// SPDX-License-Identifier: GPL-2.0
#include <asm/bug.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/zalloc.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 <stdlib.h>
#ifdef HAVE_LIBBPF_SUPPORT
#include <bpf/libbpf.h>
#include "bpf-event.h"
#include "bpf-utils.h"
#endif
#include "compress.h"
#include "env.h"
#include "namespaces.h"
#include "path.h"
#include "map.h"
#include "symbol.h"
#include "srcline.h"
#include "dso.h"
#include "dsos.h"
#include "machine.h"
#include "auxtrace.h"
#include "util.h" /* O_CLOEXEC for older systems */
#include "debug.h"
#include "string2.h"
#include "vdso.h"
#include "annotate-data.h"
#include "libdw.h"

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

void dso__set_nsinfo(struct dso *dso, struct nsinfo *nsi)
{
        nsinfo__put(RC_CHK_ACCESS(dso)->nsinfo);
        RC_CHK_ACCESS(dso)->nsinfo = nsi;
}

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__MIXEDUP_UBUNTU_DEBUGINFO]     = 'x',
                [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',
                [DSO_BINARY_TYPE__GNU_DEBUGDATA]                = 'n',
        };

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

bool dso__is_object_file(const struct dso *dso)
{
        switch (dso__binary_type(dso)) {
        case DSO_BINARY_TYPE__KALLSYMS:
        case DSO_BINARY_TYPE__GUEST_KALLSYMS:
        case DSO_BINARY_TYPE__JAVA_JIT:
        case DSO_BINARY_TYPE__BPF_PROG_INFO:
        case DSO_BINARY_TYPE__BPF_IMAGE:
        case DSO_BINARY_TYPE__OOL:
                return false;
        case DSO_BINARY_TYPE__VMLINUX:
        case DSO_BINARY_TYPE__GUEST_VMLINUX:
        case DSO_BINARY_TYPE__DEBUGLINK:
        case DSO_BINARY_TYPE__BUILD_ID_CACHE:
        case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
        case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
        case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
        case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
        case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
        case DSO_BINARY_TYPE__GNU_DEBUGDATA:
        case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
        case DSO_BINARY_TYPE__GUEST_KMODULE:
        case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
        case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
        case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
        case DSO_BINARY_TYPE__KCORE:
        case DSO_BINARY_TYPE__GUEST_KCORE:
        case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
        case DSO_BINARY_TYPE__NOT_FOUND:
        default:
                return true;
        }
}

int dso__read_binary_type_filename(const struct dso *dso,
                                   enum dso_binary_type type,
                                   const 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(dso));
                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(dso));
                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(dso));
                break;

        case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
                /*
                 * Ubuntu can mixup /usr/lib with /lib, putting debuginfo in
                 * /usr/lib/debug/lib when it is expected to be in
                 * /usr/lib/debug/usr/lib
                 */
                if (strlen(dso__long_name(dso)) < 9 ||
                    strncmp(dso__long_name(dso), "/usr/lib/", 9)) {
                        ret = -1;
                        break;
                }
                len = __symbol__join_symfs(filename, size, "/usr/lib/debug");
                snprintf(filename + len, size - len, "%s", dso__long_name(dso) + 4);
                break;

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

                last_slash = dso__long_name(dso) + dso__long_name_len(dso);
                while (last_slash != dso__long_name(dso) && *last_slash != '/')
                        last_slash--;

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

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

                build_id__snprintf(dso__bid(dso), build_id_hex, sizeof(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:
        case DSO_BINARY_TYPE__GNU_DEBUGDATA:
                __symbol__join_symfs(filename, size, dso__long_name(dso));
                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(dso));
                break;

        case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
        case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
                __symbol__join_symfs(filename, size, dso__long_name(dso));
                break;

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

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

        return ret;
}

enum {
        COMP_ID__NONE = 0,
};

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

static int is_supported_compression(const char *ext)
{
        unsigned i;

        for (i = 1; compressions[i].fmt; i++) {
                if (!strcmp(ext, compressions[i].fmt))
                        return i;
        }
        return COMP_ID__NONE;
}

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 dso__needs_decompress(struct dso *dso)
{
        return dso__symtab_type(dso) == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
                dso__symtab_type(dso) == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
}

int filename__decompress(const char *name, char *pathname,
                         size_t len, int comp, int *err)
{
        char tmpbuf[] = KMOD_DECOMP_NAME;
        int fd = -1;

        /*
         * We have proper compression id for DSO and yet the file
         * behind the 'name' can still be plain uncompressed object.
         *
         * The reason is behind the logic we open the DSO object files,
         * when we try all possible 'debug' objects until we find the
         * data. So even if the DSO is represented by 'krava.xz' module,
         * we can end up here opening ~/.debug/....23432432/debug' file
         * which is not compressed.
         *
         * To keep this transparent, we detect this and return the file
         * descriptor to the uncompressed file.
         */
        if (!compressions[comp].is_compressed(name))
                return open(name, O_RDONLY);

        fd = mkstemp(tmpbuf);
        if (fd < 0) {
                *err = errno;
                return -1;
        }

        if (compressions[comp].decompress(name, fd)) {
                *err = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
                close(fd);
                fd = -1;
        }

