root/tools/perf/util/header.c
// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <inttypes.h>
#include "string2.h"
#include <sys/param.h>
#include <sys/types.h>
#include <byteswap.h>
#include <unistd.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/compiler.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/string.h>
#include <linux/stringify.h>
#include <linux/zalloc.h>
#include <sys/stat.h>
#include <sys/utsname.h>
#include <linux/time64.h>
#include <dirent.h>
#ifdef HAVE_LIBBPF_SUPPORT
#include <bpf/libbpf.h>
#endif
#include <perf/cpumap.h>
#include <tools/libc_compat.h> // reallocarray

#include "dso.h"
#include "evlist.h"
#include "evsel.h"
#include "util/evsel_fprintf.h"
#include "header.h"
#include "memswap.h"
#include "trace-event.h"
#include "session.h"
#include "symbol.h"
#include "debug.h"
#include "cpumap.h"
#include "pmu.h"
#include "pmus.h"
#include "vdso.h"
#include "strbuf.h"
#include "build-id.h"
#include "data.h"
#include <api/fs/fs.h>
#include <api/io_dir.h>
#include "asm/bug.h"
#include "tool.h"
#include "time-utils.h"
#include "units.h"
#include "util/util.h" // perf_exe()
#include "cputopo.h"
#include "bpf-event.h"
#include "bpf-utils.h"
#include "clockid.h"

#include <linux/ctype.h>
#include <internal/lib.h>

#ifdef HAVE_LIBTRACEEVENT
#include <event-parse.h>
#endif

/*
 * magic2 = "PERFILE2"
 * must be a numerical value to let the endianness
 * determine the memory layout. That way we are able
 * to detect endianness when reading the perf.data file
 * back.
 *
 * we check for legacy (PERFFILE) format.
 */
static const char *__perf_magic1 = "PERFFILE";
static const u64 __perf_magic2    = 0x32454c4946524550ULL;
static const u64 __perf_magic2_sw = 0x50455246494c4532ULL;

#define PERF_MAGIC      __perf_magic2
#define DNAME_LEN       16

const char perf_version_string[] = PERF_VERSION;

struct perf_file_attr {
        struct perf_event_attr  attr;
        struct perf_file_section        ids;
};

void perf_header__set_feat(struct perf_header *header, int feat)
{
        __set_bit(feat, header->adds_features);
}

void perf_header__clear_feat(struct perf_header *header, int feat)
{
        __clear_bit(feat, header->adds_features);
}

bool perf_header__has_feat(const struct perf_header *header, int feat)
{
        return test_bit(feat, header->adds_features);
}

static int __do_write_fd(struct feat_fd *ff, const void *buf, size_t size)
{
        ssize_t ret = writen(ff->fd, buf, size);

        if (ret != (ssize_t)size)
                return ret < 0 ? (int)ret : -1;
        return 0;
}

static int __do_write_buf(struct feat_fd *ff,  const void *buf, size_t size)
{
        /* struct perf_event_header::size is u16 */
        const size_t max_size = 0xffff - sizeof(struct perf_event_header);
        size_t new_size = ff->size;
        void *addr;

        if (size + ff->offset > max_size)
                return -E2BIG;

        while (size > (new_size - ff->offset))
                new_size <<= 1;
        new_size = min(max_size, new_size);

        if (ff->size < new_size) {
                addr = realloc(ff->buf, new_size);
                if (!addr)
                        return -ENOMEM;
                ff->buf = addr;
                ff->size = new_size;
        }

        memcpy(ff->buf + ff->offset, buf, size);
        ff->offset += size;

        return 0;
}

/* Return: 0 if succeeded, -ERR if failed. */
int do_write(struct feat_fd *ff, const void *buf, size_t size)
{
        if (!ff->buf)
                return __do_write_fd(ff, buf, size);
        return __do_write_buf(ff, buf, size);
}

/* Return: 0 if succeeded, -ERR if failed. */
static int do_write_bitmap(struct feat_fd *ff, unsigned long *set, u64 size)
{
        u64 *p = (u64 *) set;
        int i, ret;

        ret = do_write(ff, &size, sizeof(size));
        if (ret < 0)
                return ret;

        for (i = 0; (u64) i < BITS_TO_U64(size); i++) {
                ret = do_write(ff, p + i, sizeof(*p));
                if (ret < 0)
                        return ret;
        }

        return 0;
}

/* Return: 0 if succeeded, -ERR if failed. */
int write_padded(struct feat_fd *ff, const void *bf,
                 size_t count, size_t count_aligned)
{
        static const char zero_buf[NAME_ALIGN];
        int err = do_write(ff, bf, count);

        if (!err)
                err = do_write(ff, zero_buf, count_aligned - count);

        return err;
}

#define string_size(str)                                                \
        (PERF_ALIGN((strlen(str) + 1), NAME_ALIGN) + sizeof(u32))

/* Return: 0 if succeeded, -ERR if failed. */
static int do_write_string(struct feat_fd *ff, const char *str)
{
        u32 len, olen;
        int ret;

        olen = strlen(str) + 1;
        len = PERF_ALIGN(olen, NAME_ALIGN);

        /* write len, incl. \0 */
        ret = do_write(ff, &len, sizeof(len));
        if (ret < 0)
                return ret;

        return write_padded(ff, str, olen, len);
}

static int __do_read_fd(struct feat_fd *ff, void *addr, ssize_t size)
{
        ssize_t ret = readn(ff->fd, addr, size);

        if (ret != size)
                return ret < 0 ? (int)ret : -1;
        return 0;
}

static int __do_read_buf(struct feat_fd *ff, void *addr, ssize_t size)
{
        if (size > (ssize_t)ff->size - ff->offset)
                return -1;

        memcpy(addr, ff->buf + ff->offset, size);
        ff->offset += size;

        return 0;

}

static int __do_read(struct feat_fd *ff, void *addr, ssize_t size)
{
        if (!ff->buf)
                return __do_read_fd(ff, addr, size);
        return __do_read_buf(ff, addr, size);
}

static int do_read_u32(struct feat_fd *ff, u32 *addr)
{
        int ret;

        ret = __do_read(ff, addr, sizeof(*addr));
        if (ret)
                return ret;

        if (ff->ph->needs_swap)
                *addr = bswap_32(*addr);
        return 0;
}

static int do_read_u64(struct feat_fd *ff, u64 *addr)
{
        int ret;

        ret = __do_read(ff, addr, sizeof(*addr));
        if (ret)
                return ret;

        if (ff->ph->needs_swap)
                *addr = bswap_64(*addr);
        return 0;
}

static char *do_read_string(struct feat_fd *ff)
{
        u32 len;
        char *buf;

        if (do_read_u32(ff, &len))
                return NULL;

        buf = malloc(len);
        if (!buf)
                return NULL;

        if (!__do_read(ff, buf, len)) {
                /*
                 * strings are padded by zeroes
                 * thus the actual strlen of buf
                 * may be less than len
                 */
                return buf;
        }

        free(buf);
        return NULL;
}

/* Return: 0 if succeeded, -ERR if failed. */
static int do_read_bitmap(struct feat_fd *ff, unsigned long **pset, u64 *psize)
{
        unsigned long *set;
        u64 size, *p;
        int i, ret;

        ret = do_read_u64(ff, &size);
        if (ret)
                return ret;

        set = bitmap_zalloc(size);
        if (!set)
                return -ENOMEM;

        p = (u64 *) set;

        for (i = 0; (u64) i < BITS_TO_U64(size); i++) {
                ret = do_read_u64(ff, p + i);
                if (ret < 0) {
                        free(set);
                        return ret;
                }
        }

        *pset  = set;
        *psize = size;
        return 0;
}

#ifdef HAVE_LIBTRACEEVENT
static int write_tracing_data(struct feat_fd *ff,
                              struct evlist *evlist)
{
        if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
                return -1;

        return read_tracing_data(ff->fd, &evlist->core.entries);
}
#endif

static int write_build_id(struct feat_fd *ff,
                          struct evlist *evlist __maybe_unused)
{
        struct perf_session *session;
        int err;

        session = container_of(ff->ph, struct perf_session, header);

        if (!perf_session__read_build_ids(session, true))
                return -1;

        if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
                return -1;

        err = perf_session__write_buildid_table(session, ff);
        if (err < 0) {
                pr_debug("failed to write buildid table\n");
                return err;
        }

        return 0;
}

static int write_hostname(struct feat_fd *ff,
                          struct evlist *evlist __maybe_unused)
{
        struct utsname uts;
        int ret;

        ret = uname(&uts);
        if (ret < 0)
                return -1;

        return do_write_string(ff, uts.nodename);
}

static int write_osrelease(struct feat_fd *ff,
                           struct evlist *evlist __maybe_unused)
{
        struct utsname uts;
        int ret;

        ret = uname(&uts);
        if (ret < 0)
                return -1;

        return do_write_string(ff, uts.release);
}

static int write_arch(struct feat_fd *ff,
                      struct evlist *evlist __maybe_unused)
{
        struct utsname uts;
        int ret;

        ret = uname(&uts);
        if (ret < 0)
                return -1;

        return do_write_string(ff, uts.machine);
}

static int write_e_machine(struct feat_fd *ff,
                           struct evlist *evlist __maybe_unused)
{
        /* e_machine expanded from 16 to 32-bits for alignment. */
        uint32_t e_flags;
        uint32_t e_machine = perf_session__e_machine(evlist->session, &e_flags);
        int ret;

        ret = do_write(ff, &e_machine, sizeof(e_machine));
        if (ret)
                return ret;

        return do_write(ff, &e_flags, sizeof(e_flags));
}

static int write_version(struct feat_fd *ff,
                         struct evlist *evlist __maybe_unused)
{
        return do_write_string(ff, perf_version_string);
}

static int __write_cpudesc(struct feat_fd *ff, const char *cpuinfo_proc)
{
        FILE *file;
        char *buf = NULL;
        char *s, *p;
        const char *search = cpuinfo_proc;
        size_t len = 0;
        int ret = -1;

        if (!search)
                return -1;

        file = fopen("/proc/cpuinfo", "r");
        if (!file)
                return -1;

        while (getline(&buf, &len, file) > 0) {
                ret = strncmp(buf, search, strlen(search));
                if (!ret)
                        break;
        }

        if (ret) {
                ret = -1;
                goto done;
        }

        s = buf;

        p = strchr(buf, ':');
        if (p && *(p+1) == ' ' && *(p+2))
                s = p + 2;
        p = strchr(s, '\n');
        if (p)
                *p = '\0';

        /* squash extra space characters (branding string) */
        p = s;
        while (*p) {
                if (isspace(*p)) {
                        char *r = p + 1;
                        char *q = skip_spaces(r);
                        *p = ' ';
                        if (q != (p+1))
                                while ((*r++ = *q++));
                }
                p++;
        }
        ret = do_write_string(ff, s);
done:
        free(buf);
        fclose(file);
        return ret;
}

static int write_cpudesc(struct feat_fd *ff,
                       struct evlist *evlist __maybe_unused)
{
#if defined(__powerpc__) || defined(__hppa__) || defined(__sparc__)
#define CPUINFO_PROC    { "cpu", }
#elif defined(__s390__)
#define CPUINFO_PROC    { "vendor_id", }
#elif defined(__sh__)
#define CPUINFO_PROC    { "cpu type", }
#elif defined(__alpha__) || defined(__mips__)
#define CPUINFO_PROC    { "cpu model", }
#elif defined(__arm__)
#define CPUINFO_PROC    { "model name", "Processor", }
#elif defined(__arc__)
#define CPUINFO_PROC    { "Processor", }
#elif defined(__xtensa__)
#define CPUINFO_PROC    { "core ID", }
#elif defined(__loongarch__)
#define CPUINFO_PROC    { "Model Name", }
#else
#define CPUINFO_PROC    { "model name", }
#endif
        const char *cpuinfo_procs[] = CPUINFO_PROC;
#undef CPUINFO_PROC
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(cpuinfo_procs); i++) {
                int ret;
                ret = __write_cpudesc(ff, cpuinfo_procs[i]);
                if (ret >= 0)
                        return ret;
        }
        return -1;
}


static int write_nrcpus(struct feat_fd *ff,
                        struct evlist *evlist __maybe_unused)
{
        long nr;
        u32 nrc, nra;
        int ret;

        nrc = cpu__max_present_cpu().cpu;

        nr = sysconf(_SC_NPROCESSORS_ONLN);
        if (nr < 0)
                return -1;

        nra = (u32)(nr & UINT_MAX);

        ret = do_write(ff, &nrc, sizeof(nrc));
        if (ret < 0)
                return ret;

        return do_write(ff, &nra, sizeof(nra));
}

static int write_event_desc(struct feat_fd *ff,
                            struct evlist *evlist)
{
        struct evsel *evsel;
        u32 nre, nri, sz;
        int ret;

        nre = evlist->core.nr_entries;

        /*
         * write number of events
         */
        ret = do_write(ff, &nre, sizeof(nre));
        if (ret < 0)
                return ret;

        /*
         * size of perf_event_attr struct
         */
        sz = (u32)sizeof(evsel->core.attr);
        ret = do_write(ff, &sz, sizeof(sz));
        if (ret < 0)
                return ret;

        evlist__for_each_entry(evlist, evsel) {
                ret = do_write(ff, &evsel->core.attr, sz);
                if (ret < 0)
                        return ret;
                /*
                 * write number of unique id per event
                 * there is one id per instance of an event
                 *
                 * copy into an nri to be independent of the
                 * type of ids,
                 */
                nri = evsel->core.ids;
                ret = do_write(ff, &nri, sizeof(nri));
                if (ret < 0)
                        return ret;

                /*
                 * write event string as passed on cmdline
                 */
                ret = do_write_string(ff, evsel__name(evsel));
                if (ret < 0)
                        return ret;
                /*
                 * write unique ids for this event
                 */
                ret = do_write(ff, evsel->core.id, evsel->core.ids * sizeof(u64));
                if (ret < 0)
                        return ret;
        }
        return 0;
}

static int write_cmdline(struct feat_fd *ff,
                         struct evlist *evlist __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        char pbuf[MAXPATHLEN], *buf;
        int i, ret, n;

        /* actual path to perf binary */
        buf = perf_exe(pbuf, MAXPATHLEN);

        /* account for binary path */
        n = env->nr_cmdline + 1;

        ret = do_write(ff, &n, sizeof(n));
        if (ret < 0)
                return ret;

        ret = do_write_string(ff, buf);
        if (ret < 0)
                return ret;

        for (i = 0 ; i < env->nr_cmdline; i++) {
                ret = do_write_string(ff, env->cmdline_argv[i]);
                if (ret < 0)
                        return ret;
        }
        return 0;
}


static int write_cpu_topology(struct feat_fd *ff,
                              struct evlist *evlist __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        struct cpu_topology *tp;
        u32 i;
        int ret, j;

        tp = cpu_topology__new();
        if (!tp)
                return -1;

        ret = do_write(ff, &tp->package_cpus_lists, sizeof(tp->package_cpus_lists));
        if (ret < 0)
                goto done;

        for (i = 0; i < tp->package_cpus_lists; i++) {
                ret = do_write_string(ff, tp->package_cpus_list[i]);
                if (ret < 0)
                        goto done;
        }
        ret = do_write(ff, &tp->core_cpus_lists, sizeof(tp->core_cpus_lists));
        if (ret < 0)
                goto done;

        for (i = 0; i < tp->core_cpus_lists; i++) {
                ret = do_write_string(ff, tp->core_cpus_list[i]);
                if (ret < 0)
                        break;
        }

        ret = perf_env__read_cpu_topology_map(env);
        if (ret < 0)
                goto done;

        for (j = 0; j < env->nr_cpus_avail; j++) {
                ret = do_write(ff, &env->cpu[j].core_id,
                               sizeof(env->cpu[j].core_id));
                if (ret < 0)
                        return ret;
                ret = do_write(ff, &env->cpu[j].socket_id,
                               sizeof(env->cpu[j].socket_id));
                if (ret < 0)
                        return ret;
        }

        if (!tp->die_cpus_lists)
                goto done;

        ret = do_write(ff, &tp->die_cpus_lists, sizeof(tp->die_cpus_lists));
        if (ret < 0)
                goto done;

        for (i = 0; i < tp->die_cpus_lists; i++) {
                ret = do_write_string(ff, tp->die_cpus_list[i]);
                if (ret < 0)
                        goto done;
        }

        for (j = 0; j < env->nr_cpus_avail; j++) {
                ret = do_write(ff, &env->cpu[j].die_id,
                               sizeof(env->cpu[j].die_id));
                if (ret < 0)
                        return ret;
        }

done:
        cpu_topology__delete(tp);
        return ret;
}



static int write_total_mem(struct feat_fd *ff,
                           struct evlist *evlist __maybe_unused)
{
        char *buf = NULL;
        FILE *fp;
        size_t len = 0;
        int ret = -1, n;
        uint64_t mem;

        fp = fopen("/proc/meminfo", "r");
        if (!fp)
                return -1;

        while (getline(&buf, &len, fp) > 0) {
                ret = strncmp(buf, "MemTotal:", 9);
                if (!ret)
                        break;
        }
        if (!ret) {
                n = sscanf(buf, "%*s %"PRIu64, &mem);
                if (n == 1)
                        ret = do_write(ff, &mem, sizeof(mem));
        } else
                ret = -1;
        free(buf);
        fclose(fp);
        return ret;
}

static int write_numa_topology(struct feat_fd *ff,
                               struct evlist *evlist __maybe_unused)
{
        struct numa_topology *tp;
        int ret = -1;
        u32 i;

        tp = numa_topology__new();
        if (!tp)
                return -ENOMEM;

        ret = do_write(ff, &tp->nr, sizeof(u32));
        if (ret < 0)
                goto err;

        for (i = 0; i < tp->nr; i++) {
                struct numa_topology_node *n = &tp->nodes[i];

                ret = do_write(ff, &n->node, sizeof(u32));
                if (ret < 0)
                        goto err;

                ret = do_write(ff, &n->mem_total, sizeof(u64));
                if (ret)
                        goto err;

                ret = do_write(ff, &n->mem_free, sizeof(u64));
                if (ret)
                        goto err;

                ret = do_write_string(ff, n->cpus);
                if (ret < 0)
                        goto err;
        }

        ret = 0;

err:
        numa_topology__delete(tp);
        return ret;
}

/*
 * File format:
 *
 * struct pmu_mappings {
 *      u32     pmu_num;
 *      struct pmu_map {
 *              u32     type;
 *              char    name[];
 *      }[pmu_num];
 * };
 */

static int write_pmu_mappings(struct feat_fd *ff,
                              struct evlist *evlist __maybe_unused)
{
        struct perf_pmu *pmu = NULL;
        u32 pmu_num = 0;
        int ret;

