xref: /titanic_41/usr/src/uts/common/io/kstat.c (revision 3a73e621c639ad004320f80f06dd4250c57a8f90)
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  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  * Copyright 2015 Nexenta Systems, Inc. All rights reserved.
25  */
26 
27 
28 /*
29  * kernel statistics driver
30  */
31 
32 #include <sys/types.h>
33 #include <sys/time.h>
34 #include <sys/param.h>
35 #include <sys/sysmacros.h>
36 #include <sys/file.h>
37 #include <sys/cmn_err.h>
38 #include <sys/t_lock.h>
39 #include <sys/proc.h>
40 #include <sys/fcntl.h>
41 #include <sys/uio.h>
42 #include <sys/kmem.h>
43 #include <sys/cred.h>
44 #include <sys/mman.h>
45 #include <sys/errno.h>
46 #include <sys/ioccom.h>
47 #include <sys/cpuvar.h>
48 #include <sys/stat.h>
49 #include <sys/conf.h>
50 #include <sys/ddi.h>
51 #include <sys/sunddi.h>
52 #include <sys/modctl.h>
53 #include <sys/kobj.h>
54 #include <sys/kstat.h>
55 #include <sys/atomic.h>
56 #include <sys/policy.h>
57 #include <sys/zone.h>
58 
59 static dev_info_t *kstat_devi;
60 
61 static int
read_kstat_data(int * rvalp,void * user_ksp,int flag)62 read_kstat_data(int *rvalp, void *user_ksp, int flag)
63 {
64 	kstat_t user_kstat, *ksp;
65 #ifdef _MULTI_DATAMODEL
66 	kstat32_t user_kstat32;
67 #endif
68 	void *kbuf = NULL;
69 	size_t kbufsize, ubufsize, copysize;
70 	int error = 0;
71 	uint_t model;
72 
73 	switch (model = ddi_model_convert_from(flag & FMODELS)) {
74 #ifdef _MULTI_DATAMODEL
75 	case DDI_MODEL_ILP32:
76 		if (copyin(user_ksp, &user_kstat32, sizeof (kstat32_t)) != 0)
77 			return (EFAULT);
78 		user_kstat.ks_kid = user_kstat32.ks_kid;
79 		user_kstat.ks_data = (void *)(uintptr_t)user_kstat32.ks_data;
80 		user_kstat.ks_data_size = (size_t)user_kstat32.ks_data_size;
81 		break;
82 #endif
83 	default:
84 	case DDI_MODEL_NONE:
85 		if (copyin(user_ksp, &user_kstat, sizeof (kstat_t)) != 0)
86 			return (EFAULT);
87 	}
88 
89 	ksp = kstat_hold_bykid(user_kstat.ks_kid, getzoneid());
90 	if (ksp == NULL) {
91 		/*
92 		 * There is no kstat with the specified KID
93 		 */
94 		return (ENXIO);
95 	}
96 	if (ksp->ks_flags & KSTAT_FLAG_INVALID) {
97 		/*
98 		 * The kstat exists, but is momentarily in some
99 		 * indeterminate state (e.g. the data section is not
100 		 * yet initialized).  Try again in a few milliseconds.
101 		 */
102 		kstat_rele(ksp);
103 		return (EAGAIN);
104 	}
105 
106 	/*
107 	 * If it's a fixed-size kstat, allocate the buffer now, so we
108 	 * don't have to do it under the kstat's data lock.  (If it's a
109 	 * var-size kstat or one with long strings, we don't know the size
110 	 * until after the update routine is called, so we can't do this
111 	 * optimization.)
112 	 * The allocator relies on this behavior to prevent recursive
113 	 * mutex_enter in its (fixed-size) kstat update routine.
114 	 * It's a zalloc to prevent unintentional exposure of random
115 	 * juicy morsels of (old) kernel data.
