trace-event-perl.c

Go to the documentation of this file.

/*
 * trace-event-perl.  Feed perf script events to an embedded Perl interpreter.
 *
 * Copyright (C) 2009 Tom Zanussi <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include "../util.h"
#include <EXTERN.h>
#include <perl.h>

#include "../../perf.h"
#include "../thread.h"
#include "../event.h"
#include "../trace-event.h"
#include "../evsel.h"

void boot_Perf__Trace__Context(pTHX_ CV *cv);
void boot_DynaLoader(pTHX_ CV *cv);
typedef PerlInterpreter * INTERP;

void xs_init(pTHX);

void xs_init(pTHX)
{
    const char *file = __FILE__;
    dXSUB_SYS;

    newXS("Perf::Trace::Context::bootstrap", boot_Perf__Trace__Context,
          file);
    newXS("DynaLoader::boot_DynaLoader", boot_DynaLoader, file);
}

INTERP my_perl;

#define FTRACE_MAX_EVENT                \
    ((1 << (sizeof(unsigned short) * 8)) - 1)

struct event_format *events[FTRACE_MAX_EVENT];

extern struct scripting_context *scripting_context;

static char *cur_field_name;
static int zero_flag_atom;

static void define_symbolic_value(const char *ev_name,
                  const char *field_name,
                  const char *field_value,
                  const char *field_str)
{
    unsigned long long value;
    dSP;

    value = eval_flag(field_value);

    ENTER;
    SAVETMPS;
    PUSHMARK(SP);

    XPUSHs(sv_2mortal(newSVpv(ev_name, 0)));
    XPUSHs(sv_2mortal(newSVpv(field_name, 0)));
    XPUSHs(sv_2mortal(newSVuv(value)));
    XPUSHs(sv_2mortal(newSVpv(field_str, 0)));

    PUTBACK;
    if (get_cv("main::define_symbolic_value", 0))
        call_pv("main::define_symbolic_value", G_SCALAR);
    SPAGAIN;
    PUTBACK;
    FREETMPS;
    LEAVE;
}

static void define_symbolic_values(struct print_flag_sym *field,
                   const char *ev_name,
                   const char *field_name)
{
    define_symbolic_value(ev_name, field_name, field->value, field->str);
    if (field->next)
        define_symbolic_values(field->next, ev_name, field_name);
}

static void define_symbolic_field(const char *ev_name,
                  const char *field_name)
{
    dSP;

    ENTER;
    SAVETMPS;
    PUSHMARK(SP);

    XPUSHs(sv_2mortal(newSVpv(ev_name, 0)));
    XPUSHs(sv_2mortal(newSVpv(field_name, 0)));

    PUTBACK;
    if (get_cv("main::define_symbolic_field", 0))
        call_pv("main::define_symbolic_field", G_SCALAR);
    SPAGAIN;
    PUTBACK;
    FREETMPS;
    LEAVE;
}

static void define_flag_value(const char *ev_name,
                  const char *field_name,
                  const char *field_value,
                  const char *field_str)
{
    unsigned long long value;
    dSP;

    value = eval_flag(field_value);

    ENTER;
    SAVETMPS;
    PUSHMARK(SP);

    XPUSHs(sv_2mortal(newSVpv(ev_name, 0)));
    XPUSHs(sv_2mortal(newSVpv(field_name, 0)));
    XPUSHs(sv_2mortal(newSVuv(value)));
    XPUSHs(sv_2mortal(newSVpv(field_str, 0)));

    PUTBACK;
    if (get_cv("main::define_flag_value", 0))
        call_pv("main::define_flag_value", G_SCALAR);
    SPAGAIN;
    PUTBACK;
    FREETMPS;
    LEAVE;
}

static void define_flag_values(struct print_flag_sym *field,
                   const char *ev_name,
                   const char *field_name)
{
    define_flag_value(ev_name, field_name, field->value, field->str);
    if (field->next)
        define_flag_values(field->next, ev_name, field_name);
}

static void define_flag_field(const char *ev_name,
                  const char *field_name,
                  const char *delim)
{
    dSP;

