_filter_t filter)
{
        int err;
        const char *kallsyms_filename = NULL;
        char *kallsyms_allocated_filename = NULL;
        /*
         * Step 1: if the user specified a vmlinux filename, use it and only
         * it, reporting errors to the user if it cannot be used.
         *
         * For instance, try to analyse an ARM perf.data file _without_ a
         * build-id, or if the user specifies the wrong path to the right
         * vmlinux file, obviously we can't fallback to another vmlinux (a
         * x86_86 one, on the machine where analysis is being performed, say),
         * or worse, /proc/kallsyms.
         *
         * If the specified file _has_ a build-id and there is a build-id
         * section in the perf.data file, we will still do the expected
         * validation in dso__load_vmlinux and will bail out if they don't
         * match.
         */
        if (symbol_conf.vmlinux_name != NULL) {
                err = dso__load_vmlinux(self, map,
                                        symbol_conf.vmlinux_name, filter);
                if (err > 0) {
                        dso__set_long_name(self,
                                           strdup(symbol_conf.vmlinux_name));
                        goto out_fixup;
                }
                return err;
        }

        if (vmlinux_path != NULL) {
                err = dso__load_vmlinux_path(self, map, filter);
                if (err > 0)
                        goto out_fixup;
        }

        /*
         * Say the kernel DSO was created when processing the build-id header table,
         * we have a build-id, so check if it is the same as the running kernel,
         * using it if it is.
         */
        if (self->has_build_id) {
                u8 kallsyms_build_id[BUILD_ID_SIZE];
                char sbuild_id[BUILD_ID_SIZE * 2 + 1];

                if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
                                         sizeof(kallsyms_build_id)) == 0) {
                        if (dso__build_id_equal(self, kallsyms_build_id)) {
                                kallsyms_filename = "/proc/kallsyms";
                                goto do_kallsyms;
                        }
                }
                /*
                 * Now look if we have it on the build-id cache in
                 * $HOME/.debug/[kernel.kallsyms].
                 */
                build_id__sprintf(self->build_id, sizeof(self->build_id),
                                  sbuild_id);

                if (asprintf(&kallsyms_allocated_filename,
                             "%s/.debug/[kernel.kallsyms]/%s",
                             getenv("HOME"), sbuild_id) == -1) {
                        pr_err("Not enough memory for kallsyms file lookup\n");
                        return -1;
                }

                kallsyms_filename = kallsyms_allocated_filename;

                if (access(kallsyms_filename, F_OK)) {
                        pr_err("No kallsyms or vmlinux with build-id %s "
                               "was found\n", sbuild_id);
                        free(kallsyms_allocated_filename);
                        return -1;
                }
        } else {
                /*
                 * Last resort, if we don't have a build-id and couldn't find
                 * any vmlinux file, try the running kernel kallsyms table.
                 */
                kallsyms_filename = "/proc/kallsyms";
        }

do_kallsyms:
        err = dso__load_kallsyms(self, kallsyms_filename, map, filter);
        if (err > 0)
                pr_debug("Using %s for symbols\n", kallsyms_filename);
        free(kallsyms_allocated_filename);

        if (err > 0) {
out_fixup:
                if (kallsyms_filename != NULL)
                        dso__set_long_name(self, strdup("[kernel.kallsyms]"));
                map__fixup_start(map);
                map__fixup_end(map);
        }

        return err;
}

static int dso__load_guest_kernel_sym(struct dso *self, struct map *map,
                                symbol_filter_t filter)
{
        int err;
        const char *kallsyms_filename = NULL;
        struct machine *machine;
        char path[PATH_MAX];

        if (!map->groups) {
                pr_debug("Guest kernel map hasn't the point to groups\n");
                return -1;
        }
        machine = map->groups->machine;

        if (machine__is_default_guest(machine)) {
                /*
                 * if the user specified a vmlinux filename, use it and only
                 * it, reporting errors to the user if it cannot be used.
                 * Or use file guest_kallsyms inputted by user on commandline
                 */
                if (symbol_conf.default_guest_vmlinux_name != NULL) {
                        err = dso__load_vmlinux(self, map,
                                symbol_conf.default_guest_vmlinux_name, filter);
                        goto out_try_fixup;
                }

