// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <inttypes.h>
#include <linux/kernel.h>
#include <linux/zalloc.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 "map.h"
#include "symbol.h"
#include "session.h"
#include "tool.h"
#include "sort.h"
#include "cpumap.h"
#include "perf_regs.h"
#include "asm/bug.h"
#include "auxtrace.h"
#include "thread.h"
#include "thread-stack.h"
#include "sample-raw.h"
#include "stat.h"
#include "arch/common.h"

#ifdef HAVE_ZSTD_SUPPORT
static int perf_session__process_compressed_event(struct perf_session *session,
                                                  union perf_event *event, u64 file_offset)
{
        void *src;
        size_t decomp_size, src_size;
        u64 decomp_last_rem = 0;
        size_t mmap_len, decomp_len = session->header.env.comp_mmap_len;
        struct decomp *decomp, *decomp_last = session->decomp_last;

        if (decomp_last) {
                decomp_last_rem = decomp_last->size - decomp_last->head;
                decomp_len += decomp_last_rem;
        }

        mmap_len = sizeof(struct decomp) + decomp_len;
        decomp = mmap(NULL, mmap_len, PROT_READ|PROT_WRITE,
                      MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
        if (decomp == MAP_FAILED) {
                pr_err("Couldn't allocate memory for decompression\n");
                return -1;
        }

        decomp->file_pos = file_offset;
        decomp->mmap_len = mmap_len;
        decomp->head = 0;

        if (decomp_last_rem) {
                memcpy(decomp->data, &(decomp_last->data[decomp_last->head]), decomp_last_rem);
                decomp->size = decomp_last_rem;
        }

        src = (void *)event + sizeof(struct compressed_event);
        src_size = event->pack.header.size - sizeof(struct compressed_event);

        decomp_size = zstd_decompress_stream(&(session->zstd_data), src, src_size,
                                &(decomp->data[decomp_last_rem]), decomp_len - decomp_last_rem);
        if (!decomp_size) {
                munmap(decomp, mmap_len);
                pr_err("Couldn't decompress data\n");
                return -1;
        }

        decomp->size += decomp_size;

        if (session->decomp == NULL) {
                session->decomp = decomp;
                session->decomp_last = decomp;
        } else {
                session->decomp_last->next = decomp;
                session->decomp_last = decomp;
        }

        pr_debug("decomp (B): %ld to %ld\n", src_size, decomp_size);

        return 0;
}
#else /* !HAVE_ZSTD_SUPPORT */
#define perf_session__process_compressed_event perf_session__process_compressed_event_stub
#endif

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, NULL);

        perf_env__init(&session->header.env);
        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_delete;

                        /*
                         * 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);
                        }

                        perf_evlist__init_trace_event_sample_raw(session->evlist);

                        /* Open the directory data. */
                        if (data->is_dir && perf_data__open_dir(data))
                                goto out_delete;
                }
        } else  {
                session->machines.host.env = &perf_env;
        }

        session->machines.host.single_address_space =
                perf_env__single_address_space(session->machines.host.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_delete:
        perf_session__delete(session);
 out:
        return NULL;
}

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

static void perf_session__release_decomp_events(struct perf_session *session)
{
        struct decomp *next, *decomp;
        size_t mmap_len;
        next = session->decomp;
        do {
                decomp = next;
                if (decomp == NULL)
                        break;
                next = decomp->next;
                mmap_len = decomp->mmap_len;
                munmap(decomp, mmap_len);
        } while (1);
}

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_session__release_decomp_events(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_session *session
                                                 __maybe_unused,
                                                 union perf_event *event
                                                 __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_session *session __maybe_unused,
                                       union perf_event *event)
{
        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_session *session __maybe_unused,
                                  union perf_event *event __maybe_unused)
{
        dump_printf(": unhandled!\n");
        return 0;
}


static
int process_event_thread_map_stub(struct perf_session *session __maybe_unused,
                                  union perf_event *event __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_session *session __maybe_unused,
                               union perf_event *event __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_session *session __maybe_unused,
                                   union perf_event *event __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_session *perf_session __maybe_unused,
                             union perf_event *event)
{
        if (dump_trace)
                perf_event__fprintf_stat(event, stdout);

