blob: d16c76fbfac721c5cdaf20d33628c948ca83571c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 Ravnborg048eb582005-09-09 22:32:31 +020010#include <asm/asm-offsets.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#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, fault
34
35FEXPORT(__strncpy_from_user_nocheck_asm)
36 move v0, zero
37 move v1, a1
38 .set noreorder
391: 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
472: 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
53fault: li v0, -EFAULT
54 jr ra
55
56 .section __ex_table,"a"
57 PTR 1b, fault
58 .previous