/*
* 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.
*
* Copyright (C) 1996, 1999 by Ralf Baechle
* Copyright (C) 2011 MIPS Technologies, Inc.
*/
#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
* pointer which wraps into the kernel space. We don't deal with that. If
* it happens at most some bytes of the exceptions handlers will be copied.
*/
LEAF(__strncpy_from_user_asm)
LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
and v0, a1
bnez v0, .Lfault
FEXPORT(__strncpy_from_user_nocheck_asm)
.set noreorder
move t0, zero
move v1, a1
1: EX(lbu, v0, (v1), .Lfault)
PTR_ADDIU v1, 1
R10KCBARRIER(0(ra))
beqz v0, 2f
sb v0, (a0)
PTR_ADDIU t0, 1
bne t0, a2, 1b
PTR_ADDIU a0, 1
2: PTR_ADDU v0, a1, t0
xor v0, a1
bltz v0, .Lfault
nop
jr ra # return n
move v0, t0
END(__strncpy_from_user_asm)
.Lfault: jr ra
li v0, -EFAULT
.section __ex_table,"a"
PTR 1b, .Lfault
.previous
