xref: /illumos-gate/usr/src/uts/common/os/grow.c (revision 2c5124a1)
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 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #include <sys/types.h>
31 #include <sys/inttypes.h>
32 #include <sys/param.h>
33 #include <sys/sysmacros.h>
34 #include <sys/systm.h>
35 #include <sys/signal.h>
36 #include <sys/user.h>
37 #include <sys/errno.h>
38 #include <sys/var.h>
39 #include <sys/proc.h>
40 #include <sys/tuneable.h>
41 #include <sys/debug.h>
42 #include <sys/cmn_err.h>
43 #include <sys/cred.h>
44 #include <sys/vnode.h>
45 #include <sys/vfs.h>
46 #include <sys/vm.h>
47 #include <sys/file.h>
48 #include <sys/mman.h>
49 #include <sys/vmparam.h>
50 #include <sys/fcntl.h>
51 #include <sys/lwpchan_impl.h>
52 #include <sys/nbmlock.h>
53 
54 #include <vm/hat.h>
55 #include <vm/as.h>
56 #include <vm/seg.h>
57 #include <vm/seg_dev.h>
58 #include <vm/seg_vn.h>
59 
60 int use_brk_lpg = 1;
61 int use_stk_lpg = 1;
62 
63 static int brk_lpg(caddr_t nva);
64 static int grow_lpg(caddr_t sp);
65 
66 int
67 brk(caddr_t nva)
68 {
69 	int error;
70 	proc_t *p = curproc;
71 
72 	/*
73 	 * Serialize brk operations on an address space.
74 	 * This also serves as the lock protecting p_brksize
75 	 * and p_brkpageszc.
76 	 */
77 	as_rangelock(p->p_as);
78 	if (use_brk_lpg && (p->p_flag & SAUTOLPG) != 0) {
79 		error = brk_lpg(nva);
80 	} else {
81 		error = brk_internal(nva, p->p_brkpageszc);
82 	}
83 	as_rangeunlock(p->p_as);
84 	return ((error != 0 ? set_errno(error) : 0));
85 }
86 
87 /*
88  * Algorithm: call arch-specific map_pgsz to get best page size to use,
89  * then call brk_internal().
90  * Returns 0 on success.
91  */
92 static int
93 brk_lpg(caddr_t nva)
94 {
95 	struct proc *p = curproc;
96 	size_t pgsz, len;
97 	caddr_t addr, brkend;
98 	caddr_t bssbase = p->p_bssbase;
99 	caddr_t brkbase = p->p_brkbase;
100 	int oszc, szc;
101 	int err;
102 
103 	oszc = p->p_brkpageszc;
104 
105 	/*
106 	 * If p_brkbase has not yet been set, the first call
107 	 * to brk_internal() will initialize it.
108 	 */
109 	if (brkbase == 0) {
110 		return (brk_internal(nva, oszc));
111 	}
112 
113 	len = nva - bssbase;
114 
115 	pgsz = map_pgsz(MAPPGSZ_HEAP, p, bssbase, len, 0);
116 	szc = page_szc(pgsz);
117 
118 	/*
119 	 * Covers two cases:
120 	 * 1. page_szc() returns -1 for invalid page size, so we want to
121 	 * ignore it in that case.
122 	 * 2. By design we never decrease page size, as it is more stable.
123 	 */
124 	if (szc <= oszc) {
125 		err = brk_internal(nva, oszc);
126 		/* If failed, back off to base page size. */
127 		if (err != 0 && oszc != 0) {
128 			err = brk_internal(nva, 0);
129 		}
130 		return (err);
131 	}
132 
133 	err = brk_internal(nva, szc);
134 	/* If using szc failed, map with base page size and return. */
135 	if (err != 0) {
136 		if (szc != 0) {
137 			err = brk_internal(nva, 0);
138 		}
139 		return (err);
140 	}
141 
142 	/*
143 	 * Round up brk base to a large page boundary and remap
144 	 * anything in the segment already faulted in beyond that
145 	 * point.
146 	 */
147 	addr = (caddr_t)P2ROUNDUP((uintptr_t)p->p_bssbase, pgsz);
148 	brkend = brkbase + p->p_brksize;
149 	len = brkend - addr;
150 	/* Check that len is not negative. Update page size code for heap. */
151 	if (addr >= p->p_bssbase && brkend > addr && IS_P2ALIGNED(len, pgsz)) {
152 		(void) as_setpagesize(p->p_as, addr, len, szc, B_FALSE);
153 		p->p_brkpageszc = szc;
154 	}
155 
156 	ASSERT(err == 0);
157 	return (err);		/* should always be 0 */
158 }
159 
160 /*
161  * Returns 0 on success.
