From 6de98343148c6d581eef8a7292c9e3c75d8025f1 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 23 Apr 2019 17:09:38 +0100 Subject: [PATCH] ARM: fix function graph tracer and unwinder dependencies commit 503621628b32782a07b2318e4112bd4372aa3401 upstream. Naresh Kamboju recently reported that the function-graph tracer crashes on ARM. The function-graph tracer assumes that the kernel is built with frame pointers. We explicitly disabled the function-graph tracer when building Thumb2, since the Thumb2 ABI doesn't have frame pointers. We recently changed the way the unwinder method was selected, which seems to have made it more likely that we can end up with the function- graph tracer enabled but without the kernel built with frame pointers. Fix up the function graph tracer dependencies so the option is not available when we have no possibility of having frame pointers, and adjust the dependencies on the unwinder option to hide the non-frame pointer unwinder options if the function-graph tracer is enabled. Reviewed-by: Masami Hiramatsu Tested-by: Masami Hiramatsu Signed-off-by: Russell King Signed-off-by: Sebastian Andrzej Siewior Reported-by: Danilo Cezar Zanella Signed-off-by: Greg Kroah-Hartman --- arch/arm/Kconfig | 2 +- arch/arm/Kconfig.debug | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 9a6b4aa7595a..02a818151c66 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -53,7 +53,7 @@ config ARM select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU select HAVE_EXIT_THREAD select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL) - select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL) + select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL && !CC_IS_CLANG) select HAVE_FUNCTION_TRACER if (!XIP_KERNEL) select HAVE_FUTEX_CMPXCHG if FUTEX select HAVE_GCC_PLUGINS diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index eba1905fe10b..a785d99d8c4c 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -17,8 +17,8 @@ config ARM_PTDUMP choice prompt "Choose kernel unwinder" - default UNWINDER_ARM if AEABI && !FUNCTION_GRAPH_TRACER - default UNWINDER_FRAME_POINTER if !AEABI || FUNCTION_GRAPH_TRACER + default UNWINDER_ARM if AEABI + default UNWINDER_FRAME_POINTER if !AEABI help This determines which method will be used for unwinding kernel stack traces for panics, oopses, bugs, warnings, perf, /proc//stack, @@ -43,7 +43,7 @@ config AMLOGIC_USER_FAULT config UNWINDER_ARM bool "ARM EABI stack unwinder" - depends on AEABI + depends on AEABI && !FUNCTION_GRAPH_TRACER select ARM_UNWIND help This option enables stack unwinding support in the kernel