x86: Move call to print_modules() out of show_regs()

[deliverable/linux.git] / tools / perf / util / symbol.c

#include <dirent.h>
#include <errno.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 <inttypes.h>
#include "build-id.h"
#include "util.h"
#include "debug.h"
#include "symbol.h"
#include "strlist.h"

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

#ifndef KSYM_NAME_LEN
#define KSYM_NAME_LEN 256
#endif

#ifndef NT_GNU_BUILD_ID
#define NT_GNU_BUILD_ID 3
#endif

static bool dso__build_id_equal(const struct dso *dso, u8 *build_id);
static int elf_read_build_id(Elf *elf, void *bf, size_t size);
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 *dso, struct map *map,
                                symbol_filter_t filter);
static int dso__load_guest_kernel_sym(struct dso *dso, 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,
        .annotate_src     = true,
        .symfs            = "",
};

int dso__name_len(const struct dso *dso)
{
        if (!dso)
                return strlen("[unknown]");
        if (verbose)
                return dso->long_name_len;

        return dso->short_name_len;
}

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

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

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

bool symbol_type__is_a(char symbol_type, enum map_type map_type)
{
        symbol_type = toupper(symbol_type);

        switch (map_type) {
        case MAP__FUNCTION:
                return symbol_type == 'T' || symbol_type == 'W';
        case MAP__VARIABLE:
                return symbol_type == 'D';
        default:
                return false;
        }
}

static int prefix_underscores_count(const char *str)
{
        const char *tail = str;

        while (*tail == '_')
                tail++;

        return tail - str;
}

#define SYMBOL_A 0
#define SYMBOL_B 1

static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
{
        s64 a;
        s64 b;

        /* Prefer a symbol with non zero length */
        a = syma->end - syma->start;
        b = symb->end - symb->start;
        if ((b == 0) && (a > 0))
                return SYMBOL_A;
        else if ((a == 0) && (b > 0))
                return SYMBOL_B;

        /* Prefer a non weak symbol over a weak one */
        a = syma->binding == STB_WEAK;
        b = symb->binding == STB_WEAK;
        if (b && !a)
                return SYMBOL_A;
        if (a && !b)
                return SYMBOL_B;

        /* Prefer a global symbol over a non global one */
        a = syma->binding == STB_GLOBAL;
        b = symb->binding == STB_GLOBAL;
        if (a && !b)
                return SYMBOL_A;
        if (b && !a)
                return SYMBOL_B;

        /* Prefer a symbol with less underscores */
        a = prefix_underscores_count(syma->name);
        b = prefix_underscores_count(symb->name);
        if (b > a)
                return SYMBOL_A;
        else if (a > b)
                return SYMBOL_B;

        /* If all else fails, choose the symbol with the longest name */
        if (strlen(syma->name) >= strlen(symb->name))
                return SYMBOL_A;
        else
                return SYMBOL_B;
}

static void symbols__fixup_duplicate(struct rb_root *symbols)
{
        struct rb_node *nd;
        struct symbol *curr, *next;

        nd = rb_first(symbols);

        while (nd) {
                curr = rb_entry(nd, struct symbol, rb_node);
again:
                nd = rb_next(&curr->rb_node);
                next = rb_entry(nd, struct symbol, rb_node);

                if (!nd)
                        break;

                if (curr->start != next->start)
                        continue;

                if (choose_best_symbol(curr, next) == SYMBOL_A) {
                        rb_erase(&next->rb_node, symbols);
                        goto again;
                } else {
                        nd = rb_next(&curr->rb_node);
                        rb_erase(&curr->rb_node, symbols);
                }
        }
}

static void symbols__fixup_end(struct rb_root *symbols)
{
        struct rb_node *nd, *prevnd = rb_first(symbols);
        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)
                        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 *mg, enum map_type type)
{
        struct map *prev, *curr;
        struct rb_node *nd, *prevnd = rb_first(&mg->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 = ~0ULL;
}

