dso.c

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// SPDX-License-Identifier: GPL-2.0
#include <asm/bug.h>
#include <linux/kernel.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include "compress.h"
#include "path.h"
#include "symbol.h"
#include "srcline.h"
#include "dso.h"
#include "machine.h"
#include "auxtrace.h"
#include "util.h"
#include "debug.h"
#include "string2.h"
#include "vdso.h"

static const char * const debuglink_paths[] = {
    "%.0s%s",
    "%s/%s",
    "%s/.debug/%s",
    "/usr/lib/debug%s/%s"
};

char dso__symtab_origin(const struct dso *dso)
{
    static const char origin[] = {
        [DSO_BINARY_TYPE__KALLSYMS]         = 'k',
        [DSO_BINARY_TYPE__VMLINUX]          = 'v',
        [DSO_BINARY_TYPE__JAVA_JIT]         = 'j',
        [DSO_BINARY_TYPE__DEBUGLINK]            = 'l',
        [DSO_BINARY_TYPE__BUILD_ID_CACHE]       = 'B',
        [DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO] = 'D',
        [DSO_BINARY_TYPE__FEDORA_DEBUGINFO]     = 'f',
        [DSO_BINARY_TYPE__UBUNTU_DEBUGINFO]     = 'u',
        [DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO]   = 'o',
        [DSO_BINARY_TYPE__BUILDID_DEBUGINFO]        = 'b',
        [DSO_BINARY_TYPE__SYSTEM_PATH_DSO]      = 'd',
        [DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE]      = 'K',
        [DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP] = 'm',
        [DSO_BINARY_TYPE__GUEST_KALLSYMS]       = 'g',
        [DSO_BINARY_TYPE__GUEST_KMODULE]        = 'G',
        [DSO_BINARY_TYPE__GUEST_KMODULE_COMP]       = 'M',
        [DSO_BINARY_TYPE__GUEST_VMLINUX]        = 'V',
    };

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

int dso__read_binary_type_filename(const struct dso *dso,
                   enum dso_binary_type type,
                   char *root_dir, char *filename, size_t size)
{
    char build_id_hex[SBUILD_ID_SIZE];
    int ret = 0;
    size_t len;

    switch (type) {
    case DSO_BINARY_TYPE__DEBUGLINK:
    {
        const char *last_slash;
        char dso_dir[PATH_MAX];
        char symfile[PATH_MAX];
        unsigned int i;

        len = __symbol__join_symfs(filename, size, dso->long_name);
        last_slash = filename + len;
        while (last_slash != filename && *last_slash != '/')
            last_slash--;

        strncpy(dso_dir, filename, last_slash - filename);
        dso_dir[last_slash-filename] = '\0';

        if (!is_regular_file(filename)) {
            ret = -1;
            break;
        }

        ret = filename__read_debuglink(filename, symfile, PATH_MAX);
        if (ret)
            break;

        /* Check predefined locations where debug file might reside */
        ret = -1;
        for (i = 0; i < ARRAY_SIZE(debuglink_paths); i++) {
            snprintf(filename, size,
                    debuglink_paths[i], dso_dir, symfile);
            if (is_regular_file(filename)) {
                ret = 0;
                break;
            }
        }

        break;
    }
    case DSO_BINARY_TYPE__BUILD_ID_CACHE:
        if (dso__build_id_filename(dso, filename, size, false) == NULL)
            ret = -1;
        break;

    case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
        if (dso__build_id_filename(dso, filename, size, true) == NULL)
            ret = -1;
        break;

    case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
        len = __symbol__join_symfs(filename, size, "/usr/lib/debug");
        snprintf(filename + len, size - len, "%s.debug", dso->long_name);
        break;

    case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
        len = __symbol__join_symfs(filename, size, "/usr/lib/debug");
        snprintf(filename + len, size - len, "%s", dso->long_name);
        break;

    case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
    {
        const char *last_slash;
        size_t dir_size;

        last_slash = dso->long_name + dso->long_name_len;
        while (last_slash != dso->long_name && *last_slash != '/')
            last_slash--;

        len = __symbol__join_symfs(filename, size, "");
        dir_size = last_slash - dso->long_name + 2;
        if (dir_size > (size - len)) {
            ret = -1;
            break;
        }
        len += scnprintf(filename + len, dir_size, "%s",  dso->long_name);
        len += scnprintf(filename + len , size - len, ".debug%s",
                                last_slash);
        break;
    }

    case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
        if (!dso->has_build_id) {
            ret = -1;
            break;
        }

        build_id__sprintf(dso->build_id,
                  sizeof(dso->build_id),
                  build_id_hex);
        len = __symbol__join_symfs(filename, size, "/usr/lib/debug/.build-id/");
        snprintf(filename + len, size - len, "%.2s/%s.debug",
             build_id_hex, build_id_hex + 2);
        break;

