evsel.c

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/*
 * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
 *
 * Parts came from builtin-{top,stat,record}.c, see those files for further
 * copyright notes.
 *
 * Released under the GPL v2. (and only v2, not any later version)
 */

#include <byteswap.h>
#include <errno.h>
#include <inttypes.h>
#include <linux/bitops.h>
#include <api/fs/fs.h>
#include <api/fs/tracing_path.h>
#include <traceevent/event-parse.h>
#include <linux/hw_breakpoint.h>
#include <linux/perf_event.h>
#include <linux/compiler.h>
#include <linux/err.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <dirent.h>
#include "asm/bug.h"
#include "callchain.h"
#include "cgroup.h"
#include "event.h"
#include "evsel.h"
#include "evlist.h"
#include "util.h"
#include "cpumap.h"
#include "thread_map.h"
#include "target.h"
#include "perf_regs.h"
#include "debug.h"
#include "trace-event.h"
#include "stat.h"
#include "memswap.h"
#include "util/parse-branch-options.h"

#include "sane_ctype.h"

struct perf_missing_features perf_missing_features;

static clockid_t clockid;

static int perf_evsel__no_extra_init(struct perf_evsel *evsel __maybe_unused)
{
    return 0;
}

void __weak test_attr__ready(void) { }

static void perf_evsel__no_extra_fini(struct perf_evsel *evsel __maybe_unused)
{
}

static struct {
    size_t  size;
    int (*init)(struct perf_evsel *evsel);
    void    (*fini)(struct perf_evsel *evsel);
} perf_evsel__object = {
    .size = sizeof(struct perf_evsel),
    .init = perf_evsel__no_extra_init,
    .fini = perf_evsel__no_extra_fini,
};

int perf_evsel__object_config(size_t object_size,
                  int (*init)(struct perf_evsel *evsel),
                  void (*fini)(struct perf_evsel *evsel))
{

    if (object_size == 0)
        goto set_methods;

    if (perf_evsel__object.size > object_size)
        return -EINVAL;

    perf_evsel__object.size = object_size;

set_methods:
    if (init != NULL)
        perf_evsel__object.init = init;

    if (fini != NULL)
        perf_evsel__object.fini = fini;

    return 0;
}

#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))

int __perf_evsel__sample_size(u64 sample_type)
{
    u64 mask = sample_type & PERF_SAMPLE_MASK;
    int size = 0;
    int i;

    for (i = 0; i < 64; i++) {
        if (mask & (1ULL << i))
            size++;
    }

    size *= sizeof(u64);

    return size;
}

static int __perf_evsel__calc_id_pos(u64 sample_type)
{
    int idx = 0;

    if (sample_type & PERF_SAMPLE_IDENTIFIER)
        return 0;

    if (!(sample_type & PERF_SAMPLE_ID))
        return -1;

    if (sample_type & PERF_SAMPLE_IP)
        idx += 1;

    if (sample_type & PERF_SAMPLE_TID)
        idx += 1;

    if (sample_type & PERF_SAMPLE_TIME)
        idx += 1;

    if (sample_type & PERF_SAMPLE_ADDR)
        idx += 1;

    return idx;
}

static int __perf_evsel__calc_is_pos(u64 sample_type)
{
    int idx = 1;

    if (sample_type & PERF_SAMPLE_IDENTIFIER)
        return 1;

    if (!(sample_type & PERF_SAMPLE_ID))
        return -1;

    if (sample_type & PERF_SAMPLE_CPU)
        idx += 1;

    if (sample_type & PERF_SAMPLE_STREAM_ID)
        idx += 1;

    return idx;
}

void perf_evsel__calc_id_pos(struct perf_evsel *evsel)
{
    evsel->id_pos = __perf_evsel__calc_id_pos(evsel->attr.sample_type);
    evsel->is_pos = __perf_evsel__calc_is_pos(evsel->attr.sample_type);
}

void __perf_evsel__set_sample_bit(struct perf_evsel *evsel,
                  enum perf_event_sample_format bit)
{
    if (!(evsel->attr.sample_type & bit)) {
        evsel->attr.sample_type |= bit;
        evsel->sample_size += sizeof(u64);
        perf_evsel__calc_id_pos(evsel);
    }
}

void __perf_evsel__reset_sample_bit(struct perf_evsel *evsel,
                    enum perf_event_sample_format bit)
{
    if (evsel->attr.sample_type & bit) {
        evsel->attr.sample_type &= ~bit;
        evsel->sample_size -= sizeof(u64);
        perf_evsel__calc_id_pos(evsel);
    }
}

void perf_evsel__set_sample_id(struct perf_evsel *evsel,
                   bool can_sample_identifier)
{
    if (can_sample_identifier) {
        perf_evsel__reset_sample_bit(evsel, ID);
        perf_evsel__set_sample_bit(evsel, IDENTIFIER);
    } else {
        perf_evsel__set_sample_bit(evsel, ID);
    }
    evsel->attr.read_format |= PERF_FORMAT_ID;
}

bool perf_evsel__is_function_event(struct perf_evsel *evsel)
{
#define FUNCTION_EVENT "ftrace:function"

    return evsel->name &&
           !strncmp(FUNCTION_EVENT, evsel->name, sizeof(FUNCTION_EVENT));

#undef FUNCTION_EVENT
}

void perf_evsel__init(struct perf_evsel *evsel,
              struct perf_event_attr *attr, int idx)
{
    evsel->idx     = idx;
    evsel->tracking    = !idx;
    evsel->attr    = *attr;
    evsel->leader      = evsel;
    evsel->unit    = "";
    evsel->scale       = 1.0;
    evsel->evlist      = NULL;
    evsel->bpf_fd      = -1;
    INIT_LIST_HEAD(&evsel->node);
    INIT_LIST_HEAD(&evsel->config_terms);
    perf_evsel__object.init(evsel);
    evsel->sample_size = __perf_evsel__sample_size(attr->sample_type);
    perf_evsel__calc_id_pos(evsel);
    evsel->cmdline_group_boundary = false;
    evsel->metric_expr   = NULL;
    evsel->metric_name   = NULL;
    evsel->metric_events = NULL;
    evsel->collect_stat  = false;
    evsel->pmu_name      = NULL;
}

struct perf_evsel *perf_evsel__new_idx(struct perf_event_attr *attr, int idx)
{
    struct perf_evsel *evsel = zalloc(perf_evsel__object.size);

    if (evsel != NULL)
        perf_evsel__init(evsel, attr, idx);

    if (perf_evsel__is_bpf_output(evsel)) {
        evsel->attr.sample_type |= (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME |
                        PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD),
        evsel->attr.sample_period = 1;
    }

    return evsel;
}

static bool perf_event_can_profile_kernel(void)
{
    return geteuid() == 0 || perf_event_paranoid() == -1;
}

struct perf_evsel *perf_evsel__new_cycles(bool precise)
{
    struct perf_event_attr attr = {
        .type   = PERF_TYPE_HARDWARE,
        .config = PERF_COUNT_HW_CPU_CYCLES,
        .exclude_kernel = !perf_event_can_profile_kernel(),
    };
    struct perf_evsel *evsel;

    event_attr_init(&attr);

    if (!precise)
        goto new_event;
    /*
     * Unnamed union member, not supported as struct member named
     * initializer in older compilers such as gcc 4.4.7
     *
     * Just for probing the precise_ip:
     */
    attr.sample_period = 1;

    perf_event_attr__set_max_precise_ip(&attr);
    /*
     * Now let the usual logic to set up the perf_event_attr defaults
     * to kick in when we return and before perf_evsel__open() is called.
     */
    attr.sample_period = 0;
new_event:
    evsel = perf_evsel__new(&attr);
    if (evsel == NULL)
        goto out;

    /* use asprintf() because free(evsel) assumes name is allocated */
    if (asprintf(&evsel->name, "cycles%s%s%.*s",
             (attr.precise_ip || attr.exclude_kernel) ? ":" : "",
             attr.exclude_kernel ? "u" : "",
             attr.precise_ip ? attr.precise_ip + 1 : 0, "ppp") < 0)
        goto error_free;
out:
    return evsel;
error_free:
    perf_evsel__delete(evsel);
    evsel = NULL;
    goto out;
}

/*
 * Returns pointer with encoded error via <linux/err.h> interface.
 */
struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, int idx)
{
    struct perf_evsel *evsel = zalloc(perf_evsel__object.size);
    int err = -ENOMEM;

    if (evsel == NULL) {
        goto out_err;
    } else {
        struct perf_event_attr attr = {
            .type          = PERF_TYPE_TRACEPOINT,
            .sample_type   = (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME |
                      PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD),
        };

        if (asprintf(&evsel->name, "%s:%s", sys, name) < 0)
            goto out_free;

        evsel->tp_format = trace_event__tp_format(sys, name);
        if (IS_ERR(evsel->tp_format)) {
            err = PTR_ERR(evsel->tp_format);
            goto out_free;
        }

        event_attr_init(&attr);
        attr.config = evsel->tp_format->id;
        attr.sample_period = 1;
        perf_evsel__init(evsel, &attr, idx);
    }

    return evsel;

out_free:
    zfree(&evsel->name);
    free(evsel);
out_err:
    return ERR_PTR(err);
}

const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX] = {
    "cycles",
    "instructions",
    "cache-references",
    "cache-misses",
    "branches",
    "branch-misses",
    "bus-cycles",
    "stalled-cycles-frontend",
    "stalled-cycles-backend",
    "ref-cycles",
};

static const char *__perf_evsel__hw_name(u64 config)
{
    if (config < PERF_COUNT_HW_MAX && perf_evsel__hw_names[config])
        return perf_evsel__hw_names[config];

    return "unknown-hardware";
}

static int perf_evsel__add_modifiers(struct perf_evsel *evsel, char *bf, size_t size)
{
    int colon = 0, r = 0;
    struct perf_event_attr *attr = &evsel->attr;
    bool exclude_guest_default = false;