        if (!pathname || (fd < 0))
                unlink(tmpbuf);

        if (pathname && (fd >= 0))
                strlcpy(pathname, tmpbuf, len);

        return fd;
}

static int decompress_kmodule(struct dso *dso, const char *name,
                              char *pathname, size_t len)
{
        if (!dso__needs_decompress(dso))
                return -1;

        if (dso__comp(dso) == COMP_ID__NONE)
                return -1;

        return filename__decompress(name, pathname, len, dso__comp(dso), dso__load_errno(dso));
}

int dso__decompress_kmodule_fd(struct dso *dso, const char *name)
{
        return decompress_kmodule(dso, name, NULL, 0);
}

int dso__decompress_kmodule_path(struct dso *dso, const char *name,
                                 char *pathname, size_t len)
{
        int fd = decompress_kmodule(dso, name, pathname, len);

        close(fd);
        return fd >= 0 ? 0 : -1;
}

/*
 * 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)
{
        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;
        }

        m->comp = is_supported_compression(ext + 1);
        if (m->comp > COMP_ID__NONE)
                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;
                }

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

        return 0;
}

void dso__set_module_info(struct dso *dso, struct kmod_path *m,
                          struct machine *machine)
{
        if (machine__is_host(machine))
                dso__set_symtab_type(dso, DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE);
        else
                dso__set_symtab_type(dso, DSO_BINARY_TYPE__GUEST_KMODULE);

        /* _KMODULE_COMP should be next to _KMODULE */
        if (m->kmod && m->comp) {
                dso__set_symtab_type(dso, dso__symtab_type(dso) + 1);
                dso__set_comp(dso, m->comp);
        }

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

/*
 * Global list of open DSOs and the counter.
 */
struct mutex _dso__data_open_lock;
static LIST_HEAD(dso__data_open);
static long dso__data_open_cnt GUARDED_BY(_dso__data_open_lock);

static void dso__data_open_lock_init(void)
{
        mutex_init(&_dso__data_open_lock);
}

static struct mutex *dso__data_open_lock(void) LOCK_RETURNED(_dso__data_open_lock)
{
        static pthread_once_t data_open_lock_once = PTHREAD_ONCE_INIT;

        pthread_once(&data_open_lock_once, dso__data_open_lock_init);

        return &_dso__data_open_lock;
}

static void dso__list_add(struct dso *dso) EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        list_add_tail(&dso__data(dso)->open_entry, &dso__data_open);
#ifdef REFCNT_CHECKING
        dso__data(dso)->dso = dso__get(dso);
#endif
        /* Assume the dso is part of dsos, hence the optional reference count above. */
        assert(dso__dsos(dso));
        dso__data_open_cnt++;
}

static void dso__list_del(struct dso *dso) EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        list_del_init(&dso__data(dso)->open_entry);
#ifdef REFCNT_CHECKING
        mutex_unlock(dso__data_open_lock());
        dso__put(dso__data(dso)->dso);
        mutex_lock(dso__data_open_lock());
#endif
        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) EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        do {
                int fd = open(name, O_RDONLY|O_CLOEXEC);

                if (fd >= 0)
                        return fd;

                pr_debug("dso open failed: %m\n");
                if (!dso__data_open_cnt || errno != EMFILE)
                        break;

                close_first_dso();
        } while (1);

        return -1;
}

char *dso__filename_with_chroot(const struct dso *dso, const char *filename)
{
        return filename_with_chroot(nsinfo__pid(dso__nsinfo_const(dso)), filename);
}

static char *dso__get_filename(struct dso *dso, const char *root_dir,
                               bool *decomp)
{
        char *name = malloc(PATH_MAX);

        *decomp = false;

        if (name == NULL)
                return NULL;

        if (dso__read_binary_type_filename(dso, dso__binary_type(dso),
                                            root_dir, name, PATH_MAX))
                goto out;

        if (!is_regular_file(name)) {
                char *new_name;

                if (errno != ENOENT || dso__nsinfo(dso) == NULL)
                        goto out;

                new_name = dso__filename_with_chroot(dso, name);
                if (!new_name)
                        goto out;

                free(name);
                name = new_name;
        }

        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) {
                        errno = *dso__load_errno(dso);
                        goto out;
                }

                *decomp = true;
                strcpy(name, newpath);
        }
        return name;

out:
        free(name);
        return NULL;
}

static int __open_dso(struct dso *dso, struct machine *machine)
        EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        int fd = -EINVAL;
        char *name;
        bool decomp = false;

        mutex_lock(dso__lock(dso));

        name = dso__get_filename(dso, machine ? machine->root_dir : "", &decomp);
        if (name)
                fd = do_open(name);
        else
                fd = -errno;

        if (decomp)
                unlink(name);

        mutex_unlock(dso__lock(dso));
        free(name);
        return fd;
}

static void check_data_close(void);