162  */
163 int
164 brk_internal(caddr_t nva, uint_t brkszc)
165 {
166 	caddr_t ova;			/* current break address */
167 	size_t size;
168 	int	error;
169 	struct proc *p = curproc;
170 	struct as *as = p->p_as;
171 	size_t pgsz;
172 	uint_t szc;
173 	rctl_qty_t as_rctl;
174 
175 	/*
176 	 * extend heap to brkszc alignment but use current p->p_brkpageszc
177 	 * for the newly created segment. This allows the new extension
178 	 * segment to be concatenated successfully with the existing brk
179 	 * segment.
180 	 */
181 	if ((szc = brkszc) != 0) {
182 		pgsz = page_get_pagesize(szc);
183 		ASSERT(pgsz > PAGESIZE);
184 	} else {
185 		pgsz = PAGESIZE;
186 	}
187 
188 	mutex_enter(&p->p_lock);
189 	as_rctl = rctl_enforced_value(rctlproc_legacy[RLIMIT_DATA],
190 	    p->p_rctls, p);
191 	mutex_exit(&p->p_lock);
192 
193 	/*
194 	 * If p_brkbase has not yet been set, the first call
195 	 * to brk() will initialize it.
196 	 */
197 	if (p->p_brkbase == 0)
198 		p->p_brkbase = nva;
199 
200 	/*
201 	 * Before multiple page size support existed p_brksize was the value
202 	 * not rounded to the pagesize (i.e. it stored the exact user request
203 	 * for heap size). If pgsz is greater than PAGESIZE calculate the
204 	 * heap size as the real new heap size by rounding it up to pgsz.
205 	 * This is useful since we may want to know where the heap ends
206 	 * without knowing heap pagesize (e.g. some old code) and also if
207 	 * heap pagesize changes we can update p_brkpageszc but delay adding
208 	 * new mapping yet still know from p_brksize where the heap really
209 	 * ends. The user requested heap end is stored in libc variable.
210 	 */
211 	if (pgsz > PAGESIZE) {
212 		caddr_t tnva = (caddr_t)P2ROUNDUP((uintptr_t)nva, pgsz);
213 		size = tnva - p->p_brkbase;
214 		if (tnva < p->p_brkbase || (size > p->p_brksize &&
215 		    size > (size_t)as_rctl)) {
216 			szc = 0;
217 			pgsz = PAGESIZE;
218 			size = nva - p->p_brkbase;
219 		}
220 	} else {
221 		size = nva - p->p_brkbase;
222 	}
223 
224 	/*
225 	 * use PAGESIZE to roundup ova because we want to know the real value
226 	 * of the current heap end in case p_brkpageszc changes since the last
227 	 * p_brksize was computed.
228 	 */
229 	nva = (caddr_t)P2ROUNDUP((uintptr_t)nva, pgsz);
230 	ova = (caddr_t)P2ROUNDUP((uintptr_t)(p->p_brkbase + p->p_brksize),
231 	    PAGESIZE);
232 
233 	if ((nva < p->p_brkbase) || (size > p->p_brksize &&
234 	    size > as_rctl)) {
235 		mutex_enter(&p->p_lock);
236 		(void) rctl_action(rctlproc_legacy[RLIMIT_DATA], p->p_rctls, p,
237 		    RCA_SAFE);
238 		mutex_exit(&p->p_lock);
239 		return (ENOMEM);
240 	}
241 
242 	if (nva > ova) {
243 		struct segvn_crargs crargs =
244 		    SEGVN_ZFOD_ARGS(PROT_ZFOD, PROT_ALL);
245 
246 		if (!(p->p_datprot & PROT_EXEC)) {
247 			crargs.prot &= ~PROT_EXEC;
248 		}
249 
250 		/*
251 		 * Add new zfod mapping to extend UNIX data segment
252 		 * AS_MAP_NO_LPOOB means use 0, and don't reapply OOB policies
253 		 * via map_pgszcvec(). Use AS_MAP_HEAP to get intermediate
254 		 * page sizes if ova is not aligned to szc's pgsz.
255 		 */
256 		if (szc > 0) {
257 			caddr_t rbss;
258 
259 			rbss = (caddr_t)P2ROUNDUP((uintptr_t)p->p_bssbase,
260 			    pgsz);
261 			if (IS_P2ALIGNED(p->p_bssbase, pgsz) || ova > rbss) {
262 				crargs.szc = p->p_brkpageszc ? p->p_brkpageszc :
263 				    AS_MAP_NO_LPOOB;
264 			} else if (ova == rbss) {
265 				crargs.szc = szc;
266 			} else {
267 				crargs.szc = AS_MAP_HEAP;
268 			}
269 		} else {
270 			crargs.szc = AS_MAP_NO_LPOOB;
271 		}
272 		crargs.lgrp_mem_policy_flags = LGRP_MP_FLAG_EXTEND_UP;
273 		error = as_map(as, ova, (size_t)(nva - ova), segvn_create,
274 		    &crargs);
275 		if (error) {
276 			return (error);
277 		}
278 
279 	} else if (nva < ova) {
280 		/*
281 		 * Release mapping to shrink UNIX data segment.