#define MOD_PRINT(context, mod) do {                    \
        if (!attr->exclude_##context) {             \
            if (!colon) colon = ++r;            \
            r += scnprintf(bf + r, size - r, "%c", mod);    \
        } } while(0)

    if (attr->exclude_kernel || attr->exclude_user || attr->exclude_hv) {
        MOD_PRINT(kernel, 'k');
        MOD_PRINT(user, 'u');
        MOD_PRINT(hv, 'h');
        exclude_guest_default = true;
    }

    if (attr->precise_ip) {
        if (!colon)
            colon = ++r;
        r += scnprintf(bf + r, size - r, "%.*s", attr->precise_ip, "ppp");
        exclude_guest_default = true;
    }

    if (attr->exclude_host || attr->exclude_guest == exclude_guest_default) {
        MOD_PRINT(host, 'H');
        MOD_PRINT(guest, 'G');
    }
#undef MOD_PRINT
    if (colon)
        bf[colon - 1] = ':';
    return r;
}

static int perf_evsel__hw_name(struct perf_evsel *evsel, char *bf, size_t size)
{
    int r = scnprintf(bf, size, "%s", __perf_evsel__hw_name(evsel->attr.config));
    return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
}

const char *perf_evsel__sw_names[PERF_COUNT_SW_MAX] = {
    "cpu-clock",
    "task-clock",
    "page-faults",
    "context-switches",
    "cpu-migrations",
    "minor-faults",
    "major-faults",
    "alignment-faults",
    "emulation-faults",
    "dummy",
};

static const char *__perf_evsel__sw_name(u64 config)
{
    if (config < PERF_COUNT_SW_MAX && perf_evsel__sw_names[config])
        return perf_evsel__sw_names[config];
    return "unknown-software";
}

static int perf_evsel__sw_name(struct perf_evsel *evsel, char *bf, size_t size)
{
    int r = scnprintf(bf, size, "%s", __perf_evsel__sw_name(evsel->attr.config));
    return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
}

static int __perf_evsel__bp_name(char *bf, size_t size, u64 addr, u64 type)
{
    int r;

    r = scnprintf(bf, size, "mem:0x%" PRIx64 ":", addr);

    if (type & HW_BREAKPOINT_R)
        r += scnprintf(bf + r, size - r, "r");

    if (type & HW_BREAKPOINT_W)
        r += scnprintf(bf + r, size - r, "w");

    if (type & HW_BREAKPOINT_X)
        r += scnprintf(bf + r, size - r, "x");

    return r;
}

static int perf_evsel__bp_name(struct perf_evsel *evsel, char *bf, size_t size)
{
    struct perf_event_attr *attr = &evsel->attr;
    int r = __perf_evsel__bp_name(bf, size, attr->bp_addr, attr->bp_type);
    return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
}

const char *perf_evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX]
                [PERF_EVSEL__MAX_ALIASES] = {
 { "L1-dcache", "l1-d",     "l1d",      "L1-data",      },
 { "L1-icache", "l1-i",     "l1i",      "L1-instruction",   },
 { "LLC",   "L2",                           },
 { "dTLB",  "d-tlb",    "Data-TLB",             },
 { "iTLB",  "i-tlb",    "Instruction-TLB",          },
 { "branch",    "branches", "bpu",      "btb",      "bpc",  },
 { "node",                              },
};

const char *perf_evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX]
                   [PERF_EVSEL__MAX_ALIASES] = {
 { "load",  "loads",    "read",                 },
 { "store", "stores",   "write",                },
 { "prefetch",  "prefetches",   "speculative-read", "speculative-load", },
};

const char *perf_evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX]
                       [PERF_EVSEL__MAX_ALIASES] = {
 { "refs",  "Reference",    "ops",      "access",       },
 { "misses",    "miss",                         },
};

#define C(x)        PERF_COUNT_HW_CACHE_##x
#define CACHE_READ  (1 << C(OP_READ))
#define CACHE_WRITE (1 << C(OP_WRITE))
#define CACHE_PREFETCH  (1 << C(OP_PREFETCH))
#define COP(x)      (1 << x)

/*
 * cache operartion stat
 * L1I : Read and prefetch only
 * ITLB and BPU : Read-only
 */
static unsigned long perf_evsel__hw_cache_stat[C(MAX)] = {
 [C(L1D)]   = (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
 [C(L1I)]   = (CACHE_READ | CACHE_PREFETCH),
 [C(LL)]    = (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
 [C(DTLB)]  = (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
 [C(ITLB)]  = (CACHE_READ),
 [C(BPU)]   = (CACHE_READ),
 [C(NODE)]  = (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
};

bool perf_evsel__is_cache_op_valid(u8 type, u8 op)
{
    if (perf_evsel__hw_cache_stat[type] & COP(op))
        return true;    /* valid */
    else
        return false;   /* invalid */
}

int __perf_evsel__hw_cache_type_op_res_name(u8 type, u8 op, u8 result,
                        char *bf, size_t size)
{
    if (result) {
        return scnprintf(bf, size, "%s-%s-%s", perf_evsel__hw_cache[type][0],
                 perf_evsel__hw_cache_op[op][0],
                 perf_evsel__hw_cache_result[result][0]);
    }

    return scnprintf(bf, size, "%s-%s", perf_evsel__hw_cache[type][0],
             perf_evsel__hw_cache_op[op][1]);
}

static int __perf_evsel__hw_cache_name(u64 config, char *bf, size_t size)
{
    u8 op, result, type = (config >>  0) & 0xff;
    const char *err = "unknown-ext-hardware-cache-type";

    if (type >= PERF_COUNT_HW_CACHE_MAX)
        goto out_err;

    op = (config >>  8) & 0xff;
    err = "unknown-ext-hardware-cache-op";
    if (op >= PERF_COUNT_HW_CACHE_OP_MAX)
        goto out_err;

    result = (config >> 16) & 0xff;
    err = "unknown-ext-hardware-cache-result";
    if (result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
        goto out_err;

    err = "invalid-cache";
    if (!perf_evsel__is_cache_op_valid(type, op))
        goto out_err;

    return __perf_evsel__hw_cache_type_op_res_name(type, op, result, bf, size);
out_err:
    return scnprintf(bf, size, "%s", err);
}

static int perf_evsel__hw_cache_name(struct perf_evsel *evsel, char *bf, size_t size)
{
    int ret = __perf_evsel__hw_cache_name(evsel->attr.config, bf, size);
    return ret + perf_evsel__add_modifiers(evsel, bf + ret, size - ret);
}

static int perf_evsel__raw_name(struct perf_evsel *evsel, char *bf, size_t size)
{
    int ret = scnprintf(bf, size, "raw 0x%" PRIx64, evsel->attr.config);
    return ret + perf_evsel__add_modifiers(evsel, bf + ret, size - ret);
}

const char *perf_evsel__name(struct perf_evsel *evsel)
{
    char bf[128];

    if (evsel->name)
        return evsel->name;

    switch (evsel->attr.type) {
    case PERF_TYPE_RAW:
        perf_evsel__raw_name(evsel, bf, sizeof(bf));
        break;

    case PERF_TYPE_HARDWARE:
        perf_evsel__hw_name(evsel, bf, sizeof(bf));
        break;

    case PERF_TYPE_HW_CACHE:
        perf_evsel__hw_cache_name(evsel, bf, sizeof(bf));
        break;

    case PERF_TYPE_SOFTWARE:
        perf_evsel__sw_name(evsel, bf, sizeof(bf));
        break;

    case PERF_TYPE_TRACEPOINT:
        scnprintf(bf, sizeof(bf), "%s", "unknown tracepoint");
        break;

    case PERF_TYPE_BREAKPOINT:
        perf_evsel__bp_name(evsel, bf, sizeof(bf));
        break;

    default:
        scnprintf(bf, sizeof(bf), "unknown attr type: %d",
              evsel->attr.type);
        break;
    }

    evsel->name = strdup(bf);

    return evsel->name ?: "unknown";
}

const char *perf_evsel__group_name(struct perf_evsel *evsel)
{
    return evsel->group_name ?: "anon group";
}

/*
 * Returns the group details for the specified leader,
 * with following rules.
 *
 *  For record -e '{cycles,instructions}'
 *    'anon group { cycles:u, instructions:u }'
 *
 *  For record -e 'cycles,instructions' and report --group
 *    'cycles:u, instructions:u'
 */
int perf_evsel__group_desc(struct perf_evsel *evsel, char *buf, size_t size)
{
    int ret = 0;
    struct perf_evsel *pos;
    const char *group_name = perf_evsel__group_name(evsel);

    if (!evsel->forced_leader)
        ret = scnprintf(buf, size, "%s { ", group_name);

    ret += scnprintf(buf + ret, size - ret, "%s",
             perf_evsel__name(evsel));

    for_each_group_member(pos, evsel)
        ret += scnprintf(buf + ret, size - ret, ", %s",
                 perf_evsel__name(pos));

    if (!evsel->forced_leader)
        ret += scnprintf(buf + ret, size - ret, " }");

    return ret;
}

static void __perf_evsel__config_callchain(struct perf_evsel *evsel,
                       struct record_opts *opts,
                       struct callchain_param *param)
{
    bool function = perf_evsel__is_function_event(evsel);
    struct perf_event_attr *attr = &evsel->attr;

    perf_evsel__set_sample_bit(evsel, CALLCHAIN);

    attr->sample_max_stack = param->max_stack;

    if (param->record_mode == CALLCHAIN_LBR) {
        if (!opts->branch_stack) {
            if (attr->exclude_user) {
                pr_warning("LBR callstack option is only available "
                       "to get user callchain information. "
                       "Falling back to framepointers.\n");
            } else {
                perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
                attr->branch_sample_type = PERF_SAMPLE_BRANCH_USER |
                            PERF_SAMPLE_BRANCH_CALL_STACK |
                            PERF_SAMPLE_BRANCH_NO_CYCLES |
                            PERF_SAMPLE_BRANCH_NO_FLAGS;
            }
        } else
             pr_warning("Cannot use LBR callstack with branch stack. "
                    "Falling back to framepointers.\n");
    }

    if (param->record_mode == CALLCHAIN_DWARF) {
        if (!function) {
            perf_evsel__set_sample_bit(evsel, REGS_USER);
            perf_evsel__set_sample_bit(evsel, STACK_USER);
            attr->sample_regs_user |= PERF_REGS_MASK;
            attr->sample_stack_user = param->dump_size;
            attr->exclude_callchain_user = 1;
        } else {
            pr_info("Cannot use DWARF unwind for function trace event,"
                " falling back to framepointers.\n");
        }
    }

    if (function) {
        pr_info("Disabling user space callchains for function trace event.\n");
        attr->exclude_callchain_user = 1;
    }
}

void perf_evsel__config_callchain(struct perf_evsel *evsel,
                  struct record_opts *opts,
                  struct callchain_param *param)
{
    if (param->enabled)
        return __perf_evsel__config_callchain(evsel, opts, param);
}

static void
perf_evsel__reset_callgraph(struct perf_evsel *evsel,
                struct callchain_param *param)
{
    struct perf_event_attr *attr = &evsel->attr;

    perf_evsel__reset_sample_bit(evsel, CALLCHAIN);
    if (param->record_mode == CALLCHAIN_LBR) {
        perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
        attr->branch_sample_type &= ~(PERF_SAMPLE_BRANCH_USER |
                          PERF_SAMPLE_BRANCH_CALL_STACK);
    }
    if (param->record_mode == CALLCHAIN_DWARF) {
        perf_evsel__reset_sample_bit(evsel, REGS_USER);
        perf_evsel__reset_sample_bit(evsel, STACK_USER);
    }
}

