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authorWill Deacon <will.deacon@arm.com>2012-07-06 15:45:39 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-07-09 17:41:11 +0100
commit8c56cc8be5b38e3684eba96dc9b3f7ca7e495755 (patch)
treeeccb882c8c5f1cc81fc226c769fc9ec99a45145b /arch/arm/lib
parent4295b898f5a5c7e62ae68e7a4ecc4b414622ffe6 (diff)
downloadlinux-linaro-stable-8c56cc8be5b38e3684eba96dc9b3f7ca7e495755.tar.gz
ARM: 7449/1: use generic strnlen_user and strncpy_from_user functions
This patch implements the word-at-a-time interface for ARM using the same algorithm as x86. We use the fls macro from ARMv5 onwards, where we have a clz instruction available which saves us a mov instruction when targetting Thumb-2. For older CPUs, we use the magic 0x0ff0001 constant. Big-endian configurations make use of the implementation from asm-generic. With this implemented, we can replace our byte-at-a-time strnlen_user and strncpy_from_user functions with the optimised generic versions. Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/lib')
-rw-r--r--arch/arm/lib/Makefile1
-rw-r--r--arch/arm/lib/strncpy_from_user.S43
-rw-r--r--arch/arm/lib/strnlen_user.S40
3 files changed, 0 insertions, 84 deletions
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 992769ae2599..d5060dab6e52 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -8,7 +8,6 @@ lib-y := backtrace.o changebit.o csumipv6.o csumpartial.o \
csumpartialcopy.o csumpartialcopyuser.o clearbit.o \
delay.o findbit.o memchr.o memcpy.o \
memmove.o memset.o memzero.o setbit.o \
- strncpy_from_user.o strnlen_user.o \
strchr.o strrchr.o \
testchangebit.o testclearbit.o testsetbit.o \
ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \
diff --git a/arch/arm/lib/strncpy_from_user.S b/arch/arm/lib/strncpy_from_user.S
deleted file mode 100644
index f202d7bd1647..000000000000
--- a/arch/arm/lib/strncpy_from_user.S
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * linux/arch/arm/lib/strncpy_from_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
-
-/*
- * 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: subs r2, r2, #1
- ldrusr r3, r1, 1, pl
- bmi 2f
- strb r3, [r0], #1
- teq 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
- strb r3, [r0, #0] @ null terminate
- mov r0, #-EFAULT
- mov pc, lr
- .popsection
-
diff --git a/arch/arm/lib/strnlen_user.S b/arch/arm/lib/strnlen_user.S
deleted file mode 100644
index 0ecbb459c4f1..000000000000
--- a/arch/arm/lib/strnlen_user.S
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * 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 __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
- teq r3, #0
- beq 2f
- subs 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