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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/strncpy_from_user.S | |
| parent | 28bab059a23aac6bb129b307410e5b63e132a290 (diff) | |
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/strncpy_from_user.S')
| -rw-r--r-- | arch/unicore32/lib/strncpy_from_user.S | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/unicore32/lib/strncpy_from_user.S b/arch/unicore32/lib/strncpy_from_user.S new file mode 100644 index 000000000000..ff6c304d5c7e --- /dev/null +++ b/arch/unicore32/lib/strncpy_from_user.S @@ -0,0 +1,45 @@ +/* + * 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 + |