static void apply_config_terms(struct perf_evsel *evsel,
                   struct record_opts *opts, bool track)
{
    struct perf_evsel_config_term *term;
    struct list_head *config_terms = &evsel->config_terms;
    struct perf_event_attr *attr = &evsel->attr;
    /* callgraph default */
    struct callchain_param param = {
        .record_mode = callchain_param.record_mode,
    };
    u32 dump_size = 0;
    int max_stack = 0;
    const char *callgraph_buf = NULL;

    list_for_each_entry(term, config_terms, list) {
        switch (term->type) {
        case PERF_EVSEL__CONFIG_TERM_PERIOD:
            if (!(term->weak && opts->user_interval != ULLONG_MAX)) {
                attr->sample_period = term->val.period;
                attr->freq = 0;
                perf_evsel__reset_sample_bit(evsel, PERIOD);
            }
            break;
        case PERF_EVSEL__CONFIG_TERM_FREQ:
            if (!(term->weak && opts->user_freq != UINT_MAX)) {
                attr->sample_freq = term->val.freq;
                attr->freq = 1;
                perf_evsel__set_sample_bit(evsel, PERIOD);
            }
            break;
        case PERF_EVSEL__CONFIG_TERM_TIME:
            if (term->val.time)
                perf_evsel__set_sample_bit(evsel, TIME);
            else
                perf_evsel__reset_sample_bit(evsel, TIME);
            break;
        case PERF_EVSEL__CONFIG_TERM_CALLGRAPH:
            callgraph_buf = term->val.callgraph;
            break;
        case PERF_EVSEL__CONFIG_TERM_BRANCH:
            if (term->val.branch && strcmp(term->val.branch, "no")) {
                perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
                parse_branch_str(term->val.branch,
                         &attr->branch_sample_type);
            } else
                perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
            break;
        case PERF_EVSEL__CONFIG_TERM_STACK_USER:
            dump_size = term->val.stack_user;
            break;
        case PERF_EVSEL__CONFIG_TERM_MAX_STACK:
            max_stack = term->val.max_stack;
            break;
        case PERF_EVSEL__CONFIG_TERM_INHERIT:
            /*
             * attr->inherit should has already been set by
             * perf_evsel__config. If user explicitly set
             * inherit using config terms, override global
             * opt->no_inherit setting.
             */
            attr->inherit = term->val.inherit ? 1 : 0;
            break;
        case PERF_EVSEL__CONFIG_TERM_OVERWRITE:
            attr->write_backward = term->val.overwrite ? 1 : 0;
            break;
        case PERF_EVSEL__CONFIG_TERM_DRV_CFG:
            break;
        default:
            break;
        }
    }

    /* User explicitly set per-event callgraph, clear the old setting and reset. */
    if ((callgraph_buf != NULL) || (dump_size > 0) || max_stack) {
        bool sample_address = false;

        if (max_stack) {
            param.max_stack = max_stack;
            if (callgraph_buf == NULL)
                callgraph_buf = "fp";
        }

        /* parse callgraph parameters */
        if (callgraph_buf != NULL) {
            if (!strcmp(callgraph_buf, "no")) {
                param.enabled = false;
                param.record_mode = CALLCHAIN_NONE;
            } else {
                param.enabled = true;
                if (parse_callchain_record(callgraph_buf, &param)) {
                    pr_err("per-event callgraph setting for %s failed. "
                           "Apply callgraph global setting for it\n",
                           evsel->name);
                    return;
                }
                if (param.record_mode == CALLCHAIN_DWARF)
                    sample_address = true;
            }
        }
        if (dump_size > 0) {
            dump_size = round_up(dump_size, sizeof(u64));
            param.dump_size = dump_size;
        }

        /* If global callgraph set, clear it */
        if (callchain_param.enabled)
            perf_evsel__reset_callgraph(evsel, &callchain_param);

        /* set perf-event callgraph */
        if (param.enabled) {
            if (sample_address) {
                perf_evsel__set_sample_bit(evsel, ADDR);
                perf_evsel__set_sample_bit(evsel, DATA_SRC);
                evsel->attr.mmap_data = track;
            }
            perf_evsel__config_callchain(evsel, opts, &param);
        }
    }
}

/*
 * The enable_on_exec/disabled value strategy:
 *
 *  1) For any type of traced program:
 *    - all independent events and group leaders are disabled
 *    - all group members are enabled
 *
 *     Group members are ruled by group leaders. They need to
 *     be enabled, because the group scheduling relies on that.
 *
 *  2) For traced programs executed by perf:
 *     - all independent events and group leaders have
 *       enable_on_exec set
 *     - we don't specifically enable or disable any event during
 *       the record command
 *
 *     Independent events and group leaders are initially disabled
 *     and get enabled by exec. Group members are ruled by group
 *     leaders as stated in 1).
 *
 *  3) For traced programs attached by perf (pid/tid):
 *     - we specifically enable or disable all events during
 *       the record command
 *
 *     When attaching events to already running traced we
 *     enable/disable events specifically, as there's no
 *     initial traced exec call.
 */
void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
            struct callchain_param *callchain)
{
    struct perf_evsel *leader = evsel->leader;
    struct perf_event_attr *attr = &evsel->attr;
    int track = evsel->tracking;
    bool per_cpu = opts->target.default_per_cpu && !opts->target.per_thread;

    attr->sample_id_all = perf_missing_features.sample_id_all ? 0 : 1;
    attr->inherit       = !opts->no_inherit;
    attr->write_backward = opts->overwrite ? 1 : 0;

    perf_evsel__set_sample_bit(evsel, IP);
    perf_evsel__set_sample_bit(evsel, TID);

    if (evsel->sample_read) {
        perf_evsel__set_sample_bit(evsel, READ);

        /*
         * We need ID even in case of single event, because
         * PERF_SAMPLE_READ process ID specific data.
         */
        perf_evsel__set_sample_id(evsel, false);

        /*
         * Apply group format only if we belong to group
         * with more than one members.
         */
        if (leader->nr_members > 1) {
            attr->read_format |= PERF_FORMAT_GROUP;
            attr->inherit = 0;
        }
    }

    /*
     * We default some events to have a default interval. But keep
     * it a weak assumption overridable by the user.
     */
    if (!attr->sample_period || (opts->user_freq != UINT_MAX ||
                     opts->user_interval != ULLONG_MAX)) {
        if (opts->freq) {
            perf_evsel__set_sample_bit(evsel, PERIOD);
            attr->freq      = 1;
            attr->sample_freq   = opts->freq;
        } else {
            attr->sample_period = opts->default_interval;
        }
    }

    /*
     * Disable sampling for all group members other
     * than leader in case leader 'leads' the sampling.
     */
    if ((leader != evsel) && leader->sample_read) {
        attr->freq           = 0;
        attr->sample_freq    = 0;
        attr->sample_period  = 0;
        attr->write_backward = 0;
        attr->sample_id_all  = 0;
    }

    if (opts->no_samples)
        attr->sample_freq = 0;

    if (opts->inherit_stat) {
        evsel->attr.read_format |=
            PERF_FORMAT_TOTAL_TIME_ENABLED |
            PERF_FORMAT_TOTAL_TIME_RUNNING |
            PERF_FORMAT_ID;
        attr->inherit_stat = 1;
    }

    if (opts->sample_address) {
        perf_evsel__set_sample_bit(evsel, ADDR);
        attr->mmap_data = track;
    }

    /*
     * We don't allow user space callchains for  function trace
     * event, due to issues with page faults while tracing page
     * fault handler and its overall trickiness nature.
     */
    if (perf_evsel__is_function_event(evsel))
        evsel->attr.exclude_callchain_user = 1;

    if (callchain && callchain->enabled && !evsel->no_aux_samples)
        perf_evsel__config_callchain(evsel, opts, callchain);

    if (opts->sample_intr_regs) {
        attr->sample_regs_intr = opts->sample_intr_regs;
        perf_evsel__set_sample_bit(evsel, REGS_INTR);
    }

    if (opts->sample_user_regs) {
        attr->sample_regs_user |= opts->sample_user_regs;
        perf_evsel__set_sample_bit(evsel, REGS_USER);
    }

    if (target__has_cpu(&opts->target) || opts->sample_cpu)
        perf_evsel__set_sample_bit(evsel, CPU);

    /*
     * When the user explicitly disabled time don't force it here.
     */
    if (opts->sample_time &&
        (!perf_missing_features.sample_id_all &&
        (!opts->no_inherit || target__has_cpu(&opts->target) || per_cpu ||
         opts->sample_time_set)))
        perf_evsel__set_sample_bit(evsel, TIME);

    if (opts->raw_samples && !evsel->no_aux_samples) {
        perf_evsel__set_sample_bit(evsel, TIME);
        perf_evsel__set_sample_bit(evsel, RAW);
        perf_evsel__set_sample_bit(evsel, CPU);
    }

    if (opts->sample_address)
        perf_evsel__set_sample_bit(evsel, DATA_SRC);

    if (opts->sample_phys_addr)
        perf_evsel__set_sample_bit(evsel, PHYS_ADDR);

    if (opts->no_buffering) {
        attr->watermark = 0;
        attr->wakeup_events = 1;
    }
    if (opts->branch_stack && !evsel->no_aux_samples) {
        perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
        attr->branch_sample_type = opts->branch_stack;
    }

    if (opts->sample_weight)
        perf_evsel__set_sample_bit(evsel, WEIGHT);

    attr->task  = track;
    attr->mmap  = track;
    attr->mmap2 = track && !perf_missing_features.mmap2;
    attr->comm  = track;

    if (opts->record_namespaces)
        attr->namespaces  = track;

    if (opts->record_switch_events)
        attr->context_switch = track;

    if (opts->sample_transaction)
        perf_evsel__set_sample_bit(evsel, TRANSACTION);

    if (opts->running_time) {
        evsel->attr.read_format |=
            PERF_FORMAT_TOTAL_TIME_ENABLED |
            PERF_FORMAT_TOTAL_TIME_RUNNING;
    }

    /*
     * XXX see the function comment above
     *
     * Disabling only independent events or group leaders,
     * keeping group members enabled.
     */
    if (perf_evsel__is_group_leader(evsel))
        attr->disabled = 1;

    /*
     * Setting enable_on_exec for independent events and
     * group leaders for traced executed by perf.
     */
    if (target__none(&opts->target) && perf_evsel__is_group_leader(evsel) &&
        !opts->initial_delay)
        attr->enable_on_exec = 1;

    if (evsel->immediate) {
        attr->disabled = 0;
        attr->enable_on_exec = 0;
    }

    clockid = opts->clockid;
    if (opts->use_clockid) {
        attr->use_clockid = 1;
        attr->clockid = opts->clockid;
    }

    if (evsel->precise_max)
        perf_event_attr__set_max_precise_ip(attr);

    if (opts->all_user) {
        attr->exclude_kernel = 1;
        attr->exclude_user   = 0;
    }

    if (opts->all_kernel) {
        attr->exclude_kernel = 0;
        attr->exclude_user   = 1;
    }