        /*
         * Do a first pass to count number of pmu to avoid lseek so this
         * works in pipe mode as well.
         */
        while ((pmu = perf_pmus__scan(pmu)))
                pmu_num++;

        ret = do_write(ff, &pmu_num, sizeof(pmu_num));
        if (ret < 0)
                return ret;

        while ((pmu = perf_pmus__scan(pmu))) {
                ret = do_write(ff, &pmu->type, sizeof(pmu->type));
                if (ret < 0)
                        return ret;

                ret = do_write_string(ff, pmu->name);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

/*
 * File format:
 *
 * struct group_descs {
 *      u32     nr_groups;
 *      struct group_desc {
 *              char    name[];
 *              u32     leader_idx;
 *              u32     nr_members;
 *      }[nr_groups];
 * };
 */
static int write_group_desc(struct feat_fd *ff,
                            struct evlist *evlist)
{
        u32 nr_groups = evlist__nr_groups(evlist);
        struct evsel *evsel;
        int ret;

        ret = do_write(ff, &nr_groups, sizeof(nr_groups));
        if (ret < 0)
                return ret;

        evlist__for_each_entry(evlist, evsel) {
                if (evsel__is_group_leader(evsel) && evsel->core.nr_members > 1) {
                        const char *name = evsel->group_name ?: "{anon_group}";
                        u32 leader_idx = evsel->core.idx;
                        u32 nr_members = evsel->core.nr_members;

                        ret = do_write_string(ff, name);
                        if (ret < 0)
                                return ret;

                        ret = do_write(ff, &leader_idx, sizeof(leader_idx));
                        if (ret < 0)
                                return ret;

                        ret = do_write(ff, &nr_members, sizeof(nr_members));
                        if (ret < 0)
                                return ret;
                }
        }
        return 0;
}

/*
 * Return the CPU id as a raw string.
 *
 * Each architecture should provide a more precise id string that
 * can be use to match the architecture's "mapfile".
 */
char * __weak get_cpuid_str(struct perf_cpu cpu __maybe_unused)
{
        return NULL;
}

char *get_cpuid_allow_env_override(struct perf_cpu cpu)
{
        char *cpuid;
        static bool printed;

        cpuid = getenv("PERF_CPUID");
        if (cpuid)
                cpuid = strdup(cpuid);
        if (!cpuid)
                cpuid = get_cpuid_str(cpu);
        if (!cpuid)
                return NULL;

        if (!printed) {
                pr_debug("Using CPUID %s\n", cpuid);
                printed = true;
        }
        return cpuid;
}

/* Return zero when the cpuid from the mapfile.csv matches the
 * cpuid string generated on this platform.
 * Otherwise return non-zero.
 */
int __weak strcmp_cpuid_str(const char *mapcpuid, const char *cpuid)
{
        regex_t re;
        regmatch_t pmatch[1];
        int match;

        if (regcomp(&re, mapcpuid, REG_EXTENDED) != 0) {
                /* Warn unable to generate match particular string. */
                pr_info("Invalid regular expression %s\n", mapcpuid);
                return 1;
        }

        match = !regexec(&re, cpuid, 1, pmatch, 0);
        regfree(&re);
        if (match) {
                size_t match_len = (pmatch[0].rm_eo - pmatch[0].rm_so);

                /* Verify the entire string matched. */
                if (match_len == strlen(cpuid))
                        return 0;
        }
        return 1;
}

/*
 * default get_cpuid(): nothing gets recorded
 * actual implementation must be in arch/$(SRCARCH)/util/header.c
 */
int __weak get_cpuid(char *buffer __maybe_unused, size_t sz __maybe_unused,
                     struct perf_cpu cpu __maybe_unused)
{
        return ENOSYS; /* Not implemented */
}

static int write_cpuid(struct feat_fd *ff, struct evlist *evlist)
{
        struct perf_cpu cpu = perf_cpu_map__min(evlist->core.all_cpus);
        char buffer[64];
        int ret;

        ret = get_cpuid(buffer, sizeof(buffer), cpu);
        if (ret)
                return -1;

        return do_write_string(ff, buffer);
}

static int write_branch_stack(struct feat_fd *ff __maybe_unused,
                              struct evlist *evlist __maybe_unused)
{
        return 0;
}

static int write_auxtrace(struct feat_fd *ff,
                          struct evlist *evlist __maybe_unused)
{
        struct perf_session *session;
        int err;

        if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
                return -1;

        session = container_of(ff->ph, struct perf_session, header);

        err = auxtrace_index__write(ff->fd, &session->auxtrace_index);
        if (err < 0)
                pr_err("Failed to write auxtrace index\n");
        return err;
}

static int write_clockid(struct feat_fd *ff,
                         struct evlist *evlist __maybe_unused)
{
        return do_write(ff, &ff->ph->env.clock.clockid_res_ns,
                        sizeof(ff->ph->env.clock.clockid_res_ns));
}

static int write_clock_data(struct feat_fd *ff,
                            struct evlist *evlist __maybe_unused)
{
        u64 *data64;
        u32 data32;
        int ret;

        /* version */
        data32 = 1;

        ret = do_write(ff, &data32, sizeof(data32));
        if (ret < 0)
                return ret;

        /* clockid */
        data32 = ff->ph->env.clock.clockid;

        ret = do_write(ff, &data32, sizeof(data32));
        if (ret < 0)
                return ret;

        /* TOD ref time */
        data64 = &ff->ph->env.clock.tod_ns;

        ret = do_write(ff, data64, sizeof(*data64));
        if (ret < 0)
                return ret;

        /* clockid ref time */
        data64 = &ff->ph->env.clock.clockid_ns;

        return do_write(ff, data64, sizeof(*data64));
}

static int write_hybrid_topology(struct feat_fd *ff,
                                 struct evlist *evlist __maybe_unused)
{
        struct hybrid_topology *tp;
        int ret;
        u32 i;

        tp = hybrid_topology__new();
        if (!tp)
                return -ENOENT;

        ret = do_write(ff, &tp->nr, sizeof(u32));
        if (ret < 0)
                goto err;

        for (i = 0; i < tp->nr; i++) {
                struct hybrid_topology_node *n = &tp->nodes[i];

                ret = do_write_string(ff, n->pmu_name);
                if (ret < 0)
                        goto err;

                ret = do_write_string(ff, n->cpus);
                if (ret < 0)
                        goto err;
        }

        ret = 0;

err:
        hybrid_topology__delete(tp);
        return ret;
}

static int write_dir_format(struct feat_fd *ff,
                            struct evlist *evlist __maybe_unused)
{
        struct perf_session *session;
        struct perf_data *data;

        session = container_of(ff->ph, struct perf_session, header);
        data = session->data;

        if (WARN_ON(!perf_data__is_dir(data)))
                return -1;

        return do_write(ff, &data->dir.version, sizeof(data->dir.version));
}

#ifdef HAVE_LIBBPF_SUPPORT
static int write_bpf_prog_info(struct feat_fd *ff,
                               struct evlist *evlist __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        struct rb_root *root;
        struct rb_node *next;
        int ret = 0;

        down_read(&env->bpf_progs.lock);

        ret = do_write(ff, &env->bpf_progs.infos_cnt,
                       sizeof(env->bpf_progs.infos_cnt));
        if (ret < 0 || env->bpf_progs.infos_cnt == 0)
                goto out;

        root = &env->bpf_progs.infos;
        next = rb_first(root);
        while (next) {
                struct bpf_prog_info_node *node;
                size_t len;

                node = rb_entry(next, struct bpf_prog_info_node, rb_node);
                next = rb_next(&node->rb_node);
                len = sizeof(struct perf_bpil) +
                        node->info_linear->data_len;

                /* before writing to file, translate address to offset */
                bpil_addr_to_offs(node->info_linear);
                ret = do_write(ff, node->info_linear, len);
                /*
                 * translate back to address even when do_write() fails,
                 * so that this function never changes the data.
                 */
                bpil_offs_to_addr(node->info_linear);
                if (ret < 0)
                        goto out;
        }
out:
        up_read(&env->bpf_progs.lock);
        return ret;
}

static int write_bpf_btf(struct feat_fd *ff,
                         struct evlist *evlist __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        struct rb_root *root;
        struct rb_node *next;
        int ret = 0;

        down_read(&env->bpf_progs.lock);

        ret = do_write(ff, &env->bpf_progs.btfs_cnt,
                       sizeof(env->bpf_progs.btfs_cnt));

        if (ret < 0 || env->bpf_progs.btfs_cnt == 0)
                goto out;

        root = &env->bpf_progs.btfs;
        next = rb_first(root);
        while (next) {
                struct btf_node *node;

                node = rb_entry(next, struct btf_node, rb_node);
                next = rb_next(&node->rb_node);
                ret = do_write(ff, &node->id,
                               sizeof(u32) * 2 + node->data_size);
                if (ret < 0)
                        goto out;
        }
out:
        up_read(&env->bpf_progs.lock);
        return ret;
}
#endif // HAVE_LIBBPF_SUPPORT

static int cpu_cache_level__sort(const void *a, const void *b)
{
        struct cpu_cache_level *cache_a = (struct cpu_cache_level *)a;
        struct cpu_cache_level *cache_b = (struct cpu_cache_level *)b;

        return cache_a->level - cache_b->level;
}

static bool cpu_cache_level__cmp(struct cpu_cache_level *a, struct cpu_cache_level *b)
{
        if (a->level != b->level)
                return false;

        if (a->line_size != b->line_size)
                return false;

        if (a->sets != b->sets)
                return false;

        if (a->ways != b->ways)
                return false;

        if (strcmp(a->type, b->type))
                return false;

        if (strcmp(a->size, b->size))
                return false;

        if (strcmp(a->map, b->map))
                return false;

        return true;
}

static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 level)
{
        char path[PATH_MAX], file[PATH_MAX];
        struct stat st;
        size_t len;

        scnprintf(path, PATH_MAX, "devices/system/cpu/cpu%d/cache/index%d/", cpu, level);
        scnprintf(file, PATH_MAX, "%s/%s", sysfs__mountpoint(), path);

        if (stat(file, &st))
                return 1;

        scnprintf(file, PATH_MAX, "%s/level", path);
        if (sysfs__read_int(file, (int *) &cache->level))
                return -1;

        scnprintf(file, PATH_MAX, "%s/coherency_line_size", path);
        if (sysfs__read_int(file, (int *) &cache->line_size))
                return -1;

        scnprintf(file, PATH_MAX, "%s/number_of_sets", path);
        if (sysfs__read_int(file, (int *) &cache->sets))
                return -1;

        scnprintf(file, PATH_MAX, "%s/ways_of_associativity", path);
        if (sysfs__read_int(file, (int *) &cache->ways))
                return -1;

        scnprintf(file, PATH_MAX, "%s/type", path);
        if (sysfs__read_str(file, &cache->type, &len))
                return -1;

        cache->type[len] = 0;
        cache->type = strim(cache->type);

        scnprintf(file, PATH_MAX, "%s/size", path);
        if (sysfs__read_str(file, &cache->size, &len)) {
                zfree(&cache->type);
                return -1;
        }

        cache->size[len] = 0;
        cache->size = strim(cache->size);

        scnprintf(file, PATH_MAX, "%s/shared_cpu_list", path);
        if (sysfs__read_str(file, &cache->map, &len)) {
                zfree(&cache->size);
                zfree(&cache->type);
                return -1;
        }

        cache->map[len] = 0;
        cache->map = strim(cache->map);
        return 0;
}

static void cpu_cache_level__fprintf(FILE *out, struct cpu_cache_level *c)
{
        fprintf(out, "L%d %-15s %8s [%s]\n", c->level, c->type, c->size, c->map);
}

/*
 * Build caches levels for a particular CPU from the data in
 * /sys/devices/system/cpu/cpu<cpu>/cache/
 * The cache level data is stored in caches[] from index at
 * *cntp.
 */
int build_caches_for_cpu(u32 cpu, struct cpu_cache_level caches[], u32 *cntp)
{
        u16 level;

        for (level = 0; level < MAX_CACHE_LVL; level++) {
                struct cpu_cache_level c;
                int err;
                u32 i;

                err = cpu_cache_level__read(&c, cpu, level);
                if (err < 0)
                        return err;

                if (err == 1)
                        break;

                for (i = 0; i < *cntp; i++) {
                        if (cpu_cache_level__cmp(&c, &caches[i]))
                                break;
                }

                if (i == *cntp) {
                        caches[*cntp] = c;
                        *cntp = *cntp + 1;
                } else
                        cpu_cache_level__free(&c);
        }

        return 0;
}

static int build_caches(struct cpu_cache_level caches[], u32 *cntp)
{
        u32 nr, cpu, cnt = 0;

        nr = cpu__max_cpu().cpu;

        for (cpu = 0; cpu < nr; cpu++) {
                int ret = build_caches_for_cpu(cpu, caches, &cnt);

                if (ret)
                        return ret;
        }
        *cntp = cnt;
        return 0;
}

static int write_cache(struct feat_fd *ff,
                       struct evlist *evlist __maybe_unused)
{
        u32 max_caches = cpu__max_cpu().cpu * MAX_CACHE_LVL;
        struct cpu_cache_level caches[max_caches];
        u32 cnt = 0, i, version = 1;
        int ret;

        ret = build_caches(caches, &cnt);
        if (ret)
                goto out;

        qsort(&caches, cnt, sizeof(struct cpu_cache_level), cpu_cache_level__sort);

        ret = do_write(ff, &version, sizeof(u32));
        if (ret < 0)
                goto out;

        ret = do_write(ff, &cnt, sizeof(u32));
        if (ret < 0)
                goto out;

        for (i = 0; i < cnt; i++) {
                struct cpu_cache_level *c = &caches[i];

                #define _W(v)                                   \
                        ret = do_write(ff, &c->v, sizeof(u32)); \
                        if (ret < 0)                            \
                                goto out;

                _W(level)
                _W(line_size)
                _W(sets)
                _W(ways)
                #undef _W

                #define _W(v)                                           \
                        ret = do_write_string(ff, (const char *) c->v); \
                        if (ret < 0)                                    \
                                goto out;

                _W(type)
                _W(size)
                _W(map)
                #undef _W
        }

out:
        for (i = 0; i < cnt; i++)
                cpu_cache_level__free(&caches[i]);
        return ret;
}

static int write_stat(struct feat_fd *ff __maybe_unused,
                      struct evlist *evlist __maybe_unused)
{
        return 0;
}

static int write_sample_time(struct feat_fd *ff,
                             struct evlist *evlist)
{
        int ret;

        ret = do_write(ff, &evlist->first_sample_time,
                       sizeof(evlist->first_sample_time));
        if (ret < 0)
                return ret;

        return do_write(ff, &evlist->last_sample_time,
                        sizeof(evlist->last_sample_time));
}


static int memory_node__read(struct memory_node *n, unsigned long idx)
{
        unsigned int phys, size = 0;
        char path[PATH_MAX];
        struct io_dirent64 *ent;
        struct io_dir dir;