/**
 * dso_close - Open DSO data file
 * @dso: dso object
 *
 * Open @dso's data file descriptor and updates
 * list/count of open DSO objects.
 */
static int open_dso(struct dso *dso, struct machine *machine)
        EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        int fd;
        struct nscookie nsc;

        if (dso__binary_type(dso) != DSO_BINARY_TYPE__BUILD_ID_CACHE) {
                mutex_lock(dso__lock(dso));
                nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
                mutex_unlock(dso__lock(dso));
        }
        fd = __open_dso(dso, machine);
        if (dso__binary_type(dso) != 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) EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        if (dso__data(dso)->fd >= 0) {
                close(dso__data(dso)->fd);
                dso__data(dso)->fd = -1;
                dso__data(dso)->file_size = 0;
                dso__list_del(dso);
        }
}

/**
 * dso_close - Close DSO data file
 * @dso: dso object
 *
 * Close @dso's data file descriptor and updates
 * list/count of open DSO objects.
 */
static void close_dso(struct dso *dso) EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        close_data_fd(dso);
}

static void close_first_dso(void) EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        struct dso_data *dso_data;
        struct dso *dso;

        dso_data = list_first_entry(&dso__data_open, struct dso_data, open_entry);
#ifdef REFCNT_CHECKING
        dso = dso_data->dso;
#else
        dso = container_of(dso_data, struct dso, data);
#endif
        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) EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        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) EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        bool cache_fd = may_cache_fd();

        if (!cache_fd)
                close_first_dso();
}

/**
 * dso__data_close - Close DSO data file
 * @dso: dso object
 *
 * External interface to close @dso's data file descriptor.
 */
void dso__data_close(struct dso *dso)
{
        mutex_lock(dso__data_open_lock());
        close_dso(dso);
        mutex_unlock(dso__data_open_lock());
}

static void try_to_open_dso(struct dso *dso, struct machine *machine)
        EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
{
        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;
        struct dso_data *dso_data = dso__data(dso);

        if (dso_data->fd >= 0)
                return;

        if (dso__binary_type(dso) != DSO_BINARY_TYPE__NOT_FOUND) {
                dso_data->fd = open_dso(dso, machine);
                goto out;
        }

        do {
                dso__set_binary_type(dso, binary_type_data[i++]);

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

        } while (dso__binary_type(dso) != 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;
}

/**
 * dso__data_get_fd - Get dso's data file descriptor
 * @dso: dso object
 * @machine: machine object
 *
 * External interface to find dso's file, open it and
 * returns file descriptor.  It should be paired with
 * dso__data_put_fd() if it returns non-negative value.
 */
bool dso__data_get_fd(struct dso *dso, struct machine *machine, int *fd)
{
        *fd = -1;
        if (dso__data(dso)->status == DSO_DATA_STATUS_ERROR)
                return false;

        mutex_lock(dso__data_open_lock());

        try_to_open_dso(dso, machine);

        *fd = dso__data(dso)->fd;
        if (*fd >= 0)
                return true;

        mutex_unlock(dso__data_open_lock());
        return false;
}

void dso__data_put_fd(struct dso *dso __maybe_unused)
{
        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(dso)->status_seen & flag)
                return true;

        dso__data(dso)->status_seen |= flag;

        return false;
}

#ifdef HAVE_LIBBPF_SUPPORT
static ssize_t bpf_read(struct dso *dso, u64 offset, char *data)
{
        struct bpf_prog_info_node *node;
        ssize_t size = DSO__DATA_CACHE_SIZE;
        struct dso_bpf_prog *dso_bpf_prog = dso__bpf_prog(dso);
        u64 len;
        u8 *buf;

        node = perf_env__find_bpf_prog_info(dso_bpf_prog->env, dso_bpf_prog->id);
        if (!node || !node->info_linear) {
                dso__data(dso)->status = DSO_DATA_STATUS_ERROR;
                return -1;
        }

        len = node->info_linear->info.jited_prog_len;
        buf = (u8 *)(uintptr_t)node->info_linear->info.jited_prog_insns;

        if (offset >= len)
                return -1;

        size = (ssize_t)min(len - offset, (u64)size);
        memcpy(data, buf + offset, size);
        return size;
}

static int bpf_size(struct dso *dso)
{
        struct bpf_prog_info_node *node;
        struct dso_bpf_prog *dso_bpf_prog = dso__bpf_prog(dso);

        node = perf_env__find_bpf_prog_info(dso_bpf_prog->env, dso_bpf_prog->id);
        if (!node || !node->info_linear) {
                dso__data(dso)->status = DSO_DATA_STATUS_ERROR;
                return -1;
        }

        dso__data(dso)->file_size = node->info_linear->info.jited_prog_len;
        return 0;
}
#endif // HAVE_LIBBPF_SUPPORT

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

        mutex_lock(dso__lock(dso));
        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);
        }
        mutex_unlock(dso__lock(dso));
}

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

        mutex_lock(dso__lock(dso));
        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:
        mutex_unlock(dso__lock(dso));
        return cache;
}

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

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

static ssize_t file_read(struct dso *dso, struct machine *machine,
                         u64 offset, char *data)
{
        ssize_t ret;

        mutex_lock(dso__data_open_lock());

