map.c

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#include "symbol.h"
#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include "map.h"
#include "thread.h"
#include "strlist.h"
#include "vdso.h"

const char *map_type__name[MAP__NR_TYPES] = {
    [MAP__FUNCTION] = "Functions",
    [MAP__VARIABLE] = "Variables",
};

static inline int is_anon_memory(const char *filename)
{
    return strcmp(filename, "//anon") == 0;
}

static inline int is_no_dso_memory(const char *filename)
{
    return !strcmp(filename, "[stack]") ||
           !strcmp(filename, "[heap]");
}

void map__init(struct map *self, enum map_type type,
           u64 start, u64 end, u64 pgoff, struct dso *dso)
{
    self->type     = type;
    self->start    = start;
    self->end      = end;
    self->pgoff    = pgoff;
    self->dso      = dso;
    self->map_ip   = map__map_ip;
    self->unmap_ip = map__unmap_ip;
    RB_CLEAR_NODE(&self->rb_node);
    self->groups   = NULL;
    self->referenced = false;
    self->erange_warned = false;
}

struct map *map__new(struct list_head *dsos__list, u64 start, u64 len,
             u64 pgoff, u32 pid, char *filename,
             enum map_type type)
{
    struct map *self = malloc(sizeof(*self));

    if (self != NULL) {
        char newfilename[PATH_MAX];
        struct dso *dso;
        int anon, no_dso, vdso;

        anon = is_anon_memory(filename);
        vdso = is_vdso_map(filename);
        no_dso = is_no_dso_memory(filename);

        if (anon) {
            snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", pid);
            filename = newfilename;
        }

        if (vdso) {
            pgoff = 0;
            dso = vdso__dso_findnew(dsos__list);
        } else
            dso = __dsos__findnew(dsos__list, filename);

        if (dso == NULL)
            goto out_delete;

        map__init(self, type, start, start + len, pgoff, dso);

        if (anon || no_dso) {
            self->map_ip = self->unmap_ip = identity__map_ip;

            /*
             * Set memory without DSO as loaded. All map__find_*
             * functions still return NULL, and we avoid the
             * unnecessary map__load warning.
             */
            if (no_dso)
                dso__set_loaded(dso, self->type);
        }
    }
    return self;
out_delete:
    free(self);
    return NULL;
}

/*
 * 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.
 */
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;
}

void map__delete(struct map *self)
{
    free(self);
}

void map__fixup_start(struct map *self)
{
    struct rb_root *symbols = &self->dso->symbols[self->type];
    struct rb_node *nd = rb_first(symbols);
    if (nd != NULL) {
        struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
        self->start = sym->start;
    }
}

void map__fixup_end(struct map *self)
{
    struct rb_root *symbols = &self->dso->symbols[self->type];
    struct rb_node *nd = rb_last(symbols);
    if (nd != NULL) {
        struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
        self->end = sym->end;
    }
}

#define DSO__DELETED "(deleted)"

int map__load(struct map *self, symbol_filter_t filter)
{
    const char *name = self->dso->long_name;
    int nr;

    if (dso__loaded(self->dso, self->type))
        return 0;

    nr = dso__load(self->dso, self, filter);
    if (nr < 0) {
        if (self->dso->has_build_id) {
            char sbuild_id[BUILD_ID_SIZE * 2 + 1];

            build_id__sprintf(self->dso->build_id,
                      sizeof(self->dso->build_id),
                      sbuild_id);
            pr_warning("%s with build id %s not found",
                   name, sbuild_id);
        } else
            pr_warning("Failed to open %s", name);

        pr_warning(", continuing without symbols\n");
        return -1;
    } else if (nr == 0) {
#ifdef LIBELF_SUPPORT
        const size_t len = strlen(name);
        const size_t real_len = len - sizeof(DSO__DELETED);