#define for_each_memory(mem, dir)                                       \
        while ((ent = io_dir__readdir(&dir)) != NULL)                   \
                if (strcmp(ent->d_name, ".") &&                         \
                    strcmp(ent->d_name, "..") &&                        \
                    sscanf(ent->d_name, "memory%u", &mem) == 1)

        scnprintf(path, PATH_MAX,
                  "%s/devices/system/node/node%lu",
                  sysfs__mountpoint(), idx);

        io_dir__init(&dir, open(path, O_CLOEXEC | O_DIRECTORY | O_RDONLY));
        if (dir.dirfd < 0) {
                pr_warning("failed: can't open memory sysfs data '%s'\n", path);
                return -1;
        }

        for_each_memory(phys, dir) {
                size = max(phys, size);
        }

        size++;

        n->set = bitmap_zalloc(size);
        if (!n->set) {
                close(dir.dirfd);
                return -ENOMEM;
        }

        n->node = idx;
        n->size = size;

        io_dir__rewinddir(&dir);

        for_each_memory(phys, dir) {
                __set_bit(phys, n->set);
        }

        close(dir.dirfd);
        return 0;
}

static void memory_node__delete_nodes(struct memory_node *nodesp, u64 cnt)
{
        for (u64 i = 0; i < cnt; i++)
                bitmap_free(nodesp[i].set);

        free(nodesp);
}

static int memory_node__sort(const void *a, const void *b)
{
        const struct memory_node *na = a;
        const struct memory_node *nb = b;

        return na->node - nb->node;
}

static int build_mem_topology(struct memory_node **nodesp, u64 *cntp)
{
        char path[PATH_MAX];
        struct io_dirent64 *ent;
        struct io_dir dir;
        int ret = 0;
        size_t cnt = 0, size = 0;
        struct memory_node *nodes = NULL;

        scnprintf(path, PATH_MAX, "%s/devices/system/node/",
                  sysfs__mountpoint());

        io_dir__init(&dir, open(path, O_CLOEXEC | O_DIRECTORY | O_RDONLY));
        if (dir.dirfd < 0) {
                pr_debug2("%s: couldn't read %s, does this arch have topology information?\n",
                          __func__, path);
                return -1;
        }

        while (!ret && (ent = io_dir__readdir(&dir))) {
                unsigned int idx;
                int r;

                if (!strcmp(ent->d_name, ".") ||
                    !strcmp(ent->d_name, ".."))
                        continue;

                r = sscanf(ent->d_name, "node%u", &idx);
                if (r != 1)
                        continue;

                if (cnt >= size) {
                        struct memory_node *new_nodes =
                                reallocarray(nodes, cnt + 4, sizeof(*nodes));

                        if (!new_nodes) {
                                pr_err("Failed to write MEM_TOPOLOGY, size %zd nodes\n", size);
                                ret = -ENOMEM;
                                goto out;
                        }
                        nodes = new_nodes;
                        size += 4;
                }
                ret = memory_node__read(&nodes[cnt], idx);
                if (!ret)
                        cnt += 1;
        }
out:
        close(dir.dirfd);
        if (!ret) {
                *cntp = cnt;
                *nodesp = nodes;
                qsort(nodes, cnt, sizeof(nodes[0]), memory_node__sort);
        } else
                memory_node__delete_nodes(nodes, cnt);

        return ret;
}

/*
 * The MEM_TOPOLOGY holds physical memory map for every
 * node in system. The format of data is as follows:
 *
 *  0 - version          | for future changes
 *  8 - block_size_bytes | /sys/devices/system/memory/block_size_bytes
 * 16 - count            | number of nodes
 *
 * For each node we store map of physical indexes for
 * each node:
 *
 * 32 - node id          | node index
 * 40 - size             | size of bitmap
 * 48 - bitmap           | bitmap of memory indexes that belongs to node
 */
static int write_mem_topology(struct feat_fd *ff __maybe_unused,
                              struct evlist *evlist __maybe_unused)
{
        struct memory_node *nodes = NULL;
        u64 bsize, version = 1, i, nr = 0;
        int ret;

        ret = sysfs__read_xll("devices/system/memory/block_size_bytes",
                              (unsigned long long *) &bsize);
        if (ret)
                return ret;

        ret = build_mem_topology(&nodes, &nr);
        if (ret)
                return ret;

        ret = do_write(ff, &version, sizeof(version));
        if (ret < 0)
                goto out;

        ret = do_write(ff, &bsize, sizeof(bsize));
        if (ret < 0)
                goto out;

        ret = do_write(ff, &nr, sizeof(nr));
        if (ret < 0)
                goto out;

        for (i = 0; i < nr; i++) {
                struct memory_node *n = &nodes[i];

                #define _W(v)                                           \
                        ret = do_write(ff, &n->v, sizeof(n->v));        \
                        if (ret < 0)                                    \
                                goto out;

                _W(node)
                _W(size)

                #undef _W

                ret = do_write_bitmap(ff, n->set, n->size);
                if (ret < 0)
                        goto out;
        }

out:
        memory_node__delete_nodes(nodes, nr);
        return ret;
}

static int write_compressed(struct feat_fd *ff __maybe_unused,
                            struct evlist *evlist __maybe_unused)
{
        int ret;

        ret = do_write(ff, &(ff->ph->env.comp_ver), sizeof(ff->ph->env.comp_ver));
        if (ret)
                return ret;

        ret = do_write(ff, &(ff->ph->env.comp_type), sizeof(ff->ph->env.comp_type));
        if (ret)
                return ret;

        ret = do_write(ff, &(ff->ph->env.comp_level), sizeof(ff->ph->env.comp_level));
        if (ret)
                return ret;

        ret = do_write(ff, &(ff->ph->env.comp_ratio), sizeof(ff->ph->env.comp_ratio));
        if (ret)
                return ret;

        return do_write(ff, &(ff->ph->env.comp_mmap_len), sizeof(ff->ph->env.comp_mmap_len));
}

static int __write_pmu_caps(struct feat_fd *ff, struct perf_pmu *pmu,
                            bool write_pmu)
{
        struct perf_pmu_caps *caps = NULL;
        int ret;

        ret = do_write(ff, &pmu->nr_caps, sizeof(pmu->nr_caps));
        if (ret < 0)
                return ret;

        list_for_each_entry(caps, &pmu->caps, list) {
                ret = do_write_string(ff, caps->name);
                if (ret < 0)
                        return ret;

                ret = do_write_string(ff, caps->value);
                if (ret < 0)
                        return ret;
        }

        if (write_pmu) {
                ret = do_write_string(ff, pmu->name);
                if (ret < 0)
                        return ret;
        }

        return ret;
}

static int write_cpu_pmu_caps(struct feat_fd *ff,
                              struct evlist *evlist __maybe_unused)
{
        struct perf_pmu *cpu_pmu = perf_pmus__find_core_pmu();
        int ret;

        if (!cpu_pmu)
                return -ENOENT;

        ret = perf_pmu__caps_parse(cpu_pmu);
        if (ret < 0)
                return ret;

        return __write_pmu_caps(ff, cpu_pmu, false);
}

static int write_pmu_caps(struct feat_fd *ff,
                          struct evlist *evlist __maybe_unused)
{
        struct perf_pmu *pmu = NULL;
        int nr_pmu = 0;
        int ret;

        while ((pmu = perf_pmus__scan(pmu))) {
                if (!strcmp(pmu->name, "cpu")) {
                        /*
                         * The "cpu" PMU is special and covered by
                         * HEADER_CPU_PMU_CAPS. Note, core PMUs are
                         * counted/written here for ARM, s390 and Intel hybrid.
                         */
                        continue;
                }
                if (perf_pmu__caps_parse(pmu) <= 0)
                        continue;
                nr_pmu++;
        }

        ret = do_write(ff, &nr_pmu, sizeof(nr_pmu));
        if (ret < 0)
                return ret;

        if (!nr_pmu)
                return 0;

        /*
         * Note older perf tools assume core PMUs come first, this is a property
         * of perf_pmus__scan.
         */
        pmu = NULL;
        while ((pmu = perf_pmus__scan(pmu))) {
                if (!strcmp(pmu->name, "cpu")) {
                        /* Skip as above. */
                        continue;
                }
                if (perf_pmu__caps_parse(pmu) <= 0)
                        continue;
                ret = __write_pmu_caps(ff, pmu, true);
                if (ret < 0)
                        return ret;
        }
        return 0;
}

struct cpu_domain_map **build_cpu_domain_map(u32 *schedstat_version, u32 *max_sched_domains, u32 nr)
{
        char dname[DNAME_LEN], cpumask[MAX_NR_CPUS];
        struct domain_info *domain_info;
        struct cpu_domain_map **cd_map;
        char cpulist[MAX_NR_CPUS];
        char *line = NULL;
        u32 cpu, domain;
        u32 dcount = 0;
        size_t len;
        FILE *fp;

        fp = fopen("/proc/schedstat", "r");
        if (!fp) {
                pr_err("Failed to open /proc/schedstat\n");
                return NULL;
        }

        cd_map = zalloc(sizeof(*cd_map) * nr);
        if (!cd_map)
                goto out;

        while (getline(&line, &len, fp) > 0) {
                int retval;

                if (strncmp(line, "version", 7) == 0) {
                        retval = sscanf(line, "version %d\n", schedstat_version);
                        if (retval != 1)
                                continue;

                } else if (strncmp(line, "cpu", 3) == 0) {
                        retval = sscanf(line, "cpu%u %*s", &cpu);
                        if (retval == 1) {
                                cd_map[cpu] = zalloc(sizeof(*cd_map[cpu]));
                                if (!cd_map[cpu])
                                        goto out_free_line;
                                cd_map[cpu]->cpu = cpu;
                        } else
                                continue;

                        dcount = 0;
                } else if (strncmp(line, "domain", 6) == 0) {
                        struct domain_info **temp_domains;

                        dcount++;
                        temp_domains = realloc(cd_map[cpu]->domains, dcount * sizeof(domain_info));
                        if (!temp_domains)
                                goto out_free_line;
                        else
                                cd_map[cpu]->domains = temp_domains;

                        domain_info = zalloc(sizeof(*domain_info));
                        if (!domain_info)
                                goto out_free_line;

                        cd_map[cpu]->domains[dcount - 1] = domain_info;

                        if (*schedstat_version >= 17) {
                                retval = sscanf(line, "domain%u %s %s %*s", &domain, dname,
                                                cpumask);
                                if (retval != 3)
                                        continue;

                                domain_info->dname = strdup(dname);
                                if (!domain_info->dname)
                                        goto out_free_line;
                        } else {
                                retval = sscanf(line, "domain%u %s %*s", &domain, cpumask);
                                if (retval != 2)
                                        continue;
                        }

                        domain_info->domain = domain;
                        if (domain > *max_sched_domains)
                                *max_sched_domains = domain;

                        domain_info->cpumask = strdup(cpumask);
                        if (!domain_info->cpumask)
                                goto out_free_line;

                        cpumask_to_cpulist(cpumask, cpulist);
                        domain_info->cpulist = strdup(cpulist);
                        if (!domain_info->cpulist)
                                goto out_free_line;

                        cd_map[cpu]->nr_domains = dcount;
                }
        }

out_free_line:
        free(line);
out:
        fclose(fp);
        return cd_map;
}

static int write_cpu_domain_info(struct feat_fd *ff,
                                 struct evlist *evlist __maybe_unused)
{
        u32 max_sched_domains = 0, schedstat_version = 0;
        struct cpu_domain_map **cd_map;
        u32 i, j, nr, ret;

        nr = cpu__max_present_cpu().cpu;

        cd_map = build_cpu_domain_map(&schedstat_version, &max_sched_domains, nr);
        if (!cd_map)
                return -1;

        ret = do_write(ff, &schedstat_version, sizeof(u32));
        if (ret < 0)
                goto out;

        max_sched_domains += 1;
        ret = do_write(ff, &max_sched_domains, sizeof(u32));
        if (ret < 0)
                goto out;

        for (i = 0; i < nr; i++) {
                if (!cd_map[i])
                        continue;

                ret = do_write(ff, &cd_map[i]->cpu, sizeof(u32));
                if (ret < 0)
                        goto out;

                ret = do_write(ff, &cd_map[i]->nr_domains, sizeof(u32));
                if (ret < 0)
                        goto out;

                for (j = 0; j < cd_map[i]->nr_domains; j++) {
                        ret = do_write(ff, &cd_map[i]->domains[j]->domain, sizeof(u32));
                        if (ret < 0)
                                goto out;
                        if (schedstat_version >= 17) {
                                ret = do_write_string(ff, cd_map[i]->domains[j]->dname);
                                if (ret < 0)
                                        goto out;
                        }

                        ret = do_write_string(ff, cd_map[i]->domains[j]->cpumask);
                        if (ret < 0)
                                goto out;

                        ret = do_write_string(ff, cd_map[i]->domains[j]->cpulist);
                        if (ret < 0)
                                goto out;
                }
        }

out:
        free_cpu_domain_info(cd_map, schedstat_version, nr);
        return ret;
}

static void print_hostname(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# hostname : %s\n", ff->ph->env.hostname);
}

static void print_osrelease(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# os release : %s\n", ff->ph->env.os_release);
}

static void print_arch(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# arch : %s\n", ff->ph->env.arch);
}

static void print_e_machine(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# e_machine : %u\n", ff->ph->env.e_machine);
        fprintf(fp, "#   e_flags : %u\n", ff->ph->env.e_flags);
}

static void print_cpudesc(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# cpudesc : %s\n", ff->ph->env.cpu_desc);
}

static void print_nrcpus(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# nrcpus online : %u\n", ff->ph->env.nr_cpus_online);
        fprintf(fp, "# nrcpus avail : %u\n", ff->ph->env.nr_cpus_avail);
}

static void print_version(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# perf version : %s\n", ff->ph->env.version);
}

static void print_cmdline(struct feat_fd *ff, FILE *fp)
{
        int nr, i;

        nr = ff->ph->env.nr_cmdline;

        fprintf(fp, "# cmdline : ");

        for (i = 0; i < nr; i++) {
                char *argv_i = strdup(ff->ph->env.cmdline_argv[i]);
                if (!argv_i) {
                        fprintf(fp, "%s ", ff->ph->env.cmdline_argv[i]);
                } else {
                        char *mem = argv_i;
                        do {
                                char *quote = strchr(argv_i, '\'');
                                if (!quote)
                                        break;
                                *quote++ = '\0';
                                fprintf(fp, "%s\\\'", argv_i);
                                argv_i = quote;
                        } while (1);
                        fprintf(fp, "%s ", argv_i);
                        free(mem);
                }
        }
        fputc('\n', fp);
}

static void print_cpu_topology(struct feat_fd *ff, FILE *fp)
{
        struct perf_header *ph = ff->ph;
        int cpu_nr = ph->env.nr_cpus_avail;
        int nr, i;
        char *str;

        nr = ph->env.nr_sibling_cores;
        str = ph->env.sibling_cores;

        for (i = 0; i < nr; i++) {
                fprintf(fp, "# sibling sockets : %s\n", str);
                str += strlen(str) + 1;
        }

        if (ph->env.nr_sibling_dies) {
                nr = ph->env.nr_sibling_dies;
                str = ph->env.sibling_dies;

                for (i = 0; i < nr; i++) {
                        fprintf(fp, "# sibling dies    : %s\n", str);
                        str += strlen(str) + 1;
                }
        }

        nr = ph->env.nr_sibling_threads;
        str = ph->env.sibling_threads;

        for (i = 0; i < nr; i++) {
                fprintf(fp, "# sibling threads : %s\n", str);
                str += strlen(str) + 1;
        }

        if (ph->env.nr_sibling_dies) {
                if (ph->env.cpu != NULL) {
                        for (i = 0; i < cpu_nr; i++)
                                fprintf(fp, "# CPU %d: Core ID %d, "
                                            "Die ID %d, Socket ID %d\n",
                                            i, ph->env.cpu[i].core_id,
                                            ph->env.cpu[i].die_id,
                                            ph->env.cpu[i].socket_id);
                } else
                        fprintf(fp, "# Core ID, Die ID and Socket ID "
                                    "information is not available\n");
        } else {
                if (ph->env.cpu != NULL) {
                        for (i = 0; i < cpu_nr; i++)
                                fprintf(fp, "# CPU %d: Core ID %d, "
                                            "Socket ID %d\n",
                                            i, ph->env.cpu[i].core_id,
                                            ph->env.cpu[i].socket_id);
                } else
                        fprintf(fp, "# Core ID and Socket ID "
                                    "information is not available\n");
        }
}

static void print_clockid(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# clockid frequency: %"PRIu64" MHz\n",
                ff->ph->env.clock.clockid_res_ns * 1000);
}

static void print_clock_data(struct feat_fd *ff, FILE *fp)
{
        struct timespec clockid_ns;
        char tstr[64], date[64];
        struct timeval tod_ns;
        clockid_t clockid;
        struct tm ltime;
        u64 ref;

        if (!ff->ph->env.clock.enabled) {
                fprintf(fp, "# reference time disabled\n");
                return;
        }

