xref: /freebsd/cddl/contrib/opensolaris/lib/libdtrace/common/dt_provider.c (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
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 #if defined(sun)
31 #include <sys/sysmacros.h>
32 #endif
33 
34 #include <assert.h>
35 #include <limits.h>
36 #include <strings.h>
37 #include <stdlib.h>
38 #if defined(sun)
39 #include <alloca.h>
40 #endif
41 #include <unistd.h>
42 #include <errno.h>
43 
44 #include <dt_provider.h>
45 #include <dt_module.h>
46 #include <dt_string.h>
47 #include <dt_list.h>
48 
49 static dt_provider_t *
50 dt_provider_insert(dtrace_hdl_t *dtp, dt_provider_t *pvp, uint_t h)
51 {
52 	dt_list_append(&dtp->dt_provlist, pvp);
53 
54 	pvp->pv_next = dtp->dt_provs[h];
55 	dtp->dt_provs[h] = pvp;
56 	dtp->dt_nprovs++;
57 
58 	return (pvp);
59 }
60 
61 dt_provider_t *
62 dt_provider_lookup(dtrace_hdl_t *dtp, const char *name)
63 {
64 	uint_t h = dt_strtab_hash(name, NULL) % dtp->dt_provbuckets;
65 	dtrace_providerdesc_t desc;
66 	dt_provider_t *pvp;
67 
68 	for (pvp = dtp->dt_provs[h]; pvp != NULL; pvp = pvp->pv_next) {
69 		if (strcmp(pvp->pv_desc.dtvd_name, name) == 0)
70 			return (pvp);
71 	}
72 
73 	if (strisglob(name) || name[0] == '\0') {
74 		(void) dt_set_errno(dtp, EDT_NOPROV);
75 		return (NULL);
76 	}
77 
78 	bzero(&desc, sizeof (desc));
79 	(void) strlcpy(desc.dtvd_name, name, DTRACE_PROVNAMELEN);
80 
81 	if (dt_ioctl(dtp, DTRACEIOC_PROVIDER, &desc) == -1) {
82 		(void) dt_set_errno(dtp, errno == ESRCH ? EDT_NOPROV : errno);
83 		return (NULL);
84 	}
85 
86 	if ((pvp = dt_provider_create(dtp, name)) == NULL)
87 		return (NULL); /* dt_errno is set for us */
88 
89 	bcopy(&desc, &pvp->pv_desc, sizeof (desc));
90 	pvp->pv_flags |= DT_PROVIDER_IMPL;
91 	return (pvp);
92 }
93 
94 dt_provider_t *
95 dt_provider_create(dtrace_hdl_t *dtp, const char *name)
96 {
97 	dt_provider_t *pvp;
98 
99 	if ((pvp = dt_zalloc(dtp, sizeof (dt_provider_t))) == NULL)
100 		return (NULL);
101 
102 	(void) strlcpy(pvp->pv_desc.dtvd_name, name, DTRACE_PROVNAMELEN);
103 	pvp->pv_probes = dt_idhash_create(pvp->pv_desc.dtvd_name, NULL, 0, 0);
104 	pvp->pv_gen = dtp->dt_gen;
105 	pvp->pv_hdl = dtp;
106 
107 	if (pvp->pv_probes == NULL) {
108 		dt_free(dtp, pvp);
109 		(void) dt_set_errno(dtp, EDT_NOMEM);
110 		return (NULL);
111 	}
112 
113 	pvp->pv_desc.dtvd_attr.dtpa_provider = _dtrace_prvattr;
114 	pvp->pv_desc.dtvd_attr.dtpa_mod = _dtrace_prvattr;
115 	pvp->pv_desc.dtvd_attr.dtpa_func = _dtrace_prvattr;
116 	pvp->pv_desc.dtvd_attr.dtpa_name = _dtrace_prvattr;
117 	pvp->pv_desc.dtvd_attr.dtpa_args = _dtrace_prvattr;
118 
119 	return (dt_provider_insert(dtp, pvp,
120 	    dt_strtab_hash(name, NULL) % dtp->dt_provbuckets));
121 }
122 
123 void
124 dt_provider_destroy(dtrace_hdl_t *dtp, dt_provider_t *pvp)
125 {
126 	dt_provider_t **pp;
127 	uint_t h;
128 
129 	assert(pvp->pv_hdl == dtp);
130 
131 	h = dt_strtab_hash(pvp->pv_desc.dtvd_name, NULL) % dtp->dt_provbuckets;
132 	pp = &dtp->dt_provs[h];
133 
134 	while (*pp != NULL && *pp != pvp)
135 		pp = &(*pp)->pv_next;
136 
137 	assert(*pp != NULL && *pp == pvp);
138 	*pp = pvp->pv_next;
139 
140 	dt_list_delete(&dtp->dt_provlist, pvp);
141 	dtp->dt_nprovs--;
142 
143 	if (pvp->pv_probes != NULL)
144 		dt_idhash_destroy(pvp->pv_probes);
145 
146 	dt_node_link_free(&pvp->pv_nodes);
147 	dt_free(dtp, pvp->pv_xrefs);
148 	dt_free(dtp, pvp);
149 }
150 
