dtrace_load.c revision 212093 
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: head/sys/cddl/dev/dtrace/dtrace_load.c 212093 2010-09-01 12:08:32Z rpaulo $
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	mutex_init(&dtrace_errlock,"dtrace error lock", MUTEX_DEFAULT, NULL);
77
78	mutex_enter(&dtrace_provider_lock);
79	mutex_enter(&dtrace_lock);
80	mutex_enter(&cpu_lock);
81
82	ASSERT(MUTEX_HELD(&cpu_lock));
83
84	dtrace_arena = new_unrhdr(1, INT_MAX, &dtrace_unr_mtx);
85
86	dtrace_state_cache = kmem_cache_create("dtrace_state_cache",
87	    sizeof (dtrace_dstate_percpu_t) * NCPU, DTRACE_STATE_ALIGN,
88	    NULL, NULL, NULL, NULL, NULL, 0);
89
90	ASSERT(MUTEX_HELD(&cpu_lock));
91	dtrace_bymod = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_mod),
92	    offsetof(dtrace_probe_t, dtpr_nextmod),
93	    offsetof(dtrace_probe_t, dtpr_prevmod));
94
95	dtrace_byfunc = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_func),
96	    offsetof(dtrace_probe_t, dtpr_nextfunc),
97	    offsetof(dtrace_probe_t, dtpr_prevfunc));
98
99	dtrace_byname = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_name),
100	    offsetof(dtrace_probe_t, dtpr_nextname),
101	    offsetof(dtrace_probe_t, dtpr_prevname));
102
103	if (dtrace_retain_max < 1) {
104		cmn_err(CE_WARN, "illegal value (%lu) for dtrace_retain_max; "
105		    "setting to 1", dtrace_retain_max);
106		dtrace_retain_max = 1;
107	}
108
109	/*
110	 * Now discover our toxic ranges.
111	 */
112	dtrace_toxic_ranges(dtrace_toxrange_add);
113
114	/*
115	 * Before we register ourselves as a provider to our own framework,
116	 * we would like to assert that dtrace_provider is NULL -- but that's
117	 * not true if we were loaded as a dependency of a DTrace provider.
118	 * Once we've registered, we can assert that dtrace_provider is our
119	 * pseudo provider.
120	 */
121	(void) dtrace_register("dtrace", &dtrace_provider_attr,
122	    DTRACE_PRIV_NONE, 0, &dtrace_provider_ops, NULL, &id);
123
124	ASSERT(dtrace_provider != NULL);
125	ASSERT((dtrace_provider_id_t)dtrace_provider == id);
126
127	dtrace_probeid_begin = dtrace_probe_create((dtrace_provider_id_t)
128	    dtrace_provider, NULL, NULL, "BEGIN", 0, NULL);
129	dtrace_probeid_end = dtrace_probe_create((dtrace_provider_id_t)
130	    dtrace_provider, NULL, NULL, "END", 0, NULL);
131	dtrace_probeid_error = dtrace_probe_create((dtrace_provider_id_t)
132	    dtrace_provider, NULL, NULL, "ERROR", 1, NULL);
133
134	mutex_exit(&cpu_lock);
135
136	/*
137	 * If DTrace helper tracing is enabled, we need to allocate the
138	 * trace buffer and initialize the values.
139	 */
140	if (dtrace_helptrace_enabled) {
141		ASSERT(dtrace_helptrace_buffer == NULL);
142		dtrace_helptrace_buffer =
143		    kmem_zalloc(dtrace_helptrace_bufsize, KM_SLEEP);
144		dtrace_helptrace_next = 0;
145	}
146
147	mutex_exit(&dtrace_lock);
148	mutex_exit(&dtrace_provider_lock);
149
150	mutex_enter(&cpu_lock);
151
152	/* Setup the boot CPU */
153	(void) dtrace_cpu_setup(CPU_CONFIG, 0);
154
155	mutex_exit(&cpu_lock);
156
157#if __FreeBSD_version < 800039
158	/* Enable device cloning. */
159	clone_setup(&dtrace_clones);
160
161	/* Setup device cloning events. */
162	eh_tag = EVENTHANDLER_REGISTER(dev_clone, dtrace_clone, 0, 1000);
163#else
164	dtrace_dev = make_dev(&dtrace_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
165	    "dtrace/dtrace");
166	helper_dev = make_dev(&helper_cdevsw, 0, UID_ROOT, GID_WHEEL, 0660,
167	    "dtrace/helper");
168#endif
169
170	return;
171}
172