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- /*
- * linux/arch/unicore32/lib/strncpy_from_user.S
- *
- * Code specific to PKUnity SoC and UniCore ISA
- *
- * Copyright (C) 2001-2010 GUAN Xue-tao
- *
- * 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/linkage.h>
- #include <asm/assembler.h>
- #include <asm/errno.h>
- .text
- .align 5
- /*
- * Copy a string from user space to kernel space.
- * r0 = dst, r1 = src, r2 = byte length
- * returns the number of characters copied (strlen of copied string),
- * -EFAULT on exception, or "len" if we fill the whole buffer
- */
- ENTRY(__strncpy_from_user)
- mov ip, r1
- 1: sub.a r2, r2, #1
- ldrusr r3, r1, 1, ns
- bfs 2f
- stb.w r3, [r0]+, #1
- cxor.a r3, #0
- bne 1b
- sub r1, r1, #1 @ take NUL character out of count
- 2: sub r0, r1, ip
- mov pc, lr
- ENDPROC(__strncpy_from_user)
- .pushsection .fixup,"ax"
- .align 0
- 9001: mov r3, #0
- stb r3, [r0+], #0 @ null terminate
- mov r0, #-EFAULT
- mov pc, lr
- .popsection
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