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| author | GuanXuetao <gxt@mprc.pku.edu.cn> | 2011-02-26 18:49:26 +0800 |
|---|---|---|
| committer | GuanXuetao <gxt@mprc.pku.edu.cn> | 2011-03-17 09:19:13 +0800 |
| commit | 77c93b2f2388b974253af4149aa025b4751f92ad (patch) | |
| tree | 59b3c67518e2cae1f347a2c2bc738a234b349bb4 /arch/unicore32/lib/strnlen_user.S | |
| parent | 28bab059a23aac6bb129b307410e5b63e132a290 (diff) | |
| download | linux-77c93b2f2388b974253af4149aa025b4751f92ad.tar.bz2 | |
unicore32 additional architecture files: low-level lib: uaccess
This patch implements low-level uaccess libraries.
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/unicore32/lib/strnlen_user.S')
| -rw-r--r-- | arch/unicore32/lib/strnlen_user.S | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/unicore32/lib/strnlen_user.S b/arch/unicore32/lib/strnlen_user.S new file mode 100644 index 000000000000..75863030f21d --- /dev/null +++ b/arch/unicore32/lib/strnlen_user.S @@ -0,0 +1,42 @@ +/* + * 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 |