        if (len > sizeof(DSO__DELETED) &&
            strcmp(name + real_len + 1, DSO__DELETED) == 0) {
            pr_warning("%.*s was updated (is prelink enabled?). "
                "Restart the long running apps that use it!\n",
                   (int)real_len, name);
        } else {
            pr_warning("no symbols found in %s, maybe install "
                   "a debug package?\n", name);
        }
#endif
        return -1;
    }
    /*
     * Only applies to the kernel, as its symtabs aren't relative like the
     * module ones.
     */
    if (self->dso->kernel)
        map__reloc_vmlinux(self);

    return 0;
}

struct symbol *map__find_symbol(struct map *self, u64 addr,
                symbol_filter_t filter)
{
    if (map__load(self, filter) < 0)
        return NULL;

    return dso__find_symbol(self->dso, self->type, addr);
}

struct symbol *map__find_symbol_by_name(struct map *self, const char *name,
                    symbol_filter_t filter)
{
    if (map__load(self, filter) < 0)
        return NULL;

    if (!dso__sorted_by_name(self->dso, self->type))
        dso__sort_by_name(self->dso, self->type);

    return dso__find_symbol_by_name(self->dso, self->type, name);
}

struct map *map__clone(struct map *self)
{
    struct map *map = malloc(sizeof(*self));

    if (!map)
        return NULL;

    memcpy(map, self, sizeof(*self));

    return map;
}

int map__overlap(struct map *l, struct map *r)
{
    if (l->start > r->start) {
        struct map *t = l;
        l = r;
        r = t;
    }

    if (l->end > r->start)
        return 1;

    return 0;
}

size_t map__fprintf(struct map *self, FILE *fp)
{
    return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s\n",
               self->start, self->end, self->pgoff, self->dso->name);
}

size_t map__fprintf_dsoname(struct map *map, FILE *fp)
{
    const char *dsoname = "[unknown]";

    if (map && map->dso && (map->dso->name || map->dso->long_name)) {
        if (symbol_conf.show_kernel_path && map->dso->long_name)
            dsoname = map->dso->long_name;
        else if (map->dso->name)
            dsoname = map->dso->name;
    }

    return fprintf(fp, "%s", dsoname);
}

/*
 * objdump wants/reports absolute IPs for ET_EXEC, and RIPs for ET_DYN.
 * map->dso->adjust_symbols==1 for ET_EXEC-like cases.
 */
u64 map__rip_2objdump(struct map *map, u64 rip)
{
    u64 addr = map->dso->adjust_symbols ?
            map->unmap_ip(map, rip) :   /* RIP -> IP */
            rip;
    return addr;
}

void map_groups__init(struct map_groups *mg)
{
    int i;
    for (i = 0; i < MAP__NR_TYPES; ++i) {
        mg->maps[i] = RB_ROOT;
        INIT_LIST_HEAD(&mg->removed_maps[i]);
    }
    mg->machine = NULL;
}

static void maps__delete(struct rb_root *maps)
{
    struct rb_node *next = rb_first(maps);

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

        next = rb_next(&pos->rb_node);
        rb_erase(&pos->rb_node, maps);
        map__delete(pos);
    }
}

static void maps__delete_removed(struct list_head *maps)
{
    struct map *pos, *n;

    list_for_each_entry_safe(pos, n, maps, node) {
        list_del(&pos->node);
        map__delete(pos);
    }
}

void map_groups__exit(struct map_groups *mg)
{
    int i;

    for (i = 0; i < MAP__NR_TYPES; ++i) {
        maps__delete(&mg->maps[i]);
        maps__delete_removed(&mg->removed_maps[i]);
    }
}

void map_groups__flush(struct map_groups *mg)
{
    int type;

    for (type = 0; type < MAP__NR_TYPES; type++) {
        struct rb_root *root = &mg->maps[type];
        struct rb_node *next = rb_first(root);

        while (next) {
            struct map *pos = rb_entry(next, struct map, rb_node);
            next = rb_next(&pos->rb_node);
            rb_erase(&pos->rb_node, root);
            /*
             * We may have references to this map, for
             * instance in some hist_entry instances, so
             * just move them to a separate list.
             */
            list_add_tail(&pos->node, &mg->removed_maps[pos->type]);
        }
    }
}

