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Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
67 lines
1.8 KiB
C
67 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Optimized memory copy routines.
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*
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* Copyright (C) 2004 Randolph Chung <tausq@debian.org>
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* Copyright (C) 2013-2017 Helge Deller <deller@gmx.de>
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*
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* Portions derived from the GNU C Library
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* Copyright (C) 1991, 1997, 2003 Free Software Foundation, Inc.
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*/
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#include <linux/module.h>
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#include <linux/compiler.h>
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#include <linux/uaccess.h>
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#define get_user_space() (uaccess_kernel() ? 0 : mfsp(3))
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#define get_kernel_space() (0)
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/* Returns 0 for success, otherwise, returns number of bytes not transferred. */
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extern unsigned long pa_memcpy(void *dst, const void *src,
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unsigned long len);
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unsigned long raw_copy_to_user(void __user *dst, const void *src,
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unsigned long len)
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{
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mtsp(get_kernel_space(), 1);
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mtsp(get_user_space(), 2);
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return pa_memcpy((void __force *)dst, src, len);
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}
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EXPORT_SYMBOL(raw_copy_to_user);
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unsigned long raw_copy_from_user(void *dst, const void __user *src,
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unsigned long len)
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{
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mtsp(get_user_space(), 1);
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mtsp(get_kernel_space(), 2);
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return pa_memcpy(dst, (void __force *)src, len);
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}
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EXPORT_SYMBOL(raw_copy_from_user);
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unsigned long raw_copy_in_user(void __user *dst, const void __user *src, unsigned long len)
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{
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mtsp(get_user_space(), 1);
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mtsp(get_user_space(), 2);
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return pa_memcpy((void __force *)dst, (void __force *)src, len);
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}
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void * memcpy(void * dst,const void *src, size_t count)
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{
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mtsp(get_kernel_space(), 1);
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mtsp(get_kernel_space(), 2);
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pa_memcpy(dst, src, count);
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return dst;
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}
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EXPORT_SYMBOL(raw_copy_in_user);
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EXPORT_SYMBOL(memcpy);
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bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
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{
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if ((unsigned long)unsafe_src < PAGE_SIZE)
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return false;
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/* check for I/O space F_EXTEND(0xfff00000) access as well? */
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return true;
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}
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