dtrace_load.c revision 254704 
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: stable/9/sys/cddl/dev/dtrace/dtrace_load.c 254704 2013-08-23 14:17:45Z avg $
22 *
23 */
24
25static void
26dtrace_ap_start(void *dummy)
27{
28	int i;
29
30	mutex_enter(&cpu_lock);
31
32	/* Setup the rest of the CPUs. */
33	CPU_FOREACH(i) {
34		if (i == 0)
35			continue;
36
37		(void) dtrace_cpu_setup(CPU_CONFIG, i);
38	}
39
40	mutex_exit(&cpu_lock);
41}
42
43SYSINIT(dtrace_ap_start, SI_SUB_SMP, SI_ORDER_ANY, dtrace_ap_start, NULL);
44
45static void
46dtrace_load(void *dummy)
47{
48	dtrace_provider_id_t id;
49
50	/* Hook into the trap handler. */
51	dtrace_trap_func = dtrace_trap;
52
53	/* Hang our hook for thread switches. */
54	dtrace_vtime_switch_func = dtrace_vtime_switch;
55
56	/* Hang our hook for exceptions. */
57	dtrace_invop_init();
58
59	/*
60	 * XXX This is a short term hack to avoid having to comment
61	 * out lots and lots of lock/unlock calls.
62	 */
63	mutex_init(&mod_lock,"XXX mod_lock hack", MUTEX_DEFAULT, NULL);
64
65	/*
66	 * Initialise the mutexes without 'witness' because the dtrace
67	 * code is mostly written to wait for memory. To have the
68	 * witness code change a malloc() from M_WAITOK to M_NOWAIT
69	 * because a lock is held would surely create a panic in a
70	 * low memory situation. And that low memory situation might be
71	 * the very problem we are trying to trace.
72	 */
73	mutex_init(&dtrace_lock,"dtrace probe state", MUTEX_DEFAULT, NULL);
74	mutex_init(&dtrace_provider_lock,"dtrace provider state", MUTEX_DEFAULT, NULL);
75	mutex_init(&dtrace_meta_lock,"dtrace meta-provider state", MUTEX_DEFAULT, NULL);
76#ifdef DEBUG
77	mutex_init(&dtrace_errlock,"dtrace error lock", MUTEX_DEFAULT, NULL);
78#endif
79
80	mutex_enter(&dtrace_provider_lock);
81	mutex_enter(&dtrace_lock);
82	mutex_enter(&cpu_lock);
83
84	ASSERT(MUTEX_HELD(&cpu_lock));
85
86	dtrace_arena = new_unrhdr(1, INT_MAX, &dtrace_unr_mtx);
87
88	dtrace_state_cache = kmem_cache_create("dtrace_state_cache",
89	    sizeof (dtrace_dstate_percpu_t) * NCPU, DTRACE_STATE_ALIGN,
90	    NULL, NULL, NULL, NULL, NULL, 0);
91
92	ASSERT(MUTEX_HELD(&cpu_lock));
93	dtrace_bymod = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_mod),
94	    offsetof(dtrace_probe_t, dtpr_nextmod),
95	    offsetof(dtrace_probe_t, dtpr_prevmod));
96
97	dtrace_byfunc = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_func),
98	    offsetof(dtrace_probe_t, dtpr_nextfunc),
99	    offsetof(dtrace_probe_t, dtpr_prevfunc));
100
101	dtrace_byname = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_name),
102	    offsetof(dtrace_probe_t, dtpr_nextname),
103	    offsetof(dtrace_probe_t, dtpr_prevname));
104
105	if (dtrace_retain_max < 1) {
106		cmn_err(CE_WARN, "illegal value (%lu) for dtrace_retain_max; "
107		    "setting to 1", dtrace_retain_max);
108		dtrace_retain_max = 1;
109	}
110
111	/*
112	 * Now discover our toxic ranges.
113	 */
114	dtrace_toxic_ranges(dtrace_toxrange_add);
115
116	/*
117	 * Before we register ourselves as a provider to our own framework,
118	 * we would like to assert that dtrace_provider is NULL -- but that's
119	 * not true if we were loaded as a dependency of a DTrace provider.
120	 * Once we've registered, we can assert that dtrace_provider is our
121	 * pseudo provider.
122	 */
123	(void) dtrace_register("dtrace", &dtrace_provider_attr,
124	    DTRACE_PRIV_NONE, 0, &dtrace_provider_ops, NULL, &id);
125
126	ASSERT(dtrace_provider != NULL);
127	ASSERT((dtrace_provider_id_t)dtrace_provider == id);
128
129	dtrace_probeid_begin = dtrace_probe_create((dtrace_provider_id_t)
130	    dtrace_provider, NULL, NULL, "BEGIN", 0, NULL);
131	dtrace_probeid_end = dtrace_probe_create((dtrace_provider_id_t)
132	    dtrace_provider, NULL, NULL, "END", 0, NULL);
133	dtrace_probeid_error = dtrace_probe_create((dtrace_provider_id_t)
134	    dtrace_provider, NULL, NULL, "ERROR", 1, NULL);
135
136	mutex_exit(&cpu_lock);
137
138	/*
139	 * If DTrace helper tracing is enabled, we need to allocate the
140	 * trace buffer and initialize the values.
141	 */
142	if (dtrace_helptrace_enabled) {
143		ASSERT(dtrace_helptrace_buffer == NULL);
144		dtrace_helptrace_buffer =
145		    kmem_zalloc(dtrace_helptrace_bufsize, KM_SLEEP);
146		dtrace_helptrace_next = 0;
147	}
148
149	mutex_exit(&dtrace_lock);
150	mutex_exit(&dtrace_provider_lock);
151
152	mutex_enter(&cpu_lock);
153
154	/* Setup the boot CPU */
155	(void) dtrace_cpu_setup(CPU_CONFIG, 0);
156
157	mutex_exit(&cpu_lock);
158
159#if __FreeBSD_version < 800039
160	/* Enable device cloning. */
161	clone_setup(&dtrace_clones);
162
163	/* Setup device cloning events. */
164	eh_tag = EVENTHANDLER_REGISTER(dev_clone, dtrace_clone, 0, 1000);
165#else
166	dtrace_dev = make_dev(&dtrace_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
167	    "dtrace/dtrace");
168	helper_dev = make_dev(&helper_cdevsw, 0, UID_ROOT, GID_WHEEL, 0660,
169	    "dtrace/helper");
170#endif
171
172	return;
173}
174