xref: /freebsd/sys/cddl/dev/profile/profile.c (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
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  * $FreeBSD$
24  *
25  */
26 
27 /*
28  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
29  * Use is subject to license terms.
30  */
31 
32 #include <sys/cdefs.h>
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/conf.h>
36 #include <sys/cpuvar.h>
37 #include <sys/endian.h>
38 #include <sys/fcntl.h>
39 #include <sys/filio.h>
40 #include <sys/kdb.h>
41 #include <sys/kernel.h>
42 #include <sys/kmem.h>
43 #include <sys/kthread.h>
44 #include <sys/limits.h>
45 #include <sys/linker.h>
46 #include <sys/lock.h>
47 #include <sys/malloc.h>
48 #include <sys/module.h>
49 #include <sys/mutex.h>
50 #include <sys/poll.h>
51 #include <sys/proc.h>
52 #include <sys/selinfo.h>
53 #include <sys/smp.h>
54 #include <sys/sysctl.h>
55 #include <sys/uio.h>
56 #include <sys/unistd.h>
57 #include <machine/cpu.h>
58 #include <machine/stdarg.h>
59 
60 #include <sys/dtrace.h>
61 #include <sys/dtrace_bsd.h>
62 
63 #define	PROF_NAMELEN		15
64 
65 #define	PROF_PROFILE		0
66 #define	PROF_TICK		1
67 #define	PROF_PREFIX_PROFILE	"profile-"
68 #define	PROF_PREFIX_TICK	"tick-"
69 
70 /*
71  * Regardless of platform, there are five artificial frames in the case of the
72  * profile provider:
73  *
74  *	profile_fire
75  *	cyclic_expire
76  *	cyclic_fire
77  *	[ cbe ]
78  *	[ locore ]
79  *
80  * On amd64, there are two frames associated with locore:  one in locore, and
81  * another in common interrupt dispatch code.  (i386 has not been modified to
82  * use this common layer.)  Further, on i386, the interrupted instruction
83  * appears as its own stack frame.  All of this means that we need to add one
84  * frame for amd64, and then take one away for both amd64 and i386.
85  *
86  * On SPARC, the picture is further complicated because the compiler
87  * optimizes away tail-calls -- so the following frames are optimized away:
88  *
89  * 	profile_fire
90  *	cyclic_expire
91  *
92  * This gives three frames.  However, on DEBUG kernels, the cyclic_expire
93  * frame cannot be tail-call eliminated, yielding four frames in this case.
94  *
95  * All of the above constraints lead to the mess below.  Yes, the profile
96  * provider should ideally figure this out on-the-fly by hiting one of its own
97  * probes and then walking its own stack trace.  This is complicated, however,
98  * and the static definition doesn't seem to be overly brittle.  Still, we
99  * allow for a manual override in case we get it completely wrong.
100  */
101 #ifdef __amd64
102 #define	PROF_ARTIFICIAL_FRAMES	10
103 #else
104 #ifdef __i386
105 #define	PROF_ARTIFICIAL_FRAMES	6
106 #else
107 #ifdef __sparc
108 #ifdef DEBUG
109 #define	PROF_ARTIFICIAL_FRAMES	4
110 #else
111 #define	PROF_ARTIFICIAL_FRAMES	3
112 #endif
113 #endif
114 #endif
115 #endif
116 
117 #ifdef __mips
118 /*
119  * This value is bogus just to make module compilable on mips
120  */
121 #define	PROF_ARTIFICIAL_FRAMES	3
122 #endif
123 
124 #ifdef __powerpc__
125 /*
126  * This value is bogus just to make module compilable on powerpc
127  */
128 #define	PROF_ARTIFICIAL_FRAMES	3
129 #endif
130 
131 struct profile_probe_percpu;
132 
133 #ifdef __mips
134 /* bogus */
135 #define	PROF_ARTIFICIAL_FRAMES	3
136 #endif
137 
138 #ifdef __arm__
139 #define	PROF_ARTIFICIAL_FRAMES	3
140 #endif
141 
142 #ifdef __aarch64__
143 /* TODO: verify */
144 #define	PROF_ARTIFICIAL_FRAMES	10
145 #endif
146 
147 #ifdef __riscv
148 /* TODO: verify */
149 #define	PROF_ARTIFICIAL_FRAMES	10
