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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copy_from_user.S (1687B)

      1/* SPDX-License-Identifier: GPL-2.0-only */
      2/*
      3 * User memory copy functions for kernel
      4 *
      5 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
      6 */
      7
      8/*
      9 * The right way to do this involves valignb
     10 * The easy way to do this is only speed up src/dest similar alignment.
     11 */
     12
     13/*
     14 * Copy to/from user are the same, except that for packets with a load and
     15 * a store, I don't know how to tell which kind of exception we got.
     16 * Therefore, we duplicate the function, and handle faulting addresses
     17 * differently for each function
     18 */
     19
     20/*
     21 * copy from user: loads can fault
     22 */
     23#define src_sav r13
     24#define dst_sav r12
     25#define src_dst_sav r13:12
     26#define d_dbuf r15:14
     27#define w_dbuf r15
     28
     29#define dst r0
     30#define src r1
     31#define bytes r2
     32#define loopcount r5
     33
     34#define FUNCNAME raw_copy_from_user
     35#include "copy_user_template.S"
     36
     37	/* LOAD FAULTS from COPY_FROM_USER */
     38
     39	/* Alignment loop.  r2 has been updated. Return it. */
     40	.falign
     411009:
     422009:
     434009:
     44	{
     45		r0 = r2
     46		jumpr r31
     47	}
     48	/* Normal copy loops. Do epilog. Use src-src_sav to compute distance */
     49	/* X - (A - B) == X + B - A */
     50	.falign
     518089:
     52	{
     53		memd(dst) = d_dbuf
     54		r2 += sub(src_sav,src)
     55	}
     56	{
     57		r0 = r2
     58		jumpr r31
     59	}
     60	.falign
     614089:
     62	{
     63		memw(dst) = w_dbuf
     64		r2 += sub(src_sav,src)
     65	}
     66	{
     67		r0 = r2
     68		jumpr r31
     69	}
     70	.falign
     712089:
     72	{
     73		memh(dst) = w_dbuf
     74		r2 += sub(src_sav,src)
     75	}
     76	{
     77		r0 = r2
     78		jumpr r31
     79	}
     80	.falign
     811089:
     82	{
     83		memb(dst) = w_dbuf
     84		r2 += sub(src_sav,src)
     85	}
     86	{
     87		r0 = r2
     88		jumpr r31
     89	}
     90
     91	/* COPY FROM USER: only loads can fail */
     92
     93	.section __ex_table,"a"
     94	.long 1000b,1009b
     95	.long 2000b,2009b
     96	.long 4000b,4009b
     97	.long 8080b,8089b
     98	.long 4080b,4089b
     99	.long 2080b,2089b
    100	.long 1080b,1089b
    101	.previous