arch/arm26/lib/putuser.S

   1 /*
   2  *  linux/arch/arm26/lib/putuser.S
   3  *
   4  *  Copyright (C) 2001 Russell King
   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  *  Idea from x86 version, (C) Copyright 1998 Linus Torvalds
  11  *
  12  * These functions have a non-standard call interface to make
  13  * them more efficient, especially as they return an error
  14  * value in addition to the "real" return value.
  15  *
  16  * __put_user_X
  17  *
  18  * Inputs:      r0 contains the address
  19  *              r1, r2 contains the value
  20  * Outputs:     r0 is the error code
  21  *              lr corrupted
  22  *
  23  * No other registers must be altered.  (see include/asm-arm/uaccess.h
  24  * for specific ASM register usage).
  25  *
  26  * Note that ADDR_LIMIT is either 0 or 0xc0000000
  27  * Note also that it is intended that __put_user_bad is not global.
  28  */
  29 #include <asm/asm_offsets.h>
  30 #include <asm/thread_info.h>
  31 #include <asm/errno.h>
  32
  33         .global __put_user_1
  34 __put_user_1:
  35         bic     r2, sp, #0x1f00
  36         bic     r2, r2, #0x00ff
  37         str     lr, [sp, #-4]!
  38         ldr     r2, [r2, #TI_ADDR_LIMIT]
  39         sub     r2, r2, #1
  40         cmp     r0, r2
  41         bge     __put_user_bad
  42 1:      cmp     r0, #0x02000000
  43         strlsbt r1, [r0]
  44         strgeb  r1, [r0]
  45         mov     r0, #0
  46         ldmfd   sp!, {pc}^
  47
  48         .global __put_user_2
  49 __put_user_2:
  50         bic     r2, sp, #0x1f00
  51         bic     r2, r2, #0x00ff
  52         str     lr, [sp, #-4]!
  53         ldr     r2, [r2, #TI_ADDR_LIMIT]
  54         sub     r2, r2, #2
  55         cmp     r0, r2
  56         bge     __put_user_bad
  57 2:      cmp     r0, #0x02000000
  58         strlsbt r1, [r0], #1
  59         strgeb  r1, [r0], #1
  60         mov     r1, r1, lsr #8
  61 3:      strlsbt r1, [r0]
  62         strgeb  r1, [r0]
  63         mov     r0, #0
  64         ldmfd   sp!, {pc}^
  65
  66         .global __put_user_4
  67 __put_user_4:
  68         bic     r2, sp, #0x1f00
  69         bic     r2, r2, #0x00ff
  70         str     lr, [sp, #-4]!
  71         ldr     r2, [r2, #TI_ADDR_LIMIT]
  72         sub     r2, r2, #4
  73         cmp     r0, r2
  74 4:      bge     __put_user_bad
  75         cmp     r0, #0x02000000
  76         strlst  r1, [r0]
  77         strge   r1, [r0]
  78         mov     r0, #0
  79         ldmfd   sp!, {pc}^
  80
  81         .global __put_user_8
  82 __put_user_8:
  83         bic     ip, sp, #0x1f00
  84         bic     ip, ip, #0x00ff
  85         str     lr, [sp, #-4]!
  86         ldr     ip, [ip, #TI_ADDR_LIMIT]
  87         sub     ip, ip, #8
  88         cmp     r0, ip
  89         bge     __put_user_bad
  90         cmp     r0, #0x02000000
  91 5:      strlst  r1, [r0], #4
  92 6:      strlst  r2, [r0]
  93         strge   r1, [r0], #4
  94         strge   r2, [r0]
  95         mov     r0, #0
  96         ldmfd   sp!, {pc}^
  97
  98 __put_user_bad:
  99         mov     r0, #-EFAULT
 100         mov     pc, lr
 101
 102 .section __ex_table, "a"
 103         .long   1b, __put_user_bad
 104         .long   2b, __put_user_bad
 105         .long   3b, __put_user_bad
 106         .long   4b, __put_user_bad
 107         .long   5b, __put_user_bad
 108         .long   6b, __put_user_bad
 109 .previous