// 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>
#include <bpf/libbpf.h>
#include "bpf-event.h"
#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"

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__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',
        };

        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__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) < 9 ||
                    strncmp(dso->long_name, "/usr/lib/", 9)) {
                        ret = -1;
                        break;
                }
                len = __symbol__join_symfs(filename, size, "/usr/lib/debug");
                snprintf(filename + len, size - len, "%s", dso->long_name + 4);
                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__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_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 *pathname, size_t len)
{
        char tmpbuf[] = KMOD_DECOMP_NAME;
        int fd = -1;

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

        if (dso->comp == COMP_ID__NONE)
                return -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[dso->comp].is_compressed(name))
                return open(name, O_RDONLY);

        fd = mkstemp(tmpbuf);
        if (fd < 0) {
                dso->load_errno = errno;
                return -1;
        }

        if (compressions[dso->comp].decompress(name, fd)) {
                dso->load_errno = 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;
}

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->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->comp = m->comp;
        }

        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_init(&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);
        bool decomp = false;

        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;
                }

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

        fd = do_open(name);

        if (decomp)
                unlink(name);

out:
        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)
{
        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);
        }
}

/**
 * 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)
{
        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();
}

/**
 * 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)
{
        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;
}

/**
 * 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.
 */
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 ssize_t bpf_read(struct dso *dso, u64 offset, char *data)
{
        struct bpf_prog_info_node *node;
        ssize_t size = DSO__DATA_CACHE_SIZE;
        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.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;

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

        dso->data.file_size = node->info_linear->info.jited_prog_len;
        return 0;
}

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, 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;

        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) {
                dso->data.status = DSO_DATA_STATUS_ERROR;
                ret = -errno;
                goto out;
        }

        ret = pread(dso->data.fd, data, DSO__DATA_CACHE_SIZE, offset);
out:
        pthread_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;
        }

        if (dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO)
                *ret = bpf_read(dso, cache_offset, cache->data);
        else if (dso->binary_type == 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;
        char sbuf[STRERR_BUFSIZE];

        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;
}

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

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

        if (dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO)
                return bpf_size(dso);

        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.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.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.status == DSO_DATA_STATUS_ERROR)
                return -1;

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

/**
 * 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.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);

        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;
}

static void dso__set_long_name_id(struct dso *dso, const char *name, struct dso_id *id, 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);
                /*
                 * __dsos__findnew_link_by_longname_id() 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)
                __dsos__findnew_link_by_longname_id(root, dso, NULL, id);
}

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

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;
}

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

        if (dso != NULL) {
                strcpy(dso->name, name);
                if (id)
                        dso->id = *id;
                dso__set_long_name_id(dso, dso->name, id, false);
                dso__set_short_name(dso, dso->name, false);
                dso->symbols = dso->symbol_names = RB_ROOT_CACHED;
                dso->data.cache = RB_ROOT;
                dso->inlined_nodes = RB_ROOT_CACHED;
                dso->srclines = RB_ROOT_CACHED;
                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_SPACE__USER;
                dso->needs_swap = DSO_SWAP__UNSET;
                dso->comp = COMP_ID__NONE;
                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;
}

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

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;
}

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_cached(&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;
}