120 lines
2.2 KiB
ArmAsm
120 lines
2.2 KiB
ArmAsm
/*
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* Copy to/from userspace with optional address space checking.
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*
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* Copyright 2004-2006 Atmel Corporation
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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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#include <asm/page.h>
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#include <asm/thread_info.h>
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#include <asm/asm.h>
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/*
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* __kernel_size_t
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* __copy_user(void *to, const void *from, __kernel_size_t n)
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*
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* Returns the number of bytes not copied. Might be off by
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* max 3 bytes if we get a fault in the main loop.
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*
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* The address-space checking functions simply fall through to
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* the non-checking version.
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*/
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.text
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.align 1
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.global copy_from_user
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.type copy_from_user, @function
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copy_from_user:
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branch_if_kernel r8, __copy_user
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ret_if_privileged r8, r11, r10, r10
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rjmp __copy_user
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.size copy_from_user, . - copy_from_user
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.global copy_to_user
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.type copy_to_user, @function
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copy_to_user:
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branch_if_kernel r8, __copy_user
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ret_if_privileged r8, r12, r10, r10
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.size copy_to_user, . - copy_to_user
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.global __copy_user
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.type __copy_user, @function
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__copy_user:
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mov r9, r11
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andl r9, 3, COH
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brne 6f
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/* At this point, from is word-aligned */
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1: sub r10, 4
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brlt 3f
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2:
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10: ld.w r8, r11++
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11: st.w r12++, r8
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sub r10, 4
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brge 2b
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3: sub r10, -4
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reteq 0
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/*
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* Handle unaligned count. Need to be careful with r10 here so
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* that we return the correct value even if we get a fault
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*/
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4:
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20: ld.ub r8, r11++
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21: st.b r12++, r8
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sub r10, 1
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reteq 0
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22: ld.ub r8, r11++
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23: st.b r12++, r8
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sub r10, 1
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reteq 0
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24: ld.ub r8, r11++
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25: st.b r12++, r8
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retal 0
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/* Handle unaligned from-pointer */
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6: cp.w r10, 4
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brlt 4b
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rsub r9, r9, 4
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30: ld.ub r8, r11++
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31: st.b r12++, r8
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sub r10, 1
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sub r9, 1
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breq 1b
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32: ld.ub r8, r11++
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33: st.b r12++, r8
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sub r10, 1
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sub r9, 1
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breq 1b
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34: ld.ub r8, r11++
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35: st.b r12++, r8
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sub r10, 1
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rjmp 1b
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.size __copy_user, . - __copy_user
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.section .fixup,"ax"
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.align 1
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19: sub r10, -4
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29: retal r10
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.section __ex_table,"a"
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.align 2
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.long 10b, 19b
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.long 11b, 19b
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.long 20b, 29b
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.long 21b, 29b
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.long 22b, 29b
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.long 23b, 29b
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.long 24b, 29b
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.long 25b, 29b
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.long 30b, 29b
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.long 31b, 29b
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.long 32b, 29b
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.long 33b, 29b
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.long 34b, 29b
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.long 35b, 29b
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