0131f2b2c9
Optimise 'strncpy' to use microMIPS instructions and/or optimisations for binary size reduction. When the microMIPS ISA is not being used, the library function compiles to the original binary code. Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
61 lines
1.4 KiB
ArmAsm
61 lines
1.4 KiB
ArmAsm
/*
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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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* Copyright (C) 2011 MIPS Technologies, Inc.
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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/asm-offsets.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, .Lfault
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FEXPORT(__strncpy_from_user_nocheck_asm)
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.set noreorder
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move t0, zero
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move v1, a1
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1: EX(lbu, v0, (v1), .Lfault)
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PTR_ADDIU v1, 1
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R10KCBARRIER(0(ra))
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beqz v0, 2f
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sb v0, (a0)
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PTR_ADDIU t0, 1
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bne t0, a2, 1b
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PTR_ADDIU a0, 1
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2: PTR_ADDU v0, a1, t0
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xor v0, a1
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bltz v0, .Lfault
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nop
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jr ra # return n
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move v0, t0
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END(__strncpy_from_user_asm)
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.Lfault: jr ra
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li v0, -EFAULT
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.section __ex_table,"a"
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PTR 1b, .Lfault
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.previous
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