Annotation of sys/uvm/uvm_mmap.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: uvm_mmap.c,v 1.69 2007/06/18 21:51:15 pedro Exp $ */
2: /* $NetBSD: uvm_mmap.c,v 1.49 2001/02/18 21:19:08 chs Exp $ */
3:
4: /*
5: * Copyright (c) 1997 Charles D. Cranor and Washington University.
6: * Copyright (c) 1991, 1993 The Regents of the University of California.
7: * Copyright (c) 1988 University of Utah.
8: *
9: * All rights reserved.
10: *
11: * This code is derived from software contributed to Berkeley by
12: * the Systems Programming Group of the University of Utah Computer
13: * Science Department.
14: *
15: * Redistribution and use in source and binary forms, with or without
16: * modification, are permitted provided that the following conditions
17: * are met:
18: * 1. Redistributions of source code must retain the above copyright
19: * notice, this list of conditions and the following disclaimer.
20: * 2. Redistributions in binary form must reproduce the above copyright
21: * notice, this list of conditions and the following disclaimer in the
22: * documentation and/or other materials provided with the distribution.
23: * 3. All advertising materials mentioning features or use of this software
24: * must display the following acknowledgement:
25: * This product includes software developed by the Charles D. Cranor,
26: * Washington University, University of California, Berkeley and
27: * its contributors.
28: * 4. Neither the name of the University nor the names of its contributors
29: * may be used to endorse or promote products derived from this software
30: * without specific prior written permission.
31: *
32: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
33: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
36: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
40: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
41: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42: * SUCH DAMAGE.
43: *
44: * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
45: * @(#)vm_mmap.c 8.5 (Berkeley) 5/19/94
46: * from: Id: uvm_mmap.c,v 1.1.2.14 1998/01/05 21:04:26 chuck Exp
47: */
48:
49: /*
50: * uvm_mmap.c: system call interface into VM system, plus kernel vm_mmap
51: * function.
52: */
53: #include <sys/param.h>
54: #include <sys/systm.h>
55: #include <sys/file.h>
56: #include <sys/filedesc.h>
57: #include <sys/resourcevar.h>
58: #include <sys/mman.h>
59: #include <sys/mount.h>
60: #include <sys/proc.h>
61: #include <sys/malloc.h>
62: #include <sys/vnode.h>
63: #include <sys/conf.h>
64: #include <sys/stat.h>
65:
66: #include <machine/exec.h> /* for __LDPGSZ */
67:
68: #include <miscfs/specfs/specdev.h>
69:
70: #include <sys/syscallargs.h>
71:
72: #include <uvm/uvm.h>
73: #include <uvm/uvm_device.h>
74: #include <uvm/uvm_vnode.h>
75:
76: /*
77: * Page align addr and size, returning EINVAL on wraparound.
78: */
79: #define ALIGN_ADDR(addr, size, pageoff) do { \
80: pageoff = (addr & PAGE_MASK); \
81: if (pageoff != 0) { \
82: if (size > SIZE_MAX - pageoff) \
83: return (EINVAL); /* wraparound */ \
84: addr -= pageoff; \
85: size += pageoff; \
86: } \
87: if (size != 0) { \
88: size = (vsize_t)round_page(size); \
89: if (size == 0) \
90: return (EINVAL); /* wraparound */ \
91: } \
92: } while (0)
93:
94: /*
95: * unimplemented VM system calls:
96: */
97:
98: /*
99: * sys_sbrk: sbrk system call.
100: */
101:
102: /* ARGSUSED */
103: int
104: sys_sbrk(p, v, retval)
105: struct proc *p;
106: void *v;
107: register_t *retval;
108: {
109: #if 0
110: struct sys_sbrk_args /* {
111: syscallarg(int) incr;
112: } */ *uap = v;
113: #endif
114:
115: return (ENOSYS);
116: }
117:
118: /*
119: * sys_sstk: sstk system call.
120: */
121:
122: /* ARGSUSED */
123: int
124: sys_sstk(p, v, retval)
125: struct proc *p;
126: void *v;
127: register_t *retval;
128: {
129: #if 0
130: struct sys_sstk_args /* {
131: syscallarg(int) incr;
132: } */ *uap = v;
133: #endif
134:
135: return (ENOSYS);
136: }
137:
138: /*
139: * sys_mquery: provide mapping hints to applications that do fixed mappings
140: *
141: * flags: 0 or MAP_FIXED (MAP_FIXED - means that we insist on this addr and
142: * don't care about PMAP_PREFER or such)
143: * addr: hint where we'd like to place the mapping.
