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 
17 struct 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 
26 struct 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 
34 static 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 
futex_print(struct trace_seq * s,const struct futex_args * args,const struct futex_op * fop)51 static 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 
futex_handler(struct trace_seq * s,struct tep_record * record,struct tep_event * event,void * context)69 static 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 
TEP_PLUGIN_LOADER(struct tep_handle * tep)112 int 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 
TEP_PLUGIN_UNLOADER(struct tep_handle * tep)119 void 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