1 /*        $NetBSD: dtrace_load.c,v 1.5 2019/07/23 09:06:12 hannken 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: head/sys/cddl/dev/dtrace/dtrace_load.c 309069 2016-11-23 22:50:20Z gnn $
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 #ifdef __FreeBSD__
34 #ifndef EARLY_AP_STARTUP
35 static void
dtrace_ap_start(void * dummy)36 dtrace_ap_start(void *dummy)
37 {
38           int i;
39 
40           mutex_enter(&cpu_lock);
41 
42           /* Setup the rest of the CPUs. */
43           CPU_FOREACH(i) {
44                     if (i == 0)
45                               continue;
46 
47                     (void) dtrace_cpu_setup(CPU_CONFIG, i);
48           }
49 
50           mutex_exit(&cpu_lock);
51 }
52 
53 SYSINIT(dtrace_ap_start, SI_SUB_SMP, SI_ORDER_ANY, dtrace_ap_start, NULL);
54 #endif
55 #endif
56 
57 #ifdef __NetBSD__
58 void *dtrace_modcb;
59 #endif
60 
61 static void
dtrace_load(void * dummy)62 dtrace_load(void *dummy)
63 {
64           dtrace_provider_id_t id;
65           CPU_INFO_ITERATOR cpuind;
66           struct cpu_info *cinfo;
67 
68           dtrace_debug_init(NULL);
69           dtrace_gethrtime_init(NULL);
70 
71 #ifdef __FreeBSD__
72           /*
73            * DTrace uses negative logic for the destructive mode switch, so it
74            * is required to translate from the sysctl which uses positive logic.
75            */
76           if (dtrace_allow_destructive)
77                     dtrace_destructive_disallow = 0;
78           else
79                     dtrace_destructive_disallow = 1;
80 #endif
81 
82           /* Hook into the trap handler. */
83           dtrace_trap_func = dtrace_trap;
84 
85           /* Hang our hook for thread switches. */
86           dtrace_vtime_switch_func = dtrace_vtime_switch;
87 
88           /* Hang our hook for exceptions. */
89           dtrace_invop_init();
90 
91           dtrace_taskq = taskq_create("dtrace_taskq", 1, maxclsyspri, 0, 0, 0);
92 
93 #ifdef __FreeBSD__
94           dtrace_arena = new_unrhdr(1, INT_MAX, &dtrace_unr_mtx);
95 
96           /* Register callbacks for linker file load and unload events. */
97           dtrace_kld_load_tag = EVENTHANDLER_REGISTER(kld_load,
98               dtrace_kld_load, NULL, EVENTHANDLER_PRI_ANY);
99           dtrace_kld_unload_try_tag = EVENTHANDLER_REGISTER(kld_unload_try,
100               dtrace_kld_unload_try, NULL, EVENTHANDLER_PRI_ANY);
101 #endif
102 
103 #ifdef __NetBSD__
104           dtrace_arena = vmem_create("dtrace", 1, INT_MAX, 1,
105                               NULL, NULL, NULL, 0, VM_SLEEP, IPL_NONE);
106 
107 #endif
108 
109           /*
110            * Initialise the mutexes without 'witness' because the dtrace
111            * code is mostly written to wait for memory. To have the
112            * witness code change a malloc() from M_WAITOK to M_NOWAIT
113            * because a lock is held would surely create a panic in a
114            * low memory situation. And that low memory situation might be
115            * the very problem we are trying to trace.
116            */
117           mutex_init(&dtrace_lock,"dtrace probe state", MUTEX_DEFAULT, NULL);
118           mutex_init(&dtrace_provider_lock,"dtrace provider state", MUTEX_DEFAULT, NULL);
119           mutex_init(&dtrace_meta_lock,"dtrace meta-provider state", MUTEX_DEFAULT, NULL);
120 #ifdef DEBUG
121           mutex_init(&dtrace_errlock,"dtrace error lock", MUTEX_DEFAULT, NULL);
122 #endif
123 
124           mutex_enter(&dtrace_provider_lock);
125           mutex_enter(&dtrace_lock);
126           mutex_enter(&cpu_lock);
127 
128           ASSERT(MUTEX_HELD(&cpu_lock));
129 
130           dtrace_state_cache = kmem_cache_create(__UNCONST("dtrace_state_cache"),
131               sizeof (dtrace_dstate_percpu_t) * NCPU, DTRACE_STATE_ALIGN,
132               NULL, NULL, NULL, NULL, NULL, 0);
133 
134           ASSERT(MUTEX_HELD(&cpu_lock));
135           dtrace_bymod = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_mod),
136               offsetof(dtrace_probe_t, dtpr_nextmod),
137               offsetof(dtrace_probe_t, dtpr_prevmod));
138 
139           dtrace_byfunc = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_func),
140               offsetof(dtrace_probe_t, dtpr_nextfunc),
141               offsetof(dtrace_probe_t, dtpr_prevfunc));
142 
143           dtrace_byname = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_name),
144               offsetof(dtrace_probe_t, dtpr_nextname),
145               offsetof(dtrace_probe_t, dtpr_prevname));
146 
147           if (dtrace_retain_max < 1) {
148                     cmn_err(CE_WARN, "illegal value (%lu) for dtrace_retain_max; "
149                         "setting to 1", dtrace_retain_max);
150                     dtrace_retain_max = 1;
151           }
152 
153           /*
154            * Now discover our toxic ranges.
155            */
156           dtrace_toxic_ranges(dtrace_toxrange_add);
157 
158           /*
159            * Before we register ourselves as a provider to our own framework,
160            * we would like to assert that dtrace_provider is NULL -- but that's
161            * not true if we were loaded as a dependency of a DTrace provider.
162            * Once we've registered, we can assert that dtrace_provider is our
163            * pseudo provider.
164            */
165           (void) dtrace_register("dtrace", &dtrace_provider_attr,
166               DTRACE_PRIV_NONE, 0, &dtrace_provider_ops, NULL, &id);
167 
168           ASSERT(dtrace_provider != NULL);
169           ASSERT((dtrace_provider_id_t)dtrace_provider == id);
170 
171           dtrace_probeid_begin = dtrace_probe_create((dtrace_provider_id_t)
172               dtrace_provider, NULL, NULL, "BEGIN", 0, NULL);
173           dtrace_probeid_end = dtrace_probe_create((dtrace_provider_id_t)
174               dtrace_provider, NULL, NULL, "END", 0, NULL);
175           dtrace_probeid_error = dtrace_probe_create((dtrace_provider_id_t)
176               dtrace_provider, NULL, NULL, "ERROR", 1, NULL);
177 
178           mutex_exit(&cpu_lock);
179           mutex_exit(&dtrace_lock);
180           mutex_exit(&dtrace_provider_lock);
181 
182           mutex_enter(&cpu_lock);
183 
184           /* Setup the CPUs */
185           for (CPU_INFO_FOREACH(cpuind, cinfo)) {
186                     (void) dtrace_cpu_setup(CPU_CONFIG, cpu_index(cinfo));
187           }
188 
189           mutex_exit(&cpu_lock);
190 
191 #ifdef __NetBSD__
192           dtrace_anon_init(NULL);
193 
194           dtrace_modcb = module_register_callbacks(dtrace_module_loaded,
195                                                              dtrace_module_unloaded);
196 #endif
197 #ifdef __FreeBSD__
198           dtrace_dev = make_dev(&dtrace_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
199               "dtrace/dtrace");
200           helper_dev = make_dev(&helper_cdevsw, 0, UID_ROOT, GID_WHEEL, 0660,
201               "dtrace/helper");
202 #endif
203 
204           return;
205 }
206