144: * size: size of the mapping
145: * fd: fd of the file we want to map
146: * off: offset within the file
147: */
148:
149: int
150: sys_mquery(p, v, retval)
151: struct proc *p;
152: void *v;
153: register_t *retval;
154: {
155: struct sys_mquery_args /* {
156: syscallarg(void *) addr;
157: syscallarg(size_t) len;
158: syscallarg(int) prot;
159: syscallarg(int) flags;
160: syscallarg(int) fd;
161: syscallarg(long) pad;
162: syscallarg(off_t) pos;
163: } */ *uap = v;
164: struct file *fp;
165: struct uvm_object *uobj;
166: voff_t uoff;
167: int error;
168: vaddr_t vaddr;
169: int flags = 0;
170: vsize_t size;
171: vm_prot_t prot;
172: int fd;
173:
174: vaddr = (vaddr_t) SCARG(uap, addr);
175: prot = SCARG(uap, prot);
176: size = (vsize_t) SCARG(uap, len);
177: fd = SCARG(uap, fd);
178:
179: if ((prot & VM_PROT_ALL) != prot)
180: return (EINVAL);
181:
182: if (SCARG(uap, flags) & MAP_FIXED)
183: flags |= UVM_FLAG_FIXED;
184:
185: if (fd >= 0) {
186: if ((error = getvnode(p->p_fd, fd, &fp)) != 0)
187: return (error);
188: uobj = &((struct vnode *)fp->f_data)->v_uvm.u_obj;
189: uoff = SCARG(uap, pos);
190: } else {
191: fp = NULL;
192: uobj = NULL;
193: uoff = 0;
194: }
195:
196: if (vaddr == 0)
197: vaddr = uvm_map_hint(p, prot);
198:
199: /* prevent a user requested address from falling in heap space */
200: if ((vaddr + size > (vaddr_t)p->p_vmspace->vm_daddr) &&
201: (vaddr < (vaddr_t)p->p_vmspace->vm_daddr + MAXDSIZ)) {
202: if (flags & UVM_FLAG_FIXED) {
203: error = EINVAL;
204: goto done;
205: }
206: vaddr = round_page((vaddr_t)p->p_vmspace->vm_daddr + MAXDSIZ);
207: }
208: again:
209:
210: if (uvm_map_findspace(&p->p_vmspace->vm_map, vaddr, size,
211: &vaddr, uobj, uoff, 0, flags) == NULL) {
212: if (flags & UVM_FLAG_FIXED)
213: error = EINVAL;
214: else
215: error = ENOMEM;
216: } else {
217: /* prevent a returned address from falling in heap space */
218: if ((vaddr + size > (vaddr_t)p->p_vmspace->vm_daddr)
219: && (vaddr < (vaddr_t)p->p_vmspace->vm_daddr + MAXDSIZ)) {
220: vaddr = round_page((vaddr_t)p->p_vmspace->vm_daddr +
221: MAXDSIZ);
222: goto again;
223: }
224: error = 0;
225: *retval = (register_t)(vaddr);
226: }
227: done:
228: if (fp != NULL)
229: FRELE(fp);
230: return (error);
231: }
232:
233: /*
234: * sys_mincore: determine if pages are in core or not.
235: */
236:
237: /* ARGSUSED */
238: int
239: sys_mincore(p, v, retval)
240: struct proc *p;
241: void *v;
242: register_t *retval;
243: {
244: struct sys_mincore_args /* {
245: syscallarg(void *) addr;
246: syscallarg(size_t) len;
247: syscallarg(char *) vec;
248: } */ *uap = v;
249: vm_page_t m;
250: char *vec, pgi;
251: struct uvm_object *uobj;
252: struct vm_amap *amap;
253: struct vm_anon *anon;
254: vm_map_entry_t entry;
255: vaddr_t start, end, lim;
256: vm_map_t map;
257: vsize_t len, npgs;
258: int error = 0;
259:
260: map = &p->p_vmspace->vm_map;
261:
262: start = (vaddr_t)SCARG(uap, addr);
263: len = SCARG(uap, len);
264: vec = SCARG(uap, vec);
265:
266: if (start & PAGE_MASK)
267: return (EINVAL);
268: len = round_page(len);
269: end = start + len;
270: if (end <= start)
271: return (EINVAL);
272:
273: npgs = len >> PAGE_SHIFT;
274:
275: /*
276: * Lock down vec, so our returned status isn't outdated by
277: * storing the status byte for a page.
278: */
279: if ((error = uvm_vslock(p, vec, npgs, VM_PROT_WRITE)) != 0)
280: return (error);
281:
282: vm_map_lock_read(map);
283:
284: if (uvm_map_lookup_entry(map, start, &entry) == FALSE) {
285: error = ENOMEM;
286: goto out;
287: }
288:
289: for (/* nothing */;
290: entry != &map->header && entry->start < end;
291: entry = entry->next) {
292: KASSERT(!UVM_ET_ISSUBMAP(entry));
293: KASSERT(start >= entry->start);
294:
295: /* Make sure there are no holes. */
296: if (entry->end < end &&
297: (entry->next == &map->header ||
298: entry->next->start > entry->end)) {
299: error = ENOMEM;
300: goto out;
301: }
302:
303: lim = end < entry->end ? end : entry->end;
304:
305: /*
306: * Special case for objects with no "real" pages. Those
307: * are always considered resident (mapped devices).
