1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2007-2008 John Birrell <jb@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 #include "opt_kdb.h"
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/eventhandler.h>
35 #include <sys/kdb.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/proc.h>
39 #include <sys/dtrace_bsd.h>
40 #include <sys/sysctl.h>
41 #include <sys/sysent.h>
42
43 #define KDTRACE_PROC_SIZE 64
44 #define KDTRACE_THREAD_SIZE 256
45
46 FEATURE(kdtrace_hooks,
47 "Kernel DTrace hooks which are required to load DTrace kernel modules");
48
49 static MALLOC_DEFINE(M_KDTRACE, "kdtrace", "DTrace hooks");
50
51 /* Hooks used in the machine-dependent trap handlers. */
52 dtrace_trap_func_t dtrace_trap_func;
53 dtrace_doubletrap_func_t dtrace_doubletrap_func;
54 dtrace_pid_probe_ptr_t dtrace_pid_probe_ptr;
55 dtrace_return_probe_ptr_t dtrace_return_probe_ptr;
56
57 bool __read_frequently systrace_enabled;
58 systrace_probe_func_t systrace_probe_func;
59
60 /* Return the DTrace process data size compiled in the kernel hooks. */
61 size_t
kdtrace_proc_size(void)62 kdtrace_proc_size(void)
63 {
64
65 return (KDTRACE_PROC_SIZE);
66 }
67
68 void
kdtrace_proc_ctor(struct proc * p)69 kdtrace_proc_ctor(struct proc *p)
70 {
71
72 p->p_dtrace = malloc(KDTRACE_PROC_SIZE, M_KDTRACE, M_WAITOK|M_ZERO);
73 }
74
75 void
kdtrace_proc_dtor(struct proc * p)76 kdtrace_proc_dtor(struct proc *p)
77 {
78
79 free(p->p_dtrace, M_KDTRACE);
80 p->p_dtrace = NULL;
81 }
82
83 /* Return the DTrace thread data size compiled in the kernel hooks. */
84 size_t
kdtrace_thread_size(void)85 kdtrace_thread_size(void)
86 {
87
88 return (KDTRACE_THREAD_SIZE);
89 }
90
91 void
kdtrace_thread_ctor(struct thread * td)92 kdtrace_thread_ctor(struct thread *td)
93 {
94
95 td->td_dtrace = malloc(KDTRACE_THREAD_SIZE, M_KDTRACE, M_WAITOK|M_ZERO);
96 }
97
98 void
kdtrace_thread_dtor(struct thread * td)99 kdtrace_thread_dtor(struct thread *td)
100 {
101
102 free(td->td_dtrace, M_KDTRACE);
103 td->td_dtrace = NULL;
104 }
105