        /* Compute TOD time. */
        ref = ff->ph->env.clock.tod_ns;
        tod_ns.tv_sec = ref / NSEC_PER_SEC;
        ref -= tod_ns.tv_sec * NSEC_PER_SEC;
        tod_ns.tv_usec = ref / NSEC_PER_USEC;

        /* Compute clockid time. */
        ref = ff->ph->env.clock.clockid_ns;
        clockid_ns.tv_sec = ref / NSEC_PER_SEC;
        ref -= clockid_ns.tv_sec * NSEC_PER_SEC;
        clockid_ns.tv_nsec = ref;

        clockid = ff->ph->env.clock.clockid;

        if (localtime_r(&tod_ns.tv_sec, &ltime) == NULL)
                snprintf(tstr, sizeof(tstr), "<error>");
        else {
                strftime(date, sizeof(date), "%F %T", &ltime);
                scnprintf(tstr, sizeof(tstr), "%s.%06d",
                          date, (int) tod_ns.tv_usec);
        }

        fprintf(fp, "# clockid: %s (%u)\n", clockid_name(clockid), clockid);
        fprintf(fp, "# reference time: %s = %ld.%06d (TOD) = %ld.%09ld (%s)\n",
                    tstr, (long) tod_ns.tv_sec, (int) tod_ns.tv_usec,
                    (long) clockid_ns.tv_sec, clockid_ns.tv_nsec,
                    clockid_name(clockid));
}

static void print_hybrid_topology(struct feat_fd *ff, FILE *fp)
{
        int i;
        struct hybrid_node *n;

        fprintf(fp, "# hybrid cpu system:\n");
        for (i = 0; i < ff->ph->env.nr_hybrid_nodes; i++) {
                n = &ff->ph->env.hybrid_nodes[i];
                fprintf(fp, "# %s cpu list : %s\n", n->pmu_name, n->cpus);
        }
}

static void print_dir_format(struct feat_fd *ff, FILE *fp)
{
        struct perf_session *session;
        struct perf_data *data;

        session = container_of(ff->ph, struct perf_session, header);
        data = session->data;

        fprintf(fp, "# directory data version : %"PRIu64"\n", data->dir.version);
}

#ifdef HAVE_LIBBPF_SUPPORT
static void print_bpf_prog_info(struct feat_fd *ff, FILE *fp)
{
        struct perf_env *env = &ff->ph->env;
        struct rb_root *root;
        struct rb_node *next;

        down_read(&env->bpf_progs.lock);

        root = &env->bpf_progs.infos;
        next = rb_first(root);

        if (!next)
                printf("# bpf_prog_info empty\n");

        while (next) {
                struct bpf_prog_info_node *node;

                node = rb_entry(next, struct bpf_prog_info_node, rb_node);
                next = rb_next(&node->rb_node);

                __bpf_event__print_bpf_prog_info(&node->info_linear->info,
                                                 env, fp);
        }

        up_read(&env->bpf_progs.lock);
}

static void print_bpf_btf(struct feat_fd *ff, FILE *fp)
{
        struct perf_env *env = &ff->ph->env;
        struct rb_root *root;
        struct rb_node *next;

        down_read(&env->bpf_progs.lock);

        root = &env->bpf_progs.btfs;
        next = rb_first(root);

        if (!next)
                printf("# btf info empty\n");

        while (next) {
                struct btf_node *node;

                node = rb_entry(next, struct btf_node, rb_node);
                next = rb_next(&node->rb_node);
                fprintf(fp, "# btf info of id %u\n", node->id);
        }

        up_read(&env->bpf_progs.lock);
}
#endif // HAVE_LIBBPF_SUPPORT

static void free_event_desc(struct evsel *events)
{
        struct evsel *evsel;

        if (!events)
                return;

        for (evsel = events; evsel->core.attr.size; evsel++) {
                zfree(&evsel->name);
                zfree(&evsel->core.id);
        }

        free(events);
}

static bool perf_attr_check(struct perf_event_attr *attr)
{
        if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3) {
                pr_warning("Reserved bits are set unexpectedly. "
                           "Please update perf tool.\n");
                return false;
        }

        if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) {
                pr_warning("Unknown sample type (0x%llx) is detected. "
                           "Please update perf tool.\n",
                           attr->sample_type);
                return false;
        }

        if (attr->read_format & ~(PERF_FORMAT_MAX-1)) {
                pr_warning("Unknown read format (0x%llx) is detected. "
                           "Please update perf tool.\n",
                           attr->read_format);
                return false;
        }

        if ((attr->sample_type & PERF_SAMPLE_BRANCH_STACK) &&
            (attr->branch_sample_type & ~(PERF_SAMPLE_BRANCH_MAX-1))) {
                pr_warning("Unknown branch sample type (0x%llx) is detected. "
                           "Please update perf tool.\n",
                           attr->branch_sample_type);

                return false;
        }

        return true;
}

static struct evsel *read_event_desc(struct feat_fd *ff)
{
        struct evsel *evsel, *events = NULL;
        u64 *id;
        void *buf = NULL;
        u32 nre, sz, nr, i, j;
        size_t msz;

        /* number of events */
        if (do_read_u32(ff, &nre))
                goto error;

        if (do_read_u32(ff, &sz))
                goto error;

        /* buffer to hold on file attr struct */
        buf = malloc(sz);
        if (!buf)
                goto error;

        /* the last event terminates with evsel->core.attr.size == 0: */
        events = calloc(nre + 1, sizeof(*events));
        if (!events)
                goto error;

        msz = sizeof(evsel->core.attr);
        if (sz < msz)
                msz = sz;

        for (i = 0, evsel = events; i < nre; evsel++, i++) {
                evsel->core.idx = i;

                /*
                 * must read entire on-file attr struct to
                 * sync up with layout.
                 */
                if (__do_read(ff, buf, sz))
                        goto error;

                if (ff->ph->needs_swap)
                        perf_event__attr_swap(buf);

                memcpy(&evsel->core.attr, buf, msz);

                if (!perf_attr_check(&evsel->core.attr))
                        goto error;

                if (do_read_u32(ff, &nr))
                        goto error;

                if (ff->ph->needs_swap)
                        evsel->needs_swap = true;

                evsel->name = do_read_string(ff);
                if (!evsel->name)
                        goto error;

                if (!nr)
                        continue;

                id = calloc(nr, sizeof(*id));
                if (!id)
                        goto error;
                evsel->core.ids = nr;
                evsel->core.id = id;

                for (j = 0 ; j < nr; j++) {
                        if (do_read_u64(ff, id))
                                goto error;
                        id++;
                }
        }
out:
        free(buf);
        return events;
error:
        free_event_desc(events);
        events = NULL;
        goto out;
}

static int __desc_attr__fprintf(FILE *fp, const char *name, const char *val,
                                void *priv __maybe_unused)
{
        return fprintf(fp, ", %s = %s", name, val);
}

static void print_event_desc(struct feat_fd *ff, FILE *fp)
{
        struct evsel *evsel, *events;
        u32 j;
        u64 *id;

        if (ff->events)
                events = ff->events;
        else
                events = read_event_desc(ff);

        if (!events) {
                fprintf(fp, "# event desc: not available or unable to read\n");
                return;
        }

        for (evsel = events; evsel->core.attr.size; evsel++) {
                fprintf(fp, "# event : name = %s, ", evsel->name);

                if (evsel->core.ids) {
                        fprintf(fp, ", id = {");
                        for (j = 0, id = evsel->core.id; j < evsel->core.ids; j++, id++) {
                                if (j)
                                        fputc(',', fp);
                                fprintf(fp, " %"PRIu64, *id);
                        }
                        fprintf(fp, " }");
                }

                perf_event_attr__fprintf(fp, &evsel->core.attr, __desc_attr__fprintf, NULL);

                fputc('\n', fp);
        }

        free_event_desc(events);
        ff->events = NULL;
}

static void print_total_mem(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# total memory : %llu kB\n", ff->ph->env.total_mem);
}

static void print_numa_topology(struct feat_fd *ff, FILE *fp)
{
        int i;
        struct numa_node *n;

        for (i = 0; i < ff->ph->env.nr_numa_nodes; i++) {
                n = &ff->ph->env.numa_nodes[i];

                fprintf(fp, "# node%u meminfo  : total = %"PRIu64" kB,"
                            " free = %"PRIu64" kB\n",
                        n->node, n->mem_total, n->mem_free);

                fprintf(fp, "# node%u cpu list : ", n->node);
                cpu_map__fprintf(n->map, fp);
        }
}

static void print_cpuid(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# cpuid : %s\n", ff->ph->env.cpuid);
}

static void print_branch_stack(struct feat_fd *ff __maybe_unused, FILE *fp)
{
        fprintf(fp, "# contains samples with branch stack\n");
}

static void print_auxtrace(struct feat_fd *ff __maybe_unused, FILE *fp)
{
        fprintf(fp, "# contains AUX area data (e.g. instruction trace)\n");
}

static void print_stat(struct feat_fd *ff __maybe_unused, FILE *fp)
{
        fprintf(fp, "# contains stat data\n");
}

static void print_cache(struct feat_fd *ff, FILE *fp __maybe_unused)
{
        int i;

        fprintf(fp, "# CPU cache info:\n");
        for (i = 0; i < ff->ph->env.caches_cnt; i++) {
                fprintf(fp, "#  ");
                cpu_cache_level__fprintf(fp, &ff->ph->env.caches[i]);
        }
}

static void print_compressed(struct feat_fd *ff, FILE *fp)
{
        fprintf(fp, "# compressed : %s, level = %d, ratio = %d\n",
                ff->ph->env.comp_type == PERF_COMP_ZSTD ? "Zstd" : "Unknown",
                ff->ph->env.comp_level, ff->ph->env.comp_ratio);
}

static void __print_pmu_caps(FILE *fp, int nr_caps, char **caps, char *pmu_name)
{
        const char *delimiter = "";
        int i;

        if (!nr_caps) {
                fprintf(fp, "# %s pmu capabilities: not available\n", pmu_name);
                return;
        }

        fprintf(fp, "# %s pmu capabilities: ", pmu_name);
        for (i = 0; i < nr_caps; i++) {
                fprintf(fp, "%s%s", delimiter, caps[i]);
                delimiter = ", ";
        }

        fprintf(fp, "\n");
}

static void print_cpu_pmu_caps(struct feat_fd *ff, FILE *fp)
{
        __print_pmu_caps(fp, ff->ph->env.nr_cpu_pmu_caps,
                         ff->ph->env.cpu_pmu_caps, (char *)"cpu");
}

static void print_pmu_caps(struct feat_fd *ff, FILE *fp)
{
        struct perf_env *env = &ff->ph->env;
        struct pmu_caps *pmu_caps;

        for (int i = 0; i < env->nr_pmus_with_caps; i++) {
                pmu_caps = &env->pmu_caps[i];
                __print_pmu_caps(fp, pmu_caps->nr_caps, pmu_caps->caps,
                                 pmu_caps->pmu_name);
        }

        if (strcmp(perf_env__arch(env), "x86") == 0 &&
            perf_env__has_pmu_mapping(env, "ibs_op")) {
                char *max_precise = perf_env__find_pmu_cap(env, "cpu", "max_precise");

                if (max_precise != NULL && atoi(max_precise) == 0)
                        fprintf(fp, "# AMD systems uses ibs_op// PMU for some precise events, e.g.: cycles:p, see the 'perf list' man page for further details.\n");
        }
}

static void print_pmu_mappings(struct feat_fd *ff, FILE *fp)
{
        struct perf_env *env = &ff->ph->env;
        const char *delimiter = "# pmu mappings: ";
        char *str, *tmp;
        u32 pmu_num;
        u32 type;

        pmu_num = env->nr_pmu_mappings;
        if (!pmu_num) {
                fprintf(fp, "# pmu mappings: not available\n");
                return;
        }

        str = env->pmu_mappings;

        while (pmu_num) {
                type = strtoul(str, &tmp, 0);
                if (*tmp != ':')
                        goto error;

                str = tmp + 1;
                fprintf(fp, "%s%s = %" PRIu32, delimiter, str, type);

                delimiter = ", ";
                str += strlen(str) + 1;
                pmu_num--;
        }

        fprintf(fp, "\n");

        if (!pmu_num)
                return;
error:
        fprintf(fp, "# pmu mappings: unable to read\n");
}

static void print_group_desc(struct feat_fd *ff, FILE *fp)
{
        struct perf_session *session;
        struct evsel *evsel;
        u32 nr = 0;

        session = container_of(ff->ph, struct perf_session, header);

        evlist__for_each_entry(session->evlist, evsel) {
                if (evsel__is_group_leader(evsel) && evsel->core.nr_members > 1) {
                        fprintf(fp, "# group: %s{%s", evsel->group_name ?: "", evsel__name(evsel));

                        nr = evsel->core.nr_members - 1;
                } else if (nr) {
                        fprintf(fp, ",%s", evsel__name(evsel));

                        if (--nr == 0)
                                fprintf(fp, "}\n");
                }
        }
}

static void print_sample_time(struct feat_fd *ff, FILE *fp)
{
        struct perf_session *session;
        char time_buf[32];
        double d;

        session = container_of(ff->ph, struct perf_session, header);

        timestamp__scnprintf_usec(session->evlist->first_sample_time,
                                  time_buf, sizeof(time_buf));
        fprintf(fp, "# time of first sample : %s\n", time_buf);

        timestamp__scnprintf_usec(session->evlist->last_sample_time,
                                  time_buf, sizeof(time_buf));
        fprintf(fp, "# time of last sample : %s\n", time_buf);

        d = (double)(session->evlist->last_sample_time -
                session->evlist->first_sample_time) / NSEC_PER_MSEC;

        fprintf(fp, "# sample duration : %10.3f ms\n", d);
}

static void memory_node__fprintf(struct memory_node *n,
                                 unsigned long long bsize, FILE *fp)
{
        char buf_map[100], buf_size[50];
        unsigned long long size;

        size = bsize * bitmap_weight(n->set, n->size);
        unit_number__scnprintf(buf_size, 50, size);

        bitmap_scnprintf(n->set, n->size, buf_map, 100);
        fprintf(fp, "#  %3" PRIu64 " [%s]: %s\n", n->node, buf_size, buf_map);
}

static void print_mem_topology(struct feat_fd *ff, FILE *fp)
{
        struct perf_env *env = &ff->ph->env;
        struct memory_node *nodes;
        int i, nr;

        nodes = env->memory_nodes;
        nr    = env->nr_memory_nodes;

        fprintf(fp, "# memory nodes (nr %d, block size 0x%llx):\n",
                nr, env->memory_bsize);

        for (i = 0; i < nr; i++) {
                memory_node__fprintf(&nodes[i], env->memory_bsize, fp);
        }
}

static void print_cpu_domain_info(struct feat_fd *ff, FILE *fp)
{
        struct cpu_domain_map **cd_map = ff->ph->env.cpu_domain;
        u32 nr = ff->ph->env.nr_cpus_avail;
        struct domain_info *d_info;
        u32 i, j;

        fprintf(fp, "# schedstat version        : %u\n", ff->ph->env.schedstat_version);
        fprintf(fp, "# Maximum sched domains    : %u\n", ff->ph->env.max_sched_domains);

        for (i = 0; i < nr; i++) {
                if (!cd_map[i])
                        continue;

                fprintf(fp, "# cpu              : %u\n", cd_map[i]->cpu);
                fprintf(fp, "# nr_domains       : %u\n", cd_map[i]->nr_domains);

                for (j = 0; j < cd_map[i]->nr_domains; j++) {
                        d_info = cd_map[i]->domains[j];
                        if (!d_info)
                                continue;

                        fprintf(fp, "# Domain           : %u\n", d_info->domain);

                        if (ff->ph->env.schedstat_version >= 17)
                                fprintf(fp, "# Domain name      : %s\n", d_info->dname);

