1/* 2 * linux/arch/arm/lib/strncpy_from_user.S 3 * 4 * Copyright (C) 1995-2000 Russell King 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10#include <linux/linkage.h> 11#include <asm/assembler.h> 12#include <asm/errno.h> 13 14 .text 15 .align 5 16 17/* 18 * Copy a string from user space to kernel space. 19 * r0 = dst, r1 = src, r2 = byte length 20 * returns the number of characters copied (strlen of copied string), 21 * -EFAULT on exception, or "len" if we fill the whole buffer 22 */ 23ENTRY(__strncpy_from_user) 24 mov ip, r1 251: subs r2, r2, #1 26 ldrusr r3, r1, 1, pl 27 bmi 2f 28 strb r3, [r0], #1 29 teq r3, #0 30 bne 1b 31 sub r1, r1, #1 @ take NUL character out of count 322: sub r0, r1, ip 33 mov pc, lr 34ENDPROC(__strncpy_from_user) 35 36 .pushsection .fixup,"ax" 37 .align 0 389001: mov r3, #0 39 strb r3, [r0, #0] @ null terminate 40 mov r0, #-EFAULT 41 mov pc, lr 42 .popsection 43