xref: /titanic_41/usr/src/lib/libdtrace/common/dt_provider.c (revision 6f45ec7b0b964c3be967c4880e8867ac1e7763a5)
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 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/sysmacros.h>
31 
32 #include <assert.h>
33 #include <limits.h>
34 #include <strings.h>
35 #include <stdlib.h>
36 #include <alloca.h>
37 #include <unistd.h>
38 #include <errno.h>
39 
40 #include <dt_provider.h>
41 #include <dt_module.h>
42 #include <dt_string.h>
43 #include <dt_list.h>
44 
45 static dt_provider_t *
46 dt_provider_insert(dtrace_hdl_t *dtp, dt_provider_t *pvp, uint_t h)
47 {
48 	dt_list_append(&dtp->dt_provlist, pvp);
49 
50 	pvp->pv_next = dtp->dt_provs[h];
51 	dtp->dt_provs[h] = pvp;
52 	dtp->dt_nprovs++;
53 
54 	return (pvp);
55 }
56 
57 dt_provider_t *
58 dt_provider_lookup(dtrace_hdl_t *dtp, const char *name)
59 {
60 	uint_t h = dt_strtab_hash(name, NULL) % dtp->dt_provbuckets;
61 	dtrace_providerdesc_t desc;
62 	dt_provider_t *pvp;
63 
64 	for (pvp = dtp->dt_provs[h]; pvp != NULL; pvp = pvp->pv_next) {
65 		if (strcmp(pvp->pv_desc.dtvd_name, name) == 0)
66 			return (pvp);
67 	}
68 
69 	if (strisglob(name) || name[0] == '\0') {
70 		(void) dt_set_errno(dtp, EDT_NOPROV);
71 		return (NULL);
72 	}
73 
74 	bzero(&desc, sizeof (desc));
75 	(void) strlcpy(desc.dtvd_name, name, DTRACE_PROVNAMELEN);
76 
77 	if (dt_ioctl(dtp, DTRACEIOC_PROVIDER, &desc) == -1) {
78 		(void) dt_set_errno(dtp, errno == ESRCH ? EDT_NOPROV : errno);
79 		return (NULL);
80 	}
81 
82 	if ((pvp = dt_provider_create(dtp, name)) == NULL)
83 		return (NULL); /* dt_errno is set for us */
84 
85 	bcopy(&desc, &pvp->pv_desc, sizeof (desc));
86 	pvp->pv_flags |= DT_PROVIDER_IMPL;
87 	return (pvp);
88 }
89 
90 dt_provider_t *
91 dt_provider_create(dtrace_hdl_t *dtp, const char *name)
92 {
93 	dt_provider_t *pvp;
94 
95 	if ((pvp = dt_zalloc(dtp, sizeof (dt_provider_t))) == NULL)
96 		return (NULL);
97 
98 	(void) strlcpy(pvp->pv_desc.dtvd_name, name, DTRACE_PROVNAMELEN);
99 	pvp->pv_probes = dt_idhash_create(pvp->pv_desc.dtvd_name, NULL, 0, 0);
100 	pvp->pv_gen = dtp->dt_gen;
101 	pvp->pv_hdl = dtp;
102 
103 	if (pvp->pv_probes == NULL) {
104 		dt_free(dtp, pvp);
105 		(void) dt_set_errno(dtp, EDT_NOMEM);
106 		return (NULL);
107 	}
108 
109 	pvp->pv_desc.dtvd_attr.dtpa_provider = _dtrace_prvattr;
110 	pvp->pv_desc.dtvd_attr.dtpa_mod = _dtrace_prvattr;
111 	pvp->pv_desc.dtvd_attr.dtpa_func = _dtrace_prvattr;
112 	pvp->pv_desc.dtvd_attr.dtpa_name = _dtrace_prvattr;
113 	pvp->pv_desc.dtvd_attr.dtpa_args = _dtrace_prvattr;
114 
115 	return (dt_provider_insert(dtp, pvp,
116 	    dt_strtab_hash(name, NULL) % dtp->dt_provbuckets));
117 }
118 
119 void
120 dt_provider_destroy(dtrace_hdl_t *dtp, dt_provider_t *pvp)
121 {
122 	dt_provider_t **pp;
123 	uint_t h;
124 
125 	assert(pvp->pv_hdl == dtp);
126 
127 	h = dt_strtab_hash(pvp->pv_desc.dtvd_name, NULL) % dtp->dt_provbuckets;
128 	pp = &dtp->dt_provs[h];
129 
130 	while (*pp != NULL && *pp != pvp)
131 		pp = &(*pp)->pv_next;
132 
133 	assert(*pp != NULL && *pp == pvp);
134 	*pp = pvp->pv_next;
135 
136 	dt_list_delete(&dtp->dt_provlist, pvp);
137 	dtp->dt_nprovs--;
138 
139 	if (pvp->pv_probes != NULL)
140 		dt_idhash_destroy(pvp->pv_probes);
141 
142 	dt_node_link_free(&pvp->pv_nodes);
143 	dt_free(dtp, pvp->pv_xrefs);
144 	dt_free(dtp, pvp);
145 }
146 
147 int
