root/arch/arm64/lib/copy_in_user.S

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copy from user space to user space
   4  *
   5  * Copyright (C) 2012 ARM Ltd.
   6  */
   7 
   8 #include <linux/linkage.h>
   9 
  10 #include <asm/asm-uaccess.h>
  11 #include <asm/assembler.h>
  12 #include <asm/cache.h>
  13 
  14 /*
  15  * Copy from user space to user space (alignment handled by the hardware)
  16  *
  17  * Parameters:
  18  *      x0 - to
  19  *      x1 - from
  20  *      x2 - n
  21  * Returns:
  22  *      x0 - bytes not copied
  23  */
  24         .macro ldrb1 ptr, regB, val
  25         uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val
  26         .endm
  27 
  28         .macro strb1 ptr, regB, val
  29         uao_user_alternative 9998f, strb, sttrb, \ptr, \regB, \val
  30         .endm
  31 
  32         .macro ldrh1 ptr, regB, val
  33         uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val
  34         .endm
  35 
  36         .macro strh1 ptr, regB, val
  37         uao_user_alternative 9998f, strh, sttrh, \ptr, \regB, \val
  38         .endm
  39 
  40         .macro ldr1 ptr, regB, val
  41         uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val
  42         .endm
  43 
  44         .macro str1 ptr, regB, val
  45         uao_user_alternative 9998f, str, sttr, \ptr, \regB, \val
  46         .endm
  47 
  48         .macro ldp1 ptr, regB, regC, val
  49         uao_ldp 9998f, \ptr, \regB, \regC, \val
  50         .endm
  51 
  52         .macro stp1 ptr, regB, regC, val
  53         uao_stp 9998f, \ptr, \regB, \regC, \val
  54         .endm
  55 
  56 end     .req    x5
  57 
  58 ENTRY(__arch_copy_in_user)
  59         add     end, x0, x2
  60 #include "copy_template.S"
  61         mov     x0, #0
  62         ret
  63 ENDPROC(__arch_copy_in_user)
  64 EXPORT_SYMBOL(__arch_copy_in_user)
  65 
  66         .section .fixup,"ax"
  67         .align  2
  68 9998:   sub     x0, end, dst                    // bytes not copied
  69         ret
  70         .previous