builtin-buildid-cache.c

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// SPDX-License-Identifier: GPL-2.0
/*
 * builtin-buildid-cache.c
 *
 * Builtin buildid-cache command: Manages build-id cache
 *
 * Copyright (C) 2010, Red Hat Inc.
 * Copyright (C) 2010, Arnaldo Carvalho de Melo <acme@redhat.com>
 */
#include <sys/types.h>
#include <sys/time.h>
#include <time.h>
#include <dirent.h>
#include <errno.h>
#include <unistd.h>
#include "builtin.h"
#include "perf.h"
#include "namespaces.h"
#include "util/cache.h"
#include "util/debug.h"
#include "util/header.h"
#include <subcmd/parse-options.h>
#include "util/strlist.h"
#include "util/build-id.h"
#include "util/session.h"
#include "util/symbol.h"
#include "util/time-utils.h"
#include "util/probe-file.h"

static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
{
    char root_dir[PATH_MAX];
    char *p;

    strlcpy(root_dir, proc_dir, sizeof(root_dir));

    p = strrchr(root_dir, '/');
    if (!p)
        return -1;
    *p = '\0';
    return sysfs__sprintf_build_id(root_dir, sbuildid);
}

static int build_id_cache__kcore_dir(char *dir, size_t sz)
{
    return fetch_current_timestamp(dir, sz);
}

static bool same_kallsyms_reloc(const char *from_dir, char *to_dir)
{
    char from[PATH_MAX];
    char to[PATH_MAX];
    const char *name;
    u64 addr1 = 0, addr2 = 0;
    int i, err = -1;

    scnprintf(from, sizeof(from), "%s/kallsyms", from_dir);
    scnprintf(to, sizeof(to), "%s/kallsyms", to_dir);

    for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
        err = kallsyms__get_function_start(from, name, &addr1);
        if (!err)
            break;
    }

    if (err)
        return false;

    if (kallsyms__get_function_start(to, name, &addr2))
        return false;

    return addr1 == addr2;
}

static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir,
                      size_t to_dir_sz)
{
    char from[PATH_MAX];
    char to[PATH_MAX];
    char to_subdir[PATH_MAX];
    struct dirent *dent;
    int ret = -1;
    DIR *d;

    d = opendir(to_dir);
    if (!d)
        return -1;

    scnprintf(from, sizeof(from), "%s/modules", from_dir);

    while (1) {
        dent = readdir(d);
        if (!dent)
            break;
        if (dent->d_type != DT_DIR)
            continue;
        scnprintf(to, sizeof(to), "%s/%s/modules", to_dir,
              dent->d_name);
        scnprintf(to_subdir, sizeof(to_subdir), "%s/%s",
              to_dir, dent->d_name);
        if (!compare_proc_modules(from, to) &&
            same_kallsyms_reloc(from_dir, to_subdir)) {
            strlcpy(to_dir, to_subdir, to_dir_sz);
            ret = 0;
            break;
        }
    }

    closedir(d);

    return ret;
}

static int build_id_cache__add_kcore(const char *filename, bool force)
{
    char dir[32], sbuildid[SBUILD_ID_SIZE];
    char from_dir[PATH_MAX], to_dir[PATH_MAX];
    char *p;

    strlcpy(from_dir, filename, sizeof(from_dir));

    p = strrchr(from_dir, '/');
    if (!p || strcmp(p + 1, "kcore"))
        return -1;
    *p = '\0';

    if (build_id_cache__kcore_buildid(from_dir, sbuildid) < 0)
        return -1;

    scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s",
          buildid_dir, DSO__NAME_KCORE, sbuildid);

    if (!force &&
        !build_id_cache__kcore_existing(from_dir, to_dir, sizeof(to_dir))) {
        pr_debug("same kcore found in %s\n", to_dir);
        return 0;
    }

    if (build_id_cache__kcore_dir(dir, sizeof(dir)))
        return -1;

    scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s/%s",
          buildid_dir, DSO__NAME_KCORE, sbuildid, dir);

    if (mkdir_p(to_dir, 0755))
        return -1;

    if (kcore_copy(from_dir, to_dir)) {
        /* Remove YYYYmmddHHMMSShh directory */
        if (!rmdir(to_dir)) {
            p = strrchr(to_dir, '/');
            if (p)
                *p = '\0';
            /* Try to remove buildid directory */
            if (!rmdir(to_dir)) {
                p = strrchr(to_dir, '/');
                if (p)
                    *p = '\0';
                /* Try to remove [kernel.kcore] directory */
                rmdir(to_dir);
            }
        }
        return -1;
    }

    pr_debug("kcore added to build-id cache directory %s\n", to_dir);

    return 0;
}

static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
{
    char sbuild_id[SBUILD_ID_SIZE];
    u8 build_id[BUILD_ID_SIZE];
    int err;
    struct nscookie nsc;

    nsinfo__mountns_enter(nsi, &nsc);
    err = filename__read_build_id(filename, &build_id, sizeof(build_id));
    nsinfo__mountns_exit(&nsc);
    if (err < 0) {
        pr_debug("Couldn't read a build-id in %s\n", filename);
        return -1;
    }

