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| /*
| * 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
|
|