                        fprintf(fp, "# Domain cpu map   : %s\n", d_info->cpumask);
                        fprintf(fp, "# Domain cpu list  : %s\n", d_info->cpulist);
                }
        }
}

static int __event_process_build_id(struct perf_record_header_build_id *bev,
                                    char *filename,
                                    struct perf_session *session)
{
        int err = -1;
        struct machine *machine;
        u16 cpumode;
        struct dso *dso;
        enum dso_space_type dso_space;

        machine = perf_session__findnew_machine(session, bev->pid);
        if (!machine)
                goto out;

        cpumode = bev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;

        switch (cpumode) {
        case PERF_RECORD_MISC_KERNEL:
                dso_space = DSO_SPACE__KERNEL;
                break;
        case PERF_RECORD_MISC_GUEST_KERNEL:
                dso_space = DSO_SPACE__KERNEL_GUEST;
                break;
        case PERF_RECORD_MISC_USER:
        case PERF_RECORD_MISC_GUEST_USER:
                dso_space = DSO_SPACE__USER;
                break;
        default:
                goto out;
        }

        dso = machine__findnew_dso(machine, filename);
        if (dso != NULL) {
                char sbuild_id[SBUILD_ID_SIZE];
                struct build_id bid;
                size_t size = BUILD_ID_SIZE;

                if (bev->header.misc & PERF_RECORD_MISC_BUILD_ID_SIZE)
                        size = bev->size;

                build_id__init(&bid, bev->data, size);
                dso__set_build_id(dso, &bid);
                dso__set_header_build_id(dso, true);

                if (dso_space != DSO_SPACE__USER) {
                        struct kmod_path m = { .name = NULL, };

                        if (!kmod_path__parse_name(&m, filename) && m.kmod)
                                dso__set_module_info(dso, &m, machine);

                        dso__set_kernel(dso, dso_space);
                        free(m.name);
                }

                build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
                pr_debug("build id event received for %s: %s [%zu]\n",
                         dso__long_name(dso), sbuild_id, size);
                dso__put(dso);
        }

        err = 0;
out:
        return err;
}

static int perf_header__read_build_ids_abi_quirk(struct perf_header *header,
                                                 int input, u64 offset, u64 size)
{
        struct perf_session *session = container_of(header, struct perf_session, header);
        struct {
                struct perf_event_header   header;
                u8                         build_id[PERF_ALIGN(BUILD_ID_SIZE, sizeof(u64))];
                char                       filename[0];
        } old_bev;
        struct perf_record_header_build_id bev;
        char filename[PATH_MAX];
        u64 limit = offset + size;

        while (offset < limit) {
                ssize_t len;

                if (readn(input, &old_bev, sizeof(old_bev)) != sizeof(old_bev))
                        return -1;

                if (header->needs_swap)
                        perf_event_header__bswap(&old_bev.header);

                len = old_bev.header.size - sizeof(old_bev);
                if (readn(input, filename, len) != len)
                        return -1;

                bev.header = old_bev.header;

                /*
                 * As the pid is the missing value, we need to fill
                 * it properly. The header.misc value give us nice hint.
                 */
                bev.pid = HOST_KERNEL_ID;
                if (bev.header.misc == PERF_RECORD_MISC_GUEST_USER ||
                    bev.header.misc == PERF_RECORD_MISC_GUEST_KERNEL)
                        bev.pid = DEFAULT_GUEST_KERNEL_ID;

                memcpy(bev.build_id, old_bev.build_id, sizeof(bev.build_id));
                __event_process_build_id(&bev, filename, session);

                offset += bev.header.size;
        }

        return 0;
}

static int perf_header__read_build_ids(struct perf_header *header,
                                       int input, u64 offset, u64 size)
{
        struct perf_session *session = container_of(header, struct perf_session, header);
        struct perf_record_header_build_id bev;
        char filename[PATH_MAX];
        u64 limit = offset + size, orig_offset = offset;
        int err = -1;

        while (offset < limit) {
                ssize_t len;

                if (readn(input, &bev, sizeof(bev)) != sizeof(bev))
                        goto out;

                if (header->needs_swap)
                        perf_event_header__bswap(&bev.header);

                len = bev.header.size - sizeof(bev);
                if (readn(input, filename, len) != len)
                        goto out;
                /*
                 * The a1645ce1 changeset:
                 *
                 * "perf: 'perf kvm' tool for monitoring guest performance from host"
                 *
                 * Added a field to struct perf_record_header_build_id that broke the file
                 * format.
                 *
                 * Since the kernel build-id is the first entry, process the
                 * table using the old format if the well known
                 * '[kernel.kallsyms]' string for the kernel build-id has the
                 * first 4 characters chopped off (where the pid_t sits).
                 */
                if (memcmp(filename, "nel.kallsyms]", 13) == 0) {
                        if (lseek(input, orig_offset, SEEK_SET) == (off_t)-1)
                                return -1;
                        return perf_header__read_build_ids_abi_quirk(header, input, offset, size);
                }

                __event_process_build_id(&bev, filename, session);

                offset += bev.header.size;
        }
        err = 0;
out:
        return err;
}

/* Macro for features that simply need to read and store a string. */
#define FEAT_PROCESS_STR_FUN(__feat, __feat_env) \
static int process_##__feat(struct feat_fd *ff, void *data __maybe_unused) \
{\
        free(ff->ph->env.__feat_env);                \
        ff->ph->env.__feat_env = do_read_string(ff); \
        return ff->ph->env.__feat_env ? 0 : -ENOMEM; \
}

FEAT_PROCESS_STR_FUN(hostname, hostname);
FEAT_PROCESS_STR_FUN(osrelease, os_release);
FEAT_PROCESS_STR_FUN(version, version);
FEAT_PROCESS_STR_FUN(arch, arch);
FEAT_PROCESS_STR_FUN(cpudesc, cpu_desc);
FEAT_PROCESS_STR_FUN(cpuid, cpuid);

static int process_e_machine(struct feat_fd *ff, void *data __maybe_unused)
{
        int ret;

        ret = do_read_u32(ff, &ff->ph->env.e_machine);
        if (ret)
                return ret;

        return do_read_u32(ff, &ff->ph->env.e_flags);
}

#ifdef HAVE_LIBTRACEEVENT
static int process_tracing_data(struct feat_fd *ff, void *data)
{
        ssize_t ret = trace_report(ff->fd, data, false);

        return ret < 0 ? -1 : 0;
}
#endif

static int process_build_id(struct feat_fd *ff, void *data __maybe_unused)
{
        if (perf_header__read_build_ids(ff->ph, ff->fd, ff->offset, ff->size))
                pr_debug("Failed to read buildids, continuing...\n");
        return 0;
}

static int process_nrcpus(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        int ret;
        u32 nr_cpus_avail, nr_cpus_online;

        ret = do_read_u32(ff, &nr_cpus_avail);
        if (ret)
                return ret;

        ret = do_read_u32(ff, &nr_cpus_online);
        if (ret)
                return ret;
        env->nr_cpus_avail = (int)nr_cpus_avail;
        env->nr_cpus_online = (int)nr_cpus_online;
        return 0;
}

static int process_total_mem(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        u64 total_mem;
        int ret;

        ret = do_read_u64(ff, &total_mem);
        if (ret)
                return -1;
        env->total_mem = (unsigned long long)total_mem;
        return 0;
}

static struct evsel *evlist__find_by_index(struct evlist *evlist, int idx)
{
        struct evsel *evsel;

        evlist__for_each_entry(evlist, evsel) {
                if (evsel->core.idx == idx)
                        return evsel;
        }

        return NULL;
}

static void evlist__set_event_name(struct evlist *evlist, struct evsel *event)
{
        struct evsel *evsel;

        if (!event->name)
                return;

        evsel = evlist__find_by_index(evlist, event->core.idx);
        if (!evsel)
                return;

        if (evsel->name)
                return;

        evsel->name = strdup(event->name);
}

static int
process_event_desc(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_session *session;
        struct evsel *evsel, *events = read_event_desc(ff);

        if (!events)
                return 0;

        session = container_of(ff->ph, struct perf_session, header);

        if (session->data->is_pipe) {
                /* Save events for reading later by print_event_desc,
                 * since they can't be read again in pipe mode. */
                ff->events = events;
        }

        for (evsel = events; evsel->core.attr.size; evsel++)
                evlist__set_event_name(session->evlist, evsel);

        if (!session->data->is_pipe)
                free_event_desc(events);

        return 0;
}

static int process_cmdline(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        char *str, *cmdline = NULL, **argv = NULL;
        u32 nr, i, len = 0;

        if (do_read_u32(ff, &nr))
                return -1;

        env->nr_cmdline = nr;

        cmdline = zalloc(ff->size + nr + 1);
        if (!cmdline)
                return -1;

        argv = zalloc(sizeof(char *) * (nr + 1));
        if (!argv)
                goto error;

        for (i = 0; i < nr; i++) {
                str = do_read_string(ff);
                if (!str)
                        goto error;

                argv[i] = cmdline + len;
                memcpy(argv[i], str, strlen(str) + 1);
                len += strlen(str) + 1;
                free(str);
        }
        env->cmdline = cmdline;
        env->cmdline_argv = (const char **) argv;
        return 0;

error:
        free(argv);
        free(cmdline);
        return -1;
}

static int process_cpu_topology(struct feat_fd *ff, void *data __maybe_unused)
{
        u32 nr, i;
        char *str = NULL;
        struct strbuf sb;
        struct perf_env *env = &ff->ph->env;
        int cpu_nr = env->nr_cpus_avail;
        u64 size = 0;

        env->cpu = calloc(cpu_nr, sizeof(*env->cpu));
        if (!env->cpu)
                return -1;

        if (do_read_u32(ff, &nr))
                goto free_cpu;

        env->nr_sibling_cores = nr;
        size += sizeof(u32);
        if (strbuf_init(&sb, 128) < 0)
                goto free_cpu;

        for (i = 0; i < nr; i++) {
                str = do_read_string(ff);
                if (!str)
                        goto error;

                /* include a NULL character at the end */
                if (strbuf_add(&sb, str, strlen(str) + 1) < 0)
                        goto error;
                size += string_size(str);
                zfree(&str);
        }
        env->sibling_cores = strbuf_detach(&sb, NULL);

        if (do_read_u32(ff, &nr))
                return -1;

        env->nr_sibling_threads = nr;
        size += sizeof(u32);

        for (i = 0; i < nr; i++) {
                str = do_read_string(ff);
                if (!str)
                        goto error;

                /* include a NULL character at the end */
                if (strbuf_add(&sb, str, strlen(str) + 1) < 0)
                        goto error;
                size += string_size(str);
                zfree(&str);
        }
        env->sibling_threads = strbuf_detach(&sb, NULL);

        /*
         * The header may be from old perf,
         * which doesn't include core id and socket id information.
         */
        if (ff->size <= size) {
                zfree(&env->cpu);
                return 0;
        }

        for (i = 0; i < (u32)cpu_nr; i++) {
                if (do_read_u32(ff, &nr))
                        goto free_cpu;

                env->cpu[i].core_id = nr;
                size += sizeof(u32);

                if (do_read_u32(ff, &nr))
                        goto free_cpu;

                env->cpu[i].socket_id = nr;
                size += sizeof(u32);
        }

        /*
         * The header may be from old perf,
         * which doesn't include die information.
         */
        if (ff->size <= size)
                return 0;

        if (do_read_u32(ff, &nr))
                return -1;

        env->nr_sibling_dies = nr;
        size += sizeof(u32);

        for (i = 0; i < nr; i++) {
                str = do_read_string(ff);
                if (!str)
                        goto error;

                /* include a NULL character at the end */
                if (strbuf_add(&sb, str, strlen(str) + 1) < 0)
                        goto error;
                size += string_size(str);
                zfree(&str);
        }
        env->sibling_dies = strbuf_detach(&sb, NULL);

        for (i = 0; i < (u32)cpu_nr; i++) {
                if (do_read_u32(ff, &nr))
                        goto free_cpu;

                env->cpu[i].die_id = nr;
        }

        return 0;

error:
        strbuf_release(&sb);
        zfree(&str);
free_cpu:
        zfree(&env->cpu);
        return -1;
}

static int process_numa_topology(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        struct numa_node *nodes, *n;
        u32 nr, i;
        char *str;

        /* nr nodes */
        if (do_read_u32(ff, &nr))
                return -1;

        nodes = zalloc(sizeof(*nodes) * nr);
        if (!nodes)
                return -ENOMEM;

        for (i = 0; i < nr; i++) {
                n = &nodes[i];

                /* node number */
                if (do_read_u32(ff, &n->node))
                        goto error;

                if (do_read_u64(ff, &n->mem_total))
                        goto error;

                if (do_read_u64(ff, &n->mem_free))
                        goto error;

                str = do_read_string(ff);
                if (!str)
                        goto error;

                n->map = perf_cpu_map__new(str);
                free(str);
                if (!n->map)
                        goto error;
        }
        env->nr_numa_nodes = nr;
        env->numa_nodes = nodes;
        return 0;

error:
        free(nodes);
        return -1;
}

static int process_pmu_mappings(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        char *name;
        u32 pmu_num;
        u32 type;
        struct strbuf sb;

        if (do_read_u32(ff, &pmu_num))
                return -1;

        if (!pmu_num) {
                pr_debug("pmu mappings not available\n");
                return 0;
        }

        env->nr_pmu_mappings = pmu_num;
        if (strbuf_init(&sb, 128) < 0)
                return -1;

        while (pmu_num) {
                if (do_read_u32(ff, &type))
                        goto error;

                name = do_read_string(ff);
                if (!name)
                        goto error;

                if (strbuf_addf(&sb, "%u:%s", type, name) < 0)
                        goto error;
                /* include a NULL character at the end */
                if (strbuf_add(&sb, "", 1) < 0)
                        goto error;

                if (!strcmp(name, "msr"))
                        env->msr_pmu_type = type;

                free(name);
                pmu_num--;
        }
        /* AMD may set it by evlist__has_amd_ibs() from perf_session__new() */
        free(env->pmu_mappings);
        env->pmu_mappings = strbuf_detach(&sb, NULL);
        return 0;

error:
        strbuf_release(&sb);
        return -1;
}

static int process_group_desc(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        size_t ret = -1;
        u32 i, nr, nr_groups;
        struct perf_session *session;
        struct evsel *evsel, *leader = NULL;
        struct group_desc {
                char *name;
                u32 leader_idx;
                u32 nr_members;
        } *desc;

        if (do_read_u32(ff, &nr_groups))
                return -1;

        env->nr_groups = nr_groups;
        if (!nr_groups) {
                pr_debug("group desc not available\n");
                return 0;
        }

        desc = calloc(nr_groups, sizeof(*desc));
        if (!desc)
                return -1;

        for (i = 0; i < nr_groups; i++) {
                desc[i].name = do_read_string(ff);
                if (!desc[i].name)
                        goto out_free;

                if (do_read_u32(ff, &desc[i].leader_idx))
                        goto out_free;

                if (do_read_u32(ff, &desc[i].nr_members))
                        goto out_free;
        }

        /*
         * Rebuild group relationship based on the group_desc
         */
        session = container_of(ff->ph, struct perf_session, header);

        i = nr = 0;
        evlist__for_each_entry(session->evlist, evsel) {
                if (i < nr_groups && evsel->core.idx == (int) desc[i].leader_idx) {
                        evsel__set_leader(evsel, evsel);
                        /* {anon_group} is a dummy name */
                        if (strcmp(desc[i].name, "{anon_group}")) {
                                evsel->group_name = desc[i].name;
                                desc[i].name = NULL;
                        }
                        evsel->core.nr_members = desc[i].nr_members;

                        if (i >= nr_groups || nr > 0) {
                                pr_debug("invalid group desc\n");
                                goto out_free;
                        }

                        leader = evsel;
                        nr = evsel->core.nr_members - 1;
                        i++;
                } else if (nr) {
                        /* This is a group member */
                        evsel__set_leader(evsel, leader);

                        nr--;
                }
        }

        if (i != nr_groups || nr != 0) {
                pr_debug("invalid group desc\n");
                goto out_free;
        }

        ret = 0;
out_free:
        for (i = 0; i < nr_groups; i++)
                zfree(&desc[i].name);
        free(desc);

        return ret;
}

static int process_auxtrace(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_session *session;
        int err;

        session = container_of(ff->ph, struct perf_session, header);

        err = auxtrace_index__process(ff->fd, ff->size, session,
                                      ff->ph->needs_swap);
        if (err < 0)
                pr_err("Failed to process auxtrace index\n");
        return err;
}

static int process_cache(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        struct cpu_cache_level *caches;
        u32 cnt, i, version;

        if (do_read_u32(ff, &version))
                return -1;

        if (version != 1)
                return -1;

        if (do_read_u32(ff, &cnt))
                return -1;

        caches = zalloc(sizeof(*caches) * cnt);
        if (!caches)
                return -1;

        for (i = 0; i < cnt; i++) {
                struct cpu_cache_level *c = &caches[i];

                #define _R(v)                                           \
                        if (do_read_u32(ff, &c->v))                     \
                                goto out_free_caches;                   \

                _R(level)
                _R(line_size)
                _R(sets)
                _R(ways)
                #undef _R

                #define _R(v)                                   \
                        c->v = do_read_string(ff);              \
                        if (!c->v)                              \
                                goto out_free_caches;           \