                kallsyms_filename = symbol_conf.default_guest_kallsyms;
                if (!kallsyms_filename)
                        return -1;
        } else {
                sprintf(path, "%s/proc/kallsyms", machine->root_dir);
                kallsyms_filename = path;
        }

        err = dso__load_kallsyms(self, kallsyms_filename, map, filter);
        if (err > 0)
                pr_debug("Using %s for symbols\n", kallsyms_filename);

out_try_fixup:
        if (err > 0) {
                if (kallsyms_filename != NULL) {
                        machine__mmap_name(machine, path, sizeof(path));
                        dso__set_long_name(self, strdup(path));
                }
                map__fixup_start(map);
                map__fixup_end(map);
        }

        return err;
}

static void dsos__add(struct list_head *head, struct dso *dso)
{
        list_add_tail(&dso->node, head);
}

static struct dso *dsos__find(struct list_head *head, const char *name)
{
        struct dso *pos;

        list_for_each_entry(pos, head, node)
                if (strcmp(pos->long_name, name) == 0)
                        return pos;
        return NULL;
}

struct dso *__dsos__findnew(struct list_head *head, const char *name)
{
        struct dso *dso = dsos__find(head, name);

        if (!dso) {
                dso = dso__new(name);
                if (dso != NULL) {
                        dsos__add(head, dso);
                        dso__set_basename(dso);
                }
        }

        return dso;
}

size_t __dsos__fprintf(struct list_head *head, FILE *fp)
{
        struct dso *pos;
        size_t ret = 0;

        list_for_each_entry(pos, head, node) {
                int i;
                for (i = 0; i < MAP__NR_TYPES; ++i)
                        ret += dso__fprintf(pos, i, fp);
        }

        return ret;
}

size_t machines__fprintf_dsos(struct rb_root *self, FILE *fp)
{
        struct rb_node *nd;
        size_t ret = 0;

        for (nd = rb_first(self); nd; nd = rb_next(nd)) {
                struct machine *pos = rb_entry(nd, struct machine, rb_node);
                ret += __dsos__fprintf(&pos->kernel_dsos, fp);
                ret += __dsos__fprintf(&pos->user_dsos, fp);
        }

        return ret;
}

static size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
                                      bool with_hits)
{
        struct dso *pos;
        size_t ret = 0;

        list_for_each_entry(pos, head, node) {
                if (with_hits && !pos->hit)
                        continue;
                ret += dso__fprintf_buildid(pos, fp);
                ret += fprintf(fp, " %s\n", pos->long_name);
        }
        return ret;
}

size_t machine__fprintf_dsos_buildid(struct machine *self, FILE *fp, bool with_hits)
{
        return __dsos__fprintf_buildid(&self->kernel_dsos, fp, with_hits) +
               __dsos__fprintf_buildid(&self->user_dsos, fp, with_hits);
}

size_t machines__fprintf_dsos_buildid(struct rb_root *self, FILE *fp, bool with_hits)
{
        struct rb_node *nd;
        size_t ret = 0;

        for (nd = rb_first(self); nd; nd = rb_next(nd)) {
                struct machine *pos = rb_entry(nd, struct machine, rb_node);
                ret += machine__fprintf_dsos_buildid(pos, fp, with_hits);
        }
        return ret;
}

struct dso *dso__new_kernel(const char *name)
{
        struct dso *self = dso__new(name ?: "[kernel.kallsyms]");

        if (self != NULL) {
                dso__set_short_name(self, "[kernel]");
                self->kernel = DSO_TYPE_KERNEL;
        }

        return self;
}

static struct dso *dso__new_guest_kernel(struct machine *machine,
                                        const char *name)
{
        char bf[PATH_MAX];
        struct dso *self = dso__new(name ?: machine__mmap_name(machine, bf, sizeof(bf)));

        if (self != NULL) {
                dso__set_short_name(self, "[guest.kernel]");
                self->kernel = DSO_TYPE_GUEST_KERNEL;
        }

        return self;
}

void dso__read_running_kernel_build_id(struct dso *self, struct machine *machine)
{
        char path[PATH_MAX];

        if (machine__is_default_guest(machine))

