1 /*	$NetBSD: dtrace_load.c,v 1.3 2011/08/31 21:57:16 christos Exp $	*/
2 
3 /*
4  * CDDL HEADER START
5  *
6  * The contents of this file are subject to the terms of the
7  * Common Development and Distribution License (the "License").
8  * You may not use this file except in compliance with the License.
9  *
10  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
11  * or http://www.opensolaris.org/os/licensing.
12  * See the License for the specific language governing permissions
13  * and limitations under the License.
14  *
15  * When distributing Covered Code, include this CDDL HEADER in each
16  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
17  * If applicable, add the following below this CDDL HEADER, with the
18  * fields enclosed by brackets "[]" replaced with your own identifying
19  * information: Portions Copyright [yyyy] [name of copyright owner]
20  *
21  * CDDL HEADER END
22  *
23  * $FreeBSD: src/sys/cddl/dev/dtrace/dtrace_load.c,v 1.2.2.1 2009/08/03 08:13:06 kensmith Exp $
24  *
25  */
26 
27 static void dtrace_debug_init(void *);
28 static void dtrace_anon_init(void *dummy);
29 void dtrace_gethrtime_init(void *);
30 
31 int dtrace_helptrace_size=0;
32 
33 #ifndef mutex_init
34 #define	mutex_init(a, b, c, d)	mutex_init(a, c, IPL_NONE)
35 #endif
36 
37 static void
dtrace_load(void * dummy)38 dtrace_load(void *dummy)
39 {
40 	dtrace_provider_id_t id;
41 	CPU_INFO_ITERATOR cpuind;
42 	struct cpu_info *cinfo;
43 
44 	dtrace_debug_init(NULL);
45 	dtrace_gethrtime_init(NULL);
46 
47 	/* Hook into the trap handler. */
48 	dtrace_trap_func = dtrace_trap;
49 
50 	/* Hang our hook for thread switches. */
51 	dtrace_vtime_switch_func = dtrace_vtime_switch;
52 
53 	/* Hang our hook for exceptions. */
54 	dtrace_invop_init();
55 
56 	/*
57 	 * XXX This is a short term hack to avoid having to comment
58 	 * out lots and lots of lock/unlock calls.
59 	 */
60 	mutex_init(&mod_lock,"XXX mod_lock hack", MUTEX_DEFAULT, NULL);
61 
62 	/*
63 	 * Initialise the mutexes without 'witness' because the dtrace
64 	 * code is mostly written to wait for memory. To have the
65 	 * witness code change a malloc() from M_WAITOK to M_NOWAIT
66 	 * because a lock is held would surely create a panic in a
67 	 * low memory situation. And that low memory situation might be
68 	 * the very problem we are trying to trace.
69 	 */
70 	mutex_init(&dtrace_lock,"dtrace probe state", MUTEX_DEFAULT, NULL);
71 	mutex_init(&dtrace_provider_lock,"dtrace provider state", MUTEX_DEFAULT, NULL);
72 	mutex_init(&dtrace_meta_lock,"dtrace meta-provider state", MUTEX_DEFAULT, NULL);
73 	mutex_init(&dtrace_errlock,"dtrace error lock", MUTEX_DEFAULT, NULL);
74 
75 	mutex_enter(&dtrace_provider_lock);
76 	mutex_enter(&dtrace_lock);
77 	mutex_enter(&cpu_lock);
78 
79 	ASSERT(MUTEX_HELD(&cpu_lock));
80 
81 	dtrace_arena = vmem_create("dtrace", 1, INT_MAX, 1,
82 			NULL, NULL, NULL, 0, VM_SLEEP, IPL_NONE);
83 
84 	dtrace_state_cache = kmem_cache_create(__UNCONST("dtrace_state_cache"),
85 	    sizeof (dtrace_dstate_percpu_t) * NCPU, DTRACE_STATE_ALIGN,
86 	    NULL, NULL, NULL, NULL, NULL, 0);
87 
88 	ASSERT(MUTEX_HELD(&cpu_lock));
89 	dtrace_bymod = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_mod),
90 	    offsetof(dtrace_probe_t, dtpr_nextmod),
91 	    offsetof(dtrace_probe_t, dtpr_prevmod));
92 
93 	dtrace_byfunc = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_func),
94 	    offsetof(dtrace_probe_t, dtpr_nextfunc),
95 	    offsetof(dtrace_probe_t, dtpr_prevfunc));
96 
97 	dtrace_byname = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_name),
98 	    offsetof(dtrace_probe_t, dtpr_nextname),
99 	    offsetof(dtrace_probe_t, dtpr_prevname));
100 
101 	if (dtrace_retain_max < 1) {
102 		cmn_err(CE_WARN, "illegal value (%lu) for dtrace_retain_max; "
103 		    "setting to 1", dtrace_retain_max);
104 		dtrace_retain_max = 1;
105 	}
106 
107 	/*
108 	 * Now discover our toxic ranges.
109 	 */
110 	dtrace_toxic_ranges(dtrace_toxrange_add);
111 
112 	/*
113 	 * Before we register ourselves as a provider to our own framework,
114 	 * we would like to assert that dtrace_provider is NULL -- but that's
115 	 * not true if we were loaded as a dependency of a DTrace provider.
116 	 * Once we've registered, we can assert that dtrace_provider is our
117 	 * pseudo provider.
118 	 */
119 	(void) dtrace_register("dtrace", &dtrace_provider_attr,
120 	    DTRACE_PRIV_NONE, 0, &dtrace_provider_ops, NULL, &id);
121 
122 	ASSERT(dtrace_provider != NULL);
123 	ASSERT((dtrace_provider_id_t)dtrace_provider == id);
124 
125 	dtrace_probeid_begin = dtrace_probe_create((dtrace_provider_id_t)
126 	    dtrace_provider, NULL, NULL, "BEGIN", 0, NULL);
127 	dtrace_probeid_end = dtrace_probe_create((dtrace_provider_id_t)
128 	    dtrace_provider, NULL, NULL, "END", 0, NULL);
129 	dtrace_probeid_error = dtrace_probe_create((dtrace_provider_id_t)
130 	    dtrace_provider, NULL, NULL, "ERROR", 1, NULL);
131 
132 	mutex_exit(&cpu_lock);
133 
134 	/*
135 	 * If DTrace helper tracing is enabled, we need to allocate the
136 	 * trace buffer and initialize the values.
137 	 */
138 	if (dtrace_helptrace_enabled) {
139 		ASSERT(dtrace_helptrace_buffer == NULL);
140 		dtrace_helptrace_buffer =
141 		    kmem_zalloc(dtrace_helptrace_bufsize, KM_SLEEP);
142 		dtrace_helptrace_next = 0;
143 		dtrace_helptrace_size = dtrace_helptrace_bufsize;
144 	}
145 
146 	mutex_exit(&dtrace_lock);
147 	mutex_exit(&dtrace_provider_lock);
148 
149 	mutex_enter(&cpu_lock);
150 
151 	/* Setup the CPUs */
152 	for (CPU_INFO_FOREACH(cpuind, cinfo)) {
153 		(void) dtrace_cpu_setup(CPU_CONFIG, cpu_index(cinfo));
154 	}
155 
156 	mutex_exit(&cpu_lock);
157 
158 	dtrace_anon_init(NULL);
159 #if 0
160 	dtrace_dev = make_dev(&dtrace_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "dtrace/dtrace");
161 #endif
162 
163 	return;
164 }
165