vserver 2.0 rc7

[linux-2.6.git] / arch / x86_64 / lib / putuser.S

diff --git a/arch/x86_64/lib/putuser.S b/arch/x86_64/lib/putuser.S
index 4d287ce..5828b81 100644 (file)
--- a/arch/x86_64/lib/putuser.S
+++ b/arch/x86_64/lib/putuser.S
@@ -2,80 +2,90 @@
  * __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
@@ -84,5 +94,5 @@ bad_put_user:
        .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