    build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
    err = build_id_cache__add_s(sbuild_id, filename, nsi,
                    false, false);
    pr_debug("Adding %s %s: %s\n", sbuild_id, filename,
         err ? "FAIL" : "Ok");
    return err;
}

static int build_id_cache__remove_file(const char *filename, struct nsinfo *nsi)
{
    u8 build_id[BUILD_ID_SIZE];
    char sbuild_id[SBUILD_ID_SIZE];
    struct nscookie nsc;

    int err;

    nsinfo__mountns_enter(nsi, &nsc);
    err = filename__read_build_id(filename, &build_id, sizeof(build_id));
    nsinfo__mountns_exit(&nsc);
    if (err < 0) {
        pr_debug("Couldn't read a build-id in %s\n", filename);
        return -1;
    }

    build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
    err = build_id_cache__remove_s(sbuild_id);
    pr_debug("Removing %s %s: %s\n", sbuild_id, filename,
         err ? "FAIL" : "Ok");

    return err;
}

static int build_id_cache__purge_path(const char *pathname, struct nsinfo *nsi)
{
    struct strlist *list;
    struct str_node *pos;
    int err;

    err = build_id_cache__list_build_ids(pathname, nsi, &list);
    if (err)
        goto out;

    strlist__for_each_entry(pos, list) {
        err = build_id_cache__remove_s(pos->s);
        pr_debug("Removing %s %s: %s\n", pos->s, pathname,
             err ? "FAIL" : "Ok");
        if (err)
            break;
    }
    strlist__delete(list);

out:
    pr_debug("Purging %s: %s\n", pathname, err ? "FAIL" : "Ok");

    return err;
}

static int build_id_cache__purge_all(void)
{
    struct strlist *list;
    struct str_node *pos;
    int err = 0;
    char *buf;

    list = build_id_cache__list_all(false);
    if (!list) {
        pr_debug("Failed to get buildids: -%d\n", errno);
        return -EINVAL;
    }

    strlist__for_each_entry(pos, list) {
        buf = build_id_cache__origname(pos->s);
        err = build_id_cache__remove_s(pos->s);
        pr_debug("Removing %s (%s): %s\n", buf, pos->s,
             err ? "FAIL" : "Ok");
        free(buf);
        if (err)
            break;
    }
    strlist__delete(list);

    pr_debug("Purged all: %s\n", err ? "FAIL" : "Ok");
    return err;
}

static bool dso__missing_buildid_cache(struct dso *dso, int parm __maybe_unused)
{
    char filename[PATH_MAX];
    u8 build_id[BUILD_ID_SIZE];

    if (dso__build_id_filename(dso, filename, sizeof(filename), false) &&
        filename__read_build_id(filename, build_id,
                    sizeof(build_id)) != sizeof(build_id)) {
        if (errno == ENOENT)
            return false;

        pr_warning("Problems with %s file, consider removing it from the cache\n",
               filename);
    } else if (memcmp(dso->build_id, build_id, sizeof(dso->build_id))) {
        pr_warning("Problems with %s file, consider removing it from the cache\n",
               filename);
    }

    return true;
}

static int build_id_cache__fprintf_missing(struct perf_session *session, FILE *fp)
{
    perf_session__fprintf_dsos_buildid(session, fp, dso__missing_buildid_cache, 0);
    return 0;
}

static int build_id_cache__update_file(const char *filename, struct nsinfo *nsi)
{
    u8 build_id[BUILD_ID_SIZE];
    char sbuild_id[SBUILD_ID_SIZE];
    struct nscookie nsc;

    int err;

    nsinfo__mountns_enter(nsi, &nsc);
    err = filename__read_build_id(filename, &build_id, sizeof(build_id));
    nsinfo__mountns_exit(&nsc);
    if (err < 0) {
        pr_debug("Couldn't read a build-id in %s\n", filename);
        return -1;
    }
    err = 0;

    build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
    if (build_id_cache__cached(sbuild_id))
        err = build_id_cache__remove_s(sbuild_id);

    if (!err)
        err = build_id_cache__add_s(sbuild_id, filename, nsi, false,
                        false);

    pr_debug("Updating %s %s: %s\n", sbuild_id, filename,
         err ? "FAIL" : "Ok");

    return err;
}

static int build_id_cache__show_all(void)
{
    struct strlist *bidlist;
    struct str_node *nd;
    char *buf;

    bidlist = build_id_cache__list_all(true);
    if (!bidlist) {
        pr_debug("Failed to get buildids: -%d\n", errno);
        return -1;
    }
    strlist__for_each_entry(nd, bidlist) {
        buf = build_id_cache__origname(nd->s);
        fprintf(stdout, "%s %s\n", nd->s, buf);
        free(buf);
    }
    strlist__delete(bidlist);
    return 0;
}

int cmd_buildid_cache(int argc, const char **argv)
{
    struct strlist *list;
    struct str_node *pos;
    int ret = 0;
    int ns_id = -1;
    bool force = false;
    bool list_files = false;
    bool opts_flag = false;
    bool purge_all = false;
    char const *add_name_list_str = NULL,
           *remove_name_list_str = NULL,
           *purge_name_list_str = NULL,
           *missing_filename = NULL,
           *update_name_list_str = NULL,
           *kcore_filename = NULL;
    char sbuf[STRERR_BUFSIZE];

