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.
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.
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]
21 * Portions Copyright 2006-2008 John Birrell jb@freebsd.org
27 #include "opt_kdtrace.h"
29 #include <sys/cdefs.h>
30 #include <sys/param.h>
31 #include <sys/systm.h>
34 #include <sys/eventhandler.h>
35 #include <sys/kernel.h>
36 #include <sys/limits.h>
37 #include <sys/linker.h>
38 #include <sys/linker_set.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
42 #include <sys/mutex.h>
43 #include <sys/queue.h>
46 #include <sys/dtrace.h>
47 #include <sys/dtrace_bsd.h>
50 static void sdt_getargdesc(void *, dtrace_id_t, void *, dtrace_argdesc_t *);
51 static void sdt_provide_probes(void *, dtrace_probedesc_t *);
52 static void sdt_destroy(void *, dtrace_id_t, void *);
53 static void sdt_enable(void *, dtrace_id_t, void *);
54 static void sdt_disable(void *, dtrace_id_t, void *);
56 static d_open_t sdt_open;
57 static void sdt_load(void *);
58 static int sdt_unload(void *);
59 static void sdt_create_provider(struct sdt_provider *);
60 static void sdt_create_probe(struct sdt_probe *);
61 static void sdt_kld_load(void *, struct linker_file *);
62 static void sdt_kld_unload_try(void *, struct linker_file *, int *);
64 static MALLOC_DEFINE(M_SDT, "SDT", "DTrace SDT providers");
66 static struct cdevsw sdt_cdevsw = {
67 .d_version = D_VERSION,
72 static dtrace_pattr_t sdt_attr = {
73 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
74 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
75 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
76 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
77 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
80 static dtrace_pops_t sdt_pops = {
93 static struct cdev *sdt_cdev;
95 static TAILQ_HEAD(, sdt_provider) sdt_prov_list;
97 eventhandler_tag sdt_kld_load_tag;
98 eventhandler_tag sdt_kld_unload_try_tag;
101 sdt_create_provider(struct sdt_provider *prov)
103 struct sdt_provider *curr, *newprov;
105 TAILQ_FOREACH(curr, &sdt_prov_list, prov_entry)
106 if (strcmp(prov->name, curr->name) == 0) {
107 /* The provider has already been defined. */
113 * Make a copy of prov so that we don't lose fields if its module is
114 * unloaded but the provider isn't destroyed. This could happen with
115 * a provider that spans multiple modules.
117 newprov = malloc(sizeof(*newprov), M_SDT, M_WAITOK | M_ZERO);
118 newprov->name = strdup(prov->name, M_SDT);
119 prov->sdt_refs = newprov->sdt_refs = 1;
120 TAILQ_INIT(&newprov->probe_list);
122 TAILQ_INSERT_TAIL(&sdt_prov_list, newprov, prov_entry);
124 (void)dtrace_register(newprov->name, &sdt_attr, DTRACE_PRIV_USER, NULL,
125 &sdt_pops, NULL, (dtrace_provider_id_t *)&newprov->id);
126 prov->id = newprov->id;
130 sdt_create_probe(struct sdt_probe *probe)
132 struct sdt_provider *prov;
133 char mod[DTRACE_MODNAMELEN];
134 char func[DTRACE_FUNCNAMELEN];
135 char name[DTRACE_NAMELEN];
138 TAILQ_FOREACH(prov, &sdt_prov_list, prov_entry)
139 if (strcmp(prov->name, probe->prov->name) == 0)
142 KASSERT(prov != NULL, ("probe defined without a provider"));
144 /* If no module name was specified, use the module filename. */
145 if (*probe->mod == 0) {
146 len = strlcpy(mod, probe->sdtp_lf->filename, sizeof(mod));
147 if (len > 3 && strcmp(mod + len - 3, ".ko") == 0)
150 strlcpy(mod, probe->mod, sizeof(mod));
153 * Unfortunately this is necessary because the Solaris DTrace
154 * code mixes consts and non-consts with casts to override
155 * the incompatibilies. On FreeBSD, we use strict warnings
156 * in the C compiler, so we have to respect const vs non-const.
158 strlcpy(func, probe->func, sizeof(func));
159 strlcpy(name, probe->name, sizeof(name));
161 if (dtrace_probe_lookup(prov->id, mod, func, name) != DTRACE_IDNONE)
164 TAILQ_INSERT_TAIL(&prov->probe_list, probe, probe_entry);
166 (void)dtrace_probe_create(prov->id, mod, func, name, 1, probe);
169 /* Probes are created through the SDT module load/unload hook. */
171 sdt_provide_probes(void *arg, dtrace_probedesc_t *desc)
176 sdt_enable(void *arg __unused, dtrace_id_t id, void *parg)
178 struct sdt_probe *probe = parg;
181 probe->sdtp_lf->nenabled++;
185 sdt_disable(void *arg __unused, dtrace_id_t id, void *parg)
187 struct sdt_probe *probe = parg;
189 KASSERT(probe->sdtp_lf->nenabled > 0, ("no probes enabled"));
192 probe->sdtp_lf->nenabled--;
196 sdt_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc)
198 struct sdt_argtype *argtype;
199 struct sdt_probe *probe = parg;
201 if (desc->dtargd_ndx < probe->n_args) {
202 TAILQ_FOREACH(argtype, &probe->argtype_list, argtype_entry) {
203 if (desc->dtargd_ndx == argtype->ndx) {
204 desc->dtargd_mapping = desc->dtargd_ndx;
205 strlcpy(desc->dtargd_native, argtype->type,
206 sizeof(desc->dtargd_native));
207 if (argtype->xtype != NULL)
208 strlcpy(desc->dtargd_xlate,
210 sizeof(desc->dtargd_xlate));
212 desc->dtargd_xlate[0] = '\0';
216 desc->dtargd_ndx = DTRACE_ARGNONE;
220 sdt_destroy(void *arg, dtrace_id_t id, void *parg)
222 struct sdt_probe *probe;
225 TAILQ_REMOVE(&probe->prov->probe_list, probe, probe_entry);
229 * Called from the kernel linker when a module is loaded, before
230 * dtrace_module_loaded() is called. This is done so that it's possible to
231 * register new providers when modules are loaded. We cannot do this in the
232 * provide_module method since it's called with the provider lock held
233 * and dtrace_register() will try to acquire it again.
