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 */ 8#include <linux/errno.h> 9#include <asm/asm.h> 10#include <asm/asm-offsets.h> 11#include <asm/regdef.h> 12 13#define EX(insn,reg,addr,handler) \ 149: insn reg, addr; \ 15 .section __ex_table,"a"; \ 16 PTR 9b, handler; \ 17 .previous 18 19/* 20 * Returns: -EFAULT if exception before terminator, N if the entire 21 * buffer filled, else strlen. 22 */ 23 24/* 25 * Ugly special case have to check: we might get passed a user space 26 * pointer which wraps into the kernel space. We don't deal with that. If 27 * it happens at most some bytes of the exceptions handlers will be copied. 28 */ 29 30LEAF(__strncpy_from_user_asm) 31 LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok? 32 and v0, a1 33 bnez v0, .Lfault 34 35FEXPORT(__strncpy_from_user_nocheck_asm) 36 move v0, zero 37 move v1, a1 38 .set noreorder 391: EX(lbu, t0, (v1), .Lfault) 40 PTR_ADDIU v1, 1 41 R10KCBARRIER(0(ra)) 42 beqz t0, 2f 43 sb t0, (a0) 44 PTR_ADDIU v0, 1 45 .set reorder 46 PTR_ADDIU a0, 1 47 bne v0, a2, 1b 482: PTR_ADDU t0, a1, v0 49 xor t0, a1 50 bltz t0, .Lfault 51 jr ra # return n 52 END(__strncpy_from_user_asm) 53 54.Lfault: li v0, -EFAULT 55 jr ra 56 57 .section __ex_table,"a" 58 PTR 1b, .Lfault 59 .previous 60