session.c

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// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <inttypes.h>
#include <linux/kernel.h>
#include <traceevent/event-parse.h>
#include <api/fs/fs.h>

#include <byteswap.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>

#include "evlist.h"
#include "evsel.h"
#include "memswap.h"
#include "session.h"
#include "tool.h"
#include "sort.h"
#include "util.h"
#include "cpumap.h"
#include "perf_regs.h"
#include "asm/bug.h"
#include "auxtrace.h"
#include "thread.h"
#include "thread-stack.h"
#include "stat.h"

static int perf_session__deliver_event(struct perf_session *session,
                       union perf_event *event,
                       struct perf_tool *tool,
                       u64 file_offset);

static int perf_session__open(struct perf_session *session)
{
    struct perf_data *data = session->data;

    if (perf_session__read_header(session) < 0) {
        pr_err("incompatible file format (rerun with -v to learn more)\n");
        return -1;
    }

    if (perf_data__is_pipe(data))
        return 0;

    if (perf_header__has_feat(&session->header, HEADER_STAT))
        return 0;

    if (!perf_evlist__valid_sample_type(session->evlist)) {
        pr_err("non matching sample_type\n");
        return -1;
    }

    if (!perf_evlist__valid_sample_id_all(session->evlist)) {
        pr_err("non matching sample_id_all\n");
        return -1;
    }

    if (!perf_evlist__valid_read_format(session->evlist)) {
        pr_err("non matching read_format\n");
        return -1;
    }

    return 0;
}

void perf_session__set_id_hdr_size(struct perf_session *session)
{
    u16 id_hdr_size = perf_evlist__id_hdr_size(session->evlist);

    machines__set_id_hdr_size(&session->machines, id_hdr_size);
}

int perf_session__create_kernel_maps(struct perf_session *session)
{
    int ret = machine__create_kernel_maps(&session->machines.host);

    if (ret >= 0)
        ret = machines__create_guest_kernel_maps(&session->machines);
    return ret;
}

static void perf_session__destroy_kernel_maps(struct perf_session *session)
{
    machines__destroy_kernel_maps(&session->machines);
}

static bool perf_session__has_comm_exec(struct perf_session *session)
{
    struct perf_evsel *evsel;

    evlist__for_each_entry(session->evlist, evsel) {
        if (evsel->attr.comm_exec)
            return true;
    }

    return false;
}

static void perf_session__set_comm_exec(struct perf_session *session)
{
    bool comm_exec = perf_session__has_comm_exec(session);

    machines__set_comm_exec(&session->machines, comm_exec);
}

static int ordered_events__deliver_event(struct ordered_events *oe,
                     struct ordered_event *event)
{
    struct perf_session *session = container_of(oe, struct perf_session,
                            ordered_events);

    return perf_session__deliver_event(session, event->event,
                       session->tool, event->file_offset);
}

struct perf_session *perf_session__new(struct perf_data *data,
                       bool repipe, struct perf_tool *tool)
{
    struct perf_session *session = zalloc(sizeof(*session));

    if (!session)
        goto out;

    session->repipe = repipe;
    session->tool   = tool;
    INIT_LIST_HEAD(&session->auxtrace_index);
    machines__init(&session->machines);
    ordered_events__init(&session->ordered_events, ordered_events__deliver_event);

    if (data) {
        if (perf_data__open(data))
            goto out_delete;

        session->data = data;

        if (perf_data__is_read(data)) {
            if (perf_session__open(session) < 0)
                goto out_close;

            /*
             * set session attributes that are present in perf.data
             * but not in pipe-mode.
             */
            if (!data->is_pipe) {
                perf_session__set_id_hdr_size(session);
                perf_session__set_comm_exec(session);
            }
        }
    } else  {
        session->machines.host.env = &perf_env;
    }

    if (!data || perf_data__is_write(data)) {
        /*
         * In O_RDONLY mode this will be performed when reading the
         * kernel MMAP event, in perf_event__process_mmap().
         */
        if (perf_session__create_kernel_maps(session) < 0)
            pr_warning("Cannot read kernel map\n");
    }

    /*
     * In pipe-mode, evlist is empty until PERF_RECORD_HEADER_ATTR is
     * processed, so perf_evlist__sample_id_all is not meaningful here.
     */
    if ((!data || !data->is_pipe) && tool && tool->ordering_requires_timestamps &&
        tool->ordered_events && !perf_evlist__sample_id_all(session->evlist)) {
        dump_printf("WARNING: No sample_id_all support, falling back to unordered processing\n");
        tool->ordered_events = false;
    }

    return session;

 out_close:
    perf_data__close(data);
 out_delete:
    perf_session__delete(session);
 out:
    return NULL;
}

static void perf_session__delete_threads(struct perf_session *session)
{
    machine__delete_threads(&session->machines.host);
}

void perf_session__delete(struct perf_session *session)
{
    if (session == NULL)
        return;
    auxtrace__free(session);
    auxtrace_index__free(&session->auxtrace_index);
    perf_session__destroy_kernel_maps(session);
    perf_session__delete_threads(session);
    perf_env__exit(&session->header.env);
    machines__exit(&session->machines);
    if (session->data)
        perf_data__close(session->data);
    free(session);
}

static int process_event_synth_tracing_data_stub(struct perf_tool *tool
                         __maybe_unused,
                         union perf_event *event
                         __maybe_unused,
                         struct perf_session *session
                        __maybe_unused)
{
    dump_printf(": unhandled!\n");
    return 0;
}

static int process_event_synth_attr_stub(struct perf_tool *tool __maybe_unused,
                     union perf_event *event __maybe_unused,
                     struct perf_evlist **pevlist
                     __maybe_unused)
{
    dump_printf(": unhandled!\n");
    return 0;
}

static int process_event_synth_event_update_stub(struct perf_tool *tool __maybe_unused,
                         union perf_event *event __maybe_unused,
                         struct perf_evlist **pevlist
                         __maybe_unused)
{
    if (dump_trace)
        perf_event__fprintf_event_update(event, stdout);

    dump_printf(": unhandled!\n");
    return 0;
}

static int process_event_sample_stub(struct perf_tool *tool __maybe_unused,
                     union perf_event *event __maybe_unused,
                     struct perf_sample *sample __maybe_unused,
                     struct perf_evsel *evsel __maybe_unused,
                     struct machine *machine __maybe_unused)
{
    dump_printf(": unhandled!\n");
    return 0;
}

static int process_event_stub(struct perf_tool *tool __maybe_unused,
                  union perf_event *event __maybe_unused,
                  struct perf_sample *sample __maybe_unused,
                  struct machine *machine __maybe_unused)
{
    dump_printf(": unhandled!\n");
    return 0;
}

static int process_finished_round_stub(struct perf_tool *tool __maybe_unused,
                       union perf_event *event __maybe_unused,
                       struct ordered_events *oe __maybe_unused)
{
    dump_printf(": unhandled!\n");
    return 0;
}

static int process_finished_round(struct perf_tool *tool,
                  union perf_event *event,
                  struct ordered_events *oe);

static int skipn(int fd, off_t n)
{
    char buf[4096];
    ssize_t ret;

    while (n > 0) {
        ret = read(fd, buf, min(n, (off_t)sizeof(buf)));
        if (ret <= 0)
            return ret;
        n -= ret;
    }

    return 0;
}

static s64 process_event_auxtrace_stub(struct perf_tool *tool __maybe_unused,
                       union perf_event *event,
                       struct perf_session *session
                       __maybe_unused)
{
    dump_printf(": unhandled!\n");
    if (perf_data__is_pipe(session->data))
        skipn(perf_data__fd(session->data), event->auxtrace.size);
    return event->auxtrace.size;
}

static int process_event_op2_stub(struct perf_tool *tool __maybe_unused,
                  union perf_event *event __maybe_unused,
                  struct perf_session *session __maybe_unused)
{
    dump_printf(": unhandled!\n");
    return 0;
}


static
int process_event_thread_map_stub(struct perf_tool *tool __maybe_unused,
                  union perf_event *event __maybe_unused,
                  struct perf_session *session __maybe_unused)
{
    if (dump_trace)
        perf_event__fprintf_thread_map(event, stdout);

    dump_printf(": unhandled!\n");
    return 0;
}

static
int process_event_cpu_map_stub(struct perf_tool *tool __maybe_unused,
                   union perf_event *event __maybe_unused,
                   struct perf_session *session __maybe_unused)
{
    if (dump_trace)
        perf_event__fprintf_cpu_map(event, stdout);

    dump_printf(": unhandled!\n");
    return 0;
}

static
int process_event_stat_config_stub(struct perf_tool *tool __maybe_unused,
                   union perf_event *event __maybe_unused,
                   struct perf_session *session __maybe_unused)
{
    if (dump_trace)
        perf_event__fprintf_stat_config(event, stdout);