                return;
        sprintf(path, "%s/sys/kernel/notes", machine->root_dir);
        if (sysfs__read_build_id(path, self->build_id,
                                 sizeof(self->build_id)) == 0)
                self->has_build_id = true;
}

static struct dso *machine__create_kernel(struct machine *self)
{
        const char *vmlinux_name = NULL;
        struct dso *kernel;

        if (machine__is_host(self)) {
                vmlinux_name = symbol_conf.vmlinux_name;
                kernel = dso__new_kernel(vmlinux_name);
        } else {
                if (machine__is_default_guest(self))
                        vmlinux_name = symbol_conf.default_guest_vmlinux_name;
                kernel = dso__new_guest_kernel(self, vmlinux_name);
        }

        if (kernel != NULL) {
                dso__read_running_kernel_build_id(kernel, self);
                dsos__add(&self->kernel_dsos, kernel);
        }
        return kernel;
}

int __machine__create_kernel_maps(struct machine *self, struct dso *kernel)
{
        enum map_type type;

        for (type = 0; type < MAP__NR_TYPES; ++type) {
                struct kmap *kmap;

                self->vmlinux_maps[type] = map__new2(0, kernel, type);
                if (self->vmlinux_maps[type] == NULL)
                        return -1;

                self->vmlinux_maps[type]->map_ip =
                        self->vmlinux_maps[type]->unmap_ip = identity__map_ip;

                kmap = map__kmap(self->vmlinux_maps[type]);
                kmap->kmaps = &self->kmaps;
                map_groups__insert(&self->kmaps, self->vmlinux_maps[type]);
        }

        return 0;
}

int machine__create_kernel_maps(struct machine *self)
{
        struct dso *kernel = machine__create_kernel(self);

        if (kernel == NULL ||
            __machine__create_kernel_maps(self, kernel) < 0)
                return -1;

        if (symbol_conf.use_modules && machine__create_modules(self) < 0)
                pr_debug("Problems creating module maps, continuing anyway...\n");
        /*
         * Now that we have all the maps created, just set the ->end of them:
         */
        map_groups__fixup_end(&self->kmaps);
        return 0;
}

static void vmlinux_path__exit(void)
{
        while (--vmlinux_path__nr_entries >= 0) {
                free(vmlinux_path[vmlinux_path__nr_entries]);
                vmlinux_path[vmlinux_path__nr_entries] = NULL;
        }

        free(vmlinux_path);
        vmlinux_path = NULL;
}

static int vmlinux_path__init(void)
{
        struct utsname uts;
        char bf[PATH_MAX];

        if (uname(&uts) < 0)
                return -1;

        vmlinux_path = malloc(sizeof(char *) * 5);
        if (vmlinux_path == NULL)
                return -1;

        vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
        if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
                goto out_fail;
        ++vmlinux_path__nr_entries;
        vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
        if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
                goto out_fail;
        ++vmlinux_path__nr_entries;
        snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
        vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
        if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
                goto out_fail;
        ++vmlinux_path__nr_entries;
        snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
        vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
        if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
                goto out_fail;
        ++vmlinux_path__nr_entries;
        snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
                 uts.release);
        vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
        if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
                goto out_fail;
        ++vmlinux_path__nr_entries;

        return 0;

out_fail:
        vmlinux_path__exit();
        return -1;
}

size_t machine__fprintf_vmlinux_path(struct machine *self, FILE *fp)
{
        int i;
        size_t printed = 0;
        struct dso *kdso = self->vmlinux_maps[MAP__FUNCTION]->dso;

        if (kdso->has_build_id) {
                char filename[PATH_MAX];
                if (dso__build_id_filename(kdso, filename, sizeof(filename)))
                        printed += fprintf(fp, "[0] %s\n", filename);
        }

        for (i = 0; i < vmlinux_path__nr_entries; ++i)
                printed += fprintf(fp, "[%d] %s\n",
                                   i + kdso->has_build_id, vmlinux_path[i]);

        return printed;
}

static int setup_list(struct strlist **list, const char *list_str,
                      const char *list_name)
{
        if (list_str == NULL)
                return 0;

