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* Copyright (c) 2006 Jakub Jermar
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* - The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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/** @addtogroup generic
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* @brief Copying between kernel and userspace.
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* This file contains sanitized functions for copying data
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* between kernel and userspace.
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#include <syscall/copy.h>
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#include <proc/thread.h>
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/** Copy data from userspace to kernel.
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* Provisions are made to return value even after page fault.
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* This function can be called only from syscall.
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* @param dst Destination kernel address.
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* @param uspace_src Source userspace address.
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* @param size Size of the data to be copied.
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* @return 0 on success or error code from @ref errno.h.
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int copy_from_uspace(void *dst, const void *uspace_src, size_t size)
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ASSERT(!THREAD->in_copy_from_uspace);
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if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
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if (overlaps((uintptr_t) uspace_src, size,
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KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START)) {
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* The userspace source block conflicts with kernel address space.
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ipl = interrupts_disable();
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THREAD->in_copy_from_uspace = true;
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rc = memcpy_from_uspace(dst, uspace_src, size);
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THREAD->in_copy_from_uspace = false;
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interrupts_restore(ipl);
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return !rc ? EPERM : 0;
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/** Copy data from kernel to userspace.
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* Provisions are made to return value even after page fault.
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* This function can be called only from syscall.
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* @param uspace_dst Destination userspace address.
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* @param src Source kernel address.
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* @param size Size of the data to be copied.
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* @return 0 on success or error code from @ref errno.h.
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int copy_to_uspace(void *uspace_dst, const void *src, size_t size)
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ASSERT(!THREAD->in_copy_to_uspace);
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if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
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if (overlaps((uintptr_t) uspace_dst, size,
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KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START)) {
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* The userspace destination block conflicts with kernel address space.
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ipl = interrupts_disable();
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THREAD->in_copy_to_uspace = true;
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rc = memcpy_to_uspace(uspace_dst, src, size);
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THREAD->in_copy_to_uspace = false;
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interrupts_restore(ipl);
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return !rc ? EPERM : 0;