    case DSO_BINARY_TYPE__VMLINUX:
    case DSO_BINARY_TYPE__GUEST_VMLINUX:
    case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
        __symbol__join_symfs(filename, size, dso->long_name);
        break;

    case DSO_BINARY_TYPE__GUEST_KMODULE:
    case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
        path__join3(filename, size, symbol_conf.symfs,
                root_dir, dso->long_name);
        break;

    case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
    case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
        __symbol__join_symfs(filename, size, dso->long_name);
        break;

    case DSO_BINARY_TYPE__KCORE:
    case DSO_BINARY_TYPE__GUEST_KCORE:
        snprintf(filename, size, "%s", dso->long_name);
        break;

    default:
    case DSO_BINARY_TYPE__KALLSYMS:
    case DSO_BINARY_TYPE__GUEST_KALLSYMS:
    case DSO_BINARY_TYPE__JAVA_JIT:
    case DSO_BINARY_TYPE__NOT_FOUND:
        ret = -1;
        break;
    }

    return ret;
}

static const struct {
    const char *fmt;
    int (*decompress)(const char *input, int output);
} compressions[] = {
#ifdef HAVE_ZLIB_SUPPORT
    { "gz", gzip_decompress_to_file },
#endif
#ifdef HAVE_LZMA_SUPPORT
    { "xz", lzma_decompress_to_file },
#endif
    { NULL, NULL },
};

bool is_supported_compression(const char *ext)
{
    unsigned i;

    for (i = 0; compressions[i].fmt; i++) {
        if (!strcmp(ext, compressions[i].fmt))
            return true;
    }
    return false;
}

bool is_kernel_module(const char *pathname, int cpumode)
{
    struct kmod_path m;
    int mode = cpumode & PERF_RECORD_MISC_CPUMODE_MASK;

    WARN_ONCE(mode != cpumode,
          "Internal error: passing unmasked cpumode (%x) to is_kernel_module",
          cpumode);

    switch (mode) {
    case PERF_RECORD_MISC_USER:
    case PERF_RECORD_MISC_HYPERVISOR:
    case PERF_RECORD_MISC_GUEST_USER:
        return false;
    /* Treat PERF_RECORD_MISC_CPUMODE_UNKNOWN as kernel */
    default:
        if (kmod_path__parse(&m, pathname)) {
            pr_err("Failed to check whether %s is a kernel module or not. Assume it is.",
                    pathname);
            return true;
        }
    }

    return m.kmod;
}

bool decompress_to_file(const char *ext, const char *filename, int output_fd)
{
    unsigned i;

    for (i = 0; compressions[i].fmt; i++) {
        if (!strcmp(ext, compressions[i].fmt))
            return !compressions[i].decompress(filename,
                               output_fd);
    }
    return false;
}

bool dso__needs_decompress(struct dso *dso)
{
    return dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
        dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
}

static int decompress_kmodule(struct dso *dso, const char *name, char *tmpbuf)
{
    int fd = -1;
    struct kmod_path m;

    if (!dso__needs_decompress(dso))
        return -1;

    if (kmod_path__parse_ext(&m, dso->long_name))
        return -1;

    if (!m.comp)
        goto out;

    fd = mkstemp(tmpbuf);
    if (fd < 0) {
        dso->load_errno = errno;
        goto out;
    }

    if (!decompress_to_file(m.ext, name, fd)) {
        dso->load_errno = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
        close(fd);
        fd = -1;
    }

out:
    free(m.ext);
    return fd;
}

int dso__decompress_kmodule_fd(struct dso *dso, const char *name)
{
    char tmpbuf[] = KMOD_DECOMP_NAME;
    int fd;

    fd = decompress_kmodule(dso, name, tmpbuf);
    unlink(tmpbuf);
    return fd;
}

int dso__decompress_kmodule_path(struct dso *dso, const char *name,
                 char *pathname, size_t len)
{
    char tmpbuf[] = KMOD_DECOMP_NAME;
    int fd;

    fd = decompress_kmodule(dso, name, tmpbuf);
    if (fd < 0) {
        unlink(tmpbuf);
        return -1;
    }

    strncpy(pathname, tmpbuf, len);
    close(fd);
    return 0;
}

/*
 * Parses kernel module specified in @path and updates
 * @m argument like:
 *
 *    @comp - true if @path contains supported compression suffix,
 *            false otherwise
 *    @kmod - true if @path contains '.ko' suffix in right position,
 *            false otherwise
 *    @name - if (@alloc_name && @kmod) is true, it contains strdup-ed base name
 *            of the kernel module without suffixes, otherwise strudup-ed
 *            base name of @path
 *    @ext  - if (@alloc_ext && @comp) is true, it contains strdup-ed string
 *            the compression suffix
 *
 * Returns 0 if there's no strdup error, -ENOMEM otherwise.
 */
int __kmod_path__parse(struct kmod_path *m, const char *path,
               bool alloc_name, bool alloc_ext)
{
    const char *name = strrchr(path, '/');
    const char *ext  = strrchr(path, '.');
    bool is_simple_name = false;

    memset(m, 0x0, sizeof(*m));
    name = name ? name + 1 : path;