148 dt_provider_xref(dtrace_hdl_t *dtp, dt_provider_t *pvp, id_t id)
149 {
150 	size_t oldsize = BT_SIZEOFMAP(pvp->pv_xrmax);
151 	size_t newsize = BT_SIZEOFMAP(dtp->dt_xlatorid);
152 
153 	assert(id >= 0 && id < dtp->dt_xlatorid);
154 
155 	if (newsize > oldsize) {
156 		ulong_t *xrefs = dt_zalloc(dtp, newsize);
157 
158 		if (xrefs == NULL)
159 			return (-1);
160 
161 		bcopy(pvp->pv_xrefs, xrefs, oldsize);
162 		dt_free(dtp, pvp->pv_xrefs);
163 
164 		pvp->pv_xrefs = xrefs;
165 		pvp->pv_xrmax = dtp->dt_xlatorid;
166 	}
167 
168 	BT_SET(pvp->pv_xrefs, id);
169 	return (0);
170 }
171 
172 static uint8_t
173 dt_probe_argmap(dt_node_t *xnp, dt_node_t *nnp)
174 {
175 	uint8_t i;
176 
177 	for (i = 0; nnp != NULL; i++) {
178 		if (nnp->dn_string != NULL &&
179 		    strcmp(nnp->dn_string, xnp->dn_string) == 0)
180 			break;
181 		else
182 			nnp = nnp->dn_list;
183 	}
184 
185 	return (i);
186 }
187 
188 static dt_node_t *
189 dt_probe_alloc_args(dt_provider_t *pvp, int argc)
190 {
191 	dt_node_t *args = NULL, *pnp = NULL, *dnp;
192 	int i;
193 
194 	for (i = 0; i < argc; i++, pnp = dnp) {
195 		if ((dnp = dt_node_xalloc(pvp->pv_hdl, DT_NODE_TYPE)) == NULL)
196 			return (NULL);
197 
198 		dnp->dn_link = pvp->pv_nodes;
199 		pvp->pv_nodes = dnp;
200 
201 		if (args == NULL)
202 			args = dnp;
203 		else
204 			pnp->dn_list = dnp;
205 	}
206 
207 	return (args);
208 }
209 
210 static size_t
211 dt_probe_keylen(const dtrace_probedesc_t *pdp)
212 {
213 	return (strlen(pdp->dtpd_mod) + 1 +
214 	    strlen(pdp->dtpd_func) + 1 + strlen(pdp->dtpd_name) + 1);
215 }
216 
217 static char *
218 dt_probe_key(const dtrace_probedesc_t *pdp, char *s)
219 {
220 	(void) snprintf(s, INT_MAX, "%s:%s:%s",
221 	    pdp->dtpd_mod, pdp->dtpd_func, pdp->dtpd_name);
222 	return (s);
223 }
224 
225 /*
226  * If a probe was discovered from the kernel, ask dtrace(7D) for a description
227  * of each of its arguments, including native and translated types.
228  */
229 static dt_probe_t *
230 dt_probe_discover(dt_provider_t *pvp, const dtrace_probedesc_t *pdp)
231 {
232 	dtrace_hdl_t *dtp = pvp->pv_hdl;
233 	char *name = dt_probe_key(pdp, alloca(dt_probe_keylen(pdp)));
234 
235 	dt_node_t *xargs, *nargs;
236 	dt_ident_t *idp;
237 	dt_probe_t *prp;
238 
239 	dtrace_typeinfo_t dtt;
240 	int i, nc, xc;
241 
242 	int adc = _dtrace_argmax;
243 	dtrace_argdesc_t *adv = alloca(sizeof (dtrace_argdesc_t) * adc);
244 	dtrace_argdesc_t *adp = adv;
245 
246 	assert(strcmp(pvp->pv_desc.dtvd_name, pdp->dtpd_provider) == 0);
247 	assert(pdp->dtpd_id != DTRACE_IDNONE);
248 
249 	dt_dprintf("discovering probe %s:%s id=%d\n",
250 	    pvp->pv_desc.dtvd_name, name, pdp->dtpd_id);
251 
252 	for (nc = -1, i = 0; i < adc; i++, adp++) {
253 		bzero(adp, sizeof (dtrace_argdesc_t));
254 		adp->dtargd_ndx = i;
255 		adp->dtargd_id = pdp->dtpd_id;
256 
257 		if (dt_ioctl(dtp, DTRACEIOC_PROBEARG, adp) != 0) {
258 			(void) dt_set_errno(dtp, errno);
259 			return (NULL);
260 		}
261 
262 		if (adp->dtargd_ndx == DTRACE_ARGNONE)
263 			break; /* all argument descs have been retrieved */
264 
265 		nc = MAX(nc, adp->dtargd_mapping);
266 	}
267 
268 	xc = i;
269 	nc++;
270 
271 	/*
272 	 * Now that we have discovered the number of native and translated
273 	 * arguments from the argument descriptions, allocate a new probe ident
274 	 * and corresponding dt_probe_t and hash it into the provider.