116 	 */
117 	if (!(ksp->ks_flags & (KSTAT_FLAG_VAR_SIZE | KSTAT_FLAG_LONGSTRINGS))) {
118 		kbufsize = ksp->ks_data_size;
119 		kbuf = kmem_zalloc(kbufsize + 1, KM_NOSLEEP);
120 		if (kbuf == NULL) {
121 			kstat_rele(ksp);
122 			return (EAGAIN);
123 		}
124 	}
125 	KSTAT_ENTER(ksp);
126 	if ((error = KSTAT_UPDATE(ksp, KSTAT_READ)) != 0) {
127 		KSTAT_EXIT(ksp);
128 		kstat_rele(ksp);
129 		if (kbuf != NULL)
130 			kmem_free(kbuf, kbufsize + 1);
131 		return (error);
132 	}
133 
134 	kbufsize = ksp->ks_data_size;
135 	ubufsize = user_kstat.ks_data_size;
136 
137 	if (ubufsize < kbufsize) {
138 		error = ENOMEM;
139 	} else {
140 		if (kbuf == NULL)
141 			kbuf = kmem_zalloc(kbufsize + 1, KM_NOSLEEP);
142 		if (kbuf == NULL) {
143 			error = EAGAIN;
144 		} else {
145 			error = KSTAT_SNAPSHOT(ksp, kbuf, KSTAT_READ);
146 		}
147 	}
148 
149 	/*
150 	 * The following info must be returned to user level,
151 	 * even if the the update or snapshot failed.  This allows
152 	 * kstat readers to get a handle on variable-size kstats,
153 	 * detect dormant kstats, etc.
154 	 */
155 	user_kstat.ks_ndata	= ksp->ks_ndata;
156 	user_kstat.ks_data_size	= kbufsize;
157 	user_kstat.ks_flags	= ksp->ks_flags;
158 	user_kstat.ks_snaptime	= ksp->ks_snaptime;
159 
160 	*rvalp = kstat_chain_id;
161 	KSTAT_EXIT(ksp);
162 	kstat_rele(ksp);
163 
164 	if (kbuf == NULL)
165 		goto out;
166 
167 	/*
168 	 * Copy the buffer containing the kstat back to userland.
169 	 */
170 	copysize = kbufsize;
171 
172 	switch (model) {
173 	int i;
174 #ifdef _MULTI_DATAMODEL
175 	kstat32_t *k32;
176 	kstat_t *k;
177 
178 	case DDI_MODEL_ILP32:
179 
180 		if (ksp->ks_type == KSTAT_TYPE_NAMED) {
181 			kstat_named_t *kn = kbuf;
182 			char *strbuf = (char *)((kstat_named_t *)kn +
183 			    ksp->ks_ndata);
184 
185 			for (i = 0; i < user_kstat.ks_ndata; kn++, i++)
186 				switch (kn->data_type) {
187 				/*
188 				 * Named statistics have fields of type 'long'.
189 				 * For a 32-bit application looking at a 64-bit
190 				 * kernel, forcibly truncate these 64-bit
191 				 * quantities to 32-bit values.
192 				 */
193 				case KSTAT_DATA_LONG:
194 					kn->value.i32 = (int32_t)kn->value.l;
195 					kn->data_type = KSTAT_DATA_INT32;
196 					break;
197 				case KSTAT_DATA_ULONG:
198 					kn->value.ui32 = (uint32_t)kn->value.ul;
199 					kn->data_type = KSTAT_DATA_UINT32;
200 					break;
201 				/*
202 				 * Long strings must be massaged before being
203 				 * copied out to userland.  Do that here.
204 				 */
205 				case KSTAT_DATA_STRING:
206 					if (KSTAT_NAMED_STR_PTR(kn) == NULL)
207 						break;
208 					/*
209 					 * If the string lies outside of kbuf
210 					 * copy it there and update the pointer.
211 					 */
212 					if (KSTAT_NAMED_STR_PTR(kn) <
213 					    (char *)kbuf ||
214 					    KSTAT_NAMED_STR_PTR(kn) +
215 					    KSTAT_NAMED_STR_BUFLEN(kn) >
216 					    (char *)kbuf + kbufsize + 1) {
217 						bcopy(KSTAT_NAMED_STR_PTR(kn),
218 						    strbuf,
219 						    KSTAT_NAMED_STR_BUFLEN(kn));
220 
221 						KSTAT_NAMED_STR_PTR(kn) =
222 						    strbuf;
223 						strbuf +=
224 						    KSTAT_NAMED_STR_BUFLEN(kn);
225 						ASSERT(strbuf <=
226 						    (char *)kbuf +
227 						    kbufsize + 1);
228 					}
229 					/*
230 					 * The offsets within the buffers are
231 					 * the same, so add the offset to the
232 					 * beginning of the new buffer to fix
233 					 * the pointer.
