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authorWill Deacon <will.deacon@arm.com>2013-11-06 17:20:22 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2013-12-19 17:43:06 +0000
commit12a0ef7b0ac38677bd2d85f33df5ca0a57868819 (patch)
tree59b4be2d48b136aac65c7201a975a9463917e020 /arch/arm64/lib
parent7158627686f02319c50c8d9d78f75d4c8d126ff2 (diff)
downloadlinux-12a0ef7b0ac38677bd2d85f33df5ca0a57868819.tar.gz
arm64: use generic strnlen_user and strncpy_from_user functions
This patch implements the word-at-a-time interface for arm64 using the same algorithm as ARM. We use the fls64 macro, which expands to a clz instruction via a compiler builtin. 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. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/lib')
-rw-r--r--arch/arm64/lib/Makefile8
-rw-r--r--arch/arm64/lib/strncpy_from_user.S50
-rw-r--r--arch/arm64/lib/strnlen_user.S47
3 files changed, 3 insertions, 102 deletions
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 59acc0ef0462..328ce1a99daa 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -1,6 +1,4 @@
-lib-y := bitops.o delay.o \
- strncpy_from_user.o strnlen_user.o clear_user.o \
- copy_from_user.o copy_to_user.o copy_in_user.o \
- copy_page.o clear_page.o \
- memchr.o memcpy.o memmove.o memset.o \
+lib-y := bitops.o clear_user.o delay.o copy_from_user.o \
+ copy_to_user.o copy_in_user.o copy_page.o \
+ clear_page.o memchr.o memcpy.o memmove.o memset.o \
strchr.o strrchr.o
diff --git a/arch/arm64/lib/strncpy_from_user.S b/arch/arm64/lib/strncpy_from_user.S
deleted file mode 100644
index 56e448a831a0..000000000000
--- a/arch/arm64/lib/strncpy_from_user.S
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Based on arch/arm/lib/strncpy_from_user.S
- *
- * Copyright (C) 1995-2000 Russell King
- * Copyright (C) 2012 ARM Ltd.
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <linux/linkage.h>
-#include <asm/assembler.h>
-#include <asm/errno.h>
-
- .text
- .align 5
-
-/*
- * Copy a string from user space to kernel space.
- * x0 = dst, x1 = src, x2 = 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 x4, x1
-1: subs x2, x2, #1
- bmi 2f
-USER(9f, ldrb w3, [x1], #1 )
- strb w3, [x0], #1
- cbnz w3, 1b
- sub x1, x1, #1 // take NUL character out of count
-2: sub x0, x1, x4
- ret
-ENDPROC(__strncpy_from_user)
-
- .section .fixup,"ax"
- .align 0
-9: strb wzr, [x0] // null terminate
- mov x0, #-EFAULT
- ret
- .previous
diff --git a/arch/arm64/lib/strnlen_user.S b/arch/arm64/lib/strnlen_user.S
deleted file mode 100644
index 7f7b176a5646..000000000000
--- a/arch/arm64/lib/strnlen_user.S
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Based on arch/arm/lib/strnlen_user.S
- *
- * Copyright (C) 1995-2000 Russell King
- * Copyright (C) 2012 ARM Ltd.
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#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 if too long
- */
-ENTRY(__strnlen_user)
- mov x2, x0
-1: subs x1, x1, #1
- b.mi 2f
-USER(9f, ldrb w3, [x0], #1 )
- cbnz w3, 1b
-2: sub x0, x0, x2
- ret
-ENDPROC(__strnlen_user)
-
- .section .fixup,"ax"
- .align 0
-9: mov x0, #0
- ret
- .previous