struct symbol *map_groups__find_symbol(struct map_groups *mg,
                       enum map_type type, u64 addr,
                       struct map **mapp,
                       symbol_filter_t filter)
{
    struct map *map = map_groups__find(mg, type, addr);

    if (map != NULL) {
        if (mapp != NULL)
            *mapp = map;
        return map__find_symbol(map, map->map_ip(map, addr), filter);
    }

    return NULL;
}

struct symbol *map_groups__find_symbol_by_name(struct map_groups *mg,
                           enum map_type type,
                           const char *name,
                           struct map **mapp,
                           symbol_filter_t filter)
{
    struct rb_node *nd;

    for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
        struct map *pos = rb_entry(nd, struct map, rb_node);
        struct symbol *sym = map__find_symbol_by_name(pos, name, filter);

        if (sym == NULL)
            continue;
        if (mapp != NULL)
            *mapp = pos;
        return sym;
    }

    return NULL;
}

size_t __map_groups__fprintf_maps(struct map_groups *mg,
                  enum map_type type, int verbose, FILE *fp)
{
    size_t printed = fprintf(fp, "%s:\n", map_type__name[type]);
    struct rb_node *nd;

    for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
        struct map *pos = rb_entry(nd, struct map, rb_node);
        printed += fprintf(fp, "Map:");
        printed += map__fprintf(pos, fp);
        if (verbose > 2) {
            printed += dso__fprintf(pos->dso, type, fp);
            printed += fprintf(fp, "--\n");
        }
    }

    return printed;
}

size_t map_groups__fprintf_maps(struct map_groups *mg, int verbose, FILE *fp)
{
    size_t printed = 0, i;
    for (i = 0; i < MAP__NR_TYPES; ++i)
        printed += __map_groups__fprintf_maps(mg, i, verbose, fp);
    return printed;
}

static size_t __map_groups__fprintf_removed_maps(struct map_groups *mg,
                         enum map_type type,
                         int verbose, FILE *fp)
{
    struct map *pos;
    size_t printed = 0;

    list_for_each_entry(pos, &mg->removed_maps[type], node) {
        printed += fprintf(fp, "Map:");
        printed += map__fprintf(pos, fp);
        if (verbose > 1) {
            printed += dso__fprintf(pos->dso, type, fp);
            printed += fprintf(fp, "--\n");
        }
    }
    return printed;
}

static size_t map_groups__fprintf_removed_maps(struct map_groups *mg,
                           int verbose, FILE *fp)
{
    size_t printed = 0, i;
    for (i = 0; i < MAP__NR_TYPES; ++i)
        printed += __map_groups__fprintf_removed_maps(mg, i, verbose, fp);
    return printed;
}

size_t map_groups__fprintf(struct map_groups *mg, int verbose, FILE *fp)
{
    size_t printed = map_groups__fprintf_maps(mg, verbose, fp);
    printed += fprintf(fp, "Removed maps:\n");
    return printed + map_groups__fprintf_removed_maps(mg, verbose, fp);
}

int map_groups__fixup_overlappings(struct map_groups *mg, struct map *map,
                   int verbose, FILE *fp)
{
    struct rb_root *root = &mg->maps[map->type];
    struct rb_node *next = rb_first(root);
    int err = 0;

    while (next) {
        struct map *pos = rb_entry(next, struct map, rb_node);
        next = rb_next(&pos->rb_node);

        if (!map__overlap(pos, map))
            continue;

        if (verbose >= 2) {
            fputs("overlapping maps:\n", fp);
            map__fprintf(map, fp);
            map__fprintf(pos, fp);
        }

        rb_erase(&pos->rb_node, root);
        /*
         * Now check if we need to create new maps for areas not
         * overlapped by the new map:
         */
        if (map->start > pos->start) {
            struct map *before = map__clone(pos);

            if (before == NULL) {
                err = -ENOMEM;
                goto move_map;
            }

