builtin-trace.c

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/*
 * builtin-trace.c
 *
 * Builtin 'trace' command:
 *
 * Display a continuously updated trace of any workload, CPU, specific PID,
 * system wide, etc.  Default format is loosely strace like, but any other
 * event may be specified using --event.
 *
 * Copyright (C) 2012, 2013, 2014, 2015 Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
 *
 * Initially based on the 'trace' prototype by Thomas Gleixner:
 *
 * http://lwn.net/Articles/415728/ ("Announcing a new utility: 'trace'")
 *
 * Released under the GPL v2. (and only v2, not any later version)
 */

#include <traceevent/event-parse.h>
#include <api/fs/tracing_path.h>
#include "builtin.h"
#include "util/cgroup.h"
#include "util/color.h"
#include "util/debug.h"
#include "util/env.h"
#include "util/event.h"
#include "util/evlist.h"
#include <subcmd/exec-cmd.h>
#include "util/machine.h"
#include "util/path.h"
#include "util/session.h"
#include "util/thread.h"
#include <subcmd/parse-options.h>
#include "util/strlist.h"
#include "util/intlist.h"
#include "util/thread_map.h"
#include "util/stat.h"
#include "trace/beauty/beauty.h"
#include "trace-event.h"
#include "util/parse-events.h"
#include "util/bpf-loader.h"
#include "callchain.h"
#include "print_binary.h"
#include "string2.h"
#include "syscalltbl.h"
#include "rb_resort.h"

#include <errno.h>
#include <inttypes.h>
#include <poll.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <linux/err.h>
#include <linux/filter.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include <linux/stringify.h>
#include <linux/time64.h>
#include <fcntl.h>

#include "sane_ctype.h"

#ifndef O_CLOEXEC
# define O_CLOEXEC      02000000
#endif

#ifndef F_LINUX_SPECIFIC_BASE
# define F_LINUX_SPECIFIC_BASE  1024
#endif

struct trace {
    struct perf_tool    tool;
    struct syscalltbl   *sctbl;
    struct {
        int     max;
        struct syscall  *table;
        struct {
            struct perf_evsel *sys_enter,
                      *sys_exit;
        }       events;
    } syscalls;
    struct record_opts  opts;
    struct perf_evlist  *evlist;
    struct machine      *host;
    struct thread       *current;
    struct cgroup       *cgroup;
    u64         base_time;
    FILE            *output;
    unsigned long       nr_events;
    struct strlist      *ev_qualifier;
    struct {
        size_t      nr;
        int     *entries;
    }           ev_qualifier_ids;
    struct {
        size_t      nr;
        pid_t       *entries;
    }           filter_pids;
    double          duration_filter;
    double          runtime_ms;
    struct {
        u64     vfs_getname,
                proc_getname;
    } stats;
    unsigned int        max_stack;
    unsigned int        min_stack;
    bool            not_ev_qualifier;
    bool            live;
    bool            full_time;
    bool            sched;
    bool            multiple_threads;
    bool            summary;
    bool            summary_only;
    bool            failure_only;
    bool            show_comm;
    bool            print_sample;
    bool            show_tool_stats;
    bool            trace_syscalls;
    bool            kernel_syscallchains;
    bool            force;
    bool            vfs_getname;
    int         trace_pgfaults;
    int         open_id;
};

struct tp_field {
    int offset;
    union {
        u64 (*integer)(struct tp_field *field, struct perf_sample *sample);
        void *(*pointer)(struct tp_field *field, struct perf_sample *sample);
    };
};

#define TP_UINT_FIELD(bits) \
static u64 tp_field__u##bits(struct tp_field *field, struct perf_sample *sample) \
{ \
    u##bits value; \
    memcpy(&value, sample->raw_data + field->offset, sizeof(value)); \
    return value;  \
}

TP_UINT_FIELD(8);
TP_UINT_FIELD(16);
TP_UINT_FIELD(32);
TP_UINT_FIELD(64);

#define TP_UINT_FIELD__SWAPPED(bits) \
static u64 tp_field__swapped_u##bits(struct tp_field *field, struct perf_sample *sample) \
{ \
    u##bits value; \
    memcpy(&value, sample->raw_data + field->offset, sizeof(value)); \
    return bswap_##bits(value);\
}

TP_UINT_FIELD__SWAPPED(16);
TP_UINT_FIELD__SWAPPED(32);
TP_UINT_FIELD__SWAPPED(64);

static int tp_field__init_uint(struct tp_field *field,
                   struct format_field *format_field,
                   bool needs_swap)
{
    field->offset = format_field->offset;

    switch (format_field->size) {
    case 1:
        field->integer = tp_field__u8;
        break;
    case 2:
        field->integer = needs_swap ? tp_field__swapped_u16 : tp_field__u16;
        break;
    case 4:
        field->integer = needs_swap ? tp_field__swapped_u32 : tp_field__u32;
        break;
    case 8:
        field->integer = needs_swap ? tp_field__swapped_u64 : tp_field__u64;
        break;
    default:
        return -1;
    }

    return 0;
}

static void *tp_field__ptr(struct tp_field *field, struct perf_sample *sample)
{
    return sample->raw_data + field->offset;
}

static int tp_field__init_ptr(struct tp_field *field, struct format_field *format_field)
{
    field->offset = format_field->offset;
    field->pointer = tp_field__ptr;
    return 0;
}

struct syscall_tp {
    struct tp_field id;
    union {
        struct tp_field args, ret;
    };
};

static int perf_evsel__init_tp_uint_field(struct perf_evsel *evsel,
                      struct tp_field *field,
                      const char *name)
{
    struct format_field *format_field = perf_evsel__field(evsel, name);

    if (format_field == NULL)
        return -1;

    return tp_field__init_uint(field, format_field, evsel->needs_swap);
}

#define perf_evsel__init_sc_tp_uint_field(evsel, name) \
    ({ struct syscall_tp *sc = evsel->priv;\
       perf_evsel__init_tp_uint_field(evsel, &sc->name, #name); })

static int perf_evsel__init_tp_ptr_field(struct perf_evsel *evsel,
                     struct tp_field *field,
                     const char *name)
{
    struct format_field *format_field = perf_evsel__field(evsel, name);

    if (format_field == NULL)
        return -1;

    return tp_field__init_ptr(field, format_field);
}

#define perf_evsel__init_sc_tp_ptr_field(evsel, name) \
    ({ struct syscall_tp *sc = evsel->priv;\
       perf_evsel__init_tp_ptr_field(evsel, &sc->name, #name); })

static void perf_evsel__delete_priv(struct perf_evsel *evsel)
{
    zfree(&evsel->priv);
    perf_evsel__delete(evsel);
}

static int perf_evsel__init_syscall_tp(struct perf_evsel *evsel, void *handler)
{
    evsel->priv = malloc(sizeof(struct syscall_tp));
    if (evsel->priv != NULL) {
        if (perf_evsel__init_sc_tp_uint_field(evsel, id))
            goto out_delete;

        evsel->handler = handler;
        return 0;
    }

    return -ENOMEM;

out_delete:
    zfree(&evsel->priv);
    return -ENOENT;
}

static struct perf_evsel *perf_evsel__syscall_newtp(const char *direction, void *handler)
{
    struct perf_evsel *evsel = perf_evsel__newtp("raw_syscalls", direction);

    /* older kernel (e.g., RHEL6) use syscalls:{enter,exit} */
    if (IS_ERR(evsel))
        evsel = perf_evsel__newtp("syscalls", direction);

    if (IS_ERR(evsel))
        return NULL;

    if (perf_evsel__init_syscall_tp(evsel, handler))
        goto out_delete;

    return evsel;

out_delete:
    perf_evsel__delete_priv(evsel);
    return NULL;
}

#define perf_evsel__sc_tp_uint(evsel, name, sample) \
    ({ struct syscall_tp *fields = evsel->priv; \
       fields->name.integer(&fields->name, sample); })

#define perf_evsel__sc_tp_ptr(evsel, name, sample) \
    ({ struct syscall_tp *fields = evsel->priv; \
       fields->name.pointer(&fields->name, sample); })

size_t strarray__scnprintf(struct strarray *sa, char *bf, size_t size, const char *intfmt, int val)
{
    int idx = val - sa->offset;

    if (idx < 0 || idx >= sa->nr_entries)
        return scnprintf(bf, size, intfmt, val);

    return scnprintf(bf, size, "%s", sa->entries[idx]);
}

static size_t __syscall_arg__scnprintf_strarray(char *bf, size_t size,
                        const char *intfmt,
                            struct syscall_arg *arg)
{
    return strarray__scnprintf(arg->parm, bf, size, intfmt, arg->val);
}

static size_t syscall_arg__scnprintf_strarray(char *bf, size_t size,
                          struct syscall_arg *arg)
{
    return __syscall_arg__scnprintf_strarray(bf, size, "%d", arg);
}

#define SCA_STRARRAY syscall_arg__scnprintf_strarray

struct strarrays {
    int     nr_entries;
    struct strarray **entries;
};

#define DEFINE_STRARRAYS(array) struct strarrays strarrays__##array = { \
    .nr_entries = ARRAY_SIZE(array), \
    .entries = array, \
}

size_t syscall_arg__scnprintf_strarrays(char *bf, size_t size,
                    struct syscall_arg *arg)
{
    struct strarrays *sas = arg->parm;
    int i;

    for (i = 0; i < sas->nr_entries; ++i) {
        struct strarray *sa = sas->entries[i];
        int idx = arg->val - sa->offset;

        if (idx >= 0 && idx < sa->nr_entries) {
            if (sa->entries[idx] == NULL)
                break;
            return scnprintf(bf, size, "%s", sa->entries[idx]);
        }
    }

    return scnprintf(bf, size, "%d", arg->val);
}

#ifndef AT_FDCWD
#define AT_FDCWD    -100
#endif

static size_t syscall_arg__scnprintf_fd_at(char *bf, size_t size,
                       struct syscall_arg *arg)
{
    int fd = arg->val;

    if (fd == AT_FDCWD)
        return scnprintf(bf, size, "CWD");

    return syscall_arg__scnprintf_fd(bf, size, arg);
}

#define SCA_FDAT syscall_arg__scnprintf_fd_at

static size_t syscall_arg__scnprintf_close_fd(char *bf, size_t size,
                          struct syscall_arg *arg);

#define SCA_CLOSE_FD syscall_arg__scnprintf_close_fd

size_t syscall_arg__scnprintf_hex(char *bf, size_t size, struct syscall_arg *arg)
{
    return scnprintf(bf, size, "%#lx", arg->val);
}

size_t syscall_arg__scnprintf_int(char *bf, size_t size, struct syscall_arg *arg)
{
    return scnprintf(bf, size, "%d", arg->val);
}

size_t syscall_arg__scnprintf_long(char *bf, size_t size, struct syscall_arg *arg)
{
    return scnprintf(bf, size, "%ld", arg->val);
}

static const char *bpf_cmd[] = {
    "MAP_CREATE", "MAP_LOOKUP_ELEM", "MAP_UPDATE_ELEM", "MAP_DELETE_ELEM",
    "MAP_GET_NEXT_KEY", "PROG_LOAD",
};
static DEFINE_STRARRAY(bpf_cmd);

static const char *epoll_ctl_ops[] = { "ADD", "DEL", "MOD", };
static DEFINE_STRARRAY_OFFSET(epoll_ctl_ops, 1);

static const char *itimers[] = { "REAL", "VIRTUAL", "PROF", };
static DEFINE_STRARRAY(itimers);

static const char *keyctl_options[] = {
    "GET_KEYRING_ID", "JOIN_SESSION_KEYRING", "UPDATE", "REVOKE", "CHOWN",
    "SETPERM", "DESCRIBE", "CLEAR", "LINK", "UNLINK", "SEARCH", "READ",
    "INSTANTIATE", "NEGATE", "SET_REQKEY_KEYRING", "SET_TIMEOUT",
    "ASSUME_AUTHORITY", "GET_SECURITY", "SESSION_TO_PARENT", "REJECT",
    "INSTANTIATE_IOV", "INVALIDATE", "GET_PERSISTENT",
};
static DEFINE_STRARRAY(keyctl_options);

static const char *whences[] = { "SET", "CUR", "END",
#ifdef SEEK_DATA
"DATA",
#endif
#ifdef SEEK_HOLE
"HOLE",
#endif
};
static DEFINE_STRARRAY(whences);

static const char *fcntl_cmds[] = {
    "DUPFD", "GETFD", "SETFD", "GETFL", "SETFL", "GETLK", "SETLK",
    "SETLKW", "SETOWN", "GETOWN", "SETSIG", "GETSIG", "GETLK64",
    "SETLK64", "SETLKW64", "SETOWN_EX", "GETOWN_EX",
    "GETOWNER_UIDS",
};
static DEFINE_STRARRAY(fcntl_cmds);

static const char *fcntl_linux_specific_cmds[] = {
    "SETLEASE", "GETLEASE", "NOTIFY", [5] = "CANCELLK", "DUPFD_CLOEXEC",
    "SETPIPE_SZ", "GETPIPE_SZ", "ADD_SEALS", "GET_SEALS",
    "GET_RW_HINT", "SET_RW_HINT", "GET_FILE_RW_HINT", "SET_FILE_RW_HINT",
};

static DEFINE_STRARRAY_OFFSET(fcntl_linux_specific_cmds, F_LINUX_SPECIFIC_BASE);

static struct strarray *fcntl_cmds_arrays[] = {
    &strarray__fcntl_cmds,
    &strarray__fcntl_linux_specific_cmds,
};

static DEFINE_STRARRAYS(fcntl_cmds_arrays);

static const char *rlimit_resources[] = {
    "CPU", "FSIZE", "DATA", "STACK", "CORE", "RSS", "NPROC", "NOFILE",
    "MEMLOCK", "AS", "LOCKS", "SIGPENDING", "MSGQUEUE", "NICE", "RTPRIO",
    "RTTIME",
};
static DEFINE_STRARRAY(rlimit_resources);

static const char *sighow[] = { "BLOCK", "UNBLOCK", "SETMASK", };
static DEFINE_STRARRAY(sighow);

static const char *clockid[] = {
    "REALTIME", "MONOTONIC", "PROCESS_CPUTIME_ID", "THREAD_CPUTIME_ID",
    "MONOTONIC_RAW", "REALTIME_COARSE", "MONOTONIC_COARSE", "BOOTTIME",
    "REALTIME_ALARM", "BOOTTIME_ALARM", "SGI_CYCLE", "TAI"
};
static DEFINE_STRARRAY(clockid);

static const char *socket_families[] = {
    "UNSPEC", "LOCAL", "INET", "AX25", "IPX", "APPLETALK", "NETROM",
    "BRIDGE", "ATMPVC", "X25", "INET6", "ROSE", "DECnet", "NETBEUI",
    "SECURITY", "KEY", "NETLINK", "PACKET", "ASH", "ECONET", "ATMSVC",
    "RDS", "SNA", "IRDA", "PPPOX", "WANPIPE", "LLC", "IB", "CAN", "TIPC",
    "BLUETOOTH", "IUCV", "RXRPC", "ISDN", "PHONET", "IEEE802154", "CAIF",
    "ALG", "NFC", "VSOCK",
};
static DEFINE_STRARRAY(socket_families);

static size_t syscall_arg__scnprintf_access_mode(char *bf, size_t size,
                         struct syscall_arg *arg)
{
    size_t printed = 0;
    int mode = arg->val;

    if (mode == F_OK) /* 0 */
        return scnprintf(bf, size, "F");
#define P_MODE(n) \
    if (mode & n##_OK) { \
        printed += scnprintf(bf + printed, size - printed, "%s", #n); \
        mode &= ~n##_OK; \
    }