234 					 */
235 					KSTAT_NAMED_STR_PTR(kn) =
236 					    (char *)user_kstat.ks_data +
237 					    (KSTAT_NAMED_STR_PTR(kn) -
238 					    (char *)kbuf);
239 					/*
240 					 * Make sure the string pointer lies
241 					 * within the allocated buffer.
242 					 */
243 					ASSERT(KSTAT_NAMED_STR_PTR(kn) +
244 					    KSTAT_NAMED_STR_BUFLEN(kn) <=
245 					    ((char *)user_kstat.ks_data +
246 					    ubufsize));
247 					ASSERT(KSTAT_NAMED_STR_PTR(kn) >=
248 					    (char *)((kstat_named_t *)
249 					    user_kstat.ks_data +
250 					    user_kstat.ks_ndata));
251 					/*
252 					 * Cast 64-bit ptr to 32-bit.
253 					 */
254 					kn->value.str.addr.ptr32 =
255 					    (caddr32_t)(uintptr_t)
256 					    KSTAT_NAMED_STR_PTR(kn);
257 					break;
258 				default:
259 					break;
260 				}
261 		}
262 
263 		if (user_kstat.ks_kid != 0)
264 			break;
265 
266 		/*
267 		 * This is the special case of the kstat header
268 		 * list for the entire system.  Reshape the
269 		 * array in place, then copy it out.
270 		 */
271 		k32 = kbuf;
272 		k = kbuf;
273 		for (i = 0; i < user_kstat.ks_ndata; k32++, k++, i++) {
274 			k32->ks_crtime		= k->ks_crtime;
275 			k32->ks_next		= 0;
276 			k32->ks_kid		= k->ks_kid;
277 			(void) strcpy(k32->ks_module, k->ks_module);
278 			k32->ks_resv		= k->ks_resv;
279 			k32->ks_instance	= k->ks_instance;
280 			(void) strcpy(k32->ks_name, k->ks_name);
281 			k32->ks_type		= k->ks_type;
282 			(void) strcpy(k32->ks_class, k->ks_class);
283 			k32->ks_flags		= k->ks_flags;
284 			k32->ks_data		= 0;
285 			k32->ks_ndata		= k->ks_ndata;
286 			if (k->ks_data_size > UINT32_MAX) {
287 				error = EOVERFLOW;
288 				break;
289 			}
290 			k32->ks_data_size = (size32_t)k->ks_data_size;
291 			k32->ks_snaptime	= k->ks_snaptime;
292 		}
293 
294 		/*
295 		 * XXX	In this case we copy less data than is
296 		 *	claimed in the header.
297 		 */
298 		copysize = user_kstat.ks_ndata * sizeof (kstat32_t);
299 		break;
300 #endif	/* _MULTI_DATAMODEL */
301 	default:
302 	case DDI_MODEL_NONE:
303 		if (ksp->ks_type == KSTAT_TYPE_NAMED) {
304 			kstat_named_t *kn = kbuf;
305 			char *strbuf = (char *)((kstat_named_t *)kn +
306 			    ksp->ks_ndata);
307 
308 			for (i = 0; i < user_kstat.ks_ndata; kn++, i++)
309 				switch (kn->data_type) {
310 #ifdef _LP64
311 				case KSTAT_DATA_LONG:
312 					kn->data_type =
313 					    KSTAT_DATA_INT64;
314 					break;
315 				case KSTAT_DATA_ULONG:
316 					kn->data_type =
317 					    KSTAT_DATA_UINT64;
318 					break;
319 #endif	/* _LP64 */
320 				case KSTAT_DATA_STRING:
321 					if (KSTAT_NAMED_STR_PTR(kn) == NULL)
322 						break;
323 					/*
324 					 * If the string lies outside of kbuf
325 					 * copy it there and update the pointer.