    ENTER;
    SAVETMPS;
    PUSHMARK(SP);

    XPUSHs(sv_2mortal(newSVpv(ev_name, 0)));
    XPUSHs(sv_2mortal(newSVpv(field_name, 0)));
    XPUSHs(sv_2mortal(newSVpv(delim, 0)));

    PUTBACK;
    if (get_cv("main::define_flag_field", 0))
        call_pv("main::define_flag_field", G_SCALAR);
    SPAGAIN;
    PUTBACK;
    FREETMPS;
    LEAVE;
}

static void define_event_symbols(struct event_format *event,
                 const char *ev_name,
                 struct print_arg *args)
{
    switch (args->type) {
    case PRINT_NULL:
        break;
    case PRINT_ATOM:
        define_flag_value(ev_name, cur_field_name, "0",
                  args->atom.atom);
        zero_flag_atom = 0;
        break;
    case PRINT_FIELD:
        if (cur_field_name)
            free(cur_field_name);
        cur_field_name = strdup(args->field.name);
        break;
    case PRINT_FLAGS:
        define_event_symbols(event, ev_name, args->flags.field);
        define_flag_field(ev_name, cur_field_name, args->flags.delim);
        define_flag_values(args->flags.flags, ev_name, cur_field_name);
        break;
    case PRINT_SYMBOL:
        define_event_symbols(event, ev_name, args->symbol.field);
        define_symbolic_field(ev_name, cur_field_name);
        define_symbolic_values(args->symbol.symbols, ev_name,
                       cur_field_name);
        break;
    case PRINT_HEX:
        define_event_symbols(event, ev_name, args->hex.field);
        define_event_symbols(event, ev_name, args->hex.size);
        break;
    case PRINT_BSTRING:
    case PRINT_DYNAMIC_ARRAY:
    case PRINT_STRING:
        break;
    case PRINT_TYPE:
        define_event_symbols(event, ev_name, args->typecast.item);
        break;
    case PRINT_OP:
        if (strcmp(args->op.op, ":") == 0)
            zero_flag_atom = 1;
        define_event_symbols(event, ev_name, args->op.left);
        define_event_symbols(event, ev_name, args->op.right);
        break;
    case PRINT_FUNC:
    default:
        pr_err("Unsupported print arg type\n");
        /* we should warn... */
        return;
    }

    if (args->next)
        define_event_symbols(event, ev_name, args->next);
}

static inline struct event_format *find_cache_event(struct perf_evsel *evsel)
{
    static char ev_name[256];
    struct event_format *event;
    int type = evsel->attr.config;

    if (events[type])
        return events[type];

    events[type] = event = evsel->tp_format;
    if (!event)
        return NULL;

    sprintf(ev_name, "%s::%s", event->system, event->name);

    define_event_symbols(event, ev_name, event->print_fmt.args);

    return event;
}

static void perl_process_tracepoint(union perf_event *perf_event __maybe_unused,
                    struct perf_sample *sample,
                    struct perf_evsel *evsel,
                    struct machine *machine __maybe_unused,
                    struct addr_location *al)
{
    struct format_field *field;
    static char handler[256];
    unsigned long long val;
    unsigned long s, ns;
    struct event_format *event;
    int pid;
    int cpu = sample->cpu;
    void *data = sample->raw_data;
    unsigned long long nsecs = sample->time;
    struct thread *thread = al->thread;
    char *comm = thread->comm;

    dSP;

    if (evsel->attr.type != PERF_TYPE_TRACEPOINT)
        return;

    event = find_cache_event(evsel);
    if (!event)
        die("ug! no event found for type %" PRIu64, evsel->attr.config);

    pid = raw_field_value(event, "common_pid", data);

    sprintf(handler, "%s::%s", event->system, event->name);

    s = nsecs / NSECS_PER_SEC;
    ns = nsecs - s * NSECS_PER_SEC;

    scripting_context->event_data = data;

    ENTER;
    SAVETMPS;
    PUSHMARK(SP);