    /*
     * '.' is also a valid character for module name. For example:
     * [aaa.bbb] is a valid module name. '[' should have higher
     * priority than '.ko' suffix.
     *
     * The kernel names are from machine__mmap_name. Such
     * name should belong to kernel itself, not kernel module.
     */
    if (name[0] == '[') {
        is_simple_name = true;
        if ((strncmp(name, "[kernel.kallsyms]", 17) == 0) ||
            (strncmp(name, "[guest.kernel.kallsyms", 22) == 0) ||
            (strncmp(name, "[vdso]", 6) == 0) ||
            (strncmp(name, "[vdso32]", 8) == 0) ||
            (strncmp(name, "[vdsox32]", 9) == 0) ||
            (strncmp(name, "[vsyscall]", 10) == 0)) {
            m->kmod = false;

        } else
            m->kmod = true;
    }

    /* No extension, just return name. */
    if ((ext == NULL) || is_simple_name) {
        if (alloc_name) {
            m->name = strdup(name);
            return m->name ? 0 : -ENOMEM;
        }
        return 0;
    }

    if (is_supported_compression(ext + 1)) {
        m->comp = true;
        ext -= 3;
    }

    /* Check .ko extension only if there's enough name left. */
    if (ext > name)
        m->kmod = !strncmp(ext, ".ko", 3);

    if (alloc_name) {
        if (m->kmod) {
            if (asprintf(&m->name, "[%.*s]", (int) (ext - name), name) == -1)
                return -ENOMEM;
        } else {
            if (asprintf(&m->name, "%s", name) == -1)
                return -ENOMEM;
        }

        strxfrchar(m->name, '-', '_');
    }

    if (alloc_ext && m->comp) {
        m->ext = strdup(ext + 4);
        if (!m->ext) {
            free((void *) m->name);
            return -ENOMEM;
        }
    }

    return 0;
}

void dso__set_module_info(struct dso *dso, struct kmod_path *m,
              struct machine *machine)
{
    if (machine__is_host(machine))
        dso->symtab_type = DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE;
    else
        dso->symtab_type = DSO_BINARY_TYPE__GUEST_KMODULE;

    /* _KMODULE_COMP should be next to _KMODULE */
    if (m->kmod && m->comp)
        dso->symtab_type++;

    dso__set_short_name(dso, strdup(m->name), true);
}

/*
 * Global list of open DSOs and the counter.
 */
static LIST_HEAD(dso__data_open);
static long dso__data_open_cnt;
static pthread_mutex_t dso__data_open_lock = PTHREAD_MUTEX_INITIALIZER;

static void dso__list_add(struct dso *dso)
{
    list_add_tail(&dso->data.open_entry, &dso__data_open);
    dso__data_open_cnt++;
}

static void dso__list_del(struct dso *dso)
{
    list_del(&dso->data.open_entry);
    WARN_ONCE(dso__data_open_cnt <= 0,
          "DSO data fd counter out of bounds.");
    dso__data_open_cnt--;
}

static void close_first_dso(void);

static int do_open(char *name)
{
    int fd;
    char sbuf[STRERR_BUFSIZE];

    do {
        fd = open(name, O_RDONLY|O_CLOEXEC);
        if (fd >= 0)
            return fd;

        pr_debug("dso open failed: %s\n",
             str_error_r(errno, sbuf, sizeof(sbuf)));
        if (!dso__data_open_cnt || errno != EMFILE)
            break;

        close_first_dso();
    } while (1);

    return -1;
}

static int __open_dso(struct dso *dso, struct machine *machine)
{
    int fd = -EINVAL;
    char *root_dir = (char *)"";
    char *name = malloc(PATH_MAX);

    if (!name)
        return -ENOMEM;

    if (machine)
        root_dir = machine->root_dir;

    if (dso__read_binary_type_filename(dso, dso->binary_type,
                        root_dir, name, PATH_MAX))
        goto out;

    if (!is_regular_file(name))
        goto out;

    if (dso__needs_decompress(dso)) {
        char newpath[KMOD_DECOMP_LEN];
        size_t len = sizeof(newpath);