308: */
309: if (UVM_ET_ISOBJ(entry)) {
310: KASSERT(!UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj));
311: if (entry->object.uvm_obj->pgops->pgo_releasepg
312: == NULL) {
313: pgi = 1;
314: for (/* nothing */; start < lim;
315: start += PAGE_SIZE, vec++)
316: copyout(&pgi, vec, sizeof(char));
317: continue;
318: }
319: }
320:
321: amap = entry->aref.ar_amap; /* top layer */
322: uobj = entry->object.uvm_obj; /* bottom layer */
323:
324: if (uobj != NULL)
325: simple_lock(&uobj->vmobjlock);
326:
327: for (/* nothing */; start < lim; start += PAGE_SIZE, vec++) {
328: pgi = 0;
329: if (amap != NULL) {
330: /* Check the top layer first. */
331: anon = amap_lookup(&entry->aref,
332: start - entry->start);
333: /* Don't need to lock anon here. */
334: if (anon != NULL && anon->an_page != NULL) {
335: /*
336: * Anon has the page for this entry
337: * offset.
338: */
339: pgi = 1;
340: }
341: }
342:
343: if (uobj != NULL && pgi == 0) {
344: /* Check the bottom layer. */
345: m = uvm_pagelookup(uobj,
346: entry->offset + (start - entry->start));
347: if (m != NULL) {
348: /*
349: * Object has the page for this entry
350: * offset.
351: */
352: pgi = 1;
353: }
354: }
355:
356: copyout(&pgi, vec, sizeof(char));
357: }
358:
359: if (uobj != NULL)
360: simple_unlock(&uobj->vmobjlock);
361: }
362:
363: out:
364: vm_map_unlock_read(map);
365: uvm_vsunlock(p, SCARG(uap, vec), npgs);
366: return (error);
367: }
368:
369: /*
370: * sys_mmap: mmap system call.
371: *
372: * => file offset and address may not be page aligned
373: * - if MAP_FIXED, offset and address must have remainder mod PAGE_SIZE
374: * - if address isn't page aligned the mapping starts at trunc_page(addr)
375: * and the return value is adjusted up by the page offset.
376: */
377:
378: int
379: sys_mmap(p, v, retval)
380: struct proc *p;
381: void *v;
382: register_t *retval;
383: {
384: struct sys_mmap_args /* {
385: syscallarg(void *) addr;
386: syscallarg(size_t) len;
387: syscallarg(int) prot;
388: syscallarg(int) flags;
389: syscallarg(int) fd;
390: syscallarg(long) pad;
391: syscallarg(off_t) pos;
392: } */ *uap = v;
393: vaddr_t addr;
394: struct vattr va;
395: off_t pos;
396: vsize_t size, pageoff;
397: vm_prot_t prot, maxprot;
398: int flags, fd;
399: vaddr_t vm_min_address = VM_MIN_ADDRESS;
400: struct filedesc *fdp = p->p_fd;
401: struct file *fp = NULL;
402: struct vnode *vp;
403: caddr_t handle;
404: int error;
405:
406: /*
407: * first, extract syscall args from the uap.
408: */
409:
410: addr = (vaddr_t) SCARG(uap, addr);
411: size = (vsize_t) SCARG(uap, len);
412: prot = SCARG(uap, prot);
413: flags = SCARG(uap, flags);
414: fd = SCARG(uap, fd);
415: pos = SCARG(uap, pos);
416:
417: /*
418: * Fixup the old deprecated MAP_COPY into MAP_PRIVATE, and
419: * validate the flags.
420: */
421: if ((prot & VM_PROT_ALL) != prot)
422: return (EINVAL);
423: if ((flags & MAP_FLAGMASK) != flags)
424: return (EINVAL);
425: if (flags & MAP_COPY)
426: flags = (flags & ~MAP_COPY) | MAP_PRIVATE;
427: if ((flags & (MAP_SHARED|MAP_PRIVATE)) == (MAP_SHARED|MAP_PRIVATE))
428: return (EINVAL);
429:
430: /*
431: * align file position and save offset. adjust size.
432: */
433: ALIGN_ADDR(pos, size, pageoff);
434:
435: /*
436: * now check (MAP_FIXED) or get (!MAP_FIXED) the "addr"
437: */
438:
439: if (flags & MAP_FIXED) {
440:
441: /* adjust address by the same amount as we did the offset */
442: addr -= pageoff;
443: if (addr & PAGE_MASK)
444: return (EINVAL); /* not page aligned */
445:
446: if (addr > SIZE_MAX - size)
447: return (EINVAL); /* no wrapping! */
448: if (VM_MAXUSER_ADDRESS > 0 &&
449: (addr + size) > VM_MAXUSER_ADDRESS)
450: return (EINVAL);
451: if (vm_min_address > 0 && addr < vm_min_address)
452: return (EINVAL);
453:
454: } else {
455:
456: /*
457: * not fixed: make sure we skip over the largest possible heap.
458: * we will refine our guess later (e.g. to account for VAC, etc)
459: */
460: if (addr == 0)
461: addr = uvm_map_hint(p, prot);
462: else if (!(flags & MAP_TRYFIXED) &&
463: addr < (vaddr_t)p->p_vmspace->vm_daddr)
464: addr = uvm_map_hint(p, prot);
465: }
466:
467: /*
468: * check for file mappings (i.e. not anonymous) and verify file.