    /*
     * Apply event specific term settings,
     * it overloads any global configuration.
     */
    apply_config_terms(evsel, opts, track);

    evsel->ignore_missing_thread = opts->ignore_missing_thread;

    /* The --period option takes the precedence. */
    if (opts->period_set) {
        if (opts->period)
            perf_evsel__set_sample_bit(evsel, PERIOD);
        else
            perf_evsel__reset_sample_bit(evsel, PERIOD);
    }
}

static int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
{
    if (evsel->system_wide)
        nthreads = 1;

    evsel->fd = xyarray__new(ncpus, nthreads, sizeof(int));

    if (evsel->fd) {
        int cpu, thread;
        for (cpu = 0; cpu < ncpus; cpu++) {
            for (thread = 0; thread < nthreads; thread++) {
                FD(evsel, cpu, thread) = -1;
            }
        }
    }

    return evsel->fd != NULL ? 0 : -ENOMEM;
}

static int perf_evsel__run_ioctl(struct perf_evsel *evsel,
              int ioc,  void *arg)
{
    int cpu, thread;

    for (cpu = 0; cpu < xyarray__max_x(evsel->fd); cpu++) {
        for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) {
            int fd = FD(evsel, cpu, thread),
                err = ioctl(fd, ioc, arg);

            if (err)
                return err;
        }
    }

    return 0;
}

int perf_evsel__apply_filter(struct perf_evsel *evsel, const char *filter)
{
    return perf_evsel__run_ioctl(evsel,
                     PERF_EVENT_IOC_SET_FILTER,
                     (void *)filter);
}

int perf_evsel__set_filter(struct perf_evsel *evsel, const char *filter)
{
    char *new_filter = strdup(filter);

    if (new_filter != NULL) {
        free(evsel->filter);
        evsel->filter = new_filter;
        return 0;
    }

    return -1;
}

static int perf_evsel__append_filter(struct perf_evsel *evsel,
                     const char *fmt, const char *filter)
{
    char *new_filter;

    if (evsel->filter == NULL)
        return perf_evsel__set_filter(evsel, filter);

    if (asprintf(&new_filter, fmt, evsel->filter, filter) > 0) {
        free(evsel->filter);
        evsel->filter = new_filter;
        return 0;
    }

    return -1;
}

int perf_evsel__append_tp_filter(struct perf_evsel *evsel, const char *filter)
{
    return perf_evsel__append_filter(evsel, "(%s) && (%s)", filter);
}

int perf_evsel__append_addr_filter(struct perf_evsel *evsel, const char *filter)
{
    return perf_evsel__append_filter(evsel, "%s,%s", filter);
}

int perf_evsel__enable(struct perf_evsel *evsel)
{
    return perf_evsel__run_ioctl(evsel,
                     PERF_EVENT_IOC_ENABLE,
                     0);
}

int perf_evsel__disable(struct perf_evsel *evsel)
{
    return perf_evsel__run_ioctl(evsel,
                     PERF_EVENT_IOC_DISABLE,
                     0);
}

int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
{
    if (ncpus == 0 || nthreads == 0)
        return 0;

    if (evsel->system_wide)
        nthreads = 1;

    evsel->sample_id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));
    if (evsel->sample_id == NULL)
        return -ENOMEM;

    evsel->id = zalloc(ncpus * nthreads * sizeof(u64));
    if (evsel->id == NULL) {
        xyarray__delete(evsel->sample_id);
        evsel->sample_id = NULL;
        return -ENOMEM;
    }

    return 0;
}

static void perf_evsel__free_fd(struct perf_evsel *evsel)
{
    xyarray__delete(evsel->fd);
    evsel->fd = NULL;
}

static void perf_evsel__free_id(struct perf_evsel *evsel)
{
    xyarray__delete(evsel->sample_id);
    evsel->sample_id = NULL;
    zfree(&evsel->id);
}

static void perf_evsel__free_config_terms(struct perf_evsel *evsel)
{
    struct perf_evsel_config_term *term, *h;

    list_for_each_entry_safe(term, h, &evsel->config_terms, list) {
        list_del(&term->list);
        free(term);
    }
}

void perf_evsel__close_fd(struct perf_evsel *evsel)
{
    int cpu, thread;

    for (cpu = 0; cpu < xyarray__max_x(evsel->fd); cpu++)
        for (thread = 0; thread < xyarray__max_y(evsel->fd); ++thread) {
            close(FD(evsel, cpu, thread));
            FD(evsel, cpu, thread) = -1;
        }
}

void perf_evsel__exit(struct perf_evsel *evsel)
{
    assert(list_empty(&evsel->node));
    assert(evsel->evlist == NULL);
    perf_evsel__free_fd(evsel);
    perf_evsel__free_id(evsel);
    perf_evsel__free_config_terms(evsel);
    cgroup__put(evsel->cgrp);
    cpu_map__put(evsel->cpus);
    cpu_map__put(evsel->own_cpus);
    thread_map__put(evsel->threads);
    zfree(&evsel->group_name);
    zfree(&evsel->name);
    perf_evsel__object.fini(evsel);
}

void perf_evsel__delete(struct perf_evsel *evsel)
{
    perf_evsel__exit(evsel);
    free(evsel);
}

void perf_evsel__compute_deltas(struct perf_evsel *evsel, int cpu, int thread,
                struct perf_counts_values *count)
{
    struct perf_counts_values tmp;

    if (!evsel->prev_raw_counts)
        return;

    if (cpu == -1) {
        tmp = evsel->prev_raw_counts->aggr;
        evsel->prev_raw_counts->aggr = *count;
    } else {
        tmp = *perf_counts(evsel->prev_raw_counts, cpu, thread);
        *perf_counts(evsel->prev_raw_counts, cpu, thread) = *count;
    }

    count->val = count->val - tmp.val;
    count->ena = count->ena - tmp.ena;
    count->run = count->run - tmp.run;
}

void perf_counts_values__scale(struct perf_counts_values *count,
                   bool scale, s8 *pscaled)
{
    s8 scaled = 0;

    if (scale) {
        if (count->run == 0) {
            scaled = -1;
            count->val = 0;
        } else if (count->run < count->ena) {
            scaled = 1;
            count->val = (u64)((double) count->val * count->ena / count->run + 0.5);
        }
    } else
        count->ena = count->run = 0;

    if (pscaled)
        *pscaled = scaled;
}

static int perf_evsel__read_size(struct perf_evsel *evsel)
{
    u64 read_format = evsel->attr.read_format;
    int entry = sizeof(u64); /* value */
    int size = 0;
    int nr = 1;

    if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
        size += sizeof(u64);

    if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
        size += sizeof(u64);

    if (read_format & PERF_FORMAT_ID)
        entry += sizeof(u64);

    if (read_format & PERF_FORMAT_GROUP) {
        nr = evsel->nr_members;
        size += sizeof(u64);
    }

    size += entry * nr;
    return size;
}

int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread,
             struct perf_counts_values *count)
{
    size_t size = perf_evsel__read_size(evsel);

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

    if (FD(evsel, cpu, thread) < 0)
        return -EINVAL;

    if (readn(FD(evsel, cpu, thread), count->values, size) <= 0)
        return -errno;

    return 0;
}

static int
perf_evsel__read_one(struct perf_evsel *evsel, int cpu, int thread)
{
    struct perf_counts_values *count = perf_counts(evsel->counts, cpu, thread);

    return perf_evsel__read(evsel, cpu, thread, count);
}

static void
perf_evsel__set_count(struct perf_evsel *counter, int cpu, int thread,
              u64 val, u64 ena, u64 run)
{
    struct perf_counts_values *count;

    count = perf_counts(counter->counts, cpu, thread);

    count->val    = val;
    count->ena    = ena;
    count->run    = run;
    count->loaded = true;
}

static int
perf_evsel__process_group_data(struct perf_evsel *leader,
                   int cpu, int thread, u64 *data)
{
    u64 read_format = leader->attr.read_format;
    struct sample_read_value *v;
    u64 nr, ena = 0, run = 0, i;

    nr = *data++;

    if (nr != (u64) leader->nr_members)
        return -EINVAL;

    if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
        ena = *data++;

    if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
        run = *data++;

    v = (struct sample_read_value *) data;

    perf_evsel__set_count(leader, cpu, thread,
                  v[0].value, ena, run);

    for (i = 1; i < nr; i++) {
        struct perf_evsel *counter;

        counter = perf_evlist__id2evsel(leader->evlist, v[i].id);
        if (!counter)
            return -EINVAL;

        perf_evsel__set_count(counter, cpu, thread,
                      v[i].value, ena, run);
    }

    return 0;
}

static int
perf_evsel__read_group(struct perf_evsel *leader, int cpu, int thread)
{
    struct perf_stat_evsel *ps = leader->stats;
    u64 read_format = leader->attr.read_format;
    int size = perf_evsel__read_size(leader);
    u64 *data = ps->group_data;

    if (!(read_format & PERF_FORMAT_ID))
        return -EINVAL;

    if (!perf_evsel__is_group_leader(leader))
        return -EINVAL;

    if (!data) {
        data = zalloc(size);
        if (!data)
            return -ENOMEM;

        ps->group_data = data;
    }

    if (FD(leader, cpu, thread) < 0)
        return -EINVAL;

    if (readn(FD(leader, cpu, thread), data, size) <= 0)
        return -errno;

    return perf_evsel__process_group_data(leader, cpu, thread, data);
}

int perf_evsel__read_counter(struct perf_evsel *evsel, int cpu, int thread)
{
    u64 read_format = evsel->attr.read_format;

    if (read_format & PERF_FORMAT_GROUP)
        return perf_evsel__read_group(evsel, cpu, thread);
    else
        return perf_evsel__read_one(evsel, cpu, thread);
}

int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
                  int cpu, int thread, bool scale)
{
    struct perf_counts_values count;
    size_t nv = scale ? 3 : 1;

    if (FD(evsel, cpu, thread) < 0)
        return -EINVAL;

    if (evsel->counts == NULL && perf_evsel__alloc_counts(evsel, cpu + 1, thread + 1) < 0)
        return -ENOMEM;

    if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) <= 0)
        return -errno;

    perf_evsel__compute_deltas(evsel, cpu, thread, &count);
    perf_counts_values__scale(&count, scale, NULL);
    *perf_counts(evsel->counts, cpu, thread) = count;
    return 0;
}

static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread)
{
    struct perf_evsel *leader = evsel->leader;
    int fd;

    if (perf_evsel__is_group_leader(evsel))
        return -1;

