| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20260112-headers_install-config-leak-v2-1-4d8084444603@linutronix.de>
Date: Mon, 12 Jan 2026 08:58:29 +0100
From: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
To: Vineet Gupta <vgupta@...nel.org>, Russell King <linux@...linux.org.uk>,
Dinh Nguyen <dinguyen@...nel.org>, Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
"H. Peter Anvin" <hpa@...or.com>
Cc: linux-snps-arc@...ts.infradead.org, linux-kernel@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, Arnd Bergmann <arnd@...db.de>,
Thomas Weißschuh <thomas.weissschuh@...utronix.de>
Subject: [PATCH v2 1/5] ARC: Always use SWAPE instructions and enable
ARCH_USE_BUILTIN_BSWAP
Since commit 67a697e7576 ("ARC: retire ARC750 support") all supported
CPUs have the 'swape' instruction.
Replace the custom logic with ARCH_USE_BUILTIN_BSWAP which makes
use of 'swape'.
As as side-effect, remove a leak of an internal kconfig symbol through
the UAPI headers.
Suggested-by: Arnd Bergmann <arnd@...db.de>
Link: https://lore.kernel.org/lkml/0ae2688a-5a22-405b-adaf-9b5ad712b245@app.fastmail.com/
Suggested-by: Vineet Gupta <vgupta@...nel.org>
Link: https://lore.kernel.org/lkml/a033a402-e3c5-4982-9fff-b6a4c55817ae@kernel.org/
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
---
arch/arc/Kconfig | 6 +--
arch/arc/Makefile | 3 +-
arch/arc/include/uapi/asm/swab.h | 99 ----------------------------------------
scripts/headers_install.sh | 1 -
4 files changed, 2 insertions(+), 107 deletions(-)
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index f27e6b90428e..390a14360689 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -16,6 +16,7 @@ config ARC
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_NEED_CMPXCHG_1_EMU
select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC
+ select ARCH_USE_BUILTIN_BSWAP
select ARCH_32BIT_OFF_T
select BUILDTIME_TABLE_SORT
select GENERIC_BUILTIN_DTB
@@ -121,7 +122,6 @@ choice
config ARC_CPU_770
bool "ARC770"
depends on ISA_ARCOMPACT
- select ARC_HAS_SWAPE
help
Support for ARC770 core introduced with Rel 4.10 (Summer 2011)
This core has a bunch of cool new features:
@@ -340,10 +340,6 @@ config ARC_HAS_LLSC
default y
depends on !ARC_CANT_LLSC
-config ARC_HAS_SWAPE
- bool "Insn: SWAPE (endian-swap)"
- default y
-
if ISA_ARCV2
config ARC_USE_UNALIGNED_MEM_ACCESS
diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index 0c5e6e6314f2..868805ffcfea 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -9,7 +9,7 @@ ifeq ($(CROSS_COMPILE),)
CROSS_COMPILE := $(call cc-cross-prefix, arc-linux- arceb-linux- arc-linux-gnu-)
endif
-cflags-y += -fno-common -pipe -fno-builtin -mmedium-calls -D__linux__
+cflags-y += -fno-common -pipe -fno-builtin -mmedium-calls -mswape -D__linux__
tune-mcpu-def-$(CONFIG_ISA_ARCOMPACT) := -mcpu=arc700
tune-mcpu-def-$(CONFIG_ISA_ARCV2) := -mcpu=hs38
@@ -41,7 +41,6 @@ endif
cflags-y += -fsection-anchors
cflags-$(CONFIG_ARC_HAS_LLSC) += -mlock
-cflags-$(CONFIG_ARC_HAS_SWAPE) += -mswape
ifdef CONFIG_ISA_ARCV2
diff --git a/arch/arc/include/uapi/asm/swab.h b/arch/arc/include/uapi/asm/swab.h
deleted file mode 100644
index 8d1f1ef44ba7..000000000000
--- a/arch/arc/include/uapi/asm/swab.h
+++ /dev/null
@@ -1,99 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
- *
- * 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.