326 					 */
327 					if (KSTAT_NAMED_STR_PTR(kn) <
328 					    (char *)kbuf ||
329 					    KSTAT_NAMED_STR_PTR(kn) +
330 					    KSTAT_NAMED_STR_BUFLEN(kn) >
331 					    (char *)kbuf + kbufsize + 1) {
332 						bcopy(KSTAT_NAMED_STR_PTR(kn),
333 						    strbuf,
334 						    KSTAT_NAMED_STR_BUFLEN(kn));
335 
336 						KSTAT_NAMED_STR_PTR(kn) =
337 						    strbuf;
338 						strbuf +=
339 						    KSTAT_NAMED_STR_BUFLEN(kn);
340 						ASSERT(strbuf <=
341 						    (char *)kbuf +
342 						    kbufsize + 1);
343 					}
344 
345 					KSTAT_NAMED_STR_PTR(kn) =
346 					    (char *)user_kstat.ks_data +
347 					    (KSTAT_NAMED_STR_PTR(kn) -
348 					    (char *)kbuf);
349 					ASSERT(KSTAT_NAMED_STR_PTR(kn) +
350 					    KSTAT_NAMED_STR_BUFLEN(kn) <=
351 					    ((char *)user_kstat.ks_data +
352 					    ubufsize));
353 					ASSERT(KSTAT_NAMED_STR_PTR(kn) >=
354 					    (char *)((kstat_named_t *)
355 					    user_kstat.ks_data +
356 					    user_kstat.ks_ndata));
357 					break;
358 				default:
359 					break;
360 				}
361 		}
362 		break;
363 	}
364 
365 	if (error == 0 &&
366 	    copyout(kbuf, user_kstat.ks_data, copysize))
367 		error = EFAULT;
368 	kmem_free(kbuf, kbufsize + 1);
369 
370 out:
371 	/*
372 	 * We have modified the ks_ndata, ks_data_size, ks_flags, and
373 	 * ks_snaptime fields of the user kstat; now copy it back to userland.
374 	 */
375 	switch (model) {
376 #ifdef _MULTI_DATAMODEL
377 	case DDI_MODEL_ILP32:
378 		if (kbufsize > UINT32_MAX) {
379 			error = EOVERFLOW;
380 			break;
381 		}
382 		user_kstat32.ks_ndata		= user_kstat.ks_ndata;
383 		user_kstat32.ks_data_size	= (size32_t)kbufsize;
384 		user_kstat32.ks_flags		= user_kstat.ks_flags;
385 		user_kstat32.ks_snaptime	= user_kstat.ks_snaptime;
386 		if (copyout(&user_kstat32, user_ksp, sizeof (kstat32_t)) &&
387 		    error == 0)
388 			error = EFAULT;
389 		break;
390 #endif
391 	default:
392 	case DDI_MODEL_NONE:
393 		if (copyout(&user_kstat, user_ksp, sizeof (kstat_t)) &&
394 		    error == 0)
395 			error = EFAULT;
396 		break;
397 	}
398 
399 	return (error);
400 }
401 
402 static int
write_kstat_data(int * rvalp,void * user_ksp,int flag,cred_t * cred)403 write_kstat_data(int *rvalp, void *user_ksp, int flag, cred_t *cred)
404 {
405 	kstat_t user_kstat, *ksp;
406 	void *buf = NULL;
407 	size_t bufsize;
408 	int error = 0;
409 
410 	if (secpolicy_sys_config(cred, B_FALSE) != 0)
411 		return (EPERM);
412 
413 	switch (ddi_model_convert_from(flag & FMODELS)) {
414 #ifdef _MULTI_DATAMODEL
415 		kstat32_t user_kstat32;
416 
417 	case DDI_MODEL_ILP32:
418 		if (copyin(user_ksp, &user_kstat32, sizeof (kstat32_t)))
419 			return (EFAULT);
420 		/*
421 		 * These are the only fields we actually look at.
