From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/x86/lib/putuser.S | 101 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 arch/x86/lib/putuser.S

(limited to 'arch/x86/lib/putuser.S')

diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
new file mode 100644
index 000000000..fc6ba17a7
--- /dev/null
+++ b/arch/x86/lib/putuser.S
@@ -0,0 +1,101 @@
+/*
+ * __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>
+#include <asm/smap.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	ASM_CLAC ;	\
+		ret ;		\
+		CFI_ENDPROC
+
+.text
+ENTRY(__put_user_1)
+	ENTER
+	cmp TI_addr_limit(%_ASM_BX),%_ASM_CX
+	jae bad_put_user
+	ASM_STAC
+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
+	ASM_STAC
+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
+	ASM_STAC
+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
+	ASM_STAC
+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)
+
+	_ASM_EXTABLE(1b,bad_put_user)
+	_ASM_EXTABLE(2b,bad_put_user)
+	_ASM_EXTABLE(3b,bad_put_user)
+	_ASM_EXTABLE(4b,bad_put_user)
+#ifdef CONFIG_X86_32
+	_ASM_EXTABLE(5b,bad_put_user)
+#endif
-- 
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