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-rw-r--r--kernel/arch/avr32/lib/strncpy_from_user.S60
1 files changed, 60 insertions, 0 deletions
diff --git a/kernel/arch/avr32/lib/strncpy_from_user.S b/kernel/arch/avr32/lib/strncpy_from_user.S
new file mode 100644
index 000000000..72bd50599
--- /dev/null
+++ b/kernel/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