Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * __put_user functions. |
| 3 | * |
| 4 | * (C) Copyright 2005 Linus Torvalds |
| 5 | * |
| 6 | * These functions have a non-standard call interface |
| 7 | * to make them more efficient, especially as they |
| 8 | * return an error value in addition to the "real" |
| 9 | * return value. |
| 10 | */ |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 11 | #include <linux/linkage.h> |
| 12 | #include <asm/dwarf2.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <asm/thread_info.h> |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 14 | #include <asm/asm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | |
| 16 | |
| 17 | /* |
| 18 | * __put_user_X |
| 19 | * |
| 20 | * Inputs: %eax[:%edx] contains the data |
| 21 | * %ecx contains the address |
| 22 | * |
| 23 | * Outputs: %eax is error code (0 or -EFAULT) |
| 24 | * |
| 25 | * These functions should not modify any other registers, |
| 26 | * as they get called from within inline assembly. |
| 27 | */ |
| 28 | |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 29 | #define ENTER CFI_STARTPROC ; \ |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 30 | GET_THREAD_INFO(%_ASM_BX) |
Glauber Costa | 268cf04 | 2008-06-24 12:40:55 -0300 | [diff] [blame] | 31 | #define EXIT ret ; \ |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 32 | CFI_ENDPROC |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
| 34 | .text |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 35 | ENTRY(__put_user_1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | ENTER |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 37 | cmp TI_addr_limit(%_ASM_BX),%_ASM_CX |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | jae bad_put_user |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 39 | 1: movb %al,(%_ASM_CX) |
Glauber Costa | efea505 | 2008-06-24 16:59:05 -0300 | [diff] [blame] | 40 | xor %eax,%eax |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | EXIT |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 42 | ENDPROC(__put_user_1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 44 | ENTRY(__put_user_2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | ENTER |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 46 | mov TI_addr_limit(%_ASM_BX),%_ASM_BX |
| 47 | sub $1,%_ASM_BX |
| 48 | cmp %_ASM_BX,%_ASM_CX |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | jae bad_put_user |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 50 | 2: movw %ax,(%_ASM_CX) |
Glauber Costa | efea505 | 2008-06-24 16:59:05 -0300 | [diff] [blame] | 51 | xor %eax,%eax |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | EXIT |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 53 | ENDPROC(__put_user_2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 55 | ENTRY(__put_user_4) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | ENTER |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 57 | mov TI_addr_limit(%_ASM_BX),%_ASM_BX |
| 58 | sub $3,%_ASM_BX |
| 59 | cmp %_ASM_BX,%_ASM_CX |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | jae bad_put_user |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 61 | 3: movl %eax,(%_ASM_CX) |
Glauber Costa | efea505 | 2008-06-24 16:59:05 -0300 | [diff] [blame] | 62 | xor %eax,%eax |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | EXIT |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 64 | ENDPROC(__put_user_4) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 66 | ENTRY(__put_user_8) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | ENTER |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 68 | mov TI_addr_limit(%_ASM_BX),%_ASM_BX |
| 69 | sub $7,%_ASM_BX |
| 70 | cmp %_ASM_BX,%_ASM_CX |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | jae bad_put_user |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 72 | 4: movl %_ASM_AX,(%_ASM_CX) |
| 73 | 5: movl %edx,4(%_ASM_CX) |
Glauber Costa | efea505 | 2008-06-24 16:59:05 -0300 | [diff] [blame] | 74 | xor %eax,%eax |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | EXIT |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 76 | ENDPROC(__put_user_8) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
| 78 | bad_put_user: |
Glauber Costa | 268cf04 | 2008-06-24 12:40:55 -0300 | [diff] [blame] | 79 | CFI_STARTPROC |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | movl $-14,%eax |
| 81 | EXIT |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame] | 82 | END(bad_put_user) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | |
| 84 | .section __ex_table,"a" |
Glauber Costa | 2528de4 | 2008-06-24 17:36:31 -0300 | [diff] [blame^] | 85 | _ASM_PTR 1b,bad_put_user |
| 86 | _ASM_PTR 2b,bad_put_user |
| 87 | _ASM_PTR 3b,bad_put_user |
| 88 | _ASM_PTR 4b,bad_put_user |
| 89 | _ASM_PTR 5b,bad_put_user |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | .previous |