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

static struct symbol *symbol__new(u64 start, u64 len, u8 binding,
                                  const char *name)
{
        size_t namelen = strlen(name) + 1;
        struct symbol *sym = calloc(1, (symbol_conf.priv_size +
                                        sizeof(*sym) + namelen));
        if (sym == NULL)
                return NULL;

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

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

        pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
                  __func__, name, start, sym->end);
        memcpy(sym->name, name, namelen);

        return sym;
}

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

static size_t symbol__fprintf(struct symbol *sym, FILE *fp)
{
        return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
                       sym->start, sym->end,
                       sym->binding == STB_GLOBAL ? 'g' :
                       sym->binding == STB_LOCAL  ? 'l' : 'w',
                       sym->name);
}

size_t symbol__fprintf_symname_offs(const struct symbol *sym,
                                    const struct addr_location *al, FILE *fp)
{
        unsigned long offset;
        size_t length;

        if (sym && sym->name) {
                length = fprintf(fp, "%s", sym->name);
                if (al) {
                        offset = al->addr - sym->start;
                        length += fprintf(fp, "+0x%lx", offset);
                }
                return length;
        } else
                return fprintf(fp, "[unknown]");
}

size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
{
        return symbol__fprintf_symname_offs(sym, NULL, fp);
}

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

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

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

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

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

        return dso;
}

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

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

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

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

static void symbols__insert(struct rb_root *symbols, struct symbol *sym)
{
        struct rb_node **p = &symbols->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, symbols);
}

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

        if (symbols == NULL)
                return NULL;

        n = symbols->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 *symbols, struct symbol *sym)
{
        struct rb_node **p = &symbols->rb_node;
        struct rb_node *parent = NULL;
        struct symbol_name_rb_node *symn, *s;

        symn = container_of(sym, struct symbol_name_rb_node, sym);

        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, symbols);
}

static void symbols__sort_by_name(struct rb_root *symbols,
                                  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(symbols, pos);
        }
}

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

        if (symbols == NULL)
                return NULL;

        n = symbols->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 *dso,
                                enum map_type type, u64 addr)
{
        return symbols__find(&dso->symbols[type], addr);
}

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

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

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

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

        return raw - build_id;
}

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

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

size_t dso__fprintf_symbols_by_name(struct dso *dso,
                                    enum map_type type, FILE *fp)
{
        size_t ret = 0;
        struct rb_node *nd;
        struct symbol_name_rb_node *pos;

        for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
                pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
                fprintf(fp, "%s\n", pos->sym.name);
        }

        return ret;
}

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

        if (dso->short_name != dso->long_name)
                ret += fprintf(fp, "%s, ", dso->long_name);
        ret += fprintf(fp, "%s, %sloaded, ", map_type__name[type],
                       dso->loaded ? "" : "NOT ");
        ret += dso__fprintf_buildid(dso, fp);
        ret += fprintf(fp, ")\n");
        for (nd = rb_first(&dso->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, u64 end))
{
        char *line = NULL;
        size_t n;
        int err = -1;
        FILE *file = fopen(filename, "r");

        if (file == NULL)
                goto out_failure;

        err = 0;

        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 = line[len];
                len += 2;
                symbol_name = line + len;
                len = line_len - len;

                if (len >= KSYM_NAME_LEN) {
                        err = -1;
                        break;
                }

                /*
                 * module symbols are not sorted so we add all
                 * symbols with zero length and rely on
                 * symbols__fixup_end() to fix it up.
                 */
                err = process_symbol(arg, symbol_name,
                                     symbol_type, start, 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 u8 kallsyms2elf_type(char type)
{
        if (type == 'W')
                return STB_WEAK;

        return isupper(type) ? STB_GLOBAL : STB_LOCAL;
}

static int map__process_kallsym_symbol(void *arg, const char *name,
                                       char type, u64 start, u64 end)
{
        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;

        sym = symbol__new(start, end - start + 1,
                          kallsyms2elf_type(type), 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 *dso, const char *filename,
                                  struct map *map)
{
        struct process_kallsyms_args args = { .map = map, .dso = dso, };
        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 *dso, 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, moved = 0;       
        struct rb_root *root = &dso->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 &&
                                    dso->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 *ndso;