422 		 */
423 		user_kstat.ks_kid = user_kstat32.ks_kid;
424 		user_kstat.ks_data = (void *)(uintptr_t)user_kstat32.ks_data;
425 		user_kstat.ks_data_size = (size_t)user_kstat32.ks_data_size;
426 		user_kstat.ks_ndata = user_kstat32.ks_ndata;
427 		break;
428 #endif
429 	default:
430 	case DDI_MODEL_NONE:
431 		if (copyin(user_ksp, &user_kstat, sizeof (kstat_t)))
432 			return (EFAULT);
433 	}
434 
435 	bufsize = user_kstat.ks_data_size;
436 	buf = kmem_alloc(bufsize + 1, KM_NOSLEEP);
437 	if (buf == NULL)
438 		return (EAGAIN);
439 
440 	if (copyin(user_kstat.ks_data, buf, bufsize)) {
441 		kmem_free(buf, bufsize + 1);
442 		return (EFAULT);
443 	}
444 
445 	ksp = kstat_hold_bykid(user_kstat.ks_kid, getzoneid());
446 	if (ksp == NULL) {
447 		kmem_free(buf, bufsize + 1);
448 		return (ENXIO);
449 	}
450 	if (ksp->ks_flags & KSTAT_FLAG_INVALID) {
451 		kstat_rele(ksp);
452 		kmem_free(buf, bufsize + 1);
453 		return (EAGAIN);
454 	}
455 	if (!(ksp->ks_flags & KSTAT_FLAG_WRITABLE)) {
456 		kstat_rele(ksp);
457 		kmem_free(buf, bufsize + 1);
458 		return (EACCES);
459 	}
460 
461 	/*
462 	 * With KSTAT_FLAG_VAR_SIZE, one must call the kstat's update callback
463 	 * routine to ensure ks_data_size is up to date.
464 	 * In this case it makes sense to do it anyhow, as it will be shortly
465 	 * followed by a KSTAT_SNAPSHOT().
466 	 */
467 	KSTAT_ENTER(ksp);
468 	error = KSTAT_UPDATE(ksp, KSTAT_READ);
469 	if (error || user_kstat.ks_data_size != ksp->ks_data_size ||
470 	    user_kstat.ks_ndata != ksp->ks_ndata) {
471 		KSTAT_EXIT(ksp);
472 		kstat_rele(ksp);
473 		kmem_free(buf, bufsize + 1);
474 		return (error ? error : EINVAL);
475 	}
476 
477 	/*
478 	 * We have to ensure that we don't accidentally change the type of
479 	 * existing kstat_named statistics when writing over them.
480 	 * Since read_kstat_data() modifies some of the types on their way
481 	 * out, we need to be sure to handle these types seperately.
482 	 */
483 	if (ksp->ks_type == KSTAT_TYPE_NAMED) {
484 		void *kbuf;
485 		kstat_named_t *kold;
486 		kstat_named_t *knew = buf;
487 		int i;
488 
489 #ifdef	_MULTI_DATAMODEL
490 		int model = ddi_model_convert_from(flag & FMODELS);
491 #endif
492 
493 		/*
494 		 * Since ksp->ks_data may be NULL, we need to take a snapshot
495 		 * of the published data to look at the types.
496 		 */
497 		kbuf = kmem_alloc(bufsize + 1, KM_NOSLEEP);
498 		if (kbuf == NULL) {
499 			KSTAT_EXIT(ksp);
500 			kstat_rele(ksp);
501 			kmem_free(buf, bufsize + 1);
502 			return (EAGAIN);
503 		}
504 		error = KSTAT_SNAPSHOT(ksp, kbuf, KSTAT_READ);
505 		if (error) {
506 			KSTAT_EXIT(ksp);
507 			kstat_rele(ksp);
508 			kmem_free(kbuf, bufsize + 1);
509 			kmem_free(buf, bufsize + 1);
510 			return (error);
511 		}
512 		kold = kbuf;
513 
514 		/*
515 		 * read_kstat_data() changes the types of
516 		 * KSTAT_DATA_LONG / KSTAT_DATA_ULONG, so we need to
517 		 * make sure that these (modified) types are considered
518 		 * valid.