                _R(type)
                _R(size)
                _R(map)
                #undef _R
        }

        env->caches = caches;
        env->caches_cnt = cnt;
        return 0;
out_free_caches:
        for (i = 0; i < cnt; i++) {
                free(caches[i].type);
                free(caches[i].size);
                free(caches[i].map);
        }
        free(caches);
        return -1;
}

static int process_sample_time(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_session *session;
        u64 first_sample_time, last_sample_time;
        int ret;

        session = container_of(ff->ph, struct perf_session, header);

        ret = do_read_u64(ff, &first_sample_time);
        if (ret)
                return -1;

        ret = do_read_u64(ff, &last_sample_time);
        if (ret)
                return -1;

        session->evlist->first_sample_time = first_sample_time;
        session->evlist->last_sample_time = last_sample_time;
        return 0;
}

static int process_mem_topology(struct feat_fd *ff,
                                void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        struct memory_node *nodes;
        u64 version, i, nr, bsize;
        int ret = -1;

        if (do_read_u64(ff, &version))
                return -1;

        if (version != 1)
                return -1;

        if (do_read_u64(ff, &bsize))
                return -1;

        if (do_read_u64(ff, &nr))
                return -1;

        nodes = zalloc(sizeof(*nodes) * nr);
        if (!nodes)
                return -1;

        for (i = 0; i < nr; i++) {
                struct memory_node n;

                #define _R(v)                           \
                        if (do_read_u64(ff, &n.v))      \
                                goto out;               \

                _R(node)
                _R(size)

                #undef _R

                if (do_read_bitmap(ff, &n.set, &n.size))
                        goto out;

                nodes[i] = n;
        }

        env->memory_bsize    = bsize;
        env->memory_nodes    = nodes;
        env->nr_memory_nodes = nr;
        ret = 0;

out:
        if (ret)
                free(nodes);
        return ret;
}

static int process_clockid(struct feat_fd *ff,
                           void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;

        if (do_read_u64(ff, &env->clock.clockid_res_ns))
                return -1;

        return 0;
}

static int process_clock_data(struct feat_fd *ff,
                              void *_data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        u32 data32;
        u64 data64;

        /* version */
        if (do_read_u32(ff, &data32))
                return -1;

        if (data32 != 1)
                return -1;

        /* clockid */
        if (do_read_u32(ff, &data32))
                return -1;

        env->clock.clockid = data32;

        /* TOD ref time */
        if (do_read_u64(ff, &data64))
                return -1;

        env->clock.tod_ns = data64;

        /* clockid ref time */
        if (do_read_u64(ff, &data64))
                return -1;

        env->clock.clockid_ns = data64;
        env->clock.enabled = true;
        return 0;
}

static int process_hybrid_topology(struct feat_fd *ff,
                                   void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        struct hybrid_node *nodes, *n;
        u32 nr, i;

        /* nr nodes */
        if (do_read_u32(ff, &nr))
                return -1;

        nodes = zalloc(sizeof(*nodes) * nr);
        if (!nodes)
                return -ENOMEM;

        for (i = 0; i < nr; i++) {
                n = &nodes[i];

                n->pmu_name = do_read_string(ff);
                if (!n->pmu_name)
                        goto error;

                n->cpus = do_read_string(ff);
                if (!n->cpus)
                        goto error;
        }

        env->nr_hybrid_nodes = nr;
        env->hybrid_nodes = nodes;
        return 0;

error:
        for (i = 0; i < nr; i++) {
                free(nodes[i].pmu_name);
                free(nodes[i].cpus);
        }

        free(nodes);
        return -1;
}

static int process_dir_format(struct feat_fd *ff,
                              void *_data __maybe_unused)
{
        struct perf_session *session;
        struct perf_data *data;

        session = container_of(ff->ph, struct perf_session, header);
        data = session->data;

        if (WARN_ON(!perf_data__is_dir(data)))
                return -1;

        return do_read_u64(ff, &data->dir.version);
}

#ifdef HAVE_LIBBPF_SUPPORT
static int process_bpf_prog_info(struct feat_fd *ff, void *data __maybe_unused)
{
        struct bpf_prog_info_node *info_node;
        struct perf_env *env = &ff->ph->env;
        struct perf_bpil *info_linear;
        u32 count, i;
        int err = -1;

        if (ff->ph->needs_swap) {
                pr_warning("interpreting bpf_prog_info from systems with endianness is not yet supported\n");
                return 0;
        }

        if (do_read_u32(ff, &count))
                return -1;

        down_write(&env->bpf_progs.lock);

        for (i = 0; i < count; ++i) {
                u32 info_len, data_len;

                info_linear = NULL;
                info_node = NULL;
                if (do_read_u32(ff, &info_len))
                        goto out;
                if (do_read_u32(ff, &data_len))
                        goto out;

                if (info_len > sizeof(struct bpf_prog_info)) {
                        pr_warning("detected invalid bpf_prog_info\n");
                        goto out;
                }

                info_linear = malloc(sizeof(struct perf_bpil) +
                                     data_len);
                if (!info_linear)
                        goto out;
                info_linear->info_len = sizeof(struct bpf_prog_info);
                info_linear->data_len = data_len;
                if (do_read_u64(ff, (u64 *)(&info_linear->arrays)))
                        goto out;
                if (__do_read(ff, &info_linear->info, info_len))
                        goto out;
                if (info_len < sizeof(struct bpf_prog_info))
                        memset(((void *)(&info_linear->info)) + info_len, 0,
                               sizeof(struct bpf_prog_info) - info_len);

                if (__do_read(ff, info_linear->data, data_len))
                        goto out;

                info_node = malloc(sizeof(struct bpf_prog_info_node));
                if (!info_node)
                        goto out;

                /* after reading from file, translate offset to address */
                bpil_offs_to_addr(info_linear);
                info_node->info_linear = info_linear;
                info_node->metadata = NULL;
                if (!__perf_env__insert_bpf_prog_info(env, info_node)) {
                        free(info_linear);
                        free(info_node);
                }
        }

        up_write(&env->bpf_progs.lock);
        return 0;
out:
        free(info_linear);
        free(info_node);
        up_write(&env->bpf_progs.lock);
        return err;
}

static int process_bpf_btf(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        struct btf_node *node = NULL;
        u32 count, i;
        int err = -1;

        if (ff->ph->needs_swap) {
                pr_warning("interpreting btf from systems with endianness is not yet supported\n");
                return 0;
        }

        if (do_read_u32(ff, &count))
                return -1;

        down_write(&env->bpf_progs.lock);

        for (i = 0; i < count; ++i) {
                u32 id, data_size;

                if (do_read_u32(ff, &id))
                        goto out;
                if (do_read_u32(ff, &data_size))
                        goto out;

                node = malloc(sizeof(struct btf_node) + data_size);
                if (!node)
                        goto out;

                node->id = id;
                node->data_size = data_size;

                if (__do_read(ff, node->data, data_size))
                        goto out;

                if (!__perf_env__insert_btf(env, node))
                        free(node);
                node = NULL;
        }

        err = 0;
out:
        up_write(&env->bpf_progs.lock);
        free(node);
        return err;
}
#endif // HAVE_LIBBPF_SUPPORT

static int process_compressed(struct feat_fd *ff,
                              void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;

        if (do_read_u32(ff, &(env->comp_ver)))
                return -1;

        if (do_read_u32(ff, &(env->comp_type)))
                return -1;

        if (do_read_u32(ff, &(env->comp_level)))
                return -1;

        if (do_read_u32(ff, &(env->comp_ratio)))
                return -1;

        if (do_read_u32(ff, &(env->comp_mmap_len)))
                return -1;

        return 0;
}

static int __process_pmu_caps(struct feat_fd *ff, int *nr_caps,
                              char ***caps, unsigned int *max_branches,
                              unsigned int *br_cntr_nr,
                              unsigned int *br_cntr_width)
{
        char *name, *value, *ptr;
        u32 nr_pmu_caps, i;

        *nr_caps = 0;
        *caps = NULL;

        if (do_read_u32(ff, &nr_pmu_caps))
                return -1;

        if (!nr_pmu_caps)
                return 0;

        *caps = zalloc(sizeof(char *) * nr_pmu_caps);
        if (!*caps)
                return -1;

        for (i = 0; i < nr_pmu_caps; i++) {
                name = do_read_string(ff);
                if (!name)
                        goto error;

                value = do_read_string(ff);
                if (!value)
                        goto free_name;

                if (asprintf(&ptr, "%s=%s", name, value) < 0)
                        goto free_value;

                (*caps)[i] = ptr;

                if (!strcmp(name, "branches"))
                        *max_branches = atoi(value);

                if (!strcmp(name, "branch_counter_nr"))
                        *br_cntr_nr = atoi(value);

                if (!strcmp(name, "branch_counter_width"))
                        *br_cntr_width = atoi(value);

                free(value);
                free(name);
        }
        *nr_caps = nr_pmu_caps;
        return 0;

free_value:
        free(value);
free_name:
        free(name);
error:
        for (; i > 0; i--)
                free((*caps)[i - 1]);
        free(*caps);
        *caps = NULL;
        *nr_caps = 0;
        return -1;
}

static int process_cpu_pmu_caps(struct feat_fd *ff,
                                void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        int ret = __process_pmu_caps(ff, &env->nr_cpu_pmu_caps,
                                     &env->cpu_pmu_caps,
                                     &env->max_branches,
                                     &env->br_cntr_nr,
                                     &env->br_cntr_width);

        if (!ret && !env->cpu_pmu_caps)
                pr_debug("cpu pmu capabilities not available\n");
        return ret;
}

static int process_pmu_caps(struct feat_fd *ff, void *data __maybe_unused)
{
        struct perf_env *env = &ff->ph->env;
        struct pmu_caps *pmu_caps;
        u32 nr_pmu, i;
        int ret;
        int j;

        if (do_read_u32(ff, &nr_pmu))
                return -1;

        if (!nr_pmu) {
                pr_debug("pmu capabilities not available\n");
                return 0;
        }

        pmu_caps = zalloc(sizeof(*pmu_caps) * nr_pmu);
        if (!pmu_caps)
                return -ENOMEM;

        for (i = 0; i < nr_pmu; i++) {
                ret = __process_pmu_caps(ff, &pmu_caps[i].nr_caps,
                                         &pmu_caps[i].caps,
                                         &pmu_caps[i].max_branches,
                                         &pmu_caps[i].br_cntr_nr,
                                         &pmu_caps[i].br_cntr_width);
                if (ret)
                        goto err;

                pmu_caps[i].pmu_name = do_read_string(ff);
                if (!pmu_caps[i].pmu_name) {
                        ret = -1;
                        goto err;
                }
                if (!pmu_caps[i].nr_caps) {
                        pr_debug("%s pmu capabilities not available\n",
                                 pmu_caps[i].pmu_name);
                }
        }

        env->nr_pmus_with_caps = nr_pmu;
        env->pmu_caps = pmu_caps;
        return 0;

err:
        for (i = 0; i < nr_pmu; i++) {
                for (j = 0; j < pmu_caps[i].nr_caps; j++)
                        free(pmu_caps[i].caps[j]);
                free(pmu_caps[i].caps);
                free(pmu_caps[i].pmu_name);
        }

        free(pmu_caps);
        return ret;
}

static int process_cpu_domain_info(struct feat_fd *ff, void *data __maybe_unused)
{
        u32 schedstat_version, max_sched_domains, cpu, domain, nr_domains;
        struct perf_env *env = &ff->ph->env;
        char *dname, *cpumask, *cpulist;
        struct cpu_domain_map **cd_map;
        struct domain_info *d_info;
        u32 nra, nr, i, j;
        int ret;

        nra = env->nr_cpus_avail;
        nr = env->nr_cpus_online;

        cd_map = zalloc(sizeof(*cd_map) * nra);
        if (!cd_map)
                return -1;

        env->cpu_domain = cd_map;

        ret = do_read_u32(ff, &schedstat_version);
        if (ret)
                return ret;

        env->schedstat_version = schedstat_version;

        ret = do_read_u32(ff, &max_sched_domains);
        if (ret)
                return ret;

        env->max_sched_domains = max_sched_domains;

        for (i = 0; i < nr; i++) {
                if (do_read_u32(ff, &cpu))
                        return -1;

                cd_map[cpu] = zalloc(sizeof(*cd_map[cpu]));
                if (!cd_map[cpu])
                        return -1;

                cd_map[cpu]->cpu = cpu;

                if (do_read_u32(ff, &nr_domains))
                        return -1;

                cd_map[cpu]->nr_domains = nr_domains;

                cd_map[cpu]->domains = zalloc(sizeof(*d_info) * max_sched_domains);
                if (!cd_map[cpu]->domains)
                        return -1;

                for (j = 0; j < nr_domains; j++) {
                        if (do_read_u32(ff, &domain))
                                return -1;

                        d_info = zalloc(sizeof(*d_info));
                        if (!d_info)
                                return -1;

                        assert(cd_map[cpu]->domains[domain] == NULL);
                        cd_map[cpu]->domains[domain] = d_info;
                        d_info->domain = domain;

                        if (schedstat_version >= 17) {
                                dname = do_read_string(ff);
                                if (!dname)
                                        return -1;

                                d_info->dname = dname;
                        }

                        cpumask = do_read_string(ff);
                        if (!cpumask)
                                return -1;

                        d_info->cpumask = cpumask;

                        cpulist = do_read_string(ff);
                        if (!cpulist)
                                return -1;

                        d_info->cpulist = cpulist;
                }
        }

        return ret;
}

#define FEAT_OPR(n, func, __full_only) \
        [HEADER_##n] = {                                        \
                .name       = __stringify(n),                   \
                .write      = write_##func,                     \
                .print      = print_##func,                     \
                .full_only  = __full_only,                      \
                .process    = process_##func,                   \
                .synthesize = true                              \
        }

#define FEAT_OPN(n, func, __full_only) \
        [HEADER_##n] = {                                        \
                .name       = __stringify(n),                   \
                .write      = write_##func,                     \
                .print      = print_##func,                     \
                .full_only  = __full_only,                      \
                .process    = process_##func                    \
        }

/* feature_ops not implemented: */
#define print_tracing_data      NULL
#define print_build_id          NULL

#define process_branch_stack    NULL
#define process_stat            NULL

// Only used in util/synthetic-events.c
const struct perf_header_feature_ops feat_ops[HEADER_LAST_FEATURE];

const struct perf_header_feature_ops feat_ops[HEADER_LAST_FEATURE] = {
#ifdef HAVE_LIBTRACEEVENT
        FEAT_OPN(TRACING_DATA,  tracing_data,   false),
#endif
        FEAT_OPN(BUILD_ID,      build_id,       false),
        FEAT_OPR(HOSTNAME,      hostname,       false),
        FEAT_OPR(OSRELEASE,     osrelease,      false),
        FEAT_OPR(VERSION,       version,        false),
        FEAT_OPR(ARCH,          arch,           false),
        FEAT_OPR(NRCPUS,        nrcpus,         false),
        FEAT_OPR(CPUDESC,       cpudesc,        false),
        FEAT_OPR(CPUID,         cpuid,          false),
        FEAT_OPR(TOTAL_MEM,     total_mem,      false),
        FEAT_OPR(EVENT_DESC,    event_desc,     false),
        FEAT_OPR(CMDLINE,       cmdline,        false),
        FEAT_OPR(CPU_TOPOLOGY,  cpu_topology,   true),
        FEAT_OPR(NUMA_TOPOLOGY, numa_topology,  true),
        FEAT_OPN(BRANCH_STACK,  branch_stack,   false),
        FEAT_OPR(PMU_MAPPINGS,  pmu_mappings,   false),
        FEAT_OPR(GROUP_DESC,    group_desc,     false),
        FEAT_OPN(AUXTRACE,      auxtrace,       false),
        FEAT_OPN(STAT,          stat,           false),
        FEAT_OPN(CACHE,         cache,          true),
        FEAT_OPR(SAMPLE_TIME,   sample_time,    false),
        FEAT_OPR(MEM_TOPOLOGY,  mem_topology,   true),
        FEAT_OPR(CLOCKID,       clockid,        false),
        FEAT_OPN(DIR_FORMAT,    dir_format,     false),
#ifdef HAVE_LIBBPF_SUPPORT
        FEAT_OPR(BPF_PROG_INFO, bpf_prog_info,  false),
        FEAT_OPR(BPF_BTF,       bpf_btf,        false),
#endif
        FEAT_OPR(COMPRESSED,    compressed,     false),
        FEAT_OPR(CPU_PMU_CAPS,  cpu_pmu_caps,   false),
        FEAT_OPR(CLOCK_DATA,    clock_data,     false),
        FEAT_OPN(HYBRID_TOPOLOGY,       hybrid_topology,        true),
        FEAT_OPR(PMU_CAPS,      pmu_caps,       false),
        FEAT_OPR(CPU_DOMAIN_INFO,       cpu_domain_info,        true),
        FEAT_OPR(E_MACHINE,     e_machine,      false),
};