282 		 */
283 		(void) as_unmap(as, nva, (size_t)(ova - nva));
284 	}
285 	p->p_brksize = size;
286 	return (0);
287 }
288 
289 /*
290  * Grow the stack to include sp.  Return 1 if successful, 0 otherwise.
291  * This routine assumes that the stack grows downward.
292  */
293 int
294 grow(caddr_t sp)
295 {
296 	struct proc *p = curproc;
297 	struct as *as = p->p_as;
298 	size_t oldsize = p->p_stksize;
299 	size_t newsize;
300 	int err;
301 
302 	/*
303 	 * Serialize grow operations on an address space.
304 	 * This also serves as the lock protecting p_stksize
305 	 * and p_stkpageszc.
306 	 */
307 	as_rangelock(as);
308 	if (use_stk_lpg && (p->p_flag & SAUTOLPG) != 0) {
309 		err = grow_lpg(sp);
310 	} else {
311 		err = grow_internal(sp, p->p_stkpageszc);
312 	}
313 	as_rangeunlock(as);
314 
315 	if (err == 0 && (newsize = p->p_stksize) > oldsize) {
316 		ASSERT(IS_P2ALIGNED(oldsize, PAGESIZE));
317 		ASSERT(IS_P2ALIGNED(newsize, PAGESIZE));
318 		/*
319 		 * Set up translations so the process doesn't have to fault in
320 		 * the stack pages we just gave it.
321 		 */
322 		(void) as_fault(as->a_hat, as, p->p_usrstack - newsize,
323 		    newsize - oldsize, F_INVAL, S_WRITE);
324 	}
325 	return ((err == 0 ? 1 : 0));
326 }
327 
328 /*
329  * Algorithm: call arch-specific map_pgsz to get best page size to use,
330  * then call grow_internal().
331  * Returns 0 on success.
332  */
333 static int
334 grow_lpg(caddr_t sp)
335 {
336 	struct proc *p = curproc;
337 	size_t pgsz;
338 	size_t len, newsize;
339 	caddr_t addr, saddr;
340 	caddr_t growend;
341 	int oszc, szc;
342 	int err;
343 
344 	newsize = p->p_usrstack - sp;
345 
346 	oszc = p->p_stkpageszc;
347 	pgsz = map_pgsz(MAPPGSZ_STK, p, sp, newsize, 0);
348 	szc = page_szc(pgsz);
349 
350 	/*
351 	 * Covers two cases:
352 	 * 1. page_szc() returns -1 for invalid page size, so we want to
353 	 * ignore it in that case.
354 	 * 2. By design we never decrease page size, as it is more stable.
355 	 * This shouldn't happen as the stack never shrinks.
356 	 */
357 	if (szc <= oszc) {
358 		err = grow_internal(sp, oszc);
359 		/* failed, fall back to base page size */
360 		if (err != 0 && oszc != 0) {
361 			err = grow_internal(sp, 0);
362 		}
363 		return (err);
364 	}
365 
366 	/*
367 	 * We've grown sufficiently to switch to a new page size.
368 	 * So we are going to remap the whole segment with the new page size.
369 	 */
370 	err = grow_internal(sp, szc);
371 	/* The grow with szc failed, so fall back to base page size. */
372 	if (err != 0) {
373 		if (szc != 0) {
374 			err = grow_internal(sp, 0);
375 		}
376 		return (err);
377 	}
378 
379 	/*
380 	 * Round up stack pointer to a large page boundary and remap
381 	 * any pgsz pages in the segment already faulted in beyond that
382 	 * point.
383 	 */
384 	saddr = p->p_usrstack - p->p_stksize;
385 	addr = (caddr_t)P2ROUNDUP((uintptr_t)saddr, pgsz);
386 	growend = (caddr_t)P2ALIGN((uintptr_t)p->p_usrstack, pgsz);
387 	len = growend - addr;
388 	/* Check that len is not negative. Update page size code for stack. */
389 	if (addr >= saddr && growend > addr && IS_P2ALIGNED(len, pgsz)) {
390 		(void) as_setpagesize(p->p_as, addr, len, szc, B_FALSE);
391 		p->p_stkpageszc = szc;
392 	}
393 
394 	ASSERT(err == 0);
395 	return (err);		/* should always be 0 */
396 }
397 
398 /*
399  * This routine assumes that the stack grows downward.
400  * Returns 0 on success, errno on failure.