        /*
         * dso__data(dso)->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(dso)->fd < 0) {
                dso__data(dso)->status = DSO_DATA_STATUS_ERROR;
                ret = -errno;
                goto out;
        }

        ret = pread(dso__data(dso)->fd, data, DSO__DATA_CACHE_SIZE, offset);
out:
        mutex_unlock(dso__data_open_lock());
        return ret;
}

static struct dso_cache *dso_cache__populate(struct dso *dso,
                                             struct machine *machine,
                                             u64 offset, ssize_t *ret)
{
        u64 cache_offset = offset & DSO__DATA_CACHE_MASK;
        struct dso_cache *cache;
        struct dso_cache *old;

        cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
        if (!cache) {
                *ret = -ENOMEM;
                return NULL;
        }
#ifdef HAVE_LIBBPF_SUPPORT
        if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO)
                *ret = bpf_read(dso, cache_offset, cache->data);
        else
#endif
        if (dso__binary_type(dso) == DSO_BINARY_TYPE__OOL)
                *ret = DSO__DATA_CACHE_SIZE;
        else
                *ret = file_read(dso, machine, cache_offset, cache->data);

        if (*ret <= 0) {
                free(cache);
                return NULL;
        }

        cache->offset = cache_offset;
        cache->size   = *ret;

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

        return cache;
}

static struct dso_cache *dso_cache__find(struct dso *dso,
                                         struct machine *machine,
                                         u64 offset,
                                         ssize_t *ret)
{
        struct dso_cache *cache = __dso_cache__find(dso, offset);

        return cache ? cache : dso_cache__populate(dso, machine, offset, ret);
}

static ssize_t dso_cache_io(struct dso *dso, struct machine *machine,
                            u64 offset, u8 *data, ssize_t size, bool out)
{
        struct dso_cache *cache;
        ssize_t ret = 0;

        cache = dso_cache__find(dso, machine, offset, &ret);
        if (!cache)
                return ret;

        return dso_cache__memcpy(cache, offset, data, size, out);
}

/*
 * 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. Writes update the cache only, not the backing file.
 */
static ssize_t cached_io(struct dso *dso, struct machine *machine,
                         u64 offset, u8 *data, ssize_t size, bool out)
{
        ssize_t r = 0;
        u8 *p = data;

        do {
                ssize_t ret;

                ret = dso_cache_io(dso, machine, offset, p, size, out);
                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 file_size(struct dso *dso, struct machine *machine)
{
        int ret = 0;
        struct stat st;

        mutex_lock(dso__data_open_lock());

        /*
         * dso__data(dso)->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(dso)->fd < 0) {
                ret = -errno;
                dso__data(dso)->status = DSO_DATA_STATUS_ERROR;
                goto out;
        }

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

out:
        mutex_unlock(dso__data_open_lock());
        return ret;
}

int dso__data_file_size(struct dso *dso, struct machine *machine)
{
        if (dso__data(dso)->file_size)
                return 0;

        if (dso__data(dso)->status == DSO_DATA_STATUS_ERROR)
                return -1;
#ifdef HAVE_LIBBPF_SUPPORT
        if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO)
                return bpf_size(dso);
#endif
        return file_size(dso, machine);
}

/**
 * dso__data_size - Return dso data size
 * @dso: dso object
 * @machine: machine object
 *
 * Return: dso data size
 */
off_t dso__data_size(struct dso *dso, struct machine *machine)
{
        if (dso__data_file_size(dso, machine))
                return -1;

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

static ssize_t data_read_write_offset(struct dso *dso, struct machine *machine,
                                      u64 offset, u8 *data, ssize_t size,
                                      bool out)
{
        if (dso__data_file_size(dso, machine))
                return -1;

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

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

        return cached_io(dso, machine, offset, data, size, out);
}

/**
 * dso__data_read_offset - Read data from dso file offset
 * @dso: dso object
 * @machine: machine object
 * @offset: file offset
 * @data: buffer to store data
 * @size: size of the @data buffer
 *
 * External interface to read data from dso file offset. Open
 * dso data file and use cached_read to get the data.
 */
ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
                              u64 offset, u8 *data, ssize_t size)
{
        if (dso__data(dso)->status == DSO_DATA_STATUS_ERROR)
                return -1;

        return data_read_write_offset(dso, machine, offset, data, size, true);
}

static enum dso_swap_type dso_swap_type__from_elf_data(unsigned char eidata)
{
        static const unsigned int endian = 1;

        switch (eidata) {
        case ELFDATA2LSB:
                /* We are big endian, DSO is little endian. */
                return (*(unsigned char const *)&endian != 1) ? DSO_SWAP__YES : DSO_SWAP__NO;
        case ELFDATA2MSB:
                /* We are little endian, DSO is big endian. */
                return (*(unsigned char const *)&endian != 0) ? DSO_SWAP__YES : DSO_SWAP__NO;
        default:
                return DSO_SWAP__UNSET;
        }
}

/* Reads e_machine from fd, optionally caching data in dso. */
uint16_t dso__read_e_machine(struct dso *optional_dso, int fd, uint32_t *e_flags)
{
        uint16_t e_machine = EM_NONE;
        unsigned char e_ident[EI_NIDENT];
        enum dso_swap_type swap_type;
        bool need_e_flags;

        if (e_flags)
                *e_flags = 0;

        {
                _Static_assert(offsetof(Elf32_Ehdr, e_ident) == 0, "Unexpected offset");
                _Static_assert(offsetof(Elf64_Ehdr, e_ident) == 0, "Unexpected offset");
        }
        if (pread(fd, &e_ident, sizeof(e_ident), 0) != sizeof(e_ident))
                return EM_NONE; // Read failed.

        if (memcmp(e_ident, ELFMAG, SELFMAG) != 0)
                return EM_NONE; // Not an ELF file.

        if (e_ident[EI_CLASS] == ELFCLASSNONE || e_ident[EI_CLASS] >= ELFCLASSNUM)
                return EM_NONE; // Bad ELF class (32 or 64-bit objects).

        if (e_ident[EI_VERSION] != EV_CURRENT)
                return EM_NONE; // Bad ELF version.

        swap_type = dso_swap_type__from_elf_data(e_ident[EI_DATA]);
        if (swap_type == DSO_SWAP__UNSET)
                return EM_NONE; // Bad ELF data encoding.