    XPUSHs(sv_2mortal(newSVpv(handler, 0)));
    XPUSHs(sv_2mortal(newSViv(PTR2IV(scripting_context))));
    XPUSHs(sv_2mortal(newSVuv(cpu)));
    XPUSHs(sv_2mortal(newSVuv(s)));
    XPUSHs(sv_2mortal(newSVuv(ns)));
    XPUSHs(sv_2mortal(newSViv(pid)));
    XPUSHs(sv_2mortal(newSVpv(comm, 0)));

    /* common fields other than pid can be accessed via xsub fns */

    for (field = event->format.fields; field; field = field->next) {
        if (field->flags & FIELD_IS_STRING) {
            int offset;
            if (field->flags & FIELD_IS_DYNAMIC) {
                offset = *(int *)(data + field->offset);
                offset &= 0xffff;
            } else
                offset = field->offset;
            XPUSHs(sv_2mortal(newSVpv((char *)data + offset, 0)));
        } else { /* FIELD_IS_NUMERIC */
            val = read_size(event, data + field->offset,
                    field->size);
            if (field->flags & FIELD_IS_SIGNED) {
                XPUSHs(sv_2mortal(newSViv(val)));
            } else {
                XPUSHs(sv_2mortal(newSVuv(val)));
            }
        }
    }

    PUTBACK;

    if (get_cv(handler, 0))
        call_pv(handler, G_SCALAR);
    else if (get_cv("main::trace_unhandled", 0)) {
        XPUSHs(sv_2mortal(newSVpv(handler, 0)));
        XPUSHs(sv_2mortal(newSViv(PTR2IV(scripting_context))));
        XPUSHs(sv_2mortal(newSVuv(cpu)));
        XPUSHs(sv_2mortal(newSVuv(nsecs)));
        XPUSHs(sv_2mortal(newSViv(pid)));
        XPUSHs(sv_2mortal(newSVpv(comm, 0)));
        call_pv("main::trace_unhandled", G_SCALAR);
    }
    SPAGAIN;
    PUTBACK;
    FREETMPS;
    LEAVE;
}

static void perl_process_event_generic(union perf_event *event,
                       struct perf_sample *sample,
                       struct perf_evsel *evsel,
                       struct machine *machine __maybe_unused,
                       struct addr_location *al __maybe_unused)
{
    dSP;

    if (!get_cv("process_event", 0))
        return;

    ENTER;
    SAVETMPS;
    PUSHMARK(SP);
    XPUSHs(sv_2mortal(newSVpvn((const char *)event, event->header.size)));
    XPUSHs(sv_2mortal(newSVpvn((const char *)&evsel->attr, sizeof(evsel->attr))));
    XPUSHs(sv_2mortal(newSVpvn((const char *)sample, sizeof(*sample))));
    XPUSHs(sv_2mortal(newSVpvn((const char *)sample->raw_data, sample->raw_size)));
    PUTBACK;
    call_pv("process_event", G_SCALAR);
    SPAGAIN;
    PUTBACK;
    FREETMPS;
    LEAVE;
}

static void perl_process_event(union perf_event *event,
                   struct perf_sample *sample,
                   struct perf_evsel *evsel,
                   struct machine *machine,
                   struct addr_location *al)
{
    perl_process_tracepoint(event, sample, evsel, machine, al);
    perl_process_event_generic(event, sample, evsel, machine, al);
}

static void run_start_sub(void)
{
    dSP; /* access to Perl stack */
    PUSHMARK(SP);

    if (get_cv("main::trace_begin", 0))
        call_pv("main::trace_begin", G_DISCARD | G_NOARGS);
}