- *
- * vineetg: May 2011
- * -Support single cycle endian-swap insn in ARC700 4.10
- *
- * vineetg: June 2009
- * -Better htonl implementation (5 instead of 9 ALU instructions)
- * -Hardware assisted single cycle bswap (Use Case of ARC custom instrn)
- */
-
-#ifndef __ASM_ARC_SWAB_H
-#define __ASM_ARC_SWAB_H
-
-#include <linux/types.h>
-
-/* Native single cycle endian swap insn */
-#ifdef CONFIG_ARC_HAS_SWAPE
-
-#define __arch_swab32(x) \
-({ \
- unsigned int tmp = x; \
- __asm__( \
- " swape %0, %1 \n" \
- : "=r" (tmp) \
- : "r" (tmp)); \
- tmp; \
-})
-
-#else
-
-/* Several ways of Endian-Swap Emulation for ARC
- * 0: kernel generic
- * 1: ARC optimised "C"
- * 2: ARC Custom instruction
- */
-#define ARC_BSWAP_TYPE 1
-
-#if (ARC_BSWAP_TYPE == 1) /******* Software only ********/
-
-/* The kernel default implementation of htonl is
- * return x<<24 | x>>24 |
- * (x & (__u32)0x0000ff00UL)<<8 | (x & (__u32)0x00ff0000UL)>>8;
- *
- * This generates 9 instructions on ARC (excluding the ld/st)
- *
- * 8051fd8c: ld r3,[r7,20] ; Mem op : Get the value to be swapped
- * 8051fd98: asl r5,r3,24 ; get 3rd Byte
- * 8051fd9c: lsr r2,r3,24 ; get 0th Byte
- * 8051fda0: and r4,r3,0xff00
- * 8051fda8: asl r4,r4,8 ; get 1st Byte
- * 8051fdac: and r3,r3,0x00ff0000
- * 8051fdb4: or r2,r2,r5 ; combine 0th and 3rd Bytes
- * 8051fdb8: lsr r3,r3,8 ; 2nd Byte at correct place in Dst Reg
- * 8051fdbc: or r2,r2,r4 ; combine 0,3 Bytes with 1st Byte
- * 8051fdc0: or r2,r2,r3 ; combine 0,3,1 Bytes with 2nd Byte
- * 8051fdc4: st r2,[r1,20] ; Mem op : save result back to mem
- *
- * Joern suggested a better "C" algorithm which is great since
- * (1) It is portable to any architecture
- * (2) At the same time it takes advantage of ARC ISA (rotate intrns)
- */
-
-#define __arch_swab32(x) \
-({ unsigned long __in = (x), __tmp; \
- __tmp = __in << 8 | __in >> 24; /* ror tmp,in,24 */ \
- __in = __in << 24 | __in >> 8; /* ror in,in,8 */ \
- __tmp ^= __in; \
- __tmp &= 0xff00ff; \
- __tmp ^ __in; \
-})
-
-#elif (ARC_BSWAP_TYPE == 2) /* Custom single cycle bswap instruction */
-
-#define __arch_swab32(x) \
-({ \
- unsigned int tmp = x; \
- __asm__( \
- " .extInstruction bswap, 7, 0x00, SUFFIX_NONE, SYNTAX_2OP \n"\
- " bswap %0, %1 \n"\
- : "=r" (tmp) \
- : "r" (tmp)); \
- tmp; \
-})
-
-#endif /* ARC_BSWAP_TYPE=zzz */
-
-#endif /* CONFIG_ARC_HAS_SWAPE */
-
-#if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
-#define __SWAB_64_THRU_32__
-#endif
-
-#endif
diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh
index 0e4e939efc94..727f7f82c2c7 100755
--- a/scripts/headers_install.sh
+++ b/scripts/headers_install.sh
@@ -70,7 +70,6 @@ configs=$(sed -e '
#
# The format is <file-name>:<CONFIG-option> in each line.
config_leak_ignores="
-arch/arc/include/uapi/asm/swab.h:CONFIG_ARC_HAS_SWAPE
arch/arm/include/uapi/asm/ptrace.h:CONFIG_CPU_ENDIAN_BE8
arch/nios2/include/uapi/asm/swab.h:CONFIG_NIOS2_CI_SWAB_NO
arch/nios2/include/uapi/asm/swab.h:CONFIG_NIOS2_CI_SWAB_SUPPORT
--
2.52.0
Powered by blists - more mailing lists