| 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 | */ |
| 11 | #include <asm/thread_info.h> |
| 12 | |
| 13 | |
| 14 | /* |
| 15 | * __put_user_X |
| 16 | * |
| 17 | * Inputs: %eax[:%edx] contains the data |
| 18 | * %ecx contains the address |
| 19 | * |
| 20 | * Outputs: %eax is error code (0 or -EFAULT) |
| 21 | * |
| 22 | * These functions should not modify any other registers, |
| 23 | * as they get called from within inline assembly. |
| 24 | */ |
| 25 | |
| 26 | #define ENTER pushl %ebx ; GET_THREAD_INFO(%ebx) |
| 27 | #define EXIT popl %ebx ; ret |
| 28 | |
| 29 | .text |
| 30 | .align 4 |
| 31 | .globl __put_user_1 |
| 32 | __put_user_1: |
| 33 | ENTER |
| 34 | cmpl TI_addr_limit(%ebx),%ecx |
| 35 | jae bad_put_user |
| 36 | 1: movb %al,(%ecx) |
| 37 | xorl %eax,%eax |
| 38 | EXIT |
| 39 | |
| 40 | .align 4 |
| 41 | .globl __put_user_2 |
| 42 | __put_user_2: |
| 43 | ENTER |
| 44 | movl TI_addr_limit(%ebx),%ebx |
| 45 | subl $1,%ebx |
| 46 | cmpl %ebx,%ecx |
| 47 | jae bad_put_user |
| 48 | 2: movw %ax,(%ecx) |
| 49 | xorl %eax,%eax |
| 50 | EXIT |
| 51 | |
| 52 | .align 4 |
| 53 | .globl __put_user_4 |
| 54 | __put_user_4: |
| 55 | ENTER |
| 56 | movl TI_addr_limit(%ebx),%ebx |
| 57 | subl $3,%ebx |
| 58 | cmpl %ebx,%ecx |
| 59 | jae bad_put_user |
| 60 | 3: movl %eax,(%ecx) |
| 61 | xorl %eax,%eax |
| 62 | EXIT |
| 63 | |
| 64 | .align 4 |
| 65 | .globl __put_user_8 |
| 66 | __put_user_8: |
| 67 | ENTER |
| 68 | movl TI_addr_limit(%ebx),%ebx |
| 69 | subl $7,%ebx |
| 70 | cmpl %ebx,%ecx |
| 71 | jae bad_put_user |
| 72 | 4: movl %eax,(%ecx) |
| 73 | 5: movl %edx,4(%ecx) |
| 74 | xorl %eax,%eax |
| 75 | EXIT |
| 76 | |
| 77 | bad_put_user: |
| 78 | movl $-14,%eax |
| 79 | EXIT |
| 80 | |
| 81 | .section __ex_table,"a" |
| 82 | .long 1b,bad_put_user |
| 83 | .long 2b,bad_put_user |
| 84 | .long 3b,bad_put_user |
| 85 | .long 4b,bad_put_user |
| 86 | .long 5b,bad_put_user |
| 87 | .previous |