    P_MODE(R);
    P_MODE(W);
    P_MODE(X);
#undef P_MODE

    if (mode)
        printed += scnprintf(bf + printed, size - printed, "|%#x", mode);

    return printed;
}

#define SCA_ACCMODE syscall_arg__scnprintf_access_mode

static size_t syscall_arg__scnprintf_filename(char *bf, size_t size,
                          struct syscall_arg *arg);

#define SCA_FILENAME syscall_arg__scnprintf_filename

static size_t syscall_arg__scnprintf_pipe_flags(char *bf, size_t size,
                        struct syscall_arg *arg)
{
    int printed = 0, flags = arg->val;

#define P_FLAG(n) \
    if (flags & O_##n) { \
        printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "|" : "", #n); \
        flags &= ~O_##n; \
    }

    P_FLAG(CLOEXEC);
    P_FLAG(NONBLOCK);
#undef P_FLAG

    if (flags)
        printed += scnprintf(bf + printed, size - printed, "%s%#x", printed ? "|" : "", flags);

    return printed;
}

#define SCA_PIPE_FLAGS syscall_arg__scnprintf_pipe_flags

#ifndef GRND_NONBLOCK
#define GRND_NONBLOCK   0x0001
#endif
#ifndef GRND_RANDOM
#define GRND_RANDOM 0x0002
#endif

static size_t syscall_arg__scnprintf_getrandom_flags(char *bf, size_t size,
                           struct syscall_arg *arg)
{
    int printed = 0, flags = arg->val;

#define P_FLAG(n) \
    if (flags & GRND_##n) { \
        printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "|" : "", #n); \
        flags &= ~GRND_##n; \
    }

    P_FLAG(RANDOM);
    P_FLAG(NONBLOCK);
#undef P_FLAG

    if (flags)
        printed += scnprintf(bf + printed, size - printed, "%s%#x", printed ? "|" : "", flags);

    return printed;
}

#define SCA_GETRANDOM_FLAGS syscall_arg__scnprintf_getrandom_flags

#define STRARRAY(name, array) \
      { .scnprintf  = SCA_STRARRAY, \
        .parm   = &strarray__##array, }

#include "trace/beauty/arch_errno_names.c"
#include "trace/beauty/eventfd.c"
#include "trace/beauty/futex_op.c"
#include "trace/beauty/futex_val3.c"
#include "trace/beauty/mmap.c"
#include "trace/beauty/mode_t.c"
#include "trace/beauty/msg_flags.c"
#include "trace/beauty/open_flags.c"
#include "trace/beauty/perf_event_open.c"
#include "trace/beauty/pid.c"
#include "trace/beauty/sched_policy.c"
#include "trace/beauty/seccomp.c"
#include "trace/beauty/signum.c"
#include "trace/beauty/socket_type.c"
#include "trace/beauty/waitid_options.c"

struct syscall_arg_fmt {
    size_t     (*scnprintf)(char *bf, size_t size, struct syscall_arg *arg);
    void       *parm;
    const char *name;
    bool       show_zero;
};

static struct syscall_fmt {
    const char *name;
    const char *alias;
    struct syscall_arg_fmt arg[6];
    u8     nr_args;
    bool       errpid;
    bool       timeout;
    bool       hexret;
} syscall_fmts[] = {
    { .name     = "access",
      .arg = { [1] = { .scnprintf = SCA_ACCMODE,  /* mode */ }, }, },
    { .name     = "bpf",
      .arg = { [0] = STRARRAY(cmd, bpf_cmd), }, },
    { .name     = "brk",        .hexret = true,
      .arg = { [0] = { .scnprintf = SCA_HEX, /* brk */ }, }, },
    { .name     = "clock_gettime",
      .arg = { [0] = STRARRAY(clk_id, clockid), }, },
    { .name     = "clone",      .errpid = true, .nr_args = 5,
      .arg = { [0] = { .name = "flags",     .scnprintf = SCA_CLONE_FLAGS, },
           [1] = { .name = "child_stack",   .scnprintf = SCA_HEX, },
           [2] = { .name = "parent_tidptr", .scnprintf = SCA_HEX, },
           [3] = { .name = "child_tidptr",  .scnprintf = SCA_HEX, },
           [4] = { .name = "tls",       .scnprintf = SCA_HEX, }, }, },
    { .name     = "close",
      .arg = { [0] = { .scnprintf = SCA_CLOSE_FD, /* fd */ }, }, },
    { .name     = "epoll_ctl",
      .arg = { [1] = STRARRAY(op, epoll_ctl_ops), }, },
    { .name     = "eventfd2",
      .arg = { [1] = { .scnprintf = SCA_EFD_FLAGS, /* flags */ }, }, },
    { .name     = "fchmodat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* fd */ }, }, },
    { .name     = "fchownat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* fd */ }, }, },
    { .name     = "fcntl",
      .arg = { [1] = { .scnprintf = SCA_FCNTL_CMD, /* cmd */
               .parm      = &strarrays__fcntl_cmds_arrays,
               .show_zero = true, },
           [2] = { .scnprintf =  SCA_FCNTL_ARG, /* arg */ }, }, },
    { .name     = "flock",
      .arg = { [1] = { .scnprintf = SCA_FLOCK, /* cmd */ }, }, },
    { .name     = "fstat", .alias = "newfstat", },
    { .name     = "fstatat", .alias = "newfstatat", },
    { .name     = "futex",
      .arg = { [1] = { .scnprintf = SCA_FUTEX_OP, /* op */ },
           [5] = { .scnprintf = SCA_FUTEX_VAL3, /* val3 */ }, }, },
    { .name     = "futimesat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* fd */ }, }, },
    { .name     = "getitimer",
      .arg = { [0] = STRARRAY(which, itimers), }, },
    { .name     = "getpid",     .errpid = true, },
    { .name     = "getpgid",    .errpid = true, },
    { .name     = "getppid",    .errpid = true, },
    { .name     = "getrandom",
      .arg = { [2] = { .scnprintf = SCA_GETRANDOM_FLAGS, /* flags */ }, }, },
    { .name     = "getrlimit",
      .arg = { [0] = STRARRAY(resource, rlimit_resources), }, },
    { .name     = "gettid",     .errpid = true, },
    { .name     = "ioctl",
      .arg = {
#if defined(__i386__) || defined(__x86_64__)
/*
 * FIXME: Make this available to all arches.
 */
           [1] = { .scnprintf = SCA_IOCTL_CMD, /* cmd */ },
           [2] = { .scnprintf = SCA_HEX, /* arg */ }, }, },
#else
           [2] = { .scnprintf = SCA_HEX, /* arg */ }, }, },
#endif
    { .name     = "kcmp",       .nr_args = 5,
      .arg = { [0] = { .name = "pid1",  .scnprintf = SCA_PID, },
           [1] = { .name = "pid2",  .scnprintf = SCA_PID, },
           [2] = { .name = "type",  .scnprintf = SCA_KCMP_TYPE, },
           [3] = { .name = "idx1",  .scnprintf = SCA_KCMP_IDX, },
           [4] = { .name = "idx2",  .scnprintf = SCA_KCMP_IDX, }, }, },
    { .name     = "keyctl",
      .arg = { [0] = STRARRAY(option, keyctl_options), }, },
    { .name     = "kill",
      .arg = { [1] = { .scnprintf = SCA_SIGNUM, /* sig */ }, }, },
    { .name     = "linkat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* fd */ }, }, },
    { .name     = "lseek",
      .arg = { [2] = STRARRAY(whence, whences), }, },
    { .name     = "lstat", .alias = "newlstat", },
    { .name     = "madvise",
      .arg = { [0] = { .scnprintf = SCA_HEX,      /* start */ },
           [2] = { .scnprintf = SCA_MADV_BHV, /* behavior */ }, }, },
    { .name     = "mkdirat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* fd */ }, }, },
    { .name     = "mknodat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* fd */ }, }, },
    { .name     = "mlock",
      .arg = { [0] = { .scnprintf = SCA_HEX, /* addr */ }, }, },
    { .name     = "mlockall",
      .arg = { [0] = { .scnprintf = SCA_HEX, /* addr */ }, }, },
    { .name     = "mmap",       .hexret = true,
/* The standard mmap maps to old_mmap on s390x */
#if defined(__s390x__)
    .alias = "old_mmap",
#endif
      .arg = { [0] = { .scnprintf = SCA_HEX,    /* addr */ },
           [2] = { .scnprintf = SCA_MMAP_PROT,  /* prot */ },
           [3] = { .scnprintf = SCA_MMAP_FLAGS, /* flags */ }, }, },
    { .name     = "mprotect",
      .arg = { [0] = { .scnprintf = SCA_HEX,    /* start */ },
           [2] = { .scnprintf = SCA_MMAP_PROT,  /* prot */ }, }, },
    { .name     = "mq_unlink",
      .arg = { [0] = { .scnprintf = SCA_FILENAME, /* u_name */ }, }, },
    { .name     = "mremap",     .hexret = true,
      .arg = { [0] = { .scnprintf = SCA_HEX,      /* addr */ },
           [3] = { .scnprintf = SCA_MREMAP_FLAGS, /* flags */ },
           [4] = { .scnprintf = SCA_HEX,      /* new_addr */ }, }, },
    { .name     = "munlock",
      .arg = { [0] = { .scnprintf = SCA_HEX, /* addr */ }, }, },
    { .name     = "munmap",
      .arg = { [0] = { .scnprintf = SCA_HEX, /* addr */ }, }, },
    { .name     = "name_to_handle_at",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* dfd */ }, }, },
    { .name     = "newfstatat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* dfd */ }, }, },
    { .name     = "open",
      .arg = { [1] = { .scnprintf = SCA_OPEN_FLAGS, /* flags */ }, }, },
    { .name     = "open_by_handle_at",
      .arg = { [0] = { .scnprintf = SCA_FDAT,   /* dfd */ },
           [2] = { .scnprintf = SCA_OPEN_FLAGS, /* flags */ }, }, },
    { .name     = "openat",
      .arg = { [0] = { .scnprintf = SCA_FDAT,   /* dfd */ },
           [2] = { .scnprintf = SCA_OPEN_FLAGS, /* flags */ }, }, },
    { .name     = "perf_event_open",
      .arg = { [2] = { .scnprintf = SCA_INT,    /* cpu */ },
           [3] = { .scnprintf = SCA_FD,     /* group_fd */ },
           [4] = { .scnprintf = SCA_PERF_FLAGS, /* flags */ }, }, },
    { .name     = "pipe2",
      .arg = { [1] = { .scnprintf = SCA_PIPE_FLAGS, /* flags */ }, }, },
    { .name     = "pkey_alloc",
      .arg = { [1] = { .scnprintf = SCA_PKEY_ALLOC_ACCESS_RIGHTS,   /* access_rights */ }, }, },
    { .name     = "pkey_free",
      .arg = { [0] = { .scnprintf = SCA_INT,    /* key */ }, }, },
    { .name     = "pkey_mprotect",
      .arg = { [0] = { .scnprintf = SCA_HEX,    /* start */ },
           [2] = { .scnprintf = SCA_MMAP_PROT,  /* prot */ },
           [3] = { .scnprintf = SCA_INT,    /* pkey */ }, }, },
    { .name     = "poll", .timeout = true, },
    { .name     = "ppoll", .timeout = true, },
    { .name     = "prctl", .alias = "arch_prctl",
      .arg = { [0] = { .scnprintf = SCA_PRCTL_OPTION, /* option */ },
           [1] = { .scnprintf = SCA_PRCTL_ARG2, /* arg2 */ },
           [2] = { .scnprintf = SCA_PRCTL_ARG3, /* arg3 */ }, }, },
    { .name     = "pread", .alias = "pread64", },
    { .name     = "preadv", .alias = "pread", },
    { .name     = "prlimit64",
      .arg = { [1] = STRARRAY(resource, rlimit_resources), }, },
    { .name     = "pwrite", .alias = "pwrite64", },
    { .name     = "readlinkat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* dfd */ }, }, },
    { .name     = "recvfrom",
      .arg = { [3] = { .scnprintf = SCA_MSG_FLAGS, /* flags */ }, }, },
    { .name     = "recvmmsg",
      .arg = { [3] = { .scnprintf = SCA_MSG_FLAGS, /* flags */ }, }, },
    { .name     = "recvmsg",
      .arg = { [2] = { .scnprintf = SCA_MSG_FLAGS, /* flags */ }, }, },
    { .name     = "renameat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* dfd */ }, }, },
    { .name     = "rt_sigaction",
      .arg = { [0] = { .scnprintf = SCA_SIGNUM, /* sig */ }, }, },
    { .name     = "rt_sigprocmask",
      .arg = { [0] = STRARRAY(how, sighow), }, },
    { .name     = "rt_sigqueueinfo",
      .arg = { [1] = { .scnprintf = SCA_SIGNUM, /* sig */ }, }, },
    { .name     = "rt_tgsigqueueinfo",
      .arg = { [2] = { .scnprintf = SCA_SIGNUM, /* sig */ }, }, },
    { .name     = "sched_setscheduler",
      .arg = { [1] = { .scnprintf = SCA_SCHED_POLICY, /* policy */ }, }, },
    { .name     = "seccomp",
      .arg = { [0] = { .scnprintf = SCA_SECCOMP_OP,    /* op */ },
           [1] = { .scnprintf = SCA_SECCOMP_FLAGS, /* flags */ }, }, },
    { .name     = "select", .timeout = true, },
    { .name     = "sendmmsg",
      .arg = { [3] = { .scnprintf = SCA_MSG_FLAGS, /* flags */ }, }, },
    { .name     = "sendmsg",
      .arg = { [2] = { .scnprintf = SCA_MSG_FLAGS, /* flags */ }, }, },
    { .name     = "sendto",
      .arg = { [3] = { .scnprintf = SCA_MSG_FLAGS, /* flags */ }, }, },
    { .name     = "set_tid_address", .errpid = true, },
    { .name     = "setitimer",
      .arg = { [0] = STRARRAY(which, itimers), }, },
    { .name     = "setrlimit",
      .arg = { [0] = STRARRAY(resource, rlimit_resources), }, },
    { .name     = "socket",
      .arg = { [0] = STRARRAY(family, socket_families),
           [1] = { .scnprintf = SCA_SK_TYPE, /* type */ }, }, },
    { .name     = "socketpair",
      .arg = { [0] = STRARRAY(family, socket_families),
           [1] = { .scnprintf = SCA_SK_TYPE, /* type */ }, }, },
    { .name     = "stat", .alias = "newstat", },
    { .name     = "statx",
      .arg = { [0] = { .scnprintf = SCA_FDAT,    /* fdat */ },
           [2] = { .scnprintf = SCA_STATX_FLAGS, /* flags */ } ,
           [3] = { .scnprintf = SCA_STATX_MASK,  /* mask */ }, }, },
    { .name     = "swapoff",
      .arg = { [0] = { .scnprintf = SCA_FILENAME, /* specialfile */ }, }, },
    { .name     = "swapon",
      .arg = { [0] = { .scnprintf = SCA_FILENAME, /* specialfile */ }, }, },
    { .name     = "symlinkat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* dfd */ }, }, },
    { .name     = "tgkill",
      .arg = { [2] = { .scnprintf = SCA_SIGNUM, /* sig */ }, }, },
    { .name     = "tkill",
      .arg = { [1] = { .scnprintf = SCA_SIGNUM, /* sig */ }, }, },
    { .name     = "uname", .alias = "newuname", },
    { .name     = "unlinkat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* dfd */ }, }, },
    { .name     = "utimensat",
      .arg = { [0] = { .scnprintf = SCA_FDAT, /* dirfd */ }, }, },
    { .name     = "wait4",      .errpid = true,
      .arg = { [2] = { .scnprintf = SCA_WAITID_OPTIONS, /* options */ }, }, },
    { .name     = "waitid",     .errpid = true,
      .arg = { [3] = { .scnprintf = SCA_WAITID_OPTIONS, /* options */ }, }, },
};

