xref: /freebsd/sys/kern/kern_sdt.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright 2006-2008 John Birrell <jb@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/kdb.h>
31 #include <sys/proc.h>
32 #include <sys/sdt.h>
33 
34 SDT_PROVIDER_DEFINE(sdt);
35 
36 /*
37  * Hook for the DTrace probe function. The SDT provider will set this to
38  * dtrace_probe() when it loads.
39  */
40 sdt_probe_func_t sdt_probe_func = sdt_probe_stub;
41 volatile bool __read_frequently sdt_probes_enabled;
42 
43 /*
44  * This is a stub for probe calls in case kernel DTrace support isn't
45  * enabled. It should never get called because there is no DTrace support
46  * to enable it.
47  */
48 void
49 sdt_probe_stub(uint32_t id __unused, uintptr_t arg0 __unused,
50     uintptr_t arg1 __unused, uintptr_t arg2 __unused, uintptr_t arg3 __unused,
51     uintptr_t arg4 __unused, uintptr_t arg5 __unused)
52 {
53 	printf("sdt_probe_stub: unexpectedly called\n");
54 	kdb_backtrace();
55 }
56 
57 void
58 sdt_probe(uint32_t id, uintptr_t arg0, uintptr_t arg1,
59     uintptr_t arg2, uintptr_t arg3, uintptr_t arg4)
60 {
61 	sdt_probe_func(id, arg0, arg1, arg2, arg3, arg4, 0);
62 }
63 
64 void
65 sdt_probe6(uint32_t id, uintptr_t arg0, uintptr_t arg1,
66     uintptr_t arg2, uintptr_t arg3, uintptr_t arg4, uintptr_t arg5)
67 {
68 	sdt_probe_func(id, arg0, arg1, arg2, arg3, arg4, arg5);
69 }
70