401  */
402 int
403 grow_internal(caddr_t sp, uint_t growszc)
404 {
405 	struct proc *p = curproc;
406 	size_t newsize;
407 	size_t oldsize;
408 	int    error;
409 	size_t pgsz;
410 	uint_t szc;
411 	struct segvn_crargs crargs = SEGVN_ZFOD_ARGS(PROT_ZFOD, PROT_ALL);
412 
413 	ASSERT(sp < p->p_usrstack);
414 	sp = (caddr_t)P2ALIGN((uintptr_t)sp, PAGESIZE);
415 
416 	/*
417 	 * grow to growszc alignment but use current p->p_stkpageszc for
418 	 * the segvn_crargs szc passed to segvn_create. For memcntl to
419 	 * increase the szc, this allows the new extension segment to be
420 	 * concatenated successfully with the existing stack segment.
421 	 */
422 	if ((szc = growszc) != 0) {
423 		pgsz = page_get_pagesize(szc);
424 		ASSERT(pgsz > PAGESIZE);
425 		newsize = p->p_usrstack - (caddr_t)P2ALIGN((uintptr_t)sp, pgsz);
426 		if (newsize > (size_t)p->p_stk_ctl) {
427 			szc = 0;
428 			pgsz = PAGESIZE;
429 			newsize = p->p_usrstack - sp;
430 		}
431 	} else {
432 		pgsz = PAGESIZE;
433 		newsize = p->p_usrstack - sp;
434 	}
435 
436 	if (newsize > (size_t)p->p_stk_ctl) {
437 		(void) rctl_action(rctlproc_legacy[RLIMIT_STACK], p->p_rctls, p,
438 		    RCA_UNSAFE_ALL);
439 
440 		return (ENOMEM);
441 	}
442 
443 	oldsize = p->p_stksize;
444 	ASSERT(P2PHASE(oldsize, PAGESIZE) == 0);
445 
446 	if (newsize <= oldsize) {	/* prevent the stack from shrinking */
447 		return (0);
448 	}
449 
450 	if (!(p->p_stkprot & PROT_EXEC)) {
451 		crargs.prot &= ~PROT_EXEC;
452 	}
453 	/*
454 	 * extend stack with the proposed new growszc, which is different
455 	 * than p_stkpageszc only on a memcntl to increase the stack pagesize.
456 	 * AS_MAP_NO_LPOOB means use 0, and don't reapply OOB policies via
457 	 * map_pgszcvec(). Use AS_MAP_STACK to get intermediate page sizes
458 	 * if not aligned to szc's pgsz.
459 	 */
460 	if (szc > 0) {
461 		caddr_t oldsp = p->p_usrstack - oldsize;
462 		caddr_t austk = (caddr_t)P2ALIGN((uintptr_t)p->p_usrstack,
463 		    pgsz);
464 
465 		if (IS_P2ALIGNED(p->p_usrstack, pgsz) || oldsp < austk) {
466 			crargs.szc = p->p_stkpageszc ? p->p_stkpageszc :
467 			    AS_MAP_NO_LPOOB;
468 		} else if (oldsp == austk) {
469 			crargs.szc = szc;
470 		} else {
471 			crargs.szc = AS_MAP_STACK;
472 		}
473 	} else {
474 		crargs.szc = AS_MAP_NO_LPOOB;
475 	}
476 	crargs.lgrp_mem_policy_flags = LGRP_MP_FLAG_EXTEND_DOWN;
477 
478 	if ((error = as_map(p->p_as, p->p_usrstack - newsize, newsize - oldsize,
479 	    segvn_create, &crargs)) != 0) {
480 		if (error == EAGAIN) {
481 			cmn_err(CE_WARN, "Sorry, no swap space to grow stack "
482 			    "for pid %d (%s)", p->p_pid, PTOU(p)->u_comm);
483 		}
484 		return (error);
485 	}
486 	p->p_stksize = newsize;
487 	return (0);
488 }
489 
490 /*
491  * Find address for user to map.
492  * If MAP_FIXED is not specified, we can pick any address we want, but we will
493  * first try the value in *addrp if it is non-NULL.  Thus this is implementing
494  * a way to try and get a preferred address.
495  */
496 int
497 choose_addr(struct as *as, caddr_t *addrp, size_t len, offset_t off,
498     int vacalign, uint_t flags)
499 {
500 	caddr_t basep = (caddr_t)(uintptr_t)((uintptr_t)*addrp & PAGEMASK);
501 	size_t lenp = len;
502 
503 	ASSERT(AS_ISCLAIMGAP(as));	/* searches should be serialized */
504 	if (flags & MAP_FIXED) {
505 		(void) as_unmap(as, *addrp, len);
506 		return (0);
507 	} else if (basep != NULL && ((flags & MAP_ALIGN) == 0) &&
508 	    !as_gap(as, len, &basep, &lenp, 0, *addrp)) {
509 		/* User supplied address was available */
510 		*addrp = basep;
511 	} else {
512 		/*
513 		 * No user supplied address or the address supplied was not
514 		 * available.