static int syscall_fmt__cmp(const void *name, const void *fmtp)
{
    const struct syscall_fmt *fmt = fmtp;
    return strcmp(name, fmt->name);
}

static struct syscall_fmt *syscall_fmt__find(const char *name)
{
    const int nmemb = ARRAY_SIZE(syscall_fmts);
    return bsearch(name, syscall_fmts, nmemb, sizeof(struct syscall_fmt), syscall_fmt__cmp);
}

struct syscall {
    struct event_format *tp_format;
    int         nr_args;
    struct format_field *args;
    const char      *name;
    bool            is_exit;
    struct syscall_fmt  *fmt;
    struct syscall_arg_fmt *arg_fmt;
};

/*
 * We need to have this 'calculated' boolean because in some cases we really
 * don't know what is the duration of a syscall, for instance, when we start
 * a session and some threads are waiting for a syscall to finish, say 'poll',
 * in which case all we can do is to print "( ? ) for duration and for the
 * start timestamp.
 */
static size_t fprintf_duration(unsigned long t, bool calculated, FILE *fp)
{
    double duration = (double)t / NSEC_PER_MSEC;
    size_t printed = fprintf(fp, "(");

    if (!calculated)
        printed += fprintf(fp, "         ");
    else if (duration >= 1.0)
        printed += color_fprintf(fp, PERF_COLOR_RED, "%6.3f ms", duration);
    else if (duration >= 0.01)
        printed += color_fprintf(fp, PERF_COLOR_YELLOW, "%6.3f ms", duration);
    else
        printed += color_fprintf(fp, PERF_COLOR_NORMAL, "%6.3f ms", duration);
    return printed + fprintf(fp, "): ");
}

struct thread_trace {
    u64       entry_time;
    bool          entry_pending;
    unsigned long     nr_events;
    unsigned long     pfmaj, pfmin;
    char          *entry_str;
    double        runtime_ms;
    size_t        (*ret_scnprintf)(char *bf, size_t size, struct syscall_arg *arg);
        struct {
        unsigned long ptr;
        short int     entry_str_pos;
        bool          pending_open;
        unsigned int  namelen;
        char          *name;
    } filename;
    struct {
        int   max;
        char      **table;
    } paths;

    struct intlist *syscall_stats;
};

static struct thread_trace *thread_trace__new(void)
{
    struct thread_trace *ttrace =  zalloc(sizeof(struct thread_trace));

    if (ttrace)
        ttrace->paths.max = -1;

    ttrace->syscall_stats = intlist__new(NULL);

    return ttrace;
}

static struct thread_trace *thread__trace(struct thread *thread, FILE *fp)
{
    struct thread_trace *ttrace;

    if (thread == NULL)
        goto fail;

    if (thread__priv(thread) == NULL)
        thread__set_priv(thread, thread_trace__new());

    if (thread__priv(thread) == NULL)
        goto fail;

    ttrace = thread__priv(thread);
    ++ttrace->nr_events;

    return ttrace;
fail:
    color_fprintf(fp, PERF_COLOR_RED,
              "WARNING: not enough memory, dropping samples!\n");
    return NULL;
}


void syscall_arg__set_ret_scnprintf(struct syscall_arg *arg,
                    size_t (*ret_scnprintf)(char *bf, size_t size, struct syscall_arg *arg))
{
    struct thread_trace *ttrace = thread__priv(arg->thread);

    ttrace->ret_scnprintf = ret_scnprintf;
}

#define TRACE_PFMAJ     (1 << 0)
#define TRACE_PFMIN     (1 << 1)

static const size_t trace__entry_str_size = 2048;

static int trace__set_fd_pathname(struct thread *thread, int fd, const char *pathname)
{
    struct thread_trace *ttrace = thread__priv(thread);

    if (fd > ttrace->paths.max) {
        char **npath = realloc(ttrace->paths.table, (fd + 1) * sizeof(char *));

        if (npath == NULL)
            return -1;

        if (ttrace->paths.max != -1) {
            memset(npath + ttrace->paths.max + 1, 0,
                   (fd - ttrace->paths.max) * sizeof(char *));
        } else {
            memset(npath, 0, (fd + 1) * sizeof(char *));
        }

        ttrace->paths.table = npath;
        ttrace->paths.max   = fd;
    }

    ttrace->paths.table[fd] = strdup(pathname);

    return ttrace->paths.table[fd] != NULL ? 0 : -1;
}

static int thread__read_fd_path(struct thread *thread, int fd)
{
    char linkname[PATH_MAX], pathname[PATH_MAX];
    struct stat st;
    int ret;

    if (thread->pid_ == thread->tid) {
        scnprintf(linkname, sizeof(linkname),
              "/proc/%d/fd/%d", thread->pid_, fd);
    } else {
        scnprintf(linkname, sizeof(linkname),
              "/proc/%d/task/%d/fd/%d", thread->pid_, thread->tid, fd);
    }

    if (lstat(linkname, &st) < 0 || st.st_size + 1 > (off_t)sizeof(pathname))
        return -1;

    ret = readlink(linkname, pathname, sizeof(pathname));

    if (ret < 0 || ret > st.st_size)
        return -1;

    pathname[ret] = '\0';
    return trace__set_fd_pathname(thread, fd, pathname);
}

static const char *thread__fd_path(struct thread *thread, int fd,
                   struct trace *trace)
{
    struct thread_trace *ttrace = thread__priv(thread);

    if (ttrace == NULL)
        return NULL;

    if (fd < 0)
        return NULL;

    if ((fd > ttrace->paths.max || ttrace->paths.table[fd] == NULL)) {
        if (!trace->live)
            return NULL;
        ++trace->stats.proc_getname;
        if (thread__read_fd_path(thread, fd))
            return NULL;
    }

    return ttrace->paths.table[fd];
}

size_t syscall_arg__scnprintf_fd(char *bf, size_t size, struct syscall_arg *arg)
{
    int fd = arg->val;
    size_t printed = scnprintf(bf, size, "%d", fd);
    const char *path = thread__fd_path(arg->thread, fd, arg->trace);

    if (path)
        printed += scnprintf(bf + printed, size - printed, "<%s>", path);

    return printed;
}

size_t pid__scnprintf_fd(struct trace *trace, pid_t pid, int fd, char *bf, size_t size)
{
        size_t printed = scnprintf(bf, size, "%d", fd);
    struct thread *thread = machine__find_thread(trace->host, pid, pid);

    if (thread) {
        const char *path = thread__fd_path(thread, fd, trace);

        if (path)
            printed += scnprintf(bf + printed, size - printed, "<%s>", path);

        thread__put(thread);
    }

        return printed;
}

static size_t syscall_arg__scnprintf_close_fd(char *bf, size_t size,
                          struct syscall_arg *arg)
{
    int fd = arg->val;
    size_t printed = syscall_arg__scnprintf_fd(bf, size, arg);
    struct thread_trace *ttrace = thread__priv(arg->thread);

    if (ttrace && fd >= 0 && fd <= ttrace->paths.max)
        zfree(&ttrace->paths.table[fd]);

    return printed;
}

static void thread__set_filename_pos(struct thread *thread, const char *bf,
                     unsigned long ptr)
{
    struct thread_trace *ttrace = thread__priv(thread);

    ttrace->filename.ptr = ptr;
    ttrace->filename.entry_str_pos = bf - ttrace->entry_str;
}

static size_t syscall_arg__scnprintf_filename(char *bf, size_t size,
                          struct syscall_arg *arg)
{
    unsigned long ptr = arg->val;

    if (!arg->trace->vfs_getname)
        return scnprintf(bf, size, "%#x", ptr);

    thread__set_filename_pos(arg->thread, bf, ptr);
    return 0;
}

static bool trace__filter_duration(struct trace *trace, double t)
{
    return t < (trace->duration_filter * NSEC_PER_MSEC);
}

static size_t __trace__fprintf_tstamp(struct trace *trace, u64 tstamp, FILE *fp)
{
    double ts = (double)(tstamp - trace->base_time) / NSEC_PER_MSEC;

    return fprintf(fp, "%10.3f ", ts);
}

/*
 * We're handling tstamp=0 as an undefined tstamp, i.e. like when we are
 * using ttrace->entry_time for a thread that receives a sys_exit without
 * first having received a sys_enter ("poll" issued before tracing session
 * starts, lost sys_enter exit due to ring buffer overflow).
 */
static size_t trace__fprintf_tstamp(struct trace *trace, u64 tstamp, FILE *fp)
{
    if (tstamp > 0)
        return __trace__fprintf_tstamp(trace, tstamp, fp);

    return fprintf(fp, "         ? ");
}

static bool done = false;
static bool interrupted = false;

static void sig_handler(int sig)
{
    done = true;
    interrupted = sig == SIGINT;
}

static size_t trace__fprintf_entry_head(struct trace *trace, struct thread *thread,
                    u64 duration, bool duration_calculated, u64 tstamp, FILE *fp)
{
    size_t printed = trace__fprintf_tstamp(trace, tstamp, fp);
    printed += fprintf_duration(duration, duration_calculated, fp);

    if (trace->multiple_threads) {
        if (trace->show_comm)
            printed += fprintf(fp, "%.14s/", thread__comm_str(thread));
        printed += fprintf(fp, "%d ", thread->tid);
    }

    return printed;
}

static int trace__process_event(struct trace *trace, struct machine *machine,
                union perf_event *event, struct perf_sample *sample)
{
    int ret = 0;

    switch (event->header.type) {
    case PERF_RECORD_LOST:
        color_fprintf(trace->output, PERF_COLOR_RED,
                  "LOST %" PRIu64 " events!\n", event->lost.lost);
        ret = machine__process_lost_event(machine, event, sample);
        break;
    default:
        ret = machine__process_event(machine, event, sample);
        break;
    }

    return ret;
}

static int trace__tool_process(struct perf_tool *tool,
                   union perf_event *event,
                   struct perf_sample *sample,
                   struct machine *machine)
{
    struct trace *trace = container_of(tool, struct trace, tool);
    return trace__process_event(trace, machine, event, sample);
}

static char *trace__machine__resolve_kernel_addr(void *vmachine, unsigned long long *addrp, char **modp)
{
    struct machine *machine = vmachine;