        if (dso__decompress_kmodule_path(dso, name, newpath, len) < 0) {
            fd = -dso->load_errno;
            goto out;
        }

        strcpy(name, newpath);
    }

    fd = do_open(name);

    if (dso__needs_decompress(dso))
        unlink(name);

out:
    free(name);
    return fd;
}

static void check_data_close(void);

static int open_dso(struct dso *dso, struct machine *machine)
{
    int fd;
    struct nscookie nsc;

    if (dso->binary_type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
        nsinfo__mountns_enter(dso->nsinfo, &nsc);
    fd = __open_dso(dso, machine);
    if (dso->binary_type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
        nsinfo__mountns_exit(&nsc);

    if (fd >= 0) {
        dso__list_add(dso);
        /*
         * Check if we crossed the allowed number
         * of opened DSOs and close one if needed.
         */
        check_data_close();
    }

    return fd;
}

static void close_data_fd(struct dso *dso)
{
    if (dso->data.fd >= 0) {
        close(dso->data.fd);
        dso->data.fd = -1;
        dso->data.file_size = 0;
        dso__list_del(dso);
    }
}

static void close_dso(struct dso *dso)
{
    close_data_fd(dso);
}

static void close_first_dso(void)
{
    struct dso *dso;

    dso = list_first_entry(&dso__data_open, struct dso, data.open_entry);
    close_dso(dso);
}

static rlim_t get_fd_limit(void)
{
    struct rlimit l;
    rlim_t limit = 0;

    /* Allow half of the current open fd limit. */
    if (getrlimit(RLIMIT_NOFILE, &l) == 0) {
        if (l.rlim_cur == RLIM_INFINITY)
            limit = l.rlim_cur;
        else
            limit = l.rlim_cur / 2;
    } else {
        pr_err("failed to get fd limit\n");
        limit = 1;
    }

    return limit;
}

static rlim_t fd_limit;

/*
 * Used only by tests/dso-data.c to reset the environment
 * for tests. I dont expect we should change this during
 * standard runtime.
 */
void reset_fd_limit(void)
{
    fd_limit = 0;
}

static bool may_cache_fd(void)
{
    if (!fd_limit)
        fd_limit = get_fd_limit();

    if (fd_limit == RLIM_INFINITY)
        return true;

    return fd_limit > (rlim_t) dso__data_open_cnt;
}

/*
 * Check and close LRU dso if we crossed allowed limit
 * for opened dso file descriptors. The limit is half
 * of the RLIMIT_NOFILE files opened.
*/
static void check_data_close(void)
{
    bool cache_fd = may_cache_fd();

    if (!cache_fd)
        close_first_dso();
}

void dso__data_close(struct dso *dso)
{
    pthread_mutex_lock(&dso__data_open_lock);
    close_dso(dso);
    pthread_mutex_unlock(&dso__data_open_lock);
}

static void try_to_open_dso(struct dso *dso, struct machine *machine)
{
    enum dso_binary_type binary_type_data[] = {
        DSO_BINARY_TYPE__BUILD_ID_CACHE,
        DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
        DSO_BINARY_TYPE__NOT_FOUND,
    };
    int i = 0;

    if (dso->data.fd >= 0)
        return;

    if (dso->binary_type != DSO_BINARY_TYPE__NOT_FOUND) {
        dso->data.fd = open_dso(dso, machine);
        goto out;
    }

    do {
        dso->binary_type = binary_type_data[i++];

        dso->data.fd = open_dso(dso, machine);
        if (dso->data.fd >= 0)
            goto out;

    } while (dso->binary_type != DSO_BINARY_TYPE__NOT_FOUND);
out:
    if (dso->data.fd >= 0)
        dso->data.status = DSO_DATA_STATUS_OK;
    else
        dso->data.status = DSO_DATA_STATUS_ERROR;
}

int dso__data_get_fd(struct dso *dso, struct machine *machine)
{
    if (dso->data.status == DSO_DATA_STATUS_ERROR)
        return -1;

    if (pthread_mutex_lock(&dso__data_open_lock) < 0)
        return -1;

    try_to_open_dso(dso, machine);

    if (dso->data.fd < 0)
        pthread_mutex_unlock(&dso__data_open_lock);

    return dso->data.fd;
}

void dso__data_put_fd(struct dso *dso __maybe_unused)
{
    pthread_mutex_unlock(&dso__data_open_lock);
}

bool dso__data_status_seen(struct dso *dso, enum dso_data_status_seen by)
{
    u32 flag = 1 << by;

    if (dso->data.status_seen & flag)
        return true;

    dso->data.status_seen |= flag;

