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