275 	 */
276 	xargs = dt_probe_alloc_args(pvp, xc);
277 	nargs = dt_probe_alloc_args(pvp, nc);
278 
279 	if ((xc != 0 && xargs == NULL) || (nc != 0 && nargs == NULL))
280 		return (NULL); /* dt_errno is set for us */
281 
282 	idp = dt_ident_create(name, DT_IDENT_PROBE,
283 	    DT_IDFLG_ORPHAN, pdp->dtpd_id, _dtrace_defattr, 0,
284 	    &dt_idops_probe, NULL, dtp->dt_gen);
285 
286 	if (idp == NULL) {
287 		(void) dt_set_errno(dtp, EDT_NOMEM);
288 		return (NULL);
289 	}
290 
291 	if ((prp = dt_probe_create(dtp, idp, 2,
292 	    nargs, nc, xargs, xc)) == NULL) {
293 		dt_ident_destroy(idp);
294 		return (NULL);
295 	}
296 
297 	dt_probe_declare(pvp, prp);
298 
299 	/*
300 	 * Once our new dt_probe_t is fully constructed, iterate over the
301 	 * cached argument descriptions and assign types to prp->pr_nargv[]
302 	 * and prp->pr_xargv[] and assign mappings to prp->pr_mapping[].
303 	 */
304 	for (adp = adv, i = 0; i < xc; i++, adp++) {
305 		if (dtrace_type_strcompile(dtp,
306 		    adp->dtargd_native, &dtt) != 0) {
307 			dt_dprintf("failed to resolve input type %s "
308 			    "for %s:%s arg #%d: %s\n", adp->dtargd_native,
309 			    pvp->pv_desc.dtvd_name, name, i + 1,
310 			    dtrace_errmsg(dtp, dtrace_errno(dtp)));
311 
312 			dtt.dtt_object = NULL;
313 			dtt.dtt_ctfp = NULL;
314 			dtt.dtt_type = CTF_ERR;
315 		} else {
316 			dt_node_type_assign(prp->pr_nargv[adp->dtargd_mapping],
317 			    dtt.dtt_ctfp, dtt.dtt_type);
318 		}
319 
320 		if (dtt.dtt_type != CTF_ERR && (adp->dtargd_xlate[0] == '\0' ||
321 		    strcmp(adp->dtargd_native, adp->dtargd_xlate) == 0)) {
322 			dt_node_type_propagate(prp->pr_nargv[
323 			    adp->dtargd_mapping], prp->pr_xargv[i]);
324 		} else if (dtrace_type_strcompile(dtp,
325 		    adp->dtargd_xlate, &dtt) != 0) {
326 			dt_dprintf("failed to resolve output type %s "
327 			    "for %s:%s arg #%d: %s\n", adp->dtargd_xlate,
328 			    pvp->pv_desc.dtvd_name, name, i + 1,
329 			    dtrace_errmsg(dtp, dtrace_errno(dtp)));
330 
331 			dtt.dtt_object = NULL;
332 			dtt.dtt_ctfp = NULL;
333 			dtt.dtt_type = CTF_ERR;
334 		} else {
335 			dt_node_type_assign(prp->pr_xargv[i],
336 			    dtt.dtt_ctfp, dtt.dtt_type);
337 		}
338 
339 		prp->pr_mapping[i] = adp->dtargd_mapping;
340 		prp->pr_argv[i] = dtt;
341 	}
342 
343 	return (prp);
344 }
345 
346 /*
347  * Lookup a probe declaration based on a known provider and full or partially
348  * specified module, function, and name.  If the probe is not known to us yet,
349  * ask dtrace(7D) to match the description and then cache any useful results.
