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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
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