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4968db4b9c
In non-EVA mode, a strlen_user* alias is used for the strlen_kernel* symbols since the code is identical. In EVA mode, a new strlen_user* symbol is used which uses the EVA specific instructions to load values from userspace. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
71 lines
1.6 KiB
ArmAsm
71 lines
1.6 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, 1998, 1999, 2004 by Ralf Baechle
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* Copyright (c) 1999 Silicon Graphics, Inc.
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*/
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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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* Return the size of a string including the ending NUL character up to a
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* maximum of a1 or 0 in case of error.
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*
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* Note: for performance reasons we deliberately accept that a user may
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* make strlen_user and strnlen_user access the first few KSEG0
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* bytes. There's nothing secret there. On 64-bit accessing beyond
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* the maximum is a tad hairier ...
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*/
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.macro __BUILD_STRNLEN_ASM func
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LEAF(__strnlen_\func\()_asm)
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LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
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and v0, a0
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bnez v0, .Lfault\@
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FEXPORT(__strnlen_\func\()_nocheck_asm)
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move v0, a0
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PTR_ADDU a1, a0 # stop pointer
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1: beq v0, a1, 1f # limit reached?
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.ifeqs "\func", "kernel"
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EX(lb, t0, (v0), .Lfault\@)
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.else
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EX(lbe, t0, (v0), .Lfault\@)
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.endif
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PTR_ADDIU v0, 1
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bnez t0, 1b
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1: PTR_SUBU v0, a0
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jr ra
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END(__strnlen_\func\()_asm)
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.Lfault\@:
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move v0, zero
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jr ra
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.endm
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#ifndef CONFIG_EVA
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/* Set aliases */
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.global __strnlen_user_asm
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.global __strnlen_user_nocheck_asm
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.set __strnlen_user_asm, __strnlen_kernel_asm
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.set __strnlen_user_nocheck_asm, __strnlen_kernel_nocheck_asm
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#endif
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__BUILD_STRNLEN_ASM kernel
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#ifdef CONFIG_EVA
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.set push
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.set eva
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__BUILD_STRNLEN_ASM user
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.set pop
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#endif
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