i386: prepare shared lib/putuser.S

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 98 insertions, 0 deletions

diff --git a/arch/i386/lib/putuser_32.S b/arch/i386/lib/putuser_32.S
new file mode 100644
index 0000000..f58fba1
--- /dev/null
+++ b/arch/i386/lib/putuser_32.S
@@ -0,0 +1,98 @@
+/*
+ * __put_user functions.
+ *
+ * (C) Copyright 2005 Linus Torvalds
+ *
+ * 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>
+
+
+/*
+ * __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 ; \
+		pushl %ebx ; \
+		CFI_ADJUST_CFA_OFFSET 4 ; \
+		CFI_REL_OFFSET ebx, 0 ; \
+		GET_THREAD_INFO(%ebx)
+#define EXIT	popl %ebx ; \
+		CFI_ADJUST_CFA_OFFSET -4 ; \
+		CFI_RESTORE ebx ; \
+		ret ; \
+		CFI_ENDPROC
+
+.text
+ENTRY(__put_user_1)
+	ENTER
+	cmpl TI_addr_limit(%ebx),%ecx
+	jae bad_put_user
+1:	movb %al,(%ecx)
+	xorl %eax,%eax
+	EXIT
+ENDPROC(__put_user_1)
+
+ENTRY(__put_user_2)
+	ENTER
+	movl TI_addr_limit(%ebx),%ebx
+	subl $1,%ebx
+	cmpl %ebx,%ecx
+	jae bad_put_user
+2:	movw %ax,(%ecx)
+	xorl %eax,%eax
+	EXIT
+ENDPROC(__put_user_2)
+
+ENTRY(__put_user_4)
+	ENTER
+	movl TI_addr_limit(%ebx),%ebx
+	subl $3,%ebx
+	cmpl %ebx,%ecx
+	jae bad_put_user
+3:	movl %eax,(%ecx)
+	xorl %eax,%eax
+	EXIT
+ENDPROC(__put_user_4)
+
+ENTRY(__put_user_8)
+	ENTER
+	movl TI_addr_limit(%ebx),%ebx
+	subl $7,%ebx
+	cmpl %ebx,%ecx
+	jae bad_put_user
+4:	movl %eax,(%ecx)
+5:	movl %edx,4(%ecx)
+	xorl %eax,%eax
+	EXIT
+ENDPROC(__put_user_8)
+
+bad_put_user:
+	CFI_STARTPROC simple
+	CFI_DEF_CFA esp, 2*4
+	CFI_OFFSET eip, -1*4
+	CFI_OFFSET ebx, -2*4
+	movl $-14,%eax
+	EXIT
+END(bad_put_user)
+
+.section __ex_table,"a"
+	.long 1b,bad_put_user
+	.long 2b,bad_put_user
+	.long 3b,bad_put_user
+	.long 4b,bad_put_user
+	.long 5b,bad_put_user
+.previous