350  */
351 dt_probe_t *
352 dt_probe_lookup(dt_provider_t *pvp, const char *s)
353 {
354 	dtrace_hdl_t *dtp = pvp->pv_hdl;
355 	dtrace_probedesc_t pd;
356 	dt_ident_t *idp;
357 	size_t keylen;
358 	char *key;
359 
360 	if (dtrace_str2desc(dtp, DTRACE_PROBESPEC_NAME, s, &pd) != 0)
361 		return (NULL); /* dt_errno is set for us */
362 
363 	keylen = dt_probe_keylen(&pd);
364 	key = dt_probe_key(&pd, alloca(keylen));
365 
366 	/*
367 	 * If the probe is already declared, then return the dt_probe_t from
368 	 * the existing identifier.  This could come from a static declaration
369 	 * or it could have been cached from an earlier call to this function.
370 	 */
371 	if ((idp = dt_idhash_lookup(pvp->pv_probes, key)) != NULL)
372 		return (idp->di_data);
373 
374 	/*
375 	 * If the probe isn't known, use the probe description computed above
376 	 * to ask dtrace(7D) to find the first matching probe.
377 	 */
378 	if (dt_ioctl(dtp, DTRACEIOC_PROBEMATCH, &pd) == 0)
379 		return (dt_probe_discover(pvp, &pd));
380 
381 	if (errno == ESRCH || errno == EBADF)
382 		(void) dt_set_errno(dtp, EDT_NOPROBE);
383 	else
384 		(void) dt_set_errno(dtp, errno);
385 
386 	return (NULL);
387 }
388 
389 dt_probe_t *
390 dt_probe_create(dtrace_hdl_t *dtp, dt_ident_t *idp, int protoc,
391     dt_node_t *nargs, uint_t nargc, dt_node_t *xargs, uint_t xargc)
392 {
393 	dt_module_t *dmp;
394 	dt_probe_t *prp;
395 	const char *p;
396 	uint_t i;
397 
398 	assert(idp->di_kind == DT_IDENT_PROBE);
399 	assert(idp->di_data == NULL);
400 
401 	/*
402 	 * If only a single prototype is given, set xargc/s to nargc/s to
403 	 * simplify subsequent use.  Note that we can have one or both of nargs
404 	 * and xargs be specified but set to NULL, indicating a void prototype.
405 	 */
406 	if (protoc < 2) {
407 		assert(xargs == NULL);
408 		assert(xargc == 0);
409 		xargs = nargs;
410 		xargc = nargc;
411 	}
412 
413 	if ((prp = dt_alloc(dtp, sizeof (dt_probe_t))) == NULL)
414 		return (NULL);
415 
416 	prp->pr_pvp = NULL;
417 	prp->pr_ident = idp;
418 
419 	p = strrchr(idp->di_name, ':');
420 	assert(p != NULL);
421 	prp->pr_name = p + 1;
422 
423 	prp->pr_nargs = nargs;
424 	prp->pr_nargv = dt_alloc(dtp, sizeof (dt_node_t *) * nargc);
425 	prp->pr_nargc = nargc;
426 	prp->pr_xargs = xargs;
427 	prp->pr_xargv = dt_alloc(dtp, sizeof (dt_node_t *) * xargc);
428 	prp->pr_xargc = xargc;
429 	prp->pr_mapping = dt_alloc(dtp, sizeof (uint8_t) * xargc);
430 	prp->pr_inst = NULL;
431 	prp->pr_argv = dt_alloc(dtp, sizeof (dtrace_typeinfo_t) * xargc);
432 	prp->pr_argc = xargc;
433 
434 	if ((prp->pr_nargc != 0 && prp->pr_nargv == NULL) ||
435 	    (prp->pr_xargc != 0 && prp->pr_xargv == NULL) ||
436 	    (prp->pr_xargc != 0 && prp->pr_mapping == NULL) ||
437 	    (prp->pr_argc != 0 && prp->pr_argv == NULL)) {
438 		dt_probe_destroy(prp);
439 		return (NULL);
440 	}
441 
442 	for (i = 0; i < xargc; i++, xargs = xargs->dn_list) {
443 		if (xargs->dn_string != NULL)
444 			prp->pr_mapping[i] = dt_probe_argmap(xargs, nargs);
445 		else
446 			prp->pr_mapping[i] = i;
447 
448 		prp->pr_xargv[i] = xargs;
449 
450 		if ((dmp = dt_module_lookup_by_ctf(dtp,
451 		    xargs->dn_ctfp)) != NULL)
452 			prp->pr_argv[i].dtt_object = dmp->dm_name;
453 		else
454 			prp->pr_argv[i].dtt_object = NULL;
455 
456 		prp->pr_argv[i].dtt_ctfp = xargs->dn_ctfp;
457 		prp->pr_argv[i].dtt_type = xargs->dn_type;
458 	}
459 
460 	for (i = 0; i < nargc; i++, nargs = nargs->dn_list)
461 		prp->pr_nargv[i] = nargs;
462 
463 	idp->di_data = prp;
464 	return (prp);
465 }
466 
467 void
468 dt_probe_declare(dt_provider_t *pvp, dt_probe_t *prp)
469 {