    return false;
}

static void
dso_cache__free(struct dso *dso)
{
    struct rb_root *root = &dso->data.cache;
    struct rb_node *next = rb_first(root);

    pthread_mutex_lock(&dso->lock);
    while (next) {
        struct dso_cache *cache;

        cache = rb_entry(next, struct dso_cache, rb_node);
        next = rb_next(&cache->rb_node);
        rb_erase(&cache->rb_node, root);
        free(cache);
    }
    pthread_mutex_unlock(&dso->lock);
}

static struct dso_cache *dso_cache__find(struct dso *dso, u64 offset)
{
    const struct rb_root *root = &dso->data.cache;
    struct rb_node * const *p = &root->rb_node;
    const struct rb_node *parent = NULL;
    struct dso_cache *cache;

    while (*p != NULL) {
        u64 end;

        parent = *p;
        cache = rb_entry(parent, struct dso_cache, rb_node);
        end = cache->offset + DSO__DATA_CACHE_SIZE;

        if (offset < cache->offset)
            p = &(*p)->rb_left;
        else if (offset >= end)
            p = &(*p)->rb_right;
        else
            return cache;
    }

    return NULL;
}

static struct dso_cache *
dso_cache__insert(struct dso *dso, struct dso_cache *new)
{
    struct rb_root *root = &dso->data.cache;
    struct rb_node **p = &root->rb_node;
    struct rb_node *parent = NULL;
    struct dso_cache *cache;
    u64 offset = new->offset;

    pthread_mutex_lock(&dso->lock);
    while (*p != NULL) {
        u64 end;

        parent = *p;
        cache = rb_entry(parent, struct dso_cache, rb_node);
        end = cache->offset + DSO__DATA_CACHE_SIZE;

        if (offset < cache->offset)
            p = &(*p)->rb_left;
        else if (offset >= end)
            p = &(*p)->rb_right;
        else
            goto out;
    }

    rb_link_node(&new->rb_node, parent, p);
    rb_insert_color(&new->rb_node, root);

    cache = NULL;
out:
    pthread_mutex_unlock(&dso->lock);
    return cache;
}

static ssize_t
dso_cache__memcpy(struct dso_cache *cache, u64 offset,
          u8 *data, u64 size)
{
    u64 cache_offset = offset - cache->offset;
    u64 cache_size   = min(cache->size - cache_offset, size);

    memcpy(data, cache->data + cache_offset, cache_size);
    return cache_size;
}

static ssize_t
dso_cache__read(struct dso *dso, struct machine *machine,
        u64 offset, u8 *data, ssize_t size)
{
    struct dso_cache *cache;
    struct dso_cache *old;
    ssize_t ret;

    do {
        u64 cache_offset;

        cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
        if (!cache)
            return -ENOMEM;

        pthread_mutex_lock(&dso__data_open_lock);

        /*
         * dso->data.fd might be closed if other thread opened another
         * file (dso) due to open file limit (RLIMIT_NOFILE).
         */
        try_to_open_dso(dso, machine);

        if (dso->data.fd < 0) {
            ret = -errno;
            dso->data.status = DSO_DATA_STATUS_ERROR;
            break;
        }

        cache_offset = offset & DSO__DATA_CACHE_MASK;

        ret = pread(dso->data.fd, cache->data, DSO__DATA_CACHE_SIZE, cache_offset);
        if (ret <= 0)
            break;

        cache->offset = cache_offset;
        cache->size   = ret;
    } while (0);

    pthread_mutex_unlock(&dso__data_open_lock);

    if (ret > 0) {
        old = dso_cache__insert(dso, cache);
        if (old) {
            /* we lose the race */
            free(cache);
            cache = old;
        }

        ret = dso_cache__memcpy(cache, offset, data, size);
    }

    if (ret <= 0)
        free(cache);

    return ret;
}

static ssize_t dso_cache_read(struct dso *dso, struct machine *machine,
                  u64 offset, u8 *data, ssize_t size)
{
    struct dso_cache *cache;

    cache = dso_cache__find(dso, offset);
    if (cache)
        return dso_cache__memcpy(cache, offset, data, size);
    else
        return dso_cache__read(dso, machine, offset, data, size);
}

/*
 * Reads and caches dso data DSO__DATA_CACHE_SIZE size chunks
 * in the rb_tree. Any read to already cached data is served
 * by cached data.
 */
static ssize_t cached_read(struct dso *dso, struct machine *machine,
               u64 offset, u8 *data, ssize_t size)
{
    ssize_t r = 0;
    u8 *p = data;

    do {
        ssize_t ret;

        ret = dso_cache_read(dso, machine, offset, p, size);
        if (ret < 0)
            return ret;

        /* Reached EOF, return what we have. */
        if (!ret)
            break;