            before->end = map->start - 1;
            map_groups__insert(mg, before);
            if (verbose >= 2)
                map__fprintf(before, fp);
        }

        if (map->end < pos->end) {
            struct map *after = map__clone(pos);

            if (after == NULL) {
                err = -ENOMEM;
                goto move_map;
            }

            after->start = map->end + 1;
            map_groups__insert(mg, after);
            if (verbose >= 2)
                map__fprintf(after, fp);
        }
move_map:
        /*
         * If we have references, just move them to a separate list.
         */
        if (pos->referenced)
            list_add_tail(&pos->node, &mg->removed_maps[map->type]);
        else
            map__delete(pos);

        if (err)
            return err;
    }

    return 0;
}

/*
 * XXX This should not really _copy_ te maps, but refcount them.
 */
int map_groups__clone(struct map_groups *mg,
              struct map_groups *parent, enum map_type type)
{
    struct rb_node *nd;
    for (nd = rb_first(&parent->maps[type]); nd; nd = rb_next(nd)) {
        struct map *map = rb_entry(nd, struct map, rb_node);
        struct map *new = map__clone(map);
        if (new == NULL)
            return -ENOMEM;
        map_groups__insert(mg, new);
    }
    return 0;
}

static u64 map__reloc_map_ip(struct map *map, u64 ip)
{
    return ip + (s64)map->pgoff;
}

static u64 map__reloc_unmap_ip(struct map *map, u64 ip)
{
    return ip - (s64)map->pgoff;
}

void map__reloc_vmlinux(struct map *self)
{
    struct kmap *kmap = map__kmap(self);
    s64 reloc;

    if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->unrelocated_addr)
        return;

    reloc = (kmap->ref_reloc_sym->unrelocated_addr -
         kmap->ref_reloc_sym->addr);

    if (!reloc)
        return;

    self->map_ip   = map__reloc_map_ip;
    self->unmap_ip = map__reloc_unmap_ip;
    self->pgoff    = reloc;
}

void maps__insert(struct rb_root *maps, struct map *map)
{
    struct rb_node **p = &maps->rb_node;
    struct rb_node *parent = NULL;
    const u64 ip = map->start;
    struct map *m;

    while (*p != NULL) {
        parent = *p;
        m = rb_entry(parent, struct map, rb_node);
        if (ip < m->start)
            p = &(*p)->rb_left;
        else
            p = &(*p)->rb_right;
    }

    rb_link_node(&map->rb_node, parent, p);
    rb_insert_color(&map->rb_node, maps);
}

void maps__remove(struct rb_root *self, struct map *map)
{
    rb_erase(&map->rb_node, self);
}

struct map *maps__find(struct rb_root *maps, u64 ip)
{
    struct rb_node **p = &maps->rb_node;
    struct rb_node *parent = NULL;
    struct map *m;

    while (*p != NULL) {
        parent = *p;
        m = rb_entry(parent, struct map, rb_node);
        if (ip < m->start)
            p = &(*p)->rb_left;
        else if (ip > m->end)
            p = &(*p)->rb_right;
        else
            return m;
    }

    return NULL;
}

int machine__init(struct machine *self, const char *root_dir, pid_t pid)
{
    map_groups__init(&self->kmaps);
    RB_CLEAR_NODE(&self->rb_node);
    INIT_LIST_HEAD(&self->user_dsos);
    INIT_LIST_HEAD(&self->kernel_dsos);

    self->threads = RB_ROOT;
    INIT_LIST_HEAD(&self->dead_threads);
    self->last_match = NULL;

    self->kmaps.machine = self;
    self->pid       = pid;
    self->root_dir      = strdup(root_dir);
    if (self->root_dir == NULL)
        return -ENOMEM;

    if (pid != HOST_KERNEL_ID) {
        struct thread *thread = machine__findnew_thread(self, pid);
        char comm[64];

        if (thread == NULL)
            return -ENOMEM;

        snprintf(comm, sizeof(comm), "[guest/%d]", pid);
        thread__set_comm(thread, comm);
    }