        /* Cache the need for swapping. */
        if (optional_dso) {
                assert(dso__needs_swap(optional_dso) == DSO_SWAP__UNSET ||
                       dso__needs_swap(optional_dso) == swap_type);
                dso__set_needs_swap(optional_dso, swap_type);
        }

        {
                _Static_assert(offsetof(Elf32_Ehdr, e_machine) == 18, "Unexpected offset");
                _Static_assert(offsetof(Elf64_Ehdr, e_machine) == 18, "Unexpected offset");
        }
        if (pread(fd, &e_machine, sizeof(e_machine), 18) != sizeof(e_machine))
                return EM_NONE; // e_machine read failed.

        e_machine = DSO_SWAP_TYPE__SWAP(swap_type, uint16_t, e_machine);
        if (e_machine >= EM_NUM)
                return EM_NONE; // Bad ELF machine number.

#ifdef NDEBUG
        /* In production code the e_flags are only needed on CSKY. */
        need_e_flags = e_flags && e_machine == EM_CSKY;
#else
        /* Debug code will always read the e_flags. */
        need_e_flags = e_flags != NULL;
#endif
        if (need_e_flags) {
                off_t offset = e_ident[EI_CLASS] == ELFCLASS32
                        ? offsetof(Elf32_Ehdr, e_flags)
                        : offsetof(Elf64_Ehdr, e_flags);

                if (pread(fd, e_flags, sizeof(*e_flags), offset) != sizeof(*e_flags)) {
                        *e_flags = 0;
                        return EM_NONE; // e_flags read failed.
                }
        }
        return e_machine;
}

uint16_t dso__e_machine(struct dso *dso, struct machine *machine, uint32_t *e_flags)
{
        uint16_t e_machine = EM_NONE;
        int fd;

        switch (dso__binary_type(dso)) {
        case DSO_BINARY_TYPE__KALLSYMS:
        case DSO_BINARY_TYPE__GUEST_KALLSYMS:
        case DSO_BINARY_TYPE__VMLINUX:
        case DSO_BINARY_TYPE__GUEST_VMLINUX:
        case DSO_BINARY_TYPE__GUEST_KMODULE:
        case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
        case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
        case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
        case DSO_BINARY_TYPE__KCORE:
        case DSO_BINARY_TYPE__GUEST_KCORE:
        case DSO_BINARY_TYPE__BPF_PROG_INFO:
        case DSO_BINARY_TYPE__BPF_IMAGE:
        case DSO_BINARY_TYPE__OOL:
        case DSO_BINARY_TYPE__JAVA_JIT:
                if (e_flags)
                        *e_flags = EF_HOST;
                return EM_HOST;
        case DSO_BINARY_TYPE__DEBUGLINK:
        case DSO_BINARY_TYPE__BUILD_ID_CACHE:
        case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
        case DSO_BINARY_TYPE__GNU_DEBUGDATA:
        case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
        case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
        case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
        case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
        case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
        case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
                break;
        case DSO_BINARY_TYPE__NOT_FOUND:
        default:
                if (e_flags)
                        *e_flags = 0;
                return EM_NONE;
        }

        mutex_lock(dso__data_open_lock());

        /*
         * dso__data(dso)->fd might be closed if other thread opened another
         * file (dso) due to open file limit (RLIMIT_NOFILE).
         */
        try_to_open_dso(dso, machine);
        fd = dso__data(dso)->fd;
        if (fd >= 0)
                e_machine = dso__read_e_machine(dso, fd, e_flags);
        else if (e_flags)
                *e_flags = 0;

        mutex_unlock(dso__data_open_lock());
        return e_machine;
}

/**
 * dso__data_read_addr - Read data from dso address
 * @dso: dso object
 * @machine: machine object
 * @add: virtual memory address
 * @data: buffer to store data
 * @size: size of the @data buffer
 *
 * External interface to read data from dso address.
 */
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);
}

/**
 * dso__data_write_cache_offs - Write data to dso data cache at file offset
 * @dso: dso object
 * @machine: machine object
 * @offset: file offset
 * @data: buffer to write
 * @size: size of the @data buffer
 *
 * Write into the dso file data cache, but do not change the file itself.
 */
ssize_t dso__data_write_cache_offs(struct dso *dso, struct machine *machine,
                                   u64 offset, const u8 *data_in, ssize_t size)
{
        u8 *data = (u8 *)data_in; /* cast away const to use same fns for r/w */