                        if (count == 0) {
                                curr_map = map;
                                goto filter_symbol;
                        }

                        if (dso->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++);

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

                        ndso->kernel = dso->kernel;

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

                        curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
                        map_groups__insert(kmaps, curr_map);
                        ++kernel_range;
                }
filter_symbol:
                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);
                                ++moved;
                        } else
                                ++count;
                }
        }

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

        return count + moved;
}

static bool symbol__restricted_filename(const char *filename,
                                        const char *restricted_filename)
{
        bool restricted = false;

        if (symbol_conf.kptr_restrict) {
                char *r = realpath(filename, NULL);

                if (r != NULL) {
                        restricted = strcmp(r, restricted_filename) == 0;
                        free(r);
                        return restricted;
                }
        }

        return restricted;
}

int dso__load_kallsyms(struct dso *dso, const char *filename,
                       struct map *map, symbol_filter_t filter)
{
        if (symbol__restricted_filename(filename, "/proc/kallsyms"))
                return -1;

        if (dso__load_all_kallsyms(dso, filename, map) < 0)
                return -1;

        symbols__fixup_duplicate(&dso->symbols[map->type]);
        symbols__fixup_end(&dso->symbols[map->type]);

        if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
                dso->symtab_type = SYMTAB__GUEST_KALLSYMS;
        else
                dso->symtab_type = SYMTAB__KALLSYMS;

        return dso__split_kallsyms(dso, map, filter);
}

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

        file = fopen(dso->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, STB_GLOBAL, line + len);

                if (sym == NULL)
                        goto out_delete_line;

                if (filter && filter(map, sym))
                        symbol__delete(sym);
                else {
                        symbols__insert(&dso->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
 *
 * @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 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 *dso, char *name, 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(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,
                                        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:
        elf_end(elf);
out_close:
        close(fd);

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

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 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 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;
}

static int dso__load_sym(struct dso *dso, struct map *map, const char *name,
                         int fd, symbol_filter_t filter, int kmodule,
                         int want_symtab)
{
        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, opdshdr;
        Elf_Data *syms, *opddata = NULL;
        GElf_Sym sym;
        Elf_Scn *sec, *sec_strndx, *opdsec;
        Elf *elf;
        int nr = 0;
        size_t opdidx = 0;

        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;
        }

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

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

        opdsec = elf_section_by_name(elf, &ehdr, &opdshdr, ".opd", &opdidx);
        if (opdshdr.sh_type != SHT_PROGBITS)
                opdsec = NULL;
        if (opdsec)
                opddata = elf_rawdata(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));
        if (dso->kernel == DSO_TYPE_USER) {
                dso->adjust_symbols = (ehdr.e_type == ET_EXEC ||
                                elf_section_by_name(elf, &ehdr, &shdr,
                                                     ".gnu.prelink_undo",
                                                     NULL) != NULL);
        } else {
                dso->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;

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

                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);

                /* 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 (curr_dso->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:
        elf_end(elf);
out_close:
        return err;
}

static bool dso__build_id_equal(const struct dso *dso, u8 *build_id)
{
        return memcmp(dso->build_id, build_id, sizeof(dso->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)