515 		 */
516 		map_addr(addrp, len, off, vacalign, flags);
517 	}
518 	if (*addrp == NULL)
519 		return (ENOMEM);
520 	return (0);
521 }
522 
523 
524 /*
525  * Used for MAP_ANON - fast way to get anonymous pages
526  */
527 static int
528 zmap(struct as *as, caddr_t *addrp, size_t len, uint_t uprot, int flags,
529     offset_t pos)
530 {
531 	struct segvn_crargs vn_a;
532 	int error;
533 
534 	if (((PROT_ALL & uprot) != uprot))
535 		return (EACCES);
536 
537 	if ((flags & MAP_FIXED) != 0) {
538 		caddr_t userlimit;
539 
540 		/*
541 		 * Use the user address.  First verify that
542 		 * the address to be used is page aligned.
543 		 * Then make some simple bounds checks.
544 		 */
545 		if (((uintptr_t)*addrp & PAGEOFFSET) != 0)
546 			return (EINVAL);
547 
548 		userlimit = flags & _MAP_LOW32 ?
549 		    (caddr_t)USERLIMIT32 : as->a_userlimit;
550 		switch (valid_usr_range(*addrp, len, uprot, as, userlimit)) {
551 		case RANGE_OKAY:
552 			break;
553 		case RANGE_BADPROT:
554 			return (ENOTSUP);
555 		case RANGE_BADADDR:
556 		default:
557 			return (ENOMEM);
558 		}
559 	}
560 	/*
561 	 * No need to worry about vac alignment for anonymous
562 	 * pages since this is a "clone" object that doesn't
563 	 * yet exist.
564 	 */
565 	error = choose_addr(as, addrp, len, pos, ADDR_NOVACALIGN, flags);
566 	if (error != 0) {
567 		return (error);
568 	}
569 
570 	/*
571 	 * Use the seg_vn segment driver; passing in the NULL amp
572 	 * gives the desired "cloning" effect.
573 	 */
574 	vn_a.vp = NULL;
575 	vn_a.offset = 0;
576 	vn_a.type = flags & MAP_TYPE;
577 	vn_a.prot = uprot;
578 	vn_a.maxprot = PROT_ALL;
579 	vn_a.flags = flags & ~MAP_TYPE;
580 	vn_a.cred = CRED();
581 	vn_a.amp = NULL;
582 	vn_a.szc = 0;
583 	vn_a.lgrp_mem_policy_flags = 0;
584 
585 	return (as_map(as, *addrp, len, segvn_create, &vn_a));
586 }
587 
588 static int
589 smmap_common(caddr_t *addrp, size_t len,
590     int prot, int flags, struct file *fp, offset_t pos)
591 {
592 	struct vnode *vp;
593 	struct as *as = curproc->p_as;
594 	uint_t uprot, maxprot, type;
595 	int error;
596 	int in_crit = 0;
597 
598 	if ((flags & ~(MAP_SHARED | MAP_PRIVATE | MAP_FIXED | _MAP_NEW |
599 	    _MAP_LOW32 | MAP_NORESERVE | MAP_ANON | MAP_ALIGN |
600 	    MAP_TEXT | MAP_INITDATA)) != 0) {
601 		/* | MAP_RENAME */	/* not implemented, let user know */
602 		return (EINVAL);
603 	}
604 
605 	if ((flags & MAP_TEXT) && !(prot & PROT_EXEC)) {
606 		return (EINVAL);
607 	}
608 
609 	if ((flags & (MAP_TEXT | MAP_INITDATA)) == (MAP_TEXT | MAP_INITDATA)) {
610 		return (EINVAL);
611 	}
612 
613 #if defined(__sparc)
614 	/*
615 	 * See if this is an "old mmap call".  If so, remember this
616 	 * fact and convert the flags value given to mmap to indicate
617 	 * the specified address in the system call must be used.
618 	 * _MAP_NEW is turned set by all new uses of mmap.
619 	 */
620 	if ((flags & _MAP_NEW) == 0)
621 		flags |= MAP_FIXED;
622 #endif
623 	flags &= ~_MAP_NEW;
624 
625 	type = flags & MAP_TYPE;
626 	if (type != MAP_PRIVATE && type != MAP_SHARED)
627 		return (EINVAL);
628 
629 
630 	if (flags & MAP_ALIGN) {
631 
632 		if (flags & MAP_FIXED)
633 			return (EINVAL);
634 
635 		/* alignment needs to be a power of 2 >= page size */
636 		if (((uintptr_t)*addrp < PAGESIZE && (uintptr_t)*addrp != 0) ||
637 		    !ISP2((uintptr_t)*addrp))
638 			return (EINVAL);
639 	}
640 	/*
641 	 * Check for bad lengths and file position.
642 	 * We let the VOP_MAP routine check for negative lengths
643 	 * since on some vnode types this might be appropriate.
