kernel/syscall/getpagesizes.c

   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 2007 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 #include <sys/types.h>
  29 #include <sys/systm.h>
  30 #include <vm/page.h>
  31 #include <sys/errno.h>
  32
  33 /*
  34  * Return supported page sizes.
  35  */
  36 int
  37 getpagesizes(int legacy, size_t *buf, int nelem)
  38 {
  39         int i, pagesizes = page_num_user_pagesizes(legacy);
  40         size_t *pgsza;
  41
  42         if (nelem < 0) {
  43                 return (set_errno(EINVAL));
  44         }
  45         if (nelem == 0 && buf != NULL) {
  46                 return (set_errno(EINVAL));
  47         }
  48         if (nelem == 0 && buf == NULL) {
  49                 return (pagesizes);
  50         }
  51         if (buf == NULL) {
  52                 return (set_errno(EINVAL));
  53         }
  54         if (nelem > pagesizes) {
  55                 nelem = pagesizes;
  56         }
  57         pgsza = kmem_alloc(sizeof (*pgsza) * nelem, KM_SLEEP);
  58         for (i = 0; i < nelem; i++) {
  59                 pgsza[i] = page_get_user_pagesize(i);
  60         }
  61         if (copyout(pgsza, buf, nelem * sizeof (*pgsza)) != 0) {
  62                 kmem_free(pgsza, sizeof (*pgsza) * nelem);
  63                 return (set_errno(EFAULT));
  64         }
  65         kmem_free(pgsza, sizeof (*pgsza) * nelem);
  66         return (nelem);
  67 }
  68
  69 #if defined(_SYSCALL32_IMPL)
  70
  71 /*
  72  * Some future platforms will support page sizes larger than
  73  * a 32-bit address space.
  74  */
  75 int
  76 getpagesizes32(int legacy, size32_t *buf, int nelem)
  77 {
  78         int i, pagesizes = page_num_user_pagesizes(legacy);
  79         size32_t *pgsza32;
  80         size_t pgsz;
  81         int rc;
  82
  83         if (nelem < 0) {
  84                 return (set_errno(EINVAL));
  85         }
  86         if (nelem == 0 && buf != NULL) {
  87                 return (set_errno(EINVAL));
  88         }
  89
  90         pgsza32 = kmem_alloc(sizeof (*pgsza32) * pagesizes, KM_SLEEP);
  91         for (i = 0; i < pagesizes; i++) {
  92                 pgsz = page_get_user_pagesize(i);
  93                 pgsza32[i] = (size32_t)pgsz;
  94                 if (pgsz > (size32_t)-1) {
  95                         pagesizes = i - 1;
  96                         break;
  97                 }
  98         }
  99         ASSERT(pagesizes > 0);
 100         ASSERT(page_get_user_pagesize(pagesizes - 1) <= (size32_t)-1);
 101         if (nelem > pagesizes) {
 102                 nelem = pagesizes;
 103         }
 104         if (nelem == 0 && buf == NULL) {
 105                 rc = pagesizes;
 106                 goto done;
 107         }
 108         if (buf == NULL) {
 109                 rc = set_errno(EINVAL);
 110                 goto done;
 111         }
 112         if (copyout(pgsza32, buf, nelem * sizeof (*pgsza32)) != 0) {
 113                 rc = set_errno(EFAULT);
 114                 goto done;
 115         }
 116         rc = nelem;
 117 done:
 118         kmem_free(pgsza32, sizeof (*pgsza32) *
 119             page_num_user_pagesizes(legacy));
 120         return (rc);
 121 }
 122 #endif