470 	assert(prp->pr_ident->di_kind == DT_IDENT_PROBE);
471 	assert(prp->pr_ident->di_data == prp);
472 	assert(prp->pr_pvp == NULL);
473 
474 	if (prp->pr_xargs != prp->pr_nargs)
475 		pvp->pv_flags &= ~DT_PROVIDER_INTF;
476 
477 	prp->pr_pvp = pvp;
478 	dt_idhash_xinsert(pvp->pv_probes, prp->pr_ident);
479 }
480 
481 void
482 dt_probe_destroy(dt_probe_t *prp)
483 {
484 	dt_probe_instance_t *pip, *pip_next;
485 	dtrace_hdl_t *dtp;
486 
487 	if (prp->pr_pvp != NULL)
488 		dtp = prp->pr_pvp->pv_hdl;
489 	else
490 		dtp = yypcb->pcb_hdl;
491 
492 	dt_node_list_free(&prp->pr_nargs);
493 	dt_node_list_free(&prp->pr_xargs);
494 
495 	dt_free(dtp, prp->pr_nargv);
496 	dt_free(dtp, prp->pr_xargv);
497 
498 	for (pip = prp->pr_inst; pip != NULL; pip = pip_next) {
499 		pip_next = pip->pi_next;
500 		dt_free(dtp, pip->pi_offs);
501 		dt_free(dtp, pip->pi_enoffs);
502 		dt_free(dtp, pip);
503 	}
504 
505 	dt_free(dtp, prp->pr_mapping);
506 	dt_free(dtp, prp->pr_argv);
507 	dt_free(dtp, prp);
508 }
509 
510 int
511 dt_probe_define(dt_provider_t *pvp, dt_probe_t *prp,
512     const char *fname, const char *rname, uint32_t offset, int isenabled)
513 {
514 	dtrace_hdl_t *dtp = pvp->pv_hdl;
515 	dt_probe_instance_t *pip;
516 	uint32_t **offs;
517 	uint_t *noffs, *maxoffs;
518 
519 	assert(fname != NULL);
520 
521 	for (pip = prp->pr_inst; pip != NULL; pip = pip->pi_next) {
522 		if (strcmp(pip->pi_fname, fname) == 0 &&
523 		    ((rname == NULL && pip->pi_rname[0] == '\0') ||
524 		    (rname != NULL && strcmp(pip->pi_rname, rname)) == 0))
525 			break;
526 	}
527 
528 	if (pip == NULL) {
529 		if ((pip = dt_zalloc(dtp, sizeof (*pip))) == NULL)
530 			return (-1);
531 
532 		if ((pip->pi_offs = dt_zalloc(dtp,
533 		    sizeof (uint32_t))) == NULL) {
534 			dt_free(dtp, pip);
535 			return (-1);
536 		}
537 
538 		if ((pip->pi_enoffs = dt_zalloc(dtp,
539 		    sizeof (uint32_t))) == NULL) {
540 			dt_free(dtp, pip->pi_offs);
541 			dt_free(dtp, pip);
542 			return (-1);
543 		}
544 
545 		(void) strlcpy(pip->pi_fname, fname, sizeof (pip->pi_fname));
546 		if (rname != NULL) {
547 			if (strlen(rname) + 1 > sizeof (pip->pi_rname)) {
548 				dt_free(dtp, pip->pi_offs);
549 				dt_free(dtp, pip);
550 				return (dt_set_errno(dtp, EDT_COMPILER));
551 			}
552 			(void) strcpy(pip->pi_rname, rname);
553 		}
554 
555 		pip->pi_noffs = 0;
556 		pip->pi_maxoffs = 1;
557 		pip->pi_nenoffs = 0;
558 		pip->pi_maxenoffs = 1;
559 
560 		pip->pi_next = prp->pr_inst;
561 
562 		prp->pr_inst = pip;
563 	}
564 
565 	if (isenabled) {
566 		offs = &pip->pi_enoffs;
567 		noffs = &pip->pi_nenoffs;
568 		maxoffs = &pip->pi_maxenoffs;
569 	} else {
570 		offs = &pip->pi_offs;
571 		noffs = &pip->pi_noffs;
572 		maxoffs = &pip->pi_maxoffs;
573 	}
574 
575 	if (*noffs == *maxoffs) {
576 		uint_t new_max = *maxoffs * 2;
577 		uint32_t *new_offs = dt_alloc(dtp, sizeof (uint32_t) * new_max);
578 
579 		if (new_offs == NULL)
580 			return (-1);
581 
582 		bcopy(*offs, new_offs, sizeof (uint32_t) * *maxoffs);
583 
584 		dt_free(dtp, *offs);
585 		*maxoffs = new_max;
586 		*offs = new_offs;
587 	}
588 
589 	dt_dprintf("defined probe %s %s:%s %s() +0x%x (%s)\n",
590 	    isenabled ? "(is-enabled)" : "",
591 	    pvp->pv_desc.dtvd_name, prp->pr_ident->di_name, fname, offset,
592 	    rname != NULL ? rname : fname);
593 
594 	assert(*noffs < *maxoffs);
595 	(*offs)[(*noffs)++] = offset;
596 
597 	return (0);
598 }
599 
600 /*
601  * Lookup the dynamic translator type tag for the specified probe argument and
602  * assign the type to the specified node.  If the type is not yet defined, add
603  * it to the "D" module's type container as a typedef for an unknown type.
