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kernel/linux-rt-4.4.41/arch/unicore32/lib/strnlen_user.S 966 Bytes
5113f6f70   김현기   kernel add
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  /*
   * linux/arch/unicore32/lib/strnlen_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
  
  /* Prototype: unsigned long __strnlen_user(const char *str, long n)
   * Purpose  : get length of a string in user memory
   * Params   : str - address of string in user memory
   * Returns  : length of string *including terminator*
   *	      or zero on exception, or n + 1 if too long
   */
  ENTRY(__strnlen_user)
  	mov	r2, r0
  1:
  	ldrusr	r3, r0, 1
  	cxor.a	r3, #0
  	beq	2f
  	sub.a	r1, r1, #1
  	bne	1b
  	add	r0, r0, #1
  2:	sub	r0, r0, r2
  	mov	pc, lr
  ENDPROC(__strnlen_user)
  
  	.pushsection .fixup,"ax"
  	.align	0
  9001:	mov	r0, #0
  	mov	pc, lr
  	.popsection