469: */
470: if ((flags & MAP_ANON) == 0) {
471:
472: if ((fp = fd_getfile(fdp, fd)) == NULL)
473: return (EBADF);
474:
475: FREF(fp);
476:
477: if (fp->f_type != DTYPE_VNODE) {
478: error = ENODEV; /* only mmap vnodes! */
479: goto out;
480: }
481: vp = (struct vnode *)fp->f_data; /* convert to vnode */
482:
483: if (vp->v_type != VREG && vp->v_type != VCHR &&
484: vp->v_type != VBLK) {
485: error = ENODEV; /* only REG/CHR/BLK support mmap */
486: goto out;
487: }
488:
489: if (vp->v_type == VREG && (pos + size) < pos) {
490: error = EINVAL; /* no offset wrapping */
491: goto out;
492: }
493:
494: /* special case: catch SunOS style /dev/zero */
495: if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) {
496: flags |= MAP_ANON;
497: FRELE(fp);
498: fp = NULL;
499: goto is_anon;
500: }
501:
502: /*
503: * Old programs may not select a specific sharing type, so
504: * default to an appropriate one.
505: *
506: * XXX: how does MAP_ANON fit in the picture?
507: */
508: if ((flags & (MAP_SHARED|MAP_PRIVATE)) == 0) {
509: #if defined(DEBUG)
510: printf("WARNING: defaulted mmap() share type to "
511: "%s (pid %d comm %s)\n", vp->v_type == VCHR ?
512: "MAP_SHARED" : "MAP_PRIVATE", p->p_pid,
513: p->p_comm);
514: #endif
515: if (vp->v_type == VCHR)
516: flags |= MAP_SHARED; /* for a device */
517: else
518: flags |= MAP_PRIVATE; /* for a file */
519: }
520:
521: /*
522: * MAP_PRIVATE device mappings don't make sense (and aren't
523: * supported anyway). However, some programs rely on this,
524: * so just change it to MAP_SHARED.
525: */
526: if (vp->v_type == VCHR && (flags & MAP_PRIVATE) != 0) {
527: flags = (flags & ~MAP_PRIVATE) | MAP_SHARED;
528: }
529:
530: /*
531: * now check protection
532: */
533:
534: maxprot = VM_PROT_EXECUTE;
535:
536: /* check read access */
537: if (fp->f_flag & FREAD)
538: maxprot |= VM_PROT_READ;
539: else if (prot & PROT_READ) {
540: error = EACCES;
541: goto out;
542: }
543:
544: /* check write access, shared case first */
545: if (flags & MAP_SHARED) {
546: /*
547: * if the file is writable, only add PROT_WRITE to
548: * maxprot if the file is not immutable, append-only.
549: * otherwise, if we have asked for PROT_WRITE, return
550: * EPERM.
551: */
552: if (fp->f_flag & FWRITE) {
553: if ((error =
554: VOP_GETATTR(vp, &va, p->p_ucred, p)))
555: goto out;
556: if ((va.va_flags & (IMMUTABLE|APPEND)) == 0)
557: maxprot |= VM_PROT_WRITE;
558: else if (prot & PROT_WRITE) {
559: error = EPERM;
560: goto out;
561: }
562: } else if (prot & PROT_WRITE) {
563: error = EACCES;
564: goto out;
565: }
566: } else {
567: /* MAP_PRIVATE mappings can always write to */
568: maxprot |= VM_PROT_WRITE;
569: }
570:
571: /*
572: * set handle to vnode
573: */
574:
575: handle = (caddr_t)vp;
576:
577: } else { /* MAP_ANON case */
578: /*
579: * XXX What do we do about (MAP_SHARED|MAP_PRIVATE) == 0?
580: */
581: if (fd != -1) {
582: error = EINVAL;
583: goto out;
584: }
585:
586: is_anon: /* label for SunOS style /dev/zero */
587: handle = NULL;
588: maxprot = VM_PROT_ALL;
589: pos = 0;
590: }
591:
592: if ((flags & MAP_ANON) != 0 ||
593: ((flags & MAP_PRIVATE) != 0 && (prot & PROT_WRITE) != 0)) {
594: if (size >
595: (p->p_rlimit[RLIMIT_DATA].rlim_cur - ctob(p->p_vmspace->vm_dused))) {
596: error = ENOMEM;
597: goto out;
598: }
599: }
600:
601: /*
602: * now let kernel internal function uvm_mmap do the work.