151 int
152 dt_provider_xref(dtrace_hdl_t *dtp, dt_provider_t *pvp, id_t id)
153 {
154 	size_t oldsize = BT_SIZEOFMAP(pvp->pv_xrmax);
155 	size_t newsize = BT_SIZEOFMAP(dtp->dt_xlatorid);
156 
157 	assert(id >= 0 && id < dtp->dt_xlatorid);
158 
159 	if (newsize > oldsize) {
160 		ulong_t *xrefs = dt_zalloc(dtp, newsize);
161 
162 		if (xrefs == NULL)
163 			return (-1);
164 
165 		bcopy(pvp->pv_xrefs, xrefs, oldsize);
166 		dt_free(dtp, pvp->pv_xrefs);
167 
168 		pvp->pv_xrefs = xrefs;
169 		pvp->pv_xrmax = dtp->dt_xlatorid;
170 	}
171 
172 	BT_SET(pvp->pv_xrefs, id);
173 	return (0);
174 }
175 
176 static uint8_t
177 dt_probe_argmap(dt_node_t *xnp, dt_node_t *nnp)
178 {
179 	uint8_t i;
180 
181 	for (i = 0; nnp != NULL; i++) {
182 		if (nnp->dn_string != NULL &&
183 		    strcmp(nnp->dn_string, xnp->dn_string) == 0)
184 			break;
185 		else
186 			nnp = nnp->dn_list;
187 	}
188 
189 	return (i);
190 }
191 
192 static dt_node_t *
193 dt_probe_alloc_args(dt_provider_t *pvp, int argc)
194 {
195 	dt_node_t *args = NULL, *pnp = NULL, *dnp;
196 	int i;
197 
198 	for (i = 0; i < argc; i++, pnp = dnp) {
199 		if ((dnp = dt_node_xalloc(pvp->pv_hdl, DT_NODE_TYPE)) == NULL)
200 			return (NULL);
201 
202 		dnp->dn_link = pvp->pv_nodes;
203 		pvp->pv_nodes = dnp;
204 
205 		if (args == NULL)
206 			args = dnp;
207 		else
208 			pnp->dn_list = dnp;
209 	}
210 
211 	return (args);
212 }
213 
214 static size_t
215 dt_probe_keylen(const dtrace_probedesc_t *pdp)
216 {
217 	return (strlen(pdp->dtpd_mod) + 1 +
218 	    strlen(pdp->dtpd_func) + 1 + strlen(pdp->dtpd_name) + 1);
219 }
220 
221 static char *
222 dt_probe_key(const dtrace_probedesc_t *pdp, char *s)
223 {
224 	(void) snprintf(s, INT_MAX, "%s:%s:%s",
225 	    pdp->dtpd_mod, pdp->dtpd_func, pdp->dtpd_name);
226 	return (s);
227 }
228 
229 /*
230  * If a probe was discovered from the kernel, ask dtrace(7D) for a description
231  * of each of its arguments, including native and translated types.
232  */
233 static dt_probe_t *
234 dt_probe_discover(dt_provider_t *pvp, const dtrace_probedesc_t *pdp)
235 {
236 	dtrace_hdl_t *dtp = pvp->pv_hdl;
237 	char *name = dt_probe_key(pdp, alloca(dt_probe_keylen(pdp)));
238 
239 	dt_node_t *xargs, *nargs;
240 	dt_ident_t *idp;
241 	dt_probe_t *prp;
242 
243 	dtrace_typeinfo_t dtt;
244 	int i, nc, xc;
245 
246 	int adc = _dtrace_argmax;
247 	dtrace_argdesc_t *adv = alloca(sizeof (dtrace_argdesc_t) * adc);
248 	dtrace_argdesc_t *adp = adv;
249 
250 	assert(strcmp(pvp->pv_desc.dtvd_name, pdp->dtpd_provider) == 0);
251 	assert(pdp->dtpd_id != DTRACE_IDNONE);
252 
253 	dt_dprintf("discovering probe %s:%s id=%d\n",
254 	    pvp->pv_desc.dtvd_name, name, pdp->dtpd_id);
255 
256 	for (nc = -1, i = 0; i < adc; i++, adp++) {
257 		bzero(adp, sizeof (dtrace_argdesc_t));
258 		adp->dtargd_ndx = i;
259 		adp->dtargd_id = pdp->dtpd_id;
260 
261 		if (dt_ioctl(dtp, DTRACEIOC_PROBEARG, adp) != 0) {
262 			(void) dt_set_errno(dtp, errno);
263 			return (NULL);
264 		}
265 
266 		if (adp->dtargd_ndx == DTRACE_ARGNONE)
267 			break; /* all argument descs have been retrieved */
268 
269 		nc = MAX(nc, adp->dtargd_mapping);
270 	}
271 
272 	xc = i;
273 	nc++;
274 
275 	/*
276 	 * Now that we have discovered the number of native and translated
277 	 * arguments from the argument descriptions, allocate a new probe ident
278 	 * and corresponding dt_probe_t and hash it into the provider.
