564 lines
13 KiB
ArmAsm
564 lines
13 KiB
ArmAsm
/*
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* linux/arch/arm/lib/uaccess.S
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*
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* Copyright (C) 1995, 1996,1997,1998 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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* Routines to block copy data to/from user memory
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* These are highly optimised both for the 4k page size
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* and for various alignments.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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#include <asm/errno.h>
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.text
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#define PAGE_SHIFT 12
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/* Prototype: int __copy_to_user(void *to, const char *from, size_t n)
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* Purpose : copy a block to user memory from kernel memory
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* Params : to - user memory
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* : from - kernel memory
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* : n - number of bytes to copy
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* Returns : Number of bytes NOT copied.
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*/
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.Lc2u_dest_not_aligned:
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rsb ip, ip, #4
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cmp ip, #2
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ldrb r3, [r1], #1
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USER( strbt r3, [r0], #1) @ May fault
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ldrgeb r3, [r1], #1
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USER( strgebt r3, [r0], #1) @ May fault
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ldrgtb r3, [r1], #1
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USER( strgtbt r3, [r0], #1) @ May fault
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sub r2, r2, ip
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b .Lc2u_dest_aligned
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ENTRY(__copy_to_user)
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stmfd sp!, {r2, r4 - r7, lr}
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cmp r2, #4
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blt .Lc2u_not_enough
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ands ip, r0, #3
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bne .Lc2u_dest_not_aligned
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.Lc2u_dest_aligned:
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ands ip, r1, #3
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bne .Lc2u_src_not_aligned
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/*
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* Seeing as there has to be at least 8 bytes to copy, we can
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* copy one word, and force a user-mode page fault...
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*/
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.Lc2u_0fupi: subs r2, r2, #4
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addmi ip, r2, #4
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bmi .Lc2u_0nowords
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ldr r3, [r1], #4
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USER( strt r3, [r0], #4) @ May fault
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mov ip, r0, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
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rsb ip, ip, #0
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movs ip, ip, lsr #32 - PAGE_SHIFT
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beq .Lc2u_0fupi
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/*
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* ip = max no. of bytes to copy before needing another "strt" insn
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*/
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cmp r2, ip
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movlt ip, r2
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sub r2, r2, ip
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subs ip, ip, #32
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blt .Lc2u_0rem8lp
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.Lc2u_0cpy8lp: ldmia r1!, {r3 - r6}
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stmia r0!, {r3 - r6} @ Shouldnt fault
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ldmia r1!, {r3 - r6}
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subs ip, ip, #32
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stmia r0!, {r3 - r6} @ Shouldnt fault
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bpl .Lc2u_0cpy8lp
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.Lc2u_0rem8lp: cmn ip, #16
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ldmgeia r1!, {r3 - r6}
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stmgeia r0!, {r3 - r6} @ Shouldnt fault
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tst ip, #8
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ldmneia r1!, {r3 - r4}
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stmneia r0!, {r3 - r4} @ Shouldnt fault
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tst ip, #4
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ldrne r3, [r1], #4
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strnet r3, [r0], #4 @ Shouldnt fault
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ands ip, ip, #3
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beq .Lc2u_0fupi
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.Lc2u_0nowords: teq ip, #0
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beq .Lc2u_finished
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.Lc2u_nowords: cmp ip, #2
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ldrb r3, [r1], #1
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USER( strbt r3, [r0], #1) @ May fault
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ldrgeb r3, [r1], #1
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USER( strgebt r3, [r0], #1) @ May fault
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ldrgtb r3, [r1], #1
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USER( strgtbt r3, [r0], #1) @ May fault
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b .Lc2u_finished