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;
        }

        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;
        }

        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;
}

char dso__symtab_origin(const struct dso *dso)
{
        static const char origin[] = {
                [SYMTAB__KALLSYMS]            = 'k',
                [SYMTAB__JAVA_JIT]            = 'j',
                [SYMTAB__BUILD_ID_CACHE]      = 'B',
                [SYMTAB__FEDORA_DEBUGINFO]    = 'f',
                [SYMTAB__UBUNTU_DEBUGINFO]    = 'u',
                [SYMTAB__BUILDID_DEBUGINFO]   = 'b',
                [SYMTAB__SYSTEM_PATH_DSO]     = 'd',
                [SYMTAB__SYSTEM_PATH_KMODULE] = 'K',
                [SYMTAB__GUEST_KALLSYMS]      =  'g',
                [SYMTAB__GUEST_KMODULE]       =  'G',
        };

        if (dso == NULL || dso->symtab_type == SYMTAB__NOT_FOUND)
                return '!';
        return origin[dso->symtab_type];
}

int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
{
        int size = PATH_MAX;
        char *name;
        int ret = -1;
        int fd;
        struct machine *machine;
        const char *root_dir;
        int want_symtab;

        dso__set_loaded(dso, map->type);

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

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

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

        dso->adjust_symbols = 0;

        if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
                struct stat st;

                if (lstat(dso->name, &st) < 0)
                        return -1;

                if (st.st_uid && (st.st_uid != geteuid())) {
                        pr_warning("File %s not owned by current user or root, "
                                "ignoring it.\n", dso->name);
                        return -1;
                }

                ret = dso__load_perf_map(dso, map, filter);
                dso->symtab_type = ret > 0 ? SYMTAB__JAVA_JIT :
                                              SYMTAB__NOT_FOUND;
                return ret;
        }

        /* Iterate over candidate debug images.
         * On the first pass, only load images if they have a full symtab.
         * Failing that, do a second pass where we accept .dynsym also
         */
        want_symtab = 1;
restart:
        for (dso->symtab_type = SYMTAB__BUILD_ID_CACHE;
             dso->symtab_type != SYMTAB__NOT_FOUND;
             dso->symtab_type++) {
                switch (dso->symtab_type) {
                case SYMTAB__BUILD_ID_CACHE:
                        /* skip the locally configured cache if a symfs is given */
                        if (symbol_conf.symfs[0] ||
                            (dso__build_id_filename(dso, name, size) == NULL)) {
                                continue;
                        }
                        break;
                case SYMTAB__FEDORA_DEBUGINFO:
                        snprintf(name, size, "%s/usr/lib/debug%s.debug",
                                 symbol_conf.symfs, dso->long_name);
                        break;
                case SYMTAB__UBUNTU_DEBUGINFO:
                        snprintf(name, size, "%s/usr/lib/debug%s",
                                 symbol_conf.symfs, dso->long_name);
                        break;
                case SYMTAB__BUILDID_DEBUGINFO: {
                        char build_id_hex[BUILD_ID_SIZE * 2 + 1];

                        if (!dso->has_build_id)
                                continue;

                        build_id__sprintf(dso->build_id,
                                          sizeof(dso->build_id),
                                          build_id_hex);
                        snprintf(name, size,
                                 "%s/usr/lib/debug/.build-id/%.2s/%s.debug",
                                 symbol_conf.symfs, build_id_hex, build_id_hex + 2);
                        }
                        break;
                case SYMTAB__SYSTEM_PATH_DSO:
                        snprintf(name, size, "%s%s",
                             symbol_conf.symfs, dso->long_name);
                        break;
                case SYMTAB__GUEST_KMODULE:
                        if (map->groups && machine)
                                root_dir = machine->root_dir;
                        else
                                root_dir = "";
                        snprintf(name, size, "%s%s%s", symbol_conf.symfs,
                                 root_dir, dso->long_name);
                        break;

                case SYMTAB__SYSTEM_PATH_KMODULE:
                        snprintf(name, size, "%s%s", symbol_conf.symfs,
                                 dso->long_name);
                        break;
                default:;
                }

                /* Name is now the name of the next image to try */
                fd = open(name, O_RDONLY);
                if (fd < 0)
                        continue;

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

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

                if (ret > 0) {
                        int nr_plt;