    /*
     * Leader must be already processed/open,
     * if not it's a bug.
     */
    BUG_ON(!leader->fd);

    fd = FD(leader, cpu, thread);
    BUG_ON(fd == -1);

    return fd;
}

struct bit_names {
    int bit;
    const char *name;
};

static void __p_bits(char *buf, size_t size, u64 value, struct bit_names *bits)
{
    bool first_bit = true;
    int i = 0;

    do {
        if (value & bits[i].bit) {
            buf += scnprintf(buf, size, "%s%s", first_bit ? "" : "|", bits[i].name);
            first_bit = false;
        }
    } while (bits[++i].name != NULL);
}

static void __p_sample_type(char *buf, size_t size, u64 value)
{
#define bit_name(n) { PERF_SAMPLE_##n, #n }
    struct bit_names bits[] = {
        bit_name(IP), bit_name(TID), bit_name(TIME), bit_name(ADDR),
        bit_name(READ), bit_name(CALLCHAIN), bit_name(ID), bit_name(CPU),
        bit_name(PERIOD), bit_name(STREAM_ID), bit_name(RAW),
        bit_name(BRANCH_STACK), bit_name(REGS_USER), bit_name(STACK_USER),
        bit_name(IDENTIFIER), bit_name(REGS_INTR), bit_name(DATA_SRC),
        bit_name(WEIGHT), bit_name(PHYS_ADDR),
        { .name = NULL, }
    };
#undef bit_name
    __p_bits(buf, size, value, bits);
}

static void __p_branch_sample_type(char *buf, size_t size, u64 value)
{
#define bit_name(n) { PERF_SAMPLE_BRANCH_##n, #n }
    struct bit_names bits[] = {
        bit_name(USER), bit_name(KERNEL), bit_name(HV), bit_name(ANY),
        bit_name(ANY_CALL), bit_name(ANY_RETURN), bit_name(IND_CALL),
        bit_name(ABORT_TX), bit_name(IN_TX), bit_name(NO_TX),
        bit_name(COND), bit_name(CALL_STACK), bit_name(IND_JUMP),
        bit_name(CALL), bit_name(NO_FLAGS), bit_name(NO_CYCLES),
        { .name = NULL, }
    };
#undef bit_name
    __p_bits(buf, size, value, bits);
}

static void __p_read_format(char *buf, size_t size, u64 value)
{
#define bit_name(n) { PERF_FORMAT_##n, #n }
    struct bit_names bits[] = {
        bit_name(TOTAL_TIME_ENABLED), bit_name(TOTAL_TIME_RUNNING),
        bit_name(ID), bit_name(GROUP),
        { .name = NULL, }
    };
#undef bit_name
    __p_bits(buf, size, value, bits);
}

#define BUF_SIZE        1024

#define p_hex(val)      snprintf(buf, BUF_SIZE, "%#"PRIx64, (uint64_t)(val))
#define p_unsigned(val)     snprintf(buf, BUF_SIZE, "%"PRIu64, (uint64_t)(val))
#define p_signed(val)       snprintf(buf, BUF_SIZE, "%"PRId64, (int64_t)(val))
#define p_sample_type(val)  __p_sample_type(buf, BUF_SIZE, val)
#define p_branch_sample_type(val) __p_branch_sample_type(buf, BUF_SIZE, val)
#define p_read_format(val)  __p_read_format(buf, BUF_SIZE, val)

#define PRINT_ATTRn(_n, _f, _p)             \
do {                            \
    if (attr->_f) {                 \
        _p(attr->_f);               \
        ret += attr__fprintf(fp, _n, buf, priv);\
    }                       \
} while (0)

#define PRINT_ATTRf(_f, _p) PRINT_ATTRn(#_f, _f, _p)

int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
                 attr__fprintf_f attr__fprintf, void *priv)
{
    char buf[BUF_SIZE];
    int ret = 0;

    PRINT_ATTRf(type, p_unsigned);
    PRINT_ATTRf(size, p_unsigned);
    PRINT_ATTRf(config, p_hex);
    PRINT_ATTRn("{ sample_period, sample_freq }", sample_period, p_unsigned);
    PRINT_ATTRf(sample_type, p_sample_type);
    PRINT_ATTRf(read_format, p_read_format);

    PRINT_ATTRf(disabled, p_unsigned);
    PRINT_ATTRf(inherit, p_unsigned);
    PRINT_ATTRf(pinned, p_unsigned);
    PRINT_ATTRf(exclusive, p_unsigned);
    PRINT_ATTRf(exclude_user, p_unsigned);
    PRINT_ATTRf(exclude_kernel, p_unsigned);
    PRINT_ATTRf(exclude_hv, p_unsigned);
    PRINT_ATTRf(exclude_idle, p_unsigned);
    PRINT_ATTRf(mmap, p_unsigned);
    PRINT_ATTRf(comm, p_unsigned);
    PRINT_ATTRf(freq, p_unsigned);
    PRINT_ATTRf(inherit_stat, p_unsigned);
    PRINT_ATTRf(enable_on_exec, p_unsigned);
    PRINT_ATTRf(task, p_unsigned);
    PRINT_ATTRf(watermark, p_unsigned);
    PRINT_ATTRf(precise_ip, p_unsigned);
    PRINT_ATTRf(mmap_data, p_unsigned);
    PRINT_ATTRf(sample_id_all, p_unsigned);
    PRINT_ATTRf(exclude_host, p_unsigned);
    PRINT_ATTRf(exclude_guest, p_unsigned);
    PRINT_ATTRf(exclude_callchain_kernel, p_unsigned);
    PRINT_ATTRf(exclude_callchain_user, p_unsigned);
    PRINT_ATTRf(mmap2, p_unsigned);
    PRINT_ATTRf(comm_exec, p_unsigned);
    PRINT_ATTRf(use_clockid, p_unsigned);
    PRINT_ATTRf(context_switch, p_unsigned);
    PRINT_ATTRf(write_backward, p_unsigned);
    PRINT_ATTRf(namespaces, p_unsigned);

    PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned);
    PRINT_ATTRf(bp_type, p_unsigned);
    PRINT_ATTRn("{ bp_addr, config1 }", bp_addr, p_hex);
    PRINT_ATTRn("{ bp_len, config2 }", bp_len, p_hex);
    PRINT_ATTRf(branch_sample_type, p_branch_sample_type);
    PRINT_ATTRf(sample_regs_user, p_hex);
    PRINT_ATTRf(sample_stack_user, p_unsigned);
    PRINT_ATTRf(clockid, p_signed);
    PRINT_ATTRf(sample_regs_intr, p_hex);
    PRINT_ATTRf(aux_watermark, p_unsigned);
    PRINT_ATTRf(sample_max_stack, p_unsigned);

    return ret;
}

static int __open_attr__fprintf(FILE *fp, const char *name, const char *val,
                void *priv __maybe_unused)
{
    return fprintf(fp, "  %-32s %s\n", name, val);
}

static void perf_evsel__remove_fd(struct perf_evsel *pos,
                  int nr_cpus, int nr_threads,
                  int thread_idx)
{
    for (int cpu = 0; cpu < nr_cpus; cpu++)
        for (int thread = thread_idx; thread < nr_threads - 1; thread++)
            FD(pos, cpu, thread) = FD(pos, cpu, thread + 1);
}

static int update_fds(struct perf_evsel *evsel,
              int nr_cpus, int cpu_idx,
              int nr_threads, int thread_idx)
{
    struct perf_evsel *pos;

    if (cpu_idx >= nr_cpus || thread_idx >= nr_threads)
        return -EINVAL;

    evlist__for_each_entry(evsel->evlist, pos) {
        nr_cpus = pos != evsel ? nr_cpus : cpu_idx;

        perf_evsel__remove_fd(pos, nr_cpus, nr_threads, thread_idx);

        /*
         * Since fds for next evsel has not been created,
         * there is no need to iterate whole event list.
         */
        if (pos == evsel)
            break;
    }
    return 0;
}

static bool ignore_missing_thread(struct perf_evsel *evsel,
                  int nr_cpus, int cpu,
                  struct thread_map *threads,
                  int thread, int err)
{
    pid_t ignore_pid = thread_map__pid(threads, thread);

    if (!evsel->ignore_missing_thread)
        return false;

    /* The system wide setup does not work with threads. */
    if (evsel->system_wide)
        return false;

    /* The -ESRCH is perf event syscall errno for pid's not found. */
    if (err != -ESRCH)
        return false;

    /* If there's only one thread, let it fail. */
    if (threads->nr == 1)
        return false;

    /*
     * We should remove fd for missing_thread first
     * because thread_map__remove() will decrease threads->nr.
     */
    if (update_fds(evsel, nr_cpus, cpu, threads->nr, thread))
        return false;

    if (thread_map__remove(threads, thread))
        return false;

    pr_warning("WARNING: Ignored open failure for pid %d\n",
           ignore_pid);
    return true;
}

int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
             struct thread_map *threads)
{
    int cpu, thread, nthreads;
    unsigned long flags = PERF_FLAG_FD_CLOEXEC;
    int pid = -1, err;
    enum { NO_CHANGE, SET_TO_MAX, INCREASED_MAX } set_rlimit = NO_CHANGE;

    if (perf_missing_features.write_backward && evsel->attr.write_backward)
        return -EINVAL;

    if (cpus == NULL) {
        static struct cpu_map *empty_cpu_map;

        if (empty_cpu_map == NULL) {
            empty_cpu_map = cpu_map__dummy_new();
            if (empty_cpu_map == NULL)
                return -ENOMEM;
        }

        cpus = empty_cpu_map;
    }

    if (threads == NULL) {
        static struct thread_map *empty_thread_map;

        if (empty_thread_map == NULL) {
            empty_thread_map = thread_map__new_by_tid(-1);
            if (empty_thread_map == NULL)
                return -ENOMEM;
        }

        threads = empty_thread_map;
    }

    if (evsel->system_wide)
        nthreads = 1;
    else
        nthreads = threads->nr;

    if (evsel->fd == NULL &&
        perf_evsel__alloc_fd(evsel, cpus->nr, nthreads) < 0)
        return -ENOMEM;

    if (evsel->cgrp) {
        flags |= PERF_FLAG_PID_CGROUP;
        pid = evsel->cgrp->fd;
    }

fallback_missing_features:
    if (perf_missing_features.clockid_wrong)
        evsel->attr.clockid = CLOCK_MONOTONIC; /* should always work */
    if (perf_missing_features.clockid) {
        evsel->attr.use_clockid = 0;
        evsel->attr.clockid = 0;
    }
    if (perf_missing_features.cloexec)
        flags &= ~(unsigned long)PERF_FLAG_FD_CLOEXEC;
    if (perf_missing_features.mmap2)
        evsel->attr.mmap2 = 0;
    if (perf_missing_features.exclude_guest)
        evsel->attr.exclude_guest = evsel->attr.exclude_host = 0;
    if (perf_missing_features.lbr_flags)
        evsel->attr.branch_sample_type &= ~(PERF_SAMPLE_BRANCH_NO_FLAGS |
                     PERF_SAMPLE_BRANCH_NO_CYCLES);
    if (perf_missing_features.group_read && evsel->attr.inherit)
        evsel->attr.read_format &= ~(PERF_FORMAT_GROUP|PERF_FORMAT_ID);
retry_sample_id:
    if (perf_missing_features.sample_id_all)
        evsel->attr.sample_id_all = 0;

    if (verbose >= 2) {
        fprintf(stderr, "%.60s\n", graph_dotted_line);
        fprintf(stderr, "perf_event_attr:\n");
        perf_event_attr__fprintf(stderr, &evsel->attr, __open_attr__fprintf, NULL);
        fprintf(stderr, "%.60s\n", graph_dotted_line);
    }

    for (cpu = 0; cpu < cpus->nr; cpu++) {

        for (thread = 0; thread < nthreads; thread++) {
            int fd, group_fd;

            if (!evsel->cgrp && !evsel->system_wide)
                pid = thread_map__pid(threads, thread);

            group_fd = get_group_fd(evsel, cpu, thread);
retry_open:
            pr_debug2("sys_perf_event_open: pid %d  cpu %d  group_fd %d  flags %#lx",
                  pid, cpus->map[cpu], group_fd, flags);

            test_attr__ready();

            fd = sys_perf_event_open(&evsel->attr, pid, cpus->map[cpu],
                         group_fd, flags);