603: */
604:
605: error = uvm_mmap(&p->p_vmspace->vm_map, &addr, size, prot, maxprot,
606: flags, handle, pos, p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur, p);
607:
608: if (error == 0)
609: /* remember to add offset */
610: *retval = (register_t)(addr + pageoff);
611:
612: out:
613: if (fp)
614: FRELE(fp);
615: return (error);
616: }
617:
618: /*
619: * sys_msync: the msync system call (a front-end for flush)
620: */
621:
622: int
623: sys_msync(p, v, retval)
624: struct proc *p;
625: void *v;
626: register_t *retval;
627: {
628: struct sys_msync_args /* {
629: syscallarg(void *) addr;
630: syscallarg(size_t) len;
631: syscallarg(int) flags;
632: } */ *uap = v;
633: vaddr_t addr;
634: vsize_t size, pageoff;
635: vm_map_t map;
636: int rv, flags, uvmflags;
637:
638: /*
639: * extract syscall args from the uap
640: */
641:
642: addr = (vaddr_t)SCARG(uap, addr);
643: size = (vsize_t)SCARG(uap, len);
644: flags = SCARG(uap, flags);
645:
646: /* sanity check flags */
647: if ((flags & ~(MS_ASYNC | MS_SYNC | MS_INVALIDATE)) != 0 ||
648: (flags & (MS_ASYNC | MS_SYNC | MS_INVALIDATE)) == 0 ||
649: (flags & (MS_ASYNC | MS_SYNC)) == (MS_ASYNC | MS_SYNC))
650: return (EINVAL);
651: if ((flags & (MS_ASYNC | MS_SYNC)) == 0)
652: flags |= MS_SYNC;
653:
654: /*
655: * align the address to a page boundary, and adjust the size accordingly
656: */
657: ALIGN_ADDR(addr, size, pageoff);
658: if (addr > SIZE_MAX - size)
659: return (EINVAL); /* disallow wrap-around. */
660:
661: /*
662: * get map
663: */
664:
665: map = &p->p_vmspace->vm_map;
666:
667: /*
668: * XXXCDC: do we really need this semantic?
669: *
670: * XXX Gak! If size is zero we are supposed to sync "all modified
671: * pages with the region containing addr". Unfortunately, we
672: * don't really keep track of individual mmaps so we approximate
673: * by flushing the range of the map entry containing addr.
674: * This can be incorrect if the region splits or is coalesced
675: * with a neighbor.
676: */
677: if (size == 0) {
678: vm_map_entry_t entry;
679:
680: vm_map_lock_read(map);
681: rv = uvm_map_lookup_entry(map, addr, &entry);
682: if (rv == TRUE) {
683: addr = entry->start;
684: size = entry->end - entry->start;
685: }
686: vm_map_unlock_read(map);
687: if (rv == FALSE)
688: return (EINVAL);
689: }
690:
691: /*
692: * translate MS_ flags into PGO_ flags
693: */
694: uvmflags = PGO_CLEANIT;
695: if (flags & MS_INVALIDATE)
696: uvmflags |= PGO_FREE;
697: if (flags & MS_SYNC)
698: uvmflags |= PGO_SYNCIO;
699: else
700: uvmflags |= PGO_SYNCIO; /* XXXCDC: force sync for now! */
701:
702: return (uvm_map_clean(map, addr, addr+size, uvmflags));
703: }
704:
705: /*
706: * sys_munmap: unmap a users memory
707: */
708:
709: int
710: sys_munmap(p, v, retval)
711: struct proc *p;
712: void *v;
713: register_t *retval;
714: {
715: struct sys_munmap_args /* {
716: syscallarg(void *) addr;
717: syscallarg(size_t) len;
718: } */ *uap = v;
719: vaddr_t addr;
720: vsize_t size, pageoff;
721: vm_map_t map;
722: vaddr_t vm_min_address = VM_MIN_ADDRESS;
723: struct vm_map_entry *dead_entries;
724:
725: /*
726: * get syscall args...
727: */
728:
729: addr = (vaddr_t) SCARG(uap, addr);
730: size = (vsize_t) SCARG(uap, len);
731:
732: /*
733: * align the address to a page boundary, and adjust the size accordingly
734: */
735: ALIGN_ADDR(addr, size, pageoff);
736:
737: /*
738: * Check for illegal addresses. Watch out for address wrap...
739: * Note that VM_*_ADDRESS are not constants due to casts (argh).
740: */
741: if (addr > SIZE_MAX - size)
742: return (EINVAL);
743: if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
744: return (EINVAL);
745: if (vm_min_address > 0 && addr < vm_min_address)
746: return (EINVAL);
747: map = &p->p_vmspace->vm_map;
748:
749:
750: vm_map_lock(map); /* lock map so we can checkprot */
751:
752: /*
753: * interesting system call semantic: make sure entire range is
754: * allocated before allowing an unmap.
755: */
756:
757: if (!uvm_map_checkprot(map, addr, addr + size, VM_PROT_NONE)) {
758: vm_map_unlock(map);
759: return (EINVAL);
760: }
761:
762: /*
763: * doit!