/*
 * Start trace script
 */
static int perl_start_script(const char *script, int argc, const char **argv)
{
    const char **command_line;
    int i, err = 0;

    command_line = malloc((argc + 2) * sizeof(const char *));
    command_line[0] = "";
    command_line[1] = script;
    for (i = 2; i < argc + 2; i++)
        command_line[i] = argv[i - 2];

    my_perl = perl_alloc();
    perl_construct(my_perl);

    if (perl_parse(my_perl, xs_init, argc + 2, (char **)command_line,
               (char **)NULL)) {
        err = -1;
        goto error;
    }

    if (perl_run(my_perl)) {
        err = -1;
        goto error;
    }

    if (SvTRUE(ERRSV)) {
        err = -1;
        goto error;
    }

    run_start_sub();

    free(command_line);
    return 0;
error:
    perl_free(my_perl);
    free(command_line);

    return err;
}

/*
 * Stop trace script
 */
static int perl_stop_script(void)
{
    dSP; /* access to Perl stack */
    PUSHMARK(SP);

    if (get_cv("main::trace_end", 0))
        call_pv("main::trace_end", G_DISCARD | G_NOARGS);

    perl_destruct(my_perl);
    perl_free(my_perl);

    return 0;
}

static int perl_generate_script(struct pevent *pevent, const char *outfile)
{
    struct event_format *event = NULL;
    struct format_field *f;
    char fname[PATH_MAX];
    int not_first, count;
    FILE *ofp;

    sprintf(fname, "%s.pl", outfile);
    ofp = fopen(fname, "w");
    if (ofp == NULL) {
        fprintf(stderr, "couldn't open %s\n", fname);
        return -1;
    }

    fprintf(ofp, "# perf script event handlers, "
        "generated by perf script -g perl\n");

    fprintf(ofp, "# Licensed under the terms of the GNU GPL"
        " License version 2\n\n");

    fprintf(ofp, "# The common_* event handler fields are the most useful "
        "fields common to\n");

    fprintf(ofp, "# all events.  They don't necessarily correspond to "
        "the 'common_*' fields\n");

    fprintf(ofp, "# in the format files.  Those fields not available as "
        "handler params can\n");

    fprintf(ofp, "# be retrieved using Perl functions of the form "
        "common_*($context).\n");

    fprintf(ofp, "# See Context.pm for the list of available "
        "functions.\n\n");

    fprintf(ofp, "use lib \"$ENV{'PERF_EXEC_PATH'}/scripts/perl/"
        "Perf-Trace-Util/lib\";\n");

    fprintf(ofp, "use lib \"./Perf-Trace-Util/lib\";\n");
    fprintf(ofp, "use Perf::Trace::Core;\n");
    fprintf(ofp, "use Perf::Trace::Context;\n");
    fprintf(ofp, "use Perf::Trace::Util;\n\n");

    fprintf(ofp, "sub trace_begin\n{\n\t# optional\n}\n\n");
    fprintf(ofp, "sub trace_end\n{\n\t# optional\n}\n\n");

    while ((event = trace_find_next_event(pevent, event))) {
        fprintf(ofp, "sub %s::%s\n{\n", event->system, event->name);
        fprintf(ofp, "\tmy (");

        fprintf(ofp, "$event_name, ");
        fprintf(ofp, "$context, ");
        fprintf(ofp, "$common_cpu, ");
        fprintf(ofp, "$common_secs, ");
        fprintf(ofp, "$common_nsecs,\n");
        fprintf(ofp, "\t    $common_pid, ");
        fprintf(ofp, "$common_comm,\n\t    ");

        not_first = 0;
        count = 0;

        for (f = event->format.fields; f; f = f->next) {
            if (not_first++)
                fprintf(ofp, ", ");
            if (++count % 5 == 0)
                fprintf(ofp, "\n\t    ");

            fprintf(ofp, "$%s", f->name);
        }
        fprintf(ofp, ") = @_;\n\n");

        fprintf(ofp, "\tprint_header($event_name, $common_cpu, "
            "$common_secs, $common_nsecs,\n\t             "
            "$common_pid, $common_comm);\n\n");

        fprintf(ofp, "\tprintf(\"");

        not_first = 0;
        count = 0;

        for (f = event->format.fields; f; f = f->next) {
            if (not_first++)
                fprintf(ofp, ", ");
            if (count && count % 4 == 0) {
                fprintf(ofp, "\".\n\t       \"");
            }
            count++;

