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Diffstat (limited to 'arch/arm/lib/strnlen_user.S')
| -rw-r--r-- | arch/arm/lib/strnlen_user.S | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/arm/lib/strnlen_user.S b/arch/arm/lib/strnlen_user.S new file mode 100644 index 00000000000..67bcd826812 --- /dev/null +++ b/arch/arm/lib/strnlen_user.S @@ -0,0 +1,40 @@ +/* + * linux/arch/arm/lib/strnlen_user.S + * + * Copyright (C) 1995-2000 Russell King + * + * 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 __arch_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(__arch_strnlen_user) + save_lr + mov r2, r0 +1: +USER( ldrbt r3, [r0], #1) + teq r3, #0 + beq 2f + subs r1, r1, #1 + bne 1b + add r0, r0, #1 +2: sub r0, r0, r2 + restore_pc + + .section .fixup,"ax" + .align 0 +9001: mov r0, #0 + restore_pc + .previous |