    if (machine->kptr_restrict_warned)
        return NULL;

    if (symbol_conf.kptr_restrict) {
        pr_warning("Kernel address maps (/proc/{kallsyms,modules}) are restricted.\n\n"
               "Check /proc/sys/kernel/kptr_restrict.\n\n"
               "Kernel samples will not be resolved.\n");
        machine->kptr_restrict_warned = true;
        return NULL;
    }

    return machine__resolve_kernel_addr(vmachine, addrp, modp);
}

static int trace__symbols_init(struct trace *trace, struct perf_evlist *evlist)
{
    int err = symbol__init(NULL);

    if (err)
        return err;

    trace->host = machine__new_host();
    if (trace->host == NULL)
        return -ENOMEM;

    err = trace_event__register_resolver(trace->host, trace__machine__resolve_kernel_addr);
    if (err < 0)
        goto out;

    err = __machine__synthesize_threads(trace->host, &trace->tool, &trace->opts.target,
                        evlist->threads, trace__tool_process, false,
                        trace->opts.proc_map_timeout, 1);
out:
    if (err)
        symbol__exit();

    return err;
}

static void trace__symbols__exit(struct trace *trace)
{
    machine__exit(trace->host);
    trace->host = NULL;

    symbol__exit();
}

static int syscall__alloc_arg_fmts(struct syscall *sc, int nr_args)
{
    int idx;

    if (nr_args == 6 && sc->fmt && sc->fmt->nr_args != 0)
        nr_args = sc->fmt->nr_args;

    sc->arg_fmt = calloc(nr_args, sizeof(*sc->arg_fmt));
    if (sc->arg_fmt == NULL)
        return -1;

    for (idx = 0; idx < nr_args; ++idx) {
        if (sc->fmt)
            sc->arg_fmt[idx] = sc->fmt->arg[idx];
    }

    sc->nr_args = nr_args;
    return 0;
}

static int syscall__set_arg_fmts(struct syscall *sc)
{
    struct format_field *field;
    int idx = 0, len;

    for (field = sc->args; field; field = field->next, ++idx) {
        if (sc->fmt && sc->fmt->arg[idx].scnprintf)
            continue;

        if (strcmp(field->type, "const char *") == 0 &&
             (strcmp(field->name, "filename") == 0 ||
              strcmp(field->name, "path") == 0 ||
              strcmp(field->name, "pathname") == 0))
            sc->arg_fmt[idx].scnprintf = SCA_FILENAME;
        else if (field->flags & FIELD_IS_POINTER)
            sc->arg_fmt[idx].scnprintf = syscall_arg__scnprintf_hex;
        else if (strcmp(field->type, "pid_t") == 0)
            sc->arg_fmt[idx].scnprintf = SCA_PID;
        else if (strcmp(field->type, "umode_t") == 0)
            sc->arg_fmt[idx].scnprintf = SCA_MODE_T;
        else if ((strcmp(field->type, "int") == 0 ||
              strcmp(field->type, "unsigned int") == 0 ||
              strcmp(field->type, "long") == 0) &&
             (len = strlen(field->name)) >= 2 &&
             strcmp(field->name + len - 2, "fd") == 0) {
            /*
             * /sys/kernel/tracing/events/syscalls/sys_enter*
             * egrep 'field:.*fd;' .../format|sed -r 's/.*field:([a-z ]+) [a-z_]*fd.+/\1/g'|sort|uniq -c
             * 65 int
             * 23 unsigned int
             * 7 unsigned long
             */
            sc->arg_fmt[idx].scnprintf = SCA_FD;
        }
    }

    return 0;
}

static int trace__read_syscall_info(struct trace *trace, int id)
{
    char tp_name[128];
    struct syscall *sc;
    const char *name = syscalltbl__name(trace->sctbl, id);

    if (name == NULL)
        return -1;

    if (id > trace->syscalls.max) {
        struct syscall *nsyscalls = realloc(trace->syscalls.table, (id + 1) * sizeof(*sc));

        if (nsyscalls == NULL)
            return -1;

        if (trace->syscalls.max != -1) {
            memset(nsyscalls + trace->syscalls.max + 1, 0,
                   (id - trace->syscalls.max) * sizeof(*sc));
        } else {
            memset(nsyscalls, 0, (id + 1) * sizeof(*sc));
        }

        trace->syscalls.table = nsyscalls;
        trace->syscalls.max   = id;
    }

    sc = trace->syscalls.table + id;
    sc->name = name;

    sc->fmt  = syscall_fmt__find(sc->name);

    snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->name);
    sc->tp_format = trace_event__tp_format("syscalls", tp_name);

    if (IS_ERR(sc->tp_format) && sc->fmt && sc->fmt->alias) {
        snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->fmt->alias);
        sc->tp_format = trace_event__tp_format("syscalls", tp_name);
    }

    if (syscall__alloc_arg_fmts(sc, IS_ERR(sc->tp_format) ? 6 : sc->tp_format->format.nr_fields))
        return -1;

    if (IS_ERR(sc->tp_format))
        return -1;

    sc->args = sc->tp_format->format.fields;
    /*
     * We need to check and discard the first variable '__syscall_nr'
     * or 'nr' that mean the syscall number. It is needless here.
     * So drop '__syscall_nr' or 'nr' field but does not exist on older kernels.
     */
    if (sc->args && (!strcmp(sc->args->name, "__syscall_nr") || !strcmp(sc->args->name, "nr"))) {
        sc->args = sc->args->next;
        --sc->nr_args;
    }

    sc->is_exit = !strcmp(name, "exit_group") || !strcmp(name, "exit");

    return syscall__set_arg_fmts(sc);
}

static int trace__validate_ev_qualifier(struct trace *trace)
{
    int err = 0, i;
    size_t nr_allocated;
    struct str_node *pos;

    trace->ev_qualifier_ids.nr = strlist__nr_entries(trace->ev_qualifier);
    trace->ev_qualifier_ids.entries = malloc(trace->ev_qualifier_ids.nr *
                         sizeof(trace->ev_qualifier_ids.entries[0]));

    if (trace->ev_qualifier_ids.entries == NULL) {
        fputs("Error:\tNot enough memory for allocating events qualifier ids\n",
               trace->output);
        err = -EINVAL;
        goto out;
    }

    nr_allocated = trace->ev_qualifier_ids.nr;
    i = 0;

    strlist__for_each_entry(pos, trace->ev_qualifier) {
        const char *sc = pos->s;
        int id = syscalltbl__id(trace->sctbl, sc), match_next = -1;

        if (id < 0) {
            id = syscalltbl__strglobmatch_first(trace->sctbl, sc, &match_next);
            if (id >= 0)
                goto matches;

            if (err == 0) {
                fputs("Error:\tInvalid syscall ", trace->output);
                err = -EINVAL;
            } else {
                fputs(", ", trace->output);
            }

            fputs(sc, trace->output);
        }
matches:
        trace->ev_qualifier_ids.entries[i++] = id;
        if (match_next == -1)
            continue;

        while (1) {
            id = syscalltbl__strglobmatch_next(trace->sctbl, sc, &match_next);
            if (id < 0)
                break;
            if (nr_allocated == trace->ev_qualifier_ids.nr) {
                void *entries;

                nr_allocated += 8;
                entries = realloc(trace->ev_qualifier_ids.entries,
                          nr_allocated * sizeof(trace->ev_qualifier_ids.entries[0]));
                if (entries == NULL) {
                    err = -ENOMEM;
                    fputs("\nError:\t Not enough memory for parsing\n", trace->output);
                    goto out_free;
                }
                trace->ev_qualifier_ids.entries = entries;
            }
            trace->ev_qualifier_ids.nr++;
            trace->ev_qualifier_ids.entries[i++] = id;
        }
    }

    if (err < 0) {
        fputs("\nHint:\ttry 'perf list syscalls:sys_enter_*'"
              "\nHint:\tand: 'man syscalls'\n", trace->output);
out_free:
        zfree(&trace->ev_qualifier_ids.entries);
        trace->ev_qualifier_ids.nr = 0;
    }
out:
    return err;
}

/*
 * args is to be interpreted as a series of longs but we need to handle
 * 8-byte unaligned accesses. args points to raw_data within the event
 * and raw_data is guaranteed to be 8-byte unaligned because it is
 * preceded by raw_size which is a u32. So we need to copy args to a temp
 * variable to read it. Most notably this avoids extended load instructions
 * on unaligned addresses
 */
unsigned long syscall_arg__val(struct syscall_arg *arg, u8 idx)
{
    unsigned long val;
    unsigned char *p = arg->args + sizeof(unsigned long) * idx;

    memcpy(&val, p, sizeof(val));
    return val;
}

static size_t syscall__scnprintf_name(struct syscall *sc, char *bf, size_t size,
                      struct syscall_arg *arg)
{
    if (sc->arg_fmt && sc->arg_fmt[arg->idx].name)
        return scnprintf(bf, size, "%s: ", sc->arg_fmt[arg->idx].name);

    return scnprintf(bf, size, "arg%d: ", arg->idx);
}

static size_t syscall__scnprintf_val(struct syscall *sc, char *bf, size_t size,
                     struct syscall_arg *arg, unsigned long val)
{
    if (sc->arg_fmt && sc->arg_fmt[arg->idx].scnprintf) {
        arg->val = val;
        if (sc->arg_fmt[arg->idx].parm)
            arg->parm = sc->arg_fmt[arg->idx].parm;
        return sc->arg_fmt[arg->idx].scnprintf(bf, size, arg);
    }
    return scnprintf(bf, size, "%ld", val);
}

static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size,
                      unsigned char *args, struct trace *trace,
                      struct thread *thread)
{
    size_t printed = 0;
    unsigned long val;
    u8 bit = 1;
    struct syscall_arg arg = {
        .args   = args,
        .idx    = 0,
        .mask   = 0,
        .trace  = trace,
        .thread = thread,
    };
    struct thread_trace *ttrace = thread__priv(thread);

    /*
     * Things like fcntl will set this in its 'cmd' formatter to pick the
     * right formatter for the return value (an fd? file flags?), which is
     * not needed for syscalls that always return a given type, say an fd.
     */
    ttrace->ret_scnprintf = NULL;

    if (sc->args != NULL) {
        struct format_field *field;

        for (field = sc->args; field;
             field = field->next, ++arg.idx, bit <<= 1) {
            if (arg.mask & bit)
                continue;

            val = syscall_arg__val(&arg, arg.idx);

            /*
             * Suppress this argument if its value is zero and
             * and we don't have a string associated in an
             * strarray for it.
             */
            if (val == 0 &&
                !(sc->arg_fmt &&
                  (sc->arg_fmt[arg.idx].show_zero ||
                   sc->arg_fmt[arg.idx].scnprintf == SCA_STRARRAY ||
                   sc->arg_fmt[arg.idx].scnprintf == SCA_STRARRAYS) &&
                  sc->arg_fmt[arg.idx].parm))
                continue;

            printed += scnprintf(bf + printed, size - printed,
                         "%s%s: ", printed ? ", " : "", field->name);
            printed += syscall__scnprintf_val(sc, bf + printed, size - printed, &arg, val);
        }
    } else if (IS_ERR(sc->tp_format)) {
        /*
         * If we managed to read the tracepoint /format file, then we
         * may end up not having any args, like with gettid(), so only
         * print the raw args when we didn't manage to read it.
         */
        while (arg.idx < sc->nr_args) {
            if (arg.mask & bit)
                goto next_arg;
            val = syscall_arg__val(&arg, arg.idx);
            if (printed)
                printed += scnprintf(bf + printed, size - printed, ", ");
            printed += syscall__scnprintf_name(sc, bf + printed, size - printed, &arg);
            printed += syscall__scnprintf_val(sc, bf + printed, size - printed, &arg, val);
next_arg:
            ++arg.idx;
            bit <<= 1;
        }
    }

    return printed;
}

typedef int (*tracepoint_handler)(struct trace *trace, struct perf_evsel *evsel,
                  union perf_event *event,
                  struct perf_sample *sample);

static struct syscall *trace__syscall_info(struct trace *trace,
                       struct perf_evsel *evsel, int id)
{

    if (id < 0) {

        /*
         * XXX: Noticed on x86_64, reproduced as far back as 3.0.36, haven't tried
         * before that, leaving at a higher verbosity level till that is
         * explained. Reproduced with plain ftrace with:
         *
         * echo 1 > /t/events/raw_syscalls/sys_exit/enable
         * grep "NR -1 " /t/trace_pipe
         *
         * After generating some load on the machine.
         */
        if (verbose > 1) {
            static u64 n;
            fprintf(trace->output, "Invalid syscall %d id, skipping (%s, %" PRIu64 ") ...\n",
                id, perf_evsel__name(evsel), ++n);
        }
        return NULL;
    }

    if ((id > trace->syscalls.max || trace->syscalls.table[id].name == NULL) &&
        trace__read_syscall_info(trace, id))
        goto out_cant_read;

    if ((id > trace->syscalls.max || trace->syscalls.table[id].name == NULL))
        goto out_cant_read;

    return &trace->syscalls.table[id];

out_cant_read:
    if (verbose > 0) {
        fprintf(trace->output, "Problems reading syscall %d", id);
        if (id <= trace->syscalls.max && trace->syscalls.table[id].name != NULL)
            fprintf(trace->output, "(%s)", trace->syscalls.table[id].name);
        fputs(" information\n", trace->output);
    }
    return NULL;
}

static void thread__update_stats(struct thread_trace *ttrace,
                 int id, struct perf_sample *sample)
{
    struct int_node *inode;
    struct stats *stats;
    u64 duration = 0;

    inode = intlist__findnew(ttrace->syscall_stats, id);
    if (inode == NULL)
        return;

    stats = inode->priv;
    if (stats == NULL) {
        stats = malloc(sizeof(struct stats));
        if (stats == NULL)
            return;
        init_stats(stats);
        inode->priv = stats;
    }