644 	 */
645 	if (len == 0 || (pos & (u_offset_t)PAGEOFFSET) != 0)
646 		return (EINVAL);
647 
648 	maxprot = PROT_ALL;		/* start out allowing all accesses */
649 	uprot = prot | PROT_USER;
650 
651 	if (fp == NULL) {
652 		ASSERT(flags & MAP_ANON);
653 		/* discard lwpchan mappings, like munmap() */
654 		if ((flags & MAP_FIXED) && curproc->p_lcp != NULL)
655 			lwpchan_delete_mapping(curproc, *addrp, *addrp + len);
656 		as_rangelock(as);
657 		error = zmap(as, addrp, len, uprot, flags, pos);
658 		as_rangeunlock(as);
659 		/*
660 		 * Tell machine specific code that lwp has mapped shared memory
661 		 */
662 		if (error == 0 && (flags & MAP_SHARED)) {
663 			/* EMPTY */
664 			LWP_MMODEL_SHARED_AS(*addrp, len);
665 		}
666 		return (error);
667 	} else if ((flags & MAP_ANON) != 0)
668 		return (EINVAL);
669 
670 	vp = fp->f_vnode;
671 
672 	/* Can't execute code from "noexec" mounted filesystem. */
673 	if ((vp->v_vfsp->vfs_flag & VFS_NOEXEC) != 0)
674 		maxprot &= ~PROT_EXEC;
675 
676 	/*
677 	 * These checks were added as part of large files.
678 	 *
679 	 * Return ENXIO if the initial position is negative; return EOVERFLOW
680 	 * if (offset + len) would overflow the maximum allowed offset for the
681 	 * type of file descriptor being used.
682 	 */
683 	if (vp->v_type == VREG) {
684 		if (pos < 0)
685 			return (ENXIO);
686 		if ((offset_t)len > (OFFSET_MAX(fp) - pos))
687 			return (EOVERFLOW);
688 	}
689 
690 	if (type == MAP_SHARED && (fp->f_flag & FWRITE) == 0) {
691 		/* no write access allowed */
692 		maxprot &= ~PROT_WRITE;
693 	}
694 
695 	/*
696 	 * XXX - Do we also adjust maxprot based on protections
697 	 * of the vnode?  E.g. if no execute permission is given
698 	 * on the vnode for the current user, maxprot probably
699 	 * should disallow PROT_EXEC also?  This is different
700 	 * from the write access as this would be a per vnode
701 	 * test as opposed to a per fd test for writability.
702 	 */
703 
704 	/*
705 	 * Verify that the specified protections are not greater than
706 	 * the maximum allowable protections.  Also test to make sure
707 	 * that the file descriptor does allows for read access since
708 	 * "write only" mappings are hard to do since normally we do
709 	 * the read from the file before the page can be written.
710 	 */
711 	if (((maxprot & uprot) != uprot) || (fp->f_flag & FREAD) == 0)
712 		return (EACCES);
713 
714 	/*
715 	 * If the user specified an address, do some simple checks here
716 	 */
717 	if ((flags & MAP_FIXED) != 0) {
718 		caddr_t userlimit;
719 
720 		/*
721 		 * Use the user address.  First verify that
722 		 * the address to be used is page aligned.
723 		 * Then make some simple bounds checks.
724 		 */
725 		if (((uintptr_t)*addrp & PAGEOFFSET) != 0)
726 			return (EINVAL);
727 
728 		userlimit = flags & _MAP_LOW32 ?
729 		    (caddr_t)USERLIMIT32 : as->a_userlimit;
730 		switch (valid_usr_range(*addrp, len, uprot, as, userlimit)) {
731 		case RANGE_OKAY:
732 			break;
733 		case RANGE_BADPROT:
734 			return (ENOTSUP);
735 		case RANGE_BADADDR:
736 		default:
737 			return (ENOMEM);
738 		}
739 	}
740 
741 	if ((prot & (PROT_READ | PROT_WRITE | PROT_EXEC)) &&
742 	    nbl_need_check(vp)) {
743 		int svmand;
744 		nbl_op_t nop;
745 
746 		nbl_start_crit(vp, RW_READER);
747 		in_crit = 1;
748 		error = nbl_svmand(vp, fp->f_cred, &svmand);
749 		if (error != 0)
750 			goto done;
751 		if ((prot & PROT_WRITE) && (type == MAP_SHARED)) {
752 			if (prot & (PROT_READ | PROT_EXEC)) {
753 				nop = NBL_READWRITE;
754 			} else {
755 				nop = NBL_WRITE;
756 			}
757 		} else {
758 			nop = NBL_READ;
759 		}
760 		if (nbl_conflict(vp, nop, 0, LONG_MAX, svmand, NULL)) {
761 			error = EACCES;
762 			goto done;
763 		}
764 	}
765 
766 	/* discard lwpchan mappings, like munmap() */
767 	if ((flags & MAP_FIXED) && curproc->p_lcp != NULL)
768 		lwpchan_delete_mapping(curproc, *addrp, *addrp + len);
769 
770 	/*
771 	 * Ok, now let the vnode map routine do its thing to set things up.
