From 89bace652cbfb78a2fd830025f8ea048d6eb3657 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 10 Jun 2011 14:12:21 +0000 Subject: [PATCH] ARM: always use ARM_UNWIND for thumb2 kernels Thumb2 kernels cannot be built with frame pointers, but can use the ARM_UNWIND feature for unwinding instead. This makes sure that all features that rely on unwinding includeing CONFIG_LATENCYTOP and FAULT_INJECTION_STACKTRACE_FILTER do not enable frame pointers when the unwinder is already selected, and we always build with the unwinder when we want a thumb2 kernel, to make sure we do not get the frame pointers instead. A different option would be to redefine the CONFIG_FRAME_POINTERS option on ARM to mean builing with either frame pointers or the unwinder, and then select which one to use based on the CPU architecture or another user option. That would still allow building thumb2 kernels without the unwinder but would also be more confusing. Signed-off-by: Arnd Bergmann --- arch/arm/Kconfig | 1 + lib/Kconfig.debug | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 4e1eee0c2d64..497af51e9176 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1457,6 +1457,7 @@ config THUMB2_KERNEL depends on CPU_V7 && !CPU_V6 && !CPU_V6K && EXPERIMENTAL select AEABI select ARM_ASM_UNIFIED + select ARM_UNWIND help By enabling this option, the kernel will be compiled in Thumb-2 mode. A compiler/assembler that understand the unified diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c0cb9c4bc46d..103c171ce605 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1081,7 +1081,7 @@ config FAULT_INJECTION_STACKTRACE_FILTER depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT depends on !X86_64 select STACKTRACE - select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE + select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND help Provide stacktrace filter for fault-injection capabilities @@ -1091,7 +1091,7 @@ config LATENCYTOP depends on DEBUG_KERNEL depends on STACKTRACE_SUPPORT depends on PROC_FS - select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE + select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND select KALLSYMS select KALLSYMS_ALL select STACKTRACE