cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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memcpy.c (1585B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *    Optimized memory copy routines.
      4 *
      5 *    Copyright (C) 2004 Randolph Chung <tausq@debian.org>
      6 *    Copyright (C) 2013-2017 Helge Deller <deller@gmx.de>
      7 *
      8 *    Portions derived from the GNU C Library
      9 *    Copyright (C) 1991, 1997, 2003 Free Software Foundation, Inc.
     10 */
     11
     12#include <linux/module.h>
     13#include <linux/compiler.h>
     14#include <linux/uaccess.h>
     15
     16#define get_user_space()	mfsp(SR_USER)
     17#define get_kernel_space()	SR_KERNEL
     18
     19/* Returns 0 for success, otherwise, returns number of bytes not transferred. */
     20extern unsigned long pa_memcpy(void *dst, const void *src,
     21				unsigned long len);
     22
     23unsigned long raw_copy_to_user(void __user *dst, const void *src,
     24			       unsigned long len)
     25{
     26	mtsp(get_kernel_space(), SR_TEMP1);
     27	mtsp(get_user_space(), SR_TEMP2);
     28	return pa_memcpy((void __force *)dst, src, len);
     29}
     30EXPORT_SYMBOL(raw_copy_to_user);
     31
     32unsigned long raw_copy_from_user(void *dst, const void __user *src,
     33			       unsigned long len)
     34{
     35	mtsp(get_user_space(), SR_TEMP1);
     36	mtsp(get_kernel_space(), SR_TEMP2);
     37	return pa_memcpy(dst, (void __force *)src, len);
     38}
     39EXPORT_SYMBOL(raw_copy_from_user);
     40
     41void * memcpy(void * dst,const void *src, size_t count)
     42{
     43	mtsp(get_kernel_space(), SR_TEMP1);
     44	mtsp(get_kernel_space(), SR_TEMP2);
     45	pa_memcpy(dst, src, count);
     46	return dst;
     47}
     48
     49EXPORT_SYMBOL(memcpy);
     50
     51bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
     52{
     53	if ((unsigned long)unsafe_src < PAGE_SIZE)
     54		return false;
     55	/* check for I/O space F_EXTEND(0xfff00000) access as well? */
     56	return true;
     57}