150 #endif
151 
152 typedef struct profile_probe {
153 	char		prof_name[PROF_NAMELEN];
154 	dtrace_id_t	prof_id;
155 	int		prof_kind;
156 #ifdef illumos
157 	hrtime_t	prof_interval;
158 	cyclic_id_t	prof_cyclic;
159 #else
160 	sbintime_t	prof_interval;
161 	struct callout	prof_cyclic;
162 	sbintime_t	prof_expected;
163 	struct profile_probe_percpu **prof_pcpus;
164 #endif
165 } profile_probe_t;
166 
167 typedef struct profile_probe_percpu {
168 	hrtime_t	profc_expected;
169 	hrtime_t	profc_interval;
170 	profile_probe_t	*profc_probe;
171 #ifdef __FreeBSD__
172 	struct callout	profc_cyclic;
173 #endif
174 } profile_probe_percpu_t;
175 
176 static d_open_t	profile_open;
177 static int	profile_unload(void);
178 static void	profile_create(hrtime_t, char *, int);
179 static void	profile_destroy(void *, dtrace_id_t, void *);
180 static void	profile_enable(void *, dtrace_id_t, void *);
181 static void	profile_disable(void *, dtrace_id_t, void *);
182 static void	profile_load(void *);
183 static void	profile_provide(void *, dtrace_probedesc_t *);
184 
185 static int profile_rates[] = {
186     97, 199, 499, 997, 1999,
187     4001, 4999, 0, 0, 0,
188     0, 0, 0, 0, 0,
189     0, 0, 0, 0, 0
190 };
191 
192 static int profile_ticks[] = {
193     1, 10, 100, 500, 1000,
194     5000, 0, 0, 0, 0,
195     0, 0, 0, 0, 0
196 };
197 
198 /*
199  * profile_max defines the upper bound on the number of profile probes that
200  * can exist (this is to prevent malicious or clumsy users from exhausing
201  * system resources by creating a slew of profile probes). At mod load time,
202  * this gets its value from PROFILE_MAX_DEFAULT or profile-max-probes if it's
203  * present in the profile.conf file.
204  */
205 #define	PROFILE_MAX_DEFAULT	1000	/* default max. number of probes */
206 static uint32_t profile_max = PROFILE_MAX_DEFAULT;
207 					/* maximum number of profile probes */
208 static uint32_t profile_total;		/* current number of profile probes */
209 
210 static struct cdevsw profile_cdevsw = {
211 	.d_version	= D_VERSION,
212 	.d_open		= profile_open,
213 	.d_name		= "profile",
214 };
215 
216 static dtrace_pattr_t profile_attr = {
217 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
218 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
219 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
220 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
221 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
222 };
223 
224 static dtrace_pops_t profile_pops = {
225 	.dtps_provide =		profile_provide,
226 	.dtps_provide_module =	NULL,
227 	.dtps_enable =		profile_enable,
228 	.dtps_disable =		profile_disable,
229 	.dtps_suspend =		NULL,
230 	.dtps_resume =		NULL,
231 	.dtps_getargdesc =	NULL,
232 	.dtps_getargval =	NULL,
233 	.dtps_usermode =	NULL,
234 	.dtps_destroy =		profile_destroy
235 };
236 
237 static struct cdev		*profile_cdev;
238 static dtrace_provider_id_t	profile_id;
239 static hrtime_t			profile_interval_min = NANOSEC / 5000;	/* 5000 hz */
240 static int			profile_aframes = PROF_ARTIFICIAL_FRAMES;
241 
242 SYSCTL_DECL(_kern_dtrace);
243 SYSCTL_NODE(_kern_dtrace, OID_AUTO, profile, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
244     "DTrace profile parameters");
245 SYSCTL_INT(_kern_dtrace_profile, OID_AUTO, aframes, CTLFLAG_RW, &profile_aframes,
246     0, "Skipped frames for profile provider");
247 
248 static sbintime_t
249 nsec_to_sbt(hrtime_t nsec)
250 {
251 	time_t sec;
252 
253 	/*
254 	 * We need to calculate nsec * 2^32 / 10^9
255 	 * Seconds and nanoseconds are split to avoid overflow.