            FD(evsel, cpu, thread) = fd;

            if (fd < 0) {
                err = -errno;

                if (ignore_missing_thread(evsel, cpus->nr, cpu, threads, thread, err)) {
                    /*
                     * We just removed 1 thread, so take a step
                     * back on thread index and lower the upper
                     * nthreads limit.
                     */
                    nthreads--;
                    thread--;

                    /* ... and pretend like nothing have happened. */
                    err = 0;
                    continue;
                }

                pr_debug2("\nsys_perf_event_open failed, error %d\n",
                      err);
                goto try_fallback;
            }

            pr_debug2(" = %d\n", fd);

            if (evsel->bpf_fd >= 0) {
                int evt_fd = fd;
                int bpf_fd = evsel->bpf_fd;

                err = ioctl(evt_fd,
                        PERF_EVENT_IOC_SET_BPF,
                        bpf_fd);
                if (err && errno != EEXIST) {
                    pr_err("failed to attach bpf fd %d: %s\n",
                           bpf_fd, strerror(errno));
                    err = -EINVAL;
                    goto out_close;
                }
            }

            set_rlimit = NO_CHANGE;

            /*
             * If we succeeded but had to kill clockid, fail and
             * have perf_evsel__open_strerror() print us a nice
             * error.
             */
            if (perf_missing_features.clockid ||
                perf_missing_features.clockid_wrong) {
                err = -EINVAL;
                goto out_close;
            }
        }
    }

    return 0;

try_fallback:
    /*
     * perf stat needs between 5 and 22 fds per CPU. When we run out
     * of them try to increase the limits.
     */
    if (err == -EMFILE && set_rlimit < INCREASED_MAX) {
        struct rlimit l;
        int old_errno = errno;

        if (getrlimit(RLIMIT_NOFILE, &l) == 0) {
            if (set_rlimit == NO_CHANGE)
                l.rlim_cur = l.rlim_max;
            else {
                l.rlim_cur = l.rlim_max + 1000;
                l.rlim_max = l.rlim_cur;
            }
            if (setrlimit(RLIMIT_NOFILE, &l) == 0) {
                set_rlimit++;
                errno = old_errno;
                goto retry_open;
            }
        }
        errno = old_errno;
    }

    if (err != -EINVAL || cpu > 0 || thread > 0)
        goto out_close;

    /*
     * Must probe features in the order they were added to the
     * perf_event_attr interface.
     */
    if (!perf_missing_features.write_backward && evsel->attr.write_backward) {
        perf_missing_features.write_backward = true;
        pr_debug2("switching off write_backward\n");
        goto out_close;
    } else if (!perf_missing_features.clockid_wrong && evsel->attr.use_clockid) {
        perf_missing_features.clockid_wrong = true;
        pr_debug2("switching off clockid\n");
        goto fallback_missing_features;
    } else if (!perf_missing_features.clockid && evsel->attr.use_clockid) {
        perf_missing_features.clockid = true;
        pr_debug2("switching off use_clockid\n");
        goto fallback_missing_features;
    } else if (!perf_missing_features.cloexec && (flags & PERF_FLAG_FD_CLOEXEC)) {
        perf_missing_features.cloexec = true;
        pr_debug2("switching off cloexec flag\n");
        goto fallback_missing_features;
    } else if (!perf_missing_features.mmap2 && evsel->attr.mmap2) {
        perf_missing_features.mmap2 = true;
        pr_debug2("switching off mmap2\n");
        goto fallback_missing_features;
    } else if (!perf_missing_features.exclude_guest &&
           (evsel->attr.exclude_guest || evsel->attr.exclude_host)) {
        perf_missing_features.exclude_guest = true;
        pr_debug2("switching off exclude_guest, exclude_host\n");
        goto fallback_missing_features;
    } else if (!perf_missing_features.sample_id_all) {
        perf_missing_features.sample_id_all = true;
        pr_debug2("switching off sample_id_all\n");
        goto retry_sample_id;
    } else if (!perf_missing_features.lbr_flags &&
            (evsel->attr.branch_sample_type &
             (PERF_SAMPLE_BRANCH_NO_CYCLES |
              PERF_SAMPLE_BRANCH_NO_FLAGS))) {
        perf_missing_features.lbr_flags = true;
        pr_debug2("switching off branch sample type no (cycles/flags)\n");
        goto fallback_missing_features;
    } else if (!perf_missing_features.group_read &&
            evsel->attr.inherit &&
           (evsel->attr.read_format & PERF_FORMAT_GROUP) &&
           perf_evsel__is_group_leader(evsel)) {
        perf_missing_features.group_read = true;
        pr_debug2("switching off group read\n");
        goto fallback_missing_features;
    }
out_close:
    if (err)
        threads->err_thread = thread;

    do {
        while (--thread >= 0) {
            close(FD(evsel, cpu, thread));
            FD(evsel, cpu, thread) = -1;
        }
        thread = nthreads;
    } while (--cpu >= 0);
    return err;
}

void perf_evsel__close(struct perf_evsel *evsel)
{
    if (evsel->fd == NULL)
        return;

    perf_evsel__close_fd(evsel);
    perf_evsel__free_fd(evsel);
}

int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
                 struct cpu_map *cpus)
{
    return perf_evsel__open(evsel, cpus, NULL);
}

int perf_evsel__open_per_thread(struct perf_evsel *evsel,
                struct thread_map *threads)
{
    return perf_evsel__open(evsel, NULL, threads);
}

static int perf_evsel__parse_id_sample(const struct perf_evsel *evsel,
                       const union perf_event *event,
                       struct perf_sample *sample)
{
    u64 type = evsel->attr.sample_type;
    const u64 *array = event->sample.array;
    bool swapped = evsel->needs_swap;
    union u64_swap u;

    array += ((event->header.size -
           sizeof(event->header)) / sizeof(u64)) - 1;

    if (type & PERF_SAMPLE_IDENTIFIER) {
        sample->id = *array;
        array--;
    }

    if (type & PERF_SAMPLE_CPU) {
        u.val64 = *array;
        if (swapped) {
            /* undo swap of u64, then swap on individual u32s */
            u.val64 = bswap_64(u.val64);
            u.val32[0] = bswap_32(u.val32[0]);
        }

        sample->cpu = u.val32[0];
        array--;
    }

    if (type & PERF_SAMPLE_STREAM_ID) {
        sample->stream_id = *array;
        array--;
    }

    if (type & PERF_SAMPLE_ID) {
        sample->id = *array;
        array--;
    }

    if (type & PERF_SAMPLE_TIME) {
        sample->time = *array;
        array--;
    }

    if (type & PERF_SAMPLE_TID) {
        u.val64 = *array;
        if (swapped) {
            /* undo swap of u64, then swap on individual u32s */
            u.val64 = bswap_64(u.val64);
            u.val32[0] = bswap_32(u.val32[0]);
            u.val32[1] = bswap_32(u.val32[1]);
        }

        sample->pid = u.val32[0];
        sample->tid = u.val32[1];
        array--;
    }

    return 0;
}

static inline bool overflow(const void *endp, u16 max_size, const void *offset,
                u64 size)
{
    return size > max_size || offset + size > endp;
}

#define OVERFLOW_CHECK(offset, size, max_size)              \
    do {                                \
        if (overflow(endp, (max_size), (offset), (size)))   \
            return -EFAULT;                 \
    } while (0)

#define OVERFLOW_CHECK_u64(offset) \
    OVERFLOW_CHECK(offset, sizeof(u64), sizeof(u64))

static int
perf_event__check_size(union perf_event *event, unsigned int sample_size)
{
    /*
     * The evsel's sample_size is based on PERF_SAMPLE_MASK which includes
     * up to PERF_SAMPLE_PERIOD.  After that overflow() must be used to
     * check the format does not go past the end of the event.
     */
    if (sample_size + sizeof(event->header) > event->header.size)
        return -EFAULT;

    return 0;
}

int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
                 struct perf_sample *data)
{
    u64 type = evsel->attr.sample_type;
    bool swapped = evsel->needs_swap;
    const u64 *array;
    u16 max_size = event->header.size;
    const void *endp = (void *)event + max_size;
    u64 sz;