    dump_printf(": unhandled!\n");
    return 0;
}

static int process_stat_stub(struct perf_tool *tool __maybe_unused,
                 union perf_event *event __maybe_unused,
                 struct perf_session *perf_session
                 __maybe_unused)
{
    if (dump_trace)
        perf_event__fprintf_stat(event, stdout);

    dump_printf(": unhandled!\n");
    return 0;
}

static int process_stat_round_stub(struct perf_tool *tool __maybe_unused,
                   union perf_event *event __maybe_unused,
                   struct perf_session *perf_session
                   __maybe_unused)
{
    if (dump_trace)
        perf_event__fprintf_stat_round(event, stdout);

    dump_printf(": unhandled!\n");
    return 0;
}

void perf_tool__fill_defaults(struct perf_tool *tool)
{
    if (tool->sample == NULL)
        tool->sample = process_event_sample_stub;
    if (tool->mmap == NULL)
        tool->mmap = process_event_stub;
    if (tool->mmap2 == NULL)
        tool->mmap2 = process_event_stub;
    if (tool->comm == NULL)
        tool->comm = process_event_stub;
    if (tool->namespaces == NULL)
        tool->namespaces = process_event_stub;
    if (tool->fork == NULL)
        tool->fork = process_event_stub;
    if (tool->exit == NULL)
        tool->exit = process_event_stub;
    if (tool->lost == NULL)
        tool->lost = perf_event__process_lost;
    if (tool->lost_samples == NULL)
        tool->lost_samples = perf_event__process_lost_samples;
    if (tool->aux == NULL)
        tool->aux = perf_event__process_aux;
    if (tool->itrace_start == NULL)
        tool->itrace_start = perf_event__process_itrace_start;
    if (tool->context_switch == NULL)
        tool->context_switch = perf_event__process_switch;
    if (tool->read == NULL)
        tool->read = process_event_sample_stub;
    if (tool->throttle == NULL)
        tool->throttle = process_event_stub;
    if (tool->unthrottle == NULL)
        tool->unthrottle = process_event_stub;
    if (tool->attr == NULL)
        tool->attr = process_event_synth_attr_stub;
    if (tool->event_update == NULL)
        tool->event_update = process_event_synth_event_update_stub;
    if (tool->tracing_data == NULL)
        tool->tracing_data = process_event_synth_tracing_data_stub;
    if (tool->build_id == NULL)
        tool->build_id = process_event_op2_stub;
    if (tool->finished_round == NULL) {
        if (tool->ordered_events)
            tool->finished_round = process_finished_round;
        else
            tool->finished_round = process_finished_round_stub;
    }
    if (tool->id_index == NULL)
        tool->id_index = process_event_op2_stub;
    if (tool->auxtrace_info == NULL)
        tool->auxtrace_info = process_event_op2_stub;
    if (tool->auxtrace == NULL)
        tool->auxtrace = process_event_auxtrace_stub;
    if (tool->auxtrace_error == NULL)
        tool->auxtrace_error = process_event_op2_stub;
    if (tool->thread_map == NULL)
        tool->thread_map = process_event_thread_map_stub;
    if (tool->cpu_map == NULL)
        tool->cpu_map = process_event_cpu_map_stub;
    if (tool->stat_config == NULL)
        tool->stat_config = process_event_stat_config_stub;
    if (tool->stat == NULL)
        tool->stat = process_stat_stub;
    if (tool->stat_round == NULL)
        tool->stat_round = process_stat_round_stub;
    if (tool->time_conv == NULL)
        tool->time_conv = process_event_op2_stub;
    if (tool->feature == NULL)
        tool->feature = process_event_op2_stub;
}

static void swap_sample_id_all(union perf_event *event, void *data)
{
    void *end = (void *) event + event->header.size;
    int size = end - data;

    BUG_ON(size % sizeof(u64));
    mem_bswap_64(data, size);
}

static void perf_event__all64_swap(union perf_event *event,
                   bool sample_id_all __maybe_unused)
{
    struct perf_event_header *hdr = &event->header;
    mem_bswap_64(hdr + 1, event->header.size - sizeof(*hdr));
}

static void perf_event__comm_swap(union perf_event *event, bool sample_id_all)
{
    event->comm.pid = bswap_32(event->comm.pid);
    event->comm.tid = bswap_32(event->comm.tid);

    if (sample_id_all) {
        void *data = &event->comm.comm;

        data += PERF_ALIGN(strlen(data) + 1, sizeof(u64));
        swap_sample_id_all(event, data);
    }
}

static void perf_event__mmap_swap(union perf_event *event,
                  bool sample_id_all)
{
    event->mmap.pid   = bswap_32(event->mmap.pid);
    event->mmap.tid   = bswap_32(event->mmap.tid);
    event->mmap.start = bswap_64(event->mmap.start);
    event->mmap.len   = bswap_64(event->mmap.len);
    event->mmap.pgoff = bswap_64(event->mmap.pgoff);

    if (sample_id_all) {
        void *data = &event->mmap.filename;

        data += PERF_ALIGN(strlen(data) + 1, sizeof(u64));
        swap_sample_id_all(event, data);
    }
}

static void perf_event__mmap2_swap(union perf_event *event,
                  bool sample_id_all)
{
    event->mmap2.pid   = bswap_32(event->mmap2.pid);
    event->mmap2.tid   = bswap_32(event->mmap2.tid);
    event->mmap2.start = bswap_64(event->mmap2.start);
    event->mmap2.len   = bswap_64(event->mmap2.len);
    event->mmap2.pgoff = bswap_64(event->mmap2.pgoff);
    event->mmap2.maj   = bswap_32(event->mmap2.maj);
    event->mmap2.min   = bswap_32(event->mmap2.min);
    event->mmap2.ino   = bswap_64(event->mmap2.ino);

    if (sample_id_all) {
        void *data = &event->mmap2.filename;

        data += PERF_ALIGN(strlen(data) + 1, sizeof(u64));
        swap_sample_id_all(event, data);
    }
}
static void perf_event__task_swap(union perf_event *event, bool sample_id_all)
{
    event->fork.pid  = bswap_32(event->fork.pid);
    event->fork.tid  = bswap_32(event->fork.tid);
    event->fork.ppid = bswap_32(event->fork.ppid);
    event->fork.ptid = bswap_32(event->fork.ptid);
    event->fork.time = bswap_64(event->fork.time);

    if (sample_id_all)
        swap_sample_id_all(event, &event->fork + 1);
}

static void perf_event__read_swap(union perf_event *event, bool sample_id_all)
{
    event->read.pid      = bswap_32(event->read.pid);
    event->read.tid      = bswap_32(event->read.tid);
    event->read.value    = bswap_64(event->read.value);
    event->read.time_enabled = bswap_64(event->read.time_enabled);
    event->read.time_running = bswap_64(event->read.time_running);
    event->read.id       = bswap_64(event->read.id);

    if (sample_id_all)
        swap_sample_id_all(event, &event->read + 1);
}

static void perf_event__aux_swap(union perf_event *event, bool sample_id_all)
{
    event->aux.aux_offset = bswap_64(event->aux.aux_offset);
    event->aux.aux_size   = bswap_64(event->aux.aux_size);
    event->aux.flags      = bswap_64(event->aux.flags);

    if (sample_id_all)
        swap_sample_id_all(event, &event->aux + 1);
}

static void perf_event__itrace_start_swap(union perf_event *event,
                      bool sample_id_all)
{
    event->itrace_start.pid  = bswap_32(event->itrace_start.pid);
    event->itrace_start.tid  = bswap_32(event->itrace_start.tid);

    if (sample_id_all)
        swap_sample_id_all(event, &event->itrace_start + 1);
}

static void perf_event__switch_swap(union perf_event *event, bool sample_id_all)
{
    if (event->header.type == PERF_RECORD_SWITCH_CPU_WIDE) {
        event->context_switch.next_prev_pid =
                bswap_32(event->context_switch.next_prev_pid);
        event->context_switch.next_prev_tid =
                bswap_32(event->context_switch.next_prev_tid);
    }

    if (sample_id_all)
        swap_sample_id_all(event, &event->context_switch + 1);
}

static void perf_event__throttle_swap(union perf_event *event,
                      bool sample_id_all)
{
    event->throttle.time      = bswap_64(event->throttle.time);
    event->throttle.id    = bswap_64(event->throttle.id);
    event->throttle.stream_id = bswap_64(event->throttle.stream_id);

    if (sample_id_all)
        swap_sample_id_all(event, &event->throttle + 1);
}

static u8 revbyte(u8 b)
{
    int rev = (b >> 4) | ((b & 0xf) << 4);
    rev = ((rev & 0xcc) >> 2) | ((rev & 0x33) << 2);
    rev = ((rev & 0xaa) >> 1) | ((rev & 0x55) << 1);
    return (u8) rev;
}

