arch/arm64/lib/copy_in_user.S

   1 /*
   2  * Copy from user space to user space
   3  *
   4  * Copyright (C) 2012 ARM Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/linkage.h>
  20
  21 #include <asm/cache.h>
  22 #include <linux/uaccess.h>
  23
  24 /*
  25  * Copy from user space to user space (alignment handled by the hardware)
  26  *
  27  * Parameters:
  28  *      x0 - to
  29  *      x1 - from
  30  *      x2 - n
  31  * Returns:
  32  *      x0 - bytes not copied
  33  */
  34         .macro ldrb1 ptr, regB, val
  35         uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val
  36         .endm
  37
  38         .macro strb1 ptr, regB, val
  39         uao_user_alternative 9998f, strb, sttrb, \ptr, \regB, \val
  40         .endm
  41
  42         .macro ldrh1 ptr, regB, val
  43         uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val
  44         .endm
  45
  46         .macro strh1 ptr, regB, val
  47         uao_user_alternative 9998f, strh, sttrh, \ptr, \regB, \val
  48         .endm
  49
  50         .macro ldr1 ptr, regB, val
  51         uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val
  52         .endm
  53
  54         .macro str1 ptr, regB, val
  55         uao_user_alternative 9998f, str, sttr, \ptr, \regB, \val
  56         .endm
  57
  58         .macro ldp1 ptr, regB, regC, val
  59         uao_ldp 9998f, \ptr, \regB, \regC, \val
  60         .endm
  61
  62         .macro stp1 ptr, regB, regC, val
  63         uao_stp 9998f, \ptr, \regB, \regC, \val
  64         .endm
  65
  66 end     .req    x5
  67 ENTRY(__copy_in_user)
  68         uaccess_enable_not_uao x3, x4
  69         add     end, x0, x2
  70 #include "copy_template.S"
  71         uaccess_disable_not_uao x3
  72         mov     x0, #0
  73         ret
  74 ENDPROC(__copy_in_user)
  75
  76         .section .fixup,"ax"
  77         .align  2
  78 9998:   sub     x0, end, dst                    // bytes not copied
  79         ret
  80         .previous