X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fx86_64%2Flib%2Fgetuser.S;h=3844d5e885a4deafcc035334e7d86b48351daf52;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=61a1f75aba87801fc499a649fe9f7dc729a4d2fa;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git

diff --git a/arch/x86_64/lib/getuser.S b/arch/x86_64/lib/getuser.S
index 61a1f75ab..3844d5e88 100644
--- a/arch/x86_64/lib/getuser.S
+++ b/arch/x86_64/lib/getuser.S
@@ -2,6 +2,7 @@
  * __get_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
@@ -12,12 +13,14 @@
 /*
  * __get_user_X
  *
- * Inputs:	%rax contains the address
+ * Inputs:	%rcx contains the address.
+ *		The register is modified, but all changes are undone
+ *		before returning because the C code doesn't know about it.
  *
  * Outputs:	%rax is error code (0 or -EFAULT)
  *		%rdx contains zero-extended value
  * 
- * %rbx is destroyed.
+ * %r8 is destroyed.
  *
  * These functions should not modify any other registers,
  * as they get called from within inline assembly.
@@ -26,59 +29,67 @@
 #include <linux/linkage.h>
 #include <asm/page.h>
 #include <asm/errno.h>
-#include <asm/offset.h>
+#include <asm/asm-offsets.h>
 #include <asm/thread_info.h>
 
 	.text
 	.p2align 4
 .globl __get_user_1
 __get_user_1:	
-	GET_THREAD_INFO(%rbx)
-	cmpq threadinfo_addr_limit(%rbx),%rax
+	GET_THREAD_INFO(%r8)
+	cmpq threadinfo_addr_limit(%r8),%rcx
 	jae bad_get_user
-1:	movzb (%rax),%edx
-	xorq %rax,%rax
+1:	movzb (%rcx),%edx
+	xorl %eax,%eax
 	ret
 
 	.p2align 4
 .globl __get_user_2
 __get_user_2:
-	GET_THREAD_INFO(%rbx) 
-	addq $1,%rax
-	jc bad_get_user
-	cmpq threadinfo_addr_limit(%rbx),%rax 
-	jae	 bad_get_user
-2:	movzwl -1(%rax),%edx
-	xorq %rax,%rax
+	GET_THREAD_INFO(%r8)
+	addq $1,%rcx
+	jc 20f
+	cmpq threadinfo_addr_limit(%r8),%rcx
+	jae 20f
+	decq   %rcx
+2:	movzwl (%rcx),%edx
+	xorl %eax,%eax
 	ret
+20:	decq    %rcx
+	jmp	bad_get_user
 
 	.p2align 4
 .globl __get_user_4
 __get_user_4:
-	GET_THREAD_INFO(%rbx) 
-	addq $3,%rax
-	jc bad_get_user
-	cmpq threadinfo_addr_limit(%rbx),%rax 
-	jae bad_get_user
-3:	movl -3(%rax),%edx
-	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 (%rcx),%edx
+	xorl %eax,%eax
 	ret
+30:	subq $3,%rcx
+	jmp bad_get_user
 
 	.p2align 4
 .globl __get_user_8
 __get_user_8:
-	GET_THREAD_INFO(%rbx) 
-	addq $7,%rax
-	jc bad_get_user
-	cmpq threadinfo_addr_limit(%rbx),%rax
-	jae	bad_get_user
-4:	movq -7(%rax),%rdx
-	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 (%rcx),%rdx
+	xorl %eax,%eax
 	ret
+40:	subq $7,%rcx
+	jmp bad_get_user
 
-ENTRY(bad_get_user)
 bad_get_user:
-	xorq %rdx,%rdx
+	xorl %edx,%edx
 	movq $(-EFAULT),%rax
 	ret