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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asm-uaccess.h (2382B)

      1/*
      2 * include/asm-xtensa/uaccess.h
      3 *
      4 * User space memory access functions
      5 *
      6 * These routines provide basic accessing functions to the user memory
      7 * space for the kernel. This header file provides functions such as:
      8 *
      9 * This file is subject to the terms and conditions of the GNU General Public
     10 * License.  See the file "COPYING" in the main directory of this archive
     11 * for more details.
     12 *
     13 * Copyright (C) 2001 - 2005 Tensilica Inc.
     14 */
     15
     16#ifndef _XTENSA_ASM_UACCESS_H
     17#define _XTENSA_ASM_UACCESS_H
     18
     19#include <linux/errno.h>
     20#include <asm/types.h>
     21
     22#include <asm/current.h>
     23#include <asm/asm-offsets.h>
     24#include <asm/processor.h>
     25
     26/*
     27 * user_ok determines whether the access to user-space memory is allowed.
     28 * See the equivalent C-macro version below for clarity.
     29 *
     30 * On error, user_ok branches to a label indicated by parameter
     31 * <error>.  This implies that the macro falls through to the next
     32 * instruction on success.
     33 *
     34 * Note that while this macro can be used independently, we designed
     35 * in for optimal use in the access_ok macro below (i.e., we fall
     36 * through on success).
     37 *
     38 * On Entry:
     39 * 	<aa>	register containing memory address
     40 * 	<as>	register containing memory size
     41 * 	<at>	temp register
     42 * 	<error>	label to branch to on error; implies fall-through
     43 * 		macro on success
     44 * On Exit:
     45 * 	<aa>	preserved
     46 * 	<as>	preserved
     47 * 	<at>	destroyed (actually, (TASK_SIZE + 1 - size))
     48 */
     49	.macro	user_ok	aa, as, at, error
     50	movi	\at, __XTENSA_UL_CONST(TASK_SIZE)
     51	bgeu	\as, \at, \error
     52	sub	\at, \at, \as
     53	bgeu	\aa, \at, \error
     54	.endm
     55
     56/*
     57 * access_ok determines whether a memory access is allowed.  See the
     58 * equivalent C-macro version below for clarity.
     59 *
     60 * On error, access_ok branches to a label indicated by parameter
     61 * <error>.  This implies that the macro falls through to the next
     62 * instruction on success.
     63 *
     64 * Note that we assume success is the common case, and we optimize the
     65 * branch fall-through case on success.
     66 *
     67 * On Entry:
     68 * 	<aa>	register containing memory address
     69 * 	<as>	register containing memory size
     70 * 	<at>	temp register
     71 * 	<sp>
     72 * 	<error>	label to branch to on error; implies fall-through
     73 * 		macro on success
     74 * On Exit:
     75 * 	<aa>	preserved
     76 * 	<as>	preserved
     77 * 	<at>	destroyed
     78 */
     79	.macro	access_ok  aa, as, at, sp, error
     80	user_ok    \aa, \as, \at, \error
     81.Laccess_ok_\@:
     82	.endm
     83
     84#endif	/* _XTENSA_ASM_UACCESS_H */