        *list = strlist__new(true, list_str);
        if (!*list) {
                pr_err("problems parsing %s list\n", list_name);
                return -1;
        }
        return 0;
}

int symbol__init(void)
{
        elf_version(EV_CURRENT);
        if (symbol_conf.sort_by_name)
                symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
                                          sizeof(struct symbol));

        if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
                return -1;

        if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
                pr_err("'.' is the only non valid --field-separator argument\n");
                return -1;
        }

        if (setup_list(&symbol_conf.dso_list,
                       symbol_conf.dso_list_str, "dso") < 0)
                return -1;

        if (setup_list(&symbol_conf.comm_list,
                       symbol_conf.comm_list_str, "comm") < 0)
                goto out_free_dso_list;

        if (setup_list(&symbol_conf.sym_list,
                       symbol_conf.sym_list_str, "symbol") < 0)
                goto out_free_comm_list;

        return 0;

out_free_dso_list:
        strlist__delete(symbol_conf.dso_list);
out_free_comm_list:
        strlist__delete(symbol_conf.comm_list);
        return -1;
}

int machines__create_kernel_maps(struct rb_root *self, pid_t pid)
{
        struct machine *machine = machines__findnew(self, pid);

        if (machine == NULL)
                return -1;

        return machine__create_kernel_maps(machine);
}

static int hex(char ch)
{
        if ((ch >= '0') && (ch <= '9'))
                return ch - '0';
        if ((ch >= 'a') && (ch <= 'f'))
                return ch - 'a' + 10;
        if ((ch >= 'A') && (ch <= 'F'))
                return ch - 'A' + 10;
        return -1;
}

/*
 * While we find nice hex chars, build a long_val.
 * Return number of chars processed.
 */
int hex2u64(const char *ptr, u64 *long_val)
{
        const char *p = ptr;
        *long_val = 0;

        while (*p) {
                const int hex_val = hex(*p);

                if (hex_val < 0)
                        break;

                *long_val = (*long_val << 4) | hex_val;
                p++;
        }

        return p - ptr;
}

char *strxfrchar(char *s, char from, char to)
{
        char *p = s;

        while ((p = strchr(p, from)) != NULL)
                *p++ = to;

        return s;
}

int machines__create_guest_kernel_maps(struct rb_root *self)
{
        int ret = 0;
        struct dirent **namelist = NULL;
        int i, items = 0;
        char path[PATH_MAX];
        pid_t pid;

        if (symbol_conf.default_guest_vmlinux_name ||
            symbol_conf.default_guest_modules ||
            symbol_conf.default_guest_kallsyms) {
                machines__create_kernel_maps(self, DEFAULT_GUEST_KERNEL_ID);
        }

        if (symbol_conf.guestmount) {
                items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL);
                if (items <= 0)
                        return -ENOENT;
                for (i = 0; i < items; i++) {
                        if (!isdigit(namelist[i]->d_name[0])) {
                                /* Filter out . and .. */
                                continue;
                        }
                        pid = atoi(namelist[i]->d_name);
                        sprintf(path, "%s/%s/proc/kallsyms",
                                symbol_conf.guestmount,
                                namelist[i]->d_name);
                        ret = access(path, R_OK);
                        if (ret) {
                                pr_debug("Can't access file %s\n", path);
                                goto failure;
                        }
                        machines__create_kernel_maps(self, pid);
                }
failure:
                free(namelist);
        }

        return ret;
}

int machine__load_kallsyms(struct machine *self, const char *filename,
                           enum map_type type, symbol_filter_t filter)
{
        struct map *map = self->vmlinux_maps[type];
        int ret = dso__load_kallsyms(map->dso, filename, map, filter);

        if (ret > 0) {
                dso__set_loaded(map->dso, type);
                /*
                 * Since /proc/kallsyms will have multiple sessions for the
                 * kernel, with modules between them, fixup the end of all
                 * sections.
                 */
                __map_groups__fixup_end(&self->kmaps, type);
        }

        return ret;
}

int machine__load_vmlinux_path(struct machine *self, enum map_type type,
                               symbol_filter_t filter)
{
        struct map *map = self->vmlinux_maps[type];
        int ret = dso__load_vmlinux_path(map->dso, map, filter);

        if (ret > 0) {
                dso__set_loaded(map->dso, type);
                map__reloc_vmlinux(map);
        }

        return ret;
}