            fprintf(ofp, "%s=", f->name);
            if (f->flags & FIELD_IS_STRING ||
                f->flags & FIELD_IS_FLAG ||
                f->flags & FIELD_IS_SYMBOLIC)
                fprintf(ofp, "%%s");
            else if (f->flags & FIELD_IS_SIGNED)
                fprintf(ofp, "%%d");
            else
                fprintf(ofp, "%%u");
        }

        fprintf(ofp, "\\n\",\n\t       ");

        not_first = 0;
        count = 0;

        for (f = event->format.fields; f; f = f->next) {
            if (not_first++)
                fprintf(ofp, ", ");

            if (++count % 5 == 0)
                fprintf(ofp, "\n\t       ");

            if (f->flags & FIELD_IS_FLAG) {
                if ((count - 1) % 5 != 0) {
                    fprintf(ofp, "\n\t       ");
                    count = 4;
                }
                fprintf(ofp, "flag_str(\"");
                fprintf(ofp, "%s::%s\", ", event->system,
                    event->name);
                fprintf(ofp, "\"%s\", $%s)", f->name,
                    f->name);
            } else if (f->flags & FIELD_IS_SYMBOLIC) {
                if ((count - 1) % 5 != 0) {
                    fprintf(ofp, "\n\t       ");
                    count = 4;
                }
                fprintf(ofp, "symbol_str(\"");
                fprintf(ofp, "%s::%s\", ", event->system,
                    event->name);
                fprintf(ofp, "\"%s\", $%s)", f->name,
                    f->name);
            } else
                fprintf(ofp, "$%s", f->name);
        }

        fprintf(ofp, ");\n");
        fprintf(ofp, "}\n\n");
    }

    fprintf(ofp, "sub trace_unhandled\n{\n\tmy ($event_name, $context, "
        "$common_cpu, $common_secs, $common_nsecs,\n\t    "
        "$common_pid, $common_comm) = @_;\n\n");

    fprintf(ofp, "\tprint_header($event_name, $common_cpu, "
        "$common_secs, $common_nsecs,\n\t             $common_pid, "
        "$common_comm);\n}\n\n");

    fprintf(ofp, "sub print_header\n{\n"
        "\tmy ($event_name, $cpu, $secs, $nsecs, $pid, $comm) = @_;\n\n"
        "\tprintf(\"%%-20s %%5u %%05u.%%09u %%8u %%-20s \",\n\t       "
        "$event_name, $cpu, $secs, $nsecs, $pid, $comm);\n}\n");

    fprintf(ofp,
        "\n# Packed byte string args of process_event():\n"
        "#\n"
        "# $event:\tunion perf_event\tutil/event.h\n"
        "# $attr:\tstruct perf_event_attr\tlinux/perf_event.h\n"
        "# $sample:\tstruct perf_sample\tutil/event.h\n"
        "# $raw_data:\tperf_sample->raw_data\tutil/event.h\n"
        "\n"
        "sub process_event\n"
        "{\n"
        "\tmy ($event, $attr, $sample, $raw_data) = @_;\n"
        "\n"
        "\tmy @event\t= unpack(\"LSS\", $event);\n"
        "\tmy @attr\t= unpack(\"LLQQQQQLLQQ\", $attr);\n"
        "\tmy @sample\t= unpack(\"QLLQQQQQLL\", $sample);\n"
        "\tmy @raw_data\t= unpack(\"C*\", $raw_data);\n"
        "\n"
        "\tuse Data::Dumper;\n"
        "\tprint Dumper \\@event, \\@attr, \\@sample, \\@raw_data;\n"
        "}\n");

    fclose(ofp);

    fprintf(stderr, "generated Perl script: %s\n", fname);

    return 0;
}

struct scripting_ops perl_scripting_ops = {
    .name = "Perl",
    .start_script = perl_start_script,
    .stop_script = perl_stop_script,
    .process_event = perl_process_event,
    .generate_script = perl_generate_script,
};