dtrace_unload.c revision 267654 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 *
21 * $FreeBSD: releng/9.3/sys/cddl/dev/dtrace/dtrace_unload.c 262053 2014-02-17 13:33:42Z avg $
22 *
23 */
24
25static int
26dtrace_unload()
27{
28	dtrace_state_t *state;
29	int error = 0;
30
31#if __FreeBSD_version < 800039
32	/*
33	 * Check if there is still an event handler callback
34	 * registered.
35	 */
36	if (eh_tag != 0) {
37		/* De-register the device cloning event handler. */
38		EVENTHANDLER_DEREGISTER(dev_clone, eh_tag);
39		eh_tag = 0;
40
41		/* Stop device cloning. */
42		clone_cleanup(&dtrace_clones);
43	}
44#else
45	destroy_dev(dtrace_dev);
46	destroy_dev(helper_dev);
47#endif
48
49	mutex_enter(&dtrace_provider_lock);
50	mutex_enter(&dtrace_lock);
51	mutex_enter(&cpu_lock);
52
53	ASSERT(dtrace_opens == 0);
54
55	if (dtrace_helpers > 0) {
56		mutex_exit(&cpu_lock);
57		mutex_exit(&dtrace_lock);
58		mutex_exit(&dtrace_provider_lock);
59		return (EBUSY);
60	}
61
62	if (dtrace_unregister((dtrace_provider_id_t)dtrace_provider) != 0) {
63		mutex_exit(&cpu_lock);
64		mutex_exit(&dtrace_lock);
65		mutex_exit(&dtrace_provider_lock);
66		return (EBUSY);
67	}
68
69	dtrace_provider = NULL;
70	EVENTHANDLER_DEREGISTER(kld_load, dtrace_kld_load_tag);
71	EVENTHANDLER_DEREGISTER(kld_unload_try, dtrace_kld_unload_try_tag);
72
73	if ((state = dtrace_anon_grab()) != NULL) {
74		/*
75		 * If there were ECBs on this state, the provider should
76		 * have not been allowed to detach; assert that there is
77		 * none.
78		 */
79		ASSERT(state->dts_necbs == 0);
80		dtrace_state_destroy(state);
81	}
82
83	bzero(&dtrace_anon, sizeof (dtrace_anon_t));
84
85	mutex_exit(&cpu_lock);
86
87	if (dtrace_helptrace_enabled) {
88		kmem_free(dtrace_helptrace_buffer, 0);
89		dtrace_helptrace_buffer = NULL;
90	}
91
92	if (dtrace_probes != NULL) {
93		kmem_free(dtrace_probes, 0);
94		dtrace_probes = NULL;
95		dtrace_nprobes = 0;
96	}
97
98	dtrace_hash_destroy(dtrace_bymod);
99	dtrace_hash_destroy(dtrace_byfunc);
100	dtrace_hash_destroy(dtrace_byname);
101	dtrace_bymod = NULL;
102	dtrace_byfunc = NULL;
103	dtrace_byname = NULL;
104
105	kmem_cache_destroy(dtrace_state_cache);
106
107	delete_unrhdr(dtrace_arena);
108
109	if (dtrace_toxrange != NULL) {
110		kmem_free(dtrace_toxrange, 0);
111		dtrace_toxrange = NULL;
112		dtrace_toxranges = 0;
113		dtrace_toxranges_max = 0;
114	}
115
116	ASSERT(dtrace_vtime_references == 0);
117	ASSERT(dtrace_opens == 0);
118	ASSERT(dtrace_retained == NULL);
119
120	mutex_exit(&dtrace_lock);
121	mutex_exit(&dtrace_provider_lock);
122
123	mutex_destroy(&dtrace_meta_lock);
124	mutex_destroy(&dtrace_provider_lock);
125	mutex_destroy(&dtrace_lock);
126#ifdef DEBUG
127	mutex_destroy(&dtrace_errlock);
128#endif
129
130	taskq_destroy(dtrace_taskq);
131
132	/* Reset our hook for exceptions. */
133	dtrace_invop_uninit();
134
135	/*
136	 * Reset our hook for thread switches, but ensure that vtime isn't
137	 * active first.
138	 */
139	dtrace_vtime_active = 0;
140	dtrace_vtime_switch_func = NULL;
141
142	/* Unhook from the trap handler. */
143	dtrace_trap_func = NULL;
144
145	return (error);
146}
147