        BUG_ON(ret > size);

        r      += ret;
        p      += ret;
        offset += ret;
        size   -= ret;

    } while (size);

    return r;
}

static int data_file_size(struct dso *dso, struct machine *machine)
{
    int ret = 0;
    struct stat st;
    char sbuf[STRERR_BUFSIZE];

    if (dso->data.file_size)
        return 0;

    if (dso->data.status == DSO_DATA_STATUS_ERROR)
        return -1;

    pthread_mutex_lock(&dso__data_open_lock);

    /*
     * dso->data.fd might be closed if other thread opened another
     * file (dso) due to open file limit (RLIMIT_NOFILE).
     */
    try_to_open_dso(dso, machine);

    if (dso->data.fd < 0) {
        ret = -errno;
        dso->data.status = DSO_DATA_STATUS_ERROR;
        goto out;
    }

    if (fstat(dso->data.fd, &st) < 0) {
        ret = -errno;
        pr_err("dso cache fstat failed: %s\n",
               str_error_r(errno, sbuf, sizeof(sbuf)));
        dso->data.status = DSO_DATA_STATUS_ERROR;
        goto out;
    }
    dso->data.file_size = st.st_size;

out:
    pthread_mutex_unlock(&dso__data_open_lock);
    return ret;
}

off_t dso__data_size(struct dso *dso, struct machine *machine)
{
    if (data_file_size(dso, machine))
        return -1;

    /* For now just estimate dso data size is close to file size */
    return dso->data.file_size;
}

static ssize_t data_read_offset(struct dso *dso, struct machine *machine,
                u64 offset, u8 *data, ssize_t size)
{
    if (data_file_size(dso, machine))
        return -1;

    /* Check the offset sanity. */
    if (offset > dso->data.file_size)
        return -1;

    if (offset + size < offset)
        return -1;

    return cached_read(dso, machine, offset, data, size);
}

ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
                  u64 offset, u8 *data, ssize_t size)
{
    if (dso->data.status == DSO_DATA_STATUS_ERROR)
        return -1;

    return data_read_offset(dso, machine, offset, data, size);
}

ssize_t dso__data_read_addr(struct dso *dso, struct map *map,
                struct machine *machine, u64 addr,
                u8 *data, ssize_t size)
{
    u64 offset = map->map_ip(map, addr);
    return dso__data_read_offset(dso, machine, offset, data, size);
}

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);

    return map;
}

struct dso *machine__findnew_kernel(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 = machine__findnew_dso(machine, 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, false);
        dso->kernel = dso_type;
    }

    return dso;
}

/*
 * Find a matching entry and/or link current entry to RB tree.
 * Either one of the dso or name parameter must be non-NULL or the
 * function will not work.
 */
static struct dso *__dso__findlink_by_longname(struct rb_root *root,
                           struct dso *dso, const char *name)
{
    struct rb_node **p = &root->rb_node;
    struct rb_node  *parent = NULL;

    if (!name)
        name = dso->long_name;
    /*
     * Find node with the matching name
     */
    while (*p) {
        struct dso *this = rb_entry(*p, struct dso, rb_node);
        int rc = strcmp(name, this->long_name);

        parent = *p;
        if (rc == 0) {
            /*
             * In case the new DSO is a duplicate of an existing
             * one, print a one-time warning & put the new entry
             * at the end of the list of duplicates.
             */
            if (!dso || (dso == this))
                return this;    /* Find matching dso */
            /*
             * The core kernel DSOs may have duplicated long name.
             * In this case, the short name should be different.
             * Comparing the short names to differentiate the DSOs.
             */
            rc = strcmp(dso->short_name, this->short_name);
            if (rc == 0) {
                pr_err("Duplicated dso name: %s\n", name);
                return NULL;
            }
        }
        if (rc < 0)
            p = &parent->rb_left;
        else
            p = &parent->rb_right;
    }
    if (dso) {
        /* Add new node and rebalance tree */
        rb_link_node(&dso->rb_node, parent, p);
        rb_insert_color(&dso->rb_node, root);
        dso->root = root;
    }
    return NULL;
}

static inline struct dso *__dso__find_by_longname(struct rb_root *root,
                          const char *name)
{
    return __dso__findlink_by_longname(root, NULL, name);
}

void dso__set_long_name(struct dso *dso, const char *name, bool name_allocated)
{
    struct rb_root *root = dso->root;

    if (name == NULL)
        return;

    if (dso->long_name_allocated)
        free((char *)dso->long_name);

    if (root) {
        rb_erase(&dso->rb_node, root);
        /*
         * __dso__findlink_by_longname() isn't guaranteed to add it
         * back, so a clean removal is required here.
         */
        RB_CLEAR_NODE(&dso->rb_node);
        dso->root = NULL;
    }