772 	 */
773 	error = VOP_MAP(vp, pos, as,
774 	    addrp, len, uprot, maxprot, flags, fp->f_cred, NULL);
775 
776 	if (error == 0) {
777 		/*
778 		 * Tell machine specific code that lwp has mapped shared memory
779 		 */
780 		if (flags & MAP_SHARED) {
781 			/* EMPTY */
782 			LWP_MMODEL_SHARED_AS(*addrp, len);
783 		}
784 		if (vp->v_type == VREG &&
785 		    (flags & (MAP_TEXT | MAP_INITDATA)) != 0) {
786 			/*
787 			 * Mark this as an executable vnode
788 			 */
789 			mutex_enter(&vp->v_lock);
790 			vp->v_flag |= VVMEXEC;
791 			mutex_exit(&vp->v_lock);
792 		}
793 	}
794 
795 done:
796 	if (in_crit)
797 		nbl_end_crit(vp);
798 	return (error);
799 }
800 
801 #ifdef _LP64
802 /*
803  * LP64 mmap(2) system call: 64-bit offset, 64-bit address.
804  *
805  * The "large file" mmap routine mmap64(2) is also mapped to this routine
806  * by the 64-bit version of libc.
807  *
808  * Eventually, this should be the only version, and have smmap_common()
809  * folded back into it again.  Some day.
810  */
811 caddr_t
812 smmap64(caddr_t addr, size_t len, int prot, int flags, int fd, off_t pos)
813 {
814 	struct file *fp;
815 	int error;
816 
817 	if (flags & _MAP_LOW32)
818 		error = EINVAL;
819 	else if (fd == -1 && (flags & MAP_ANON) != 0)
820 		error = smmap_common(&addr, len, prot, flags,
821 		    NULL, (offset_t)pos);
822 	else if ((fp = getf(fd)) != NULL) {
823 		error = smmap_common(&addr, len, prot, flags,
824 		    fp, (offset_t)pos);
825 		releasef(fd);
826 	} else
827 		error = EBADF;
828 
829 	return (error ? (caddr_t)(uintptr_t)set_errno(error) : addr);
830 }
831 #endif	/* _LP64 */
832 
833 #if defined(_SYSCALL32_IMPL) || defined(_ILP32)
834 
835 /*
836  * ILP32 mmap(2) system call: 32-bit offset, 32-bit address.
837  */
838 caddr_t
839 smmap32(caddr32_t addr, size32_t len, int prot, int flags, int fd, off32_t pos)
840 {
841 	struct file *fp;
842 	int error;
843 	caddr_t a = (caddr_t)(uintptr_t)addr;
844 
845 	if (flags & _MAP_LOW32)
846 		error = EINVAL;
847 	else if (fd == -1 && (flags & MAP_ANON) != 0)
848 		error = smmap_common(&a, (size_t)len, prot,
849 		    flags | _MAP_LOW32, NULL, (offset_t)pos);
850 	else if ((fp = getf(fd)) != NULL) {
851 		error = smmap_common(&a, (size_t)len, prot,
852 		    flags | _MAP_LOW32, fp, (offset_t)pos);
853 		releasef(fd);
854 	} else
855 		error = EBADF;
856 
857 	ASSERT(error != 0 || (uintptr_t)(a + len) < (uintptr_t)UINT32_MAX);
858 
859 	return (error ? (caddr_t)(uintptr_t)set_errno(error) : a);
860 }
861 
862 /*
863  * ILP32 mmap64(2) system call: 64-bit offset, 32-bit address.
864  *
865  * Now things really get ugly because we can't use the C-style
866  * calling convention for more than 6 args, and 64-bit parameter
867  * passing on 32-bit systems is less than clean.