279 	 */
280 	xargs = dt_probe_alloc_args(pvp, xc);
281 	nargs = dt_probe_alloc_args(pvp, nc);
282 
283 	if ((xc != 0 && xargs == NULL) || (nc != 0 && nargs == NULL))
284 		return (NULL); /* dt_errno is set for us */
285 
286 	idp = dt_ident_create(name, DT_IDENT_PROBE,
287 	    DT_IDFLG_ORPHAN, pdp->dtpd_id, _dtrace_defattr, 0,
288 	    &dt_idops_probe, NULL, dtp->dt_gen);
289 
290 	if (idp == NULL) {
291 		(void) dt_set_errno(dtp, EDT_NOMEM);
292 		return (NULL);
293 	}
294 
295 	if ((prp = dt_probe_create(dtp, idp, 2,
296 	    nargs, nc, xargs, xc)) == NULL) {
297 		dt_ident_destroy(idp);
298 		return (NULL);
299 	}
300 
301 	dt_probe_declare(pvp, prp);
302 
303 	/*
304 	 * Once our new dt_probe_t is fully constructed, iterate over the
305 	 * cached argument descriptions and assign types to prp->pr_nargv[]
306 	 * and prp->pr_xargv[] and assign mappings to prp->pr_mapping[].
307 	 */
308 	for (adp = adv, i = 0; i < xc; i++, adp++) {
309 		if (dtrace_type_strcompile(dtp,
310 		    adp->dtargd_native, &dtt) != 0) {
311 			dt_dprintf("failed to resolve input type %s "
312 			    "for %s:%s arg #%d: %s\n", adp->dtargd_native,
313 			    pvp->pv_desc.dtvd_name, name, i + 1,
314 			    dtrace_errmsg(dtp, dtrace_errno(dtp)));
315 
316 			dtt.dtt_object = NULL;
317 			dtt.dtt_ctfp = NULL;
318 			dtt.dtt_type = CTF_ERR;
319 		} else {
320 			dt_node_type_assign(prp->pr_nargv[adp->dtargd_mapping],
321 			    dtt.dtt_ctfp, dtt.dtt_type);
322 		}
323 
324 		if (dtt.dtt_type != CTF_ERR && (adp->dtargd_xlate[0] == '\0' ||
325 		    strcmp(adp->dtargd_native, adp->dtargd_xlate) == 0)) {
326 			dt_node_type_propagate(prp->pr_nargv[
327 			    adp->dtargd_mapping], prp->pr_xargv[i]);
328 		} else if (dtrace_type_strcompile(dtp,
329 		    adp->dtargd_xlate, &dtt) != 0) {
330 			dt_dprintf("failed to resolve output type %s "
331 			    "for %s:%s arg #%d: %s\n", adp->dtargd_xlate,
332 			    pvp->pv_desc.dtvd_name, name, i + 1,
333 			    dtrace_errmsg(dtp, dtrace_errno(dtp)));
334 
335 			dtt.dtt_object = NULL;
336 			dtt.dtt_ctfp = NULL;
337 			dtt.dtt_type = CTF_ERR;
338 		} else {
339 			dt_node_type_assign(prp->pr_xargv[i],
340 			    dtt.dtt_ctfp, dtt.dtt_type);
341 		}
342 
343 		prp->pr_mapping[i] = adp->dtargd_mapping;
344 		prp->pr_argv[i] = dtt;
345 	}
346 
347 	return (prp);
348 }
349 
350 /*
351  * Lookup a probe declaration based on a known provider and full or partially
352  * specified module, function, and name.  If the probe is not known to us yet,
353  * ask dtrace(7D) to match the description and then cache any useful results.
