| /* | |
| * 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 | |