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.Lc2u_not_enough:
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movs ip, r2
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bne .Lc2u_nowords
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.Lc2u_finished: mov r0, #0
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ldmfd sp!, {r2, r4 - r7, pc}
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.Lc2u_src_not_aligned:
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bic r1, r1, #3
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ldr r7, [r1], #4
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cmp ip, #2
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bgt .Lc2u_3fupi
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beq .Lc2u_2fupi
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.Lc2u_1fupi: subs r2, r2, #4
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addmi ip, r2, #4
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bmi .Lc2u_1nowords
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mov r3, r7, pull #8
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ldr r7, [r1], #4
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orr r3, r3, r7, push #24
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USER( strt r3, [r0], #4) @ May fault
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mov ip, r0, lsl #32 - PAGE_SHIFT
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rsb ip, ip, #0
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movs ip, ip, lsr #32 - PAGE_SHIFT
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beq .Lc2u_1fupi
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cmp r2, ip
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movlt ip, r2
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sub r2, r2, ip
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subs ip, ip, #16
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blt .Lc2u_1rem8lp
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.Lc2u_1cpy8lp: mov r3, r7, pull #8
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ldmia r1!, {r4 - r7}
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subs ip, ip, #16
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orr r3, r3, r4, push #24
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mov r4, r4, pull #8
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orr r4, r4, r5, push #24
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mov r5, r5, pull #8
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orr r5, r5, r6, push #24
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mov r6, r6, pull #8
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orr r6, r6, r7, push #24
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stmia r0!, {r3 - r6} @ Shouldnt fault
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bpl .Lc2u_1cpy8lp
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.Lc2u_1rem8lp: tst ip, #8
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movne r3, r7, pull #8
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ldmneia r1!, {r4, r7}
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orrne r3, r3, r4, push #24
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movne r4, r4, pull #8
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orrne r4, r4, r7, push #24
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stmneia r0!, {r3 - r4} @ Shouldnt fault
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tst ip, #4
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movne r3, r7, pull #8
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ldrne r7, [r1], #4
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orrne r3, r3, r7, push #24
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strnet r3, [r0], #4 @ Shouldnt fault
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ands ip, ip, #3
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beq .Lc2u_1fupi
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.Lc2u_1nowords: mov r3, r7, get_byte_1
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teq ip, #0
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beq .Lc2u_finished
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cmp ip, #2
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USER( strbt r3, [r0], #1) @ May fault
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movge r3, r7, get_byte_2
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USER( strgebt r3, [r0], #1) @ May fault
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movgt r3, r7, get_byte_3
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USER( strgtbt r3, [r0], #1) @ May fault
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b .Lc2u_finished
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.Lc2u_2fupi: subs r2, r2, #4
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addmi ip, r2, #4
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bmi .Lc2u_2nowords
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mov r3, r7, pull #16
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ldr r7, [r1], #4
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orr r3, r3, r7, push #16
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USER( strt r3, [r0], #4) @ May fault
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mov ip, r0, lsl #32 - PAGE_SHIFT
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rsb ip, ip, #0
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movs ip, ip, lsr #32 - PAGE_SHIFT
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beq .Lc2u_2fupi
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cmp r2, ip
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movlt ip, r2
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sub r2, r2, ip
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subs ip, ip, #16
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blt .Lc2u_2rem8lp
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.Lc2u_2cpy8lp: mov r3, r7, pull #16
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ldmia r1!, {r4 - r7}
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subs ip, ip, #16
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orr r3, r3, r4, push #16
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mov r4, r4, pull #16
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orr r4, r4, r5, push #16
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mov r5, r5, pull #16
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orr r5, r5, r6, push #16
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mov r6, r6, pull #16
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orr r6, r6, r7, push #16
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stmia r0!, {r3 - r6} @ Shouldnt fault