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

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

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

static int perf_session__process_compressed_event_stub(struct perf_session *session __maybe_unused,
                                                       union perf_event *event __maybe_unused,
                                                       u64 file_offset __maybe_unused)
{
       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->ksymbol == NULL)
                tool->ksymbol = perf_event__process_ksymbol;
        if (tool->bpf_event == NULL)
                tool->bpf_event = perf_event__process_bpf_event;
        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;
        if (tool->compressed == NULL)
                tool->compressed = perf_session__process_compressed_event;
}

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 void perf_event__namespaces_swap(union perf_event *event,
                                        bool sample_id_all)
{
        u64 i;

        event->namespaces.pid           = bswap_32(event->namespaces.pid);
        event->namespaces.tid           = bswap_32(event->namespaces.tid);
        event->namespaces.nr_namespaces = bswap_64(event->namespaces.nr_namespaces);

        for (i = 0; i < event->namespaces.nr_namespaces; i++) {
                struct perf_ns_link_info *ns = &event->namespaces.link_info[i];

                ns->dev = bswap_64(ns->dev);
                ns->ino = bswap_64(ns->ino);
        }

        if (sample_id_all)
                swap_sample_id_all(event, &event->namespaces.link_info[i]);
}

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.fmt  = bswap_32(event->auxtrace_error.fmt);
        event->auxtrace_error.ip   = bswap_64(event->auxtrace_error.ip);
        if (event->auxtrace_error.fmt)
                event->auxtrace_error.time = bswap_64(event->auxtrace_error.time);
}

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_NAMESPACES]          = perf_event__namespaces_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 (event->header.type == PERF_RECORD_SAMPLE && evlist->trace_event_sample_raw)
                evlist->trace_event_sample_raw(evlist, event, sample);

        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,
               perf_evsel__name(evsel),
               event->read.value);

        if (!evsel)
                return;

        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;
        }

        /*
         * There's no reason to deliver sample
         * for zero period, bail out.
         */
        if (!sample->period)
                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);
        case PERF_RECORD_KSYMBOL:
                return tool->ksymbol(tool, event, sample, machine);
        case PERF_RECORD_BPF_EVENT:
                return tool->bpf_event(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;

        if (event->header.type != PERF_RECORD_COMPRESSED ||
            tool->compressed == perf_session__process_compressed_event_stub)
                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(session, event);
        case PERF_RECORD_HEADER_BUILD_ID:
                return tool->build_id(session, event);
        case PERF_RECORD_FINISHED_ROUND:
                return tool->finished_round(tool, event, oe);
        case PERF_RECORD_ID_INDEX:
                return tool->id_index(session, event);
        case PERF_RECORD_AUXTRACE_INFO:
                return tool->auxtrace_info(session, event);
        case PERF_RECORD_AUXTRACE:
                /* setup for reading amidst mmap */
                lseek(fd, file_offset + event->header.size, SEEK_SET);
                return tool->auxtrace(session, event);
        case PERF_RECORD_AUXTRACE_ERROR:
                perf_session__auxtrace_error_inc(session, event);
                return tool->auxtrace_error(session, event);
        case PERF_RECORD_THREAD_MAP:
                return tool->thread_map(session, event);
        case PERF_RECORD_CPU_MAP:
                return tool->cpu_map(session, event);
        case PERF_RECORD_STAT_CONFIG:
                return tool->stat_config(session, event);
        case PERF_RECORD_STAT:
                return tool->stat(session, event);
        case PERF_RECORD_STAT_ROUND:
                return tool->stat_round(session, event);
        case PERF_RECORD_TIME_CONV:
                session->time_conv = event->time_conv;
                return tool->time_conv(session, event);
        case PERF_RECORD_HEADER_FEATURE:
                return tool->feature(session, event);
        case PERF_RECORD_COMPRESSED:
                err = tool->compressed(session, event, file_offset);
                if (err)
                        dump_event(session->evlist, event, file_offset, &sample);
                return err;
        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);
}