764: */
765: uvm_unmap_remove(map, addr, addr + size, &dead_entries, p);
766:
767: vm_map_unlock(map); /* and unlock */
768:
769: if (dead_entries != NULL)
770: uvm_unmap_detach(dead_entries, 0);
771:
772: return (0);
773: }
774:
775: /*
776: * sys_mprotect: the mprotect system call
777: */
778:
779: int
780: sys_mprotect(p, v, retval)
781: struct proc *p;
782: void *v;
783: register_t *retval;
784: {
785: struct sys_mprotect_args /* {
786: syscallarg(void *) addr;
787: syscallarg(size_t) len;
788: syscallarg(int) prot;
789: } */ *uap = v;
790: vaddr_t addr;
791: vsize_t size, pageoff;
792: vm_prot_t prot;
793:
794: /*
795: * extract syscall args from uap
796: */
797:
798: addr = (vaddr_t)SCARG(uap, addr);
799: size = (vsize_t)SCARG(uap, len);
800: prot = SCARG(uap, prot);
801:
802: if ((prot & VM_PROT_ALL) != prot)
803: return (EINVAL);
804:
805: /*
806: * align the address to a page boundary, and adjust the size accordingly
807: */
808: ALIGN_ADDR(addr, size, pageoff);
809: if (addr > SIZE_MAX - size)
810: return (EINVAL); /* disallow wrap-around. */
811:
812: return (uvm_map_protect(&p->p_vmspace->vm_map, addr, addr+size,
813: prot, FALSE));
814: }
815:
816: /*
817: * sys_minherit: the minherit system call
818: */
819:
820: int
821: sys_minherit(p, v, retval)
822: struct proc *p;
823: void *v;
824: register_t *retval;
825: {
826: struct sys_minherit_args /* {
827: syscallarg(void *) addr;
828: syscallarg(size_t) len;
829: syscallarg(int) inherit;
830: } */ *uap = v;
831: vaddr_t addr;
832: vsize_t size, pageoff;
833: vm_inherit_t inherit;
834:
835: addr = (vaddr_t)SCARG(uap, addr);
836: size = (vsize_t)SCARG(uap, len);
837: inherit = SCARG(uap, inherit);
838:
839: /*
840: * align the address to a page boundary, and adjust the size accordingly
841: */
842: ALIGN_ADDR(addr, size, pageoff);
843: if (addr > SIZE_MAX - size)
844: return (EINVAL); /* disallow wrap-around. */
845:
846: return (uvm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size,
847: inherit));
848: }
849:
850: /*
851: * sys_madvise: give advice about memory usage.
852: */
853:
854: /* ARGSUSED */
855: int
856: sys_madvise(p, v, retval)
857: struct proc *p;
858: void *v;
859: register_t *retval;
860: {
861: struct sys_madvise_args /* {
862: syscallarg(void *) addr;
863: syscallarg(size_t) len;
864: syscallarg(int) behav;
865: } */ *uap = v;
866: vaddr_t addr;
867: vsize_t size, pageoff;
868: int advice, error;
869:
870: addr = (vaddr_t)SCARG(uap, addr);
871: size = (vsize_t)SCARG(uap, len);
872: advice = SCARG(uap, behav);
873:
874: /*
875: * align the address to a page boundary, and adjust the size accordingly
876: */
877: ALIGN_ADDR(addr, size, pageoff);
878: if (addr > SIZE_MAX - size)
879: return (EINVAL); /* disallow wrap-around. */
880:
881: switch (advice) {
882: case MADV_NORMAL:
883: case MADV_RANDOM:
884: case MADV_SEQUENTIAL:
885: error = uvm_map_advice(&p->p_vmspace->vm_map, addr,
886: addr + size, advice);
887: break;
888:
889: case MADV_WILLNEED:
890: /*
891: * Activate all these pages, pre-faulting them in if
892: * necessary.
893: */
894: /*
895: * XXX IMPLEMENT ME.
896: * Should invent a "weak" mode for uvm_fault()
897: * which would only do the PGO_LOCKED pgo_get().
898: */
899: return (0);
900:
901: case MADV_DONTNEED:
902: /*
903: * Deactivate all these pages. We don't need them
904: * any more. We don't, however, toss the data in
905: * the pages.
906: */
907: error = uvm_map_clean(&p->p_vmspace->vm_map, addr, addr + size,
908: PGO_DEACTIVATE);
909: break;
910:
911: case MADV_FREE:
912: /*
913: * These pages contain no valid data, and may be
914: * garbage-collected. Toss all resources, including
915: * any swap space in use.
916: */
917: error = uvm_map_clean(&p->p_vmspace->vm_map, addr, addr + size,
918: PGO_FREE);
919: break;
920:
921: case MADV_SPACEAVAIL:
922: /*
923: * XXXMRG What is this? I think it's:
924: *
925: * Ensure that we have allocated backing-store
926: * for these pages.
927: *
928: * This is going to require changes to the page daemon,
929: * as it will free swap space allocated to pages in core.
930: * There's also what to do for device/file/anonymous memory.
