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> |
| 14 | |
| 15 | |
| 16 | /* |
| 17 | * __put_user_X |
| 18 | * |
| 19 | * Inputs: %eax[:%edx] contains the data |
| 20 | * %ecx contains the address |
| 21 | * |
| 22 | * Outputs: %eax is error code (0 or -EFAULT) |
| 23 | * |
| 24 | * These functions should not modify any other registers, |
| 25 | * as they get called from within inline assembly. |
| 26 | */ |
| 27 | |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 28 | #define ENTER CFI_STARTPROC ; \ |
| 29 | pushl %ebx ; \ |
| 30 | CFI_ADJUST_CFA_OFFSET 4 ; \ |
| 31 | CFI_REL_OFFSET ebx, 0 ; \ |
| 32 | GET_THREAD_INFO(%ebx) |
| 33 | #define EXIT popl %ebx ; \ |
| 34 | CFI_ADJUST_CFA_OFFSET -4 ; \ |
| 35 | CFI_RESTORE ebx ; \ |
| 36 | ret ; \ |
| 37 | CFI_ENDPROC |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
| 39 | .text |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 40 | ENTRY(__put_user_1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | ENTER |
| 42 | cmpl TI_addr_limit(%ebx),%ecx |
| 43 | jae bad_put_user |
| 44 | 1: movb %al,(%ecx) |
| 45 | xorl %eax,%eax |
| 46 | EXIT |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 47 | ENDPROC(__put_user_1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 49 | ENTRY(__put_user_2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | ENTER |
| 51 | movl TI_addr_limit(%ebx),%ebx |
| 52 | subl $1,%ebx |
| 53 | cmpl %ebx,%ecx |
| 54 | jae bad_put_user |
| 55 | 2: movw %ax,(%ecx) |
| 56 | xorl %eax,%eax |
| 57 | EXIT |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 58 | ENDPROC(__put_user_2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 60 | ENTRY(__put_user_4) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | ENTER |
| 62 | movl TI_addr_limit(%ebx),%ebx |
| 63 | subl $3,%ebx |
| 64 | cmpl %ebx,%ecx |
| 65 | jae bad_put_user |
| 66 | 3: movl %eax,(%ecx) |
| 67 | xorl %eax,%eax |
| 68 | EXIT |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 69 | ENDPROC(__put_user_4) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 71 | ENTRY(__put_user_8) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | ENTER |
| 73 | movl TI_addr_limit(%ebx),%ebx |
| 74 | subl $7,%ebx |
| 75 | cmpl %ebx,%ecx |
| 76 | jae bad_put_user |
| 77 | 4: movl %eax,(%ecx) |
| 78 | 5: movl %edx,4(%ecx) |
| 79 | xorl %eax,%eax |
| 80 | EXIT |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 81 | ENDPROC(__put_user_8) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | |
| 83 | bad_put_user: |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 84 | CFI_STARTPROC simple |
| 85 | CFI_DEF_CFA esp, 2*4 |
| 86 | CFI_OFFSET eip, -1*4 |
| 87 | CFI_OFFSET ebx, -2*4 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | movl $-14,%eax |
| 89 | EXIT |
Jan Beulich | 00e065e | 2007-05-02 19:27:05 +0200 | [diff] [blame^] | 90 | END(bad_put_user) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | |
| 92 | .section __ex_table,"a" |
| 93 | .long 1b,bad_put_user |
| 94 | .long 2b,bad_put_user |
| 95 | .long 3b,bad_put_user |
| 96 | .long 4b,bad_put_user |
| 97 | .long 5b,bad_put_user |
| 98 | .previous |