                        nr_plt = dso__synthesize_plt_symbols(dso, name, map, filter);
                        if (nr_plt > 0)
                                ret += nr_plt;
                        break;
                }
        }

        /*
         * If we wanted a full symtab but no image had one,
         * relax our requirements and repeat the search.
         */
        if (ret <= 0 && want_symtab) {
                want_symtab = 0;
                goto restart;
        }

        free(name);
        if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
                return 0;
        return ret;
}

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

        for (nd = rb_first(&mg->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 *dso,
                                           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 = dso->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, dso->build_id,
                                 sizeof(dso->build_id)) == 0)
                dso->has_build_id = true;

        return 0;
}

static int map_groups__set_modules_path_dir(struct map_groups *mg,
                                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*/
                snprintf(path, sizeof(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;

                        ret = map_groups__set_modules_path_dir(mg, 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(mg, MAP__FUNCTION,
                                                       dso_name);
                        if (map == NULL)
                                continue;

                        long_name = strdup(path);
                        if (long_name == NULL) {
                                ret = -1;
                                goto out;
                        }
                        dso__set_long_name(map->dso, long_name);
                        map->dso->lname_alloc = 1;
                        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 *machine)
{
        char *version;
        char modules_path[PATH_MAX];

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

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

        return map_groups__set_modules_path_dir(&machine->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 *map = calloc(1, (sizeof(*map) +
                                     (dso->kernel ? sizeof(struct kmap) : 0)));
        if (map != NULL) {
                /*
                 * ->end will be filled after we load all the symbols
                 */
                map__init(map, type, start, 0, 0, dso);
        }

        return map;
}

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

        if (dso == NULL)
                return NULL;

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

        if (machine__is_host(machine))
                dso->symtab_type = SYMTAB__SYSTEM_PATH_KMODULE;
        else
                dso->symtab_type = SYMTAB__GUEST_KMODULE;
        map_groups__insert(&machine->kmaps, map);
        return map;
}

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

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

        if (symbol__restricted_filename(path, "/proc/modules"))
                return -1;

        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(machine, start, name);
                if (map == NULL)
                        goto out_delete_line;
                dso__kernel_module_get_build_id(map->dso, machine->root_dir);
        }

        free(line);
        fclose(file);

        return machine__set_modules_path(machine);

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

int dso__load_vmlinux(struct dso *dso, struct map *map,
                      const char *vmlinux, symbol_filter_t filter)
{
        int err = -1, fd;
        char symfs_vmlinux[PATH_MAX];

        snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
                 symbol_conf.symfs, vmlinux);
        fd = open(symfs_vmlinux, O_RDONLY);
        if (fd < 0)
                return -1;

        dso__set_long_name(dso, (char *)vmlinux);
        dso__set_loaded(dso, map->type);
        err = dso__load_sym(dso, map, symfs_vmlinux, fd, filter, 0, 0);
        close(fd);

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

        return err;
}

int dso__load_vmlinux_path(struct dso *dso, 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(dso, NULL, 0);
        if (filename != NULL) {
                err = dso__load_vmlinux(dso, map, filename, filter);
                if (err > 0) {
                        dso__set_long_name(dso, filename);
                        goto out;
                }
                free(filename);
        }

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

static int dso__load_kernel_sym(struct dso *dso, 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 kallsyms or 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.kallsyms_name != NULL) {
                kallsyms_filename = symbol_conf.kallsyms_name;
                goto do_kallsyms;
        }

        if (symbol_conf.vmlinux_name != NULL) {
                err = dso__load_vmlinux(dso, map,
                                        symbol_conf.vmlinux_name, filter);
                if (err > 0) {
                        dso__set_long_name(dso,
                                           strdup(symbol_conf.vmlinux_name));
                        goto out_fixup;
                }
                return err;
        }

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

        /* do not try local files if a symfs was given */
        if (symbol_conf.symfs[0] != 0)
                return -1;