931: */
932: return (EINVAL);
933:
934: default:
935: return (EINVAL);
936: }
937:
938: return (error);
939: }
940:
941: /*
942: * sys_mlock: memory lock
943: */
944:
945: int
946: sys_mlock(p, v, retval)
947: struct proc *p;
948: void *v;
949: register_t *retval;
950: {
951: struct sys_mlock_args /* {
952: syscallarg(const void *) addr;
953: syscallarg(size_t) len;
954: } */ *uap = v;
955: vaddr_t addr;
956: vsize_t size, pageoff;
957: int error;
958:
959: /*
960: * extract syscall args from uap
961: */
962: addr = (vaddr_t)SCARG(uap, addr);
963: size = (vsize_t)SCARG(uap, len);
964:
965: /*
966: * align the address to a page boundary and adjust the size accordingly
967: */
968: ALIGN_ADDR(addr, size, pageoff);
969: if (addr > SIZE_MAX - size)
970: return (EINVAL); /* disallow wrap-around. */
971:
972: if (atop(size) + uvmexp.wired > uvmexp.wiredmax)
973: return (EAGAIN);
974:
975: #ifdef pmap_wired_count
976: if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) >
977: p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur)
978: return (EAGAIN);
979: #else
980: if ((error = suser(p, 0)) != 0)
981: return (error);
982: #endif
983:
984: error = uvm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, FALSE,
985: 0);
986: return (error == 0 ? 0 : ENOMEM);
987: }
988:
989: /*
990: * sys_munlock: unlock wired pages
991: */
992:
993: int
994: sys_munlock(p, v, retval)
995: struct proc *p;
996: void *v;
997: register_t *retval;
998: {
999: struct sys_munlock_args /* {
1000: syscallarg(const void *) addr;
1001: syscallarg(size_t) len;
1002: } */ *uap = v;
1003: vaddr_t addr;
1004: vsize_t size, pageoff;
1005: int error;
1006:
1007: /*
1008: * extract syscall args from uap
1009: */
1010:
1011: addr = (vaddr_t)SCARG(uap, addr);
1012: size = (vsize_t)SCARG(uap, len);
1013:
1014: /*
1015: * align the address to a page boundary, and adjust the size accordingly
1016: */
1017: ALIGN_ADDR(addr, size, pageoff);
1018: if (addr > SIZE_MAX - size)
1019: return (EINVAL); /* disallow wrap-around. */
1020:
1021: #ifndef pmap_wired_count
1022: if ((error = suser(p, 0)) != 0)
1023: return (error);
1024: #endif
1025:
1026: error = uvm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, TRUE,
1027: 0);
1028: return (error == 0 ? 0 : ENOMEM);
1029: }
1030:
1031: /*
1032: * sys_mlockall: lock all pages mapped into an address space.
1033: */
1034:
1035: int
1036: sys_mlockall(p, v, retval)
1037: struct proc *p;
1038: void *v;
1039: register_t *retval;
1040: {
1041: struct sys_mlockall_args /* {
1042: syscallarg(int) flags;
1043: } */ *uap = v;
1044: int error, flags;
1045:
1046: flags = SCARG(uap, flags);
1047:
1048: if (flags == 0 ||
1049: (flags & ~(MCL_CURRENT|MCL_FUTURE)) != 0)
1050: return (EINVAL);
1051:
1052: #ifndef pmap_wired_count
1053: if ((error = suser(p, 0)) != 0)
1054: return (error);
1055: #endif
1056:
1057: error = uvm_map_pageable_all(&p->p_vmspace->vm_map, flags,
1058: p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
1059: if (error != 0 && error != ENOMEM)
1060: return (EAGAIN);
1061: return (error);
1062: }
1063:
1064: /*
1065: * sys_munlockall: unlock all pages mapped into an address space.
1066: */
1067:
1068: int
1069: sys_munlockall(p, v, retval)
1070: struct proc *p;
1071: void *v;
1072: register_t *retval;
1073: {
1074:
1075: (void) uvm_map_pageable_all(&p->p_vmspace->vm_map, 0, 0);
1076: return (0);
1077: }
1078:
1079: /*
1080: * uvm_mmap: internal version of mmap
1081: *
1082: * - used by sys_mmap, exec, and sysv shm
1083: * - handle is a vnode pointer or NULL for MAP_ANON (XXX: not true,
1084: * sysv shm uses "named anonymous memory")
1085: * - caller must page-align the file offset
1086: */
1087:
1088: int
1089: uvm_mmap(map, addr, size, prot, maxprot, flags, handle, foff, locklimit, p)
1090: vm_map_t map;
1091: vaddr_t *addr;
1092: vsize_t size;
1093: vm_prot_t prot, maxprot;
1094: int flags;
1095: caddr_t handle; /* XXX: VNODE? */
1096: voff_t foff;
1097: vsize_t locklimit;
1098: struct proc *p;
1099: {
1100: struct uvm_object *uobj;
1101: struct vnode *vp;
1102: int error;
1103: int advice = UVM_ADV_NORMAL;
1104: uvm_flag_t uvmflag = 0;
1105: vsize_t align = 0; /* userland page size */
1106:
1107: /*
1108: * check params
1109: */
1110:
1111: if (size == 0)
1112: return(0);
1113: if (foff & PAGE_MASK)
1114: return(EINVAL);
1115: if ((prot & maxprot) != prot)
1116: return(EINVAL);
1117:
1118: /*
1119: * for non-fixed mappings, round off the suggested address.
1120: * for fixed mappings, check alignment and zap old mappings.
1121: */
1122:
1123: if ((flags & MAP_FIXED) == 0) {
1124: *addr = round_page(*addr); /* round */
1125: } else {
1126: if (*addr & PAGE_MASK)
1127: return(EINVAL);
1128: uvmflag |= UVM_FLAG_FIXED;
1129: uvm_unmap_p(map, *addr, *addr + size, p); /* zap! */
1130: }
1131:
1132: /*
1133: * handle anon vs. non-anon mappings. for non-anon mappings attach
1134: * to underlying vm object.