/*
 * XXX this is hack in attempt to carry flags bitfield
 * through endian village. ABI says:
 *
 * Bit-fields are allocated from right to left (least to most significant)
 * on little-endian implementations and from left to right (most to least
 * significant) on big-endian implementations.
 *
 * The above seems to be byte specific, so we need to reverse each
 * byte of the bitfield. 'Internet' also says this might be implementation
 * specific and we probably need proper fix and carry perf_event_attr
 * bitfield flags in separate data file FEAT_ section. Thought this seems
 * to work for now.
 */
static void swap_bitfield(u8 *p, unsigned len)
{
    unsigned i;

    for (i = 0; i < len; i++) {
        *p = revbyte(*p);
        p++;
    }
}

/* exported for swapping attributes in file header */
void perf_event__attr_swap(struct perf_event_attr *attr)
{
    attr->type      = bswap_32(attr->type);
    attr->size      = bswap_32(attr->size);

#define bswap_safe(f, n)                    \
    (attr->size > (offsetof(struct perf_event_attr, f) +    \
               sizeof(attr->f) * (n)))
#define bswap_field(f, sz)          \
do {                        \
    if (bswap_safe(f, 0))           \
        attr->f = bswap_##sz(attr->f);  \
} while(0)
#define bswap_field_16(f) bswap_field(f, 16)
#define bswap_field_32(f) bswap_field(f, 32)
#define bswap_field_64(f) bswap_field(f, 64)

    bswap_field_64(config);
    bswap_field_64(sample_period);
    bswap_field_64(sample_type);
    bswap_field_64(read_format);
    bswap_field_32(wakeup_events);
    bswap_field_32(bp_type);
    bswap_field_64(bp_addr);
    bswap_field_64(bp_len);
    bswap_field_64(branch_sample_type);
    bswap_field_64(sample_regs_user);
    bswap_field_32(sample_stack_user);
    bswap_field_32(aux_watermark);
    bswap_field_16(sample_max_stack);

    /*
     * After read_format are bitfields. Check read_format because
     * we are unable to use offsetof on bitfield.
     */
    if (bswap_safe(read_format, 1))
        swap_bitfield((u8 *) (&attr->read_format + 1),
                  sizeof(u64));
#undef bswap_field_64
#undef bswap_field_32
#undef bswap_field
#undef bswap_safe
}

static void perf_event__hdr_attr_swap(union perf_event *event,
                      bool sample_id_all __maybe_unused)
{
    size_t size;

    perf_event__attr_swap(&event->attr.attr);

    size = event->header.size;
    size -= (void *)&event->attr.id - (void *)event;
    mem_bswap_64(event->attr.id, size);
}

static void perf_event__event_update_swap(union perf_event *event,
                      bool sample_id_all __maybe_unused)
{
    event->event_update.type = bswap_64(event->event_update.type);
    event->event_update.id   = bswap_64(event->event_update.id);
}

static void perf_event__event_type_swap(union perf_event *event,
                    bool sample_id_all __maybe_unused)
{
    event->event_type.event_type.event_id =
        bswap_64(event->event_type.event_type.event_id);
}

static void perf_event__tracing_data_swap(union perf_event *event,
                      bool sample_id_all __maybe_unused)
{
    event->tracing_data.size = bswap_32(event->tracing_data.size);
}

static void perf_event__auxtrace_info_swap(union perf_event *event,
                       bool sample_id_all __maybe_unused)
{
    size_t size;

    event->auxtrace_info.type = bswap_32(event->auxtrace_info.type);

    size = event->header.size;
    size -= (void *)&event->auxtrace_info.priv - (void *)event;
    mem_bswap_64(event->auxtrace_info.priv, size);
}

static void perf_event__auxtrace_swap(union perf_event *event,
                      bool sample_id_all __maybe_unused)
{
    event->auxtrace.size      = bswap_64(event->auxtrace.size);
    event->auxtrace.offset    = bswap_64(event->auxtrace.offset);
    event->auxtrace.reference = bswap_64(event->auxtrace.reference);
    event->auxtrace.idx       = bswap_32(event->auxtrace.idx);
    event->auxtrace.tid       = bswap_32(event->auxtrace.tid);
    event->auxtrace.cpu       = bswap_32(event->auxtrace.cpu);
}

static void perf_event__auxtrace_error_swap(union perf_event *event,
                        bool sample_id_all __maybe_unused)
{
    event->auxtrace_error.type = bswap_32(event->auxtrace_error.type);
    event->auxtrace_error.code = bswap_32(event->auxtrace_error.code);
    event->auxtrace_error.cpu  = bswap_32(event->auxtrace_error.cpu);
    event->auxtrace_error.pid  = bswap_32(event->auxtrace_error.pid);
    event->auxtrace_error.tid  = bswap_32(event->auxtrace_error.tid);
    event->auxtrace_error.ip   = bswap_64(event->auxtrace_error.ip);
}

static void perf_event__thread_map_swap(union perf_event *event,
                    bool sample_id_all __maybe_unused)
{
    unsigned i;

    event->thread_map.nr = bswap_64(event->thread_map.nr);

    for (i = 0; i < event->thread_map.nr; i++)
        event->thread_map.entries[i].pid = bswap_64(event->thread_map.entries[i].pid);
}

static void perf_event__cpu_map_swap(union perf_event *event,
                     bool sample_id_all __maybe_unused)
{
    struct cpu_map_data *data = &event->cpu_map.data;
    struct cpu_map_entries *cpus;
    struct cpu_map_mask *mask;
    unsigned i;

    data->type = bswap_64(data->type);

    switch (data->type) {
    case PERF_CPU_MAP__CPUS:
        cpus = (struct cpu_map_entries *)data->data;

        cpus->nr = bswap_16(cpus->nr);

        for (i = 0; i < cpus->nr; i++)
            cpus->cpu[i] = bswap_16(cpus->cpu[i]);
        break;
    case PERF_CPU_MAP__MASK:
        mask = (struct cpu_map_mask *) data->data;

        mask->nr = bswap_16(mask->nr);
        mask->long_size = bswap_16(mask->long_size);

        switch (mask->long_size) {
        case 4: mem_bswap_32(&mask->mask, mask->nr); break;
        case 8: mem_bswap_64(&mask->mask, mask->nr); break;
        default:
            pr_err("cpu_map swap: unsupported long size\n");
        }
    default:
        break;
    }
}

static void perf_event__stat_config_swap(union perf_event *event,
                     bool sample_id_all __maybe_unused)
{
    u64 size;

    size  = event->stat_config.nr * sizeof(event->stat_config.data[0]);
    size += 1; /* nr item itself */
    mem_bswap_64(&event->stat_config.nr, size);
}

static void perf_event__stat_swap(union perf_event *event,
                  bool sample_id_all __maybe_unused)
{
    event->stat.id     = bswap_64(event->stat.id);
    event->stat.thread = bswap_32(event->stat.thread);
    event->stat.cpu    = bswap_32(event->stat.cpu);
    event->stat.val    = bswap_64(event->stat.val);
    event->stat.ena    = bswap_64(event->stat.ena);
    event->stat.run    = bswap_64(event->stat.run);
}

static void perf_event__stat_round_swap(union perf_event *event,
                    bool sample_id_all __maybe_unused)
{
    event->stat_round.type = bswap_64(event->stat_round.type);
    event->stat_round.time = bswap_64(event->stat_round.time);
}

typedef void (*perf_event__swap_op)(union perf_event *event,
                    bool sample_id_all);

static perf_event__swap_op perf_event__swap_ops[] = {
    [PERF_RECORD_MMAP]        = perf_event__mmap_swap,
    [PERF_RECORD_MMAP2]       = perf_event__mmap2_swap,
    [PERF_RECORD_COMM]        = perf_event__comm_swap,
    [PERF_RECORD_FORK]        = perf_event__task_swap,
    [PERF_RECORD_EXIT]        = perf_event__task_swap,
    [PERF_RECORD_LOST]        = perf_event__all64_swap,
    [PERF_RECORD_READ]        = perf_event__read_swap,
    [PERF_RECORD_THROTTLE]        = perf_event__throttle_swap,
    [PERF_RECORD_UNTHROTTLE]      = perf_event__throttle_swap,
    [PERF_RECORD_SAMPLE]          = perf_event__all64_swap,
    [PERF_RECORD_AUX]         = perf_event__aux_swap,
    [PERF_RECORD_ITRACE_START]    = perf_event__itrace_start_swap,
    [PERF_RECORD_LOST_SAMPLES]    = perf_event__all64_swap,
    [PERF_RECORD_SWITCH]          = perf_event__switch_swap,
    [PERF_RECORD_SWITCH_CPU_WIDE]     = perf_event__switch_swap,
    [PERF_RECORD_HEADER_ATTR]     = perf_event__hdr_attr_swap,
    [PERF_RECORD_HEADER_EVENT_TYPE]   = perf_event__event_type_swap,
    [PERF_RECORD_HEADER_TRACING_DATA] = perf_event__tracing_data_swap,
    [PERF_RECORD_HEADER_BUILD_ID]     = NULL,
    [PERF_RECORD_ID_INDEX]        = perf_event__all64_swap,
    [PERF_RECORD_AUXTRACE_INFO]   = perf_event__auxtrace_info_swap,
    [PERF_RECORD_AUXTRACE]        = perf_event__auxtrace_swap,
    [PERF_RECORD_AUXTRACE_ERROR]      = perf_event__auxtrace_error_swap,
    [PERF_RECORD_THREAD_MAP]      = perf_event__thread_map_swap,
    [PERF_RECORD_CPU_MAP]         = perf_event__cpu_map_swap,
    [PERF_RECORD_STAT_CONFIG]     = perf_event__stat_config_swap,
    [PERF_RECORD_STAT]        = perf_event__stat_swap,
    [PERF_RECORD_STAT_ROUND]      = perf_event__stat_round_swap,
    [PERF_RECORD_EVENT_UPDATE]    = perf_event__event_update_swap,
    [PERF_RECORD_TIME_CONV]       = perf_event__all64_swap,
    [PERF_RECORD_HEADER_MAX]      = NULL,
};