    if (ttrace->entry_time && sample->time > ttrace->entry_time)
        duration = sample->time - ttrace->entry_time;

    update_stats(stats, duration);
}

static int trace__printf_interrupted_entry(struct trace *trace)
{
    struct thread_trace *ttrace;
    size_t printed;

    if (trace->failure_only || trace->current == NULL)
        return 0;

    ttrace = thread__priv(trace->current);

    if (!ttrace->entry_pending)
        return 0;

    printed  = trace__fprintf_entry_head(trace, trace->current, 0, false, ttrace->entry_time, trace->output);
    printed += fprintf(trace->output, "%-70s) ...\n", ttrace->entry_str);
    ttrace->entry_pending = false;

    return printed;
}

static int trace__fprintf_sample(struct trace *trace, struct perf_evsel *evsel,
                 struct perf_sample *sample, struct thread *thread)
{
    int printed = 0;

    if (trace->print_sample) {
        double ts = (double)sample->time / NSEC_PER_MSEC;

        printed += fprintf(trace->output, "%22s %10.3f %s %d/%d [%d]\n",
                   perf_evsel__name(evsel), ts,
                   thread__comm_str(thread),
                   sample->pid, sample->tid, sample->cpu);
    }

    return printed;
}

static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel,
                union perf_event *event __maybe_unused,
                struct perf_sample *sample)
{
    char *msg;
    void *args;
    size_t printed = 0;
    struct thread *thread;
    int id = perf_evsel__sc_tp_uint(evsel, id, sample), err = -1;
    struct syscall *sc = trace__syscall_info(trace, evsel, id);
    struct thread_trace *ttrace;

    if (sc == NULL)
        return -1;

    thread = machine__findnew_thread(trace->host, sample->pid, sample->tid);
    ttrace = thread__trace(thread, trace->output);
    if (ttrace == NULL)
        goto out_put;

    trace__fprintf_sample(trace, evsel, sample, thread);

    args = perf_evsel__sc_tp_ptr(evsel, args, sample);

    if (ttrace->entry_str == NULL) {
        ttrace->entry_str = malloc(trace__entry_str_size);
        if (!ttrace->entry_str)
            goto out_put;
    }

    if (!(trace->duration_filter || trace->summary_only || trace->min_stack))
        trace__printf_interrupted_entry(trace);

    ttrace->entry_time = sample->time;
    msg = ttrace->entry_str;
    printed += scnprintf(msg + printed, trace__entry_str_size - printed, "%s(", sc->name);

    printed += syscall__scnprintf_args(sc, msg + printed, trace__entry_str_size - printed,
                       args, trace, thread);

    if (sc->is_exit) {
        if (!(trace->duration_filter || trace->summary_only || trace->failure_only || trace->min_stack)) {
            trace__fprintf_entry_head(trace, thread, 0, false, ttrace->entry_time, trace->output);
            fprintf(trace->output, "%-70s)\n", ttrace->entry_str);
        }
    } else {
        ttrace->entry_pending = true;
        /* See trace__vfs_getname & trace__sys_exit */
        ttrace->filename.pending_open = false;
    }

    if (trace->current != thread) {
        thread__put(trace->current);
        trace->current = thread__get(thread);
    }
    err = 0;
out_put:
    thread__put(thread);
    return err;
}

static int trace__resolve_callchain(struct trace *trace, struct perf_evsel *evsel,
                    struct perf_sample *sample,
                    struct callchain_cursor *cursor)
{
    struct addr_location al;
    int max_stack = evsel->attr.sample_max_stack ?
            evsel->attr.sample_max_stack :
            trace->max_stack;

    if (machine__resolve(trace->host, &al, sample) < 0 ||
        thread__resolve_callchain(al.thread, cursor, evsel, sample, NULL, NULL, max_stack))
        return -1;

    return 0;
}

static int trace__fprintf_callchain(struct trace *trace, struct perf_sample *sample)
{
    /* TODO: user-configurable print_opts */
    const unsigned int print_opts = EVSEL__PRINT_SYM |
                        EVSEL__PRINT_DSO |
                        EVSEL__PRINT_UNKNOWN_AS_ADDR;

    return sample__fprintf_callchain(sample, 38, print_opts, &callchain_cursor, trace->output);
}

static const char *errno_to_name(struct perf_evsel *evsel, int err)
{
    struct perf_env *env = perf_evsel__env(evsel);
    const char *arch_name = perf_env__arch(env);

    return arch_syscalls__strerrno(arch_name, err);
}

static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel,
               union perf_event *event __maybe_unused,
               struct perf_sample *sample)
{
    long ret;
    u64 duration = 0;
    bool duration_calculated = false;
    struct thread *thread;
    int id = perf_evsel__sc_tp_uint(evsel, id, sample), err = -1, callchain_ret = 0;
    struct syscall *sc = trace__syscall_info(trace, evsel, id);
    struct thread_trace *ttrace;

    if (sc == NULL)
        return -1;

    thread = machine__findnew_thread(trace->host, sample->pid, sample->tid);
    ttrace = thread__trace(thread, trace->output);
    if (ttrace == NULL)
        goto out_put;

    trace__fprintf_sample(trace, evsel, sample, thread);

    if (trace->summary)
        thread__update_stats(ttrace, id, sample);

    ret = perf_evsel__sc_tp_uint(evsel, ret, sample);

    if (id == trace->open_id && ret >= 0 && ttrace->filename.pending_open) {
        trace__set_fd_pathname(thread, ret, ttrace->filename.name);
        ttrace->filename.pending_open = false;
        ++trace->stats.vfs_getname;
    }

    if (ttrace->entry_time) {
        duration = sample->time - ttrace->entry_time;
        if (trace__filter_duration(trace, duration))
            goto out;
        duration_calculated = true;
    } else if (trace->duration_filter)
        goto out;

    if (sample->callchain) {
        callchain_ret = trace__resolve_callchain(trace, evsel, sample, &callchain_cursor);
        if (callchain_ret == 0) {
            if (callchain_cursor.nr < trace->min_stack)
                goto out;
            callchain_ret = 1;
        }
    }

    if (trace->summary_only || (ret >= 0 && trace->failure_only))
        goto out;

    trace__fprintf_entry_head(trace, thread, duration, duration_calculated, ttrace->entry_time, trace->output);

    if (ttrace->entry_pending) {
        fprintf(trace->output, "%-70s", ttrace->entry_str);
    } else {
        fprintf(trace->output, " ... [");
        color_fprintf(trace->output, PERF_COLOR_YELLOW, "continued");
        fprintf(trace->output, "]: %s()", sc->name);
    }

    if (sc->fmt == NULL) {
        if (ret < 0)
            goto errno_print;
signed_print:
        fprintf(trace->output, ") = %ld", ret);
    } else if (ret < 0) {
errno_print: {
        char bf[STRERR_BUFSIZE];
        const char *emsg = str_error_r(-ret, bf, sizeof(bf)),
               *e = errno_to_name(evsel, -ret);

        fprintf(trace->output, ") = -1 %s %s", e, emsg);
    }
    } else if (ret == 0 && sc->fmt->timeout)
        fprintf(trace->output, ") = 0 Timeout");
    else if (ttrace->ret_scnprintf) {
        char bf[1024];
        struct syscall_arg arg = {
            .val    = ret,
            .thread = thread,
            .trace  = trace,
        };
        ttrace->ret_scnprintf(bf, sizeof(bf), &arg);
        ttrace->ret_scnprintf = NULL;
        fprintf(trace->output, ") = %s", bf);
    } else if (sc->fmt->hexret)
        fprintf(trace->output, ") = %#lx", ret);
    else if (sc->fmt->errpid) {
        struct thread *child = machine__find_thread(trace->host, ret, ret);

        if (child != NULL) {
            fprintf(trace->output, ") = %ld", ret);
            if (child->comm_set)
                fprintf(trace->output, " (%s)", thread__comm_str(child));
            thread__put(child);
        }
    } else
        goto signed_print;

    fputc('\n', trace->output);

    if (callchain_ret > 0)
        trace__fprintf_callchain(trace, sample);
    else if (callchain_ret < 0)
        pr_err("Problem processing %s callchain, skipping...\n", perf_evsel__name(evsel));
out:
    ttrace->entry_pending = false;
    err = 0;
out_put:
    thread__put(thread);
    return err;
}

static int trace__vfs_getname(struct trace *trace, struct perf_evsel *evsel,
                  union perf_event *event __maybe_unused,
                  struct perf_sample *sample)
{
    struct thread *thread = machine__findnew_thread(trace->host, sample->pid, sample->tid);
    struct thread_trace *ttrace;
    size_t filename_len, entry_str_len, to_move;
    ssize_t remaining_space;
    char *pos;
    const char *filename = perf_evsel__rawptr(evsel, sample, "pathname");

    if (!thread)
        goto out;

    ttrace = thread__priv(thread);
    if (!ttrace)
        goto out_put;

    filename_len = strlen(filename);
    if (filename_len == 0)
        goto out_put;

    if (ttrace->filename.namelen < filename_len) {
        char *f = realloc(ttrace->filename.name, filename_len + 1);

        if (f == NULL)
            goto out_put;

        ttrace->filename.namelen = filename_len;
        ttrace->filename.name = f;
    }

    strcpy(ttrace->filename.name, filename);
    ttrace->filename.pending_open = true;

    if (!ttrace->filename.ptr)
        goto out_put;

    entry_str_len = strlen(ttrace->entry_str);
    remaining_space = trace__entry_str_size - entry_str_len - 1; /* \0 */
    if (remaining_space <= 0)
        goto out_put;

    if (filename_len > (size_t)remaining_space) {
        filename += filename_len - remaining_space;
        filename_len = remaining_space;
    }

    to_move = entry_str_len - ttrace->filename.entry_str_pos + 1; /* \0 */
    pos = ttrace->entry_str + ttrace->filename.entry_str_pos;
    memmove(pos + filename_len, pos, to_move);
    memcpy(pos, filename, filename_len);

    ttrace->filename.ptr = 0;
    ttrace->filename.entry_str_pos = 0;
out_put:
    thread__put(thread);
out:
    return 0;
}

static int trace__sched_stat_runtime(struct trace *trace, struct perf_evsel *evsel,
                     union perf_event *event __maybe_unused,
                     struct perf_sample *sample)
{
        u64 runtime = perf_evsel__intval(evsel, sample, "runtime");
    double runtime_ms = (double)runtime / NSEC_PER_MSEC;
    struct thread *thread = machine__findnew_thread(trace->host,
                            sample->pid,
                            sample->tid);
    struct thread_trace *ttrace = thread__trace(thread, trace->output);

    if (ttrace == NULL)
        goto out_dump;

    ttrace->runtime_ms += runtime_ms;
    trace->runtime_ms += runtime_ms;
out_put:
    thread__put(thread);
    return 0;

out_dump:
    fprintf(trace->output, "%s: comm=%s,pid=%u,runtime=%" PRIu64 ",vruntime=%" PRIu64 ")\n",
           evsel->name,
           perf_evsel__strval(evsel, sample, "comm"),
           (pid_t)perf_evsel__intval(evsel, sample, "pid"),
           runtime,
           perf_evsel__intval(evsel, sample, "vruntime"));
    goto out_put;
}

static int bpf_output__printer(enum binary_printer_ops op,
                   unsigned int val, void *extra __maybe_unused, FILE *fp)
{
    unsigned char ch = (unsigned char)val;

    switch (op) {
    case BINARY_PRINT_CHAR_DATA:
        return fprintf(fp, "%c", isprint(ch) ? ch : '.');
    case BINARY_PRINT_DATA_BEGIN:
    case BINARY_PRINT_LINE_BEGIN:
    case BINARY_PRINT_ADDR:
    case BINARY_PRINT_NUM_DATA:
    case BINARY_PRINT_NUM_PAD:
    case BINARY_PRINT_SEP:
    case BINARY_PRINT_CHAR_PAD:
    case BINARY_PRINT_LINE_END:
    case BINARY_PRINT_DATA_END:
    default:
        break;
    }

    return 0;
}

static void bpf_output__fprintf(struct trace *trace,
                struct perf_sample *sample)
{
    binary__fprintf(sample->raw_data, sample->raw_size, 8,
            bpf_output__printer, NULL, trace->output);
}

static int trace__event_handler(struct trace *trace, struct perf_evsel *evsel,
                union perf_event *event __maybe_unused,
                struct perf_sample *sample)
{
    int callchain_ret = 0;

    if (sample->callchain) {
        callchain_ret = trace__resolve_callchain(trace, evsel, sample, &callchain_cursor);
        if (callchain_ret == 0) {
            if (callchain_cursor.nr < trace->min_stack)
                goto out;
            callchain_ret = 1;
        }
    }

    trace__printf_interrupted_entry(trace);
    trace__fprintf_tstamp(trace, sample->time, trace->output);

    if (trace->trace_syscalls)
        fprintf(trace->output, "(         ): ");

    fprintf(trace->output, "%s:", evsel->name);

    if (perf_evsel__is_bpf_output(evsel)) {
        bpf_output__fprintf(trace, sample);
    } else if (evsel->tp_format) {
        event_format__fprintf(evsel->tp_format, sample->cpu,
                      sample->raw_data, sample->raw_size,
                      trace->output);
    }

    fprintf(trace->output, "\n");

    if (callchain_ret > 0)
        trace__fprintf_callchain(trace, sample);
    else if (callchain_ret < 0)
        pr_err("Problem processing %s callchain, skipping...\n", perf_evsel__name(evsel));
out:
    return 0;
}

static void print_location(FILE *f, struct perf_sample *sample,
               struct addr_location *al,
               bool print_dso, bool print_sym)
{

    if ((verbose > 0 || print_dso) && al->map)
        fprintf(f, "%s@", al->map->dso->long_name);

    if ((verbose > 0 || print_sym) && al->sym)
        fprintf(f, "%s+0x%" PRIx64, al->sym->name,
            al->addr - al->sym->start);
    else if (al->map)
        fprintf(f, "0x%" PRIx64, al->addr);
    else
        fprintf(f, "0x%" PRIx64, sample->addr);
}