1135: */
1136:
1137: if (flags & MAP_ANON) {
1138: if ((flags & MAP_FIXED) == 0 && size >= __LDPGSZ)
1139: align = __LDPGSZ;
1140: foff = UVM_UNKNOWN_OFFSET;
1141: uobj = NULL;
1142: if ((flags & MAP_SHARED) == 0)
1143: /* XXX: defer amap create */
1144: uvmflag |= UVM_FLAG_COPYONW;
1145: else
1146: /* shared: create amap now */
1147: uvmflag |= UVM_FLAG_OVERLAY;
1148:
1149: } else {
1150:
1151: vp = (struct vnode *) handle; /* get vnode */
1152: if (vp->v_type != VCHR) {
1153: uobj = uvn_attach((void *) vp, (flags & MAP_SHARED) ?
1154: maxprot : (maxprot & ~VM_PROT_WRITE));
1155:
1156: #ifndef UBC
1157: /*
1158: * XXXCDC: hack from old code
1159: * don't allow vnodes which have been mapped
1160: * shared-writeable to persist [forces them to be
1161: * flushed out when last reference goes].
1162: * XXXCDC: interesting side effect: avoids a bug.
1163: * note that in WRITE [ufs_readwrite.c] that we
1164: * allocate buffer, uncache, and then do the write.
1165: * the problem with this is that if the uncache causes
1166: * VM data to be flushed to the same area of the file
1167: * we are writing to... in that case we've got the
1168: * buffer locked and our process goes to sleep forever.
1169: *
1170: * XXXCDC: checking maxprot protects us from the
1171: * "persistbug" program but this is not a long term
1172: * solution.
1173: *
1174: * XXXCDC: we don't bother calling uncache with the vp
1175: * VOP_LOCKed since we know that we are already
1176: * holding a valid reference to the uvn (from the
1177: * uvn_attach above), and thus it is impossible for
1178: * the uncache to kill the uvn and trigger I/O.
1179: */
1180: if (flags & MAP_SHARED) {
1181: if ((prot & VM_PROT_WRITE) ||
1182: (maxprot & VM_PROT_WRITE)) {
1183: uvm_vnp_uncache(vp);
1184: }
1185: }
1186: #else
1187: /* XXX for now, attach doesn't gain a ref */
1188: VREF(vp);
1189: #endif
1190: } else {
1191: uobj = udv_attach((void *) &vp->v_rdev,
1192: (flags & MAP_SHARED) ? maxprot :
1193: (maxprot & ~VM_PROT_WRITE), foff, size);
1194: /*
1195: * XXX Some devices don't like to be mapped with
1196: * XXX PROT_EXEC, but we don't really have a
1197: * XXX better way of handling this, right now
1198: */
1199: if (uobj == NULL && (prot & PROT_EXEC) == 0) {
1200: maxprot &= ~VM_PROT_EXECUTE;
1201: uobj = udv_attach((void *) &vp->v_rdev,
1202: (flags & MAP_SHARED) ? maxprot :
1203: (maxprot & ~VM_PROT_WRITE), foff, size);
1204: }
1205: advice = UVM_ADV_RANDOM;
1206: }
1207:
1208: if (uobj == NULL)
1209: return((vp->v_type == VREG) ? ENOMEM : EINVAL);
1210:
1211: if ((flags & MAP_SHARED) == 0)
1212: uvmflag |= UVM_FLAG_COPYONW;
1213: }
1214:
1215: /*
1216: * set up mapping flags
1217: */
1218:
1219: uvmflag = UVM_MAPFLAG(prot, maxprot,
1220: (flags & MAP_SHARED) ? UVM_INH_SHARE : UVM_INH_COPY,
1221: advice, uvmflag);
1222:
1223: error = uvm_map_p(map, addr, size, uobj, foff, align, uvmflag, p);
1224:
1225: if (error == 0) {
1226: /*
1227: * POSIX 1003.1b -- if our address space was configured
1228: * to lock all future mappings, wire the one we just made.
1229: */
1230: if (prot == VM_PROT_NONE) {
1231: /*
1232: * No more work to do in this case.
1233: */
1234: return (0);
1235: }
1236:
1237: vm_map_lock(map);
1238:
1239: if (map->flags & VM_MAP_WIREFUTURE) {
1240: if ((atop(size) + uvmexp.wired) > uvmexp.wiredmax
1241: #ifdef pmap_wired_count
1242: || (locklimit != 0 && (size +
1243: ptoa(pmap_wired_count(vm_map_pmap(map)))) >
1244: locklimit)
1245: #endif
1246: ) {
1247: error = ENOMEM;
1248: vm_map_unlock(map);
1249: /* unmap the region! */
1250: uvm_unmap(map, *addr, *addr + size);
1251: goto bad;
1252: }
1253: /*
1254: * uvm_map_pageable() always returns the map
1255: * unlocked.
1256: */
1257: error = uvm_map_pageable(map, *addr, *addr + size,
1258: FALSE, UVM_LK_ENTER);
1259: if (error != 0) {
1260: /* unmap the region! */
1261: uvm_unmap(map, *addr, *addr + size);
1262: goto bad;
1263: }
1264: return (0);
1265: }
1266:
1267: vm_map_unlock(map);
1268:
1269: return (0);
1270: }
1271:
1272: /*
1273: * errors: first detach from the uobj, if any.
1274: */
1275:
1276: if (uobj)
1277: uobj->pgops->pgo_detach(uobj);
1278:
1279: bad:
1280: return (error);
1281: }
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