tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 * Copyright (C) 2011 MIPS Technologies, Inc.
8 */
9#include <linux/errno.h>
10#include <asm/asm.h>
11#include <asm/asm-offsets.h>
12#include <asm/regdef.h>
13
14#define EX(insn,reg,addr,handler) \
159: insn reg, addr; \
16 .section __ex_table,"a"; \
17 PTR 9b, handler; \
18 .previous
19
20/*
21 * Returns: -EFAULT if exception before terminator, N if the entire
22 * buffer filled, else strlen.
23 */
24
25/*
26 * Ugly special case have to check: we might get passed a user space
27 * pointer which wraps into the kernel space. We don't deal with that. If
28 * it happens at most some bytes of the exceptions handlers will be copied.
29 */
30
31LEAF(__strncpy_from_user_asm)
32 LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
33 and v0, a1
34 bnez v0, .Lfault
35
36FEXPORT(__strncpy_from_user_nocheck_asm)
37 .set noreorder
38 move t0, zero
39 move v1, a1
401: EX(lbu, v0, (v1), .Lfault)
41 PTR_ADDIU v1, 1
42 R10KCBARRIER(0(ra))
43 beqz v0, 2f
44 sb v0, (a0)
45 PTR_ADDIU t0, 1
46 bne t0, a2, 1b
47 PTR_ADDIU a0, 1
482: PTR_ADDU v0, a1, t0
49 xor v0, a1
50 bltz v0, .Lfault
51 nop
52 jr ra # return n
53 move v0, t0
54 END(__strncpy_from_user_asm)
55
56.Lfault: jr ra
57 li v0, -EFAULT
58
59 .section __ex_table,"a"
60 PTR 1b, .Lfault
61 .previous