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

        return data_read_write_offset(dso, machine, offset, data, size, false);
}

/**
 * dso__data_write_cache_addr - Write data to dso data cache at dso address
 * @dso: dso object
 * @machine: machine object
 * @add: virtual memory address
 * @data: buffer to write
 * @size: size of the @data buffer
 *
 * External interface to write into the dso file data cache, but do not change
 * the file itself.
 */
ssize_t dso__data_write_cache_addr(struct dso *dso, struct map *map,
                                   struct machine *machine, u64 addr,
                                   const u8 *data, ssize_t size)
{
        u64 offset = map__map_ip(map, addr);

        return dso__data_write_cache_offs(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);
                dso__put(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__set_kernel(dso, dso_type);
        }

        return dso;
}

static void __dso__set_long_name_id(struct dso *dso, const char *name, bool name_allocated)
{
        if (dso__long_name_allocated(dso))
                free((char *)dso__long_name(dso));

        RC_CHK_ACCESS(dso)->long_name = name;
        RC_CHK_ACCESS(dso)->long_name_len = strlen(name);
        dso__set_long_name_allocated(dso, name_allocated);
}

static void dso__set_long_name_id(struct dso *dso, const char *name, bool name_allocated)
{
        struct dsos *dsos = dso__dsos(dso);

        if (name == NULL)
                return;

        if (dsos) {
                /*
                 * Need to avoid re-sorting the dsos breaking by non-atomically
                 * renaming the dso.
                 */
                down_write(&dsos->lock);
                __dso__set_long_name_id(dso, name, name_allocated);
                dsos->sorted = false;
                up_write(&dsos->lock);
        } else {
                __dso__set_long_name_id(dso, name, name_allocated);
        }
}

static int __dso_id__cmp(const struct dso_id *a, const struct dso_id *b)
{
        if (a->mmap2_valid && b->mmap2_valid) {
                if (a->maj > b->maj) return -1;
                if (a->maj < b->maj) return 1;

                if (a->min > b->min) return -1;
                if (a->min < b->min) return 1;

                if (a->ino > b->ino) return -1;
                if (a->ino < b->ino) return 1;
        }
        if (a->mmap2_ino_generation_valid && b->mmap2_ino_generation_valid) {
                if (a->ino_generation > b->ino_generation) return -1;
                if (a->ino_generation < b->ino_generation) return 1;
        }
        if (build_id__is_defined(&a->build_id) && build_id__is_defined(&b->build_id)) {
                if (a->build_id.size != b->build_id.size)
                        return a->build_id.size < b->build_id.size ? -1 : 1;
                return memcmp(a->build_id.data, b->build_id.data, a->build_id.size);
        }
        return 0;
}

const struct dso_id dso_id_empty = {
        {
                .maj = 0,
                .min = 0,
                .ino = 0,
                .ino_generation = 0,
        },
        .mmap2_valid = false,
        .mmap2_ino_generation_valid = false,
        {
                .size = 0,
        }
};

void __dso__improve_id(struct dso *dso, const struct dso_id *id)
{
        struct dsos *dsos = dso__dsos(dso);
        struct dso_id *dso_id = dso__id(dso);
        bool changed = false;

        /* dsos write lock held by caller. */

        if (id->mmap2_valid && !dso_id->mmap2_valid) {
                dso_id->maj = id->maj;
                dso_id->min = id->min;
                dso_id->ino = id->ino;
                dso_id->mmap2_valid = true;
                changed = true;
        }
        if (id->mmap2_ino_generation_valid && !dso_id->mmap2_ino_generation_valid) {
                dso_id->ino_generation = id->ino_generation;
                dso_id->mmap2_ino_generation_valid = true;
                changed = true;
        }
        if (build_id__is_defined(&id->build_id) && !build_id__is_defined(&dso_id->build_id)) {
                dso_id->build_id = id->build_id;
                changed = true;
        }
        if (changed && dsos)
                dsos->sorted = false;
}

int dso_id__cmp(const struct dso_id *a, const struct dso_id *b)
{
        if (a == &dso_id_empty || b == &dso_id_empty) {
                /* There is no valid data to compare so the comparison always returns identical. */
                return 0;
        }

        return __dso_id__cmp(a, b);
}

int dso__cmp_id(struct dso *a, struct dso *b)
{
        return __dso_id__cmp(dso__id(a), dso__id(b));
}

void dso__set_long_name(struct dso *dso, const char *name, bool name_allocated)
{
        dso__set_long_name_id(dso, name, name_allocated);
}

static void __dso__set_short_name(struct dso *dso, const char *name, bool name_allocated)
{
        if (dso__short_name_allocated(dso))
                free((char *)dso__short_name(dso));

        RC_CHK_ACCESS(dso)->short_name            = name;
        RC_CHK_ACCESS(dso)->short_name_len        = strlen(name);
        dso__set_short_name_allocated(dso, name_allocated);
}

void dso__set_short_name(struct dso *dso, const char *name, bool name_allocated)
{
        struct dsos *dsos = dso__dsos(dso);

        if (name == NULL)
                return;

        if (dsos) {
                /*
                 * Need to avoid re-sorting the dsos breaking by non-atomically
                 * renaming the dso.
                 */
                down_write(&dsos->lock);
                __dso__set_short_name(dso, name, name_allocated);
                dsos->sorted = false;
                up_write(&dsos->lock);
        } else {
                __dso__set_short_name(dso, name, name_allocated);
        }
}