256 	 */
257 	sec = nsec / NANOSEC;
258 	nsec = nsec % NANOSEC;
259 	return (((sbintime_t)sec << 32) | ((sbintime_t)nsec << 32) / NANOSEC);
260 }
261 
262 static hrtime_t
263 sbt_to_nsec(sbintime_t sbt)
264 {
265 
266 	return ((sbt >> 32) * NANOSEC +
267 	    (((uint32_t)sbt * (hrtime_t)NANOSEC) >> 32));
268 }
269 
270 static void
271 profile_probe(profile_probe_t *prof, hrtime_t late)
272 {
273 	struct thread *td;
274 	struct trapframe *frame;
275 	uintfptr_t pc, upc;
276 
277 	td = curthread;
278 	pc = upc = 0;
279 
280 	/*
281 	 * td_intr_frame can be unset if this is a catch-up event upon waking up
282 	 * from idle sleep. This can only happen on a CPU idle thread. Use a
283 	 * representative arg0 value in this case so that one of the probe
284 	 * arguments is non-zero.
285 	 */
286 	frame = td->td_intr_frame;
287 	if (frame != NULL) {
288 		if (TRAPF_USERMODE(frame))
289 			upc = TRAPF_PC(frame);
290 		else
291 			pc = TRAPF_PC(frame);
292 	} else if (TD_IS_IDLETHREAD(td))
293 		pc = (uintfptr_t)&cpu_idle;
294 
295 	dtrace_probe(prof->prof_id, pc, upc, late, 0, 0);
296 }
297 
298 static void
299 profile_fire(void *arg)
300 {
301 	profile_probe_percpu_t *pcpu = arg;
302 	profile_probe_t *prof = pcpu->profc_probe;
303 	hrtime_t late;
304 
305 	late = sbt_to_nsec(sbinuptime() - pcpu->profc_expected);
306 
307 	profile_probe(prof, late);
308 	pcpu->profc_expected += pcpu->profc_interval;
309 	callout_schedule_sbt_curcpu(&pcpu->profc_cyclic,
310 	    pcpu->profc_expected, 0, C_DIRECT_EXEC | C_ABSOLUTE);
311 }
312 
313 static void
314 profile_tick(void *arg)
315 {
316 	profile_probe_t *prof = arg;
317 
318 	profile_probe(prof, 0);
319 	prof->prof_expected += prof->prof_interval;
320 	callout_schedule_sbt(&prof->prof_cyclic,
321 	    prof->prof_expected, 0, C_DIRECT_EXEC | C_ABSOLUTE);
322 }
323 
324 static void
325 profile_create(hrtime_t interval, char *name, int kind)
326 {
327 	profile_probe_t *prof;
328 
329 	if (interval < profile_interval_min)
330 		return;
331 
332 	if (dtrace_probe_lookup(profile_id, NULL, NULL, name) != 0)
333 		return;
334 
335 	atomic_add_32(&profile_total, 1);
336 	if (profile_total > profile_max) {
337 		atomic_add_32(&profile_total, -1);
338 		return;
339 	}
340 
341 	prof = kmem_zalloc(sizeof (profile_probe_t), KM_SLEEP);
342 	(void) strcpy(prof->prof_name, name);
343 #ifdef illumos
344 	prof->prof_interval = interval;
345 	prof->prof_cyclic = CYCLIC_NONE;
346 #else
347 	prof->prof_interval = nsec_to_sbt(interval);
348 	callout_init(&prof->prof_cyclic, 1);
349 #endif
350 	prof->prof_kind = kind;
351 	prof->prof_id = dtrace_probe_create(profile_id,
352 	    NULL, NULL, name,
353 	    profile_aframes, prof);
354 }
355 
356 /*ARGSUSED*/
357 static void
358 profile_provide(void *arg, dtrace_probedesc_t *desc)
359 {
360 	int i, j, rate, kind;
361 	hrtime_t val = 0, mult = 1, len = 0;
362 	char *name, *suffix = NULL;
363 
