1/* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1996, 1999 by Ralf Baechle 7 * Copyright (C) 2011 MIPS Technologies, Inc. 8 */ 9#include <linux/errno.h> 10#include <asm/asm.h> 11#include <asm/asm-offsets.h> 12#include <asm/export.h> 13#include <asm/regdef.h> 14 15#define EX(insn,reg,addr,handler) \ 169: insn reg, addr; \ 17 .section __ex_table,"a"; \ 18 PTR 9b, handler; \ 19 .previous 20 21/* 22 * Returns: -EFAULT if exception before terminator, N if the entire 23 * buffer filled, else strlen. 24 */ 25 26/* 27 * Ugly special case have to check: we might get passed a user space 28 * pointer which wraps into the kernel space. We don't deal with that. If 29 * it happens at most some bytes of the exceptions handlers will be copied. 30 */ 31 32 .macro __BUILD_STRNCPY_ASM func 33LEAF(__strncpy_from_\func\()_asm) 34 LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok? 35 and v0, a1 36 bnez v0, .Lfault\@ 37 38 move t0, zero 39 move v1, a1 40.ifeqs "\func","kernel" 411: EX(lbu, v0, (v1), .Lfault\@) 42.else 431: EX(lbue, v0, (v1), .Lfault\@) 44.endif 45 PTR_ADDIU v1, 1 46 R10KCBARRIER(0(ra)) 47 sb v0, (a0) 48 beqz v0, 2f 49 PTR_ADDIU t0, 1 50 PTR_ADDIU a0, 1 51 bne t0, a2, 1b 522: PTR_ADDU v0, a1, t0 53 xor v0, a1 54 bltz v0, .Lfault\@ 55 move v0, t0 56 jr ra # return n 57 END(__strncpy_from_\func\()_asm) 58 59.Lfault\@: 60 li v0, -EFAULT 61 jr ra 62 63 .section __ex_table,"a" 64 PTR 1b, .Lfault\@ 65 .previous 66 67 .endm 68 69#ifndef CONFIG_EVA 70 /* Set aliases */ 71 .global __strncpy_from_user_asm 72 .set __strncpy_from_user_asm, __strncpy_from_kernel_asm 73EXPORT_SYMBOL(__strncpy_from_user_asm) 74#endif 75 76__BUILD_STRNCPY_ASM kernel 77EXPORT_SYMBOL(__strncpy_from_kernel_asm) 78 79#ifdef CONFIG_EVA 80 .set push 81 .set eva 82__BUILD_STRNCPY_ASM user 83 .set pop 84EXPORT_SYMBOL(__strncpy_from_user_asm) 85#endif 86