2 * Copyright (c) 2007-2008 John Birrell <jb@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/eventhandler.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
39 #include <sys/dtrace_bsd.h>
40 #include <sys/sysctl.h>
42 #define KDTRACE_PROC_SIZE 64
43 #define KDTRACE_THREAD_SIZE 256
45 FEATURE(kdtrace_hooks,
46 "Kernel DTrace hooks which are required to load DTrace kernel modules");
48 static MALLOC_DEFINE(M_KDTRACE, "kdtrace", "DTrace hooks");
50 /* Return the DTrace process data size compiled in the kernel hooks. */
55 return (KDTRACE_PROC_SIZE);
59 kdtrace_proc_ctor(void *arg __unused, struct proc *p)
62 p->p_dtrace = malloc(KDTRACE_PROC_SIZE, M_KDTRACE, M_WAITOK|M_ZERO);
66 kdtrace_proc_dtor(void *arg __unused, struct proc *p)
69 if (p->p_dtrace != NULL) {
70 free(p->p_dtrace, M_KDTRACE);
75 /* Return the DTrace thread data size compiled in the kernel hooks. */
80 return (KDTRACE_THREAD_SIZE);
84 kdtrace_thread_ctor(void *arg __unused, struct thread *td)
87 td->td_dtrace = malloc(KDTRACE_THREAD_SIZE, M_KDTRACE, M_WAITOK|M_ZERO);
91 kdtrace_thread_dtor(void *arg __unused, struct thread *td)
94 if (td->td_dtrace != NULL) {
95 free(td->td_dtrace, M_KDTRACE);
101 * Initialise the kernel DTrace hooks.
104 init_dtrace(void *dummy __unused)
107 EVENTHANDLER_REGISTER(process_ctor, kdtrace_proc_ctor, NULL,
108 EVENTHANDLER_PRI_ANY);
109 EVENTHANDLER_REGISTER(process_dtor, kdtrace_proc_dtor, NULL,
110 EVENTHANDLER_PRI_ANY);
111 EVENTHANDLER_REGISTER(thread_ctor, kdtrace_thread_ctor, NULL,
112 EVENTHANDLER_PRI_ANY);
113 EVENTHANDLER_REGISTER(thread_dtor, kdtrace_thread_dtor, NULL,
114 EVENTHANDLER_PRI_ANY);
117 SYSINIT(kdtrace, SI_SUB_KDTRACE, SI_ORDER_FIRST, init_dtrace, NULL);