From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Wed, 30 Aug 2017 08:25:59 +0000
Subject: Initial file dump from open source release

---
 arch/avr32/lib/strncpy_from_user.S | 60 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 arch/avr32/lib/strncpy_from_user.S

(limited to 'arch/avr32/lib/strncpy_from_user.S')

diff --git a/arch/avr32/lib/strncpy_from_user.S b/arch/avr32/lib/strncpy_from_user.S
new file mode 100644
index 00000000..72bd5059
--- /dev/null
+++ b/arch/avr32/lib/strncpy_from_user.S
@@ -0,0 +1,60 @@
+/*
+ * Copy to/from userspace with optional address space checking.
+ *
+ * Copyright 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/errno.h>
+
+#include <asm/page.h>
+#include <asm/thread_info.h>
+#include <asm/asm.h>
+
+	/*
+	 * long strncpy_from_user(char *dst, const char *src, long count)
+	 *
+	 * On success, returns the length of the string, not including
+	 * the terminating NUL.
+	 *
+	 * If the string is longer than count, returns count
+	 *
+	 * If userspace access fails, returns -EFAULT
+	 */
+	.text
+	.align	1
+	.global	strncpy_from_user
+	.type	strncpy_from_user, "function"
+strncpy_from_user:
+	mov	r9, -EFAULT
+	branch_if_kernel r8, __strncpy_from_user
+	ret_if_privileged r8, r11, r10, r9
+
+	.global	__strncpy_from_user
+	.type	__strncpy_from_user, "function"
+__strncpy_from_user:
+	cp.w	r10, 0
+	reteq	0
+
+	mov	r9, r10
+
+1:	ld.ub	r8, r11++
+	st.b	r12++, r8
+	cp.w	r8, 0
+	breq	2f
+	sub	r9, 1
+	brne	1b
+
+2:	sub	r10, r9
+	retal	r10
+
+	.section .fixup, "ax"
+	.align	1
+3:	mov	r12, -EFAULT
+	retal	r12
+
+	.section __ex_table, "a"
+	.align	2
+	.long	1b, 3b
-- 
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