struct header_print_data {
        FILE *fp;
        bool full; /* extended list of headers */
};

static int perf_file_section__fprintf_info(struct perf_file_section *section,
                                           struct perf_header *ph,
                                           int feat, int fd, void *data)
{
        struct header_print_data *hd = data;
        struct feat_fd ff;

        if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
                pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
                                "%d, continuing...\n", section->offset, feat);
                return 0;
        }
        if (feat >= HEADER_LAST_FEATURE) {
                pr_warning("unknown feature %d\n", feat);
                return 0;
        }
        if (!feat_ops[feat].print)
                return 0;

        ff = (struct  feat_fd) {
                .fd = fd,
                .ph = ph,
        };

        if (!feat_ops[feat].full_only || hd->full)
                feat_ops[feat].print(&ff, hd->fp);
        else
                fprintf(hd->fp, "# %s info available, use -I to display\n",
                        feat_ops[feat].name);

        return 0;
}

int perf_header__fprintf_info(struct perf_session *session, FILE *fp, bool full)
{
        struct header_print_data hd;
        struct perf_header *header = &session->header;
        int fd = perf_data__fd(session->data);
        struct stat st;
        time_t stctime;
        int ret, bit;

        hd.fp = fp;
        hd.full = full;

        ret = fstat(fd, &st);
        if (ret == -1)
                return -1;

        stctime = st.st_mtime;
        fprintf(fp, "# captured on    : %s", ctime(&stctime));

        fprintf(fp, "# header version : %u\n", header->version);
        fprintf(fp, "# data offset    : %" PRIu64 "\n", header->data_offset);
        fprintf(fp, "# data size      : %" PRIu64 "\n", header->data_size);
        fprintf(fp, "# feat offset    : %" PRIu64 "\n", header->feat_offset);

        perf_header__process_sections(header, fd, &hd,
                                      perf_file_section__fprintf_info);

        if (session->data->is_pipe)
                return 0;

        fprintf(fp, "# missing features: ");
        for_each_clear_bit(bit, header->adds_features, HEADER_LAST_FEATURE) {
                if (bit)
                        fprintf(fp, "%s ", feat_ops[bit].name);
        }

        fprintf(fp, "\n");
        return 0;
}

struct header_fw {
        struct feat_writer      fw;
        struct feat_fd          *ff;
};

static int feat_writer_cb(struct feat_writer *fw, void *buf, size_t sz)
{
        struct header_fw *h = container_of(fw, struct header_fw, fw);

        return do_write(h->ff, buf, sz);
}

static int do_write_feat(struct feat_fd *ff, int type,
                         struct perf_file_section **p,
                         struct evlist *evlist,
                         struct feat_copier *fc)
{
        int err;
        int ret = 0;

        if (perf_header__has_feat(ff->ph, type)) {
                if (!feat_ops[type].write)
                        return -1;

                if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))
                        return -1;

                (*p)->offset = lseek(ff->fd, 0, SEEK_CUR);

                /*
                 * Hook to let perf inject copy features sections from the input
                 * file.
                 */
                if (fc && fc->copy) {
                        struct header_fw h = {
                                .fw.write = feat_writer_cb,
                                .ff = ff,
                        };

                        /* ->copy() returns 0 if the feature was not copied */
                        err = fc->copy(fc, type, &h.fw);
                } else {
                        err = 0;
                }
                if (!err)
                        err = feat_ops[type].write(ff, evlist);
                if (err < 0) {
                        pr_debug("failed to write feature %s\n", feat_ops[type].name);

                        /* undo anything written */
                        lseek(ff->fd, (*p)->offset, SEEK_SET);

                        return -1;
                }
                (*p)->size = lseek(ff->fd, 0, SEEK_CUR) - (*p)->offset;
                (*p)++;
        }
        return ret;
}

static int perf_header__adds_write(struct perf_header *header,
                                   struct evlist *evlist, int fd,
                                   struct feat_copier *fc)
{
        int nr_sections;
        struct feat_fd ff = {
                .fd  = fd,
                .ph = header,
        };
        struct perf_file_section *feat_sec, *p;
        int sec_size;
        u64 sec_start;
        int feat;
        int err;

        nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
        if (!nr_sections)
                return 0;

        feat_sec = p = calloc(nr_sections, sizeof(*feat_sec));
        if (feat_sec == NULL)
                return -ENOMEM;

        sec_size = sizeof(*feat_sec) * nr_sections;

        sec_start = header->feat_offset;
        lseek(fd, sec_start + sec_size, SEEK_SET);

        for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) {
                if (do_write_feat(&ff, feat, &p, evlist, fc))
                        perf_header__clear_feat(header, feat);
        }

        lseek(fd, sec_start, SEEK_SET);
        /*
         * may write more than needed due to dropped feature, but
         * this is okay, reader will skip the missing entries
         */
        err = do_write(&ff, feat_sec, sec_size);
        if (err < 0)
                pr_debug("failed to write feature section\n");
        free(ff.buf); /* TODO: added to silence clang-tidy. */
        free(feat_sec);
        return err;
}

int perf_header__write_pipe(int fd)
{
        struct perf_pipe_file_header f_header;
        struct feat_fd ff = {
                .fd = fd,
        };
        int err;

        f_header = (struct perf_pipe_file_header){
                .magic     = PERF_MAGIC,
                .size      = sizeof(f_header),
        };

        err = do_write(&ff, &f_header, sizeof(f_header));
        if (err < 0) {
                pr_debug("failed to write perf pipe header\n");
                return err;
        }
        free(ff.buf);
        return 0;
}

static int perf_session__do_write_header(struct perf_session *session,
                                         struct evlist *evlist,
                                         int fd, bool at_exit,
                                         struct feat_copier *fc,
                                         bool write_attrs_after_data)
{
        struct perf_file_header f_header;
        struct perf_header *header = &session->header;
        struct evsel *evsel;
        struct feat_fd ff = {
                .ph = header,
                .fd = fd,
        };
        u64 attr_offset = sizeof(f_header), attr_size = 0;
        int err;

        if (write_attrs_after_data && at_exit) {
                /*
                 * Write features at the end of the file first so that
                 * attributes may come after them.
                 */
                if (!header->data_offset && header->data_size) {
                        pr_err("File contains data but offset unknown\n");
                        err = -1;
                        goto err_out;
                }
                header->feat_offset = header->data_offset + header->data_size;
                err = perf_header__adds_write(header, evlist, fd, fc);
                if (err < 0)
                        goto err_out;
                attr_offset = lseek(fd, 0, SEEK_CUR);
        } else {
                lseek(fd, attr_offset, SEEK_SET);
        }

        evlist__for_each_entry(session->evlist, evsel) {
                evsel->id_offset = attr_offset;
                /* Avoid writing at the end of the file until the session is exiting. */
                if (!write_attrs_after_data || at_exit) {
                        err = do_write(&ff, evsel->core.id, evsel->core.ids * sizeof(u64));
                        if (err < 0) {
                                pr_debug("failed to write perf header\n");
                                goto err_out;
                        }
                }
                attr_offset += evsel->core.ids * sizeof(u64);
        }

        evlist__for_each_entry(evlist, evsel) {
                if (evsel->core.attr.size < sizeof(evsel->core.attr)) {
                        /*
                         * We are likely in "perf inject" and have read
                         * from an older file. Update attr size so that
                         * reader gets the right offset to the ids.
                         */
                        evsel->core.attr.size = sizeof(evsel->core.attr);
                }
                /* Avoid writing at the end of the file until the session is exiting. */
                if (!write_attrs_after_data || at_exit) {
                        struct perf_file_attr f_attr = {
                                .attr = evsel->core.attr,
                                .ids  = {
                                        .offset = evsel->id_offset,
                                        .size   = evsel->core.ids * sizeof(u64),
                                }
                        };
                        err = do_write(&ff, &f_attr, sizeof(f_attr));
                        if (err < 0) {
                                pr_debug("failed to write perf header attribute\n");
                                goto err_out;
                        }
                }
                attr_size += sizeof(struct perf_file_attr);
        }

        if (!header->data_offset) {
                if (write_attrs_after_data)
                        header->data_offset = sizeof(f_header);
                else
                        header->data_offset = attr_offset + attr_size;
        }
        header->feat_offset = header->data_offset + header->data_size;

        if (!write_attrs_after_data && at_exit) {
                /* Write features now feat_offset is known. */
                err = perf_header__adds_write(header, evlist, fd, fc);
                if (err < 0)
                        goto err_out;
        }

        f_header = (struct perf_file_header){
                .magic     = PERF_MAGIC,
                .size      = sizeof(f_header),
                .attr_size = sizeof(struct perf_file_attr),
                .attrs = {
                        .offset = attr_offset,
                        .size   = attr_size,
                },
                .data = {
                        .offset = header->data_offset,
                        .size   = header->data_size,
                },
                /* event_types is ignored, store zeros */
        };

        memcpy(&f_header.adds_features, &header->adds_features, sizeof(header->adds_features));

        lseek(fd, 0, SEEK_SET);
        err = do_write(&ff, &f_header, sizeof(f_header));
        if (err < 0) {
                pr_debug("failed to write perf header\n");
                goto err_out;
        } else {
                lseek(fd, 0, SEEK_END);
                err = 0;
        }
err_out:
        free(ff.buf);
        return err;
}

int perf_session__write_header(struct perf_session *session,
                               struct evlist *evlist,
                               int fd, bool at_exit)
{
        return perf_session__do_write_header(session, evlist, fd, at_exit, /*fc=*/NULL,
                                             /*write_attrs_after_data=*/false);
}

size_t perf_session__data_offset(const struct evlist *evlist)
{
        struct evsel *evsel;
        size_t data_offset;

        data_offset = sizeof(struct perf_file_header);
        evlist__for_each_entry(evlist, evsel) {
                data_offset += evsel->core.ids * sizeof(u64);
        }
        data_offset += evlist->core.nr_entries * sizeof(struct perf_file_attr);

        return data_offset;
}

int perf_session__inject_header(struct perf_session *session,
                                struct evlist *evlist,
                                int fd,
                                struct feat_copier *fc,
                                bool write_attrs_after_data)
{
        return perf_session__do_write_header(session, evlist, fd, true, fc,
                                             write_attrs_after_data);
}

static int perf_header__getbuffer64(struct perf_header *header,
                                    int fd, void *buf, size_t size)
{
        if (readn(fd, buf, size) <= 0)
                return -1;

        if (header->needs_swap)
                mem_bswap_64(buf, size);

        return 0;
}

int perf_header__process_sections(struct perf_header *header, int fd,
                                  void *data,
                                  int (*process)(struct perf_file_section *section,
                                                 struct perf_header *ph,
                                                 int feat, int fd, void *data))
{
        struct perf_file_section *feat_sec, *sec;
        int nr_sections;
        int sec_size;
        int feat;
        int err;

        nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
        if (!nr_sections)
                return 0;

        feat_sec = sec = calloc(nr_sections, sizeof(*feat_sec));
        if (!feat_sec)
                return -1;

        sec_size = sizeof(*feat_sec) * nr_sections;

        lseek(fd, header->feat_offset, SEEK_SET);

        err = perf_header__getbuffer64(header, fd, feat_sec, sec_size);
        if (err < 0)
                goto out_free;

        for_each_set_bit(feat, header->adds_features, HEADER_LAST_FEATURE) {
                err = process(sec++, header, feat, fd, data);
                if (err < 0)
                        goto out_free;
        }
        err = 0;
out_free:
        free(feat_sec);
        return err;
}

static const int attr_file_abi_sizes[] = {
        [0] = PERF_ATTR_SIZE_VER0,
        [1] = PERF_ATTR_SIZE_VER1,
        [2] = PERF_ATTR_SIZE_VER2,
        [3] = PERF_ATTR_SIZE_VER3,
        [4] = PERF_ATTR_SIZE_VER4,
        0,
};

/*
 * In the legacy file format, the magic number is not used to encode endianness.
 * hdr_sz was used to encode endianness. But given that hdr_sz can vary based
 * on ABI revisions, we need to try all combinations for all endianness to
 * detect the endianness.
 */
static int try_all_file_abis(uint64_t hdr_sz, struct perf_header *ph)
{
        uint64_t ref_size, attr_size;
        int i;

        for (i = 0 ; attr_file_abi_sizes[i]; i++) {
                ref_size = attr_file_abi_sizes[i]
                         + sizeof(struct perf_file_section);
                if (hdr_sz != ref_size) {
                        attr_size = bswap_64(hdr_sz);
                        if (attr_size != ref_size)
                                continue;

                        ph->needs_swap = true;
                }
                pr_debug("ABI%d perf.data file detected, need_swap=%d\n",
                         i,
                         ph->needs_swap);
                return 0;
        }
        /* could not determine endianness */
        return -1;
}

#define PERF_PIPE_HDR_VER0      16

static const size_t attr_pipe_abi_sizes[] = {
        [0] = PERF_PIPE_HDR_VER0,
        0,
};

/*
 * In the legacy pipe format, there is an implicit assumption that endianness
 * between host recording the samples, and host parsing the samples is the
 * same. This is not always the case given that the pipe output may always be
 * redirected into a file and analyzed on a different machine with possibly a
 * different endianness and perf_event ABI revisions in the perf tool itself.
 */
static int try_all_pipe_abis(uint64_t hdr_sz, struct perf_header *ph)
{
        u64 attr_size;
        int i;

        for (i = 0 ; attr_pipe_abi_sizes[i]; i++) {
                if (hdr_sz != attr_pipe_abi_sizes[i]) {
                        attr_size = bswap_64(hdr_sz);
                        if (attr_size != hdr_sz)
                                continue;

                        ph->needs_swap = true;
                }
                pr_debug("Pipe ABI%d perf.data file detected\n", i);
                return 0;
        }
        return -1;
}

bool is_perf_magic(u64 magic)
{
        if (!memcmp(&magic, __perf_magic1, sizeof(magic))
                || magic == __perf_magic2
                || magic == __perf_magic2_sw)
                return true;

        return false;
}

static int check_magic_endian(u64 magic, uint64_t hdr_sz,
                              bool is_pipe, struct perf_header *ph)
{
        int ret;

        /* check for legacy format */
        ret = memcmp(&magic, __perf_magic1, sizeof(magic));
        if (ret == 0) {
                ph->version = PERF_HEADER_VERSION_1;
                pr_debug("legacy perf.data format\n");
                if (is_pipe)
                        return try_all_pipe_abis(hdr_sz, ph);

                return try_all_file_abis(hdr_sz, ph);
        }
        /*
         * the new magic number serves two purposes:
         * - unique number to identify actual perf.data files
         * - encode endianness of file
         */
        ph->version = PERF_HEADER_VERSION_2;

        /* check magic number with one endianness */
        if (magic == __perf_magic2)
                return 0;

        /* check magic number with opposite endianness */
        if (magic != __perf_magic2_sw)
                return -1;

        ph->needs_swap = true;

        return 0;
}

int perf_file_header__read(struct perf_file_header *header,
                           struct perf_header *ph, int fd)
{
        ssize_t ret;

        lseek(fd, 0, SEEK_SET);

        ret = readn(fd, header, sizeof(*header));
        if (ret <= 0)
                return -1;

        if (check_magic_endian(header->magic,
                               header->attr_size, false, ph) < 0) {
                pr_debug("magic/endian check failed\n");
                return -1;
        }

        if (ph->needs_swap) {
                mem_bswap_64(header, offsetof(struct perf_file_header,
                             adds_features));
        }

        if (header->size > header->attrs.offset) {
                pr_err("Perf file header corrupt: header overlaps attrs\n");
                return -1;
        }

        if (header->size > header->data.offset) {
                pr_err("Perf file header corrupt: header overlaps data\n");
                return -1;
        }

        if ((header->attrs.offset <= header->data.offset &&
             header->attrs.offset + header->attrs.size > header->data.offset) ||
            (header->attrs.offset > header->data.offset &&
             header->data.offset + header->data.size > header->attrs.offset)) {
                pr_err("Perf file header corrupt: Attributes and data overlap\n");
                return -1;
        }

        if (header->size != sizeof(*header)) {
                /* Support the previous format */
                if (header->size == offsetof(typeof(*header), adds_features))
                        bitmap_zero(header->adds_features, HEADER_FEAT_BITS);
                else
                        return -1;
        } else if (ph->needs_swap) {
                /*
                 * feature bitmap is declared as an array of unsigned longs --
                 * not good since its size can differ between the host that
                 * generated the data file and the host analyzing the file.
                 *
                 * We need to handle endianness, but we don't know the size of
                 * the unsigned long where the file was generated. Take a best
                 * guess at determining it: try 64-bit swap first (ie., file
                 * created on a 64-bit host), and check if the hostname feature
                 * bit is set (this feature bit is forced on as of fbe96f2).
                 * If the bit is not, undo the 64-bit swap and try a 32-bit
                 * swap. If the hostname bit is still not set (e.g., older data
                 * file), punt and fallback to the original behavior --
                 * clearing all feature bits and setting buildid.
                 */
                mem_bswap_64(&header->adds_features,
                            BITS_TO_U64(HEADER_FEAT_BITS));

                if (!test_bit(HEADER_HOSTNAME, header->adds_features)) {
                        /* unswap as u64 */
                        mem_bswap_64(&header->adds_features,
                                    BITS_TO_U64(HEADER_FEAT_BITS));