/*
 * When perf record finishes a pass on every buffers, it records this pseudo
 * event.
 * We record the max timestamp t found in the pass n.
 * Assuming these timestamps are monotonic across cpus, we know that if
 * a buffer still has events with timestamps below t, they will be all
 * available and then read in the pass n + 1.
 * Hence when we start to read the pass n + 2, we can safely flush every
 * events with timestamps below t.
 *
 *    ============ PASS n =================
 *       CPU 0         |   CPU 1
 *                     |
 *    cnt1 timestamps  |   cnt2 timestamps
 *          1          |         2
 *          2          |         3
 *          -          |         4  <--- max recorded
 *
 *    ============ PASS n + 1 ==============
 *       CPU 0         |   CPU 1
 *                     |
 *    cnt1 timestamps  |   cnt2 timestamps
 *          3          |         5
 *          4          |         6
 *          5          |         7 <---- max recorded
 *
 *      Flush every events below timestamp 4
 *
 *    ============ PASS n + 2 ==============
 *       CPU 0         |   CPU 1
 *                     |
 *    cnt1 timestamps  |   cnt2 timestamps
 *          6          |         8
 *          7          |         9
 *          -          |         10
 *
 *      Flush every events below timestamp 7
 *      etc...
 */
static int process_finished_round(struct perf_tool *tool __maybe_unused,
                  union perf_event *event __maybe_unused,
                  struct ordered_events *oe)
{
    if (dump_trace)
        fprintf(stdout, "\n");
    return ordered_events__flush(oe, OE_FLUSH__ROUND);
}

int perf_session__queue_event(struct perf_session *s, union perf_event *event,
                  u64 timestamp, u64 file_offset)
{
    return ordered_events__queue(&s->ordered_events, event, timestamp, file_offset);
}

static void callchain__lbr_callstack_printf(struct perf_sample *sample)
{
    struct ip_callchain *callchain = sample->callchain;
    struct branch_stack *lbr_stack = sample->branch_stack;
    u64 kernel_callchain_nr = callchain->nr;
    unsigned int i;

    for (i = 0; i < kernel_callchain_nr; i++) {
        if (callchain->ips[i] == PERF_CONTEXT_USER)
            break;
    }

    if ((i != kernel_callchain_nr) && lbr_stack->nr) {
        u64 total_nr;
        /*
         * LBR callstack can only get user call chain,
         * i is kernel call chain number,
         * 1 is PERF_CONTEXT_USER.
         *
         * The user call chain is stored in LBR registers.
         * LBR are pair registers. The caller is stored
         * in "from" register, while the callee is stored
         * in "to" register.
         * For example, there is a call stack
         * "A"->"B"->"C"->"D".
         * The LBR registers will recorde like
         * "C"->"D", "B"->"C", "A"->"B".
         * So only the first "to" register and all "from"
         * registers are needed to construct the whole stack.
         */
        total_nr = i + 1 + lbr_stack->nr + 1;
        kernel_callchain_nr = i + 1;

        printf("... LBR call chain: nr:%" PRIu64 "\n", total_nr);

        for (i = 0; i < kernel_callchain_nr; i++)
            printf("..... %2d: %016" PRIx64 "\n",
                   i, callchain->ips[i]);

        printf("..... %2d: %016" PRIx64 "\n",
               (int)(kernel_callchain_nr), lbr_stack->entries[0].to);
        for (i = 0; i < lbr_stack->nr; i++)
            printf("..... %2d: %016" PRIx64 "\n",
                   (int)(i + kernel_callchain_nr + 1), lbr_stack->entries[i].from);
    }
}

static void callchain__printf(struct perf_evsel *evsel,
                  struct perf_sample *sample)
{
    unsigned int i;
    struct ip_callchain *callchain = sample->callchain;

    if (perf_evsel__has_branch_callstack(evsel))
        callchain__lbr_callstack_printf(sample);

    printf("... FP chain: nr:%" PRIu64 "\n", callchain->nr);

    for (i = 0; i < callchain->nr; i++)
        printf("..... %2d: %016" PRIx64 "\n",
               i, callchain->ips[i]);
}

static void branch_stack__printf(struct perf_sample *sample)
{
    uint64_t i;

    printf("... branch stack: nr:%" PRIu64 "\n", sample->branch_stack->nr);

    for (i = 0; i < sample->branch_stack->nr; i++) {
        struct branch_entry *e = &sample->branch_stack->entries[i];

        printf("..... %2"PRIu64": %016" PRIx64 " -> %016" PRIx64 " %hu cycles %s%s%s%s %x\n",
            i, e->from, e->to,
            (unsigned short)e->flags.cycles,
            e->flags.mispred ? "M" : " ",
            e->flags.predicted ? "P" : " ",
            e->flags.abort ? "A" : " ",
            e->flags.in_tx ? "T" : " ",
            (unsigned)e->flags.reserved);
    }
}

static void regs_dump__printf(u64 mask, u64 *regs)
{
    unsigned rid, i = 0;

    for_each_set_bit(rid, (unsigned long *) &mask, sizeof(mask) * 8) {
        u64 val = regs[i++];

        printf(".... %-5s 0x%" PRIx64 "\n",
               perf_reg_name(rid), val);
    }
}

static const char *regs_abi[] = {
    [PERF_SAMPLE_REGS_ABI_NONE] = "none",
    [PERF_SAMPLE_REGS_ABI_32] = "32-bit",
    [PERF_SAMPLE_REGS_ABI_64] = "64-bit",
};

static inline const char *regs_dump_abi(struct regs_dump *d)
{
    if (d->abi > PERF_SAMPLE_REGS_ABI_64)
        return "unknown";

    return regs_abi[d->abi];
}

static void regs__printf(const char *type, struct regs_dump *regs)
{
    u64 mask = regs->mask;

    printf("... %s regs: mask 0x%" PRIx64 " ABI %s\n",
           type,
           mask,
           regs_dump_abi(regs));

    regs_dump__printf(mask, regs->regs);
}

static void regs_user__printf(struct perf_sample *sample)
{
    struct regs_dump *user_regs = &sample->user_regs;

    if (user_regs->regs)
        regs__printf("user", user_regs);
}

static void regs_intr__printf(struct perf_sample *sample)
{
    struct regs_dump *intr_regs = &sample->intr_regs;

    if (intr_regs->regs)
        regs__printf("intr", intr_regs);
}

static void stack_user__printf(struct stack_dump *dump)
{
    printf("... ustack: size %" PRIu64 ", offset 0x%x\n",
           dump->size, dump->offset);
}

static void perf_evlist__print_tstamp(struct perf_evlist *evlist,
                       union perf_event *event,
                       struct perf_sample *sample)
{
    u64 sample_type = __perf_evlist__combined_sample_type(evlist);

    if (event->header.type != PERF_RECORD_SAMPLE &&
        !perf_evlist__sample_id_all(evlist)) {
        fputs("-1 -1 ", stdout);
        return;
    }

    if ((sample_type & PERF_SAMPLE_CPU))
        printf("%u ", sample->cpu);

    if (sample_type & PERF_SAMPLE_TIME)
        printf("%" PRIu64 " ", sample->time);
}

static void sample_read__printf(struct perf_sample *sample, u64 read_format)
{
    printf("... sample_read:\n");

    if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
        printf("...... time enabled %016" PRIx64 "\n",
               sample->read.time_enabled);

    if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
        printf("...... time running %016" PRIx64 "\n",
               sample->read.time_running);

    if (read_format & PERF_FORMAT_GROUP) {
        u64 i;

        printf(".... group nr %" PRIu64 "\n", sample->read.group.nr);

        for (i = 0; i < sample->read.group.nr; i++) {
            struct sample_read_value *value;

            value = &sample->read.group.values[i];
            printf("..... id %016" PRIx64
                   ", value %016" PRIx64 "\n",
                   value->id, value->value);
        }
    } else
        printf("..... id %016" PRIx64 ", value %016" PRIx64 "\n",
            sample->read.one.id, sample->read.one.value);
}

