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Subject[PATCH] ARM: require GCC for FRAME_POINTER
Date
To produce a meaningful backtrace with FRAME_POINTER enabled the
kernel needs a specific function prologue:
mov ip, sp
stmfd sp!, {fp, ip, lr, pc}
sub fp, ip, #4

To get to the required prologue gcc uses apcs and no-sched-prolog.
This compiler options are not available on clang, and clang is not
able to generate the required prologue. Make the FRAME_POINTER
config symbol dependent on GCC.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stefan Agner <stefan@agner.ch>
---
arch/arm/Kconfig.debug | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 693f84392f1b..cb65cf67dfa2 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -54,7 +54,7 @@ config DEBUG_WX
# n, but then RMK will have to kill you ;).
config FRAME_POINTER
bool
- depends on !THUMB2_KERNEL
+ depends on !THUMB2_KERNEL && CC_IS_GCC
default y if !ARM_UNWIND || FUNCTION_GRAPH_TRACER
help
If you say N here, the resulting kernel will be slightly smaller and
--
2.18.0
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