diff options
Diffstat (limited to 'arch/x86_64/lib/putuser.S')
-rw-r--r-- | arch/x86_64/lib/putuser.S | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/arch/x86_64/lib/putuser.S b/arch/x86_64/lib/putuser.S new file mode 100644 index 000000000000..0dee1fdcb162 --- /dev/null +++ b/arch/x86_64/lib/putuser.S | |||
@@ -0,0 +1,89 @@ | |||
1 | /* | ||
2 | * __put_user functions. | ||
3 | * | ||
4 | * (C) Copyright 1998 Linus Torvalds | ||
5 | * (C) Copyright 2005 Andi Kleen | ||
6 | * | ||
7 | * These functions have a non-standard call interface | ||
8 | * to make them more efficient, especially as they | ||
9 | * return an error value in addition to the "real" | ||
10 | * return value. | ||
11 | */ | ||
12 | |||
13 | /* | ||
14 | * __put_user_X | ||
15 | * | ||
16 | * Inputs: %rcx contains the address | ||
17 | * %rdx contains new value | ||
18 | * | ||
19 | * Outputs: %rax is error code (0 or -EFAULT) | ||
20 | * | ||
21 | * %r8 is destroyed. | ||
22 | * | ||
23 | * These functions should not modify any other registers, | ||
24 | * as they get called from within inline assembly. | ||
25 | */ | ||
26 | |||
27 | #include <linux/linkage.h> | ||
28 | #include <asm/page.h> | ||
29 | #include <asm/errno.h> | ||
30 | #include <asm/offset.h> | ||
31 | #include <asm/thread_info.h> | ||
32 | |||
33 | .text | ||
34 | .p2align 4 | ||
35 | .globl __put_user_1 | ||
36 | __put_user_1: | ||
37 | GET_THREAD_INFO(%r8) | ||
38 | cmpq threadinfo_addr_limit(%r8),%rcx | ||
39 | jae bad_put_user | ||
40 | 1: movb %dl,(%rcx) | ||
41 | xorl %eax,%eax | ||
42 | ret | ||
43 | |||
44 | .p2align 4 | ||
45 | .globl __put_user_2 | ||
46 | __put_user_2: | ||
47 | GET_THREAD_INFO(%r8) | ||
48 | addq $1,%rcx | ||
49 | jc bad_put_user | ||
50 | cmpq threadinfo_addr_limit(%r8),%rcx | ||
51 | jae bad_put_user | ||
52 | 2: movw %dx,-1(%rcx) | ||
53 | xorl %eax,%eax | ||
54 | ret | ||
55 | |||
56 | .p2align 4 | ||
57 | .globl __put_user_4 | ||
58 | __put_user_4: | ||
59 | GET_THREAD_INFO(%r8) | ||
60 | addq $3,%rcx | ||
61 | jc bad_put_user | ||
62 | cmpq threadinfo_addr_limit(%r8),%rcx | ||
63 | jae bad_put_user | ||
64 | 3: movl %edx,-3(%rcx) | ||
65 | xorl %eax,%eax | ||
66 | ret | ||
67 | |||
68 | .p2align 4 | ||
69 | .globl __put_user_8 | ||
70 | __put_user_8: | ||
71 | GET_THREAD_INFO(%r8) | ||
72 | addq $7,%rcx | ||
73 | jc bad_put_user | ||
74 | cmpq threadinfo_addr_limit(%r8),%rcx | ||
75 | jae bad_put_user | ||
76 | 4: movq %rdx,-7(%rcx) | ||
77 | xorl %eax,%eax | ||
78 | ret | ||
79 | |||
80 | bad_put_user: | ||
81 | movq $(-EFAULT),%rax | ||
82 | ret | ||
83 | |||
84 | .section __ex_table,"a" | ||
85 | .quad 1b,bad_put_user | ||
86 | .quad 2b,bad_put_user | ||
87 | .quad 3b,bad_put_user | ||
88 | .quad 4b,bad_put_user | ||
89 | .previous | ||