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/alternative.h>
  22 #include <asm/assembler.h>
  23 #include <asm/cache.h>
  24 #include <asm/cpufeature.h>
  25 #include <asm/sysreg.h>
  26
  27 /*
  28  * Copy from user space to user space (alignment handled by the hardware)
  29  *
  30  * Parameters:
  31  *      x0 - to
  32  *      x1 - from
  33  *      x2 - n
  34  * Returns:
  35  *      x0 - bytes not copied
  36  */
  37         .macro ldrb1 ptr, regB, val
  38         uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val
  39         .endm
  40
  41         .macro strb1 ptr, regB, val
  42         uao_user_alternative 9998f, strb, sttrb, \ptr, \regB, \val
  43         .endm
  44
  45         .macro ldrh1 ptr, regB, val
  46         uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val
  47         .endm
  48
  49         .macro strh1 ptr, regB, val
  50         uao_user_alternative 9998f, strh, sttrh, \ptr, \regB, \val
  51         .endm
  52
  53         .macro ldr1 ptr, regB, val
  54         uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val
  55         .endm
  56
  57         .macro str1 ptr, regB, val
  58         uao_user_alternative 9998f, str, sttr, \ptr, \regB, \val
  59         .endm
  60
  61         .macro ldp1 ptr, regB, regC, val
  62         uao_ldp 9998f, \ptr, \regB, \regC, \val
  63         .endm
  64
  65         .macro stp1 ptr, regB, regC, val
  66         uao_stp 9998f, \ptr, \regB, \regC, \val
  67         .endm
  68
  69 end     .req    x5
  70 ENTRY(__copy_in_user)
  71 ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
  72             CONFIG_ARM64_PAN)
  73         add     end, x0, x2
  74 #include "copy_template.S"
  75 ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
  76             CONFIG_ARM64_PAN)
  77         mov     x0, #0
  78         ret
  79 ENDPROC(__copy_in_user)
  80
  81         .section .fixup,"ax"
  82         .align  2
  83 9998:   sub     x0, end, dst                    // bytes not copied
  84         ret
  85         .previous