@@ -68,7 +68,7 @@ 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
@@ -47,8 +47,8 @@ config DEBUG_WX
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/<pid>/stack,
@@ -65,7 +65,7 @@ config UNWINDER_FRAME_POINTER
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
Danilo Cezar Zanella reported broken function graph tracer in the v4.19 tree. This was caused by the backport of commit f9b58e8c7d031 ("ARM: 8800/1: use choice for kernel unwinders") which ended in the v4.19-stable tree as of v4.19.222. It is also part of v4.14-stable since v4.14.259. It is also part of v4.9-stable since v4.9.299. ------->8--------- From: Russell King <rmk+kernel@armlinux.org.uk> Date: Tue, 23 Apr 2019 17:09:38 +0100 Subject: [PATCH] ARM: fix function graph tracer and unwinder dependencies Upstream commit 503621628b32782a07b2318e4112bd4372aa3401 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 <mhiramat@kernel.org> Tested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reported-by: Danilo Cezar Zanella <danilo.zanella@iag.usp.br> --- arch/arm/Kconfig | 2 +- arch/arm/Kconfig.debug | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-)