    dso->long_name       = name;
    dso->long_name_len   = strlen(name);
    dso->long_name_allocated = name_allocated;

    if (root)
        __dso__findlink_by_longname(root, dso, NULL);
}

void dso__set_short_name(struct dso *dso, const char *name, bool name_allocated)
{
    if (name == NULL)
        return;

    if (dso->short_name_allocated)
        free((char *)dso->short_name);

    dso->short_name       = name;
    dso->short_name_len   = strlen(name);
    dso->short_name_allocated = name_allocated;
}

static void dso__set_basename(struct dso *dso)
{
       /*
        * basename() may modify path buffer, so we must pass
        * a copy.
        */
       char *base, *lname = strdup(dso->long_name);

       if (!lname)
               return;

       /*
        * basename() may return a pointer to internal
        * storage which is reused in subsequent calls
        * so copy the result.
        */
       base = strdup(basename(lname));

       free(lname);

       if (!base)
               return;

       dso__set_short_name(dso, base, true);
}

int dso__name_len(const struct dso *dso)
{
    if (!dso)
        return strlen("[unknown]");
    if (verbose > 0)
        return dso->long_name_len;

    return dso->short_name_len;
}

bool dso__loaded(const struct dso *dso)
{
    return dso->loaded;
}

bool dso__sorted_by_name(const struct dso *dso)
{
    return dso->sorted_by_name;
}

void dso__set_sorted_by_name(struct dso *dso)
{
    dso->sorted_by_name = true;
}

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

    if (dso != NULL) {
        strcpy(dso->name, name);
        dso__set_long_name(dso, dso->name, false);
        dso__set_short_name(dso, dso->name, false);
        dso->symbols = dso->symbol_names = RB_ROOT;
        dso->data.cache = RB_ROOT;
        dso->inlined_nodes = RB_ROOT;
        dso->srclines = RB_ROOT;
        dso->data.fd = -1;
        dso->data.status = DSO_DATA_STATUS_UNKNOWN;
        dso->symtab_type = DSO_BINARY_TYPE__NOT_FOUND;
        dso->binary_type = DSO_BINARY_TYPE__NOT_FOUND;
        dso->is_64_bit = (sizeof(void *) == 8);
        dso->loaded = 0;
        dso->rel = 0;
        dso->sorted_by_name = 0;
        dso->has_build_id = 0;
        dso->has_srcline = 1;
        dso->a2l_fails = 1;
        dso->kernel = DSO_TYPE_USER;
        dso->needs_swap = DSO_SWAP__UNSET;
        RB_CLEAR_NODE(&dso->rb_node);
        dso->root = NULL;
        INIT_LIST_HEAD(&dso->node);
        INIT_LIST_HEAD(&dso->data.open_entry);
        pthread_mutex_init(&dso->lock, NULL);
        refcount_set(&dso->refcnt, 1);
    }

    return dso;
}

void dso__delete(struct dso *dso)
{
    if (!RB_EMPTY_NODE(&dso->rb_node))
        pr_err("DSO %s is still in rbtree when being deleted!\n",
               dso->long_name);

    /* free inlines first, as they reference symbols */
    inlines__tree_delete(&dso->inlined_nodes);
    srcline__tree_delete(&dso->srclines);
    symbols__delete(&dso->symbols);

    if (dso->short_name_allocated) {
        zfree((char **)&dso->short_name);
        dso->short_name_allocated = false;
    }

    if (dso->long_name_allocated) {
        zfree((char **)&dso->long_name);
        dso->long_name_allocated = false;
    }

    dso__data_close(dso);
    auxtrace_cache__free(dso->auxtrace_cache);
    dso_cache__free(dso);
    dso__free_a2l(dso);
    zfree(&dso->symsrc_filename);
    nsinfo__zput(dso->nsinfo);
    pthread_mutex_destroy(&dso->lock);
    free(dso);
}

struct dso *dso__get(struct dso *dso)
{
    if (dso)
        refcount_inc(&dso->refcnt);
    return dso;
}

void dso__put(struct dso *dso)
{
    if (dso && refcount_dec_and_test(&dso->refcnt))
        dso__delete(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;
}