static int trace__pgfault(struct trace *trace,
              struct perf_evsel *evsel,
              union perf_event *event __maybe_unused,
              struct perf_sample *sample)
{
    struct thread *thread;
    struct addr_location al;
    char map_type = 'd';
    struct thread_trace *ttrace;
    int err = -1;
    int callchain_ret = 0;

    thread = machine__findnew_thread(trace->host, sample->pid, sample->tid);

    if (sample->callchain) {
        callchain_ret = trace__resolve_callchain(trace, evsel, sample, &callchain_cursor);
        if (callchain_ret == 0) {
            if (callchain_cursor.nr < trace->min_stack)
                goto out_put;
            callchain_ret = 1;
        }
    }

    ttrace = thread__trace(thread, trace->output);
    if (ttrace == NULL)
        goto out_put;

    if (evsel->attr.config == PERF_COUNT_SW_PAGE_FAULTS_MAJ)
        ttrace->pfmaj++;
    else
        ttrace->pfmin++;

    if (trace->summary_only)
        goto out;

    thread__find_symbol(thread, sample->cpumode, sample->ip, &al);

    trace__fprintf_entry_head(trace, thread, 0, true, sample->time, trace->output);

    fprintf(trace->output, "%sfault [",
        evsel->attr.config == PERF_COUNT_SW_PAGE_FAULTS_MAJ ?
        "maj" : "min");

    print_location(trace->output, sample, &al, false, true);

    fprintf(trace->output, "] => ");

    thread__find_symbol(thread, sample->cpumode, sample->addr, &al);

    if (!al.map) {
        thread__find_symbol(thread, sample->cpumode, sample->addr, &al);

        if (al.map)
            map_type = 'x';
        else
            map_type = '?';
    }

    print_location(trace->output, sample, &al, true, false);

    fprintf(trace->output, " (%c%c)\n", map_type, al.level);

    if (callchain_ret > 0)
        trace__fprintf_callchain(trace, sample);
    else if (callchain_ret < 0)
        pr_err("Problem processing %s callchain, skipping...\n", perf_evsel__name(evsel));
out:
    err = 0;
out_put:
    thread__put(thread);
    return err;
}

static void trace__set_base_time(struct trace *trace,
                 struct perf_evsel *evsel,
                 struct perf_sample *sample)
{
    /*
     * BPF events were not setting PERF_SAMPLE_TIME, so be more robust
     * and don't use sample->time unconditionally, we may end up having
     * some other event in the future without PERF_SAMPLE_TIME for good
     * reason, i.e. we may not be interested in its timestamps, just in
     * it taking place, picking some piece of information when it
     * appears in our event stream (vfs_getname comes to mind).
     */
    if (trace->base_time == 0 && !trace->full_time &&
        (evsel->attr.sample_type & PERF_SAMPLE_TIME))
        trace->base_time = sample->time;
}

static int trace__process_sample(struct perf_tool *tool,
                 union perf_event *event,
                 struct perf_sample *sample,
                 struct perf_evsel *evsel,
                 struct machine *machine __maybe_unused)
{
    struct trace *trace = container_of(tool, struct trace, tool);
    struct thread *thread;
    int err = 0;

    tracepoint_handler handler = evsel->handler;

    thread = machine__findnew_thread(trace->host, sample->pid, sample->tid);
    if (thread && thread__is_filtered(thread))
        goto out;

    trace__set_base_time(trace, evsel, sample);

    if (handler) {
        ++trace->nr_events;
        handler(trace, evsel, event, sample);
    }
out:
    thread__put(thread);
    return err;
}

static int trace__record(struct trace *trace, int argc, const char **argv)
{
    unsigned int rec_argc, i, j;
    const char **rec_argv;
    const char * const record_args[] = {
        "record",
        "-R",
        "-m", "1024",
        "-c", "1",
    };

    const char * const sc_args[] = { "-e", };
    unsigned int sc_args_nr = ARRAY_SIZE(sc_args);
    const char * const majpf_args[] = { "-e", "major-faults" };
    unsigned int majpf_args_nr = ARRAY_SIZE(majpf_args);
    const char * const minpf_args[] = { "-e", "minor-faults" };
    unsigned int minpf_args_nr = ARRAY_SIZE(minpf_args);

    /* +1 is for the event string below */
    rec_argc = ARRAY_SIZE(record_args) + sc_args_nr + 1 +
        majpf_args_nr + minpf_args_nr + argc;
    rec_argv = calloc(rec_argc + 1, sizeof(char *));

    if (rec_argv == NULL)
        return -ENOMEM;

    j = 0;
    for (i = 0; i < ARRAY_SIZE(record_args); i++)
        rec_argv[j++] = record_args[i];

    if (trace->trace_syscalls) {
        for (i = 0; i < sc_args_nr; i++)
            rec_argv[j++] = sc_args[i];

        /* event string may be different for older kernels - e.g., RHEL6 */
        if (is_valid_tracepoint("raw_syscalls:sys_enter"))
            rec_argv[j++] = "raw_syscalls:sys_enter,raw_syscalls:sys_exit";
        else if (is_valid_tracepoint("syscalls:sys_enter"))
            rec_argv[j++] = "syscalls:sys_enter,syscalls:sys_exit";
        else {
            pr_err("Neither raw_syscalls nor syscalls events exist.\n");
            free(rec_argv);
            return -1;
        }
    }

    if (trace->trace_pgfaults & TRACE_PFMAJ)
        for (i = 0; i < majpf_args_nr; i++)
            rec_argv[j++] = majpf_args[i];

    if (trace->trace_pgfaults & TRACE_PFMIN)
        for (i = 0; i < minpf_args_nr; i++)
            rec_argv[j++] = minpf_args[i];

    for (i = 0; i < (unsigned int)argc; i++)
        rec_argv[j++] = argv[i];

    return cmd_record(j, rec_argv);
}

static size_t trace__fprintf_thread_summary(struct trace *trace, FILE *fp);

static bool perf_evlist__add_vfs_getname(struct perf_evlist *evlist)
{
    struct perf_evsel *evsel = perf_evsel__newtp("probe", "vfs_getname");

    if (IS_ERR(evsel))
        return false;

    if (perf_evsel__field(evsel, "pathname") == NULL) {
        perf_evsel__delete(evsel);
        return false;
    }

    evsel->handler = trace__vfs_getname;
    perf_evlist__add(evlist, evsel);
    return true;
}

static struct perf_evsel *perf_evsel__new_pgfault(u64 config)
{
    struct perf_evsel *evsel;
    struct perf_event_attr attr = {
        .type = PERF_TYPE_SOFTWARE,
        .mmap_data = 1,
    };

    attr.config = config;
    attr.sample_period = 1;

    event_attr_init(&attr);

    evsel = perf_evsel__new(&attr);
    if (evsel)
        evsel->handler = trace__pgfault;

    return evsel;
}

static void trace__handle_event(struct trace *trace, union perf_event *event, struct perf_sample *sample)
{
    const u32 type = event->header.type;
    struct perf_evsel *evsel;

    if (type != PERF_RECORD_SAMPLE) {
        trace__process_event(trace, trace->host, event, sample);
        return;
    }

    evsel = perf_evlist__id2evsel(trace->evlist, sample->id);
    if (evsel == NULL) {
        fprintf(trace->output, "Unknown tp ID %" PRIu64 ", skipping...\n", sample->id);
        return;
    }

    trace__set_base_time(trace, evsel, sample);

    if (evsel->attr.type == PERF_TYPE_TRACEPOINT &&
        sample->raw_data == NULL) {
        fprintf(trace->output, "%s sample with no payload for tid: %d, cpu %d, raw_size=%d, skipping...\n",
               perf_evsel__name(evsel), sample->tid,
               sample->cpu, sample->raw_size);
    } else {
        tracepoint_handler handler = evsel->handler;
        handler(trace, evsel, event, sample);
    }
}

static int trace__add_syscall_newtp(struct trace *trace)
{
    int ret = -1;
    struct perf_evlist *evlist = trace->evlist;
    struct perf_evsel *sys_enter, *sys_exit;

    sys_enter = perf_evsel__syscall_newtp("sys_enter", trace__sys_enter);
    if (sys_enter == NULL)
        goto out;

    if (perf_evsel__init_sc_tp_ptr_field(sys_enter, args))
        goto out_delete_sys_enter;

    sys_exit = perf_evsel__syscall_newtp("sys_exit", trace__sys_exit);
    if (sys_exit == NULL)
        goto out_delete_sys_enter;

    if (perf_evsel__init_sc_tp_uint_field(sys_exit, ret))
        goto out_delete_sys_exit;

    perf_evsel__config_callchain(sys_enter, &trace->opts, &callchain_param);
    perf_evsel__config_callchain(sys_exit, &trace->opts, &callchain_param);

    perf_evlist__add(evlist, sys_enter);
    perf_evlist__add(evlist, sys_exit);

    if (callchain_param.enabled && !trace->kernel_syscallchains) {
        /*
         * We're interested only in the user space callchain
         * leading to the syscall, allow overriding that for
         * debugging reasons using --kernel_syscall_callchains
         */
        sys_exit->attr.exclude_callchain_kernel = 1;
    }

    trace->syscalls.events.sys_enter = sys_enter;
    trace->syscalls.events.sys_exit  = sys_exit;

    ret = 0;
out:
    return ret;

out_delete_sys_exit:
    perf_evsel__delete_priv(sys_exit);
out_delete_sys_enter:
    perf_evsel__delete_priv(sys_enter);
    goto out;
}

static int trace__set_ev_qualifier_filter(struct trace *trace)
{
    int err = -1;
    struct perf_evsel *sys_exit;
    char *filter = asprintf_expr_inout_ints("id", !trace->not_ev_qualifier,
                        trace->ev_qualifier_ids.nr,
                        trace->ev_qualifier_ids.entries);

    if (filter == NULL)
        goto out_enomem;

    if (!perf_evsel__append_tp_filter(trace->syscalls.events.sys_enter,
                      filter)) {
        sys_exit = trace->syscalls.events.sys_exit;
        err = perf_evsel__append_tp_filter(sys_exit, filter);
    }

    free(filter);
out:
    return err;
out_enomem:
    errno = ENOMEM;
    goto out;
}

static int trace__set_filter_loop_pids(struct trace *trace)
{
    unsigned int nr = 1;
    pid_t pids[32] = {
        getpid(),
    };
    struct thread *thread = machine__find_thread(trace->host, pids[0], pids[0]);

    while (thread && nr < ARRAY_SIZE(pids)) {
        struct thread *parent = machine__find_thread(trace->host, thread->ppid, thread->ppid);

        if (parent == NULL)
            break;

        if (!strcmp(thread__comm_str(parent), "sshd")) {
            pids[nr++] = parent->tid;
            break;
        }
        thread = parent;
    }

    return perf_evlist__set_filter_pids(trace->evlist, nr, pids);
}

static int trace__run(struct trace *trace, int argc, const char **argv)
{
    struct perf_evlist *evlist = trace->evlist;
    struct perf_evsel *evsel, *pgfault_maj = NULL, *pgfault_min = NULL;
    int err = -1, i;
    unsigned long before;
    const bool forks = argc > 0;
    bool draining = false;

    trace->live = true;

    if (trace->trace_syscalls && trace__add_syscall_newtp(trace))
        goto out_error_raw_syscalls;

    if (trace->trace_syscalls)
        trace->vfs_getname = perf_evlist__add_vfs_getname(evlist);

    if ((trace->trace_pgfaults & TRACE_PFMAJ)) {
        pgfault_maj = perf_evsel__new_pgfault(PERF_COUNT_SW_PAGE_FAULTS_MAJ);
        if (pgfault_maj == NULL)
            goto out_error_mem;
        perf_evsel__config_callchain(pgfault_maj, &trace->opts, &callchain_param);
        perf_evlist__add(evlist, pgfault_maj);
    }

    if ((trace->trace_pgfaults & TRACE_PFMIN)) {
        pgfault_min = perf_evsel__new_pgfault(PERF_COUNT_SW_PAGE_FAULTS_MIN);
        if (pgfault_min == NULL)
            goto out_error_mem;
        perf_evsel__config_callchain(pgfault_min, &trace->opts, &callchain_param);
        perf_evlist__add(evlist, pgfault_min);
    }

    if (trace->sched &&
        perf_evlist__add_newtp(evlist, "sched", "sched_stat_runtime",
                   trace__sched_stat_runtime))
        goto out_error_sched_stat_runtime;

    /*
     * If a global cgroup was set, apply it to all the events without an
     * explicit cgroup. I.e.:
     *
     *  trace -G A -e sched:*switch
     *
     * Will set all raw_syscalls:sys_{enter,exit}, pgfault, vfs_getname, etc
     * _and_ sched:sched_switch to the 'A' cgroup, while:
     *
     * trace -e sched:*switch -G A
     *
     * will only set the sched:sched_switch event to the 'A' cgroup, all the
     * other events (raw_syscalls:sys_{enter,exit}, etc are left "without"
     * a cgroup (on the root cgroup, sys wide, etc).
     *
     * Multiple cgroups:
     *
     * trace -G A -e sched:*switch -G B
     *
     * the syscall ones go to the 'A' cgroup, the sched:sched_switch goes
     * to the 'B' cgroup.
     *
     * evlist__set_default_cgroup() grabs a reference of the passed cgroup
     * only for the evsels still without a cgroup, i.e. evsel->cgroup == NULL.
     */
    if (trace->cgroup)
        evlist__set_default_cgroup(trace->evlist, trace->cgroup);

    err = perf_evlist__create_maps(evlist, &trace->opts.target);
    if (err < 0) {
        fprintf(trace->output, "Problems parsing the target to trace, check your options!\n");
        goto out_delete_evlist;
    }

    err = trace__symbols_init(trace, evlist);
    if (err < 0) {
        fprintf(trace->output, "Problems initializing symbol libraries!\n");
        goto out_delete_evlist;
    }

    perf_evlist__config(evlist, &trace->opts, &callchain_param);

    signal(SIGCHLD, sig_handler);
    signal(SIGINT, sig_handler);

    if (forks) {
        err = perf_evlist__prepare_workload(evlist, &trace->opts.target,
                            argv, false, NULL);
        if (err < 0) {
            fprintf(trace->output, "Couldn't run the workload!\n");
            goto out_delete_evlist;
        }
    }

    err = perf_evlist__open(evlist);
    if (err < 0)
        goto out_error_open;

    err = bpf__apply_obj_config();
    if (err) {
        char errbuf[BUFSIZ];

        bpf__strerror_apply_obj_config(err, errbuf, sizeof(errbuf));
        pr_err("ERROR: Apply config to BPF failed: %s\n",
             errbuf);
        goto out_error_open;
    }