354  */
355 dt_probe_t *
356 dt_probe_lookup(dt_provider_t *pvp, const char *s)
357 {
358 	dtrace_hdl_t *dtp = pvp->pv_hdl;
359 	dtrace_probedesc_t pd;
360 	dt_ident_t *idp;
361 	size_t keylen;
362 	char *key;
363 
364 	if (dtrace_str2desc(dtp, DTRACE_PROBESPEC_NAME, s, &pd) != 0)
365 		return (NULL); /* dt_errno is set for us */
366 
367 	keylen = dt_probe_keylen(&pd);
368 	key = dt_probe_key(&pd, alloca(keylen));
369 
370 	/*
371 	 * If the probe is already declared, then return the dt_probe_t from
372 	 * the existing identifier.  This could come from a static declaration
373 	 * or it could have been cached from an earlier call to this function.
374 	 */
375 	if ((idp = dt_idhash_lookup(pvp->pv_probes, key)) != NULL)
376 		return (idp->di_data);
377 
378 	/*
379 	 * If the probe isn't known, use the probe description computed above
380 	 * to ask dtrace(7D) to find the first matching probe.
381 	 */
382 	if (dt_ioctl(dtp, DTRACEIOC_PROBEMATCH, &pd) == 0)
383 		return (dt_probe_discover(pvp, &pd));
384 
385 	if (errno == ESRCH || errno == EBADF)
386 		(void) dt_set_errno(dtp, EDT_NOPROBE);
387 	else
388 		(void) dt_set_errno(dtp, errno);
389 
390 	return (NULL);
391 }
392 
393 dt_probe_t *
394 dt_probe_create(dtrace_hdl_t *dtp, dt_ident_t *idp, int protoc,
395     dt_node_t *nargs, uint_t nargc, dt_node_t *xargs, uint_t xargc)
396 {
397 	dt_module_t *dmp;
398 	dt_probe_t *prp;
399 	const char *p;
400 	uint_t i;
401 
402 	assert(idp->di_kind == DT_IDENT_PROBE);
403 	assert(idp->di_data == NULL);
404 
405 	/*
406 	 * If only a single prototype is given, set xargc/s to nargc/s to
407 	 * simplify subsequent use.  Note that we can have one or both of nargs
408 	 * and xargs be specified but set to NULL, indicating a void prototype.
409 	 */
410 	if (protoc < 2) {
411 		assert(xargs == NULL);
412 		assert(xargc == 0);
413 		xargs = nargs;
414 		xargc = nargc;
415 	}
416 
417 	if ((prp = dt_alloc(dtp, sizeof (dt_probe_t))) == NULL)
418 		return (NULL);
419 
420 	prp->pr_pvp = NULL;
421 	prp->pr_ident = idp;
422 
423 	p = strrchr(idp->di_name, ':');
424 	assert(p != NULL);
425 	prp->pr_name = p + 1;
426 
427 	prp->pr_nargs = nargs;
428 	prp->pr_nargv = dt_alloc(dtp, sizeof (dt_node_t *) * nargc);
429 	prp->pr_nargc = nargc;
430 	prp->pr_xargs = xargs;
431 	prp->pr_xargv = dt_alloc(dtp, sizeof (dt_node_t *) * xargc);
432 	prp->pr_xargc = xargc;
433 	prp->pr_mapping = dt_alloc(dtp, sizeof (uint8_t) * xargc);
434 	prp->pr_inst = NULL;
435 	prp->pr_argv = dt_alloc(dtp, sizeof (dtrace_typeinfo_t) * xargc);
436 	prp->pr_argc = xargc;
437 
438 	if ((prp->pr_nargc != 0 && prp->pr_nargv == NULL) ||
439 	    (prp->pr_xargc != 0 && prp->pr_xargv == NULL) ||
440 	    (prp->pr_xargc != 0 && prp->pr_mapping == NULL) ||
441 	    (prp->pr_argc != 0 && prp->pr_argv == NULL)) {
442 		dt_probe_destroy(prp);
443 		return (NULL);
444 	}
445 
446 	for (i = 0; i < xargc; i++, xargs = xargs->dn_list) {
447 		if (xargs->dn_string != NULL)
448 			prp->pr_mapping[i] = dt_probe_argmap(xargs, nargs);
449 		else
450 			prp->pr_mapping[i] = i;
451 
452 		prp->pr_xargv[i] = xargs;
453 
454 		if ((dmp = dt_module_lookup_by_ctf(dtp,
455 		    xargs->dn_ctfp)) != NULL)
456 			prp->pr_argv[i].dtt_object = dmp->dm_name;
457 		else
458 			prp->pr_argv[i].dtt_object = NULL;
459 
460 		prp->pr_argv[i].dtt_ctfp = xargs->dn_ctfp;
461 		prp->pr_argv[i].dtt_type = xargs->dn_type;
462 	}
463 
464 	for (i = 0; i < nargc; i++, nargs = nargs->dn_list)
465 		prp->pr_nargv[i] = nargs;
466 
467 	idp->di_data = prp;
468 	return (prp);
469 }
470 
471 void
472 dt_probe_declare(dt_provider_t *pvp, dt_probe_t *prp)
473 {
