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| author | Stefan Agner <stefan@agner.ch> | 2019-05-28 01:40:50 +0300 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2019-06-19 19:44:25 +0300 |
| commit | 3fe1ee40b2a2db271513a498c475c13572dcb4c6 (patch) | |
| tree | 64a85ad53e8d01b6443c4f1eb1146b5465dfa1c4 /arch/arm/mach-tango | |
| parent | 24cb4bc8f0c9ee346826f33e6dcbdbc533cc6ad8 (diff) | |
| download | linux-3fe1ee40b2a2db271513a498c475c13572dcb4c6.tar.xz | |
ARM: use arch_extension directive instead of arch argument
The LLVM Target parser currently does not allow to specify the security
extension as part of -march (see also LLVM Bug 40186 [0]). When trying
to use Clang with LLVM's integrated assembler, this leads to build
errors such as this:
clang-8: error: the clang compiler does not support '-Wa,-march=armv7-a+sec'
Use ".arch_extension sec" to enable the security extension in a more
portable fasion. Also make sure to use ".arch armv7-a" in case a v6/v7
multi-platform kernel is being built.
Note that this is technically not exactly the same as the old code
checked for availabilty of the security extension by calling as-instr.
However, there are already other sites which use ".arch_extension sec"
unconditionally, hence de-facto we need an assembler capable of
".arch_extension sec" already today (arch/arm/mm/proc-v7.S). The
arch extension "sec" is available since binutils 2.21 according to
its documentation [1].
[0] https://bugs.llvm.org/show_bug.cgi?id=40186
[1] https://sourceware.org/binutils/docs-2.21/as/ARM-Options.html
Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Mans Rullgard <mans@mansr.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'arch/arm/mach-tango')
| -rw-r--r-- | arch/arm/mach-tango/Makefile | 3 | ||||
| -rw-r--r-- | arch/arm/mach-tango/smc.S | 2 |
2 files changed, 2 insertions, 3 deletions
diff --git a/arch/arm/mach-tango/Makefile b/arch/arm/mach-tango/Makefile index da6c633d3cc0..97cd04508fa1 100644 --- a/arch/arm/mach-tango/Makefile +++ b/arch/arm/mach-tango/Makefile @@ -1,7 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 -plus_sec := $(call as-instr,.arch_extension sec,+sec) -AFLAGS_smc.o := -Wa,-march=armv7-a$(plus_sec) - obj-y += setup.o smc.o obj-$(CONFIG_SMP) += platsmp.o obj-$(CONFIG_SUSPEND) += pm.o diff --git a/arch/arm/mach-tango/smc.S b/arch/arm/mach-tango/smc.S index 361a8dc89804..b1752aaa72bc 100644 --- a/arch/arm/mach-tango/smc.S +++ b/arch/arm/mach-tango/smc.S @@ -1,6 +1,8 @@ /* SPDX-License-Identifier: GPL-2.0 */ #include <linux/linkage.h> + .arch armv7-a + .arch_extension sec ENTRY(tango_smc) push {lr} mov ip, r1 |