519 		 */
520 		for (i = 0; i < ksp->ks_ndata; i++, kold++, knew++) {
521 			switch (kold->data_type) {
522 #ifdef	_MULTI_DATAMODEL
523 			case KSTAT_DATA_LONG:
524 				switch (model) {
525 				case DDI_MODEL_ILP32:
526 					if (knew->data_type ==
527 					    KSTAT_DATA_INT32) {
528 						knew->value.l =
529 						    (long)knew->value.i32;
530 						knew->data_type =
531 						    KSTAT_DATA_LONG;
532 					}
533 					break;
534 				default:
535 				case DDI_MODEL_NONE:
536 #ifdef _LP64
537 					if (knew->data_type ==
538 					    KSTAT_DATA_INT64) {
539 						knew->value.l =
540 						    (long)knew->value.i64;
541 						knew->data_type =
542 						    KSTAT_DATA_LONG;
543 					}
544 #endif /* _LP64 */
545 					break;
546 				}
547 				break;
548 			case KSTAT_DATA_ULONG:
549 				switch (model) {
550 				case DDI_MODEL_ILP32:
551 					if (knew->data_type ==
552 					    KSTAT_DATA_UINT32) {
553 						knew->value.ul =
554 						    (ulong_t)knew->value.ui32;
555 						knew->data_type =
556 						    KSTAT_DATA_ULONG;
557 					}
558 					break;
559 				default:
560 				case DDI_MODEL_NONE:
561 #ifdef _LP64
562 					if (knew->data_type ==
563 					    KSTAT_DATA_UINT64) {
564 						knew->value.ul =
565 						    (ulong_t)knew->value.ui64;
566 						knew->data_type =
567 						    KSTAT_DATA_ULONG;
568 					}
569 #endif /* _LP64 */
570 					break;
571 				}
572 				break;
573 #endif /* _MULTI_DATAMODEL */
574 			case KSTAT_DATA_STRING:
575 				if (knew->data_type != KSTAT_DATA_STRING) {
576 					KSTAT_EXIT(ksp);
577 					kstat_rele(ksp);
578 					kmem_free(kbuf, bufsize + 1);
579 					kmem_free(buf, bufsize + 1);
580 					return (EINVAL);
581 				}
582 
583 #ifdef _MULTI_DATAMODEL
584 				if (model == DDI_MODEL_ILP32)
585 					KSTAT_NAMED_STR_PTR(knew) =
586 					    (char *)(uintptr_t)
587 						knew->value.str.addr.ptr32;
588 #endif
589 				/*
590 				 * Nothing special for NULL
591 				 */
592 				if (KSTAT_NAMED_STR_PTR(knew) == NULL)
593 					break;
594 
595 				/*
596 				 * Check to see that the pointers all point
597 				 * to within the buffer and after the array
598 				 * of kstat_named_t's.
599 				 */
600 				if (KSTAT_NAMED_STR_PTR(knew) <
601 				    (char *)
602 				    ((kstat_named_t *)user_kstat.ks_data +
603 				    ksp->ks_ndata)) {
604 					KSTAT_EXIT(ksp);
605 					kstat_rele(ksp);
606 					kmem_free(kbuf, bufsize + 1);
607 					kmem_free(buf, bufsize + 1);
608 					return (EINVAL);
609 				}
610 				if (KSTAT_NAMED_STR_PTR(knew) +
611 				    KSTAT_NAMED_STR_BUFLEN(knew) >
612 				    ((char *)user_kstat.ks_data +
613 				    ksp->ks_data_size)) {
614 					KSTAT_EXIT(ksp);
615 					kstat_rele(ksp);
616 					kmem_free(kbuf, bufsize + 1);
617 					kmem_free(buf, bufsize + 1);
618 					return (EINVAL);
619 				}
620 
621 				/*
622 				 * Update the pointers within the buffer
623 				 */
624 				KSTAT_NAMED_STR_PTR(knew) =
625 				    (char *)buf +
626 				    (KSTAT_NAMED_STR_PTR(knew) -
627 				    (char *)user_kstat.ks_data);
628 				break;
629 			default:
630 				break;
631 			}
632 		}
633 
634 		kold = kbuf;
635 		knew = buf;
636 
637 		/*
638 		 * Now make sure the types are what we expected them to be.
