113 lines
3.0 KiB
ArmAsm
113 lines
3.0 KiB
ArmAsm
/*
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* linux/arch/arm26/lib/getuser.S
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*
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* Copyright (C) 2001 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Idea from x86 version, (C) Copyright 1998 Linus Torvalds
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*
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* These functions have a non-standard call interface to make them more
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* efficient, especially as they return an error value in addition to
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* the "real" return value.
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*
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* __get_user_X
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*
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* Inputs: r0 contains the address
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* Outputs: r0 is the error code
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* r1, r2 contains the zero-extended value
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* lr corrupted
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*
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* No other registers must be altered. (see include/asm-arm/uaccess.h
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* for specific ASM register usage).
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*
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* Note that ADDR_LIMIT is either 0 or 0xc0000000.
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* Note also that it is intended that __get_user_bad is not global.
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*/
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#include <asm/asm-offsets.h>
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#include <asm/thread_info.h>
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#include <asm/errno.h>
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.global __get_user_1
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__get_user_1:
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bic r1, sp, #0x1f00
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bic r1, r1, #0x00ff
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str lr, [sp, #-4]!
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ldr r1, [r1, #TI_ADDR_LIMIT]
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sub r1, r1, #1
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cmp r0, r1
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bge __get_user_bad
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cmp r0, #0x02000000
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1: ldrlsbt r1, [r0]
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ldrgeb r1, [r0]
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mov r0, #0
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ldmfd sp!, {pc}^
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.global __get_user_2
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__get_user_2:
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bic r2, sp, #0x1f00
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bic r2, r2, #0x00ff
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str lr, [sp, #-4]!
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ldr r2, [r2, #TI_ADDR_LIMIT]
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sub r2, r2, #2
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cmp r0, r2
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bge __get_user_bad
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cmp r0, #0x02000000
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2: ldrlsbt r1, [r0], #1
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3: ldrlsbt r2, [r0]
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ldrgeb r1, [r0], #1
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ldrgeb r2, [r0]
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orr r1, r1, r2, lsl #8
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mov r0, #0
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ldmfd sp!, {pc}^
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.global __get_user_4
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__get_user_4:
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bic r1, sp, #0x1f00
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bic r1, r1, #0x00ff
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str lr, [sp, #-4]!
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ldr r1, [r1, #TI_ADDR_LIMIT]
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sub r1, r1, #4
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cmp r0, r1
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bge __get_user_bad
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cmp r0, #0x02000000
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4: ldrlst r1, [r0]
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ldrge r1, [r0]
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mov r0, #0
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ldmfd sp!, {pc}^
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.global __get_user_8
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__get_user_8:
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bic r2, sp, #0x1f00
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bic r2, r2, #0x00ff
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str lr, [sp, #-4]!
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ldr r2, [r2, #TI_ADDR_LIMIT]
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sub r2, r2, #8
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cmp r0, r2
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bge __get_user_bad_8
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cmp r0, #0x02000000
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5: ldrlst r1, [r0], #4
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6: ldrlst r2, [r0]
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ldrge r1, [r0], #4
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ldrge r2, [r0]
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mov r0, #0
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ldmfd sp!, {pc}^
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__get_user_bad_8:
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mov r2, #0
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__get_user_bad:
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mov r1, #0
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mov r0, #-EFAULT
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ldmfd sp!, {pc}^
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.section __ex_table, "a"
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.long 1b, __get_user_bad
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.long 2b, __get_user_bad
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.long 3b, __get_user_bad
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.long 4b, __get_user_bad
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.long 5b, __get_user_bad_8
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.long 6b, __get_user_bad_8
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.previous
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