474 	assert(prp->pr_ident->di_kind == DT_IDENT_PROBE);
475 	assert(prp->pr_ident->di_data == prp);
476 	assert(prp->pr_pvp == NULL);
477 
478 	if (prp->pr_xargs != prp->pr_nargs)
479 		pvp->pv_flags &= ~DT_PROVIDER_INTF;
480 
481 	prp->pr_pvp = pvp;
482 	dt_idhash_xinsert(pvp->pv_probes, prp->pr_ident);
483 }
484 
485 void
486 dt_probe_destroy(dt_probe_t *prp)
487 {
488 	dt_probe_instance_t *pip, *pip_next;
489 	dtrace_hdl_t *dtp;
490 
491 	if (prp->pr_pvp != NULL)
492 		dtp = prp->pr_pvp->pv_hdl;
493 	else
494 		dtp = yypcb->pcb_hdl;
495 
496 	dt_node_list_free(&prp->pr_nargs);
497 	dt_node_list_free(&prp->pr_xargs);
498 
499 	dt_free(dtp, prp->pr_nargv);
500 	dt_free(dtp, prp->pr_xargv);
501 
502 	for (pip = prp->pr_inst; pip != NULL; pip = pip_next) {
503 		pip_next = pip->pi_next;
504 		dt_free(dtp, pip->pi_offs);
505 		dt_free(dtp, pip->pi_enoffs);
506 		dt_free(dtp, pip);
507 	}
508 
509 	dt_free(dtp, prp->pr_mapping);
510 	dt_free(dtp, prp->pr_argv);
511 	dt_free(dtp, prp);
512 }
513 
514 int
515 dt_probe_define(dt_provider_t *pvp, dt_probe_t *prp,
516     const char *fname, const char *rname, uint32_t offset, int isenabled)
517 {
518 	dtrace_hdl_t *dtp = pvp->pv_hdl;
519 	dt_probe_instance_t *pip;
520 	uint32_t **offs;
521 	uint_t *noffs, *maxoffs;
522 
523 	assert(fname != NULL);
524 
525 	for (pip = prp->pr_inst; pip != NULL; pip = pip->pi_next) {
526 		if (strcmp(pip->pi_fname, fname) == 0 &&
527 		    ((rname == NULL && pip->pi_rname[0] == '\0') ||
528 		    (rname != NULL && strcmp(pip->pi_rname, rname)) == 0))
529 			break;
530 	}
531 
532 	if (pip == NULL) {
533 		if ((pip = dt_zalloc(dtp, sizeof (*pip))) == NULL)
534 			return (-1);
535 
536 		if ((pip->pi_offs = dt_zalloc(dtp,
537 		    sizeof (uint32_t))) == NULL) {
538 			dt_free(dtp, pip);
539 			return (-1);
540 		}
541 
542 		if ((pip->pi_enoffs = dt_zalloc(dtp,
543 		    sizeof (uint32_t))) == NULL) {
544 			dt_free(dtp, pip->pi_offs);
545 			dt_free(dtp, pip);
546 			return (-1);
547 		}
548 
549 		(void) strlcpy(pip->pi_fname, fname, sizeof (pip->pi_fname));
550 		if (rname != NULL) {
551 			if (strlen(rname) + 1 > sizeof (pip->pi_rname)) {
552 				dt_free(dtp, pip->pi_offs);
553 				dt_free(dtp, pip);
554 				return (dt_set_errno(dtp, EDT_COMPILER));
555 			}
556 			(void) strcpy(pip->pi_rname, rname);
557 		}
558 
559 		pip->pi_noffs = 0;
560 		pip->pi_maxoffs = 1;
561 		pip->pi_nenoffs = 0;
562 		pip->pi_maxenoffs = 1;
563 
564 		pip->pi_next = prp->pr_inst;
565 
566 		prp->pr_inst = pip;
567 	}
568 
569 	if (isenabled) {
570 		offs = &pip->pi_enoffs;
571 		noffs = &pip->pi_nenoffs;
572 		maxoffs = &pip->pi_maxenoffs;
573 	} else {
574 		offs = &pip->pi_offs;
575 		noffs = &pip->pi_noffs;
576 		maxoffs = &pip->pi_maxoffs;
577 	}
578 
579 	if (*noffs == *maxoffs) {
580 		uint_t new_max = *maxoffs * 2;
581 		uint32_t *new_offs = dt_alloc(dtp, sizeof (uint32_t) * new_max);
582 
583 		if (new_offs == NULL)
584 			return (-1);
585 
586 		bcopy(*offs, new_offs, sizeof (uint32_t) * *maxoffs);
587 
588 		dt_free(dtp, *offs);
589 		*maxoffs = new_max;
590 		*offs = new_offs;
591 	}
592 
593 	dt_dprintf("defined probe %s %s:%s %s() +0x%x (%s)\n",
594 	    isenabled ? "(is-enabled)" : "",
595 	    pvp->pv_desc.dtvd_name, prp->pr_ident->di_name, fname, offset,
596 	    rname != NULL ? rname : fname);
597 
598 	assert(*noffs < *maxoffs);
599 	(*offs)[(*noffs)++] = offset;
600 
601 	return (0);
602 }
603 
604 /*
605  * Lookup the dynamic translator type tag for the specified probe argument and
606  * assign the type to the specified node.  If the type is not yet defined, add
607  * it to the "D" module's type container as a typedef for an unknown type.
