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 <linux/export.h> 11 #include <asm/asm.h> 12 #include <asm/asm-offsets.h> 13 #include <asm/regdef.h> 14 15 #define EX(insn,reg,addr,handler) \ 16 9: insn reg, addr; \ 17 .section __ex_table,"a"; \ 18 PTR_WD 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 LEAF(__strncpy_from_user_asm) 33 move t0, zero 34 move v1, a1 35 #ifdef CONFIG_EVA 36 .set push 37 .set eva 38 1: EX(lbue, v0, (v1), .Lfault) 39 .set pop 40 #else 41 1: EX(lbu, v0, (v1), .Lfault) 42 #endif 43 PTR_ADDIU v1, 1 44 R10KCBARRIER(0(ra)) 45 sb v0, (a0) 46 beqz v0, 2f 47 PTR_ADDIU t0, 1 48 PTR_ADDIU a0, 1 49 bne t0, a2, 1b 50 2: PTR_ADDU v0, a1, t0 51 xor v0, a1 52 bltz v0, .Lfault 53 move v0, t0 54 jr ra # return n 55 END(__strncpy_from_user_asm) 56 57 .Lfault: 58 li v0, -EFAULT 59 jr ra 60 61 .section __ex_table,"a" 62 PTR_WD 1b, .Lfault 63 .previous 64 65 EXPORT_SYMBOL(__strncpy_from_user_asm) 66