kernel/generic/src/syscall/copy.c

   1 /*
   2  * Copyright (c) 2006 Jakub Jermar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup generic
  30  * @{
  31  */
  32
  33 /**
  34  * @file
  35  * @brief       Copying between kernel and userspace.
  36  *
  37  * This file contains sanitized functions for copying data
  38  * between kernel and userspace.
  39  */
  40
  41 #include <syscall/copy.h>
  42 #include <proc/thread.h>
  43 #include <mm/as.h>
  44 #include <macros.h>
  45 #include <arch.h>
  46 #include <errno.h>
  47 #include <typedefs.h>
  48
  49 /** Copy data from userspace to kernel.
  50  *
  51  * Provisions are made to return value even after page fault.
  52  *
  53  * This function can be called only from syscall.
  54  *
  55  * @param dst Destination kernel address.
  56  * @param uspace_src Source userspace address.
  57  * @param size Size of the data to be copied.
  58  *
  59  * @return 0 on success or error code from @ref errno.h.
  60  */
  61 int copy_from_uspace(void *dst, const void *uspace_src, size_t size)
  62 {
  63         ipl_t ipl;
  64         int rc;
  65
  66         ASSERT(THREAD);
  67         ASSERT(!THREAD->in_copy_from_uspace);
  68
  69         if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
  70                 if (overlaps((uintptr_t) uspace_src, size,
  71                         KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START)) {
  72                         /*
  73                          * The userspace source block conflicts with kernel address space.
  74                          */
  75                         return EPERM;
  76                 }
  77         }
  78
  79         ipl = interrupts_disable();
  80         THREAD->in_copy_from_uspace = true;
  81
  82         rc = memcpy_from_uspace(dst, uspace_src, size);
  83
  84         THREAD->in_copy_from_uspace = false;
  85
  86         interrupts_restore(ipl);
  87         return !rc ? EPERM : 0;
  88 }
  89
  90 /** Copy data from kernel to userspace.
  91  *
  92  * Provisions are made to return value even after page fault.
  93  *
  94  * This function can be called only from syscall.
  95  *
  96  * @param uspace_dst Destination userspace address.
  97  * @param src Source kernel address.
  98  * @param size Size of the data to be copied.
  99  *
 100  * @return 0 on success or error code from @ref errno.h.
 101  */
 102 int copy_to_uspace(void *uspace_dst, const void *src, size_t size)
 103 {
 104         ipl_t ipl;
 105         int rc;
 106
 107         ASSERT(THREAD);
 108         ASSERT(!THREAD->in_copy_to_uspace);
 109
 110         if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
 111                 if (overlaps((uintptr_t) uspace_dst, size,
 112                         KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START)) {
 113                         /*
 114                          * The userspace destination block conflicts with kernel address space.
 115                          */
 116                         return EPERM;
 117                 }
 118         }
 119
 120         ipl = interrupts_disable();
 121         THREAD->in_copy_to_uspace = true;
 122
 123         rc = memcpy_to_uspace(uspace_dst, src, size);
 124
 125         THREAD->in_copy_to_uspace = false;
 126
 127         interrupts_restore(ipl);
 128         return !rc ? EPERM : 0;
 129 }
 130
 131 /** @}
 132  */