        /*
         * 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 (dso->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(dso, 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(dso->build_id, sizeof(dso->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(dso, 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(dso, strdup("[kernel.kallsyms]"));
                map__fixup_start(map);
                map__fixup_end(map);
        }

        return err;
}

static int dso__load_guest_kernel_sym(struct dso *dso, 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(dso, 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(dso, 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(dso, 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 *machines, FILE *fp)
{
        struct rb_node *nd;
        size_t ret = 0;

        for (nd = rb_first(machines); 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 *machine, FILE *fp,
                                     bool with_hits)
{
        return __dsos__fprintf_buildid(&machine->kernel_dsos, fp, with_hits) +
               __dsos__fprintf_buildid(&machine->user_dsos, fp, with_hits);
}

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

        for (nd = rb_first(machines); 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;
}

static struct dso*
dso__kernel_findnew(struct machine *machine, const char *name,
                    const char *short_name, int dso_type)
{
        /*
         * The kernel dso could be created by build_id processing.
         */
        struct dso *dso = __dsos__findnew(&machine->kernel_dsos, name);

        /*
         * We need to run this in all cases, since during the build_id
         * processing we had no idea this was the kernel dso.
         */
        if (dso != NULL) {
                dso__set_short_name(dso, short_name);
                dso->kernel = dso_type;
        }

        return dso;
}

void dso__read_running_kernel_build_id(struct dso *dso, 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, dso->build_id,
                                 sizeof(dso->build_id)) == 0)
                dso->has_build_id = true;
}

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

        if (machine__is_host(machine)) {
                vmlinux_name = symbol_conf.vmlinux_name;
                if (!vmlinux_name)
                        vmlinux_name = "[kernel.kallsyms]";

                kernel = dso__kernel_findnew(machine, vmlinux_name,
                                             "[kernel]",
                                             DSO_TYPE_KERNEL);
        } else {
                char bf[PATH_MAX];

                if (machine__is_default_guest(machine))
                        vmlinux_name = symbol_conf.default_guest_vmlinux_name;
                if (!vmlinux_name)
                        vmlinux_name = machine__mmap_name(machine, bf,
                                                          sizeof(bf));

                kernel = dso__kernel_findnew(machine, vmlinux_name,
                                             "[guest.kernel]",
                                             DSO_TYPE_GUEST_KERNEL);
        }

        if (kernel != NULL && (!kernel->has_build_id))
                dso__read_running_kernel_build_id(kernel, machine);

        return kernel;
}

struct process_args {
        u64 start;
};

static int symbol__in_kernel(void *arg, const char *name,
                             char type __used, u64 start, u64 end __used)
{
        struct process_args *args = arg;

        if (strchr(name, '['))
                return 0;

        args->start = start;
        return 1;
}

/* Figure out the start address of kernel map from /proc/kallsyms */
static u64 machine__get_kernel_start_addr(struct machine *machine)
{
        const char *filename;
        char path[PATH_MAX];
        struct process_args args;

        if (machine__is_host(machine)) {
                filename = "/proc/kallsyms";
        } else {
                if (machine__is_default_guest(machine))
                        filename = (char *)symbol_conf.default_guest_kallsyms;
                else {
                        sprintf(path, "%s/proc/kallsyms", machine->root_dir);
                        filename = path;
                }
        }

        if (symbol__restricted_filename(filename, "/proc/kallsyms"))
                return 0;

        if (kallsyms__parse(filename, &args, symbol__in_kernel) <= 0)
                return 0;

        return args.start;
}

int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
{
        enum map_type type;
        u64 start = machine__get_kernel_start_addr(machine);

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

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

                machine->vmlinux_maps[type]->map_ip =
                        machine->vmlinux_maps[type]->unmap_ip =
                                identity__map_ip;
                kmap = map__kmap(machine->vmlinux_maps[type]);
                kmap->kmaps = &machine->kmaps;
                map_groups__insert(&machine->kmaps,
                                   machine->vmlinux_maps[type]);
        }

        return 0;
}

void machine__destroy_kernel_maps(struct machine *machine)
{
        enum map_type type;