                        /* unswap as u32 */
                        mem_bswap_32(&header->adds_features,
                                    BITS_TO_U32(HEADER_FEAT_BITS));
                }

                if (!test_bit(HEADER_HOSTNAME, header->adds_features)) {
                        bitmap_zero(header->adds_features, HEADER_FEAT_BITS);
                        __set_bit(HEADER_BUILD_ID, header->adds_features);
                }
        }

        memcpy(&ph->adds_features, &header->adds_features,
               sizeof(ph->adds_features));

        ph->data_offset  = header->data.offset;
        ph->data_size    = header->data.size;
        ph->feat_offset  = header->data.offset + header->data.size;
        return 0;
}

static int perf_file_section__process(struct perf_file_section *section,
                                      struct perf_header *ph,
                                      int feat, int fd, void *data)
{
        struct feat_fd fdd = {
                .fd     = fd,
                .ph     = ph,
                .size   = section->size,
                .offset = section->offset,
        };

        if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
                pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
                          "%d, continuing...\n", section->offset, feat);
                return 0;
        }

        if (feat >= HEADER_LAST_FEATURE) {
                pr_debug("unknown feature %d, continuing...\n", feat);
                return 0;
        }

        if (!feat_ops[feat].process)
                return 0;

        return feat_ops[feat].process(&fdd, data);
}

static int perf_file_header__read_pipe(struct perf_pipe_file_header *header,
                                       struct perf_header *ph,
                                       struct perf_data *data)
{
        ssize_t ret;

        ret = perf_data__read(data, header, sizeof(*header));
        if (ret <= 0)
                return -1;

        if (check_magic_endian(header->magic, header->size, true, ph) < 0) {
                pr_debug("endian/magic failed\n");
                return -1;
        }

        if (ph->needs_swap)
                header->size = bswap_64(header->size);

        return 0;
}

static int perf_header__read_pipe(struct perf_session *session)
{
        struct perf_header *header = &session->header;
        struct perf_pipe_file_header f_header;

        if (perf_file_header__read_pipe(&f_header, header, session->data) < 0) {
                pr_debug("incompatible file format\n");
                return -EINVAL;
        }

        return f_header.size == sizeof(f_header) ? 0 : -1;
}

static int read_attr(int fd, struct perf_header *ph,
                     struct perf_file_attr *f_attr)
{
        struct perf_event_attr *attr = &f_attr->attr;
        size_t sz, left;
        size_t our_sz = sizeof(f_attr->attr);
        ssize_t ret;

        memset(f_attr, 0, sizeof(*f_attr));

        /* read minimal guaranteed structure */
        ret = readn(fd, attr, PERF_ATTR_SIZE_VER0);
        if (ret <= 0) {
                pr_debug("cannot read %d bytes of header attr\n",
                         PERF_ATTR_SIZE_VER0);
                return -1;
        }

        /* on file perf_event_attr size */
        sz = attr->size;

        if (ph->needs_swap)
                sz = bswap_32(sz);

        if (sz == 0) {
                /* assume ABI0 */
                sz =  PERF_ATTR_SIZE_VER0;
        } else if (sz > our_sz) {
                pr_debug("file uses a more recent and unsupported ABI"
                         " (%zu bytes extra)\n", sz - our_sz);
                return -1;
        }
        /* what we have not yet read and that we know about */
        left = sz - PERF_ATTR_SIZE_VER0;
        if (left) {
                void *ptr = attr;
                ptr += PERF_ATTR_SIZE_VER0;

                ret = readn(fd, ptr, left);
        }
        /* read perf_file_section, ids are read in caller */
        ret = readn(fd, &f_attr->ids, sizeof(f_attr->ids));

        return ret <= 0 ? -1 : 0;
}

#ifdef HAVE_LIBTRACEEVENT
static int evsel__prepare_tracepoint_event(struct evsel *evsel, struct tep_handle *pevent)
{
        struct tep_event *event;
        char bf[128];

        /* already prepared */
        if (evsel->tp_format)
                return 0;

        if (pevent == NULL) {
                pr_debug("broken or missing trace data\n");
                return -1;
        }

        event = tep_find_event(pevent, evsel->core.attr.config);
        if (event == NULL) {
                pr_debug("cannot find event format for %d\n", (int)evsel->core.attr.config);
                return -1;
        }

        if (!evsel->name) {
                snprintf(bf, sizeof(bf), "%s:%s", event->system, event->name);
                evsel->name = strdup(bf);
                if (evsel->name == NULL)
                        return -1;
        }

        evsel->tp_format = event;
        return 0;
}

static int evlist__prepare_tracepoint_events(struct evlist *evlist, struct tep_handle *pevent)
{
        struct evsel *pos;

        evlist__for_each_entry(evlist, pos) {
                if (pos->core.attr.type == PERF_TYPE_TRACEPOINT &&
                    evsel__prepare_tracepoint_event(pos, pevent))
                        return -1;
        }

        return 0;
}
#endif

int perf_session__read_header(struct perf_session *session)
{
        struct perf_data *data = session->data;
        struct perf_header *header = &session->header;
        struct perf_file_header f_header;
        struct perf_file_attr   f_attr;
        u64                     f_id;
        int nr_attrs, nr_ids, i, j, err;
        int fd = perf_data__fd(data);

        session->evlist = evlist__new();
        if (session->evlist == NULL)
                return -ENOMEM;

        session->evlist->session = session;
        session->machines.host.env = &header->env;

        /*
         * We can read 'pipe' data event from regular file,
         * check for the pipe header regardless of source.
         */
        err = perf_header__read_pipe(session);
        if (!err || perf_data__is_pipe(data)) {
                data->is_pipe = true;
                return err;
        }

        if (perf_file_header__read(&f_header, header, fd) < 0)
                return -EINVAL;

        if (header->needs_swap && data->in_place_update) {
                pr_err("In-place update not supported when byte-swapping is required\n");
                return -EINVAL;
        }

        /*
         * Sanity check that perf.data was written cleanly; data size is
         * initialized to 0 and updated only if the on_exit function is run.
         * If data size is still 0 then the file contains only partial
         * information.  Just warn user and process it as much as it can.
         */
        if (f_header.data.size == 0) {
                pr_warning("WARNING: The %s file's data size field is 0 which is unexpected.\n"
                           "Was the 'perf record' command properly terminated?\n",
                           data->file.path);
        }

        if (f_header.attr_size == 0) {
                pr_err("ERROR: The %s file's attr size field is 0 which is unexpected.\n"
                       "Was the 'perf record' command properly terminated?\n",
                       data->file.path);
                return -EINVAL;
        }

        nr_attrs = f_header.attrs.size / f_header.attr_size;
        lseek(fd, f_header.attrs.offset, SEEK_SET);

        for (i = 0; i < nr_attrs; i++) {
                struct evsel *evsel;
                off_t tmp;

                if (read_attr(fd, header, &f_attr) < 0)
                        goto out_errno;

                if (header->needs_swap) {
                        f_attr.ids.size   = bswap_64(f_attr.ids.size);
                        f_attr.ids.offset = bswap_64(f_attr.ids.offset);
                        perf_event__attr_swap(&f_attr.attr);
                }

                tmp = lseek(fd, 0, SEEK_CUR);
                evsel = evsel__new(&f_attr.attr);

                if (evsel == NULL)
                        goto out_delete_evlist;

                evsel->needs_swap = header->needs_swap;
                /*
                 * Do it before so that if perf_evsel__alloc_id fails, this
                 * entry gets purged too at evlist__delete().
                 */
                evlist__add(session->evlist, evsel);

                nr_ids = f_attr.ids.size / sizeof(u64);
                /*
                 * We don't have the cpu and thread maps on the header, so
                 * for allocating the perf_sample_id table we fake 1 cpu and
                 * hattr->ids threads.
                 */
                if (perf_evsel__alloc_id(&evsel->core, 1, nr_ids))
                        goto out_delete_evlist;

                lseek(fd, f_attr.ids.offset, SEEK_SET);

                for (j = 0; j < nr_ids; j++) {
                        if (perf_header__getbuffer64(header, fd, &f_id, sizeof(f_id)))
                                goto out_errno;

                        perf_evlist__id_add(&session->evlist->core, &evsel->core, 0, j, f_id);
                }

                lseek(fd, tmp, SEEK_SET);
        }

#ifdef HAVE_LIBTRACEEVENT
        perf_header__process_sections(header, fd, &session->tevent,
                                      perf_file_section__process);

        if (evlist__prepare_tracepoint_events(session->evlist, session->tevent.pevent))
                goto out_delete_evlist;
#else
        perf_header__process_sections(header, fd, NULL, perf_file_section__process);
#endif

        return 0;
out_errno:
        return -errno;

out_delete_evlist:
        evlist__delete(session->evlist);
        session->evlist = NULL;
        return -ENOMEM;
}

int perf_event__process_feature(struct perf_session *session,
                                union perf_event *event)
{
        struct feat_fd ff = { .fd = 0 };
        struct perf_record_header_feature *fe = (struct perf_record_header_feature *)event;
        int type = fe->header.type;
        u64 feat = fe->feat_id;
        int ret = 0;
        bool print = dump_trace;

        if (type < 0 || type >= PERF_RECORD_HEADER_MAX) {
                pr_warning("invalid record type %d in pipe-mode\n", type);
                return 0;
        }
        if (feat == HEADER_RESERVED || feat >= HEADER_LAST_FEATURE) {
                pr_warning("invalid record type %d in pipe-mode\n", type);
                return -1;
        }

        ff.buf  = (void *)fe->data;
        ff.size = event->header.size - sizeof(*fe);
        ff.ph = &session->header;

        if (feat_ops[feat].process && feat_ops[feat].process(&ff, NULL)) {
                ret = -1;
                goto out;
        }

        if (session->tool->show_feat_hdr) {
                if (!feat_ops[feat].full_only ||
                    session->tool->show_feat_hdr >= SHOW_FEAT_HEADER_FULL_INFO) {
                        print = true;
                } else {
                        fprintf(stdout, "# %s info available, use -I to display\n",
                                feat_ops[feat].name);
                }
        }

        if (dump_trace)
                printf(", ");

        if (print) {
                if (feat_ops[feat].print)
                        feat_ops[feat].print(&ff, stdout);
                else
                        printf("# %s", feat_ops[feat].name);
        }

out:
        free_event_desc(ff.events);
        return ret;
}

size_t perf_event__fprintf_event_update(union perf_event *event, FILE *fp)
{
        struct perf_record_event_update *ev = &event->event_update;
        struct perf_cpu_map *map;
        size_t ret;

        ret = fprintf(fp, "\n... id:    %" PRI_lu64 "\n", ev->id);

        switch (ev->type) {
        case PERF_EVENT_UPDATE__SCALE:
                ret += fprintf(fp, "... scale: %f\n", ev->scale.scale);
                break;
        case PERF_EVENT_UPDATE__UNIT:
                ret += fprintf(fp, "... unit:  %s\n", ev->unit);
                break;
        case PERF_EVENT_UPDATE__NAME:
                ret += fprintf(fp, "... name:  %s\n", ev->name);
                break;
        case PERF_EVENT_UPDATE__CPUS:
                ret += fprintf(fp, "... ");

                map = cpu_map__new_data(&ev->cpus.cpus);
                if (map) {
                        ret += cpu_map__fprintf(map, fp);
                        perf_cpu_map__put(map);
                } else
                        ret += fprintf(fp, "failed to get cpus\n");
                break;
        default:
                ret += fprintf(fp, "... unknown type\n");
                break;
        }

        return ret;
}

size_t perf_event__fprintf_attr(union perf_event *event, FILE *fp)
{
        return perf_event_attr__fprintf(fp, &event->attr.attr, __desc_attr__fprintf, NULL);
}

int perf_event__process_attr(const struct perf_tool *tool __maybe_unused,
                             union perf_event *event,
                             struct evlist **pevlist)
{
        u32 i, n_ids;
        u64 *ids;
        struct evsel *evsel;
        struct evlist *evlist = *pevlist;

        if (dump_trace)
                perf_event__fprintf_attr(event, stdout);

        if (evlist == NULL) {
                *pevlist = evlist = evlist__new();
                if (evlist == NULL)
                        return -ENOMEM;
        }

        evsel = evsel__new(&event->attr.attr);
        if (evsel == NULL)
                return -ENOMEM;

        evlist__add(evlist, evsel);

        n_ids = event->header.size - sizeof(event->header) - event->attr.attr.size;
        n_ids = n_ids / sizeof(u64);
        /*
         * We don't have the cpu and thread maps on the header, so
         * for allocating the perf_sample_id table we fake 1 cpu and
         * hattr->ids threads.
         */
        if (perf_evsel__alloc_id(&evsel->core, 1, n_ids))
                return -ENOMEM;

        ids = perf_record_header_attr_id(event);
        for (i = 0; i < n_ids; i++) {
                perf_evlist__id_add(&evlist->core, &evsel->core, 0, i, ids[i]);
        }

        return 0;
}

int perf_event__process_event_update(const struct perf_tool *tool __maybe_unused,
                                     union perf_event *event,
                                     struct evlist **pevlist)
{
        struct perf_record_event_update *ev = &event->event_update;
        struct evlist *evlist;
        struct evsel *evsel;
        struct perf_cpu_map *map;

        if (dump_trace)
                perf_event__fprintf_event_update(event, stdout);

        if (!pevlist || *pevlist == NULL)
                return -EINVAL;

        evlist = *pevlist;

        evsel = evlist__id2evsel(evlist, ev->id);
        if (evsel == NULL)
                return -EINVAL;

        switch (ev->type) {
        case PERF_EVENT_UPDATE__UNIT:
                free((char *)evsel->unit);
                evsel->unit = strdup(ev->unit);
                break;
        case PERF_EVENT_UPDATE__NAME:
                free(evsel->name);
                evsel->name = strdup(ev->name);
                break;
        case PERF_EVENT_UPDATE__SCALE:
                evsel->scale = ev->scale.scale;
                break;
        case PERF_EVENT_UPDATE__CPUS:
                map = cpu_map__new_data(&ev->cpus.cpus);
                if (map) {
                        perf_cpu_map__put(evsel->core.pmu_cpus);
                        evsel->core.pmu_cpus = map;
                } else
                        pr_err("failed to get event_update cpus\n");
        default:
                break;
        }

        return 0;
}

#ifdef HAVE_LIBTRACEEVENT
int perf_event__process_tracing_data(const struct perf_tool *tool __maybe_unused,
                                     struct perf_session *session,
                                     union perf_event *event)
{
        ssize_t size_read, padding, size = event->tracing_data.size;
        int fd = perf_data__fd(session->data);
        char buf[BUFSIZ];

        /*
         * The pipe fd is already in proper place and in any case
         * we can't move it, and we'd screw the case where we read
         * 'pipe' data from regular file. The trace_report reads
         * data from 'fd' so we need to set it directly behind the
         * event, where the tracing data starts.
         */
        if (!perf_data__is_pipe(session->data)) {
                off_t offset = lseek(fd, 0, SEEK_CUR);

                /* setup for reading amidst mmap */
                lseek(fd, offset + sizeof(struct perf_record_header_tracing_data),
                      SEEK_SET);
        }

        size_read = trace_report(fd, &session->tevent, session->trace_event_repipe);
        padding = PERF_ALIGN(size_read, sizeof(u64)) - size_read;

        if (readn(fd, buf, padding) < 0) {
                pr_err("%s: reading input file", __func__);
                return -1;
        }
        if (session->trace_event_repipe) {
                int retw = write(STDOUT_FILENO, buf, padding);
                if (retw <= 0 || retw != padding) {
                        pr_err("%s: repiping tracing data padding", __func__);
                        return -1;
                }
        }

        if (size_read + padding != size) {
                pr_err("%s: tracing data size mismatch", __func__);
                return -1;
        }

        evlist__prepare_tracepoint_events(session->evlist, session->tevent.pevent);

        return size_read + padding;
}
#endif

int perf_event__process_build_id(const struct perf_tool *tool __maybe_unused,
                                 struct perf_session *session,
                                 union perf_event *event)
{
        __event_process_build_id(&event->build_id,
                                 event->build_id.filename,
                                 session);
        return 0;
}