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

        return dso__short_name_len(dso);
}

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

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

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

struct dso *dso__new_id(const char *name, const struct dso_id *id)
{
        RC_STRUCT(dso) *dso = zalloc(sizeof(*dso) + strlen(name) + 1);
        struct dso *res;
        struct dso_data *data;

        if (!dso)
                return NULL;

        if (ADD_RC_CHK(res, dso)) {
                strcpy(dso->name, name);
                if (id)
                        dso->id = *id;
                dso__set_long_name_id(res, dso->name, false);
                dso__set_short_name(res, dso->name, false);
                dso->symbols = RB_ROOT_CACHED;
                dso->symbol_names = NULL;
                dso->symbol_names_len = 0;
                dso->inlined_nodes = RB_ROOT_CACHED;
                dso->srclines = RB_ROOT_CACHED;
                dso->data_types = RB_ROOT;
                dso->global_vars = 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_srcline = 1;
                dso->a2l_fails = 1;
                dso->kernel = DSO_SPACE__USER;
                dso->is_kmod = 0;
                dso->needs_swap = DSO_SWAP__UNSET;
                dso->comp = COMP_ID__NONE;
                mutex_init(&dso->lock);
                refcount_set(&dso->refcnt, 1);
                data = &dso->data;
                data->cache = RB_ROOT;
                data->fd = -1;
                data->status = DSO_DATA_STATUS_UNKNOWN;
                INIT_LIST_HEAD(&data->open_entry);
#ifdef REFCNT_CHECKING
                data->dso = NULL; /* Set when on the open_entry list. */
#endif
        }
        return res;
}

struct dso *dso__new(const char *name)
{
        return dso__new_id(name, NULL);
}

void dso__delete(struct dso *dso)
{
        if (dso__dsos(dso))
                pr_err("DSO %s is still in rbtree when being deleted!\n", dso__long_name(dso));

        /* free inlines first, as they reference symbols */
        inlines__tree_delete(&RC_CHK_ACCESS(dso)->inlined_nodes);
        srcline__tree_delete(&RC_CHK_ACCESS(dso)->srclines);
        symbols__delete(&RC_CHK_ACCESS(dso)->symbols);
        RC_CHK_ACCESS(dso)->symbol_names_len = 0;
        zfree(&RC_CHK_ACCESS(dso)->symbol_names);
        annotated_data_type__tree_delete(dso__data_types(dso));
        global_var_type__tree_delete(dso__global_vars(dso));

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

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

        dso__data_close(dso);
        auxtrace_cache__free(RC_CHK_ACCESS(dso)->auxtrace_cache);
        dso_cache__free(dso);
        dso__free_a2l(dso);
        dso__free_libdw(dso);
        dso__free_symsrc_filename(dso);
        nsinfo__zput(RC_CHK_ACCESS(dso)->nsinfo);
        mutex_destroy(dso__lock(dso));
        RC_CHK_FREE(dso);
}

struct dso *dso__get(struct dso *dso)
{
        struct dso *result;

        if (RC_CHK_GET(result, dso))
                refcount_inc(&RC_CHK_ACCESS(dso)->refcnt);

        return result;
}

void dso__put(struct dso *dso)
{
#ifdef REFCNT_CHECKING
        if (dso && dso__data(dso) && refcount_read(&RC_CHK_ACCESS(dso)->refcnt) == 2)
                dso__data_close(dso);
#endif
        if (dso && refcount_dec_and_test(&RC_CHK_ACCESS(dso)->refcnt))
                dso__delete(dso);
        else
                RC_CHK_PUT(dso);
}

int dso__swap_init(struct dso *dso, unsigned char eidata)
{
        enum dso_swap_type type = dso_swap_type__from_elf_data(eidata);

        dso__set_needs_swap(dso, type);
        if (type == DSO_SWAP__UNSET) {
                pr_err("unrecognized DSO data encoding %d\n", eidata);
                return -EINVAL;
        }
        return 0;
}

void dso__set_build_id(struct dso *dso, const struct build_id *bid)
{
        dso__id(dso)->build_id = *bid;
}

bool dso__build_id_equal(const struct dso *dso, const struct build_id *bid)
{
        const struct build_id *dso_bid = dso__bid(dso);

        if (dso_bid->size > bid->size && dso_bid->size == BUILD_ID_SIZE) {
                /*
                 * For the backward compatibility, it allows a build-id has
                 * trailing zeros.
                 */
                return !memcmp(dso_bid->data, bid->data, bid->size) &&
                        !memchr_inv(&dso_bid->data[bid->size], 0,
                                    dso_bid->size - bid->size);
        }

        return dso_bid->size == bid->size &&
               memcmp(dso_bid->data, bid->data, dso_bid->size) == 0;
}

void dso__read_running_kernel_build_id(struct dso *dso, struct machine *machine)
{
        char path[PATH_MAX];
        struct build_id bid = { .size = 0, };

        if (machine__is_default_guest(machine))
                return;
        sprintf(path, "%s/sys/kernel/notes", machine->root_dir);
        sysfs__read_build_id(path, &bid);
        dso__set_build_id(dso, &bid);
}

int dso__kernel_module_get_build_id(struct dso *dso,
                                    const char *root_dir)
{
        char filename[PATH_MAX];
        struct build_id bid = { .size = 0, };
        /*
         * kernel module short names are of the form "[module]" and
         * we need just "module" here.
         */
        const char *name = dso__short_name(dso) + 1;

