From a05b9608456e0d4464c6f7ca8572324ace57a3f4 Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Mon, 8 Jul 2019 20:38:15 +0100 Subject: ARM: 8875/1: Kconfig: default to AEABI w/ Clang Clang produces references to __aeabi_uidivmod and __aeabi_idivmod for arm-linux-gnueabi and arm-linux-gnueabihf targets incorrectly when AEABI is not selected (such as when OABI_COMPAT is selected). While this means that OABI userspaces wont be able to upgraded to kernels built with Clang, it means that boards that don't enable AEABI like s3c2410_defconfig will stop failing to link in KernelCI when built with Clang. Link: https://github.com/ClangBuiltLinux/linux/issues/482 Link: https://groups.google.com/forum/#!msg/clang-built-linux/yydsAAux5hk/GxjqJSW-AQAJ Suggested-by: Arnd Bergmann Signed-off-by: Nick Desaulniers Reviewed-by: Arnd Bergmann Reviewed-by: Linus Walleij Signed-off-by: Russell King --- arch/arm/Kconfig | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/arm/Kconfig') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 33b00579beff..eae53c69a177 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1568,8 +1568,9 @@ config ARM_PATCH_IDIV code to do integer division. config AEABI - bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && !CPU_V7M && !CPU_V6 && !CPU_V6K - default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K + bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \ + !CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG + default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG help This option allows for the kernel to be compiled using the latest ARM ABI (aka EABI). This is only useful if you are using a user -- cgit v1.2.3-59-g8ed1b From b0fe66cf095016e0b238374c10ae366e1f087d11 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 4 Sep 2019 01:13:15 +0100 Subject: ARM: 8905/1: Emit __gnu_mcount_nc when using Clang 10.0.0 or newer Currently, multi_v7_defconfig + CONFIG_FUNCTION_TRACER fails to build with clang: arm-linux-gnueabi-ld: kernel/softirq.o: in function `_local_bh_enable': softirq.c:(.text+0x504): undefined reference to `mcount' arm-linux-gnueabi-ld: kernel/softirq.o: in function `__local_bh_enable_ip': softirq.c:(.text+0x58c): undefined reference to `mcount' arm-linux-gnueabi-ld: kernel/softirq.o: in function `do_softirq': softirq.c:(.text+0x6c8): undefined reference to `mcount' arm-linux-gnueabi-ld: kernel/softirq.o: in function `irq_enter': softirq.c:(.text+0x75c): undefined reference to `mcount' arm-linux-gnueabi-ld: kernel/softirq.o: in function `irq_exit': softirq.c:(.text+0x840): undefined reference to `mcount' arm-linux-gnueabi-ld: kernel/softirq.o:softirq.c:(.text+0xa50): more undefined references to `mcount' follow clang can emit a working mcount symbol, __gnu_mcount_nc, when '-meabi gnu' is passed to it. Until r369147 in LLVM, this was broken and caused the kernel not to boot with '-pg' because the calling convention was not correct. Always build with '-meabi gnu' when using clang but ensure that '-pg' (which is added with CONFIG_FUNCTION_TRACER and its prereq CONFIG_HAVE_FUNCTION_TRACER) cannot be added with it unless this is fixed (which means using clang 10.0.0 and newer). Link: https://github.com/ClangBuiltLinux/linux/issues/35 Link: https://bugs.llvm.org/show_bug.cgi?id=33845 Link: https://github.com/llvm/llvm-project/commit/16fa8b09702378bacfa3d07081afe6b353b99e60 Reviewed-by: Matthias Kaehlcke Reviewed-by: Nick Desaulniers Reviewed-by: Stefan Agner Signed-off-by: Nathan Chancellor Signed-off-by: Russell King --- arch/arm/Kconfig | 2 +- arch/arm/Makefile | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/arm/Kconfig') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index eae53c69a177..859b49d0d077 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -78,7 +78,7 @@ config ARM select HAVE_FAST_GUP if ARM_LPAE select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG - select HAVE_FUNCTION_TRACER if !XIP_KERNEL + select HAVE_FUNCTION_TRACER if !XIP_KERNEL && (CC_IS_GCC || CLANG_VERSION >= 100000) select HAVE_GCC_PLUGINS select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7) select HAVE_IDE if PCI || ISA || PCMCIA diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 977f4e66f145..d6273b660629 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -115,6 +115,10 @@ ifeq ($(CONFIG_ARM_UNWIND),y) CFLAGS_ABI +=-funwind-tables endif +ifeq ($(CONFIG_CC_IS_CLANG),y) +CFLAGS_ABI += -meabi gnu +endif + # Accept old syntax despite ".syntax unified" AFLAGS_NOWARN :=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W) -- cgit v1.2.3-59-g8ed1b