604  */
605 dt_node_t *
606 dt_probe_tag(dt_probe_t *prp, uint_t argn, dt_node_t *dnp)
607 {
608 	dtrace_hdl_t *dtp = prp->pr_pvp->pv_hdl;
609 	dtrace_typeinfo_t dtt;
610 	size_t len;
611 	char *tag;
612 
613 	len = snprintf(NULL, 0, "__dtrace_%s___%s_arg%u",
614 	    prp->pr_pvp->pv_desc.dtvd_name, prp->pr_name, argn);
615 
616 	tag = alloca(len + 1);
617 
618 	(void) snprintf(tag, len + 1, "__dtrace_%s___%s_arg%u",
619 	    prp->pr_pvp->pv_desc.dtvd_name, prp->pr_name, argn);
620 
621 	if (dtrace_lookup_by_type(dtp, DTRACE_OBJ_DDEFS, tag, &dtt) != 0) {
622 		dtt.dtt_object = DTRACE_OBJ_DDEFS;
623 		dtt.dtt_ctfp = DT_DYN_CTFP(dtp);
624 		dtt.dtt_type = ctf_add_typedef(DT_DYN_CTFP(dtp),
625 		    CTF_ADD_ROOT, tag, DT_DYN_TYPE(dtp));
626 
627 		if (dtt.dtt_type == CTF_ERR ||
628 		    ctf_update(dtt.dtt_ctfp) == CTF_ERR) {
629 			xyerror(D_UNKNOWN, "cannot define type %s: %s\n",
630 			    tag, ctf_errmsg(ctf_errno(dtt.dtt_ctfp)));
631 		}
632 	}
633 
634 	bzero(dnp, sizeof (dt_node_t));
635 	dnp->dn_kind = DT_NODE_TYPE;
636 
637 	dt_node_type_assign(dnp, dtt.dtt_ctfp, dtt.dtt_type);
638 	dt_node_attr_assign(dnp, _dtrace_defattr);
639 
640 	return (dnp);
641 }
642 
643 /*ARGSUSED*/
644 static int
645 dt_probe_desc(dtrace_hdl_t *dtp, const dtrace_probedesc_t *pdp, void *arg)
646 {
647 	if (((dtrace_probedesc_t *)arg)->dtpd_id == DTRACE_IDNONE) {
648 		bcopy(pdp, arg, sizeof (dtrace_probedesc_t));
649 		return (0);
650 	}
651 
652 	return (1);
653 }
654 
655 dt_probe_t *
656 dt_probe_info(dtrace_hdl_t *dtp,
657     const dtrace_probedesc_t *pdp, dtrace_probeinfo_t *pip)
658 {
659 	int m_is_glob = pdp->dtpd_mod[0] == '\0' || strisglob(pdp->dtpd_mod);
660 	int f_is_glob = pdp->dtpd_func[0] == '\0' || strisglob(pdp->dtpd_func);
661 	int n_is_glob = pdp->dtpd_name[0] == '\0' || strisglob(pdp->dtpd_name);
662 
663 	dt_probe_t *prp = NULL;
664 	const dtrace_pattr_t *pap;
665 	dt_provider_t *pvp;
666 	dt_ident_t *idp;
667 
668 	/*
669 	 * Attempt to lookup the probe in our existing cache for this provider.