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

        sysfs__read_build_id(filename, &bid);
        dso__set_build_id(dso, &bid);
        return 0;
}

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

        build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(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(dso));

        if (dso__short_name(dso) != dso__long_name(dso))
                ret += fprintf(fp, "%s, ", dso__long_name(dso));
        ret += fprintf(fp, "%sloaded, ", dso__loaded(dso) ? "" : "NOT ");
        ret += dso__fprintf_buildid(dso, fp);
        ret += fprintf(fp, ")\n");
        for (nd = rb_first_cached(dso__symbols(dso)); 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 = -1;
        enum dso_type type = DSO__TYPE_UNKNOWN;

        if (dso__data_get_fd(dso, machine, &fd)) {
                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(dso);
        /*
         * 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) {
                errno = errnum;
                scnprintf(buf, buflen, "%m");

                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;
}

bool perf_pid_map_tid(const char *dso_name, int *tid)
{
        return sscanf(dso_name, "/tmp/perf-%d.map", tid) == 1;
}

bool is_perf_pid_map_name(const char *dso_name)
{
        int tid;

        return perf_pid_map_tid(dso_name, &tid);
}

struct find_file_offset_data {
        u64 ip;
        u64 offset;
};

/* This will be called for each PHDR in an ELF binary */
static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg)
{
        struct find_file_offset_data *data = arg;

        if (start <= data->ip && data->ip < start + len) {
                data->offset = pgoff + data->ip - start;
                return 1;
        }
        return 0;
}

static const u8 *__dso__read_symbol(struct dso *dso, const char *symfs_filename,
                                    u64 start, size_t len,
                                    u8 **out_buf, u64 *out_buf_len, bool *is_64bit)
{
        struct nscookie nsc;
        int fd;
        ssize_t count;
        struct find_file_offset_data data = {
                .ip = start,
        };
        u8 *code_buf = NULL;
        int saved_errno;

        nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
        fd = open(symfs_filename, O_RDONLY);
        saved_errno = errno;
        nsinfo__mountns_exit(&nsc);
        if (fd < 0) {
                errno = saved_errno;
                return NULL;
        }
        if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data, is_64bit) <= 0) {
                close(fd);
                errno = ENOENT;
                return NULL;
        }
        code_buf = malloc(len);
        if (code_buf == NULL) {
                close(fd);
                errno = ENOMEM;
                return NULL;
        }
        count = pread(fd, code_buf, len, data.offset);
        saved_errno = errno;
        close(fd);
        if ((u64)count != len) {
                free(code_buf);
                errno = saved_errno;
                return NULL;
        }
        *out_buf = code_buf;
        *out_buf_len = len;
        return code_buf;
}

/*
 * Read a symbol into memory for disassembly by a library like capstone of
 * libLLVM. If memory is allocated out_buf holds it.
 */
const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
                           const struct map *map, const struct symbol *sym,
                           u8 **out_buf, u64 *out_buf_len, bool *is_64bit)
{
        u64 start = map__rip_2objdump(map, sym->start);
        u64 end = map__rip_2objdump(map, sym->end);
        size_t len = end - start;

        *out_buf = NULL;
        *out_buf_len = 0;
        *is_64bit = false;

        if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_IMAGE) {
                /*
                 * Note, there is fallback BPF image disassembly in the objdump
                 * version but it currently does nothing.
                 */
                errno = EOPNOTSUPP;
                return NULL;
        }
        if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO) {
#ifdef HAVE_LIBBPF_SUPPORT
                struct bpf_prog_info_node *info_node;
                struct perf_bpil *info_linear;

                *is_64bit = sizeof(void *) == sizeof(u64);
                info_node = perf_env__find_bpf_prog_info(dso__bpf_prog(dso)->env,
                                                         dso__bpf_prog(dso)->id);
                if (!info_node) {
                        errno = SYMBOL_ANNOTATE_ERRNO__BPF_MISSING_BTF;
                        return NULL;
                }
                info_linear = info_node->info_linear;
                assert(len <= info_linear->info.jited_prog_len);
                *out_buf_len = len;
                return (const u8 *)(uintptr_t)(info_linear->info.jited_prog_insns);
#else
                pr_debug("No BPF program disassembly support\n");
                errno = EOPNOTSUPP;
                return NULL;
#endif
        }
        return __dso__read_symbol(dso, symfs_filename, start, len,
                                  out_buf, out_buf_len, is_64bit);
}

struct debuginfo *dso__debuginfo(struct dso *dso)
{
        char *name;
        bool decomp = false;
        struct debuginfo *dinfo = NULL;

        mutex_lock(dso__lock(dso));

        name = dso__get_filename(dso, "", &decomp);
        if (name)
                dinfo = debuginfo__new(name);

        if (decomp)
                unlink(name);

        mutex_unlock(dso__lock(dso));
        free(name);
        return dinfo;
}