| /* |
| * __put_user functions. |
| * |
| * (C) Copyright 1998 Linus Torvalds |
| * (C) Copyright 2005 Andi Kleen |
| * |
| * These functions have a non-standard call interface |
| * to make them more efficient, especially as they |
| * return an error value in addition to the "real" |
| * return value. |
| */ |
| |
| /* |
| * __put_user_X |
| * |
| * Inputs: %rcx contains the address |
| * %rdx contains new value |
| * |
| * Outputs: %rax is error code (0 or -EFAULT) |
| * |
| * %r8 is destroyed. |
| * |
| * These functions should not modify any other registers, |
| * as they get called from within inline assembly. |
| */ |
| |
| #include <linux/linkage.h> |
| #include <asm/page.h> |
| #include <asm/errno.h> |
| #include <asm/asm-offsets.h> |
| #include <asm/thread_info.h> |
| |
| .text |
| .p2align 4 |
| .globl __put_user_1 |
| __put_user_1: |
| GET_THREAD_INFO(%r8) |
| cmpq threadinfo_addr_limit(%r8),%rcx |
| jae bad_put_user |
| 1: movb %dl,(%rcx) |
| xorl %eax,%eax |
| ret |
| |
| .p2align 4 |
| .globl __put_user_2 |
| __put_user_2: |
| GET_THREAD_INFO(%r8) |
| addq $1,%rcx |
| jc 20f |
| cmpq threadinfo_addr_limit(%r8),%rcx |
| jae 20f |
| decq %rcx |
| 2: movw %dx,(%rcx) |
| xorl %eax,%eax |
| ret |
| 20: decq %rcx |
| jmp bad_put_user |
| |
| .p2align 4 |
| .globl __put_user_4 |
| __put_user_4: |
| GET_THREAD_INFO(%r8) |
| addq $3,%rcx |
| jc 30f |
| cmpq threadinfo_addr_limit(%r8),%rcx |
| jae 30f |
| subq $3,%rcx |
| 3: movl %edx,(%rcx) |
| xorl %eax,%eax |
| ret |
| 30: subq $3,%rcx |
| jmp bad_put_user |
| |
| .p2align 4 |
| .globl __put_user_8 |
| __put_user_8: |
| GET_THREAD_INFO(%r8) |
| addq $7,%rcx |
| jc 40f |
| cmpq threadinfo_addr_limit(%r8),%rcx |
| jae 40f |
| subq $7,%rcx |
| 4: movq %rdx,(%rcx) |
| xorl %eax,%eax |
| ret |
| 40: subq $7,%rcx |
| jmp bad_put_user |
| |
| bad_put_user: |
| movq $(-EFAULT),%rax |
| ret |
| |
| .section __ex_table,"a" |
| .quad 1b,bad_put_user |
| .quad 2b,bad_put_user |
| .quad 3b,bad_put_user |
| .quad 4b,bad_put_user |
| .previous |