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 38FEXPORT(__strncpy_from_\func\()_nocheck_asm) 39 move t0, zero 40 move v1, a1 41.ifeqs "\func","kernel" 421: EX(lbu, v0, (v1), .Lfault\@) 43.else 441: EX(lbue, v0, (v1), .Lfault\@) 45.endif 46 PTR_ADDIU v1, 1 47 R10KCBARRIER(0(ra)) 48 sb v0, (a0) 49 beqz v0, 2f 50 PTR_ADDIU t0, 1 51 PTR_ADDIU a0, 1 52 bne t0, a2, 1b 532: PTR_ADDU v0, a1, t0 54 xor v0, a1 55 bltz v0, .Lfault\@ 56 move v0, t0 57 jr ra # return n 58 END(__strncpy_from_\func\()_asm) 59 60.Lfault\@: 61 li v0, -EFAULT 62 jr ra 63 64 .section __ex_table,"a" 65 PTR 1b, .Lfault\@ 66 .previous 67 68 .endm 69 70#ifndef CONFIG_EVA 71 /* Set aliases */ 72 .global __strncpy_from_user_asm 73 .global __strncpy_from_user_nocheck_asm 74 .set __strncpy_from_user_asm, __strncpy_from_kernel_asm 75 .set __strncpy_from_user_nocheck_asm, __strncpy_from_kernel_nocheck_asm 76EXPORT_SYMBOL(__strncpy_from_user_asm) 77EXPORT_SYMBOL(__strncpy_from_user_nocheck_asm) 78#endif 79 80__BUILD_STRNCPY_ASM kernel 81EXPORT_SYMBOL(__strncpy_from_kernel_asm) 82EXPORT_SYMBOL(__strncpy_from_kernel_nocheck_asm) 83 84#ifdef CONFIG_EVA 85 .set push 86 .set eva 87__BUILD_STRNCPY_ASM user 88 .set pop 89EXPORT_SYMBOL(__strncpy_from_user_asm) 90EXPORT_SYMBOL(__strncpy_from_user_nocheck_asm) 91#endif 92