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bpl .Lc2u_2cpy8lp
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.Lc2u_2rem8lp: tst ip, #8
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movne r3, r7, pull #16
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ldmneia r1!, {r4, r7}
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orrne r3, r3, r4, push #16
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movne r4, r4, pull #16
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orrne r4, r4, r7, push #16
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stmneia r0!, {r3 - r4} @ Shouldnt fault
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tst ip, #4
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movne r3, r7, pull #16
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ldrne r7, [r1], #4
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orrne r3, r3, r7, push #16
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strnet r3, [r0], #4 @ Shouldnt fault
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ands ip, ip, #3
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beq .Lc2u_2fupi
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.Lc2u_2nowords: mov r3, r7, get_byte_2
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teq ip, #0
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beq .Lc2u_finished
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cmp ip, #2
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USER( strbt r3, [r0], #1) @ May fault
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movge r3, r7, get_byte_3
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USER( strgebt r3, [r0], #1) @ May fault
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ldrgtb r3, [r1], #0
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USER( strgtbt r3, [r0], #1) @ May fault
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b .Lc2u_finished
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.Lc2u_3fupi: subs r2, r2, #4
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addmi ip, r2, #4
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bmi .Lc2u_3nowords
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mov r3, r7, pull #24
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ldr r7, [r1], #4
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orr r3, r3, r7, push #8
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USER( strt r3, [r0], #4) @ May fault
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mov ip, r0, lsl #32 - PAGE_SHIFT
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rsb ip, ip, #0
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movs ip, ip, lsr #32 - PAGE_SHIFT
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beq .Lc2u_3fupi
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cmp r2, ip
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movlt ip, r2
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sub r2, r2, ip
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subs ip, ip, #16
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blt .Lc2u_3rem8lp
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.Lc2u_3cpy8lp: mov r3, r7, pull #24
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ldmia r1!, {r4 - r7}
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subs ip, ip, #16
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orr r3, r3, r4, push #8
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mov r4, r4, pull #24
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orr r4, r4, r5, push #8
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mov r5, r5, pull #24
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orr r5, r5, r6, push #8
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mov r6, r6, pull #24
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orr r6, r6, r7, push #8
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stmia r0!, {r3 - r6} @ Shouldnt fault
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bpl .Lc2u_3cpy8lp
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.Lc2u_3rem8lp: tst ip, #8
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movne r3, r7, pull #24
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ldmneia r1!, {r4, r7}
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orrne r3, r3, r4, push #8
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movne r4, r4, pull #24
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orrne r4, r4, r7, push #8
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stmneia r0!, {r3 - r4} @ Shouldnt fault
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tst ip, #4
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movne r3, r7, pull #24
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ldrne r7, [r1], #4
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orrne r3, r3, r7, push #8
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strnet r3, [r0], #4 @ Shouldnt fault
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ands ip, ip, #3
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beq .Lc2u_3fupi
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.Lc2u_3nowords: mov r3, r7, get_byte_3
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teq ip, #0
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beq .Lc2u_finished
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cmp ip, #2
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USER( strbt r3, [r0], #1) @ May fault
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ldrgeb r3, [r1], #1
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USER( strgebt r3, [r0], #1) @ May fault
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ldrgtb r3, [r1], #0
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USER( strgtbt r3, [r0], #1) @ May fault
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b .Lc2u_finished
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ENDPROC(__copy_to_user)
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.section .fixup,"ax"
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.align 0
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9001: ldmfd sp!, {r0, r4 - r7, pc}
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.previous
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/* Prototype: unsigned long __copy_from_user(void *to,const void *from,unsigned long n);
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* Purpose : copy a block from user memory to kernel memory
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* Params : to - kernel memory
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* : from - user memory
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* : n - number of bytes to copy
