| /* | |
| * 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 | |
| */ | |
| #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) | |
| move v0, zero | |
| move v1, a1 | |
| .set noreorder | |
| 1: EX(lbu, t0, (v1), .Lfault) | |
| PTR_ADDIU v1, 1 | |
| R10KCBARRIER(0(ra)) | |
| beqz t0, 2f | |
| sb t0, (a0) | |
| PTR_ADDIU v0, 1 | |
| .set reorder | |
| PTR_ADDIU a0, 1 | |
| bne v0, a2, 1b | |
| 2: PTR_ADDU t0, a1, v0 | |
| xor t0, a1 | |
| bltz t0, .Lfault | |
| jr ra # return n | |
| END(__strncpy_from_user_asm) | |
| .Lfault: li v0, -EFAULT | |
| jr ra | |
| .section __ex_table,"a" | |
| PTR 1b, .Lfault | |
| .previous |