static void dump_event(struct perf_evlist *evlist, union perf_event *event,
               u64 file_offset, struct perf_sample *sample)
{
    if (!dump_trace)
        return;

    printf("\n%#" PRIx64 " [%#x]: event: %d\n",
           file_offset, event->header.size, event->header.type);

    trace_event(event);

    if (sample)
        perf_evlist__print_tstamp(evlist, event, sample);

    printf("%#" PRIx64 " [%#x]: PERF_RECORD_%s", file_offset,
           event->header.size, perf_event__name(event->header.type));
}

static void dump_sample(struct perf_evsel *evsel, union perf_event *event,
            struct perf_sample *sample)
{
    u64 sample_type;

    if (!dump_trace)
        return;

    printf("(IP, 0x%x): %d/%d: %#" PRIx64 " period: %" PRIu64 " addr: %#" PRIx64 "\n",
           event->header.misc, sample->pid, sample->tid, sample->ip,
           sample->period, sample->addr);

    sample_type = evsel->attr.sample_type;

    if (evsel__has_callchain(evsel))
        callchain__printf(evsel, sample);

    if ((sample_type & PERF_SAMPLE_BRANCH_STACK) && !perf_evsel__has_branch_callstack(evsel))
        branch_stack__printf(sample);

    if (sample_type & PERF_SAMPLE_REGS_USER)
        regs_user__printf(sample);

    if (sample_type & PERF_SAMPLE_REGS_INTR)
        regs_intr__printf(sample);

    if (sample_type & PERF_SAMPLE_STACK_USER)
        stack_user__printf(&sample->user_stack);

    if (sample_type & PERF_SAMPLE_WEIGHT)
        printf("... weight: %" PRIu64 "\n", sample->weight);

    if (sample_type & PERF_SAMPLE_DATA_SRC)
        printf(" . data_src: 0x%"PRIx64"\n", sample->data_src);

    if (sample_type & PERF_SAMPLE_PHYS_ADDR)
        printf(" .. phys_addr: 0x%"PRIx64"\n", sample->phys_addr);

    if (sample_type & PERF_SAMPLE_TRANSACTION)
        printf("... transaction: %" PRIx64 "\n", sample->transaction);

    if (sample_type & PERF_SAMPLE_READ)
        sample_read__printf(sample, evsel->attr.read_format);
}

static void dump_read(struct perf_evsel *evsel, union perf_event *event)
{
    struct read_event *read_event = &event->read;
    u64 read_format;

    if (!dump_trace)
        return;

    printf(": %d %d %s %" PRIu64 "\n", event->read.pid, event->read.tid,
           evsel ? perf_evsel__name(evsel) : "FAIL",
           event->read.value);

    read_format = evsel->attr.read_format;

    if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
        printf("... time enabled : %" PRIu64 "\n", read_event->time_enabled);

    if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
        printf("... time running : %" PRIu64 "\n", read_event->time_running);

    if (read_format & PERF_FORMAT_ID)
        printf("... id           : %" PRIu64 "\n", read_event->id);
}

static struct machine *machines__find_for_cpumode(struct machines *machines,
                           union perf_event *event,
                           struct perf_sample *sample)
{
    struct machine *machine;

    if (perf_guest &&
        ((sample->cpumode == PERF_RECORD_MISC_GUEST_KERNEL) ||
         (sample->cpumode == PERF_RECORD_MISC_GUEST_USER))) {
        u32 pid;

        if (event->header.type == PERF_RECORD_MMAP
            || event->header.type == PERF_RECORD_MMAP2)
            pid = event->mmap.pid;
        else
            pid = sample->pid;

        machine = machines__find(machines, pid);
        if (!machine)
            machine = machines__findnew(machines, DEFAULT_GUEST_KERNEL_ID);
        return machine;
    }

    return &machines->host;
}

static int deliver_sample_value(struct perf_evlist *evlist,
                struct perf_tool *tool,
                union perf_event *event,
                struct perf_sample *sample,
                struct sample_read_value *v,
                struct machine *machine)
{
    struct perf_sample_id *sid = perf_evlist__id2sid(evlist, v->id);

    if (sid) {
        sample->id     = v->id;
        sample->period = v->value - sid->period;
        sid->period    = v->value;
    }

    if (!sid || sid->evsel == NULL) {
        ++evlist->stats.nr_unknown_id;
        return 0;
    }

    return tool->sample(tool, event, sample, sid->evsel, machine);
}

static int deliver_sample_group(struct perf_evlist *evlist,
                struct perf_tool *tool,
                union  perf_event *event,
                struct perf_sample *sample,
                struct machine *machine)
{
    int ret = -EINVAL;
    u64 i;

    for (i = 0; i < sample->read.group.nr; i++) {
        ret = deliver_sample_value(evlist, tool, event, sample,
                       &sample->read.group.values[i],
                       machine);
        if (ret)
            break;
    }

    return ret;
}

static int
 perf_evlist__deliver_sample(struct perf_evlist *evlist,
                 struct perf_tool *tool,
                 union  perf_event *event,
                 struct perf_sample *sample,
                 struct perf_evsel *evsel,
                 struct machine *machine)
{
    /* We know evsel != NULL. */
    u64 sample_type = evsel->attr.sample_type;
    u64 read_format = evsel->attr.read_format;

    /* Standard sample delivery. */
    if (!(sample_type & PERF_SAMPLE_READ))
        return tool->sample(tool, event, sample, evsel, machine);

    /* For PERF_SAMPLE_READ we have either single or group mode. */
    if (read_format & PERF_FORMAT_GROUP)
        return deliver_sample_group(evlist, tool, event, sample,
                        machine);
    else
        return deliver_sample_value(evlist, tool, event, sample,
                        &sample->read.one, machine);
}

static int machines__deliver_event(struct machines *machines,
                   struct perf_evlist *evlist,
                   union perf_event *event,
                   struct perf_sample *sample,
                   struct perf_tool *tool, u64 file_offset)
{
    struct perf_evsel *evsel;
    struct machine *machine;

    dump_event(evlist, event, file_offset, sample);

    evsel = perf_evlist__id2evsel(evlist, sample->id);

    machine = machines__find_for_cpumode(machines, event, sample);

    switch (event->header.type) {
    case PERF_RECORD_SAMPLE:
        if (evsel == NULL) {
            ++evlist->stats.nr_unknown_id;
            return 0;
        }
        dump_sample(evsel, event, sample);
        if (machine == NULL) {
            ++evlist->stats.nr_unprocessable_samples;
            return 0;
        }
        return perf_evlist__deliver_sample(evlist, tool, event, sample, evsel, machine);
    case PERF_RECORD_MMAP:
        return tool->mmap(tool, event, sample, machine);
    case PERF_RECORD_MMAP2:
        if (event->header.misc & PERF_RECORD_MISC_PROC_MAP_PARSE_TIMEOUT)
            ++evlist->stats.nr_proc_map_timeout;
        return tool->mmap2(tool, event, sample, machine);
    case PERF_RECORD_COMM:
        return tool->comm(tool, event, sample, machine);
    case PERF_RECORD_NAMESPACES:
        return tool->namespaces(tool, event, sample, machine);
    case PERF_RECORD_FORK:
        return tool->fork(tool, event, sample, machine);
    case PERF_RECORD_EXIT:
        return tool->exit(tool, event, sample, machine);
    case PERF_RECORD_LOST:
        if (tool->lost == perf_event__process_lost)
            evlist->stats.total_lost += event->lost.lost;
        return tool->lost(tool, event, sample, machine);
    case PERF_RECORD_LOST_SAMPLES:
        if (tool->lost_samples == perf_event__process_lost_samples)
            evlist->stats.total_lost_samples += event->lost_samples.lost;
        return tool->lost_samples(tool, event, sample, machine);
    case PERF_RECORD_READ:
        dump_read(evsel, event);
        return tool->read(tool, event, sample, evsel, machine);
    case PERF_RECORD_THROTTLE:
        return tool->throttle(tool, event, sample, machine);
    case PERF_RECORD_UNTHROTTLE:
        return tool->unthrottle(tool, event, sample, machine);
    case PERF_RECORD_AUX:
        if (tool->aux == perf_event__process_aux) {
            if (event->aux.flags & PERF_AUX_FLAG_TRUNCATED)
                evlist->stats.total_aux_lost += 1;
            if (event->aux.flags & PERF_AUX_FLAG_PARTIAL)
                evlist->stats.total_aux_partial += 1;
        }
        return tool->aux(tool, event, sample, machine);
    case PERF_RECORD_ITRACE_START:
        return tool->itrace_start(tool, event, sample, machine);
    case PERF_RECORD_SWITCH:
    case PERF_RECORD_SWITCH_CPU_WIDE:
        return tool->context_switch(tool, event, sample, machine);
    default:
        ++evlist->stats.nr_unknown_events;
        return -1;
    }
}

static int perf_session__deliver_event(struct perf_session *session,
                       union perf_event *event,
                       struct perf_tool *tool,
                       u64 file_offset)
{
    struct perf_sample sample;
    int ret;

    ret = perf_evlist__parse_sample(session->evlist, event, &sample);
    if (ret) {
        pr_err("Can't parse sample, err = %d\n", ret);
        return ret;
    }

    ret = auxtrace__process_event(session, event, &sample, tool);
    if (ret < 0)
        return ret;
    if (ret > 0)
        return 0;

    return machines__deliver_event(&session->machines, session->evlist,
                       event, &sample, tool, file_offset);
}

static s64 perf_session__process_user_event(struct perf_session *session,
                        union perf_event *event,
                        u64 file_offset)
{
    struct ordered_events *oe = &session->ordered_events;
    struct perf_tool *tool = session->tool;
    struct perf_sample sample = { .time = 0, };
    int fd = perf_data__fd(session->data);
    int err;

    dump_event(session->evlist, event, file_offset, &sample);

