* __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.
+ * to make them more efficient, especially as they
+ * return an error value in addition to the "real"
+ * return value.
*/
/*
* __put_user_X
*
- * Inputs: %rax contains the address
- * %rdx contains the value
+ * Inputs: %rcx contains the address
+ * %rdx contains new value
*
* Outputs: %rax is error code (0 or -EFAULT)
- * %rbx is corrupted (will contain "current_task").
+ *
+ * %r8 is destroyed.
*
* These functions should not modify any other registers,
* as they get called from within inline assembly.
*/
-/* FIXME: putuser.S should be really merged with getuser.S, and preprocessor should be used to keep code duplication lower */
-
#include <linux/linkage.h>
#include <asm/page.h>
#include <asm/errno.h>
#include <asm/offset.h>
#include <asm/thread_info.h>
-.text
-.p2align
+ .text
+ .p2align 4
.globl __put_user_1
__put_user_1:
- GET_THREAD_INFO(%rbx)
- cmpq threadinfo_addr_limit(%rbx),%rax
+ GET_THREAD_INFO(%r8)
+ cmpq threadinfo_addr_limit(%r8),%rcx
jae bad_put_user
-1: movb %dl,(%rax)
- xorq %rax,%rax
+1: movb %dl,(%rcx)
+ xorl %eax,%eax
ret
-.p2align
+ .p2align 4
.globl __put_user_2
__put_user_2:
- GET_THREAD_INFO(%rbx)
- addq $1,%rax
- jc bad_put_user
- cmpq threadinfo_addr_limit(%rbx),%rax
- jae bad_put_user
-2: movw %dx,-1(%rax)
- xorq %rax,%rax
+ 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
+ .p2align 4
.globl __put_user_4
__put_user_4:
- GET_THREAD_INFO(%rbx)
- addq $3,%rax
- jc bad_put_user
- cmpq threadinfo_addr_limit(%rbx),%rax
- jae bad_put_user
-3: movl %edx,-3(%rax)
- xorq %rax,%rax
+ 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
+ .p2align 4
.globl __put_user_8
__put_user_8:
- GET_THREAD_INFO(%rbx)
- addq $7,%rax
- jc bad_put_user
- cmpq threadinfo_addr_limit(%rbx),%rax
- jae bad_put_user
-4: movq %rdx,-7(%rax)
- xorq %rax,%rax
+ 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
-ENTRY(bad_put_user)
bad_put_user:
movq $(-EFAULT),%rax
ret
.quad 1b,bad_put_user
.quad 2b,bad_put_user
.quad 3b,bad_put_user
- .quad 4b,bad_put_user
+ .quad 4b,bad_put_user
.previous