linux/tools/lib/traceevent/plugins/plugin_futex.c
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   1// SPDX-License-Identifier: LGPL-2.1
   2/*
   3 * Copyright (C) 2017 National Instruments Corp.
   4 *
   5 * Author: Julia Cartwright <julia@ni.com>
   6 *
   7 */
   8#include <stdio.h>
   9#include <stdlib.h>
  10#include <string.h>
  11#include <linux/futex.h>
  12
  13#include "event-parse.h"
  14
  15#define ARRAY_SIZE(_a) (sizeof(_a) / sizeof((_a)[0]))
  16
  17struct futex_args {
  18        unsigned long long      uaddr;
  19        unsigned long long      op;
  20        unsigned long long      val;
  21        unsigned long long      utime; /* or val2 */
  22        unsigned long long      uaddr2;
  23        unsigned long long      val3;
  24};
  25
  26struct futex_op {
  27        const char      *name;
  28        const char      *fmt_val;
  29        const char      *fmt_utime;
  30        const char      *fmt_uaddr2;
  31        const char      *fmt_val3;
  32};
  33
  34static const struct futex_op futex_op_tbl[] = {
  35        {            "FUTEX_WAIT", " val=0x%08llx", " utime=0x%08llx",               NULL,             NULL },
  36        {            "FUTEX_WAKE",     " val=%llu",              NULL,               NULL,             NULL },
  37        {              "FUTEX_FD",     " val=%llu",              NULL,               NULL,             NULL },
  38        {         "FUTEX_REQUEUE",     " val=%llu",      " val2=%llu", " uaddr2=0x%08llx",             NULL },
  39        {     "FUTEX_CMP_REQUEUE",     " val=%llu",      " val2=%llu", " uaddr2=0x%08llx", " val3=0x%08llx" },
  40        {         "FUTEX_WAKE_OP",     " val=%llu",      " val2=%llu", " uaddr2=0x%08llx", " val3=0x%08llx" },
  41        {         "FUTEX_LOCK_PI",            NULL, " utime=0x%08llx",               NULL,             NULL },
  42        {       "FUTEX_UNLOCK_PI",            NULL,              NULL,               NULL,             NULL },
  43        {      "FUTEX_TRYLOCK_PI",            NULL,              NULL,               NULL,             NULL },
  44        {     "FUTEX_WAIT_BITSET", " val=0x%08llx", " utime=0x%08llx",               NULL, " val3=0x%08llx" },
  45        {     "FUTEX_WAKE_BITSET",     " val=%llu",              NULL,               NULL, " val3=0x%08llx" },
  46        { "FUTEX_WAIT_REQUEUE_PI", " val=0x%08llx", " utime=0x%08llx", " uaddr2=0x%08llx", " val3=0x%08llx" },
  47        {  "FUTEX_CMP_REQUEUE_PI",     " val=%llu",      " val2=%llu", " uaddr2=0x%08llx", " val3=0x%08llx" },
  48};
  49
  50
  51static void futex_print(struct trace_seq *s, const struct futex_args *args,
  52                        const struct futex_op *fop)
  53{
  54        trace_seq_printf(s, " uaddr=0x%08llx", args->uaddr);
  55
  56        if (fop->fmt_val)
  57                trace_seq_printf(s, fop->fmt_val, args->val);
  58
  59        if (fop->fmt_utime)
  60                trace_seq_printf(s,fop->fmt_utime, args->utime);
  61
  62        if (fop->fmt_uaddr2)
  63                trace_seq_printf(s, fop->fmt_uaddr2, args->uaddr2);
  64
  65        if (fop->fmt_val3)
  66                trace_seq_printf(s, fop->fmt_val3, args->val3);
  67}
  68
  69static int futex_handler(struct trace_seq *s, struct tep_record *record,
  70                         struct tep_event *event, void *context)
  71{
  72        const struct futex_op *fop;
  73        struct futex_args args;
  74        unsigned long long cmd;
  75
  76        if (tep_get_field_val(s, event, "uaddr", record, &args.uaddr, 1))
  77                return 1;
  78
  79        if (tep_get_field_val(s, event, "op", record, &args.op, 1))
  80                return 1;
  81
  82        if (tep_get_field_val(s, event, "val", record, &args.val, 1))
  83                return 1;
  84
  85        if (tep_get_field_val(s, event, "utime", record, &args.utime, 1))
  86                return 1;
  87
  88        if (tep_get_field_val(s, event, "uaddr2", record, &args.uaddr2, 1))
  89                return 1;
  90
  91        if (tep_get_field_val(s, event, "val3", record, &args.val3, 1))
  92                return 1;
  93
  94        cmd = args.op & FUTEX_CMD_MASK;
  95        if (cmd >= ARRAY_SIZE(futex_op_tbl))
  96                return 1;
  97
  98        fop = &futex_op_tbl[cmd];
  99
 100        trace_seq_printf(s, "op=%s", fop->name);
 101
 102        if (args.op & FUTEX_PRIVATE_FLAG)
 103                trace_seq_puts(s, "|FUTEX_PRIVATE_FLAG");
 104
 105        if (args.op & FUTEX_CLOCK_REALTIME)
 106                trace_seq_puts(s, "|FUTEX_CLOCK_REALTIME");
 107
 108        futex_print(s, &args, fop);
 109        return 0;
 110}
 111
 112int TEP_PLUGIN_LOADER(struct tep_handle *tep)
 113{
 114        tep_register_event_handler(tep, -1, "syscalls", "sys_enter_futex",
 115                                   futex_handler, NULL);
 116        return 0;
 117}
 118
 119void TEP_PLUGIN_UNLOADER(struct tep_handle *tep)
 120{
 121        tep_unregister_event_handler(tep, -1, "syscalls", "sys_enter_futex",
 122                                     futex_handler, NULL);
 123}
 124