    /* These events are processed right away */
    switch (event->header.type) {
    case PERF_RECORD_HEADER_ATTR:
        err = tool->attr(tool, event, &session->evlist);
        if (err == 0) {
            perf_session__set_id_hdr_size(session);
            perf_session__set_comm_exec(session);
        }
        return err;
    case PERF_RECORD_EVENT_UPDATE:
        return tool->event_update(tool, event, &session->evlist);
    case PERF_RECORD_HEADER_EVENT_TYPE:
        /*
         * Depreceated, but we need to handle it for sake
         * of old data files create in pipe mode.
         */
        return 0;
    case PERF_RECORD_HEADER_TRACING_DATA:
        /* setup for reading amidst mmap */
        lseek(fd, file_offset, SEEK_SET);
        return tool->tracing_data(tool, event, session);
    case PERF_RECORD_HEADER_BUILD_ID:
        return tool->build_id(tool, event, session);
    case PERF_RECORD_FINISHED_ROUND:
        return tool->finished_round(tool, event, oe);
    case PERF_RECORD_ID_INDEX:
        return tool->id_index(tool, event, session);
    case PERF_RECORD_AUXTRACE_INFO:
        return tool->auxtrace_info(tool, event, session);
    case PERF_RECORD_AUXTRACE:
        /* setup for reading amidst mmap */
        lseek(fd, file_offset + event->header.size, SEEK_SET);
        return tool->auxtrace(tool, event, session);
    case PERF_RECORD_AUXTRACE_ERROR:
        perf_session__auxtrace_error_inc(session, event);
        return tool->auxtrace_error(tool, event, session);
    case PERF_RECORD_THREAD_MAP:
        return tool->thread_map(tool, event, session);
    case PERF_RECORD_CPU_MAP:
        return tool->cpu_map(tool, event, session);
    case PERF_RECORD_STAT_CONFIG:
        return tool->stat_config(tool, event, session);
    case PERF_RECORD_STAT:
        return tool->stat(tool, event, session);
    case PERF_RECORD_STAT_ROUND:
        return tool->stat_round(tool, event, session);
    case PERF_RECORD_TIME_CONV:
        session->time_conv = event->time_conv;
        return tool->time_conv(tool, event, session);
    case PERF_RECORD_HEADER_FEATURE:
        return tool->feature(tool, event, session);
    default:
        return -EINVAL;
    }
}

int perf_session__deliver_synth_event(struct perf_session *session,
                      union perf_event *event,
                      struct perf_sample *sample)
{
    struct perf_evlist *evlist = session->evlist;
    struct perf_tool *tool = session->tool;

    events_stats__inc(&evlist->stats, event->header.type);

    if (event->header.type >= PERF_RECORD_USER_TYPE_START)
        return perf_session__process_user_event(session, event, 0);

    return machines__deliver_event(&session->machines, evlist, event, sample, tool, 0);
}

static void event_swap(union perf_event *event, bool sample_id_all)
{
    perf_event__swap_op swap;

    swap = perf_event__swap_ops[event->header.type];
    if (swap)
        swap(event, sample_id_all);
}

int perf_session__peek_event(struct perf_session *session, off_t file_offset,
                 void *buf, size_t buf_sz,
                 union perf_event **event_ptr,
                 struct perf_sample *sample)
{
    union perf_event *event;
    size_t hdr_sz, rest;
    int fd;

    if (session->one_mmap && !session->header.needs_swap) {
        event = file_offset - session->one_mmap_offset +
            session->one_mmap_addr;
        goto out_parse_sample;
    }

    if (perf_data__is_pipe(session->data))
        return -1;

    fd = perf_data__fd(session->data);
    hdr_sz = sizeof(struct perf_event_header);

    if (buf_sz < hdr_sz)
        return -1;

    if (lseek(fd, file_offset, SEEK_SET) == (off_t)-1 ||
        readn(fd, buf, hdr_sz) != (ssize_t)hdr_sz)
        return -1;

    event = (union perf_event *)buf;

    if (session->header.needs_swap)
        perf_event_header__bswap(&event->header);

    if (event->header.size < hdr_sz || event->header.size > buf_sz)
        return -1;

    rest = event->header.size - hdr_sz;

    if (readn(fd, buf, rest) != (ssize_t)rest)
        return -1;

    if (session->header.needs_swap)
        event_swap(event, perf_evlist__sample_id_all(session->evlist));

out_parse_sample:

    if (sample && event->header.type < PERF_RECORD_USER_TYPE_START &&
        perf_evlist__parse_sample(session->evlist, event, sample))
        return -1;

    *event_ptr = event;

    return 0;
}

static s64 perf_session__process_event(struct perf_session *session,
                       union perf_event *event, u64 file_offset)
{
    struct perf_evlist *evlist = session->evlist;
    struct perf_tool *tool = session->tool;
    int ret;

    if (session->header.needs_swap)
        event_swap(event, perf_evlist__sample_id_all(evlist));

    if (event->header.type >= PERF_RECORD_HEADER_MAX)
        return -EINVAL;

    events_stats__inc(&evlist->stats, event->header.type);

    if (event->header.type >= PERF_RECORD_USER_TYPE_START)
        return perf_session__process_user_event(session, event, file_offset);

    if (tool->ordered_events) {
        u64 timestamp = -1ULL;

        ret = perf_evlist__parse_sample_timestamp(evlist, event, &timestamp);
        if (ret && ret != -1)
            return ret;

        ret = perf_session__queue_event(session, event, timestamp, file_offset);
        if (ret != -ETIME)
            return ret;
    }

    return perf_session__deliver_event(session, event, tool, file_offset);
}

void perf_event_header__bswap(struct perf_event_header *hdr)
{
    hdr->type = bswap_32(hdr->type);
    hdr->misc = bswap_16(hdr->misc);
    hdr->size = bswap_16(hdr->size);
}

struct thread *perf_session__findnew(struct perf_session *session, pid_t pid)
{
    return machine__findnew_thread(&session->machines.host, -1, pid);
}

int perf_session__register_idle_thread(struct perf_session *session)
{
    struct thread *thread;
    int err = 0;

    thread = machine__findnew_thread(&session->machines.host, 0, 0);
    if (thread == NULL || thread__set_comm(thread, "swapper", 0)) {
        pr_err("problem inserting idle task.\n");
        err = -1;
    }

    if (thread == NULL || thread__set_namespaces(thread, 0, NULL)) {
        pr_err("problem inserting idle task.\n");
        err = -1;
    }

    /* machine__findnew_thread() got the thread, so put it */
    thread__put(thread);
    return err;
}

static void
perf_session__warn_order(const struct perf_session *session)
{
    const struct ordered_events *oe = &session->ordered_events;
    struct perf_evsel *evsel;
    bool should_warn = true;

    evlist__for_each_entry(session->evlist, evsel) {
        if (evsel->attr.write_backward)
            should_warn = false;
    }

    if (!should_warn)
        return;
    if (oe->nr_unordered_events != 0)
        ui__warning("%u out of order events recorded.\n", oe->nr_unordered_events);
}

static void perf_session__warn_about_errors(const struct perf_session *session)
{
    const struct events_stats *stats = &session->evlist->stats;

    if (session->tool->lost == perf_event__process_lost &&
        stats->nr_events[PERF_RECORD_LOST] != 0) {
        ui__warning("Processed %d events and lost %d chunks!\n\n"
                "Check IO/CPU overload!\n\n",
                stats->nr_events[0],
                stats->nr_events[PERF_RECORD_LOST]);
    }

    if (session->tool->lost_samples == perf_event__process_lost_samples) {
        double drop_rate;

        drop_rate = (double)stats->total_lost_samples /
                (double) (stats->nr_events[PERF_RECORD_SAMPLE] + stats->total_lost_samples);
        if (drop_rate > 0.05) {
            ui__warning("Processed %" PRIu64 " samples and lost %3.2f%%!\n\n",
                    stats->nr_events[PERF_RECORD_SAMPLE] + stats->total_lost_samples,
                    drop_rate * 100.0);
        }
    }

    if (session->tool->aux == perf_event__process_aux &&
        stats->total_aux_lost != 0) {
        ui__warning("AUX data lost %" PRIu64 " times out of %u!\n\n",
                stats->total_aux_lost,
                stats->nr_events[PERF_RECORD_AUX]);
    }

    if (session->tool->aux == perf_event__process_aux &&
        stats->total_aux_partial != 0) {
        bool vmm_exclusive = false;