364 	const struct {
365 		char *prefix;
366 		int kind;
367 	} types[] = {
368 		{ PROF_PREFIX_PROFILE, PROF_PROFILE },
369 		{ PROF_PREFIX_TICK, PROF_TICK },
370 		{ 0, 0 }
371 	};
372 
373 	const struct {
374 		char *name;
375 		hrtime_t mult;
376 	} suffixes[] = {
377 		{ "ns", 	NANOSEC / NANOSEC },
378 		{ "nsec",	NANOSEC / NANOSEC },
379 		{ "us",		NANOSEC / MICROSEC },
380 		{ "usec",	NANOSEC / MICROSEC },
381 		{ "ms",		NANOSEC / MILLISEC },
382 		{ "msec",	NANOSEC / MILLISEC },
383 		{ "s",		NANOSEC / SEC },
384 		{ "sec",	NANOSEC / SEC },
385 		{ "m",		NANOSEC * (hrtime_t)60 },
386 		{ "min",	NANOSEC * (hrtime_t)60 },
387 		{ "h",		NANOSEC * (hrtime_t)(60 * 60) },
388 		{ "hour",	NANOSEC * (hrtime_t)(60 * 60) },
389 		{ "d",		NANOSEC * (hrtime_t)(24 * 60 * 60) },
390 		{ "day",	NANOSEC * (hrtime_t)(24 * 60 * 60) },
391 		{ "hz",		0 },
392 		{ NULL }
393 	};
394 
395 	if (desc == NULL) {
396 		char n[PROF_NAMELEN];
397 
398 		/*
399 		 * If no description was provided, provide all of our probes.
400 		 */
401 		for (i = 0; i < sizeof (profile_rates) / sizeof (int); i++) {
402 			if ((rate = profile_rates[i]) == 0)
403 				continue;
404 
405 			(void) snprintf(n, PROF_NAMELEN, "%s%d",
406 			    PROF_PREFIX_PROFILE, rate);
407 			profile_create(NANOSEC / rate, n, PROF_PROFILE);
408 		}
409 
410 		for (i = 0; i < sizeof (profile_ticks) / sizeof (int); i++) {
411 			if ((rate = profile_ticks[i]) == 0)
412 				continue;
413 
414 			(void) snprintf(n, PROF_NAMELEN, "%s%d",
415 			    PROF_PREFIX_TICK, rate);
416 			profile_create(NANOSEC / rate, n, PROF_TICK);
417 		}
418 
419 		return;
420 	}
421 
422 	name = desc->dtpd_name;
423 
424 	for (i = 0; types[i].prefix != NULL; i++) {
425 		len = strlen(types[i].prefix);
426 
427 		if (strncmp(name, types[i].prefix, len) != 0)
428 			continue;
429 		break;
430 	}
431 
432 	if (types[i].prefix == NULL)
433 		return;
434 
435 	kind = types[i].kind;
436 	j = strlen(name) - len;
437 
438 	/*
439 	 * We need to start before any time suffix.
440 	 */
441 	for (j = strlen(name); j >= len; j--) {
442 		if (name[j] >= '0' && name[j] <= '9')
443 			break;
444 		suffix = &name[j];
445 	}
446 
447 	ASSERT(suffix != NULL);
448 
449 	/*
450 	 * Now determine the numerical value present in the probe name.
451 	 */
452 	for (; j >= len; j--) {
453 		if (name[j] < '0' || name[j] > '9')
454 			return;
455 
456 		val += (name[j] - '0') * mult;
457 		mult *= (hrtime_t)10;
458 	}
459 
460 	if (val == 0)
461 		return;
462 
463 	/*
464 	 * Look-up the suffix to determine the multiplier.
465 	 */
466 	for (i = 0, mult = 0; suffixes[i].name != NULL; i++) {
467 		if (strcasecmp(suffixes[i].name, suffix) == 0) {
468 			mult = suffixes[i].mult;
469 			break;
470 		}
471 	}
472 
473 	if (suffixes[i].name == NULL && *suffix != '\0')
474 		return;
475 
476 	if (mult == 0) {
477 		/*
478 		 * The default is frequency-per-second.
