xref: /netbsd-src/sys/kern/kern_sdt.c (revision 6cd39ddb8550f6fa1bff3fed32053d7f19fd0453)
1 /*	$NetBSD: kern_sdt.c,v 1.2 2015/10/02 16:54:15 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2010 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by CoyotePoint Systems, Inc. It was developed under contract to
9  * CoyotePoint by Darran Hunt.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*-
35  * Copyright 2006-2008 John Birrell <jb@FreeBSD.org>
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  *
46  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
49  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56  * SUCH DAMAGE.
57  *
58  * $FreeBSD: src/sys/kern/kern_sdt.c,v 1.1.4.1 2009/08/03 08:13:06 kensmith Exp $
59  *
60  * Backend for the Statically Defined Tracing (SDT) kernel support. This is
61  * required to allow a module to load even though DTrace kernel support may
62  * not be present. A module may be built with SDT probes in it.
63  *
64  */
65 #ifdef _KERNEL_OPT
66 #include "opt_dtrace.h"
67 #endif
68 
69 #include <sys/cdefs.h>
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/sdt.h>
73 
74 void sdt_probe_stub(u_int32_t, uintptr_t, uintptr_t,
75 	uintptr_t, uintptr_t, uintptr_t);
76 
77 __link_set_decl(sdt_providers_set, struct sdt_provider);
78 __link_set_decl(sdt_probes_set, struct sdt_probe);
79 __link_set_decl(sdt_argtypes_set, struct sdt_argtype);
80 
81 /*
82  * Hook for the DTrace probe function. The 'sdt' provider will set this
83  * to dtrace_probe when it loads.
84  */
85 sdt_probe_func_t sdt_probe_func = sdt_probe_stub;
86 
87 /*
88  * This is a stub for probe calls in case kernel DTrace support isn't
89  * compiled in. It should never get called because there is no DTrace
90  * support to enable it.
91  */
92 void
93 sdt_probe_stub(u_int32_t id, uintptr_t arg0, uintptr_t arg1,
94     uintptr_t arg2, uintptr_t arg3, uintptr_t arg4)
95 {
96 	struct sdt_provider * const * provider;
97 	struct sdt_probe * const * probe;
98 	struct sdt_argtype * const * argtype;
99 	printf("%s: XXX should not be called\n", __func__);
100 	printf("providers: ");
101 	__link_set_foreach(provider, sdt_providers_set)
102 		printf("%s ", (*provider)->name);
103 	printf("\nprobes: ");
104 	__link_set_foreach(probe, sdt_probes_set)
105 		printf("%s ", (*probe)->name);
106 	printf("\nargtypes: ");
107 	__link_set_foreach(argtype, sdt_argtypes_set)
108 		printf("%s ", (*argtype)->type);
109 	printf("\n");
110 }
111 
112 /*
113  * initialize the SDT dtrace probe function
114  */
115 void
116 sdt_init(void *dtrace_probe)
117 {
118 
119 	sdt_probe_func = dtrace_probe;
120 }
121 
122 /*
123  * Disable the SDT dtrace probe function
124  */
125 void
126 sdt_exit(void)
127 {
128 
129 	sdt_probe_func = sdt_probe_stub;
130 }
131