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

                if (machine->vmlinux_maps[type] == NULL)
                        continue;

                kmap = map__kmap(machine->vmlinux_maps[type]);
                map_groups__remove(&machine->kmaps,
                                   machine->vmlinux_maps[type]);
                if (kmap->ref_reloc_sym) {
                        /*
                         * ref_reloc_sym is shared among all maps, so free just
                         * on one of them.
                         */
                        if (type == MAP__FUNCTION) {
                                free((char *)kmap->ref_reloc_sym->name);
                                kmap->ref_reloc_sym->name = NULL;
                                free(kmap->ref_reloc_sym);
                        }
                        kmap->ref_reloc_sym = NULL;
                }

                map__delete(machine->vmlinux_maps[type]);
                machine->vmlinux_maps[type] = NULL;
        }
}

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

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

        if (symbol_conf.use_modules && machine__create_modules(machine) < 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(&machine->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];

        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;

        /* only try running kernel version if no symfs was given */
        if (symbol_conf.symfs[0] != 0)
                return 0;

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

        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 *machine, FILE *fp)
{
        int i;
        size_t printed = 0;
        struct dso *kdso = machine->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;
}

static bool symbol__read_kptr_restrict(void)
{
        bool value = false;

        if (geteuid() != 0) {
                FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
                if (fp != NULL) {
                        char line[8];

                        if (fgets(line, sizeof(line), fp) != NULL)
                                value = atoi(line) != 0;

                        fclose(fp);
                }
        }

        return value;
}

int symbol__init(void)
{
        const char *symfs;

        if (symbol_conf.initialized)
                return 0;

        symbol_conf.priv_size = ALIGN(symbol_conf.priv_size, sizeof(u64));

        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;

        /*
         * A path to symbols of "/" is identical to ""
         * reset here for simplicity.
         */
        symfs = realpath(symbol_conf.symfs, NULL);
        if (symfs == NULL)
                symfs = symbol_conf.symfs;
        if (strcmp(symfs, "/") == 0)
                symbol_conf.symfs = "";
        if (symfs != symbol_conf.symfs)
                free((void *)symfs);

        symbol_conf.kptr_restrict = symbol__read_kptr_restrict();

        symbol_conf.initialized = true;
        return 0;

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

void symbol__exit(void)
{
        if (!symbol_conf.initialized)
                return;
        strlist__delete(symbol_conf.sym_list);
        strlist__delete(symbol_conf.dso_list);
        strlist__delete(symbol_conf.comm_list);
        vmlinux_path__exit();
        symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
        symbol_conf.initialized = false;
}

int machines__create_kernel_maps(struct rb_root *machines, pid_t pid)
{
        struct machine *machine = machines__findnew(machines, 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 *machines)
{
        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(machines, 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(machines, pid);
                }
failure:
                free(namelist);
        }

        return ret;
}

void machines__destroy_guest_kernel_maps(struct rb_root *machines)
{
        struct rb_node *next = rb_first(machines);

        while (next) {
                struct machine *pos = rb_entry(next, struct machine, rb_node);

                next = rb_next(&pos->rb_node);
                rb_erase(&pos->rb_node, machines);
                machine__delete(pos);
        }
}

int machine__load_kallsyms(struct machine *machine, const char *filename,
                           enum map_type type, symbol_filter_t filter)
{
        struct map *map = machine->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(&machine->kmaps, type);
        }

        return ret;
}

int machine__load_vmlinux_path(struct machine *machine, enum map_type type,
                               symbol_filter_t filter)
{
        struct map *map = machine->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;
}

struct map *dso__new_map(const char *name)
{
        struct map *map = NULL;
        struct dso *dso = dso__new(name);

        if (dso)
                map = map__new2(0, dso, MAP__FUNCTION);

        return map;
}