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* Returns : Number of bytes NOT copied.
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*/
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.Lcfu_dest_not_aligned:
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rsb ip, ip, #4
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cmp ip, #2
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USER( ldrbt r3, [r1], #1) @ May fault
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strb r3, [r0], #1
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USER( ldrgebt r3, [r1], #1) @ May fault
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strgeb r3, [r0], #1
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USER( ldrgtbt r3, [r1], #1) @ May fault
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strgtb r3, [r0], #1
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sub r2, r2, ip
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b .Lcfu_dest_aligned
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ENTRY(__copy_from_user)
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stmfd sp!, {r0, r2, r4 - r7, lr}
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cmp r2, #4
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blt .Lcfu_not_enough
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ands ip, r0, #3
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bne .Lcfu_dest_not_aligned
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.Lcfu_dest_aligned:
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ands ip, r1, #3
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bne .Lcfu_src_not_aligned
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/*
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* Seeing as there has to be at least 8 bytes to copy, we can
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* copy one word, and force a user-mode page fault...
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*/
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.Lcfu_0fupi: subs r2, r2, #4
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addmi ip, r2, #4
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bmi .Lcfu_0nowords
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USER( ldrt r3, [r1], #4)
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str r3, [r0], #4
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mov ip, r1, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
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rsb ip, ip, #0
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movs ip, ip, lsr #32 - PAGE_SHIFT
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beq .Lcfu_0fupi
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/*
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* ip = max no. of bytes to copy before needing another "strt" insn
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*/
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cmp r2, ip
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movlt ip, r2
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sub r2, r2, ip
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subs ip, ip, #32
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blt .Lcfu_0rem8lp
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.Lcfu_0cpy8lp: ldmia r1!, {r3 - r6} @ Shouldnt fault
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stmia r0!, {r3 - r6}
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ldmia r1!, {r3 - r6} @ Shouldnt fault
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subs ip, ip, #32
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stmia r0!, {r3 - r6}
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bpl .Lcfu_0cpy8lp
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.Lcfu_0rem8lp: cmn ip, #16
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ldmgeia r1!, {r3 - r6} @ Shouldnt fault
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stmgeia r0!, {r3 - r6}
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tst ip, #8
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ldmneia r1!, {r3 - r4} @ Shouldnt fault
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stmneia r0!, {r3 - r4}
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tst ip, #4
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ldrnet r3, [r1], #4 @ Shouldnt fault
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strne r3, [r0], #4
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ands ip, ip, #3
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beq .Lcfu_0fupi
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.Lcfu_0nowords: teq ip, #0
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beq .Lcfu_finished
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.Lcfu_nowords: cmp ip, #2
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USER( ldrbt r3, [r1], #1) @ May fault
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strb r3, [r0], #1
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USER( ldrgebt r3, [r1], #1) @ May fault
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strgeb r3, [r0], #1
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USER( ldrgtbt r3, [r1], #1) @ May fault
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strgtb r3, [r0], #1
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b .Lcfu_finished
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.Lcfu_not_enough:
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movs ip, r2
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bne .Lcfu_nowords
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.Lcfu_finished: mov r0, #0
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add sp, sp, #8
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ldmfd sp!, {r4 - r7, pc}
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.Lcfu_src_not_aligned:
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bic r1, r1, #3
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USER( ldrt r7, [r1], #4) @ May fault
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cmp ip, #2
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bgt .Lcfu_3fupi
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beq .Lcfu_2fupi
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.Lcfu_1fupi: subs r2, r2, #4
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addmi ip, r2, #4
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bmi .Lcfu_1nowords
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mov r3, r7, pull #8
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USER( ldrt r7, [r1], #4) @ May fault
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orr r3, r3, r7, push #24
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str r3, [r0], #4