670 	 * If none is found and an explicit probe ID was specified, discover
671 	 * that specific probe and cache its description and arguments.
672 	 */
673 	if ((pvp = dt_provider_lookup(dtp, pdp->dtpd_provider)) != NULL) {
674 		size_t keylen = dt_probe_keylen(pdp);
675 		char *key = dt_probe_key(pdp, alloca(keylen));
676 
677 		if ((idp = dt_idhash_lookup(pvp->pv_probes, key)) != NULL)
678 			prp = idp->di_data;
679 		else if (pdp->dtpd_id != DTRACE_IDNONE)
680 			prp = dt_probe_discover(pvp, pdp);
681 	}
682 
683 	/*
684 	 * If no probe was found in our cache, convert the caller's partial
685 	 * probe description into a fully-formed matching probe description by
686 	 * iterating over up to at most two probes that match 'pdp'.  We then
687 	 * call dt_probe_discover() on the resulting probe identifier.
688 	 */
689 	if (prp == NULL) {
690 		dtrace_probedesc_t pd;
691 		int m;
692 
693 		bzero(&pd, sizeof (pd));
694 		pd.dtpd_id = DTRACE_IDNONE;
695 
696 		/*
697 		 * Call dtrace_probe_iter() to find matching probes.  Our
698 		 * dt_probe_desc() callback will produce the following results:
699 		 *
700 		 * m < 0 dtrace_probe_iter() found zero matches (or failed).
701 		 * m > 0 dtrace_probe_iter() found more than one match.
702 		 * m = 0 dtrace_probe_iter() found exactly one match.
703 		 */
704 		if ((m = dtrace_probe_iter(dtp, pdp, dt_probe_desc, &pd)) < 0)
705 			return (NULL); /* dt_errno is set for us */
706 
707 		if ((pvp = dt_provider_lookup(dtp, pd.dtpd_provider)) == NULL)
708 			return (NULL); /* dt_errno is set for us */
709 
710 		/*
711 		 * If more than one probe was matched, then do not report probe
712 		 * information if either of the following conditions is true:
713 		 *
714 		 * (a) The Arguments Data stability of the matched provider is
715 		 *	less than Evolving.
716 		 *
717 		 * (b) Any description component that is at least Evolving is
718 		 *	empty or is specified using a globbing expression.
719 		 *
720 		 * These conditions imply that providers that provide Evolving
721 		 * or better Arguments Data stability must guarantee that all
722 		 * probes with identical field names in a field of Evolving or
723 		 * better Name stability have identical argument signatures.
724 		 */
725 		if (m > 0) {
726 			if (pvp->pv_desc.dtvd_attr.dtpa_args.dtat_data <
727 			    DTRACE_STABILITY_EVOLVING) {
728 				(void) dt_set_errno(dtp, EDT_UNSTABLE);
729 				return (NULL);
730 			}
731 
732 
733 			if (pvp->pv_desc.dtvd_attr.dtpa_mod.dtat_name >=
734 			    DTRACE_STABILITY_EVOLVING && m_is_glob) {
735 				(void) dt_set_errno(dtp, EDT_UNSTABLE);
736 				return (NULL);
737 			}
738 
739 			if (pvp->pv_desc.dtvd_attr.dtpa_func.dtat_name >=
740 			    DTRACE_STABILITY_EVOLVING && f_is_glob) {
741 				(void) dt_set_errno(dtp, EDT_UNSTABLE);
742 				return (NULL);
743 			}
744 
745 			if (pvp->pv_desc.dtvd_attr.dtpa_name.dtat_name >=
746 			    DTRACE_STABILITY_EVOLVING && n_is_glob) {
747 				(void) dt_set_errno(dtp, EDT_UNSTABLE);
748 				return (NULL);
749 			}
750 		}
751 
752 		/*
753 		 * If we matched a probe exported by dtrace(7D), then discover
754 		 * the real attributes.  Otherwise grab the static declaration.
755 		 */
756 		if (pd.dtpd_id != DTRACE_IDNONE)
757 			prp = dt_probe_discover(pvp, &pd);
758 		else
759 			prp = dt_probe_lookup(pvp, pd.dtpd_name);
760 
761 		if (prp == NULL)
762 			return (NULL); /* dt_errno is set for us */
763 	}
764 
765 	assert(pvp != NULL && prp != NULL);
766 
767 	/*
768 	 * Compute the probe description attributes by taking the minimum of
769 	 * the attributes of the specified fields.  If no provider is specified
770 	 * or a glob pattern is used for the provider, use Unstable attributes.
