1 /*
2 * This file is subject to the terms and condi
3 * License. See the file "COPYING" in the mai
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 termin
23 * buffer filled, else strlen.
24 */
25
26 /*
27 * Ugly special case have to check: we might g
28 * pointer which wraps into the kernel space.
29 * it happens at most some bytes of the except
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
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)
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.