        (void)sysfs__read_bool("module/kvm_intel/parameters/vmm_exclusive",
                               &vmm_exclusive);

        ui__warning("AUX data had gaps in it %" PRIu64 " times out of %u!\n\n"
                    "Are you running a KVM guest in the background?%s\n\n",
                stats->total_aux_partial,
                stats->nr_events[PERF_RECORD_AUX],
                vmm_exclusive ?
                "\nReloading kvm_intel module with vmm_exclusive=0\n"
                "will reduce the gaps to only guest's timeslices." :
                "");
    }

    if (stats->nr_unknown_events != 0) {
        ui__warning("Found %u unknown events!\n\n"
                "Is this an older tool processing a perf.data "
                "file generated by a more recent tool?\n\n"
                "If that is not the case, consider "
                "reporting to linux-kernel@vger.kernel.org.\n\n",
                stats->nr_unknown_events);
    }

    if (stats->nr_unknown_id != 0) {
        ui__warning("%u samples with id not present in the header\n",
                stats->nr_unknown_id);
    }

    if (stats->nr_invalid_chains != 0) {
        ui__warning("Found invalid callchains!\n\n"
                "%u out of %u events were discarded for this reason.\n\n"
                "Consider reporting to linux-kernel@vger.kernel.org.\n\n",
                stats->nr_invalid_chains,
                stats->nr_events[PERF_RECORD_SAMPLE]);
    }

    if (stats->nr_unprocessable_samples != 0) {
        ui__warning("%u unprocessable samples recorded.\n"
                "Do you have a KVM guest running and not using 'perf kvm'?\n",
                stats->nr_unprocessable_samples);
    }

    perf_session__warn_order(session);

    events_stats__auxtrace_error_warn(stats);

    if (stats->nr_proc_map_timeout != 0) {
        ui__warning("%d map information files for pre-existing threads were\n"
                "not processed, if there are samples for addresses they\n"
                "will not be resolved, you may find out which are these\n"
                "threads by running with -v and redirecting the output\n"
                "to a file.\n"
                "The time limit to process proc map is too short?\n"
                "Increase it by --proc-map-timeout\n",
                stats->nr_proc_map_timeout);
    }
}

static int perf_session__flush_thread_stack(struct thread *thread,
                        void *p __maybe_unused)
{
    return thread_stack__flush(thread);
}

static int perf_session__flush_thread_stacks(struct perf_session *session)
{
    return machines__for_each_thread(&session->machines,
                     perf_session__flush_thread_stack,
                     NULL);
}

volatile int session_done;

static int __perf_session__process_pipe_events(struct perf_session *session)
{
    struct ordered_events *oe = &session->ordered_events;
    struct perf_tool *tool = session->tool;
    int fd = perf_data__fd(session->data);
    union perf_event *event;
    uint32_t size, cur_size = 0;
    void *buf = NULL;
    s64 skip = 0;
    u64 head;
    ssize_t err;
    void *p;

    perf_tool__fill_defaults(tool);

    head = 0;
    cur_size = sizeof(union perf_event);

    buf = malloc(cur_size);
    if (!buf)
        return -errno;
    ordered_events__set_copy_on_queue(oe, true);
more:
    event = buf;
    err = readn(fd, event, sizeof(struct perf_event_header));
    if (err <= 0) {
        if (err == 0)
            goto done;

        pr_err("failed to read event header\n");
        goto out_err;
    }

    if (session->header.needs_swap)
        perf_event_header__bswap(&event->header);

    size = event->header.size;
    if (size < sizeof(struct perf_event_header)) {
        pr_err("bad event header size\n");
        goto out_err;
    }

    if (size > cur_size) {
        void *new = realloc(buf, size);
        if (!new) {
            pr_err("failed to allocate memory to read event\n");
            goto out_err;
        }
        buf = new;
        cur_size = size;
        event = buf;
    }
    p = event;
    p += sizeof(struct perf_event_header);

    if (size - sizeof(struct perf_event_header)) {
        err = readn(fd, p, size - sizeof(struct perf_event_header));
        if (err <= 0) {
            if (err == 0) {
                pr_err("unexpected end of event stream\n");
                goto done;
            }

            pr_err("failed to read event data\n");
            goto out_err;
        }
    }

    if ((skip = perf_session__process_event(session, event, head)) < 0) {
        pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n",
               head, event->header.size, event->header.type);
        err = -EINVAL;
        goto out_err;
    }

    head += size;

    if (skip > 0)
        head += skip;

    if (!session_done())
        goto more;
done:
    /* do the final flush for ordered samples */
    err = ordered_events__flush(oe, OE_FLUSH__FINAL);
    if (err)
        goto out_err;
    err = auxtrace__flush_events(session, tool);
    if (err)
        goto out_err;
    err = perf_session__flush_thread_stacks(session);
out_err:
    free(buf);
    if (!tool->no_warn)
        perf_session__warn_about_errors(session);
    ordered_events__free(&session->ordered_events);
    auxtrace__free_events(session);
    return err;
}

static union perf_event *
fetch_mmaped_event(struct perf_session *session,
           u64 head, size_t mmap_size, char *buf)
{
    union perf_event *event;

    /*
     * Ensure we have enough space remaining to read
     * the size of the event in the headers.
     */
    if (head + sizeof(event->header) > mmap_size)
        return NULL;

    event = (union perf_event *)(buf + head);

    if (session->header.needs_swap)
        perf_event_header__bswap(&event->header);

    if (head + event->header.size > mmap_size) {
        /* We're not fetching the event so swap back again */
        if (session->header.needs_swap)
            perf_event_header__bswap(&event->header);
        return NULL;
    }

    return event;
}

/*
 * On 64bit we can mmap the data file in one go. No need for tiny mmap
 * slices. On 32bit we use 32MB.
 */
#if BITS_PER_LONG == 64
#define MMAP_SIZE ULLONG_MAX
#define NUM_MMAPS 1
#else
#define MMAP_SIZE (32 * 1024 * 1024ULL)
#define NUM_MMAPS 128
#endif

static int __perf_session__process_events(struct perf_session *session,
                      u64 data_offset, u64 data_size,
                      u64 file_size)
{
    struct ordered_events *oe = &session->ordered_events;
    struct perf_tool *tool = session->tool;
    int fd = perf_data__fd(session->data);
    u64 head, page_offset, file_offset, file_pos, size;
    int err, mmap_prot, mmap_flags, map_idx = 0;
    size_t  mmap_size;
    char *buf, *mmaps[NUM_MMAPS];
    union perf_event *event;
    struct ui_progress prog;
    s64 skip;

    perf_tool__fill_defaults(tool);

    page_offset = page_size * (data_offset / page_size);
    file_offset = page_offset;
    head = data_offset - page_offset;

    if (data_size == 0)
        goto out;

    if (data_offset + data_size < file_size)
        file_size = data_offset + data_size;

    ui_progress__init_size(&prog, file_size, "Processing events...");

    mmap_size = MMAP_SIZE;
    if (mmap_size > file_size) {
        mmap_size = file_size;
        session->one_mmap = true;
    }

    memset(mmaps, 0, sizeof(mmaps));

    mmap_prot  = PROT_READ;
    mmap_flags = MAP_SHARED;

    if (session->header.needs_swap) {
        mmap_prot  |= PROT_WRITE;
        mmap_flags = MAP_PRIVATE;
    }
remap:
    buf = mmap(NULL, mmap_size, mmap_prot, mmap_flags, fd,
           file_offset);
    if (buf == MAP_FAILED) {
        pr_err("failed to mmap file\n");
        err = -errno;
        goto out_err;
    }
    mmaps[map_idx] = buf;
    map_idx = (map_idx + 1) & (ARRAY_SIZE(mmaps) - 1);
    file_pos = file_offset + head;
    if (session->one_mmap) {
        session->one_mmap_addr = buf;
        session->one_mmap_offset = file_offset;
    }

more:
    event = fetch_mmaped_event(session, head, mmap_size, buf);
    if (!event) {
        if (mmaps[map_idx]) {
            munmap(mmaps[map_idx], mmap_size);
            mmaps[map_idx] = NULL;
        }

        page_offset = page_size * (head / page_size);
        file_offset += page_offset;
        head -= page_offset;
        goto remap;
    }

    size = event->header.size;

    if (size < sizeof(struct perf_event_header) ||
        (skip = perf_session__process_event(session, event, file_pos)) < 0) {
        pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n",
               file_offset + head, event->header.size,
               event->header.type);
        err = -EINVAL;
        goto out_err;
    }