771 	 */
772 	if (pdp->dtpd_provider[0] == '\0' || strisglob(pdp->dtpd_provider))
773 		pap = &_dtrace_prvdesc;
774 	else
775 		pap = &pvp->pv_desc.dtvd_attr;
776 
777 	pip->dtp_attr = pap->dtpa_provider;
778 
779 	if (!m_is_glob)
780 		pip->dtp_attr = dt_attr_min(pip->dtp_attr, pap->dtpa_mod);
781 	if (!f_is_glob)
782 		pip->dtp_attr = dt_attr_min(pip->dtp_attr, pap->dtpa_func);
783 	if (!n_is_glob)
784 		pip->dtp_attr = dt_attr_min(pip->dtp_attr, pap->dtpa_name);
785 
786 	pip->dtp_arga = pap->dtpa_args;
787 	pip->dtp_argv = prp->pr_argv;
788 	pip->dtp_argc = prp->pr_argc;
789 
790 	return (prp);
791 }
792 
793 int
794 dtrace_probe_info(dtrace_hdl_t *dtp,
795     const dtrace_probedesc_t *pdp, dtrace_probeinfo_t *pip)
796 {
797 	return (dt_probe_info(dtp, pdp, pip) != NULL ? 0 : -1);
798 }
799 
800 /*ARGSUSED*/
801 static int
802 dt_probe_iter(dt_idhash_t *ihp, dt_ident_t *idp, dt_probe_iter_t *pit)
803 {
804 	const dt_probe_t *prp = idp->di_data;
805 
806 	if (!dt_gmatch(prp->pr_name, pit->pit_pat))
807 		return (0); /* continue on and examine next probe in hash */
808 
809 	(void) strlcpy(pit->pit_desc.dtpd_name, prp->pr_name, DTRACE_NAMELEN);
810 	pit->pit_desc.dtpd_id = idp->di_id;
811 	pit->pit_matches++;
812 
813 	return (pit->pit_func(pit->pit_hdl, &pit->pit_desc, pit->pit_arg));
814 }
815 
816 int
817 dtrace_probe_iter(dtrace_hdl_t *dtp,
818     const dtrace_probedesc_t *pdp, dtrace_probe_f *func, void *arg)
819 {
820 	const char *provider = pdp ? pdp->dtpd_provider : NULL;
821 	dtrace_id_t id = DTRACE_IDNONE;
822 
823 	dtrace_probedesc_t pd;
824 	dt_probe_iter_t pit;
825 	int cmd, rv;
826 
827 	bzero(&pit, sizeof (pit));
828 	pit.pit_hdl = dtp;
829 	pit.pit_func = func;
830 	pit.pit_arg = arg;
831 	pit.pit_pat = pdp ? pdp->dtpd_name : NULL;
832 
833 	for (pit.pit_pvp = dt_list_next(&dtp->dt_provlist);
834 	    pit.pit_pvp != NULL; pit.pit_pvp = dt_list_next(pit.pit_pvp)) {
835 
836 		if (pit.pit_pvp->pv_flags & DT_PROVIDER_IMPL)
837 			continue; /* we'll get these later using dt_ioctl() */
838 
839 		if (!dt_gmatch(pit.pit_pvp->pv_desc.dtvd_name, provider))
840 			continue;
841 
842 		(void) strlcpy(pit.pit_desc.dtpd_provider,
843 		    pit.pit_pvp->pv_desc.dtvd_name, DTRACE_PROVNAMELEN);
844 
845 		if ((rv = dt_idhash_iter(pit.pit_pvp->pv_probes,
846 		    (dt_idhash_f *)dt_probe_iter, &pit)) != 0)
847 			return (rv);
848 	}
849 
850 	if (pdp != NULL)
851 		cmd = DTRACEIOC_PROBEMATCH;
852 	else
853 		cmd = DTRACEIOC_PROBES;
854 
855 	for (;;) {
856 		if (pdp != NULL)
857 			bcopy(pdp, &pd, sizeof (pd));
858 
859 		pd.dtpd_id = id;
860 
861 		if (dt_ioctl(dtp, cmd, &pd) != 0)
862 			break;
863 		else if ((rv = func(dtp, &pd, arg)) != 0)
864 			return (rv);
865 
866 		pit.pit_matches++;
867 		id = pd.dtpd_id + 1;
868 	}
869 
870 	switch (errno) {
871 	case ESRCH:
872 	case EBADF:
873 		return (pit.pit_matches ? 0 : dt_set_errno(dtp, EDT_NOPROBE));
874 	case EINVAL:
875 		return (dt_set_errno(dtp, EDT_BADPGLOB));
876 	default:
877 		return (dt_set_errno(dtp, errno));
878 	}
879 }
880