M7350/kernel/arch/mips/lib/strncpy_user.S

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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
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* Copyright (C) 1996, 1999 by Ralf Baechle
* Copyright (C) 2011 MIPS Technologies, Inc.
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*/
#include <linux/errno.h>
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/regdef.h>
#define EX(insn,reg,addr,handler) \
9: insn reg, addr; \
.section __ex_table,"a"; \
PTR 9b, handler; \
.previous
/*
* Returns: -EFAULT if exception before terminator, N if the entire
* buffer filled, else strlen.
*/
/*
* 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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.macro __BUILD_STRNCPY_ASM func
LEAF(__strncpy_from_\func\()_asm)
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LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
and v0, a1
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bnez v0, .Lfault\@
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FEXPORT(__strncpy_from_\func\()_nocheck_asm)
move t0, zero
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move v1, a1
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.ifeqs "\func","kernel"
1: EX(lbu, v0, (v1), .Lfault\@)
.else
1: EX(lbue, v0, (v1), .Lfault\@)
.endif
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PTR_ADDIU v1, 1
R10KCBARRIER(0(ra))
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sb v0, (a0)
beqz v0, 2f
PTR_ADDIU t0, 1
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PTR_ADDIU a0, 1
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bne t0, a2, 1b
2: PTR_ADDU v0, a1, t0
xor v0, a1
bltz v0, .Lfault\@
move v0, t0
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jr ra # return n
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END(__strncpy_from_\func\()_asm)
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.Lfault\@:
li v0, -EFAULT
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jr ra
.section __ex_table,"a"
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PTR 1b, .Lfault\@
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.previous
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.endm
#ifndef CONFIG_EVA
/* Set aliases */
.global __strncpy_from_user_asm
.global __strncpy_from_user_nocheck_asm
.set __strncpy_from_user_asm, __strncpy_from_kernel_asm
.set __strncpy_from_user_nocheck_asm, __strncpy_from_kernel_nocheck_asm
#endif
__BUILD_STRNCPY_ASM kernel
#ifdef CONFIG_EVA
.set push
.set eva
__BUILD_STRNCPY_ASM user
.set pop
#endif