diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/x86_64/lib/usercopy.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/x86_64/lib/usercopy.c')
-rw-r--r-- | arch/x86_64/lib/usercopy.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/x86_64/lib/usercopy.c b/arch/x86_64/lib/usercopy.c new file mode 100644 index 000000000000..db8abba1ad81 --- /dev/null +++ b/arch/x86_64/lib/usercopy.c | |||
@@ -0,0 +1,153 @@ | |||
1 | /* | ||
2 | * User address space access functions. | ||
3 | * | ||
4 | * Copyright 1997 Andi Kleen <ak@muc.de> | ||
5 | * Copyright 1997 Linus Torvalds | ||
6 | * Copyright 2002 Andi Kleen <ak@suse.de> | ||
7 | */ | ||
8 | #include <asm/uaccess.h> | ||
9 | |||
10 | /* | ||
11 | * Copy a null terminated string from userspace. | ||
12 | */ | ||
13 | |||
14 | #define __do_strncpy_from_user(dst,src,count,res) \ | ||
15 | do { \ | ||
16 | long __d0, __d1, __d2; \ | ||
17 | might_sleep(); \ | ||
18 | __asm__ __volatile__( \ | ||
19 | " testq %1,%1\n" \ | ||
20 | " jz 2f\n" \ | ||
21 | "0: lodsb\n" \ | ||
22 | " stosb\n" \ | ||
23 | " testb %%al,%%al\n" \ | ||
24 | " jz 1f\n" \ | ||
25 | " decq %1\n" \ | ||
26 | " jnz 0b\n" \ | ||
27 | "1: subq %1,%0\n" \ | ||
28 | "2:\n" \ | ||
29 | ".section .fixup,\"ax\"\n" \ | ||
30 | "3: movq %5,%0\n" \ | ||
31 | " jmp 2b\n" \ | ||
32 | ".previous\n" \ | ||
33 | ".section __ex_table,\"a\"\n" \ | ||
34 | " .align 8\n" \ | ||
35 | " .quad 0b,3b\n" \ | ||
36 | ".previous" \ | ||
37 | : "=r"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1), \ | ||
38 | "=&D" (__d2) \ | ||
39 | : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \ | ||
40 | : "memory"); \ | ||
41 | } while (0) | ||
42 | |||
43 | long | ||
44 | __strncpy_from_user(char *dst, const char __user *src, long count) | ||
45 | { | ||
46 | long res; | ||
47 | __do_strncpy_from_user(dst, src, count, res); | ||
48 | return res; | ||
49 | } | ||
50 | |||
51 | long | ||
52 | strncpy_from_user(char *dst, const char __user *src, long count) | ||
53 | { | ||
54 | long res = -EFAULT; | ||
55 | if (access_ok(VERIFY_READ, src, 1)) | ||
56 | __do_strncpy_from_user(dst, src, count, res); | ||
57 | return res; | ||
58 | } | ||
59 | |||
60 | /* | ||
61 | * Zero Userspace | ||
62 | */ | ||
63 | |||
64 | unsigned long __clear_user(void __user *addr, unsigned long size) | ||
65 | { | ||
66 | long __d0; | ||
67 | might_sleep(); | ||
68 | /* no memory constraint because it doesn't change any memory gcc knows | ||
69 | about */ | ||
70 | asm volatile( | ||
71 | " testq %[size8],%[size8]\n" | ||
72 | " jz 4f\n" | ||
73 | "0: movq %[zero],(%[dst])\n" | ||
74 | " addq %[eight],%[dst]\n" | ||
75 | " decl %%ecx ; jnz 0b\n" | ||
76 | "4: movq %[size1],%%rcx\n" | ||
77 | " testl %%ecx,%%ecx\n" | ||
78 | " jz 2f\n" | ||
79 | "1: movb %b[zero],(%[dst])\n" | ||
80 | " incq %[dst]\n" | ||
81 | " decl %%ecx ; jnz 1b\n" | ||
82 | "2:\n" | ||
83 | ".section .fixup,\"ax\"\n" | ||
84 | "3: lea 0(%[size1],%[size8],8),%[size8]\n" | ||
85 | " jmp 2b\n" | ||
86 | ".previous\n" | ||
87 | ".section __ex_table,\"a\"\n" | ||
88 | " .align 8\n" | ||
89 | " .quad 0b,3b\n" | ||
90 | " .quad 1b,2b\n" | ||
91 | ".previous" | ||
92 | : [size8] "=c"(size), [dst] "=&D" (__d0) | ||
93 | : [size1] "r"(size & 7), "[size8]" (size / 8), "[dst]"(addr), | ||
94 | [zero] "r" (0UL), [eight] "r" (8UL)); | ||
95 | return size; | ||
96 | } | ||
97 | |||
98 | |||
99 | unsigned long clear_user(void __user *to, unsigned long n) | ||
100 | { | ||
101 | if (access_ok(VERIFY_WRITE, to, n)) | ||
102 | return __clear_user(to, n); | ||
103 | return n; | ||
104 | } | ||
105 | |||
106 | /* | ||
107 | * Return the size of a string (including the ending 0) | ||
108 | * | ||
109 | * Return 0 on exception, a value greater than N if too long | ||
110 | */ | ||
111 | |||
112 | long strnlen_user(const char __user *s, long n) | ||
113 | { | ||
114 | long res = 0; | ||
115 | char c; | ||
116 | |||
117 | if (!access_ok(VERIFY_READ, s, n)) | ||
118 | return 0; | ||
119 | |||
120 | while (1) { | ||
121 | if (res>n) | ||
122 | return n+1; | ||
123 | if (__get_user(c, s)) | ||
124 | return 0; | ||
125 | if (!c) | ||
126 | return res+1; | ||
127 | res++; | ||
128 | s++; | ||
129 | } | ||
130 | } | ||
131 | |||
132 | long strlen_user(const char __user *s) | ||
133 | { | ||
134 | long res = 0; | ||
135 | char c; | ||
136 | |||
137 | for (;;) { | ||
138 | if (get_user(c, s)) | ||
139 | return 0; | ||
140 | if (!c) | ||
141 | return res+1; | ||
142 | res++; | ||
143 | s++; | ||
144 | } | ||
145 | } | ||
146 | |||
147 | unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len) | ||
148 | { | ||
149 | if (access_ok(VERIFY_WRITE, to, len) && access_ok(VERIFY_READ, from, len)) { | ||
150 | return copy_user_generic((__force void *)to, (__force void *)from, len); | ||
151 | } | ||
152 | return len; | ||
153 | } | ||