479 		 */
480 		val = NANOSEC / val;
481 	} else {
482 		val *= mult;
483 	}
484 
485 	profile_create(val, name, kind);
486 }
487 
488 /* ARGSUSED */
489 static void
490 profile_destroy(void *arg, dtrace_id_t id, void *parg)
491 {
492 	profile_probe_t *prof = parg;
493 
494 #ifdef illumos
495 	ASSERT(prof->prof_cyclic == CYCLIC_NONE);
496 #else
497 	ASSERT(!callout_active(&prof->prof_cyclic) && prof->prof_pcpus == NULL);
498 #endif
499 	kmem_free(prof, sizeof (profile_probe_t));
500 
501 	ASSERT(profile_total >= 1);
502 	atomic_add_32(&profile_total, -1);
503 }
504 
505 #ifdef illumos
506 /*ARGSUSED*/
507 static void
508 profile_online(void *arg, cpu_t *cpu, cyc_handler_t *hdlr, cyc_time_t *when)
509 {
510 	profile_probe_t *prof = arg;
511 	profile_probe_percpu_t *pcpu;
512 
513 	pcpu = kmem_zalloc(sizeof (profile_probe_percpu_t), KM_SLEEP);
514 	pcpu->profc_probe = prof;
515 
516 	hdlr->cyh_func = profile_fire;
517 	hdlr->cyh_arg = pcpu;
518 
519 	when->cyt_interval = prof->prof_interval;
520 	when->cyt_when = gethrtime() + when->cyt_interval;
521 
522 	pcpu->profc_expected = when->cyt_when;
523 	pcpu->profc_interval = when->cyt_interval;
524 }
525 
526 /*ARGSUSED*/
527 static void
528 profile_offline(void *arg, cpu_t *cpu, void *oarg)
529 {
530 	profile_probe_percpu_t *pcpu = oarg;
531 
532 	ASSERT(pcpu->profc_probe == arg);
533 	kmem_free(pcpu, sizeof (profile_probe_percpu_t));
534 }
535 
536 /* ARGSUSED */
537 static void
538 profile_enable(void *arg, dtrace_id_t id, void *parg)
539 {
540 	profile_probe_t *prof = parg;
541 	cyc_omni_handler_t omni;
542 	cyc_handler_t hdlr;
543 	cyc_time_t when;
544 
545 	ASSERT(prof->prof_interval != 0);
546 	ASSERT(MUTEX_HELD(&cpu_lock));
547 
548 	if (prof->prof_kind == PROF_TICK) {
549 		hdlr.cyh_func = profile_tick;
550 		hdlr.cyh_arg = prof;
551 
552 		when.cyt_interval = prof->prof_interval;
553 		when.cyt_when = gethrtime() + when.cyt_interval;
554 	} else {
555 		ASSERT(prof->prof_kind == PROF_PROFILE);
556 		omni.cyo_online = profile_online;
557 		omni.cyo_offline = profile_offline;
558 		omni.cyo_arg = prof;
559 	}
560 
561 	if (prof->prof_kind == PROF_TICK) {
562 		prof->prof_cyclic = cyclic_add(&hdlr, &when);
563 	} else {
564 		prof->prof_cyclic = cyclic_add_omni(&omni);
565 	}
566 }
567 
568 /* ARGSUSED */
569 static void
570 profile_disable(void *arg, dtrace_id_t id, void *parg)
571 {
572 	profile_probe_t *prof = parg;
573 
574 	ASSERT(prof->prof_cyclic != CYCLIC_NONE);
575 	ASSERT(MUTEX_HELD(&cpu_lock));
576 
577 	cyclic_remove(prof->prof_cyclic);
578 	prof->prof_cyclic = CYCLIC_NONE;
579 }
580 
581 #else
582 
583 static void
584 profile_enable_omni(profile_probe_t *prof)
585 {
586 	profile_probe_percpu_t *pcpu;
587 	int cpu;
588 
589 	prof->prof_pcpus = kmem_zalloc((mp_maxid + 1) * sizeof(pcpu), KM_SLEEP);
590 	CPU_FOREACH(cpu) {
591 		pcpu = kmem_zalloc(sizeof(profile_probe_percpu_t), KM_SLEEP);
592 		prof->prof_pcpus[cpu] = pcpu;
593 		pcpu->profc_probe = prof;
594 		pcpu->profc_expected = sbinuptime() + prof->prof_interval;
595 		pcpu->profc_interval = prof->prof_interval;
596 		callout_init(&pcpu->profc_cyclic, 1);
597 		callout_reset_sbt_on(&pcpu->profc_cyclic,