    /*
     * Better not use !target__has_task() here because we need to cover the
     * case where no threads were specified in the command line, but a
     * workload was, and in that case we will fill in the thread_map when
     * we fork the workload in perf_evlist__prepare_workload.
     */
    if (trace->filter_pids.nr > 0)
        err = perf_evlist__set_filter_pids(evlist, trace->filter_pids.nr, trace->filter_pids.entries);
    else if (thread_map__pid(evlist->threads, 0) == -1)
        err = trace__set_filter_loop_pids(trace);

    if (err < 0)
        goto out_error_mem;

    if (trace->ev_qualifier_ids.nr > 0) {
        err = trace__set_ev_qualifier_filter(trace);
        if (err < 0)
            goto out_errno;

        pr_debug("event qualifier tracepoint filter: %s\n",
             trace->syscalls.events.sys_exit->filter);
    }

    err = perf_evlist__apply_filters(evlist, &evsel);
    if (err < 0)
        goto out_error_apply_filters;

    err = perf_evlist__mmap(evlist, trace->opts.mmap_pages);
    if (err < 0)
        goto out_error_mmap;

    if (!target__none(&trace->opts.target) && !trace->opts.initial_delay)
        perf_evlist__enable(evlist);

    if (forks)
        perf_evlist__start_workload(evlist);

    if (trace->opts.initial_delay) {
        usleep(trace->opts.initial_delay * 1000);
        perf_evlist__enable(evlist);
    }

    trace->multiple_threads = thread_map__pid(evlist->threads, 0) == -1 ||
                  evlist->threads->nr > 1 ||
                  perf_evlist__first(evlist)->attr.inherit;

    /*
     * Now that we already used evsel->attr to ask the kernel to setup the
     * events, lets reuse evsel->attr.sample_max_stack as the limit in
     * trace__resolve_callchain(), allowing per-event max-stack settings
     * to override an explicitely set --max-stack global setting.
     */
    evlist__for_each_entry(evlist, evsel) {
        if (evsel__has_callchain(evsel) &&
            evsel->attr.sample_max_stack == 0)
            evsel->attr.sample_max_stack = trace->max_stack;
    }
again:
    before = trace->nr_events;

    for (i = 0; i < evlist->nr_mmaps; i++) {
        union perf_event *event;
        struct perf_mmap *md;

        md = &evlist->mmap[i];
        if (perf_mmap__read_init(md) < 0)
            continue;

        while ((event = perf_mmap__read_event(md)) != NULL) {
            struct perf_sample sample;

            ++trace->nr_events;

            err = perf_evlist__parse_sample(evlist, event, &sample);
            if (err) {
                fprintf(trace->output, "Can't parse sample, err = %d, skipping...\n", err);
                goto next_event;
            }

            trace__handle_event(trace, event, &sample);
next_event:
            perf_mmap__consume(md);

            if (interrupted)
                goto out_disable;

            if (done && !draining) {
                perf_evlist__disable(evlist);
                draining = true;
            }
        }
        perf_mmap__read_done(md);
    }

    if (trace->nr_events == before) {
        int timeout = done ? 100 : -1;

        if (!draining && perf_evlist__poll(evlist, timeout) > 0) {
            if (perf_evlist__filter_pollfd(evlist, POLLERR | POLLHUP) == 0)
                draining = true;

            goto again;
        }
    } else {
        goto again;
    }

out_disable:
    thread__zput(trace->current);

    perf_evlist__disable(evlist);

    if (!err) {
        if (trace->summary)
            trace__fprintf_thread_summary(trace, trace->output);

        if (trace->show_tool_stats) {
            fprintf(trace->output, "Stats:\n "
                           " vfs_getname : %" PRIu64 "\n"
                           " proc_getname: %" PRIu64 "\n",
                trace->stats.vfs_getname,
                trace->stats.proc_getname);
        }
    }

out_delete_evlist:
    trace__symbols__exit(trace);

    perf_evlist__delete(evlist);
    cgroup__put(trace->cgroup);
    trace->evlist = NULL;
    trace->live = false;
    return err;
{
    char errbuf[BUFSIZ];

out_error_sched_stat_runtime:
    tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "sched", "sched_stat_runtime");
    goto out_error;

out_error_raw_syscalls:
    tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "raw_syscalls", "sys_(enter|exit)");
    goto out_error;

out_error_mmap:
    perf_evlist__strerror_mmap(evlist, errno, errbuf, sizeof(errbuf));
    goto out_error;

out_error_open:
    perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));

out_error:
    fprintf(trace->output, "%s\n", errbuf);
    goto out_delete_evlist;

out_error_apply_filters:
    fprintf(trace->output,
        "Failed to set filter \"%s\" on event %s with %d (%s)\n",
        evsel->filter, perf_evsel__name(evsel), errno,
        str_error_r(errno, errbuf, sizeof(errbuf)));
    goto out_delete_evlist;
}
out_error_mem:
    fprintf(trace->output, "Not enough memory to run!\n");
    goto out_delete_evlist;

out_errno:
    fprintf(trace->output, "errno=%d,%s\n", errno, strerror(errno));
    goto out_delete_evlist;
}

static int trace__replay(struct trace *trace)
{
    const struct perf_evsel_str_handler handlers[] = {
        { "probe:vfs_getname",       trace__vfs_getname, },
    };
    struct perf_data data = {
        .file      = {
            .path = input_name,
        },
        .mode      = PERF_DATA_MODE_READ,
        .force     = trace->force,
    };
    struct perf_session *session;
    struct perf_evsel *evsel;
    int err = -1;

    trace->tool.sample    = trace__process_sample;
    trace->tool.mmap      = perf_event__process_mmap;
    trace->tool.mmap2     = perf_event__process_mmap2;
    trace->tool.comm      = perf_event__process_comm;
    trace->tool.exit      = perf_event__process_exit;
    trace->tool.fork      = perf_event__process_fork;
    trace->tool.attr      = perf_event__process_attr;
    trace->tool.tracing_data  = perf_event__process_tracing_data;
    trace->tool.build_id      = perf_event__process_build_id;
    trace->tool.namespaces    = perf_event__process_namespaces;

    trace->tool.ordered_events = true;
    trace->tool.ordering_requires_timestamps = true;

    /* add tid to output */
    trace->multiple_threads = true;

    session = perf_session__new(&data, false, &trace->tool);
    if (session == NULL)
        return -1;

    if (trace->opts.target.pid)
        symbol_conf.pid_list_str = strdup(trace->opts.target.pid);

    if (trace->opts.target.tid)
        symbol_conf.tid_list_str = strdup(trace->opts.target.tid);

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

    trace->host = &session->machines.host;

    err = perf_session__set_tracepoints_handlers(session, handlers);
    if (err)
        goto out;

    evsel = perf_evlist__find_tracepoint_by_name(session->evlist,
                             "raw_syscalls:sys_enter");
    /* older kernels have syscalls tp versus raw_syscalls */
    if (evsel == NULL)
        evsel = perf_evlist__find_tracepoint_by_name(session->evlist,
                                 "syscalls:sys_enter");

    if (evsel &&
        (perf_evsel__init_syscall_tp(evsel, trace__sys_enter) < 0 ||
        perf_evsel__init_sc_tp_ptr_field(evsel, args))) {
        pr_err("Error during initialize raw_syscalls:sys_enter event\n");
        goto out;
    }

    evsel = perf_evlist__find_tracepoint_by_name(session->evlist,
                             "raw_syscalls:sys_exit");
    if (evsel == NULL)
        evsel = perf_evlist__find_tracepoint_by_name(session->evlist,
                                 "syscalls:sys_exit");
    if (evsel &&
        (perf_evsel__init_syscall_tp(evsel, trace__sys_exit) < 0 ||
        perf_evsel__init_sc_tp_uint_field(evsel, ret))) {
        pr_err("Error during initialize raw_syscalls:sys_exit event\n");
        goto out;
    }

    evlist__for_each_entry(session->evlist, evsel) {
        if (evsel->attr.type == PERF_TYPE_SOFTWARE &&
            (evsel->attr.config == PERF_COUNT_SW_PAGE_FAULTS_MAJ ||
             evsel->attr.config == PERF_COUNT_SW_PAGE_FAULTS_MIN ||
             evsel->attr.config == PERF_COUNT_SW_PAGE_FAULTS))
            evsel->handler = trace__pgfault;
    }

    setup_pager();

    err = perf_session__process_events(session);
    if (err)
        pr_err("Failed to process events, error %d", err);

    else if (trace->summary)
        trace__fprintf_thread_summary(trace, trace->output);

out:
    perf_session__delete(session);

    return err;
}

static size_t trace__fprintf_threads_header(FILE *fp)
{
    size_t printed;

    printed  = fprintf(fp, "\n Summary of events:\n\n");

    return printed;
}

DEFINE_RESORT_RB(syscall_stats, a->msecs > b->msecs,
    struct stats    *stats;
    double      msecs;
    int     syscall;
)
{
    struct int_node *source = rb_entry(nd, struct int_node, rb_node);
    struct stats *stats = source->priv;

    entry->syscall = source->i;
    entry->stats   = stats;
    entry->msecs   = stats ? (u64)stats->n * (avg_stats(stats) / NSEC_PER_MSEC) : 0;
}

static size_t thread__dump_stats(struct thread_trace *ttrace,
                 struct trace *trace, FILE *fp)
{
    size_t printed = 0;
    struct syscall *sc;
    struct rb_node *nd;
    DECLARE_RESORT_RB_INTLIST(syscall_stats, ttrace->syscall_stats);

    if (syscall_stats == NULL)
        return 0;

    printed += fprintf(fp, "\n");

    printed += fprintf(fp, "   syscall            calls    total       min       avg       max      stddev\n");
    printed += fprintf(fp, "                               (msec)    (msec)    (msec)    (msec)        (%%)\n");
    printed += fprintf(fp, "   --------------- -------- --------- --------- --------- ---------     ------\n");

    resort_rb__for_each_entry(nd, syscall_stats) {
        struct stats *stats = syscall_stats_entry->stats;
        if (stats) {
            double min = (double)(stats->min) / NSEC_PER_MSEC;
            double max = (double)(stats->max) / NSEC_PER_MSEC;
            double avg = avg_stats(stats);
            double pct;
            u64 n = (u64) stats->n;

            pct = avg ? 100.0 * stddev_stats(stats)/avg : 0.0;
            avg /= NSEC_PER_MSEC;

            sc = &trace->syscalls.table[syscall_stats_entry->syscall];
            printed += fprintf(fp, "   %-15s", sc->name);
            printed += fprintf(fp, " %8" PRIu64 " %9.3f %9.3f %9.3f",
                       n, syscall_stats_entry->msecs, min, avg);
            printed += fprintf(fp, " %9.3f %9.2f%%\n", max, pct);
        }
    }

    resort_rb__delete(syscall_stats);
    printed += fprintf(fp, "\n\n");

    return printed;
}

static size_t trace__fprintf_thread(FILE *fp, struct thread *thread, struct trace *trace)
{
    size_t printed = 0;
    struct thread_trace *ttrace = thread__priv(thread);
    double ratio;

    if (ttrace == NULL)
        return 0;

    ratio = (double)ttrace->nr_events / trace->nr_events * 100.0;

    printed += fprintf(fp, " %s (%d), ", thread__comm_str(thread), thread->tid);
    printed += fprintf(fp, "%lu events, ", ttrace->nr_events);
    printed += fprintf(fp, "%.1f%%", ratio);
    if (ttrace->pfmaj)
        printed += fprintf(fp, ", %lu majfaults", ttrace->pfmaj);
    if (ttrace->pfmin)
        printed += fprintf(fp, ", %lu minfaults", ttrace->pfmin);
    if (trace->sched)
        printed += fprintf(fp, ", %.3f msec\n", ttrace->runtime_ms);
    else if (fputc('\n', fp) != EOF)
        ++printed;

    printed += thread__dump_stats(ttrace, trace, fp);

    return printed;
}

static unsigned long thread__nr_events(struct thread_trace *ttrace)
{
    return ttrace ? ttrace->nr_events : 0;
}

