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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * __put_user functions. | |
3 | * | |
4 | * (C) Copyright 2005 Linus Torvalds | |
5cbbc3b1 GC |
5 | * (C) Copyright 2005 Andi Kleen |
6 | * (C) Copyright 2008 Glauber Costa | |
1da177e4 LT |
7 | * |
8 | * These functions have a non-standard call interface | |
9 | * to make them more efficient, especially as they | |
10 | * return an error value in addition to the "real" | |
11 | * return value. | |
12 | */ | |
00e065ea JB |
13 | #include <linux/linkage.h> |
14 | #include <asm/dwarf2.h> | |
1da177e4 | 15 | #include <asm/thread_info.h> |
5cbbc3b1 | 16 | #include <asm/errno.h> |
2528de43 | 17 | #include <asm/asm.h> |
1da177e4 LT |
18 | |
19 | ||
20 | /* | |
21 | * __put_user_X | |
22 | * | |
23 | * Inputs: %eax[:%edx] contains the data | |
24 | * %ecx contains the address | |
25 | * | |
26 | * Outputs: %eax is error code (0 or -EFAULT) | |
27 | * | |
28 | * These functions should not modify any other registers, | |
29 | * as they get called from within inline assembly. | |
30 | */ | |
31 | ||
00e065ea | 32 | #define ENTER CFI_STARTPROC ; \ |
2528de43 | 33 | GET_THREAD_INFO(%_ASM_BX) |
268cf048 | 34 | #define EXIT ret ; \ |
00e065ea | 35 | CFI_ENDPROC |
1da177e4 LT |
36 | |
37 | .text | |
00e065ea | 38 | ENTRY(__put_user_1) |
1da177e4 | 39 | ENTER |
2528de43 | 40 | cmp TI_addr_limit(%_ASM_BX),%_ASM_CX |
1da177e4 | 41 | jae bad_put_user |
2528de43 | 42 | 1: movb %al,(%_ASM_CX) |
efea505d | 43 | xor %eax,%eax |
1da177e4 | 44 | EXIT |
00e065ea | 45 | ENDPROC(__put_user_1) |
1da177e4 | 46 | |
00e065ea | 47 | ENTRY(__put_user_2) |
1da177e4 | 48 | ENTER |
2528de43 GC |
49 | mov TI_addr_limit(%_ASM_BX),%_ASM_BX |
50 | sub $1,%_ASM_BX | |
51 | cmp %_ASM_BX,%_ASM_CX | |
1da177e4 | 52 | jae bad_put_user |
2528de43 | 53 | 2: movw %ax,(%_ASM_CX) |
efea505d | 54 | xor %eax,%eax |
1da177e4 | 55 | EXIT |
00e065ea | 56 | ENDPROC(__put_user_2) |
1da177e4 | 57 | |
00e065ea | 58 | ENTRY(__put_user_4) |
1da177e4 | 59 | ENTER |
2528de43 GC |
60 | mov TI_addr_limit(%_ASM_BX),%_ASM_BX |
61 | sub $3,%_ASM_BX | |
62 | cmp %_ASM_BX,%_ASM_CX | |
1da177e4 | 63 | jae bad_put_user |
2528de43 | 64 | 3: movl %eax,(%_ASM_CX) |
efea505d | 65 | xor %eax,%eax |
1da177e4 | 66 | EXIT |
00e065ea | 67 | ENDPROC(__put_user_4) |
1da177e4 | 68 | |
00e065ea | 69 | ENTRY(__put_user_8) |
1da177e4 | 70 | ENTER |
2528de43 GC |
71 | mov TI_addr_limit(%_ASM_BX),%_ASM_BX |
72 | sub $7,%_ASM_BX | |
73 | cmp %_ASM_BX,%_ASM_CX | |
1da177e4 | 74 | jae bad_put_user |
5cbbc3b1 GC |
75 | 4: mov %_ASM_AX,(%_ASM_CX) |
76 | #ifdef CONFIG_X86_32 | |
2528de43 | 77 | 5: movl %edx,4(%_ASM_CX) |
5cbbc3b1 | 78 | #endif |
efea505d | 79 | xor %eax,%eax |
1da177e4 | 80 | EXIT |
00e065ea | 81 | ENDPROC(__put_user_8) |
1da177e4 LT |
82 | |
83 | bad_put_user: | |
268cf048 | 84 | CFI_STARTPROC |
5cbbc3b1 | 85 | movl $-EFAULT,%eax |
1da177e4 | 86 | EXIT |
00e065ea | 87 | END(bad_put_user) |
1da177e4 LT |
88 | |
89 | .section __ex_table,"a" | |
2528de43 GC |
90 | _ASM_PTR 1b,bad_put_user |
91 | _ASM_PTR 2b,bad_put_user | |
92 | _ASM_PTR 3b,bad_put_user | |
93 | _ASM_PTR 4b,bad_put_user | |
5cbbc3b1 | 94 | #ifdef CONFIG_X86_32 |
2528de43 | 95 | _ASM_PTR 5b,bad_put_user |
5cbbc3b1 | 96 | #endif |
1da177e4 | 97 | .previous |