608  */
609 dt_node_t *
610 dt_probe_tag(dt_probe_t *prp, uint_t argn, dt_node_t *dnp)
611 {
612 	dtrace_hdl_t *dtp = prp->pr_pvp->pv_hdl;
613 	dtrace_typeinfo_t dtt;
614 	size_t len;
615 	char *tag;
616 
617 	len = snprintf(NULL, 0, "__dtrace_%s___%s_arg%u",
618 	    prp->pr_pvp->pv_desc.dtvd_name, prp->pr_name, argn);
619 
620 	tag = alloca(len + 1);
621 
622 	(void) snprintf(tag, len + 1, "__dtrace_%s___%s_arg%u",
623 	    prp->pr_pvp->pv_desc.dtvd_name, prp->pr_name, argn);
624 
625 	if (dtrace_lookup_by_type(dtp, DTRACE_OBJ_DDEFS, tag, &dtt) != 0) {
626 		dtt.dtt_object = DTRACE_OBJ_DDEFS;
627 		dtt.dtt_ctfp = DT_DYN_CTFP(dtp);
628 		dtt.dtt_type = ctf_add_typedef(DT_DYN_CTFP(dtp),
629 		    CTF_ADD_ROOT, tag, DT_DYN_TYPE(dtp));
630 
631 		if (dtt.dtt_type == CTF_ERR ||
632 		    ctf_update(dtt.dtt_ctfp) == CTF_ERR) {
633 			xyerror(D_UNKNOWN, "cannot define type %s: %s\n",
634 			    tag, ctf_errmsg(ctf_errno(dtt.dtt_ctfp)));
635 		}
636 	}
637 
638 	bzero(dnp, sizeof (dt_node_t));
639 	dnp->dn_kind = DT_NODE_TYPE;
640 
641 	dt_node_type_assign(dnp, dtt.dtt_ctfp, dtt.dtt_type);
642 	dt_node_attr_assign(dnp, _dtrace_defattr);
643 
644 	return (dnp);
645 }
646 
647 /*ARGSUSED*/
648 static int
649 dt_probe_desc(dtrace_hdl_t *dtp, const dtrace_probedesc_t *pdp, void *arg)
650 {
651 	if (((dtrace_probedesc_t *)arg)->dtpd_id == DTRACE_IDNONE) {
652 		bcopy(pdp, arg, sizeof (dtrace_probedesc_t));
653 		return (0);
654 	}
655 
656 	return (1);
657 }
658 
659 dt_probe_t *
660 dt_probe_info(dtrace_hdl_t *dtp,
661     const dtrace_probedesc_t *pdp, dtrace_probeinfo_t *pip)
662 {
663 	int m_is_glob = pdp->dtpd_mod[0] == '\0' || strisglob(pdp->dtpd_mod);
664 	int f_is_glob = pdp->dtpd_func[0] == '\0' || strisglob(pdp->dtpd_func);
665 	int n_is_glob = pdp->dtpd_name[0] == '\0' || strisglob(pdp->dtpd_name);
666 
667 	dt_probe_t *prp = NULL;
668 	const dtrace_pattr_t *pap;
669 	dt_provider_t *pvp;
670 	dt_ident_t *idp;
671 
672 	/*
673 	 * Attempt to lookup the probe in our existing cache for this provider.