    /*
     * used for cross-endian analysis. See git commit 65014ab3
     * for why this goofiness is needed.
     */
    union u64_swap u;

    memset(data, 0, sizeof(*data));
    data->cpu = data->pid = data->tid = -1;
    data->stream_id = data->id = data->time = -1ULL;
    data->period = evsel->attr.sample_period;
    data->cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
    data->misc    = event->header.misc;
    data->id = -1ULL;
    data->data_src = PERF_MEM_DATA_SRC_NONE;

    if (event->header.type != PERF_RECORD_SAMPLE) {
        if (!evsel->attr.sample_id_all)
            return 0;
        return perf_evsel__parse_id_sample(evsel, event, data);
    }

    array = event->sample.array;

    if (perf_event__check_size(event, evsel->sample_size))
        return -EFAULT;

    if (type & PERF_SAMPLE_IDENTIFIER) {
        data->id = *array;
        array++;
    }

    if (type & PERF_SAMPLE_IP) {
        data->ip = *array;
        array++;
    }

    if (type & PERF_SAMPLE_TID) {
        u.val64 = *array;
        if (swapped) {
            /* undo swap of u64, then swap on individual u32s */
            u.val64 = bswap_64(u.val64);
            u.val32[0] = bswap_32(u.val32[0]);
            u.val32[1] = bswap_32(u.val32[1]);
        }

        data->pid = u.val32[0];
        data->tid = u.val32[1];
        array++;
    }

    if (type & PERF_SAMPLE_TIME) {
        data->time = *array;
        array++;
    }

    if (type & PERF_SAMPLE_ADDR) {
        data->addr = *array;
        array++;
    }

    if (type & PERF_SAMPLE_ID) {
        data->id = *array;
        array++;
    }

    if (type & PERF_SAMPLE_STREAM_ID) {
        data->stream_id = *array;
        array++;
    }

    if (type & PERF_SAMPLE_CPU) {

        u.val64 = *array;
        if (swapped) {
            /* undo swap of u64, then swap on individual u32s */
            u.val64 = bswap_64(u.val64);
            u.val32[0] = bswap_32(u.val32[0]);
        }

        data->cpu = u.val32[0];
        array++;
    }

    if (type & PERF_SAMPLE_PERIOD) {
        data->period = *array;
        array++;
    }

    if (type & PERF_SAMPLE_READ) {
        u64 read_format = evsel->attr.read_format;

        OVERFLOW_CHECK_u64(array);
        if (read_format & PERF_FORMAT_GROUP)
            data->read.group.nr = *array;
        else
            data->read.one.value = *array;

        array++;

        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
            OVERFLOW_CHECK_u64(array);
            data->read.time_enabled = *array;
            array++;
        }

        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
            OVERFLOW_CHECK_u64(array);
            data->read.time_running = *array;
            array++;
        }

        /* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
        if (read_format & PERF_FORMAT_GROUP) {
            const u64 max_group_nr = UINT64_MAX /
                    sizeof(struct sample_read_value);

            if (data->read.group.nr > max_group_nr)
                return -EFAULT;
            sz = data->read.group.nr *
                 sizeof(struct sample_read_value);
            OVERFLOW_CHECK(array, sz, max_size);
            data->read.group.values =
                    (struct sample_read_value *)array;
            array = (void *)array + sz;
        } else {
            OVERFLOW_CHECK_u64(array);
            data->read.one.id = *array;
            array++;
        }
    }

    if (evsel__has_callchain(evsel)) {
        const u64 max_callchain_nr = UINT64_MAX / sizeof(u64);

        OVERFLOW_CHECK_u64(array);
        data->callchain = (struct ip_callchain *)array++;
        if (data->callchain->nr > max_callchain_nr)
            return -EFAULT;
        sz = data->callchain->nr * sizeof(u64);
        OVERFLOW_CHECK(array, sz, max_size);
        array = (void *)array + sz;
    }

    if (type & PERF_SAMPLE_RAW) {
        OVERFLOW_CHECK_u64(array);
        u.val64 = *array;

        /*
         * Undo swap of u64, then swap on individual u32s,
         * get the size of the raw area and undo all of the
         * swap. The pevent interface handles endianity by
         * itself.
         */
        if (swapped) {
            u.val64 = bswap_64(u.val64);
            u.val32[0] = bswap_32(u.val32[0]);
            u.val32[1] = bswap_32(u.val32[1]);
        }
        data->raw_size = u.val32[0];

        /*
         * The raw data is aligned on 64bits including the
         * u32 size, so it's safe to use mem_bswap_64.
         */
        if (swapped)
            mem_bswap_64((void *) array, data->raw_size);

        array = (void *)array + sizeof(u32);

        OVERFLOW_CHECK(array, data->raw_size, max_size);
        data->raw_data = (void *)array;
        array = (void *)array + data->raw_size;
    }

    if (type & PERF_SAMPLE_BRANCH_STACK) {
        const u64 max_branch_nr = UINT64_MAX /
                      sizeof(struct branch_entry);

        OVERFLOW_CHECK_u64(array);
        data->branch_stack = (struct branch_stack *)array++;

        if (data->branch_stack->nr > max_branch_nr)
            return -EFAULT;
        sz = data->branch_stack->nr * sizeof(struct branch_entry);
        OVERFLOW_CHECK(array, sz, max_size);
        array = (void *)array + sz;
    }

    if (type & PERF_SAMPLE_REGS_USER) {
        OVERFLOW_CHECK_u64(array);
        data->user_regs.abi = *array;
        array++;

        if (data->user_regs.abi) {
            u64 mask = evsel->attr.sample_regs_user;

            sz = hweight_long(mask) * sizeof(u64);
            OVERFLOW_CHECK(array, sz, max_size);
            data->user_regs.mask = mask;
            data->user_regs.regs = (u64 *)array;
            array = (void *)array + sz;
        }
    }

    if (type & PERF_SAMPLE_STACK_USER) {
        OVERFLOW_CHECK_u64(array);
        sz = *array++;

        data->user_stack.offset = ((char *)(array - 1)
                      - (char *) event);

        if (!sz) {
            data->user_stack.size = 0;
        } else {
            OVERFLOW_CHECK(array, sz, max_size);
            data->user_stack.data = (char *)array;
            array = (void *)array + sz;
            OVERFLOW_CHECK_u64(array);
            data->user_stack.size = *array++;
            if (WARN_ONCE(data->user_stack.size > sz,
                      "user stack dump failure\n"))
                return -EFAULT;
        }
    }

    if (type & PERF_SAMPLE_WEIGHT) {
        OVERFLOW_CHECK_u64(array);
        data->weight = *array;
        array++;
    }

    if (type & PERF_SAMPLE_DATA_SRC) {
        OVERFLOW_CHECK_u64(array);
        data->data_src = *array;
        array++;
    }

    if (type & PERF_SAMPLE_TRANSACTION) {
        OVERFLOW_CHECK_u64(array);
        data->transaction = *array;
        array++;
    }

    data->intr_regs.abi = PERF_SAMPLE_REGS_ABI_NONE;
    if (type & PERF_SAMPLE_REGS_INTR) {
        OVERFLOW_CHECK_u64(array);
        data->intr_regs.abi = *array;
        array++;

        if (data->intr_regs.abi != PERF_SAMPLE_REGS_ABI_NONE) {
            u64 mask = evsel->attr.sample_regs_intr;

            sz = hweight_long(mask) * sizeof(u64);
            OVERFLOW_CHECK(array, sz, max_size);
            data->intr_regs.mask = mask;
            data->intr_regs.regs = (u64 *)array;
            array = (void *)array + sz;
        }
    }

    data->phys_addr = 0;
    if (type & PERF_SAMPLE_PHYS_ADDR) {
        data->phys_addr = *array;
        array++;
    }

    return 0;
}

int perf_evsel__parse_sample_timestamp(struct perf_evsel *evsel,
                       union perf_event *event,
                       u64 *timestamp)
{
    u64 type = evsel->attr.sample_type;
    const u64 *array;

    if (!(type & PERF_SAMPLE_TIME))
        return -1;

    if (event->header.type != PERF_RECORD_SAMPLE) {
        struct perf_sample data = {
            .time = -1ULL,
        };

        if (!evsel->attr.sample_id_all)
            return -1;
        if (perf_evsel__parse_id_sample(evsel, event, &data))
            return -1;

        *timestamp = data.time;
        return 0;
    }

    array = event->sample.array;

    if (perf_event__check_size(event, evsel->sample_size))
        return -EFAULT;

    if (type & PERF_SAMPLE_IDENTIFIER)
        array++;

    if (type & PERF_SAMPLE_IP)
        array++;

    if (type & PERF_SAMPLE_TID)
        array++;

    if (type & PERF_SAMPLE_TIME)
        *timestamp = *array;

    return 0;
}

size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type,
                     u64 read_format)
{
    size_t sz, result = sizeof(struct sample_event);

    if (type & PERF_SAMPLE_IDENTIFIER)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_IP)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_TID)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_TIME)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_ADDR)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_ID)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_STREAM_ID)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_CPU)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_PERIOD)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_READ) {
        result += sizeof(u64);
        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
            result += sizeof(u64);
        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
            result += sizeof(u64);
        /* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
        if (read_format & PERF_FORMAT_GROUP) {
            sz = sample->read.group.nr *
                 sizeof(struct sample_read_value);
            result += sz;
        } else {
            result += sizeof(u64);
        }
    }

    if (type & PERF_SAMPLE_CALLCHAIN) {
        sz = (sample->callchain->nr + 1) * sizeof(u64);
        result += sz;
    }

    if (type & PERF_SAMPLE_RAW) {
        result += sizeof(u32);
        result += sample->raw_size;
    }

    if (type & PERF_SAMPLE_BRANCH_STACK) {
        sz = sample->branch_stack->nr * sizeof(struct branch_entry);
        sz += sizeof(u64);
        result += sz;
    }

    if (type & PERF_SAMPLE_REGS_USER) {
        if (sample->user_regs.abi) {
            result += sizeof(u64);
            sz = hweight_long(sample->user_regs.mask) * sizeof(u64);
            result += sz;
        } else {
            result += sizeof(u64);
        }
    }

    if (type & PERF_SAMPLE_STACK_USER) {
        sz = sample->user_stack.size;
        result += sizeof(u64);
        if (sz) {
            result += sz;
            result += sizeof(u64);
        }
    }

    if (type & PERF_SAMPLE_WEIGHT)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_DATA_SRC)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_TRANSACTION)
        result += sizeof(u64);

    if (type & PERF_SAMPLE_REGS_INTR) {
        if (sample->intr_regs.abi) {
            result += sizeof(u64);
            sz = hweight_long(sample->intr_regs.mask) * sizeof(u64);
            result += sz;
        } else {
            result += sizeof(u64);
        }
    }

    if (type & PERF_SAMPLE_PHYS_ADDR)
        result += sizeof(u64);

    return result;
}

int perf_event__synthesize_sample(union perf_event *event, u64 type,
                  u64 read_format,
                  const struct perf_sample *sample)
{
    u64 *array;
    size_t sz;
    /*
     * used for cross-endian analysis. See git commit 65014ab3
     * for why this goofiness is needed.
     */
    union u64_swap u;

    array = event->sample.array;

    if (type & PERF_SAMPLE_IDENTIFIER) {
        *array = sample->id;
        array++;
    }

    if (type & PERF_SAMPLE_IP) {
        *array = sample->ip;
        array++;
    }

    if (type & PERF_SAMPLE_TID) {
        u.val32[0] = sample->pid;
        u.val32[1] = sample->tid;
        *array = u.val64;
        array++;
    }

    if (type & PERF_SAMPLE_TIME) {
        *array = sample->time;
        array++;
    }

    if (type & PERF_SAMPLE_ADDR) {
        *array = sample->addr;
        array++;
    }

    if (type & PERF_SAMPLE_ID) {
        *array = sample->id;
        array++;
    }

    if (type & PERF_SAMPLE_STREAM_ID) {
        *array = sample->stream_id;
        array++;
    }

    if (type & PERF_SAMPLE_CPU) {
        u.val32[0] = sample->cpu;
        u.val32[1] = 0;
        *array = u.val64;
        array++;
    }

    if (type & PERF_SAMPLE_PERIOD) {
        *array = sample->period;
        array++;
    }

    if (type & PERF_SAMPLE_READ) {
        if (read_format & PERF_FORMAT_GROUP)
            *array = sample->read.group.nr;
        else
            *array = sample->read.one.value;
        array++;