/*
 * Threads are identified by pid and tid, and the idle task has pid == tid == 0.
 * So here a single thread is created for that, but actually there is a separate
 * idle task per cpu, so there should be one 'struct thread' per cpu, but there
 * is only 1. That causes problems for some tools, requiring workarounds. For
 * example get_idle_thread() in builtin-sched.c, or thread_stack__per_cpu().
 */
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_decomp_events(struct perf_session *session);

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;

        err = __perf_session__process_decomp_events(session);
        if (err)
                goto out_err;

        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;
}

static int __perf_session__process_decomp_events(struct perf_session *session)
{
        s64 skip;
        u64 size, file_pos = 0;
        struct decomp *decomp = session->decomp_last;

        if (!decomp)
                return 0;

        while (decomp->head < decomp->size && !session_done()) {
                union perf_event *event = fetch_mmaped_event(session, decomp->head, decomp->size, decomp->data);

                if (!event)
                        break;

                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",
                                decomp->file_pos + decomp->head, event->header.size, event->header.type);
                        return -EINVAL;
                }

                if (skip)
                        size += skip;

                decomp->head += size;
        }

        return 0;
}

/*
 * 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

struct reader;

typedef s64 (*reader_cb_t)(struct perf_session *session,
                           union perf_event *event,
                           u64 file_offset);

struct reader {
        int              fd;
        u64              data_size;
        u64              data_offset;
        reader_cb_t      process;
};

static int
reader__process_events(struct reader *rd, struct perf_session *session,
                       struct ui_progress *prog)
{
        u64 data_size = rd->data_size;
        u64 head, page_offset, file_offset, file_pos, size;
        int err = 0, mmap_prot, mmap_flags, map_idx = 0;
        size_t  mmap_size;
        char *buf, *mmaps[NUM_MMAPS];
        union perf_event *event;
        s64 skip;

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

        ui_progress__init_size(prog, data_size, "Processing events...");

        data_size += rd->data_offset;

        mmap_size = MMAP_SIZE;
        if (mmap_size > data_size) {
                mmap_size = data_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, rd->fd,
                   file_offset);
        if (buf == MAP_FAILED) {
                pr_err("failed to mmap file\n");
                err = -errno;
                goto out;
        }
        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;

        skip = -EINVAL;

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

        if (skip)
                size += skip;

        head += size;
        file_pos += size;

        err = __perf_session__process_decomp_events(session);
        if (err)
                goto out;

        ui_progress__update(prog, size);

        if (session_done())
                goto out;

        if (file_pos < data_size)
                goto more;

out:
        return err;
}

static s64 process_simple(struct perf_session *session,
                          union perf_event *event,
                          u64 file_offset)
{
        return perf_session__process_event(session, event, file_offset);
}

static int __perf_session__process_events(struct perf_session *session)
{
        struct reader rd = {
                .fd             = perf_data__fd(session->data),
                .data_size      = session->header.data_size,
                .data_offset    = session->header.data_offset,
                .process        = process_simple,
        };
        struct ordered_events *oe = &session->ordered_events;
        struct perf_tool *tool = session->tool;
        struct ui_progress prog;
        int err;

        perf_tool__fill_defaults(tool);

        if (rd.data_size == 0)
                return -1;

        ui_progress__init_size(&prog, rd.data_size, "Processing events...");

        err = reader__process_events(&rd, session, &prog);
        if (err)
                goto out_err;
        /* 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)
{
        if (perf_session__register_idle_thread(session) < 0)
                return -ENOMEM;

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

        return __perf_session__process_events(session);
}

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_session *session,
                                 union perf_event *event)
{
        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;
}