674 	 * If none is found and an explicit probe ID was specified, discover
675 	 * that specific probe and cache its description and arguments.
676 	 */
677 	if ((pvp = dt_provider_lookup(dtp, pdp->dtpd_provider)) != NULL) {
678 		size_t keylen = dt_probe_keylen(pdp);
679 		char *key = dt_probe_key(pdp, alloca(keylen));
680 
681 		if ((idp = dt_idhash_lookup(pvp->pv_probes, key)) != NULL)
682 			prp = idp->di_data;
683 		else if (pdp->dtpd_id != DTRACE_IDNONE)
684 			prp = dt_probe_discover(pvp, pdp);
685 	}
686 
687 	/*
688 	 * If no probe was found in our cache, convert the caller's partial
689 	 * probe description into a fully-formed matching probe description by
690 	 * iterating over up to at most two probes that match 'pdp'.  We then
691 	 * call dt_probe_discover() on the resulting probe identifier.
692 	 */
693 	if (prp == NULL) {
694 		dtrace_probedesc_t pd;
695 		int m;
696 
697 		bzero(&pd, sizeof (pd));
698 		pd.dtpd_id = DTRACE_IDNONE;
699 
700 		/*
701 		 * Call dtrace_probe_iter() to find matching probes.  Our
702 		 * dt_probe_desc() callback will produce the following results:
703 		 *
704 		 * m < 0 dtrace_probe_iter() found zero matches (or failed).
705 		 * m > 0 dtrace_probe_iter() found more than one match.
706 		 * m = 0 dtrace_probe_iter() found exactly one match.
707 		 */
708 		if ((m = dtrace_probe_iter(dtp, pdp, dt_probe_desc, &pd)) < 0)
709 			return (NULL); /* dt_errno is set for us */
710 
711 		if ((pvp = dt_provider_lookup(dtp, pd.dtpd_provider)) == NULL)
712 			return (NULL); /* dt_errno is set for us */
713 
714 		/*
715 		 * If more than one probe was matched, then do not report probe
716 		 * information if either of the following conditions is true:
717 		 *
718 		 * (a) The Arguments Data stability of the matched provider is
719 		 *	less than Evolving.
720 		 *
721 		 * (b) Any description component that is at least Evolving is
722 		 *	empty or is specified using a globbing expression.
723 		 *
724 		 * These conditions imply that providers that provide Evolving
725 		 * or better Arguments Data stability must guarantee that all
726 		 * probes with identical field names in a field of Evolving or
727 		 * better Name stability have identical argument signatures.
728 		 */
729 		if (m > 0) {
730 			if (pvp->pv_desc.dtvd_attr.dtpa_args.dtat_data <
731 			    DTRACE_STABILITY_EVOLVING) {
732 				(void) dt_set_errno(dtp, EDT_UNSTABLE);
733 				return (NULL);
734 			}
735 
736 
737 			if (pvp->pv_desc.dtvd_attr.dtpa_mod.dtat_name >=
738 			    DTRACE_STABILITY_EVOLVING && m_is_glob) {
739 				(void) dt_set_errno(dtp, EDT_UNSTABLE);
740 				return (NULL);
741 			}
742 
743 			if (pvp->pv_desc.dtvd_attr.dtpa_func.dtat_name >=
744 			    DTRACE_STABILITY_EVOLVING && f_is_glob) {
745 				(void) dt_set_errno(dtp, EDT_UNSTABLE);
746 				return (NULL);
747 			}
748 
749 			if (pvp->pv_desc.dtvd_attr.dtpa_name.dtat_name >=
750 			    DTRACE_STABILITY_EVOLVING && n_is_glob) {
751 				(void) dt_set_errno(dtp, EDT_UNSTABLE);
752 				return (NULL);
753 			}
754 		}
755 
756 		/*
757 		 * If we matched a probe exported by dtrace(7D), then discover
758 		 * the real attributes.  Otherwise grab the static declaration.
759 		 */
760 		if (pd.dtpd_id != DTRACE_IDNONE)
761 			prp = dt_probe_discover(pvp, &pd);
762 		else
763 			prp = dt_probe_lookup(pvp, pd.dtpd_name);
764 
765 		if (prp == NULL)
766 			return (NULL); /* dt_errno is set for us */
767 	}
768 
769 	assert(pvp != NULL && prp != NULL);
770 
771 	/*
772 	 * Compute the probe description attributes by taking the minimum of
773 	 * the attributes of the specified fields.  If no provider is specified
774 	 * or a glob pattern is used for the provider, use Unstable attributes.