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mov ip, r1, lsl #32 - PAGE_SHIFT
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rsb ip, ip, #0
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movs ip, ip, lsr #32 - PAGE_SHIFT
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beq .Lcfu_1fupi
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cmp r2, ip
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movlt ip, r2
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sub r2, r2, ip
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subs ip, ip, #16
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blt .Lcfu_1rem8lp
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.Lcfu_1cpy8lp: mov r3, r7, pull #8
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ldmia r1!, {r4 - r7} @ Shouldnt fault
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subs ip, ip, #16
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orr r3, r3, r4, push #24
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mov r4, r4, pull #8
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orr r4, r4, r5, push #24
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mov r5, r5, pull #8
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orr r5, r5, r6, push #24
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mov r6, r6, pull #8
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orr r6, r6, r7, push #24
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stmia r0!, {r3 - r6}
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bpl .Lcfu_1cpy8lp
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.Lcfu_1rem8lp: tst ip, #8
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movne r3, r7, pull #8
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ldmneia r1!, {r4, r7} @ Shouldnt fault
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orrne r3, r3, r4, push #24
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movne r4, r4, pull #8
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orrne r4, r4, r7, push #24
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stmneia r0!, {r3 - r4}
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tst ip, #4
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movne r3, r7, pull #8
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USER( ldrnet r7, [r1], #4) @ May fault
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orrne r3, r3, r7, push #24
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strne r3, [r0], #4
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ands ip, ip, #3
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beq .Lcfu_1fupi
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.Lcfu_1nowords: mov r3, r7, get_byte_1
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teq ip, #0
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beq .Lcfu_finished
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cmp ip, #2
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strb r3, [r0], #1
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movge r3, r7, get_byte_2
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strgeb r3, [r0], #1
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movgt r3, r7, get_byte_3
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strgtb r3, [r0], #1
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b .Lcfu_finished
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.Lcfu_2fupi: subs r2, r2, #4
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addmi ip, r2, #4
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bmi .Lcfu_2nowords
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mov r3, r7, pull #16
|
|
USER( ldrt r7, [r1], #4) @ May fault
|
|
orr r3, r3, r7, push #16
|
|
str r3, [r0], #4
|
|
mov ip, r1, lsl #32 - PAGE_SHIFT
|
|
rsb ip, ip, #0
|
|
movs ip, ip, lsr #32 - PAGE_SHIFT
|
|
beq .Lcfu_2fupi
|
|
cmp r2, ip
|
|
movlt ip, r2
|
|
sub r2, r2, ip
|
|
subs ip, ip, #16
|
|
blt .Lcfu_2rem8lp
|
|
|
|
|
|
.Lcfu_2cpy8lp: mov r3, r7, pull #16
|
|
ldmia r1!, {r4 - r7} @ Shouldnt fault
|
|
subs ip, ip, #16
|
|
orr r3, r3, r4, push #16
|
|
mov r4, r4, pull #16
|
|
orr r4, r4, r5, push #16
|
|
mov r5, r5, pull #16
|
|
orr r5, r5, r6, push #16
|
|
mov r6, r6, pull #16
|
|
orr r6, r6, r7, push #16
|
|
stmia r0!, {r3 - r6}
|
|
bpl .Lcfu_2cpy8lp
|
|
|
|
.Lcfu_2rem8lp: tst ip, #8
|
|
movne r3, r7, pull #16
|
|
ldmneia r1!, {r4, r7} @ Shouldnt fault
|
|
orrne r3, r3, r4, push #16
|
|
movne r4, r4, pull #16
|
|
orrne r4, r4, r7, push #16
|
|
stmneia r0!, {r3 - r4}
|
|
tst ip, #4
|
|
movne r3, r7, pull #16
|
|
USER( ldrnet r7, [r1], #4) @ May fault
|
|
orrne r3, r3, r7, push #16
|
|
strne r3, [r0], #4
|
|
ands ip, ip, #3
|
|
beq .Lcfu_2fupi
|
|
.Lcfu_2nowords: mov r3, r7, get_byte_2
|
|
teq ip, #0
|
|
beq .Lcfu_finished
|
|
cmp ip, #2
|
|
strb r3, [r0], #1
|
|
movge r3, r7, get_byte_3
|
|
strgeb r3, [r0], #1
|
|
USER( ldrgtbt r3, [r1], #0) @ May fault
|
|
strgtb r3, [r0], #1
|
|
b .Lcfu_finished
|
|
|
|
.Lcfu_3fupi: subs r2, r2, #4
|
|
addmi ip, r2, #4
|
|
bmi .Lcfu_3nowords
|
|
mov r3, r7, pull #24
|
|
USER( ldrt r7, [r1], #4) @ May fault
|
|
orr r3, r3, r7, push #8
|
|
str r3, [r0], #4
|
|
mov ip, r1, lsl #32 - PAGE_SHIFT
|
|
rsb ip, ip, #0
|
|
movs ip, ip, lsr #32 - PAGE_SHIFT
|
|
beq .Lcfu_3fupi
|
|
cmp r2, ip
|
|
movlt ip, r2
|
|
sub r2, r2, ip
|
|
subs ip, ip, #16
|
|
blt .Lcfu_3rem8lp
|
|
|
|
.Lcfu_3cpy8lp: mov r3, r7, pull #24
|
|
ldmia r1!, {r4 - r7} @ Shouldnt fault
|
|
orr r3, r3, r4, push #8
|
|
mov r4, r4, pull #24
|
|
orr r4, r4, r5, push #8
|
|
mov r5, r5, pull #24
|
|
orr r5, r5, r6, push #8
|
|
mov r6, r6, pull #24
|
|
orr r6, r6, r7, push #8
|
|
stmia r0!, {r3 - r6}
|
|
subs ip, ip, #16
|
|
bpl .Lcfu_3cpy8lp
|
|
|
|
.Lcfu_3rem8lp: tst ip, #8
|
|
movne r3, r7, pull #24
|
|
ldmneia r1!, {r4, r7} @ Shouldnt fault
|
|
orrne r3, r3, r4, push #8
|
|
movne r4, r4, pull #24
|
|
orrne r4, r4, r7, push #8
|
|
stmneia r0!, {r3 - r4}
|
|
tst ip, #4
|
|
movne r3, r7, pull #24
|
|
USER( ldrnet r7, [r1], #4) @ May fault
|
|
orrne r3, r3, r7, push #8
|
|
strne r3, [r0], #4
|
|
ands ip, ip, #3
|
|
beq .Lcfu_3fupi
|
|
.Lcfu_3nowords: mov r3, r7, get_byte_3
|
|
teq ip, #0
|
|
beq .Lcfu_finished
|
|
cmp ip, #2
|
|
strb r3, [r0], #1
|
|
USER( ldrgebt r3, [r1], #1) @ May fault
|
|
strgeb r3, [r0], #1
|
|
USER( ldrgtbt r3, [r1], #1) @ May fault
|
|
strgtb r3, [r0], #1
|
|
b .Lcfu_finished
|
|
ENDPROC(__copy_from_user)
|
|
|
|
.section .fixup,"ax"
|
|
.align 0
|
|
/*
|
|
* We took an exception. r0 contains a pointer to
|
|
* the byte not copied.
|
|
*/
|
|
9001: ldr r2, [sp], #4 @ void *to
|
|
sub r2, r0, r2 @ bytes copied
|
|
ldr r1, [sp], #4 @ unsigned long count
|
|
subs r4, r1, r2 @ bytes left to copy
|
|
movne r1, r4
|
|
blne __memzero
|
|
mov r0, r4
|
|
ldmfd sp!, {r4 - r7, pc}
|
|
.previous
|
|
|