DEFINE_RESORT_RB(threads, (thread__nr_events(a->thread->priv) < thread__nr_events(b->thread->priv)),
    struct thread *thread;
)
{
    entry->thread = rb_entry(nd, struct thread, rb_node);
}

static size_t trace__fprintf_thread_summary(struct trace *trace, FILE *fp)
{
    size_t printed = trace__fprintf_threads_header(fp);
    struct rb_node *nd;
    int i;

    for (i = 0; i < THREADS__TABLE_SIZE; i++) {
        DECLARE_RESORT_RB_MACHINE_THREADS(threads, trace->host, i);

        if (threads == NULL) {
            fprintf(fp, "%s", "Error sorting output by nr_events!\n");
            return 0;
        }

        resort_rb__for_each_entry(nd, threads)
            printed += trace__fprintf_thread(fp, threads_entry->thread, trace);

        resort_rb__delete(threads);
    }
    return printed;
}

static int trace__set_duration(const struct option *opt, const char *str,
                   int unset __maybe_unused)
{
    struct trace *trace = opt->value;

    trace->duration_filter = atof(str);
    return 0;
}

static int trace__set_filter_pids(const struct option *opt, const char *str,
                  int unset __maybe_unused)
{
    int ret = -1;
    size_t i;
    struct trace *trace = opt->value;
    /*
     * FIXME: introduce a intarray class, plain parse csv and create a
     * { int nr, int entries[] } struct...
     */
    struct intlist *list = intlist__new(str);

    if (list == NULL)
        return -1;

    i = trace->filter_pids.nr = intlist__nr_entries(list) + 1;
    trace->filter_pids.entries = calloc(i, sizeof(pid_t));

    if (trace->filter_pids.entries == NULL)
        goto out;

    trace->filter_pids.entries[0] = getpid();

    for (i = 1; i < trace->filter_pids.nr; ++i)
        trace->filter_pids.entries[i] = intlist__entry(list, i - 1)->i;

    intlist__delete(list);
    ret = 0;
out:
    return ret;
}

static int trace__open_output(struct trace *trace, const char *filename)
{
    struct stat st;

    if (!stat(filename, &st) && st.st_size) {
        char oldname[PATH_MAX];

        scnprintf(oldname, sizeof(oldname), "%s.old", filename);
        unlink(oldname);
        rename(filename, oldname);
    }

    trace->output = fopen(filename, "w");

    return trace->output == NULL ? -errno : 0;
}

static int parse_pagefaults(const struct option *opt, const char *str,
                int unset __maybe_unused)
{
    int *trace_pgfaults = opt->value;

    if (strcmp(str, "all") == 0)
        *trace_pgfaults |= TRACE_PFMAJ | TRACE_PFMIN;
    else if (strcmp(str, "maj") == 0)
        *trace_pgfaults |= TRACE_PFMAJ;
    else if (strcmp(str, "min") == 0)
        *trace_pgfaults |= TRACE_PFMIN;
    else
        return -1;

    return 0;
}

static void evlist__set_evsel_handler(struct perf_evlist *evlist, void *handler)
{
    struct perf_evsel *evsel;

    evlist__for_each_entry(evlist, evsel)
        evsel->handler = handler;
}

/*
 * XXX: Hackish, just splitting the combined -e+--event (syscalls
 * (raw_syscalls:{sys_{enter,exit}} + events (tracepoints, HW, SW, etc) to use
 * existing facilities unchanged (trace->ev_qualifier + parse_options()).
 *
 * It'd be better to introduce a parse_options() variant that would return a
 * list with the terms it didn't match to an event...
 */
static int trace__parse_events_option(const struct option *opt, const char *str,
                      int unset __maybe_unused)
{
    struct trace *trace = (struct trace *)opt->value;
    const char *s = str;
    char *sep = NULL, *lists[2] = { NULL, NULL, };
    int len = strlen(str) + 1, err = -1, list, idx;
    char *strace_groups_dir = system_path(STRACE_GROUPS_DIR);
    char group_name[PATH_MAX];

    if (strace_groups_dir == NULL)
        return -1;

    if (*s == '!') {
        ++s;
        trace->not_ev_qualifier = true;
    }

    while (1) {
        if ((sep = strchr(s, ',')) != NULL)
            *sep = '\0';

        list = 0;
        if (syscalltbl__id(trace->sctbl, s) >= 0 ||
            syscalltbl__strglobmatch_first(trace->sctbl, s, &idx) >= 0) {
            list = 1;
        } else {
            path__join(group_name, sizeof(group_name), strace_groups_dir, s);
            if (access(group_name, R_OK) == 0)
                list = 1;
        }

        if (lists[list]) {
            sprintf(lists[list] + strlen(lists[list]), ",%s", s);
        } else {
            lists[list] = malloc(len);
            if (lists[list] == NULL)
                goto out;
            strcpy(lists[list], s);
        }

        if (!sep)
            break;

        *sep = ',';
        s = sep + 1;
    }

    if (lists[1] != NULL) {
        struct strlist_config slist_config = {
            .dirname = strace_groups_dir,
        };

        trace->ev_qualifier = strlist__new(lists[1], &slist_config);
        if (trace->ev_qualifier == NULL) {
            fputs("Not enough memory to parse event qualifier", trace->output);
            goto out;
        }

        if (trace__validate_ev_qualifier(trace))
            goto out;
    }

    err = 0;

    if (lists[0]) {
        struct option o = OPT_CALLBACK('e', "event", &trace->evlist, "event",
                           "event selector. use 'perf list' to list available events",
                           parse_events_option);
        err = parse_events_option(&o, lists[0], 0);
    }
out:
    if (sep)
        *sep = ',';

    return err;
}

static int trace__parse_cgroups(const struct option *opt, const char *str, int unset)
{
    struct trace *trace = opt->value;

    if (!list_empty(&trace->evlist->entries))
        return parse_cgroups(opt, str, unset);

    trace->cgroup = evlist__findnew_cgroup(trace->evlist, str);

    return 0;
}

int cmd_trace(int argc, const char **argv)
{
    const char *trace_usage[] = {
        "perf trace [<options>] [<command>]",
        "perf trace [<options>] -- <command> [<options>]",
        "perf trace record [<options>] [<command>]",
        "perf trace record [<options>] -- <command> [<options>]",
        NULL
    };
    struct trace trace = {
        .syscalls = {
            . max = -1,
        },
        .opts = {
            .target = {
                .uid       = UINT_MAX,
                .uses_mmap = true,
            },
            .user_freq     = UINT_MAX,
            .user_interval = ULLONG_MAX,
            .no_buffering  = true,
            .mmap_pages    = UINT_MAX,
            .proc_map_timeout  = 500,
        },
        .output = stderr,
        .show_comm = true,
        .trace_syscalls = true,
        .kernel_syscallchains = false,
        .max_stack = UINT_MAX,
    };
    const char *output_name = NULL;
    const struct option trace_options[] = {
    OPT_CALLBACK('e', "event", &trace, "event",
             "event/syscall selector. use 'perf list' to list available events",
             trace__parse_events_option),
    OPT_BOOLEAN(0, "comm", &trace.show_comm,
            "show the thread COMM next to its id"),
    OPT_BOOLEAN(0, "tool_stats", &trace.show_tool_stats, "show tool stats"),
    OPT_CALLBACK(0, "expr", &trace, "expr", "list of syscalls/events to trace",
             trace__parse_events_option),
    OPT_STRING('o', "output", &output_name, "file", "output file name"),
    OPT_STRING('i', "input", &input_name, "file", "Analyze events in file"),
    OPT_STRING('p', "pid", &trace.opts.target.pid, "pid",
            "trace events on existing process id"),
    OPT_STRING('t', "tid", &trace.opts.target.tid, "tid",
            "trace events on existing thread id"),
    OPT_CALLBACK(0, "filter-pids", &trace, "CSV list of pids",
             "pids to filter (by the kernel)", trace__set_filter_pids),
    OPT_BOOLEAN('a', "all-cpus", &trace.opts.target.system_wide,
            "system-wide collection from all CPUs"),
    OPT_STRING('C', "cpu", &trace.opts.target.cpu_list, "cpu",
            "list of cpus to monitor"),
    OPT_BOOLEAN(0, "no-inherit", &trace.opts.no_inherit,
            "child tasks do not inherit counters"),
    OPT_CALLBACK('m', "mmap-pages", &trace.opts.mmap_pages, "pages",
             "number of mmap data pages",
             perf_evlist__parse_mmap_pages),
    OPT_STRING('u', "uid", &trace.opts.target.uid_str, "user",
           "user to profile"),
    OPT_CALLBACK(0, "duration", &trace, "float",
             "show only events with duration > N.M ms",
             trace__set_duration),
    OPT_BOOLEAN(0, "sched", &trace.sched, "show blocking scheduler events"),
    OPT_INCR('v', "verbose", &verbose, "be more verbose"),
    OPT_BOOLEAN('T', "time", &trace.full_time,
            "Show full timestamp, not time relative to first start"),
    OPT_BOOLEAN(0, "failure", &trace.failure_only,
            "Show only syscalls that failed"),
    OPT_BOOLEAN('s', "summary", &trace.summary_only,
            "Show only syscall summary with statistics"),
    OPT_BOOLEAN('S', "with-summary", &trace.summary,
            "Show all syscalls and summary with statistics"),
    OPT_CALLBACK_DEFAULT('F', "pf", &trace.trace_pgfaults, "all|maj|min",
             "Trace pagefaults", parse_pagefaults, "maj"),
    OPT_BOOLEAN(0, "syscalls", &trace.trace_syscalls, "Trace syscalls"),
    OPT_BOOLEAN('f', "force", &trace.force, "don't complain, do it"),
    OPT_CALLBACK(0, "call-graph", &trace.opts,
             "record_mode[,record_size]", record_callchain_help,
             &record_parse_callchain_opt),
    OPT_BOOLEAN(0, "kernel-syscall-graph", &trace.kernel_syscallchains,
            "Show the kernel callchains on the syscall exit path"),
    OPT_UINTEGER(0, "min-stack", &trace.min_stack,
             "Set the minimum stack depth when parsing the callchain, "
             "anything below the specified depth will be ignored."),
    OPT_UINTEGER(0, "max-stack", &trace.max_stack,
             "Set the maximum stack depth when parsing the callchain, "
             "anything beyond the specified depth will be ignored. "
             "Default: kernel.perf_event_max_stack or " __stringify(PERF_MAX_STACK_DEPTH)),
    OPT_BOOLEAN(0, "print-sample", &trace.print_sample,
            "print the PERF_RECORD_SAMPLE PERF_SAMPLE_ info, for debugging"),
    OPT_UINTEGER(0, "proc-map-timeout", &trace.opts.proc_map_timeout,
            "per thread proc mmap processing timeout in ms"),
    OPT_CALLBACK('G', "cgroup", &trace, "name", "monitor event in cgroup name only",
             trace__parse_cgroups),
    OPT_UINTEGER('D', "delay", &trace.opts.initial_delay,
             "ms to wait before starting measurement after program "
             "start"),
    OPT_END()
    };
    bool __maybe_unused max_stack_user_set = true;
    bool mmap_pages_user_set = true;
    const char * const trace_subcommands[] = { "record", NULL };
    int err;
    char bf[BUFSIZ];

    signal(SIGSEGV, sighandler_dump_stack);
    signal(SIGFPE, sighandler_dump_stack);

    trace.evlist = perf_evlist__new();
    trace.sctbl = syscalltbl__new();

    if (trace.evlist == NULL || trace.sctbl == NULL) {
        pr_err("Not enough memory to run!\n");
        err = -ENOMEM;
        goto out;
    }

    argc = parse_options_subcommand(argc, argv, trace_options, trace_subcommands,
                 trace_usage, PARSE_OPT_STOP_AT_NON_OPTION);

    if ((nr_cgroups || trace.cgroup) && !trace.opts.target.system_wide) {
        usage_with_options_msg(trace_usage, trace_options,
                       "cgroup monitoring only available in system-wide mode");
    }

    err = bpf__setup_stdout(trace.evlist);
    if (err) {
        bpf__strerror_setup_stdout(trace.evlist, err, bf, sizeof(bf));
        pr_err("ERROR: Setup BPF stdout failed: %s\n", bf);
        goto out;
    }

    err = -1;

    if (trace.trace_pgfaults) {
        trace.opts.sample_address = true;
        trace.opts.sample_time = true;
    }

    if (trace.opts.mmap_pages == UINT_MAX)
        mmap_pages_user_set = false;

    if (trace.max_stack == UINT_MAX) {
        trace.max_stack = input_name ? PERF_MAX_STACK_DEPTH : sysctl__max_stack();
        max_stack_user_set = false;
    }

#ifdef HAVE_DWARF_UNWIND_SUPPORT
    if ((trace.min_stack || max_stack_user_set) && !callchain_param.enabled) {
        record_opts__parse_callchain(&trace.opts, &callchain_param, "dwarf", false);
    }
#endif

    if (callchain_param.enabled) {
        if (!mmap_pages_user_set && geteuid() == 0)
            trace.opts.mmap_pages = perf_event_mlock_kb_in_pages() * 4;

        symbol_conf.use_callchain = true;
    }

    if (trace.evlist->nr_entries > 0)
        evlist__set_evsel_handler(trace.evlist, trace__event_handler);

    if ((argc >= 1) && (strcmp(argv[0], "record") == 0))
        return trace__record(&trace, argc-1, &argv[1]);

    /* summary_only implies summary option, but don't overwrite summary if set */
    if (trace.summary_only)
        trace.summary = trace.summary_only;

    if (!trace.trace_syscalls && !trace.trace_pgfaults &&
        trace.evlist->nr_entries == 0 /* Was --events used? */) {
        pr_err("Please specify something to trace.\n");
        return -1;
    }

    if (!trace.trace_syscalls && trace.ev_qualifier) {
        pr_err("The -e option can't be used with --no-syscalls.\n");
        goto out;
    }

    if (output_name != NULL) {
        err = trace__open_output(&trace, output_name);
        if (err < 0) {
            perror("failed to create output file");
            goto out;
        }
    }

    trace.open_id = syscalltbl__id(trace.sctbl, "open");

    err = target__validate(&trace.opts.target);
    if (err) {
        target__strerror(&trace.opts.target, err, bf, sizeof(bf));
        fprintf(trace.output, "%s", bf);
        goto out_close;
    }

    err = target__parse_uid(&trace.opts.target);
    if (err) {
        target__strerror(&trace.opts.target, err, bf, sizeof(bf));
        fprintf(trace.output, "%s", bf);
        goto out_close;
    }

    if (!argc && target__none(&trace.opts.target))
        trace.opts.target.system_wide = true;

    if (input_name)
        err = trace__replay(&trace);
    else
        err = trace__run(&trace, argc, argv);

out_close:
    if (output_name != NULL)
        fclose(trace.output);
out:
    return err;
}