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/export.h>
13#include <asm/regdef.h>
14
15#define EX(insn,reg,addr,handler) \
169: insn reg, addr; \
17 .section __ex_table,"a"; \
18 PTR 9b, handler; \
19 .previous
20
21/*
22 * Returns: -EFAULT if exception before terminator, N if the entire
23 * buffer filled, else strlen.
24 */
25
26/*
27 * Ugly special case have to check: we might get passed a user space
28 * pointer which wraps into the kernel space. We don't deal with that. If
29 * it happens at most some bytes of the exceptions handlers will be copied.
30 */
31
32 .macro __BUILD_STRNCPY_ASM func
33LEAF(__strncpy_from_\func\()_asm)
34 LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
35 and v0, a1
36 bnez v0, .Lfault\@
37
38FEXPORT(__strncpy_from_\func\()_nocheck_asm)
39 move t0, zero
40 move v1, a1
41.ifeqs "\func","kernel"
421: EX(lbu, v0, (v1), .Lfault\@)
43.else
441: EX(lbue, v0, (v1), .Lfault\@)
45.endif
46 PTR_ADDIU v1, 1
47 R10KCBARRIER(0(ra))
48 sb v0, (a0)
49 beqz v0, 2f
50 PTR_ADDIU t0, 1
51 PTR_ADDIU a0, 1
52 bne t0, a2, 1b
532: PTR_ADDU v0, a1, t0
54 xor v0, a1
55 bltz v0, .Lfault\@
56 move v0, t0
57 jr ra # return n
58 END(__strncpy_from_\func\()_asm)
59
60.Lfault\@:
61 li v0, -EFAULT
62 jr ra
63
64 .section __ex_table,"a"
65 PTR 1b, .Lfault\@
66 .previous
67
68 .endm
69
70#ifndef CONFIG_EVA
71 /* Set aliases */
72 .global __strncpy_from_user_asm
73 .global __strncpy_from_user_nocheck_asm
74 .set __strncpy_from_user_asm, __strncpy_from_kernel_asm
75 .set __strncpy_from_user_nocheck_asm, __strncpy_from_kernel_nocheck_asm
76EXPORT_SYMBOL(__strncpy_from_user_asm)
77EXPORT_SYMBOL(__strncpy_from_user_nocheck_asm)
78#endif
79
80__BUILD_STRNCPY_ASM kernel
81EXPORT_SYMBOL(__strncpy_from_kernel_asm)
82EXPORT_SYMBOL(__strncpy_from_kernel_nocheck_asm)
83
84#ifdef CONFIG_EVA
85 .set push
86 .set eva
87__BUILD_STRNCPY_ASM user
88 .set pop
89EXPORT_SYMBOL(__strncpy_from_user_asm)
90EXPORT_SYMBOL(__strncpy_from_user_nocheck_asm)
91#endif