| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
| Sam Ravnborg | 048eb58 | 2005-09-09 22:32:31 +0200 | [diff] [blame] | 10 | #include <asm/asm-offsets.h> |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <asm/regdef.h> |
| 12 | |
| 13 | #define EX(insn,reg,addr,handler) \ |
| 14 | 9: 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 | |
| 30 | LEAF(__strncpy_from_user_asm) |
| 31 | LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok? |
| 32 | and v0, a1 |
| 33 | bnez v0, fault |
| 34 | |
| 35 | FEXPORT(__strncpy_from_user_nocheck_asm) |
| 36 | move v0, zero |
| 37 | move v1, a1 |
| 38 | .set noreorder |
| 39 | 1: EX(lbu, t0, (v1), fault) |
| 40 | PTR_ADDIU v1, 1 |
| 41 | beqz t0, 2f |
| 42 | sb t0, (a0) |
| 43 | PTR_ADDIU v0, 1 |
| 44 | bne v0, a2, 1b |
| 45 | PTR_ADDIU a0, 1 |
| 46 | .set reorder |
| 47 | 2: PTR_ADDU t0, a1, v0 |
| 48 | xor t0, a1 |
| 49 | bltz t0, fault |
| 50 | jr ra # return n |
| 51 | END(__strncpy_from_user_asm) |
| 52 | |
| 53 | fault: li v0, -EFAULT |
| 54 | jr ra |
| 55 | |
| 56 | .section __ex_table,"a" |
| 57 | PTR 1b, fault |
| 58 | .previous |