sdt.c revision 251238 
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 * Portions Copyright 2006-2008 John Birrell jb@freebsd.org
22 *
23 * $FreeBSD: head/sys/cddl/dev/sdt/sdt.c 251238 2013-06-02 01:05:36Z markj $
24 *
25 */
26
27#ifndef KDTRACE_HOOKS
28#define KDTRACE_HOOKS
29#endif
30
31#include <sys/cdefs.h>
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/conf.h>
35#include <sys/kernel.h>
36#include <sys/limits.h>
37#include <sys/lock.h>
38#include <sys/linker.h>
39#include <sys/module.h>
40#include <sys/mutex.h>
41
42#include <sys/dtrace.h>
43#include <sys/sdt.h>
44
45#define SDT_ADDR2NDX(addr) (((uintptr_t)(addr)) >> 4)
46
47static d_open_t sdt_open;
48static int	sdt_unload(void);
49static void	sdt_getargdesc(void *, dtrace_id_t, void *, dtrace_argdesc_t *);
50static void	sdt_provide_probes(void *, dtrace_probedesc_t *);
51static void	sdt_destroy(void *, dtrace_id_t, void *);
52static void	sdt_enable(void *, dtrace_id_t, void *);
53static void	sdt_disable(void *, dtrace_id_t, void *);
54static void	sdt_load(void *);
55static int	sdt_provider_unreg_callback(struct sdt_provider *prov,
56		    void *arg);
57
58static struct cdevsw sdt_cdevsw = {
59	.d_version	= D_VERSION,
60	.d_open		= sdt_open,
61	.d_name		= "sdt",
62};
63
64static dtrace_pattr_t sdt_attr = {
65{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
66{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
67{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
68{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
69{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
70};
71
72static dtrace_pops_t sdt_pops = {
73	sdt_provide_probes,
74	NULL,
75	sdt_enable,
76	sdt_disable,
77	NULL,
78	NULL,
79	sdt_getargdesc,
80	NULL,
81	NULL,
82	sdt_destroy
83};
84
85static struct cdev		*sdt_cdev;
86
87static int
88sdt_argtype_callback(struct sdt_argtype *argtype, void *arg)
89{
90	dtrace_argdesc_t *desc = arg;
91
92	if (desc->dtargd_ndx == argtype->ndx) {
93		desc->dtargd_mapping = desc->dtargd_ndx; /* XXX */
94		strlcpy(desc->dtargd_native, argtype->type,
95		    sizeof(desc->dtargd_native));
96		desc->dtargd_xlate[0] = '\0'; /* XXX */
97	}
98
99	return (0);
100}
101
102static void
103sdt_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc)
104{
105	struct sdt_probe *probe = parg;
106
107	if (desc->dtargd_ndx < probe->n_args)
108		(void) (sdt_argtype_listall(probe, sdt_argtype_callback, desc));
109	else
110		desc->dtargd_ndx = DTRACE_ARGNONE;
111
112	return;
113}
114
115static int
116sdt_probe_callback(struct sdt_probe *probe, void *arg __unused)
117{
118	struct sdt_provider *prov = probe->prov;
119	char mod[64];
120	char func[64];
121	char name[64];
122
123	/*
124	 * Unfortunately this is necessary because the Solaris DTrace
125	 * code mixes consts and non-consts with casts to override
126	 * the incompatibilies. On FreeBSD, we use strict warnings
127	 * in gcc, so we have to respect const vs non-const.
128	 */
129	strlcpy(mod, probe->mod, sizeof(mod));
130	strlcpy(func, probe->func, sizeof(func));
131	strlcpy(name, probe->name, sizeof(name));
132
133	if (dtrace_probe_lookup(prov->id, mod, func, name) != 0)
134		return (0);
135
136	(void) dtrace_probe_create(prov->id, probe->mod, probe->func,
137	    probe->name, 1, probe);
138
139	return (0);
140}
141
142static int
143sdt_provider_entry(struct sdt_provider *prov, void *arg)
144{
145	return (sdt_probe_listall(prov, sdt_probe_callback, NULL));
146}
147
148static void
149sdt_provide_probes(void *arg, dtrace_probedesc_t *desc)
150{
151	if (desc != NULL)
152		return;
153
154	(void) sdt_provider_listall(sdt_provider_entry, NULL);
155}
156
157static void
158sdt_destroy(void *arg, dtrace_id_t id, void *parg)
159{
160	/* Nothing to do here. */
161}
162
163static void
164sdt_enable(void *arg, dtrace_id_t id, void *parg)
165{
166	struct sdt_probe *probe = parg;
167
168	probe->id = id;
169}
170
171static void
172sdt_disable(void *arg, dtrace_id_t id, void *parg)
173{
174	struct sdt_probe *probe = parg;
175
176	probe->id = 0;
177}
178
179static int
180sdt_provider_reg_callback(struct sdt_provider *prov, void *arg __unused)
181{
182	return (dtrace_register(prov->name, &sdt_attr, DTRACE_PRIV_USER,
183	    NULL, &sdt_pops, NULL, (dtrace_provider_id_t *) &prov->id));
184}
185
186static void
187sdt_load(void *dummy)
188{
189	/* Create the /dev/dtrace/sdt entry. */
190	sdt_cdev = make_dev(&sdt_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
191	    "dtrace/sdt");
192
193	sdt_probe_func = dtrace_probe;
194
195	sdt_register_callbacks(sdt_provider_reg_callback, NULL,
196	    sdt_provider_unreg_callback, NULL, sdt_probe_callback, NULL);
197}
198
199static int
200sdt_provider_unreg_callback(struct sdt_provider *prov, void *arg __unused)
201{
202	return (dtrace_unregister(prov->id));
203}
204
205static int
206sdt_unload()
207{
208	int error = 0;
209
210	sdt_probe_func = sdt_probe_stub;
211
212	sdt_deregister_callbacks();
213
214	destroy_dev(sdt_cdev);
215
216	return (error);
217}
218
219/* ARGSUSED */
220static int
221sdt_modevent(module_t mod __unused, int type, void *data __unused)
222{
223	int error = 0;
224
225	switch (type) {
226	case MOD_LOAD:
227		break;
228
229	case MOD_UNLOAD:
230		break;
231
232	case MOD_SHUTDOWN:
233		break;
234
235	default:
236		error = EOPNOTSUPP;
237		break;
238
239	}
240
241	return (error);
242}
243
244/* ARGSUSED */
245static int
246sdt_open(struct cdev *dev __unused, int oflags __unused, int devtype __unused, struct thread *td __unused)
247{
248	return (0);
249}
250
251SYSINIT(sdt_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, sdt_load, NULL);
252SYSUNINIT(sdt_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, sdt_unload, NULL);
253
254DEV_MODULE(sdt, sdt_modevent, NULL);
255MODULE_VERSION(sdt, 1);
256MODULE_DEPEND(sdt, dtrace, 1, 1, 1);
257MODULE_DEPEND(sdt, opensolaris, 1, 1, 1);
258