        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
            *array = sample->read.time_enabled;
            array++;
        }

        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
            *array = sample->read.time_running;
            array++;
        }

        /* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
        if (read_format & PERF_FORMAT_GROUP) {
            sz = sample->read.group.nr *
                 sizeof(struct sample_read_value);
            memcpy(array, sample->read.group.values, sz);
            array = (void *)array + sz;
        } else {
            *array = sample->read.one.id;
            array++;
        }
    }

    if (type & PERF_SAMPLE_CALLCHAIN) {
        sz = (sample->callchain->nr + 1) * sizeof(u64);
        memcpy(array, sample->callchain, sz);
        array = (void *)array + sz;
    }

    if (type & PERF_SAMPLE_RAW) {
        u.val32[0] = sample->raw_size;
        *array = u.val64;
        array = (void *)array + sizeof(u32);

        memcpy(array, sample->raw_data, sample->raw_size);
        array = (void *)array + sample->raw_size;
    }

    if (type & PERF_SAMPLE_BRANCH_STACK) {
        sz = sample->branch_stack->nr * sizeof(struct branch_entry);
        sz += sizeof(u64);
        memcpy(array, sample->branch_stack, sz);
        array = (void *)array + sz;
    }

    if (type & PERF_SAMPLE_REGS_USER) {
        if (sample->user_regs.abi) {
            *array++ = sample->user_regs.abi;
            sz = hweight_long(sample->user_regs.mask) * sizeof(u64);
            memcpy(array, sample->user_regs.regs, sz);
            array = (void *)array + sz;
        } else {
            *array++ = 0;
        }
    }

    if (type & PERF_SAMPLE_STACK_USER) {
        sz = sample->user_stack.size;
        *array++ = sz;
        if (sz) {
            memcpy(array, sample->user_stack.data, sz);
            array = (void *)array + sz;
            *array++ = sz;
        }
    }

    if (type & PERF_SAMPLE_WEIGHT) {
        *array = sample->weight;
        array++;
    }

    if (type & PERF_SAMPLE_DATA_SRC) {
        *array = sample->data_src;
        array++;
    }

    if (type & PERF_SAMPLE_TRANSACTION) {
        *array = sample->transaction;
        array++;
    }

    if (type & PERF_SAMPLE_REGS_INTR) {
        if (sample->intr_regs.abi) {
            *array++ = sample->intr_regs.abi;
            sz = hweight_long(sample->intr_regs.mask) * sizeof(u64);
            memcpy(array, sample->intr_regs.regs, sz);
            array = (void *)array + sz;
        } else {
            *array++ = 0;
        }
    }

    if (type & PERF_SAMPLE_PHYS_ADDR) {
        *array = sample->phys_addr;
        array++;
    }

    return 0;
}

struct format_field *perf_evsel__field(struct perf_evsel *evsel, const char *name)
{
    return pevent_find_field(evsel->tp_format, name);
}

void *perf_evsel__rawptr(struct perf_evsel *evsel, struct perf_sample *sample,
             const char *name)
{
    struct format_field *field = perf_evsel__field(evsel, name);
    int offset;

    if (!field)
        return NULL;

    offset = field->offset;

    if (field->flags & FIELD_IS_DYNAMIC) {
        offset = *(int *)(sample->raw_data + field->offset);
        offset &= 0xffff;
    }

    return sample->raw_data + offset;
}

u64 format_field__intval(struct format_field *field, struct perf_sample *sample,
             bool needs_swap)
{
    u64 value;
    void *ptr = sample->raw_data + field->offset;

    switch (field->size) {
    case 1:
        return *(u8 *)ptr;
    case 2:
        value = *(u16 *)ptr;
        break;
    case 4:
        value = *(u32 *)ptr;
        break;
    case 8:
        memcpy(&value, ptr, sizeof(u64));
        break;
    default:
        return 0;
    }

    if (!needs_swap)
        return value;

    switch (field->size) {
    case 2:
        return bswap_16(value);
    case 4:
        return bswap_32(value);
    case 8:
        return bswap_64(value);
    default:
        return 0;
    }

    return 0;
}

u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
               const char *name)
{
    struct format_field *field = perf_evsel__field(evsel, name);

    if (!field)
        return 0;

    return field ? format_field__intval(field, sample, evsel->needs_swap) : 0;
}

bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
              char *msg, size_t msgsize)
{
    int paranoid;

    if ((err == ENOENT || err == ENXIO || err == ENODEV) &&
        evsel->attr.type   == PERF_TYPE_HARDWARE &&
        evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
        /*
         * If it's cycles then fall back to hrtimer based
         * cpu-clock-tick sw counter, which is always available even if
         * no PMU support.
         *
         * PPC returns ENXIO until 2.6.37 (behavior changed with commit
         * b0a873e).
         */
        scnprintf(msg, msgsize, "%s",
"The cycles event is not supported, trying to fall back to cpu-clock-ticks");

        evsel->attr.type   = PERF_TYPE_SOFTWARE;
        evsel->attr.config = PERF_COUNT_SW_CPU_CLOCK;

        zfree(&evsel->name);
        return true;
    } else if (err == EACCES && !evsel->attr.exclude_kernel &&
           (paranoid = perf_event_paranoid()) > 1) {
        const char *name = perf_evsel__name(evsel);
        char *new_name;
        const char *sep = ":";

        /* Is there already the separator in the name. */
        if (strchr(name, '/') ||
            strchr(name, ':'))
            sep = "";

        if (asprintf(&new_name, "%s%su", name, sep) < 0)
            return false;

        if (evsel->name)
            free(evsel->name);
        evsel->name = new_name;
        scnprintf(msg, msgsize,
"kernel.perf_event_paranoid=%d, trying to fall back to excluding kernel samples", paranoid);
        evsel->attr.exclude_kernel = 1;

        return true;
    }

    return false;
}

static bool find_process(const char *name)
{
    size_t len = strlen(name);
    DIR *dir;
    struct dirent *d;
    int ret = -1;

    dir = opendir(procfs__mountpoint());
    if (!dir)
        return false;

    /* Walk through the directory. */
    while (ret && (d = readdir(dir)) != NULL) {
        char path[PATH_MAX];
        char *data;
        size_t size;

        if ((d->d_type != DT_DIR) ||
             !strcmp(".", d->d_name) ||
             !strcmp("..", d->d_name))
            continue;

        scnprintf(path, sizeof(path), "%s/%s/comm",
              procfs__mountpoint(), d->d_name);

        if (filename__read_str(path, &data, &size))
            continue;

        ret = strncmp(name, data, len);
        free(data);
    }

    closedir(dir);
    return ret ? false : true;
}

int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
                  int err, char *msg, size_t size)
{
    char sbuf[STRERR_BUFSIZE];
    int printed = 0;

    switch (err) {
    case EPERM:
    case EACCES:
        if (err == EPERM)
            printed = scnprintf(msg, size,
                "No permission to enable %s event.\n\n",
                perf_evsel__name(evsel));

        return scnprintf(msg + printed, size - printed,
         "You may not have permission to collect %sstats.\n\n"
         "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n"
         "which controls use of the performance events system by\n"
         "unprivileged users (without CAP_SYS_ADMIN).\n\n"
         "The current value is %d:\n\n"
         "  -1: Allow use of (almost) all events by all users\n"
         "      Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK\n"
         ">= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN\n"
         "      Disallow raw tracepoint access by users without CAP_SYS_ADMIN\n"
         ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
         ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n"
         "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"
         "  kernel.perf_event_paranoid = -1\n" ,
                 target->system_wide ? "system-wide " : "",
                 perf_event_paranoid());
    case ENOENT:
        return scnprintf(msg, size, "The %s event is not supported.",
                 perf_evsel__name(evsel));
    case EMFILE:
        return scnprintf(msg, size, "%s",
             "Too many events are opened.\n"
             "Probably the maximum number of open file descriptors has been reached.\n"
             "Hint: Try again after reducing the number of events.\n"
             "Hint: Try increasing the limit with 'ulimit -n <limit>'");
    case ENOMEM:
        if (evsel__has_callchain(evsel) &&
            access("/proc/sys/kernel/perf_event_max_stack", F_OK) == 0)
            return scnprintf(msg, size,
                     "Not enough memory to setup event with callchain.\n"
                     "Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack\n"
                     "Hint: Current value: %d", sysctl__max_stack());
        break;
    case ENODEV:
        if (target->cpu_list)
            return scnprintf(msg, size, "%s",
     "No such device - did you specify an out-of-range profile CPU?");
        break;
    case EOPNOTSUPP:
        if (evsel->attr.sample_period != 0)
            return scnprintf(msg, size,
    "%s: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'",
                     perf_evsel__name(evsel));
        if (evsel->attr.precise_ip)
            return scnprintf(msg, size, "%s",
    "\'precise\' request may not be supported. Try removing 'p' modifier.");
#if defined(__i386__) || defined(__x86_64__)
        if (evsel->attr.type == PERF_TYPE_HARDWARE)
            return scnprintf(msg, size, "%s",
    "No hardware sampling interrupt available.\n");
#endif
        break;
    case EBUSY:
        if (find_process("oprofiled"))
            return scnprintf(msg, size,
    "The PMU counters are busy/taken by another profiler.\n"
    "We found oprofile daemon running, please stop it and try again.");
        break;
    case EINVAL:
        if (evsel->attr.write_backward && perf_missing_features.write_backward)
            return scnprintf(msg, size, "Reading from overwrite event is not supported by this kernel.");
        if (perf_missing_features.clockid)
            return scnprintf(msg, size, "clockid feature not supported.");
        if (perf_missing_features.clockid_wrong)
            return scnprintf(msg, size, "wrong clockid (%d).", clockid);
        break;
    default:
        break;
    }

    return scnprintf(msg, size,
    "The sys_perf_event_open() syscall returned with %d (%s) for event (%s).\n"
    "/bin/dmesg | grep -i perf may provide additional information.\n",
             err, str_error_r(err, sbuf, sizeof(sbuf)),
             perf_evsel__name(evsel));
}

struct perf_env *perf_evsel__env(struct perf_evsel *evsel)
{
    if (evsel && evsel->evlist)
        return evsel->evlist->env;
    return NULL;
}