236 sdt_kld_load(void *arg __unused, struct linker_file *lf)
238 struct sdt_provider **prov, **begin, **end;
239 struct sdt_probe **probe, **p_begin, **p_end;
240 struct sdt_argtype **argtype, **a_begin, **a_end;
242 if (linker_file_lookup_set(lf, "sdt_providers_set", &begin, &end, NULL))
244 for (prov = begin; prov < end; prov++)
245 sdt_create_provider(*prov);
247 if (linker_file_lookup_set(lf, "sdt_probes_set", &p_begin, &p_end,
250 for (probe = p_begin; probe < p_end; probe++) {
251 (*probe)->sdtp_lf = lf;
252 sdt_create_probe(*probe);
253 TAILQ_INIT(&(*probe)->argtype_list);
256 if (linker_file_lookup_set(lf, "sdt_argtypes_set", &a_begin, &a_end,
259 for (argtype = a_begin; argtype < a_end; argtype++) {
260 (*argtype)->probe->n_args++;
261 TAILQ_INSERT_TAIL(&(*argtype)->probe->argtype_list, *argtype,
267 sdt_kld_unload_try(void *arg __unused, struct linker_file *lf, int *error __unused)
269 struct sdt_provider *prov, **curr, **begin, **end, *tmp;
272 /* We already have an error, so don't do anything. */
274 else if (linker_file_lookup_set(lf, "sdt_providers_set", &begin, &end, NULL))
275 /* No DTrace providers are declared in this file. */
279 * Go through all the providers declared in this linker file and
280 * unregister any that aren't declared in another loaded file.
282 for (curr = begin; curr < end; curr++) {
283 TAILQ_FOREACH_SAFE(prov, &sdt_prov_list, prov_entry, tmp) {
284 if (strcmp(prov->name, (*curr)->name) == 0) {
285 if (prov->sdt_refs == 1) {
286 TAILQ_REMOVE(&sdt_prov_list, prov,
288 dtrace_unregister(prov->id);
289 free(prov->name, M_SDT);
300 sdt_linker_file_cb(linker_file_t lf, void *arg __unused)
303 sdt_kld_load(NULL, lf);
309 sdt_load(void *arg __unused)
312 TAILQ_INIT(&sdt_prov_list);
314 /* Create the /dev/dtrace/sdt entry. */
315 sdt_cdev = make_dev(&sdt_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
318 sdt_probe_func = dtrace_probe;
320 sdt_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, sdt_kld_load, NULL,
321 EVENTHANDLER_PRI_ANY);
322 sdt_kld_unload_try_tag = EVENTHANDLER_REGISTER(kld_unload_try,
323 sdt_kld_unload_try, NULL, EVENTHANDLER_PRI_ANY);
325 /* Pick up probes from the kernel and already-loaded linker files. */
326 linker_file_foreach(sdt_linker_file_cb, NULL);
330 sdt_unload(void *arg __unused)
332 struct sdt_provider *prov, *tmp;
334 EVENTHANDLER_DEREGISTER(kld_load, sdt_kld_load_tag);
335 EVENTHANDLER_DEREGISTER(kld_unload_try, sdt_kld_unload_try_tag);
337 sdt_probe_func = sdt_probe_stub;
339 TAILQ_FOREACH_SAFE(prov, &sdt_prov_list, prov_entry, tmp) {
340 TAILQ_REMOVE(&sdt_prov_list, prov, prov_entry);
341 dtrace_unregister(prov->id);
342 free(prov->name, M_SDT);
346 destroy_dev(sdt_cdev);
353 sdt_modevent(module_t mod __unused, int type, void *data __unused)
377 sdt_open(struct cdev *dev __unused, int oflags __unused, int devtype __unused,
378 struct thread *td __unused)
384 SYSINIT(sdt_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, sdt_load, NULL);
385 SYSUNINIT(sdt_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, sdt_unload, NULL);
387 DEV_MODULE(sdt, sdt_modevent, NULL);
388 MODULE_VERSION(sdt, 1);
389 MODULE_DEPEND(sdt, dtrace, 1, 1, 1);
390 MODULE_DEPEND(sdt, opensolaris, 1, 1, 1);