868  */
869 
870 struct mmaplf32a {
871 	caddr_t addr;
872 	size_t len;
873 #ifdef _LP64
874 	/*
875 	 * 32-bit contents, 64-bit cells
876 	 */
877 	uint64_t prot;
878 	uint64_t flags;
879 	uint64_t fd;
880 	uint64_t offhi;
881 	uint64_t offlo;
882 #else
883 	/*
884 	 * 32-bit contents, 32-bit cells
885 	 */
886 	uint32_t prot;
887 	uint32_t flags;
888 	uint32_t fd;
889 	uint32_t offhi;
890 	uint32_t offlo;
891 #endif
892 };
893 
894 int
895 smmaplf32(struct mmaplf32a *uap, rval_t *rvp)
896 {
897 	struct file *fp;
898 	int error;
899 	caddr_t a = uap->addr;
900 	int flags = (int)uap->flags;
901 	int fd = (int)uap->fd;
902 #ifdef _BIG_ENDIAN
903 	offset_t off = ((u_offset_t)uap->offhi << 32) | (u_offset_t)uap->offlo;
904 #else
905 	offset_t off = ((u_offset_t)uap->offlo << 32) | (u_offset_t)uap->offhi;
906 #endif
907 
908 	if (flags & _MAP_LOW32)
909 		error = EINVAL;
910 	else if (fd == -1 && (flags & MAP_ANON) != 0)
911 		error = smmap_common(&a, uap->len, (int)uap->prot,
912 		    flags | _MAP_LOW32, NULL, off);
913 	else if ((fp = getf(fd)) != NULL) {
914 		error = smmap_common(&a, uap->len, (int)uap->prot,
915 		    flags | _MAP_LOW32, fp, off);
916 		releasef(fd);
917 	} else
918 		error = EBADF;
919 
920 	if (error == 0)
921 		rvp->r_val1 = (uintptr_t)a;
922 	return (error);
923 }
924 
925 #endif	/* _SYSCALL32_IMPL || _ILP32 */
926 
927 int
928 munmap(caddr_t addr, size_t len)
929 {
930 	struct proc *p = curproc;
931 	struct as *as = p->p_as;
932 
933 	if (((uintptr_t)addr & PAGEOFFSET) != 0 || len == 0)
934 		return (set_errno(EINVAL));
935 
936 	if (valid_usr_range(addr, len, 0, as, as->a_userlimit) != RANGE_OKAY)
937 		return (set_errno(EINVAL));
938 
939 	/*
940 	 * Discard lwpchan mappings.
941 	 */
942 	if (p->p_lcp != NULL)
943 		lwpchan_delete_mapping(p, addr, addr + len);
944 	if (as_unmap(as, addr, len) != 0)
945 		return (set_errno(EINVAL));
946 
947 	return (0);
948 }
949 
950 int
951 mprotect(caddr_t addr, size_t len, int prot)
952 {
953 	struct as *as = curproc->p_as;
954 	uint_t uprot = prot | PROT_USER;
955 	int error;
956 
957 	if (((uintptr_t)addr & PAGEOFFSET) != 0 || len == 0)
958 		return (set_errno(EINVAL));
959 
960 	switch (valid_usr_range(addr, len, prot, as, as->a_userlimit)) {
961 	case RANGE_OKAY:
962 		break;
963 	case RANGE_BADPROT:
964 		return (set_errno(ENOTSUP));
965 	case RANGE_BADADDR:
966 	default:
967 		return (set_errno(ENOMEM));
968 	}
969 
970 	error = as_setprot(as, addr, len, uprot);
971 	if (error)
972 		return (set_errno(error));
973 	return (0);
974 }
975 
976 #define	MC_CACHE	128			/* internal result buffer */
977 #define	MC_QUANTUM	(MC_CACHE * PAGESIZE)	/* addresses covered in loop */
978 
979 int
980 mincore(caddr_t addr, size_t len, char *vecp)
981 {
982 	struct as *as = curproc->p_as;
983 	caddr_t ea;			/* end address of loop */
984 	size_t rl;			/* inner result length */
985 	char vec[MC_CACHE];		/* local vector cache */
986 	int error;
987 	model_t model;
988 	long	llen;
989 
990 	model = get_udatamodel();
991 	/*
992 	 * Validate form of address parameters.
993 	 */
994 	if (model == DATAMODEL_NATIVE) {
995 		llen = (long)len;
996 	} else {
997 		llen = (int32_t)(size32_t)len;
998 	}
999 	if (((uintptr_t)addr & PAGEOFFSET) != 0 || llen <= 0)
1000 		return (set_errno(EINVAL));
1001 
1002 	if (valid_usr_range(addr, len, 0, as, as->a_userlimit) != RANGE_OKAY)
1003 		return (set_errno(ENOMEM));
1004 
1005 	/*
1006 	 * Loop over subranges of interval [addr : addr + len), recovering
1007 	 * results internally and then copying them out to caller.  Subrange
1008 	 * is based on the size of MC_CACHE, defined above.
1009 	 */
1010 	for (ea = addr + len; addr < ea; addr += MC_QUANTUM) {
1011 		error = as_incore(as, addr,
1012 		    (size_t)MIN(MC_QUANTUM, ea - addr), vec, &rl);
1013 		if (rl != 0) {
1014 			rl = (rl + PAGESIZE - 1) / PAGESIZE;
1015 			if (copyout(vec, vecp, rl) != 0)
1016 				return (set_errno(EFAULT));
1017 			vecp += rl;
1018 		}
1019 		if (error != 0)
1020 			return (set_errno(ENOMEM));
1021 	}
1022 	return (0);
1023 }
1024