639 		 */
640 		for (i = 0; i < ksp->ks_ndata; i++, kold++, knew++)
641 			if (kold->data_type != knew->data_type) {
642 				KSTAT_EXIT(ksp);
643 				kstat_rele(ksp);
644 				kmem_free(kbuf, bufsize + 1);
645 				kmem_free(buf, bufsize + 1);
646 				return (EINVAL);
647 			}
648 
649 		kmem_free(kbuf, bufsize + 1);
650 	}
651 
652 	error = KSTAT_SNAPSHOT(ksp, buf, KSTAT_WRITE);
653 	if (!error)
654 		error = KSTAT_UPDATE(ksp, KSTAT_WRITE);
655 	*rvalp = kstat_chain_id;
656 	KSTAT_EXIT(ksp);
657 	kstat_rele(ksp);
658 	kmem_free(buf, bufsize + 1);
659 	return (error);
660 }
661 
662 /*ARGSUSED*/
663 static int
kstat_ioctl(dev_t dev,int cmd,intptr_t data,int flag,cred_t * cr,int * rvalp)664 kstat_ioctl(dev_t dev, int cmd, intptr_t data, int flag, cred_t *cr, int *rvalp)
665 {
666 	int rc = 0;
667 
668 	switch (cmd) {
669 
670 	case KSTAT_IOC_CHAIN_ID:
671 		*rvalp = kstat_chain_id;
672 		break;
673 
674 	case KSTAT_IOC_READ:
675 		rc = read_kstat_data(rvalp, (void *)data, flag);
676 		break;
677 
678 	case KSTAT_IOC_WRITE:
679 		rc = write_kstat_data(rvalp, (void *)data, flag, cr);
680 		break;
681 
682 	default:
683 		/* invalid request */
684 		rc = EINVAL;
685 	}
686 	return (rc);
687 }
688 
689 /* ARGSUSED */
690 static int
kstat_info(dev_info_t * dip,ddi_info_cmd_t infocmd,void * arg,void ** result)691 kstat_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
692 	void **result)
693 {
694 	switch (infocmd) {
695 	case DDI_INFO_DEVT2DEVINFO:
696 		*result = kstat_devi;
697 		return (DDI_SUCCESS);
698 	case DDI_INFO_DEVT2INSTANCE:
699 		*result = NULL;
700 		return (DDI_SUCCESS);
701 	}
702 	return (DDI_FAILURE);
703 }
704 
705 static int
kstat_attach(dev_info_t * devi,ddi_attach_cmd_t cmd)706 kstat_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
707 {
708 	if (cmd != DDI_ATTACH)
709 		return (DDI_FAILURE);
710 
711 	if (ddi_create_minor_node(devi, "kstat", S_IFCHR,
712 	    0, DDI_PSEUDO, NULL) == DDI_FAILURE) {
713 		ddi_remove_minor_node(devi, NULL);
714 		return (DDI_FAILURE);
715 	}
716 	kstat_devi = devi;
717 	return (DDI_SUCCESS);
718 }
719 
720 static int
kstat_detach(dev_info_t * devi,ddi_detach_cmd_t cmd)721 kstat_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
722 {
723 	if (cmd != DDI_DETACH)
724 		return (DDI_FAILURE);
725 
726 	ddi_remove_minor_node(devi, NULL);
727 	return (DDI_SUCCESS);
728 }
729 
730 static struct cb_ops kstat_cb_ops = {
731 	nulldev,		/* open */
732 	nulldev,		/* close */
733 	nodev,			/* strategy */
734 	nodev,			/* print */
735 	nodev,			/* dump */
736 	nodev,			/* read */
737 	nodev,			/* write */
738 	kstat_ioctl,		/* ioctl */
739 	nodev,			/* devmap */
740 	nodev,			/* mmap */
741 	nodev,			/* segmap */
742 	nochpoll,		/* poll */
743 	ddi_prop_op,		/* prop_op */
744 	0,			/* streamtab  */
745 	D_NEW | D_MP		/* Driver compatibility flag */
746 };
747 
748 static struct dev_ops kstat_ops = {
749 	DEVO_REV,		/* devo_rev, */
750 	0,			/* refcnt  */
751 	kstat_info,		/* get_dev_info */
752 	nulldev,		/* identify */
753 	nulldev,		/* probe */
754 	kstat_attach,		/* attach */
755 	kstat_detach,		/* detach */
756 	nodev,			/* reset */
757 	&kstat_cb_ops,		/* driver operations */
758 	(struct bus_ops *)0,	/* no bus operations */
759 	NULL,			/* power */
760 	ddi_quiesce_not_needed,		/* quiesce */
761 };
762 
763 static struct modldrv modldrv = {
764 	&mod_driverops, "kernel statistics driver", &kstat_ops,
765 };
766 
767 static struct modlinkage modlinkage = {
768 	MODREV_1, &modldrv, NULL
769 };
770 
771 int
_init(void)772 _init(void)
773 {
774 	return (mod_install(&modlinkage));
775 }
776 
777 int
_fini(void)778 _fini(void)
779 {
780 	return (mod_remove(&modlinkage));
781 }
782 
783 int
_info(struct modinfo * modinfop)784 _info(struct modinfo *modinfop)
785 {
786 	return (mod_info(&modlinkage, modinfop));
787 }
788