775 	 */
776 	if (pdp->dtpd_provider[0] == '\0' || strisglob(pdp->dtpd_provider))
777 		pap = &_dtrace_prvdesc;
778 	else
779 		pap = &pvp->pv_desc.dtvd_attr;
780 
781 	pip->dtp_attr = pap->dtpa_provider;
782 
783 	if (!m_is_glob)
784 		pip->dtp_attr = dt_attr_min(pip->dtp_attr, pap->dtpa_mod);
785 	if (!f_is_glob)
786 		pip->dtp_attr = dt_attr_min(pip->dtp_attr, pap->dtpa_func);
787 	if (!n_is_glob)
788 		pip->dtp_attr = dt_attr_min(pip->dtp_attr, pap->dtpa_name);
789 
790 	pip->dtp_arga = pap->dtpa_args;
791 	pip->dtp_argv = prp->pr_argv;
792 	pip->dtp_argc = prp->pr_argc;
793 
794 	return (prp);
795 }
796 
797 int
798 dtrace_probe_info(dtrace_hdl_t *dtp,
799     const dtrace_probedesc_t *pdp, dtrace_probeinfo_t *pip)
800 {
801 	return (dt_probe_info(dtp, pdp, pip) != NULL ? 0 : -1);
802 }
803 
804 /*ARGSUSED*/
805 static int
806 dt_probe_iter(dt_idhash_t *ihp, dt_ident_t *idp, dt_probe_iter_t *pit)
807 {
808 	const dt_probe_t *prp = idp->di_data;
809 
810 	if (!dt_gmatch(prp->pr_name, pit->pit_pat))
811 		return (0); /* continue on and examine next probe in hash */
812 
813 	(void) strlcpy(pit->pit_desc.dtpd_name, prp->pr_name, DTRACE_NAMELEN);
814 	pit->pit_desc.dtpd_id = idp->di_id;
815 	pit->pit_matches++;
816 
817 	return (pit->pit_func(pit->pit_hdl, &pit->pit_desc, pit->pit_arg));
818 }
819 
820 int
821 dtrace_probe_iter(dtrace_hdl_t *dtp,
822     const dtrace_probedesc_t *pdp, dtrace_probe_f *func, void *arg)
823 {
824 	const char *provider = pdp ? pdp->dtpd_provider : NULL;
825 	dtrace_id_t id = DTRACE_IDNONE;
826 
827 	dtrace_probedesc_t pd;
828 	dt_probe_iter_t pit;
829 	int cmd, rv;
830 
831 	bzero(&pit, sizeof (pit));
832 	pit.pit_hdl = dtp;
833 	pit.pit_func = func;
834 	pit.pit_arg = arg;
835 	pit.pit_pat = pdp ? pdp->dtpd_name : NULL;
836 
837 	for (pit.pit_pvp = dt_list_next(&dtp->dt_provlist);
838 	    pit.pit_pvp != NULL; pit.pit_pvp = dt_list_next(pit.pit_pvp)) {
839 
840 		if (pit.pit_pvp->pv_flags & DT_PROVIDER_IMPL)
841 			continue; /* we'll get these later using dt_ioctl() */
842 
843 		if (!dt_gmatch(pit.pit_pvp->pv_desc.dtvd_name, provider))
844 			continue;
845 
846 		(void) strlcpy(pit.pit_desc.dtpd_provider,
847 		    pit.pit_pvp->pv_desc.dtvd_name, DTRACE_PROVNAMELEN);
848 
849 		if ((rv = dt_idhash_iter(pit.pit_pvp->pv_probes,
850 		    (dt_idhash_f *)dt_probe_iter, &pit)) != 0)
851 			return (rv);
852 	}
853 
854 	if (pdp != NULL)
855 		cmd = DTRACEIOC_PROBEMATCH;
856 	else
857 		cmd = DTRACEIOC_PROBES;
858 
859 	for (;;) {
860 		if (pdp != NULL)
861 			bcopy(pdp, &pd, sizeof (pd));
862 
863 		pd.dtpd_id = id;
864 
865 		if (dt_ioctl(dtp, cmd, &pd) != 0)
866 			break;
867 		else if ((rv = func(dtp, &pd, arg)) != 0)
868 			return (rv);
869 
870 		pit.pit_matches++;
871 		id = pd.dtpd_id + 1;
872 	}
873 
874 	switch (errno) {
875 	case ESRCH:
876 	case EBADF:
877 		return (pit.pit_matches ? 0 : dt_set_errno(dtp, EDT_NOPROBE));
878 	case EINVAL:
879 		return (dt_set_errno(dtp, EDT_BADPGLOB));
880 	default:
881 		return (dt_set_errno(dtp, errno));
882 	}
883 }
884