1 files changed, 97 insertions, 0 deletions

diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
new file mode 100644
index 000000000000..36b0d15ae6e9
--- /dev/null
+++ b/arch/x86/lib/putuser.S
@@ -0,0 +1,97 @@
+/*
+ * __put_user functions.
+ *
+ * (C) Copyright 2005 Linus Torvalds
+ * (C) Copyright 2005 Andi Kleen
+ * (C) Copyright 2008 Glauber Costa
+ *
+ * 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.
+ */
+#include <linux/linkage.h>
+#include <asm/dwarf2.h>
+#include <asm/thread_info.h>
+#include <asm/errno.h>
+#include <asm/asm.h>
+
+
+/*
+ * __put_user_X
+ *
+ * Inputs:      %eax[:%edx] contains the data
+ *              %ecx contains the address
+ *
+ * Outputs:     %eax is error code (0 or -EFAULT)
+ *
+ * These functions should not modify any other registers,
+ * as they get called from within inline assembly.
+ */
+
+#define ENTER   CFI_STARTPROC ; \
+                GET_THREAD_INFO(%_ASM_BX)
+#define EXIT    ret ; \
+                CFI_ENDPROC
+
+.text
+ENTRY(__put_user_1)
+        ENTER
+        cmp TI_addr_limit(%_ASM_BX),%_ASM_CX
+        jae bad_put_user
+1:      movb %al,(%_ASM_CX)
+        xor %eax,%eax
+        EXIT
+ENDPROC(__put_user_1)
+
+ENTRY(__put_user_2)
+        ENTER
+        mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+        sub $1,%_ASM_BX
+        cmp %_ASM_BX,%_ASM_CX
+        jae bad_put_user
+2:      movw %ax,(%_ASM_CX)
+        xor %eax,%eax
+        EXIT
+ENDPROC(__put_user_2)
+
+ENTRY(__put_user_4)
+        ENTER
+        mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+        sub $3,%_ASM_BX
+        cmp %_ASM_BX,%_ASM_CX
+        jae bad_put_user
+3:      movl %eax,(%_ASM_CX)
+        xor %eax,%eax
+        EXIT
+ENDPROC(__put_user_4)
+
+ENTRY(__put_user_8)
+        ENTER
+        mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+        sub $7,%_ASM_BX
+        cmp %_ASM_BX,%_ASM_CX
+        jae bad_put_user
+4:      mov %_ASM_AX,(%_ASM_CX)
+#ifdef CONFIG_X86_32
+5:      movl %edx,4(%_ASM_CX)
+#endif
+        xor %eax,%eax
+        EXIT
+ENDPROC(__put_user_8)
+
+bad_put_user:
+        CFI_STARTPROC
+        movl $-EFAULT,%eax
+        EXIT
+END(bad_put_user)
+
+.section __ex_table,"a"
+        _ASM_PTR 1b,bad_put_user
+        _ASM_PTR 2b,bad_put_user
+        _ASM_PTR 3b,bad_put_user
+        _ASM_PTR 4b,bad_put_user
+#ifdef CONFIG_X86_32
+        _ASM_PTR 5b,bad_put_user
+#endif
+.previous