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

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;
}

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;
}

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

    list_for_each_entry(pos, head, node) {
        if (with_hits && !pos->hit && !dso__is_vdso(pos))
            continue;
        if (pos->has_build_id) {
            have_build_id = true;
            continue;
        }
        nsinfo__mountns_enter(pos->nsinfo, &nsc);
        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;
        }
        nsinfo__mountns_exit(&nsc);
    }

    return have_build_id;
}

void __dsos__add(struct dsos *dsos, struct dso *dso)
{
    list_add_tail(&dso->node, &dsos->head);
    __dso__findlink_by_longname(&dsos->root, dso, NULL);
    /*
     * It is now in the linked list, grab a reference, then garbage collect
     * this when needing memory, by looking at LRU dso instances in the
     * list with atomic_read(&dso->refcnt) == 1, i.e. no references
     * anywhere besides the one for the list, do, under a lock for the
     * list: remove it from the list, then a dso__put(), that probably will
     * be the last and will then call dso__delete(), end of life.
     *
     * That, or at the end of the 'struct machine' lifetime, when all
     * 'struct dso' instances will be removed from the list, in
     * dsos__exit(), if they have no other reference from some other data
     * structure.
     *
     * E.g.: after processing a 'perf.data' file and storing references
     * to objects instantiated while processing events, we will have
     * references to the 'thread', 'map', 'dso' structs all from 'struct
     * hist_entry' instances, but we may not need anything not referenced,
     * so we might as well call machines__exit()/machines__delete() and
     * garbage collect it.
     */
    dso__get(dso);
}

void dsos__add(struct dsos *dsos, struct dso *dso)
{
    down_write(&dsos->lock);
    __dsos__add(dsos, dso);
    up_write(&dsos->lock);
}

struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
{
    struct dso *pos;

    if (cmp_short) {
        list_for_each_entry(pos, &dsos->head, node)
            if (strcmp(pos->short_name, name) == 0)
                return pos;
        return NULL;
    }
    return __dso__find_by_longname(&dsos->root, name);
}

struct dso *dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
{
    struct dso *dso;
    down_read(&dsos->lock);
    dso = __dsos__find(dsos, name, cmp_short);
    up_read(&dsos->lock);
    return dso;
}

struct dso *__dsos__addnew(struct dsos *dsos, const char *name)
{
    struct dso *dso = dso__new(name);

    if (dso != NULL) {
        __dsos__add(dsos, dso);
        dso__set_basename(dso);
        /* Put dso here because __dsos_add already got it */
        dso__put(dso);
    }
    return dso;
}

struct dso *__dsos__findnew(struct dsos *dsos, const char *name)
{
    struct dso *dso = __dsos__find(dsos, name, false);

    return dso ? dso : __dsos__addnew(dsos, name);
}

struct dso *dsos__findnew(struct dsos *dsos, const char *name)
{
    struct dso *dso;
    down_write(&dsos->lock);
    dso = dso__get(__dsos__findnew(dsos, name));
    up_write(&dsos->lock);
    return dso;
}

size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
                   bool (skip)(struct dso *dso, int parm), int parm)
{
    struct dso *pos;
    size_t ret = 0;

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

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

    list_for_each_entry(pos, head, node) {
        ret += dso__fprintf(pos, fp);
    }

    return ret;
}

size_t dso__fprintf_buildid(struct dso *dso, FILE *fp)
{
    char sbuild_id[SBUILD_ID_SIZE];

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

size_t dso__fprintf(struct dso *dso, 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, "%sloaded, ", dso__loaded(dso) ? "" : "NOT ");
    ret += dso__fprintf_buildid(dso, fp);
    ret += fprintf(fp, ")\n");
    for (nd = rb_first(&dso->symbols); nd; nd = rb_next(nd)) {
        struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
        ret += symbol__fprintf(pos, fp);
    }

    return ret;
}

enum dso_type dso__type(struct dso *dso, struct machine *machine)
{
    int fd;
    enum dso_type type = DSO__TYPE_UNKNOWN;

    fd = dso__data_get_fd(dso, machine);
    if (fd >= 0) {
        type = dso__type_fd(fd);
        dso__data_put_fd(dso);
    }

    return type;
}

int dso__strerror_load(struct dso *dso, char *buf, size_t buflen)
{
    int idx, errnum = dso->load_errno;
    /*
     * This must have a same ordering as the enum dso_load_errno.
     */
    static const char *dso_load__error_str[] = {
    "Internal tools/perf/ library error",
    "Invalid ELF file",
    "Can not read build id",
    "Mismatching build id",
    "Decompression failure",
    };

    BUG_ON(buflen == 0);

    if (errnum >= 0) {
        const char *err = str_error_r(errnum, buf, buflen);

        if (err != buf)
            scnprintf(buf, buflen, "%s", err);

        return 0;
    }

    if (errnum <  __DSO_LOAD_ERRNO__START || errnum >= __DSO_LOAD_ERRNO__END)
        return -1;

    idx = errnum - __DSO_LOAD_ERRNO__START;
    scnprintf(buf, buflen, "%s", dso_load__error_str[idx]);
    return 0;
}