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];
140 TAILQ_FOREACH(prov, &sdt_prov_list, prov_entry)
141 if (strcmp(prov->name, probe->prov->name) == 0)
144 KASSERT(prov != NULL, ("probe defined without a provider"));
146 /* If no module name was specified, use the module filename. */
147 if (*probe->mod == 0) {
148 len = strlcpy(mod, probe->sdtp_lf->filename, sizeof(mod));
149 if (len > 3 && strcmp(mod + len - 3, ".ko") == 0)
152 strlcpy(mod, probe->mod, sizeof(mod));
155 * Unfortunately this is necessary because the Solaris DTrace
156 * code mixes consts and non-consts with casts to override
157 * the incompatibilies. On FreeBSD, we use strict warnings
158 * in the C compiler, so we have to respect const vs non-const.
160 strlcpy(func, probe->func, sizeof(func));
164 for (len = 0; len < (sizeof(name) - 1) && *from != '\0';
165 len++, from++, to++) {
166 if (from[0] == '_' && from[1] == '_') {
174 if (dtrace_probe_lookup(prov->id, mod, func, name) != DTRACE_IDNONE)
177 TAILQ_INSERT_TAIL(&prov->probe_list, probe, probe_entry);
179 (void)dtrace_probe_create(prov->id, mod, func, name, 1, probe);
182 /* Probes are created through the SDT module load/unload hook. */
184 sdt_provide_probes(void *arg, dtrace_probedesc_t *desc)
189 sdt_enable(void *arg __unused, dtrace_id_t id, void *parg)
191 struct sdt_probe *probe = parg;
194 probe->sdtp_lf->nenabled++;
198 sdt_disable(void *arg __unused, dtrace_id_t id, void *parg)
200 struct sdt_probe *probe = parg;
202 KASSERT(probe->sdtp_lf->nenabled > 0, ("no probes enabled"));
205 probe->sdtp_lf->nenabled--;
209 sdt_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc)
211 struct sdt_argtype *argtype;
212 struct sdt_probe *probe = parg;
214 if (desc->dtargd_ndx < probe->n_args) {
215 TAILQ_FOREACH(argtype, &probe->argtype_list, argtype_entry) {
216 if (desc->dtargd_ndx == argtype->ndx) {
217 desc->dtargd_mapping = desc->dtargd_ndx;
218 strlcpy(desc->dtargd_native, argtype->type,
219 sizeof(desc->dtargd_native));
220 if (argtype->xtype != NULL)
221 strlcpy(desc->dtargd_xlate,
223 sizeof(desc->dtargd_xlate));
225 desc->dtargd_xlate[0] = '\0';
229 desc->dtargd_ndx = DTRACE_ARGNONE;
233 sdt_destroy(void *arg, dtrace_id_t id, void *parg)
235 struct sdt_probe *probe;
238 TAILQ_REMOVE(&probe->prov->probe_list, probe, probe_entry);
242 * Called from the kernel linker when a module is loaded, before
243 * dtrace_module_loaded() is called. This is done so that it's possible to
244 * register new providers when modules are loaded. We cannot do this in the
245 * provide_module method since it's called with the provider lock held
246 * and dtrace_register() will try to acquire it again.
249 sdt_kld_load(void *arg __unused, struct linker_file *lf)
251 struct sdt_provider **prov, **begin, **end;
252 struct sdt_probe **probe, **p_begin, **p_end;
253 struct sdt_argtype **argtype, **a_begin, **a_end;
255 if (linker_file_lookup_set(lf, "sdt_providers_set", &begin, &end, NULL))
257 for (prov = begin; prov < end; prov++)
258 sdt_create_provider(*prov);
260 if (linker_file_lookup_set(lf, "sdt_probes_set", &p_begin, &p_end,
263 for (probe = p_begin; probe < p_end; probe++) {
264 (*probe)->sdtp_lf = lf;
265 sdt_create_probe(*probe);
266 TAILQ_INIT(&(*probe)->argtype_list);
269 if (linker_file_lookup_set(lf, "sdt_argtypes_set", &a_begin, &a_end,
272 for (argtype = a_begin; argtype < a_end; argtype++) {
273 (*argtype)->probe->n_args++;
274 TAILQ_INSERT_TAIL(&(*argtype)->probe->argtype_list, *argtype,
280 sdt_kld_unload_try(void *arg __unused, struct linker_file *lf, int *error __unused)
282 struct sdt_provider *prov, **curr, **begin, **end, *tmp;
285 /* We already have an error, so don't do anything. */
287 else if (linker_file_lookup_set(lf, "sdt_providers_set", &begin, &end, NULL))
288 /* No DTrace providers are declared in this file. */
292 * Go through all the providers declared in this linker file and
293 * unregister any that aren't declared in another loaded file.
295 for (curr = begin; curr < end; curr++) {
296 TAILQ_FOREACH_SAFE(prov, &sdt_prov_list, prov_entry, tmp) {
297 if (strcmp(prov->name, (*curr)->name) == 0) {
298 if (prov->sdt_refs == 1) {
299 TAILQ_REMOVE(&sdt_prov_list, prov,
301 dtrace_unregister(prov->id);
302 free(prov->name, M_SDT);
313 sdt_linker_file_cb(linker_file_t lf, void *arg __unused)
316 sdt_kld_load(NULL, lf);
322 sdt_load(void *arg __unused)
325 TAILQ_INIT(&sdt_prov_list);
327 /* Create the /dev/dtrace/sdt entry. */
328 sdt_cdev = make_dev(&sdt_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
331 sdt_probe_func = dtrace_probe;
333 sdt_kld_load_tag = EVENTHANDLER_REGISTER(kld_load, sdt_kld_load, NULL,
334 EVENTHANDLER_PRI_ANY);
335 sdt_kld_unload_try_tag = EVENTHANDLER_REGISTER(kld_unload_try,
336 sdt_kld_unload_try, NULL, EVENTHANDLER_PRI_ANY);
338 /* Pick up probes from the kernel and already-loaded linker files. */
339 linker_file_foreach(sdt_linker_file_cb, NULL);
343 sdt_unload(void *arg __unused)
345 struct sdt_provider *prov, *tmp;
347 EVENTHANDLER_DEREGISTER(kld_load, sdt_kld_load_tag);
348 EVENTHANDLER_DEREGISTER(kld_unload_try, sdt_kld_unload_try_tag);
350 sdt_probe_func = sdt_probe_stub;
352 TAILQ_FOREACH_SAFE(prov, &sdt_prov_list, prov_entry, tmp) {
353 TAILQ_REMOVE(&sdt_prov_list, prov, prov_entry);
354 dtrace_unregister(prov->id);
355 free(prov->name, M_SDT);
359 destroy_dev(sdt_cdev);
366 sdt_modevent(module_t mod __unused, int type, void *data __unused)
390 sdt_open(struct cdev *dev __unused, int oflags __unused, int devtype __unused,
391 struct thread *td __unused)
397 SYSINIT(sdt_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, sdt_load, NULL);
398 SYSUNINIT(sdt_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, sdt_unload, NULL);
400 DEV_MODULE(sdt, sdt_modevent, NULL);
401 MODULE_VERSION(sdt, 1);
402 MODULE_DEPEND(sdt, dtrace, 1, 1, 1);
403 MODULE_DEPEND(sdt, opensolaris, 1, 1, 1);