    return 0;
}

static void dsos__delete(struct list_head *self)
{
    struct dso *pos, *n;

    list_for_each_entry_safe(pos, n, self, node) {
        list_del(&pos->node);
        dso__delete(pos);
    }
}

void machine__exit(struct machine *self)
{
    map_groups__exit(&self->kmaps);
    dsos__delete(&self->user_dsos);
    dsos__delete(&self->kernel_dsos);
    free(self->root_dir);
    self->root_dir = NULL;
}

void machine__delete(struct machine *self)
{
    machine__exit(self);
    free(self);
}

struct machine *machines__add(struct rb_root *self, pid_t pid,
                  const char *root_dir)
{
    struct rb_node **p = &self->rb_node;
    struct rb_node *parent = NULL;
    struct machine *pos, *machine = malloc(sizeof(*machine));

    if (!machine)
        return NULL;

    if (machine__init(machine, root_dir, pid) != 0) {
        free(machine);
        return NULL;
    }

    while (*p != NULL) {
        parent = *p;
        pos = rb_entry(parent, struct machine, rb_node);
        if (pid < pos->pid)
            p = &(*p)->rb_left;
        else
            p = &(*p)->rb_right;
    }

    rb_link_node(&machine->rb_node, parent, p);
    rb_insert_color(&machine->rb_node, self);

    return machine;
}

struct machine *machines__find(struct rb_root *self, pid_t pid)
{
    struct rb_node **p = &self->rb_node;
    struct rb_node *parent = NULL;
    struct machine *machine;
    struct machine *default_machine = NULL;

    while (*p != NULL) {
        parent = *p;
        machine = rb_entry(parent, struct machine, rb_node);
        if (pid < machine->pid)
            p = &(*p)->rb_left;
        else if (pid > machine->pid)
            p = &(*p)->rb_right;
        else
            return machine;
        if (!machine->pid)
            default_machine = machine;
    }

    return default_machine;
}

struct machine *machines__findnew(struct rb_root *self, pid_t pid)
{
    char path[PATH_MAX];
    const char *root_dir = "";
    struct machine *machine = machines__find(self, pid);

    if (machine && (machine->pid == pid))
        goto out;

    if ((pid != HOST_KERNEL_ID) &&
        (pid != DEFAULT_GUEST_KERNEL_ID) &&
        (symbol_conf.guestmount)) {
        sprintf(path, "%s/%d", symbol_conf.guestmount, pid);
        if (access(path, R_OK)) {
            static struct strlist *seen;

            if (!seen)
                seen = strlist__new(true, NULL);

            if (!strlist__has_entry(seen, path)) {
                pr_err("Can't access file %s\n", path);
                strlist__add(seen, path);
            }
            machine = NULL;
            goto out;
        }
        root_dir = path;
    }

    machine = machines__add(self, pid, root_dir);

out:
    return machine;
}

void machines__process(struct rb_root *self, machine__process_t process, void *data)
{
    struct rb_node *nd;

    for (nd = rb_first(self); nd; nd = rb_next(nd)) {
        struct machine *pos = rb_entry(nd, struct machine, rb_node);
        process(pos, data);
    }
}

char *machine__mmap_name(struct machine *self, char *bf, size_t size)
{
    if (machine__is_host(self))
        snprintf(bf, size, "[%s]", "kernel.kallsyms");
    else if (machine__is_default_guest(self))
        snprintf(bf, size, "[%s]", "guest.kernel.kallsyms");
    else
        snprintf(bf, size, "[%s.%d]", "guest.kernel.kallsyms", self->pid);

    return bf;
}

void machines__set_id_hdr_size(struct rb_root *machines, u16 id_hdr_size)
{
    struct rb_node *node;
    struct machine *machine;

    for (node = rb_first(machines); node; node = rb_next(node)) {
        machine = rb_entry(node, struct machine, rb_node);
        machine->id_hdr_size = id_hdr_size;
    }

    return;
}