arch/arm/lib/copy_from_user.S

   1 /*
   2  *  linux/arch/arm/lib/copy_from_user.S
   3  *
   4  *  Author:     Nicolas Pitre
   5  *  Created:    Sep 29, 2005
   6  *  Copyright:  MontaVista Software, Inc.
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License version 2 as
  10  *  published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/linkage.h>
  14 #include <asm/assembler.h>
  15 #include <asm/unwind.h>
  16
  17 /*
  18  * Prototype:
  19  *
  20  *      size_t arm_copy_from_user(void *to, const void *from, size_t n)
  21  *
  22  * Purpose:
  23  *
  24  *      copy a block to kernel memory from user memory
  25  *
  26  * Params:
  27  *
  28  *      to = kernel memory
  29  *      from = user memory
  30  *      n = number of bytes to copy
  31  *
  32  * Return value:
  33  *
  34  *      Number of bytes NOT copied.
  35  */
  36
  37 #ifdef CONFIG_CPU_USE_DOMAINS
  38
  39 #ifndef CONFIG_THUMB2_KERNEL
  40 #define LDR1W_SHIFT     0
  41 #else
  42 #define LDR1W_SHIFT     1
  43 #endif
  44
  45         .macro ldr1w ptr reg abort
  46         ldrusr  \reg, \ptr, 4, abort=\abort
  47         .endm
  48
  49         .macro ldr4w ptr reg1 reg2 reg3 reg4 abort
  50         ldr1w \ptr, \reg1, \abort
  51         ldr1w \ptr, \reg2, \abort
  52         ldr1w \ptr, \reg3, \abort
  53         ldr1w \ptr, \reg4, \abort
  54         .endm
  55
  56         .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
  57         ldr4w \ptr, \reg1, \reg2, \reg3, \reg4, \abort
  58         ldr4w \ptr, \reg5, \reg6, \reg7, \reg8, \abort
  59         .endm
  60
  61 #else
  62
  63 #define LDR1W_SHIFT     0
  64
  65         .macro ldr1w ptr reg abort
  66         USERL(\abort, W(ldr) \reg, [\ptr], #4)
  67         .endm
  68
  69         .macro ldr4w ptr reg1 reg2 reg3 reg4 abort
  70         USERL(\abort, ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4})
  71         .endm
  72
  73         .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
  74         USERL(\abort, ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8})
  75         .endm
  76
  77 #endif /* CONFIG_CPU_USE_DOMAINS */
  78
  79         .macro ldr1b ptr reg cond=al abort
  80         ldrusr  \reg, \ptr, 1, \cond, abort=\abort
  81         .endm
  82
  83 #define STR1W_SHIFT     0
  84
  85         .macro str1w ptr reg abort
  86         W(str) \reg, [\ptr], #4
  87         .endm
  88
  89         .macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
  90         stmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
  91         .endm
  92
  93         .macro str1b ptr reg cond=al abort
  94         str\cond\()b \reg, [\ptr], #1
  95         .endm
  96
  97         .macro enter reg1 reg2
  98         mov     r3, #0
  99         stmdb   sp!, {r0, r2, r3, \reg1, \reg2}
 100         .endm
 101
 102         .macro usave reg1 reg2
 103         UNWIND( .save {r0, r2, r3, \reg1, \reg2}        )
 104         .endm
 105
 106         .macro exit reg1 reg2
 107         add     sp, sp, #8
 108         ldmfd   sp!, {r0, \reg1, \reg2}
 109         .endm
 110
 111         .text
 112
 113 ENTRY(arm_copy_from_user)
 114 #ifdef CONFIG_CPU_SPECTRE
 115         get_thread_info r3
 116         ldr     r3, [r3, #TI_ADDR_LIMIT]
 117         uaccess_mask_range_ptr r1, r2, r3, ip
 118 #endif
 119
 120 #include "copy_template.S"
 121
 122 ENDPROC(arm_copy_from_user)
 123
 124         .pushsection .fixup,"ax"
 125         .align 0
 126         copy_abort_preamble
 127         ldmfd   sp!, {r1, r2, r3}
 128         sub     r0, r0, r1
 129         rsb     r0, r0, r2
 130         copy_abort_end
 131         .popsection
 132