    struct perf_data data = {
        .mode  = PERF_DATA_MODE_READ,
    };
    struct perf_session *session = NULL;
    struct nsinfo *nsi = NULL;

    const struct option buildid_cache_options[] = {
    OPT_STRING('a', "add", &add_name_list_str,
           "file list", "file(s) to add"),
    OPT_STRING('k', "kcore", &kcore_filename,
           "file", "kcore file to add"),
    OPT_STRING('r', "remove", &remove_name_list_str, "file list",
            "file(s) to remove"),
    OPT_STRING('p', "purge", &purge_name_list_str, "file list",
            "file(s) to remove (remove old caches too)"),
    OPT_BOOLEAN('P', "purge-all", &purge_all, "purge all cached files"),
    OPT_BOOLEAN('l', "list", &list_files, "list all cached files"),
    OPT_STRING('M', "missing", &missing_filename, "file",
           "to find missing build ids in the cache"),
    OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
    OPT_STRING('u', "update", &update_name_list_str, "file list",
            "file(s) to update"),
    OPT_INCR('v', "verbose", &verbose, "be more verbose"),
    OPT_INTEGER(0, "target-ns", &ns_id, "target pid for namespace context"),
    OPT_END()
    };
    const char * const buildid_cache_usage[] = {
        "perf buildid-cache [<options>]",
        NULL
    };

    argc = parse_options(argc, argv, buildid_cache_options,
                 buildid_cache_usage, 0);

    opts_flag = add_name_list_str || kcore_filename ||
        remove_name_list_str || purge_name_list_str ||
        missing_filename || update_name_list_str ||
        purge_all;

    if (argc || !(list_files || opts_flag))
        usage_with_options(buildid_cache_usage, buildid_cache_options);

    /* -l is exclusive. It can not be used with other options. */
    if (list_files && opts_flag) {
        usage_with_options_msg(buildid_cache_usage,
            buildid_cache_options, "-l is exclusive.\n");
    }

    if (ns_id > 0)
        nsi = nsinfo__new(ns_id);

    if (missing_filename) {
        data.file.path = missing_filename;
        data.force     = force;

        session = perf_session__new(&data, false, NULL);
        if (session == NULL)
            return -1;
    }

    if (symbol__init(session ? &session->header.env : NULL) < 0)
        goto out;

    setup_pager();

    if (list_files) {
        ret = build_id_cache__show_all();
        goto out;
    }

    if (add_name_list_str) {
        list = strlist__new(add_name_list_str, NULL);
        if (list) {
            strlist__for_each_entry(pos, list)
                if (build_id_cache__add_file(pos->s, nsi)) {
                    if (errno == EEXIST) {
                        pr_debug("%s already in the cache\n",
                             pos->s);
                        continue;
                    }
                    pr_warning("Couldn't add %s: %s\n",
                           pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
                }

            strlist__delete(list);
        }
    }

    if (remove_name_list_str) {
        list = strlist__new(remove_name_list_str, NULL);
        if (list) {
            strlist__for_each_entry(pos, list)
                if (build_id_cache__remove_file(pos->s, nsi)) {
                    if (errno == ENOENT) {
                        pr_debug("%s wasn't in the cache\n",
                             pos->s);
                        continue;
                    }
                    pr_warning("Couldn't remove %s: %s\n",
                           pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
                }

            strlist__delete(list);
        }
    }

    if (purge_name_list_str) {
        list = strlist__new(purge_name_list_str, NULL);
        if (list) {
            strlist__for_each_entry(pos, list)
                if (build_id_cache__purge_path(pos->s, nsi)) {
                    if (errno == ENOENT) {
                        pr_debug("%s wasn't in the cache\n",
                             pos->s);
                        continue;
                    }
                    pr_warning("Couldn't remove %s: %s\n",
                           pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
                }

            strlist__delete(list);
        }
    }

    if (purge_all) {
        if (build_id_cache__purge_all()) {
            pr_warning("Couldn't remove some caches. Error: %s.\n",
                str_error_r(errno, sbuf, sizeof(sbuf)));
        }
    }

    if (missing_filename)
        ret = build_id_cache__fprintf_missing(session, stdout);

    if (update_name_list_str) {
        list = strlist__new(update_name_list_str, NULL);
        if (list) {
            strlist__for_each_entry(pos, list)
                if (build_id_cache__update_file(pos->s, nsi)) {
                    if (errno == ENOENT) {
                        pr_debug("%s wasn't in the cache\n",
                             pos->s);
                        continue;
                    }
                    pr_warning("Couldn't update %s: %s\n",
                           pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
                }

            strlist__delete(list);
        }
    }

    if (kcore_filename && build_id_cache__add_kcore(kcore_filename, force))
        pr_warning("Couldn't add %s\n", kcore_filename);

out:
    perf_session__delete(session);
    nsinfo__zput(nsi);

    return ret;
}