    if (skip)
        size += skip;

    head += size;
    file_pos += size;

    ui_progress__update(&prog, size);

    if (session_done())
        goto out;

    if (file_pos < file_size)
        goto more;

out:
    /* do the final flush for ordered samples */
    err = ordered_events__flush(oe, OE_FLUSH__FINAL);
    if (err)
        goto out_err;
    err = auxtrace__flush_events(session, tool);
    if (err)
        goto out_err;
    err = perf_session__flush_thread_stacks(session);
out_err:
    ui_progress__finish();
    if (!tool->no_warn)
        perf_session__warn_about_errors(session);
    /*
     * We may switching perf.data output, make ordered_events
     * reusable.
     */
    ordered_events__reinit(&session->ordered_events);
    auxtrace__free_events(session);
    session->one_mmap = false;
    return err;
}

int perf_session__process_events(struct perf_session *session)
{
    u64 size = perf_data__size(session->data);
    int err;

    if (perf_session__register_idle_thread(session) < 0)
        return -ENOMEM;

    if (!perf_data__is_pipe(session->data))
        err = __perf_session__process_events(session,
                             session->header.data_offset,
                             session->header.data_size, size);
    else
        err = __perf_session__process_pipe_events(session);

    return err;
}

bool perf_session__has_traces(struct perf_session *session, const char *msg)
{
    struct perf_evsel *evsel;

    evlist__for_each_entry(session->evlist, evsel) {
        if (evsel->attr.type == PERF_TYPE_TRACEPOINT)
            return true;
    }

    pr_err("No trace sample to read. Did you call 'perf %s'?\n", msg);
    return false;
}

int map__set_kallsyms_ref_reloc_sym(struct map *map, const char *symbol_name, u64 addr)
{
    char *bracket;
    struct ref_reloc_sym *ref;
    struct kmap *kmap;

    ref = zalloc(sizeof(struct ref_reloc_sym));
    if (ref == NULL)
        return -ENOMEM;

    ref->name = strdup(symbol_name);
    if (ref->name == NULL) {
        free(ref);
        return -ENOMEM;
    }

    bracket = strchr(ref->name, ']');
    if (bracket)
        *bracket = '\0';

    ref->addr = addr;

    kmap = map__kmap(map);
    if (kmap)
        kmap->ref_reloc_sym = ref;

    return 0;
}

size_t perf_session__fprintf_dsos(struct perf_session *session, FILE *fp)
{
    return machines__fprintf_dsos(&session->machines, fp);
}

size_t perf_session__fprintf_dsos_buildid(struct perf_session *session, FILE *fp,
                      bool (skip)(struct dso *dso, int parm), int parm)
{
    return machines__fprintf_dsos_buildid(&session->machines, fp, skip, parm);
}

size_t perf_session__fprintf_nr_events(struct perf_session *session, FILE *fp)
{
    size_t ret;
    const char *msg = "";

    if (perf_header__has_feat(&session->header, HEADER_AUXTRACE))
        msg = " (excludes AUX area (e.g. instruction trace) decoded / synthesized events)";

    ret = fprintf(fp, "\nAggregated stats:%s\n", msg);

    ret += events_stats__fprintf(&session->evlist->stats, fp);
    return ret;
}

size_t perf_session__fprintf(struct perf_session *session, FILE *fp)
{
    /*
     * FIXME: Here we have to actually print all the machines in this
     * session, not just the host...
     */
    return machine__fprintf(&session->machines.host, fp);
}

struct perf_evsel *perf_session__find_first_evtype(struct perf_session *session,
                          unsigned int type)
{
    struct perf_evsel *pos;

    evlist__for_each_entry(session->evlist, pos) {
        if (pos->attr.type == type)
            return pos;
    }
    return NULL;
}

int perf_session__cpu_bitmap(struct perf_session *session,
                 const char *cpu_list, unsigned long *cpu_bitmap)
{
    int i, err = -1;
    struct cpu_map *map;

    for (i = 0; i < PERF_TYPE_MAX; ++i) {
        struct perf_evsel *evsel;

        evsel = perf_session__find_first_evtype(session, i);
        if (!evsel)
            continue;

        if (!(evsel->attr.sample_type & PERF_SAMPLE_CPU)) {
            pr_err("File does not contain CPU events. "
                   "Remove -C option to proceed.\n");
            return -1;
        }
    }

    map = cpu_map__new(cpu_list);
    if (map == NULL) {
        pr_err("Invalid cpu_list\n");
        return -1;
    }

    for (i = 0; i < map->nr; i++) {
        int cpu = map->map[i];

        if (cpu >= MAX_NR_CPUS) {
            pr_err("Requested CPU %d too large. "
                   "Consider raising MAX_NR_CPUS\n", cpu);
            goto out_delete_map;
        }

        set_bit(cpu, cpu_bitmap);
    }

    err = 0;

out_delete_map:
    cpu_map__put(map);
    return err;
}

void perf_session__fprintf_info(struct perf_session *session, FILE *fp,
                bool full)
{
    if (session == NULL || fp == NULL)
        return;

    fprintf(fp, "# ========\n");
    perf_header__fprintf_info(session, fp, full);
    fprintf(fp, "# ========\n#\n");
}


int __perf_session__set_tracepoints_handlers(struct perf_session *session,
                         const struct perf_evsel_str_handler *assocs,
                         size_t nr_assocs)
{
    struct perf_evsel *evsel;
    size_t i;
    int err;

    for (i = 0; i < nr_assocs; i++) {
        /*
         * Adding a handler for an event not in the session,
         * just ignore it.
         */
        evsel = perf_evlist__find_tracepoint_by_name(session->evlist, assocs[i].name);
        if (evsel == NULL)
            continue;

        err = -EEXIST;
        if (evsel->handler != NULL)
            goto out;
        evsel->handler = assocs[i].handler;
    }

    err = 0;
out:
    return err;
}

int perf_event__process_id_index(struct perf_tool *tool __maybe_unused,
                 union perf_event *event,
                 struct perf_session *session)
{
    struct perf_evlist *evlist = session->evlist;
    struct id_index_event *ie = &event->id_index;
    size_t i, nr, max_nr;

    max_nr = (ie->header.size - sizeof(struct id_index_event)) /
         sizeof(struct id_index_entry);
    nr = ie->nr;
    if (nr > max_nr)
        return -EINVAL;

    if (dump_trace)
        fprintf(stdout, " nr: %zu\n", nr);

    for (i = 0; i < nr; i++) {
        struct id_index_entry *e = &ie->entries[i];
        struct perf_sample_id *sid;

        if (dump_trace) {
            fprintf(stdout, " ... id: %"PRIu64, e->id);
            fprintf(stdout, "  idx: %"PRIu64, e->idx);
            fprintf(stdout, "  cpu: %"PRId64, e->cpu);
            fprintf(stdout, "  tid: %"PRId64"\n", e->tid);
        }

        sid = perf_evlist__id2sid(evlist, e->id);
        if (!sid)
            return -ENOENT;
        sid->idx = e->idx;
        sid->cpu = e->cpu;
        sid->tid = e->tid;
    }
    return 0;
}

int perf_event__synthesize_id_index(struct perf_tool *tool,
                    perf_event__handler_t process,
                    struct perf_evlist *evlist,
                    struct machine *machine)
{
    union perf_event *ev;
    struct perf_evsel *evsel;
    size_t nr = 0, i = 0, sz, max_nr, n;
    int err;

    pr_debug2("Synthesizing id index\n");

    max_nr = (UINT16_MAX - sizeof(struct id_index_event)) /
         sizeof(struct id_index_entry);

    evlist__for_each_entry(evlist, evsel)
        nr += evsel->ids;

    n = nr > max_nr ? max_nr : nr;
    sz = sizeof(struct id_index_event) + n * sizeof(struct id_index_entry);
    ev = zalloc(sz);
    if (!ev)
        return -ENOMEM;

    ev->id_index.header.type = PERF_RECORD_ID_INDEX;
    ev->id_index.header.size = sz;
    ev->id_index.nr = n;

    evlist__for_each_entry(evlist, evsel) {
        u32 j;

        for (j = 0; j < evsel->ids; j++) {
            struct id_index_entry *e;
            struct perf_sample_id *sid;

            if (i >= n) {
                err = process(tool, ev, NULL, machine);
                if (err)
                    goto out_err;
                nr -= n;
                i = 0;
            }

            e = &ev->id_index.entries[i++];

            e->id = evsel->id[j];

            sid = perf_evlist__id2sid(evlist, e->id);
            if (!sid) {
                free(ev);
                return -ENOENT;
            }

            e->idx = sid->idx;
            e->cpu = sid->cpu;
            e->tid = sid->tid;
        }
    }

    sz = sizeof(struct id_index_event) + nr * sizeof(struct id_index_entry);
    ev->id_index.header.size = sz;
    ev->id_index.nr = nr;

    err = process(tool, ev, NULL, machine);
out_err:
    free(ev);

    return err;
}