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59 lines
1.3 KiB
ArmAsm
59 lines
1.3 KiB
ArmAsm
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/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (c) 1996, 1999 by Ralf Baechle
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*/
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#include <linux/errno.h>
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#include <asm/asm.h>
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#include <asm/offset.h>
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#include <asm/regdef.h>
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#define EX(insn,reg,addr,handler) \
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9: insn reg, addr; \
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.section __ex_table,"a"; \
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PTR 9b, handler; \
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.previous
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/*
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* Returns: -EFAULT if exception before terminator, N if the entire
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* buffer filled, else strlen.
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*/
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/*
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* Ugly special case have to check: we might get passed a user space
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* pointer which wraps into the kernel space. We don't deal with that. If
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* it happens at most some bytes of the exceptions handlers will be copied.
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*/
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LEAF(__strncpy_from_user_asm)
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LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
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and v0, a1
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bnez v0, fault
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FEXPORT(__strncpy_from_user_nocheck_asm)
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move v0, zero
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move v1, a1
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.set noreorder
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1: EX(lbu, t0, (v1), fault)
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PTR_ADDIU v1, 1
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beqz t0, 2f
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sb t0, (a0)
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PTR_ADDIU v0, 1
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bne v0, a2, 1b
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PTR_ADDIU a0, 1
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.set reorder
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2: PTR_ADDU t0, a1, v0
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xor t0, a1
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bltz t0, fault
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jr ra # return n
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END(__strncpy_from_user_asm)
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fault: li v0, -EFAULT
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jr ra
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.section __ex_table,"a"
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PTR 1b, fault
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.previous
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