598 		    pcpu->profc_expected, 0, profile_fire, pcpu,
599 		    cpu, C_DIRECT_EXEC | C_ABSOLUTE);
600 	}
601 }
602 
603 static void
604 profile_disable_omni(profile_probe_t *prof)
605 {
606 	profile_probe_percpu_t *pcpu;
607 	int cpu;
608 
609 	ASSERT(prof->prof_pcpus != NULL);
610 	CPU_FOREACH(cpu) {
611 		pcpu = prof->prof_pcpus[cpu];
612 		ASSERT(pcpu->profc_probe == prof);
613 		ASSERT(callout_active(&pcpu->profc_cyclic));
614 		callout_stop(&pcpu->profc_cyclic);
615 		callout_drain(&pcpu->profc_cyclic);
616 		kmem_free(pcpu, sizeof(profile_probe_percpu_t));
617 	}
618 	kmem_free(prof->prof_pcpus, (mp_maxid + 1) * sizeof(pcpu));
619 	prof->prof_pcpus = NULL;
620 }
621 
622 /* ARGSUSED */
623 static void
624 profile_enable(void *arg, dtrace_id_t id, void *parg)
625 {
626 	profile_probe_t *prof = parg;
627 
628 	if (prof->prof_kind == PROF_TICK) {
629 		prof->prof_expected = sbinuptime() + prof->prof_interval;
630 		callout_reset_sbt(&prof->prof_cyclic,
631 		    prof->prof_expected, 0, profile_tick, prof,
632 		    C_DIRECT_EXEC | C_ABSOLUTE);
633 	} else {
634 		ASSERT(prof->prof_kind == PROF_PROFILE);
635 		profile_enable_omni(prof);
636 	}
637 }
638 
639 /* ARGSUSED */
640 static void
641 profile_disable(void *arg, dtrace_id_t id, void *parg)
642 {
643 	profile_probe_t *prof = parg;
644 
645 	if (prof->prof_kind == PROF_TICK) {
646 		ASSERT(callout_active(&prof->prof_cyclic));
647 		callout_stop(&prof->prof_cyclic);
648 		callout_drain(&prof->prof_cyclic);
649 	} else {
650 		ASSERT(prof->prof_kind == PROF_PROFILE);
651 		profile_disable_omni(prof);
652 	}
653 }
654 #endif
655 
656 static void
657 profile_load(void *dummy)
658 {
659 	/* Create the /dev/dtrace/profile entry. */
660 	profile_cdev = make_dev(&profile_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
661 	    "dtrace/profile");
662 
663 	if (dtrace_register("profile", &profile_attr, DTRACE_PRIV_USER,
664 	    NULL, &profile_pops, NULL, &profile_id) != 0)
665 		return;
666 }
667 
668 
669 static int
670 profile_unload()
671 {
672 	int error = 0;
673 
674 	if ((error = dtrace_unregister(profile_id)) != 0)
675 		return (error);
676 
677 	destroy_dev(profile_cdev);
678 
679 	return (error);
680 }
681 
682 /* ARGSUSED */
683 static int
684 profile_modevent(module_t mod __unused, int type, void *data __unused)
685 {
686 	int error = 0;
687 
688 	switch (type) {
689 	case MOD_LOAD:
690 		break;
691 
692 	case MOD_UNLOAD:
693 		break;
694 
695 	case MOD_SHUTDOWN:
696 		break;
697 
698 	default:
699 		error = EOPNOTSUPP;
700 		break;
701 
702 	}
703 	return (error);
704 }
705 
706 /* ARGSUSED */
707 static int
708 profile_open(struct cdev *dev __unused, int oflags __unused, int devtype __unused, struct thread *td __unused)
709 {
710 	return (0);
711 }
712 
713 SYSINIT(profile_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, profile_load, NULL);
714 SYSUNINIT(profile_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, profile_unload, NULL);
715 
716 DEV_MODULE(profile, profile_modevent, NULL);
717 MODULE_VERSION(profile, 1);
718 MODULE_DEPEND(profile, dtrace, 1, 1, 1);
719 MODULE_DEPEND(profile, opensolaris, 1, 1, 1);
720